eBook Chapters

Abstract

Conversion of an already arid land into a desert through indiscriminate human actions magnified by droughts. Such actions include overgrazing, repeated burning, intensive farming, and stripping of vegetation for firewood. One quarter of the earth’s surface is threatened by desertification - an area of over 3.6 billion hectares. Since 1990, Six million hectares of productive land are lost every year due to land degradation. Desertification threatens the liveihoods of more than one billion people and has already made over 135 million people homeless. Desertification does not occur in linear, easily mappable patterns. Deserts advance erratically, forming patches on their borders. Areas far from natural deserts can degrade quickly to barren soil, rock, or sand through poor land management.

Concept and Definition

Desertification is a major problem in the drylands of India, affecting the way of life for its inhabitants. The problem is more severe in the arid lands in the northwestern part of the country. There have been a few numbers of definitions of the word “Desertification”. However for simplicity of its origin and meaning we would refer to two of the frequently used ones; (1) proposed in 1991 by UNEP: “Land degradation in arid, semi-arid and dry sub-humid areas resulting mainly from adverse human impact and (2) prepared for the Earth Summit at Rio, held in June 1992, for inclusion in Agenda 21, as “Land degradation in arid, semi-arid and dry sub-humid areas resulting from climatic variations and human activities. (Anonymous 1992).

Comparing two of these initial definitions, it would show that first one indicated desertification as a state of natural resources like soil and vegetation, mainly resulting from human activity while the second one included climate as a major cause. However, it reduced the emphasis of human activities as being the primary responsible factor and tried to link the possible impact of climate change on desertification. But the simplicity of the 1992 definition of desertification helped researchers to bring in sharp focus on the special environmental and socio-economic problems of the drylands.

So over the years, the key words that explains the term “desertification” has been changing or are being amended for specific purposes. This would at least mean that the problem of desertification is still debated world-wide, and its impact is not limited to some nations/regions as was presumed and discussed in first of UNCCD platforms. Therefore, as a precaution and combating this process, few catchy words like non-sustainable management, productivity, over-exploitation of natural resources, dryland livelihood, droughts are found to surround the word desertification. Earlier, some, people equated desertification with advancing boundaries of the existing desert and in India, examples of expansion / contraction of geographical boundary of Thar desert was a public debate among various researchers and planners. In the same time, some of the definitions tried to broaden its geographical scope so that greater populations suffering from adverse effects of land degradation would benefit out of various remedial measures.

Introduction

Desertification is now accepted as a major environmental issue because of the fact that 69.5 percent area of the world’s dry lands and more than 1.2 billion people in over 110 countries living in this habitat are affected by various land degradation processes. During last 20 years, researchers have focused their discussion either on a condition or a cause or a set of processes to assess different paradigms of desertification. Several studies carried out in arid western part of Rajasthan (Singh et al., 1992, Kar, A. 1993b, Kar, 1995, Dregne, H.E. 2000, Kar et al.2007) show that wind erosion is still a major problem. Though, there are many instances of location specific problems like water erosion, salinity/ alkalinity and water logging, about 75% area in arid western Rajasthan is affected by wind erosion hazard of different intensities (SAC, 2007, Kar et al. 2009). Decreasing rainfall gradient from east to west and increasing wind strength in that direction are responsible for the spatial variability in sand reactivation pattern. Water erosion in the form of sheet, rill and gully erosion is a major problem in areas, where average annual rainfall exceeds 350 mm, the rainfall intensity is high and the topographic and soil characteristics favour high run-off. Destruction of vegetation cover and excessive ploughing of shallow soils, especially on the sloping lands, accelerate the problem.

Introduction

Desertification, which is considered a major threat in the drylands of the world, is not about advancing boundaries of the existing deserts, but about land degradation in the arid, semi-arid and the dry sub-humid regions, which together form the drylands (Anon., 1995). Secular variation in climate that has resulted in periodic expansion and contraction of the desert boundaries and regional-scale changes in vegetation condition (Tucker et al., 1991; Nemani et al., 2003; Hickler et al., 2005) is one of the drivers of desertification. Human activities constitute the other major driver. According to Geist and Lambin (2004) the prominent core variables that drive degradation are climatic, economic, institutional, national policies, population growth and remote influences.

We let you know that the type of people in a given region is closely linked to the kind of resources found in the concerned region; and which are necessary for human beings to survive.

In fact, more than 100 countries possess arid lands, where more than 40% of the global population lives. The soils of these regions present too much fragility and they are too degraded that they can’t allow people to survive.

Let’s emphasize that in Africa, two third of the total area are arid zones. Thus, for Africans, the type of their struggle for adaptation to the context of their land, illustrates their ingenious capacity to model their hostile surroundings and to leave marks of their cultures all over prehistory and history.

Social organizations in those arid areas are closely linked to modes of exploitation and valuation of resources (water and land). However, human productions in those areas are doubly menaced; on one side by the action of humans who exploit resources for their immediate needs, and on the other side, by climate adverse effects during long periods of drought. It means that climate change and violent meteorological phenomenon worsen circumstances. That leads to environmental degradation and biodiversity reduction; alarming deterioration of vital conditions; and intensification of poverty, both in rural and urban areas; particularly among women and young. Consequently, there are non durable (viable) agricultural practices, overexploitation, overgrazing, excessive and illegal forestry exploitation; destruction of forests and bushes by non-controlled fires, pillages and conflicts with weapons; reduction of vegetation, due to the scarcity of rain; of water in general and menaces of heaps of sands.

Agroforestry systems are more complex than the agricultural systems. The long-term nature of trials involving woody species and the varying objectives of agroforestry trials demand that adequate caution be exercised in their design. Several characteristics of the trees like slow growth, long term effects on their surroundings, long life, age of trees, the area over which the influence of trees extend, etc. complicate the issue of designing experiments for these systems. Agroforestry experiments are often established on marginal sites which include sloping lands, and sites with infertile and degraded soils. It is thus difficult to find homogeneous sites of such problem areas, especially sloping lands where plots along contour lines are long and linear. Germplasm of many agroforestry tree species are usually collected from different origins which lack uniformity. Therefore, experimental materials in an agroforestry experiment may not be of uniform quality.

There are several features of agroforestry systems that require some modification of the methods usually used in agricultural experiments. Important issues related to agroforestry experiments include

Agroforestry systems are more complex than the agricultural systems. The long-term nature of trials involving woody species and the varying objectives of agroforestry trials demand that adequate caution be exercised in their design. Several characteristics of the trees like slow growth, long-term effects on their surroundings, long life, age of trees, the area over which the influence of trees extend, etc. complicate the issue of designing experiments for these systems. Agroforestry experiments are often established on marginal sites which include sloping lands, and sites with infertile and degraded soils. It is thus difficult to find homogeneous sites of such problem areas, especially sloping lands where plots along contour lines are long and linear. Germplasm of many agroforestry tree species are usually collected from different origins which lack uniformity. Therefore, experimental materials in an agroforestry experiment may not be of uniform quality.

There are several features of agroforestry systems that require some modification of the methods usually used in agricultural experiments. Important issues related to agroforestry experiments include

Introduction

In almost all biological studies, it will be impossible to account for every individual in a population. Therefore, it is necessary to examine a sub-group of the total population and extrapolate from this to the whole population. The process by which the sub-group of the population is selected is sampling. Nearly, all statistical tests make a fundamental assumption that sampling of individual will be at random from all the individuals that could possibly be sampled. It is very important that timing is taken into account either by sampling strategy or by later analysis. Most population will be affected by season, time of day and local weather conditions.

What is considered here is the problem faced by an ecologist working in the field and trying to design a suitable sampling strategy. The use of the very powerful statistical technique; analysis of variance (ANOVA) is more common in the situation of a controlled experiment, where, we are analyzing the effects of different levels of a treatment (e.g. feed, fertilizer, temperature etc.) on some measured aspect of population, Then, to get a true estimate of the effect of the treatment, experimental design will be of paramount importance.

Greenhouse refers to a structure which provide relatively better environment for plant growth. The goal is to create congenial temperature and relative humidity in desired range. The greenhouse covered with polythene sheet, also called as polyhouse, has polythene sheet (UV stabilized 200 micron LDPE sheet) as covering over a relatively rigid frame (made of GI pipes, angle iron, boomboo or wooden) which entraps the solar energy to increase the temperature and provide light for plant propagation. A normal greenhouse has four basic components: 1) frame made from rigid material like GI pipes, wood or bamboo; 2) glazing material, which is transparent to provide enough light for plant propagation; 3) climate control system, which may be natural ventilation or forced ventilation using fans with or without cooling pads, shading nets, pigment painting, etc. and 4) plant growing medium (soil or artificial media like cocopeats) with needful arrangement for supplying inputs (water, fertilizers, pesticides, etc.). The design of greenhouse involves structural design of frame with enough climate control mechanism. It mainly depends on shape, size, material of frame, local climatic conditions, wind pressure, and desired height from crop production point of view. Fabrication of greenhouse should be such that it provides enough structural stability with wind pressure and other factors, perfect joints, anchoring of polythene, and minimum hindrances in crop production practices.

Design and Construction of a greenhouse involves five distinctly different aspects viz. (a) Basic form or type, (b) structure/designs, (c) covering materials and its fixing, (d) foundation and constructional detail, and (e) crop-support, irrigation and drainage planning.

All the above aspects are interlinked. To have a clear idea, these individual aspects are discussed separately.

4.1. Basic Forms of Greenhouse

Before considering anything about construction, one should finalize the form of construction. There are different forms of greenhouses for different climatic and crop situations. These types of structures are planned according to the requirement of farmer/promoter and obviously according to the purpose. Now we will describe, in brief, some of the important form or type of greenhouses.

4.1.1. Greenhouse covered with transparent and impervious material

These structures are covered with water/rain impermeable transparent materials which allow necessary solar radiation for optimal growth of plants. Simultaneously it protects crops from temperature-fluctuation, rain, wind, and creates a favourable situation in respect of CO₂ and humidity. This covering is also used to prevent the re-radiation of heat energy and conserve the heat generated in daytime to raise night temperature inside.

Two principal hatchery systems are widely adopted in aquaculture: the large-tank hatchery system and the small-tank hatchery system. Recently, hybrid systems have emerged that integrate advantageous features from both approaches, particularly addressing constraints related to spawner availability.
KEY DETERMINANTS IN HATCHERY DESIGN
Three major factors govern the design of an aquaculture hatchery:
1. Target Species: The specific biological and ecological requirements of the species to be cultured are critical. Hatchery infrastructure must accommodate these needs, and as such, a clearly defined target species is essential before initiating the design process.
2. Production Target: The hatchery’s output goal is determined by market demand and available financial investment. For species such as Penaeus monodon, where fry production is reliant on wild spawner collection, output is naturally capped by spawner availability. In contrast, species like P. japonicus and white shrimp, which have abundant spawner supply, allow for scalable production targets.
3. Financial Inputs: Investment capacity influences not only the scale of operations but also the complexity and automation of the hatchery. In Japan, for example, large-scale hatcheries culturing P. japonicus feature tanks with capacities reaching up to 2,500 cubic meters. In Southeast Asia, where P. monodon is the primary hatchery species and wild spawner availability is limited, smaller tank capacities are the norm.

Introduction

Agriculture is the most important sector of Indian Economy. The agriculture sector accounts for 18 per cent of India’s gross domestic product (GDP) and provides employment to 50 per cent of the countries workforce. India has emerged as the second-largest producer of fruits and vegetables in the world. Formerly agriculture was more dependent on nature and all the operations were carried out manually, however new technologies have been developed to increase the production and productivity of crops (Rangbhal, 2018).

Introduction

Technologies and tools that have developed in the recent information technology revolution can play a very vital role in overcoming most of the present problems related to agriculture and rural development. In order to achieve the goal of an economically sound and stable society through environmentally friendly systems of agricultural production, it is imperative to have a comprehensive data storage system. This will not only help in providing systematic and periodic information to the planners, decision-makers and developmental agencies, but also help to manage our limited natural resources efficiently. The development of a data warehouse is one of the recent tools in the field of information technology that can fulfill the demands of the information that is required in the field of agriculture research, management and education

1. Context

Women play a critical role in agriculture, and agriculture continues to remain the major livelihood strategy for women as well as millions of small, marginal and poor farming households in India. Despite this, farm women lack access to extension services as extension programmes rarely identify women as an integral client. Farm women and men have differential needs for knowledge, information, technology and skills as often they are involved in different activities spread over time and cropping seasons. Besides these, men and women farmers have differential access to assets, information, markets, credits, and other services that are necessary for using new knowledge, technologies and skills. Ignoring women while delivering services and technologies creates a gap as many of the agricultural operations are performed by women only.

It is estimated that if women had the same access to productive resources as men, they could increase yields on their farms by 20-30 per cent (FAO, 2011). Yields on plots managed by women are lower than those managed by men, as they do not have the same access to inputs. If they did, their yields would go up, they would produce more, and overall agricultural production would increase. It isn’t merely about enhancing productivity but also about being fair and equitable. Women are a significant part of the agricultural workforce and they deserve to be consulted prior to formulation of agricultural development plans and policies. SDG 5 on Gender Equality “Achieve gender equality and empower all women and girls” is closely aligned to this aspect. Moreover, enhanced access to services can help women grow more food, have more say in the family, and could potentially lead to more income and food in women’s hands-leading to better food security and nutrition for the entire family as they are the major caregivers in the family.

Bottom or demersal trawling continues to be one of the most important fishing methods of the world. In India more than 35,230 trawlers of various sizes ranging from 9 to 30 m L_OA with engine power ranging from 45 to 495 hp @ 2000 rpm are in operation. Trawl is a bag net towed through water to filter out fishes, the mouth of which is kept open horizontally by means of a beam or otter boards and vertically by means of floats and sinkers. Horizontal mouth opening is also effected by dragging the net from two boats known as bull trawling or pair trawling. The principle of trawling is the movement of the net under water filtering the water through the mesh in the netting, without either permitting the fish to escape or gilling them (Fig. 1). Trawl net is fabricated using polyethylene netting after cutting and shaping the panels as per the design

Greenhouses should provide a controlled environment for plant production with sufficient sunlight, temperature and humidity. Greenhouses need exposure to maximum light, particularly in the morning hours. Consider the location of existing trees and buildings when choosing your greenhouse site. Water, fuel and electricity make environmental controls possible that are essential for favourable results. For this reason, use reliable heating, cooling and ventilation.

The greenhouse temperature requirements depend upon which plants are to be grown. Most plants require day temperatures of 70 to 80 degrees F, with night temperatures somewhat lower. Relative humidity may also require some control, depending on the plants cultured. Some plants grow best in cool greenhouses with night temperatures of 50 degrees F after they are transplanted from the seeding tray. These plants include azalea, daisy, carnation, aster, beet, calendula, camellia, carrot, cineraria, cyclamen, cymbidium orchid, lettuce, pansy, parsley, primrose, radish, snapdragon, sweet pea and many bedding plants. Some plants grow best in warm greenhouses with night temperatures of 65 degrees F. These plants include rose, tomato, poinsettia, lily, hyacinth, cattleya orchid, gloxinia, geranium, gardenia, daffodil, chrysanthemum, coleus, Christmas cactus, calla, caladium, begonia, African violet, amaryllis and tulip. Tropical plants usually grow best in high humidity with night temperatures of 70 degrees F.

ABSTRACT

Bio-engineering is the use of vegetation, either alone or in conjunction with civil engineering structures, to reduce instability and erosion of slopes. Such structures are advocated in hilly area mainly because they provide one of the best ways to armour slopes against erosion. Bio-engineering, in the context of upland slope protection and erosion reduction, combines mechanical, biological, and ecological concepts to arrest and prevent shallow slope failures and erosion. This chapter presents the design consideration and construction practices for stabilization of slopes using bioengineering technologies along with a brief review on the salient features and characteristics of the bioengineering processes.

Specifications

These structures are generally used for the storing grain in the bags. The length of the structure is about twice the width or greater than that. Special care should be taken to make the side walls, floor and roof in constructing the structure. The walls are made of bricks or stones laid either in lime mortar (1:2) or cement mortar (1:6). The thickness is restricted to a minimum of 37.5 cm or maximum of 45 cm. The height of the walls on which the trusses are placed is kept about 5.5 m. Each of the structures is provided with two large size doors of 2.4 × 2.4 m and top ventilators.

Aim

To design a belt conveying system

Theory

The design of belt conveying system is based on available space, horizontal conveying length, conveying lift, characteristics of the materials to be conveyed and capacity requirement.

On the basis of overall requirement and information, the belt width, belt speed, required horsepower, maximum belt tension and breaking strength of the belt, diameter of the pulleys and idlers and quantity of belt (thickness) are determined to design a belt conveyor (Fig.32.1).

Aim

To design bench terrace

1. Components of bench terrace

The bench terrace essentially consists of the four components namely: riser, outlet channel, platform and shoulder bund

Aim

To design a bucket elevator

Theory

The bucket elevator’s capacity mainly depends on bucket size, conveying speed, bucket design and spacing, the way of loading and unloading, the bucket and the characteristic of bulk material.

Bucket elevators with a belt carrier can be used at fairly speeds of 2.5 to 4 m/s. The speed of the belt depends on the head pulley.

If the belt speed is too low, the discharge of the grains become more difficult, with too high speed the buckets are not fed well.

1.0 General

 The design of canal involves following three major aspects:

 A Irrigation and drainage canal network planning.

 B Determination of discharge / capacities of  canals and drainages.

 C Determination of shape and size i.e. geometrical dimensions of the proposed canal section, generally

 known as design of canal section. More appropriately it can be called as design of internal section

 of canal. It can be further divided in three following parts viz.

 i. Design of unlined canals:

 ii. Design of lined canals: or a canal may be partly lined and partly unlined.

 iii. Choice between the unlined and lined canals. This aspect should be distinguished from the selection of type of lining. However, the scope of choice of lining may include both the aspects.

 The design of canal section remains incomplete without the design of its embankments, either in lined or unlined canal, so the next aspect is

 iv. Design of canal embankments. Still to complete the design of a canal one more aspect is required i.e.

 v. Canal aesthetics and canal arboriculture.

Aim

• To design the contour bunds

Design parameters

The design of contour bund includes determination of following parameters:

• Choice of bund
• Spacing of bunds
• Size of bund
• Alignment of bund

1. Choice of bund

The choice of bund should be selected weather the contour bund or graded bund depends on the annual rainfall, soil condition and types of outlets used.

13.1 Introduction

In 1935 Prof. Ronald A. Fisher laid the foundation for the subject in his monumental work entitled “The Designs of Experiments”. Experimental designs concern the arranging of treatments or variables in such a manner that the inferences and conclusions regarding the effects of these treatments can be easily done and their reliability measured. Experiments are made with a view to find the validity of a particular hypothesis and to have an idea about the extent of the reliability that can be placed on a particular conclusion arrived. The selection of the design will have a very great bearing on the accuracy of the ultimate results. By a random selection of experimental units it is possible to remove the ambiguity about the casual interpretation of the observed associations. Random sampling is the most essential ingredient of all experimental designs. Besides, there are many devices for increasing the precision of the inference and the calculations.

In 1935, Prof. Ronald A. Fisher laid the foundation for the subject in his monumental work entitled “The Designs of Experiments”. Experimental designs concern the arranging of treatments in such a manner that the inferences and conclusions regarding the effects of these treatments can be easily done and their reliability measured. Experiments are made with a view to find the validity of a particular hypothesis and to have an idea about the extent of the reliability that can be placed on a particular conclusion arrived. The selection of the design will have a very great bearing on the accuracy of the ultimate results. By a random selection of experimental units it is possible to remove the ambiguity about the casual interpretation of the observed associations. Random sampling is the most essential ingredient of all experimental designs. Besides, there are many devices for increasing the precision of the inference and the calculations.

To understand design of experiments, let us first get acquainted with some important terms and concepts associated with design of experiments:

• Experiment: Experiment is a scientifically planned method. The experiment is conducted draw a valid conclusion about a particular problem. The conclusion is based on statistically observation.

• Treatment: The object or the procedures under comparison in an experiment are known as treatment. For Example: Fertilizers, varieties, cultivation practices, irrigation level in case of agricultural experiments and drugs, breeds, farms, etc. in case of animal experiments.

• Yield: The response of the treatment is measured by some indicator such as crop production, milk production, body temperature, etc. Such an indicator is called yield. The treatments are applied to some units such as field plots, sample of cows, sample of patients, etc. and the effect on the yield is observed.

• Experimental material: The experimental material is nothing but a set of experimental units. In other words, the material which is used in experiment is known as experimental material. For Example: A piece of land i.e. Agricultural field in agricultural experiments and a group of cattle i.e. animals in animal experiments.

Design of Experiment was first elaborated by R. A. Fisher (1935).

• Design of Experiment: Proper allotment of treatments to the available experimental units.

• Treatment: It is the factor whose effect is to be studied. Example: Application of drugs, feeds, conditions, methods, etc.

• Experimental units: The subjects or individuals upon which an experiment is conducted.

Example: Laboratory animals like mice, rat, monkeys, primates; livestock like cattle, buffalo, sheep, goat, poultry; plants, a plot of land, etc.

Necessity of designing an experiment

1. To get maximum information from the available resources.

2. To know the effect of treatment on experimental units and to make comparison between treatments.

3. To know whether the difference between the effect of two treatments is significant or not.

4. A well designed experiment has a well defined method of statistical analysis of data.

5. To minimize error in the whole experimental procedure.

6. An ill designed experiment is not likely to give proper estimates of parameters and comparisons between treatments with desired precision even if the method of data analysis is very good.

7. The design of experiment is essential to get all the important treatment effects to be compared independently.

A scientific experiment is a planned research to obtain new facts or to confirm or refute the results of previous experiments. Research is usually conducted in a controlled environment to study the effect of one or more variables on observations. The objective of research may be to answer a question, verify a hypothesis, or estimate the effect of an independent variable on a dependent variable. After stating the research problem, we need to outline the methodology (or materials and methods) of the research, which includes developing an experimental design.

Scientific experiments are conducted to study the causal relationships between independent variable(s) and dependent variable(s). The researcher manipulates one or more independent variables and measures their effect on one or more dependent variables. Designing an experiment is planning an experiment. It is a complete sequence of steps taken before experimenting to ensure that appropriate data are obtained to perform a data analysis to get valid inferences about the problem. It must be seen that the data collected are relevant to the problem investigated. E.g., studying the effect of breed, age, feed, etc. on milk output. Here, the objects like breed, age, feed, etc. are called treatments. That is, any specific experimental conditions (like the addition of feed additives, new feed formula, etc.) applied to the experimental units are called treatments. The basic objects on which the experiment is done are called experimental units (E.g., a bird, an insect, an animal). However, the responses in all the experimental units receiving the same treatments may not be similar, due to the inherent differences in the experimental units, called experimental error, caused by extraneous factors.

12.1 Introduction
 
The design of the experiment includes (i) planning of the experiment (ii) obtaining the relevant information from it regarding the statistical hypothesis under study and (iii) making a statistical analysis of the data. Design of experiment may be defined as the logical construction of the experiment in which the degree of the uncertainty with which the inference is drawn may be well defined. It may also be redefined as the choice of treatments, the method of assigning treatments to experimental units and arrangement of experimental units in varies patterns to suit the requirement of particular problems, are combined known as the design of experiment.

An experiment is a systematic process or activity which leads to collection of information on certain objects to give an answer to the objectives of the researcher.

The experiment in which certain absolute values like average, correlation coefficient, median, mode, etc are worked out to describe the population is known as absolute experiment.

The experiment in which the effects of different objects under consideration are compared is known as comparative experiment.

The variable whose change we wish to study is called as Response variable. For example- yield, mortality rate of insects etc.

The variable whose effect on the response variable we wish to study is termed as Factor. For example - variety, fertilizer, insecticide etc.

Here factor is the independent variable and response variable is the dependent variable.

The various levels of a factor whose effect on the response variable we wish to study are known as Treatment.

Aim

To design a graded bunds

The procedure in design of contour bund is followed while design a graded bund. A stability of 10-25%, should be given to contour bund. This is called graded bund.

Example: Design a graded bund length of 500 m with an average land slope of 3.5% in a sandy loam soil. Vertical distance between consecutive bund is 2.5 m. Rainfall intensity for the time of concentration and for the recurrence interval is 18.5 cm/hr. The runoff coefficient is 0.3. For stability, the grade provided for first 100 m is 0.1%, for next 200 m is 0.15% and for last 200 m is 0.18%. For the sandy loam soil, side slope of the bund and slope of seepage line are 1.5:1 and 5:1 respectively is assumed.

Aim

To design the grassed water ways or open channel

Geometric characteristics of different waterways

The shape of open channel is dependent upon the field conditions and types of the construction equipments used.

The common shapes of open channels generally used are (i) Parabolic or semi circular (ii) Triangular (iii) Rectangular and (iv) Trapezoidal section.

The parabolic shape approximates a natural channel. The reason is that in natural course of channel flow, the trapezoidal and triangular sections tend to become in parabolic shape due to deposition of sediments and bank erosion.

Aim

To design of greenhouse cooling system

To determine the rate of air exchange in an active summer and winter cooling system.

Theory

Elevation factor (F_elev)

Elevation factor is directly proportional to the elevation. The values of elevation factors, used to correct the rate of air removal for a particular elevation. The rate of air removal from the greenhouse increase as the elevation of the greenhouse site increases.

Theory

Heat required for heating greenhouses is based on the quantity of heat lost through different structural components of greenhouses per unit time. Shapes of greenhouse (A-frame and quonset) and structural components (roof, wall, gable, curtain wall, curved covering and end) are mainly influencing the calculation of heat requirement. The amount of heat lost from a greenhouse depends on glazing materials, exposed surface area of the house, inside desired temperature, outside existing temperature, wind speed, and condition of house (old, new, tight or loose). The outside temperature should be based on the lowest average expected temperature during the heating season.

4.1 Introduction

Experts predict that the global population will exceed 9.6 billion by 2050. This, coupled with the rise of urbanization, the scarcity of arable land, and the destructive effects of climate change, poses significant challenges for agriculture and food production worldwide. To combat these challenges, new horticultural research techniques must be implemented to enhance productivity and efficiency, improve nutrition, and ensure food security, especially during times of crisis like the COVID-19 pandemic. Greenhouse technology has made remarkable strides in recent years, allowing for the manipulation of internal growth elements like temperature, light intensity, and CO2 concentration to create optimal growing conditions

5. 1 Irrigation Channels

Canal or channel is an artificially made conduit through which water is supplied to the field from river, tank, reservoir or wells. The open channel is the most common type of water conveyance system. If the pipes and drains are partially full behave like open channel. The irrigation channel may be lined or unlined and the flow is either uniform or varied.

The canal may be classified in following ways.

(a) Classification based on the source of supply

(i) Permanent or perennial canal

(ii) Inundation canal

5.1 Irrigation Channels
Canal or channel is an artificially made conduit through which water is supplied to the field from river, tank, reservoir or wells. The open channel is the most common type of water conveyance system. If the pipes and drains are partially full behave like open channel. The irrigation channel may be lined or unlined and the flow is either uniform or varied.

The canal may be classified in following ways.

a) Classification based on the source of supply i) Permanent or perennial canal ii) Inundation canal

A canal is said to be permanent when it is fed by a permanent source of supply and has permanent networks of distribution of supplies. Inundation canals draw their supplies from river usually when water stage exceeds a predetermined level. Headworks are not provided for diversion of river water to canal. However, canal head regulators are provided to regulate the canal head as required time to time to accommodate the changing pattern of river course.

A canal of approximate discharge of less than 80 cumecs (3000 cusecs) discharge may be called a medium or low capacity canal).

3.1 Mehboob Section

A Mehboob Section is only a modification of best trapezoidal section by making its complete bottom circular as shown in figure 3.1. Also see figure 1.6 and para 1.7. That is why these canals are also known as canals of zero bed width, or trapezoidal canals with curved bottom, or cup shaped canals.

But these cannot be called as triangular canals with curves, as often spoken. In fact it is a truncated triangle circumscribing the semi circle. Trapezium is also a truncated triangle circum scribing a circle.

More accurately it can be said as a combination of semi circular and best trapezoidal section so as to take full advantage of their hydraulic efficiency and practicability.

This is such a beautiful section that the designer can never commit a mistake, even if he wants to commit a mistake. The dimensions are so geometrically fixed that no one can play with any dimension.

The value of this section was realised for the first time by Er S I Mehboob (1943) in his Punjab Irrigation Branch Paper No.260" Lining of Canals". There after this canal section became well known as Mehboob Section after his name. He also stated that the most economical section i.e. the maximum area for the minimum perimeter is when the centre of the arc is at the full supply line of the section. This is also evident in figure 1.6. This is also the condition for all best hydraulic sections. This section is also useful to a higher silt carrying capacity than a wide shallow one..

Abstract

The paper presents the innovation of solar tunnel dryer; it is a walk in type semi-cylindrical poly house framed structure with UV-stabilized polythene sheet, where products on large scale could be dried under controlled environment. Chilly drying in solar tunnel dryer to reduce the moisture content from 83.4 % (w.b.) to about 9 % (w.b.) and Aonla pulp from moisture content of 81 %(w.b.) to safe moisture content 9.5 %(w.b.) successfully dried. 20-30^ºC of higher temperature was obtained in solar tunnel dryer over the ambient temperature, depends on product. In comparison to open sun drying to obtain the same level of moisture contents resulting in a net saving in drying time of 40-50% for solar tunnel dryer over open sun drying.

A. Rectangular Canals

5.1 Design of Best Rectangular Canals

After the Mehboob and Trapezoidal canals, next best section is rectangle. This section is also generally adopted for small discharges say upto 10 cumecs (350 cusecs). This section ranks at No. 4. Yet, this is the only section most commonly adopted for flumes of discharges upto140 cumecs (5000 cusecs). Typical example is Orsang acqueduct, 1 km. long for 1140 cumecs (40000 cusecs) in ractangular sections on Narmada Canal Project, Gujrat, India, built in the years from 1990 – 2000. Such sections are common in power house canals due to limitation of space and very sharp curves. It is free from the effect of change of side slopes as in the trapezoidal canals (see para 3.3) Still some small side slope (batter) is adopted in thick masonry / concrete lining. It adds to structural stability with economy in thickness of wall and as well as hydraulic efficiency. It may still be called as rectangular section.

Details of its hydraulic efficiency in comparison to semi circle, Mehboob and trapeziodal sections are discussed in chapter 1, para 1.8

The pipe network in a drip system consists of a mainline, sub mains, laterals, and distributors. The layout of the pipes depends on the physical factors like shape and size of the area, topography and any other obstacles in the field. In any field there may be the scope of different layout of the pipes. The most economic one should be selected. In general, contour line is followed in laying the laterals in sloping land, sub main length usually be shorten in uphill and equally spaced laterals on either side of a sub main in a flat land provides good layout.

Hydraulic Formulae /Head Losses in Pipes

There are numerous equations for solving the head loss in pipes. The most commonly used are the Darcy-Weisbach, Hazen-William and Scobey’s.

P rotected cultivation technology envisages immense promise, especially for high-value crops against various biotic and abiotic stresses. The climatic parameters stress conditions like unusually low and high temperature, humidity, solar radiation, wind velocity comes under abiotic stresses. The present climate change scenario dealing with various biotic and abiotic stress conditions poses serious threat to agricultural production throughout the world. It is estimated that due to one-degree rise in temperature during rabi season, wheat production declines by 4-5 million tonnes in India. Similarly due to prevailing low temperature and frost like conditions, especially in Northern India, several million tonnes of horticultural crops like tomato, brinjal etc. got wasted every year. Protected cultivation technology deals with following types of protected structures :

A greenhouse with all measures of climate control is one important component for integrated greenhouse crop production and protection. However, the growing period is very often limited to few months in the year, because of insufficient ventilation and cooling in summer as well as heating in winter. Structures and shapes of greenhouses are adapted insufficiently to climate conditions. Climate control and greenhouse structures have to be adapted and optimized with regard to outside climate, and growers must be trained in these adapted technologies. A greenhouse structure with light transmittance (through framework and cladding material), ventilation, heating, cooling, and protection from insect pests by screening, as well as all influences of management, irrigation, fertilization, water quality, physical and biological plant protection is an integrated system. Greenhouse structures should be designed according to the climate conditions and to the general design criteria, as well as to the locally available and cost-effective materials. The import of greenhouses from countries with a different climate fails very often, because they are not adapted to the local conditions. Even an appropriate greenhouse structure can fail if mounting and continuous maintenance are not guaranteed. Temperatures and global radiation allow open-air crop production throughout the year in many subtropical and tropical countries.

Vegetable and flower production are significantly influenced by the seasonality and weather conditions. The extent of their production causes considerable fluctuations in the prices and quality of vegetables. Striking a balance between all-season availability of vegetables and flowers with minimum environmental impact, and still to remain competitive, is a major challenge for the implementation of modern technology of crop production.

Aim

To design a screw conveyor

Theory

The screw conveyor consists of screw blade, screw shaft, coupling, tubular trough, cover, inlet and outlet gates, bearings and drive mechanism.

A shaft with spiral screw revolves in the tubular trough. The screw shaft is supported by end and hanger bearings. The rotation of screw pushes the grain along the trough.

The screw blade or flight is a continuous one-piece helix, shaped from a flat strip of steel welded on to the shaft.

The screw shaft is usually a joint less tube with thick sides and a high tensile strength to reduce the weight.

Concept: Operations conducted before and after harvest are essential components of the system for producing high-quality seeds. If enough care is not taken in the initial stage, there most likely won’t be any resources left to get high-quality seed. Like this, carefully produced, high-quality seed may lose a significant percentage of its worth if post-harvest management protocols are not adhered to. Its quality is highly correlated with soundness, fullness, and homogeneity of physical characteristics (size, shape, density, colour, and appendages), in addition to mechanical planting’s simplicity and improved crop establishment. Improving the seed that has been gathered and getting it ready for secure storage till needed are accomplished through the effective and efficient process of seed processing. To increase the quality of the seed lot, the goal of seed processing must be to optimize the physical properties of the seed and the constituents of the harvested seed mass. The three main steps in seed processing are conditioning, grading, and applying protectants or enriching with nutrients. These steps are completed in compliance with established protocols and standards (McDonald and Copeland 1997; Agrawal 1996; Jorgensen and Stevens, 2004). The distinct qualities of the crops and the surroundings are taken into consideration while adjusting the machines and operations.

Aim

To design shallow and deep bins

Theory

The structure behaves as a deep or shallow bin depending upon its relative dimensions such as depth and diameter or width. It is decided from the concept of the plane of rupture.

Plane of rupture: The plane of rupture is that surface down which a wedge of material bounded by one wall face, the free surface, and the plane of rupture would start sliding if bounding wall were to move.

A canal of more than 80 cumecs (3000 cusecs) approximetly may be called as a high capacity canal.

It has already been pointed out in chapter 1, that for the best section of any shape, R is always equal to d/2 only, and such depth is the most optimum depth. But such channels are not always practical or most economical due to many other practical reasons, (see para 4.1 and 6.3) and many times shallower depth then this depth is adopted. Typical examples are lining of existing earthen channels, given in para 6.3.

All the best sections have fixed ratio of dimensions very near to the semi circle. For large discharges, radius of semi circle increases that, means depth of canal as well as velocity increases. But higher velocity is not permissible with every type of lining (see table 2.1 and para 2.3). Similarly depth also has limitation of construction, maintenance, stability of slopes, etc. see example–4.2.

Because of limiting velocities and depth, deeper canal section are not practically feasible/possible. Therefore for large discharges, say more than 100 cumecs, Mehboob or best trapizodal sections are just not possible/practical, and recourse has to be taken to trapezoidal section with increased bed width then depth. This section is hydraulically inefficient or uneconomical. Larger the B/D ratio, larger is the inefficiency and section is more costly. (For Mehboob Section, B:D ratio is zero and for best trapizodal section it is much less than 1, see para 3.1, table 3.1 para 3.5 and table 3.4).

Kaushik Kumar

Design Thinking

Design thinking has emerged as one of the skill set in the recent competitive environment.Basic science has been mainly involved in development of various models that fulfills the requirements of engineering domain.

However, the engineering graduates being produced did not possess the required industrial skills and hence were perceived by academia and industrialists as ineligible to be employed in various industries.

Chicken’s eggs have been used as a food item by human beings since antiquity. The egg is composed largely of the proteins out of the three most important dietary essentials (proteins, fats and carbohydrates). The egg proteins are highly digestible and remarkably complete, containing the most important essential amino acids. The amino acid profile of egg is similar to the ideal balance of amino acids needed by humans. It also supplies various minerals, some in significant amounts, and contains a range of vitamins. The nutritive excellence of the egg enhances the value of any food in which it is incorporated. Meeting consumer demands is a constant challenge for the poultry industry. Present day consumers desire somewhat distinct products with respect to safety, healthfulness, freshness, taste, color, etc. To remain competent, various companies have developed several designer and specialty eggs which have appeared in supermarkets.

14.1 Introduction

Eggs are an essential food for humans due to the high nutritional quality and quantity that they contain. Eggs are one of the most consumed foods all over the world because of its nutritious profile, range of uses, and relatively inexpensive cost as a food source. Intakes of total lipids, cholesterol, and saturated fatty acids in human diets can be attributed, in part, to the consumption of animal products. Due to the high amounts of cholesterol (about 200-300 mg/100 g) and saturated fat (approximately 3 g/100 g), eggs have been considered to be contentious foods by several health organisations and nutritional experts.

Abstract

Designer foods are known by various names like medical foods, fortified foods, nutritional foods, nutraceutical foods, pharma foods etc. These foods are nutritious, maintain health and prevent diseases. Such foods must possess characteristics like modified composition; limit the presence of certain potentially harmful components and include certain desirable ingredients either naturally or by intentional addition. The term designer food emerged some years ago to describe foods tailored to specific concentration and proportion of nutrients that are important to health. These are designed and produced by using different approaches. The term ‘designer foods’ is subjected to change based on nutritional labelling regulations, new developments, consumer perceptions and expectations. Grain improvement through biotechnology emphasizes crop upgrading with a specific challenge to manipulate the endosperm composition in order to improve its intrinsic properties for diet and health. Breeding fruits with higher bioactive compounds for disease resistance and improved composition have stimulated interest in the nutraceutical and processing aspects of the fruits Nutritive and genetic interventions to alter milk composition for specific health and processing opportunities are gaining importance in dairy biotechnology. Designer eggs having modified fat provide choices with different nutritional benefits. The options suggested for designer meat and meat products are through production practices, post-harvest procedures and reformulation techniques. All these features of designer foods will be presented with suitable examples.