رضا اسدی
-
موضوع تحقیق
امروزه تقاضا برای آلکن ها (الفین ها)، به ویژه اتیلن و پروپیلن، به سرعت رو به افزایش است و انتظار می رود که به طور مداوم رشد کند. آلکان ها (پارافین ها) به دلیل ارزان بودن و فراوان بودن مواد اولیه شیمیایی محبوبی هستند، به همین دلیل مطالعات زیادی جهت پیدا کردن روش جایگزین مناسب انجام گردیده است. در این کار پژوهشی از چارچوب فلزی آلی CuBTC به عنوان پایه کاتالیست مبتنی بر منگنز در فرآیند هیدروژن زدایی اکسایشی پروپان جهت تولید پروپیلن استفاده شده است.
روش تحقیقبارگذاری اکسید فلزی منگنز بر روی پایه CuBTC به روش تلقیح تر انجام گرفت. به منظور شناسایی و مشخصه یابی کاتالیست های سنتزشده از آنالیزهای XRD، FTIR، EDX، SEM و BET بهره گرفته شد. همچنین از طراحی آزمایش به روش مرکب مرکزی به منظور بررسی فاکتورهای اساسی دما داخل راکتور، میزان بارگذاری اکسید فلزی منگنز و نسبت پروپان به اکسیژن و تاثیر متقابل این پارامترها با یکدیگر جهت تولید پروپیلن در فرآیند هیدروژن زدایی اکسایشی پروپان استفاده گردید. بنابراین میزان بارگذاری اکسید منگنز در محدوده 5 -1 درصد وزنی منگنز، دمای داخل راکتور در بازه 280-140 درجه سانتی گراد و نسبت پروپان به اکسیژن در محدوده 3-1 به عنوان متغیرهای ورودی به طراحی آزمایش وارد شدند.
نتایج اصلیپس از انجام آزمون های راکتوری و تجزیه و تحلیل نتایج به دست آمده به وسیله نرم افزار طراحی آزمایش مشاهده گردید، مدل های آماری پیشنهادشده توسط نرم افزار برای درصد تبدیل، درصد گزینش پذیری و بازده فرآیند هیدروژن زدایی اکسایشی با دقت قابل قبول 95% مورد تایید قرار گرفت. بهینه سازی بازده فرآیند هیدروژن زدایی اکسایشی با مقدار بیشینه 9/4 با درصد تبدیل 38/28، درصد گزینش پذیری 14/18 در دمای 278 درجه سانتی گراد، بارگذاری اکسید فلزی 74/3 درصد و نسبت پروپان به اکسیژن 5/1 انجام گرفت که دقت بین داده آزمایشگاهی و داده پیش بینی شده 93% محاسبه گردید.
کلید واژگان: هیدروژن زدایی اکسایشی, پروپان, پروپیلن, CuBTC, طراحی آزمایشResearch subjectBecause of the rising global demand for propylene, various extensive studies and research have been done in order to develop alternative ways that are both more energy-efficient and require less energy. In this research, CuBTC is used as a manganese catalyst base in the oxidative dehydrogenation of propane to produce propylene. The wet impregnation method is used to manufacture the catalysts.
Research approachWet impregnation is used to prepare the catalysts, which is a step in the manufacturing process. Analyses such as FTIR, XRD, BET, SEM, and EDX are used to examine and describe catalysts that have been created. On the basis of the central composition method, we have investigated the impacts of reaction temperature, manganese loading percentage, oxygen-to-propylene ratio, and their interactions on the synthesis of propylene in this study. The central composite method's input parameters include manganese concentrations ranging from 1 to 5 percent, a propane-to-oxygen ratio ranging from 1 to 3 percent, and a temperature ranging from 140 to 280 degrees Celsius.
Main resultsAfter that, it is shown that the projected models for propane conversion, propylene selectivity, and oxidative dehydrogenation efficiency percentage are about 95 percent based on reactor testing and evaluation of the Design-Expert software results. It was possible to improve the efficiency of the oxidation dehydration process by 4.9 percent by using a conversion percentage of 28.38 percent, a selectivity of 18.14 percent at 278 degrees Celsius, a metal oxide loading of 3.74 percent, and propane to oxygen ratio of 1.5 percent. When laboratory data were compared to predicted data, the correlation coefficient was 93% in favor of the laboratory data.
Keywords: Oxidative Dehydrogenation, Propane, Propylene, Manganese, CuBTC, Design Expert -
Background & Objective
Understanding the various strategies used in the Covid-19 pandemic and its consequences can help to benefit better and more effectively in the future and identify its potential challenges and more effective and efficient solutions to deal with the epidemic. Put such things in front of policymakers in the health system. In this study, we intend to do a systematic review of the types of eHealth strategies used in the Povem Covid-19, the implications and weaknesses, and related challenges.
MethodThe present study is a scoping review. Keywords have been selected based on MESH and review of related texts in two main dimensions (Covid-19 disease and eHealth. In this study, valid scientific data sources including:PubMed / Medline, Web of Science, Embase, Cochrane Library, searched.
ResultsOf the 5,105 search results from databases and other sources, 3,683 records remained after the duplicate results were removed. We reviewed the remaining studies by title and abstract and identified 71 articles for further review of the full text. 21 studies had inclusion criteria. These studies focus on a variety of eHealth strategies, including electronic health record templates, robotic clinical care, virtual intensive care unit, cloud-based system for effective Covid-19 monitoring and control, mobile decision support system, COVID-19 self-assessment tool Web-based, ICU monitoring technology, call tracking, Internet hospitals, identification, screening and diagnosis of patients with Covid-19, and spatial and temporal reporting via network and GPS were centralized.
ConclusionSuch strategies have been successful in controlling hospital infections, reducing the relationship between treatment staff and patients, more accurate and faster diagnosis, providing services to a wide range of patients and providing quality services. However, taking advantage of such strategies in Pendmi Covid-19 has faced challenges such as resource constraints, legal barriers, and privacy. Collaborating with governments and local health forces with the public can greatly facilitate the benefit of eHealth strategies in a pandemic
Keywords: COVID-19 pandemic, Scoping Review, eHealth, strategy -
Background and objective
Hemodialysis (HD) is a life-saving treatment for End Stage Renal Disease (ESRD) patients who have lost both kidneys. Despite that central venous catheter (CVC) placement is a common vascular access to be able to do HD, but risk of cardiovascular diseases, including stroke in patients with ESRD is 5–30 times greater than that in the general population. Specially, cerebrovascular accident (CVA) is one of significant complications after CVC insertion and the average annual stroke incidence is reported 19.5 per 10000 [person-years] in 2019. So, it is important to understand the set of factors that affect the incidence of CVA in this vulnerable population of patients.
Method468 HD patients who underwent vascular access surgery over 2013-2018 in Hasheminejad Kidney Center were studied included 368 cuffed tunneled CVC and 100 non-cuffed CVC.
ResultsStudied patients aged 12-86 (mean age, 54.85) years, containing 324 females and 144 males, during 5 years. Finally, 19 patients (4.06% of all HD patients) with CVA identified. Of these, more than three fourths, 15 (78.95%) and 12 (63.16%), of them were hypertensive and diabetic, respectively, with an overall proportion 52.63% (10 individuals) of them were males and the remaining were females. One of CVA patients has 37 years and the rest of the patients are 50 to 73 years old (mean = 61). Risk factor of CVA most is happened in HD patients with CVC insertion before AVF (16 of 19 =84.21%).
ConclusionThere was no occasion to emphasize on young or old ages as the warning signs of stroke in HD patients. But it was concluded that “CVC placement before AVF”, “hypertension” and “diabetes mellitus” are CVA risk factors, respectively; and eventually "In ESRD patients, CVC placement can increase Risk of CVA incident" the investigators conclude. Funding: This work was supported by the Iran National Science Foundation (INSF) in post-doctoral course of the first author (MR-NNA-97006815)
Keywords: Hemodialysis, CVA, CVC, decision tree -
Background and Objective
The health industry is a competitive and lucrative industry that has attracted many investors. Therefore, hospitals must create competitive advantages to stay in the competitive market. Patient satisfaction with the services provided in hospitals is one of the most basic competitive advantages of this industry. Therefore, identifying and analyzing the factors affecting the increase of patient satisfaction is an undeniable necessity that has been addressed in this study.
MethodsBecause patient satisfaction characteristics used in hospitals may have a hidden relationship with each other, data mining approaches and tools to analyze patient satisfaction according to the questionnaire used We used the hospital. After preparing the data, the characteristics mentioned in the questionnaire for patients, classification models were applied to the collected and cleared data, and with the feature selection methods, effective characteristics Patients were identified and analyzed for satisfaction or dissatisfaction.
ResultsBased on the findings of the present study, it can be concluded that the factors of patient mentality of the physician's expertise and skill, appropriate and patient behavior of the physician and food quality (hoteling) respectively have a higher chance of increasing patient satisfaction with Establish services provided in the hospital.
ConclusionComparing the approach used in this study with other studies showed that due to the hidden effects of variables on each other and the relatively large number of variables studied, one of the best options for analyzing patient satisfaction questionnaire data, Use of data mining tools and approaches
Keywords: Machine Learning Algorithms, Patient satisfaction Data mining Clustering Feature selection -
با پیشرفت صنایع مختلف در جهان یکی از مشکلات مهمی که با آن مواجه هستیم آلودگی محیط زیست به فلزات سنگین است.یکی از سمی ترین فلزات سنگین که حتی در غلظت های پایین مشکل ساز است، Cr(IV) می باشد. در این مطالعه حذف این ماده سمی با راندمان بالا به وسیله ی جاذب مغناطیسی UIO-66-MnFe2O4-TiO2 مورد بررسی قرار گرفت. به این منظور نانو کامپوزیت مغناطیسی(UIO-66-MnFe2O4-TiO2) بر روی بستر چارچوب های آلی فلزی (MOF)، به منظور جذب سطحی Cr(IV) سنتز شد. انتخاب روش هیدروترمال برای سنتز UIO-66 علاوه بر سادگی موجب ساختUIO-66 به صورت خالص و کار آمد گشت که در طول آزمایش ها راندمان بسیار بالایی را ایجاد کرد. به جهت مغناطیسی کردن جاذب از نانو ذرات MnFe2O4 کمک گرفته شد. برای افزایش خواص مغناطیسی و افزایش راندمان بارگذاری نانو ذره ی MnFe2O4 ، از نانو ذره TiO2 کمک گرفته شد تا میزان بارگذاری برروی جاذب افزایش یابد. آزمون های XRD، SEM، FT-IR،BET، VSM و EDX به منظور بررسی سطح و راستی آزمایی ساخت جاذب استفاده شد. تاثیر چهار متغیر موثر در طول آزمایش جذب سطحی همچون میزان جاذب (05/0 تا 25/0 گرم)، pH (2 تا 6)، زمان جذب (15 تا 75 دقیقه)، غلظت اولیه یون فلزی (200 تا 1000 میلی گرم بر لیتر) در پنج سطح (2- تا 2+) با استفاده از طراحی آزمایش به روش سطح پاسخ (RSM) و طراحی مرکب مرکزی (CCD) بررسی شد. بهترین شرایط برای متغیرهای مستقل برای غلظت اولیه فلز میزان 552 mg/l مشخص شد. میزان بهینه ی pH در طول آزمایش برابر با 4 به دست آمد. در نهایت میزان بهینه برای پارامتر های زمان جذب و میزان جاذب به ترتیب 3/42 min و 143/0 gr و همچنین حداکثر میزان جذب 98 درصد به دست آمد. بررسی و مطالعه سینتیک و ایزوترم جذب نشان داد که مدل شبه مرتبه دوم و ایزوترم لانگمویر به خوبی داده های Cr(IV) را پوشش می دهد. پس از پایان فرایند می توان جاذب را با یک میدان مغناطیسی از محیط خارج کرد.
کلید واژگان: UIO-66-MnFe2O4-TiO2, چهارچوب آلی فلزی MOF, جذب سطحی, کروم Cr (VI), طراحی آزمایشResearch subjectOne of the major problems we face with the growth of various industries around the world is the environmental pollution of heavy metals. One of the most toxic heavy metals that is problematic even at low concentrations is Cr (IV).
Research approachIn this study, the removal of this toxic heavy metal was investigated with high efficiency by UIO-66-MnFe2O4-TiO2 magnetic adsorbent. For this purpose, magnetic nanocomposite (UIO-66-MnFe2O4-TiO2) was synthesized based on metal-organic framework (MOF) for adsorption of Cr (IV). The choice of the hydrothermal method for the synthesis of UIO-66 in addition to its simplicity resulted in the production of pure and efficient UIO-66, which produced very high efficiency during the experiments. MnFe2O4 nanoparticles were used to magnetize the adsorbent. To increase the magnetic properties and increase the loading efficiency of the MnFe2O4 nanoparticles, TiO2 nanoparticles were used to increase the loading rate on the adsorbent. XRD, SEM, FT-IR, BET, VSM and EDX tests were used to the characterization of the adsorbent properties.
Main resultsEffect of four effective variables during adsorption experiments such as adsorbent content (0.05 to 0.25 g), pH (2 to 6), adsorption time (15 to 75 min), initial metal ion concentration (200 to 1000 mg / l) at five levels (+2 to +2) were investigated using experimental design with response surface methodology (RSM) and central composite design (CCD). The best conditions were determined for the independent variables for the initial metal concentration of 552 mg /l. The optimum pH was obtained 4 during the experiment. Finally, the optimum values were achieved for adsorption parameters such as adsorption time and adsorbent amount were 42.3 min and 0.143 gr, respectively, and also the maximum adsorption rate was obtained 98%. Investigation of the adsorption isotherm kinetics showed that the pseudo-second-order model and Langmuir isotherm fit the Cr (IV) data well. After the adsorption process, the adsorbent can be removed from the environment by a magnetic field.
Keywords: UIO-66-MnFe2O4-TiO2, MOF, Adsorption, Cr(VI), Expereimental Design -
Background and Objective
Despite managerial advances in hospital services, patient admission to hospitals is still one of the problems that in addition to imposing additional treatment costs, consumables and equipment depreciation, wastes time in providing services to New patients and also dissatisfaction of patients and staff. Accordingly, in this study, the effect of each of the factors of patient admission in Hasheminejad hospital has been identified and determined.
MethodsIn order to achieve the purpose of the study, first the files of 314 patients admitted in 2019-2020 in this hospital were reviewed and the main reasons for patient admission were extracted. Then, by using fuzzy hierarchical analysis, the effect of each of the identified causes was determined. In the next stage, based on the brainstorming techniques with the presence of 20 experts in this field and also the fish bone technique, the identified causes were identified. In the final stage, based on the opinion of experts and brainstorming technique, executive solutions to reduce patient admission were presented and using the approach of fuzzy hierarchical analysis from the point of view of 3 criteria, cost and time required for implementation and feasibility of implementation. Were prioritized.
ResultsIn this study, 5 main causes of disease recurrence, treatment follow-up, nosocomial infections, cancellation of surgeries, disease complications and medication for patient admission were identified in three treatment groups: urology, nephrology and vascular surgery. Based on the output of the hierarchical analysis approach, it was found that: Nosocomial infections with an effect of 0.285 and follow-up treatment with an effect of 0.229 had the highest effect on patients' return to the hospital, also cancellation of surgery had the least effect compared to other factors. In the referral of patients to the hospital, seven practical solutions were presented. Based on the output of fuzzy hierarchical analysis approach, the solutions for recording and tracking hospital infections with the help of the Internet of Things, the development of specialized nutritional training programs by hospital nutrition experts, with scores of 0.182 and 0.165 had the highest executive priority.
ConclusionThe use of strategies proposed in this study to reduce patient admission to the hospital is recommended to senior hospital managers.
Keywords: Patient Admission, Fuzzy Hierarchical Analysis Process (FAHP), Referral reasons, Multiple-Criteria Decision Analysis (MCDM) -
Background and Objective
The purpose of this study is to provide a developed model of human resource management and the model of staff evaluation, especially nurses in clinical wards in Shahid Hasheminejad Hospital.
MethodThe research method is qualitative-descriptive which has been done in two stages: 1- reviewing the current situation and 2- presenting the developed model. In the first phase, 32 unstructured and open interviews were conducted with officials of different units and senior managers of the hospital. Also, the current evaluation documents of the hospital were reviewed and analyzed using the content analysis technique. In the second stage, were presented, the models using the brainstorming technique in the panel of experts and using the analysis of the previous stage.
ResultsAccording to the presented model, in specialized committees with the presence of officials, based on the needs of the hospital, hospital jobs and positions are defined and a description of the duties of each position and the minimum capabilities required to obtain positions are compiled separately. The description of tasks developed over time, based on the strategic goals of the organization, instructions and programs of superior organizations such as accreditation is variable and dynamic. Human resources manager through superior organizations to attract the appropriate staff. After 3 months of recruiting a pilot, a test is taken to determine whether to continue working with him. According to the presented model, in the clinical wards of Hasheminejad Hospital during the year, 4 types of evaluation, evaluation based on job description, evaluation of the sample employee, general evaluation and end-of-year evaluation are performed. Finally, based on the results of 4 evaluations, educational priorities are determined based on the score of each process and per person, and the educational path is presented and implemented.
ConclusionBased on the implementation of the model provided in one of the clinical wards of the hospital, it was observed that in addition to comprehensive evaluation of staff, the model provides continuous improvement in staff performance and subsequently increases the quality of services and patient satisfaction. Is. Also, due to the participation of staff in the evaluation, their satisfaction has increased.
Keywords: Human Resource Management, Staff Performance Evaluation, Hospital -
Background and Objectives
Outsourcing has been considered by hospital managers as a model to reduce the financial burden and modify the financial system. The external suppliers must be qualified for the services they ought to provide to the hospitals. The use of the Balance Scorecard and the Analysis of Hierarchical Process can help assessing suppliers' capability to solve existing problems in the field.
MethodsThis qualitative study was carried out from January to March 2018 in one of the teaching hospital in Tehran city, Iran. The following steps were taken for designing the intended model. First, the Balanced Scorecard (BSC) aspects were adapted to the concept of the health supply chain using the Focus Group method with 10 hospital experts and suppliers. The criteria determined based on the previous studies, strategic objectives of the hospital and the opinions of 5 hospital experts through Delphi method. Then, the identified criteria were classified in four aspects of the BSC. Finally, the hierarchical model was presented in the form of an evaluation balanced scorecard.
ResultsThe results of the study led to identification of 19 criteria in four aspects of the BSC. In financial section, 5 criteria were identified for internal processes and innovation aspects, and 4 criteria for customers’ aspect. In the next step, a four-level hierarchical model was designed for evaluating performance of the supplier. The first level was evaluation of supplier, the second level contained the BSC aspects, the third level was the determined criteria and, finally, the fourth level encompassed the suppliers’ affaires.
ConclusionThe combination of the supply chain concept and the BSC offers useful and effective criteria for evaluation of suppliers. A hierarchical model is an appropriate tool for evaluating suppliers.
Keywords: Supplier, evaluation, Supply chain, balanced scorecard (BSC), Outsourcing, Hospital service
- این فهرست شامل مطالبی از ایشان است که در سایت مگیران نمایه شده و توسط نویسنده تایید شدهاست.
- مگیران تنها مقالات مجلات ایرانی عضو خود را نمایه میکند. بدیهی است مقالات منتشر شده نگارنده/پژوهشگر در مجلات خارجی، همایشها و مجلاتی که با مگیران همکاری ندارند در این فهرست نیامدهاست.
- اسامی نویسندگان همکار در صورت عضویت در مگیران و تایید مقالات نمایش داده می شود.