460 research outputs found

    Study on the growth and development of brinjal shoot and fruit borer with different diets

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    A laboratory experiment was conducted with two natural and one artificial diet on the growth and development of brinjal shoot and fruit borer (BSFB). The population of BSFB used in the study was in the 2nd instar larvae. Among the different diet, brinjal was the best for growth, development and longevity of larvae and pupae and prolongation of larval and pupal period. The mean length of full grown larvae fed with natural the food brinjal were 9.37, 9.80 and 12.44 mm from generations 1, 2 and 3, respectively. The larval and pupal duration on brinjal food media were 13.10 and 8.17, 12.80 and 8.23 and 13.10 and 8.03 days in generations 1, 2 and 3, respectively. The percentages of adult emergence from pupae raised in brinjal were 65.38, 47.95 and 33.78 in generations 1, 2 and 3, respectively.Key words: Brinjal, brinjal shoot and fruit borer (BSFB), natural and artificial diet

    LBM-MHD Data-Driven Approach to Predict Rayleigh–Bénard Convective Heat Transfer by Levenberg–Marquardt Algorithm

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    This study aims to consider lattice Boltzmann method (LBM)–magnetohydrodynamics (MHD) data to develop equations to predict the average rate of heat transfer quantitatively. The present approach considers a 2D rectangular cavity with adiabatic side walls, and the bottom wall is heated while the top wall is kept cold. Rayleigh–Bénard (RB) convection was considered a heat-transfer phenomenon within the cavity. The Hartmann (Ha) number, by varying the inclination angle (θ), was considered in developing the equations by considering the input parameters, namely, the Rayleigh (Ra) numbers, Darcy (Da) numbers, and porosity (ϵ) of the cavity in different segments. Each segment considers a data-driven approach to calibrate the Levenberg–Marquardt (LM) algorithm, which is highly linked with the artificial neural network (ANN) machine learning method. Separate validations have been conducted in corresponding sections to showcase the accuracy of the equations. Overall, coefficients of determination (R2) were found to be within 0.85 to 0.99. The significant findings of this study present mathematical equations to predict the average Nusselt number (Nu¯). The equations can be used to quantitatively predict the heat transfer without directly simulating LBM. In other words, the equations can be considered validations methods for any LBM-MHD model, which considers RB convection within the range of the parameters in each equation

    Lattice boltzmann simulation of magnetic field effect on electrically conducting fluid at inclined angles in rayleigh-bénard convection

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    The magneto-hydrodynamics (MHD) effect is studied at different inclined angles in Rayleigh-Bénard (RB) convection inside a rectangular enclosure using the lattice Boltzmann method (LBM). The enclosure is filled with electrically conducting fluids of different characteristics. These characteristics are definedbyPrandtlnumber,Pr. The considered Pr values for this study are 10 and 70. The influence of other dimensionless parameters Rayleigh numbers Ra ¼ 103; 104; 105; 106 and Hartmann numbers Ha = 0, 10, 25, 50, 100, on fluid flow and heat transfer, are also investigated considering different inclined angles φ of magnetic field by analyzing computed local Nusselt numbers and average Nusselt numbers. The results of the study show the undoubted prediction capability of LBM for the current problem. The simulated results demonstrate that the augmentation in heat transfer is directly related to Ra values, but it is opposite while observing the characteristics of Ha values. However, it is also found that φ has a significant impact on heat transfer for different fluids. Besides, isotherms are found to be always parallel to the horizontal axis at Ra ¼ 103 as conduction over-comes the convection in the heat transfer, but this behaviour is not seen at Ra ¼ 104 when Ha > 25. Furthermore,at Ra ¼ 106, oscillatory instability appears but LBM is still able to provide a complete map of this predicted beha-vior. An appropriate validation with previous numerical studies demonstrates the accuracy of the present approach

    Large-Eddy Simulation of Airflow and Pollutant Dispersion in a Model Street Canyon Intersection of Dhaka City

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    The atmospheric flow and dispersion of traffic exhaust were numerically studied in this work while considering a model street canyon intersection of a city. The finite volume method (FVM)-based large-eddy simulation (LES) technique in line with ANSYS Fluent have been used for flow and pollutant dispersion modelling through the consideration of the atmospheric boundary layer (ABL). Hexahedral elements are considered for computational domain discretization in order to numerically solve problems using FVM-LES. The turbulence parameters were superimposed through a spectral synthesizer in the existing LES model through ANSYS Fluent as part of ’damage control’ due to the unsteady k−ϵ simulation. Initially, the code is validated with an experimental study of an urban street canyon where the width and height ratio is in unity. After validation, a model urban street canyon intersection was investigated in this work. The model shows a high pollutant concentration in the intersecting corner areas of the buildings. Additionally, the study of this model intersection shows a high level of pollutant concentration at the leeward wall of downwind building in the case of increased height of an upwind building. Most importantly, it was realized from the street intersection design that three-dimensional interconnection between the dominating canyon vortices and roof level flow plays a pivotal role in pollutant concentration level on the windward walls. The three-dimensional extent of corner eddies and their interconnections with dominating vortices were found to be extremely important as they facilitate enhanced ventilation. Corner eddies only form for the streets towards the freeway and not for the streets towards the intersection. The results and key findings of this work offer qualitative and quantitative data for the estimation, planning, and implementation of exposure mitigation in an urban environment

    Non-destructive maturity index of “Amritsagor” banana using RGB and HSV values

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    Massive changes in physicochemical composition and color variation usually occur in fruits during maturation and ripening. This study is conducted to implement an image processing system and develop a maturity color chart of banana. Actually, natural ripening color is different than impose ripening. Maturity color chart will help the consumer when it will be in the packet of banana. The earliest physiological maturity (stage-1) was marked as the stage when the flesh color was olive green and the pulp turning yellow and the subsequent maturity stages determined whenever changes the color as stage-2 (green smoke), stage-3 (apple green), stage-4 (olive drab), stage-5 (yellow) and stage-6 (golden rod) color. For each of the maturity stages, physical (peel color, firmness, and weight loss) and biochemical (anthocyanin content, carotenoids content, titrable acidity, pH, total soluble solids, ascorbic acid, reducing sugar, non-reducing sugar, and total sugar) maturity indices were determined. We had classified the maturity stages of banana based on the RGB (Red, Green, and Blue) and HSV (Hue, Saturation and Value) values. Average, median, minimum and maximum values were used in this study. After completing the qualitative analysis of RGB and HSV values we found the correlation coefficient of RGB and HSV values. The red color (R) values of bananas would increase when stages increase and the hue (H) means the pure color of bananas decreases when stages increase. Therefore, we can say that maturity stages of bananas mainly depend on R and H values. In case of Amritsagor banana at stage-6 (golden rod) color, TSS (Total Soluble Solid) (2.1%), TA (Titrable Acidity) (0.96%), pH (5.2), sugar (1.25%), vitamin C (2.5 mg/100g), reducing sugar (1.04%), non-reducing sugar (0.2%), anthocyanin (0.55 mg/100g) carotenoids (0.38 mg/100g) and at stage-1 (olive green) color, pH (6.8), vitamin C (8.75 mg/100g) are significantly highest. The results show that as maturation progressed, firmness decreased gradually and flesh color turned olive green to golden rod with ripening. Total soluble solids increased while TA (Titrable acidity) gradually increased with maturity. The results revealed that, there is a significant relationship between nutritional value, firmness and fruit skin color. So, the fruit of stage-1 (olive green) is suitable for harvesting and stages-6 (golden rod) color is suitable for consumption. Actually this message for grower/ owner or who would like to harvest and consumer. Fruit is banana, to observe the change of color keep it at room temperature. Neither artificial nor chemical system used here. Each and every box will carry the real maturity color chart

    Topological Surface States Protected From Backscattering by Chiral Spin Texture

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    Topological insulators are a new class of insulators in which a bulk gap for electronic excitations is generated by strong spin orbit coupling. These novel materials are distinguished from ordinary insulators by the presence of gapless metallic boundary states, akin to the chiral edge modes in quantum Hall systems, but with unconventional spin textures. Recently, experiments and theoretical efforts have provided strong evidence for both two- and three-dimensional topological insulators and their novel edge and surface states in semiconductor quantum well structures and several Bi-based compounds. A key characteristic of these spin-textured boundary states is their insensitivity to spin-independent scattering, which protects them from backscattering and localization. These chiral states are potentially useful for spin-based electronics, in which long spin coherence is critical, and also for quantum computing applications, where topological protection can enable fault-tolerant information processing. Here we use a scanning tunneling microscope (STM) to visualize the gapless surface states of the three-dimensional topological insulator BiSb and to examine their scattering behavior from disorder caused by random alloying in this compound. Combining STM and angle-resolved photoemission spectroscopy, we show that despite strong atomic scale disorder, backscattering between states of opposite momentum and opposite spin is absent. Our observation of spin-selective scattering demonstrates that the chiral nature of these states protects the spin of the carriers; they therefore have the potential to be used for coherent spin transport in spintronic devices.Comment: to be appear in Nature on August 9, 200

    British Association of Dermatologists National Clinical Audit on the Management of Hidradenitis Suppurativa in the UK.

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    BACKGROUND: The first UK guidelines for the management of hidradenitis suppurativa (HS) were published by the British Association of Dermatologists (BAD) in 2018. The guidelines contained a set of audit criteria. AIM: To evaluate current HS management against the audit standards in the BAD guidelines. METHODS: BAD members were invited to complete audit questionnaires between January and May 2020 for five consecutive patients with HS per department. RESULTS: In total, 88 centres participated, providing data for 406 patients. Disease staging using the Hurley system and disease severity using a validated tool during follow-ups was documented in 75% and 56% of cases, respectively, while quality of life and pain were documented in 49% and 50% of cases, respectively. Screening for cardiovascular disease risk factors was as follows: smoking 75%, body mass index 27% and others such as lipids and diabetes 57%. Screening for depression and anxiety was performed in 40% and 25% of cases, respectively. Support for smokers or obese patients was documented in 35% and 23% of cases. In total, 182 patients were on adalimumab, of whom 68% had documentation of baseline disease severity, and 76% were reported as having inadequate response or contraindications to systemic treatments; 44% of patients continued on adalimumab despite having < 25% improvement in lesion count. CONCLUSION: UK dermatologists performed well against several audit standards, including documenting disease staging at baseline and smoking status. However, improvements are needed, particularly with regard to screening and management of comorbidities that could reduce the long-term complications associated with HS. A re-audit is required to evaluate changes in practice in the future

    Reduced functional measure of cardiovascular reserve predicts admission to critical care unit following kidney transplantation

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    Background: There is currently no effective preoperative assessment for patients undergoing kidney transplantation that is able to identify those at high perioperative risk requiring admission to critical care unit (CCU). We sought to determine if functional measures of cardiovascular reserve, in particular the anaerobic threshold (VO2AT) could identify these patients. Methods: Adult patients were assessed within 4 weeks prior to kidney transplantation in a University hospital with a 37-bed CCU, between April 2010 and June 2012. Cardiopulmonary exercise testing (CPET), echocardiography and arterial applanation tonometry were performed. Results: There were 70 participants (age 41.7614.5 years, 60% male, 91.4% living donor kidney recipients, 23.4% were desensitized). 14 patients (20%) required escalation of care from the ward to CCU following transplantation. Reduced anaerobic threshold (VO2AT) was the most significant predictor, independently (OR = 0.43; 95% CI 0.27–0.68; p,0.001) and in the multivariate logistic regression analysis (adjusted OR = 0.26; 95% CI 0.12–0.59; p = 0.001). The area under the receiveroperating- characteristic curve was 0.93, based on a risk prediction model that incorporated VO2AT, body mass index and desensitization status. Neither echocardiographic nor measures of aortic compliance were significantly associated with CCU admission. Conclusions: To our knowledge, this is the first prospective observational study to demonstrate the usefulness of CPET as a preoperative risk stratification tool for patients undergoing kidney transplantation. The study suggests that VO2AT has the potential to predict perioperative morbidity in kidney transplant recipients

    One-dimensional Topological Edge States of Bismuth Bilayers

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    The hallmark of a time-reversal symmetry protected topologically insulating state of matter in two-dimensions (2D) is the existence of chiral edge modes propagating along the perimeter of the system. To date, evidence for such electronic modes has come from experiments on semiconducting heterostructures in the topological phase which showed approximately quantized values of the overall conductance as well as edge-dominated current flow. However, there have not been any spectroscopic measurements to demonstrate the one-dimensional (1D) nature of the edge modes. Among the first systems predicted to be a 2D topological insulator are bilayers of bismuth (Bi) and there have been recent experimental indications of possible topological boundary states at their edges. However, the experiments on such bilayers suffered from irregular structure of their edges or the coupling of the edge states to substrate's bulk states. Here we report scanning tunneling microscopy (STM) experiments which show that a subset of the predicted Bi-bilayers' edge states are decoupled from states of Bi substrate and provide direct spectroscopic evidence of their 1D nature. Moreover, by visualizing the quantum interference of edge mode quasi-particles in confined geometries, we demonstrate their remarkable coherent propagation along the edge with scattering properties that are consistent with strong suppression of backscattering as predicted for the propagating topological edge states.Comment: 15 pages, 5 figures, and supplementary materia

    Comparative analysis of sequence characteristics of imprinted genes in human, mouse, and cattle

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    Genomic imprinting is an epigenetic mechanism that results in monoallelic expression of genes depending on parent-of-origin of the allele. Although the conservation of genomic imprinting among mammalian species has been widely reported for many genes, there is accumulating evidence that some genes escape this conservation. Most known imprinted genes have been identified in the mouse and human, with few imprinted genes reported in cattle. Comparative analysis of genomic imprinting across mammalian species would provide a powerful tool for elucidating the mechanisms regulating the unique expression of imprinted genes. In this study we analyzed the imprinting of 22 genes in human, mouse, and cattle and found that in only 11 was imprinting conserved across the three species. In addition, we analyzed the occurrence of the sequence elements CpG islands, C + G content, tandem repeats, and retrotransposable elements in imprinted and in nonimprinted (control) cattle genes. We found that imprinted genes have a higher G + C content and more CpG islands and tandem repeats. Short interspersed nuclear elements (SINEs) were notably fewer in number in imprinted cattle genes compared to control genes, which is in agreement with previous reports for human and mouse imprinted regions. Long interspersed nuclear elements (LINEs) and long terminal repeats (LTRs) were found to be significantly underrepresented in imprinted genes compared to control genes, contrary to reports on human and mouse. Of considerable significance was the finding of highly conserved tandem repeats in nine of the genes imprinted in all three species
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