Abstract: In the present work, the effect of load and sliding
distance on the performance tribology of commercially used
aluminium-silicon engine block and piston was evaluated at ambient
conditions with humidity of 80% under dry sliding conditions using a
pin-on-disc with two different loads of 5N and 20N yielding applied
pressure of 0.30MPa and 1.4MPa, respectively, at sliding velocity of
0.29ms-1 and with varying sliding distance ranging from 260m-
4200m. Factors and conditions that had significant effect were
identified. The results showed that the load and the sliding distance
affect the wear rate of the alloys and the wear rate increased with
increasing load for both the alloys. Wear rate also increases almost
linearly at low loads and increase to a maximum then attain a plateau
with increasing sliding distance. For both applied loads the piston
alloy showed the better performance due to higher Ni and Mg
content. The worn surface and wear debris was characterized by
optical microscope, SEM and EDX analyzer. The worn surface was
characterized by surface with shallow grooves at loads while the
groove width and depth increased as the loads increases. Oxidative
wear was found to be the predominant mechanisms in the dry sliding
of Al-Si alloys at low loads.
Abstract: Heavy metals are one of the major groups of
contaminants in the environment and many of them are toxic even at
very low concentration in plants and animals. However, some metals
play important roles in the biological function of many enzymes in
living organisms. Metals such as zinc, iron, and cooper are important
for survival and activity of enzymes in plants, however heavy metals
can inhibit enzyme which is responsible for defense system of plants.
Polyphenol oxidase (PPO) is a copper-containing metalloenzyme
which is responsible for enzymatic browning reaction of plants.
Enzymatic browning is a major problem for the handling of
vegetables and fruits in food industry. It can be increased and
effected with many different futures such as metals in the nature and
ground. In the present work, PPO was isolated and characterized
from green leaves of red poppy plant (Papaverr hoeas). Then, the
effect of some known antibrowning agents which can form
complexes with metals and metals were investigated on the red poppy
PPO activity. The results showed that glutathione was the most
potent inhibitory effect on PPO activity. Cu(II) and Fe(II) metals
increased the enzyme activities however, Sn(II) had the maximum
inhibitory effect and Zn(II) and Pb(II) had no significant effect on the
enzyme activity. In order to reduce the effect of heavy metals, the
effects of metal-antibrowning agent complexes on the PPO activity
were determined. EDTA and metal complexes had no significant
effect on the enzyme. L-ascorbic acid and metal complexes decreased
but L-ascorbic acid-Cu(II)-complex had no effect. Glutathione–metal
complexes had the best inhibitory effect on Red poppy leaf PPO
activity.
Abstract: The aim of the paper was to elaborate a novel calculator BasWilCalc, that allows to estimate the actual amount of biomass on the basket willow plantations. The proposed method is based on the results of field experiment conducted during years 2011-2013 on basket willow plantation in the south-western part of Poland. As input data the results of destructive measurements of the diameter, length and weight of willow stems and non-destructive biometric measurements of diameter in the middle of stems and their length during the growing season performed at weekly intervals were used. Performed analysis enabled to develop the algorithm which, due to the fact that energy plantations are of known and constant planting structure, allows to estimate the actual amount of willow basket biomass on the plantation with a given probability and accuracy specified by the model, based on the number of stems measured and the age of the plantation.
Abstract: The mathematical analysis on radiation obtained and
the development of the solar photovoltaic (PV) array groundwater
pumping is needed in the rural areas of Thohoyandou for sizing and
power performance subject to the climate conditions within the area.
A simple methodology approach is developed for the directed
coupled solar, controller and submersible ground water pump system.
The system consists of a PV array, pump controller and submerged
pump, battery backup and charger controller. For this reason, the
theoretical solar radiation is obtained for optimal predictions and
system performance in order to achieve different design and
operating parameters. Here the examination of the PV schematic
module in a Direct Current (DC) application is used for obtainable
maximum solar power energy for water pumping. In this paper, a
simple efficient photovoltaic water pumping system is presented with
its theoretical studies and mathematical modeling of photovoltaics
(PV) system.
Abstract: This paper is about method to produce a stable and
accurate constant output pulse width regardless of the amplitude,
period and pulse width variation of the input signal source. The pulse
generated is usually being used in numerous applications as the
reference input source to other circuits in the system. Therefore, it is
crucial to produce a clean and constant pulse width to make sure the
system is working accurately as expected.
Abstract: Calcium phosphate coating (CaP) has been employed
for protein delivery, but the typical direct protein adsorption on the
coating led to low incorporation content and fast release of the
protein from the coating. By using bovine serum albumin (BSA) as a
model protein, rapid biomimetic co-precipitation between calcium
phosphate and BSA was employed to control the distribution of BSA
within calcium phosphate coating during biomimetic formation on
titanium surface for only 6 h at 50oC in an accelerated calcium
phosphate solution. As a result, the amount of BSA incorporation and
release duration could be increased by using a rapid biomimetic coprecipitation
technique. Up to 43 fold increases in the BSA
incorporation content and the increase from 6 h to more than 360 h in
release duration compared to typical direct adsorption technique were
observed depending on the initial BSA concentration used during coprecipitation
(1, 10 and 100 μg.ml-1). From x-ray diffraction and
Fourier transform infrared spectroscopy studies, the coating
composition was not altered with the incorporation of BSA by this
rapid biomimetic co-precipitation and mainly comprised octacalcium
phosphate and hydroxyapatite. However, the microstructure of
calcium phosphate crystals changed from straight, plate-like units to
curved, plate-like units with increasing BSA content.
Abstract: The article presents the concept of an electromagnetic
circuit generator with permanent magnets mounted on the surface
rotor core designed for single phase work. Computation field-circuit
model was shown. The spectrum of time course of voltages in the
idle work was presented. The cross section with graphically
presentation of magnetic induction in particular parts of
electromagnetic circuits was presented. Distribution of magnetic
induction at the rated load point for each phase was shown. The time
course of voltages and currents for each phases for rated power were
displayed. An analysis of laboratory results and measurement of load
characteristics of the generator was discussed. The work deals with
three electromagnetic circuits of generators with permanent magnet
where output voltage characteristics versus rated power were
expressed.
Abstract: The purpose of this research is to study of consumer
perception and understanding consumer buying behavior that related
between satisfied and factors affecting the purchasing. Methodology
can be classified between qualitative and quantitative approaches for
the qualitative research were interviews from middlemen who bought
organic vegetables, and middlemen related to production and
marketing system. A questionnaire was utilized as a tool to collect
data. Statistics utilized in this research included frequency,
percentage, mean, standard deviation, and multiple regression
analysis. The result show the reason to decision buying motives is
Fresh products of organic vegetables is the most significant factor on
individuals’ income, with a b of –.143, t = –2.470, the price of
organic vegetables is the most significant factor on individuals’
income, with a b of .176, t = 2.561, p value = .011. The results show
that most people with higher income think about the organic products
are expensive and have negative attitudes towards organic vegetable
as individuals with low and medium income level. Therefore,
household income had a significant influence on the purchasing
decision.
Abstract: The purpose of this research was to identify factors
that influenced the success of e-commerce implementation within
SMEs businesses. In order to achieve the objectives of this research,
the researcher collected data from random firms in Thailand, both the
users and those who are not using the e-commerce. The data was
comprised of the results of 310 questionnaires, as well as 10
interviews with owner/managers of businesses who are currently
using e-commerce successfully. The data were analyzed by using
descriptive statistics, which included frequency, percentages, mean,
and the standard deviation of pertinent factors. Independent t-test and
one-way ANOVA test were also used. The findings of this research
revealed that 50% of all the firms surveyed had e-commerce website,
whereas, over 20% of all firms surveyed had developing an ecommerce
strategy. The result findings also indicate that
organizational factors, technological factors and environment factors
as significant factors effecting success of e-commerce
implementation in SMEs. From the hypotheses testing, the findings
revealed that the different level of support use ecommerce by
owner/manager had different success in e-commerce implementation.
Moreover, the difference in e-commerce management approach
affected the success in terms of higher total sales for the business or
higher number of retained or returning customers.
Abstract: Copper being one of the major intrinsic residual
impurities in steel possesses the tendency to induce severe
microstructural distortions if not controlled within certain limits.
Hence, this paper investigates the effect of this element on the
mechanical properties of construction steel with a view to ascertain
its safe limits for effective control. The experiment entails collection
of statistically scheduled samples of hot rolled profiles with varied
copper concentrations in the range of 0.12-0.39 wt. %. From these
samples were prepared standard test specimens subjected to tensile,
impact, hardness and microstructural analyses. Results show a rather
huge compromise in mechanical properties as the specimens
demonstrated 54.3%, 74.2% and 64.9% reduction in tensile strength,
impact energy and hardness respectively as copper content increases
from 0.12 wt. % to 0.39 wt. %. The steel’s abysmal performance is
due to the severe distortion of the microstructure occasioned by the
development of incoherent complex compounds which weaken the
pearlite reinforcing phase. It is concluded that the presence of copper
above 0.22 wt. % is deleterious to construction steel performance.
Abstract: Mass flow measurement is the basis of most technoeconomic
formulations in the chemical industry. This calls for
reliable and accurate detection of mass flow. Flow measurement
laboratory experiments were conducted using various instruments.
These consisted of orifice plates, various sized rotameters, wet gas
meter and soap bubble meter. This work was aimed at evaluating
appropriate operating conditions and accuracy of the aforementioned
devices. The experimental data collected were compared to
theoretical predictions from Bernoulli’s equation and calibration
curves supplied by the instrument’s manufacturers. The results
obtained showed that rotameters were more reliable for measuring
high and low flow rates; while soap-bubble meters and wet-gas
meters were found to be suitable for measuring low flow rates. The
laboratory procedures and findings of the actual work can assist
engineering students and professionals in conducting their flow
measurement laboratory test work.
Abstract: For a given a simple connected graph, we present
some new bounds via a new approach for a special topological index
given by the sum of the real number power of the non-zero
normalized Laplacian eigenvalues. To use this approach presents an
advantage not only to derive old and new bounds on this topic but
also gives an idea how some previous results in similar area can be
developed.
Abstract: An anthropometric study applied to 1,115 students of
the Faculty of Chemical Sciences and Engineering of the
Autonomous University of California. Thirteen individual
measurements were taken in a sitting position. The results obtained
allow forming a reliable anthropometric database for statistical
studies and analysis and inferences of specific distributions, so the
opinion of experts in occupational medicine recommendations may
emit to reduce risks resulting in an alteration of the vital signs during
the execution of their school activities. Another use of these analyses
is to use them as a reliable reference for future deeper research, to the
design of spaces, tools, utensils, workstations, with anthropometric
dimensions and ergonomic characteristics suitable to use.
Abstract: This paper presents an anthropometric study
conducted to 300 employees in a maquiladora industry that belongs
to the cluster of medical products as part of a research project to
pretend simulate workplace conditions under which operators
conduct their activities. This project is relevant because traditionally
performed a study to design ergonomic workspaces according to
anthropometric profile of users, however, this paper demonstrates the
importance of making decisions when the infrastructure cannot be
adapted for economic whichever put emphasis on user activity.
Abstract: Economic Dispatch (ED) is one of the most
challenging problems of power system since it is difficult to determine
the optimum generation scheduling to meet the particular load demand
with the minimum fuel costs while all constraints are satisfied. The
objective of the Economic Dispatch Problems (EDPs) of electric
power generation is to schedule the committed generating units
outputs so as to meet the required load demand at minimum operating
cost while satisfying all units and system equality and inequality
constraints. In this paper, an efficient and practical steady-state genetic
algorithm (SSGAs) has been proposed for solving the economic
dispatch problem. The objective is to minimize the total generation
fuel cost and keep the power flows within the security limits. To
achieve that, the present work is developed to determine the optimal
location and size of capacitors in transmission power system where,
the Participation Factor Algorithm and the Steady State Genetic
Algorithm are proposed to select the best locations for the capacitors
and determine the optimal size for them.
Abstract: In this work, we propose the application of Japanese
“Origami” art for a floating function of a small aerial vehicle such as a
hexarotor. A preliminary experiment was conducted using Origami
magic balls mounted under a hexarotor. This magic ball can expand
and shrink using an air pump during free flying. Using this interesting
and functional concept, it promises to reduce the resistance of wind as
well as reduce the energy consumption when the Origami balls are
deflated. This approach can be particularly useful in rescue emergency
situations. Furthermore, there are many unexpected reasons that may
cause the multi-rotor has to land on the surface of water due to
problems with the communication between the aircraft and the ground
station. In addition, a complementary experiment was designed to
prove that the hexarotor can fly maintaining the stability and also,
takes off and lands on the surface of water using air balloons.
Abstract: No matter how much perfect we become in our
practical skills regarding the implementation of learned ideas, the
need of technical writing capability cannot be neglected being a
professional. Technical writing is a way of communicating the ideas
in written which otherwise need to be presented orally. Technical
writing skills have always been the need of the time, as they are
required for internal as well as external official communication in
both formal and informal manner. Moreover, they are the best way to
capture the attention of your customers by presenting information in
effective manner. This paper aims to analyze the importance of
technical writing skills in professional industries of Pakistan by
conducting a survey. Survey results presented in this paper clearly
depicts the importance of formal and informal written communication
media used in different professional industries in Pakistan. Analysis
and discussion of the extent to which the alternative ways of
communication besides technical writing have got importance in
Pakistan is also an important aspect of this survey.
Abstract: Historical and ancestral bonds of the countries in the
Middle East have led to similarities in culture and context of their
societies. In addition, economical resources, such as the oil industry,
have generally been an integrative point in the region. Higher
education of a country is influenced by different national and
international factors and, regarding the mentioned bonds, it is inviting
to study the development of the countries of the Middle East in
higher education and draw some practical implications which can be
used in the educational policymaking of the region. This review
includes a data analysis on the population of international students in
the countries of the Middle East. As its second objective, a review
study on the successful countries, that is, those which host the highest
number of international students, and the strategies they have
developed to reach this state among the countries of the region, has
been conducted. Suggestions are made as to the strategies in higher
education systems of these countries which could prove useful and
practical in the development of internationalization of higher
education in the region, specifically with regard to the recruitment of
international students.
Abstract: Ficus deltoidea from the Moraceae family is a popular
medicinal herb in Malaysia. It possesses strong antioxidant and antiinflammatory
properties. In the present study, the anti-inflammatory
effects of F. deltoidea extract on UVB-irradiated HaCaT
Keratinocytes were investigated. HaCaT Keratinocytes were UVBirradiated
(12.5 mJ/cm3) and were treated with 0.05, 0.08 or 0.1% of
F. deltoidea extract. Cell viability following UVB irradiation was
significantly higher in the groups treated with the F. deltoidea extract
at doses of 0.05, 0.08 or 0.1% than in control group with UVB
irradiation only. Tumor necrosis factor-α (TNF-α), interleukin-1α
(IL-1α), interleukin-6 (IL-6) and cyclooxygenase (COX-2) play
primary roles in the inflammation process upon UV irradiation and
are known to be stimulated by UVB irradiation. Treatment with the
F. deltoidea extract dramatically inhibited the UV-induced TNF-α,
IL-1α, IL-6, and COX-2 expression. These results suggest that the F.
deltoidea extract inhibits the production of pro-inflammatory
cytokines and may be an effective protective agent for the treatment
of skin diseases.
Abstract: This entry concerned with dense silica bricks
microstructure was produced as a part of a project within the
Technology Agency of the Czech Republic which is being
implemented in cooperation of the biggest producer of refractories
the P-D Refractories CZ company with the research organisation
Brno University of Technology. The paper is focused on the
influence of mixture homogenisation and the influence of grain size
of the mineraliser on the resulting utility properties of the material as
well as its microstructure. It has a decisive influence on the durability
of the material in a building structure. This paper is a continuation of
a previously published study dealing with the suitability of various
types of mineralising agents in terms of density, strength and mineral
composition of silica brick.
The entry describes the influence of the method of mixture
homogenisation and the influence of granulometry of the applied Femineralising
agent on the resulting silica microstructure. Porosity,
density, phase composition and microstructure of the experimentally
prepared silica bricks samples were examined and the results were
discussed in context with the technology of homogenisation and
firing temperature used. The properties of silica bricks samples were
compared to the sample without any Fe-mineraliser.