Abstract: We investigate the performance of an integrated cascade (IC) refrigeration system which uses environment friendly zeotropic mixtures. Computational calculation has been carried out by varying pressure level at the evaporator and the condenser of the system. Effects of mass flow rate of the refrigerant on the coefficient of performance (COP) are presented. We show that the integrated cascade system produces ultra-low temperatures in the evaporator by using environment friendly zeotropic mixture.
Abstract: This paper presents results of numerical and experimental studies on a two-dimensional (2D) flapping elliptic airfoil in a forward flight condition at Reynolds number of 5000. The study is motivated from an earlier investigation which shows that the deterioration in thrust performance of a sinusoidal heaving and pitching 2D (NACA0012) airfoil at high flapping frequency can be recovered by changing the effective angle of attack profile to square wave, sawtooth, or cosine wave shape. To better understand why such modifications lead to superior thrust performance, we take a closer look at the transient aerodynamic force behavior of an airfoil when the effective angle of attack profile changes gradually from a generic smooth trapezoidal profile to a sinusoid shape by modifying the base length of the trapezoid. The choice of using a smooth trapezoidal profile is to avoid the infinite acceleration condition encountered in the square wave profile. Our results show that the enhancement in the time-averaged thrust performance at high flapping frequency can be attributed to the delay and reduction in the drag producing valley region in the transient thrust force coefficient when the effective angle of attack profile changes from sinusoidal to trapezoidal.
Abstract: Among other traditional and non-traditional
additives, polymers have shown an efficient performance in the field
and improved sustainability. Polyacrylamide (PAM) is one such
additive that has demonstrated many advantages including a
reduction in permeability, an increase in durability and the provision
of strength characteristics. However, information about its effect on
the improved geotechnical characteristics is very limited to the field
performance monitoring. Therefore, a laboratory investigation was
carried out to examine the basic and engineering behaviors of three
types of soils treated with a PAM additive. The results showed an
increase in dry density and unconfined compressive strength for all
the soils. The results further demonstrated an increase in unsoaked
CBR and a reduction in permeability for all stabilized samples.
Abstract: To focus on the vibration mode of a cone loudspeaker,
which acts as an electroacoustic transducer, excitation experiments
were performed using two types of loudspeaker units: one employing
an impulse hammer and the other a sweep signal. The on-axis sound
pressure frequency properties of the loudspeaker were evaluated, and
the characteristic properties of the loudspeakers were successfully
determined in both excitation experiments. Moreover, under
conditions identical to the experiment conditions, a coupled analysis of
the vibration-acoustics of the cone loudspeaker was performed using
an acoustic analysis software program that considers the impact of
damping caused by air viscosity. The result of sound pressure
frequency properties with the numerical analysis are the most closely
match that measured in the excitation experiments over a wide range
of frequency bands.
Abstract: 10 clinically healthy hemal nodes were collected from male bulls aged 2-3 years. Light microscopy revealed a capsule of connective tissue consisted mainly of collagen fiber surrounding hemal node, numerous erythrocytes were found in wide subcapsular sinus under the capsule. The parenchyma of the hemal node was divided into cortex and medulla. Diffused lymphocytes, and lymphoid follicles, having germinal centers were the main components of the cortex, while in the medulla there was wide medullary sinus, diffused lymphocytes and few lymphoid nodules. The area occupied with lymph nodules was larger than that occupied with non-nodular structure of lymphoid cords and blood sinusoids. Electron microscopy revealed the cellular components of hemal node including elements of circulating erythrocytes intermingled with lymphocytes, plasma cells, mast cells, reticular cells, macrophages, megakaryocytes and endothelial cells lining the blood sinuses. The lymphocytes were somewhat triangular in shape with cytoplasmic processes extending between adjacent erythrocytes. Nuclei were triangular to oval in shape, lightly stained with clear nuclear membrane indentation and clear nucleoli. The reticular cells were elongated in shape with cytoplasmic processes extending between adjacent lymphocytes, rough endoplasmic reticulum, ribosomes and few lysosomes were seen in their cytoplasm. Nucleus was elongated in shape with less condensed chromatin. Plasma cells were oval to irregular in shape with numerous dilated rough endoplasmic reticulum containing electron lucent material occupying the whole cytoplasm and few mitochondria were found. Nuclei were centrally located and oval in shape with heterochromatin emarginated and often clumped near the nuclear membrane. Occasionally megakaryocytes and mast cells were seen among lymphocytes. Megakaryocytes had multilobulated nucleus and free ribosomes often appearing as small aggregates in their cytoplasm, while mast cell had their characteristic electron dense granule in the cytoplasm, few electron lucent granules were found also, we conclude that, the main function of the hemal node of cattle is proliferation of lymphocytes. No role for plasma cell in erythrophagocytosis could be suggested.
Abstract: The soil profile at site of the bridge project includes soft fine grained soil layer located between 5.0 m to 11.0 m in depth, it has high water content, low SPT no., and low bearing capacity. The clay layer induces high settlement due to surcharge application of earth embankment at ramp T1, ramp T2, and ramp T3 especially at heights from 9m right 3m. Calculated settlement for embankment heights less than 3m may be accepted regarding Saudi Code for soil and foundation. The soil and groundwater at the project site comprise high contents of sulfates and chlorides of high aggressively on concrete and steel bars, respectively. Regarding results of the study, it has been recommended to use stone column piles or new technology named PCC piles as soil improvement to improve the bearing capacity of the weak layer. The new technology is cast in-situ thin wall concrete pipe piles (PCC piles), it has economically advantageous and high workability. The technology can save time of implementation and cost of application is almost 30% of other types of piles.
Abstract: Learning outcomes of a course (CLOs) and the abilities at the time of graduation referred to as Student Outcomes (SOs) are required to be assessed for ABET accreditation. A question in an assessment must target a CLO as well as an SO and must represent a required level of competence. This paper presents the idea of an Expert System (ES) to select a proper question to satisfy ABET accreditation requirements. For ES implementation, seven attributes of a question are considered including the learning outcomes and Bloom’s Taxonomy level. A database contains all the data about a course including course content topics, course learning outcomes and the CLO-SO relationship matrix. The knowledge base of the presented ES contains a pool of questions each with tags of the specified attributes. Questions and the attributes represent expert opinions. With implicit rule base the inference engine finds the best possible question satisfying the required attributes. It is shown that the novel idea of such an ES can be implemented and applied to a course with success. An application example is presented to demonstrate the working of the proposed ES.
Abstract: Healthcare waste management continues to present an
array of challenges for developing countries, and Liberia is of no
exception. There is insufficient information available regarding the
generation, handling, and disposal of health care waste. This face
serves as an impediment to healthcare management schemes. The
specific objective of this study is to present an evaluation of the
current health care management practices in Liberia. It also presented
procedures, techniques used, methods of handling, transportation, and
disposal methods of wastes as well as the quantity and composition
of health care waste. This study was conducted as an investigative
case study, covering three different health care facilities; a hospital, a
health center, and a clinic in Monrovia, Montserrado County. The
average waste generation was found to be 0-7kg per day at the clinic
and health center and 8-15kg per/day at the hospital. The composition
of the waste includes hazardous and non-hazardous waste i.e. plastic,
papers, sharps, and pathological elements etc. Nevertheless, the
investigation showed that the healthcare waste generated by the
surveyed healthcare facilities were not properly handled because of
insufficient guidelines for separate collection, and classification, and
adequate methods for storage and proper disposal of generated
wastes. This therefore indicates that there is a need for improvement
within the healthcare waste management system to improve the
existing situation.
Abstract: The main objective of this paper is to establish the relationship between models of state organization and the various types of collective identity expressed by the Spanish. The question of nationalism and identity ascription in Spain has always been a topic of special importance due to the presence in that country of territories where the population emits very different opinions of nationalist sentiment than the rest of Spain. The current situation of sovereignty challenge of Catalonia to the central government exemplifies the importance of the subject matter. In order to analyze this process of interrelation, we use a secondary data mining by applying the multiple correspondence analysis technique (MCA). As a main result a typology of four types of expression of collective identity based on models of State organization are shown, which are connected with the party position on this issue.
Abstract: Copreneurship is a term used to describe the business
pattern of operations run by married couples who share commitment,
goals, and responsibilities in handling a business. Research conducted
overseas showed that copreneurship business activities grew quickly
and played a role in elevating families’ and nations’ socio-economic
standards. In Malaysia, copreneurship has long been cultivated by
spouses. Thus, this study aimed to explore the factors that motivate
married partners to start a copreneurship business, and who is the
dominant partner in the management of this business. The study
participants are four entrepreneurial couples who are SME business
operators selected through purposive sampling. In-depth interviews
and direct observation were used as methods of measurement for
triangulation of qualitative data in this study. The findings of the
interviews were administered using NVivo 8.0 software. The result
shows that freedom is a key factor that drives entrepreneurs to set up
copreneurship businesses, and that the husband dominates the
management aspects of the business. The study gives an overview of
the parties involved in entrepreneurship to provide understanding of
the copreneurship concept as it is practiced. This study provides
academic value by creating understanding of the importance of a
harmonious family institution specifically for forming entrepreneurs
in the familial environment in Malaysia.
Abstract: Despite the benefits of innovation diffusion in the
South African public service, implementation thereof seems to be
problematic, particularly with regard to e-governance which would
enhance the quality of service delivery, especially accessibility,
choice, and mode of operation. This paper reports on differences
between the public service and the private sector in terms of
innovation diffusion. Innovation diffusion will be investigated to
explore identified obstacles that are hindering successful
implementation of e-governance. The research inquiry is underpinned
by the diffusion of innovation theory, which is premised on the
assumption that innovation has a distinct channel, time, and mode of
adoption within the organisation. A comparative thematic document
analysis was conducted to investigate organisational differences with
regard to innovation diffusion. A similar approach has been followed
in other countries, where the same conceptual framework has been
used to guide document analysis in studies in both the private and the
public sectors. As per the recommended conceptual framework, three
organisational characteristics were emphasised, namely the external
characteristics of the organisation, the organisational structure, and
the inherent characteristics of the leadership. The results indicated
that the main difference in the external characteristics lies in the
focus and the clientele of the private sector. With regard to
organisational structure, private organisations have veto power,
which is not the case in the public service. Regarding leadership,
similarities were observed in social and environmental responsibility
and employees’ attitudes towards immediate supervision. Differences
identified included risk taking, the adequacy of leadership
development, organisational approaches to motivation and
involvement in decision making, and leadership style. Due to the
organisational differences observed, it is recommended that
differentiated strategies be employed to ensure effective innovation
diffusion, and ultimately e-governance. It is recommended that the
results of this research be used to stimulate discussion on ways to
improve collaboration between the mentioned sectors, to capitalise on
the benefits of each sector.
Abstract: The purpose of this paper is to show how state plays a
regulatory role in the relations of distribution by analyzing tax and
expenditure in Turkey. This paper has two main arguments. First,
state intervenes in economic and social life via budget policies and
steers the relations of distribution within the scope of the
reproduction of the capital accumulation and legitimacy. Secondly, a
great amount of public expenditure benefits capital owners while
state gains its tax income mainly from low and middle income
groups.
Abstract: MicroRNAs are small non-coding RNA found in
many different species. They play crucial roles in cancer such as
biological processes of apoptosis and proliferation. The identification
of microRNA-target genes can be an essential first step towards to
reveal the role of microRNA in various cancer types. In this paper,
we predict miRNA-target genes for lung cancer by integrating
prediction scores from miRanda and PITA algorithms used as a
feature vector of miRNA-target interaction. Then, machine-learning
algorithms were implemented for making a final prediction. The
approach developed in this study should be of value for future studies
into understanding the role of miRNAs in molecular mechanisms
enabling lung cancer formation.
Abstract: Cavities are frequently found beneath conduits on pile
foundations in old embankments. Cavity reduces seepage length
significantly and consequently causes piping failure of embankments.
Case studies of embankment failures indicate that the relative
settlement between ground and pile supported-concrete conduit was
the main reason of the cavity. In this paper, an attempt to simulate the
cavity-induced piping failure mechanism was made using finite
element numerical method. Piping potential is examined by carrying
out parametric study for influencing factors such as cavity length,
water level, and flow conditions. The concentration of hydraulic
gradient adjacent to cavity was found. It is found that the hydraulic
gradient close to the cavity exceeds considerably the critical hydraulic
gradient causing piping. Piping failure potential due to the existence of
cavity is evaluated and contour map for the potential risk of an
embankment for piping failure is proposed.
Abstract: Liquid storage tanks have become widespread during the recent decades due to their extensive usage. Analysis of liquid containing tanks is known to be complex due to hydrodynamic force exerted on tank which makes the analysis a complex one. The objective of this research is to carry out analysis of liquid domain along with structural interaction for various geometries of circular tanks considering seismic effects. An attempt has been made to determine hydrodynamic pressure distribution on the tank wall considering impulsive and convective components of liquid mass. To get a better picture, a comparative study of Draft IS 1893 Part 2, ACI 350.3 and Eurocode 8 for Circular Shaped Tank has been performed. Further, the differences in the magnitude of shear and moment at base as obtained from static (IS 3370 IV) and dynamic (Draft IS 1892 Part 2) analysis of ground supported circular tank highlight the need for us to mature from the old code to a newer code, which is more accurate and reliable.
Abstract: Electric field is an important fundamental concept in
electrostatics. In high-school, generally Thai students have already
learned about definition of electric field, electric field due to a point
charge, and superposition of electric fields due to multiple-point
charges. Those are the prerequisite basic knowledge students holding
before entrancing universities. In the first-year university level,
students will be quickly revised those basic knowledge and will be
then introduced to a more complicated topic—electric field due to
continuous charged distributions. We initially found that our
freshman students, who were from the Faculty of Science and
enrolled in the introductory physic course (SCPY 158), often
seriously struggled with the basic physics concepts—superposition of
electric fields and inverse square law and mathematics being relevant
to this topic. These also then resulted on students’ understanding of
advanced topics within the course such as Gauss's law, electric
potential difference, and capacitance. Therefore, it is very important
to determine students' understanding of electric field due to
continuous charged distributions. The open-ended question about
sketching net electric field vectors from a uniformly charged
insulating rod was administered to 260 freshman science students as
pre- and post-tests. All of their responses were analyzed and
classified into five levels of understandings. To get deep
understanding of each level, 30 students were interviewed toward
their individual responses. The pre-test result found was that about
90% of students had incorrect understanding. Even after completing
the lectures, there were only 26.5% of them could provide correct
responses. Up to 50% had confusions and irrelevant ideas. The result
implies that teaching methods in Thai high schools may be
problematic. In addition for our benefit, these students’ alternative
conceptions identified could be used as a guideline for developing the
instructional method currently used in the course especially for
teaching electrostatics.
Abstract: Present study focused on the utilization of solar
energy by the help of photovoltaic greenhouse solar dryer under
forced mode. A single slope photovoltaic greenhouse solar dryer has
been proposed and thermal modelling has been developed. Various
parameters have been calculated by thermal modelling such as
greenhouse room temperature, cell temperature, crop temperature and
air temperature at exit of greenhouse. Further cell efficiency, thermal
efficiency, and overall thermal efficiency have been calculated for a
typical day of May and November. It was found that system can
generate equivalent thermal energy up to 7.65 kW and 6.66 kW per
day for clear day of May and November respectively.
Abstract: The effectiveness of microchannels in enhancing heat
transfer has been demonstrated in the semiconductor industry. In
order to tap the microscale heat transfer effects into macro
geometries, overcoming the cost and technological constraints,
microscale passages were created in macro geometries machined
using conventional fabrication methods. A cylindrical insert was
placed within a pipe, and geometrical profiles were created on the
outer surface of the insert to enhance heat transfer under steady-state
single-phase liquid flow conditions. However, while heat transfer
coefficient values of above 10 kW/m2·K were achieved, the heat
transfer enhancement was accompanied by undesirable pressure drop
increment. Therefore, this study aims to address the high pressure
drop issue using Constructal theory, a universal design law for both
animate and inanimate systems. Two designs based on Constructal theory were developed to study
the effectiveness of Constructal features in reducing the pressure drop
increment as compared to parallel channels, which are commonly
found in microchannel fabrication. The hydrodynamic and heat
transfer performance for the Tree insert and Constructal fin (Cfin)
insert were studied using experimental methods, and the underlying
mechanisms were substantiated by numerical results. In technical
terms, the objective is to achieve at least comparable increment in
both heat transfer coefficient and pressure drop, if not higher
increment in the former parameter. Results show that the Tree insert improved the heat transfer
performance by more than 16 percent at low flow rates, as compared
to the Tree-parallel insert. However, the heat transfer enhancement
reduced to less than 5 percent at high Reynolds numbers. On the
other hand, the pressure drop increment stayed almost constant at 20
percent. This suggests that the Tree insert has better heat transfer
performance in the low Reynolds number region. More importantly,
the Cfin insert displayed improved heat transfer performance along
with favourable hydrodynamic performance, as compared to Cfinparallel
insert, at all flow rates in this study. At 2 L/min, the
enhancement of heat transfer was more than 30 percent, with 20
percent pressure drop increment, as compared to Cfin-parallel insert.
Furthermore, comparable increment in both heat transfer coefficient
and pressure drop was observed at 8 L/min. In other words, the Cfin
insert successfully achieved the objective of this study. Analysis of the results suggests that bifurcation of flows is
effective in reducing the increment in pressure drop relative to heat
transfer enhancement. Optimising the geometries of the Constructal
fins is therefore the potential future study in achieving a bigger stride
in energy efficiency at much lower costs.
Abstract: Flue gas desulfurization gypsum (FGD) is a waste
material arouse from coal power plants. Hydroxyapatite (HAP) is a
biomaterial with porous structure. In this study, FGD gypsum which
retrieved from coal power plant in Turkey was characterized and
HAP particles which can be used as an adsorbent in wastewater
treatment application were synthesized from the FGD gypsum. The
raw materials are characterized by using X Ray Diffraction (XRD)
and Fourier transform infrared spectroscopy (FT-IR) techniques and
produced HAP are characterized by using XRD. As a result, HAP
particles were synthesized at the molar ratio of 5:10, 5:15, 5:20, 5:24,
at room temperature, in alkaline medium (pH=11) and in 1 hour-reaction
time. Among these conditions, 5:20 had the best result.
Abstract: Digital technologies offer many opportunities in the
design and implementation of brand communication and advertising.
Augmented reality (AR) is an innovative technology in marketing
communication that focuses on the fact that virtual interaction with a
product ad offers additional value to consumers. AR enables
consumers to obtain (almost) real product experiences by the way of
virtual information even before the purchase of a certain product.
Aim of AR applications in relation with advertising is in-depth
examination of product characteristics to enhance product knowledge
as well as brand knowledge. Interactive design of advertising
provides observers with an intense examination of a specific
advertising message and therefore leads to better brand knowledge.
The elaboration likelihood model and the central route to persuasion
strongly support this argumentation. Nevertheless, AR in brand
communication is still in an initial stage and therefore scientific
findings about the impact of AR on information processing and brand
attitude are rare. The aim of this paper is to empirically investigate
the potential of AR applications in combination with traditional print
advertising. To that effect an experimental design with different
levels of interactivity is built to measure the impact of interactivity of
an ad on different variables o advertising effectiveness.