•The performance of solar still coupled with parabolic trough collector (PTC) was experimentally studied.•Freshwater productivity for solar still with PTC is higher than that for conventional solar ...still.•Daily productivity of conventional solar still and solar still with tracked PTC is 10.93 and 4.51 kg/m2 in summer.•The efficiency of solar still in summer is greater than winter and the efficiency of conventional solar still is the largest.•Cost of one liter of yield freshwater for solar still with tracked PTC is the lowest (0.0234 $/L).
The performance of coupling parabolic trough collector (PTC) with double slope solar still is investigated experimentally. The incident solar energy on the PTC is transferred to the solar still by oil pipes connected with finned-piped loop heat exchanger imbedded in the solar still. The experiments are conducted at summer and winter times for three systems; conventional solar still, solar still with fixed PTC and with tracked PTC and for two cases of saline water depth in the basin 20 and 30 mm. The results illustrate that the solar still with PTC has higher sill temperature and productivity compared with conventional solar still. The freshwater productivity of solar still with tracked PTC is higher than that of fixed PTC by about 28.1% and for conventional solar still by about 142.3% at saline water depth 20 mm in summer. Freshwater productivity is about 8.53 kg/m2/ day and 4.03 kg/m2/day for solar still coupled with fixed PTC in the summer and winter respectively. The results also illustrate that the performance of solar still in winter is smaller than summer for all studied cases and systems. In summer and at saline water depth 20 mm, the daily efficiency of the conventional solar still, solar still with fixed PTC and solar still with tracked PTC are 36.87, 23.26 and 29.81% respectively.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The coronavirus has come to the world and spread with great wide among the countries of the world and has resulted in numerous infections that exceeded 167,181,023 million patients and are close to ...3.5 deaths by September 2021. It also brought with it panic and fear, halted many activities, and led to the decline of the global economy. It changed human behavior and forced people to change their lifestyles to avoid infection. One of the most sectors that must be taken into consideration through pandemic coronavirus (COVID-19) around the globe is the air conditioning systems. The HVAC systems depend on the air as a heat transfer medium. The air contains a group of pollutants, viruses, and bacteria, and it affects and destroys human life. The air filter plays a major role as an important component in the air conditioning systems. Thus, it requires more effort by researchers to improve its design to prevent the ultra-size of particles loaded with coronavirus (COVID-19). This paper provides insight into the design of existing combined air-conditioners on their suitability and their impact on the spread of the hybrid coronavirus epidemic and review efforts to obtain a highly efficient air filter to get rid of super-sized particles for protection against epidemic infection. In addition, important guideline recommendations have been made to limit the spread of the COVID-19 virus and to obtain indoor air quality in air-conditioned places.
•Indoor air quality is important in our society and provides healthy human comfort.•Increasing the temperatures and humidity dampen the activity of the COVID-19.•The air carries suspended particles of the COVID-19, which leads to an increase in infected cases.•Improper use of filters leads to spread of the bacterial and viruses' indoor environment.•Mandatory recommendations are drawn to benefit the global community to limit the spread of the deadly COVID-19.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this study, for the environmental development, the antifungal, antibacterial, and antioxidant activities of a water extract of flowers from
(Labill.) H. L. Wendl. were evaluated. The extract ...concentrations were prepared by dissolving them in 10% DMSO. Wood samples of
were treated with water extract, and the antifungal activity was examined at concentrations of 0%, 1%, 2%, and 3% against three mold fungi;
MH352452,
MH352450, and
MH352451 that cause root rot, cankers, and green fruit rot, respectively, isolated from infected
L. Antibacterial evaluation of the extract was assayed against four phytopathogenic bacteria, including
and
, using the micro-dilution method to determine the minimum inhibitory concentrations (MICs). Further, the antioxidant capacity of the water extract was measured via 2,2'-diphenylpicrylhydrazyl (DPPH). Phenolic and flavonoid compounds in the water extract were analyzed using HPLC: benzoic acid, caffeine, and
-coumaric acid were the most abundant phenolic compounds; while the flavonoid compounds naringenin, quercetin, and kaempferol were identified compared with the standard flavonoid compounds. The antioxidant activity of the water extract in terms of IC
was considered weak (463.71 μg/mL) compared to the standard used, butylated hydroxytoluene (BHT) (6.26 μg/mL). The MIC values were 200, 300, 300, and 100 µg/mL against the growth of
,
,
, and
, respectively, which were lower than the positive control used (Tobramycin 10 μg/disc). By increasing the extract concentration, the percentage inhibition of fungal mycelial was significantly increased compared to the control treatment, especially against
, suggesting that the use of
flower extract as an environmentally friendly wood bio-preservative inhibited the growth of molds that cause discoloration of wood and wood products.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Arsenic (As) recognized as a group I human carcinogen additionally poses a threat to plants which limit growth, metabolic activity, and productivity. Melatonin (MEL) is a naturally occurring compound ...in plants that have been recognized to mediate numerous morphological, physiological and molecular processes. Conversely, the role of MEL in inducing As-tolerance remains inexpressible and the plausible mechanisms in inducing As tolerance have remained largely unknown. The present investigation was designed to understand the protective role of MEL concentrations in rosemary herbs cultivated under As contamination.
Arsenic evoked a deleterious decline on herb productivity, photosynthetic pigment, ion concentration, water status, ascorbic acid, essential oil (EO) yield and induced malformation of the chloroplast. Alternatively, increased organic osmolytes, oxidative impairment criteria, additionally antioxidant enzymes, phenol, flavonoid, anthocyanin, and EO%. Exogenous application of MEL with or without As, considerably increased growth, photosynthetic pigment, ion concentration, organic osmolytes as well as EO yield regarding polluted or non-polluted treatment respectively. Moreover, MEL treatment stabilized the cell membrane integrity, suppressed oxidative impairment criteria, and enhanced antioxidant capacity, additionally upregulation antioxidant enzymes.
Plant treated with As showed a significant increase in As contamination and a bioconcentration factor in both root and shoot system. MEL supplementation under normal or As concentration, reduced As accumulation and bioconcentration factors, in either shoot or root systems. Additionally As decrease transfer factor, however, supplementation of MEL further decreased it.
Application of 50 μM MEL might help the herbs to withstand As stress by strengthening their antioxidant machinery and osmoregulation capacity.
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•Arsenic hampered rosemary growth and essential oil yield.•Arsenic evoked oxidative stress.•Exogenous MEL improved growth and decreased cytotoxic ROS and MDA.•Melatonin counteracts the malformation in cell organelles.•Application of melatonin may compensate from the arsenic injury.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The green synthesis of silver nanoparticles (SNPs) using plant extracts is an eco-friendly method. It is a single step and offers several advantages such as time reducing, cost-effective and ...environmental non-toxic. Silver nanoparticles are a type of Noble metal nanoparticles and it has tremendous applications in the field of diagnostics, therapeutics, antimicrobial activity, anticancer and neurodegenerative diseases. In the present work, the aqueous extracts of aerial parts of Lampranthus coccineus and Malephora lutea F. Aizoaceae were successfully used for the synthesis of silver nanoparticles. The formation of silver nanoparticles was early detected by a color change from pale yellow to reddish-brown color and was further confirmed by transmission electron microscope (TEM), UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), and energy-dispersive X-ray diffraction (EDX). The TEM analysis of showed spherical nanoparticles with a mean size between 12.86 nm and 28.19 nm and the UV- visible spectroscopy showed λmax of 417 nm, which confirms the presence of nanoparticles. The neuroprotective potential of SNPs was evaluated by assessing the antioxidant and cholinesterase inhibitory activity. Metabolomic profiling was performed on methanolic extracts of L. coccineus and M. lutea and resulted in the identification of 12 compounds, then docking was performed to investigate the possible interaction between the identified compounds and human acetylcholinesterase, butyrylcholinesterase, and glutathione transferase receptor, which are associated with the progress of Alzheimer's disease. Overall our SNPs highlighted its promising potential in terms of anticholinesterase and antioxidant activity as plant-based anti-Alzheimer drug and against oxidative stress.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this work, the performance characteristics of a vapor compression refrigeration system associated with a chilled water air conditioning unit utilized nanofluids (Al2O3, TiO2, and a hybrid of ...Al2O3/TiO2 based H2O) were experimentally investigated. The tested parameters were; nanoparticle concentration, nanoparticle type, nanofluid flow rate, nanoparticle hybridization ratios, and air velocity. The study incorporated different concentration ratios of nanoparticles 0.05, 0.1, 0.2, 0.3, 0.4, 0.6 and 1% for Al2O3/H2O whereas 0.1, 0.3, 0.4, 0.6 and 1% for TiO2/H2O. Five different concentrations of hybrid nanoparticles Al2O3/TiO2 were employed by 0.1/0.1, 0.2/0.1, 0.3/0.1, 0.3/0.2 and 0.3/0.3 wt%. Experiments were done at air velocity ranging 0.61–1.9 m/s whilst the fluid flow rate was varied by 0.12–0.3 m3/s. Experimental results indicated that the single nanofluid of Al2O3/H2O contributed a higher coefficient of performance and a lower elapsed time for cooling the fluid of a chiller system. Higher values of the VCRS coefficient of performance were obtained at lower values of air velocity of air conditioner and higher values of the nanofluid flow rate of the chiller unit. The Al2O3/H2O provided lower values of compression ratio and higher values of the refrigeration effect in comparison with TiO2/H2O by approximately 4.1% and 5.3%, respectively.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Parabolic trough/parabolic dish-desalination plant designs were critically reviewed.•A performance assessment and economic analyses of hybrid desalination plants are analyzed.•RO plant powered by ...parabolic trough is more economical than parabolic trough-MED-TVC plant.•Hybrid MED-RO system with parabolic trough is a promising technology.•System performance characteristics, challenges, and future strategies are discussed.
In this review, current status and recent progress in concentrated solar power (CSP) desalination technology has been presented. Special focus has been considered for designs and hybridization configurations, thermodynamic performance assessment, and economic analyses of hybrid solar desalination systems driven by only the parabolic trough, or/parabolic dish CSP systems. Studies that combined solar parabolic trough/dish with different desalination technologies such as multi-effect distillation (MED), reverse osmosis (RO), humidification-dehumidification (HDH), multi-stage flash (MSF), and thermal vapor compression (TVC) either for only freshwater production or for co-generation of power and freshwater are discussed in details. Comparison among the reviewed solar concentrated parabolic trough desalinating systems shows that the MED-TVC system powered by parabolic trough solar field is more appropriate than a parabolic trough-RO combination from a thermodynamic viewpoint. In addition, solar parabolic trough and dish collectors can operate the thermal cycles to drive RO desalination system with lower cost of producing water than the MED process. It can be concluded that adopting parabolic trough CSP-desalination technology was a better option for improving the economic advantages of hybrid CSP-desalination industry than adopting parabolic dish CSP-desalination technology. Furthermore, the hybrid MED-RO system with parabolic trough technology is characterized by high reliability, high freshwater generating efficiency, and low desalination cost. Nevertheless, more theoretical and experimental data are needed to optimize these hybrid systems to gain higher efficiency and lower operating cost in the future.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, SAZU, SBCE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
Brain tumor classification is a crucial task to evaluate the tumors and make a treatment decision according to their classes. There are many imaging techniques used to detect brain tumors. However, ...MRI is commonly used due to its superior image quality and the fact of relying on no ionizing radiation. Deep learning (DL) is a subfield of machine learning and recently showed a remarkable performance, especially in classification and segmentation problems. In this paper, a DL model based on a convolutional neural network is proposed to classify different brain tumor types using two publicly available datasets. The former one classifies tumors into (meningioma, glioma, and pituitary tumor). The other one differentiates between the three glioma grades (Grade II, Grade III, and Grade IV). The datasets include 233 and 73 patients with a total of 3064 and 516 images on T1-weighted contrast-enhanced images for the first and second datasets, respectively. The proposed network structure achieves a significant performance with the best overall accuracy of 96.13% and 98.7%, respectively, for the two studies. The results indicate the ability of the model for brain tumor multi-classification purposes.
Preoxygenation before anesthetic induction and tracheal intubation is a widely accepted maneuver, designed to increase the body oxygen stores and thereby delay the onset of arterial hemoglobin ...desaturation during apnea. Because difficulties with ventilation and intubation are unpredictable, the need for preoxygenation is desirable in all patients. During emergence from anesthesia, residual effects of anesthetics and inadequate reversal of neuromuscular blockade can lead to hypoventilation, hypoxemia, and loss of airway patency. In accordance, routine preoxygenation before the tracheal extubation has also been recommended. The objective of this article is to discuss the physiologic basis, clinical benefits, and potential concerns about the use of preoxygenation. The effectiveness of preoxygenation is assessed by its efficacy and efficiency. Indices of efficacy include increases in the fraction of alveolar oxygen, increases in arterial oxygen tension, and decreases in the fraction of alveolar nitrogen. End points of maximal preoxygenation (efficacy) are an end-tidal oxygen concentration of 90% or an end-tidal nitrogen concentration of 5%. Efficiency of preoxygenation is reflected in the rate of decline in oxyhemoglobin desaturation during apnea. All investigations have demonstrated that maximal preoxygenation markedly delays arterial hemoglobin desaturation during apnea. This advantage may be blunted in high-risk patients. Various maneuvers have been introduced to extend the effect of preoxygenation. These include elevation of the head, apneic diffusion oxygenation, continuous positive airway pressure (CPAP) and/or positive end-expiratory pressure (PEEP), bilevel positive airway pressure, and transnasal humidified rapid insufflation ventilatory exchange. The benefit of apneic diffusion oxygenation is dependent on achieving maximal preoxygenation, maintaining airway patency, and the existence of a high functional residual capacity to body weight ratio. Potential risks of preoxygenation include delayed detection of esophageal intubation, absorption atelectasis, production of reactive oxygen species, and undesirable hemodynamic effects. Because the duration of preoxygenation is short, the hemodynamic effects and the accumulation of reactive oxygen species are insufficient to negate its benefits. Absorption atelectasis is a consequence of preoxygenation. Two approaches have been proposed to reduce the absorption atelectasis during preoxygenationa modest decrease in the fraction of inspired oxygen to 0.8, and the use of recruitment maneuvers, such as CPAP, PEEP, and/or a vital capacity maneuver (all of which are commonly performed during the administration of anesthesia). Although a slight decrease in the fraction of inspired oxygen reduces atelectasis, it does so at the expense of a reduction in the protection afforded during apnea.
•Develops a two-level dual-channel supply chain with online customization and returns.•Pricing, production/ordered quantity, and number of shipments are decision variable.•The effect of different ...return policies on the optimal decisions is considered.•The dual-channel strategy outperforms the single-channel strategy.•Extensive analysis was performed with managerial insights and findings provided.
In the last few decades, the rapid development of e-commerce technologies has encouraged many manufacturers to adopt an online channel in addition to their existing traditional retail channel, which resulted in redesigning their supply chain channel structure. Additionally, an increasing number of manufacturers nowadays offer a return policy to attract more customers and to stay competitive. This paper studies a supply chain system, which is comprised of production, refurbishing, collection, and waste disposal processes. A return policy in which customers can return the purchased item for a refund is also considered. Two selling strategies, a single-channel strategy (i.e., a retail channel) and a dual-channel (i.e., a retail channel and an online channel) strategy are discussed from which mathematical models are developed. The purpose is to examine the effect of different return policies on the behavior of SC systems before and after adopting the dual-channel. In both strategies, the paper analyzes the change in the profit, the pricing and inventory decisions. Numerical examples and sensitivity analyses are provided with their results discussed. The findings of this paper demonstrate that in both strategies, the more generous the return policy is, the higher the demand, the selling prices and the overall profit. The findings also indicate that adopting a dual-channel strategy is more profitable to the supply chain.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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