Design of a mechanically closed-loop test rig for testing aviation industry’s gearboxes

Due to the wide usage of rotary equipment and the necessity of their testing for maintenance and repair, test rigs have become necessary. The mechanical closed-loop test rig developed in Sharif University of Technology branch of ACECR (Academic Centre of Education, Culture and Research) is a test rig with low energy losses that is suitable for testing high power gearboxes such as aerospace or wind turbine gearboxes. It can be loaded up to 489Hp at a maximum speed of 3000 rpm, and the test components can be tested in different testing conditions including a variety of torques and speeds. This paper describes the preliminary, conceptual, and detailed design, steps including frame work design, control system design, hydraulic system and torque generator design asn well as a dynamic and static analysis of the whole system. Also a simplified model of the system is presented and qualified, and some data of test rig’s working conditions is presented. These data includes the temperature change of the gearboxes, their vibration in time, and also the variation of torque, hydraulic pressure, and motor speed. Furthermore, the relation between these parameters is investigated to determine the behaviour of the system. The validity of the system’s dynamic modelling is also investigated and verified

Nano silver-coated polypropylene water filter: I. manufacture by electron beam gun using a modified Balzers 760 machine

As adequate freshwater supplies decrease steadily, novel technologies are required for water purification. Nanotechnology, a new scientific frontier, promises to revolutionize innovation in many industries. Advancements in nanotechnology are being applied in the water-purification industry to keep harmful bacteria out of drinking water. Due to its bactericidal properties, nano silver is used in many products as an antibacterial. This study aimed to produce a nano silver-coated water-treatment polypropylene filter via the physical vapor deposition method using the Balzers 760 machine equipped with an electron beam gun ESQ 110. The Balzers machine was modified in order to enable coating of the cylindrical filters in a homogenous manner. The nano silver particles were made by electron beam bombardment of the silver metal, which were subsequently deposited on the polypropylene filter evenly. The thickness of the nano layer coated on the filter was about 55.0nm in average, as revealed by the microprocessor unit of the Balzers machine during the coating process. The thickness of the nano layer and the chemical composition of the produced filters were studied by scanning electron microscopy, atomic force microscopy and the X-ray diffraction technique. The filter system produced in this work has the potential to be used as an efficient and cost-effective water treatment method. The inductively coupled plasma/mass spectrometry (ICP/MS) studies revealed that there was no nano silver particle present in the filtered water sample. Hence, there is no risk of contamination of drinking water with the silver nano particles upon application of the manufactured filters. This is the first report on the manufacture of nano silver-coated cylindrical polypropylene filter using the electron beam gun technique

Complete removal of pathogenic bacteria from drinking water using nano silver-coated cylindrical polypropylene filters.

An attempt was made to investigate the removal of Escherichia coli bacteria from drinking water using nano silver-coated polypropylene water filter. For the production of nano silver filters, a modified Balzers 760 machine equipped with an electron beam gun was used. The nano-silver particles were made by electron beam bombardment of the silver metal, which were subsequently deposited on the polypropylene filters evenly. The thickness of the nano layer coated on the filters was 35.0 nm. The nano silver-coated filters were characterized using scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and atomic force microscopy. The antibacterial efficiency of the filters was evaluated using the membrane filter method. At a flow rate of 3 l/h, the output count of E. coli was zero after 7 h filtration when the input water had a bacterial load of 103 colony-forming units (cfu) per milliliter. The inductively coupled plasma/mass spectrometry (ICP/MS) results showed that the 35 nm layer of the silver nanoparticles were stable on the water filter and were not washed away by water flow even after 72 h

Assessment of relationship among sleepiness with polysomnographic parameters in patients with OSA

Background: Sleepiness that occurs at inappropriate or undesirable times or that interferes with daytime activities is generally considered excessive daytime sleepiness. Obstructive Sleep Apnea (OSA) is one of the most common causes of excessive daytime sleepiness. The aim of this study is to finds out the most important nocturnal polysomnographic parameters influencing daytime sleepiness in patients with OSA. Materials and Methods: Considering the inclusion and exclusion criteria, 112 patients referred to Baqiyatallah subspeciality sleep clinic in Qom city were selected. Patients, demographic and Epworth Sleepiness Scale (ESS) data were gathered and then comparison among ESS with polysomnography and anthropometric parameter was performed. Chi-square was used for analysis of qualitative parameters. Data analysis was done by SPSS v.18. P value was significant (˂0.05). Results: The mean age of the cases was 55.07 with male frequency 58.9% and female 41.1%. Body mass index was 34.34, apnea hypopnea index 43.62, mean Arousal Index 30.64 and mean ESS was 12.83. There was significant relationship among ESS>10 with arousal index (p=0.009) and mean O2 saturation (p=0.029), But we didn’t detected correlation between ESS>10 with other polysomnographic parameters. Conclusion: According to the data, the most important parameters of sleepiness in obstructive sleep apnea patients were sleep fragmentation and mean O2 saturation

Manufacturing of nanoliposomal extract from Sargassum boveanum algae and investigating its release behavior and antioxidant activity

In this paper, the fabrication of algal extract-loaded nanoliposomes was optimized based on the central composite response surface design. Different concentrations of phenolic compounds (500, 1,000, and 1,500 ppm) of algal extract and lecithin (0.5, 1.25, and 2% w/w) were applied for preparation of nanoliposomes at process temperatures of 30, 50, and 70°C. Dependent variables were zeta potential, entrapment efficiency, size, and particle size distribution. The particle size of the loaded nanoliposomes ranged from 86.6 to 118.7 nm and zeta potential from −37.3 to −50.7 mV. The optimal conditions were as follows: 0.5% lecithin, 30°C process temperature, and 1,313 ppm of the phenolic compounds extracted from algae. Under these conditions, the experimental entrapment efficiency of the phenolic compounds was 45.5 ± 1.2%. FTIR analysis has verified the encapsulation of algal extract in nanoliposomes. Algal extract phenolic compounds also increased phase transition temperature (Tc) of nanoliposomes (1.6°C to 6.3°C). Moreover, the thermo-oxidative protection of nanoliposomes for the algal extract has been proved by examining the DSC thermograms. It has been demonstrated that the formulated nanoliposomes have a good stability during storage conditions, and they are able to control the release of phenolic compounds at different pH values. During the encapsulation process, the antioxidant activity of the algal extract has been maintained to an acceptable level. Consequently, algal extract-loaded nanoliposomes can be used as a natural antioxidant in lipid-based foods

Genetic variation of some hawthorn species based on phenotypic characteristics and RAPD marker

Hawthorn (Crataegus spp.) is an important forest fruit species in Iran. Genetic variability among some genotypes of hawthorn was investigated using morphological traits and random amplified polymorphic DNA (RAPD) marker. The collected genotypes belonged to four species of Crataegus genus. High variability among genotypes was found for most of the traits. Results from the principal component analysis (PCA) indicated that 85.05% of the observed variability was accounted by the first five components. The first two components explained about 55.24% of the total achieved variability. In PCA, fruit weight, fruit length, fruit diameter, fruit moisture, fruit dry matter, leaf length, leaf area, leaf width, number of leaves per node, seed weight and seed length were predominant in the first two components, indicating that they were useful for the assessment of hawthorn germplasm characterization. A total of 58 polymorphic bands were produced with 10 RAPD primers. The bands' sizes ranged from 180 to 2700 bp. The number of the observed polymorphic bands for each primer ranged from 4 to 8, with an average of 5.8 alleles per locus. The polymorphism information content was observed to be the highest (0.79) in the Oligo_32 locus, whereas the Oligo_339 locus had the lowest value of 0.64, with an average of 0.72, among the RAPD primers. The Jaccard's genetic similarity coefficient ranged from 0.12 to 0.95 among the genotypes. At a similarity coefficient of 0.46, the unweighted pair group method with arithmetic mean (UPGMA) cluster analysis divided the genotypes into three major groups

The effects of training mothers with ADHD children based on Adler- Dreikurs\' instructions on parenting styles and oppositional behavior in their children

Parent-child interaction in children with attention deficit hyperactivity disorder very important impact leaves on behavioral problems, Therefore, one of the ways of enhancing parenting style and subsequently reduce behavioral problems, Psychological training in behavior management of children with attention deficit disorder / hyperactivity for parents. So the present study is to investigate the effectiveness of training mothers with Adler- Dreikurs approach on enhancing parenting style and decreasing their children’s oppositional behavioral problems. The research method was quasi-experimental with pre-and-post design with control group. Therefore, 24 mothers whose children were diagnosed as ADHD were chosen through at-hand sampling and were matched into experimental and control groups. The research instruments were CSI-4, and parenting style questioners for Parents. Training mothers with Adler- Dreikurs approach was accomplished in ten 90-minutes sessions. In the end, the two groups completed the questionnaires as post-test. The data was analyzed using ANCOVA. The results indicated the effect of instructing Adler-Dreikurs methods on improving authoritarian parenting style scores in mothers (P<0/05) and also the effect of this experimental instruction on decreasing authoritative and neglectful parenting practices scores and oppositional behavioral (P<0/05) of experimental group in comparison with control group. The results totally showed that behavioral training to mothers improves their parenting style and prevents rising confusion in parent-child relationships and also emotional problems in mothers of children with ADHD disorder

Work-Related Musculoskeletal Disorders in Truck Drivers and Official Workers

Work-related musculoskeletal disorders (WMSDs) are common among drivers and official workers. Musculoskeletal disorders are frequent causes of absenteeism in many countries. The aim of this study was to determine the prevalence of musculoskeletal disorders and risk factors associated with these symptoms. A total of 346 workers and truck drivers were participated in this case-control study. All the participants were interviewed using a self- administered questionnaire containing demographic data and a Nordic questionnaire about presence site and characteristics of pain. Then the data were gathered, and the prevalence of the mentioned parameters and the relationship between variables in the questionnaire were analyzed statistically. The results of this study revealed that 78.6% out of truck drivers and 55.5% out of official workers had musculoskeletal disorders in on-year and there was a significant difference between two groups in this regard (P<0.001). On the whole, the most common symptoms were neck 47 (27.2%), followed by lumbar pain 42 (24.3%) in truck drivers and knee 63 (36.4%) and lumbar symptom 21 (12.1%) in one-year in official workers. In this study, musculoskeletal disorders showed statistically significant association with work duration, age and BMI (P<0.001). Within the limits of this study, it can be concluded that the musculoskeletal troubles have a high frequency among the drivers and official workers. Both groups usually remain on a prolonged uncomfortable postures and high static muscle load which may imply a risk for development of the troubles

Impact of Landuse Change on River Floodplain Using Public Domain Hydraulic Model

Floodplains are land areas adjacent to rivers and streams that are subjected to recurring inundation. Owing to their continually changing nature, floodplains and other flood-prone areas need to be examined in the light of how they might affect or be affected by landuse change. In this research, the effect of land use changes on floodplain is investigated. Major landuse change has occurred in Azaran watershed during the investigation period. Irrigated farmland has decreased by about 52%. However, bare lands, dry farm lands, and rangeland have increased by 12.40%, 17.25% and14.46%, respectively. The extent of floodplain was determined based on the annual maximum instantaneous flood for different return periods using Hydrologic Engineering Centers River Analysis System (HEC-RAS) coupled with HEC-GeoRAS which is a tool for processing geospatial data in ArcGIS. Water surface profile data and velocity data exported from HEC-RAS simulations were processed by HEC-GeoRAS for floodplain mapping. It was found that the floodplain has increased due to land use change from 1956 to 2007. This study showed that floodplain areas in irrigated farmlands have increased by 151.99% and 68.63% for return period of 25 and 50 years, respectively