179 research outputs found

    An experimental investigation of the effective parameters on wet washing of biodiesel purification

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    The purity level of biodiesel has a strong effect on fuel properties and on engine life. Therefore, a purification step is necessary. Generally, there are two accepted methods for purifying biodiesel: wet washing and dry washing. In this research, the effective parameters on wet purification of biodiesel were investigated. Three types of biodiesel wash water (tap water, distilled water and water with 3% phosphoric acid), three wet washing temperatures (30, 45 and 60°C), and three levels of water to biodiesel ratios (0.5, 1 and 1.5 v/v) were used. In order to perform the wet washing of biodiesel, a bubble washing technique was used. The catalyst, soap and water residue were considered as the criteria to choose the optimum water washing condition and were measured after the wet washing of crude biodiesel. The results showed that the best condition for catalyst and soap removal from biodiesel are acidified water, a temperature of 60°C and a water to biodiesel ratio of 1.5 (v/v). Also, the least amount of water residue in the final purified biodiesel was observed when using tap water at a temperature of 60°C and a water to biodiesel ratio of 0.5 (v/v)

    The most useful medicinal herbs to treat diabetes

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    Diabetes mellitus is a syndrome that is characterized by hyperglycemia, change in the metabolism of lipids, carbohydrates, and proteins, and in the long term, with eye, kidney, cardiovascular, and neurological complications. Plenty of plants from different regions of the world have been investigated for anti-diabetic effects. This review article was designed to report some of the most important medicinal plants with hypoglycemic properties according to reliable clinical and laboratory evidence, and also touched on the medicinal plants that are prescribed in Iranian traditional medicine, for the treatment of diabetes. The information in this review was obtained from the eligible articles retrieved using the search terms diabetes mellitus, medicinal plants, type 1 diabetes and medicinal plants, type 2 diabetes and medicinal plants, and the effect of extract and essential oil of medicinal plants affecting diabetized tissues in the human body indexed in databases such as Iran medex, Irandoc, ISI, PubMed, Scopus, SID, Magiran, Google Scholar, etc. Based on the results drawn in this review the plants, Urtica, Trigonella foenum-graecum, Allium sativum, Carthamus tinctorius, Ferula assa-foetida, Bauhinia, Gymnema sylvestre, Swertia, Combretum, Sarcopoterium, Liriope, Caesalpinia bonduc, Coccinia grandis, Syzygium cumini, Mangifera indica, Momordica charantia, Ocimum tenuiflorum, Pterocarpus, Tinospora cordifoli, Salvia officinalis, Panax, Cinnamomum verum, Abelmoschus moschatus, Vachellia nilotica, Achyranthes, Fabaceae, Mentha, Asphodelaceae, Andrographis paniculata L, Artemisia herba-alba, Artemisia dracunculus, Azadirachta indica, Caesalpinioideae, Pachira aquatic, Gongronema latifolium, Nigella Sativa, Tinospora cordifolia (guduchi), Chrysanthemum morifolium, Zingiber zerumbet, Symphytum, Cactaceae, Symplocos, Perilla frutescens, Terminalia chebula and Aloe vera are effective to controland treat diabetes

    The most useful medicinal herbs to treat diabetes

    Get PDF
    Diabetes mellitus is a syndrome that is characterized by hyperglycemia, change in the metabolism of lipids, carbohydrates, and proteins, and in the long term, with eye, kidney, cardiovascular, and neurological complications. Plenty of plants from different regions of the world have been investigated for anti-diabetic effects. This review article was designed to report some of the most important medicinal plants with hypoglycemic properties according to reliable clinical and laboratory evidence, and also touched on the medicinal plants that are prescribed in Iranian traditional medicine, for the treatment of diabetes. The information in this review was obtained from the eligible articles retrieved using the search terms diabetes mellitus, medicinal plants, type 1 diabetes and medicinal plants, type 2 diabetes and medicinal plants, and the effect of extract and essential oil of medicinal plants affecting diabetized tissues in the human body indexed in databases such as Iran medex, Irandoc, ISI, PubMed, Scopus, SID, Magiran, Google Scholar, etc. Based on the results drawn in this review the plants, Urtica, Trigonella foenum-graecum, Allium sativum, Carthamus tinctorius, Ferula assa-foetida, Bauhinia, Gymnema sylvestre, Swertia, Combretum, Sarcopoterium, Liriope, Caesalpinia bonduc, Coccinia grandis, Syzygium cumini, Mangifera indica, Momordica charantia, Ocimum tenuiflorum, Pterocarpus, Tinospora cordifoli, Salvia officinalis, Panax, Cinnamomum verum, Abelmoschus moschatus, Vachellia nilotica, Achyranthes, Fabaceae, Mentha, Asphodelaceae, Andrographis paniculata L, Artemisia herba-alba, Artemisia dracunculus, Azadirachta indica, Caesalpinioideae, Pachira aquatic, Gongronema latifolium, Nigella Sativa, Tinospora cordifolia (guduchi), Chrysanthemum morifolium, Zingiber zerumbet, Symphytum, Cactaceae, Symplocos, Perilla frutescens, Terminalia chebula and Aloe vera are effective to controland treat diabetes

    Comparison of topical paromomycin sulfate (twice/day) with intralesional meglumine antimoniate for the treatment of cutaneous leishmaniasis caused by L. major

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    This is an open study to compare the cure rate of cutaneous leishmaniasis caused by L. major and treated with either paromomycin sulfate or intralesional injection of meglumine antimoniate. Sixty parasitologically proven cases with 1-3 lesions were included and divided randomly into two equal groups; one group received 1 ml of meglumine antimonate intradermally every other day for 20 days, the other group received the ointment containing 15 parmomycin sulfate in urea twice daily for 20 days. The patients were clinically evaluated at 1 and 6 weeks after treatment was completed. The results of clinical evaluation at 1 week after treatment completed showed a cure rate of 18 out of 27 (66) in the meglumine antimonate injected group and 20 out of 29 (68) in the paromomycin sulfate treated group. The chi square test was used to compare the cure rate between the two groups and showed no significant difference (p = 0.85)

    Numerical study of rolling process on the plastic strain distribution in wire + arc additive manufactured Ti-6Al-4V

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    Wire+arc additive manufacturing (WAAM) is an additive manufacturing (AM) process that employs wire as the feedstock and an arc as energy source, to construct near net-shape components at high build rates. Ti-6Al-4V deposits typically form large columnar prior β grains that can grow through the entire component height, leading to anisotropy and lower mechanical properties, compared to the equivalent wrought alloy. Cold-working techniques such as rolling can be used to promote grain refinement in Ti-6Al-4V WAAM parts, thus increasing strength and eliminating anisotropy concomitantly. Additionally, rolling can be beneficial in terms of reduction of residual stress and distortion. The aim of this study is to illustrate the effect of rolling process parameters on the plastic deformation characteristics in Ti-6Al-4V WAAM structures. To produce a certain refinement of the microstructure, a certain amount of strain is typically required; thus suitable design guidelines for practical applications are needed. The effect of different rolling process parameters, in particular, rolling load and roller profile radius on the plastic strain distribution is investigated based on the finite element method. From a numerical point of view, the effect of the stiffness of the roller is investigated, e.g. deformable vs. rigid roller. Results indicate that for an identical rolling load, the deformable roller produces lower equivalent plastic strains due to its own elastic deformation. Additionally, a lower friction coefficient produces higher equivalent plastic strains near the top surface but, it has an insignificant effect on the plastic deformation further away from the top surface. However, numerically the computation time significantly increased for a higher friction coefficient. Larger roller profile radii lead to lower plastic strain near the top surface, but simultaneously had nearly no noticeable effect on plastic strains at deeper depth. In addition, the effect of interspace between rollers on the uniformity of the plastic strain during multi-pass rolling was investigated for a selected example. The results show that a higher uniform plastic strain distribution is obtained when the interspace between two rollers is equal to the residual width of the groove produced by a single rolling pas

    Numerical investigation of the effect of rolling on the localized stress and strain induction for wire + arc additive manufactured structures

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    Cold rolling can be used in-process or post-process to improve microstructure, mechanical properties and residual stress in directed-energy-deposition techniques, such as the high deposition rate wire + arc additive manufacturing (WAAM) process. Finite element simulations of the rolling process are employed to investigate the effect of rolling parameters, in particular rolling load and roller profile radius on the residual stress field as well as plastic strain distribution for the profiled roller. The results show the response to rolling of commonly used structural metals in WAAM, i.e., AA2319, S335JR steel and Ti-6Al-4V, taking into account the presence of residual stresses. The rolling load leads to changes in the location and the maximum value of the compressive residual stresses, as well as the depth of the compressive residual stresses. However, the roller profile radius only changes the maximum value of these compressive residual stresses. Changing the rolling load influences the equivalent plastic strain close to the top surface of the wall as well as in deeper areas, whereas the influence of the roller profile radius is negligible. The plastic strain distribution is virtually unaffected by the initial residual stresses prior to rolling. Finally, design curves were generated from the simulations for different materials, suggesting ideal rolling load and roller profile combinations for microstructural improvement requiring certain plastic strains at a specific depth of the additive structure

    Association of vitamin D level and vitamin D deficiency with risk of preeclampsia: A systematic review and updated meta-analysis

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    Objectives: Because of the immune modulatory effects of vitamin D3 in preeclampsia, we intend to have a systematic review and meta-analysis on association of both 25-hydroxy vitamin D (25-OHD) level (parametric approach) and 25-OHD deficiency (non-parametric approach) with preeclampsia. As well, for the parametric part, we used receiver operating characteristic (ROC) curve model. Materials and methods: We used Web of Science, PubMed and Science Direct data bases through searching in titles. Google Scholar search engine was used in order to find missing papers. Finally 23 studies were imported. Both random and fixed models were reported. Results: Based on the forest plot, lower levels of 25-OHD were significantly associated with risk of preeclampsia (fixed and random P < 0.001). Based on the forest plot, vitamin D deficiency (25-OHD < 20 ng/ml) was significantly associated with risk of preeclampsia (fixed P < 0.0001; random P = 0.0029; fixed OR = 1.33; random OR = 1.54). Based on ROC curve results, we found 2 cutoffs of 10.60 and 20.05 ng/ml. Conclusion: Women with vitamin D deficiency at cutoff 20 ng/ml are more at risk of preeclampsia. This association can be specific up to 90 at 10.60 ng/ml cutoff. Treatment of vitamin D deficiency is necessary before pregnancy. © 201

    Association of vitamin D level and vitamin D deficiency with risk of preeclampsia: A systematic review and updated meta-analysis

    Get PDF
    Objectives: Because of the immune modulatory effects of vitamin D3 in preeclampsia, we intend to have a systematic review and meta-analysis on association of both 25-hydroxy vitamin D (25-OHD) level (parametric approach) and 25-OHD deficiency (non-parametric approach) with preeclampsia. As well, for the parametric part, we used receiver operating characteristic (ROC) curve model. Materials and methods: We used Web of Science, PubMed and Science Direct data bases through searching in titles. Google Scholar search engine was used in order to find missing papers. Finally 23 studies were imported. Both random and fixed models were reported. Results: Based on the forest plot, lower levels of 25-OHD were significantly associated with risk of preeclampsia (fixed and random P < 0.001). Based on the forest plot, vitamin D deficiency (25-OHD < 20 ng/ml) was significantly associated with risk of preeclampsia (fixed P < 0.0001; random P = 0.0029; fixed OR = 1.33; random OR = 1.54). Based on ROC curve results, we found 2 cutoffs of 10.60 and 20.05 ng/ml. Conclusion: Women with vitamin D deficiency at cutoff 20 ng/ml are more at risk of preeclampsia. This association can be specific up to 90 at 10.60 ng/ml cutoff. Treatment of vitamin D deficiency is necessary before pregnancy. © 201
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