An exact solution of mechanical buckling for functionally graded material bimorph circular plates

Presented herein is the exact solution of mechanical buckling response of FGM (Functionally Graded Material) bimorph circular plates, performed under uniform radial compression, by means of the classic theory and the non-linear Von-Karman assumptions, for both simply supported and clamped boundary conditions. Material properties are assumed to be symmetric with respect to the middle surface and are graded in the thickness direction according to a simple power law, in a way that the middle surface is pure metal and the two sides are pure ceramic. Using the energy method the non-linear equilibrium equations are derived and the stability equations have been used, so as to determine the critical buckling pressure, considering the adjacent equilibrium criterion, and finally a closed-form solution has been achieved for it. The effect of different factors, including thickness to radius variation rate of the plate, volumetric percentage of material index, and Poisson's ratio on the critical buckling compression have been investigated for two simply supported and clamped boundary conditions, and the result

The effects of improvement plan on the emergency services in Kashani & Hajar Hospitals of Shahrekord

زمینه و هدف: به دلیل نقش و اهمیت بخش اورژانس، وزارت بهداشت درمان و آموزش پزشکی از مدتها پیش به دنبال ساماندهی بخش های اورژانس بوده است. طرح بهینه سازی اورژانس ها از سال 1381 در دو مرکز آموزشی درمانی کاشانی و هاجر شهرکرد به مرحله اجرا در آمد. مطالعه حاضر با هدف بررسی تأثیرات اجرای این طرح انجام شد تا ضمن مشخص نمودن نقاط قوت و ضعف اجرای طرح، جهت توسعه آن در سایر بخش های اورژانس استان برنامه ریزی لازم بعمل آید. روش بررسی: این مطالعه از نوع مطالعات مداخله ای و با روش مطالعه قبل و بعد در جامعه مورد مطالعه صورت گرفته است. با توجه به اهداف پژوهش بخش های اورژانس دو مرکز درمانی آیت اله کاشانی و هاجر شهرکرد به عنوان جامعه پژوهش انتخاب و مورد ارزیابی قرار گرفتند. بدین منظور 264 نفر در قبل و بعد از اجرای طرح بر حسب نوع بیماری در مراکز مذکور به روش غیر احتمالی آسان انتخاب و به منظور زمان سنجی ارائه خدمات از حداقل 35 تا حداکثر 60 مورد بر حسب واحد خدمت دهنده و جنبه های مورد ارزیابی در واحدهای مختلف چون آزمایشگاه رادیولوژی و سی سی یو انتخاب و مورد بررسی قرار گرفتند. اطلاعات به روش استفاده از پرونده و سوابق بیماران، روش مشاهده به منظور ارزیابی ساختار، فرآیند و عملکرد اورژانسها و با استفاده از سه نوع پرسشنامه در 6 ماهه اول سال 81 و 82 جمع آوری و با استفاده از آزمون آماری t-test مورد تجزیه و تحلیل قرار گرفت. یافته ها: با توجه به ارزیابی ساختار نیروی انسانی، اجرای طرح موجب ارتقاء وضعیت ساختار با شرح وظایف و عملکرد به میزان 98/13 و 67/16 به ترتیب در اورژانس کاشانی و هاجر گردیده همچنین وضعیت آموزش بخش های مذکور نسبت به قبل، بیمارستان کاشانی با 29/14 و بیمارستان هاجر با 72/10 و هر دو به وضعیت متوسط بهبود یافته است. میانگین فاصله زمانی بین ورود تا اولین ویزیت بیماران با ایسکمی مغزی به میزان 9 دقیقه افزایش یافت که معنی دار نبود. همچنین میانگین فاصله زمانی ورود بیماران با سکته مغزی و انجام سی تی اسکن به میزان 56 دقیقه کاهش یافته که معنی دار نیست. میانگین فاصله زمانی ورود بیماران جراحی مغز و اعصاب تا اولین ویزیت 9 دقیقه کاهش یافته است (01/0

Quantity and quality of solid wastes produced in dental offices of babol city

Introduction: Dental wastes due to having bacterial disease-causing agents and toxic chemicals are categorized in hazardous wastes. The aim of this study was to evaluate the quantity and composition of dental waste produced by general and specialized dental offices in babol city. Materials &Methods: From all dental offices (170 and 40 dental offices were related to general and specialized respectively) in babol city, 20 general and 5 specialized offices were randomly selected. Waste samples were collected three times a week (Sunday, Monday and Tuesday), 50 sub-groups were separated and weighted by a digital scale with accuracy of 0.01 gram. The data were presented by excel and word software in figures and tables. Results: The total wastes of general and specialized offices were 11829 and 2831.5 kg/year, respectively. The percentages of domestic-type, infectious, pharmaceutical and toxic wastes in general dental offices were 52.5%, 42.5%, 4.7% and 0.3%; and in specialized offices were 42.5%, 50%, 7% and 0.5%, respectively. Most components in a variety of dental waste included plastic, paper, plaster molds, glass and metal. Conclusion: Due to the large contents of plastic, paper, plaster molds, glass and metals in domestic- type and infectious wastes produced in the general and specialized dental offices, it is necessary to manage the wastes and their separation and recycling in source place

Effect of Chelation Therapy on Lead-induced Hepatotoxicity: A Case Series

Background: Opium use is one of the common causes of lead toxicity. Lead poisoning can lead to hepatic, hematologic, musculoskeletal, neurological, and cardiovascular damages. In this study, we investigated the reversibility of lead-induced liver damage following chelation therapy.Methods: We reviewed the medical records of patients with opium-induced lead poisoning regarding elevation in hepatobiliary enzymes level including Alanine Transaminase (ALT), Aspartate Transaminase (AST), and Alkaline Phosphatase (ALP) to normal level and recorded patients’ age, treatment regimen, liver enzymes level before and after treatment; we also investigated other laboratory findings to rule out other causes of liver enzymes increase.Results: We evaluated 10 male patients with the mean age of 48.3±7.42 years. All patients were referred with the chief complain of abdominal cramps (100%). The mean lead level in patients was 84.48±9.95 µg/dL. The mean serum levels of ALT, AST, and ALP significantly decreased after the treatment with chelating agents ([ALT=117.8±60.22µg/dL-76.9±40.73µg/dL, P=0.022], [AST=100.9±63.96µg/dL-69.9±37.41µg/dL, P=0.028], [ALP=449.8±234.81 µg/dL-338.3±131.22µg/dL, P=0.037]). There was no significant correlation between patients’ lead level and liver enzymes level before and after the treatment.Conclusion: The results of this study showed that the treatment with chelating agents reverses the liver injury following the lead intoxication

Experimental investigation of bed evolution resulting from dam break

This study examines the relations of structures and shapes of streambed evolution after dam break floods. A flume was used to simulate dam-break floods with variations of initial upstream water levels and variance, from uniform to graded, of the bed sediments. Detailed measurements of the evolution and composition were made during these experiments. The data indicate that intense scour occurred immediately downstream of the “dam break” in both uniform and graded sediments. The resulting bed surfaces of graded sediments showed coarse-fine-coarse structures in the areas with the lowest scour and highest deposition and various type of cluster (i.e. line and heap). This pattern was not observed in beds of uniform sediment. The scour hole changes from circular to oval-shaped in both uniform and graded sediments with increasing bed slopes. Keywords: Dam break, Experimental, Bed-surface composition, Graded and uniform sediment, Scour

Evaluation of quality and quantity of solid wastes in Babol Dental Faculty–North of Iran

Introduction: Dental wastes are a main part of urban solid wastes in each society and have pathogenic agents and toxic chemicals, which put health of patients, personnel and other referees to dental clinics in danger. The present study was done to recognize the quality and quantity of the different generated wastes at various parts of the Faculty of Dentistry-Babol University of Medical Sciences. Methods: The whole solid wastes generated in the odd and even days (Monday, Tuesday and Wednesday) of the middle of the week from the second month of each season were examined. Various dental solid wastes including general, infectious and hazardous chemical wastes were weighted by typical scale. Results: The generation rate of the solid wastes were: total dental wastes: 291.2 kg including general solid wastes: 251.3 kg (%86.3), infectious wastes and sharps: 38 kg (%13) and hazardous chemical waste: 2 kg (%0.7). The total amount of wastes in a year was 69888 kg. The solid wastes are daily produced according to each active dental unit as total, domestic-type, infectious and the hazardous chemical wastes were 3.07 kg, 2.65 kg, 0.4 kg and 0.02 kg, respectively. Conclusions: Considering the quality and quantity of the generated dental solid wastes especially infectious wastes and their unfavorable effects on the peoples' health and environment, it is necessary to compile a distinct policy for the management of these medical solid wastes. Also, holding training workshops, knowledge of the staffs in the dentistry care centers should be increased to avoid possible dangers

Biopolymeric Nanoparticles, Pickering Nanoemulsions and Nanophytosomes for Loading of Zataria multiflora Essential Oil as a Biopreservative

Background and Objective: Essential oils include low solubility, poor bioavailability and rapid release, which may limit their use as bioactive compounds in foods and medicine. Nanoencapsulation can preserve inherent qualities of essential oils and improve their physicochemical characteristics and health benefits. Focus of the present study was on the loading of essential oils from Zataria multiflora in pickering nanoemulsions, nanoparticles and nanophytosome. In addition, the present study assessed how these systems affected their physicochemical characteristics and antioxidant and antimicrobial activities, compared to free-essential oils. Material and Methods: Encapsulation of Zataria multiflora Boiss essential oil in nanocarriers as a novel phytoconstituents delivery system was carried out using three various methods. Physicochemical characterization of nanocarriers was studied using dynamic light scattering, Fourier transform infrared spectroscopy, field emission scanning electron microscope, confocal laser scanning microscopy, optical microscope and antioxidant activity. The minimum inhibitory and bactericidal concentration assessment effects against Listeria monocytogenes at 24 h and temperatures (10, 25 and 37 °C) were investigated. Encapsulated Zataria multiflora Boiss essential oil with subinhibitory concentrations (0.25, 0.5 and 0.75) in hamburger formulation was selected as a food model for chemical, microbiological and sensory evaluation. Results and Conclusion: In general, this study compared three types of biocarriers with free essential oils. Primarily, nanophytosome showed promising results in delaying oxidation and in antimicrobial and sensory assessments, compared to two other nanocarriers. In conclusion, essential oil nanophytosomes of Zataria multiflora Boiss include the potential as an efficient natural food preservative. Conflict of interest: The authors declare no conflict of interest