300 research outputs found
The structure of smart schools in the educational system
ABSTRACT General Education in schools in the country is a traditional education or audio only. The maximum of multimedia action about training issues is installation of some colored posters on the classroom's blackboard .In The visual -auditory training, we are trying to present training with film, animation, video clips and ... . In this method, Survival of Subject is almost 20 years, while the survival time of this transfer is less. In general schools, teacher's lesson plans include a set of guidelines, curriculum, extra practice questions, and class exams and... . But in multimedia schools in addition to these, the teacher uses multimedia training materials including films, photos, audio, slides, to improve education quality and Survival of training. This is the first step toward to the smart schools. There are two different approaches about the impact of ICT on the educational system (and especially in schools). Some believe that the effect of new technologies is simply the gradual and makes efficient transfer of the traditional school program and in fact, information access is faster. Another approach is that new information and communication technology in schools changes the education and tools substantially. In This view, information technology surpasses on the borders of traditional education system. This change should be step by step and with tact and thought. KEY WORDS: smart schools, educational system, information and communication technology
Simultaneous preconcentration of lead and cadmium ions with methyltrioctylammonium chloride supported on microcrystalline naphthalene and determination by flame atomic absorption spectrometry
A sensitive and selective preconcentration method has been developed for the determination of trace amounts of lead and cadmium ions by using naphthalene-methyltrioctylammonium chloride as an adsorbent. Lead and cadmium ions were retained by the adsorbent in the minicolumn as PbI42- and CdI42-, respectively. The column was washed by 5 mL of 2 mol L-1 nitric acid solution to elute the adsorbed cations. The collected eluents then were determined by flame atomic absorption spectrometry (FAAS). Potential factors affecting on the recovery of the analytes were investigated. Meanwhile optimum conditions were established. The preconcentration factor for lead (II) and cadmium (II) have been 300 and 100, respectively. The calibration curves were linear in the range of 3 to 100 ng mL-1 for Pb2+ and in the range of 1 to 100 ng mL-1 for Cd2+, in the original water samples. The detection limits for Pb2+ and Cd2+ are 0.42 and 0.072 ng mL-1 respectively. On the other hand, the relative standard deviation (RSD) for 11 replicate measurements of 20 ng mL-1 Pb2+ and Cd2+ were 2.2% and 1.4% in the initial solution respectively (n=11). The developed method was successfully applied for the determination of trace Pb2+ and Cd2+ ions in a variety of water samples
Sensorless Control of a Single-Phase AC-DC Boost Converter without Measuring Input Voltage and Current
It is well-known that the accurate measurement of input voltage and current, as the feedforward and feedback terms, plays a crucial role in the nonlinear controller design for power factor compensation of an AC-DC boost converter. This paper addresses the problem of the simultaneous estimation of the input voltage and current from the output voltage in a full-bridge AC-DC boost converter. In the lossless model of the system, those variables are unobservable from the output voltage when the control input is zero. To overcome this, the system dynamics are immersed in a proper form by a new filtered transformation. The phase and amplitude of the input voltage, along with the input current, are globally estimated from the output voltage by a fifth-dimensional estimator. Unlike some existing results, the stability of the proposed estimator does not rely on a priori knowledge about the parasitic resistances and is guaranteed exponentially under the persistence of excitation conditions on the control signal. An application of the proposed estimator is presented in conjunction with a dynamic controller to form a sensorless control algorithm that does not require any sensor on the input side and controls the system only by the feedback from the output voltage. Processor-in-the-loop (PIL) studies conducted by OPAL-RT OP 5700 are used to assess the performances of the proposed estimator and controller
The Effect of Gut Microbiota and Probiotics on Metabolism in Fish and Shrimp
The present paper presents an overview of the effects of gut microbiota and probiotics on lipid-, carbohydrate-, protein- and amino acid metabolism in fish and shrimp. In probiotic fish studies, the zebrafish (Danio rerio) model is the most frequently used, and probiotic administration reveals the effect on glucose homeostasis, anti-lipidemic effects and increasing short-chain fatty acids, and increased expressions of genes related to carbohydrate metabolism and innate immunity, along with down-regulation of oxidative stress-related genes. Further, improved length of the intestinal villi and expression of nutrient transporters in fish owing to probiotics exposure have been documented. The present review will present an appraisal of the effect of intestinal microbiota and probiotic administration on the metabolism of nutrients and metabolites related to stress and immunity in diverse fish- and shrimp species. Furthermore, to give the reader satisfactory information on the topics discussed, some information from endothermic animals is also presented
Productivity improvement from economic concept to an engineering tool
In broad terms, productivity is defined as the ratio of all outputs to all inputs. In this paper, productivity is distinctly used as an engineering tool and from practical viewpoint. With such engineering look, productivity is an adequate tool for evaluation of the advancement in competitive market, work assessment, profit/loss analysis, decision and even developing or changing the activity. Productivity measurement seems to be an easy task but this is a misconception. In fact the concept remains to be one of the most complex and unknown criteria. It is for this reason that attempts have been made here to accurately define productivity and hence simplify its measurement. A case study has been adopted and the productivity of Eastern Alborz Coal Mines in Iran has been calculated for years 2001-2008. The resulting values and the component models are then subject to analysis. These results are examined in terms of practicability and it is shown that the method prescribed is a pragmatic approach in all similar system situations
Application of INAA to determine major elements concentrations in head hair of street children of Isfahan city, Iran
The street children phenomena and the number of street children is an increasing social problem in Isfahan and other big and growing towns. Because of the number of street children and the way that they affect society in childhood and when they become old, it is important to study their health and have baseline data on theire health problems. Hair element analysis is an important tool in the nutritional and environmental pollutions and measuring pollutions and measuring elemental concentrations in recently-grown hair provides a good way of studing their health. This study aimed to assess major element concentrations in the hair of street children in Isfahan using instrumental neutron activation analysis method. Six major elements (Ca, Cl, K, Mg, Na and S) of 17 Iranian street children (Isfahan) were determined. Data analysis found different profiles of the concentrations of Ca, K, Mg and S in samples. These results were discussed with reference to show of nutritional and environmental effects
Vibration of wavy single-walled carbon nanotubes based on nonlocal Euler Bernoulli and Timoshenko models
Effects of Zingiber officinale as Feed Additive on the Common Carp Body Composition
The present study was conducted to evaluate the use of ginger powder in diet of common carp, Cyprinus capio (27±3 gr). Different levels of the plant powder (0, 0.25.0.5, 1 and 2 gr / per 100gr food) were spread on commercial diet. The feed was offered by 8 weeks. Results showed that fish fed experimental diets had no significant difference (P>0.05) in amount of NFE, but have significant difference in protein, lipid, ash, moisture percent and kcal energy from different diet (p<0.05) while in kruskal-wallis test illustrated significant difference in amount of carbohydrate and body fiber (p<0.05). So, the best results in amount of protein, lipid, and energy shown in maximum dosage of ginger powder in carp commercial diet and low amount of them shown in control group. There were high amount of carbohydrate and low amount of fiber in control group. There was the lack of fiber in control group and upper level of ash in the third treatment. So, this study presents that; to be improving the body composition of common carp we use the herbal medicine like Ginger powder in their commercial diets
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