The solar air_heater (SAH) is one of the main devices that are used for harnessing solar energy for multipurpose functions. The double-pass solar air_heater (DPSAH) is an advanced model with ducts ...that transport the air to the two leaves of the loops. This technology is applied where space heating, thermal energy for drying processes, heat pumping applications, etc. are required. This investigation aims to determine the thermal characteristics of an air heater with a double-pass design that works by using CFD simulation. The study is to be carried out by (air flow rate and pressure distribution) measurement within the system. The process relies on the mixture containing both CO2 and O2 as the medium through which the process takes place. The CFD (Computational Fluid Dynamics) analysis results support that CO2 is an efficient working fluid resulting in better heat exchange. This is evident in the fact that supplementary thermal efficiency at the exhaust duct is 1.76% higher than that of air only. Additionally, the mixture of CO2 and air demonstrates increased efficiency with a 15.2% increase in efficiency relative to air alone. It is due to the different specific heat capacities of the gases that the mixture has a higher average specific heat. Therefore, the gas can store more energy, leading to higher thermal efficiency. The outcomes of this experiment demonstrate the possibility of gas combination for the enrichment of the DPSAH efficiency. This research enlightens on thermal energy systems and is an asset in improving the proficiency of solar air heating systems operation.
Solar collector absorber tubes perform a significant function in solar power devices that concentrate the solar energy into a single cylindrical absorber tube. Characteristically, this type of tube ...is covered with a smooth surface. The purpose of this study is to simulate the convectional behaviour of these absorber tubes with the help of numerical calculation methods like Computational Fluid Dynamics (CFD). The collector tube CAD model has been made using the Creo design software and the ANSYS CFX software is used for the CFD simulations corresponding to the three mass_flow rates (0.005Kg/s, 0.010Kg/s, and 0.015Kg/s). The heat transfer is improved by tweaking the absorber tube with a C-shaped corrugated roughness profile. The choice of the Shear Stress Transport turbulence (SSTT) model for analysis is justified by its capability to accurately predict both laminar and turbulent flows, which is why it is considered to be suitable for the absorber tube with a cross-sectional shape. Findings demonstrated that the use of C-shaped artificial roughness led to a substantial rise in convective heat transfer, for 6.016% of the thermal conductivity was taken into account. The SST turbulence model verifies its efficacy by predicting the fluid flow patterns across the absorber tubes. This study forms the basis for developing new mechanical efficiency metrics for solar collector absorber tubes, which is significant for solar energy technology development.
The book will help you build effective business intelligence dashboards using the latest features of QlikView. You will create different types of visualizations such as bar charts, interactive plots, ...and more. With this book, you will learn how to gain actionable insights from your data and communicate them across to relevant stakeholders in.
Despite its compactness, the human eye can easily focus on different distances by adjusting the shape of its lens with the help of ciliary muscles. In contrast, traditional man-made optical systems ...achieve focusing by physical displacement of the lenses used. But in recent years, advances in miniaturization technology have led to optical systems that no longer require complicated mechanical systems to tune and adjust optical performance. These systems have found wide use in photonics, displays and biomedical systems. They are either based on arrays of microlenses with fixed focal lengths, or use external control to adjust the microlens focal length. An intriguing example is the tunable liquid lens, where electrowetting or external pressure manipulates the shape of a liquid droplet and thereby adjusts its optical properties. Here we demonstrate a liquid lens system that allows for autonomous focusing. The central component is a stimuli-responsive hydrogel integrated into a microfluidic system and serving as the container for a liquid droplet, with the hydrogel simultaneously sensing the presence of stimuli and actuating adjustments to the shape—and hence focal length—of the droplet. By working at the micrometre scale where ionic diffusion and surface tension scale favourably, we can use pinned liquid–liquid interfaces to obtain stable devices and realize response times of ten to a few tens of seconds. The microlenses, which can have a focal length ranging from -∞ to +∞ (divergent and convergent), are also readily integrated into arrays that may find use in applications such as sensing, medical diagnostics and lab-on-a-chip technologies.
In this work, the authors have demonstrated the use of machine learning (ML) models in the prediction of bulk modulus for High Entropy Alloys (HEA). For the first time, ML has been used for ...optimizing the composition of HEA to achieve enhanced bulk modulus values. A total of 12 ML algorithms were trained to classify the elemental composition as HEA or non-HEA. Among these models, Gradient Boosting Classifier (GBC) was found to be the most accurate, with a test accuracy of 78%. Further, six regression models were trained to predict the bulk modulus of HEAs, and the best results were obtained by LASSO Regression model with an R-square value of 0.98 and an adjusted R-Square value of 0.97 for the test data set. This work effectively bridges the gap in the discovery and property analysis of HEAs. By accelerating material discovery via providing alternate means for designing virtual alloy compositions having favourable bulk modulus for respective applications, this work opens new avenues of applications of HEAs.
Purpose: The aim of this study was to evaluate the efficacy and safety of intravitreal moxifloxacin injections in the treatment of acute post-cataract surgery endophthalmitis with visual acuity equal ...to or greater than hand movements. Methods: Fifty two patients with post-cataract surgery endophthalmitis who presented within 6 weeks with visual acuity equal to or greater than hand movements received two intravitreal moxifloxacin injections 48 h apart. Patients with prior history of ocular disease or treatment were excluded. Patients were followed up to 3 months either for resolution of endophthalmitis or worsening of disease. Number of patients who achieved visual acuity equal to or better than 20/40 and 20/200 at the third-month follow-up visit were compared with the number of patients at presentation, using Chi-square test. In addition, pretreatment LogMAR visual acuity at the time of presentation was compared with posttreatment visual acuity at end of third month using paired t test. Results: Fifty (96.15%) patients showed complete resolution of endophthalmitis while three patients required vitrectomy. Forty-one (78.85%) and 49 (94.23%) patients achieved visual acuity equal to or better than 20/40 and 20/200, respectively, at the third-month follow-up visit as compared to eight (15.38%) and 13 (25%) patients, respectively, at presentation (P < 0.05). In addition, mean LogMAR visual acuity at the time of presentation was 0.755 which improved to 0.307 at the third-month follow-up visit (P < 0.05). None of the patients developed hypersensitivity reactions to intravitreal moxifloxacin. Conclusion: Intravitreal moxifloxacin injections showed promising results in acute post-cataract surgery endophthalmitis.
There have been multiple attempts to predict the expression of the genes based on the sequence, epigenetics, and various other factors. To improve those predictions, we have decided to investigate ...adding protein-specific 3D interactions that play a significant role in the condensation of the chromatin structure in the cell nucleus. To achieve this, we have used the architecture of one of the state-of-the-art algorithms, ExPecto, and investigated the changes in the model metrics upon adding the spatially relevant data. We have used ChIA-PET interactions that are mediated by cohesin (24 cell lines), CTCF (4 cell lines), and RNAPOL2 (4 cell lines). As the output of the study, we have developed the Spatial Gene Expression (SpEx) algorithm that shows statistically significant improvements in most cell lines. We have compared ourselves to the baseline ExPecto model, which obtained a 0.82 Spearman's rank correlation coefficient (SCC) score, and 0.85, which is reported by newer Enformer were able to obtain the average correlation score of 0.83. However, in some cases (e.g. RNAPOL2 on GM12878), our improvement reached 0.04, and in some cases (e.g. RNAPOL2 on H1), we reached an SCC of 0.86.
A low-cost, fully integrated sample-to-answer, quantitative PCR (qPCR) system that can be used for detection of HIV-1 proviral DNA in infants at the point-of-care in resource-limited settings has ...been developed and tested. The system is based on a novel DNA extraction method, which uses a glass fiber membrane, a disposable assay card that includes on-board reagent storage, provisions for thermal cycling and fluorescence detection, and a battery-operated portable analyzer. The system is capable of automated PCR mix assembly using a novel reagent delivery system and performing qPCR. HIV-1 and internal control targets are detected using two spectrally separated fluorophores, FAM and Quasar 670. In this report, a proof-of-concept of the platform is demonstrated. Initial results with whole blood demonstrate that the test is capable of detecting HIV-1 in blood samples containing greater than 5000 copies of HIV-1. In resource-limited settings, a point-of-care HIV-1 qPCR test would greatly increase the number of test results that reach the infants caregivers, allowing them to pursue anti-retroviral therapy.
Gelephu, located in the Himalayan region, has undergone significant development activities due to its suitable topography and geographic location. This has led to rapid urbanization in recent years. ...Assessing land use land cover (LULC) dynamics and Normalized Difference Vegetation Index (NDVI) can provide important information about urbanization trends and changes in vegetation health, respectively. The use of Geographic Information Systems (GIS) and Remote Sensing (RS) techniques based on various satellite products offers a unique opportunity to analyze these changes at a local scale. Exploring Bhutan’s mandate to maintain 60% forest cover and analyzing LULC transitions and vegetation changes using Sentinel-2 satellite imagery at 10 m resolution can provide important insights into potential future impacts. To examine these, we first performed LULC mapping for Gelephu for 2016 and 2023 using a Random Forest (RF) classifier and identified LULC changes. Second, the study assessed the dynamics of vegetation change within the study area by analysing the NDVI for the same period. Furthermore, the study also characterized the resulting LULC change for Gelephu Thromde, a sub-administrative municipal entity, as a result of the notable intensity of the infrastructure development activities. The current study used a framework to collect Sentinel-2 satellite data, which was then used for pre-and post-processing to create LULC and NDVI maps. The classification model achieved high accuracy, with an area under the curve (AUC) of up to 0.89. The corresponding LULC and NDVI statistics were analysed to determine the current status of the LULC and vegetation indices, respectively. The LULC change analysis reveals urban growth of 5.65% and 15.05% for Gelephu and Gelephu Thromde, respectively. The NDVI assessment shows significant deterioration in vegetation health with a 75.11% loss of healthy vegetation in Gelephu between 2016 and 2023. The results serve as a basis for strategy adaption required to examine the environmental protection and sustainable development management, and the policy interventions to minimize and balance the ecosystem, taking into account urban landscape.
IntroductionHaglund’s deformity is an abnormal bony postero-superior calcaneal prominence which causes the posterior heel pain. Surgery is the choice of treatment after failed conservative ...management. Both open and endoscopic techniques are used to treat this condition. In this article, we discuss endoscopic calcaneoplasty for the management of such cases.MethodsAll included patients underwent bi-portal endoscopic calcaneoplasty. Clinical outcomes were assessed by using the visual analog scale (VAS) score and the American Orthopaedic Foot and Ankle Society (AOFAS) score. The radiological outcome was assessed by a change in the Fowler-Philip angle (FPA). All patients were followed at one month, three months, and six months postoperatively.ResultsA total of 22 patients were included in this prospective study. Patients were followed up to six months postoperatively. The mean VAS score was 6.32 ± 0.65 which was significantly reduced to 0.91 ± 0.68 (p < 0.001) at six months. Similarly, AOFAS Score was improved to 90.01 ± 2.67 (p < 0.001) from 64.36 ± 7.07 preoperatively. The mean Fowler Philip Angle was reduced from 72.45° ± 3.74° to 65.77° ± 2.25° at six months (p < 0.001).ConclusionBi-portal endoscopic calcaneoplasty significantly improves clinical outcomes in Haglund’s deformity. Compared to open procedures, bi-portal endoscopic calcaneoplasty offers several advantages, including shorter recovery times, smaller incisions, and better clinical results for Haglund's deformity.
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