Mechanical and thermo-mechanical analysis based numerical simulation of granite powder filled polymer composites for wind turbine blade     

M. J. Pawar  Amar Patnaik  Ravindra Nagar 《Fibers and Polymers》2016,17(7):1078-1089

In present article fabrication and characterization of unfilled and granite powder filled carbon epoxy composites are reported. Addition of carbon fiber shows positive effect on mechanical performance of the composites. However, incorporation of granite powder has negative hybridizing effect on the properties such as tensile strength, flexural strength and inter-laminar shear strength. The storage modulus evaluated at 30 °C is in close agreement with flexural modulus of composites. Further, successful attempt is made for numerical simulation of actual geometry of wind turbine blade. The results obtained from numerical analysis are comparable with experimental results.  相似文献   

Measuring near‐saturated hydraulic conductivity of soils by quasi unit‐gradient percolation—1. Theory and numerical analysis     

Subharthi Sarkar  Kai Germer  Rajib Maity  Wolfgang Durner 《植物养料与土壤学杂志》2019,182(4):524-534

The saturated and near‐saturated hydraulic conductivity of soils, k_u, is a sensitive indicator of soil structure and a key parameter for solute transport and soil aeration. In this contribution, we present and numerically investigate a double‐disk method to determine k_u in the laboratory by steady‐state percolation at different suction steps. Tension infiltration of water takes place at the top of a soil column through a porous disk with a smaller diameter than the soil sample. This leaves part of the soil surface open and ensures a proper soil ventilation. Drainage takes place at the base through a porous disk with the full diameter of the soil column at exactly the same tension as applied to the top boundary. Since the infiltration area is less than the percolation area, the water flow diverges and the equality of steady flow rate and hydraulic conductivity, which characterizes the standard unit‐gradient experiment, is no longer valid. To develop a general relationship between observed steady flow rate and unsaturated hydraulic conductivity, the experiment was simulated with the Richards‐equation solver HYDRUS 2D/3D, for twelve different soil classes. We found for tensions in the range 1 cm < 10 cm, an infiltration disk diameter of 4.5 cm diameter and a sample diameter of 8 cm diameter that the flux rate at any given tension was about 0.7 times the respective hydraulic conductivity, with an error of less than 10%.  相似文献   

Effect of inorganic nitrogen nutrition on cytokinin-induced potato microtuber production in vitro   总被引：1，自引：1，他引：0  

Debabrata Sarkar  Prakash S. Naik 《Potato Research》1998,41(3):211-217

Summary The effect of inorganic nitrogen nutrition on the induction and development of microtubers by cytokinin-induced tuberization was studied in four potato genotypes belonging to different maturity groups. The objective of this study was to investigate whether a reduction in total nitrogen level in the Murashige & Skoog medium would improve cytokinin-induced tuberization rate. The effect of three levels of total nitrogen (15, 30 and 45 meq) on tuberization was studied at constant (20 meq K) and varying potassium levels approximating to 5, 10 and 15 meq. Reducing the total nitrogen supply increased the number but decreased the size of nitrogen level on the rate of assimilate partitioning (harvest index) during cytokinin-induced microtuberization.  相似文献   

A mechanized harvest system for freshwater fishpond     

K.K. Sharma  Bikash Sarkar  S. Chand  S.K. Nayak 《Aquacultural Engineering》2009,41(3):147-151

Development of a prototype-mechanized fish harvesting system for carp from a rectangular shaped fishpond is described in this paper. The system consists of motorized trolleys on the longer dykes of fishpond, rail, boom pipe, netting arrangement and ON/OFF arrangements. The trolleys move on the rail tracks with constant speed of 3 m/min and takes about 15 min to complete the harvesting operation. The overall mean harvest efficiency of Indian major carps (IMC) with mechanized fish harvesting system has been estimated to be around 80% per operation. The whole harvesting operation is done mechanically except collection of harvested fishes at the end of operation, which presently requires two persons getting into the pond and lifting out the fishes from the net.  相似文献   

Autoregressive technique in length growth modelling of two Indian major carp, Catla catla (Hamilton) and Labeo rohita (Hamilton), reared under two holding conditions     

T K Basu  B Bhattacharyya  S K Sarkar  S Ganguly  C Medda 《Aquaculture Research》1998,29(9):625-634

An autoregressive analysis was performed on data from an investigation of the velocity and acceleration of the day-to-day length increments of two Indian major carp, Catla catla (Hamilton) and Labeo rohita (Hamilton), hatched in artificial (Chinese-style hatchery) and semi-natural (improvised pits) holding conditions. The autoregressive model, which was capable of providing short- and long-term predictions, was tested in parallel with a time regressive model and an instantaneous growth rate model. The estimate simulating short-term predictions was found to describe the data more efficiently than the other estimates of the models. Product-moment correlations comparing the two holding systems revealed no source-specific variation of growth between the species. However, the significant length velocity correlation suggests that the artificial system has greater efficacy.  相似文献   

Comparison of water use efficiency,profitability and consumer preferences of different rice varieties in Punjab,Pakistan     

Naseer  Muhammad Asad ur Rehman  Ashfaq  Muhammad  Razzaq  Amar  Ali  Qamar 《Paddy and Water Environment》2020,18(1):273-282

Paddy and Water Environment - Due to rapid population growth, water scarcity and food insecurity have become the major problems for Pakistan. Therefore, the efficient utilization of limited...  相似文献   

Karyotype analysis and chromosomal evolution in Asian species of Corchorus (Malvaceae s. l.)     

Prosanta Saha  Debabrata Sarkar  Avijit Kundu  Subhabrata Majumder  Swapan K. Datta  Karabi Datta 《Genetic Resources and Crop Evolution》2014,61(6):1173-1188

Here, we report the karyotypes and mean haploid idiograms of the ten Asian Corchorus species (2n = 2x = 14). Chromosomes were small, with a mean chromosome length of 2.30 μm. The largest chromosome was recorded in C. pseudo-olitorius (3.50 μm) and the shortest in C. pseudocapsularis (1.60 μm). The karyotypes of the two cultivated species (C. capsularis and C. olitorius) and C. pseudo-olitorius were the most diverse and specialized, whereas those of C. depressus and C. trilocularis were the least diverse. C. fascicularis had the most asymmetrical and C. urticifolius the most symmetrical karyotypes. An increase in genome size was accompanied by increasing karyotype diversity in terms of morphologically distinct chromosome types and interchromosomal asymmetry, with uneven distribution of additional DNA throughout the karyotype. A positive correlation between interchromosomal asymmetry and dispersion index suggested that size differences between chromosomes were mainly associated with karyotype asymmetry. Karyotypes of the Corchorus species became progressively asymmetrical in the course of evolution. Relationships among the ten Corchorus species were defined by using a neighbor-joining tree inferred from inter-simple sequence repeat data. C. fascicularis and C. pseudocapsularis, with shorter karyotypes and smaller genomes, were closely related to C. pseudo-olitorius and C. capsularis, respectively, which were characterized by relatively longer karyotypes and larger genomes. However, the two cultivated species with different levels of interchromosomal asymmetries, dispersion indices and genome sizes were distantly related. Taking this molecular evidence into consideration, we have discussed chromosomal evolution in relation to karyological data including genome size.  相似文献   

Wheat Straw Burial Improves Physiological Traits,Yield and Grain Quality of Rice by Regulating Antioxidant System and Nitrogen Assimilation Enzymes under Alternate Wetting and Drying Irrigation     

Yousef Alhaj Hamoud  Hiba Shaghaleh  Wang Ruke  Willy Franz Gouertoumbo  Amar Ali Adam hamad  Mohamed Salah Sheteiwy  Wang Zhenchang  Guo Xiangping 《水稻科学》2022,29(5):473-488

Wheat straw burial has great potential to sustain rice production under alternate wetting and drying (AWD) irrigation. A field experiment was conducted with three wheat straw burial treatments, including without straw burial (NSB), with light straw burial of 300 kg/hm² (LSB) and dense straw burial of 800 kg/hm² (DSB), as well as three AWD regimes: alternate wetting/moderate drying (AWMD), alternate wetting/severe drying (AWSD) and alternate wetting/critical drying (AWCD). The rice growth and grain quality were higher in LSB and NSB than those in NSB under the same AWD regime. The AWMD × DSB treatment resulted in the highest yield, brown rice rate, milled rice rate, amylose content and protein content. Conversely, the AWCD × NSB treatment led to the lowest yield, brown rice rate, milled rice rate, amylose content and protein content. The active absorption area and nitrate reductase activity of roots were higher in the AWMD × DSB treatment than those in the AWCD × NSB treatment, as the former increased organic carbon and nitrogen contents in the rhizosphere, whereas the latter reduced their availability. Total soluble protein content and glutamine synthetase activity were greater in the AWMD × DSB treatment than those in the AWCD × NSB treatment. The activities of superoxide dismutase and catalase were higher in the AWMD × DSB treatment compared with the AWCD × NSB treatment, leading to the amelioration of oxidative cell injury, as shown by a lower malonaldehyde level. This study suggested that farmers should implement AWMD irrigation after leaving the straw residues in the field, followed by deep tillage to improve soil quality and mitigate the drought stress cycles of AWD. This approach can improve rice growth and grain quality and alleviate the problems of disposal of straw residues and water scarcity for sustainable rice production.  相似文献   

Cytotoxicity of Senecio in macrophages is mediated via its induction of oxidative stress     

Samiran Bandyopadhyay  Goutam Mandal  Piu Saha  Mihir Sarkar 《Research in veterinary science》2009,87(1):85-90

In Arunachal Pradesh and other sub-Himalayan areas of India, accidental consumption of Senecio plants by yaks is often fatal as the plant contains toxic alkaloids like Seneciophylline. The present investigation was undertaken to demonstrate the pro-oxidant effects of an ethanolic extract of Seneciochrysanthemoides (S-EtOH). S-EtOH impaired viability in macrophages, the IC₅₀ being 13.8 ± 1.11 μg/mL. The effect of S-EtOH (1 μg/mL) on generation of reactive oxygen species (ROS) in macrophages was measured by flow cytometry using 2′,7′-dichlorofluorescein diacetate (H₂DCFDA) where it caused a significant increase in the mean fluorescence channel (MFC) from 8.55 ± 0.03 to 47.32 ± 2.25 (p < 0.001). S-EtOH also effected a 3.8-fold increase in extracellular nitric oxide (NO) generation from 4.90 ± 0.72 μM to 18.79 ± 0.32 μM (p < 0.001), a 2.2-fold increase in intracellular NO production, the MFC increasing from 14.95 ± 0.48 to 33.34 ± 1.66 (p < 0.001), and concomitantly depleted non protein thiols as analyzed by flow cytometry using mercury orange, with a reduction in MFC from 632.5 ± 49.44 to 407.4 ± 12.61 (p < 0.01). Additionally, S-EtOH (14 μg/mL, 24 h) caused apoptosis as evident by increased Annexin V binding and terminal deoxynucleotidyl transferase mediated dUTP DNA nick end labeling. Taken together, the cytotoxicity of S-EtOH can be partly attributed to its capacity to inflict oxidative damage via generation of both reactive oxygen and nitrogen species culminating in apoptosis.  相似文献   

Initial screening studies on potential of high phenolic-linked plant clonal systems for nitrate removal in cold latitudes   总被引：1，自引：0，他引：1  

Derong Lin  Lijiang Hu  Hong You  Dipayan Sarkar  Baoshan Xing  Kalidas Shetty 《Journal of Soils and Sediments》2010,10(5):923-932

Purpose  

Nitrate removal is a major challenge in drinking water systems and is more acute in colder latitudes due to low metabolic conversion rates of biological systems. To achieve rapid nitrate removal, designed plant systems in greenhouse microenvironments has potential. In such localized controlled microenvironments, higher temperatures can be managed for plant growth in an appropriate growth medium through which nitrate-contaminated water is fed for denitrification.  相似文献