Thermal Analysis of a Solar Assisted Cold Storage Unit for the Storage of Agricultural Perishables Produce

A solar based cold storage unit for the preservation of food products is an excellent way to reduce post-harvest losses at lower energy costs. Energy optimization is essential to improve the reliability of the system. In the case of cooling, a major factor to reduce energy consumption is the uniform distribution of air inside the cooling chamber to maintain the even temperature of stored products. For this, a detailed thermal analysis is required to analyse the cooling process for energy saving and optimum conditions. In the current study, an energy and exergy based thermal analysis of a solar assisted cold storage unit is presented. A parametric investigation and a proper understanding about the influence of thermodynamics on the cooling process were obtained. All the experimentally calculated parameters (energy utilized, energy utilization ratio, energy loss and exergy efficiency) were subjected to a model curve fitting using Sigmaplot-12 and a polynomial cubic model was found best fitted based on the values of coefficient of determination. Thermal analysis showed variations in the rate of energy utilization, energy utilization ratio, exergy losses and exergy efficiency in the range of 3–18 kJ/s, 0.37–0.80, 0.8–2.25 kJ/s and 40–60%, respectively. The average value of COP of the system was found to be 3.95.

Projected Adaptive Cubic Regularization Algorithm with Derivative-Free Filter Technique for Box Constrained Optimization

An adaptive projected affine scaling algorithm of cubic regularization method using a filter technique for solving box constrained optimization without derivatives is put forward in the passage. The affine scaling interior-point cubic model is based on the quadratic probabilistic interpolation approach on the objective function. The new iterations are obtained by the solutions of the projected adaptive cubic regularization algorithm with filter technique. We prove the convergence of the proposed algorithm under some assumptions. Finally, experiments results showed that the presented algorithm is effective in detail.

Trait anxiety predicts amygdalar responses during direct processing of threat-related pictures

Previous studies on the associations between trait anxiety and amygdalar responses to threat stimuli have resulted in mixed findings, possibly due to sample characteristics, specific tasks, and analytical methods. The present functional magnetic resonance imaging (fMRI) study aimed to investigate linear or non-linear associations between trait anxiety and amygdalar responses in a sample of participants with low, medium, and high trait anxiety scores. During scanning, participants were presented with threat-related or neutral pictures and had either to solve an emotional task or an emotional-unrelated distraction task. Results showed that only during the explicit task trait anxiety was associated with right amygdalar responses to threat-related pictures as compared to neutral pictures. The best model was a cubic model with increased amygdala responses for very low and medium trait anxiety values but decreased amygdala activation for very high trait anxiety values. The findings imply a non-linear relation between trait anxiety and amygdala activation depending on task conditions.

Subsurface Microstructural Evolution during Scratch Testing on Bcc Iron

Subsurface microstructures influence the friction and wear behavior of metallic tribological systems, among other factors. To gain a basic understanding of the microstructural changes occurring during sliding processes, face-centered cubic model systems, for example a copper system with a sapphire sphere sliding against it, were previously characterized. Such systems showed the evolution of the dislocation self-organization phenomenon called the dislocation trace line. To test the occurrence of this dislocation arrangement in bcc metals, in this study a ruby ball was slid against electropolished bcc iron under an increasing normal load. The wear track topography and subsurface microstructure were characterized using white light interferometry and scanning transmission electron microscopy. The analysis suggested that at least for bcc iron, the evolution of a dislocation trace line is connected with the onset of pronounced plastic deformation.

Process Optimization and Modeling of Phenol Adsorption onto Sludge-Based Activated Carbon Intercalated MgAlFe Ternary Layered Double Hydroxide Composite

A sewage sludge-based activated carbon (SBAC) intercalated MgAlFe ternary layered double hydroxide (SBAC-MgAlFe-LDH) composite was synthesized via the coprecipitation method. The adsorptive performance of the composite for phenol uptake from the aqueous phase was evaluated via the response surface methodology (RSM) modeling technique. The SBAC-MgAlFe-LDH phenol uptake capacity data were well-fitted to reduced RSM cubic model (R2 = 0.995, R2-adjusted = 0.993, R2-predicted = 0.959 and p-values < 0.05). The optimum phenol adsorption onto the SBAC-MgAlFe-LDH was achieved at 35 °C, 125 mg/L phenol, and pH 6. Under the optimal phenol uptake conditions, pseudo-first-order and Avrami fractional-order models provided a better representation of the phenol uptake kinetic data, while the equilibrium data models’ fitting follows the order; Liu > Langmuir > Redlich–Peterson > Freundlich > Temkin. The phenol uptake mechanism was endothermic in nature and predominantly via a physisorption process (ΔG° = −5.33.56 to −5.77 kJ/mol) with the involvement of π–π interactions between the phenol molecules and the functionalities on the SBAC-LDH surface. The maximum uptake capacity (216.76 mg/g) of SBAC-MgAlFe-LDH was much higher than many other SBAC-based adsorbents. The improved uptake capacity of SBAC-LDH was attributed to the effective synergetic influence of SBAC-MgAlFe-LDH, which yielded abundant functionalized surface groups that favored higher aqueous phase uptake of phenol molecules. This study showcases the potential of SBAC-MgAlFe-LDH as an effective adsorbent material for remediation of phenolic wastewater.

Static Buckling Analysis of a Quadratic-Cubic Model Structure Using the Phase Plane Method and Method of Asymptotics

The exact and asymptotic analyses of the buckling of a quadratic-cubic model structure subjected to static loading are discussed. The governing equation is first solved using the phase plane method and next, using the method of asymptotics. In the asymptotic method, we discuss the possibilities of using regular perturbation method in asymptotic expansions of the relevant variables to get an approximate analytical solution to the problem. Finally, the two results are compared using numerical results obtained with the aid of Q-Basic codes. In the two methods discussed in this work, it is clearly seen that the static buckling loads decrease as the imperfection parameters increase. It is also observed that the static buckling loads obtained using the exact method are higher than those obtained using the method of asymptotics.

Fe/S Co-Doped Titanium Dioxide Nanotubes: Optimization of the Photoelectrocatalytic Degradation Kinetics of Phenol Red

Photoelectrocatalysis has emerged as a promising technology to degrade recalcitrant pollutants such as textile dyes in wastewater completely. Titanium dioxide is typically used as a photocatalyst, but its wide bandgap constrains its use to the use of ultraviolet light. To extend its use to the visible-light region, we doped titanium dioxide nanotubes with iron and sulfur. We used them as a photoelectrode for the photoelectrocatalytic degradation of a model pollutant – phenol red. Response surface methodology using a Box-Behnken design of experiments was used to investigate the effects of initial dye concentration, applied potential, and dopant loading on phenol red degradation kinetics. Statistical analysis showed that our reduced cubic model adequately correlates these parameters. The fastest dye degradation rate was achieved at the optimized conditions: initial phenol red concentration = 5.0326 mg L-1, applied voltage = 29.9686 V, and dopant loading = 1.2244 wt.%. Complete degradation of phenol red may be achieved after 11.77 hours of treatment under the optimized conditions in a batch reactor. Our model's robustness enables it to be used for process modeling and a basis for designing scaled-up photoelectrocatalytic reactors.

Abstract 067: Does BP Trajectory Across Childhood Predict Adult HTN? The International Childhood CV Cohorts Consortium

The relationship between single measures of systolic blood pressure (SBP) in youth and adult levels is weak. We sought to define trajectories of SBP over childhood to determine ability to predict adult hypertension (HTN). In the International Childhood CV Cohort (i3C) Consortium, we constructed SBP trajectories in 11,482 participants (mean age 8.0 + 2.0 years at time of first measure, 47% male, 25% non-Caucasian) who had at least 3 SBPs in youth between the ages of 4 and <20 years assessed with at least 5 years between measures. To account for differences in normal BP by age, sex and height, trajectories were constructed using SBP percentile as defined by the 2017 Clinical Practice Guideline for BP management in youth. We then assessed HTN status (by survey) at mean age 46.7 years in 5,357 of the participants (mean age at first assessment 8.1 + 1.9 years, at self-assessment of HTN 46.7 + 5.7 years. 41% male, 23% non-Caucasian). SAS Proc Traj was employed to construct models with differing numbers of trajectories where all individual trajectories were significant (whether linear, quadratic or cubic). Model fit for each number of trajectories (up to 9) was assessed and trajectories were examined for clinical relevance. The final model selected included 6 trajectories. The prevalence of adult HTN was lowest in the group with low SBP across childhood and adolescence (Low-Low = 20%) and was highest in the group with persistently high SBP (High-High, 49%, chi square <0.001). At first assessment, participants in the High-High group were slightly older (8.7 vs 7.7 years), heavier (BMI 65.2 vs 45.1%), had higher BP (112/61 vs 90/48 mmHg; 27% vs 86% for SBP) and, higher Tchol, LDL, TG, Insulin, Glucose and lower HDL although means were within normal limits (all p<0.001). We conclude that trajectories of BP across childhood may identify youth at high risk for development of HTN in adulthood.

Modelling of COVID-19 positive cases at tertiary care hospital of Bundelkhand region of Uttar Pradesh using regression models

Background: Corona viruses signify a most important group of viruses mostly affecting human beings. It is a respiratory infection with common signs and symptoms of fever, cough, sore throat, headache, and loss of taste, loss of smell, respiratory symptoms. In India till 31st December 2020, the total number of confirmed cases were 1,02,86,310; with active number of cases were 2,52,699 number of cases recovered were 98,81,732 while number of deaths were 1,49,018. Objective of the study was to find the quadratic and cubic model of COVID-19 positive cases at tertiary care hospital of Bundelkhand region of Uttar Pradesh.Methods: A hospital based study was carried out with confirmed covid-19 cases admitted to Government Medical College Banda, UP. 1486 cases have been taken from the period of 1st April 2020 up to 31st December 2020.Results: In this study maximum cases (30.14%) belongs to the age group of 30-45 years. Male population is more than females in all districts. In this study the cubic model shows the best fit with the highest R-square value. Difference in the proportion in each age group (p value<0.001) and sign and symptoms (p value < 0.001) were statistically significant.Conclusions: The current study focused on presenting trends in the Bundelkhand region, Uttar Pradesh with respect to the outbreak of COVID-19. The spread of COVID-19 cases follow cubic model. We conclude that cases of COVID-19 will decline in the coming days heading towards the reduction in daily number of cases.

Analysis of electromagnetic absorption in new design of PIFA antenna using metamaterials

This paper presents the design, simulation and fabrication of a miniaturized wearable dual-band antenna on a semi-flex substrate; she is operable at 2.45/5.8 GHz for wireless local area network applications. The electrical and radiation characteristics of this proposed antenna were obtained by means of a technical of insertion of a slot to tune the operating frequencies. To study the impact of the electromagnetic radiation of the structure of the human body, it is necessary to minimize the back radiation towards the user. Therefore, in this work, a multi-band artificial magnetic conductor (AMC) was placed directly above a dual-band planar inverted F antenna to achieve a miniaturization with excellent radiation performance. The simulation results were designed and simulated using Studio commercial software (CST). A good agreement was achieved between the results of simulation and the experimental. The Comparison of measurement results indicates that the gain improved from 1,84 dB to 3,8 dB, in the lower band, and from 2,4 dB to 4,1 in the upper band, when the antenna is backed by the AMC plane. The front-to-back ratio of the AMC backed PIFA antenna was also enhanced. Then, to ensure that the proposed AMC is harmless to the human body, this prototype was placed on three-layer human tissue cubic model. It was observed that the through inclusion of plane AMC, the peak specific absorption rate (SAR) decreased to 1,45 and 1,1 W/kg at 2,45 and 5.8 GHz, respectively (a reduction of around 3,7 W/kg, compared with an antenna without (AMC).