Students´ Knowledge about Nanotechnology and the Importance to Introduce Nanotechnology into Chemistry Lessons

The primary objective of this study was to find out what students already know about nanotechnology in order to design a context based module with a nanotechnology background. Therefore a questionnaire was distributed to 116 German students in grade 11. Questions referred to the first thought of the students´ mind when they hear the word nanotechnology, to the size of a nanometer, to if something can be seen at the nanometer scale with the unaided eye, to their self-assessment concerning nanotechnology and to the surface-to-volume ratio of nanoparticles. The findings of the students´ answers were informative and allowed us to design a module in the future that can lead students at school level to understanding nanotechnology

Photo-catalytic Removal of Methyl Orange Dye by Polyaniline Modified ZnO using Visible Radiation

Polyaniline modified zinc oxide (PANI/ZnO) nanocomposite was synthesized by in-situ polymerization process. The as-synthesized nano-ZnO, PANI and PANI/ZnO nanocomposite were characterized by X-ray diffraction (XRD), FT-IR, and UV-Vis spectroscopy. The UV–visible spectroscopy studies showed that the absorption peak for PANI/ZnO nanocomposite has a red shift toward visible wavelengths compared with the ZnO nanoparticles and PANI. Photocatalytic efficiency of PANI/ZnO nanocomposite was investigated for the degradation of methyl orange (MeO) dye as a model organic compound under Visible light irradiation. The photocatalytic activities of ZnO, PANI and PANI/ZnO nanocomposite were studied. The results showed that ZnO/PANI nanocomposite had greater photocatalytic activity than ZnO nanoparticles and PANI under visible light irradiation. According to these results, application of PANI as a shell on the surface of ZnO nanoparticles causes the enhanced photocatalytic activity of the PANI/ZnO nanocomposite. Influence of some operational parameters such as: amount of photocatalyst, pH of solution, and MeO dye initial concentration on the photodegradation reaction rate was investigated. The optimum values of pH and catalyst dose found to be 6 and 1.50 gmL-1 respectively. It was demonstrated that the photocatalytic degradation of MeO follows pseudo first-order kinetics. The PANI/ZnO nanocomposite photocatalysts have good photocatalytic stability and can be reused three times with only gradual loss of activity. Thus, the PANI/ZnO nanocomposites are efficient photocatalytic materials for degrading contaminated colored wastewater for reuse in textile industries under mild conditions.Keywords: PANI/ZnO Nanocomposite; Methyl orange; Visible light; photo-catalysis; Degradation rate constan

Manufacturing Technology of Lead Zirconate Titanate Cylindrical Elements for Passive Transducer Arrays

State-of-the-art technology has been developed for the fabrication of 33 mm hollow cylindrical elements from Lanthanum-dooed lead zirconate titanate-based material suitable for oassive surveillance arrays of SONAR systems. It covers properties of the material composition, isostatic pressing technique, precision machining, sintering to produce dielectrically sound distortion-free cylindrical elements, ceramic grinding, electroding, poling to achieve electromechanical properties, and evaluation of dielectric, piezoelectric, and elastic properties of the cylinders

Field Experiments on Jute Soil Stabilisers

The Central Road Research Institute has been constantly working in the area of geotextiles since early 1980s. A number of laboratory studies on evaluation of geotextiles for their suitability for road application, as well as, actual field trials have been carried out by the Institute. Recently, a project was taken up for the development and promotion of jute based geotextiles for road applications. A number of field trials have been carried out using jute based geotextiles for various applications. The paper presents summary of field experiments carried out to improve the soil behavior, improvement in the stability of road side slopes and the filtration function in fills behind a retaining wall using jute geotextiles

Importance of carotid intimal medial thickness measurement in patients with coronary artery disease

Background: Prevalence of CAD in urban India is about double that of rural India and about 4-fold higher than in United States. Mortality related to CAD is high in Indian Population. Early diagnosis can prevent the CAD related morbidity and mortality. Aims and objectives is to study and compare the CIMT among the patients with CAD and asymptomatic control group.Methods: Hundred patients with CAD were studied for the CIMT and compared with age and sex matched asymptomatic control subjects in Department of Medicine of G. R. Medical College, Gwalior for one year from 2012 to 2013. Details on history, risk factors and presenting symptoms were recorded for all. High resolution B mode ultrasonography was performed to assess CIMT of carotid arteries.Results: CAD was more prevalent among males (78%) having mean age of 56.82±8.91 years. Majority of CAD patients had dyslipidemia (42%) followed by hypertension (21%), diabetes (13%) and smoking (17%). Majority of the CAD patients had chest pain (98%) followed by breathlessness (54%) and sweating (12%) as the most common presenting symptom. Mean CIMT was significantly more among the CAD patients (0.76±0.34) as compared to those without it (0.63±0.22) (p<0.001).Conclusions: CIMT was found to be more in CAD as compared to asymptomatic control subjects. CIMT can be an important tool for assessing CAD and atherosclerosis

Design Optimization of High-Frequency Power Transformer by Genetic Algorithm and Simulated Annealing

This paper highlights the transformer design optimization problem. The objective of transformer design optimization problem requires minimizing the total mass (or cost) of the core and wire material by satisfying constraints imposed by international standards and transformer user specification. The constraints include appropriate limits on efficiency, voltage regulation, temperature rise, no-load current and winding fill factor. The design optimizations seek a constrained minimum mass (or cost) solution by optimally setting the transformer geometry parameters and require magnetic properties. This paper shows the above design problems can be formulated in genetic algorithm(GA) and simulated annealing (SA) format. The importance of the GA and SA format stems for two main features. First it provides efficient and reliable solution for the design optimization problem with several variables. Second, it guaranteed that the obtained solution is global optimum. This paper includes a demonstration of the application of the GP technique to transformer design.Key word—Optimization, Power Transformer, Genetic Algorithm (GA), Simulated Annealing Technique (SA)DOI:http://dx.doi.org/10.11591/ijece.v1i2.8