Thermal Convection in Non-Fourier Fluids and Application to Liquid Helium II

This thesis examines different conditions for which non-Fourier effects can be significant in the flow of fluids. Non-Fourier fluids of dual-phase-lagging type (DPL) possess a relaxation time and a retardation time, reflecting the delay in the response of the heat flux and the temperature gradient with respect to one another. For non-Fourier fluids of single-phase-lagging type (SPL) the retardation time is zero. Non-Fourier fluids span a wide range of applications, including liquid helium, nanofluids and rarefied gases. The parallels between non-Fourier fluids and polymeric solutions are established. The instability of steady natural convection of a thin layer of non-Fourier fluid (SPL) between two horizontal (and vertical) surfaces maintained at different temperatures is studied. The SPL model is particularly relevant to liquid helium II, and nanofluids with high nanoparticle concentration. Linear stability analysis is employed to obtain the critical state parameters such as critical Rayleigh (Grashof) numbers. In both cases, as the fluid becomes more non-Fourier, oscillatory convection increasingly becomes the mode of preference, compared to both conduction and stationary convection. Critical Rayleigh (Grashof) number decreases for fluids with higher non-Fourier levels. By invoking the role of the eigenvectors to detect and quantify short-time behavior, transient growth of energy of disturbances in is studied. The energy of the perturbations is introduced in terms of the primary variables as a disturbance measure in order to quantify the size of the disturbance. It is found that nonlinearities are not required for the energy growth, and a significant energy growth can be observed even if the flow is stable. The post-critical convective state for Rayleigh-Benard convection is studied using a nonlinear spectral-amplitude-perturbation approach in a fluid layer heated from below. In the spectral method the flow and temperature fields are expanded periodically along the layer and orthonormal shape functions are used in the transverse direction. A combined amplitude-perturbation approach is developed to solve the nonlinear spectral system in the post critical range, even far from the linear stability threshold. Also, to leading order, the Lorenz model is recovered. Comparison with experimental results is made and a very good qualitative agreement is obtained

Effect of different conditioning methods on the surface roughness of dental amalgam: SEM analysis

The purpose of this study was incorporation of SEM micrographs for evaluating the effect of different mechanical and chemical treatments on surface roughness of dental amalgam. Amalgam was condensed in 18 plastic molds and the following modification methods were accomplished on samples surface: 1) Chemical solutions (5 groups) on fresh amalgam 2) Chemical solutions (5 groups) on aged amalgam 3) Sandblast on aged amalgam 4) Sandblast on fresh amalgam (2 groups) before & after primary setting. 5) Use of diamond bur (0.10 coarse) on aged amalgam. 6) Acid etch (37% phosphoric acid) on fresh amalgam. 7) Metal etch on fresh amalgam. 8) Varnish solvent in amalgam capsule, trituration &condensation (fresh). 9) Standard sample without any treatment. All groups were analyzed by SEM (×l00, ×500 magnifications were used for roughness quantification and chemical analysis respectively). The numbers of surface peaks were counted in 5 area of each micrograph and consequently the data were assessed by K-S & student T- tests. All groups have statistically significant difference with control except three ones (incorporation of phosphoric acid, EDTA+NH3, and NaOH+I2 on fresh amalgam). Sandblast, diamond bur & metal etch reduced surface roughness and use of chemical solutions showed different reactions

Effect of different conditioning methods on the surface roughness of dental amalgam: SEM analysis

The purpose of this study was incorporation of SEM micrographs for evaluating the effect of different mechanical and chemical treatments on surface roughness of dental amalgam. Amalgam was condensed in 18 plastic molds and the following modification methods were accomplished on samples surface: 1) Chemical solutions (5 groups) on fresh amalgam 2) Chemical solutions (5 groups) on aged amalgam 3) Sandblast on aged amalgam 4) Sandblast on fresh amalgam (2 groups) before & after primary setting. 5) Use of diamond bur (0.10 coarse) on aged amalgam. 6) Acid etch (37% phosphoric acid) on fresh amalgam. 7) Metal etch on fresh amalgam. 8) Varnish solvent in amalgam capsule, trituration &condensation (fresh). 9) Standard sample without any treatment. All groups were analyzed by SEM (×l00, ×500 magnifications were used for roughness quantification and chemical analysis respectively). The numbers of surface peaks were counted in 5 area of each micrograph and consequently the data were assessed by K-S & student T- tests. All groups have statistically significant difference with control except three ones (incorporation of phosphoric acid, EDTA+NH3, and NaOH+I2 on fresh amalgam). Sandblast, diamond bur & metal etch reduced surface roughness and use of chemical solutions showed different reactions

Evidence for an early accounting system found at Tal-e Mash Karim, a Chalcolithic site in Iran

Investigating the accounting systems and their progressive development during the prehistoric period is a critical issue in recognition of human societies, their communication, and formation of inter- and intra-regional trade system transformed to innovation of writing systems. The present study aims at studying the typology and classification of the Chalcolithic (Middle Bakun, 4500 BC) period. Numerical objects discovered in Tal-e Mash Karim in Semirom district located in Esfahan province, Iran. The discovered cultural materials contain 32 numerical tokens and a clay tallying slab. The numerical tokens are divided into three main categories and seven subcategories. On that basis, round and oval shape tokens for measuring agricultural products and flat and disc shape tokens are representing animals and animal products related productions. The discovery of a tallying slab beside the artifacts all is proving the existence on an early accounting system

How does geographical branding improve the efficiency of the apple supply chain?

Brands are among the most valuable assets of agricultural businesses. Geographical branding can play a fundamental role in national and international markets by creating a competitive identity. On the other hand, orchard owners in a certain geographical region can understand the status of a product’s supply chain. Nonetheless, few studies have focused on how branding can influence the status of a product’s supply chain. Thus, the present study aimed to analyze the effect of geographical branding on improving the apple supply chain. The research is an applied study in terms of the goal, conducted by the survey methodology. Data were collected by distributing 360 questionnaires among apple orchard owners in Damavand County sampled by simple randomization. Cochran’s formula estimated the sample size. The research instrument was a research-made questionnaire. Data were analyzed by structural equation modeling. According to the results, special brand value, brand loyalty, brand image, brand attitude, brand experience, brand purchasing intention, and brand identity were the components found to improve the efficiency of the Apple supply chain significantly

Methods of Improving the Dimensions of Psychological Empowerment of Employees of SAMT Organization in the Condition of COVID-19

The main premise of the present paper is that the former methods for fully enhancing the dimensions of psychological empowerment may not be fully effective in the context of the Corona epidemic. For this reason, the aim of this paper is to model and applied systematically to promote empowerment in times of crisis is epidemic. The present study was conducted by mixed method as an explanatory approach. Explanatory approach indicates the precedence of the quantitative method. In this research, first the quantitative points of the research are identified by quantitative data and then more accurate information is obtained based on a qualitative method about the detected domain information.The results showed that the methods of mutual and continuous monitoring (in terms of competence and effectiveness), improving the informal environment (in terms of participation), integration of organizational and individual funds (in terms of the right to choose and participate), developments and interactions at organizational levels (In terms of effectiveness) and upgrading organizational communication knowledge (in terms of sense of participation) will specifically help to enhance the empowerment dimension in the employees of Samt organization in coronary conditions

Investigating the health literacy influencing ways on the adoption of smoking preventive behaviors in Health Belief Model developed by health literacy

زمینه و اهداف: ادغام سواد سلامت به الگوی اعتقاد بهداشتی، به تقویت عملکرد این الگو در پیش‌بینی رفتارهای پیشگیرانه از مصرف سیگار یاری می‌رساند، اما نوع این تاثیر و نحوه عملکرد سواد سلامت در این الگوی ترکیبی، تاکنون مشخص نشده است. لذا این مطالعه با هدف تعیین راه‌های تاثیر سواد سلامت بر اتخاذ رفتارهای پیشگیرانه از مصرف سیگار در الگوی اعتقاد بهداشتی تلفیقی با سواد سلامت انجام شد.  مواد و روش‌ها: در این مطالعه مقطعی-تحلیلی، 340 نفر از دانشجویان خوابگاهی دانشگاه علوم پزشکی شهید بهشتی تهران با روش نمونه‌گیری خوشه‌ای یک مرحله‌ای وارد مطالعه شدند. ابزار گردآوری داده‌ها شامل پرسشنامه روا و پایای مبتنی بر الگوی اعتقاد بهداشتی درباره پیشگیری از مصرف سیگار و پرسشنامه سنجش سواد سلامت (HELIA) بود. داده‌ها با نرم‌افزار SPSS نسخه 16 و روش تحلیل مسیر مبتنی بر رگرسیون تک متغیره و چندگانه، تحلیل شدند. تمامی مراحل مطالعه حاضر طبق موازین اخلاقی اجرا گردید.    یافته‌ها: سواد سلامت تاثیری مستقیم و معنادار بر تمامی سازه‌های الگو و اتخاذ رفتار داشت. همچنین از طریق تاثیر بر سازه‌های الگو، به‌طور غیرمستقیم بر اتخاذ رفتار تاثیر داشت و از بین این تاثیرات، فقط تاثیر آن از طریق متغیرهای حساسیت‌درک ‌شده و خودکارآمدی بر روی اتخاذ رفتار، معنادار بود. ضمنا تاثیر غیرمستقیم سواد سلامت بر اتخاذ رفتار بیشتر از تاثیر مستقیم آن بود. نتیجه‌گیری: با استفاده از الگوی اعتقاد بهداشتی تلفیقی با سواد سلامت و تاکید بر متغیرهای حساسیت‌درک ‌شده و خودکارآمدی، می‌توان تا حدودی سواد سلامت و در نتیجه اتخاذ رفتارهای پیشگیرانه از مصرف سیگار را در دانشجویان ارتقا داد.Background and Aims: Incorporation of health literacy (HL) into health belief model (HBM) assist in strengthening the performance of this model in predicting smoking preventive behavior. However, the type of such an effect and the way in which the HL works in this hybrid model has not yet been determined. Therefore, this study was aimed to determine the influencing ways of HL on adoption of smoking preventive behavior in HBM incorporated with HL. Materials and Methods: In this cross-sectional study, 340 dormitory students of Shahid Beheshti University of Medical Sciences in Tehran were enrolled using single-stage cluster sampling. The data collection tool was a valid and reliable questionnaire based on HBM on smoking prevention and HL questionnaire (HELIA). Data were analyzed using SPSS version 16 and path analysis method based on single-variable and multiple regressions. All stages of the study were conducted ethically. Results: HL had a direct and statistically significant effect on all structures of the model and adoption of behavior. Also, it indirectly influenced adoption of behavior by influencing the structures of the model. Only perceived susceptibility and self-efficacy variables significantly affect adoption of behavior. In addition, the indirect effect of HL on the adoption of behavior was greater than its direct effect. Conclusion: It is possible to improve the degree of HL and, therefore, the adoption of smoking preventive behavior among students through the use of HBM incorporated with HL, which emphasizes on perceived susceptibility and self-efficacy variables

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely