Scope For Improvement In Efficiency Research Articles

Rainwater Harvesting for Metro Rail Projects in India – Scope for Efficiency Improvement

Abstract Rainwater Harvesting (RWH), although an ancient technique of artificial recharge to groundwater and reuse of stored rainwater, has been improved with the developing technology. RWH systems have many benefits in rural as well as in urban areas of arid and semi-arid regions. Almost all metro cities of India are facing problems of water logging and flooding even after a short heavy rainfall. In metro cities RWH could be helpful for artificially recharging groundwater in depleted water level areas; reduction of flood risk in urban areas; assured source for an effective alternative water supply solution and use of harvested water during water scarcity period. Nevertheless, most of the studies in literature focused on the potential of RWH for buildings, institutional areas for reducing water consumption, whereas few examples were examined for their efficient use. Almost all big cities in India are planning metro rails which have huge potential for RWH with its elevated stations, viaduct (elevated corridor) and depot areas. This work aimed to investigate and realize the RWH potential especially for metro rails which are in the implementation stage for different cities in India. This paper also highlighted the legislations of RWH of different states where metro rails were implemented. It also emphasized on the root cause of inefficiency of the RWH system and how to increase the efficiency.

Copper Chalcopyrites for Solar Energy Applications

Solar photovoltaic (PV) technology is a reliable and environmental friendly alternative for electricity generation. There are a number of solar PV technologies at different maturity levels, ranging from well-established and commercialized silicon PV to still in conceptual and R&D phase quantum dot and organic/polymer solar cells. Chalcopyrite solar cells, named so because of the thin absorber layer of Cu-based chalcopyrite materials used in these cells, are one of the frontrunners in thin-film PV technology owing to their tunable direct bandgap, large absorption coefficient and long-term stability. Among all Cu-chalcopyrite materials, copper indium selenide (CISe) and copper indium gallium selenide (CIGSe) are most suitable for use as light-absorbing layer. Although CISe and CIGSe absorber-based PV modules are being produced commercially for several years now, the technology is yet to mature fully as there is still scope for improvement in efficiency, manufacturability and cost reduction. The present article discusses the status of CISe-/CIGSe-based thin-film PV technology while primarily focusing on the absorber material. Different vacuum and non-vacuum methods for fabricating these materials are reviewed along with their merits/demerits and suitability to large-scale production. Current status of commercial maturity for CIGSe PV is discussed while providing general process details of selected industrial manufacturers. Existing bottlenecks for this technology are deliberated, and future directions for improvement in laboratory-scale efficiency and manufacturability are outlined.

Effect of trailing edge thickness on the performance of a helium turboexpander used in cryogenic refrigeration and liquefaction cycles

Turboexpanders in cryogenic refrigeration and liquefaction cycles, which is of radial inflow configuration, constitute stationary and rotating components like nozzle, a rotating wheel and a diffuser. The relative motion between the stationary and rotating components and the interactions of secondary flows and vortices at different stages make the turboexpander flow unsteady. Computational Fluid Dynamics (CFD) analysis of this flow is essential to identify the scope for improvement in efficiency. The trailing edge vortex formed due to the mixing of the pressure and suction side streams is an important phenomenon to analyse, as this leads to efficiency degradation of the machine. Additionally, there are mechanical vibrations and dynamic loading associated with. This flow non-uniformity at the exit should be suppressed as this may affect the pressure recovery process in the diffuser and thereby the turboexpander’s performance. The strength of this vortex depends upon the geometrical parameters like trailing edge shape, thickness etc. In this paper, transient CFD analyses of a cryogenic turboexpander designed for helium refrigeration and liquefaction cycles using Ansys CFX® were performed to investigate the effect of trailing edge thickness on the turboexpander performance and the performance characteristics and the flow patterns were compared to understand the flow characteristics in each case.

Emergency care within hospitals: can it be done more efficiently?

Cardiac Arrest Teams (CATs) are frequently activated by nurses when patients experience 'false arrests' (FAs). In those cases activation of the Rapid Response Team (RRT) might be more efficient. The authors determined the level of urgency of FAs to find a scope for improvement in efficiency within emergency care. CAT-activations for FAs in a university hospital from September 2009 to 2012 were retrospectively analysed and classified as urgent or less-urgent. In 26% (107/405) the CAT was activated for FAs. Calls were classified as urgent in 43% (46/107). Less urgent calls comprised 57% (61/107) of the FAs, difference 14% (95%CI: 1% to 26%). A significant part of the CAT-activations for FAs were less urgent and an RRT-activation might be more efficient. To minimise the CAT-activations for FAs, nurses need to recognise early patients who clinically deteriorate. Therefore, nurses should use the Modified Early Warning Score correctly.

Efficiency of social sector expenditure in India: a case of health and education in selected Indian states

Social sector expenditure in India captures a number of important aspects including health, nutrition, education, water supply, sanitation, housing and welfare, among others. Over a period of time, besides budgetary outlay on this sector, private sector has also played a considerable role. Thus, efficiency of expenditure in this sector by state government has to be reckoned both in terms of relative levels of various aspects across the states and in terms of comparable benchmarks for different aspects of the sector. This paper attempts an analysis of social sector efficiency focusing on two major aspects: health and education. Unlike other studies on the Indian context, this analysis focusing on major states in India uses both non-parametric and parametric approaches. Although both approaches provide benchmarks to judge relative efficiency across states, the former provides a yardstick more at an aggregative level without parametric restrictions, whereas the latter is used for major focus on health care aspects. Results of free disposal hull analysis are suggestive of a considerably more scope for improvement in efficiency of public expenditure in health relative to education. Our results of stochastic frontier analysis indicate considerable state level disparities which could be reduced through a mix of strategies involving reallocation of factors (namely, manpower and supply of consumables) within the sector, mobilizing additional resources possibly through enhanced budgetary emphasis, or encouraging more private sector participation. Based on our results, this may enhance efficiency by nearly 20% in health care sector and increase availability and equity across low performing and poorer states like Madhya Pradesh and Uttar Pradesh.

Effects of Regulatory Governance on Indian Thermal Power Efficiency: Results from a Stochastic Frontier Modeling

This paper tests the impact of institutional quality on the performance of thermal power sector in India. We estimate a translog inefficiency effects stochastic frontier model using plant age, plant capacity and an index of regulatory governance as determinants of inefficiency. The dataset comprises a panel of 77 coal-based thermal power plants during the period 1994-95 to 2010-11. The mean technical efficiency is 76.7% which means there is wide scope for efficiency improvement in the sector. However, this is 4% points higher than previous estimates which measured productivity up to the year 2001-02. Results are robust to various model specifications and regulatory governance positively impacts plant performance. While technical efficiency is highly sensitive to unbundling of state electricity boards, it is not impacted significantly by the experience of regulators. The policy implication is that the quality of regulatory capacity and experience need to be enhanced for the desired sectoral performance.

Highly efficient factorial designs for cDNA microarray experiments: use of approximate theory together with a step-up step-down procedure

A general method for obtaining highly efficient factorial designs of relatively small sizes is developed for cDNA microarray experiments. It allows the main effects and interactions to be of possibly unequal importance. First, the approximate theory is employed to get an optimal design measure which is then discretized. It is, however, observed that a naïve discretization may fail to yield an exact design of the stipulated size and, even when it yields such an exact design, there is often scope for improvement in efficiency. To address these issues, we propose a step-up/down procedure which is seen to work very well. The resulting designs turn out to be quite robust to possible dye-color effects and heteroscedasticity. We focus on the baseline and all-to-next parametrizations but our method works equally well also for hybrids of the two and other parametrizations.

Strategies to improve urban water delivery in West Bengal, India: An analysis of water institutions and benchmarking of water delivery organizations

The study examines the status of urban water delivery in India through a case study of the state of West Bengal in India. The state has been selected as a unit of study to bring out the regional variances that are not captured at a more aggregate or country level study. The study focuses on various types of urban local bodies in the state, the organizational and institutional structure for water delivery and issues around them. The study also benchmarks various urban local bodies for their water service delivery through data envelopment analysis. The study finds that in the current state of fragmented institutions and shared responsibilities between various water organizations, there needs to be a focused policy guideline for integrated development of the water sector in the state. The study also identifies certain categories of urban local bodies, for which there are further scope for efficiency improvement.

Efficiency and Productivity Change of Banks: Evidence from a Small Island Development State

This paper employs a nonparametric approach to estimate the efficiency and productivity of the Mauritian banking sector during 2001-2006. The measurement of efficiency is done using the Data Envelopment Analysis (DEA). Productivity growth is decomposed into technical efficiency and technological change using the Malmquist indices. Using labour, fixed assets and loanable funds as inputs and total loans and fee based income as outputs in the analysis, it is observed that the mean efficiency score of banks in Mauritius when compared to other countries is lower. The Malmquist Total Factor Productivity results obtained indicate that annual productivity growth averaged 4.9% across all commercial banks and was largely attributable to technological progress. The results have important implications for bank managers, policy makers, bank regulators and other stakeholders of the Mauritian economy. It is believed that there is considerable scope for efficiency improvements in this sector, particularly for Mauritian Bank to consolidate and enhance their competiveness in the region.

The future of European defence policy: An economic perspective

European defence policy has been dominated by politics. This paper shows how economic principles can be used to derive guidelines for the formulation of European defence policy. The inefficiencies of the EU's existing defence arrangements are identified. It is shown that there is scope for efficiency improvements in the EU's Armed Forces and its defence industries.

Technological efficiency improvements: beyond the prospects of first-law efficiencies

Efficiency improvements of technology are said to be one of the most important possibilities to satisfy the energy requirements of a growing global population and to mitigate adverse energy-related environmental impacts, such as climate change, at the same time. On the basis of the classical concept of first-law efficiency, however, conventional energy analyses lead to the impression that efficiency improvement potentials are almost exhausted. This paper explains why prevailing energy conversion efficiencies are grossly overestimated when measured in terms of first-law efficiencies. Using a stylised example, we compare the concepts of first-law and second-law efficiency. Our comparison indicates that estimates of current efficiency improvement potentials depend heavily upon the efficiency concept employed. In fact, there still seems to be much scope for efficiency improvements.

Performance enhancement in coal fired thermal power plants. Part II: steam turbines

This paper presents the results of the performance enhancement study on 22 coal fired thermal power stations of capacities 30–500 MW. The oldest units (30 MW) have served for 33yr and the newer units (500 MW) have been in operation since 7yr. The turbine efficiencies are in the range 31·00–41·90% as compared to the design range of 34·80–43·97%. The isentropic efficiencies are in the range 74·13–86·40% as compared to design values of 83·20–89·10%. Considerable scope for efficiency improvement through low cost solutions: operational optimization, capital overhaul, simple modifications, etc., exists for all classes of units. The efficiencies can be restored to their design values. The developments in turbines over the last quarter of this century which have led to improved isentropic and thermal efficiencies must be adopted for existing units through retrofits, upgrades and revamps. The turbine efficiencies can be improved to 38·0% for 30 MW units and to 47% for 500 MW units. The maximum potential is for improvement in 210 and 500 MW units followed by 110 and 120 MW units. The potential for 30 and 62·5 MW units is rather limited because of their low capacity share, lack of interest in manufacturers to sell spares (because of the low volume of requirement) and large pay back periods for modernisation schemes. Copyright © 1999 John Wiley & Sons, Ltd.