Proposal of a Reflector-Enhanced Solar Still Concept and Its Comparison with Conventional Solar Stills

Water scarcity is a global concern and poses significant problems to countries with arid and semi-arid climates, like Iran. Considering financial difficulties, a lack of knowledge about high-tech alternatives, low incomes, a lack of access to high-tech tools, and low maintenance capabilities in developing countries, solar still desalination is a decent technology for providing proper water, especially for rural areas. However, the low water-production rate using this method dictates a very vast area requirement for solar still farms in order to provide significant amounts of water. In this research, we proposed a mirror-enhanced solar still and mathematically compared its water-production rate to that of conventional ones. In comparison to conventional solar stills, our proposed reflector-enhanced solar still benefits from several improvements, including lower glass temperatures, increased water basing temperatures, and receiving much more solar irradiation. Hence, the proposed system can increase water production from 7.5 L/day to 24 L/day. The results showed that the proposed method is highly effective and could be used in field-scale projects in arid and semi-arid climates

The Effect of the Open and Closed System Suctions on Cardiopulmonary Parameters: Time and Costs in Patients Under Mechanical Ventilation

Background: One of the measures to keep the airway open is suctioning of endotracheal tube in patients under ventilation. This procedure can be accompanied with some complications. Selection of appropriate method of suctioning can prevent incidence of acute complications. Objectives: This study aimed to compare the effects of the open and closed system suctioning methods on blood pressure, mean arterial pressure, heart rate, percentage of arterial oxygen saturation, time, and costs in patients under mechanical ventilation. Patients and Methods: This clinical trial study was conducted on 40 patients in ICU. Patients’ blood pressure, heart rate, arterial oxygen saturation, related costs, and length of suctioning procedure were measured and recorded immediately before and one, five, ten, and fifteen minutes after suctioning. Data were analyzed using paired t test and repeated measure analysis of variance. Results: No significant differences were observed between the two suctioning methods in terms of mean systolic blood pressure (P = 0.075), diastolic blood pressure (P = 0.405), and mean arterial pressure (P = 0.257) in the five consecutive measurements. However, significant changes were observed in heart rate (P = 0.025) and percentage of arterial oxygen saturation (P < 0.001). The mean lengths of time in open and closed suctioning methods were 5.59 ± 0.211 and 4.34 ± 0.039 seconds, respectively (P < 0.001). The cost of the closed system was lower than the open method for the patients who were admitted to ICU for longer than two days. Conclusions: Closed suction caused fewer disturbances in patients’ hemodynamic condition, took shorter time, and is more economical. Therefore, this method can replace open suction method in caring of severely critically ill patients

Transport critical current of Solenoidal MgB2/Cu Coils Fabricated Using a Wind-Reaction In-situ Technique

In this letter, we report the results of transport Jc of solenoid coils upto 100 turns fabricated with Cu-sheathed MgB2 wires using a wind-reaction in-situ technique. Despite the low density of single core and some reaction between Mg and Cu-sheath, our results demonstrate the decrease in transport Jc with increasing length of MgB2 wires is insignificant. Solenoid coils with diameter as small as 10 mm can be readily fabricated using a wind-reaction in-situ technique. The Jc of coils is essentially the same as in the form of straight wires. A Jc of 133,000 A/cm2 and 125,000 A/cm2 at 4 K and self field has been achieved for a small coil wound using Cu-sheathed tape and Cu-sheathed wire respectively. These results indicate that the MgB2 wires have a great potential for lage scale applicationsComment: 6 pages, 4 figures, 1 tabl

Mental Health Changes and Its Predictors in Adolescents using the Path Analytic Model: A 7-Year Observational Study.

OBJECTIVE: This 7-year observational study examines the hours of TV-watching, phone conversation with friends, using the internet, and physical activity as predictors of mental health among adolescents in south of Iran. METHODS: At the baseline (in 2005), the participants were 2584 high school students in the 9th to 11th grade. At the baseline, 30% of the available participants (n = 775) were selected in the follow-up (2012) using convenience sampling method. This study used the path analysis to examine the predictors of mental health and to obtain direct, indirect and total effects of the independent variables. RESULTS: At the baseline (2005), female gender, internet use, maternal education, physical activity and father's education were associated with mental health (p<0.05). Baseline mental health, internet use and physical activity predicted mental health of the participants in the follow up (p<0.05). CONCLUSION: The findings of the study revealed that better mental health in later life is associated with better mental health at baseline, male gender, higher physical activity and phone communication with friends, and less use of the internet and TV

Mechanism of Enhancement in Electromagnetic Properties of MgB2 by Nano SiC Doping

A comparative study of pure, SiC, and C doped MgB2 wires has revealed that the SiC doping allowed C substitution and MgB2 formation to take place simultaneously at low temperatures. C substitution enhances Hc2, while the defects, small grain size, and nanoinclusions induced by C incorporation and low-temperature processing are responsible for the improvement in Jc. The irreversibility field (Hirr) for the SiC doped sample reached the benchmarking value of 10 T at 20 K, exceeding that of NbTi at 4.2 K. This dual reaction model also enables us to predict desirable dopants for enhancing the performance properties of MgB2

Haematological, blood biochemical and immunological responses to gradual acclimation to low-salinity water in Walton’s mudskipper Periophthalmus waltoni Koumans, 1941 (Perciformes: Gobiidae)

The present study investigates and reports the effects of gradual acclimation to low salinity water on some haematological, biochemical and immunological responses in Walton’s mudskipper, Pe-riophthalmus waltoni. For this purpose, mudskippers caught from Persian Gulf coastal area (Bandar Khamir, Hormozgan Province, Iran) were maintained in laboratory aquaria with half seawater (50% SW, 17 ppt) and fed daily with frozen blood worms (Chironomus spp.) for one month prior to the start of experiments. After acclimation, groups of 18 individuals were either directly transferred to 50% SW (control), or acclimated to low salinity water during two sub-periods. In the first sub-period, fish were exposed to low salinity water namely to a gradual water salinity decrease of 1 ppt per day (during 17 days) until the final salinity of 0.4 ppt was reached. Afterwards, fish continued to maintain in this point of salinity (0.4 ppt), for further 15 days until day 32 (second sub-period). Fish were sampled on day 0, 17 and 32. Statistical analysis showed a significant influence of reduced salinity on erythrocytes, haemoglobin, haematocrit, leukocytes, lymphocytes, neutrophils, monocytes and on all biochemical and immunological parameters tested on day 17. However, these indices returned to the control level on day 32. Based on results, the extremely euryhaline P. waltoni can be acclimated to freshwater medium without showing any health disturbance if a gradual decrease in salinity is carried out for a long period of time