Evaluation of properties of composite with carbon nanotubes

katedra: KSP; přílohy: 2x CD ROM; rozsah: 45 s. (7 917 znaků)This Bachelor thesis called Evaluation of properties of composite with carbon nanotubes is divided into three parts. The first is theoretical part which deals with the composite materials, the carbon nanotubes, the injection moudling. The second is experimental part which deals with the used material PLASTICYLTM PA1503, it is a mixture of carbon nanotubes (CNT) and polyamid 6. Then here injection mold, injection molding machine ARBURG 270S, injection parameters are described and test of the mechanical properties of samples. The last part deals with the discussion of the results.Bakalářská práce s názvem Hodnocení vlastností kompozitu s uhlíkovými nanotrubičkami je rozdělena do tří částí. První je teoretická část, která se zabývá kompozitními materiály, uhlíkovými nanotrubičkami, technologií vstřikování. Druhá je experimentální část, která se zabývá použitým materiálem PLASTICYLTM PA1503, tj. směs uhlíkových nanotrubiček (CNT) a polyamidu 6. Poté jsou zde popsány vstřikovací forma, vstřikovací lis ARBURG 270S, parametry vstřikování a test mechanických vlastností zkušebních vzorků. Poslední část se zabývá diskusí výsledků

Hopfield lagrange network based method for economic emission dispatch problem of fixed-head hydro thermal systems

This paper proposes a Hopfield Lagrange Network (HLN) based method (HLNM) for economic emission dispatch of fixed head hydrothermal systems. HLN is a combination of Lagrange function and continuous Hopfield neural network where the Lagrange function is directly used as the energy function for the continuous Hopfield neural network. In the proposed method, HLN is used to find a set of non-dominated solutions and a fuzzy based mechanism is then exploited to determine the best compromise solution among the obtained ones. The proposed method has been tested on four hydrothermal systems and the obtained results in terms of total fuel cost, emission, and computational time have been compared to those other methods in the literature. The result comparisons have indicated that the proposed method is favorable for solving the economic emission dispatch problem of fixed-head hydrothermal systems

An Overview of Cham Islam in An Giang Vietnam

Located in the upstream of the Vietnamese Mekong Delta, An Giang is characterized by an agricultural province, which has both plains and hills, and has a border about 100km with Cambodia. An Giang is also the province with the largest number of Cham Islam living in the South. According to official document, the province has 15,327 Cham Islam, accounting for 0.67% of An Giang population. Although the population is less than the other ethnics of the province, the Cham community in An Giang always shows the spirit of solidarity and mutual affection. Cham Islam plays an important role and contribute to unique culture in An Giang. This paper aims to clarify the progress of establishment, development and residential distribution of Cham ethnic group in An Giang, Vietnam. Authors utilized qualitative data gathered from exchange learning and in-depth interviews to examine how Cham Islam has emerged and developed in the study areas. It also focuses on their features of economy, culture, society, education and training, health, architecture, religion, and belief in comparison with Cham people in the central of Vietnam. Consequently, the researcher figures out the similarity and distinction of Cham people in the two regions; thereby, affirms positive values which need to be inherited and promoted in order to help Cham community integrate and develop in contemporary context

Adaptation and Validation of the Vietnamese Translated Diabetes Knowledge Questionnaire

Objectives: There is no existing Vietnamese diabetes knowledge questionnaire. This impedes assessment of patient knowledge that will be helpful in providing effective diabetes intervention. We aimed to validate the Vietnamese Translated Diabetes Knowledge Questionnaire (DKQ). Methodology: Translation and adaptation strictly followed the guidelines of Beaton et al. Internal consistency was assessed by Cronbach's alpha coefficient, test-retest reliability was assessed by Fleiss' Kappa coefficient, and validity value was determined among type 2 diabetes patients in a general hospital. Results: The Vietnamese version of the DKQ had good internal consistency (Cronbach's alpha for all items = 0.898) and stability (Kappa coefficient >0.600). The average score for all equivalence criteria was 1.00, demonstrating good equivalence to the original. The significant difference between knowledge score and education level (p <0.001) confirmed construct validity. Conclusion: Our study provided a reliable Vietnamese version of the DKQ. Future studies may apply the version in different regions in Vietnam to determine external validity

Modified cuckoo search algorithm for solving nonconvex economic load dispatch problems

This paper presents the application of modified cuckoo search algorithm (MCSA) for solving economic load dispatch (ELD) problems. The MCSA method is developed to improve the search ability and solution quality of the conventional CSA method. In the MCSA, the evaluation of eggs has divided the initial eggs into two groups, the top egg group with good quality and the abandoned group with worse quality. Moreover, the value of the updated step size in MCSA is adapted as generating a new solution for the abandoned group and the top group via the Levy flights so that a large zone is searched at the beginning and a local zone is foraged as the maximum number of iterations is nearly reached. The MCSA method has been tested on different systems with different characteristics of thermal units and constraints. The result comparison with other methods in the literature has indicated that the MCSA method can be a powerful method for solving the EL

Prevalence and Associated Factors of Erectile Dysfunction among Married Men in Vietnam

BackgroundSexuality is an essential part of life; however, erectile dysfunction (ED) has been one of the most common complaints among men with sexual health issues all over the world. ED includes dysfunction in erection and penile erectile pain. In Vietnam, ED is a subject a not readily discussed. Thus, relatively little is known about ED among Vietnamese men.AimsTo identify the prevalence of ED and its associated variables and the need for treatment of ED among married men in Vietnam.MethodsThis was a cross-sectional study. A total sample size included 746 married men, aged 20–60 years, living in four representative wards of the Hue City and randomly selected by systematic sampling methods. Respondents completed a self-reported questionnaire. The International Index of Erectile Function (IIEF-5) scale was used to determine ED severity, and the Depression Anxiety Stress Scales (DASS-21) was used to measure depression, anxiety, and stress. Quality of life was assessed using the WHO Quality of Life score (WHOQoL). A multivariate logistic regression model was used to determine the relationships between independent variables and ED.ResultsMean age of married men was 44.3 ± 8.7. Two-thirds (66.9%) of respondents experienced ED symptoms. In terms of severity, 40.8% reported mild ED; 20.3% mild–moderate ED; 5.0% moderate ED; and 0.8% severe ED. Depression, anxiety, and stress problems were 5.0, 3.6, and 2.8%, respectively. One-third (33.1%) of the respondents reported having low quality of life, and 32.6% reported having medium quality of life. The vast majority (86.9%) had consensual sex with their wives/partners. Variables associated with increased IIEF-5 score were increased WHOQoL score, increased body mass index (BMI), religion, and no consumption of alcohol. Increasing age, disease history, increased anxiety, and no consensual sex with their wife/partner were associated with a lower IIEF-5 score. If experiencing ED, 55.5% would seek help from medical doctors, 55.1% discussed it with their wives/partners, and 23.1% turned to their friends for help.ConclusionThe prevalence of ED was high, although only 5.8% experienced moderate to severe ED. The key factors associated with ED were age, religion, disease history, BMI, alcohol consumption, anxiety, quality of life, and consensual sex with their wives/partners. Sexual health education should be more specifically targeted for men, including the provision of local sexual health-care services for men

Approximation of mild solutions of the linear and nonlinear elliptic equations

In this paper, we investigate the Cauchy problem for both linear and semi-linear elliptic equations. In general, the equations have the form $$\frac{\partial^{2}}{\partial t^{2}}u\left(t\right)=\mathcal{A}u\left(t\right)+f\left(t,u\left(t\right)\right),\quad t\in\left[0,T\right],$$ where $\mathcal{A}$ is a positive-definite, self-adjoint operator with compact inverse. As we know, these problems are well-known to be ill-posed. On account of the orthonormal eigenbasis and the corresponding eigenvalues related to the operator, the method of separation of variables is used to show the solution in series representation. Thereby, we propose a modified method and show error estimations in many accepted cases. For illustration, two numerical examples, a modified Helmholtz equation and an elliptic sine-Gordon equation, are constructed to demonstrate the feasibility and efficiency of the proposed method.Comment: 29 pages, 16 figures, July 201

An efficient cuckoo-inspired meta-heuristic algorithm for multiobjective short-term hydrothermal scheduling

This paper proposes an efficient Cuckoo-Inspired Meta-Heuristic Algorithm (CIMHA) for solving multi-objective short-term hydrothermal scheduling (ST-HTS) problem. The objective is to simultaneously minimize the total cost and emission of thermal units while all constraints such as power balance, water discharge, and generation limitations must be satisfied. The proposed CIMHA is a newly developed meta-heuristic algorithm inspired by the intelligent reproduction strategy of the cuckoo bird. It is efficient for solving optimization problems with complicated objective and constraints because the method has few control parameters. The proposed method has been tested on different systems with various numbers of objective functions, and the obtained results have been compared to those from other methods available in the literature. The result comparisons have indicated that the proposed method is more efficient than many other methods for the test systems in terms of total cost, total emission, and computational time. Therefore, the proposed CIMHA can be a favorable method for solving the multi-objective ST-HTS problems