Combined effect of the magnetic field, orientation, and filling ratio on cylindrical pulsating heat pipe using distilled water and distilled water/Fe3O4 nanofluid

To investigate the effect of the magnetic field, a pulsating heat pipe was made in the shape of a cylinder and Fe3O4 nanoparticles (%0.1 wt) were used with the base fluid of distilled water as the working fluid. (Tetramethyl ammonium hydroxide) TMAH surfactant was used as a stabilizer. To investigate the effect of gravity on the performance of the pipe, the device was tested at different angles from zero to 90 degrees. In this research, the effect of different variables, including the type of working fluid (distilled water vs. nanofluid), filling ratio, slope, and amount of heat input to the evaporator (30–300 W), in two different states, once without the influence of the magnetic field and once again with the application of a magnetic field was investigated. The results of the tests showed that the performance of the device at 50 % filling ratio is better than 60 % filling ratio. The use of nanoparticles improved the performance of the device. Inclining the device increases the thermal resistance so that the device performs poorly in the horizontal mode in all modes except when it is under the influence of a magnetic field. The use of nanofluid, as well as the application of a magnetic field, makes the start-up time of the device decrease by 37 % and 30 %, respectively, compared to distilled water. The temperature of the start of fluctuations also decreases by 24 % and 32 %, respectively

Lexical and Syntactic Development of Dizygotic Persian-Speaking Twins from 21 to 31 Months

The present study examines the lexical and syntactic development of dissimilar Persian-speaking twins named Behzad and Behnam over a period of ten months (from the beginning of 21 months to the beginning of 31 months). This study seeks to find out what differences and similarities there are in the syntactic and lexical development of these twins, despite the fact that the two children grow up in the same language environment. The data of this study were collected through rapid observation and recording of data in a notebook, audio and video recording using a video camera and audio recorder, as well as the diary of the mother of the twins in which children's language products were recorded. The investigation of the collected data and their comparative analysis each month shows a significant difference between the lexical and syntactic development of the twins. Although in the early months of the study, Behzad had a much higher language ability compared to his twin brother, Behnam, from the fourth month of the study, a significant increase in Behnam's lexical and syntactic growth rate was observed. Considering that the language development environment of these two children, both in the family and in the kindergarten, has often been the same, the existence of differences in the lexical and syntactic developmental stages of these two children can be attributed to the difference in innate and inherited linguistic talent of these two children. Dizygotic twins do not have exactly the same chromosomal structure. The results of this study show creative mental activities in two children, which is evidenced by the existence of numerous cases of over-extension and overgeneralization

The Relationship between Metabolic Control and Growth in Children with Type I Diabetes Mellitus in Southwest of Iran

Background. Metabolic control is an important factor in growth of children with type I diabetes. This study assessed the relationship between growth and metabolic control in such children. Materials and Methods. 83 children with diabetes were studied. They were examined for weight and height gain and HbA1C was quantified every 3 months for one year. The growth process was studied in patients who were divided into 3 groups according to their HbA1C amounts, consisting of good, intermediate, and poor metabolic control. Results. Mean age of cases was 7.6 ± 2. The presenting sign at the onset of disease was diabetic ketoacidosis in 44.6%. The average HbA1C amount was 8.89%. The average weight SDS at diagnosis was −0.18 and at the end of the study was 0.45 (P<0.001). The average height SDS at diagnosis was −0.04 and at the end of the study was −0.07 (P=0.64). A significant difference in weight SDS changes was only seen between patients with good and poor metabolic control (P=0.04). Conclusion. Poor metabolic control can decrease height growth but has minimal influence on weight. Metabolic control was not the only predictive factor of physical growth in children with diabetes

Viscosity of nanofluids: A review of recent experimental studies

During the past decade, nanotechnology with its rapid development has grabbed the attention of scientists, scholars, and engineers. Nanofluids are one of the surprising outcomes of this technology that could increase the efficiency of thermal systems remarkably. Nanofluids containing solid nanoparticles have a higher viscosity than common working fluids; hence, measuring the viscosity is necessary for designing thermal systems and estimating the required pumping power. In the current review study, an attempt has been made to cover the latest experimental studies performed on the viscosity of nanofluids. An experimental investigation is very vital for the analysis since the theoretical models usually underestimate the nanofluid viscosity. Through experiments, the real effects of volume fraction, temperature, particle size, and shape on the viscosity of nanofluids will be determined