Reactive oligomer to improve the impact characteristics of structural composites used in civil and medical applications

Composite materials are increasingly utilized in many civil engineering and medical applications such as conveying tubes and pipelines, making artificial human parts, dental applications, reinforcing structures, etc. The glass reinforced composite is one of the most common composite that is used for its good mechanical properties and also its rationally low price. Polymeric resins such as epoxy are used as the constitutive material in producing glass reinforced composites. In this research paper we improve the impact resistance of the glass-reinforced composite using Hycar reactive oligomer. Mechanical impact strength tests have been conducted using a notched sample. The obtained test results show that the impact resistance of Hycar modified glass-reinforced composite is enhanced by addition of the Hycar to the glass reinforced composite. Moreover the glass transition temperature (T g) of the samples has been measured experimentally using a differential scanning calorimeter (DSC) instrument. The results of measuring T g however shows that these g improvements in impact resistance of the composite material are accompanied with a slight reduction in the glass transition temperature of the modified composite samples. Moreover the damaged surfaces of fractured samples were investigated using scanning electron microscopy (SEM) techniques. © IDOSI Publications, 2012

Mechanical characteristics of tire/clay modified epoxy used in fabrication of medical prostheses and artificial human parts

Epoxy is used in many dental and medical applications such as manufacturing prostheses. This polymer is not toxic and is a good candidate for easily forming of artificial hand, leg, etc. In recent years, the recycled waste tire has been concerned as inexpensive modifier for improving the toughness characteristics of many thermoset resins such as epoxy. Herein, the influence of addition of nanoclay on mechanical characteristics of waste tire-modified epoxy was investigated. Mechanical properties i.e. compressive and flexural characteristics, fracture toughness and impact strength of the samples were investigated. The fracture surfaces of the specimens were examined using scanning electron microscope (SEM). Moreover the glass transition temperature (Tg) of the samples were measured. Results reveal that nanoclay can improve the mechanical characteristics of waste tire-modified epoxies. © IDOSI Publications, 2012

Biotechnology: Two Decades of Experimentation with Genetically Modified Foods

Background and Objective: Over the recent years, genetically modified food in varieties of corn, soybeans, canola and cotton have been introduced to the global market. This study reviews the health and nutritional value of genetically modified foods in the past two decades.Results and Conclusions: Contrary to the present biotechnological claims, transgenic products did not prove to be so flawless, and actually failed to maintain social satisfaction. Genetically modified foods could not gain an increase in the yield potential. Planting natural products and genetically modified products in parallel lines will absolutely result in genetic infection from the side of genetically modified foods. One of the major anxieties of the anti- genetically modified foods activism is the claim that genetically modified crops would alter the consumable parts of the plant quality and safety. Genetically modified foods have shown to have inadequate efficiency and potential adverse effects in both fields of health and biodiversity. This review has presented studies of genetically modified foods performances in the past two decades, and concludes that the wide application and the over generalization of genetically modified foods are not fundamentally recommended.Conflict of interest: Authors declare that there is no conflict of interest

Evaluation of Microbiological Water Quality and Coastal Waters Quality Index of Persian Gulf in Bandar Abbas Coastal City, Iran

The goals of this study were to assess the microbiological quality and coastal water quality index (CWQI) in the Persian Gulf alongshore of Bandar Abbas city. Water samples were collected from five different coastal sites in spring and summer seasons. To assess the microbiological quality: Total Coliforms, Fecal Coliforms, Fecal Streptococci and Clostridium perfringens were measured. Also, eight physicochemical parameters (DO, BOD, TSS, Turbidity, Temperature, pH, Nitrate, Phosphate) were examined for calculating the CWQI. The mean for microbiological indicators was respectively, 3667, 1055, 50, 211 MPN/100ml. for physicochemical parameters, the average of water temperature was 32 °C, electrical conductivity was 57mmho/cm, the turbidity was 70.7 NTU, pH 8.1, and also the average concentration of phosphate, nitrate, nitrite, and ammonium was 180, 18.2, 4.9, 12.16μmol/L, and the mean of concentration BOD, COD and DO were 4.89, 11 and 6.8mg/L, respectively. In addition, the water quality index for all months and at selected stations was 65. The results showed that in the most samples the levels of microbiological indicators were exceeded the national standard and guideline values. Also, the computed CWQI showed that quality of water was weak. All the extracted results are closely related to the inlets connected to the sea. These inlets except the Ghadir station will affect the rest of the stations. In general, in low tide, the Bactria index was more than high tide

Biological Removal of Cadmium by Halomonas elongate IBRC-M10433 in Different Conditions: Optimization by Taguchi Statistical Approach

The biological removing method is cheap and safe for the environment. The Cadmium is toxic and harmful for the environment; therefore, the biological removing programs were developed for deletion of this metal from waste. Detection of persisting bacteria to toxic metals and using them for removing heavy metal from arouses environments and wastewaters is very important. In this study the ability of Halomonas elongate IBRC-M10433 bacterium was achieved from Urmia Salt Lake was tested to remove of Cadmium in wastewaters. For achievement optimised of different environmental factors such as Cadmium, Glucose and salt for removal of Cadmium from H. elongate IBRC-M10433, we used Taguchi method. Results from this study showed that H. elongate IBRC-M10433 persists to Cadmium metal. The largest Cadmium removal (85%) was seen in the culture that contains 50 ppm Cadmium, Glucose 10 g/L and NaCl 200 g/L

Examining Working Methods on Reducing Expenses in Islamic Azad Universities: Perspective of Faculty Members of Isfahan (Khorasgan) Branch

Islamic Azad universities are autonomous and non-profit institutions where almost all the expenses are provided through students` tuitions. In recent years in accordance with extreme quantitative development of institutions of higher education, reduction in the number of university student candidates, paltry increase in tuitions, and considerable increase in construction and current expenses, management of expenses in Azad universities has turned into a vital concern. The present study aims to examine working methods for decreasing the expenses of the universities, investigating the effect of five factors including targeting activities, organizing manpower, mechanizing systems, controlling, observing, and downsizing the university, on reducing expenses in Islamic Azad Universities. The study is conducted in descriptive survey method and the population of the study was all 320 faculty members of Islamic Azad university of Isfahan (Khorasgan) in March, 2014. 175 people were chosen by Morgan Table through available random sampling as the sample of the study. The instruments were questionnaires designed by the researcher and the data was analyzed through Uni-variate t Test, Friedman Test, and Analysis Variance through spss-19 software. The result revealed that all five factors in the study have significant effects on reducing expenses in the universities and manpower had the highest effect whereas, controlling and observing had the least effect. DOI: 10.5901/mjss.2015.v6n3s1p44

The effect of 11+Kids program on the scores of musculoskeletal screening tests

Background: Children and adolescents are more vulnerable to injuries than other groups. Therefore, it is necessary to use screening tests to identify players who are more susceptible to be injured and in parallel, using intervention programs to reduce the risk of injury. Aim: The purpose of this study was to investigate effect of 11+Kids program on the scores of musculoskeletal screening testsMaterials and Methods: Forty-eight players were randomly assigned into the FIFA 11+Kids (mean±SD; age= 12.70±1.30 years; weight= 44.34±6.16 kg; height= 1.52±0.09 m) and control groups (mean±SD; age= 12.91±1.31 years; weight= 45.51±8.13 kg; height= 1.55±0.11 m). The FIFA 11+ Kids performed instead of the usual warm-up for 8 weeks, while the control group performed their usual warm-up program. Functional movement screen (FMS) and special football jump-landing task (SFJLT) tests were examined in pre-test and post-test. Results: The independent t-test showed no significant differences between the FIFA 11+ Kids and the control group in the FMS test (P= 0.055). Furthermore, results showed significant differences between groups in the SFJLT test (P= 0.001). Conclusion: Performing 8 weeks of FIFA 11+Kids can improve the musculoskeletal screening test score of SFJLT as a field-assessment soccer-specific jumping-landing test. It is suggestive that a field-based assessment tool to identify prone athletes is more beneficial than the FMS test of adolescent male soccer players

Natural Gas Condensate Desulfurization via Polyacrylonitrile/Ag Nanocomposite Nanofibers: Optimization and Kinetics/isotherms Studies

In the present study for the first time, a novel polyacrylonitrile-silver nanocomposite nanofiber was synthesized by electrospinning for adsorbing sulfur compounds in natural gas condensate. The synthesized material was characterized by SEM, EDAX, and XRD. The presence of C, N, O, and Ag proved that the composite was synthesized successfully. In order to achieve the best adsorption conditions, the effect of contact time, adsorbent dosage and initial sulfur compound concentration was examined. Under optimal values, efficiency of greater than 90% was found. In addition, different isotherms and kinetics models were tested to describe the sorption process. It was found that Freundlich (0.9900) was superior to Langmuir (0.9688), Temkin (0.9648) and Dubinin-Radushkevich (0.8273) models, revealing that sulfur compounds tend to for, multilayers on the heterogeneous surface of polyacrylonitrile-silver nanocomposite nanofiber. The energy value of the adsorption was 23.57 kJ/mol, indicating chemisorption reactions. Based on kinetics studies, the desulfurization by nanofibers followed Pseudo-second-order and Elovich kinetics. Finally, the desulfurization function of nanocomposite was studied and validated using adsorbent columns. The obtained results demonstrate polyacrylonitrile-silver nanocomposite nanofiber as a promising material in the field of desulfurization

Effects of an aquatic protocol on electromyography activation and strength of lower limb muscles in blind women

Purpose: Visual impairment poses considerable challenges to mobility and everyday tasks, frequently leading to a more sedentary lifestyle and reduced physical fitness levels. Therefore, this study investigated the effects of a tailored aquatic exercise protocol on muscle activation and strength in visually impaired individuals.Materials and Methods: Thirty women who were blind (mean age = 29.03 ± 2.20 years) were randomly assigned to an experimental (EXPrado et al.) group and a control (CO) group. The EX group participated in three weekly 60-minute aquatic sessions, while the CO group maintained regular activities. Electromyography (EMG) activation and onset time were measured in the tibialis anterior, gastrocnemius medialis, rectus femoris, and biceps femoris. Muscle strength was also assessed in the ankle dorsiflexors and plantarflexors, as well as the knee flexors and extensors.Results: The EX group showed increased EMG activation for the tibialis anterior, gastrocnemius medialis, rectus femoris, and biceps femoris in both anterior-posterior (2.23 MVIC%, 95% CI: 1.13 to 3.34, p &lt; 0.001) and posterior-anterior directions (2.35 MVIC%, 95% CI: 1.80 to 2.91, p &lt; 0.001) compared to CO group. Onset time decreased significantly in the EX group relative to CO group (anterior-posterior: -108.07 ms, 95% CI: -117.23 to -98.89, p &lt; 0.001; posterior-anterior: -98.72 ms, 95% CI: -106.54 to -90.90, p &lt; 0.001). Muscle strength significantly increased in the EX group compared to the CO group, with greater strength in ankle dorsiflexors (4.42 N/kg, 95% CI: 3.42 to 5.42, p &lt; 0.001) and knee extensors (2.72 N/kg, 95% CI: 1.04 to 4.40, p &lt; 0.001).Conclusions: The aquatic exercise program improved neuromuscular function and strength in women with visual impairments, supporting its use in rehabilitation.<br/

Comparison between the performance of four metaheuristic algorithms in training a multilayer perceptron machine for gold grade estimation

Reserve evaluation is a very difficult and complex process. The most important and yet most challenging part of this process is grade estimation. Its difficulty derived from challenges in obtaining required data from the deposit by drilling boreholes, which is a very time consuming and costly act itself. Classic methods which are used to model the deposit are based on some preliminary assumptions about reserve continuity and grade spatial distribution which are not true about all kind of reserves. In this paper, a multilayer perceptron (MLP) artificial neural network (ANN) is applied to solve the problem of ore grade estimation of highly sparse data from zarshouran gold deposit in Iran. The network is trained using four metaheuristic algorithms in separate stages for each algorithm. These algorithms are artificial bee colony (ABC), genetic algorithm (GA), imperialist competitive algorithm (ICA) and particle swarm optimization (PSO). The accuracy of predictions obtained from each algorithm in each stage of experiments were compared with real gold grade values. We used unskillful value to check the accuracy and stability of each network. Results showed that the network trained with ABC algorithm outperforms other networks that trained with other algorithms in all stages having least unskillful value of 13.91 for validation data. Therefore, it can be more suitable for solving the problem of predicting ore grade values using highly sparse data