Abstract: Antioxidants contribute to endogenous photoprotection
and are important for the maintenance of skin health. The study was carried out to compare the skin hydration and transepidermal
water loss (TEWL) effects of a stable cosmetic preparation
containing flavonoids, following two applications a day over a period
of tenth week. The skin trans-epidermal water loss and skin hydration
effect was measured at the beginning and up to the end of study period of ten weeks. Any effect produced was measured by Corneometer and TEWA meter (Non-invasive probe).
Two formulations were developed for this study design. Formulation one the control formulation in which no apple juice
extract( Flavonoids) was incorporated while second one was the active formulation in which the apple juice extract (3%) containing
flavonoids was incorporated into water in oil emulsion using Abil EM 90 as an emulsifier. Stable formulations (control and Active)
were applied on human cheeks (n = 12) for a study period of 10 weeks. Result of each volunteer of skin hydration and TEWL was
measured by corneometer and TEWA meter. By using ANOVA and Paired sample t test as a statistical evaluation, result of both base and
formulation were compared. Statistical significant results (p≤0.05)
were observed regarding skin hydration and TEWL when two creams, control and Formulation were compared. It showed that
desired formulation (Active) may have interesting application as an
active moisturizing cream on healthy skin.
Abstract: In the present work, study of the vibration of thin cylindrical shells made of a functionally gradient material (FGM) composed of stainless steel and nickel is presented. Material properties are graded in the thickness direction of the shell according to volume fraction power law distribution. The objective is to study the natural frequencies, the influence of constituent volume fractions and the effects of boundary conditions on the natural frequencies of the FG cylindrical shell. The study is carried out using third order shear deformation shell theory. The governing equations of motion of FG cylindrical shells are derived based on shear deformation theory. Results are presented on the frequency characteristics, influence of constituent volume fractions and the effects of free-free boundary conditions.
Abstract: The equilibrium process of plasma nitrogen species by
chemical kinetic reactions along various pressures is successfully
investigated. The equilibrium process is required in industrial
application to obtain the stable condition when heating up the
material for having homogenous reaction. Nitrogen species densities
is modeled by a continuity equation and extended Arrhenius form.
These equations are used to integrate the change of density over the
time. The integration is to acquire density and the reaction rate of
each reaction where temperature and time dependence are imposed.
A comparison is made with global model within pressure range of 1-
100mTorr and the temperature of electron is set to be higher than
other nitrogen species. The results shows that the chemical kinetic
model only agrees for high pressure because of no power imposed;
while the global model considers the external power along the
pressure range then the electron and nitrogen species give highly
quantity densities by factor of 3 to 5.
Abstract: In deregulated operating regime power system security is an issue that needs due thoughtfulness from researchers in the horizon of unbundling of generation and transmission. Electric power systems are exposed to various contingencies. Network contingencies often contribute to overloading of branches, violation of voltages and also leading to problems of security/stability. To maintain the security of the systems, it is desirable to estimate the effect of contingencies and pertinent control measurement can be taken on to improve the system security. This paper presents the application of particle swarm optimization algorithm to find the optimal location of multi type FACTS devices in a power system in order to eliminate or alleviate the line over loads. The optimizations are performed on the parameters, namely the location of the devices, their types, their settings and installation cost of FACTS devices for single and multiple contingencies. TCSC, SVC and UPFC are considered and modeled for steady state analysis. The selection of UPFC and TCSC suitable location uses the criteria on the basis of improved system security. The effectiveness of the proposed method is tested for IEEE 6 bus and IEEE 30 bus test systems.
Abstract: With a growing number of digital libraries and other
open education repositories being made available throughout the
world, effective search and retrieval tools are necessary to access the
desired materials that surpass the effectiveness of traditional, allinclusive
search engines. This paper discusses the design and use of
Folksemantic, a platform that integrates OpenCourseWare search,
Open Educational Resource recommendations, and social network
functionality into a single open source project. The paper describes
how the system was originally envisioned, its goals for users, and
data that provides insight into how it is actually being used. Data
sources include website click-through data, query logs, web server
log files and user account data. Based on a descriptive analysis of its
current use, modifications to the platform's design are recommended
to better address goals of the system, along with recommendations
for additional phases of research.
Abstract: Non-premixed turbulent combustion Computational Fluid Dynamics (CFD) has been carried out in a simplified methanefuelled coaxial jet combustor employing Large Eddy Simulation (LES). The objective of this study is to evaluate the performance of LES in modelling non-premixed combustion using a commercial software, FLUENT, and investigate the effects of the grid density and chemistry models employed on the accuracy of the simulation results. A comparison has also been made between LES and Reynolds Averaged Navier-Stokes (RANS) predictions. For LES grid sensitivity test, 2.3 and 6.2 million cell grids are employed with the equilibrium model. The chemistry model sensitivity analysis is achieved by comparing the simulation results from the equilibrium chemistry and steady flamelet models. The predictions of the mixture fraction, axial velocity, species mass fraction and temperature by LES are in good agreement with the experimental data. The LES results are similar for the two chemistry models but influenced considerably by the grid resolution in the inner flame and near-wall regions.
Abstract: The significance of environmental protection is wellknown in today's world. The execution of any program depends on sufficient knowledge and required familiarity with environment and its pollutants. Taking advantage of a systematic method, as a new science, in environmental planning can solve many problems. In this article, air pollution in Tehran and its relationship with health and population growth have been analyzed using dynamic systems. Firstly, by using casual loops, the relationship between the parameters effective on air pollution in Tehran were taken into consideration, then these casual loops were turned into flow diagrams [6], and finally, they were simulated using the software Vensim [16]in order to conclude what the effect of each parameter will be on air pollution in Tehran in the next 10 years, how changing of one or more parameters influences other parameters, and which parameter among all other parameters requires to be controlled more.
Abstract: As the advancement of technology, online shopping channel develops rapidly in recent years. According to the report of Taiwan Network Information Center, there are almost eighty percents of internet population shopping in online channel. Synthesizing insights from the previous research, this study develops the conceptual model to integrate Theory of Perceived Risk (TPR) and Technology Acceptance Model (TAM) to apply in online shopping. Using data collected from 637 respondents from online survey website, we use structural equation modeling to test measurement and structural models. The results suggest the need for consideration of perceived risk as an antecedent in the Technology Acceptance Model. The limitations and implications are discussed.
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: 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: 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: RFID system, in which we give identification number to each item and detect it with radio frequency, supports more variable service than barcode system can do. For example, a refrigerator with RFID reader and internet connection will automatically notify expiration of food validity to us. But, in spite of its convenience, RFID system has some security threats, because anybody can get ID information of item easily. One of most critical threats is privacy invasion. Existing privacy protection schemes or systems have been proposed, and these schemes or systems defend normal users from attempts that any attacker tries to get information using RFID tag value. But, these systems still have weakness that attacker can get information using analogous value instead of original tag value. In this paper, we mention this type of attack more precisely and suggest 'Tag Broker Model', which can defend it. Tag broker in this model translates original tag value to random value, and user can only get random value. Attacker can not use analogous tag value, because he/she is not able to know original one from it.
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: 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: 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: This paper features the trajectory planning design of a indigenously developed 4-Axis SCARA robot which is used for doing successful robotic manipulation task in the laboratory. Once, a trajectory is being designed and given as input to the robot, the robot's gripper tip moves along that specified trajectory. Trajectories have to be designed in the work space only. The main idea of this paper is to design a continuous path trajectory model for the indigenously developed SCARA robot arm during its maneuvering from one point to another point (during pick and place operations) in a workspace avoiding all the obstacles in its path of motion.
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: Web-based systems have become increasingly
important due to the fact that the Internet and the World Wide Web
have become ubiquitous, surpassing all other technological
developments in our history. The Internet and especially companies
websites has rapidly evolved in their scope and extent of use, from
being a little more than fixed advertising material, i.e. a "web
presences", which had no particular influence for the company's
business, to being one of the most essential parts of the company's
core business.
Traditional software engineering approaches with process models
such as, for example, CMM and Waterfall models, do not work very
well since web system development differs from traditional
development. The development differs in several ways, for example,
there is a large gap between traditional software engineering designs
and concepts and the low-level implementation model, many of the
web based system development activities are business oriented (for
example web application are sales-oriented, web application and
intranets are content-oriented) and not engineering-oriented.
This paper aims to introduce Increment Iterative extreme
Programming (IIXP) methodology for developing web based
systems. In difference to the other existence methodologies, this
methodology is combination of different traditional and modern
software engineering and web engineering principles.
Abstract: We present a preliminary x-ray study on human-hair
microstructures for a health-state indicator, in particular a cancer
case. As an uncomplicated and low-cost method of x-ray technique,
the human-hair microstructure was analyzed by wide-angle x-ray
diffractions (XRD) and small-angle x-ray scattering (SAXS). The
XRD measurements exhibited the simply reflections at the d-spacing
of 28 Å, 9.4 Å and 4.4 Å representing to the periodic distance of the
protein matrix of the human-hair macrofibrous and the diameter and
the repeated spacing of the polypeptide alpha helixes of the
photofibrils of the human-hair microfibrous, respectively. When
compared to the normal cases, the unhealthy cases including to the
breast- and ovarian-cancer cases obtained higher normalized ratios of
the x-ray diffracting peaks of 9.4 Å and 4.4 Å. This likely resulted
from the varied distributions of microstructures by a molecular
alteration. As an elemental analysis by x-ray fluorescence (XRF), the
normalized quantitative ratios of zinc(Zn)/calcium(Ca) and
iron(Fe)/calcium(Ca) were determined. Analogously, both Zn/Ca and
Fe/Ca ratios of the unhealthy cases were obtained higher than both of
the normal cases were. Combining the structural analysis by XRD
measurements and the elemental analysis by XRF measurements
exhibited that the modified fibrous microstructures of hair samples
were in relation to their altered elemental compositions. Therefore,
these microstructural and elemental analyses of hair samples will be
benefit to associate with a diagnosis of cancer and genetic diseases.
This functional method would lower a risk of such diseases by the
early diagnosis. However, the high-intensity x-ray source, the highresolution
x-ray detector, and more hair samples are necessarily
desired to develop this x-ray technique and the efficiency would be
enhanced by including the skin and fingernail samples with the
human-hair analysis.