•PCM in metallic macro-encapsulate inside DPSAHS was investigated.•Rectangular and cylindrical metallic macro-encapsulate was tested.•Energy and cost analysis of DPSAHS with and without storage was ...conducted.•An average encapsulate efficiency of 47.2% and 67% was obtained.•Cost of heating 1 kg of hot air was $0.0074.
The present experimental work attempts to sustain the thermal response of the double-pass solar air heater system (DPSAHS) by the thermal lag of phase change material (PCM). At the same time, this analysis investigates the role of metallic macro-encapsulation on the heat storage and recovery from PCM integrated inside the DPASHS. The objectives are to investigate the influence of the geometry of encapsulation used for storage and to examine whether the discrete units allow faster charging and discharging of organic paraffin wax (PCM). In this work, an average encapsulate efficiency of 47.2% and 67% was obtained respectively for rectangular and cylindrical macro-encapsulates equipped DPSAHS. A performance comparison of DPSAHS with and without storage was presented. An overall cost analysis shows that with a small margin in constructional cost, operational time of DPSAHS was improved. The cost of heating 1 kg of hot air was 0.0074$. The overall work aims to support marginal and subsistent farmers to deal with improper drying during winter on which the potential sunshine hours are limited to 7 h/day at Calicut (11o32'N, 75o93'E) located in peninsular India.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Corallana mishrai sp. nov. collected from dead mangrove roots at Kodiyaghat, South Andaman, Andaman Islands, India is described and illustrated in detail. Corallana mishrai sp. nov. the first ...definitive record of the genus from India, is characterized by: frontal lamina with short straight (or very weakly convex) lateral margins and the anterior margin forming a strong acute median point; pleotelson length 0.76 greatest width, posterior margin with 5 robust setae; uropodal exopod 7 times longer than greatest width, extending beyond endopod by one fourth of its length; endopod lateral margin slightly convex with 4 RS and PMS, apex forms a slightly obtuse angle with long simple setae, mesial margin weakly convex with 2 RS and PMS; mandible bidentate; transverse row of 6 tubercles present on pereonite 1 and pleonites 2, 3 and 4 lacking lateral tubercles. The status of the genus and its species are reviewed, and two species are transferred to new combinations: Argathona kulai (Bruce, 1982) comb. nov. and Tachaea bidentata (Jones et al. 1983) comb. nov.
Eurydice andamanensis sp. nov. and Eurydice mohani sp. nov. are described from intertidal sandy beaches of South Andaman, Andaman Islands. Eurydice andamanensis sp. nov. can be identified by the ...posterior margin of pleotelson being one-fourth of the pleotelson in width, weakly convex with 11 plumose marginal setae and 4 robust setae; appendix masculina 0.8 times as long as endopod, projecting slightly beyond endopod distal margin by one-third of its length, distally broad, widely rounded, curved medially and mesial margin with 4 small acute cuticular scales; Eurydice mohani sp. nov. can be identified by the posterior margin of pleotelson with 6 plumose marginal setae, pleotelson without distinct depression on anterodorsal surface; appendix masculina 0.4 times as long as endopod, projecting beyond mid-region of endopod by 0.02 of its length, lateral margin with a sinuate notch and apex is rounded.
http://www.zoobank.org/urn:lsid:zoobank.org:pub:AFF18D66-4CE3-4D73-BAAA-39083D542008
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Anaerobic Digestion (AD) is one of the promising wastestoenergy (WtE) technologies that convert organic wastes to useful gaseous fuel (biogas). In this process methane is produced in the presence of ...methanogens (bacteria). The survival and activities of methanogens are based on several parameters such as pH, temperature, organic loading rate, types of biodigester. Moreover, these parameters influence the production of biogas in terms of yield and composition. Maintaining an appropriate temperaturefor AD is highly critical and energy intensive. This study reviews the various hybrid technologies assistedbio gas production schemes particularly from renewable energy sources. Also discuss the direct and indirect solar assisted bio-digester impacts and recommendation to improve its performance. In addition, the performance analysis Solar Photovoltaic (PV) and thermal collector assisted bio gas plants; besides their impact on the performance of anaerobic digesters. Since opportunities of solar energy are attractive, the effective utilization of the same is selected for the discussion. Besides, the various constraints that affect the yield and composition of biogas are also evaluated along with the current biogas technologies and the biodigesters. The environmental benefits, challenges and socio-economic factors are also discussed for the successful implementation of various technologies.
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•The influencing parameters for biogas generation are discussed.•Various pre-treatments are included to improve the biogas yield.•Different types of biodigesters and its experimental methodologies are briefed.•Socio economic benefits and challenges of solar assisted biodigesters are discussed.•Various types of solar-assisted bio digesters are elaborated and its performance are compared with conventional biogas plant.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Low temperature growth of vertically aligned ZnO nanorod arrays over Mg:GaN substrate with highly crystalline ZnO/GaN interface.•The heterojunction show good UV response.•The device is able to ...detect UV light pulses well below milli seconds time scale.•The heterojunction has highly selective UV detection capability.
n-type ZnO nanorods are vertically grown over p-type Mg:GaN substrate by simple hydrothermal process to form a p-GaN/n-ZnO nanorods heterojunction. The heterojunction showed good rectifying behavior. The defect states in the heterojunction are analyzed in detail using photoluminescence studies. The device response is studied for various biasing conditions and UV light pulse illumination frequencies. The present device has the fastest UV response on comparison with devices based on solution grown ZnO nanorods. The device showed reproducible results even after long exposure to room temperature and humidity environment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The present work seeks to address the forced convection heat transfer behaviour of a double-pass solar air heater system (DPSAHS) provided with asymmetric channel flow configuration used for solar ...drying of agro-products. Outdoor experiments were performed on a DPSAHS having a constant channel depth ratio of 1.5. Thermal response of the DPSAHS under different influencing parameters such as flow rate, channel depth, and thermophysical properties of the working fluid was experimentally determined. The influence of ambient parameters such as solar intensity, ambient temperature, wind speed, and relative humidity on the thermodynamic behaviour of the DPSAHS was also investigated. Among which, solar intensity and ambient temperature were found to be the major parameters influencing the energy and exergy efficiency followed by wind speed. Relative humidity was found to have the least percentage contribution towards the thermal characteristics of the system. Overall thermal efficiency and exergy efficiency were found to vary in the range of 20–41% and 5.6–18% at two different mass flow rates of 0.02 kg s
−1
and 0.03 kg s
−1
, respectively. The results also inferred that the influence of thermophysical property variation on the thermodynamic performance depends upon the operating temperature range and on the nature of working fluid. Air temperature in the lower channel was found to be an average 3 °C higher than that of upper channel passage corresponding to two different mass flow rates. Hence, the thermodynamic behaviour of DPSAHS was found to be strongly influenced by the variation in channel depth, ambient parameters, and mass flow rate. The obtained experimental results were also compared with the available literatures.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•A Molten Salt Natural Circulation Loop (MSNCL) has been setup.•Various steady state and transient experiments have been carried out in the loop.•Natural circulation steady state correlation is ...compared with the experimental data.•In-house developed code, LeBENC, has been validated with the steady state and transient experimental data.
Molten salts are increasingly getting attention as a coolant and storage medium in solar thermal power plants and as a liquid fuel, blanket and coolant in High Temperature Reactors (HTR). A Molten Salt Natural Circulation Loop (MSNCL) has been setup for thermal hydraulics, instrument development and material related studies relevant to HTR and solar power plants. The loop mainly consists of heated section, air heat exchanger, valves, various tanks and argon gas control system. All the components and piping of the loop are made of Inconel 625. Steady state natural circulation experiments at different power level have been performed in the loop. Transient studies for startup of natural circulation, loss of heat sink, heater trip and step change in heater power have also been carried out. A one dimensional code LeBENC, developed in-house to simulate the natural circulation characteristics in closed loops, has been validated with the experimental data obtained from MSNCL. This paper deals with the description of the loop and experimental studies carried out in the loop. Detailed validation of the LeBENC code with the experimental data has also been discussed in the paper.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The paper deals with the standing stock of macrobenthic infauna and associated environmental factors influencing the benthic community in the shelf region of the northwest Indian coast. The data were ...collected onboard FORV Sagar Sampada during the winter monsoon (January-February, 2003) to understand the community structure and the factors influencing the benthic distribution. The environmental parameters, sediment characteristics and macrobenthic infauna were collected at 26 stations distributed in the depths between 30 and 200 m extending from Mormugao to Porbander. Total benthic abundance was high in lower depths (50-75 m), and low values noticed at 30 m depth contour was peculiar. Polychaetes were the dominant group and were more abundant in shallow and middle depths with moderate organic matter, clay and relatively high dissolved oxygen. On the other hand crustaceans and molluscs were more abundant in deeper areas having sandy sediment and low temperature. High richness and diversity of whole benthic groups observed in deeper depths counter balanced the opposite trend shown by polychaete species. Generally benthos preferred medium grain sized texture with low organic matter and high organic matter had an adverse effect especially on filter feeders. Deposit feeding polychaetes dominated in shallow depths while carnivore species in the middle depths. Ecologically, benthos were controlled by a combination of factors such as temperature, salinity, dissolved oxygen, sand and organic matter and no single factor could be considered as an ecological master factor.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper attempts to address and generalize the impact of elementary heat transfer aiding to phase transition of phase change material (PCM) enclosed within a thin cylindrical macro-encapsulate. A ...transient, three-dimensional solver with user-defined functions is modeled to study the solidification and melting characteristics of PCM aided by conduction heat transfer and external convection effects within a solar air heater system (SAHS). The conservative equations are discretized using Finite volume method (FVM). The effect of convection between the macro-encapsulate and the working fluid is captured by interface modeling. The present analysis is divided into two segments, namely, phase change assisted by conduction heat transfer alone and combined conduction-convection effects. The obtained results suggest that with conduction assisted heat transfer, only 27% of the PCM portion from the bottom of the macro-encapsulate has undergone complete melting. During the discharging cycle, as the bottom part of PCM gets solidified quickly, the heat contained within the upper regions cannot escape easily through the bottom face of macro-encapsulate. However, in the combined mode, over 70% of the PCM has undergone complete melting within the stipulated time. In addition, during the discharging cycle there was no entrapment of stored heat within the macro-encapsulate in the combined mode.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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