ENHANCED SPECIFIC HEAT OF MOLTEN SALT NANOFLUIDS

Concentrated solar power uses general thermodynamic cycles (such as Rankine or Gas turbine cycle) to produce electricity and thus its efficiency primarily relies on the operating temperature of thermal energy storage. Current thermal energy storage medium is organic material such as synthetic oil or fatty acid. However, these materials are not stable at high temperatures due to their thermal decomposition. Using molten salts as thermal energy storage medium is a very attractive option since they are thermally stable at high temperatures (over 600 °C). They also have very lower vapor pressure (for reducing mechanical stress on structure materials), less reactive, and abundant in nature in comparison with the conventional thermal energy storage materials. However, their low specific heat hinders the use of molten salts as thermal energy storage materials. The low specific heat of molten salts can be enhanced by doping with nanoparticles. Solvents doped with nanoparticles (termed as nanofluids) are well known for their large enhancement of thermal conductivity. In this study, the low specific heat of molten salts were enhanced by doping with nanoparticles. SiO2 nanoparticles were dispersed in a mixture of Li2CO3-K2CO3 at 1% concentration by weight showed 25% enhanced specific heat. From the subsequent material characterization study, a large amount of special fractal-like nanostructures was observed all over the nanofluids. Four different sizes of nanoparticles were tested to prepare nanofluids to verify the effect of nanoparticles on specific heat and the result showed almost no variation in specific heat with nanoparticle size. This implies that nanoparticles may not have direct effect on the enhanced specific heat but may help the formation of the fractal-like nanostructures. The fractal-like nanostructures are formed by molten salt molecules electrostatically interacting with nearby nanoparticles and may be responsible for the enhanced specific heat of nanofluids. To verify this, two batches of nanofluids were prepared and one was treated with a very small amount of hydroxide to interrupt the proposed electrostatic interaction. The result showed that the one treated with hydroxide did not form the fractal-like nanostructures and no specific heat enhancement was observed, while the other nanofluid showed constant 25 % enhanced specific heat. In order to have a better understanding of the effects of the formed nanostructures in nanofluid sample, the rheological properties of the pure and nanofluid samples were studied. The results shows increase not only in the average value of viscosity on the nanofluid sample, but also changing in the behavior of the fluids. That is, the nanofluid samples shows high amount of non-Newtonian behavior compare to the one of pure samples which shows Newtonian behavior. Based on the experimental results, and applying proposed theories to have a better understanding of thermophysical properties of nanostructures, this study proposes a new specific heat mechanism theories of molten salt. A comparison study was conducted using the proposed mechanism to explain the difference between conventional nanofluids whose specific heat decreases and molten salt-based nanofluids whose specific heat increases. The result of this study is expected to not only help to design advanced thermal energy storage for concentrated solar power applications but also help to answer unsolved questions in the field of nanofluids

In situ production of titanium dioxide nanoparticles in molten salt phase for thermal energy storage and heat-transfer fluid applications

In this study, TiO2 nanoparticles (average particle size 16 nm) were successfully produced in molten salt phase and were showed to significantly enhance the specific heat capacity of a binary eutectic mixture of sodium and potassium nitrate (60/40) by 5.4 % at 390 °C and 7.5 % at 445 °C for 3.0 wt% of precursors used. The objective of this research was to develop a cost-effective alternate method of production which is potentially scalable, as current techniques utilized are not economically viable for large quantities. Enhancing the specific heat capacity of molten salt would promote more competitive pricing for electricity production by concentrating solar power plant. Here, a simple precursor (TiOSO4) was added to a binary eutectic mixture of potassium and sodium nitrate, heated to 450 °C, and cooled to witness the production of nanoparticles

The Global Incidence, Mortality, and Burden of Breast Cancer in 2019: Correlation With Smoking, Drinking, and Drug Use

Female breast cancer (FBC) is the most common type of cancer and is associated with a considerable disease burden as well as significant mortality rates. The present study aimed to provide an update on the incidence, mortality, and burden of FBC in 2019, based on the Global Burden of Disease (GBD) Study. Materials The incidence, death rate, disability-adjusted life years (DALYs), years of life lost (YLLs), years lived with disability (YLDs), the age-standardized rates (ASR) of FBC in 204 countries, and a variety of classifications, were retrieved from the Global Burden of Disease Study. Data on tobacco use, alcohol consumption, and drug use were collected. The incidence, mortality, and burden of FBC were registered and compared between regions. Associations between age-standardized incidence rates and age-standardized mortality rates of FBC with smoking, drinking, and drug use were determined. Results The highest incidence of FBC was observed in countries with a high socioeconomic status such as those of the European continent. Despite the lower incidence of FBC in countries with a low socio-demographic index (SDI), mortality rates secondary to FBC are higher in these countries than in high-income countries. The highest age-standardized mortality rate has been reported in the Eastern Mediterranean Region (EMRO), followed by the African Region (AFRO). The highest age-standardized rates of DALY and YLL per 100,000 population in 2019 were observed in lower-income countries, while the highest ASR of YLD per 100,000 population was reported in high-income countries. Conclusion The present GBD-based study provides a comprehensive review of the incidence, mortality, and burden of FBC in 2019. The incidence of FBC is higher in regions with a higher socioeconomic status, whereas mortality rates and DALYs are higher in poorly developed regions. We suggest better screening measures and early detection programs for the latter regions

The Association between Body Image and Eating Disorders, Anxiety and Depression in Patients with Polycystic Ovary Syndrome (PCOS) in Hamedan, Iran

Background: Given the various issues that Polycystic ovary syndrome (PCOS) can cause in women and the need to address its consequences and provide solutions to improve the course of the disease and alleviate its symptoms, the present study aimed to investigate the association between body image and eating disorders, anxiety, and depression in individuals with PCOS.Methods: This observational study was conducted on 150 girls with PCOS in Hamadan, Iran in 2023. Convenience sampling method was used to select unmarried girls of reproductive age with PCOS. The participants were asked to complete certain questionnaires, including demographic questionnaires, the eating disorders examination questionnaire (EDE-QS), the hospital anxiety and depression scale (HADS), and the body shape questionnaire (BSQ). The collected data were analyzed using Stata-13 software, with a significance level of P<0.05.Results: The multivariable logistic regression analysis revealed that individuals with concerns about their body image had a significantly higher risk of disordered eating, approximately 25 times greater than those without concerns after adjusting for BMI, age, and PCO duration (Odds Ratio [OR]=29.25; 95%CI: 6.22, 137.67; P<0.001). The results of the logistic regression indicated that individuals with body image concerns were 2.23 times more likely to experience depression (OR=2.23; 95%CI: 1.16, 4.30; P=0.02) and two times more likely to experience anxiety (OR=2.00; 95%CI: 1.04, 3.84; P=0.04) compared with those without concerns.Conclusions: Large number of girls are concerned about their body image. This causes eating disorders, anxiety and depression in these people. These findings highlight the importance of providing timely and appropriate treatment for PCO

A review of barriers and facilitators to mammography in Asian women

Aim: Breast cancer is the most common cancer among women in Asia and one of the major health problems in most countries in the region. Despite extensive advances in treatment, early diagnosis is one of the main methods for increasing the survival rate. It is necessary to evaluate the barriers and facilitators of screening in different societies. This study was conducted to identify the barriers and facilitators of mammography in Asia. Materials and methods: To identify the barriers and facilitators of mammography in Asia, a comprehensive search was carried out in databases such as Medline, Web of Science Core Collection and Scopus using keywords, including breast cancer, screening, mammography, barriers, facilitators and the names of each Asian country, as well as a combination of these keywords were used to help the search. Full-text, English language and original articles were included in this study. Results: In total, 71 articles were entered into the study. The findings of this study revealed various barriers to mammography in Asian women, including knowledge, sociodemo-graphic factors, cost and insurance, cultural factors, belief, attitude and feeling, fear, pain and embarrassment, self-efficacy, religious, psychological factors, time constraint, fatalism, professional recommendations, communication, social support and access. Also, knowledge, attitude and belief, perceived risk, professional and social factors were found to be facilitators of mammography. Conclusion: Knowing the barriers and facilitators to access mammography is the first step in the development of a successful screening program. Awareness and various personal, professional and social factors have emerged as the major barriers to access to mammography in most Asian countries

Effects of counseling on lifestyle of menopause women and their spouses: a randomized, controlled trial study (RCT)

Background: Menopause is a part of the normal aging process, but considerably affect the different aspects of women and their spouse lifestyle. Stabilizing a healthy lifestyle is important way to control predisposing factors of disease conditions in menopause women, thus counseling may have a major role for improving lifestyle in women and their spouse. Objective: The present study aimed to assess the influence of counseling on lifestyle of menopause women and their spouses. Methods: An interventional trials study was performed on 120 consecutive Iranian couples (menopause women and their spouses) who were resident in Hamadan. The subjects were randomly assigned to receive counseling service as intervention group or did not receive this service as control group. The lifestyle assessment was performed before counseling, and also after the first session (2 months later) and second session (2 months after the first session) of counseling. The control group did not receive any counseling. In total, five sessions were programmed for one hour as couple Counseling at home. Results: The scores of nutritional habits and physical activity level at baseline were significantly similar between the two groups. However, both nutritional habit and physical activity scores were significantly increased after regular counseling in the intervention group, while these scores remained unchanged in the control group. Conclusion: Counseling has beneficial effects on lifestyle modification in both menopause women and their spouses regarding improvement of nutritional habits and physical activity

Investigating the relationship between DMFT index of pregnant women and neonates’ low birth weight in Hamadan in 2016

Introduction: Low birth weight (LBW), defined as a weight less than 2500 g, is strongly associated with a neonatal mortality. Many studies show a positive association between periodontal disease of pregnant mothers and LBW, but few studies have been conducted on the relationship between the dental decays and the LBW. Thus, due to the lack of information in this field, the present study was conducted to evaluate the relationship between DMFT index of the pregnant women in Hamadan and neonates’ LBW. Materials and Methods: This case-control study was conducted on the pregnant women of Hamadan in 2016. The experimental group consisted of 114 pregnant mothers who had normal vaginal delivery and their neonates’ birth weight was less than 2500 g. The control group consisted of 147 pregnant mothers who had normal vaginal delivery and their neonates’ birth weight was over 2500 g. The data were collected based on an interview and examination. The data collection tool was a questionnaire consisting of two sections, including demographic characteristics and dental information. The data were analyzed using descriptive and analytical statistics with SPSS version16 software and P <0.05 was considered as the significance level. Results: The results showed that the mothers in the experimental and control groups were significantly different in terms of DMFT index (P=0.003). The mean of DMFT index in the experimental and control groups were 13.03 and 10.66, respectively. This difference was statistically significant. The correlation coefficient revealed no significant relationship between DMFT index and the neonatal weight in the control group (p=0.532). Conclusion: According to the results of the present study, there is a positive relationship between the dental decays of the pregnant women and the neonates’ LBW. To prevent neonates’ LBW, the public health providers and mass media should provide essential oral hygiene promoting and maintaining programs for pregnant women. Also, due to limited number of studies in this area, further studies in different populations and races seem to be necessary. © 2020, Venezuelan Society of Pharmacology and Clinical and Therapeutic Pharmacology. All rights reserved

Relationship between Plasma Concentrations of Maternal Zinc during Pregnancy and the Risk for Orofacial Cleft

Aim: Recent studies have suggested the occurrence of a variety of abnormalities including oral clefts following the deficiency of nutritional elements. The present study aimed to address the association between plasma concentrations of maternal zinc and the risk of an infant being born with an orofacial cleft. Materials and Methods: In this case-control study conducted in Hamadan, Iran, 2015, 48 mothers of children with an isolated cleft lip with or without cleft palate and 48 control mothers of children with no congenital malformations were recruited. The concentration of zinc in the whole blood was measured using flame atomic absorption spectrometry method. Data were analyzed by the use of descriptive and analytical statistics in SPSS version 16. Results and Discussion: Plasma level of zinc in a group with orofacial clefts was 16.87 +/- 8.17 mu mol/L, and in the control group was 19.28 +/- 8.83 that was statistically similar between the groups (t = -1.329, P = 0.187). T-test showed that the two groups did not have a significant difference in zinc level. The odds ratio (OR) for the case and control group was 1.6, which indicates there was no significant difference in zinc deficiency between the two groups (OR = 1.66, 95 confidence interval = 0.61-4.54, P = 0.426). Conclusion: Despite lower zinc plasma levels in women of the case group, the difference in concentration of this element was not statistically significant between the two groups. In general, there is no definitive conclusion on whether the deficiency of nutritional elements during pregnancy is the cause of malformations or not, and it is still necessary to further studies

Relationship between dental plaque formation and salivary cortisol level in pregnant women

Purpose: Understanding how increased level of salivary cortisol contributes to the development of dental biofilm during pregnancy can help inthe prevention of dental caries and periodontal diseases. This study aims to evaluate the relationship between salivary cortisol level and dental biofilm formation in pregnant women. Patients and methods: This descriptive-analytic study was conducted in Hamadan, Iran in 2011. Forty consecutive pregnant women with no history of abortion, stillbirth, or any known physical or psychological disorders at weeks 25 and 33 of gestation were included. Salivary samples were collected for measurement of cortisol levels by Enzyme Linked Immunoabsorbent Assay (ELISA) method. The amount and extension of dental biofilms were determined by using a disclosing agent. Data were analyzed using descriptive and analytical statistics in SPSS version 16. Results: The mean levels of salivary cortisol at weeks 25 and 33 of gestation were respectively, 2.45 +/- 1.56 mug/dl and 5.24 +/- 4.07 mug/dl which demonstrates a significant difference (P<0.001). Evaluation of dental biofilm at two time intervals revealed a significant increase in amount of dental biofilm at week 33 of gestational period (34.65 +/- 10.9 vs. 42.45 +/- 12.35, P<0.001). Elevated levels of dental biofilm were significantly correlated with salivary cortisol levels at week 33 (r=0.494, P=0.001),however, it was not significant at week 25 of gestation (r=0.148, P=0.361). Conclusion: The findings suggested that increased levels of salivary cortisol can predict dental biofilm formation and accumulation in pregnant women in the last weeks of gestation