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• The performance of modified hemispheric solar still was investigated. • Multi additives were applied: V-corrugated basin, black cotton wick, paraffin wax PCM, and sheep fat PCM. • The freshwater productivity was maximumly augmented by 39.6 %. • The thermal performance improvement reached 39.75 % (energy) and 44.04 % (exergy). • The freshwater price was reduced by 17.5 % using all additives. Solar still is a developing solar desalination method that has been introduced to face the shortage of freshwater with low energy consumption. However, this method is challenged by its low productivity. Therefore, the following work aimed to improve the freshwater productivity and reduce the produced water price. Herein, the performance of a hemispheric solar still equipped with four alternative combinations was experimentally studied; and its thermo-economic performance was assessed. The experimental work had four stages, firstly the distiller's flat basin was replaced by a V-corrugated basin. Secondly, the corrugated basin was covered with a black cotton wick material. Thirdly, paraffin wax, as a phase change material (PCM), was contained under the wick-coated corrugated basin for latent thermal storage purpose. Finally, paraffin was replaced with sheep fat PCM. Each modified distiller was compared to a conventional one from 8 A.M. until 9 P.M. under the climate conditions of Suez City, Egypt lies at (29. 5825 °N, 32.5734°E) in terms of the thermal performance, daily productivity, and freshwater price. The four cases showed increasing in the daily productivity by ratios of 11 %, 25.7 %, 34.1 %, and 39.6 % respectively. The fourth case showed the best water productivity and thermal performance. It had daily productivity of 4737.5 mL/m2 and 45 % thermal efficiency. Furthermore, the thermal performance in terms of the thermal and exergy efficiencies improved by 39.75 % and 44.04 %, whereas the average total heat transfer coefficient increased by 5.5 %. Moreover, the freshwater price was 0.0137 $/L, likewise, 17.5 % cost reduction. [ABSTRACT FROM AUTHOR]

Objective: Chronic hand eczema (CHE) is a common inflammatory skin disease with a major psychological and socioeconomic impacts on patients' quality of life (QoL) and work ability. To the best of knowledge, this study is the first randomized-controlled trial conducted to evaluate the effect of paraffin bath therapy in management of hand eczema and its related symptoms. Design: This study was a parallel-group, active-control, randomized clinical trial with measures at pretreatment, 6th week, and 12th week of treatment. Settings: The study took place at the Outpatient Clinic of Faculty of Physical Therapy, Cairo University, and some licensed rehabilitation centers in Cairo for a 1-year period. Subjects: Sixty patients with moderate to severe CHE were randomly assigned into two groups of equal number; the paraffin bath therapy group and the control group. Interventions: The paraffin group received paraffin bath therapy for 5 days a week for 12 weeks, in addition to the routine skin care program, while the control group only received the routine skin care program. Outcome measures: SCORing Atopic Dermatitis (SCORAD) was used to assess the severity of atopic dermatitis and dermatology life quality index (DLQI) to assess the effect of CHE on quality of patients' life. All measurements were obtained before, at the 6th week, and at the 12th week of treatment. Results: Marked improvement in the severity of the disease symptoms was observed, reflected by a highly decrease in objective SCORAD score in the paraffin group over time more than the control group. The percentage of reduction was 28.6% in paraffin group versus 0.41% in control group. Subjective item score (itching and sleepiness) was reduced in the paraffin group more than the control group with a percentage of improvement (47% and 5.5%), respectively. Regarding QoL measure, there were highly positive changes in DLQI in paraffin group more than the control group. The percentage of improvement was 60% in paraffin group and 3.8% in control group. Conclusions: Paraffin bath therapy applied for a 12-week duration seems to be effective, both in reducing severity of eczema symptoms and improving QoL in patients with CHE. [ABSTRACT FROM AUTHOR]

Polymeric flow improvers represent one of the most important chemicals used in oil industry especially with waxy crudes. The chemical structure of such chemicals is particularly important. In this study, we prepared a family of additives by chemical modification of octadecene- co -maleic anhydride copolymers (OM). The copolymerization of octadecene (OD) with maleic anhydride (MA) was performed at variable ratios of OD:MA (1:1, 1:2 and 2:1). OM copolymers were chemically modified by grafting three different alcohols: dodecanol, hexadecanol or docosanol. Grafts were characterized through molecular weight using GPC, melting temperature and enthalpy of melting by DSC and chemical structure through 1 HNMR. The comb-like copolymers were assessed as flow improvers for an Egyptian waxy crude oil by measuring their performance as pour point depressants in addition to their assessment as viscosity improvers through rheological behavior. The data indicate that the additive must retain a hydrophobic–lypophobic balance, low crystallinity and matching melting temperature with that of crude wax in order to inhibit the paraffin and wax crystal depositions. [ABSTRACT FROM AUTHOR]

In this study, a paraffin/aluminum foam (AF) composite for thermal regulation of a photovoltaic (PV) system was performed. A comparative performance evaluation of three PV systems, i.e., PV without any modifications, PV incorporated with paraffin wax as phase change material PCM (PV-PCM), and PV incorporated with enhanced PCM comprising AF embedded in PCM (PV-PCM/AF) was performed. Outdoor experiments were conducted in summer and winter weather conditions of Benha city, Egypt, located at (latitude 30.466° North and longitude 31.185° East). The comparative analysis of the three PV configurations based on electrical efficiency, exergy efficiency, energy payback time, exergoeconomic, and enviroeconomic parameters was presented and discussed. The findings revealed that, against the unmodified PV configuration, the electrical efficiency of PV-PCM and PV-PCM/AF systems in summer was enhanced by 9% and 14%, respectively. While, the corresponding enhancement in winter was 3.7% and 4.8%, respectively. Also, it was found that the cost of electricity generation for PV-PCM and PV-PCM/AF systems was 0.1165 and 0.1145 $/kWh, respectively, against 0.1162 $/kWh for the PV system. Finally, it can be concluded that PV-PCM/AF is the most effective system based on exergy efficiency, exergy cost, and CO 2 avoidance rates. • A comparative 4 E performance analysis of PV, PV-PCM, and PV-PCM/AF was performed. • Using AF with PCM shortened the melting time by 37%. • Using AF with PCM enhanced the average electrical efficiency by 14%. • PV-PCM/AF is the most effective system based on exergoeconomic parameter and CO 2 mitigations. [ABSTRACT FROM AUTHOR]