Using Porous Media to Enhancement of Heat Transfer in Heat Exchangers

According to increasing human needs for energy and to avoid energy waste, researchers are struggling to increase the efficiency of energy production and energy conversion. One of these methods is increasing heat transfer and reducing heat dissipation in heat exchangers. Using porous materials in the fluid flow is one of the passive methods to increase heat transfer in heat exchangers. The existence of porous media in the flow path, improve the matrix of thermal conductivity and effective flow thermal capacity and also matrix of porous-solid increase radiation heat transfer, especially in two phase flow (gas-water) systems. In this paper, recent studies on the effect of using porous media on enhancement the amount of heat transfer in heat exchangers has been investigated via using porous media with difference porosity percentage, material and geometric structure in the flow path in numerical simulations and laboratory studies

Family medicine in Iran: facing the health system challenges

OBJECTIVE: This study aimed to understand the perspectives of policy makers and decision makers of Iran's health system about the implementation of family medicine in Iran urban areas. MATERIALS/PATIENTS & METHODS: This study is a qualitative study with framework analysis. Purposive semi-structured interviews were conducted with Policy and decision makers in the five main organizations of Iran health care system. The codes were extracted using inductive and deductive methods. RESULTS: According to 27 semi-structured interviews were conducted with Policy and decision makers, three main themes and 8 subthemes extracted, including: The development of referral system, better access to health care and the management of chronic diseases. CONCLUSION: Family medicine is a viable means for a series of crucial reforms in the face of the current challenges of health system. Implementation of family medicine can strengthen the PHC model in Iran urban areas. Attempting to create a general consensus among various stakeholders is essential for effective implementation of the project. BACKGROUND: In response to the current fragmented context of health systems, it is essential to support the revitalization of primary health care in order to provide a stronger sense of direction and integrity. Around the world, family medicine recognized as a core discipline for strengthening primary health care setting

The experience of implementing the board of trustees� policy in teaching hospitals in Iran: An example of health system decentralization

Background: In 2004, the health system in Iran initiated an organizational reform aiming to increase the autonomy of teaching hospitals and make them more decentralized. The policy led to the formation of a board of trustees in each hospital and significant modifications in hospitals� financing. Since the reform aimed to improve its predecessor policy (implementation of hospital autonomy began in 1995), it expected to increase user satisfaction, as well as enhance effectiveness and efficiency of healthcare services in targeted hospitals. However, such expectations were never realized. In this research, we explored the perceptions and views of expert stakeholders as to why the board of trustees� policy did not achieve its perceived objectives. Methods: We conducted 47 semi-structured face-to-face interviews and two focus group discussions (involving 8 and 10 participants, respectively) with experts at high, middle, and low levels of Iran�s health system, using purposive and snowball sampling. We also collected a comprehensive set of relevant documents. Interviews were transcribed verbatim and analyzed thematically, following a mixed inductive-deductive approach. Results: Three main themes emerged from the analysis. The implementation approach (including the processes, views about the policy and the links between the policy components), using research evidence about the policy (local and global), and policy context (health system structure, health insurers capacity, hospitals� organization and capacity and actors� interrelationships) affected the policy outcomes. Overall, the implementation of hospital decentralization policies in Iran did not seem to achieve their intended targets as a result of assumed failure to take full consideration of the above factors in policy implementation into account. Conclusion: The implementation of the board of trustees� policy did not achieve its desired goals in teaching hospitals in Iran. Similar decentralization policies in the past and their outcomes were overlooked, while the context was not prepared appropriately and key stakeholders, particularly the government, did not support the decentralization of Iran�s health system. © 2015 by Kerman University of Medical Sciences

The Future of Advertising and Publishing

The rise of digital media has fundamentally changed the relationship between marketers and publishers. As audiences increasingly move toward mobile consumption, publishers have had to adapt their business models based on new standards set by social media platforms and advertisers. They are now in competition with large tech companies to reach, and to own, the same audiences. The adtech ecosystem, which was designed by platforms and advertisers to capitalize on the growing amount of data retained about readers, has produced a mess of publishers’ main monetization strategies—leaving the entire space in dire need of evaluation and experimentation. On October 20, 2017, the Tow Center for Digital Journalism at Columbia University, the Digital Initiative at Harvard Business School, and the Shorenstein Center on Media, Politics, and Public Policy at the Harvard Kennedy School hosted a Policy Exchange Forum (PEF) and public conference to explore these shifts in “The Future of Advertising and Publishing.” The PEF took place in the morning and comprised a closed discussion (by invitation only) built around two major questions: What is the future of the relationship between publishers and advertisers? More specifically, how can platforms, news publishers, and advertisers ensure a robust future for news publishers by shaping the quality of advertising

Optical conductivity of ABA stacked graphene trilayer : mid-IR resonance due to band nesting

The band structure and the optical conductivity of an ABA (Bernal-type) stacked graphene trilayer are calculated. It is shown that, under appropriate doping, a strong resonant peak develops in the optical conductivity, located at the frequency corresponding to approximately 1.4 times the interlayer hopping energy and caused by the 'nesting' of two nearly parabolic bands in the electronic spectrum. The intensity of this resonant absorption can be controlled by adjusting the gate voltage. The effect is robust with respect to increasing temperature.Financial support from the COMPETE Programme (FEDER) and the Portuguese Foundation for Science and Technology (FCT) through Projects PEst-C/FIS/UI0607/2013 and PTDC/FIS/113199/2009, as well as MATEPRO Project (ON2 Program) is gratefully acknowledged. ZR thanks the hospitality of the Physics Center of Minho University during her stay in Portugal. YVB, NMRP, RR and MIV acknowledge support by the EC under Graphene Flagship (contract no. CNECT-ICT-604391)

Prevalence and intensity of catastrophic health care expenditures in Iran from 2008 to 2015: a study on Iranian household income and expenditure survey.

BACKGROUND: Households exposure to catastrophic health expenditure is a valuable measure to monitor financial protection in health sector payments. The present study had two aims: first, to estimate the prevalence and intensity of catastrophic health expenditures (CHE) in Iran. Second, to investigate main factors that influence the probability of CHE. METHODS: CHE is defined as an occasion in which a household's out-of-pocket (OOP) spending exceeds 40% of the total income that remains after subtraction of living expenses. This study used the data from eight national repeated cross-sectional surveys on households' income and expenditure. The proportion of households facing CHE, as a prevalence measure, was estimated for rural and urban areas. The intensity of CHE was also calculated using overshoot and mean positive overshoot (MPO) measures. The factors affecting the CHE were also analyzed using logistic random effects regression model. We also used ArcMap 10.1 to display visually disparities across the country. RESULTS: An increasing number of Iranians has been subject to catastrophic health care costs over the study period in both rural and urban areas (CHE = 2.57% in 2008 and 3.25% in 2015). In the same period, the overshoot of CHE and the mean positive overshoot ranged from 0.26% to 0.65% and from 12.26% to 20.86%, respectively. The average absolute monetary value of OOP spending per month has been low in rural areas over the years, but the prevalence of CHE has been higher than urban areas. Generally put, rural settlement, higher income, receiving inpatient and outpatient services, and existence of elderly people in the household led to increase in CHE prevalence (p < 0.05). Interestingly, provinces with more limited geographical and cultural accessibility had the lowest CHE. CONCLUSIONS: According to the findings, Iran's healthcare system has failed to realize the aim of five-year national development plan regarding CHE prevalence (1% CHE prevalence according to the plan). Therefore, revision of financial health care protection policies focusing on pre-payments seems mandatory. For instance, these policies should extend the interventions that target low-income populations particularly in rural areas, provide more coverage for catastrophic medical services in basic benefit packages, and develop supplementary health insurance