002673   Sharma H R (NO, Tractebel Engineering Pvt. Ltd., New Delhi) : Major issues and way forward for expeditious hydro power development. Wat Energy int 2013, 70(8), 22-6.

1 illus

002672   Schwyter P;Schneider P (NO, ABB Switzerland Ltd., Switzerland) : Smart, utility-grade wi-fi mesh for distribution grids. Wat Energy int 2013, 70(11), 4-6.

All over the world, utilities are facing tremendous changes and challenges driven by deregulated markets, decentralized alternative power generation concepts and resulting Smart Grid requirements. Smart grids need a demanding and reliable 2-way communication infrastructure; not only to manage the backbone but additionally to secure supervision and control along the distribution lines down to the end user equipment including its power consumption & production behavior. Market deregulation has brought an increased cost pressure, the need to minimize aggregated commercial and technical losses (ATC) and on top of it contractual obligations for a defined service delivery performance. To achieve these goals, a robust, high performing and cost-efficient communication infrastructure is required. Technically however, there is no unique solution that can be proposed, because each utility is exposed to very individual internal and external restrictions such as already existing infrastructure, network topologies, specific applications and, last but not least, legislation/market regulation. The main focus of this paper is about wireless solutions for the distribution layer, particularly the use of Wi-Fi Mesh for utility-grade applications. It's a demanding environment where the various flavours of IEEE 802.11 standards need to be combined with special measures to comply with the utilities'and customers' expectations.

2 illus, 3 ref

002671   Sahu S P;Prakash A;Singh K B (NO, , AcSIR, CSIR-CIMER, Dhanbad, Email: satya.prakash42@gmail.com) : Need of mine subsidence compensation act and pertinent funding source in India. Indian Min Engng J 2014, 53(1), 22-9.

Subsidence due to underground mining creates deleterious effects to the surface properties and therefore becomes a matter of concern to landowners and general public. Damage to surface structures due to subsidence movements gives rise to public chaos and conflicts. The conflict can however be resolved by providing a balance between coal production and protection of environment by sound subsidence management or by compensation. For introducing and framing a suitable and significant compensation act in India the existing subsidence compensation act of three major countries, namely, United Kingdom, Pennsylvania (USA) and New South Wales (Australia) are reviewed. The paper encompasses a wide approach for the commencement and implementation of compensation act along with source of funding in India based on such worldwide established acts.

5 illus, 6 tables

002670   Ryu H Y;Jeong S M;Kang Y C;Kim J G (Chemical Engineering Dep, Chungbuk National Univ, Heungduk-gu, Cheongju-si, Chungbuk 361-763, Republic of Korea, Email: smjeong@chungbuk.ac.kr) : Electrochemical carbon formation from a graphite anode in Li₂O/LiCl molten salt. Asian J Chem 2013, 25(12), 7019-22.

Electrochemical carbon formation from a graphite anode has been investigated in an LiCl molten salt containing oxygen ions. Carbon can be formed via various chemical or electrochemical routes. The carbon dust produced during electrolysis probably contaminates the salt and it leads to a decrease of the current efficiency and the purity of the metal product. A possible reaction path for carbon formation during electrolysis has been proposed in this study.

6 illus, 9 ref

002669   Rathore A S;Varshney A;Pradhan M;Bajpai S (NO, NIT, Raipur, Chhattisgarh, Email: anujay6291@gmail.com) : Induction furnace slag: an eco friendly alternative to natural sand. Indian Min Engng J 2014, 53(2), 11-14.

4 illus, 5 tables, 9 ref

002668   Rama Rao V S;Bhajantri M R;Bhosekar V V (NO, Central Water and Power Research Station, Khadakwasla, Pune) : Hydropower development in himalayan region - swot approach of hydraulic factors. Wat Energy int 2013, 70(11), 43-8.

Power requirement in the country is increasing every year as there is severe imbalance between the demand and supply. Though it was observed that there is great potential for the country to generate hydro power, still the production is not as much as resource available. According to one estimate India has the potential of producing 1,50,000 MW of hydro power of which about 20 percent has been harnessed so far. Many projects are under construction to increase the hydro power production. The major areas considered are the Himalayan based river systems in the states of Himachal Pradesh, Jammu and Kashmir, Uttarakhand and some North Eastern states. But whenever dam protagonists go for dam construction, antagonist are always there to detract them showing the cases of failure of dams and thereby consequences. Buildingup of dams has been the bone of contention between the environmentalists and the policy makers since many decades. These kinds of complicated issues can be better addressed with SWOT based approach. SWOT technique is a strategic managerial tool useful in matching the system to the social environment in which it operates. In the present context, with the help of SWOT approach the authors tried to explain how to overcome the negative factors of hydropower development in Himalayan region with the positive factors.

6 illus, 1 table, 9 ref

002667   Qi X;Wang D;Xin H;Qi G (Faculty of Safety Engineering, China Univ of Mining and Technology, Xuzhou, China, Email: qixuyao@gmail.com) : Effects of sulfur components on crossing point temperature of coal. Asian J Chem 2013, 25(12), 6957-9.

The crossing point temperature of initial and blended dried coal samples were tested. The weight percentages of FeS₂ in blended coal samples were 3, 5 and 7%. 50 g of coal particles ranging from 0.18 mm to 0.38 mm in size were put into a coal vessel attached at the center of oven. The temperature program increased the temperature at a rate of 0.8 °C/min. Dry-air was permitted to flow into the coal vessel at different rates. The results indicate that the effects of sulfur components depend on reaction conditions and coal ranks. The reactivity of sulfur components in the coal is low under dry and low temperature conditions. These components form a film that covers the coal surface and slightly inhibits the self-heating of the coal. The inhibition degrees are different for different ranks of coal, which is due to the types and amount of active groups. It is usually more obvious for lower ranks of coal.

2 illus, 3 tables, 17 ref

002666   Park Y S;Kim J G;Seo H S;Ha Y K;Song K (Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong-gu, Daejeon 305-353, Republic of Korea, Email: nyspark@kaeri.re.kr) : Lattice parameter changes for spent UO₂ fuels with and without Gd. Asian J Chem 2013, 25(12), 7006-8.

The microstructural changes of spent nuclear fuels discharged from pressurized water reactors were investigated. The changes in the lattice parameters from the core to the rim of spent UO₂ fuel specimens were measured using a radiation-shielded micro X-ray diffraction system (μ-XRD). For comparison, two different types of spent fuel pellets of 41 GWd/tU burnup were chosen as sample specimens, one containing PWR UO₂ fuel and the other containing Gd-bearing UO₂ fuel. The Gd-bearing UO₂ fuel was chosen to investigate the effect of Gd on the lattice parameter of spent UO₂ fuel. The lattice constant from the core to the rim of the specimen was larger for the spent UO₂ fuel than for the fresh UO₂ before irradiation. Although an overall lattice expansion was observed across the radius, the lattice contracts slightly near the outer surface of the fuel pellet. Based on the position where this lattice contraction was initiated, we predicted the thickness of the 'rim' region as 100 μm. For spent Gd-bearing UO₂ fuel, the lattice across the radius of specimen is larger than that of fresh Gd-bearing UO₂ fuel but smaller than that of fresh UO₂ due to Gd dissolution in the UO₂ lattice.

5 illus, 18 ref

002665   Park I T;Kim W;Kim E J;Bae S E;Kim J Y;Shin H C (School of Materials Science and Engineering, Pusan National Univ, San30, Jangjeon-dong, Geumjeong-gu, Busan 609-735, Republic of Korea) : Electrochemical reactivity of chemically roughened tungsten electrodes. Asian J Chem 2013, 25(12), 7037-40.

A variety of rough tungsten electrodes were created and their surface morphology and apparent electrochemical reactivity were analyzed, in order to explore their feasibility as a highly reactive working electrode in electrochemical cells. For this purpose, tungsten electrodes with different surface irregularities were prepared by a chemical etching process and the self-similar fractal dimensions of their surfaces were determined. Then, the integrated charges for hydrogen evolution on their surfaces were estimated in the potentiostatic condition as a measure of their surface reactivity.

6 illus, 6 ref

002664   Nanda N K;Gopalakrishna S J (NO, NMDC Ltd, Masab Tank, Hyderabad-500 173, Email: drjoiskrishna@gmail.com) : Beneficiation studies on banded hematite jasper (BHJ) of Donimalai area. Indian Min Engng J 2014, 53(2), 15-20.

The exploitation of high grade iron ore reserves is on the rise to meet the demands of the rapidly growing steel industry and rise in the export over the last decade has resulted in depletion of high iron ore reserves. Minerals being non renewable assets, call of the hour is judicious utilization of the available resources. The thrust on the iron ore producers is to enhance the mine life by exploring the means of utilizing low/lean grade Iron resources. Apart from low grade iron dumps, every mine is associated with huge reserves of banded iron formations like Banded Hematite Jasper (BHJ)/Banded Hematite Quartzite (BHQ). The onus on the mining industry is to develop suitable process technology for their optimal usage. Considering the need under the circumstances and demand of the nature for mineral conservation, the studies were carried out to beneficiate the BHJ ores of Donimalai range. The sample under investigation analyzes 41.2% Fe and 39.10% SiO₂. The liberation studies reveal that the hematite grains can be liberated below 150 microns. The ground sample was subjected to different concentration techniques, however, gravity concentration proved to be relatively better than the other. Thus, the studies were emphasized using gravity concentration technique and spiral concentration as primary unit operation. Initially, bench scale studies were conducted using spiral test rig at feed pulp densities of 20, 30 & 40% solids and at two different splitter positions to arrive at suitable operating condition. The tests at 40% solids were encouraging and further tests were carried out at this solid concentration. Based on the response of bench scale studies, the sample was treated in rougher, cleaner and scavenger spirals in closed circuit. The bench and pilot scale studies reveal that it is possible to produce concentrate with Fe <62> 64.5% with a yield of about 30%. Perhaps, development of process for beneficiation of spiral tailings with a combination of HGMS and column flotation would improve the yield of the concentrate.

4 illus, 14 tables, 6 ref

002663   Misra R N;Nakhasi D (NO, , SJVN, Ltd.) : Hydropower development in India. Wat Energy int 2013, 70(8), 27-30.

The paper discusses the various constraints and challenges facing the development of hydropower in India like lack of infrastructure facilities construction Power, land acquisition, Power evacuation infrastructure, Lack of trained & skilled manpower, silt problems, geological issues, natural hazards, lack of hydrological data, poor contract management, & inadequate investigations & mismatch between policies of Centre & State. In order to overcome these problems, various suggestions have also been given.

1 table

002662   Lu Y;Liao A (Key Laboratory of Chemical and Biological Transforming Process, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Nanning 530006, P.R. China, Email: luyanyue@163.com) : Modeling and experimental study on air-gap membrane distillation. Asian J Chem 2013, 25(12), 6873-6.

Membrane distillation (MD) is an attractive separation process compared to the traditional separation processes such as distillation or reverse osmosis. Requiring lower operation temperature and being able to use low-grade thermal energy are the major features of membrane distillation. Membrane distillation can be classified into four configurations. Air gap membrane distillation (AGMD) is one of the most versatile membrane distillation configurations which can be applied to almost any applications. The model of air gap membrane distillation module is established in this paper based on the mechanism of heat and mass transfer. The outlet temperature of hot feed stream and cold stream can be predicted by this model. Thereafter the design of air gap membrane distillation system can be achieved based on the presented module model. Many experiments have been done to validate the rationality of the model.

4 illus, 1 table, 10 ref

002661   Lee S;Ha Y G;Lee S A;Park J H;Song K (Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353, Republic of Korea, Email: sylee@kaeri.re.kr) : Minimization of uranium process blank during chemical treatments of a swipe sample. Asian J Chem 2013, 25(12), 7003-5.

A uranium background derived from the chemical treatment of a swipe sample was determined using multi-collector inductively coupled plasma mass spectrometry. Prior to the mass spectrometric analysis, sequential acid digestion and chemical separation can be utilized to avoid polyatomic ion interference. This chemical process may increase the amount of uranium in the process blank, which has an effect on an accurate isotopic measurement of uranium in the sample. As a result of a uranium background analysis, a significant portion of uranium in process blank was provided from a plutonium elute solution used for chemical separation. Careful treatments for cleaning bottles and using pure reagents reduce the amount of uranium in the process blank. Additionally, the uranium background can be controlled by checking the amount of uranium in each process. An isotope dilution mass spectrometry technique was utilized to determine ultra-trace uranium (pico-gram level) in the process blank. An isotopic analysis was also performed by varying the concentration of HNO₃ (DI, 3% and 5% of HNO₃) used to dissolve the sample for mass spectrometric measurements.

2 illus, 1 table, 10 ref

002660   Kumar A;Poddar B K;Sinha S K;Kumari L (Bio-Environment Division, CIMFR, Barwa Road, Dhanbad-826 015) : Effective approach for the improvement in efficacy of life saving filter typed safety breathing apparatus. J Indian Chem Soc 2014, 91(1), 63-6.

Filter typed self rescuer (FSR) is a traditional safety breathing apparatus to make breathable air free from carbon monoxide and dust. The performance evaluation of canister of FSR from different manufacturing companies such as Joseph Leslie Dragger (Germany), Hunan Coal Company (China), Fraser (Poland) and MSA (India) Ltd., Kolkata were evaluated as per IS 9563 : 1980 by open circuit artificial mechanical human lung simulation machine. According to Indian standard the breathing resistance and conversion of carbon monoxide into non-poisonous carbon dioxide gas was found rational in the FSR of MSA (India) Ltd., Kolkata. The scope for modification exists in the canister of FSR for reducing the inhalation temperature and dust filter to improve its duration of action.

3 illus, 10 ref

002659   Kim G H;Kim T H;Choi B S;Jeong K S;Hyun D; Moon J (Decontamination and Decommissioning Research Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-g, Daejeon 305-353, Republic of Korea, Email: ghkim7@kaeri.re.kr) : Radiological assessment of the dose distribution around reactor pressure vessel. Asian J Chem 2013, 25(12), 7047-50.

For a reasonable design of a decommissioning scenario, the dose distribution around the reactor pressure vessel of a commercial nuclear power plant (NPP) was assessed preferentially using an MCNP code based on the concentration of ^{60Co. The regions of the dose calculation were composed of two parts; one is between the reactor pressure vessel and the biological shield of a cylindrical-type and the other is at the reactor pressure vessel pool of a rectangular-type. The highest dose value was 22.9 Sv/h at 4.35 m from the bottom of the reactor pressure vessel and the lowest dose value was 10.8 mSv/h at the top of the biological shield. It was shown that the dose is so high that workers could not work around the reactor pressure vessel without radiation protective actions based on the domestic criteria (100 mSv/5 yrs and 50 mSv/yr).}

5 illus, 1 table, 5 ref

002658   Im H J; (Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu,Daejeon 305-353, Republic of Korea, Email: imhj@kaeri.re.kr) : Pre-irradiation of boric acid solutions in a research reactor. Asian J Chem 2013, 25(12), 7013-15.

Interpretation of coolant chemistry performance is very important because the performance can be an effective indicator in monitoring operational safety of nuclear power plants. To determine the radiolysis degree of boric acid solutions, which are added for neutron absorption to control core reactivity during the nuclear power plant operation, and understand the physico-chemical nature of the process under neutron irradiation in a nuclear reactor, the preparation and safety check points for the irradiation of boric acid solutions are discussed.

2 illus, 2 tables, 9 ref

002657   Hungund C P S;Patil S (Statistics Dep, Gulbarga Univ, Gulbarga-585 106, Email: cpshgu@gmail.com) : Estimation of reliabilities of thermal power plant-a case study. Int J agric statist Sci 2014, 10(1), 53-8.

To sustain smoother flow of electricity generation of thermal power plant, it is very important to understand the pattern of successive failures (working hours) and production downtime (repair hours). Since exponential distribution is a commonly assumed model for working hours and repair hours, the applicability of exponential distribution is tested through Chi-Square test of Goodness of Fit (GoF). Also an attempt is made to find out the best suitable analysis for fitting production down times.

7 tables, 4 ref

002656   Goel C B;Thakurdesai S (NO, Texas Instruments (India) Pvt. Ltd., Bangalore) : Last mile connectivity challenges in smart grid. Wat Energy int 2013, 70(11), 7-11.

Automatic data collection from utility energy meters (HT, LT and consumer) is the first step towards making the power grid smarter. A complex network of these meters all the way to the substation is called Advanced Metering Infrastructure (AMI) and the last mile of this network is called the Automated Meter Reading (AMR) network. This paper describes a number of technologies that can be utilised in setting up an Automated Meter Reading network in India and the challenges involved in this process. The establishment of Smart Grid is at an advanced stage in some other countries of the world. This paper also tells which of these technologies are selected by these countries and the reasons for their selection with respect to geographical and infrastructural factors. The paper describes both wireless and wired technologies and also compares the advantages and disadvantages of both. In setting up wireless networks, ensuring a sustained connectivity is one of the biggest challenges because of a wide variation in the location of meters in different localities of the same area. In this paper, various factors like the frequency band (2.4 GHz or Sub-1 GHz), network topology (peer to peer, star and mesh networks) and various standards like Zigbee, WM-Bus, WiFi are introduced and compared. This paper illustrates the steps that can be taken to ensure continued connectivity. For wired connectivity, power line communication is the only viable alternative for AMI. In power line communication, the noise generated by different loads on the power line and the dynamic changes in the line impedances is the major challenge. This paper shows the latest advancement in PLC technology which makes the use of OFDM modulation as compared to SFSK which was used in yesteryear installations and explains how it helps in addressing the challenges mentioned earlier. This paper also gives an update on the standardizations that are happening and being followed worldwide. Given the diversity of urban planning architectures and geographical and infrastructural differences at various places in India, it may be possible that instead of selecting a single technology, a hybrid AMR network has to be designed. This paper also describes the challenges involved in commissioning of such networks and what steps can be taken to make these networks more reliable.

1 illus, 1 table, 6 ref

002655   Garg S;Bhardwaj A;Taneja D S;Sondhi S K (Soil & Water Engineering Dep, Punjab Agricultural Univ, Ludhiana) : Performance evaluation of solar photovoltaic (SPV) pumping system under field conditions. Wat Energy int 2013, 70(8), 16-21.

A study has been carried out to evaluate the performance of solar photovoltaic (SPV) pumping system under field conditions. Performance parameters such as array output, total head, overall efficiency and conversion efficiency have been determined. Performance characteristics curve for SPV pumping system have been developed. The value of solar insolation was observed to vary from 6.7 to 7.4kwh/m^{2/day. The motor input power varied from 480 watts to 550 watts. The conversion efficiency was found to vary from 2.78% to 7.42%. The clouds significantly affected voltage, current, rpm and discharge but the temperature did not change, which reveals that temperature has no effect on development of voltage or current in the solar photovoltaic cells. The maximum operational efficiency achieved was 60% for a head range of 8.3 m to 9.7 m and discharge of 1.9 l/s to 3.0 l/s which is quite high under the field conditions.}

6 illus, 1 table, 7 ref

002654   Choi K S;Lee C H;Ahn H J;Park Y J;Song K (Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, Daedeok-daero 989-111, Yuseong-gu, Daejeon, Republic of Korea, Email: nkschoi@kaeri.re.kr) : Proficiency testing for the evaluation of the quality of analytical results in the nuclear industry. Asian J Chem 2013, 25(12), 6997-9.

To evaluate the quality of analytical results in the nuclear industry, we participated in proficiency testing, called EQRAIN trace elements No. 17, which was held under the auspices of the commission for the establishment of analysis methods. The concentrations of 15 elements (Cd, Ni, Eu, As, Fe, U, Sm, Li, Nd, Zr, Pb, Cr, Al, B and Ca) were determined by ICP-AES. Although standard solutions on a volume basis were prepared for a calibration curve, the density of the mother standard solution was not used to calculate the concentration of the standard diluted solution. Based on preliminary tests, the analytical results with a background correction were more accurate than those without background correction. To obtain accurate and reproducible analytical results, an analysis was performed in triplicate using a two-point calibration on five different dates. The relative variations of all elements except Zr were within less than ± 2%. However, as the relative variation of Zr was incompatible at 3.6%, the content of Zr will be measured using a high-performance ICP-AES.

4 tables, 10 ref

002653   Choi K C;Songh B C;Ahn H J;Park Y J;Song K (Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353, Republic of Korea, Email: nkcchoi@kaeri.re.kr) : Effect of <. Asian J Chem 2013, 25(12), 7016-18.

The effect of ^{3H and 14C interference on the separation and quantification of 129I from iron scraps and heating insulators as a low and intermediate-level radwaste has been studied. The iron scraps and heating insulators were liquidized using an acid digestion pretreatment method. Then, an anion-exchange resin adsorption method was used to separate the 129I and 14C in the pretreated aqueous solution. The 3H remained in the aqueous phase after the back-extraction and was removed by low-temperature evaporation at 70 °C. Through the chemical separation and evaporation, most of the 14C and 3H were removed and no radioactivity was detected. In the separation extraction, the average recovery rate of 129I was approximately 80.8%.}

2 illus, 3 tables, 11 ref

002652   Bouzon L (NO, , ABB Ltd.) : Renewable generation plant communications. Wat Energy int 2013, 70(11), 25-8.

This technical report has been motivating discussions on the use of Mesh Networks, to meet the demand of Electric System, in special case, Renewable Generation, as part of integration with other information systems and telecommunications, automation of operations and greater mobility to perform the services. Mesh Network allow the inclusion of the management of Power Plant Grid's Communication System as good solution for different network sizes and applications. Interconnecting between renewable power plant, like wind turbines, reclosers, solar farms, etc. (Renewable Generation) with Collector Substations. The system provides a mean of communication to cover the operational needs, with broadband. A feature of these Systems and flexibility for implementations, and topology changes. The facilities are simple and quick, and with reduced amount of cabling and lower infrastructure costs.

1 illus, 3 tables, 4 ref

002651   Bose T;Jain A K;Roy D (NO, Birla Corporation Ltd, Satna, Email: tb1973@gmail.com) : Overview of the Sagmania limestone mine of Satna cement works & energy saving initiatives. Indian Min Engng J 2014, 53(1), 18-21.

1 illus, 1 table

002650   Bhuria N R;Sachan A (Civil Engineering Dep, Indian Institute of Technology, Gandhinagar-382 424, Email: ajanta@iitgn.ac.in) : Shear strength and constant rate of strain consolidation behaviour of cement-treated slurry-consolidated soft soil. Curr Sci 2014, 106(7), 972-9.

This article focuses on the compressibility and shear strength behaviour of cement-treated soft soil at different cement content and curing time. The soil was found to be too soft (SPT N = 1) to collect the undisturbed samples from soil site. Therefore, a pneumatic slurry consolidation set-up has been developed in the laboratory to produce remoulded specimens of soft soil with same in situ density and water content. These representative slurry-consolidated remoulded specimens were tested using unconfined compression (UC) and constant rate of strain (CRS) set-up to evaluate the shear strength and compressibility behaviour of soil before and after cement treatment. The conventional 1D consolidation set-up (oedometer) was found to be unsuitable to determine the compressibility behaviour of cement-treated soft soil due to its long testing duration (~10 days), which caused major discrepancy in compressibility results of treated soft soil at the chosen curing time. Thus, the CRS set-up has been developed in the laboratory to accelerate the consolidation process for cement-treated soft soil. A wide range of cement contents (2%, 4%, 6% and 8%) and curing periods (1, 3, 7 and 28 days) were explored to study the compressibility and shear strength parameters of highly compressible soft soil with respect to the cement content and curing time used for its treatment.

6 illus, 2 tables, 26 ref

002649   Bhosekar V V;Bhajantri M R (NO, Central Water and Power Research Station, Pune) : Hydraulic deisgn considerations for spillways in Himalayan regions. Wat Energy int 2013, 70(11), 49-56.

The rapid altitudinal variations with swift flowing perennial rivers have made Himalayan region a natural haven for large-scale hydro power production. Because of fragile geology and steep Slopes, soil erosion rate is high during snowmelt and monsoon. Special type of spillways are required for the dual purpose of passing the floods as well as for flushing of the sediment deposited in the reservoir. During last two decades, CWPRS has made significant contributions to number of projects in evolving hydraulically safe and efficient designs of spillways in Himalayan region. The present paper describes various hydraulic design considerations while selecting type of spillway and energy dissipater for run-of-the river projects in Himalayan region. It is also emphasized that although no design procedures are readily available for such such type of spillways, experience from the hydraulic model studies and prototype to evolve suitable layout of spillways, energy dissipators and power intakes provide useful guidelines.

7 illus, 4 ref

002648   Awasthi S;Prasad V;Rangnekar S (NO, BHEL, New Delhi) : Operational strategies to increase generation of large hydroelectric power plants. Wat Energy int 2013, 70(8), 7-11.

In view of environmental concerns, there is increasing awareness on judicious use of natural resources. Large hydroelectric power plants require huge quantity of water for their operation. As a general practice, generating units in a hydroelectric power plant are operated to meet the electrical load demand without consideration of the efficiencies of the units which leads to excess discharge of water. It now needs more attention on optimum utilization of water in hydroelectric power plants. This paper presents the strategic planning for optimal operation of large hydroelectric power plants such that water is conserved. Thus, more power is generated with the same quantity of water.

4 illus, 9 ref

002647   Alvarez M A;Arzuaga T (NO, CG Automation BU, Spain) : Comprehensive cybersecurity strategy for smartgrid equipment manufacturers. Wat Energy int 2013, 70(11), 12-16.

The benefits in the evolution of traditional electrical grid into the Smart Grid, are more evident every day. However, this evolution is also offering more rewards to potential attackers as well as a wider range of potential attack vectors due to the increase in the use of communications and the integration of operational systems in the internet. This has led to an increased awareness of the need for implementation of Cybersecurity measures in the Smart Grid. Cybersecurity field has not been part of the body of knowledge of electrical grid designers, though. So, even if equipment manufacturers are beginning to deal with the inclusion of Cyber Security features to their developments, they are not always following the best approach but trying to find and follow recommendations and best practices guides. However, there are no fixed rules that ensure the security of equipment yet. The main aim of this paper is to use a pragmatic approach to create a reference guide for a first approach of equipment manufacturers to the world of cybersecurity. To achieve this, it is necessary to analyze very different aspects ranging from the work of public agencies such as NERC CIP or penetration testing techniques (such as those made by Digital Bond in S4), to international standards (IEC62351 ...), key management procedures. All of this should also be combined with the study of known Cybersecurity attacks such as Stuxnet. This paper takes into account that the implementation of Cybersecurity is a quite different task compared with the ones usually tackled by manufacturers. On one hand, it must be considered that it is not a concrete and definite task, but a set of decision making and measurement implementation rules relatively unconnected to one another. However, they help in the prevention of a whole range of risks for equipment. On the other hand, and, unlike what happens with other features, the implementation of security measures does not 100% guarantee the security of equipment, so the task does never end, and in addition to the prevention methods, detection methods should also be implemented to offer quick detection of new vulnerabilities. The combination of prevention and detection will sometimes fail, so a good Cybersecurity system must also consider mitigation and recovery techniques. This paper proposes as a practical approach the decomposition of the system in use cases as concise and clear as possible. The different steps proposed for use cases are as follows: Initial analysis based on abstract concepts such as confidentiality, integrity and availability (CIA model). Analysis of risks and vulnerabilities, focusing primarily on scaled potential attacks. Selection of generic methodologies for prevention, detection and response. Selection of the security features both hardware (chip key storage, cryptographic coprocessors, biometric protection ...) and software (security libraries, logs and event managers ...). Tracking a top-down methodology for writing use cases, favours Cybersecurity non based on "magic formulas ", but on common sense.

7 illus, 4 ref

001836   Zhu Y R;Yi T F;Ma H T;Ma Y Q;Jiang L J;Zhu R S (School of Chemistry and Chemical Engineering, Anhui Univ of Technology, Maanshan, Anhui 243002, People's Republic of China, Email: tfyihit@163.com) : Improved electrochemical performance of Ag-modified Li₄Ti₅O₁₂ anode material in a broad voltage window. J chem Sci 2014, 126(1), 17-23.

Li₄Ti₅O₁₂/Ag composites were synthesized by a solid-state method. The effect of Ag modification on the physical and electrochemical properties is discussed by the characterizations of X-ray diffraction, scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, cycling and rate tests. The lattice parameter of Li₄Ti₅O₁₂ with a low Ag content is almost not changed, but the lattice parameter becomes larger due to the high content of Ag. Li₄Ti₅O₁₂/Ag material has a uniform particle size which is about 1 μm. Modification of appropriate Ag is beneficial to the reversible intercalation and deintercala-tion of Li^{+. Modification of Ag not only decreases the charge transfer resistance of Li₄Ti₅O₁₂ material, but also improves the diffusion coefficient of lithium ion. Li₄Ti₅O₁₂/Ag (3 mass%) material has the lowest charge transfer resistance, the highest diffusion coefficient of lithium ion and the best rate cycling performance.}

8 illus, 1 table, 47 ref

001835   Wang Y;Peng C;Zhang W (College of Aerospace Science and Engineering, National University of D, , Changsha 410073, PR China, Email: wynudt@gmail.com) : Mechanical and electrical behavior of a novel satellite multifunctional structural battery. J scient ind Res 2014, 73(3), 163-7.

A novel multifunctional structural battery (MFSB) has been designed using gel polymer lithium-ion (GPLI) batteries, carbon fiber reinforced polymer (CFRP) composite and polymethacrylimide (PMI) foam for satellite mass and volume reduction. Typical mechanical and electrical experiments were carried out and found that the designed MFSB can survive the vibration of spacecraft launch and mechanical load up to serviceable limit of either CFRP skins or PMI foams causes no electrical degradation of the embedded GPLI battery, presenting considerable potential for satellite application.

3 illus, 1 table, 23 ref

001834   Vedala S;Venkateswara Rao K;Sushama M; Seshasai Kumar V (Electrical and Electronics Engineeering, Jawaharlal Nehru Technological Univ, Hyderabad, Hyderabad-500 085, Email: kalagadda2003@gmail.com) : Microstructural, optical and morphological studies of SnO₂ nanoparticles obtained by sol-gel method. Invertis J renewable Energy 2014, 4(2), 83-6.

Tin oxide (SnO₂) nanoparticles were synthesized by the reaction of SnCl₄.5H₂O via sol-gel method using surfactant. Ammonia is added to neutralize pH in the sol-gel reaction. The samples were characterized by XRD analysis showed well - 281 - crystallized tetragonal rutile SnO₂ can be obtained for the sample calcined at 400 °C for 2 hrs. Optical studies of the samples were investigated by Fourier transform infrared spectroscopy. Surface morphology was studied using Scanning electron microscopy and Transmission electron microscopy. Our results suggest that the temperature plays an major rolefor the growth of nanoparticles.

8 illus, 2 tables, 8 ref

001833   Tiwari S K;Shukla D K;Chandra R (NO, , ) : Effect of tool tilt on formation of tunnel in friction stir welded 5083 joints: an experimental study. J Mater metall Engng 2014, 4(2), 10-15.

Friction stir welding (FSW) being a solid-state joining process is immune to the various defects faced in traditional fusion welding process. However, defects such as voids, joint line remnants and tunnel defects are common imperfections in FSW. In the present study, an attempt has been made to investigate the effect of tool tilt on the formation of tunnel defect, while keeping all other process parameters constant. Tool tilt is a significant parameter as it influences the flow patterns of the stir zone, frictional forces and the heat generated. The study has shown that the tool tilt can alter the flow of plasticized material in the stir zone and for that reason can control the quality of weld.

001832   Tiwari M R;Tiwari K K;Toliwal S D (Sophisticated Instrumentation Center for Applied Research & Testing (, , Vallabh Vidyanagar-388 120, Email: mrtiwari_2007@yahoo.co.in) : Studies on thermal stability of palm -sesame oil blends during deep fat frying. J scient ind Res 2014, 73(3), 153-6.

Effect of blending Palm oil (PO) with Sesame oil (SeO) in different ratios has been investigated to get blends with low cost and better nutritional advantage relative to SeO. The blend of PO with SeO is also prepared with Saturated Acid: Monounsaturated Acid: Polyunsaturated oil (S: M: P) in the ratios of 1:1:1 in view of its nutritional significance. Studies were conducted on individual and blended oils to determine thermal stability at 180°C in oven for 12 hours and during Deep Fat Frying (DFF) of dry potato chips at 180°C for 9 hours. The individual and blended oils were analyzed for physico-chemical properties and fatty acid composition and were then used to determine the thermal stability and DFF studies. The changes in fatty acid composition and physico-chemical characteristics of individual and blended oils at the end 12 hours for thermal stability and at the end of 9 hours for DFF studies have been reported.

2 tables, 13 ref

001831   Thokal P V;Deodhar Kulkarni V A;Pawar S S (NO, , ) : Energy efficient LED driver using PIC. Res Rev: J embedded syst Applic 2014, 2(2), 1-6.

Tremendous growth of LED lighting in offline applications, such as office lighting, public buildings, and street lighting is increasing, and that increase is predicted to continue for the future years. In these applications, - 280 - LEDs replace linear or high-power CFL fluorescent lamps, high-intensity discharge (HID) lamps such as metal halide and high-pressure sodium, as well as mercury vapor lamps which consume more power than LEDs lamp. These applications require an LED driver. In this paper we propose a method which describes an intelligent control circuitry to drive a string of LEDs with current regulation and pulse modulation (PWM)-based dimming technique using PIC microcontroller.

001830   Subbarao E C (Tata Research Development and Design Centre, , 54B Hadapsar Industrial Estate, Pune-411 013, Email: ecsubbarao@yahoo.com) : India's higher engineering education: opportunities and tough choices. Curr Sci 2013, 104(1), 55-66.

The five Indian Institutesof Technology set up between 1951 and 1961 have established a great reputation for undergraduate engineering education, as good as and, in fact, better than most institutions in the world. But this achievement did not extend to postgraduate engineering education, particularly the training of PhDs leading to cited publications, exploitable patents, innovative products and entrepreneurship. An attempt is made here to analyse the reasons for this and suggest achievable, though tough, pathways.

11 tables, 28 ref

001829   Singh M P;Singh S P;Singh A P (NO, , ) : Water permeability of hybrid steel fiber reinforced concrete. J Constr Engng Technol Mgmt 2014, 4(2), 30-7.

Results of an investigation conducted to study the water permeability of (HySFRC) are presented. Steel fibers of different lengths, i.e., 12.5, 25 and 50 mm having constant diameter of 0.6 mm were systematically combined in different mix proportions to obtain mono, binary and ternary combinations corresponding to 0.5, 1.0 and 1.5% fiber volume fractions. A reference concrete mix containing no fibers was also cast for comparison purpose. A total number of 480 cube specimens of size 100 x 100 x 100 mm were tested for water permeability at 7, 28, 90 and 120 days of curing. Though the compressive strength and split tensile strength tests were also conducted, the results are not reported in this paper. However, the results of compressive strength tests and split tensile tests have been used to arrive at the most appropriate fiber combination. It has, therefore, been observed that a fiber combination of 33% 12.5 mm + 33% 25 mm + 33% 50 mm long fibers can be adjudged as the most appropriate combination to be employed in HySFRC for water permeability, compressive strength and split tensile strength requirements.

001828   Singh K;Manish Kumar;Garg G (NO, , ) : Synthesis, characterization and biological activity: Co(II), Ni(II), Cu(II) and Zn(II) complexes of Schiff Bases derived from 4-cyanobenzaldehye and 4-amino-5-mercapto-3-methyl/ethyl-1,2,4-triazoles. J Modern Chem chem Technol 2014, 5(2), .

Co(II), Ni(II), Cu(II) and Zn(II) complexes of bidentate Schiff bases derived from the condensation of 4-amino-5-mercapto-3-methyl-1,2,4-triazole and 4-amino-3-ethyl-5-mercapto-1,2,4-triazole with 4-cyanobenzaldehyde have been synthesized. The synthesized Schiff bases and their metal complexes were then characterized by elemental analysis, spectroscopic methods (IR, NMR, electronic spectra), magnetic moment measurement and thermogravimetric techniques. The electronic spectra and magnetic moment studies suggest octahedral geometry for Co(II), Ni(II) and Zn(II) complexes and square planar geometry for Cu(II) complexes. The newly synthesized Schiff bases and their metal complexes were screened against bacteria (Bacillus pumilus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli) and fungi (Aspergillus niger and Penicillium).

001827   Shant R;Thummuluru G;Mahajan A;Goyal R K; Kathayat T S (NO, , ) : Micro crack formation in high frequency electric resistance welding. J Mater metall Engng 2014, 4(2), 32-9.

The present paper discusses about the formation of micro cracks in base metal adjacent to the weld area during High Frequency-Electric Resistance Welding (HF-ERW) of 10'' outside diameter pipe. The micro crack formation has been analyzed with respect to chemical composition, microstructure, inclusion level, welding parameters and angle of weld flow lines.

001826   Shah K A;Devashrayee N M (NO, , ) : Implementation of 2nd order CMOS Gm-C IF tuning filter operating at GSM and FM band: wireless system with Monte Carlo analysis. J Elect Des Technol 2014, 5(2), 9-24.

Designed folded cascode OTA has a 52 dB DC gain and provides a unit gain bandwidth of around 400 MHz. Design of CMOS Gm-C 2nd order biquad filter implementation using OTA, operating at center frequency 70 and 10.6 MHz. The filter can be operated at center frequency of 70 MHz under 1.8 V power supply and is suitable for intermediate frequency (IF) range in most of the wireless systems operating at 900 MHz GSM and at 88-108 MHz FM.

001825   Setak M;Karimi H (Industrial Engineering Dep, K.N.Toosi University of Technology, Tehran, Ira, Email: setak@kntu.ac.ir) : Hub covering location problem under gradual decay function. J scient ind Res 2014, 73(3), 145-8.

This paper developed a mathematical model framework using the single allocation strategy for hub covering location problem. The model encompassed the transportation time covering under gradual decay function. Within a certain transportation time for the origin and destination nodes among two hubs, the route is fully covered, and beyond another specified transportation time the route is not covered. Between these two given service times, the coverage is linear for the routes. A tabu search has been used to solve some problems such as CAB and AP. The quality of solutions obtained using TS have been compared with the achieved one using CPLEX solver. Plenty of experimental study evaluated the performance of the gradual decay function.

21 ref

001824   Saxena A;Ojha K;Pathak A K (NO, , ) : Underbalanced drilling and its advancements. J Petrol Engng Technol 2014, 4(2), 37-51.

Ever increasing global energy demand associated with depletion of conventional hydrocarbon resources drives exploration and production (E&P) industry to invent advanced new technologies in frontier areas of drilling, production and reservoir engineering to enhance hydrocarbon production from unconventional resources or depleted reservoirs. Demand to produce from a low pressure marginal reservoir and the discoveries of naturally fractured reservoirs lead to the development of new drilling techniques like underbalanced drilling along with other technological advances. Underbalanced drilling (UBD) technology can overcome a number of problems encountered during drilling, which is otherwise impossible with conventional overbalanced drilling. However, in-depth understanding of the characteristic behavior of different components during operation is an essential criteria for efficient application of this technology. In drilling operation, drilling fluid plays a very important role in controlling the entire operation efficiently without any interruption or damage to the reservoir. Foam-based drilling fluid, one of the most favored techniques of UBD needs a thorough study for its applicability and - 278 - smooth functioning under bottom hole condition. Foam fluid is very much unpredictable for its very sensitive rheological behavior, specifically for small variation in pressure, temperature, and composition along with other parameters during drilling. Hence, utmost care should be taken for proper designing of foam-based fluid, failing of which may negatively affect the process. Present paper deals with the developments of foam fluid as an efficient drilling fluid since its inception, composition and rheology, merits and demerits, comparison with conventional fluids which will help the researchers working in the field to get the intensive information without consulting a large literature.

001823   Saad M;Mangesh S (NO, , ) : Analysis of LSDCCFF at MM technology. J Elect Des Technol 2014, 5(2), 32-9.

Ttraditional low swing differential conditional capture flip-flop (LSDCCFF) for LC resonant clock distribution network has wide range of applications but has poor power consumption. These characteristics can be improved by using the modified LSDCCFF. This paper presents the design of modified LSDCCFF with less delay and low operating power. The implementation of the circuit is done using LSDCCFF. By using voltage scaling technique, the average power consumption can be reduced. An analysis of the LSDCCFF is presented. The design has been implemented in 0.09 μm technology.The modified LSDCCFF exhibits a D-Q delay of 1.32 ns, and average power consumption of 8.87μw.

001822   Reddy K P J;Sharath N (Laboratory for Hypersonic and Shock Wave Research, Aero-space Engineer, Indian Institute of Science, Bangalore-560 012, Email: laser@aero.iisc.ernet.in) : Manually operated piston-driven shock tube. Curr Sci 2013, 104(2), 172-8.

A simple hand-operated shock tube capable of producing Mach 2 shock waves is described. Performance of this miniature shock tube using compressed high pressure air created by a manually operated piston in the driver section of the shock tube as driver gas with air at 1 atm pressure as the test gas in the driven tube is presented. The performance of the shock tube is found to match well with the theoretically estimated values using normal shock relations. Applications of this shock tube named Reddy tube, include study of blast-induced traumatic brain injuries and high temperature chemical kinetics.

9 illus, 1 table, 10 ref

001821   Rao, Y. H.; Venkateshwarlu, M.; Papanna, G.; Ramalingeshwara Rao, B (K.G.Reddy College of Engineering and Technology, , Hyderabad-501 504, Email: mamila_v@rediffmail.com) : Palaeomagnetism of Khairmalia Volcanics, south of Chittorgarh - implications related to the basal age of the Proterozoic Vindhyan Supergroup. Curr Sci 2013, 104(3), 364-7.

Palaeomagnetic studies were carried out on the basal Khairmalia volcanic rocks of the Proterozoic Vindhyan Supergroup. Two hundred and ten specimens prepared from 30 oriented block samples from 10 sites near Khairmalia, south of Chittorgarh, Rajasthan were studied. They are characterized by mean characteristic - 277 - remanent magnetization D= 8° and I= 9°(α₉₅= 16.3; k= 23.11). Virtual geomagnetic pole is estimated at 68.6°N; 231.3°E (dp= 8.3 and dm= 16.4). Plot on the Proterozoic apparent polar wander path1 indicates that the volcanics may have erupted ca. 1800 Ma.

5 illus, 1 table, 12 ref

001820   Rai D C;Dhanapal S (Civil Engineering Dep, Indian Institute of Technology Kanpur, Kanpur-208 106, Email: dcrai@iitk.ac.in) : Bricks and mortars in Lucknow monuments of c. 17-18 century. Curr Sci 2013, 104(2), 238-44.

Lucknow monuments which date back to 17-18^{th century are large masonry structures built using thin burnt-clay bricks (lakhauri) and lime-crushed brick aggregate (surkhi) mortars. Studies were carried out to characterize engineering properties of old masonry materials and new mortars being used for the renovation work. Mechanical properties of reclaimed lakhauribricks were found comparable to good-quality contemporary bricks of the neighbouring region. Moreover, XRD and SEM-EDS analyses indicated that mineralogical composition is not too different, except few minerals. The limesurkhimortar used in old masonry work was found to be lime rich with binder to aggregate ratio of about 1:2 to 3 by volume and is similar to those used in Byzantine structures of Western and Central Asia. The renovation mortar had poor hydraulic property compared to old mortars indicated by TG-DTA analyses.}

8 illus, 5 tables, 10 ref

001819   Qazi H H A (NO, , ) : Improvement of mechanical properties of aluminum by conventional casing and deformation process. J Mater metall Engng 2014, 4(2), 16-20.

Nowadays, Aluminum-Zinc alloy system are the major and rapid development in the field of automotive and aerospace industries for growing demand of efficient vehicles and aircrafts to reduce energy consumption and air pollution. Aluminum is a very soft metal by nature. Different alloying elements were added in the past to increase its strength and toughness. Zinc is considered as a major alloying element in aluminum to increase its strength and toughness. Present experimental work was conducted to determine the appropriate amount of zinc to be added in pure aluminum to increase its mechanical properties. A wide range of experimental work was conducted on pure aluminum to determine the appropriate amount of zinc to be added to develop Al-Zn alloy using conventional foundry method. Pure aluminum was mixed with different percentages of zinc with constant percentage of magnesium and copper. The molten alloys were cast in metal mold. Wrought alloys have high strength as compared to cast alloy so after casting, the alloy was subjected to mechanical rolling. Standard samples were prepared for tensile tests and a number of samples were age hardened. Various characterization techniques were used to investigate the chemical composition, tensile strength, ductility (elongation), and hardness. It has been observed that the alloy containing 5% Zn and 2% Mg, gives highest strength, and have good ductility in heat-treated condition.

001818   Osaghae G N (NO, , ) : Role of cost estimation/tendering in engineering projects in Nigeria. J Constr Engng Technol Mgmt 2014, 4(2), 38-42.

Energy is the bedrock of development of any nations as the overall development of the economy is tied to its energy supply. Despite the potential huge deposit of energy resources in the world, adequate provision of infrastructure to raise the living standard of the people has always been denied. Energy supply contracts most times are stalled due to factors attributable to poor cost planning and failure to adopt a suitable method for price adjustments or incentivized pay and among others as hiring the wrong contractors, setting unrealistic goals, inadequate contract details, inflexible contracts, having limited or poor understanding of expectations, poor project and contract management by the engineers and energy contractors, failure to understand scope or statement of work before bidding or contract negotiations. The beneficial role played by effective cost estimation in contracts which is preceded by a project execution, necessitated the paramount need for this technical paper. This paper discusses cost estimation methods and how various elements of cost estimation are prepared for engineering contracts.

001817   Ogbunude B C;Emenike E;Ebuka A (NO, , ) : Improved prediction of fluid contacts using calibrated material balance models. J Petrol Engng Technol 2014, 4(2), 25-36.

Demand for oil has been on the high in the recent past and will continue as search for sustainable alternative energy sources intensifies. The exploration and exploitation of oil from subsurface reservoirs have posed several environmental challenges which include flaring and improper water disposal to name a few, caused by excessive production of gas and water. Hence, it is important to establish a reservoir performance monitoring scheme that will ensure that appropriate fluids are produced from the reservoir within the economic producing life of each well-draining a given reservoir by monitoring the fluid contact levels. Furthermore, appropriate reservoir monitoring will help to improve productivity and recovery of old wells, calibrate predictive reservoir models and identify opportunities for optimum reservoir development. A key tool used in reservoir performance monitoring is the post production log, particularly the Pulsed Neutron Capture (PNC) and Pulsed Neutron Spectroscopy (PNS) logs which make use of high energy neutrons to determine the fluid contacts in the reservoir. This campaign however is very expensive; hence an alternative and less expensive method of determining and predicting the present and future fluid contacts will be discussed. This involves using calibrated material balance models to predict the fluid contacts based on the pore volume (voidage) replacement by the displacing fluid. This will help in generating fluid contacts on a more frequent time interval.

001816   Mcdonald S (Power Specialist, Victaulic, , , Email: victaulic.Com) : Elements of success in hydro plant construction. Indian J Pwr River Valley Dev 2013, 63(7-8), 111-2.

2 illus

001815   Malik K;Sonawane N A;Singh M N;Gupta I D (Central Water and Power Research Station, , Pune-24, Email: kuldeep.cwprs@gmail.com) : Optimization of design of power intake for Loharinag Pala HEPP, Uttarakhand. Indian J Pwr River Valley Dev 2013, 63(7-8), 105-10.

Vortices at power intake structures may cause severe damage to the construction and associated mechanical parts, in addition to discharge losses, The main factors responsible for vortex formation include eccentric orientation of the intake, asymmetric approach flow conditions, obstructions in the flow, and non-uniform velocity distribution, All these factors were at play for the original design of intake at Loharinag Pala hydroelectric power project on river Bhagirathi in Uttarakhand. where water will be carried from the head regulator at crest level of RL 2142 m through a 95 In long channel to an intake pool with bottom at RL 21 33 m to feed three power intakes of 4.25 m diameter with invert level at RL 2136 m for generation of 6oo MW of powel: Physical model studies were conducted to optimize the design of power intake of Loharinag Pala project by proposing several modifications like change in the shape of intake pool, gradient of the bottom of intake pool, and the geometry of the intake structure itself A number of typical and site specific aspects associated with the power intake system were studied on the model which may be of interest to hydraulic - 275 - research fraternity. The authors therefore, wish to share their findings in providing practical and optimum solution to such typical problems in design of power intake through this paper.

9 illus, 7 ref

001814   Maheswari A;Gnanambal I (EEE Dep, K.S.R College of Engineering, Tiruchengode, Tamilnadu, Email: dramaheswari@gmail.com) : Low Order Harmonic Reduction of Three Phase Multilevel Inverter. J scient ind Res 2014, 73(3), 168-72.

In this paper, a cascaded H-Bridge multilevel inverter has been proposed using unequal dc power sources and less number of switches. A standard cascaded multilevel inverter requires h number of dc sources for (2h + 1) levels. This proposed scheme allows less number of unequal DC power sources without the requirement of transformers. Cascaded H-Bridge multilevel inverter fed induction motor shows the better performance due to fundamental frequency switching scheme. High quality output is derived due to the absence of lower order harmonics. High conversion efficiency is also achieved for induction motor drive when it is operated with the proposed inverter. The performance of three phase cascaded H-Bridge multilevel inverter with unequal dc sources is simulated by using MATLAB platform. Harmonic analysis is done on cascaded H-Bridge seven level inverter and experimental results are presented to demonstrate the superiority of the proposed system.

4 illus, 1 table, 15 ref