This investigation addresses bioconvection of oxytactic microorganisms in a porous square enclosure by thermal radiation impact. The bioconvection flow and heat transfer in porous media are ...formulated based on Darcy model of Boussinesq approximation. Appropriate transformations lead to the non-dimensionalized governing partial differential equations. Galerkin finite element method for the resulting equations is computed. The role of relevant parameters on the streamlines, isotherms, isoconcentrations of oxygen and microorganisms and average Nusselt number is analysed in the outputs. It is revealed that the flow intensity of bioconvection is pronounced with larger Rayleigh number and reduced with radiation parameter. Furthermore, the temperature distribution is affected significantly with Rayleigh number. Radiation parameter serves to fasten the heat transfer in the enclosure. Oxygen density is enhanced with Rayleigh number and radiation parameter. The profile of motile isoconcentrations is boosted with Rayleigh number. The stability of microorganisms is improved with the radiation parameter.
Satellite avionics and electronic components are getting compact and have high power density. Thermal management systems are essential for their optimal operational performance and survival. Thermal ...management systems keep the electronic components within a safe temperature range. Phase change materials (PCMs) have high thermal capacity, so they are promising for thermal control applications. This work adopted a PCM-integrated thermal control device (TCD) to manage the small satellite subsystems under zero gravity conditions thermally. The TCD's outer dimensions were selected upon a typical small satellite subsystem. The PCM adopted was the organic PCM of RT 35. Pin fins with different geometries were adopted to boost the lower thermal conductivity of the PCM. Six-pin fins geometries were used. First, the conventional geometries were square, circular, and triangular. Second, the novel geometries were cross-shaped, I-shaped, and V-shaped fins. The fins were designed at two-volume fractions of 20% and 50%. The electronic subsystem was assumed to be "ON" for 10 min releasing 20 W of heat, and "OFF" for 80 min. The findings show a remarkable decrease in the TCD's base plate temperature by 5.7 ℃ as the fins' number changed from 15 to 80 for square fins. The results also show that the novel cross-shaped, I-shaped, and V-shaped pin fins could significantly enhance thermal performance. The cross-shaped, I-shaped, and V-shaped reported a decrease in the temperature by about 1.6%, 2.6%, and 6.6%, respectively, relative to the circular fin geometry. V-shaped fins could also increase the PCM melt fraction by 32.3%.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for the COVID-19 pandemic, which generated more than 1.82 million deaths in 2020 alone, in addition to 83.8 million ...infections. Currently, there is no antiviral medication to treat COVID-19. In the search for drug leads, marine-derived metabolites are reported here as prospective SARS-CoV-2 inhibitors. Two hundred and twenty-seven terpene natural products isolated from the biodiverse Red-Sea ecosystem were screened for inhibitor activity against the SARS-CoV-2 main protease (M
) using molecular docking and molecular dynamics (MD) simulations combined with molecular mechanics/generalized Born surface area binding energy calculations. On the basis of
analyses, six terpenes demonstrated high potency as M
inhibitors with Δ
≤ -40.0 kcal/mol. The stability and binding affinity of the most potent metabolite, erylosides B, were compared to the human immunodeficiency virus protease inhibitor, lopinavir. Erylosides B showed greater binding affinity towards SARS-CoV-2 M
than lopinavir over 100 ns with Δ
values of -51.9 vs. -33.6 kcal/mol, respectively. Protein-protein interactions indicate that erylosides B biochemical signaling shares gene components that mediate severe acute respiratory syndrome diseases, including the cytokine- and immune-signaling components
,
, and
. Pathway enrichment analysis and Boolean network modeling were performed towards a deep dissection and mining of the erylosides B target-function interactions. The current study identifies erylosides B as a promising anti-COVID-19 drug lead that warrants further
and
testing.
•Passive cooling of a triple-junction solar cell using a straight fins heat sink.•A comprehensive 3D heat transfer and electrical model is developed.•Effects of air temperature, concentration ratio, ...and fins length have been studied.•The cooling system enabled to realize a higher CR of 1250 suns producing 43.4 W/cm2.•Taguchi analysis showed the CR has the greatest effect on the cell performance.
An efficient cooling system is crucial for solar cells operating under high concentration ratios to maintain the cell temperature below the maximum allowable temperature limit and to ensure higher efficiency. The current study focuses on the passive cooling of a triple-junction solar cell using a straight fins heat sink. A comprehensive 3D heat transfer and electrical model integrating the CPV cell full layers and the straight fins heat sink is developed and numerically simulated. The effects of ambient temperature, wind speed, and concentration ratio have been studied over various lengths of the straight fins heat sink. In harsh weather conditions of 45 °C ambient temperature, 1 m/s wind speed, and 500 suns, the straight fins reduced cell temperature by approximately 421.2 °C to 432.1 °C with reference to the uncooled cell depending on fins length. Accordingly, the cooling system enabled to realize a higher concentration of 1250 suns producing 43.4 W/cm2 while the uncooled cell is limited at 72.5 suns with an electrical output of 2.5 W/cm2. Environmental analysis showed that cooling of CPV system using straight fins could reduce annual carbon dioxide emissions by 903 and 1705 tons/m2 at a solar concentration of 500 and 1000 suns respectively. Additionally, Taguchi analysis is performed to find the most affecting parameter on the cell performance and the optimum fin length. The analysis showed that concentration ratio has the most significant effect on the performance of the system, followed by ambient temperature and then fin length. Conversely, the impact of wind speed can be neglected.
•This paper present using saline water as a cooling agent for solar panels.•Six different salinities were tested at two different solar radiation intensities.•New internal and external configuration ...evaporation-based systems were tested.•Results indicated the feasibility of using saline water up to 35 ppt as a cooling agent.•More enhancements were achieved using the new proposed configurations.
This paper is one of the first to propose seawater for cooling PV panels. It presents and describes a novel experimental investigation for cooling solar panels using saturated activated alumina with saline water. Six different water salinities of (0, 5, 10, 35, 80, and 337) particles per thousands (PPT) saltwater were used at different radiation intensities. Additionally, new internal and external configuration of materials’ containers are suggested. Two radiation intensities of 800 W/m2 and 1000 W/m2 were selected and applied for the complete test period of 6 h. Experiments were repeated for a periodic cycle of four months to monitor the salt effect on the activated alumina tablets; This was done by using an optical microscope to look at the microscopical state. Results showed that saturated activated alumina tablets with saline water gives the same cooling performance as using pure water. At salinities higher than 35 PPT, the tablets depreciation rate and porosity increase, hence limiting the usability to systems with salinities less than 35 PPT. The proposed modifications for the internal and external configuration enhanced the cooling effect of the system by (3–4) °C, compared with the old configurations.
Recent literature has demonstrated ergonomic risk to surgeons in the operating room. One method used in other industries to mitigate these ergonomic risks is the incorporation of microbreaks. Thus, ...intraoperative microbreaks with exercises in a non-crossover design were studied. Fifty-six attending surgeons from 4 Medical Centers volunteered first in a day of their regular surgeries and then second day where there were microbreaks with exercises that could be performed in the sterile field, answering questions after each case, without significantly increasing the duration of their surgeries. Surgeons self-reported improvement or no change in their mental focus (88%) and physical performance (100%) for the surgical day incorporating microbreaks with exercises. Discomfort in the shoulders was significantly reduced while distractions and flow impact was minimal. Eighty-seven percent of the surgeons wanted to incorporate the microbreaks with exercises into their OR routine. Intraoperative microbreaks with exercises may be a way to mitigate work-related musculoskeletal fatigue, pain and injury.
•Surgeons report high prevalence of neck, shoulder and back pain and discomfort.•Intraoperative microbreaks/stretches did not significantly increase surgical duration.•Microbreaks improved self-reported physical performance and mental focus.•Body part discomfort improved (significantly for shoulders) with microbreaks.•87% of surgeons wanted to incorporate microbreaks with stretches in their OR routine.
The European Organisation for Research and Treatment of Cancer (EORTC; protocol 08031) phase II trial investigated the feasibility of trimodality therapy consisting of induction chemotherapy followed ...by extrapleural pneumonectomy and post-operative radiotherapy in patients with malignant pleural mesothelioma (with a severity of cT3N1M0 or less). Induction chemotherapy consisted of three courses of cisplatin 75 mg·m⁻² and pemetrexed 500 mg·m⁻². Nonprogressing patients underwent extrapleural pneumonectomy followed by post-operative radiotherapy (54 Gy, 30 fractions). Our primary end-point was "success of treatment" and our secondary end-points were toxicity, and overall and progression-free survival. 59 patients were registered, one of whom was ineligible. Subjects' median age was 57 yrs. The subjects' TNM scores were as follows: cT1, T2 and T3, 36, 16 and six patients, respectively; cN0 and N1, 57 and one patient, respectively. 55 (93%) patients received three cycles of chemotherapy with only mild toxicity. 46 (79%) patients received surgery and 42 (74%) had extrapleural pneumonectomy with a 90-day mortality of 6.5%. Post-operative radiotherapy was completed in 37 (65%) patients. Grade 3-4 toxicity persisted after 90 days in three (5.3%) patients. Median overall survival time was 18.4 months (95% CI 15.6-32.9) and median progression-free survival was 13.9 months (95% CI 10.9-17.2). Only 24 (42%) patients met the definition of success (one-sided 90% CI 0.36-1.00). Although feasible, trimodality therapy in patients with mesothelioma was not completed within the strictly defined timelines of this protocol and adjustments are necessary.
We will apply two mathematical methods, namely the exp
(
-
φ
(
ξ
)
)
-expansion and sine–cosine in deterministic and stochastic ways for solving the deterministic and stochastic cases of the ...simplified MCH equation. This nonlinear equation can be turned into another nonlinear ordinary differential equation by appropriate transformation. The methods that we use are efficient and powerful in solving wide classes of nonlinear equations. The solutions obtained are in the form of trigonometric, hyperbolic, exponential and rational functions and a variety of special solutions like kink-shaped, bell-type soliton solutions. Moreover, these solutions reflect some interesting physical interpretation for nonlinear problems. We will also study the stochastic case from the point random wave transformation or some disturbances in the equation itself. The convergence conditions will be discussed.
Hydrogel electrolytes are essential components of a plethora of functional devices due to their flexibility and high electronic and ionic conductivity. However, they suffer from poor water retention ...(dehydration) during operation. Consequently, the overall performance of the hydrogel-based devices is severely declined as a result of conductivity fading of the hydrogel with poor self-regeneration. To this end, the rational tailoring of hydrogel electrolytes with high conductivity, self-regeneration, non-flammability, anti-freezing ability, stability, and intrinsic redox activity is necessary to enable the fabrication of highly durable devices. Herein, we demonstrate the design and synthesis of highly ionic conductive LiBr@PVA-based electrolytes. Upon the use of the synthesized hydrogel electrolytes in supercapacitor devices, they revealed intrinsic redox activity with outstanding water retention capability and self-regeneration characteristics. The mechanism of regeneration and water retention is thoroughly investigated. Also, the devices showed an improved self-discharge potential (SDP) rate compared to those previously reported using polymeric electrolytes with redox additives. Moreover, the synthesized LiBr@PVA-based electrolytes exhibited high anti-freezing properties with stable electrochemical performance before and after regeneration. Our study provides a universal method to fabricate large-scale hydrogel electrolytes with unique properties and opens the door to fabricate high-performance solid state devices.
We report the rational tailoring of LiBr@PVA-based hydrogel electrolytes with high conductivity, self-regeneration, non-flammability, anti-freezing ability, stability, and intrinsic redox activity with exceptional self-discharge potential.
PDF
