Abstract: With the presence of a uniform vertical magnetic field and suspended particles, thermocapillary instability in a horizontal liquid layer is investigated. The resulting eigenvalue is solved by the Galerkin technique for various basic temperature gradients. It is found that the presence of magnetic field always has a stability effect of increasing the critical Marangoni number.
Abstract: Polyurethanes (PURs) are very versatile polymeric
materials with a wide range of physical and chemical properties.
PURs have desirable properties such as high abrasion resistance, tear
strength, shock absorption, flexibility and elasticity. Although they
have relatively poor thermal stability, this can be improved by using
treated clay. Polyurethane/clay nanocomposites have been
synthesized from renewable sources. A polyol for the production of
polyurethane by reaction with an isocyanate was obtained by the
synthesis of palm oil-based oleic acid with glycerol. Dodecylbenzene
sulfonic acid (DBSA) was used as catalyst and emulsifier. The
unmodified clay (kunipia-F) was treated with cetyltrimethyl
ammonium bromide (CTAB-mont) and octadodecylamine (ODAmont).
The d-spacing in CTAB-mont and ODA-mont were 1.571 nm
and 1.798 nm respectively and larger than that of the pure-mont
(1.142 nm). The organoclay was completely intercalated in the
polyurethane, as confirmed by a wide angle x-ray diffraction
(WAXD) pattern.
The results showed that adding clay demonstrated better thermal
stability in comparison with the virgin polyurethane. Onset
degradation of pure PU is at 200oC, and is lower than that of the
CTAB-mont PU and ODA-mont PU which takes place at about
318oC and 330oC, respectively. The mechanical properties (including
the dynamic mechanical properties) of pure polyurethane (PU) and
PU/clay nanocomposites, were measured. The modified organoclay
had a remarkably beneficial effect on the strength and elongation at
break of the nanocomposites, which both increased with increasing
clay content with the increase of the tensile strength of more than
214% and 267% by the addition of only 5 wt% of the
montmorillonite CTAB-mont PU and ODA-mont PU, respectively.
Abstract: Development of intelligent assembly cell conception includes new solution kind of how to create structures of automated and flexible assembly system. The current trend of the final product quality increasing is affected by time analysis of the entire manufacturing process. The primary requirement of manufacturing is to produce as many products as soon as possible, at the lowest possible cost, but of course with the highest quality. Such requirements may be satisfied only if all the elements entering and affecting the production cycle are in a fully functional condition. These elements consist of sensory equipment and intelligent control elements that are essential for building intelligent manufacturing systems. Intelligent behavior of the system as the control system will repose on monitoring of important parameters of the system in the real time. Intelligent manufacturing system itself should be a system that can flexibly respond to changes in entering and exiting the process in interaction with the surroundings.
Abstract: We investigated the response of testosterone (T),
growth hormone (GH), cortisol (C), steroid hormone binding
globulin (SHBG), insulin-like growth factor (IGF-1), insulin-like
growth factor binding protein-3 (IGFBP-3), and some anaboliccatabolic
indexes, i.e.: T/C, T/SHBG, and IGF-1/IGFBP-3 to
maximal exercise in endurance-trained athletes (TREN) and
untrained subjects (CG). The baseline concentration of IGF-1 was
higher in athletes (TREN) when compared to the CG (p
Abstract: Industrial surveys shows that manufacturing
companies define the qualities of thermal removing process based on
the dimension and physical appearance of the cutting material
surface. Therefore, the roughness of the surface area of the material
cut by the plasma arc cutting process and the rate of the removed
material by the manual plasma arc cutting machine was importantly
considered. Plasma arc cutter Selco Genesis 90 was used to cut
Standard AISI 1017 Steel of 200 mm x100 mm x 6 mm manually
based on the selected parameters setting. The material removal rate
(MRR) was measured by determining the weight of the specimens
before and after the cutting process. The surface roughness (SR)
analysis was conducted using Mitutoyo CS-3100 to determine the
average roughness value (Ra). Taguchi method was utilized to
achieve optimum condition for both outputs studied. The
microstructure analysis in the region of the cutting surface is
performed using SEM. The results reveal that the SR values are
inversely proportional to the MRR values. The quality of the surface
roughness depends on the dross peak that occurred after the cutting
process.
Abstract: Cassava is one of the top five crops in Cameroon. Its
evolution has remained constant since the independence period and
the production has more than tripled. It is a crop with multiple
industrial capacities but the sector-s business opportunities are
underexploited. Using Strengths, Weaknesses, Opportunities and
Threats analysis method, this paper examines the cassava actual state.
It appraises the sector-s strengths (S), considers suitable measures to
strengthen weaknesses (W), evaluates strategies to fully benefit from
the sector numerous business opportunities (O) and explore means to
convert threats (T) into opportunities. Data were collected from the
ministry of agriculture and rural development and different actors.
The results show that cassava sector embodies many business
opportunities and stands as a raw material provider for many
industries but ultimately requires challenges to be tackled
appropriately.
Abstract: Dual bell nozzle is a promising one among the altitude
adaptation nozzle concepts, which offer increased nozzle
performance in rocket engines. Its advantage is the simplicity it offers
due to the absence of any additional mechanical device or movable
parts. Hence it offers reliability along with improved nozzle
performance as demanded by future launch vehicles. Among other
issues, the flow transition to the extension nozzle of a dual bell
nozzle is one of the major issues being studied in the development of
dual bell nozzle. A parameter named over-expansion factor, which
controls the value of the wall inflection angle, has been reported to
have substantial influence in this transition process. This paper
studies, through CFD and cold flow experiments, the effect of overexpansion
factor on flow transition in dual bell nozzles.
Abstract: In determining the electromagnetic properties of
magnetic materials, hysteresis modeling is of high importance. Many
models are available to investigate those characteristics but they tend
to be complex and difficult to implement. In this paper a new
qualitative hysteresis model for ferromagnetic core is presented,
based on the function approximation capabilities of adaptive neuro
fuzzy inference system (ANFIS). The proposed ANFIS model
combined the neural network adaptive capabilities and the fuzzy
logic qualitative approach can restored the hysteresis curve with a
little RMS error. The model accuracy is good and can be easily
adapted to the requirements of the application by extending or
reducing the network training set and thus the required amount of
measurement data.
Abstract: the purpose of this research is to identify and clarify
factors which have positive effect among user satisfaction and their
social networking through websites. The examined factors in this
research are; innovation, ease of use, trustworthy and customer
support which are defined as satisfaction factors. To obtain reliable
research approaches and to have better result in this research four
hypothesizes used to test. This hypothesis testing has been done by
correlation, regression and test of normality by using “SPSS16" also
the data which was analyzed by this software. this data was gathered
from prepaid questionnaire.
Abstract: The alterations in pancreas gland secretion hormones
following an aerobic and exhausting exercise was the purpose of this
study. Sixteen healthy men participated in the study. The blood
samples of these participants were taken in four stages under fasting
condition. The first sample was taken before Bruce exhausting and
aerobic test, the second sample was taken after Bruce exercise and
the third and forth stages samples were taken 24 and 48 hours after
the exercises respectively. The final results indicated that a strenuous
aerobic exercise can have a significant effect on glucagon and insulin
concentration of blood serum. The increase in blood serum insulin
was higher after 24 and 48 hours. It seems that an intensive exercise
has little effect on changes in glucagon concentration of blood serum.
Also, disorder in secretion in glucagon and insulin concentration of
serum disturbs athletes- exercise.
Abstract: Environmental contamination is a common problem in ex-industrial and industrial sites. This article gives a brief description of general applied environmental investigation methodologies and possible remediation applications in Latvia. Most of contaminated areas are situated in former and active industrial, military areas and ports. Industrial and logistic activities very often have been with great impact for more than hundred years thus the contamination level with heavy metals, hydrocarbons, pesticides, persistent organic pollutants is high and is threatening health and environment in general. 242 territories now are numbered as contaminated and fixed in the National Register of contaminated territories in Latvia. Research and remediation of contamination in densely populated areas are of important environmental policy domain. Four different investigation case studies of contaminated areas are given describing the history of use, environmental quality assessment as well as planned environmental management actions. All four case study locations are situated in Riga - the capital of the Republic of Latvia. The aim of this paper is to analyze the situation and problems with management of contaminated areas in Latvia, give description of field research methods and recommendations for remediation industry based on scientific data and innovations.
Abstract: Electronic nose (array of chemical sensors) are widely
used in food industry and pollution control. Also it could be used to
locate or detect the direction of the source of emission odors. Usually
this task is performed by electronic nose (ENose) cooperated with
mobile vehicles, but when a source is instantaneous or surrounding is
hard for vehicles to reach, problem occurs. Thus a method for
stationary ENose to detect the direction of the source and locate the
source will be required. A novel method which uses the ratio between
the responses of different sensors as a discriminant to determine the
direction of source in natural wind surroundings is presented in this
paper. The result shows that the method is accurate and easily to be
implemented. This method could be also used in movably, as an
optimized algorithm for robot tracking source location.
Abstract: Robust nonlinear integrated navigation of GPS and
low cost MEMS is a hot topic of research these days. A robust filter
is required to cope up with the problem of unpredictable
discontinuities and colored noises associated with low cost sensors.
H∞ filter is previously used in Extended Kalman filter and Unscented
Kalman filter frame. Unscented Kalman filter has a problem of
Cholesky matrix factorization at each step which is a very unstable
operation. To avoid this problem in this research H∞ filter is
designed in Square root Unscented filter framework and found 50%
more robust towards increased level of colored noises.
Abstract: In this study, fuzzy rule-based classifier is used for the
diagnosis of congenital heart disease. Congenital heart diseases are
defined as structural or functional heart disease. Medical data sets
were obtained from Pediatric Cardiology Department at Selcuk
University, from years 2000 to 2003. Firstly, fuzzy rules were
generated by using medical data. Then the weights of fuzzy rules
were calculated. Two different reasoning methods as “weighted vote
method" and “singles winner method" were used in this study. The
results of fuzzy classifiers were compared.
Abstract: In this paper a polymer electrolyte membrane (PEM)
fuel cell power system including burner, steam reformer, heat
exchanger and water heater has been considered to meet the
electrical, heating, cooling and domestic hot water loads of
residential building which in Tehran. The system uses natural gas as
fuel and works in CHP mode. Design and operating conditions of a
PEM fuel cell system is considered in this study. The energy
requirements of residential building and the number of fuel cell
stacks to meet them have been estimated. The method involved
exergy analysis and entropy generation thorough the months of the
year. Results show that all the energy needs of the building can be
met with 12 fuel cell stacks at a nominal capacity of 8.5 kW. Exergy
analysis of the CHP system shows that the increase in the ambient air
temperature from 1oC to 40oC, will have an increase of entropy
generation by 5.73%.Maximum entropy generates for 15 hour in 15th
of June and 15th of July is estimated to amount at 12624 (kW/K).
Entropy generation of this system through a year is estimated to
amount to 1004.54 GJ/k.year.
Abstract: The overriding goal of software engineering is to
provide a high quality system, application or a product. To achieve
this goal, software engineers must apply effective methods coupled
with modern tools within the context of a mature software process
[2]. In addition, it is also must to assure that high quality is realized.
Although many quality measures can be collected at the project
levels, the important measures are errors and defects. Deriving a
quality measure for reusable components has proven to be
challenging task now a days. The results obtained from the study are
based on the empirical evidence of reuse practices, as emerged from
the analysis of industrial projects. Both large and small companies,
working in a variety of business domains, and using object-oriented
and procedural development approaches contributed towards this
study. This paper proposes a quality metric that provides benefit at
both project and process level, namely defect removal efficiency
(DRE).
Abstract: Conventional industrial monitoring systems are
tedious, inefficient and the at times integrity of the data is
unreliable. The objective of this system is to monitor industrial
processes specifically the fluid level which will measure the
instantaneous fluid level parameter and respond by text
messaging the exact value of the parameter to the user when
being enquired by a privileged access user. The development of
the embedded program code and the circuit for fluid level
measuring are discussed as well. Suggestions for future
implementations and efficient remote monitoring works are
included.
Abstract: In this paper we present the modeling, design, and
experimental testing of a nerve cuff multi-electrode system for
diameter-selective vagus nerve stimulation.
The multi-electrode system contained ninety-nine platinum
electrodes embedded within a self-curling spiral silicone sheet. The
electrodes were organized in a matrix having nine parallel groups,
each containing eleven electrodes.
Preliminary testing of the nerve cuff was performed in an isolated
segment of a swinish left cervical vagus nerve. For selective vagus
nerve stimulation, precisely defined current quasitrapezoidal,
asymmetric and biphasic stimulating pulses were applied to
preselected locations along the left vagus segment via appointed
group of three electrodes within the cuff. Selective stimulation was
obtained by anodal block. However, these pulses may not be safe for
a long-term application because of a frequently used high imbalance
between the cathodic and anodic part of the stimulating pulse.
Preliminary results show that the cuff was capable of exciting A
and B-fibres, and, that for a certain range of parameters used in
stimulating pulses, the contribution of A-fibres to the CAP was
slightly reduced and the contribution of B-fibres was slightly larger.
Results also showed that measured CAPs are not greatly
influenced by the imbalance between a charge Qc injected in cathodic
and Qa in anodic phase of quasitrapezoidal, asymmetric and biphasic
pulses.
Abstract: This paper proposes a VPN Accelerator Board
(VPN-AB), a virtual private network (VPN) protocol designed for
trust channel security system (TCSS). TCSS supports safety
communication channel between security nodes in internet. It
furnishes authentication, confidentiality, integrity, and access control
to security node to transmit data packets with IPsec protocol. TCSS
consists of internet key exchange block, security association block,
and IPsec engine block. The internet key exchange block negotiates
crypto algorithm and key used in IPsec engine block. Security
Association blocks setting-up and manages security association
information. IPsec engine block treats IPsec packets and consists of
networking functions for communication. The IPsec engine block
should be embodied by H/W and in-line mode transaction for high
speed IPsec processing. Our VPN-AB is implemented with high speed
security processor that supports many cryptographic algorithms and
in-line mode. We evaluate a small TCSS communication environment,
and measure a performance of VPN-AB in the environment. The
experiment results show that VPN-AB gets a performance throughput
of maximum 15.645Gbps when we set the IPsec protocol with
3DES-HMAC-MD5 tunnel mode.
Abstract: Our results showed that treatment with both
cyclooxygenase (COX1 or COX2) inhibitors impair reproduction
parameters of the medaka. Resveratrol (COX1 inhibitor) caused an
decrease in the number of spawning females at the first week of
feeding fish with experimental diets. In the group treated with NS-
398 (COX2 inhibitor) we found the lowest sperm velocity parameters
and decreased linearity of movement. The ovaries of the medaka fed
feed supplemented with Resveratrol or NS-398 were confirmed to
have a lower share of matured oocytes however during the
experiment (four weeks) the number of eggs spawned by females was
similar. Both inhibitors in fish diet (20 mg/kg body weight/day)
caused a decrease in the embryo survival. Our results revealed that
for the medaka female reproduction, activity of both COX enzymes
might be necessary whereas males reproduction competence, as
expressed by sperm motility parameters, might be related to COX2
activity.