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Cyanobacterial flora and the physico-chemical environment of six tropical fresh water lakes of Udaipur, India.
JPandey,Usha Pandey,<br>J.Pandey,Usha Pandey
環境科學學報(英文版) , 2002,
Abstract: The cyanobacteria and physico chemical environments of six tropical fresh water lakes of Udaipur, India were investigated. These lakes receive varying nutrient inputs from different sources. Altogether 51 species of cyanobacteria were recorded. Species composition varied between lakes and between seasons. Lake VI (Baghdara), which receives nutrients from natural sources only, differed considerably from the others in water chemistry and composition of dominant species. Lake II (Swaroop Sagar), eutrophied due to sewage inputs, was species poor. Non diazotrophs, represented by 27 species, dominated during summer. With few exceptions, N 2 fixing species, both heterocystous and unicellular diazotrophs (represented by 24 species), were dominant during winter. Microcystis aeruginosa, Phormidium sp. and Anabaena flos aque were the dominant taxa of lakes characterized by sewage eutrophication. The study shows that both species diversity and community composition were affected by water chemistry.
Microstructure and Wear Characteristics of Al-4.5Cu-5Pb Alloy
Om Prakas Pandey,<br>
材料科學技術學報 , 1998,
Abstract: Al-4.5Cu-5Pb alloy was prepared by sand and chill casting. The same alloy was also spray deposited at a gas pressure of 1.6 MPa. The microstructural features exhibit a coarse to fine dendritic morphology for sand and chill cast alloys. Equiaxed grains were observed for spray fOrmed alloys. Wear testing employing a pin-on-disc type set-up, reveaIs considerably lower wear of spray deposited alloy compared to that of chill and sand cast alloys. The morphological features of wear track on specimen and debris indicated a mixed oxidative-cum-adhesive wear mechanisms for these alloys tested in the present investigation
Power Producing Preheaters—An Approach to Generate Clean Energy in Cement Plants  [PDF]
Amitesh Pandey
Energy and Power Engineering (EPE) , 2016, DOI: 10.4236/epe.2016.84019
Abstract: Demand of cement in developing countries is directly proportional to the development rate of that country. But increasing input cost of cement manufacturing, decreasing margin of profit, scarcity of raw coal availability and emission of greenhouse gases are some constraints, which restrict the growth of cement industry. Hence to combat with all these adverse situations simultaneously, this project report introduces and efforts to generate clean and green energy with the help of combination of preheater tower, which is available in all integrated cement plants and an augmented wind turbine. Hence, the technology is named as “Power Producing Preheaters” or 3P.H. Introduction of 3P.H. in cement industry, generates a definite amount of clean and green energy (as per site conditions), which is directly used in cement production to avoid grid connectivity cost of wind turbine output. Calculations are done to show the overall cost of project, its payback period and reduction in emission of greenhouse gases along with its benefits in cement industry.
Spatial and Temporal Variability of Soil Moisture  [PDF]
Vanita Pandey, Pankaj K. Pandey
International Journal of Geosciences (IJG) , 2010, DOI: 10.4236/ijg.2010.12012
Abstract: The characterization of temporal and spatial variability of soil moisture is highly relevant for understanding the many hydrological processes, to model the processes better and to apply them to conservation planning. Considerable variability in space and time coupled with inadequate and uneven distribution of irrigation water results in uneven yield in an area Spatial and temporal variability highly affect the heterogeneity of soil water, solute transport and leaching of chemicals to ground water. Spatial variability of soil moisture helps in mapping soil properties across the field and variability in irrigation requirement. While the temporal variability of water content and infiltration helps in irrigation management, the temporal correlation structure helps in forecasting next irrigation. Kriging is a geostatistical technique for interpolation that takes into account the spatial auto-correlation of a variable to produce the best linear unbiased estimate. The same has been used for data interpolation for the C. T. A. E. Udaipur India. These interpolated data were plotted against distance to show variability between the krigged value and observed value. The range of krigged soil moisture values was smaller than the observed one. The goal of this study was to map layer-wise soil moisture up to 60 cm depth which is useful for irrigation planning.
Bioactivity of the compounds in genus Dysoxylum

V Lakshmi,K Pandey,SK Agarwal,<br>
生態學報 , 2009,
Abstract: The diets of the wolf Canis lupus, red fox Vulpes vulpes and raccoon dog Nyctereutes ussurienusis Matschie were studied in the grassland of eastern Inner Mongolia from August to October in 2007 and from March to July in 2008. Feces were collected from dens and latrines. The frequency of occurrence and the dry weight of the remains of each food item in the feces were calculated. Livestock (50.65% frequency of occurrence) constituted the bulk of the wolf diet, while small rodents (76.31% frequency of occurrence) were most frequently eaten by the foxes. Small rodents (22.69% frequency of occurrence) were important to the raccoon dogs but they also frequently consumed birds (39.81% frequency of occurrence) and insects (26.39% frequency of occurrence). The wolf was the most omnivorous and the red fox was the least omnivorous of these three kinds of canidae according to the diversity index. The food niches of the wolf and the red fox overlapped more than that of the raccoon dog and other species. These three kinds of canidae shared many resources and consequently competition occurred to them. However, their diets also differed to some extent which helped them to avoid competition. Furthermore, raccoon dogs were dormant in winter when food was scarce, which may be the reason why all these species could coexist in a rather unproductive grassland.
Microstructural Features of Spray-Deposited Immiscible Bearing Alloys Al-43Sn and Al-7Sn-1.3Cu-1.3Ni
OPPandey,<br>O.P.Pandey
材料科學技術學報 , 2003,
Abstract: Two commercial grade aluminum based immiscible bearing alloys were spray-deposited using convergent-divergent type of nozzle. The processing parameters for spray-deposition were adjusted in such a way that most of the droplets arrived on the deposition substrate in either liquid or semi-liquid state. The microstructural features of spray-formed and as-cast alloys are compared. In spray-formed alloys equiaxed grains were observed. The cell boundaries and intercellular regions were observed to be decorated with sub-micron sized particles whereas in normal casting the second phase was observed to be segregated along grain boundaries. The morphology and distribution of second phase were observed to have similarity with those in over-spread and atomized powders produced under similar processing conditions. The microstructural features observed with variation in spray conditions are discussed in detail.
Analytical modeling of drain current and RF performance for double-gate fully depleted nanoscale SOI MOSFETs
Analytical Modeling of Drain Current and RF Performance for Double Gate Fully Depleted Nano-scale SOI MOSFETS

Rajiv Sharm,Sujata Pandey,Shail Bala Jain,<br>Rajiv Sharm,Sujata Pandey,Shail Bala Jain
半導體學報 , 2012,
Abstract: A new 2D analytical drain current model is presented for symmetric double-gate fully depleted nanoscale SOI MOSFETs. Investigation of device parameters like transconductance for double-gate fully depleted nanoscale SOI MOSFETs is also carried out. Finally this work is concluded by modeling the cut-off frequency, which is one of the main figures of merit for analog/RF performance for double-gate fully depleted nanoscale SOI MOSFETs. The results of the modeling are compared with those obtained by a 2D ATLAS device simulator to verify the accuracy of the proposed model.
Digitally controlled oscillator design with a variable capacitance XOR gate
Digitally Controlled Oscillator design with Variable Capacitance XOR Gate

Manoj Kumar,Sandeep K Arya,Sujata Pandey,<br>Manoj Kumar,Sandeep K. Ary,Sujata Pandey
半導體學報 , 2011,
Abstract: A digitally controlled oscillator (DCO) using a three-transistor XOR gate as the variable load has been presented. A delay cell using an inverter and a three-transistor XOR gate as the variable capacitance is also proposed. Three-, five- and seven-stage DCO circuits have been designed using the proposed delay cell. The output frequency is controlled digitally with bits applied to the delay cells. The three-bit DCO shows output frequency and power consumption variation in the range of 3.2486-4.0267 GHz and 0.6121-0.3901 mW, respectively, with a change in the control word 111-000. The five-bit DCO achieves frequency and power of 1.8553-2.3506 GHz and 1.0202-0.6501 mW, respectively, with a change in the control word 11111-00000. Moreover, the seven-bit DCO shows a frequency and power consumption variation of 1.3239-1.6817 GHz and 1.4282-0.9102 mW, respectively, with a varying control word 1111111-0000000. The power consumption and output frequency of the proposed circuits have been compared with earlier reported circuits and the present approaches show significant improvements.
EFFECTS OF HUMAN ACTIVITIES ON STRUCTURE AND COMPOSITION OF WOODY SPECIES OF THE NOKREK BIOSPHERE RESERVE OF MEGHALAYA,NORTHEAST INDIA
EFFECTS OF HUMAN ACTIVITIES ON STRUCTURE AND COMPOSITION OF WOODY SPECIES OF THE NOKREK BIOSPHERE RESERVE OF MEGHALAYA, NORTHEAST INDIA

Tripathi OP,Pandey HN,Tripathi RS,<br>Tripathi OP,Pandey HN,Tripathi RS
植物生態學報 , 2008,
Abstract: Aims Our study was conducted in the Nokrek Biosphere Reserve (NBR) in the Garo hills districts of Meghalaya, Northeast India. Our aim was to assess the effects of human activities on plant diversity,population structure and regeneration.Methods We selected a representative 1.2 hm2 stand in both the core and buffer zones of NBR. Structure and composition were determined by randomly sampling square quadrats, population structure was assessed by determining age structure, and regeneration was assessed by measuring densities of seedling, sapling and adult trees.Important findings More woody species were recorded from the core zone than the buffer zone (87 vs. 81 species), and there were a large number of tropical, temperate, and Sino-Himalayan, Burma-Malaysian and Malayan elements, primitive families and primitive genera. The trees were distributed in three distinct strata,canopy, subcanopy and sapling. Subcanopy and sapling layers had the highest species richness (81% -88% ). Lauraceae and Euphorbiaceae were the dominant families in terms of the number of species, and a large number of families were represented by single species. Most woody species (57 % - 79 % ) were contagiously distributed and had low frequency ( < 20% ). Although stand density was high in the buffer zone, its basal area was low compared to the stand in the core zone. Low similarity and high β-diversity indicate marked differences in species composition of the stands. Shannon diversity index was high in both the stands, while Simpson dominance index was low. The diameter-class distribution for dominant species revealed that the most had a large number of young individuals in their populations. Preponderance of tree seedlings, followed by a steep decline in population density of saplings and adult trees, indicated that the seedling to sapling stage was the most critical in the life cycle of the tree populations. Most species (42 % - 48 % ) had no regeneration,25 % - 35 % had good/fair regeneration, and the rest had poor regeneration or reoccurred as immigrants.
Preservation Artifacts and Loss Pattern of Arsenic: A Case Study from Highly Contaminated Location in Central-East India  [PDF]
Piyush Kant Pandey, Hansa Zankyani, Madhurima Pandey
Journal of Environmental Protection (JEP) , 2011, DOI: 10.4236/jep.2011.29139
Abstract: Arsenic is the focus of public attention because of its wider prevalence and toxicity. Proper sampling is important in characterizing toxic water contaminants in the groundwater. The present paper studies aspects of sampling, preservation artifacts, analytical issues etc. in a natural arsenic contaminated groundwater. The samples were collected from arsenic contaminated groundwater at three locations of village Kaudikasa in Rajnandgaon (Chhattisgarh). The standard method of sampling and preservation of arsenic was examined. The permitted sample holding time in this state is 180 days which has been found to be unrealistic on examination. The communication also compares the loss pattern of arsenic in unpreserved samples with samples preserved and kept at 4?C. It was found that about As losses during hold- ing after preservation were about 0% in one day, 35% in seven day, 70% in fifteen day, and 65% in thirty days time. Hence, the present recommended method of preservation leads to huge under reporting of As in natural samples. If the pattern of losses observed at the present location exists at other locations then the actual As levels could be much higher than the reported ones.
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