فهرست مطالب hamid emadi
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امروزه سوخت بیودیزل به عنوان یکی از منابع اصلی برای جایگزینی سوخت های فسیلی در حال تولید و مصرف در سراسر دنیا است. در این پژوهش از روی اکسید دوپه شده با کبالت به عنوان نانوکاتالیزگر برای تولید بیودیزل از روغن سویا به روش تبادل استری استفاده شده است. در ابتدا نانوکاتالیزگرهای مورد استفاده با روش مایکروویو تهیه شدند و به وسیله ی روشهای پراش اشعه ایکس (XRD)، میکروسکوپ الکترونی روبشی (SEM) و طیف بینی انرژی پخش اشعه ایکس (EDS) شناسایی گردیدند. در مرحله بعد کاتالیزگرهای تهیه شده در واکنش تولید بیودیزل از روغن سویا مورد استفاده قرار گرفتند. بیودیزل تولید شده با استفاده از طیف سنجی رزونانس مغناطیسی هسته (NMR) و کروماتوگرافی گازی -طیف نگار جرمی (GC-MS) شناسایی شده است. شرایط بهینه واکنش تولید بیودیزل با نانوکاتالیزگر روی اکسید دوپه شده با کبالت، در زمان 3 ساعت، دمایC 60، غلظت کاتالیزگر 3% وزنی و نسبت مولی روغن به متانول 1 به 41 به درصد تبدیل 98%منجر شد. در بخش دیگری از این پژوهش، از تابش مایکروویو با توان 250 وات به عنوان منبع تامین انرژی در واکنش تولید بیودیزل استفاده گردید که در حضور 4% وزنی کاتالیزگر و نسبت مولی روغن به متانول 1 به 20 منجر به درصد تبدیل 91% در 180 ثانیه شد.کلید واژگان: بیودیزل, ترانس استری شدن, مایکروویو, نانوکاتالیزگر}Today, biodiesel is being produced and consumed around the world as one of the main sources for replacing fossil fuels. In current research, cobalt doped zinc oxide was used as nanocatalyst to produce biodiesel from soybean oil by transesterification reaction. The nanocatalysts used were first prepared by microwave method and identified by X-ray diffraction (XRD), scanning electron microscopy (SEM) and x-ray energy dispersive spectroscopy (EDS). In the next step, the prepared catalysts were used in the reaction of biodiesel production from soybean oil. The produced biodiesel was characterized using nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectroscopy (GC-MS). Optimal reaction conditions of biodiesel production with cobalt doped zinc oxide nanocatalyst obtained, at 3 h, temperature 60 ˚C, catalyst concentration 3% by weight, and molar ratio of oil to methanol 1 to 41 resulted in 98% efficiency. In another part of this research, microwave radiation with a power of 250 W was used as a source of energy in the biodiesel production reaction which in the presence of 4% by weight of catalyst and molar ratio of oil to methanol 1 to 20 resulted in 91% efficiency in 180 s.Keywords: Biodiesel, transesterification, microwave, nanocatalyst}
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In the current study, a facile and in situ synthesis route for the preparation of mesoporous SiO2-Fe3O4 magnetic nanocomposite using iron (III) acetylacetonate via microwave-assisted solvothermal method is proposed. To char-acterize the samples, XRD, EDS, SEM, TEM, BET, and VSM were applied, and their potential applications as drug carriers, hyperthermia, and MRI contrast agents were investigated. The results confirmed that the magnetic nanocomposite could be used as a drug carrier, and its drug release rate is affected by the magnetic field. Also, the product applications as both hyperthermia and MRI contrast agent for T2 weighted images were approved.
Keywords: Fe3O4@SBA-15, Magnetic nanocomposite, Drug carrier, Hyperthermia, MRI} -
برندسازی مشارکتی، یکی از جدیدترین مباحث در پیوندهای اقتصادی می باشد که تحت استراتژی برندسازی مشارکتی مدت زمان کوتاهی است که در ایران مطرح شده است. این پژوهش سعی در اثبات اثربخشی استراتژی یاد شده داشته و می کوشد که یک الگوی عملی برای استقرار موفقیت آمیز آن ارائه دهد. در این ارتباط، خوشه های کسب و کار در فاز خودروهای ریلی به عنوان عنصر مطالعه محوری در نظر گرفته شد و سپس از طریق مناسب ترین روش های محاسباتی، روش تحلیل سلسله مراتبی، شاخص های مهمی که نقش کلیدی در موفقیت برندسازی مشترک در صنایع مرتبط با خودروهای ریلی را بازی می نمایند استخراج نموده و از طریق آن شرکت های مستعد برندسازی مشترک ارزیابی شده اند. در نهایت با انتخاب مناسب ترین شرکت ها، برای این پیوند استراتژیک، برآورد اقتصادی مربوطه را به پایان رساندیم.
کلید واژگان: امکان سنجی, برندسازی مشارکتی, خوشه های کسب و کار}Co-branding is one of the most new topics in economic links, which has been recently discussed in Iran under the co-branding strategy. This research seeks to prove the effectiveness of the strategy and tries to provide a practical model for its successful implementation. In this regard, business clusters in rail cars phase, are considered as a central element of the study and then through the most appropriate computational methods, significant parameters that play a key role in the success of the co-branding in the rail cars industry are extracted and subsequently, The companies with co-branding potential are evaluated. Finally, the most suitable companies for this strategic alliance, have been chosen.
Keywords: Co-Branding, Co-Branding Feasibility, Business Clusters} -
Breaking HIV News to Clients: SPIKES Strategy in Post-Test Counseling SessionBreaking bad news is one of the most burdensome tasks physicians face in their everyday practice. It becomes even more challenging in the context of HIV patients because of stigma and discrimination. The aim of the current study is to evaluate the quality of giving HIV seroconversion news according to SPIKES protocol. Numbers of 154 consecutive HIV patients from Imam Khomeini Hospital testing and counseling center were enrolled in this study. Patients were inquired about how they were given the HIV news and whether or not they received pre- and post-test counseling sessions. Around 51% of them were men, 80% had high school education, and 56% were employed. Regarding marital status, 32% were single, and 52% were married at the time of the interview. Among them, 31% had received the HIV news in a counseling center, and only 29% had pre-test counseling. SPIKES criteria were significantly met when the HIV news was given in an HIV counseling and testing center (P.valueKeywords: Breaking bad news, HIV counseling, testing, SPIKES}
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In this study demographic, clinical, paraclinical, microbiological, and therapeutic features of patients with community-acquired acute bacterial meningitis admitted to a referral center for infectious diseases in Iran, have been evaluated.
Medical records of adult (> 18 years) individuals with confirmed diagnosis of community-acquired bacterial meningitis during a 4-year period were retrospectively reviewed. All required data were obtained from patients medical charts. Available findings about antimicrobial susceptibility of isolated bacteria from CSF and/or blood were also collected. Kirby-Bauer disc diffusion method was used to determine their antimicrobial susceptibility profile. Details of medical management including antibiotic regimen, duration, patients outcome, and possible sequelae of meningitis were recorded.
The most commonly isolated microorganism from CSF or blood of patients was Streptococcus pneumonia (33.33%) followed by Neisseria meningitidis (27.78%) and Haemophilus influenza (16.67%). The most common antimicrobial regimen was ceftriaxone plus vancomycin (69.44%) followed by ceftriaxone plus vancomycin plus ampicillin (11.11%). Neurological sequelae of meningitis including cranial nerve palsy, deafness, and hemiparesis were identified in 4 (11.11%), 2 (5.56%), and 1 (2.78%) subjects, respectively. Regarding mortality, only 3 (8.33%) patients died from bacterial meningitis and the remaining 33 individuals discharged from the hospital.
In conclusion, findings of the current study demonstrated that the mean incidence of acute bacterial meningitis in a referral infectious diseases ward in Iran was 9 episodes per year. The majority cases of community-acquired acute bacterial meningitis admitted to our center had negative CSF culture and classic triad of meningitis was absent in them.Keywords: Community acquired meningitis, Antimicrobial resistance pattern, Clinical data} -
BackgroundCryptosporidiumis known as an opportunist disease-causing agent in man in recent decades. It causes diarrhea and intestinal disorders in the immune deficit and immune competent individuals. This study was aimed to investigate the clinical characteristics of HIV/AIDS patients withcryptosporidiosisinfection.MethodsThis cross-sectional descriptive study was performed on 53 HIV/AIDS patients referred to the Behavior Disease Consultation Center of Imam Khomeini Hospital in Tehran, Iran in 2013. First, the patients were studied clinically and the context data were recorded in a questionnaire for parasitological examination and referred to the laboratory for eosinophil count, and CD4 count per ml of blood.ResultsCryptosporidiosiswas observed in 4 (7.6%) of the total 53 HIV/AIDS patients. The highest prevalence of infection was observed in the age range of 30-39 yr.Itwas observed in different sexes as 5.7% of male and 1.9% of female, but statistically was insignificant (P=0.163).75% of patients had no intestinal symptom, 11.4% with acute diarrhea and 3.8% with chronic diarrhea. Cryptosporidiosis cases were observed in 5.7% of patients without intestinal symptom.ConclusionPractitioners in the clinicalexamination for the detectionof the opportunistic intestinal protozoan infection should use clinical and paraclinical characteristics of the HIV/AIDS patients for the diagnostic of Cryptosporidium and other opportunistic parasitic diseases.Keywords: HIV, AIDS, Cryptosporidiosis, Clinical characteristic}
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