NUMERICAL SIMULATION OF CONFINED NANO-IMPINGING JET IN MICROSCALE COOLING APPLICATION USING DSMC METHOD

ABSTRACT In this study, we simulate rarefied gas flow through a confined nano-impinging jet using direct simulation Monte Carlo (DSMC) method. The effects of geometrical parameters, pressure ratio, and wall conditions on the heat transfer from a hot surface are examined. Hot surface modeled via diffusive constant wall temperature. Various inlet/confining surface conditions such as specular, adiabatic, and constant temperature are implemented and the effects of them on the wall heat flux rates are studied. The results show that Knudsen number, velocity slip, and temperature jump are main reasons which specify magnitudes of wall heat flux rates. Among all geometrical parameters, H/W ratio has the greatest effect on heat transfer, where H is jet distance from the hot surface and W is the jet width. For different values of pressure ratio, the biggest quantity of wall heat flux rate relates to the lowest velocity slip case. Also for inlet/confining walls with constant temperature condition equal to coolant flow temperature, heat transfer from the hot surface was the maximum

Health impact assessment of air pollution in Shiraz, Iran : a two-part study

We aimed to assess health-impacts of short-term exposure to the air pollutants including PM10, SO2, and NO2 in Shiraz, Iran in a two-part study from 2008 to 2010. In part I, local relative risks (RRs) and baseline incidences (BIs) were calculate using generalized additive models. In part II, we estimated the number of excess hospitalizations (NEHs) due to cardiovascular diseases (CDs), respiratory diseases (RDs), respiratory diseases in elderly group (RDsE-people older than 65 years old), and chronic obstructive pulmonary diseases (COPDs) as a result of exposure to air pollutants using AirQ model, which is proposed approach for air pollution health impact assessment by World Health Organization. In part I, exposure to increase in daily mean concentration of PM10 was associated with hospitalizations due to RDs with a RR of 1.0049 [95% confidence interval (CI), 1.0004 to 1.0110]. In addition, exposure to increase in daily mean concentration of SO2 and NO2 were associated with hospitalizations due to RDsE and COPDs with RRs of 1.0540 [95% CI, 1.0050 to 1.1200], 1.0950 [95% CI, 1.0700 to 1.1100], 1.0280 [95% CI, 1.0110 to 1.0450] and 1.0360 [95% CI, 1.0210 to 1.0510] per 10 μg/m3 rise of these pollutants, respectively. In part II, the maximum NEHs due to CDs because of exposure to PM10 were in 2009-1489 excess cases (ECs). The maximum NEHs due to RDs because of exposure to PM10 were in 2009-1163 ECs. Meanwhile, the maximum NEHs due to RDsE and COPDs because of exposure to SO2 were in 2008, which are 520 and 900 ECs, respectively. In conclusion, elevated morbidity risks were found from acute exposure to air pollutants

The global, regional, and national burden of gastro-oesophageal reflux disease in 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

Background Gastro-oesophageal reflux disease is a common chronic ailment that causes uncomfortable symptoms and increases the risk of oesophageal adenocarcinoma. We aimed to report the burden of gastro-oesophageal reflux disease in 195 countries and territories between 1990 and 2017, using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017. Methods We did a systematic review to identify measurements of the prevalence of gastro-oesophageal reflux disease in geographically defined populations worldwide between 1990 and 2017. These estimates were analysed with DisMod-MR, a Bayesian mixed-effects meta-regression tool that incorporates predictive covariates and adjustments for differences in study design in a geographical cascade of models. Fitted values for broader geographical units inform prior distributions for finer geographical units. Prevalence was estimated for 195 countries and territories. Reports of the frequency and severity of symptoms among individuals with gastro-oesophageal reflux disease were used to estimate the prevalence of cases with no, mild to moderate, or severe to very severe symptoms at a given time; these estimates were multiplied by disability weights to estimate years lived with disability (YLD). Findings Data to estimate gastro-oesophageal reflux disease burden were scant, totalling 144 location-years (unique measurements from a year and location, regardless of whether a study reported them alongside measurements for other locations or years) of prevalence data. These came from six (86%) of seven GBD super-regions, 11 (52%) of 21 GBD regions, and 39 (20%) of 195 countries and territories. Mean estimates of age-standardised prevalence for all locations in 2017 ranged from 4408 cases per 100 000 population to 14 035 cases per 100 000 population. Age-standardised prevalence was highest (>11 000 cases per 100 000 population) in the USA, Italy, Greece, New Zealand, and several countries in Latin America and the Caribbean, north Africa and the Middle East, and eastern Europe; it was lowest (<7000 cases per 100 000 population) in the high-income Asia Pacific, east Asia, Iceland, France, Denmark, and Switzerland. Global prevalence peaked at ages 75–79 years, at 18 820 (95% uncertainty interval [95% UI] 13 770–24 000) cases per 100 000 population. Global age-standardised prevalence was stable between 1990 and 2017 (8791 [95% UI 7772–9834] cases per 100 000 population in 1990 and 8819 [7781–9863] cases per 100 000 population in 2017, percentage change 0·3% [–0·3 to 0·9]), but all-age prevalence increased by 18·1% (15·6–20·4) between 1990 and 2017, from 7859 (6905–8851) cases per 100  000 population in 1990 to 9283 (8189–10 400) cases per 100  000 population in 2017. YLDs increased by 67·1% (95% UI 63·5–70·3) between 1990 and 2017, from 3·60 million (1·93–6·12) in 1990 to 6·01 million (3·22–10·19) in 2017. Interpretation Gastro-oesophageal reflux disease is common worldwide, although less so in much of eastern Asia. The stability of our global age-standardised prevalence estimates over time suggests that the epidemiology of the disease has not changed, but the estimates of all-age prevalence and YLDs, which increased between 1990 and 2017, suggest that the burden of gastro-oesophageal reflux disease is nonetheless increasing as a result of ageing and population growth. Funding Bill & Melinda Gates Foundation

Investigating the Effect of Firm Level Factors on Debt Maturity Structure

There are various factors which have the relationship with debt maturity structure in the firm level that several theories have applied to present these factors. Therefore, in this research, the variables of profitability, dividend policy, business risk and taxation as affecting factors on debt maturity structure have been examined under two theories of signaling and tax. In order to do that, four hypotheses have been presented. The statistical population of the research is comprised of listed companies in Tehran Stock Exchange and the research period is the years during 2001 to 2009. Employed statistical model, is multi variable regression and for data analysis, panel data has been used. The results of research hypotheses examination in the level of whole sample represent that there are positive relationship between dividend policy and profitability with debt maturity structure. On the other hand, there is negative relationship between taxation rate with debt maturity structure. Furthermore, there is no significant relationship between business risk with maturity debt structure. The findings are consistent with tax hypothesis, while is not consistent with signaling hypothesis. There are also various correlation results in different industries

Future Value of Firm, Capital Structure, Dividend Policy, and Profitability in Listed Companies on Tehran Stock Exchange

The relationship between Future Value of Firm with capital structures, dividend policies and profitability of listed companies on Tehran Stock Exchange has been analyzed in this research. Two hypotheses have been considered: The relation of capital structure, dividend policies and profitability with the value of firms is studied in the first hypothesis, and the relation of variable Future Value of Firm has been considered in the 2nd hypothesis. For analysis of the 1st hypothesis a multi-variable linear regression model, and for the 2nd hypothesis, a Logistic model is used. The statistical population is the listed Production Companies on Tehran Stock Exchange within the years 2001 to 2008. To define the statistical sample, the systematic elimination method has been used, which was considered in 110 companies. The results obtained from analysis data infer on the confirmation of both hypotheses through using Panel data. There is a significant as well, reciprocal relation among the dividend policies and the Firm's value. There is also a significant and positive relation among the considered variables with future values of Firms. Moreover, the findings have showed the probability of increasing the Future Value of Firm with increasing the relations of capital structure, dividend policies and probability

Evaluation of a [67Ga]-Thiosemicarbazone Complex as Tumor Imaging Agent

[67Ga]labeled 2-acetylpyridine 4,4-dimethylthiosemicarbazone ([67Ga]- [APTSM2]2+) was prepared using freshly prepared [67Ga]GaCl3 and 2-acetylpyridine 4,4-dimethylthiosemicarbazone (APTSM2) for 30 min at 90°C (radiochemical purity: &gt;97% ITLC, &gt;98% HPLC, specific activity: 15–20 Ci/mmol). Stability of the complex was checked in human serum for 37°C. The biodistribution of the labeled compound in vital organs of normal and fibrosarcoma bearing mice were compared with that of free Ga3+ cation up to 24h. Initial SPECT images and biodistribution results showed significant tumor uptake in fibrosarcoma-bearing mice after 2 hour post injection

The Effect of L-carnitine Supplementation on Liver Function, Folate and Vitamin B12 Levels in Patients with Type 2 Diabetes Mellitus: A Randomized, Double-Blind, Clinical Trial

Carnitine is necessary for allowing the long-chain fatty acids to pass the inner mitochondrial membrane to induce β -oxidation. Lack of carnitine and abnormalities of mitochondria play an important role in forming fatty deposition in the liver, and hence, developing steatohepatitis. Carnitine and acylcarnitine identified in human erythrocytes and intra-erythrocyte acetylcarnitine have a significant relationship with the plasma levels. Methods: The present study was conducted to investigate the possible effects of L-carnitine on liver function, folate and vitamin B12 levels in patients with type 2 diabetes mellitus (T2DM). In this study, 70 patients with T2DM were randomly assigned to either a L-carnitine (CG) and a placebo group (PG). For 12 weeks, the first group received 1000 mg/d oral L-carnitine, whereas the second group received 1000 mg/day wheat starch as placebo. The alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), folate, Vitamin B12, complete blood count (CBC) including blood cells and indicators related to anemia were assessed at baseline. Results: 64 patients managed to complete the study (32 in each group). The results indicated that consumption of L-carnitine compared with placebo had no significant effect on liver enzymes, folate, vitamin B12, and CBC with differential. Conclusions:  Daily intake of 1000 mg L-carnitine for 12 weeks had no effect on liver function and anemia indicators including CBC, folate, and vitamins B12