119 research outputs found
Response of nectarines to organic fertilization under the rain-fed ecosystem of Northwest Himalayas
No full textFeedforward Learning Control for Individual Blade Pitch Control of Modern Two-Bladed Wind Turbines
No full textWind is arguably the most promising source of sustainable energy. However, it is still considered to be an expensive option compared to fossil fuels. Recent developments have achieved significant cost reductions and increased the reliability on wind energy. The main reason for this has been the application of innovative and effective control strategies. All turbine designs over time have been involved in reducing the overall cost of energy by either maximizing energy yield or minimizing the effect of loads to increase the life of the wind turbine. Minimizing the effect of loads is the main focus in this thesis. Control strategies currently used in the industry involve changing the pitch angle for each individual blade to reduce the loads and are called Individual Blade Pitch Control (IPC). However, this strategy causes considerable wear and tear to the large pitch bearings in the wind turbines due to high frequency pitch control action. Thus, control strategies which not only reduce loads, but also provide smoother pitch control action are investigated in this report. It is observed that periodic loads faced by the blades of the wind turbine can be represented by a limited number of parameters such as rotor speed, they are slowly changing and more importantly, account for much of the fatigue causing loads. Thus, this thesis report focuses on applying suitable control strategies to primarily reduce periodic loads. Moreover, since the loads are periodic and slowly varying, the use of basis functions as the input space of a feedforward controller can result in smoother pitch activity. The aforementioned strategy has previously been applied on the ``\emph{Smart Rotor}'' concept which is a mechanism where each blade is equipped with trailing edge flaps similar to an airplane wing to change the lift profile of the blade to reduce loads. This strategy has been successfully applied to the \acs{IPC} mechanism and has resulted in lower pitch activity. The control methodology applied to IPC discussed above is a feedforward controller which consists of parametrized basis functions. The algorithm discussed involves a learning technique where the control parameters are calculated through successive correction in each trial period by ensuring that the wind turbine does not repeat its ``mistakes''. Consequently, the feedforward control is adaptive as it can adjust the controller parameters to compensate for changes in plant dynamics during operation. However, since the controller is based on a model linearized for a particular set of operating conditions such as wind speed, the performance of the controller deteriorates during turbulent wind conditions. Additionally, since it takes a few revolutions for the control parameters to converge and that if the rotor speed changes during this time, the parameters calculated are no longer optimal.Delft Center for Systems and ControlMechanical, Maritime and Materials Engineerin
A role for SUMO modification in transcriptional repression and activation
No full textSince the discovery of the SUMO (small ubiquitin-related modifier) family of proteins just over a decade ago, a plethora of substrates have been uncovered including many regulators of transcription. Conjugation of SUMO to target proteins has generally been considered as a repressive modification. However, there are now a growing number of examples where SUMOylation has been shown to activate transcription. Here, we discuss whether there is something intrinsically repressive about SUMOylation, or if the outcome of this modification in the context of transcription will prove to be largely substrate-dependent. We highlight some of the technical challenges that will be faced by attempting to answer this question
Soil Solarization: An Eco-Friendly Alternative to Chemical Pesticides for the Management of Diseases in Plants
No full text57-62The annual crop loss due
to pests and diseases in our country is around 18 per cent of total crop
produce, which amounts to loss of more than Rs 30,000 crores annually. This
necessitated the use of pesticides for managing the pests in different crops
and pesticide consumption in India
increase from 434 MT in 1954 to approximately 90,000 MT till now. No doubt, we
were able to check the immediate threat of the pests for a short term but
resistance to pesticides is now known in over 504 insect and mite pests in
comparison to only 7 insect-pest in 1954. Similarly, several species of fungi
are also resistant to different fungicides. Above all, due to indiscriminate
use of pesticides in our country, our drinking water in rivers and wells is
laced with pesticides. Majority of mineral water sort drink brands available in
the market found to contain residues of banned pesticides, which were above
safer limits. According to a report of Indian Council of Medical Research released in 1993, 2,205 samples of
milk were collected from 12 states in India contained residues of DDT
complex and Lindane insecticides, which have been banned and
not sage to human
health. Analysis of 13 brands of wheat flour packing in the country's major
wheat consuming zones were found to have Lindane. Another report of Indian
Council of Medical Research in 1996 disclosed that 51 per cent of food
commodities were found contaminated with pesticides out of which 20 per cent
had excess limits than minimum residue levels fixed. The concern of
agricultural produce contaminated with pesticides was again
echoed in the report of
All India Co-ordinate Research Project released in 1999 which showed that 60 per
cent food commodities were found contaminated with pesticides, out of which 14
per cent were above minimum residue level. The repot further states that] 00
per cent vegetables and fruits samples and collected from 16 states were found
to be contaminated with pesticides. Further, 183 pesticides have been
registered in our country and safer limits (minimum
residue levels) for only
70 pesticides have been fixed
Nitrogen fertigation for nectarines (Prunus persica var nucipersica): Lateral and vertical nutrient acquisition and cropping behavior in rainfed agroecosystem
No full textThe present investigation was planned and focused with the objective to compare the effect of nitrogen (N) fertigation and conventional soil fertilization on growth and nutrient dynamics for the establishment of Snow Queen nectarines (Prunus persica var. nucipersica). We determined if the frequency of application of fertigation that could modify cropping behavior of the plantations in integrated horticultural based cropping system under rainfed ecosystem. In the experiment, all plants received the same amount of water with sufficient fertilizer N but the treatment included four fertigation frequencies applied weekly intervals of the recommended dose (RD) of N fertilizers over conventional soil fertilization scheduled at 25% (25% RD-N fertigation), 50% (50% RD-N fertigation), 75% (75% RD-N fertigation) and 100% (100% RD-N fertigation) in the Randomized Block Design replicated thrice. The availability of nutrients at root zone of the trees significantly influenced vegetative growth attributes, the uptake of macro- and micronutrient cations and fruit quality characteristics. Given the fact that all treatments applied with adequate and equal amount of fertilizer and water, however, 75% RD-N fertigation frequency had significantly affected cropping behavior and uptake efficiency both vertically as well as horizontally. The N availability steadily increased with increased depth up to 30 cm after that declined in all the distances at fertigation with 75% RD-N. Highest available P and K in soil was confined to 0-15 cm of soil layer under all fertigation levels and decreased with increase in distance from the emitters and soil depth. With regards to exchangeable Ca and Mg, the contents were decreased in the surface soil than in the subsoil. This superior application also recorded improved vertical and horizontal distribution of available macro- and micronutrient cations in soil, leaf nutrient concentration and fruit quality attributes for growth parameters and fruit quality characteristics which in turn saved 25% of the inorganic fertilizers application
Asia: Israel: The story of the Jews from 2000 B.C. to 1770 A.D. and an epilogue on the years 1771-73 <i>By</i> George H. Singh. The author, Udaipur; Sole distributors Ispcklph Publishers, Delhi, vi, 267p. Rs.20.00.
No full textA time delay model using a convolution integral to describe salmon migration, 2004
No full textThis study examines the use of mathematical models in understanding the migration of juvenile fall Chinook salmon of the Snake River in the Pacific Northwest. This salmon population is currently listed as threatened under the U.S. Endangered Species Act, and special management actions are required to ensure its recovery. Based on the premise that these fish showed a substantial delay in their seaward migration after being released into the river, this study develops two mathematical models and analyzes them with regard to how well each characterizes the effects of this delay on the migration rate of the fish. The specific objectives of this study are to estimate parameters and construct confidence intervals for the data, determine whether the models' results are consistent with the data through goodness-of-fit tests, and to demonstrate the important link between mathematical theory and logic and the life sciences. Data from Passive Integrated Transponders (PIT)-tagged fish released at Billy Creek, Washington state in 1995, 1997, 1998, and 2000 were fed into a simple migration model, a migration model with a delay term, and a more complex migration model combining a delay term and a fish-length term via a convolution integral. The selected model for each release always had a delay term incorporated into the migration model. Results of the study lend credence to the theory that juvenile Snake River fall Chinook salmon delay before migration and indicate that the models with a delay parameter consistently improve the fit of the model to the data. Results also demonstrate the practical benefits of applying mathematical models to analyze life science data
Sex trafficking of girls and women : Evidence from Anantapur district, Andhra Pradesh
No full textA crucial gap in the trafficking literature from India is the dearth of primary data and micro studies that could be used for vulnerability mapping of the source areas and addressing the identified risk factors. The present paper is a small attempt to contribute to plugging the gap in the context of Andhra Pradesh, identified as a hot spot in the trafficking literature. This paper is based on case studies of 78 women who had been trafficked from their places of origin in Anantapur district in Andhra Pradesh to metropolitan cities across India and who have since returned to their homes. The paper attempted to identify the individual and family circumstances that contribute to the causes of trafficking, to highlight in particular the gendered vulnerabilities that set these women up for trafficking, and to capture the process of the trafficking experience. The findings of the study are located in the dynamic interplay of the social structural context and specificities of the district that contribute to causes of trafficking and the individual circumstances and agency of the women. The case studies reported in this paper are a pointer to the compelling urgency of interventions that will go beyond the forced / voluntary divide in trafficking and sex work.Andhra Pradesh, India, trafficking
Genetic diversity and hybridization potential of wild and commercial pomegranate populations for bacterial blight resistance
No full textPomegranate (Punica granatum L.), valued for its nutritional and antioxidant properties, faces severe yield losses due to bacterial blight caused by Xanthomonas citri pv. punicae. Given the ecological resilience and genetic potential of wild populations, identifying resistant genotypes from indigenous germplasm is vital for sustainable breeding. This study assessed genetic diversity and structure among 23 pomegranate genotypes wild Daru accessions and commercial cultivars previously screened for blight resistance. Twenty simple sequence repeats markers yielded 1119 bands, with 1036 (92.58%) being polymorphic. Primers ESP05, ESP06, ESP13, and ESP14 exhibited 100% polymorphism. Polymorphism information content (PIC) values ranged from 0.08 to 0.460 (mean = 0.321), confirming moderate informativeness. Diversity indices revealed mean alleles per locus (Na = 2.14), effective alleles (Ne = 1.906), and Shannon’s index (I = 0.627). Commercial cultivars displayed greater diversity (Na = 3.00; He = 0.52) and private alleles (0.60) than wild populations, particularly Wild KL (from Kullu) (Na = 1.45; He = 0.25). Analysis of molecular variance revealed that 91% of the genetic variation observed is within populations. Pairwise population differentiation ranged from 0.091 to 0.289, indicating moderate to high differentiation, with gene flow values between 0.615 and 2.494. Principal coordinate analysis, Neighbor joining clustering, and STRUCTURE analysis (ΔK = 2) revealed two major clusters: commercial and wild types, with signs of admixture. Unique resistance-associated bands were identified in wild genotypes SH-14, SH-16, SR-15, and SL-23, linked to traits like acidity, tannins, and anthocyanins. Wild genotypes SR-11, SH-16, SL-22, and SL-23, selected as male parents, were hybridized with cultivars Bhagwa, Kandhari Kabuli, and Phule Super Bhagwa. The Bhagwa × SH-16 cross showed highest fruit set (88.90%), and Bhagwa × SL-23 had highest retention (66.67%). These F1 progenies offer a promising genetic base for developing bacterial blight-resistant pomegranate cultivars with improved horticultural traits
Effect of conjoint use of bio-organics and chemical fertilizers on yield, soil properties under French bean–cauliflower-based cropping system
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