Full-Factorial Experimental Design to Determine the Impacts of Influential Parameters on the Porosity and Mechanical Strength of LLDEP Microporous Membrane Fabricated via Thermally Induced Phase Separation Method

Membrane separation processes have a wide application in liquid and gas purification industries. They enjoy advantages such as convenient processibility, easy and lower production and operational costs. Thermally induced phase separation (TIPS) process, due to its wide advantages, has won special attention in recent decades. In this process, a homogenous solution of polymer-diluent at a temperature above the polymer melting point is formed and the solution is then cast in the favorite shape. In order to create a porous structure, the diluent is extracted. In this work, microporous LLDPE membrane is fabricated and full factorial experimental design is used to evaluate the individual as well as mutual impacts of polymer concentration, membrane thickness and cooling bath temperature on the porosity and mechanical strength of the membrane. The results obtained from the analysis of variance of membrane porosity and mechanical strength, showed that the impact of cooling bath temperature is much more important than polymer concentration and membrane thickness. Higher cooling bath temperature, lower polymer concentration and membrane thickness result in higher porosity

Study on the Impact of Polymer Concentration and Coagulation Bath Temperature on the Porosity of Polyethylene Membranes Fabricated Via TIPS Method

Microporous high density polyethylene flat membranes were fabricated via thermally induced phase separation (TIPS) method. Effects of polymer concentration and coagulation bath temperature on the membrane morphology and porosity were investigated. To the best of our knowledge, there is no work about the order of magnitude and degree of importance of influential parameters and their interactions on the microstructure of fabricated membranes. The results showed that the porosity of membranes decreased as the polymer concentration increased. It was also shown that, due to the short contact time and rapid phase inversion between coagulation bath and membrane’s outer surfaces, bath temperature mainly affects on the outer surface porosity. The results obtained from analysis of variance (ANOVA) using 95% confidence interval on the membrane porosity revealed that the effect of polymer concentration is more important than coagulation bath temperature

Effects of Curcumin on Iron Overload in Rats

Background: Iron overload, common in patients with hematological disorders, is a key target in drug development. This study investigated the effects of curcumin on iron overload in rats. Methods: Forty male Wistar rats weighing 139.78 ± 11.95 gm (Mean ± SD) were divided into three equal groups: (i) controls; (ii) iron overload group that received six doses of iron dextran 1000 mg/kg–1 by intraperitoneal injections (i.p.); and (iii) iron overload curcumin group that received six doses of curcumin (1000 mg/kg BW by i.p.).  In addition to six doses of iron dextran 1000 mg/kg–1 by i.p., we studied the effects of curcumin on liver function enzymes (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]); antioxidant enzymes (malondialdehyde [MDA], total oxidant status [TOS], total antioxidant status [TAS]); hematological parameters (hemoglobin [Hb], hematocrit [Hct], red blood cells [RBC], white blood cells [WBC], mean corpus volume [MCV], mean corpuscular hemoglobin [MCH], mean corpuscular hemoglobin concentration [MCHC]); and iron parameters (serum iron profile, transferrin, total iron-binding capacity [TIBC], ferritin, and transferrin saturation [TS%]). Results: Curcumin caused a significant decrease in the Hct and Hb concentrations in Group III (P < 0.05). It also significantly reduced the serum levels of ALT (52.45 ± 4.51 vs 89.58 ± 4.65 U/L) and AST (148.03 ± 6.47 vs 265.27 ± 13.02 U/L) at the end of the study (P < 0.05). The TIBC, transferrin levels, and TS significantly decreased when the rats were administered curcumin serum iron (P < 0.05). The TAS level significantly increased in Group III in comparison to Group I (the control group) (P < 0.05). At the end of the study, curcumin significantly reduced the serum levels of TOS (12.03 ± 2.8 vs 16.95 ± 5.05 mmol H2O2/L) while the TAS (1.98 ± 0.42 vs 1.06 ± 0.33 mmol Trolox equiv./L) was increased. Conclusion: The findings of the present study suggest the therapeutic potential of curcumin against iron overload

Embedding neat and carboxylated nanodiamonds into polypropylene membranes to enhance antifouling properties

The aim of the present work is to enhance the antifouling properties of polypropylene (PP) membrane based on hydrophilicity improvement. Different contents of neat and modified nanodiamond (0.25, 0.50, 0.75 and 1.00 wt.%) were embedded into PP membranes. Nanodiamond nanoparticles were carboxylated by heat treatment method and the presence of carboxyl functional groups on the surface of nanoparticles was confirmed by FTIR analysis. Membranes were then characterized by FESEM, contact angle and tensile strength tests. At the same content of nanoparticles, hydrophilicity, pure water flux and tensile strength of PP/ND-COOH membranes were more than those of PP/ND membranes. Membranes embedded with 0.75 wt. % of neat and modified nanoparticles were used in a submerged membrane bioreactor (SMBR) system along with neat PP membrane. The results showed that critical flux values for neat PP, PP/ND and PP/ND-COOH membranes were 7, 18 and 22 L/(m2.h), respectively. Analysis of fouling mechanisms revealed that antifouling properties of 0.75 wt. % PP/ND-COOH membrane were higher than those of other two ones so that irreversible fouling ratio decreased from 88.9% for neat PP to 47.8% for PP/ND-COOH membrane

Anti-fouling behaviors of surface functionalized high density polyethylene membrane in microfiltration of bovine serum albumin protein

An essential characteristic for high performance inherently hydrophobic membranes such as microporous high density polyethylene (HDPE) membranes is to have a hydrophilic surface. In this project, wet chemical functionalization as a facile and effective method was developed to give a hydrophilic property to HDPE membranes using polar functional groups. KClO3, K2Cr2O7 and KMnO4 were selected as oxidizing agents. The optimum concentrations and treatment time intervals were determined for each oxidizing agent. Water contact angle and pure water flux measurements were conducted to evaluate the surface hydrophilicity and membrane performance, respectively. The results showed that among different oxidizing agents, 1wt% K2Cr2O7 solution with 60 min immersion time had the highest impact on the pure water flux. The percentage of re-construction phenomenon was about 4.70%, 21.94% and 32.6% for the HDPE membranes treated by KClO3, K2Cr2O7 and KMnO4, respectively. In addition, the attenuated total reflectance spectra-Fourier transform infrared spectroscopy (ATR-FTIR) results confirmed the presence of hydroxyl groups (O–H peak appeared at 3418.78 cm−1) in the membrane modified by KClO3. Bovine serum albumin (BSA) filtration experiments revealed that the total fouling ratio (TFR) and irreversible fouling ratio (IFR) decreased from 88.10% and 42.60% for pristine membrane to 65%, 68% and 72%and 26.60%, 29.30% and 35% for the modified membranes treated by KClO3, K2Cr2O7 and KMnO4, respectively. The results indicated that incorporation of hydrophilic functional groups on the surface of HDPE membranes improved the fouling resistance behavior

Preparation and characterization of polyethylene/ glass fiber composite membrane prepared via thermally induced phase separation method

Grinded glass fiber (GGF) embedded high density polyethylene (HDPE) membranes were prepared via thermally induced phase separation method. FESEM images showed that all the membranes had leafy structure, indicating a solid-liquid mechanism during phase separation. The results of EDX and TGA analyses confirmed that the fibers were dispersed in the HDPE matrix uniformly. Normalized water flux of the membranes increased from 1 for the neat HDPE membrane to more than 4 for 10 wt% GGF/HDPE membrane. Moreover, the contact angle decreased from 129° to 94° as the GGF content increased in the membranes, showing an improvement in the surface hydrophilicity of the membranes. The AFM results revealed that the surface roughness of the membranes was increased with increasing the GGF content. The results of abrasion test revealed that the GGF/HDPE membranes had a more abrasion resistance than the neat HDPE membrane. Finally, the fouling behavior of the membranes was investigated by the filtration of BSA protein solution and the results showed that with increasing the glass fiber content, total fouling ratio decreased from 90% for the neat HDPE membrane to 62% for 10 wt% GGF/HDPE membrane, indicating that the antifouling properties of the membranes were improved due to the presence of glass fiber

Effects of the nozzle arrangement and aerator configuration in slug bubble production to enhance the foulant removal from a flat sheet membrane bioreactor

Membrane bioreactors (MBRs) are high-tech systems for water recycling and reusing of unconventional water resources such as municipal wastewater. However, the fouling of polymeric membranes is the main impediment to the market development of MBR. The polyolefin-based membranes are subjected to more severe organic fouling than other hydrophilic membranes due to their inherent strong hydrophobic properties, therefore, proposing efficient, fast, and economic fouling mitigation methods is vital for durable and long-standing performance. In this research, the hydrodynamics of a lab-scale membrane bioreactor with different configurations of aerators and nozzle sizes were used to investigate the air scouring efficiency. It was gained that aerators with higher air flow rates, e.g., 5.5 m/s can produce slug bubbles which are capable of foulant removal from the membrane surface. In comparison with a non-central aerator, the satisfactory scouring zone of the central aerator is narrow and the edge nozzles on both sides of the aerator are blocked. Under constant air flow rate, when the inlet air is injected into the aerator from two and three points, not only the end nozzles are blocked but also the liquid is penetrated into the aerator and the shear stress on the membrane surface decreased to 0.765 Pa. In the case of the non-central aerator, the satisfactory scouring zone becomes wider and neither nozzle blockage nor liquid penetration down to the aerator has occurred. The distribution of bubbles was optically evaluated by video imaging through the transparent plexiglass tank using aerators with different inlet flow rates and various configurations. Numerical simulations and related experimental analyses demonstrated that air inlet velocity has an important role in creating larger slug bubbles. It was shown that a non-central aerator in which the central nozzle in front of the inlet air stream is blocked, produces slug bubbles and sufficient air scoring on the flat sheet membrane. Configuration of a non-central aerator with 4 nozzles not only increased the satisfactory zone of each aerator without blockage of edge nozzles and liquid penetration into the aerator but also provided a higher shear rate over 1.104 Pa under a constant flow rate, which consequently removed the foulant from the membrane surface

The effects of daylight exposure on melatonin levels, Kiss1 expression, and melanoma formation in mice

Aim To determine how daylight exposure in mice affects melatonin protein expression in blood and Kiss1 gene expression in the hypothalamus. The second aim was to assess the relationship between skin cancer formation, daylight exposure, melatonin blood level, and kisspeptin gene expression level. Methods New-born mice (n = 96) were assigned into the blind group or daylight group. The blind group was raised in the dark and the daylight group was raised under 12 hours light/12 hours dark cycle for 17 weeks. At the end of the 11th week, melanoma cell line was inoculated to mice, and tumor growth was observed for 6 weeks. At the end of the experiment, melatonin level was measured from blood serum and Kiss1 expression from the hypothalamus. Results The blind group had significantly higher melatonin and lower Kiss1 expression levels than the daylight group. Tumor volume was inversely proportional to melatonin levels and directly proportional to Kiss1 expression levels. Tumor growth speed was lower in the blind than in the daylight group. Conclusion Melatonin and Kiss1 were shown to be nvolved in tumor suppression. They were affected by daylight and were mutually affected by each other

Gebe farelerde ve yavrularında ağrı eşiği, depresyon, öğrenme - hafıza üzerine müziğin etkisinin araştırılması

Duyguları yoğunlaştıran bir özelliğe sahip müzik birçok medeniyette dini duyguların güçlenmesi ve hastalıkların tedavisinde yaygın bir yöntem olarak kullanılmıştır. Müzik, etkileyici özelliğinden dolayı psikolojik ve fizyolojik bozuklukların tedavisi için araştırılmıştır. Müzik terapisi, tansiyon düşürme, vücudun yatıştırılması, ağrının azalması gibi birçok hastalığın tedavisinde sağlık hizmetleri kapsamında gelişen bir alan haline gelmiştir. Müzik, sıkıntılı tedavi süreçlerinde hastaları rahatlatmakta, kronik ağrıları kontrol altına almayı sağlamakta, felçli, parkinson ve alzaimer hastalarının tedavisine yardımcı olmakta, bebeklerin ve embriyoların beyin ve zeka gelişimini arttırmaktadır. Müziğin, üzerinde kısmen de olsa durulmuş olan hususlardan biri de hayvanlar üzerindeki etkileridir. Genellikle hayvanların tepkilerine ve üretkenliklerine odaklandığı düşünülen bazı örnekler, müziğin hayvanları da etkileyen bir güce sahip olduğunu göstermektedir. Müziğin etkisinin denendiği pek çok çalışmadan da anlaşılmaktadır ki tüm canlıların vücut işleyişleri, ritimleri, hareketleri, duyduğu uyaranlar gibi etkilerin müzik ile etkili hale getirilebileceği görülmektedir. Hayvanlar arasında, fareler müzikten en çok etkilenen türlerden biridir. Fareler üzerinde müzikle tedavi amaçlı çalışmalar yapıldığı ve anlamlı sonuçlara ulaşıldığı görülmektedir. Bu çalışmalardan yola çıkarak gebe fareler ve yavrularına müzikle tedavi yöntemi uygulanarak belirli sonuçlar elde edilmeye çalışılmıştır. Araştırmada Balb/c türü dişi ve erkek fareler kullanılmıştır. Gebe kalan dişi farelere gebeliği boyunca ve yavrularına yetişkinlik süresine ulaşıncaya kadar belirlenen müzik türü dinletilmiştir. Farelerde ve yavrularında ağrı eşiği, depresyon ve öğrenme-bellek farklılıklarını ortaya çıkarmak için sırasıyla kuyruk çekme refleksi ve sıcak plaka testi, zorunlu yüzdürme testi ve barnes labirenti testi uygulanmıştır. Kontrol ve deney gruplarına uygulanan davranış testleri sonrasında, müzikte prenatal ve postnatal dönemlerdeki psikofizyolojik değişiklikler incelenmiştir. Barnes Labirenti, Zorunlu Yüzme Testi, Tail Flick Analjezi Ölçüm Testi ve Hot Plate Analjezi Ölçüm Testi verileri tek yönlü varyans analizi (ANOVA), post hoc Tukey’in çoklu karşılaştırmalar testi ile değerlendiriliştir . Elde edilen sonuçlar ile müzik dinletilen deney grubunun kontrol grubuna kıyasla depresyona daha dirençli olduğu, öğrenmenin belleğe aktarılmasında az da olsa etkisi olduğu ve ağrılı uyarana karşı daha dirençli olduğu belirlenmiştir

The role of climatic-design-operational parameters on combined PV/T collector performance: a critical review

PV/T technology attracted numerous researchers and professionals during the last decades. There are many review papers in the literature evaluated the R&D aspects of PV/T collectors. In fact, there are abundant of case studies discussed the parameters of climate, design and operational conditions affected the PV/T collector performance. But, a comprehensive compilation of the information of those case studies is still a missing link in the literature. Hence, this paper intended to review thoroughly the information regarding the parameters affecting the PV/T collector performance mainly and PV module performance partially. The parameters are supported with the most available R&D to measure the accurate influence of each parameter on the performance. The outcomes from the study are highlighted in lessons learned section