eChapters

Aim: To obtain balanced two-phase supply from three-phase supply by Scott arrangement of two single-phase transformers.

The phase conversion from three to two phase is needed in special cases, such as in supplying 2-phase electric arc furnaces. Scott connection of two-single phase transformers is employed for conversion of a three-phase system to two phase system or vice-versa. Rating of one transformer should be 15% greater than that of the other, but in practical two identical transformers are used for interchangeability and spares. The 50% tap of one transformer (Main transformer) is connected to 86.6% tap of the other transformer (Teaser transformer). The secondaries for balanced supply system have equal number of turns.

Aim: To determine the Efficiency Vs Load characteristics (External characteristics) of D.C. shunt motor Swinburne’s method.

This method is an indirect method of testing a DC machine. It is named after Sir James Swinburne. Swinburne’s test is the most commonly used and simplest method of testing of shunt and compound wound DC machines which have constant flux. In this test the efficiency of the machine at any load is pre-determined. We can run the machine as a motor or as a generator. The iron and friction losses are determined by measuring the input to the DC machine at no-load. The machine is to be run as a motor at normal voltage and speed. The Swinburne’s method includes all the losses in the field circuit and winding which do not occur actually in the machine but the error introduced due to this is quite insignificant and still shows the accurate results. In this method of testing no-load losses are measured separately and eventually we can determine the efficiency.

Aim

(a) Perform load test on 3-phase induction motor.

(b) Compute Torque, Output power, Input power, Efficiency, Input power factor and Slip for every load setting and to determine how speed, efficiency, power factor, stator current torque, and slip of an induction motor vary with load.

The load test on induction motor is performed to compute its complete performance i.e. torque, slip, efficiency, power factor etc. During this test, the motor is operated at rated voltage and frequency and normally loaded mechanically by brake and pulley arrangement from the observed data, the performance can be calculated, following the steps given below.

Aim: Study of 3 point and 4-point starter.

Theory

A 3-point starter in simple words is a device that helps in the starting and running of a shunt field or compound excited dc motor. Now the question is why these types of dc motors requires the assistance of the starter in the f irst case. The only explanation to that is given by the presence of back emf Eb , which plays a critical role in governing the operation of the motor. The back emf, develops as the motor armature starts to rotate in presence of the magnetic field, by generating action and counters the supply voltage. This also essentially means that the back emf at the starting is zero, and develops gradually as the motor gathers speed.

Introduction

Though the potential benefits generated by the drip irrigation method are apparent, the adoption of drip irrigation is yet to be widely promoted across different regions and states in India. Several factors such as huge initial investment, small size of holding, lack of technical support, nature of cropping pattern, access to water and socio-economic conditions of farmers etc. (Namara et al, 2005, Suresh Kumar, 2012) are constraining adoption of drip irrigation. In some cases, even after the adoption of drip irrigation, the farmers, particularly, the small farmers have often discontinued use of drip irrigation for several reasons such as due to lack of maintenance, irrelevant cultural background, and unreliable water supply (Kulecho and Weatherhead, 2005).

Background and Technology Intervention

Owing to the subsequent monsoon failures and unavailability of water for irrigation, Tamil Nadu farmers have switched over to drip irrigation which is not only saving huge quantity of water for them, but also preventing irrigation run off and providing deep water percolation. In Tamil Nadu, usage of drip irrigation is prevalent among vegetable and fruit growers and organic farmers.

To relieve the plants from stress or strain of water logging and water scarcity, Tamil Nadu Horticulture Development Agency has played a key role by rightly intervening the farmers through drip irrigation technology and thereby improving water use efficiency.

Background and Technology Intervention

The primary resource affected by the climate change is water. In arid and semi-arid regions of India, any shortfall in water supply due to climate change will enhance competition for water use for a wide range of economic, social and environmental applications. The population growth with the improved living conditions also increases the demand for food production and thereby increasing the demand of water in multiple folds in the river basins (UNESCO-WWAP, 2009). The major portion of water available in the Indian River basins are used for cultivating rice and thus poses major challenges to water management, especially during unfavourable climatic conditions.

Background and Technology Intervention

To increase the water use efficiency coupling piped network and micro irrigation, Department of Agricultural Engineering along with the Tamil Nadu Government introduced a project on “Water conveyance works of modernization of on-farm irrigation network in 5(R) and 7(R) sluices Parambikulam Aliyar Project (PAP)” covering a total area of 109.86 acres in both the sluices.

Significance of this project is to improve the water use efficiency in canal command areas where the farmers were unable to cultivate annual / long term crop due to alternate supply of water in each zone. PAP command area has 4 zones and each zone receives water once in 135 days in a 2 year span through open channel leading farmers to adopt flood irrigation.

Background and Technology intervention

Instead of open channel irrigation, intervention of PVC pipeline system using gravitational hydraulic pressure can convey efficient water without the use of power. This will reduce conveyance loss and improve timely and equitable distribution of water to all farmers. As large number of open wells with pump sets are available, uninterrupted power supply is not available for on time irrigation during summer seasons. During such times, savings from tank water will be more helpful allowing the farmer to manage groundwater greatly.

Background and Technology Intervention

Andhra Pradesh is India’s fourth largest state in terms of area and fifth in terms of population. Its capital Hyderabad is one of the largest and fastest growing cities in Southern India occupying 650 square kilometers along the bank of Musi River. History says that, the fifth sultan, Muhammad Quli Qutab Shah established Hyderabad on the banks of Musi River in 1591 to avoid the acute water shortages experienced at Golconda during his rule. Today, due to rapid urbanization and increased economic activities, the river has become a receptacle of untreated domestic and industrial waste dumping out of Hyderabad. It is estimated that nearly 350 MLD (Million Liters a Day) of polluted water and sewage originating from the twin cities of Hyderabad and Secunderabad flow into the river. Though this river water which is at the downstream of the city remains highly polluted and considered a major disaster in Hyderabad, it is a significant resource for semi-arid and peri-urban population where the cultivation of fodder grass, paddy and vegetables have contributed largely to the household food security.

Background and Technology Intervention

Tanks are one of the oldest structures in India that has been serving as an important water harvesting device since time immemorial. The total number of irrigation tanks in India is estimated to be around 2, 08,000 of which, three states in South India viz., Andhra Pradesh, Tamil Nadu and Karnataka accounts for nearly 1, 27,000 tanks irrigating 1.8 million hectares of land (Gandhiraj, 2009, Siva Subramanian, 2006, Sakthivadivel et al. 2004, Vaidhyanathan, 2001). In Tamil Nadu for instance, there are more than 39,000 tanks at present many of which were constructed during 18th and 19th centuries by kings, zamindars and Britishers (Jagadeesan, M 2011; Palanisami and Easter 2000: 9). Similarly in Telangana region of Andhra Pradesh, tank irrigation developed extensively since ancient times. The district of Warangal and Karim Nagar have several old irrigation tank structures.

Background and Technology Intervention

Managed Aquifer Recharge (MAR) describes planned storage and treatment of water in aquifers which can provide cheapest form of new safe water supply for towns and small communities (British Geological Survey, 2006). It is a part of a groundwater manager’s tool which is useful for replenishing and re-pressurising depleted aquifers, controlling saline intrusion or land subsidence as well as improving water quality through filtration and chemical and biological processes. MAR can enhance volumes of groundwater abstracted through different package of measures and restore groundwater balance. It also plays a vital role in smoothing out supply and demand fluctuations, stabilizing over-exploited groundwater levels, reducing evaporation losses and runoff, maintaining environmental flows in streams and rivers, improving water quality and augmenting the reuse of waste and storm water. In recent times, MAR uptake has been very limited.

About 60 per cent of total arable land (142 million ha) in India is rain-fed, characterized by low productivity, low income, low employment with high incidence of poverty and a bulk of fragile and marginal land. Watershed development program is, therefore, considered as an effective tool for addressing many of these problems and recognized as a potential engine for agricultural growth and development in fragile and marginal rain-fed areas. The Government of India has accorded high priority to the holistic and sustainable development of rain-fed areas through the integrated watershed development program since the 7th Five Year Plan (1985-90) and since then a number of watershed programs have been specifically launched in the rain-fed areas with the sole objective to improve the livelihood of poor rural households in a sustainable manner.

Background

Analysing changes in the cropping patterns is an important prerequisite for optimization and evaluation of water use efficiency and water resource management. Cropping pattern changes in India could not only be seen as resulting from the pursuit for higher economic returns, but also as a feedback response to limited water resources. Although a systematic framework is still needed for future cropping pattern planning in the country by taking food security, continued agricultural expansion and other constraints into consideration, the existing cropping pattern may provide an insight with which alternative cropping patter may be proposed for a right intervention in enhancing water productivity and food security.

Introduction

Technical innovation is a process by which new or improved technologies are developed and brought to widespread use (Ambuj Sagar, 2013). Technical innovations are interlinked by research, development, demonstration and deployment which involves a range of organizations and personals with institutional arrangements underpinning the growth and advancement of different kinds of technologies. In the area of water productivity, technical innovations has helped expand water supplies through improved exploration and recovery techniques, increased water use efficiency, improved water availability and reduced environmental impact of water and its usage.

Introduction

The COVID-19, the Global Pandemic has affected the world and is still continuing with its various mutations even today. This has created a long-lasting impact and many sectors like energy, transport, industries, and residential buildings, have critically experienced impacts from the pandemic (Qarnain, Muthuvel, and Bathrinath 2020). It has directly and indirectly impacted every household’s operations. The mandatory COVID – 19 protocols, lockdowns, Work From Home (WFH) schedules and the major fear of every one of contracting the disease if going out itself has forced people to stay indoors and forced residents to use more energy for their daily routine activities, (routines like watching more TV, using environment control devices like fans, AC, room heaters etc.) giving rise to higher energy usage resulting in high energy bills and subsequent scarcity in the energy supply.

Introduction

Painting is the practice of applying paint, pigment, colour or other medium to a solid surface (support base), Abdellatif MD, 2017. The medium is commonly applied to the base with a brush, but other implements, such as knives, sponges, and airbrushes, can be used. Interior wall painting is a repetitive, exhausting and hazardous process. In almost all the developing countries, the increasing population stimulates the construction-related activities such as interior finishing and painting. Painting is classically done by humans and generally requires exhaustive physical efforts and involves exposure to dangerous chemicals.

Introduction

The deterioration of interior air quality brought on by dangerous chemicals and other factors is known as indoor air pollution, which can be up to 10 times worse than outside air pollution. This is due to the fact that confined spaces foster the buildup of potential pollutants more than do open spaces. In underdeveloped countries, statistics show that indoor air pollution has a far worse effect on health than outside air pollution. Indoor air pollution can be defined as ‘ the totality of attributes of indoor air that affects a person’s health and well-being’ ( Singh & Jamal, 2012). Indoor air pollution from solid fuels was to blame for 3.5 million fatalities, 16% of particulate matter pollution, and 4.5% of global daily-adjusted life years in 2010. (DALY).

The primitive people were living as part of the environment along with other f lora and fauna in a perfect synchrony. Prior to industrialisation the people were living in an environment friendly manner without causing much damage to natural resources. During the time they were making good progress and were building huge structures which are of technical excellence even today. Post industrialisation the whole scenario changed very fast. The population increased many fold, people started making more goods than required to have a market hold to earn more – the human greed increased beyond limit.

Introduction

Global warming needs a shift to automobile solutions that reduces/ do not produce greenhouse gas emissions. Automobile related pollution is the major source for reduction in air quality in Indian cities. India need to reduce dependency on a fossil- fuel and reduced transportation related emissions. People living in some of the Indian cities are being affected by noise pollution and electric vehicles may contribute to a reduction in noise pollution levels in the cities. Energy efficiency and emissions are two important contributing factors in transportation across the globe.