Abstract: A multiple-option analytical model for the evaluation of the energy performance and distribution of aerodynamic forces acting on a vertical-axis Darrieus wind turbine depending on both rotor architecture and operating conditions is presented. For this purpose, a numerical algorithm, capable of generating the desired rotor conformation depending on design geometric parameters, is coupled to a Single/Double-Disk Multiple-Streamtube Blade Element – Momentum code. Both single and double-disk configurations are analyzed and model predictions are compared to literature experimental data in order to test the capability of the code for predicting rotor performance. Effective airfoil characteristics based on local blade Reynolds number are obtained through interpolation of literature low-Reynolds airfoil databases. Some corrections are introduced inside the original model with the aim of simulating also the effects of blade dynamic stall, rotor streamtube expansion and blade finite aspect ratio, for which a new empirical relationship to better fit the experimental data is proposed. In order to predict also open field rotor operation, a freestream wind shear profile is implemented, reproducing the effect of atmospheric boundary layer.
Abstract: Abai Kunanbayev is famous for being enlightener,
composer, interpreter, social agent, philosopher, reformer, who
wanted to enrich Kazakh literature by emergence with Russian and
European culture, and also as a founder of Kazakh written literary
language. Abai Kunanbayev was born in 1845 in East Kazakhstan
area and passed away in 1904 in his hometown. His oeuvre absorbed
and reflected all changes in the life of Kazakh society of the second
half of XIX century. Because ХІХ century, especially its second half,
was an important transition period for Kazakhstan, which radically
changed traditional way of Kazakh society and predetermined further
development in consequence of activation of Russian colonial policy
and approval of commodity-money relations in Steppe Land.Abai
Kunanbayev, besides Arabic and Persian common words and
loanwords from Quran in his words of edification, had used a lot of
words of Arabic, Persian, Latin, Russian, Nogai, Shaghatai, Polish,
Greek, Turkish, which are used in the Kazakh language.
Abstract: Today, Higher Education in a global scope is subordinated to the greater institutional controls through the policies of the Quality of Education. These include processes of over evaluation of all the academic activities: students- and professors- performance, educational logistics, managerial standards for the administration of institutions of higher education, as well as the establishment of the imaginaries of excellence and prestige as the foundations on which universities of the XXI century will focus their present and future goals and interests. But at the same time higher education systems worldwide are facing the most profound crisis of sense and meaning and attending enormous mutations in their identity. Based in a qualitative research approach, this paper shows the social configurations that the scholars at the Universities in Mexico build around the discourse of the Quality of Education, and how these policies put in risk the social recognition of these individuals.
Abstract: Sedimentation formation is a complex hydraulic phenomenon that has emerged as a major operational and maintenance consideration in modern hydraulic engineering in general and river engineering in particular. Sediments accumulation along the river course and their eventual storage in a form of islands affect water intake in the canal systems that are fed by the storage reservoirs. Without proper management, sediment transport can lead to major operational challenges in water distribution system of arid regions like the Dez and Hamidieh command areas. The paper aims to investigate sedimentation in the Western Canal of Dez Diversion Weir using the SHARC model and compare the results with the two intake structures of the Hamidieh dam in Iran using SSIIM model. The objective was to identify the factors which influence the process, check reliability of outcome and provide ways in which to mitigate the implications on operation and maintenance of the structures. Results estimated sand and silt bed loads concentrations to be 193 ppm and 827ppm respectively. This followed ,ore or less similar pattern in Hamidieh where the sediment formation impeded water intake in the canal system. Given the available data on average annual bed loads and average suspended sediment loads of 165ppm and 837ppm in the Dez, there was a significant statistical difference (16%) between the sand grains, whereas no significant difference (1.2%) was find in the silt grain sizes. One explanation for such finding being that along the 6 Km river course there was considerable meandering effects which explains recent shift in the hydraulic behavior along the stream course under investigation. The sand concentration in downstream relative to present state of the canal showed a steep descending curve. Sediment trapping on the other hand indicated a steep ascending curve. These occurred because the diversion weir was not considered in the simulation model. The comparative study showed very close similarities in the results which explains the fact that both software can be used as accurate and reliable analytical tools for simulation of the sedimentation in hydraulic engineering.
Abstract: Swarm principles are increasingly being used to design controllers for the coordination of multi-robot systems or, in general, multi-agent systems. This paper proposes a two-dimensional Lagrangian swarm model that enables the planar agents, modeled as point masses, to swarm whilst effectively avoiding each other and obstacles in the environment. A novel method, based on an extended Lyapunov approach, is used to construct the model. Importantly, the Lyapunov method ensures a form of practical stability that guarantees an emergent behavior, namely, a cohesive and wellspaced swarm with a constant arrangement of individuals about the swarm centroid. Computer simulations illustrate this basic feature of collective behavior. As an application, we show how multiple planar mobile unicycle-like robots swarm to eventually form patterns in which their velocities and orientations stabilize.
Abstract: The present study investigates numerically the
phenomenon of vortex-shedding and its suppression in twodimensional
mixed convective flow past a square cylinder under the
joint influence of buoyancy and free-stream orientation with respect
to gravity. The numerical experiments have been conducted at a
fixed Reynolds number (Re) of 100 and Prandtl number (Pr) of 0.71,
while Richardson number (Ri) is varied from 0 to 1.6 and freestream
orientation, α, is kept in the range 0o≤ α ≤ 90o, with 0o
corresponding to an upward flow and 90o representing a cross-flow
scenario, respectively. The continuity, momentum and energy
equations, subject to Boussinesq approximation, are discretized using
a finite difference method and are solved by a semi-explicit pressure
correction scheme. The critical Richardson number, leading to the
suppression of the vortex-shedding (Ric), is estimated by using
Stuart-Landau theory at various free-stream orientations and the
neutral curve is obtained in the Ri-α plane. The neutral curve
exhibits an interesting non-monotonic behavior with Ric first
increasing with increasing values of α upto 45o and then decreasing
till 70o. Beyond 70o, the neutral curve again exhibits a sharp
increasing asymptotic trend with Ric approaching very large values
as α approaches 90o. The suppression of vortex shedding is not
observed at α = 90o (cross-flow). In the unsteady flow regime, the
Strouhal number (St) increases with the increase in Richardson
number.
Abstract: In this paper we present a new approach to deal with
image segmentation. The fact that a single segmentation result do not
generally allow a higher level process to take into account all the
elements included in the image has motivated the consideration of
image segmentation as a multiobjective optimization problem. The
proposed algorithm adopts a split/merge strategy that uses the result
of the k-means algorithm as input for a quantum evolutionary
algorithm to establish a set of non-dominated solutions. The
evaluation is made simultaneously according to two distinct features:
intra-region homogeneity and inter-region heterogeneity. The
experimentation of the new approach on natural images has proved
its efficiency and usefulness.
Abstract: Drilling is the most common machining operation and it forms the highest machining cost in many manufacturing activities including automotive engine production. The outcome of this operation depends upon many factors including utilization of proper cutting tool geometry, cutting tool material and the type of coating used to improve hardness and resistance to wear, and also cutting parameters. With the availability of a large array of tool geometries, materials and coatings, is has become a challenging task to select the best tool and cutting parameters that would result in the lowest machining cost or highest profit rate. This paper describes an algorithm developed to help achieve good performances in drilling operations by automatically determination of proper cutting tools and cutting parameters. It also helps determine machining sequences resulting in minimum tool changes that would eventually reduce machining time and cost where multiple tools are used.
Abstract: The present article comprises a theoretical study of
structures Performat radical (HCO3) with H2O molecule. We make
use of ab initio quantum chemical methods. Unrestricted Hartee-Fock
(UHF) with the basis set6-311+g(2df,2p) and density functional
theory (B3LYP) with the basis set 6-311+g(2df,2p) and also we done
atoms in molecules (AIM) theory for them. We have found four
stable geometries the PerformatRadical(HCO3) with H2O.
Abstract: The development of entrepreneurial competences of
farmers has been pointed out as a necessary condition for the
modernization of land in facing the phenomenon of globalization.
However, the educational processes involved in such a development
have been studied little, especially in emerging economies. This
research aims to enlighten some of the critical issues behind the early
stages of the transformation of farmers into entrepreneurs, through in
depth interviews with farmers, entrepreneurial promoters and public
officials participating in a public pilot project in Mexico. Although
major impacts were expected only in the long run, important positive
changes in the mind set of farmers and other participants were found
in early stages of the intervention. Apparently, the farmers started a
process of becoming more conscious about the importance of
preserving the aquiferous resources, as well as more market and
entrepreneurial oriented.
Abstract: A computer model of Quantum Theory (QT) has been
developed by the author. Major goal of the computer model was
support and demonstration of an as large as possible scope of QT.
This includes simulations for the major QT (Gedanken-) experiments
such as, for example, the famous double-slit experiment.
Besides the anticipated difficulties with (1) transforming exacting
mathematics into a computer program, two further types of problems
showed up, namely (2) areas where QT provides a complete mathematical
formalism, but when it comes to concrete applications the
equations are not solvable at all, or only with extremely high effort;
(3) QT rules which are formulated in natural language and which do
not seem to be translatable to precise mathematical expressions, nor
to a computer program.
The paper lists problems in all three categories and describes also
the possible solutions or circumventions developed for the computer
model.
Abstract: A new conserving approach in the context of Immersed Boundary Method (IBM) is presented to simulate one dimensional, incompressible flow in a moving boundary problem. The method employs control volume scheme to simulate the flow field. The concept of ghost node is used at the boundaries to conserve the mass and momentum equations. The Present method implements the conservation laws in all cells including boundary control volumes. Application of the method is studied in a test case with moving boundary. Comparison between the results of this new method and a sharp interface (Image Point Method) IBM algorithm shows a well distinguished improvement in both pressure and velocity fields of the present method. Fluctuations in pressure field are fully resolved in this proposed method. This approach expands the IBM capability to simulate flow field for variety of problems by implementing conservation laws in a fully Cartesian grid compared to other conserving methods.
Abstract: A simple and dexterous in situ method was introduced to load CdS nanocrystals into organofunctionalized mesoporous, which used an ion-exchange method. The products were extensively characterized by combined spectroscopic methods. X- ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) demonstrated both the maintenance of pore symmetry (space group p6mm) of SBA-15 and the presence of CdS nanocrystals with uniform sizes of about 6 - 8 nm inside the functionalized SBA-15 channels. These mesoporous silica-supported CdS composites showed room temperature photoluminescence properties with a blue shift, indicating the quantum size effect of nanocrystalline CdS.
Abstract: Gene expression profiling is rapidly evolving into a
powerful technique for investigating tumor malignancies. The
researchers are overwhelmed with the microarray-based platforms
and methods that confer them the freedom to conduct large-scale
gene expression profiling measurements. Simultaneously,
investigations into cross-platform integration methods have started
gaining momentum due to their underlying potential to help
comprehend a myriad of broad biological issues in tumor diagnosis,
prognosis, and therapy. However, comparing results from different
platforms remains to be a challenging task as various inherent
technical differences exist between the microarray platforms. In this
paper, we explain a simple ratio-transformation method, which can
provide some common ground for cDNA and Affymetrix platform
towards cross-platform integration. The method is based on the
characteristic data attributes of Affymetrix- and cDNA- platform. In
the work, we considered seven childhood leukemia patients and their
gene expression levels in either platform. With a dataset of 822
differentially expressed genes from both these platforms, we carried
out a specific ratio-treatment to Affymetrix data, which subsequently
showed an improvement in the relationship with the cDNA data.
Abstract: The computer, among the most important inventions of the twentieth century, has become an increasingly important component in our everyday lives. Computer games also have become increasingly popular among people day-by-day, owing to their features based on realistic virtual environments, audio and visual features, and the roles they offer players. In the present study, the metaphors students have for computer games are investigated, as well as an effort to fill the gap in the literature. Students were asked to complete the sentence—‘Computer game is like/similar to….because….’— to determine the middle school students’ metaphorical images of the concept for ‘computer game’. The metaphors created by the students were grouped in six categories, based on the source of the metaphor. These categories were ordered as ‘computer game as a means of entertainment’, ‘computer game as a beneficial means’, ‘computer game as a basic need’, ‘computer game as a source of evil’, ‘computer game as a means of withdrawal’, and ‘computer game as a source of addiction’, according to the number of metaphors they included.
Abstract: The present paper was concerned primarily with the
analysis, simulation of the air flow and thermal patterns in a lecture
room. The paper is devoted to numerically investigate the influence
of location and number of ventilation and air conditioning supply and
extracts openings on air flow properties in a lecture room. The work
focuses on air flow patterns, thermal behaviour in lecture room where
large number of students. The effectiveness of an air flow system is
commonly assessed by the successful removal of sensible and latent
loads from occupants with additional of attaining air pollutant at a
prescribed level to attain the human thermal comfort conditions and
to improve the indoor air quality; this is the main target during the
present paper. The study is carried out using computational fluid
dynamics (CFD) simulation techniques as embedded in the
commercially available CFD code (FLUENT 6.2). The CFD
modelling techniques solved the continuity, momentum and energy
conservation equations in addition to standard k – ε model equations
for turbulence closure.
Throughout the investigations, numerical validation is carried out by
way of comparisons of numerical and experimental results. Good
agreement is found among both predictions.
Abstract: Towards the end of 19th century, the discovery of tin
and the growing importance of rubber, had led Malaya to once again
become the centre of attraction to western colonization, which later
on caused the region to be influxed by cheap labour from China and
India. One of the factors which attracted the alien communities was
the characteristics of social relation offered by the Malays. If one
analyzes the history of social relation of the Malays either among
themselves or their relation with alien communities, it is apparent that
the community places high regards to values such as tolerant,
cooperative, respectful and helpful with each other. In fact, all these
values are deeply rooted in the value of 'budi'. With the arrival of
Islam, the value of 'budi' had been well assimilated with Islamic
values thus giving birth to the value of 'budi-Islam'. Through 'budi-
Islam', the Malay conducted their dealings with British as well the
other communities during the time of peace or conflict. This value is
well nurtured due to the geographical circumstances like the fertile,
naturally rich land and bountiful marine life. Besides, a set of Malay
customs known as 'adat' custom contributed in enhancing the values
of budi.
Abstract: Fischer-Tropsch synthesis is one of the most
important catalytic reactions that convert the synthetic gas to light
and heavy hydrocarbons. One of the main issues is selecting the type
of reactor. The slurry bubble reactor is suitable choice for Fischer-
Tropsch synthesis because of its good qualification to transfer heat
and mass, high durability of catalyst, low cost maintenance and
repair. The more common catalysts for Fischer-Tropsch synthesis are
Iron-based and Cobalt-based catalysts, the advantage of these
catalysts on each other depends on which type of hydrocarbons we
desire to produce. In this study, Fischer-Tropsch synthesis is modeled
with Iron and Cobalt catalysts in a slurry bubble reactor considering
mass and momentum balance and the hydrodynamic relations effect
on the reactor behavior. Profiles of reactant conversion and reactant
concentration in gas and liquid phases were determined as the
functions of residence time in the reactor. The effects of temperature,
pressure, liquid velocity, reactor diameter, catalyst diameter, gasliquid
and liquid-solid mass transfer coefficients and kinetic
coefficients on the reactant conversion have been studied. With 5%
increase of liquid velocity (with Iron catalyst), H2 conversions
increase about 6% and CO conversion increase about 4%, With 8%
increase of liquid velocity (with Cobalt catalyst), H2 conversions
increase about 26% and CO conversion increase about 4%. With
20% increase of gas-liquid mass transfer coefficient (with Iron
catalyst), H2 conversions increase about 12% and CO conversion
increase about 10% and with Cobalt catalyst H2 conversions increase
about 10% and CO conversion increase about 6%. Results show that
the process is sensitive to gas-liquid mass transfer coefficient and
optimum condition operation occurs in maximum possible liquid
velocity. This velocity must be more than minimum fluidization
velocity and less than terminal velocity in such a way that avoid
catalysts particles from leaving the fluidized bed.
Abstract: The primary purpose of this article is an attempt to
find the implication of globalization on education. Globalization has
an important role as a process in the economical, political, cultural
and technological dimensions in the life of the contemporary human
being and has been affected by it. Education has its effects in this
procedure and while influencing it through educating global citizens
having universal human features and characteristics, has been
influenced by this phenomenon too. Nowadays, the role of education
is not just to develop in the students the knowledge and skills
necessary for the new kinds of jobs. If education wants to help
students be prepared of the new global society, it has to make them
engaged productive and critical citizens for the global era, so that
they can reflect about their roles as key actors in a dynamic often
uneven, matrix of economic and cultural exchanges. If education
wants to reinforce and raise the national identity, the value system
and the children and teenagers, it should make them ready for living
in the global era of this century. The used method in this research is
documentary and analyzing the documents. Studies in this field show
globalization has influences on the processes of the production,
distribution and consuming of knowledge. The happening of this
event in the information era has not only provide the necessary
opportunities for the exchanges of education worldwide but also has
privileges for the developing countries which enables them to
strengthen educational bases of their society and have an important
step toward their future.
Abstract: A learning management system (commonly
abbreviated as LMS) is a software application for the administration,
documentation, tracking, and reporting of training programs,
classroom and online events, e-learning programs, and training
content (Ellis 2009). (Hall 2003) defines an LMS as \"software that
automates the administration of training events. All Learning
Management Systems manage the log-in of registered users, manage
course catalogs, record data from learners, and provide reports to
management\". Evidence of the worldwide spread of e-learning in
recent years is easy to obtain. In April 2003, no fewer than 66,000
fully online courses and 1,200 complete online programs were listed
on the TeleCampus portal from TeleEducation (Paulsen 2003). In the
report \" The US market in the Self-paced eLearning Products and
Services:2010-2015 Forecast and Analysis\" The number of student
taken classes exclusively online will be nearly equal (1% less) to the
number taken classes exclusively in physical campuses. Number of
student taken online course will increase from 1.37 million in 2010 to
3.86 million in 2015 in USA. In another report by The Sloan
Consortium three-quarters of institutions report that the economic
downturn has increased demand for online courses and programs.