Experimental Investigation on the Energy and Exergy Efficiency of the Vacuum Membrane Distillation System with Its Various Configurations.

This paper addresses a retrofitting vacuum membrane distillation (VMD) setup to reduce the accumulated pressure inside the permeated side. This modification is necessary to extend the operation of the VMD to extreme operation conditions of higher hot water temperatures. This modification, denoted as a hybrid configuration, proposes the injection of a cold water stream into the VMD cell without mixing it with the permeate. Energy and exergy efficiency analyses were performed to assess the effectiveness of the hybrid configuration. The performance of the modified system indicated an improvement in terms of permeate flux (J), the gain output ratio (GOR), and the utilitarian exergetic efficiency (ηex,u), which reach up to two and three times that of the base configuration of the VMD system. However, the exergetic efficiency (ηex) of the hybrid system showed marginal improvement compared to the base case over the tested range of hot water temperatures. This is because the enhanced vapor production is penalized by excess energy consumption. Moreover, the highest exergy destruction percentages occurred in the operational components (e.g., heater and chillers) which fall in the range of 19.0-68.9%. The exergy destruction percentage in the original components (e.g., the VMD cell and condenser) did not exceed 8.3%. Furthermore, this study indicated that the hybrid configuration requires additional tuning and optimization to perform efficiently over wide operating conditions.

Concept and analysis of hybrid reversal multi-stage flash and membrane distillation desalination system.

The concept and analysis of integrating membrane distillations (MD) with reversal once-through Multistage Flash (RV-MSF) desalination is presented. The analysis is based on numerical simulation. The MD vessels are integrated into the terminal ends of the RV-MSF system to leverage the thermal energy associated with these terminal streams. Hybridisation at the last MSF stage, i.e. by replacing the brine cooler, contributes marginally to the overall production rate which amounts to 2%. However, it is found that hybridisation at stage one, i.e. utilising the energy of the MSF reject brine can increase the overall production rate by 65%. For seawater feed temperature of 80 oC and 24 MSF stages, 5 MD vessels in series can be integrated with the RV-MSF process. This ultimate hybridisation helped improve the recovery ratio from 7 to 23%, decreasing the specific cooling water requirement from 23 to 12 kg/kg and reducing the specific energy consumption from 129 to 41 kWh/m3 with respect to the stand-alone RV-MSF system. However, this achievement incurs an additional specific area for heat transfer which increased from 29 to 65 m2/(kg/s). This is because a large number of MD modules are incorporated into the hybridisation.

Experimental investigation of novel ternary amine-based deep eutectic solvents for CO2 capture.

This study investigates the effect of using water as a low-viscosity component in ternary amine-based deep eutectic solvents (DESs) on the physicochemical properties, thermal stability, and CO2 absorption capacity of the resulting DESs. It should be emphasized that water is a component of the ternary DES. The effect of water content in the DES, type of hydrogen bond acceptors (HBAs), hydrogen bond donors (HBDs), and HBA:HBD ratio on the above parameters was investigated. Moreover, the effect of temperature and pressure on the CO2 absorption capacity of DESs was predicted using the predictive model COSMO-RS. This model was also used to predict the CO2 solubility in the DESs and the results were compared with the experimental values. The results showed that the addition of small amounts of water, e.g., 5 and 10 wt% during preparation, can significantly decrease the viscosity of the resulting DESs, up to 25% at room temperature, while maintaining the high CO2 absorption capacity and high thermal stability. The ternary DESs based on MEA exhibited a high CO2 absorption capacity of 0.155-0.170 g CO2 / g DES. The ternary DESs were found to be thermally stable with a decomposition temperature of 125°C, which promotes the use of such solvents in post-combustion capture processes. Finally, COSMO-RS proved to be a suitable tool for qualitative prediction of CO2 solubility in DESs and demonstration of trends related to the effects of temperature, pressure, molar ratio, water content, HBD and HBA on CO2 solubility.

Fasting Versus Non-Fasting Total Testosterone Levels in Women During the Childbearing Period.

Background Total testosterone in men should be measured in the fasting state early in the morning with at least two samples according to guidelines. For women, no such a recommendation is available despite the importance of testosterone in this demographic. The aim of this study is to evaluate the effect of fasting versus non-fasting state on the total testosterone levels in women during the reproductive period. Methods This study was conducted at Faiha Specialized Diabetes, Endocrine and Metabolism Center in Basrah, (Southern Iraq) between January 2022 to November 2022. The total enrolled women were 109; their age was 18-45 years. The presentation was for different complaints; 56 presented for medical consultation with 45 apparently healthy women accompanying the patients as well as eight volunteering female doctors. Testosterone levels were measured by electrochemiluminescence immunoassays using the Roche Cobas e411 platform (Roche Holding, Basel, Switzerland). Two samples were collected from each woman; one was fasting and another was non-fasting the following day, and all samples were taken before 10 am. Results  For all of the participants, the mean ± SD fasting was significantly higher as compared to the non-fasting testosterone (27.39±18.8 ng/dL and 24.47±18.6 ng/dL respectively, p-value 0.01). The mean fasting testosterone level was also significantly higher in the apparently healthy group, (p-value 0.01). In women who presented with hirsutism, menstrual irregularities and or hair fall, no difference was seen in the testosterone levels between fasting and non-fasting states (p-value 0.4).  Conclusion In the apparently healthy women of childbearing age, serum testosterone levels were higher in the fasting versus the non-fasting states. In women who presented with complaints of hirsutism, menstrual irregularities, and or hair fall, the serum testosterone levels were not affected by the fasting states.

Exploring the use of Sentinel-2 datasets and environmental variables to model wheat crop yield in smallholder arid and semi-arid farming systems.

Low levels of agricultural productivity are associated with the persistence of food insecurity, poverty, and other socio-economic stresses. Mapping and monitoring agricultural dynamics and production in real-time at high spatial resolution are essential for ensuring food security and shaping policy interventions. However, an accurate yield estimation might be challenging in some arid and semi-arid regions since input datasets are generally scarce, and access is restricted due to security challenges. This work examines how well Sentinel-2 satellite sensor-derived data, topographic and climatic variables, can be used as covariates to accurately model and predict wheat crop yield at the farm level using statistical models in low data settings of arid and semi-arid regions, using Sulaimani governorate in Iraq as an example. We developed a covariate selection procedure that assessed the correlations between the covariates and their relationships with wheat crop yield. Potential non-linear relationships were investigated in the latter case using regression splines. In the absence of substantial non-linear relationships between the covariates and crop yield, and residual spatial autocorrelation, we fitted a Bayesian multiple linear regression model to model and predict crop yield at 10 m resolution. Out of the covariates tested, our results showed significant relationships between crop yield and mean cumulative NDVI during the growing season, mean elevation, mean end of the season, mean maximum temperature and mean the start of the season at the farm level. For in-sample prediction, we estimated an R2 value of 51 % for the model, whereas for out-of-sample prediction, this was 41 %, both of which indicate reasonable predictive performance. The calculated root-mean-square error for out-of-sample prediction was 69.80, which is less than the standard deviation of 89.23 for crop yield, further showing that the model performed well by reducing prediction variability. Besides crop yield estimates, the model produced uncertainty metrics at 10 m resolution. Overall, this study showed that Sentinel-2 data can be valuable for upscaling field measurement of crop yield in arid and semi-arid regions. In addition, the environmental covariates can strengthen the model predictive power. The method may be applicable in other areas with similar environments, particularly in conflict zones, to increase the availability of agricultural statistics.

Optimal Control of Direct Contact Membrane Distillation Operated under Fluctuating Energy Source.

An optimal control strategy was tested to regulate the flow rate of the cold stream to maximize the time-averaged water production of a laboratory-scale membrane distillation (MD) process. The MD process is operated under fluctuating inlet hot temperatures at a fixed flow rate for the hot stream. The inlet hot temperature fluctuates due to fluctuation in the supplied renewable energy source, such as solar energy. The simulation revealed the possibility of enhancing the average water production by up to 4.2%, by alternating the flow rate of the cold stream relative to a fixed flow rate of the hot stream. The enhancement was limited because, when using a long membrane, the mass flux degrades when the ratio of the cold stream to the hot stream flow rates is either very high or low. By modifying the control strategy to adapt the membrane length in addition to the flow rate of the cold stream, highly improved performance could be obtained. In fact, up to 40% enhancement in the average water production was observed.

Performance Comparison of Cross- and Forward-Flow Configurations for Multiple-Effect Vacuum Membrane Distillation.

This work addresses retrofitting the infrastructure of multiple-effect vacuum membrane distillation (V-MEMD) units by using cross-flow configuration (CFC). In this configuration, the feed water is evenly divided and distributed over the effects. In this case, the feed water stream for each effect is kept at a high temperature and low flow rate. This will lead to an increase in the vapor pressure gradient across the hydrophobic membrane and can also maintain the thermal energy of the stream inside the individual effect. It is found that CFC improves internal and global performance indicators of productivity, energy, and exergy. A mathematical model was used to investigate the performance of such a modification as compared to the forward-flow configuration (FFC). The cross-flow configuration led to a clear improvement in the internal performance indicators of the V-MEMD unit, where specifically the mass flux, recovery ratio, gain output ratio, and heat recovery factor were increased by 2 to 3 folds. Moreover, all the global performance indicators were also enhanced by almost 2 folds, except for the performance indicators related to the heat pump, which is used to cool the cold water during the operation of the V-MEMD unit. For the heat pump system, the specific electrical energy consumption, SEEC, and the exergy destruction percentage, Ψdes, under the best-operating conditions, were inferior when the feed water flow was less than 159 L/h. This can be attributed to the fact that the heat rejected from the heat pump system is not fully harnessed.

Electroreduction of CO2 and Quantification in New Transition-Metal-Based Deep Eutectic Solvents Using Single-Atom Ag Electrocatalyst.

Deep eutectic solvents (DESs) are efficient media for CO2 capture, and an electroreduction process using the deterministic surface of single-atom electrocatalysts is a facile way to screen gas absorption capacities of novel DESs. Using newly prepared transition-metal-based DESs indexed as TDESs, the interfacial mechanism, detection, quantification, and coordination modes of CO2 were determined for the first time. The CO2 has a minimum detection time of 300 s, whereas 500 s of continous ambient CO2 saturation provided ZnCl2/ethanolamine (EA) (1:4) and CoCl2/EA (1:4) TDESs with a maximum CO2 absorption capacity of 0.2259 and 0.1440 mmol/L, respectively. The results indicated that CO2 coordination modes of η1 (C) and η2 (O, O) with Zn in ZnCl2/EA (1:4) TDESs are conceivable. We found that the transition metals in TDESs form an interface at the compact layer of the electrocatalyst, while CO2 •-/CO2 reside in the diffuse layer. These findings are important because they provide reliable inferences about interfacial phenomena for facile screening of CO2 capture capacity of DESs or other green solvents.

Optimal Control of a Reverse Osmosis Plant for Brackish Water Desalination Driven by Intermittent Wind Power.

This work addresses the design of an online control system that continuously regulates a reverse osmosis (RO) desalination plant driven by wind power aided by water storage tanks. The control objective is to produce the exact hourly water demand in the presence of wind power intermittency, disturbances, and operational limitations. The manipulated variables are the RO feed pressure and the active number of RO vessels. The control system helped to decrease the annual water deficit by 20% under nominal conditions and when the plant is under the influence of disturbances. Moreover, the control system managed to decrease the annual water deficit by 73% when the plant operated under a shortage of an active number of wind turbines and RO vessels. The loss of redistributed production ratio (LPb) and the loss of raw production ratio (LP) were used as the controlled variables representing the proposed control objective. LPb was superior to LP by creating conservative control actions that produce the required water demand without violating the required water purity.

Evaluation of gene flow and genetic diversity in rice accessions across Kurdistan region-iraq using SSR markers.

BACKGROUND: In recent years, farmers have complained that the only way to obtain seeds is to select plants that show good performance under local climate conditions in the region. This study aimed to investigate the diversity of rice accessions grown in the region to build a breeding program. METHODS AND RESULTS: A total of 62 accessions of rice from farmers and research stations were collected from the Kurdistan region, including short-grain and long-grain types, for molecular genetics and diversity analysis. In this study, 37 polymorphic simple sequence repeat (SSR) markers were selected with several molecular genetics software programs. The results show that these SSR markers are very effective for this investigation, generating a total of 152 observed alleles (Na), 75.166 Effective number of alleles (Ne) and an average of 4.1 and 2.03 alleles per locus, respectively. The average polymorphic information content (PIC) per locus was recorded as 0.404. The research presented here confirms two subpopulations, japonica (C1 and C2) and indica (C3), based on molecular genetics data analysis. Analysis of molecular variance revealed that the 72% variance was due to the variation among populations and 28% within the population. CONCLUSIONS: Altogether, these results indicate that there is very low gene flow. These results show the importance of the study of genetic diversity and relationships for starting breeding and improvement programs for rice in the Kurdistan region.

Cardiac MR images of thalassemia major patients with myocardial iron overload: a data note.

OBJECTIVE: Patients with thalassemia major (TM) have the highest mortality rate due to heart failure induced by myocardial iron overload. However, T2* weighted MR imaging is currently a gold standard approach for measuring iron overload. Examining ventricular volumes with magnetic resonance imaging (MR imaging) and measuring myocardial iron overload in TM patients allows for an early prediction of heart failure. This dataset includes cardiac MR images of TM patients and the control group with clinical and echocardiographic data. This dataset may be useful to researchers investigating myocardial iron overload. This dataset can also be used for medical image processing applications, such as ventricle segmentation. DATA DESCRIPTION: This study provides open-source cardiac MR images of 50 subjects and clinical and echocardiographic data. From February 2016 to January 2019, all images and clinical data were obtained from the MRI department of a general hospital in Mashhad, Iran. All the images are 16-bit gray-scale and stored in DICOM format. All patient-specific information is removed from image headers to preserve patient privacy. In addition, all images associated with each subject are compressed and saved in the RAR format.

Modelling the evolution of the coronavirus disease (COVID-19) in Saudi Arabia.

INTRODUCTION: The ongoing COVID-19 pandemic has claimed hundreds of thousands of lives around the world. Health planners are seeking ways to forecast the evolution of the pandemic. In this study, a mathematical model was proposed for Saudi Arabia, the country with the highest reported number of COVID-19 cases in the Arab world. METHODOLOGY: The proposed model was adapted from the model used for the Middle East respiratory syndrome outbreak in South Korea. Using time-dependent parameters, the model incorporated the effects of both population-wide self-protective measures and government actions. Data before and after the government imposed control policies on 3 March 2020 were used to validate the model. Predictions for the disease's progression were provided together with the evaluation of the effectiveness of the mitigation measures implemented by the government and self-protective measures taken by the population. RESULTS: The model predicted that, if the government had continued to implement its strong control measures, then the scale of the pandemic would have decreased by 99% by the end of June 2020. Under the current relaxed policies, the model predicted that the scale of the pandemic will have decreased by 99% by 10 August 2020. The error between the model's predictions and actual data was less than 6.5%. CONCLUSIONS: Although the proposed model did not capture all of the effects of human behaviors and government actions, it was validated as a result of its time-dependent parameters. The model's accuracy indicates that it can be used by public health policymakers.

Optimization of Wind Driven RO Plant for Brackish Water Desalination during Wind Speed Fluctuation with and without Battery.

This work aimed to carry out an optimal investigation of the design and operation of a large capacity reverse osmosis (RO) desalination plant powered by wind energy. Different scenarios involving two design options, such as using storage tanks or batteries, and operation options, such as using variable or fixed feed pressure, were analyzed and optimized. In addition, another operation option, of using a fixed number of RO vessels or a varying number of active RO vessels, was also considered. It was found that an optimized plant using storage tanks can provide a less expensive water cost and a less complicated plant structure. Moreover, the use of a variable feed pressure can help in attenuating the disturbances incurred in the form of wind intermittency. Conversely, the use of fixed feed pressure and constantly supplied power per vessel can run the RO units smoothly, leading to a predictable production rate. However, this requires operating the plant on different active sets of vessels each hour, which mandates additional automatic control systems. The water cost when storage tanks are utilized can be as low as 7.42 $/m3, while it is around 19.7 $/m3 when a battery is used.

Language in a Time of COVID-19: Literacy Bias Ethnic Minorities Face During COVID-19 from Online Information in the UK.

OBJECTIVES: To investigate the readability and presence of translated online information readily available to the British public during COVID-19. DESIGN: A cross-sectional study was performed. The terms "Coronavirus", "COVID-19", "Lockdown", "Social Distancing", "Handwashing", "Furlough Scheme" and "Sick pay" were inputted into the popular search engine, Google. Websites were categorised by their source (i.e. Government, Non-Governmental Organisation, NHS and Commercial) and theme (i.e. general COVID-19 information, population practise and employment rulings). Reliable calculators for assessing readability (Simple Measure of Gobbledygook, Gunning Fog Index, Flesch-Kincaid Grade Level, Coleman-Liau Index and Automated Readability Index) were used. MAIN OUTCOME MEASURES: The median scores with the interquartile range from each calculator of the pooled data were observed. The presence of accompanying translated material and graphic information was also counted and presented as counts and percentages. The number of readable websites (i.e. a score ≤ 8) for each source and theme category were also recorded. SETTING: UK Internet servers. RESULTS: The median scores of the pooled data (n = 148) had shown that the majority of websites were unreadable to the average British reader according to each calculator used (SMOG 1.3%; GF 6.8%; FK 35.8%; CL 2.6%; ARI 40%). Only 3.4% and 6.8% of the pooled websites had readily available translated material and accompanying graphic material, respectively. CONCLUSION: Readability of COVID-19 information is below national standards and that there is a lack of accompanying translated and graphics-based material online. This may lead to an amplified level of misunderstanding in BAME populations about the COVID-19 pandemic and the rulings put in place.

Performance of p-Toluenesulfonic Acid-Based Deep Eutectic Solvent in Denitrogenation: Computational Screening and Experimental Validation.

Deep eutectic solvents (DESs) are green solvents developed as an alternative to conventional organic solvents and ionic liquids to extract nitrogen compounds from fuel oil. DESs based on p-toluenesulfonic acid (PTSA) are a new solvent class still under investigation for extraction/separation. This study investigated a new DES formed from a combination of tetrabutylphosphonium bromide (TBPBr) and PTSA at a 1:1 molar ratio. Two sets of ternary liquid-liquid equilibrium experiments were performed with different feed concentrations of nitrogen compounds ranging up to 20 mol% in gasoline and diesel model fuel oils. More than 99% of quinoline was extracted from heptane and pentadecane using the DES, leaving the minutest amount of the contaminant. Selectivity was up to 11,000 for the heptane system and up to 24,000 for the pentadecane system at room temperature. The raffinate phase's proton nuclear magnetic resonance (1H-NMR) spectroscopy and GC analysis identified a significantly small amount of quinoline. The selectivity toward quinoline was significantly high at low solute concentrations. The root-mean-square deviation between experimental data and the non-random two-liquid (NRTL) model was 1.12% and 0.31% with heptane and pentadecane, respectively. The results showed that the TBPBr/PTSADES is considerably efficient in eliminating nitrogen compounds from fuel oil.

Polyethylene glycol-based deep eutectic solvents as a novel agent for natural gas sweetening.

Deep eutectic solvents (DESs) have received significant attention as potential extracting agents in recent years due to their favorable characteristics including low cost, easy preparation and environmentally safe starting materials. Experimentally screening for highly efficient DESs meeting various requirements for natural gas sweetening remains a challenging task. Thus, an extensive database of estimated Henry's law constants (Hi) and solubilities (xi) of CO2 in 170 different DESs at 25°C has been constructed using the COSMO-RS method to select potential DESs. Based on the COSMO-RS study, three DESs, namely tetrabutylammonium bromide (TBAB)+polyethylene glycol (PEG-8) (on a molar basis 1:4), TBAB+octanoic acid (OCT) (1:4), and methyltriphenylphosphonium bromide (MTPB)+PEG-8 (1:10), were chosen for further experimentation up to 2 bar at 25°C using a vapor-liquid equilibria (VLE) apparatus. Reliable thermophysical properties were determined experimentally, and a detailed equilibrium-based model was developed for one of the glycol-based DESs (i.e., TBAB+PEG-8 (1:4)). This information is an essential prerequisite for carrying out process simulations of natural gas sweetening plants using ASPEN PLUS. The simulation results for the proposed DES were compared to those of monoethylene glycol (MEG). Here, we find that the aqueous TBAB+PEG-8 (1:4) solvent shows ~60% lower total energy consumption and higher CO2 removal when compared to those using the MEG solvent.

Developing and validating a dynamic model of water production by direct-contact membrane distillation.

We consider the development and fitting of a dynamic model for desalinated water production by a direct-contact membrane distillation (DCMD) unit. Two types of dynamic-model structures, namely, lumped parameter and spatial, were evaluated. Both the models were validated using experimental response data generated by step testing the inlet hot stream temperature of a DCMD pilot plant. Both the model structures failed to follow the dynamic response adequately. However, a modification of the model by adding a heat loss term resulted in enhanced predictions for both model structures. The overall relative error in the model-plant mismatch was approximately 3%. This is reasonable considering the random uncertainties associated with the plant operation. This observation also improves our understanding of the importance of using better correlations for heat-transfer coefficients, to develop a more reliable and accurate predictive model for a wide range of operating conditions.

Secondary adrenal insufficiency induced by long-term use of opioid analgesics.

The effects of long-term use of opioid analgesics on the hypothalamic-pituitary-adrenal axis are not well recognized. We report a 41-year-old woman on chronic opioid therapy hospitalized for cardiovascular collapse following a right stellate ganglion nerve block. She developed severe hypotension after the procedure. Morning cortisol was low. The results from the cosyntropin test were consistent with secondary adrenal insufficiency. Her secondary adrenal insufficiency was likely due to long-term use of opioid analgesics for pain in the absence of other etiologies.

Enhancement of brackish water desalination using hybrid membrane distillation and reverse osmosis systems.

Desalination of geothermal brackish water by membrane distillation (MD) provides a low recovery rate, but integrating MD with reverse osmosis (RO) can maximize the production rate. In this study, different design configurations of a hybrid system involving brine recycling and cascading are studied via simulations, and the performance improvement due to the process integration is substantiated via the increased recovery rate and reduced specific energy consumption. Brine recycling is also found to improve the recovery rate considerably to 40% at an energy cost of 0.9 $/m3. However, this achievement is only valid when the final brine is recycled to the RO feed: when the final brine is recycled to the MD feed, the overall performance degrades because the recycled brine cools the feed and causes a serious reduction in the driving force and the consequent production rate. Configuring the hybrid system in multiple stages connected in series increases the recovery rate to 90% and reduces the specific energy consumption to 0.9 MJ/kg. Although the specific energy cost increases dramatically because external inter-stage heating is implemented, using a free energy source (such as a geothermal or waste-energy source) for inter-stage heating could provide the optimum configuration.

Letrozole, an aromatase inhibitor, reduces post-peak age-related regression of rooster reproductive performance.

This study was designed to evaluate orally administrated Letrozole (Lz) on reproductive performance, plasma testosterone and estradiol concentrations and relative abundance of mRNA of GnRH, FSH and LH in roosters. Ross 308 roosters (n=32) that were 40-weeks of age were individually housed and received a basal standard diet supplemented different amounts of capsulated Lz [0 (Lz-0), 0.5 (Lz-0.5), 1 (Lz-1) or 1.5 (Lz-1.5), mg Lz/bird/day] for 12 weeks. Sperm quality variables and plasma testosterone and estradiol concentrations were assessed from the first to the tenth week of the treatment period. Semen samples from the 11th to 12th week were used for artificial insemination and eggs were collected and allotted to assess fertility and hatchability rates. Relative abundance of hypothalamic and pituitary GnRH, LH and FSH mRNA was evaluated at the end of 12th week. The results indicated that total and forward sperm motility as well as egg hatchability rate were greater in the Lz-0.5 group. Greater sperm concentrations, ejaculate volume, sperm plasma membrane integrity, testis index and fertility rates were recorded for both Lz-0.5 and Lz-1 groups compared with the Lz-0 group (P<0.05). Body weight, percentage of sperm abnormalities, and sperm plasma membrane functionality were not affected by treatment. Testosterone and estradiol concentrations were negatively related with greater testosterone concentrations in the Lz-1.5 group which had lesser estradiol concentrations. Relative mRNA transcript abundance for GnRH, LH and FSH was Lz dose responsive being greater in the treated groups; however, this trend plateaued for GnRH and for the relative abundance of both LH and FSH mRNA was less in the Lz-1.5 group than the other treatment groups. It is concluded that Lz may be an effective treatment to improve age related post-peak reproductive performance of roosters.