155 research outputs found

    GIS BASED MORPHOMETRIC CHARACTERISTICS OF KADAVANAR RIVER BASIN IN TAMIL NADU, INDIA

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    The Remote Sensing and GIS technique is an effective tool for analyzing the morphological characteristics of a river basin. The geographical location of Kadavanar river basin between latitudes 10° 52' 34.70"N and 10° 10' 57.59"N, and longitudes 77° 37' 48.14"E and 78° 13' 27.69"E, and one of the contributors to Cauvery river. The study focused on the river basin linear, areal, and relief aspects of morphometric characteristics. The study concentrated on the morphometric parameters and evolution of the stream order (U), stream length (Lu), bifurcation ratio (Rb), drainage density (Dd), stream frequency (Fs), drainage texture (Rt), elongation ratio (Re), circularity ratio (Rc), form factor (Rf), basin relief (Bh), relief ratio (Rh) and ruggedness number (Rn). The Kadavanar basin has a six-order of the drainage system, with a total of 841 stream networks, of which are 653 in the first-order, 143 in the second-order, 34 in the third-order, 8 in the fourth-order, 2 in the fifth-order stream, and 1 in the sixth-order stream according to morphometric study. The first order of the stream has a longer overall length, which decreases as the stream order increases. The average bifurcation ratio is 3.80, signifying that there were more structural disruptions due to geological influence. There has observed a low drainage density of the value of 0.91 km/km2. It indicates that the river basin has a dense vegetation cover and is highly permeable. The basin morphometric study revealed that it has a slight risk of soil erosion and flood of the basin, indicating that surface runoff of the upland region of the river basin is significantly infiltration gently downstream of the basin, contributing to the groundwater potentiality of the region. Further study of Remote Sensing and GIS techniques is more effective in developing an appropriate natural resource for the groundwater management system of the region

    Nutritional and rheological properties of pumpkin seed based fruits spread

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    Fruit spread is prepared by combining sugar with processed fruit juice, concentrated fruit juice, or whole fruit. Pumpkin (Curcurbita maxima) seeds are commonly seen as industrial waste and discarded. Pumpkin seed was roasted and made into powder form.  β-carotene rich fruits such as mango, papaya, and muskmelon were used to extract the pulp. To obtain a desired consistency of fruit spread, the fruit pulp (25%) was blended with roasted seed powder (70%) Fruits were scattered at 5° to 10° Brix and sugar was added. To extend the shelf life and improve the quality of the spreads, they were pasteurised at 60°C for 30 minutes. The spreads were packaged in two different types of packaging material food grade glass containers and polypropylene containers. They were kept in refrigerated conditions at 4°C for further analysis. After organoleptic evaluation, the fruits spreads were analysed for nutritional content, textural properties and microbial content. Pumpkin seed based fruit spreads have 15.23 to 15.64% moisture, 6.7 to 7.18 %  protein, 4.53  to 4.89% fat, 5.29 to 5.69% fiber and 15.36  to 28.67% carbohydrates. The pumpkin seed based fruit spreads had 15.41 to 23.04°Brix of total soluble solids. The fruit spreads had 85.82 to 764.54 g hardness, -88.54 to-205.45 g adhesiveness, 0.87 to 0.95 springiness,0.48 to 0.74 cohesiveness, 64.78 to 344.06 gumminess and 61.53 to 311.64 chewiness. The pumpkin seed based fruits spread had viscosities of 2.21 to 3.58 centipoises. The mango based fruit spreads had the highest score values among the fruit spreads. The fruit spread encompassed enormous bioactive compounds when compared to other fruit spreads available on the market

    Performance and Structure of LiNi0.5Mn1.5O4 Prepared from Various Ni Precursors for Lithium Ion Batteries

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    LiNi0.5Mn1.5O4 compounds were prepared through a solid-state reaction using various Ni precursors. The effect of the precursors on the electrochemical performance of LiNi0.5Mn1.5O4 was investigated. LiNi0.5Mn1.5O4 made from Ni(NO3)2•6H2O shows the best charge-discharge performance. The reversible capacity of LiNi0.5Mn1.5O4 is about 145mAh g–1 and remained at 143mAh g–1 after 10 cycles at 3.0 to 5.0 V. The XRD results showed that the precursors and dispersion method had significant effects on their structures. Pure spinel phase can be obtained with a high energy ball-milling method and Ni(NO3)2•6H2O as precursor. A trace amount of the NiO phase was detected in LiNi0.5Mn1.5O4 with the manual grinding method when Ni(CH3COO)2•6H2O, NiO and Ni2O3 were used as precursors.Keywords: LiNi0.5Mn1.5O

    Synthesis and optimisation of IrO2 electrocatalysts by Adams fusion method for solid polymer electrolyte electrolysers

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    IrO2 as an anodic electrocatalyst for the oxygen evolution reaction (OER) in solid polymer electrolyte (SPE) electrolysers was synthesised by adapting the Adams fusion method. Optimisation of the IrO2 electrocatalyst was achieved by varying the synthesis duration (0.5 – 4 hours) and temperature (250 - 500°C). The physical properties of the electrocatalysts were characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction (XRD). Electrochemical characterisation of the electrocatalysts toward the OER was evaluated by chronoamperometry (CA). CA analysis revealed the best electrocatalytic activity towards the OER for IrO2 synthesised for 2 hours at 350oC which displayed a better electrocatalytic activity than the commercial IrO2 electrocatalyst used in this study. XRD and TEM analyses revealed an increase in crystallinity and average particle size with increasing synthesis duration and temperature which accounted for the decreasing electrocatalytic activity. At 250°C the formation of an active IrO2 electrocatalyst was not favoured

    Effect of okra plant resistance on transmission rate of okra enation leaf curl virus by its vector whitefly, Bemisia tabaci

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    The present study aimed to investigate the effect of age of the okra plants that showed varying whitefly resistance responses on the transmission rate of okra enation leaf curl virus (OELCV) by its vector whitefly Bemisia tabaci. The OELCV infected whitefly adults were collected from whitefly colonies and were challenged on the test okra accessions (Upl mona 2, Co 1, Arka anamika and AE 64) of differential ages which were individually caged (7, 10 and 15 d after germination) with glass chimney and the number of such whiteflies used were at the rate of 2, 4, 6, 8, 10, 12, 14 and 20 adults per plant. Observations were made on the virus symptom expression 30 d after challenge. The efficiency of transmission was determined. The efficiency of transmission of OELCV was the highest (maximum T and P*, 0.80, 1.00 and 0.08, 0.10) when 7 d old seedlings were inoculated (Arka anamika and AE 64 respectively) and transmission had decreased as the age of seedlings increased. The estimated transmission rate for single whitefly (P*) increased with an increase in the number of whiteflies used per plant. Okra plant resistance to B. tabaci significantly changed the transmission rates of OELCV on okra. Understanding the resistance mechanisms of the okra accessions and interactions between plant viruses and their insect host can pave the way for novel approaches to protect plants from virus infection

    Thermal conductivity and temperature profiles of the micro porous layers used for the polymer electrolyte membrane fuel cell

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    The thermal conductivity and the thickness change with pressure of several different micro porous layers (MPL) used for the polymer electrolyte membrane fuel cell (PEMFC) were measured. The MPL were made with different compositions of carbon and polytetrafluoroethylene (PTFE). A one-dimensional thermal PEMFC model was used to estimate the impact that the MPL has on the temperature profiles though the PEMFC. The thermal conductivity was found to vary from as low as 0.05 up to as high as 0.12 W K 1 m 1 while the compaction pressure was varied from 4 bar and up to around 16 bar resulting in a decrease in thickness of approximately 40%. The PTFE content, which varied between 10 and 25%, did not result in any significant change in the compression or thermal conductivity. Both the thickness and the thermal conductivity changed irreversibly with compaction pressure. Considering a MPL thermal conductivity of 0.1 W K 1 m 1, a MPL thickness of 45 mm, a current density of 10 kAm 2 (1.0 A cm 2), liquid water (production and sorption), and a 30 mm membrane it was found that the MPL is responsible for a temperature increase of up to 2 C. This contribution can be lowered by integrating the MPL into the porous transport layer.Web of Scienc

    Development of Unsupported Ru and Ni Based Oxides with Enhanced Performance for the Oxygen Evolution Reaction in Acidic Media

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    The high cost of catalyst materials suitable for the oxygen evolution reaction (OER) in polymer electrolyte membrane water electrolyzers (PEMWE) is still a major hurdle that needs overcoming before commercial PEMWE can have a meaningful impact as a technology in the hydrogen economy. Metal oxides based on precious metals are currently still the most reliable and most used materials as catalysts in PEMWE; however, alternative or modified materials are desirable to help reduce the cost associated with the catalyst component. In this study, we report on binary metal oxide catalysts based on Ru and Ni. Ni-based electrodes are typically used in alkaline water electrolyzers due to their high performance, robustness and low cost; however, Ni and NiO electrodes do not show promising performance in acidic environments due to corrosion. By combining NiO with acid stable RuO2, we have demonstrated that the performance of the RuO2 catalyst can be improved and due to the lower cost of Ni, the cost of the catalyst can ultimately be reduced. The Ni addition was limited to 10 mol% to achieve improved OER performance followed by noticeable performance degradation as the Ni composition was increased. The metal oxide catalysts were synthesized via a modified Adams fusion method that produced nano-sized catalysts with superior performance compared to a state-of-art commercial RuO2 catalyst. Physical characterizations were performed via high-resolution transmission electron microscopy, X-ray diffraction, energy dispersive X-ray, and Brunauer Emmett Teller analyses. OER performances were evaluated via cyclic voltammetry, linear sweep voltammetry, chronopotentiometry, and chronoamperometry analyses

    The holistic phase model of early adult crisis

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    The objective of the current study was to explore the structural, temporal and experiential manifestations of crisis episodes in early adulthood, using a holistic-systemic theoretical framework. Based on an analysis of 50 interviews with individuals about a crisis episode between the ages of 25 and 35, a holistic model was developed. The model comprises four phases: (1) Locked-in, (2) Separation/Time-out, (3) Exploration and (4) Rebuilding, which in turn have characteristic features at four levels—person-in-environment, identity, motivation and affect-cognition. A crisis starts out with a commitment at work or home that has been made but is no longer desired, and this is followed by an emotionally volatile period of change as that commitment is terminated. The positive trajectory of crisis involves movement through an exploratory period towards active rebuilding of a new commitment, but ‘fast-forward’ and ‘relapse’ loops can interrupt Phases 3 and 4 and make a positive resolution of the episode less likely. The model shows conceptual links with life stage theories of emerging adulthood and early adulthood, and it extends current understandings of the transitional developmental challenges that young adults encounter

    On the Formation of Collective Memories: The Role of a Dominant Narrator.

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    To test our hypothesis that conversations can contribute to the formation of collective memory, we asked participants to study stories and to recall them individually (pregroup recollection), then as a group (group recounting), and then once again individually (postgroup recollection). One way that postgroup collective memories can be formed under these circumstances is if unshared pregroup recollections in the group recounting influences others\u27 postgroup recollections. In the present research, we explored (using tests of recall and recognition) whether the presence of a dominant narrator can facilitate the emergence of unshared pregroup recollections in a group recounting and whether this emergence is associated with changes in postgroup recollections. We argue that the formation of a collective memory through conversation is not inevitable but is limited by cognitive factors, such as conditions for social contagion, and by situational factors, such as the presence of a narrator
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