300 research outputs found

    Double Soft Graviton Theorems and BMS Symmetries

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    It is now well understood that Ward identities associated to the (extended) BMS algebra are equivalent to single soft graviton theorems. In this work, we show that if we consider nested Ward identities constructed out of two BMS charges, a class of double soft factorization theorems can be recovered. By making connections with earlier works in the literature, we argue that at the sub-leading order, these double soft graviton theorems are the so-called consecutive double soft graviton theorems. We also show how these nested Ward identities can be understood as Ward identities associated to BMS symmetries in scattering states defined around (non-Fock) vacua parametrized by supertranslations or superrotations.Comment: 29 pages, minor changes added, footnote 3 removed, consistency check with Ref:22 settle

    Designing a Cavity Backed Microstrip Antenna with Enhanced Isolation for the Development of a Continuous Wave Ground Penetrating Radar

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    This paper presents an improved design of a rectangular microstrip antenna at 920 MHz by backing it with an appropriate cavity wall to enhance the isolation between the transmitter and receiver antenna for use in applications, where the weak received power gets masked by the direct coupled power between two antennas. Antennas having 0.12 λ cavity wall with separation gap of 0.36 λ resulted in an isolation of 52.6 dB at a resonance frequency of 920 MHz with maximum and minimum isolation of 71.4 dB and 49.1 dB, respectively for 5% BW of the antenna designed. These antennas were fabricated and tested, which are used in the development of Continuous Wave Ground Penetrating Radar with an online graphical user interface; leading to the validation of the usefulness of proposed antennas. The isolation achieved at an optimised separation of the antennas enabled detection of metal targets as small as a bunch of wire buried 20 cm in the soil and non-metal, like wood and plastic buried in soil. It enabled the detection of a circular steel target of radius 12.5 cm buried at a depth of 65 cm in loose semi-dry pebbled soil

    Through Wall Imaging Radar Antenna with a Focus on Opening New Research Avenues

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    This review paper is an effort to develop insight into the development in antennas for through wall imaging radar application. Review on literature on antennas for use in through wall imaging radar, fulfilling one or more requirements/specifications such as ultrawide bandwidth, stable and high gain, stable unidirectional radiation pattern, wide scanning angle, compactness ensuring portability and facilitating real-time efficient and simple imaging is presented. The review covers variants of Vivaldi, Bow tie, Horn, Spiral, Patch and Magneto-electric dipole antennas demonstrated as suitable antennas for the through wall imaging radar application. With an aim to open new research avenues for making better through wall imaging radar antenna, review on relevant compressive reflector antennas, surface integrated waveguide antennas, plasma antennas, metamaterial antennas and single frequency dynamically configurable meta-surface antennas are incorporated. The review paper brings out possibilities of designing an optimum through wall imaging radar antenna and prospects of future research on the antenna to improve radiation pattern and facilitate overall simple and efficient imaging by the through wall imaging radar

    System of wheat intensification (SWI) – A new approach for increasing wheat yield in small holder farming system

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    Given the confluence of water scarcity, declining area under wheat and continuing increase in population, raising wheat productivity has become a serious concern to the wheat scientists. Yield contribution from irrigation is more significant in wheat. Increase in the irrigation management levels for wheat is probably more relevant and easier to improve water productivity. But transplanted wheat seems high water requiring and economically less feasible. Seedlings have usually poor survival rate, and are often more fragile than rice seedlings at the two leaves stage. Besides plants do not grow quickly and vigorously, and show a delay in development compared to the direct seeding treatment. All yield parameters are often lower compared to the direct seeding treatment due to transplanting of aged seedlings, greater shock of transplantation, high plant density, improper amount and timing of water deliveries. Therefore, applying SRI (system of rice intensification) practices is expected to have a positive impact on the wheat plants, similar to the impact on rice. SWI is a new concept and goes with the SRI principle. It can reduce weeding time to one-third and to one-half of the time needed for current weeding practice. Herbicide use is effective with SWI, but farmers are inventing or modifying tools that reduce the labour time required for weeding. Thus, SWI is a methodology aimed at increasing the yield of wheat, where all agronomic principles are put into practices to provide high wheat yield per drop of water and per kg of agricultural inputs like fertilizer, seed etc

    Zinc Fertilization in Potato: A Physiological and Bio-chemical Study

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    Aims: More than 54% of soils in West Bengal are Zinc (Zn) deficient and therefore, Zn−fertilization is assumed to play a key role not only for increasing potato yield but also for combating wide spread deficiency of micronutrients (mainly Zn) in many potato growing areas of the state. Place and Duration of Study: A two-year field experiment was conducted during winter 2013-14 and 2014-15 at to assess the advantages of Zn nutrition in potato cv. Kufri Jyoti under alluvial soil (Entisols) of West Bengal, India Methodology: The experiment was laid out in randomized block design (RBD) having five treatments and four replications The potato was fertilized with five zinc levels (0, 1.5, 3.0, 4.5 and 6.0 kg Zn ha−1) through zinc sulphate heptahydrate i.e. ZnSO4, 7H2O (commercial grade Multi-Zn contained 21% Zn) at the time of planting. A uniform dose of NPK at 200:150:150 kg ha−1 RDF was applied in all the plots in the form of urea (46% N), single super phosphate (16% P2O5), and muriate of potash (60% K2O). Results: Application Zn fertilizer at 4.5 kg ha−1 recorded significantly higher germination %, plant height, leaf area index (LAI), dry matter accumulation (DMA) and number of tubers hill−1. Total number and yield of tuber ha−1 were also changed significantly (P≤ .05) with the levels of Zn-fertilization. Quality parameters like total soluble solids (TSS), total acidity, ascorbic acid, starch and amount of total sugar contents of fresh potato tuber as well as organoleptic quality of chips (colour) also influenced significantly (P≤ .05) with varied levels of Zn fertilization. Conclusion: Results suggest that application of 4.5 kg Zn ha−1 in combination with recommended dose fertilizer (RDF) of NPK (i.e. 200:150:150 kg ha−1) is vital for optimizing yield components, yield and quality of potato (cv. Kufri Jyoti) in trans-Gangetic plains of West Bengal, India

    Boundaries in Free Higher Derivative Conformal Field Theories

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    We consider free higher derivative theories of scalars and Dirac fermions in the presence of a boundary in general dimension. We establish a method for finding consistent conformal boundary conditions in these theories by removing certain boundary primaries from the spectrum. A rich set of renormalization group flows between various conformal boundary conditions is revealed, triggered by deformations quadratic in the boundary primaries. We compute the free energy of these theories on a hemisphere, and show that the boundary aa-theorem is generally violated along boundary flows as a consequence of bulk non-unitarity. We further characterize the boundary theory by computing the two-point function of the displacement operator.Comment: 49 pages, 2 figures. v2: References and minor comments added. v3: Comments adde

    Effect of integrated nutrient management on the nutrient accumulation and status of post-harvest soil of brinjal (Solanum melongena L.) under Nadia conditions (West Bengal), India

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    A field experiment was carried out at the Central Research Farm, Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India to study the effects of integrated nutrient management on the nutrient accumulation (dry weight recoveries) in brinjal and plant nutrient status of the post- harvest soil of brinjal under Nadia conditions. The results revealed that the treatment consisting of 75% RDF (RDF i.e. N:P:K:: 125:100:50) + Azospirillum + phosphate solubilising bacteria (PSB) + Borax @ 10 kg ha-1 recorded the highest oxidizable organic carbon (8.049 g kg-1), total nitrogen (1.05 g kg-1) , available nitrogen (212.67g kg-1), available phosphorus (76.20g kg-1) and available potassium (177.59 g kg-1) in the post harvest soils of brinjal. On the other hand, 75% RDF + Azospirillum + PSB + FeSO4 @ 50 kg ha-1 recorded the highest available iron (26.14 kg ha-1) and the treatment consisting of 75% RDF + Azospirillum + PSB + ZnSOâ‚„ @ 25 kg ha-1 recorded the highest soil available zinc (7.62 kg ha-1) while 75% RDF + Azo + PSB + Borax @ 10 kg ha-1 recorded the highest available Boron content (0.78 kg ha-1) of the post harvest soil of Brinjal. Highest brinjal yield (14.96 t ha-1) was supported by the treatment consisting of 75% RDF + Azospirillum + PSB + Boron @ 10 Kg ha-1. Meager information was available regarding the performance of integrated application of organics and micronutrient on brinjal in the experimental location. The present study may enlighten this unexplored section of nutrient management in brinjal

    When eating becomes business

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    A alimentação é um grande negócio no Brasil e em todo o mundo. A empresa brasileira 3G Capital, por exemplo, foi notícia por sua aquisição de marcas internacionais renomadas como Budweiser, Kraft-Heinz e Burger King. A liderança gerencial atual do Brasil marca uma mudança notável de sua posição histórica como exportador de commodities, apesar de dominante. No entanto, a escala não é a única medida da importância econômica da alimentação; nas sociedades industriais modernas, a produção e a venda de alimentos ainda fornecem subsistência básica para inúmeras pessoas, especialmente as mais marginalizadas, de catadores de açaí na Amazônia a vendedores de comida artesanal nas ruas de São Paulo. Entender o negócio da alimentação requer várias ferramentas analíticas atravessando fronteiras sociais e geográficas. Essa análise deve estar em sintonia com a multiplicidade de problemas de saúde pública e integração social que ainda permanecem e, em alguns casos, resultaram do sucesso do agronegócio moderno e do processamento industrial de alimentos. Esta edição especial visa a apresentar os métodos e resultados na área de Estudos sobre Alimentação aos leitores da RAE-Revista de Administração de Empresas para estimular diálogos em nível internacional e interdisciplinar, levando a uma melhor compreensão e práticas inovadoras no sistema alimentar mundial

    Area Characteristics and Consumer Nutrition Environments in Restaurants: an Examination of Hispanic Caribbean Restaurants in New York City

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    Hispanics in the USA, particularly those of Caribbean descent, experience high levels of diet-related diseases and dietary risk factors. Restaurants are an increasingly important yet understudied source of food and may present opportunities to positively influence urban food environments. We sought to explore food environments further, by examining the association between neighborhood characteristics and restaurant consumer nutrition environments within New York City’s Hispanic Caribbean (HC) restaurant environments. We applied an adapted version of the Nutrition Environment Measurements Survey for Restaurants (NEMS-R) to evaluate a random sample of HC restaurants (n=89). NEMS-HCR scores (continuous and categorized as low, medium, and high based on data distribution) were examined against area sociodemographic characteristics using bivariate and logistic regression analysis. HC restaurants located in Hispanic geographic enclaves had a higher proportion of fried menu items (p6), compared with their medium (aOR: 6.6, 95% CI: 1.8–24.6) and large counterparts (aOR: 5.6, 95% CI: 1.5–21.4). This research is the first to examine the association between restaurant location and consumer nutrition environments, providing information to contribute to future interventions and policies seeking to improve urban food environments in communities disproportionately affected by diet-related conditions, as in the case of HC communities in New York City
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