71 research outputs found
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طی دهههای اخیر کالاهای ارزان قیمت چینی سهم عمده ای از بازار مصرفی کـشورهای مختلـف و از جملـه ایـران را بـه خـود اختصاص داده اند. یکی از سؤالات مطرح در این زمینه این است که علل و عوامل مؤثر بر پایین بودن قیمت کالاهای چینی کدامند؟ یکی از فرضیات مطرح برای پاسخگویی به این پرسش، بهره برداری چین از مزیت نسبی نیروی کار در زمینه تولید و صدور کالاهای کاربر توسط این کشور است. در این تحقیق رشد سریع صادرات چین در سه دهه اخیر، با استفاده از نظریه هکشر- اوهلین بیان میشود. به این منظور با استفاده از جدول داده- ستانده سال 2000 چین، محتوای عوامل تولید صادرات و واردات چین محاسبه شده و با استفاده از آزمونهای لئونتیف و لیمر نشان داده میشود که کشور چین در صدور کالاهای کاربر دارای مزیت نسبی است
The efficiency of biological sludge on hexavalent chromium removal from aqueous solution
Background and aims: Out of different techniques for chromium (Cr) removal, biological treatment has a special status. This study was conducted to determine the efficacy of biological sludge on hexavalent Cr (VI) removal from aqueous solutions. Methods: In this experimental study, the required sludge was collected from municipal sewage refinery after aeration basin and introduced into the reactor and Cr and nutrients were added to it. The effect of dissolved oxygen (DO), Cr initial concentration, pH, temperature, glucose concentration, and contact time on chromium removal rate was evaluated. At each step, the samples withdrawn from the reactor were filtered and Cr (VI) level was measured using HACH Company instructions and spectrophotometry. Results: The findings of this study showed that at 2 mg/L DO, 80 mg/L Cr initial concentration, 5000 mg/L sludge concentration, pH= 3, 30°C temperature, 250 mg/L introduced glucose concentration, and 24 h contact time, about 97.5 % of Cr (VI) was removed. As DO, pH, and the introduced glucose concentration decreased and the initial sludge concentration increased, temperature and contact time of Cr removal efficiency increased. Conclusion: The results of this study showed that use of the activated sludge of sewage refinery could be used for Cr removal with regards to environmental aspects
The Comparative Analysis of the Exegetical Method of Avicenna and Sheikh-i Ishraq
The ideas of Avicenna and Sheikh-i Ishraq as the scholars of Peripatetic and Illumination Philosophy have always received the critical attention of the reviewers. One of the most important discussions in this regard is the exegetical method of the above philosophers: Sheikh-i Ishraq, contrary to Avicenna, does not have an independent exegesis but his exegetical ideas can be inferred from his collection of writings. In fact, Avicenna has a completely rational trend whereas the exegetical trend of Sheikh-i Ishraq is mystical. The exegetical method of Avicenna has been rational while Sheikh-i Ishraq has often used an innovative method. Furthermore, Avicenna has rarely applied the Qur’an to the Qur’an method in his rational arguments. The abovementioned philosophers have one thing in common in their commentaries and that is impartiality in interpretation and not using the traditions in the interpretation of the Qur’an.
© Mahdavi Fard, A.A; Shakeri Movvahid, A. (2020) The Comparative Analysis of the Exegetical Method of Avicenna and Sheikh-i Ishraq. Biannual Journal of Comparative Exegetical Researches, 6 (11) 235-251. Doi: 10.22091/ptt.2020.4404.158
Mathematical Modeling and Optimization of Fused Filament Fabrication (FFF) Process Parameters for Shape Deviation Control of Polyamide 6 Using Taguchi Method
Fused filament fabrication (FFF) is a layer-by-layer additive manufacturing (AM) process for producing parts. For industries to gain a competitive advantage, reducing product development cycle time is a basic goal. As a result, industries’ attention has turned away from traditional product development processes toward rapid prototyping techniques. Because different process parameters employed in this method significantly impact the quality of FFF manufactured parts, it is essential to optimize FFF process parameters to enhance component quality. The paper presents optimization of fused filament fabrication process parameters to improve the shape deviation such as cylindricity and circularity of 3D printed parts with the Taguchi optimization method. The effect of thickness, infill pattern, number of walls, and layer height was investigated as variable parameters for experiments on cylindricity and circularity. The MarkForged® used Nylon White (PA6) to create the parts. ANOVA and the S/N ratio are also used to evaluate and optimize the influence of chosen factors. As a result, it was concluded that the hexagonal infill pattern, the thickness of 5 mm, wall layer of 2, and a layer height of 1.125 mm were known to be the optimal process parameters for circularity and cylindricity in experiments. Then a linear regression model was created to observe the relationship between the control variables with cylindricity and circularity. The results were confirmed by a confirmation test
Multifunctional polymeric nanoplatforms for brain diseases diagnosis, therapy and theranostics
The blood–brain barrier (BBB) acts as a barrier to prevent the central nervous system (CNS) from damage by substances that originate from the blood circulation. The BBB limits drug penetration into the brain and is one of the major clinical obstacles to the treatment of CNS diseases. Nanotechnology-based delivery systems have been tested for overcoming this barrier and releasing related drugs into the brain matrix. In this review, nanoparticles (NPs) from simple to developed delivery systems are discussed for the delivery of a drug to the brain. This review particularly focuses on polymeric nanomaterials that have been used for CNS treatment. Polymeric NPs such as polylactide (PLA), poly (D, L-lactide-co-glycolide) (PLGA), poly (ε-caprolactone) (PCL), poly (alkyl cyanoacrylate) (PACA), human serum albumin (HSA), gelatin, and chitosan are discussed in detail
Biosorption of lead using Penicillium notatum dead biomass from aqueous solutions
Lead is one of the stable and biodegradable pollutants released from industrial, agricultural and technological development activities more than the permitted level in the environment. This metal, due to its toxicity, even at low concentrations, has adverse effects on the environment and health of living organisms. The aim of this study is to investigate the bio-absorption of lead by the fungus Penicillium notatum in aqueous solutions. For this purpose, the fungus Penicillium notatum PTCC 5074 was prepared from the Iranian Scientific Research Organization as lyophilisation and to culture and reproduce it in the culture medium of potato dextrose agar and sabouraud dextrose broth. In this study, the effect of some parameters such as lead concentration, ion intensity, biomass concentration, temperature and contact time on the rate of adsorption of lead by abiotic biomass at pH = 5 were evaluated. The maximum absorption rate was 180.75 mg g(-1) under optimal conditions (concentration of metal = 228 mg L-1, ion intensity = 43.2 mg L-1 Ca2+, biomass concentration = 1.2 g L-1 of dry weight of biomass, temperature = 33 degrees C, and contact time = 105 min). Absorption data were better fitted by Langmuir model R-2 = 0.9820). Also, due to the thermodynamic constants, it was found that lead absorption process is thermally abiotic by a biomass. Gibbs free energy values (Delta G) showed that all absorption processes are spontaneous and physical. The false quadratic equation (R-2 = 1) has the best compatibility with regard to kinetic data. BET, SEM and EDX tests were also used to determine the biomass characteristics
Seroepidemiological Survey of Crimean-Congo Hemorrhagic Fever Among Livestock in Southern Iran, Jahrom, 2015-2016
Crimean-Congo Hemorrhagic Fever Virus (CCHFV) can efficiently replicate in livestock without causing recognizable clinical symptoms. In this regard, epidemiological studies would be necessary to determine the status of the disease and its risk factors in different geographical areas. This study was designed to evaluate the seroepidemiological situation of CCHF among livestock of Jahrom city in Fars province. Between 2015 and 2016, 240 livestock serum samples investigated for the presence of anti-CCHF IgG using ELISA assay. Forty-three (17.9%) samples were positive for CCHF virus IgG antibody. The highest seropositivity rate was observed among goats (69.8%). In addition, the highest infection rate was observed among animal older than 5 years. The results of this study indicate that the rate of CCHF in livestock from Jahrom city is lower than other parts suggesting that the risk of human transmission is low in this region. However, further research with bigger sample size is recommended to provide exhaustive information on CCHF circulation in this area
Yield and yield components of common bean as influenced by wheat residue and nitrogen rates under water deficit conditions
Incorporation of crop residues into agricultural system has become a worldwide efficient practice for enhancing crop production. The main objectives of this experiment was to investigate the major role of incorporating wheat (Triticum aestivum L.) residues and nitrogen (N) fertilizers rates under different water requirements (WR) on growth, seed yield and yield components of common bean (Phaseolus vulgaris L.). The results showed that seed yield under 80% WR in retained crop residue plots was & SIM;11% higher than WR treatment with no residue incorporation. Seed yield was not significantly different between residue retention and removal treatments in 2016, whereas it was higher (12% and 17%) under residue retained plots compared to removed ones in subsequent years. Seed yields responded to N up to 170 and 225 kg ha(-1) in removed and retained residue treatments, respectively in 2017 and 2018. Annual increment of seed yield in residue retained plots (36%) was 2.11 times higher than the residue removed ones (17%). There was higher soil N content in 50% residue retention with 225 kg N ha(-1) under both water deficit treatments in all years. The highest soil organic carbon (SOC) was achieved with normal irrigation in retained residue plots with 225 kg N ha(-1) in all years. Overall, wheat residue incorporation into the soil and N-supply substantially contributed to counteracting yield declines of common bean under water deficit conditions.& nbsp;(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Peer reviewe
Comparison of Interferon-Gamma (IFNG) +874 T/A single nucleotide polymorphism in hepatitis C virus infected patients and non-infected controls in Mashhad, Iran
This study was financially supported by Mashhad University of Medical Sciences, Mashhad, Iran (Grant No. 900513).Peer reviewedPublisher PD
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