Abstract: Carbon Fiber Reinforced Plastics (CFRPs) are widely
used for advanced applications, in particular in aerospace, automotive
and wind energy industries. Once cured to near net shape, CFRP
parts need several finishing operations such as trimming, milling or
drilling in order to accommodate fastening hardware and meeting the
final dimensions. The present research aims to study the effect of the
cutting temperature in trimming on the mechanical strength of high
performance CFRP laminates used for aeronautics applications. The
cutting temperature is of great importance when dealing with
trimming of CFRP. Temperatures higher than the glass-transition
temperature (Tg) of the resin matrix are highly undesirable: they
cause degradation of the matrix in the trimmed edges area, which can
severely affect the mechanical performance of the entire component.
In this study, a 9.50mm diameter CVD diamond coated carbide tool
with six flutes was used to trim 24-plies CFRP laminates. A
300m/min cutting speed and 1140mm/min feed rate were used in the
experiments. The tool was heated prior to trimming using a
blowtorch, for temperatures ranging from 20°C to 300°C. The
temperature at the cutting edge was measured using embedded KType
thermocouples. Samples trimmed for different cutting
temperatures, below and above Tg, were mechanically tested using
three-points bending short-beam loading configurations. New cutting
tools as well as worn cutting tools were utilized for the experiments.
The experiments with the new tools could not prove any correlation
between the length of cut, the cutting temperature and the mechanical
performance. Thus mechanical strength was constant, regardless of
the cutting temperature. However, for worn tools, producing a cutting
temperature rising up to 450°C, thermal damage of the resin was
observed. The mechanical tests showed a reduced mean resistance in
short beam configuration, while the resistance in three point bending
decreases with increase of the cutting temperature.
Abstract: Rapid prototyping is a new group of manufacturing
processes, which allows fabrication of physical of any complexity
using a layer by layer deposition technique directly from a computer
system. The rapid prototyping process greatly reduces the time and
cost necessary to bring a new product to market. The prototypes
made by these systems are used in a range of industrial application
including design evaluation, verification, testing, and as patterns for
casting processes. These processes employ a variety of materials and
mechanisms to build up the layers to build the part. The present work
was to build a FDM prototyping machine that could control the X-Y
motion and material deposition, to generate two-dimensional and
three-dimensional complex shapes. This study focused on the
deposition of wax material. This work was to find out the properties
of the wax materials used in this work in order to enable better
control of the FDM process. This study will look at the integration of
a computer controlled electro-mechanical system with the traditional
FDM additive prototyping process. The characteristics of the wax
were also analysed in order to optimise the model production process.
These included wax phase change temperature, wax viscosity and
wax droplet shape during processing.
Abstract: The ferrites ZnFe2O4, CdFe2O4 and CuFe2O4 are
synthesized in laboratory conditions using ceramic technology. Their
homogeneity and structure are proven by X-Ray diffraction analysis
and Mössbauer spectroscopy. The synthesized ferrites are subjected
to strong acid and high temperature leaching with solutions of H2SO4,
HCl and HNO3. The results indicate that the highest degree of
leaching of Zn, Cd and Cu from the ferrites is achieved by use of
HCl. The charging of five zinc sulfide concentrates was optimized using
the criterion of minimal amount of zinc ferrite produced when
roasting the concentrates in a fluidized bed. The results obtained are
interpreted in terms of the hydrometallurgical zinc production and
maximum recovery of zinc, copper and cadmium from initial zinc
concentrates after their roasting.
Abstract: In recent years, the power system has been changed
and a flexible power pricing system such as demand response has been
sought in Japan. The demand response system works simply in the
household sector and the owner as the decision-maker, can benefit
from power saving. On the other hand, the execution of demand
response in the office building is more complex than in the household
because various people such as owners, building administrators and
occupants are involved in the decision-making process. While the
owners benefit from demand saving, the occupants are exposed to
restricted benefits of a demand-saved environment. One of the reasons
is that building systems are usually under centralized management and
each occupant cannot choose freely whether to participate in demand
response or not. In addition, it is unclear whether incentives give
occupants the motivation to participate. However, the recent
development of IT and building systems enables the personalized
control of the office environment where each occupant can control the
lighting level or temperature individually. Therefore, it can be possible
to have a system which each occupant can make a decision of whether
or not to participate in demand response in the office building. This study investigates personal responses to demand response
requests, under the condition where each occupant can adjust their
brightness individually in their workspace. Once workers participate
in the demand response, their desk-lights are automatically turned off.
The participation rates in the demand response events are compared
among four groups, which are divided by different motivation, the
presence, or absence of incentives and the method of participation. The
result shows that there are significant differences of participation rates
in demand response event between four groups. The method of
participation has a large effect on the participation rate. The “Opt-out”
groups where the occupants are automatically enrolled in a demand
response event if they do not express non-participation have the
highest participation rate in the four groups. Incentives also have an
effect on the participation rate. This study also reports on the impact of low illumination office
environment on the occupants, such as stress or fatigue. The
electrocardiogram and the questionnaire are used to investigate the
autonomic nervous activity and subjective fatigue symptoms of the
occupants. There is no big difference between dim workspace during
demand response event and bright workspace in autonomic nervous
activity and fatigue.
Abstract: The activation volume of 6082T6 aluminum is
investigated at different temperatures for grain size variants. The
deformation activation volume was computed on the basis of the
relationship between the Boltzmann’s constant k, the testing
temperatures, the material strain rate sensitivity and the material yield
stress grain size variants. The material strain rate sensitivity is
computed as a function of yield stress and strain rate grain size
variants. The effect of the material strain rate sensitivity and the
deformation activation volume of 6082T6 aluminum at different
temperatures of 3-D grain are discussed. It is shown that the strain rate sensitivities and activation volume
are negative for the grain size variants during the deformation of
nanostructured materials. It is also observed that the activation
volume vary in different ways with the equivalent radius, semi minor
axis radius, semi major axis radius and major axis radius. From the
obtained results it is shown that the variation of activation volume
increase and decrease with the testing temperature. It was revealed
that, increase in strain rate sensitivity led to decrease in activation
volume whereas increase in activation volume led to decrease in
strain rate sensitivity.
Abstract: In this study, we examine some spectral properties
of non-selfadjoint matrix-valued difference equations consisting of
a polynomial-type Jost solution. The aim of this study is to
investigate the eigenvalues and spectral singularities of the difference
operator L which is expressed by the above-mentioned difference
equation. Firstly, thanks to the representation of polynomial type Jost
solution of this equation, we obtain asymptotics and some analytical
properties. Then, using the uniqueness theorems of analytic functions,
we guarantee that the operator L has a finite number of eigenvalues
and spectral singularities.
Abstract: Myocardial infarction is one of the leading causes of
death in the world. Some of these deaths occur even before the
patient reaches the hospital. Myocardial infarction occurs as a result
of impaired blood supply. Because the most of these deaths are due to
coronary artery disease, hence the awareness of the warning signs of
a heart attack is essential. Some heart attacks are sudden and intense,
but most of them start slowly, with mild pain or discomfort, then
early detection and successful treatment of these symptoms is vital to
save them. Therefore, importance and usefulness of a system
designing to assist physicians in early diagnosis of the acute heart
attacks is obvious. The main purpose of this study would be to enable patients to
become better informed about their condition and to encourage them
to seek professional care at an earlier stage in the appropriate
situations. For this purpose, the data were collected on 711 heart
patients in Iran hospitals. 28 attributes of clinical factors can be
reported by patients; were studied. Three logistic regression models
were made on the basis of the 28 features to predict the risk of heart
attacks. The best logistic regression model in terms of performance
had a C-index of 0.955 and with an accuracy of 94.9%. The variables,
severe chest pain, back pain, cold sweats, shortness of breath, nausea
and vomiting, were selected as the main features.
Abstract: On account of the concern of the fossil fuel is
depleting and its negative effects on the environment, interest in
alternative energy sources is increasing day by day. However,
considering the importance of transportation in human life, instead of
oil and its derivatives fueled vehicles with internal combustion
engines, electric vehicles which are sensitive to the environment and
working with electrical energy has begun to develop. In this study,
simulation was carried out for providing energy management and
recovering regenerative braking in fuel cell-battery hybrid electric
vehicle. The main power supply of the vehicle is fuel cell on the other
hand not only instantaneous power is supplied by the battery but also
the energy generated due to regenerative breaking is stored in the
battery. Obtained results of the simulation is analyzed and discussed.
Abstract: Dead wood and habitat tree such as fallen logs, snags,
stumps and cracks and loos bark etc. are regarded as an important
ecological component of forests on which many forest dwelling
species depend on presence of them within forest ecosystems.
Meanwhile its relation to management history in Caspian forest has
gone unreported. The aim of research was to compare the amounts of
dead wood and habitat trees in the forests with historically different
intensities of management, including: forests with the long term
implication of management (PS), the short term implication of
management (NS) which were compared with semi virgin forest
(GS). The number of 405 individual dead and habitat trees were
recorded and measured at 109 sampling locations. ANOVA revealed
volume of dead tree in the form and decay classes significantly differ
within sites and dead volume in the semi virgin forest significantly
higher than managed sites. Comparing the amount of dead and
habitat tree in three sites showed that, dead tree volume related with
management history and significantly differ in three study sites.
Meanwhile, frequency of habitat trees was significantly different
within sites. The highest amount of habitat trees including cavities,
cracks and loose bark and fork split trees was recorded in virgin site
and lowest recorded in the sites with the long term implication of
management. It can be concluded that forest management cause
reduction of the amount of dead and habitat tree specially in a large
size, thus managing this forest according to ecological sustainable
principles require a commitment to maintaining stand structure that
allow, continued generation of dead trees in a full range of size.
Abstract: One of the tasks of optical surveillance is to detect
anomalies in large amounts of image data. However, if the size of the
anomaly is very small, limited information is available to distinguish
it from the surrounding environment. Spectral detection provides a
useful source of additional information and may help to detect
anomalies with a size of a few pixels or less. Unfortunately, spectral
cameras are expensive because of the difficulty of separating two
spatial in addition to one spectral dimension. We investigate the
possibility of modifying a simple spectral line detector for outdoor
detection. This may be especially useful if the area of interest forms a
line, such as the horizon. We use a monochrome CCD that also
enables detection into the near infrared. A simple camera is attached
to the setup to determine which part of the environment is spectrally
imaged. Our preliminary results indicate that sensitive detection of
very small targets is indeed possible. Spectra could be taken from the
various targets by averaging columns in the line image. By imaging a
set of lines of various widths we found narrow lines that could not be
seen in the color image but remained visible in the spectral line
image. A simultaneous analysis of the entire spectra can produce
better results than visual inspection of the line spectral image. We are
presently developing calibration targets for spatial and spectral
focusing and alignment with the spatial camera. This will present
improved results and more use in outdoor application.
Abstract: The reheating furnace is used to reheat the steel slabs
before the hot-rolling process. The supported system includes the
stationary/moving beams, and the skid buttons which block some
thermal radiation transmitted to the bottom of the slabs. Therefore, it is
important to analyze the steel slab temperature distribution during the
heating period. A three-dimensional mathematical transient heat
transfer model for the prediction of temperature distribution within the
slab has been developed. The effects of different skid button height
(H=60mm, 90mm, and 120mm) and different gap distance between
two slabs (S=50mm, 75mm, and 100mm) on the slab skid mark
formation and temperature profiles are investigated. Comparison with
the in-situ experimental data from Steel Company in Taiwan shows
that the present heat transfer model works well for the prediction of
thermal behavior of the slab in the reheating furnace. It is found that
the skid mark severity decreases with an increase in the skid button
height. The effect of gap distance is important only for the slab edge
planes, while it is insignificant for the slab central planes.
Abstract: This paper presents the influence of the vertical
seismic component on the non-linear dynamics analysis of three
different structures. The subject structures were analyzed and
designed according to recent codes. This paper considers three types
of buildings: 5-, 10-, and 15-story buildings. The non-linear
dynamics analysis of the structures with assuming elastic-perfectlyplastic
behavior was performed using RAM PERFORM-3D software;
the horizontal component was taken into consideration with and
without the incorporation of the corresponding vertical component.
Dynamic responses obtained for the horizontal component acting
alone were compared with those obtained from the simultaneous
application of both seismic components. The results show that the
effect of the vertical component of ground motion may increase the
axial load significantly in the interior columns and, consequently, the
stories. The plastic mechanisms would be changed. The P-Delta
effect is expected to increase. The punching base plate shear of the
columns should be considered. Moreover, the vertical component
increases the input energy when the structures exhibit inelastic
behavior and are taller.
Abstract: Automated Teller Machines (ATMs) can be
considered among one of the most important service facilities in the
banking industry. The investment in ATMs and the impact on the
banking industry is growing steadily in every part of the world. The
banks take into consideration many factors like safety, convenience,
visibility, and cost in order to determine the optimum locations of
ATMs. Today, ATMs are not only available in bank branches but
also at retail locations. Another important factor is the cash
management in ATMs. A cash demand model for every ATM is
needed in order to have an efficient cash management system. This
forecasting model is based on historical cash demand data which is
highly related to the ATMs location. So, the location and the cash
management problem should be considered together. This paper
provides a general review on studies, efforts and development in
ATMs location and cash management problem.
Abstract: Wicking and evaporation of water in porous knitted fabrics is investigated by combining experimental and analytical approaches: The standard wicking model from Lucas and Washburn is enhanced to account for evaporation and gravity effects. The goal is to model the effect of gravity and evaporation on wicking using simple analytical expressions and investigate the influence of fabrics geometrical parameters, such as porosity and thickness on evaporation impact on maximum reachable height values. The results show that fabric properties have a significant influence on evaporation effect. In this paper, an experimental study of determining water kinetics from different knitted fabrics were gravimetrically investigated permitting the measure of the mass and the height of liquid rising in fabrics in various atmospheric conditions. From these measurements, characteristic pore parameters (capillary radius and permeability) can be determined.
Abstract: Red pepper (Capsicum annum L.) has long been
recognized as a good source of antioxidants, being rich in ascorbic
acid and other phytochemicals. In Turkish cuisine red pepper is
sometimes consumed raw in salads and baked as a garnish, but its
most wide consumption type is red pepper paste. The processing of
red pepper into pepper paste includes various thermal treatment steps
such as heating and pasteurizing. There are reports demonstrating an
enhancement or reduction in antioxidant activity of vegetables after
thermal treatment. So this study was conducted to investigate the
total phenolic, ascorbic acid and total carotenoids as well as free
radical scavenging activity of raw red pepper and various red pepper
pastes obtainable on the market. The samples were analyzed for
radical-scavenging activity (RSA) and total polyphenol (TP) content
using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Folin-Ciocalteu
methods, respectively. Total carotenoids and ascorbic acid contents
were determined spectrophotometrically. Results suggest that hot
pepper paste contained significantly (P0.05) difference in RSA, ascorbic acid and total carotenoids
content between sweet and hot red pepper paste products. It is
concluded that the red pepper paste, that has a wide range of
consumption in Turkish cuisine, presents a good dose of phenolic
compounds and antioxidant capacity and it should be regarded as a
functional food.
Abstract: With the increasing population and intensive land use,
huge traffic demand is generating worldwide both in developing and
developed countries. As a developing country, Bangladesh is also
facing the same problem in recent years by producing huge numbers
of daily trips. As a matter of fact, extensive traffic demand is
increasing day by day. Also, transport system in Dhaka is
heterogeneous, reflecting the heterogeneity in the socio-economic
and land use patterns. Trips produced here are for different purposes
such as work, business, educational etc. Due to the significant
concentration of educational institutions a large share of the trips are
generated by educational purpose. And one of the major percentages
of educational trips is produced by university going students and
most of them are travelled by car, bus, train, taxi, rickshaw etc. The
aim of the study was to find out the university students’ perception on
public transit ridership. A survey was conducted among 330 students
from eight different universities. It was found out that 26% of the
trips produced by university going students are travelled by public
bus service and only 5% are by train. Percentage of car share is 16%
and 12% of the trips are travelled by private taxi. It has been
observed from the study, students those who prefer bus instead of
other options, 42 percent of their family resides outside Dhaka. And
those who prefer walking, of them, over 40 percent students’ family
reside outside of Dhaka and of them over 85 percent students have a
tendency to live in a mess. On the contrary, students travelling by car
represents, most of their family reside in Dhaka. The study also
revealed that the most important reason that restricts students not to
use public transit is poor service. Negative attitudes such as
discomfort, uneasiness in using public transit also reduces the usage
of public transit. The poor waiting area is another major cause of not
using public transit. Insufficient security also plays a significant role
in not using public transit. On the contrary, the fare is not a problem
for students those who use public transit as a mode of transportation.
Students also think stations are not far away from their home or
institution and they do not need to wait long for the buses or trains. It
was also found accessibility to public transit is moderate.
Abstract: An integrated modeling approach was used in this study for energy planning and climate change mitigation assessment. The main objective of this study was to develop various green-house gas (GHG) mitigations scenarios in the energy demand and supply sectors for the state of Florida. The Long range energy alternative planning (LEAP) model was used in this study to examine the energy alternative and GHG emissions reduction scenarios for short and long term (2010-2050). One of the energy analysis and GHG mitigation scenarios was developed by taking into account the available renewable energy resources potential for power generation in the state of Florida. This will help to compare and analyze the GHG reduction measure against “Business As Usual” and ‘State of Florida Policy” scenarios. Two master scenarios: “Electrification” and “Energy efficiency and Lifestyle” were developed through combination of various mitigation scenarios: technological changes and energy efficiency and conservation. The results show a net reduction of the energy demand and GHG emissions by adopting these two energy scenarios compared to the business as usual.
Abstract: A large variety of pipe flange is required in marine
and construction industry. Pipe flanges are usually welded or screwed
to the pipe end and are connected with bolts. This approach is very
simple and widely used for a long time; however, it results in high
development cost and low productivity, and the productions made by
this approach usually have safety problem at the welding area. In this
research, a new approach of forming pipe flange based on cold
forging and floating die concept is presented. This innovative
approach increases the effectiveness of the material usage and save
the time cost compared with conventional welding method. To ensure the dimensional accuracy of the final product, the finite
element analysis (FEA) was carried out to simulate the process of
cold forging, and the orthogonal experiment methods were used to
investigate the influence of four manufacturing factors (pin die angle,
pipe flange angle, rpm, pin die distance from clamp jig) and predicted
the best combination of them. The manufacturing factors were
obtained by numerical and experimental studies and it shows that the
approach is very useful and effective for the forming of pipe flange,
and can be widely used later.
Abstract: Objectives: To determine the nutritional status and
risk factors associated with women practicing geophagia in QwaQwa,
South Africa. Materials and Methods: An observational epidemiological study
design was adopted which included an exposed (geophagia) and nonexposed
(control) group. A food frequency questionnaire, anthropometric measurements and blood sampling were applied to
determine nutritional status of participants. Logistic regression
analysis was performed in order to identify factors that were likely to
be associated with the practice of geophagia. Results: The mean total energy intake for the geophagia group (G)
and control group (C) were 10324.31 ± 2755.00 kJ and 10763.94 ±
2556.30 kJ respectively. Both groups fell within the overweight
category according to the mean Body Mass Index (BMI) of each
group (G= 25.59 kg/m2; C= 25.14 kg/m2). The mean serum iron
levels of the geophagia group (6.929 μmol/l) were significantly lower
than that of the control group (13.75 μmol/l) (p = 0.000). Serum
transferrin (G=3.23g/l; C=2.7054g/l) and serum transferrin saturation
(G=8.05%; C=18.74%) levels also differed significantly between
groups (p=0.00). Factors that were associated with the practice of
geophagia included haemoglobin (Odds ratio (OR):14.50), serumiron
(OR: 9.80), serum-ferritin (OR: 3.75), serum-transferrin (OR:
6.92) and transferrin saturation (OR: 14.50). A significant negative
association (p=0.014) was found between women who were wageearners
and those who were not wage-earners and the practice of
geophagia (OR: 0.143; CI: 0.027; 0.755). These findings seem to
indicate that a permanent income may decrease the likelihood of
practising geophagia. Key Findings: Geophagia was confirmed to be a risk factor for
iron deficiency in this community. The significantly strong
association between geophagia and iron deficiency emphasizes the
importance of identifying the practice of geophagia in women,
especially during their child bearing years.
Abstract: Zinc borate is an important inorganic hydrate borate
material, which can be used as a flame retardant agent and corrosion
resistance material. This compound can loss its structural water
content at higher than 290°C. Due to thermal stability; Zinc Borate
can be used as flame retardant at high temperature process of plastic
and gum. In this study, the ultrasonic reaction of zinc borates were
studied using hydrozincite (Zn5(CO3)2·(OH)6) and boric acid
(H3BO3) raw materials. Before the synthesis raw materials were
characterized by X-Ray Diffraction (XRD) and Fourier Transform
Infrared Spectroscopy (FT-IR). Ultrasonic method is a new
application on the zinc borate synthesis. The synthesis parameters
were set to 90°C reaction temperature and 55 minutes of reaction
time, with 1:1, 1:2, 1:3, 1:4 and 1:5 molar ratio of starting materials
(Zn5(CO3)2·(OH)6 : H3BO3). After the zinc borate synthesis, the
products were analyzed by XRD and FT-IR. As a result, optimum
molar ratio of 1:5 is determined for the synthesis of zinc borates with
ultrasonic method.