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Medium 9789381159194


Anil Kumar Shukla Laxmi Publications PDF




Learning Objectives

Upon completion of this chapter, you should be able to do the following:

Explain the principal properties of an optical detector and fiber optic receiver.

Detail semiconductor optical detector performance and capability requirements necessary for the successful implementation of fiber optic systems.

List the main components of a fiber optic receiver.

Discuss receiver sensitivity, dynamic range, and other key operational parameters used to define receiver performance.



























Chapter 6 taught you that a fiber optic transmitter is an electro-optic device capable of accepting electrical signals, converting them into optical signals, and launching the optical signals into an optical fiber. The optical signals propagating in the fiber become weakened and distorted because of scattering, absorption, and dispersion. The fiber optic device responsible for converting the weakened and distorted optical signal back to an electrical signal is a fiber optic receiver.

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Medium 9789351382492


Saradindu Panda Laxmi Publications PDF





A carry lookahead adder is a type of adder used in digital logic. It can be contrasted with the simpler, but usually slower, ripple carry adder.

A ripple-carry adder works in the same way as pencil-and-paper methods of addition.

Starting at the rightmost (least significant) digit position, the two corresponding digits are added and a result obtained. It is also possible that there may be a carry out of this digit position

(for example, in pencil-and-paper methods, “9 + 5 = 4, carry 1”). Accordingly all digit positions other than the rightmost need to take into account the possibility of having to add an extra 1, from a carry that has come in from the next position to the right.

This means that no digit position can have an absolutely final value until it has been established whether or not a carry is coming in from the right. Moreover, unless the sum without a carry is 9 (in pencil-the-paper methods) or 1 (in binary arithmetic), it is not even possible to tell whether or not a given digit position is going to pass on a carry to the position on its left. At worst, when a whole sequence of sums comes to ...99999999... (in decimal) or ...11111111... (in binary), nothing can be deduced at all until the value of the carry coming in from the right is known, and that carry is then propagated to the left, one step at a time, as each digit position evaluated “9 + 1 = 0, carry 1” or “1 + 1 = 0, carry 1”. It is the “rippling” of the carry from right to left that gives a ripple-carry adder its name, and its slowness. When adding 32-bit integers, for instance, allowance has to be made for the possibility that a carry could have to ripple through everyone of the 32 one-bit adders.

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12 The Development and Prospect of Discovery of Bt Toxin Genes

Soberon, M.; Gao, Y.; Bravo, A. CABI PDF


The Development and Prospect of Discovery of Bt Toxin Genes

Jie Zhang,* Changlong Shu and Zeyu Wang

State Key Laboratory for Biology of Plant Diseases and Insect

Pests, Institute of Plant Protection, Chinese Academy of

Agricultural Sciences, Beijing, People’s Republic of China


Bacillus thuringiensis (Bt) Cry protein-based insect control has proven to be effective in reducing the use of chemical insecticides and in increasing crop yields. However, Bt crops increase selection pressure for resistant insects and accelerate their succession. The discovery and application of different Bt toxins that have no crossresistance with known toxins has been proposed as a strategy for the management of resistant insects. Additionally, the discovery of novel Bt toxins with a new insecticidal spectrum will control insect succession. In fact, the discovery of new Bt toxins is one of the most important areas in

Bt research, and the most advanced molecular biology methods available have been applied to this task. In this chapter, we summarize the published methods for Bt toxin discovery.

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Dr. R.K. Bansal Laxmi Publications PDF







Hydraulic machines are defined as those machines which convert either hydraulic energy (energy possessed by water) into mechanical energy (which is further converted into electrical energy ) or mechanical energy into hydraulic energy. The hydraulic machines, which convert the hydraulic energy into mechanical energy, are called turbines while the hydraulic machines which convert the mechanical energy into hydraulic energy are called pumps. Thus the study of hydraulic machines consists of study of turbines and pumps. Turbines consists of mainly study of Pelton turbine, Francis Turbine and

Kaplan Turbine while pumps consist of study of centrifugal pump and reciprocating pumps.



Turbines are defined as the hydraulic machines which convert hydraulic energy into mechanical energy. This mechanical energy is used in running an electric generator which is directly coupled to the shaft of the turbine. Thus the mechanical energy is converted into electrical energy. The electric power which is obtained from the hydraulic energy (energy of water) is known as Hydroelectric power.

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Medium 9789380386324


Dr. A.J. Nair Laxmi Publications PDF






In This Chapter









Biological Fuel Generation

Single-cell Protein

Sewage Treatment

Environmental Biotechnology

Medical Biotechnology

Agriculture and Forest Biotechnology

Food and Beverage Biotechnology

Safety in Biotechnology



e are slowly depleting our fossil fuel energy resulting in the need to seek out alternative sources of energy. So far, these have included the harnessing of hydro, tidal, wave and wind power, the capture of solar and geothermal energy supplies, and nuclear power.

There is now a growing appreciation of biological solar energy systems and biotechnological advances in this area will soon bring economic reality to selected processes. As fossil-fuel resources are depleted and become increasingly more expensive, conversion of organic residues to liquid fuels will become a more economically-attractive consideration.

There are three main directions that can be followed to achieve biomass supplies:

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Medium 9781780645681

4 Empowering Smallholder Farmers with Profitable and Sustainable Farming Using Conservation Agriculture: The Case of East Africa

Kassam, A.H.; Mkomwa, S.; Friedrich, T. CABI PDF


Empowering Smallholder Farmers with Profitable and Sustainable

Farming Using Conservation

Agriculture: The Case of

East Africa

Saidi Mkomwa,1* Simon Lugandu,2 Peter Kuria1 and Weldone Mutai1

African Conservation Tillage Network, Nairobi, Kenya; 2African

Conservation Tillage Network, Dar Es Salaam, Tanzania


4.1  Introduction

Agriculture is the backbone for East Africa (EA) economies and plays a key role in their industrial development and trade. Agriculture accounts for more than 32% of the region’s gross domestic product (GDP), employs about 80% of its labour force, accounts for about 65% of foreign exchange earnings and contributes more than 50% of raw materials to the industrial sector (EAC, 2015a). Agriculture is dominated by smallholder farmers, the majority of whom are women, who produce as much as 80% of the food consumed. Most of these farmers have 0.5–2 ha of land, earn less than US$1 a day, and face 3–5 hunger months in a year (Diagana, 2003). Many children under 5 years of age go without a balanced diet. Smallholder agriculture is often seen as a sector in which low incomes, low productivity and vulnerability predominate, with the perception of it being a source of rural poverty and food insecurity, rather than a solution. Some areas in the region are experiencing a reduction in food production by up to 50% due to land degradation, soil erosion, drought and climate change (UNEP, 2009).

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Dr. R.K. Bansal Laxmi Publications PDF






The laminar flow has been discussed in chapter 9. In laminar flow the fluid particles move along straight parallel path in layers or laminae, such that the paths of individual fluid particles do not cross those of neighbouring particles. Laminar flow is possible only at low velocities and when the fluid is highly viscous. But when the velocity is increased or fluid is less viscous, the fluid particles do not move in straight paths. The fluid particles move in random manner resulting in general mixing of the particles. This type of flow is called turbulent flow.

A laminar flow changes to turbulent flow when (i) velocity is increased or (ii) diameter of a pipe is increased or (iii) the viscosity of fluid is decreased. O. Reynold was first to demonstrate that the rVD

. transition from laminar to turbulent depends not only on the mean velocity but on the quantity m rVD

This quantity is a dimensionless quantity and is called Reynolds number (Re). In case of circular m pipe if Re < 2000 the flow is said to be laminar and if Re > 4000, the flow is said to be turbulent. If

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Medium 9781786391216

10: Cell Cycle and Cell Size Regulation during Maize Seed Development: Current Understanding and Challenging Questions

Larkins, B.A. CABI PDF


Cell Cycle and Cell Size Regulation during Maize Seed Development: Current

Understanding and Challenging Questions

Paolo A. Sabelli*

School of Plant Sciences, University of Arizona, Tucson, Arizona, USA

10.1 Introduction

Formation of the maize seed and that of related cereals occurs through coordination of different biological processes, including cell proliferation, cell fate specification, endoreduplication, cell differentiation, accumulation of storage metabolites, and programmed cell death (PCD). Development of the three genetically distinct seed compartments, the sporophyte (i.e. the embryo), the triploid endosperm, and the maternal pericarp, involves extensive crosstalk and tight regulation between and within maternal and filial structures, with genetic, epigenetic, and environmental factors playing important roles. The objective of this chapter is to provide a perspective on the roles of cell cycle and cell size regulation during maize seed development, with an emphasis on what is not yet understood about these processes.

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Medium 9781786395146

3 Household Pests and Their Control – Flies

Dhang, P. CABI PDF


Household Pests and Their

Control – Flies

Flies are pests with high public health significance.

They are also nuisance pests frequenting garbage, dead animals, decomposing organic matter and farm manure. Their larvae live and develop in organic material. Once emerged, adults fly out to nearby structures and move indoors through open doors and windows, attracted by food flavour, warmth and moisture.

●● Flies have a single pair of wings for flying; their hindwings are modified as halteres, which act as high-speed sensors for rotational movement and allow them to evade approaching objects.

A few notable species of pest flies are discussed in the following sections.


The egg hatches into a larva after between 6 and 12 h at 35°C. Larvae have three larval instars. The larvae are called ‘maggots’. The first instar larvae measure approximately 1–3 mm, the second instar 3–5 mm and third instar 5–12 mm in length. The larva has a cylindrical body and a conical anterior tapering and a rounded posterior, with no appendages. The larvae feed on all forms of decomposition products. The larvae try to escape light by burrowing into the food such as manure. The third instar larva is called the pre-pupa. They stop feeding, ready to pupate, and seek drier substrata. The period of development from egg to pupa depends on nutrition and temperature, with a minimum of 3–4 days at 35°C.

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Medium 9781780642789

Lentil (Lens culinaris Medik.)

Kumar, P.; Sharma, M.K. CAB International PDF

LENTIL (Lens culinaris Medik.)



Plate 376. Light green foliage of lentil crop.

(Photo by Dr Manoj Kumar Sharma.)

1. Nitrogen deficiency in lentil is usually found during the initial stages of crop growth when root symbiotic nitrogen-fixation nodules are yet to develop.

2. Nitrogen deficiency may occur during later stages of crop growth when the symbiotic nitrogen-supplying mechanism is disturbed for some reason such as nodule infestation, nodule pathogenic disease or physiological causes. Poor nodulation because of improper Rhizobium strain or unfavourable environmental conditions may also cause nitrogen deficiency.

3. Nitrogen-deficient lentil plants are stunted with thin, spindly stems and pale green to pale yellow foliage.

4. Nitrogen is mobile in plants and under short supply conditions it is easily mobilized from older to younger leaves. The deficiency symptoms appear first and more severely on old leaves. The younger leaves usually remain green and apparently healthy (Plate 375).

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Medium 9788131805817


Administrator Laxmi Publications PDF


B-H curve, 68


Bilateral Elements, 80

1-phase Transformer, 175

Branch, 79

3-phase Transformer, 175



Calibration, 140

Absolute Instruments, 127

Capacitor Start, 264

Active Elements, 79

Capacitor Run Induction Motors, 264

Active Network, 79

Active Power, 36

Characteristics of dc Motor, 228

Advantages of Three Phase Induction

Motor, 254

Circuit Impedance, 57

Circuit Parameters, 194

Air Damping, 131

Circuit, 79

All Day Efficiency of the Transformer, 189

Coercive Force, 70

Alternating Voltage or Current, 9

Coil, 218

Alternator, 268

Commutator and Brushes, 219

Ampere Turns, 64

Compound DC Machines, 223

Angular Velocity, 11

Concept of Grid, 280

Apparent Power, 36

Conditions for Synchronization, 271

Armature Control Method, 231

Conductance, 66

Armature Drop, 227

Conductor, 218

Armature System, 218

Constant Loss, 187

Armature Winding, 218

Controlling Torque, 129, 130

Asynchronous Motor, 246

Conversion of Voltage Source into Current

Source, 81

Attraction Type Moving Iron Instruments,


Autotransfer Starter, 251

Copper Loss in Transformer, 187

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Medium 9789381159118


Rajesh Mehra; Vikrant Vij Laxmi Publications PDF

146 PLC’s & SCADA





After reading this chapter, you will be able to explain:






SCADA software Installation

SCADA project development

Basics of PLC interfacing with SCADA

Working with developed projects


In this chapter we will discuss how a PLC can be interfaced with a SCADA that stands for

�Supervisory Control and Data Acquisition�. Our discussion will begin with SCADA software installation, followed by project development aspects of SCADA.



The RSView32 is used as SCADA software for Allen Bradley PLCs. As part of the installation process, RSView32 creates program folders and modifies registry entries. To make these modifications, the currently logged in user must have administrative rights on the computer on which RSView32 is to be installed. The steps to install the software are as follows:

1. Close all open Windows programs.

2. Place the RSView32 CD-ROM into your CD-ROM drive. The CD-ROM should run automatically. If the CD-ROM does not start automatically. Then run D:\Setup.exe, where

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Medium 9789381159323


Dr. Sangeeta Chaudhary Laxmi Publications PDF







For reason associated with economics of generation and transmission, the electric power available is usually an a.c. supply. The supply voltage varies sinusoidally and has a frequency of 50 Hz. It is used for lighting, heating and electric motors. But, there are many applications (e.g., electronic circuits) where d.c. supply is needed. When such a d.c. supply is required, the main a.c. supply is rectified by using crystal diode. The following two rectifier circuits can be used:

(i) Half-wave rectifier

(ii) Full-wave rectifier.


(U.P. Tech. Sem. Exam., 2004–05)


In half-wave rectification, the rectifier conducts current only during the positive half-cycle of input a.c. supply. The negative half-cycles of a.c. supply are suppressed i.e., during negative half-cycles, no current is conducted and hence no voltage appears across the load. Therefore, current always flows in one direction (i.e., d.c.) through the load though after every half-cycle.

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Medium 9781855206786

Chapter 10: Fuel System

Andrew Everett Brooklands Books ePub

The E30 range uses a variety of different fuel systems with three fuel injection systems, and a couple of carburettors too. Some of these are now getting rare and Bosch Motronic as used on all 1988 onwards cars is the most common.

All M10-engined 316 cars used a carburettor. The early cars in 1982 and early 1983 used the Pierburg 2B which was sort of okay but later cars used the dreaded Pierburg 2BE, the ultimate nightmare carburettor. BMW were forced by emissions regulations to use this carburettor when what they should have done is equip it with an injection system. A horribly complex device, it used various sensors, vacuum control units and was electronically controlled with a Bosch ECU. It really was a terrible thing and when it starts to malfunction, the only sensible course of action is to take it off, throw it away and fit a Weber replacement. Many of the repair parts are no longer available for the Pierburg and there is very little service information around. You would not be the first owner to spend £100 on parts, along with many hours of tearing your hair out, only to give up. If you can find one, you can go the second-hand route and try a different carburettor but there are not many good ones about. Even the 316s ending up in breaker's yards now seem to have had Weber carburettors fitted and, of course, these offer a good saving over new ones. As for buying new carburettor bits to try and make yours work, do not bother. The parts are very expensive and you have absolutely no guarantee that the damned thing will work. ECUs do not often fail but it is not unknown. Before assuming the carburettor is at fault, check all the ignition system, make sure the fuel pump is delivering enough fuel and check all the vacuum pipes and electrical connections you never know, you might be lucky. A carburettor and inlet manifold assembly from an old 2002 or E21 316 can be fitted but again, the age of these parts is against you. If ever there was a reasoned argument to buy a 318i, this is it!

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Medium 9781780645353

23: Evaluating the Economic Efficiency of Subsidies Based on the Basic Output Equations for Agricultural Enterprises in the North-western Regions of Russia

Schmitz, A.; Meyers, W.H. CABI PDF


Evaluating the Economic

Efficiency of Subsidies Based on the Basic Output Equations for

Agricultural Enterprises in the

North-western Regions of Russia

David Epstein*

North-West Research Institute of Agricultural Economics,

St Petersburg, Russia


The existing approaches to estimating the efficiency of subsidies on agricultural production are considered. The basic output regression equations have been enhanced by including more factors (subsidies, production profitability and quality of enterprise management) in addition to the primary ones (labour, land, fixed assets and material inputs). This enhancement allows the derivation of statistically authentic estimates of subsidy efficiency.

Calculations based on data from 371 agricultural enterprises for 2007 and 2008 show a statistically significant positive effect of subsidies on production in the Northwestern Federal District of Russia.

Problem Definition

There exists a broad scope of literature on the impact of budget support of agriculture in Russia that can be divided into two types: (i) a general theoretical approach to the issue from a ­certain point of view that potentially makes c­ oncrete estimations possible; and (ii) the estimation of the efficiency of budget support based on some particular parameters in some concrete cases. Very often, it is performed with the help of econometric models. Both types of literature are of significant interest. However, one should bear in mind the principal difficulty of determining the economic effect of budget subsidies. The difficulty lies in singling out the impact of budget subsidies from the

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