Abstract: Optimization of a microwave-assisted extraction of cherry laurel (Prunus laurocerasus) fruit using methanol was studied. The influence of process parameters (microwave power, plant material-to-solvent ratio and the extraction time) on the extraction efficiency were optimized by using response surface methodology. The predicted maximum yield of extractive substances (41.85 g/100 g fresh plant material) was obtained at microwave power of 600 W and plant material to solvent ratio of 0.2 g/cm3 after 26 minutes of extraction, while a mean value of 40.80±0.41 g/100 g fresh plant material was obtained from laboratory experiments. This proves applicability of the model in predicting optimal extraction conditions with minimal laborious and time consuming. The results indicated that all process parameters were effective on the extraction efficiency, while the most important factor was extraction time. In order to rationalize production the optimal economical condition which gave a large total extract yield with minimal energy and solvent consumption was found.
Abstract: In all industries which are related to heat, suitable
thermal ranges are defined for each device to operate well.
Consideration of these limits requires a thermal control unit beside
the main system. The Satellite Thermal Control Unit exploits from
different methods and facilities individually or mixed. For enhancing
heat transfer between primary surface and the environment,
utilization of radiating extended surfaces are common. Especially for
large temperature differences; variable thermal conductivity has a
strong effect on performance of such a surface .In most literatures,
thermo-physical properties, such as thermal conductivity, are
assumed as constant. However, in some recent researches the
variation of these parameters is considered. This may be helpful for
the evaluation of fin-s temperature distribution in relatively large
temperature differences. A new method is introduced to evaluate
temperature-dependent thermal conductivity values. The finite
volume method is employed to simulate numerically the temperature
distribution in a space radiating fin. The present modeling is carried
out for Aluminum as fin material and compared with previous
method. The present results are also compared with those of two
other analytical methods and good agreement is shown.
Abstract: Creation and maintenance of knowledge management
systems has been recognized as an important research area.
Consecutively lack of accurate results from knowledge management
systems limits the organization to apply their knowledge
management processes. This leads to a failure in getting the right
information to the right people at the right time thus followed by a
deficiency in decision making processes. An Intranet offers a
powerful tool for communication and collaboration, presenting data
and information, and the means that creates and shares knowledge,
all in one easily accessible place. This paper proposes an archetype
describing how a knowledge management system, with the support
of intranet capabilities, could very much increase the accuracy of
capturing, storing and retrieving knowledge based processes thereby
increasing the efficiency of the system. This system will expect a
critical mass of usage, by the users, for intranet to function as
knowledge management systems. This prototype would lead to a
design of an application that would impose creation and maintenance
of an effective knowledge management system through intranet. The
aim of this paper is to introduce an effective system to handle
capture, store and distribute knowledge management in a form that
may not lead to any failure which exists in most of the systems. The
methodology used in the system would require all the employees, in
the organization, to contribute the maximum to deliver the system to
a successful arena. The system is still in its initial mode and thereby
the authors are under the process to practically implement the ideas,
as mentioned in the system, to produce satisfactory results.
Abstract: Non-isothermal stagnation-point flow with consideration of thermal radiation is studied numerically. A set of partial differential equations that governing the fluid flow and energy is converted into a set of ordinary differential equations which is solved by Runge-Kutta method with shooting algorithm. Dimensionless wall temperature gradient and temperature boundary layer thickness for different combinaton of values of Prandtl number Pr and radiation parameter NR are presented graphically. Analyses of results show that the presence of thermal radiation in the stagnation-point flow is to increase the temperature boundary layer thickness and decrease the dimensionless wall temperature gradient.
Abstract: In this work, sorption of nickel from aqueous solution on hypnea valentiae, red macro algae, was investigated. Batch experiments have been carried out to find the effect of various parameters such as pH, temperature, sorbent dosage, metal concentration and contact time on the sorption of nickel using hypnea valentiae. Response surface methodology (RSM) is employed to optimize the process parameters. Based on the central composite design, quadratic model was developed to correlate the process variables to the response. The most influential factor on each experimental design response was identified from the analysis of variance (ANOVA). The optimum conditions for the sorption of nickel were found to be: pH – 5.1, temperature – 36.8oC, sorbent dosage – 5.1 g/L, metal concentration – 100 mg/L and contact time – 30 min. At these optimized conditions the maximum removal of nickel was found to be 91.97%. A coefficient of determination R2 value 0.9548 shows the fitness of response surface methodology in this work.
Abstract: The stop watch is used to measure the time required
for a certain event. This is different from normal clocks in many
ways, one of which is the accuracy of time. The stop watch requires
much more accuracy than the normal clocks. In this paper, an
ATmega8535 microcontroller was used to control the stop watch, by
which perfect accuracy can be ensured. For compiling the C code and
for loading the compiled .hex file into the microcontroller, AVR
studio and PonyProg were used respectively. The stop watch is also
different from traditional stop watches, as it contains two different
timing modes namely 'Split timing' and 'Lap timing'.
Abstract: Electrical discharge machining (EDM) is well
established machining technique mainly used to machine complex
geometries on difficult-to-machine materials and high strength
temperature resistant alloys. In the present research, the objective is
to study the shape of the electrode and establish the application of
liquid nitrogen in reducing distortion of the electrode during
electrical discharge machining of M2 grade high speed steel using
copper electrodes. Study of roundness was performed on the
electrode to observe the shape of the electrode for both conventional
EDM and EDM with cryogenically cooled electrode. Scanning
Electron Microscope (SEM) has been used to study the shape of
electrode tip. The effect of various parameters such as discharge
current and pulse on time has been studied to understand the behavior
of distortion of electrode. It has been concluded that the shape
retention is better in case of liquid nitrogen cooled electrode.
Abstract: Collaborative planning, forecasting and
replenishment (CPFR) coordinates the various supply chain
management activities including production and purchase planning,
demand forecasting and inventory replenishment between supply
chain trading partners. This study proposes a systematic way of
analyzing CPFR supporting factors using fuzzy cognitive map
(FCM) approach. FCMs have proven particularly useful for solving
problems in which a number of decision variables and
uncontrollable variables are causally interrelated. Hence the FCMs
of CPFR are created to show the relationships between the factors
that influence on effective implementation of CPFR in the supply
chain.
Abstract: This paper is concerned with calculating boiler
efficiency as one of the most important types of performance
measurements in any steam power plant. That has a key role in
determining the overall effectiveness of the whole system within the
power station. For this calculation, a Visual-Basic program was
developed, and a steam power plant known as El-Khmus power
plant, Libya was selected as a case study. The calculation of the
boiler efficiency was applied by using heating balance method. The
findings showed how the maximum heat energy which produced
from the boiler increases the boiler efficiency through increasing the
temperature of the feed water, and decreasing the exhaust
temperature along with humidity levels of the of fuel used within the
boiler.
Abstract: Recently, the Field Programmable Gate Array (FPGA) technology offers the potential of designing high performance systems at low cost. The discrete wavelet transform has gained the reputation of being a very effective signal analysis tool for many practical applications. However, due to its computation-intensive nature, current implementation of the transform falls short of meeting real-time processing requirements of most application. The objectives of this paper are implement the Haar and Daubechies wavelets using FPGA technology. In addition, the Bit Error Rate (BER) between the input audio signal and the reconstructed output signal for each wavelet is calculated. From the BER, it is seen that the implementations execute the operation of the wavelet transform correctly and satisfying the perfect reconstruction conditions. The design procedure has been explained and designed using the stat-ofart Electronic Design Automation (EDA) tools for system design on FPGA. Simulation, synthesis and implementation on the FPGA target technology has been carried out.
Abstract: Public procurement is one of the most
important areas in the public sector that introduces a possibility for a
corruption. Due to the volume of the funds that are
allocated through this institution (in the EU countries it is between 10
– 15% of GDP), it has very serious implications for the efficiency of
public expenditures and the overall economic efficiency as
well. Indicators that are usually used for the measurement of the
corruption (such as Corruption Perceptions Index - CPI) show that
the worst situation is in the post-communist countries
and Mediterranean countries.
The presented paper uses the Czech Republic as an example of a
post-communist country and analyses the factors which influence
the scope of corruption in public procurement. Moreover, the
paper discusses indicators that could point at the public procurement
market inefficiency. The presented results show that post-communist
states use the institute of public contracts significantly more than the
old member countries of the continental Europe. It has a very
important implication because it gives more space for corruption.
Furthermore, it appears that the inefficient functioning of public
procurement market is clearly manifested in the low number of bids,
low level of market transparency and an ineffective control
system. Some of the observed indicators are statistically significantly
correlated with the CPI.
Abstract: A numerical study has been conducted to investigate the influence of fin pitch and relative humidity on the heat transfer performance of the fin-and-tube heat exchangers having plain fin geometry under dehumidifying conditions. The analysis is done using the ratio between the heat transfer coefficients in totally wet conditions and those in totally dry conditions using the appropriate correlations for both dry and wet conditions. For a constant relative humidity, it is found that the heat transfer coefficient increases with the increase of the air frontal velocity. By contrast, the fin efficiency decreases when the face velocity is increased. Apparently, this phenomenon is attributed to the path of condensate drainage. For the influence of relative humidity, the results showed an increase in heat transfer performance and a decrease in wet fin efficiency when relative humidity increases. This is due to the higher amount of mass transfer encountered at higher relative humidity. However, it is found that the effect of fin pitch on the heat transfer performance depends strongly on the face velocity. At lower frontal velocity the heat transfer increases with fin pitch. Conversely, an increase in fin pitch gives lower heat transfer coefficients when air velocity is increased.
Abstract: This article is presented an experimental and modeling
study of a four-bed pressure swing adsorption process using
zeolite13X to provide oxygen-enriched air. The binary mixture N2/O2
(79/21 vol %) was used as a feed stream. The effects of purge/feed
ratio (P/F), adsorption pressure, cyclic time and product flow rate on
product purity and recovery under nonisothermal condition were
studied. The adsorption dynamics of process were determined using
a mathematical model incorporated mass and energy balances. A
Mathlab code using finite difference method was developed to solve
the set of coupled differential-algebraic equations, and the simulation
results are agreed well with experimental results.
Abstract: Mammalian genomes contain large number of
retroelements (SINEs, LINEs and LTRs) which could affect
expression of protein coding genes through associated transcription
factor binding sites (TFBS). Activity of the retroelement-associated
TFBS in many genes is confirmed experimentally but their global
functional impact remains unclear. Human SINEs (Alu repeats) and
mouse SINEs (B1 and B2 repeats) are known to be clustered in GCrich
gene rich genome segments consistent with the view that they
can contribute to regulation of gene expression. We have shown
earlier that Alu are involved in formation of cis-regulatory modules
(clusters of TFBS) in human promoters, and other authors reported
that Alu located near promoter CpG islands have an increased
frequency of CpG dinucleotides suggesting that these Alu are
undermethylated. Human Alu and mouse B1/B2 elements have an
internal bipartite promoter for RNA polymerase III containing
conserved sequence motif called B-box which can bind basal
transcription complex TFIIIC. It has been recently shown that TFIIIC
binding to B-box leads to formation of a boundary which limits
spread of repressive chromatin modifications in S. pombe. SINEassociated
B-boxes may have similar function but conservation of
TFIIIC binding sites in SINEs located near mammalian promoters
has not been studied earlier. Here we analysed abundance and
distribution of retroelements (SINEs, LINEs and LTRs) in annotated
sequences of the Database of mammalian transcription start sites
(DBTSS). Fractions of SINEs in human and mouse promoters are
slightly lower than in all genome but >40% of human and mouse
promoters contain Alu or B1/B2 elements within -1000 to +200 bp
interval relative to transcription start site (TSS). Most of these SINEs
is associated with distal segments of promoters (-1000 to -200 bp
relative to TSS) indicating that their insertion at distances >200 bp
upstream of TSS is tolerated during evolution. Distribution of SINEs
in promoters correlates negatively with the distribution of CpG
sequences. Using analysis of abundance of 12-mer motifs from the
B1 and Alu consensus sequences in genome and DBTSS it has been
confirmed that some subsegments of Alu and B1 elements are poorly
conserved which depends in part on the presence of CpG
dinucleotides. One of these CpG-containing subsegments in B1
elements overlaps with SINE-associated B-box and it shows better
conservation in DBTSS compared to genomic sequences. It has been
also studied conservation in DBTSS and genome of the B-box
containing segments of old (AluJ, AluS) and young (AluY) Alu
repeats and found that CpG sequence of the B-box of old Alu is
better conserved in DBTSS than in genome. This indicates that Bbox-
associated CpGs in promoters are better protected from
methylation and mutation than B-box-associated CpGs in genomic
SINEs. These results are consistent with the view that potential
TFIIIC binding motifs in SINEs associated with human and mouse
promoters may be functionally important. These motifs may protect
promoters from repressive histone modifications which spread from
adjacent sequences. This can potentially explain well known
clustering of SINEs in GC-rich gene rich genome compartments and
existence of unmethylated CpG islands.
Abstract: In this paper we study numerical methods for solving Sylvester matrix equations of the form AX +XBT +CDT = 0. A new projection method is proposed. The union of Krylov subspaces in A and its inverse and the union of Krylov subspaces in B and its inverse are used as the right and left projection subspaces, respectively. The Arnoldi-like process for constructing the orthonormal basis of the projection subspaces is outlined. We show that the approximate solution is an exact solution of a perturbed Sylvester matrix equation. Moreover, exact expression for the norm of residual is derived and results on finite termination and convergence are presented. Some numerical examples are presented to illustrate the effectiveness of the proposed method.
Abstract: A new and cost effective RP-HPLC method was
developed and validated for simultaneous analysis of non steroidal
anti inflammatory dugs Diclofenac sodium (DFS), Flurbiprofen
(FLP) and an opioid analgesic Tramadol (TMD) in advanced drug
delivery systems (Liposome and Microcapsules), marketed brands
and human plasma. Isocratic system was employed for the flow of
mobile phase consisting of 10 mM sodium dihydrogen phosphate
buffer and acetonitrile in molar ratio of 67: 33 with adjusted pH of
3.2. The stationary phase was hypersil ODS column (C18, 250×4.6
mm i.d., 5 μm) with controlled temperature of 30 C°. DFS in
liposomes, microcapsules and marketed drug products was
determined in range of 99.76-99.84%. FLP and TMD in
microcapsules and brands formulation were 99.78 - 99.94 % and
99.80 - 99.82 %, respectively. Single step liquid-liquid extraction
procedure using combination of acetonitrile and trichloroacetic acid
(TCA) as protein precipitating agent was employed. The detection
limits (at S/N ratio 3) of quality control solutions and plasma samples
were 10, 20, and 20 ng/ml for DFS, FLP and TMD, respectively.
The Assay was acceptable in linear dynamic range. All other
validation parameters were found in limits of FDA and ICH method
validation guidelines. The proposed method is sensitive, accurate and
precise and could be applicable for routine analysis in
pharmaceutical industry as well as in human plasma samples for
bioequivalence and pharmacokinetics studies.
Abstract: This paper proposes an adaptive sliding mode
controller which combines adaptive control and sliding
mode control to control a nonlinear robotic manipulator
with uncertain parameters. We use an adaptive algorithm
based on the concept of sliding mode control to alleviate the
chattering phenomenon of control input. Adaptive laws are
developed to obtain the gain of switching input and the
boundary layer parameters. The stability and convergence
of the robotic manipulator control system are guaranteed
by applying the Lyapunov theorem. Simulation results
demonstrate that the chattering of control input can be
alleviated effectively. The proposed controller scheme can
assure robustness against a large class of uncertainties and
achieve good trajectory tracking performance.
Abstract: In mammalian reproductive tract, the oviduct secretes
huge number of growth factors and cytokines that create an optimal
micro-environment for the initial stages of preimplantation embryos.
Secretion of these growth factors is stage-specific. Among them,
VEGF is a potent mitogen for vascular endothelium and stimulates
vascular permeability. Apart from angiogenesis, VEGF in the oviduct
may be involved in regulating the oocyte maturation and subsequent
developmental process during embryo production in vitro. In
experiment 1, to evaluate the effect of VEGF during IVM of porcine
COC and subsequent developmental ability after PA and SCNT. The
results from these experiments indicated that maturation rates among
the different VEGF concentrations were not significant different. In
experiment 2, total intracellular GSH concentrations of oocytes
matured with VEGF (5-50 ng/ml) were increased significantly
compared to a control and VEGF group (500 ng/ml). In experiment 3,
the blastocyst formation rates and total cell number per blastocyst
after parthenogenesis of oocytes matured with VEGF (5-50 ng/ml)
were increased significantly compared to a control and VEGF group
(500 ng/ml). Similarly, in experiment 4, the blastocyst formation rate
and total cell number per blastocyst after SCNT and IVF of oocytes
matured with VEGF (5 ng/ml) were significantly higher than that of
oocytes matured without VEGF group. In experiment 5, at 10 hour
after the onset of IVF, pronuclear formation rate was evaluated.
Monospermy was significantly higher in VEGF-matured oocytes than
in the control, and polyspermy and sperm penetration per oocyte
were significantly higher in the control group than in the VEGFmatured
oocytes. Supplementation with VEGF during IVM
significantly improved male pronuclear formation as compared with
the control. In experiment 6, type III cortical granule distribution in
oocytes was more common in VEGF-matured oocytes than in the
control. In conclusion, the present study suggested that
supplementation of VEGF during IVM may enhance the
developmental potential of porcine in vitro embryos through increase
of the intracellular GSH level, higher MPN formation and increased
fertilization rate as a consequence of an improved cytoplasmic
maturation.
Abstract: The unanticipated destruct of more of the steel moment frames in Northridge earthquake, altered class of regard to the beamto- column connections in moment frames. Panel zone is one the significant part of joints which, it-s stiffness and rigidity has an important effect on the behavior and ductility of the frame. Specifically that behavior of panel zone has a very significant effect on the special moment frames. In this paper , meanwhile the relations for modeling of panel zone in frames are expressed , special moment frames with different spans and stories were studied in the way of performance-based design. The frames designed in according with Iranian steel building code. The effect of panel zone is also considered and in the case of non-existence of performance level, by changing in intimacies and parameter of panel zone, performance level is considered.
Abstract: Objective of this study was to study and compare the effectiveness of inspectors who had different workloads for feed forward and feedback training. The visual search task was simulated to search for specified alphabets called defects. These defects were included of four alphabets in Thai and English such as s ภ, ถ, X, and V with different background. These defects were combined in the specified alphabets and were given the different three backgrounds i.e., Thai, English, and mixed English and Thai alphabets. Sixty students were chosen as a sample in this study and test for final selection subject. Finally, five subjects were taken into testing process. They were asked to search for defects after they were provided basic information. Experiment design was used factorial design and subjects were trained for feed forward and the feedback training. The results show that both trainings were affected on mean search time. It was also found that the feedback training can increase the effectiveness of visual inspectors rather than the feed forward training significantly different at the level of .05