Abstract: In the present work, detailed analysis on flow characteristics of a pair of immiscible liquids through horizontal pipeline is simulated by using ANSYS FLUENT 6.2. Moderately viscous oil and water (viscosity ratio = 107, density ratio = 0.89 and interfacial tension = 0.024 N/m) have been taken as system fluids for the study. Volume of Fluid (VOF) method has been employed by assuming unsteady flow, immiscible liquid pair, constant liquid properties, and co-axial flow. Meshing has been done using GAMBIT. Quadrilateral mesh type has been chosen to account for the surface tension effect more accurately. From the grid independent study, we have selected 47037 number of mesh elements for the entire geometry. Simulation successfully predicts slug, stratified wavy, stratified mixed and annular flow, except dispersion of oil in water, and dispersion of water in oil. Simulation results are validated with horizontal literature data and good conformity is observed. Subsequently, we have simulated the hydrodynamics (viz., velocity profile, area average pressure across a cross section and volume fraction profile along the radius) of stratified wavy and annular flow at different phase velocities. The simulation results show that in the annular flow, total pressure of the mixture decreases with increase in oil velocity due to the fact that pipe cross section is completely wetted with water. Simulated oil volume fraction shows maximum at the centre in core annular flow, whereas, in stratified flow, maximum value appears at upper side of the pipeline. These results are in accord with the actual flow configuration. Our findings could be useful in designing pipeline for transportation of crude oil.
Abstract: This work studied the ability of adipose tissue-derived
mesenchymal stromal cells (MSCs) to form stroma for expansion of
cord blood hematopoietic cells. We showed that 72-hour interaction
of MSCs with cord blood mononuclear cells (MNCs) in vitro at
atmospheric (20%) and low (5%) O2 conditions increased the
expression of ICAM-1, HCAM (at the beginning of interaction) on
MSCs. Viability of MSCs and MNCs were maintained at high level.
Adhesion of MNCs to MSCs was faster at 20% O2. MSCs promoted
the proliferation of adhered MNCs to form the suspension containing
great number of hematopoietic colony-forming units, and this effect
was more pronounced at 5% O2. Thus, adipose-derived MSCs
supplied sufficient stromal support to cord blood MNCs both at 20%
and 5% О2, providing their adhesion with further expansion of new
generation of different hematopoietic lineages.
Abstract: A theoretical study has been presented to describe the boundary layer flow and heat transfer on an exponentially shrinking sheet with a variable wall temperature and suction, in the presence of magnetic field. The governing nonlinear partial differential equations are converted into ordinary differential equations by similarity transformation, which are then solved numerically using the shooting method. Results for the skin friction coefficient, local Nusselt number, velocity profiles as well as temperature profiles are presented through graphs and tables for several sets of values of the parameters. The effects of the governing parameters on the flow and heat transfer characteristics are thoroughly examined.
Abstract: The concept of corporate social responsibility (CSR) in the Czech Republic has evolved notably during the last few years and an issue that started as an interest- and motive-based activity for businesses is becoming more commonplace. Governments have a role to play in ensuring that corporations behave according to the rules and norms of society and can legislate, foster, collaborate with businesses and endorse good practice in order to facilitate the development of CSR. The purpose of this paper is to examine the opportunities and options of CSR in government policy and research its relevance to a business sector. An increasing number of companies is engaging in responsible activities, the public awareness of CSR is rising, and customers are giving higher importance to CSR of companies in their choice. By drawing on existing CSR approach in Czech and understanding of CSR are demonstrated. The paper provides an overview, more detailed government approach of CSR.
Abstract: FMEA has been used for several years and proved its efficiency for system’s risk analysis due to failures. Risk priority number found in FMEA is used to rank failure modes that may occur in a system. There are some guidelines in the literature to assign the values of FMEA components known as Severity, Occurrence and Detection. This paper propose a method to assign the value for occurrence in more realistic manner representing the state of the system under study rather than depending totally on the experience of the analyst. This method uses the hazard function of a system to determine the value of occurrence depending on the behavior of the hazard being constant, increasing or decreasing.
Abstract: The applicability of Net Present Value (NPV) in an
investment project is becoming more and more popular in the field
of engineering economics. The classical NPV methodology involves
only the precise and accurate data of the investment project. In the
present communication, we give a new mathematical model for NPV
which uses the concept of intuitionistic fuzzy set theory. The proposed
model is based on triangular intuitionistic fuzzy number, which may
be known as Intuitionistic Fuzzy Net Present Value (IFNPV). The
model has been applied to an example and the results are presented.
Abstract: The classroom of the 21st century is an ever changing forum for new and innovative thoughts and ideas. With increasing technology and opportunity, students have rapid access to information that only decades ago would have taken weeks to obtain. Unfortunately, new techniques and technology is not a cure for the fundamental problems that have plagued the classroom ever since education was established. Class size has been an issue long debated in academia. While it is difficult to pin point an exact number, it is clear that in this case more does not mean better. By looking into the success and pitfalls of classroom size the true advantages of smaller classes will become clear. Previously, one class was comprised of 50 students. Being seventeen and eighteen-year-old students, sometimes it was quite difficult for them to stay focused. To help them understand and gain much knowledge, a researcher introduced “The Theory of Multiple Intelligence” and this, in fact, enabled students to learn according to their own learning preferences no matter how they were being taught. In this lesson, the researcher designed a cycle of learning activities involving all intelligences so that everyone had equal opportunities to learn.
Abstract: Amyloid aggregation of polypeptides is related to a
growing number of pathologic states known as amyloid disorders. In
recent years, blocking or reversing amyloid aggregation via the use of
small compounds are considered as two useful approaches in
hampering the development of these diseases. In this research, we
have compared the ability of several manganese-salen derivatives, as
synthetic compounds, and apigenin, as a natural flavonoid, to inhibit
of hen egg-white lysozyme (HEWL) aggregation, as an in vitro
model system.
Different spectroscopic analyses such as Thioflavin T (ThT) and
Anilinonaphthalene-8-sulfonic acid (ANS) fluorescence, Congo red
(CR) absorbance along with transmission electron microscopy were
used in this work to monitor the HEWL aggregation kinetic and
inhibition. Our results demonstrated that both type of compounds
were capable to prevent the formation of lysozyme amyloid
aggregation in vitro. In addition, our data indicated that synthetic
compounds had higher activity to inhibit of the β-sheet structures
relative to natural compound. Regarding the higher antioxidant
activities of the salen derivatives, it can be concluded that in addition
to aromatic rings of each of the compounds, the potent antioxidant
properties of salen derivatives contributes to lower lysozyme fibril
accumulation.
Abstract: Multi-component data envelopment analysis (MC-DEA) is a popular technique for measuring aggregate performance of the decision making units (DMUs) along with their components. However, the conventional MC-DEA is limited to crisp input and output data which may not always be available in exact form. In real life problems, data may be imprecise or fuzzy. Therefore, in this paper, we propose (i) a fuzzy MC-DEA (FMC-DEA) model in which shared and undesirable fuzzy resources are incorporated, (ii) the proposed FMC-DEA model is transformed into a pair of crisp models using α cut approach, (iii) fuzzy aggregate performance of a DMU and fuzzy efficiencies of components are defined to be fuzzy numbers, and (iv) a numerical example is illustrated to validate the proposed approach.
Abstract: An optimisation method using both global and local
optimisation is implemented to determine the flapping profile which
will produce the most lift for an experimental wing-actuation system.
The optimisation method is tested using a numerical quasi-steady
analysis. Results of an optimised flapping profile show a 20% increase
in lift generated as compared to flapping profiles obtained by high
speed cinematography of a Sympetrum frequens dragonfly. Initial
optimisation procedures showed 3166 objective function evaluations.
The global optimisation parameters - initial sample size and stage
one sample size, were altered to reduce the number of function
evaluations. Altering the stage one sample size had no significant
effect. It was found that reducing the initial sample size to 400
would allow a reduction in computational effort to approximately
1500 function evaluations without compromising the global solvers
ability to locate potential minima. To further reduce the optimisation
effort required, we increase the local solver’s convergence tolerance
criterion. An increase in the tolerance from 0.02N to 0.05N decreased
the number of function evaluations by another 20%. However, this
potentially reduces the maximum obtainable lift by up to 0.025N.
Abstract: A continuous time model of the interaction between
crop insect pests and naturally beneficial pest enemies is created
using a set of simultaneous, non-linear, ordinary differential
equations incorporating natural death rates based on the Weibull
distribution. The crop pest is present in all its life-cycle stages of:
egg, larva, pupa and adult. The beneficial insects, parasitoid wasps,
may be present in either or all parasitized: eggs, larva and pupa.
Population modelling is used to estimate the quantity of the natural
pest enemies that should be introduced into the pest infested
environment to suppress the pest population density to an
economically acceptable level within a prescribed number of days.
The results obtained illustrate the effect of different combinations of
parasitoid wasps, using the Pascal distribution to estimate their
success in parasitizing different pest developmental stages, to deliver
pest control to a sustainable level. Effective control, within a
prescribed number of days, is established by the deployment of two
or all three species of wasps, which partially destroy pest: egg, larvae
and pupae stages. The selected scenarios demonstrate effective
sustainable control of the pest in less than thirty days.
Abstract: Heat transfer from flat tube is studied numerically. Reynolds number is defined base on equivalent circular tube which is varied in range of 100 to 300. In these range of Reynolds number flow is considered to be laminar, unsteady, and incompressible. Equations are solved by using finite volume method. Results show that increasing l/D from 1 to 2 has insignificant effect on heat transfer and Nusselt number of flat tube is slightly lower than circular tube. However, thermal-hydraulic performance of flat tube is up to 2.7 times greater than circular tube.
Abstract: Sustainable tall buildings that provide comfortable,
healthy and efficient indoor environments are clearly desirable as the
densification of living and working space for the world’s increasing
population proceeds. For environmental concerns, these buildings
must also be energy efficient. One component of these tasks is the
provision of indoor air quality and thermal comfort, which can be
enhanced with natural ventilation by the supply of fresh air. Working
spaces can only be naturally ventilated with connections to the
outdoors utilizing operable windows, double facades, ventilation
stacks, balconies, patios, terraces and skygardens. Large amounts of
fresh air can be provided to the indoor spaces without mechanical
air-conditioning systems, which are widely employed in
contemporary tall buildings.
This paper tends to present the concept of natural ventilation for
sustainable tall office buildings in order to achieve healthy and
comfortable working spaces, as well as energy efficient
environments. Initially the historical evolution of ventilation
strategies for tall buildings is presented, beginning with natural
ventilation and continuing with the introduction of mechanical airconditioning
systems. Then the emergence of natural ventilation due
to the health and environmental concerns in tall buildings is handled,
and the strategies for implementing this strategy are revealed. In the
next section, a number of case studies that utilize this strategy are
investigated. Finally, how tall office buildings can benefit from this
strategy is discussed.
Abstract: Sustainability, being the urgent issue of our time, is
closely related with the innovations in technology. Nanotechnology
(NT), although not a new science, can be regarded relatively a new
science for buildings with brand new materials and applications. This
paper tends to give a research review of current and near future
applications of nanotechnology (NT) for achieving high-performance
and healthy buildings for a sustainable future. In the introduction, the
driving forces for the sustainability of construction industry are
explained. Then, the term NT is defined, and significance of
innovations in NT for a sustainable construction industry is revealed.
After presenting the application areas of NT and nanomaterials for
buildings with a number of cases, challenges in the adoption of this
technology are put forward, and finally the impacts of nanoparticles
and nanomaterials on human health and environment are discussed.
Abstract: Recently there has been a dramatic proliferation in
the number of social networking sites (SNSs) users; however, little
is published about what motivates college students to use SNSs in
education. The main goal of this research is to explore the college
students’ motives for using SNSs in education. A conceptual
framework has therefore been developed to identify the main
factors that influence/motivate students to use social networking
sites for learning purposes. To achieve the research objectives a
quantitative method was used to collect data. A questionnaire has
been distributed amongst college students. The results reveal that
social influence, perceived enjoyment, institute regulation,
perceived usefulness, ranking up-lift, attractiveness,
communication tools, free of charge, sharing material and course
nature all play an important role in the motivation of college
students to use SNSs for learning purposes.
Abstract: Today, the means of following the developments in
the area of science and technology is to keep up with the pace of the
advancements in this area. As is in every profession, apart from their
personal efforts, the training of teachers in the period after they start
their careers is only possible through in-service training. The aim of
the present study is to determine the views of Information
Technologies (IT) teachers regarding the in-service training courses
organized by the Ministry of National Education. In this study, in
which quantitative research methods and techniques were employed,
the views of 196 IT teachers were collected by using the “Views on
In-service Training” questionnaire developed by the authors of the
paper. Independent groups t-test was used to determine whether the
views of IT teachers regarding in-service training differed depending
on gender, age and professional seniority. One-way analysis of
variance (ANOVA) was used to investigate whether the views of IT
teachers regarding in-service training differed depending on the
number of in-service training courses they joined and the type of inservice
training course they wanted to take. According to the findings
obtained in the study, the views of IT teachers on in-service training
did not show a significant difference depending on gender and age,
whereas those views differed depending on professional seniority, the
number of in-service training courses they joined and the type of inservice
training course they wanted to take.
Abstract: Each of the countries around the world has different
ways of management and many of them depend on people to
administrate their country. Thailand, for example, empowers the
sovereignty of Thai people under constitution; however, our Thai
voting system is not able to flow fast enough under the current
Political management system. The sovereignty of Thai people is
addressing this problem through representatives during current
elections, in order to set a new policy for the countries ideology to
change in the House and the Cabinet.
This is particularly important in a democracy to be developed
under our current political institution. The Organic Act on Political
Parties 2007 is the establishment we have today that is causing
confrontations within the establishment. There are many political
parties that will soon be abolished. Many political parties have
already been subsidized. This research study is to analyze the legal
problems with the political party establishment under the Organic Act
on Political Parties 2007.
This will focus on the freedom of each political establishment
compared to an effective political operation. Textbooks and academic
papers will be referenced from studies home and abroad.
The study revealed that Organic Act on Political Parties 2007 has
strict provisions on the political structure over the number of
members and the number of branches involved within political
parties system.
Such operations shall be completed within one year; but under the
existing laws the small parties are not able to participate with the
bigger parties. The cities are capable of fulfilling small political party
requirements but fail to become coalesced because the current laws
won't allow them to be united as one. It is important to allow all
independent political parties to join our current political structure.
Board members can’t help the smaller parties to become a large
organization under the existing Thai laws.
Creating a new establishment that functions efficiently throughout
all branches would be one solution to these legal problems between
all political parties. With this new operation, individual political
parties can participate with the bigger parties during elections. Until
current political institutions change their system to accommodate
public opinion, these current Thai laws will continue to be a problem
with all political parties in Thailand.
Abstract: Data Grid is a geographically distributed environment that deals with data intensive application in scientific and enterprise computing. Data replication is a common method used to achieve efficient and fault-tolerant data access in Grids. In this paper, a dynamic data replication strategy, called Enhanced Latest Access Largest Weight (ELALW) is proposed. This strategy is an enhanced version of Latest Access Largest Weight strategy. However, replication should be used wisely because the storage capacity of each Grid site is limited. Thus, it is important to design an effective strategy for the replication replacement task. ELALW replaces replicas based on the number of requests in future, the size of the replica, and the number of copies of the file. It also improves access latency by selecting the best replica when various sites hold replicas. The proposed replica selection selects the best replica location from among the many replicas based on response time that can be determined by considering the data transfer time, the storage access latency, the replica requests that waiting in the storage queue and the distance between nodes. Simulation results utilizing the OptorSim show our replication strategy achieve better performance overall than other strategies in terms of job execution time, effective network usage and storage resource usage.
Abstract: In recent years many finite elements have been
developed for plate bending analysis. The formulated elements are
based on the strain based approach. This approach leads to the
representation of the displacements by higher order polynomial terms
without the need for the introduction of additional internal and
unnecessary degrees of freedom. Good convergence can also be
obtained when the results are compared with those obtained from the
corresponding displacement based elements, having the same total
number of degrees of freedom. Furthermore, the plate bending
elements are free from any shear locking since they converge to the
Kirchhoff solution for thin plates contrarily for the corresponding
displacement based elements. In this paper the efficiency of the strain
based approach compared to well known displacement formulation is
presented. The results obtained by a new formulated plate bending
element based on the strain approach and Kirchhoff theory are
compared with some others elements. The good convergence of the
new formulated element is confirmed.
Abstract: This study presents the numerical simulation of three-dimensional incompressible steady and laminar fluid flow and conjugate heat transfer of a trapezoidal microchannel heat sink using water as a cooling fluid in a silicon substrate. Navier-Stokes equations with conjugate energy equation are discretized by finite-volume method. We perform numerical computations for a range of 50 ≦ Re ≦ 600, 0.05W ≦ P ≦ 0.8W, 20W/cm2 ≦q"≦ 40W/cm2. The present study demonstrates the numerical optimization of a trapezoidal microchannel heat sink design using the response surface methodology (RSM) and the genetic algorithm method (GA). The results show that the average Nusselt number increases with an increase in the Reynolds number or pumping power, and the thermal resistance decreases as the pumping power increases. The thermal resistance of a trapezoidal microchannel is minimized for a constant heat flux and constant pumping power.