Flow modelling around propeller for a deep drafted vessel in very shallow water

Computational fluid dynamics (CFD) codes, are recently used as efficient tools to understand flow characteristics such as wake development around propeller. This thesis presents numerical modelling of flow characteristics in the stern region for a deep drafted LNG carrier with the effect of propeller and rudder in shallow water. The modelling was conducted based on the B5-75 type propeller, with a diameter (D) of 7.7m, which was designed at MARIN in the Netherlands. The ANSYS Fluent version 12 software was used to solve the Reynold Averaged Navier Stokes (RANS) equations, and ICEM CFD as a mesh generator. The propeller was meshed using tetra unstructured mesh in a flow field based on 3D incompressible Navier-stokes solver. Two turbulent models were applied in the ANSYS Fluent; which are the standard k-epsilon (k-e) model for the steady simulation and transient shear stress transport (SST) k-omega (k-?) for the unsteady simulation. For the computational domain, the propeller blades were mounted on two finite long constant radius cylinders. The two types of cylinder domains, were developed; stator domain and rotor domain. For the stator domain, the inlet flow was 2D from blade, the outlet flow at 6D and the outer boundary was 3.6D. The upstream for the rotor domain was maintained at 0.2D but the downstream was extended between 0.4D and 0.7D, and the outer boundary at 1.4D. The turbulent model was simulated in the rotor domain by using the stator-rotor approaches such as the multiple reference frame (MRF) and the sliding mesh (SM) method. Comparisons with the published experiments were presented, and the dependence of the numerical solutions on the computational parameters was studied extensively. The thrust and torque of the propeller were generally predicted with a small error when it was compared with the published experiments. The difference in performance of propeller in the open water test is about 10 percent, likely due to mesh strategy as well as mesh resolution and quality. The performance of the propeller was also studied. It was found that the rudder placed in front of propeller increased the efficiency of the propeller and produced greater thrust increments when the rudder was deflected to -70 and -200. The presence of the rudder which acts by cancelling the trailing vortices from the tip of propeller slipstream leads to increase of thrust and torque of propeller. There was, as expected, a difference in the velocity concentration between propeller only and propeller-hull interaction. The effects of propeller and rudder on the velocity profiles in the region for the LNG carrier in shallow water are clearly identified. Especially in very shallow water, (h/T = 1.1), the extreme velocity profile is concentrated in vicinity of top part of the stern and seabed regions

El aprendizaje de la literatura inglesa en Malasia: una revisión de la literatura

Literature has been a core component in English education. By learning literature, learners can learn English without having to understand the grammatical rules directly. With literature, learners can learn both the language and the other elements of it such as culture, moral values, life lessons and relatable situations. Such is the importance of literature; the Ministry of Education Malaysia has integrated it as part of the English curriculum to help increase the level of English proficiency among Malaysian students. However, this has created divisive opinions from various parties due to many challenges and issues faced by teachers and students. This paper aims to investigate the current issues and challenges faced by secondary school teachers and students in learning and teaching English literature. Through this paper, the researchers have highlighted the brief history of the introduction of literature in the English education and how the role of literature has developed throughout the years. Next, a closer look at the challenges and issues faced by teachers and students from previous studies and research have been highlighted for future researchers to take into consideration. By looking at previous studies, it has been discovered that motivation and attitudes towards learning English literature could be major factors that future researchers can further look into.La literatura ha sido un componente central en la educación del inglés. Al aprender literatura, los alumnos pueden aprender inglés sin tener que entender las reglas gramaticales directamente. Con la literatura, los alumnos pueden aprender tanto el idioma como otros elementos del mismo, como la cultura, los valores morales, las lecciones de vida y las situaciones relacionadas. Tal es la importancia de la literatura; El Ministerio de Educación de Malasia lo ha integrado como parte del plan de estudios de inglés para ayudar a aumentar el nivel de dominio del inglés entre los estudiantes de Malasia. Sin embargo, esto ha creado opiniones divisivas de varias partes debido a muchos desafíos y problemas que enfrentan los maestros y estudiantes. Este documento tiene como objetivo investigar los problemas y desafíos actuales que enfrentan los maestros y estudiantes de secundaria en el aprendizaje y la enseñanza de la literatura inglesa. A través de este documento, los investigadores han destacado la breve historia de la introducción de la literatura en la educación en inglés y cómo se ha desarrollado el papel de la literatura a lo largo de los años. A continuación, se destacó una mirada más cercana a los desafíos y problemas que enfrentan los maestros y estudiantes de estudios e investigaciones anteriores para que los futuros investigadores los tengan en cuenta. Al observar estudios anteriores, se descubrió que la motivación y las actitudes hacia el aprendizaje de la literatura inglesa podrían ser factores importantes que los futuros investigadores pueden investigar más a fondo

Determination of tube theory parameters using a simple grid model as an example

Although the tube theory is successful in describing entangled polymers qualitatively, a more quantitative description requires precise and consistent definitions of its parameters. Here we investigate the simplest model of entangled polymers, namely a single Rouse chain in a cubic lattice of line obstacles, and illustrate the typical problems and uncertainties of the tube theory. In particular we show that in general one needs 3 entanglement related parameters, but only 2 combinations of them are relevant for the long-time dynamics. Conversely, the plateau modulus can not be determined from these two parameters and requires a more detailed model of entanglements with explicit entanglement forces, such as the slipsprings model. It is shown that for the grid model the Rouse time within the tube is larger than the Rouse time of the free chain, in contrast to what the standard tube theory assumes

Analysis on Sex Education in Schools Across Malaysia

AbstractThe objective of this research is to analyse the respondent's perceptions on whether sex education or elements of it are being taught in Malaysian schools. This issue should be highlighted since there are so many sex-related social problems among the teenagers.Before giving their feedback, the respondents were first introduced on the aspects of sexuality education based on UNESCO's 2009 curriculum guideline. Based from the data received, 90% of the respondents agreed that sex education has not been taught in Malaysian schools. The respondents explained that the informal information given by most of the teachers were vague thus defeating the purpose of the students to learn on the issues

Minimization of tool path length of drilling process using particle swarm optimization (PSO)

In the era of challenging economic, the industry in our country has been forced to produce a good quality product and increase the productivity of machining process simultaneously in order to compete with other countries. Drrilling process is one of a very important cutting process in industry. In a drilling for machining by Computer Numerical Control (CNC) such as drilling machines, the parameter of the tool routing path for the machining operation plays a very important role to minimize the machining time (Tiwari 2013, Rao and Kalyankar 2012) . This machine can be used with procedures for drilling, spreading, weaning and threading with a lot of the holes precisely. In order to increase the efficiency and productivity of drilling process, optimization on parameters of process can lead to better performance. Optimization of holes drilling operations will lead to reduction in time order and better productivity of manufacturing systems. Optimizing the tool path has played an important role, especially in mass production because reducing the time to produce one piece eventually lead to a significant reduction in the cost of the entire series (Pezer, 2016). In various publications and articles, scientists and researchers adapted several methods of artificial intelligence (AI) or hybrid optimization method for tool path artificial immune system (AIS), genetic algorithms (GA), Artificial Neural networks (ANN) Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO) (Narooei and Ramli, 2014). These methods were been proven that can produce better performance and increase the productivity of drilling process. Therefore, in this study, the Particle Swarm Optimization (PSO) algorithm was develop in order to minimizing the tool path length in the drilling process which can produce the better results for the required machining time process. For this study, the main purpose is to apply the Particle Swarm Optimization (PSO) algorithm for use in searching for the optimal tool routing path for in simulation of drilling proces

The Impact of Telecom Infrastructure on the Economic Growth: The Case of Oil-producing and Non-Oil Producing Arab Countries

This study attempts to assess the impact of investment in the infrastructure of the telecommunications sector on economic growth in the Arab countries, using advanced econometric techniques, such as fully modified ordinary least squares, and panel data analysis utilizing cross sectional data covering 12 countries and a period of 20 years 1996-2015. The study finds evidence that investment in infrastructure for the telecommunications sector has a positive and significant effect on economic growth in non-oil producing countries in the long-term; it shows that a 10% increase in the number of telecom subscribers leads to an increase of 3% in real gross domestic product in these countries. The results also show that there is no impact for telecommunication on the economic growth of oil-producing countries. In light of the above findings, policy makers should pay more attention to the telecom sector in the Arab countries, and encourage investment in this sector. Keywords: Telecom Infrastructure, Economic Growth, Fully Modified Ordinary Least Squares, Oil Countries, Co-integration, Arab Countries JEL Classification: O1

The roles of top management and users in strategic IS planning: a perspective of SMEs

Research on the strategic Information Systems (IS) planning is typically concentrated on large firms. However, the outcomes of this research may not be sufficient to adequately apply to Small and Medium Enterprises (SMEs). Responding to the limited body of work in SMEs with respect to strategic IS planning, this research aims to fill the gap in the body of literature. Having limited resources available, financially and technically, strategic IS planning is getting more crucial for SMEs. Prior work suggests that a high level of internal competencies such as IT leadership by the owner or the top management of the firm are important for progressive IT development to take place in SMEs. Having said that IS is getting paramount for firm’s survival to optimize IS effectively, it is incumbent to investigate the factors influencing strategic IS planning amongst the SMEs. This study contributes to research and practice by providing in-depth insights into the IS planning processes in SMEs with a particular focus on the roles of top management and users. Researchers can use these results, which are somewhat different from larger organizations, to revise IS planning phases

Application of wavelet analysis in tool wear evaluation using image processing method

Tool wear plays a significant role for proper planning and control of machining parameters to maintain the product quality. However, existing tool wear monitoring methods using sensor signals still have limitations. Since the cutting tool operates directly on the work-piece during machining process, the machined surface provides valuable information about the cutting tool condition. Therefore, the objective of present study is to evaluate the tool wear based on the workpiece profile signature by using wavelet analysis. The effect of wavelet families, scale of wavelet and statistical features of the continuous wavelet coefficient on the tool wear is studied. The surface profile of workpiece was captured using a DSLR camera. Invariant moment method was applied to extract the surface profile up to sub-pixel accuracy. The extracted surface profile was analyzed by using continuous wavelet transform (CWT) written in MATLAB. The re-sults showed that average, RMS and peak to valley of CWT coefficients at all scale increased with tool wear. Peak to valley at higher scale is more sensitive to tool wear. Haar was found to be more effective and significant to correlate with tool wear with highest R2 which is 0.9301

The impact of industrial supplier-manufacturer relationship on strategic outsourcing success

Outsourcing is generally recognized as a strategy for producing cost savings; however, by simply following a traditional cost-focused approach, industries may be missing opportunities to gain further competitive advantage.Similarly, poor outsourcing performance of manufacturing industry could be improved through relational-oriented exchanges and its antecedents.Researches that examine the link among relational-oriented exchanges and their antecedents; and outsourcing performances in the manufacturing industry is still in its early development stage.Owing to high competition and risks in a manufacturing environment, the present study aims at investigating the link between relational-oriented exchanges, the antecedent of relational-oriented exchanges and outsourcing performances.Data was collected from 224 electrical and electronic industries in Malaysia via a postal survey and analyzed by using statistical package for social science (SPSS) version 19. The result of the findings of the investigation revealed that dependence and communication behavior are significantly related to relational-oriented exchanges while trust is insignificant.And also, relational-oriented exchange is directly significant to outsourcing performances

Antecedents of Green Warehousing: A Theoretical Framework and Future Direction

In todays competitive logistics environment, green and sustainable approaches are gaining academic interest. This paper aims to develop a theoretical framework to enhance understanding and academic knowledge on the antecedents of green warehouse practices (GWP). This paper employs content analysis approach to extract the potential factors to GWP. It then reviews and synthesises the GWP factors by applying two prominent management concepts of stakeholder and institutional theories. Through the review and discussion, six GWP factors; employee involvement, top management commitment, owner support, governmental pressure, industry competition, and customer demand are highlighted. Additionally, six propositions of GWP are presented and the framework developed in this conceptual paper underlines the internal and external GWP instigators. The conceptual nature of this paper offers a preliminary insights of GWP where the synergy between external and internal elements must coexist to successfully implement GWP. The developed theoretical framework presents a platform for future empirical GWP studies