Electrical and Electronics Engineering|Md Benozir Hossain

Definition of statistical research methods|Data Science

2018-07-11T10:06:00.001+06:00

Treatment: In an experiment, the manner in which
researchers handle subjects is called a treatment. Researchers are
specifically interested in how different treatments might yield
differing results.

Observational Study: An observational study is when an experimenter watches a group of subjects and does not introduce a treatment.

Example: A Survey or collection of data.

Independent Variable: The independent variable of a
study is the variable that experimenters choose to manipulate; it is
usually plotted along the x-axis of a graph.

Definition of Visualizing Data|Data Science

2018-07-11T10:03:00.001+06:00

Definition of Visualizing Data|Data Science

Frequency Distribution

Frequency: The frequency of a data set is the number of times a certain outcome occurs.

Proportion: A proportion is the fraction of counts
over the total sample. A proportion can be turned into a percentage by
multiplying the proportion by 100.

Histogram: is a graphical representation of the
distribution of data, discrete intervals (bins) are decided upon to form
widths for our boxes. Adjusting the bin size of a histogram will
compact or spread out the distribution.

Smart Home Automation Basic Concept|How it Works

2018-05-21T11:18:00.001+06:00

Smart Home Automation Basic Concept|How it Works | Smart AI Automation|Machine Learning|Md Benozir Hossain: The Home Automation idea has existed for a long time. The terms Smart Home or Intelligent Home took after and has been utilized to present the idea of organizing machines and gadgets in the house. Home automation basic concept Systems speaks to an extraordinary research opportunity in making new fields in designing, and Figuring.

The Next Generation Traction Transformers-Future Tech

2017-09-17T11:25:00.001+06:00

The Next Generation Traction Transformers-Future Tech

Traction transformers are always design and manufactured according to a specific railway system and based on detailed parameters. Traction systems can be divided into two major groups, AC (alternating current) and DC (direct current) systems. Typical system set-ups are: 15 kV AC 16 2/3 Hz. 25 kV AC 50 Hz.

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How it works The Switchgear substation Equipment's

2017-07-27T11:53:00.001+06:00

How it works The Switch gear substation Equipment's

The switchgear refers to the series of the switching devices required for a low, medium or excessive voltage electrical circuit. It consists of switching and protection gadgets such as fuses, circuit breakers, isolators, disconnect switches, relays and other devices that manipulate the drift of electricity.

These devices are used to change the electric energy on and off for transformers, motors, generators, transmission lines, and electricity networks in homes, commercial, industrial, transmission and distribution systems.

The switchgear consists of two fundamental components:

Power switching/conducting aspect such as a circuit breaker, fuse, or lightning arrester that can disconnect the drift of strength when there is a fault.

Power control components such as protective relays, manage panels, contemporary transformers and different devices to monitor, defend and control the electricity conduction elements and the electrical equipment.

The switch gears are used at a variety of points of an installation. In the industrial setup, the switch gear controls the strength to the manufacturing techniques whilst at the utilities, the switch gear is used to run the electric grid. In commercial buildings, it is used to furnish and manipulate power to the masses whilst imparting safety to the hundreds and the installation.

The switch gear permits the switching on and off of the generators, electrical equipment, transmission, distributors and different circuits at some stage in the ordinary working conditions. However, underneath fault conditions, the switch gear is designed to become aware of the faults and interrupt the float of electrical energy to the affected section, for that reason disconnecting and setting apart it from the wholesome circuit.

For efficient operation, the switch gear be speedy in operation and have an choice of manual manipulate to be used when the automated feature is no longer working.

The switch gears are required at all switching factors of an electrical network. The ratings of the gadgets at every stage rely on the voltage levels at that point. Other than in distribution and transmission networks, the switch gears are used in residential, commercial, industrial circuits.

he switch gears are classified according to the voltage levels involved in the circuit of application.

The three classes are:

High voltage Switch gear
Medium voltage Switch gear &
Low voltage Switch gear

Engineering Words for EEE CSE Job Viva Question Answers

2017-05-10T13:54:00.001+06:00

Engineering Words for EEE CSE Job Viva MCQ Question Answers

Capacity

The greatest load a weighing machine is designed to weigh.

Sometimes marked on it as ‘Max’.

Calibration

Specific types of measurement performed on measuring

instruments to establish the relationship between the indicated values and known values of a measured quantity.

NB: The term ‘calibration’ as defined internationally does not include adjustment of the instrument.

Range

The least and greatest load for which a machine is or can be used, and for which continuous mass values will be displayed with the same resolution.

Repeatability

A measure of a weighing machine’s ability to display the same result when repeated measurements are made under the same weighing conditions.

Resolution

The mass value of the smallest scale or digital interval displayed

by the weighing machine. Sometimes marked on it as ‘d’.

Span

The mass value of the difference between the greatest and least

load for which continuous mass values will be displayed with the

same resolution.

Sensitivity

The number of divisions change in reading per

unit mass.

Tare

Facility which enables the weighing machine reading to be

adjusted to read zero with an object on the load receptor.

Turning point

The reading at the extremity of the swing of the pointer, ie, where

it changes its direction of motion.

Not applicable to digital indicating devices.

Uncertainty

The amount by which a true value may differ from a measured

value, at a given confidence level.

Nine Point Calibration of Needle Detector

2017-01-09T13:41:00.001+06:00

Industrial sensor : Nine Point Calibration of Needle Detector

A model garments is doing all merchandise to be checked 100% with a industrial sensor before cargo in the end producing operations are completed. This check is being allotted when the ultimate examination and packaging of the garment (incl. attachment of swing tickets) however before packing/boxing the products within the metal free port and are being the a part of the ultimate internal control procedure. Industrial metal detectors are associate degree aid to stop metal contamination and are the most effective thanks to make sure that needle management procedures are effective, however don't seem to be to getting used to switch an efficient needle replacement policy. Metal detection are being enforced inside the assembly method and employed in conjunction with the broken needle procedure.

Metal Detector standardization Procedure: Machines ar being tag each operating day with this take a look at card, at the start and at thend of every reviewheap, likewise as once the machine is started up, then each hour and at the top of a operating day likewise as when any electricity cuts. If a difficulty is found with the machine at future standardisation, the products that were done since the last fortunate standardisation want re-checking, therefore the smaller the gap between calibrations checks the smaller the amount of products that ar being re-checked. If the machine is to be got wind of order when a check, it's being organized for imperative repair and a replacement to hide for the time the machine are going to be out of order. this can be being done through a static sensor. it's being ensured tho', that no orders leave the manufacturing plant, that's not been checked, particularly just in case of kids swears. The following sensor standardisation procedure ar being adhered to once checking the machine. Please see below diagram for the dimension across the belt of the sensor and wherever the take a look at card ought to sit once tested at rock bottom, center and high position: CROSS SECTION TUNNEL NEEDLE DETECTOR

TOP A7 A8 A9
CENTRE A4 A5 A6
BOTTOM A1 A2 A3

Metal Detector standardization Checklist:

Switch on the machine and set the sensitivity level to but one.2mm sphere. Position the take a look at card directly onto the transporter at position A1. Let the cardboard submit to the search head. The sensor is being activated and also the alarm is sound. Repeat the higher than steps 1-3 with the take a look at card in positions A2 and A3. Again the detector is being activated and also the alarm is sound. The take a look at card is golf stroke through on its own, we have a tendency to don't seem to be place it on a paper or place it through with a garment. Repeat steps 1-3 with the take a look at card positioned within the middle of a stand (7-8cm high) or on high of a stand that's around 3-4cm high (depending on the peak of the gap between transporter and high of machine) at positions A4, A5, A6. Again the sensor is being activated and also the alarm is in sound.

The stand are being a non-detectable block made from plastic material. Repeat steps 1-3 with the take a look at card on the highest of a stand (7-8cm high or as high because the gap permits for) at positions A7, A8, A9 and once more the sensor standardization procedure aer being activated and also the alarm are in sound. Records are being unbroken of all of those checks by satisfaction the visit kind. In case the machine fails to pass the standardization take a look at, it's instantly being turned off associate degree re-calibrated by an authorized technician. All merchandise checked when the last standardization is being re-checked once traditional operations of the detector are re-established.

Machines are being tag a minimum of each six months by the manufacturer. Calibration certificates are being obtained and being unbroken for auditing functions. If for any reason the detector are being settled, it's being re-calibrated by the supplier’s authorized technical service. Regular maintenance (at least annually) of the detector is being allotted by the supplier’s authorized technical service supported the periods got wind of by them. Records for maintenance and any re-calibration created by the provider are being unbroken, just in case these got to be provided throughout any audits. Metal detection: When playacting the metal detection it's being ensured that merchandise are placed on the moving transporter one by one with comfortable area in between merchandise, so there's no overlap. If merchandise ar being shipped e.g. on hangers that are metal and can't be more matured the sensor, the products ar being started the hanger, more matured the sensor and so re-hung. it's permissible for the hangers to be touched through the metal via a door. This method are dominant by the authorised person and solely the proper quantity of hangers per order are to be control at anybody time, no spare hangers to be hold on. As a general guideline tho' clothes be metal detected as last as potential within the production method and any metal metal things are being connected within the metal free port, like security tags, hangers etc. The metal free port don't seem to be getting used for general storage and are being tidy. Once product is boxed or decorated is to be taken to dispatch. Handheld sensor conjointly used for this In case of stone laundry the clothes are being metal checked before laundry because the stone mud contains little metal particles that have associate degree adverse result to metal detection. Any clothes or a part of a garment that are being outsourced for the appliance of a print, embroidery or the other method ar being metal detected upon receipt back to the manufacturing plant, before continued production. this can be to make sure that no whole or broken needle items, staples, alternative stray metals or sharp objects arwithin the came back items. The manufacturing plant are ensuring that procedures are in situ to make sure that each one clothes as well as repaired and re-inspected don't attend packing while not being checked by the detector. Clear separation and identification of the clothes that are waiting to be checked which are being checked to be strictly created. Records are being unbroken for all clothes that are passing through the sensor and are being completed as product passes through the machine to verify compliance with this demand. If the alarm sounds, all clothes on the halted transporter are being place into a sealed bag, white and fast in a very secure rejection box, to be set close to the sensor. The rejection bin are being taken to a clearly marked space and totally checked for contamination by the allotted person. If the metal components are found and also the garment passes through the conveyor industrial metal detectors with success, the garment are often came back to the majority.
If the metal half can't be found, the contaminated product are being place into a polybag with details clearly marked thereon and so placed within the rejection bin (s. photo) fast off from the manufacturing plant floor and also the GARMENT are BEING DESTROYED when authorized close by the manufacturing plant manager. Under NO circumstances will it's came back to stock for cargo. If a product is metal detected in its packaging, take away the packaging and sight the merchandise and packaging on an individual basis as some packaging will contain traces of metal, particularly if recycled, e.g. card, thus might forestall the merchandise being rejected. The rejection bin are being fast with a chosen person holding the key. The bin has a slit at the highest through that the garment are often more matured.
The slit is being large enough to let the garment match through, however sufficiently little to avoid a hand fitting through it. Any action is being recorded consequently and any found metal components are being taped firmly to the metal detection failure record by sticky tape confirming supply of stuff and action taken to stop future contamination. Records of garment destruction are being unbroken for a minimum of five years for auditing functions. After the tested merchandise are packed in a very carton, the carton are being marked with a stamp stating date and ‘tested’. Any merchandise that are being came back from the {storage ara|cargo area|cargo deck|cargo hold|hold|enclosure} / warehouse to the sewing/finishing floor are being checked once more with the commercial sensor and also the cartons should be re-stamped with date and ‘tested’. Requirements on the sensor machine and accessories: There are two sorts of conveyor metal detectors: General Purpose Metal Detectors, that sight all metals (use them for clothes that don't have any metal parts like zippers, press studs, buckles etc.) Ferrous solely Metal Detectors (use them to examine clothes that contain approved non-ferrous, non-magnetic components). We advocate to use metal sightors that detect metal metals solely, so clothes are often more matured the detector with metal parts on like zippers, press studs, buckles etc.
Please specify once ordering parts that they have to be non-ferrous and non-magnetic. A complete metal detection system contains of a digital sensor, transporter, alarm reject system and take a look atsign. Any new metal detectors purchased should have a printer or production information recording facility to record standardization checks, the fashion numbers of product detected and contaminants detected. The {metal sightor|detector|sensor|sensing element} ought to be ready to detect a metal half that is akin to a diameter of one.2mm metal sphere at any purpose of the sensor aperture at the equipped belt speed. The sphere ought to be stainless steel of AISI 52100 grade with AFBMA GD ten size tolerance mounted on a take a look at card. Please solely use approved take a look at cards from nominative suppliers/manufacturers, don'tstructure your own! The take a look at card should be obtainable in the least times with the sensor it belongs to. In case of clothes with accessories, the sensor should be capable of ignoring a sample of non-ferrous accessories and permitting it to pass unseen. just in case of clothes while not accessories, the needle detector should a minimum of ignore a non-ferrous take a look at coin. A sample to check your machine are often obtained from the machine manufacturer. When passing the one.2mm take a look at card with the accessories or the take a look at coin, the needle sightor should detect the one.2mm metal take a look at card.
Machines should have associate degree sonic alarm with automatic belt stop just in case any metal is detected. The transporter should not be ready to operate once the detector is faulty or changed. The sonic alarm and transporter ought to solely be capable of being re-set by a key switch. Metal detectors should be put in to the manufacturer’s tips and also the manufacturer should approve the sitting of metal detectors. Power fluctuation causes false alarms. thus the installation of a regulator can minimize the matter. All metal parts should be non-ferrous to submit to a metal sensor. Non-ferrous (non-detectable) and nickel free metal parts (such as snaps, rivets, zippers etc.) ought to be used in the least times and ar necessary for childrens wear to avoid warning throughout the detection. A special coating is applied to those parts creating them non-ferrous. thus it should be ensured that the trim provider is alerted to deliver non-ferrous parts for such clothes. The manufacturing plant ought to make sure this can be the case by checking incoming things with a metal detector before attaching them in bulk. Machine Location and Set-up: The sensor ought to be placed at the top of production (after all stitching operations, attachment of swing tickets and packing) in a very therefore known as flying field system. The detection machine ought to be positioned [*fr1] into the packing space, then protected and separated by a solid panel/wall (fence isn't comfortable, as things are often more matured it), therefore the product ends on the opposite facet through the machine in associate degree isolated metal free zone/area. {this is|this is often|this will be} to eliminate any external interference and to avoid that merchandise can bypass the metal detection by mistake.
Please see icon for flying field system: industrial sensor setup Industrial sensor location The detector should be put in in a very permanent location freed from alternative metal objects like metal frames, doors, shelves etc. to avoid electrical interference. It is suggested that the manufacturing plant has a minimum of two conveyor metal detectors in the least times, to be ready to keep on checking just in case the one among them breaks down. It has to be ensured tho' that any spare sight or is in sensible operating order and ready to detect a metal a part of one.2mm metal sphere. Best observe are often found in victimization two sensors placed at ninety degrees or perhaps through a twin head metal detector. Position across the transporter in a very nine purpose check. Only authorized personnel ought to have a key that controls set-up and standardization of the machine.
The key should not be left within the machine. Only authorized and trained personnel ought to be in operation and maintaining the sensor. The coaching ought to be control by the manufacturer or associate degree approved agent and trained employees ought to be ready to build minor changes once required. Records should be unbroken of all coaching, maintenance, service and repairs. The in operation personnel ought to be professionalized as full time staff. An organization chart with the names of individuals answerable and their photograph should be announce at this space (incl. the person answerable of the method likewise as the other operators). The metal detection policy should be translated into the native language, displayed wherever applicable and also the management should make sure that staff absolutely perceive the policy. The policy ought to be a part of your induction programmer for brand spanking new staff. Cellular phones and alternative electronic devices should be unbroken off from the detector throughout operation. The supervisor ought to make sure that the allotted personnel should not wear consumer goods with pockets and may not wear things of bimetal origin (e.g. wrist joint watches, rings, mobile phones, belts etc.) or carry a cell phone whereas in operation the machine. Uniforms for the authorised staff operating within the metal free port ought to have a distinct color to the remainder of the manufacturing plant.
The ara the metal checked merchandise are going into, must be a secured ‘metal free zone’ (so e.g. no clippers or scissors for cutting gum tape allowed), that's not too open and segregated/separated/isolated to avoid any potential contamination with the continuing production. The zone must be declared and clearly marked as metal free and solely authorised personnel ought to be allowed into the zone. This once more ought to be clearly marked and communicated to everyone and personnel ought to be known as authorised, e.g. through totally different colored uniforms or ID cards. The fencing of this zone ought to be solid, so it are often avoided that metal objects are often more matured the fence and cause contamination. Entry to the present space should be restricted and monitored. nobody ought to be allowed access carrying any metal tool, e.g. scissors, blades, clippers, needle, stapling machine and or spare metal parts. Unauthorized personnel ar prohibited from accessing the metal free space.
Anybody getting into the metal free port ought to be recorded with name, signature, in-time, out-time, purpose and signatures by person answerable & manager and once more once going the realm. The entrance to the metal free port ought to be fast throughout breaks and at the top of the day when guaranteeing that nobody is left behind. All product should submit to the sensor into the secured ‘metal free zone’. Once the merchandise has more matured the sensor, it should be placed in a very selected quarantine space inside the metal free port till the subsequent standardization check has been with success completed, solely then will the merchandise be discharged from the quarantine space for additional packing.
Packing will occur during this metal free port, however no kimbal/tag guns ought to be used. Hangers are often inserted into clothes and or place into the cartons during this space. Tools that ar employed in the metal free port ought to be numbered, recorded and unbroken at fastened places. The manager ought to check quantities of those tools before and when operating.

Invention of Touch Screen and How it Works

2016-09-04T13:56:00.001+06:00

Invention of Touch Screen and How it Works

Automobiles, airplanes, computers, and steam engines—touchscreens belong within the company of those illustrious inventions as a result of they lack a novel discoverer and a definitive, "Eureka" moment of invention: in alternative words, no single man or girl fictional the touchscreen.

The first invention that bears any reasonably likeness to employing a fashionable touchscreen was known as a light-weight pen (featured within the image up above), a stylus with a electric eye in one finish, and a wire running into the pc at the opposite finish, that would draw graphics on a screen. it absolutely was developed within the early Nineteen Fifties and shaped a neighborhood of 1 of the primary pc systems to feature graphics, Project windstorm. light-weight pens did not extremely work like fashionable touchscreens, however, as a result of there was nothing special concerning the screen itself: all the clever stuff happened within the pen and therefore the pc it absolutely was wired up to.

Elographics Seventies touchscreen style from USA Patent three,911,215.

During the Sixties and early Seventies, another key strand within the development of touchscreens came from the work of pc scientists UN agency specialised in a very field known as human-computer interaction (HCI), that sought-after to bridge the gap between individuals and computers. Among them were politico Engelbart, discoverer of the pc mouse; Ivan Sutherland, a pioneer of tricks and virtual reality; and Alan Kay, a colleague of Sutherland's UN agency helped to pioneer the graphical program (or GUI—the picture-based desktop used on nearly all fashionable computers).

The first gismo that worked in any manner sort of a fashionable touchscreen was known as a "Discriminating Contact detector," and it absolutely was proprietary on Oct seven, 1975 by martyr S. Hurst and William C. Colwell of Elographics, Inc. very like a contemporary resistive touchscreen, it absolutely was a tool with 2 electrically conducting contact layers separated by associate insulating layer that you simply may press in conjunction with a pen. Crucially, it absolutely was designed to be operated "with a piece instrument [the patent drawings show a pen] and not by any portion of a writer's hand". thus it wasn't sort of a fashionable, finger-operated touchscreen device.

Early touchscreen by Elographics was proprietary in 1975. it's associate outer case (26, yellow) and a high contact layer (27, orange) on that you'll be able to write with something you wish (28). As you scribble away, you press the highest contact layer (blue, 23) down onto very cheap one (10, green) by squashing the little, well-spaced material buttons (dark blue, 25). associate conductor (12) picks up the contact and uses resistance to work out that a part of the screen you have touched. From USA Patent #3,911,215: Discriminating Contact detector by martyr S. Hurst and William C. Colwell, Elographics, Inc., courtesy folks Patent and Trademark workplace.

An Apple Newton next to associate Apple iPhone.

Many people assume touchscreens solely arrived once Steve Jobs undraped Apple's iPhone in 2007—but touch-operated, hand-held computers had already been around for twenty years by then. one amongst the primary was the Linus Write-Top, an outsized pill pc free in 1987. 5 years later, Apple free the relative of its iPhone within the form of Newton, a hand-held pc factory-made by the japanese Sharp Corporation. Operated by a pen-like stylus, it featured pioneering however somewhat erratic handwriting recognition however was ne'er a poster success. Touchscreen input and handwriting recognition conjointly featured within the Palm series of PDAs (personal digital assistants), that were massively common within the mid-1990s.

From iPhones and iPads ,Andriod to ebooks and tablets, all fashionable touchscreen gadgets owe one thing to those pioneering inventors and their scribbling machines!

Airbus Electrical System Wiring Schematics

2016-05-02T12:50:00.000+06:00

Airbus Electrical System Wiring Schematics

These schematics square measure simply tailored several} craft panel installations and there square measure many common parts that would be used for any craft panel. it's additionally a wonderful example of real-life implementation of the open supply astronautics styles originally from Vx Aviation that square measure enclosed within the Maker Plane repository, The repair shed Workshop. you may see installation of the subsequent open supply avionics:

AXIS-9A Dynon Wiring Hub
AXIS-25A Avionics Cross-connect Wiring Hub
GBX-1A Avionics Ground Bus
AMX-2A 10 Channel Audio Mixer
IL-6A Lamp Controller
The schematics include the following diagrams to help you with your own panel designs:
Master Switch and Starter
Ignition
Avionics Master
EFIS wiring
EMS
Autopilot
Trim
Lights (NAV, Strobe, Landing, Cabin etc)
Audio
Smoke (Vern does aerobatic flying!)
Infinity Grip wiring
Wig-wag oscillator driver
Servo Controller

This is a fantastic resource and hope that it helps you in your own project! This essentially takes care of ninety nine of the LSA paradigm electrical system.

Project EEE 2016-SELF SWITCHING POWER SUPPLY

2016-02-28T18:00:00.000+06:00

Embedded system requires a regulated power supply. This power supply circuit gives a variable regulated supply and switches off in no load condition.Through an arrangement of voltage regulator 7805 and a potentio-meter the output voltage is varied from 3.7V to 8.7V. Another feature of this power supply is, when no load is there it automatically switches off. It is achieved through an arrangement of transistors and relay.

HARDWARE REQUIREMENT:

TRANSFORMER.
RECTIFIER.
FILTER
REGULATOR.
RELAY.
TRANSISTOR (BC 547 & BC 557).
RESISTOR.
CAPACITOR.
1N4007.

Electricity EEE Mcq job interview question answers

2016-01-04T12:14:00.002+06:00

Basic Electricity Mcq job interview question answers.

1. One Newton meter is same as -One Joule

2. One angstrom is equal to- 10"10 m

3. Conductance: mho ::Resisance: ohm

4.Negative temperature co-efficient - Electrolytes

5. Nichrome wire is an alloy of- Nickel and Chromium

6.The number of electrons in the outer most orbit of carbon atom is- 4

7.Voltage dependent resistors are use to- supress surges

10. Voltage dependent resistors are usually made from- nichrome

11. All good conductors have high -conductance

12. Semi-conductors are the materials having electrical conductivity much less than most of the metals but much greater than that of typical insulators.

13. An open resistor, when checked with an ohm-meter reads -Infinite

14.A rheostat differs from an potentiometer in the respect that it- has a wattage rating

15. A semi-conductor is a material whose conductivity is same as between that of a conductor and an insulator.

Electricity

Automatic Gain Controller Circuit Diagram

2015-12-10T12:42:00.005+06:00

Automatic Gain Controller Circuit

A.G.C : Automatic gain control is a technique found in many electronic devices. The advantage or peak output signal level is used to adjust teh gain to a suitable level, enabling the circuit to work satisfactorily with a greater rang of input signal levels. Examples, without AGC the sound emitted from an AM radio receiver would vary to an extreme extent from a weak to a strong signal, the AGC effectively reduces the volume if the signal s strong and raises it when i is weaker.

Public and Private Financial Development Effectiveness in Bangladesh

2015-12-08T14:17:00.001+06:00

Introduction :

Bangladesh has made significant economic and social advances in the last three decades or so fo its existence. With large population, the country has achieved a measure of food self-sufficiency; In the face of low per capita incomes and widespread illiteracy, it has made successful strides toward demographic transition and reduced its population growth rate from 2.5 percent per year in the early 1980s to less than 1.5 percent per year in 2005(Bangladesh Bureau of Statistics 2007b). In a number of other social indicators, such as infant morality, life expectancy, primary school enrollment, female enrollment in school and adult literacy, Bangladesh has made considerable improvements over the years.

The Development what it is :

According to the World Bank, as many as half of the world’s six billion inhabitants live on the equivalent of less than $2 per day, and about one-fourth of the world lives on the equivalent of less than $1.25 per day (Chen & Ravallion, 2008). Meanwhile, people in the 20 richest countries earn, on average, 39 times more than people living in the poorest 20 states (Milanovic, 2007).

At the same time, the extent of world poverty has declined significantly during recent years. For example, the World Bank estimates that from 1981-2005 the percentage of people living on less than $1 per day was halved, decreasing from 52 percent to 26 percent during this period (Chen & Ravallion, 2008).

These contrasting trends highlight both the problems and the progress associated with the process of “development.” On one hand, development has resulted in serious inequities between states, whereby large numbers of the world’s inhabitants are mired in poverty, especially in Africa, while inhabitants of the world’s richest countries live in both relative and absolute luxury. And yet, due to development trends, populations in poor countries are becoming wealthier over time—a process linked to globalization because countries in the developing world can raise their standards of living by integrating with highly developed states.

The term “development” in international parlance therefore encompasses the need and the means by which to provide better lives for people in poor countries. It includes not only economic growth, although that is crucial, but also human development—providing for health, nutrition, education, and a clean environment.

Public and private financing for development:

Public Finance for Development:

Public finance and development is to understand how a state moves from collecting a low level of public revenue of around 10% of national income towards collecting around 40%. In the process, tax bases are typically shifting from trade taxes and excises towards labor income and other broad bases, such as value added. To study this process is fundamentally a challenge of appreciating incentives and constraints. Incentives are shaped by political institutions, existing power structures, and societal demands that the state perform certain functions. Constraints are imposed by a society’s economic environment, social cleavages, and political interests. Over time, these constraints can be shifted and governments play a key role for such shifts. Governments might invest to improve the working of the economy and the efficiency of public goods provision. They may also try to create a sense of national identity and propose reforms to political institutions. Analyzing such issues requires a dynamic framework and our chapter has sketched one. We believe that the factors highlighted in this framework provide substance to Schumpeter’s insights about the centrality of taxation to understanding state development, namely:

“The fiscal history of a people is above all an essential part of its general history. An enormous influence on the fate of nations emanates from the economic bleeding which the needs of the state necessitates, and from the use to which the results are put.” (Joseph Schumpeter, The Crisis of the Tax State, 1918)

If developing states are to be able to support their citizens at a level now taken for granted by citizens in developed countries, this requires a series of investments, making the state more effective and responsive. Uncovering the preconditions for such investments to take place is a central task for research on public finance and development.

Private finance for development:

Achieving development goals will require the mobilization of resources from private sources, including FDI, bank loans, capital markets, and private transfers (e.g., remittances).For most developing countries, FDI is the preferred private financing modality given its potential to strengthen productivity and growth, and help diversify the economy. Although many developing economies have enjoyed increased access to international capital markets over the past decade, there is an increasing mismatch between available financing and investment needs. This is partly due to fragile market conditions in the wake of the global financial crisis, which constrain the availability of the type of long-term finance needed to support productivity-enhancing investment.

Accessing long-term finance for infrastructure is critical and will require greater attention to investment in

project preparation and policies and instruments that

can lower risk and strengthen the confidence of investors over a long-term horizon.

Innovative sources of finance:

Development partners are helping to develop new tools to help generate financing for development. The paper discusses a number of these: Pull mechanisms for development, which involve

ex-post economic incentives for innovation to solve a well-defined problem. By linking payments to the actual impact of an innovation, they can lay the foundations for a self-sustaining, competitive

market for the relevant product.

A number of African countries have adopted the resources-for-infrastructure (RfI) financing model to overcome limited capital market access and domestic capacity constraints. Under RfI, oil or mineral extraction rights are exchanged for turnkey infrastructure, complementing standard tax and royalty regimes. Diaspora resources (via diaspora bonds and remittance-backed bonds) could help finance infrastructure projects. The annual savings of developing country diasporas—US$400 billion by some estimates—represent a hitherto untapped source of financing for development.

Linking climate finance and development finance can enhance development impact by allowing the

fight against poverty to take climate effects into account and vice versa. Comprehensive carbon

pricing policies, the removal of inefficient fuel subsidies, and cap-and-trade schemes are promising

options to mobilize larger and higher-return investments.

The role of the World Bank Group and regional development banks:

The World Bank Group and its regional counterparts can add value through a combination of technical expertise, prudent risk management policies, application of clear standards to project design, execution, and corporate governance, a long-term perspective, and cross-country experience. Multilateral development banks (MDB) can bring financing partners into specific deals, for example, in the form of syndications or through co-financing arrangements. Generally, the MDBs’ stamp of approval and role as an“ honest broker” in disputes can help to reassure investors and contribute to a project’s viability, which in turn reduces the cost of engagement, including to private investors. MDBs can also contribute to extending maturities of private flows to finance productive investments.

Public-Private Partnerships(PPP) in the People's Republic of Bangladesh :

In August 2010, the Government of Bangladesh issued the Policy and Strategy for Public Private Partnership (PPP) to facilitate the development of core sector public infrastructure and services vital for the people of Bangladesh. The PPP program is part of the Government's Vision 2021 goal to ensure a more rapid, inclusive growth trajectory, and to better meet the need for enhanced, high quality public services in a fiscally sustainable manner.

The recent socio economic success story of Bangladesh has been widely acknowledged locally and internationally. On the social front Bangladesh has made significant strides in meeting several of the UN Millennium Development Goals such as reducing income disparity ratio, attaining gender parity in education, reduction in infant mortality etc. In addition, Bangladesh has made remarkable progress in reducing the prevalence of underweight children, increasing enrolment at primary schools,lowering the maternal mortality ratio and improving immunization coverage. On the economic front it is one of the few countries to have demonstrated consistently strong GDP growth rate averaging over 6% over the last five years despite the general global slowdown. Over the same period per capita income has increased from $638 in 2009 to over $1000 in 2013. The foundation to this path of socio-economic growth, success and prosperity for Bangladesh has been set out in the Vision 2021; the Vision that sees Bangladesh progress to a middle income country by the year 2021. The strategy for implementing Vision 2021 identifies the need to increase investments in infrastructure from around 2% to 6% of GDP as one of the key requirements to achievement of the vision. Therefore, the government has identified and prioritised the Public Private Partnership (PPP) as one of the key initiatives to meet this investment priority and close the infrastructure gap. Bangladesh’s success has been built on the foundations of a very dynamic and vibrant private sector. The public sector has worked together with the private sector in different modalities in delivering infrastructure projects for nearly two decades. As such it is keen to build on this strength and forge a lasting partnership between the public and private sector for the accelerated development of our country. Through the PPP program the government intends to pursue opportunities that benefit the private sector through generating a profitable revenue stream one that delivers to its citizens much needed social and economic public infrastructure services and fulfil the commitment of government to meet its social obligations and development imperatives.

History of PPP Projects in Bangladesh A policy framework for PPPs was introduced in Bangladesh as early as the mid 1990’s with the Private Sector Power Generation Policy (PSPGP) 1996. This marked the launch of PPP projects in the power sector, with the 450MW Meghnaghat and 360MW Haripur Power Projects; two early success stories. The policy for encouraging partnerships with the private sector continued throughout the 2000’s with the introduction of PSIG 2004 (Private Sector Infrastructure Guidelines 2004). The Policy and Strategy for Public-Private Partnership (PPP), 2010 (PPP Policy 2010) has now been introduced (replacing the PSIG 2004) to update the policy framework and incorporate best international practice to further boost the use of the PPPs across multiple sectors and to provide a clear and transparent regulatory and procedural framework.

NTRODUCTION TO THE PPP PROGRAM:

Public Private Partnerships (PPPs): PPPs are co-operative ventures between the public and private sectors built on the expertise of each partner that best meets clearly defined public needs through appropriate allocation of resources, risks and rewards. The partnership is reinforced through legally binding arrangements, typically medium to long term, between the public and private sectors whereby services that traditionally have been provided by the public sector are delivered by the private sector, with clear agreement on shared objectives and allocation of risk for delivery of public infrastructure and/ or public services. PPPs do not include outsourcing of a simple function of a public service, turnkey construction contracts, which are categorized as public procurement projects; or the privatization of utilities where there is limited on-going role for public sector.

PPPs regulated in Bangladesh:

The Policy and Strategy for Public Private Partnership (PPP) 2010 and the Guidelines for Formulation, Appraisal and Approval of Large Projects, Medium Projects and Small Projects, 2010; all gazetted on August 2010 establish the PPP Policy Framework for Bangladesh. These documents are updated and supplemented from time to time by specific PPP guidelines providing further details (for e.g. the Guidelines for Viability Gap Financing 2012).

Sectors are covered by PPPs:

PPPs can be used for the delivery of public service projects in any social or economic infrastructure sector. Globally there are many successfully examples of PPPs in a wide range of sectors including Transport (e.g. Port, Airport, Highway, Railway, Bridge); Energy (e.g. Power Plants, Transmission Lines); Civil Accommodation (e.g. Economic Zones, Public Buildings, Convention Centers, Sports Facilities, Commercial Development, Residential Housing, Education Buildings); Health (e.g. Hospitals, Health Care, Dialysis and Diagnostics); Tourism and Hospitality; Water, Sewerage and Waste; IT infrastructure and Agriculture. In Bangladesh PPP projects have already been delivered or are being developed in many of the sectors listed above.

Benefits of PPPs:

PPP projects can deliver a solution that provides services to citizens, enables the government to meet its responsibility of provision of services while providing the requisite financial returns to the private sector. Hence well-structured PPP projects are widely acknowledged to deliver a ‘win-win solution’ that benefits all stakeholders.

UNDERSTANDING PPPs :

Different contractual models for PPPs applied in Bangladesh:

A number of different contractual models of PPPs have been developed globally and are widely applied in projects. Each PPP model represents a different allocation of risk and responsibility between the public and private sector. These can differ in relation to size of investment by the private sector, the basis of the revenue stream, the responsibilities undertaken in relation to construction, operation, maintenance and service performance, ownership of asset and the length of the contract period. Where the public sector retains too much risk or it transfers most of it to the private sector than it falls outside the framework of a PPP. The range of contractual models that typically fall under the PPP framework is set out in the figure below. The PPP contractual model is determined on a case by case basis following the conclusion of the feasibility and market engagement study that will determine the optimum option to deliver the public sector objectives through a viable, bankable and sustainable project for the private sector.

Difference between Traditional Public Procurement and PPPs :

In traditional public procurement the focus is on the delivery of an asset, however, PPPs focus on the delivery of service outputs which require the construction, operation and on-going maintenance of assets. This conceptual difference means that the roles and responsibilities carried out by the public and private sector in traditional procurement and PPPs differ depending upon the specific contractual model that is being applied to the PPP. For example, in a BOT public sector retains responsibility for specifying the project scope, service requirements and standards. Public sector takes responsibility for providing land that is free from encumbrances and carrying out any linked projects (for e.g. relocation of utilities). Private sector takes responsibility for detailed design construction, financing, operation and maintenance of the asset. The revenue payment risk can be taken by the private sector, by the public sector or be shared between the parties.

Interested private sector investors participate in PPP projects:

The public agency with the mandate for the PPP project has responsibility for the procurement and selection of a private sector investor. The procurement process to be used is detailed in the PPP policy framework, which mainly provides for the option of a single stage or a two stage open and competitive tender process. The two stage procurement starts with the Request for Qualification (RFQ) being issued to interested investors. An inter-ministerial committee evaluates the qualification submissions to select the pre-qualified bidders. This is followed by issuing the Request for Proposal (RFP) to the pre-qualified bidders. The same inter-ministerial committee will complete the evaluation to recommend the preferred bidder. On selection of the preferred bidder the public agency (supported by the PPP Office) will negotiate on issues specified in the RFP (if any), following which the legal vetting is completed on any non-standard contractual provisions. The public agency will seek final approval from the approving authority, before awarding the contract to the preferred bidder. In the single stage procurement the RFQ and the RFP Stage is combined into a single RFP stage; however the remaining steps remain unchanged. In both single and two stage procurement processes the public agency may issue a Request for Registration of Interest prior to the formal procurement launch. This is an optional stage designed to support the market engagement process, create awareness and help enhance the procurement documentation.

Figure: GDP Growth of Bangladesh 2015

Effectiveness in Developping:

As development theory and empirical experience from developing countries suggest, external assistance can fill in for lacking resources by

(a) Augmenting limited domestic saving
(b) Providing the additional foreign exchange required to finance critical capital requirements and imports of raw materials and
(c) Assisting with the development of human capital and the promotin capacity.

However, as recent history indicates, frequently these potential benefits of external assistance have not been realized and instances of aid ineffectiveness appear to be as numerous as instances of aid effectiveness.

The three major contributor of Bangladesh are the World Bank, the Asian Development Bank(ADB) and the Government of Japan(GOJ).During 1971 to 2008 the country received about $48 billion of foreign aid with annual flow of aid that has ranged from about $10 billion to some $1.5 billion.

Remarks:

Bangladesh has made impressive improvement in the past decades or so in key social indicators such as fertility, life expectancy, school enrollment for girls and child immunization, which compare favorably with other low-income countries, including its South Asian neighbors. Bangladesh GDP growth rate 6.12 percent in 2015. Bangladesh aspires to become a middle-income country of the next decade if it can accelerate its pace growth to 7.5 percent.

What is 5G Technology How it Works

2015-12-06T11:52:00.001+06:00

What is 5G How it Works

About 5G :
The "G" in 3G, 4G and 5G stands for "generation." thus 5G are going to be the fifth generation of wireless network technology.
The standards for 5G haven't however been set. in step with Bill Smith, president of AT&T's network operations, 5G can probably be outlined in 2018, and also the standards for 5G can written someday in 2019 by the standards-setting International Telecommunication Union, a branch of the United Nations. The standards can verify that wireless technologies may be known as "5G," moreover as what its characteristics should embrace, like how briskly it'll be.
Still, it's doable to form a really educated guess regarding what 5G can seem like supported the rising 5G technologies that the wireless trade is experimenting with.

How 5G Works :
A lot of the wireless companies' 5G experimentation is happening in super-high frequencies -- as high as seventy three,000 MHz. Today's telephone networks broadcast signal during a vary of 700 Mc to three,500 MHz.
The advantage of high-frequency signals is that they are capable of providing considerably quicker knowledge speeds. The disadvantage is that they travel a lot of shorter distances and that they cannot simply penetrate walls. which means thousands -- even perhaps millions -- of mini cell towers, or "small cells" would wish to be placed on prime of each lamp post, each building, within each home and doubtless each area.
That presents a bunch of issues. however will telephone firms presumably method all that data? There square measure firms, like Google's recently noninheritable Alpental, that square measure acting on those "backhaul" problems. however they are not therefore near an answer, consistent with Akshay Sharma, wireless infrastructure analyst at Gartne.
That's why 5G would possibly complement 4G, instead of outright replace it. In buildings and in jam-pawncked areas, 5G would possibly offer a speed boost. however once you are driving down the main road, 4G might be your solely choice -- a minimum of for a moment.

Basic top EEE MCQ Questions Answers Electricity and magnetism

2015-12-03T13:44:00.002+06:00

Basic EEE MCQ Questions Answers Electricity and magnetism

1. Who discovered the relationship between magnetism and Electricity for the theory of electromagnetism? Ans:- Hans Christian Oersted.

2. Who demonstrated the theory of electromagnetic induction in1831? Ans: Michael Faraday

3. Developed the electromagnetic theory of light in 1862. Ans: James Clerk Maxwell

4. Whenever a flux inking a coil or current changes and emf is induced in it. This is known as-Ans: Faradays first law of electromagnetic induction.

5. The force of attraction or repulsion between two magnetic poles is directly proportional to their strengths Ans: Coulomb’s first law

6. The polarity of the induced voltage will oppose the change in the magnetic flux causing the induction Called.. Ans: Lenz’ Law

7. Lenz’ Law is the consequence of the law of conservation of.. Ans: Energy

8. Lenz’ Law states that the direction of the induced emf and hence current.. Ans: Always opposes the cause producing it.

9. The process by which an emf and hence current is generated or induced in a conductors when there is a change in the magnetic flux linking the conductor is called… Ans: Electromagnetic Induction.

10. The emf induced in a coil due to the change of its own flux linked with it is called.. Ans: Self induced emf

Pulse Semiconductor Designing Battery-backed MEMORY using high speed SRAM

2015-11-07T12:45:00.002+06:00

The structure of a traditional embedded system has not modified for several decades. Figure one shows the block level diagram of a typical embedded system. A microcontroller or microchip is at the center of the system. relying upon the applying, system designers add or take away interfaces and peripherals as required. If the interior memory of the controller isn't ample, external reminiscences like Flash, SRAM and DRAMs ar used. Typically, Flash holds the code that's dead by the controller whereas SRAMs ar accustomed store runtime temporary variables and retain essential blocks of application knowledge. Power budget and performance have forever been 2 of the shaping criteria for choice of system parts, be it the controller or any peripherals. If performance is essential, designers tend to pick out the quickest parts, commercialism off for the next power budget. Similarly, if power is that the most significant criteria— like in a very battery-backed system—then designers tend to pick out parts with the smallest amount power consumption. As a result, embedded systems ar typically classified into 3 categories:
1. forever “ON” Systems: These systems guarantee that they're going to forever be power-driven from Associate in Nursing uninterrupted power supply. These ar high performance systems designed to control at the best frequency of operation.
2.Battery-powered Systems: Associate in Nursing on-board battery is that the solely supply of power for these systems (i.e. a mobile phone). whereas performance is a crucial criteria for such systems, having longer battery life first-rate the priority list. thus these systems ar designed with parts that consume the bottom power.
3.Battery-backed Systems: These systems should be able to operate dependably even though they lose their aboard power offer. To avoid the loss of essential knowledge throughout these power failures, system designers offer atiny low battery (typically a 240mAh coin battery) to produce make a copy for essential functions like SRAM retention and maintaining the period clock (RTC). A battery-backed system operates on the out there power offer throughout traditional operational conditions. betting on the memory mapping, it will execute code from Flash then store ends up in SRAM. It becomes essential to store this knowledge even throughout power failures. Figure 1. diagram of a typical embedded system
Figure 2. Power consumption pattern of a battery-backed system to handle this issue, the SRAM is connected to Associate in Nursing alternate on board battery. throughout traditional operation, the on-board offer powers the system, and through equipment failure, a supervisor chip can switch the SRAM offer to the aboard battery and place the SRAM in its standby mode of operation. sit down with “Design Recommendation for Battery-Backed SRAMs” for additional details on specific battery-backed system implementation techniques.

Figure two shows the everyday power usage of SRAM in a very battery-backed system. The supervisor routes the board power offer throughout traditional modes of operation. On equipment failure, the SRAM is switched to the on-board battery and is disabled by the supervisor chip. The system will stay during this mode for as long because the battery lasts. Once board power offer resumes, the supervisor chip can bit by bit resume powering the SRAM

Networking basic mcq answers

2015-10-27T18:50:00.000+06:00

Basic of Computer Networking Technology

■ Network consists of 2 or additional entities sharing
resources and data.
■ Samples of basic networks embody your human
network, faculty lunchrooms, eating house feeding,
and business contact development.
■ The aptitude to share is increased once data
is keep on computers.
■ Laptop networks incorporates 2 or additional
computers that area unit connected and ready to
communicate.
■ Networked computers share resources and
information.
■ Powerful networks result once further computers
are additional to the communication potentialities.
■ As additional and additional information becomes offered over a
network, some reasonably an effect system should be
established.
■ The hierarchy of information ought to be utilized in network
planning.
■ Access to information keep to a higher place during this chain is additional
strictly controlled, which suggests fewer individuals will
view that information.
■ information is outlined as a chunk or items of knowledge.
■ the gathering, correct manipulation, and effective tracking makes information
management on networks therefore vital.

Basic MCQ questions Computer Fundamentals

2015-09-15T14:53:00.001+06:00

Basic MCQ questions Computer Fundamentals

1. What are the five basic operations performed by the computer?

2. Define ALU, CU and CPU.

3. Choose the correct answer.
(a) The task of performing arithmetic and logical operations is called: (i) ALU (ii) editing (iii) storage (iv) Output
(b) The ALU and CU jointly are known as (i) RAM (ii) ROM (iii) CPU (iv) None of above
(c) The process of producing results from the data for getting useful information is called: (i) output (ii) input (iii) processing (iv) storage

Pros and cons of drone the future technology

2015-08-18T19:06:00.001+06:00

Pros and Cons of Drone the future Technology

Unmanned aerial vehicles, or drones, became a vital and polemic a part of military capability in recent years. they're conjointly utilized in agriculture, for picture taking and multiple different applications that need low cost and in depth aerial police investigation. however thus far of these drones have had human pilots; the distinction is that their pilots ar on the bottom and fly the craft remotely.

The next step with drone technology is to develop machines that fly themselves, gap them up to a wider vary of applications. For this to happen, drones should be able to sense and reply to their native surroundings, sterilization their height and flying flight so as to avoid colliding with different objects in their path. In nature, birds, fish and insects will all congregate in swarms, every animal responding to its neighbor virtually instantly to permit the swarm to fly or swim as one unit. Drones will emulate this.

With reliable autonomy and collision turning away, drones will begin to require on tasks too dangerous or remote for humans to hold out: checking power lines, as an example, or delivering medical provides in AN emergency. Drone delivery machines are going to be able to notice the most effective route to their destination, and take into consideration different flying vehicles and obstacles. In agriculture, autonomous drones will collect and method large amounts of visual knowledge from the air, permitting precise and economical use of inputs like fertilizer and irrigation.

In Jan 2014, Intel and Ascending Technologies showcased model multi-copter drones that might navigate an on-stage obstacle course and mechanically avoid those that walked into their path. The machines use Intel’s Real Sense camera module, that weighs simply 8g and is a smaller amount than 4mm thick. This level of collision turning away can lead off a way forward for shared airspace, with several drones flying in proximity to humans and in operation in and close to the designed surroundings to perform a large number of tasks. Drones ar primarily robots in operation in 3, instead of 2, dimensions; advances in next-generation artificial intelligence technology can accelerate this trend.

Flying vehicles can ne'er be safe, whether or not operated by humans or as intelligent machines. For widespread adoption, sense and avoid drones should be able to operate dependably within the most troublesome conditions: at midnight, in blizzards or mud storms. not like our current digital mobile devices (which are literally immobile, since we've to hold them around), drones are going to be transformational as they're self-mobile and have the capability of flying within the three-dimensional world that's on the far side our direct human reach. Once present, they'll immensely expand our presence, productivity and human expertise.

Basic About 3D Printing

2015-08-09T12:10:00.000+06:00

About 3D Printing

3D printing (also recognize as additive manufacturing) could be a processes wont to build a three-dimensional object while not the employment of dies, molds or machining. In 3D printing additive processes square measure used, within which sequential layers of fabric square measure arranged down beneath pc management.These objects will typically be of nearly any form or pure mathematics, and square measure created from a 3D model or another electronic knowledge supply. 3d printing so allows to production of elements which might not be doable with ancient producing techniques. A 3D printer could be a style of industrial automaton, and may vary from tiny scale shopper models to giant plant units.

3D printing within the term's original sense refers to processes that consecutive deposit material onto a powder bed with inkjet printer heads. a lot of recently the which means of the term has distended to include a wider sort of techniques like extrusion and sintering based mostly processes. Technical standards typically use the term additive producing for this broader sense.

Use of GSM BTS in Future Technology

2015-07-30T12:57:00.000+06:00

Use of GSM BTS in Future Technology

1. The highly development of the 3G networks are most advance technology and higher efficiency.

2. The GSM network is the most widely applied network in the world.

3. The GSM network is still favored and constantly envolves due to the maturity of technical applications and business model.

How Magnetic Resonance Imaging (MRI) Works

2015-07-01T23:19:00.000+06:00

Magnetic Resonance Imaging (MRI)

Assignment

ABSTRACT

The technique of functional magnetic resonance imaging is rapidly moving from one of technical

interest to wide clinical application. MRI stands for Magnetic Resonance Imaging, a noninvasive diagnostic technique that uses harmless radio waves rather than x-rays to create images. It is particularly useful for imaging of soft tissues such as the brain, spinal cord, muscles and ligaments and detecting abnormal tissues.

An MRI scanner is a cylindrical machine, used to get images of the human body. An MRI machine consists of a round tunnel within where the patient lies on a narrow table. An image of this is seen to the right. Surrounding the tube is a large cylindrical magnet.

In an MRI scanner, the human body is subjected to a very strong magnetic field and it is made to absorb and then radiate energy at the Larmor precession frequency of the hydrogen nuclei present in water. The intensity with which these radiations are emitted by the body are recorded by the MRI scanner which displays an image of the portion of the body under test on its monitor. The portions containing larger amount of water look darker on the screen as compared to those having little water. If different colours are assigned to different intensities, then a colored picture can be obtained. Since water content in the bones and teeth etc. is very small, these parts of the body are nearly invisible and therefore it is very easy to see through the bones in the case of MRI scanners. For this purpose along with a few others, makes MRI scanners very useful for medical science.

Introduction

Magnetic resonance imaging (MRI), nuclear magnetic resonance imaging (NMRI), or magnetic resonance tomography (MRT) is a medical imaging technique used in radiology to visualize detailed internal structures. MRI makes use of the property of nuclear magnetic resonance (NMR) to image nuclei of atoms inside the body.

The property of Nuclear Magnetic Resonance (NMR) was first described by Purcell and Bloch in 1946, work for which they received the Nobel prize in 1952. Since then NMR has become a

powerful tool in the analysis of chemical composition and structure. In 1973 Lauterbur and

Mansfield used the principles of NMR to describe a technique for determining physical structure.

Since then Magnetic Resonance Imaging (MRI) has been used in many biomedical, chemical and

engineering applications.

An MRI machine uses a powerful magnetic field to align the magnetization of some atoms in the body, and radio frequency fields to systematically alter the alignment of this magnetization. This causes the nuclei to produce a rotating magnetic field detectable by the scanner—and this information is recorded to construct an image of the scanned area of the body. Strong magnetic field gradients cause nuclei at different locations to rotate at different speeds. 3-D spatial information can be obtained by providing gradients in each direction.

During an MRI Scan, the patient is within a stable magnetic field which is 10,000 - 30,000 times stronger than the earth's magnetic field. Protons are tiny particles that are present in water molecules throughout the body. These are aligned by the incredibly strong magnetic field, noting that there are no water molecules in the human skeleton, only in bodily tissue. Radio waves are transmitted in pulses, and these protons produce echoes that are emitted out of the body. These echoes are received by the MRI scanner, and are then reconstructed into images of the body by a computer. These images are very precise and give a clear anatomical view of the body from any angle.

Background

Magnetic Resonance Imaging (MRI) uses the magnetic properties of hydrogen and its interaction with both a large external magnetic field and radio waves to produce highly detailed images of the human body.

Some Basic principles of magnetism-

The magnetic properties of the hydrogen nucleus, and its interaction with the externally applied magnetic field . In its early days, MRI was known as NMR. This stands for Nuclear Magnetic Resonance. Although the name has changed (primarily due to the negative connotation of the word “nuclear”), the basic principles are the same. . We derive our images from the magnetic resonance properties of nuclear particles (specifically hydrogen).

In order to perform MRI, we first need a strong magnetic field. The field strength of the magnets used for MR is measured in units of Tesla.

One(1) Tesla is equal to 10,000 Gauss. The magnetic field of the earth is approximately 0.5 Gauss. Given that relationship, a 1.0 T magnet has a magnetic field approximately 20,000 times stronger than that of the earth. The type of magnets used for MR imaging usually belongs to one of three types; permanent, resistive, and superconductive .A permanent magnet is sometimes referred to as a vertical field magnet. These magnets are constructed of two magnets (one at each pole).

The patient lies on a scanning table between these two plates. Advantages of these systems are:

1) Relatively low cost, 2) No electricity or cryogenic liquids are needed to maintain the magnetic field, 3) Their more open design may help alleviate some patient anxiety, 4) Nearly non-existant fringe field. It should be noted that not all vertical field magnets are permanent magnets.

Resistive magnets are constructed from a coil of wire. The more turns to the coil, and the more current in the coil, the higher the magnetic field .These types of magnets are most often designed to produce a horizontal field due to their solenoid design.

Some vertical field systems are based on resistive magnets. The main advantages of these types of magnets are: #No liquid cryogen,

# The ability to “turn off” the magnetic field,

# Relatively small fringe field.

Superconducting magnets are the most common. They are made from coils of wire (as are resistive magnets) and thus produce a horizontal field. They use liquid helium to keep the magnet wire at 4 degrees Kelvin where there is no resistance. The current flows through the wire without having to be connected to an external power source. The main advantage of superconducting magnets is their ability to attain field strengths of up to 3 Tesla for clinical imagers and up to 10 Tesla or more for small bore spectroscopy magnets.

Magnetic Properties of Matter

Magnetism is a fundamental property of matter. The three types of magnetic properties are: diamagnetic, paramagnetic, and ferromagnetic.

Outside a magnetic field, diamagnetic substances exhibit no magnetic properties. When placed in a magnetic field,diamagnetic substances will exhibit a negative interaction with the external magnetic field. In other words they are not attracted to, but rather slightly repelled by the magnetic field. These substances are said to have a negative magneticsusceptibility

Paramagnetic

Substances also exhibit no magnetic properties outside a magnetic field. When placed in a magnetic field, however, these substances exhibit a slight positive interaction with the external magnetic field and are slightly attracted. The magnetic field is intensified within the sample causing an increase in the local magnetic field. These substances are said to have a positive magnetic susceptibility

Ferromagnetic

Substances are quite different. When placed in a magnetic field they exhibit an extremely strong attraction to the magnetic field. The local magnetic field in the center of the substance is greatly increased. These substances (such as iron) retain magnetic properties when removed from the magnetic field. Objects made of ferromagnetic substances should not be brought into the scan room as they can become projectiles; being pulled at great speed toward the center of the MR imager. An object that has become permanently magnetized is referred to as a permanent magnet. A permanent magnet, such as a bar magnet, has two poles and is referred to as a dipole.

Atomic Structure

The nucleus of an atom consists of two particles; protons and neutrons. The protons have a positive charge and the neutrons have a neutral charge. The atomic number represents the number of protons in the nucleus. The atomic mass number is the total number of protons and neutrons. Orbiting the nucleus are the electrons, which carry a negative charge.

All of these particles are in motion. Both the neutrons and protons spin about their axis. The electrons, in addition to orbiting the nucleus, also spin about their axis. The spinning of the nuclear particles produces angular momentum. If an atom has an even number of both protons and neutrons, then the angular momentum is zero. If an atom has an uneven number of neutrons or protons, then the atom has a certain angular momentum. The angular momentum is expressed as a vector quantity having both magnitude and direction.

In addition to spin angular momentum, certain nuclei exhibit magnetic properties. Because a proton has mass, a positive charge, and spins, it produces a small magnetic field much like a bar magnet. This small magnetic field of the proton is referred to as the magnetic moment. The magnetic moment is also a vector quantity having both magnitude and direction and is oriented in the same direction as the angular momentum. The ratio between the angular momentum and the magnetic moment gives us a constant known as the gyromagnetic ratio, which is specific to each magnetically active nuclei. There are several nuclei, which are magnetically active.Hydrogen has a significant magnetic moment and is nearly 100% abundant in the human body. For these reasons, we use only the hydrogen proton in routine clinical imaging, and that is where we will focus our attention from here on.The nucleus of the hydrogen atom contains a single proton. Because ofthis, as previously mentioned, it possesses a significant magnetic moment. The proton will behave as a tiny bar magnet.

Creating an MR Signal

A radio wave is actually an oscillating electromagnetic field. The RF field is also referred to as the B1 field. It is oriented perpendicular to the main magnetic field. If we apply a pulse of RF energy into the tissue at the Larmor frequency, we first find the individual spins begin to precess in phase, as will the net magnetization vector. As the RF pulse continues, some of the spins in the lower energy state absorb energy from the RF field and make a transition into the higher energy state. This has the effect of “tipping” the net magnetization toward the transverse plane.

For the purpose of this explanation, we will assume sufficient energy isapplied to produce a 90-degree flip of the net magnetization. In such an example, it is said that a 90-degree flip angle, or a 90-degree pulse has been applied

Application

MRIs are a relatively new technology to hit the medical world, and have completely revolutionized medical imaging and the diagnosing process as we know it. In-vivo images can be taken of the human body, meaning that internal images can be seen without making any incisions. Completely non-intrusive procedures are used, which makes MRI's very effective, but somewhat expensive, for doctors to use.

MRIs are administered to patients suffering from the following:

#inflammation or infection in an organ

#degenerative diseases

#strokes

#musculoskeletal disorders

#tumors

#other irregularities that exist in tissue or organs in their body

High-resolution images of organs or any area of the body can be made without the need for using x-rays because MRIs use radio frequency (RF) light. Since they use RF light, MRIs do not present any known health risks to the patients; however anyone with metal implants could not receive a MRI. If a person's nervous system needed to be studied, an MRI image would be the best imaging method to use, especially if the brain or spinal cord needed to be investigated.

Functional MRI's are done to determine which parts of the brain have control over which uses of the human body. These MRIs are critical in determining motor imagery, speech portions of the brain, and diagnosing which parts of the brain may be affected by a tumor. Some operations are deferred because a portion of the brain that is vital may be removed, and this is only determined via functional MRIs.

Benefits of MRI

The MRI scan is a painless and safe scan that produces clearer images of the body and its tissues, at any angle. This is particularly useful in detecting soft tissue tumours throughout the body. An MRI is nearly twice as sensitive as X-ray mammography in detecting breast cancer in women that have a high genetic risk of the disease. It uses no radiation for scanning and therefore eliminates the health risk of x-rays that do use radiation.

Risks of MRI

While an MRI scan is a relatively safe procedure as there is no damaging radiation involved, there are still several risks. If the patient is pregnant, or suspects they may be, a doctor should be informed because the effects on an unborn baby are poorly understood. There is also the risk of patients being injured if they forget to remove pieces of metal from their body or their clothing. There have been cases where patients have been injured due to metal left behind by the previous patient. If sedation is required due to claustrophobia, then there are associated risks of over-medication. If a contrast dye is used, which helps to show up some parts of the body more clearly, there is a small risk of allergic reaction.

Limitations of MRI

An MRI is a very expensive and time consuming investigation compared to other methods such as x-ray and CT scan. Some parts of the body, like bone, are better examined using simpler techniques such as an X-Ray. An MRI may not always be able to tell the difference between some disease processes. It is also not a very good investigation for emergencies or accidents because of the long time it takes and the fact that all equipment has to be removed from the room while the machine is running.

Specialized Types of MRI

Magnetic Resonance Angiography (MRA): This type of MRI is designed to show the blood vessels. It is most often used to examine the arteries and veins of the head, neck, brain and heart. Usually, a contrast dye is injected, which cannot leave the blood vessels meaning that they show up much brighter than the areas around them. An example of this technique is seen to the right. Functional MRI: This type of MRI is done on the brain, and not only shows the structure of the brain, but also how much activity is taking place in each part. This has been used to find out what parts of the brain are most active during certain situations or tasks. Cardiac MRI: This can be used for several different conditions and is dealt with separately.

Conclusion

It is possible that an MRI may show that everything is completely normal; however, there are several things that could be seen on an MRI and this will vary depending on where in the body the scan is being done. An MRI is very good at showing up problems with soft tissues such as muscles and ligaments and is the most sensitive investigation for spinal and joint problems. For this reason, MRI is often used in sports-related injuries, allowing the doctor to see even very small tears or areas of swelling and inflammation. Almost all other organs can be examined in some detail using an MRI, showing problems in structure and function. MRI is most often used to show problems with the soft tissues of the body which can be genetic or caused by some disease process like a tumor. This includes areas like the brain, and an MRI can give a particularly clear image of the brain's structure. This is particularly useful for conditions such as a brain tumor where an MRI is often used to find out exactly where in the brain it is, allowing much more effective surgery.

How Electrical Engineers Are Discover Health Care

2015-07-01T01:57:00.000+06:00

How Electrical Engineers Are Discover Health Care : Mechatronics

Electrical engineers are professionals dedicated to developing electrical solutions and equipment. They are responsible for providing a variety of industries with powerful, long-term solutions, designed to help solve many types of problems.
One of the most prominent industries to benefit from the aid of electric engineering is the field of medicine. With more intelligent innovations regularly being made, doctors and medical professionals are able to work with stronger and more reliable medical equipment, helping their patients in ways never thought possible before. Since the 1950s, there have been numerous contributions made by skilled electrical engineers to the field of medicine. Many medical professionals believe that even further advancements can be made, helping revolutionize the field and providing patients with more extensive medical care options for their illnesses.
To learn more about relationship between electrical engineers and health care checkout the infographic below created by the New Jersey Institute of Technology’s Masters in Electrical Engineering program.

Major Milestones
Engineers have always collaborated with doctors to some degree, and, as time went on, their contributions have become more and more defining. In 1958, engineers helped develop the first portable pacemaker, designed specifically for external wear, helping improve mobility for those who suffer from heart conditions. Later, in 1960, engineers helped develop an implanted pacemaker, which helped extend the life of ten dying patients during the first clinical use. Two years later, John Charnley developed a low friction, high-density cement for hip transplants. In the 1980s, slow release drug systems were invented, helping revolutionize chemotherapy and providing cancer patients with an easier way to fight against the disease. In 1983, 3D printing was developed, which would help further revolutionize advancements in all fields of medicine.
Overall Trends
All electrical developments are geared towards providing medical solutions with a more reliable degree of miniaturization. This means that these advancements are made with portability and ease of use in mind. Microsensors, software developments, and wireless access are all at the forefront of developments, ensuring that patients are never too far from the aid that they need. These advancements also help improve surgical developments and ensure a speedy recovery. With automatic delivery systems developed as well, patients now have a much easier and more efficient way to get the medicine they need on a microscopic level.
Hospitals and Wireless Mechatronics
Hospitals currently stay up to date with engineering developments in order to strengthen the way they communicate with their patients and with each other. Over 86% of all hospitals use cell phones, 83% use mobile workstations, and 82% use PDAs and tablets. These devices make communications much more efficient because they help reduce internal and external interference between groups. Vital sign monitors are made even more efficient with the inclusion of such technology because doctors can stay on top of their patients’ needs as regularly as possible.
Current Solutions
Current technological solutions have already come a long way since their first developmental roots. With advancements in robotics, surgeons can use a remove surgery system, with mechanized robotic arms that perform all of the tasks, making incisions and following the surgeon’s movements. Defibrillator units can also help monitor patients, keeping track of heart rates through wireless signals with a connection between the implanted device and an offsite monitor. Doctors may also use disposable X rays now, which are endoscopic cameras inserted into capsules for easy access to the patient’s internal systems, without worrying about disposal.
Direct Contributions Made by Engineers
Outside of medical changes made by doctors and surgeons, engineers can help contribute directly to the field through their own specialized inventions. Engineers are regularly constructing high-powered prostheses, artificial limbs that can provide distinct electronic advantages. Slowly, advancements are reaching the point where these devices can function almost as well as the original limb. There are numerous brain implants and devices available as well, designed to help provide patients with a better way to retain and restore mental functions. These implants can help control the prostheses, and provide their own advantages for those who need them most.
Future Developments
In addition to existing technological advancements, engineers are always striving to improve the field with further developments. One of the most frequently discussed advancements is the improvement of 3D printing systems, allowing them to be expanded for use in a variety of medical fields, such as dentistry. Ultimately, the goal is to create 3D human organs that can be used seamlessly by the body. Smart pants are another projected development, which will deliver a small, electrical pulse through the body to help stimulate circulation and blood flow. This will help reduce as many as 60,000 annual deaths related to bedsores and poor circulation.

Geared Stepping Motors Basic working Principle & Advantages

2015-05-18T14:43:00.001+06:00

Working Principle and Advantages of Geared Stepping Motors

Speed reduction package have acquire wide use with the general objectives of accelerating force and reducing speed.
However, they're additionally utilized in combination with stepping motors requiring high positioning preciseness for the sake of higher resolution, lower vibration, high inertia drive, and
downsizing.
Here we are going to justify the benefits of meshed stepping motors examination the case for choosing the motor alone and the case for choosing a meshed sort.
This choice procedure calculates the minimum positioning time and calculates numerous parameters for 2 totally different conditions: once the motor alone is chosen for the drive for the index table within the figure on the left and once a meshed sort motor is chosen.
Therefore, this procedure encompasses a totally different sequence in places
from the choice procedure given below.

Drive Inertia:

The ratio of the moment of inertia of the load converted for the motor output shaft and the moment of inertia rotor is called the inertia ratio and expressed with the following equation :

Gear Motor Rotation

SEMICONDUCTORS MCQ VIVA Electrical Elentronics Answers

2015-04-28T17:17:00.003+06:00

SEMICONDUCTORS Devices MCQ-EEE,CSE,ETE

1. The diode is best described as:
a) Switch c) Electrical Storage Device
b) Check Valve d) Electrical Momentum

2. A silicon diode begins to conduct current at
approximately:
a) 7 volts c) 0.7 lb.
b) 0.7 volts d) 7 lbs.

3. NPN transistors have:
a) 2 leads c) 2 diodes
b) 3 leads d) b & c

4. NPN and PNP transistors are used to:
a) Create Power c) Control Current
b) Change Resistance d) Control Capacitance

5. The ratio of collector current to base current in a
transistor is called:
a) Beta (b) c) Current Control
b) Amplification d) FET

6. A diode made of Gallium Arsenide is called:
a) Zener Diode c) LED
b) Power Diode d) Detector Diode

7. A Field Effect Transistor controls Source to Drain
current by:
a) Diode Conduction c) Base Voltage
b) Base Current d) Gate Diode

8. A Zener Diode is used as:
a) Voltage Reference c) Resistance Control
b) Current Reference d) b & c

9. An Integrated Circuit contains:
a) Diodes and Resistors c) Inductors
b) Transistors and Small d) a & b
Capacitors

10. If the arrow in the symbol for a transistor points
toward the base lead, the transistor is a:
a) NPN Transistor c) FET Transistor
b) PNP Transistor

Ans : 1.b 2.b 3.d 4.c 5.a 6.c 7.d 8.a 9.d 10.b
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