Abstract: Large-scale machine tools for the manufacturing of
large work pieces, e.g. blades, casings or gears for wind turbines,
feature pose-dependent dynamic behavior. Small structural damping
coefficients lead to long decay times for structural vibrations that
have negative impacts on the production process. Typically, these
vibrations are handled by increasing the stiffness of the structure by
adding mass. This is counterproductive to the needs of sustainable
manufacturing as it leads to higher resource consumption both in
material and in energy. Recent research activities have led to higher
resource efficiency by radical mass reduction that is based on controlintegrated
active vibration avoidance and damping methods. These
control methods depend on information describing the dynamic
behavior of the controlled machine tools in order to tune the
avoidance or reduction method parameters according to the current
state of the machine. This paper presents the appearance, consequences and challenges
of the pose-dependent dynamic behavior of lightweight large-scale
machine tool structures in production. It starts with the theoretical
introduction of the challenges of lightweight machine tool structures
resulting from reduced stiffness. The statement of the pose-dependent
dynamic behavior is corroborated by the results of the experimental
modal analysis of a lightweight test structure. Afterwards, the
consequences of the pose-dependent dynamic behavior of lightweight
machine tool structures for the use of active control and vibration
reduction methods are explained. Based on the state of the art of
pose-dependent dynamic machine tool models and the modal
investigation of an FE-model of the lightweight test structure, the
criteria for a pose-dependent model for use in vibration reduction are
derived. The description of the approach for a general posedependent
model of the dynamic behavior of large lightweight
machine tools that provides the necessary input to the aforementioned
vibration avoidance and reduction methods to properly tackle
machine vibrations is the outlook of the paper.
Abstract: This study presents experimental and optimization of
nanoparticle mass concentration and heat input based on the total
thermal resistance (Rth) of loop heat pipe (LHP), employed for PCCPU
cooling. In this study, silica nanoparticles (SiO2) in water with
particle mass concentration ranged from 0% (pure water) to 1% is
considered as the working fluid within the LHP. The experimental
design and optimization is accomplished by the design of
experimental tool, Response Surface Methodology (RSM). The
results show that the nanoparticle mass concentration and the heat
input have significant effect on the Rth of LHP. For a given heat
input, the Rth is found to decrease with the increase of the
nanoparticle mass concentration up to 0.5% and increased thereafter.
It is also found that the Rth is decreased when the heat input is
increased from 20W to 60W. The results are optimized with the
objective of minimizing the Rth, using Design-Expert software, and
the optimized nanoparticle mass concentration and heat input are
0.48% and 59.97W, respectively, the minimum thermal resistance
being 2.66 (ºC/W).
Abstract: Excessive fretting wear at the taper-trunnion junction
(trunnionosis) apparently contributes to the high failure rates of hip
implants. Implant wear and corrosion lead to the release of metal
particulate debris and subsequent release of metal ions at the tapertrunnion
surface. This results in a type of metal poisoning referred to
as metallosis. The consequences of metal poisoning include;
osteolysis (bone loss), osteoarthritis (pain), aseptic loosening of the
prosthesis and revision surgery. Follow up after revision surgery,
metal debris particles are commonly found in numerous locations. Background: A stable connection between the femoral ball head
(taper) and stem (trunnion) is necessary to prevent relative motions
and corrosion at the taper junction. Hence, the importance of
component assembly cannot be over-emphasized. Therefore, the aim
of this study is to determine the influence of head-stem junction
assembly by press fitting and the subsequent
disengagement/disassembly on the connection strength between the
taper ball head and stem. Methods: CoCr femoral heads were assembled with High stainless
hydrogen steel stem (trunnion) by Push-in i.e. press fit; and
disengaged by pull-out test. The strength and stability of the two
connections were evaluated by measuring the head pull-out forces
according to ISO 7206-10 standards. Findings: The head-stem junction strength linearly increases with
assembly forces.
Abstract: Polycyclic Aromatic Hydrocarbons (PAHs) are
formed mainly because of incomplete combustion of organic
materials during industrial, domestic activities or natural occurrence.
Their toxicity and contamination of terrestrial and aquatic ecosystem
have been established. However, with limited validity index, previous
research has focused on PAHs isomer pair ratios of variable
physicochemical properties in source identification. The objective of
this investigation was to determine the empirical validity of Pearson
Correlation Coefficient (PCC) and Cluster Analysis (CA) in PAHs
source identification along soil samples of different land uses.
Therefore, 16 PAHs grouped, as Endocrine Disruption Substances
(EDSs) were determined in 10 sample stations in top and sub soils
seasonally. PAHs was determined the use of Varian 300 gas
chromatograph interfaced with flame ionization detector. Instruments
and reagents used are of standard and chromatographic grades
respectively. PCC and CA results showed that the classification of
PAHs along pyrolitic and petrogenic organics used in source
signature is about the predominance PAHs in environmental matrix.
Therefore, the distribution of PAHs in the studied stations revealed
the presence of trace quantities of the vast majority of the sixteen
PAHs, which may ultimately inhabit the actual source signature
authentication. Therefore, factors to be considered when evaluating
possible sources of PAHs could be; type and extent of bacterial
metabolism, transformation products/substrates, and environmental
factors such as salinity, pH, oxygen concentration, nutrients, light
intensity, temperature, co-substrates, and environmental medium are
hereby recommended as factors to be considered when evaluating
possible sources of PAHs.
Abstract: Well logging records can help to answer many
questions from a wide range of special interested information and
basic petrophysical properties to formation evaluation of oil and gas
reservoirs. The accurate calculations of porosity in carbonate
reservoirs are the most challenging aspects of the well logging
analysis. Many equations have been developed over the years based
on known physical principles or on empirically derived relationships,
which are used to calculate porosity, estimate lithology, and water
saturation; however these parameters are calculated from well logs by
using modern technique in a current study. Nasiriya oil field is one of
the giant oilfields in the Middle East, and the formation under study
is the Mishrif carbonate formation which is the shallowest
hydrocarbon bearing zone in this oilfield. Neurolog software was
used to digitize the scanned copies of the available logs.
Environmental corrections had been made as per Schlumberger charts
2005, which supplied in the Interactive Petrophysics software. Three
saturation models have been used to calculate water saturation of
carbonate formations, which are simple Archie equation, Dual water
model, and Indonesia model. Results indicate that the Mishrif
formation consists mainly of limestone, some dolomite, and shale.
The porosity interpretation shows that the logging tools have a good
quality after making the environmental corrections. The average
formation water saturation for Mishrif formation is around 0.4-
0.6.This study is provided accurate behavior of petrophysical
properties with depth for this formation by using modern software.
Abstract: Non-linear dynamic time history analysis is
considered as the most advanced and comprehensive analytical
method for evaluating the seismic response and performance of
multi-degree-of-freedom building structures under the influence of
earthquake ground motions. However, effective and accurate
application of the method requires the implementation of advanced
hysteretic constitutive models of the various structural components
including masonry infill panels. Sophisticated computational research
tools that incorporate realistic hysteresis models for non-linear
dynamic time-history analysis are not popular among the professional
engineers as they are not only difficult to access but also complex and
time-consuming to use. In addition, commercial computer programs
for structural analysis and design that are acceptable to practicing
engineers do not generally integrate advanced hysteretic models
which can accurately simulate the hysteresis behavior of structural
elements with a realistic representation of strength degradation,
stiffness deterioration, energy dissipation and ‘pinching’ under cyclic
load reversals in the inelastic range of behavior. In this scenario,
push-over or non-linear static analysis methods have gained
significant popularity, as they can be employed to assess the seismic
performance of building structures while avoiding the complexities
and difficulties associated with non-linear dynamic time-history
analysis. “Push-over” or non-linear static analysis offers a practical
and efficient alternative to non-linear dynamic time-history analysis
for rationally evaluating the seismic demands. The present paper is
based on the analytical investigation of the effect of distribution of
masonry infill panels over the elevation of planar masonry infilled
reinforced concrete [R/C] frames on the seismic demands using the
capacity spectrum procedures implementing nonlinear static analysis
[pushover analysis] in conjunction with the response spectrum
concept. An important objective of the present study is to numerically
evaluate the adequacy of the capacity spectrum method using
pushover analysis for performance based design of masonry infilled
R/C frames for near-field earthquake ground motions.
Abstract: The paper is focused to the evaluation railway tracks
in the Slovakia by using Multi-Criteria method. Evaluation of railway
tracks has important impacts for the assessment of investment in
technical equipment. Evaluation of railway tracks also has an
important impact for the allocation of marshalling yards. Marshalling
yards are in transport model as centers for the operation assigned
catchment area. This model is one of the effective ways to meet the
development strategy of the European Community's railways. By
applying this model in practice, a transport company can guarantee a
higher quality of service and then expect an increase in performance.
The model is also applicable to other rail networks. This model
supplements a theoretical problem of train formation problem of new
ways of looking at evaluation of factors affecting the organization of
wagon flows.
Abstract: The article includes the results and conclusions from
empirical researches that had been done. The research focuses on the
impact of investments made in small and medium-sized enterprises
financed from EU funds on the competitiveness of these companies.
The researches includes financial results in sales revenue and net
income, expenses, and many other new products/services on offer,
higher quality products and services, more modern methods of
production, innovation in management processes, increase in the
number of customers, increase in market share, increase in
profitability of production and provision of services. The main
conclusions are that, companies with direct investments under this
measure shall apply the modern methods of production. The
consequence of this is to increase the quality of our products and
services. Furthermore, both small and medium-sized enterprises have
introduced new products and services. Investments were carried out,
thus enabling better work organization in enterprises. Entrepreneurs
would guarantee higher quality of service, which would result in
better relationships with their customers, what is more, noting the rise
in number of clients. More than half of the companies indicated that
the investments contributed to the increase in market share. Same
thing as for market reach and brand recognition of particular
company. An interesting finding is that, investments in small
enterprises were more effective than medium-sized enterprises.
Abstract: This study aimed to 1) develop pre-service teachers’
leadership skills through camp-based learning, and 2) develop preservice
teachers’ teamwork skills through camp-based learning. An
applied research methodology was used. The target group was
derived from a purposive selection. It involved 32 fourth-year
students in Early Childhood Education Program enrolling a course
entitled Seminar in Early Childhood Education provided during
second semester of academic year 2013. The treatment was camp-based
learning activities which applied a PDCA process including
four stages: 1) plan, 2) do, 3) check, and 4) act. Research instruments
were a learning camp program, a camp-based learning management
plan, a 5-level assessment form for leadership skills and a 5-level
assessment form for assessing teamwork skills. Data were analyzed
using descriptive statistics. Results were: 1) pre-service teachers’
leadership skills yielded the before treatment average score at x= 3.4,
S.D.=0.6 2and the after-treatment average score at x 4.29 , S.D.=0.66
pre-service teachers’ teamwork skills yielded the before-treatment
average score at x=3.31, S.D.=0.60 and the after-treatment average
score at x=4.42, S.D.=0.66 Both differences were statistically
significant at the .05 level. Thus, the pre-service teachers’ leadership
and teamwork skills were significantly improved through the camp-based
learning approach.
Abstract: The wider growing Finite Element Method (FEM)
application is caused by its benefits of cost saving and environment
friendly. Also, by using FEM a deep understanding of certain
phenomenon can be achieved. This paper observed the role of
material properties and volumetric change when Solid State Phase
Transformation (SSPT) takes place in residual stress formation due to
a welding process of ferritic steels through coupled Thermo-
Metallurgy-Mechanical (TMM) analysis. The correctness of FEM residual stress prediction was validated by
experiment. From parametric study of the FEM model, it can be
concluded that the material properties change tend to over-predicts
residual stress in the weld center whilst volumetric change tend to
underestimates it. The best final result is the compromise of both by
incorporates them in the model which has a better result compared to
a model without SSPT.
Abstract: Many herbal medicinal products are considered
potential anti-hypercholesterolemic agents with encouraging safety
profiles, however only a limited amount of clinical research exists to
support their efficacy. The present study was designed to compare the
antihypercholesterolemic and antioxidant activities of the crude
ethanolic extracts of Citrus reticulata fruit peel, Zingiber officinale
rhizome and Sesamum indicum seeds. Forty-five rats were used throughout the experiment which are
extended for four weeks. These were divided into nine groups, five
rats per each group as follows; group 1 was the normal control group
(rats only fed standard normal rat diet), group 2 was the
hypercholesterolemic control group (rats fed only
hypercholesterolemic diet which contained 1% cholesterol plus 10%
saturated animal fat added to the normal rat diet), groups 3 and 4
were fed hypercholesterolemic diet in addition to Citrus reticulata
ethanolic extract at doses of (250mg/kg (group 3) and 500mg/kg
(group 4)) administered daily via oral route, groups 5 and 6 were
given hypercholesterolemic diet in addition to Zingiber officinale
ethanolic extract at doses of (250mg/kg (group 5) and 500mg/kg
(group 6)) daily through oral route, groups 7 and 8 fed on
hypercholesterolemic diet in addition to Sesamum indicum ethanolic
extract at doses of (250mg/kg (group 7) and 500mg/kg (group 8))
daily orally; and group 9 rats were given hypercholesterolemic diet in
addition to atorvastatin (0.18mg/kg) daily via oral route as a standard
reference antihypercholesterolemic drug. Blood samples from all
groups were drawn from the retro-orbital venous plexus four weeks
following treatment after overnight fasting and the lipid profile (total
cholesterol (TC), high density lipoprotein-cholesterol (HDL-C), low
density lipoprotein-cholesterol (LDL-C) and triglyceride levels) were
measured and the risk ratio (TC/HDL-C) was assessed. The
antioxidant activity of the three plants extracts was determined using
DPPH free-radical antioxidant assay. Results of in vivo and in vitro
antihypercholesterolemic and antioxidant assay respectively, revealed
that the three extracts possess comparable antioxidant and
antihypercholesterolemic activities.
Abstract: The purpose of the study was to examine lifelong
education for teachers as a tool for achieving effective teaching and
learning. Lifelong education enhances social inclusion, personal
development, citizenship, employability, teaching and learning,
community and the nation. It is imperative that the teacher needs to
update his knowledge regularly to be able to perform optimally, since
he has a major position in the inculcation of desirable elements in
students, and the challenges of lifelong education were also
discussed. Descriptive survey design was adopted for the study. A
simple random sampling technique was used to select 80 teachers as
sample from a population of 105 senior secondary school teachers in
Makurdi Local Government Area of Benue State. A 20-item self
designed questionnaire subjected to expert validation and reliability
was used to collect data. The reliability Alpha coefficient of 0.87 was
established using Cronbach’s Alpha technique, mean scores and
standard deviation were used to answer the 2 research questions
while chi-square was used to analyse data for the 2 null hypotheses,
which states that lifelong education for teachers is not a significant
tool for achieving effective teaching and lifelong education for
teachers does not significantly impact on effective learning. The
findings of the study revealed that, lifelong education for teachers can
be used as a tool for achieving effective teaching and learning, and
the study recommended among others that government, organizations
and individuals should in collaboration put lifelong education
programmes for teachers on the priority list. The paper concluded
that the strategic position of lifelong education for teachers towards
enhanced teaching, learning and the production of quality manpower
in the society makes it imperative for all hands to be on “deck” to
support the programme financially and otherwise.
Abstract: This investigation is focused on using of Mon dance
in Pathum Thani Province’s tradition and has the following
objectives: 1) to study the background of Mon dance in Pathum
Thani Province; 2) to study Mon dance in Pathum Thani Province;
and 3) to study of using Mon dance in Pathum Thani province’s
tradition. This qualitative research was conducted in Pathum Thani
province (in the central of Thailand). Data was collected from
documentary study and field data by means of observation, interview,
and group discussion. Workshops were also held with a total of 100
attendees, comprised of 20 key informants, 40 casual informants and
40 general informants. Data was validated using the triangulation
technique and the findings are presented using the descriptive
analysis. The results of the study show that the historical background
of Mon dance in Pathum Thani Province initiated during the war
evacuation from Martaban (south of Burma) to settle down in Sam
Khok, Pathum Thani Province in Ayutthaya period to Rattanakosin.
The study found that Mon dance typically consists of 12-13 dancing
process. The melodies have 12-13 songs. Piphat Mon (Mon
traditional music ensemble) is used in the performance. Performers
are dressed in Mon traditional costumes. The performers are 6-12
women and depending on the employer’s demands. Length of the
performance varies from the duration of music orchestration. Rituals
and customs performed are paying homage to teachers before the
performance. The offerings are composed of flowers, incense sticks,
candles, money gifts which are well arranged on a tray with pedestal,
and also liquors, tobaccos and pure water for asking propitiousness.
For the use of Mon dance in Pathum Thani Province’s tradition, it is
found that the dance is commonly performed in the funeral
ceremonial tradition at present because the physical postures of the
performance are considered graceful and exquisite. In addition, as for
its value, it has long been believed since the ancient times that Mon
dance was a sacred thing considered as the dignity and glorification
especially for funeral ceremonies of priest or royal hierarchy classes.
However, Mon dance has continued to be used in the traditions
associated with Mon people activities in Pathum Thani Province for
instance customary welcome for honor guest and Songkran festival.
Abstract: Wireless Sensor Networks (WSNs), which sense
environmental data with battery-powered nodes, require multi-hop
communication. This power-demanding task adds an extra workload
that is unfairly distributed across the network. As a result, nodes run
out of battery at different times: this requires an impractical
individual node maintenance scheme. Therefore we investigate a new
Cooperative Sensing approach that extends the WSN operational life
and allows a more practical network maintenance scheme (where all
nodes deplete their batteries almost at the same time). We propose a
novel cooperative algorithm that derives a piecewise representation
of the sensed signal while controlling approximation accuracy.
Simulations show that our algorithm increases WSN operational life
and spreads communication workload evenly. Results convey a
counterintuitive conclusion: distributing workload fairly amongst
nodes may not decrease the network power consumption and yet
extend the WSN operational life. This is achieved as our cooperative
approach decreases the workload of the most burdened cluster in the
network.
Abstract: In turbulent modern economy, the companies need to
properly manage their business processes. Well-defined and stable
business processes ensure security of crucial data and applications,
and provide a quality product or service to the end customer. On the
other side, constant changes on the market, new regulatory
provisions, and emerging new technologies require the need of
issuing prompt and effective changes of business process. In this
article, we explore the use of agile principles in working with
business process management (BPM) solutions. We deal with
difficulties in BPM development cycle, review the benefits of using
agility, and choose the basic agile principles that ensure the success
of a BPM project.
Abstract: Round addition differential fault analysis using
operation skipping for lightweight block ciphers with on-the-fly key
scheduling is presented. For 64-bit KLEIN, it is shown that only a pair
of correct and faulty ciphertexts can be used to derive the secret master
key. For PRESENT, one correct ciphertext and two faulty ciphertexts
are required to reconstruct the secret key. Furthermore, secret key
extraction is demonstrated for the LBlock Feistel-type lightweight
block cipher.
Abstract: In this paper genetic based test data compression is
targeted for improving the compression ratio and for reducing the
computation time. The genetic algorithm is based on extended pattern
run-length coding. The test set contains a large number of X value
that can be effectively exploited to improve the test data
compression. In this coding method, a reference pattern is set and its
compatibility is checked. For this process, a genetic algorithm is
proposed to reduce the computation time of encoding algorithm. This
coding technique encodes the 2n compatible pattern or the inversely
compatible pattern into a single test data segment or multiple test data
segment. The experimental result shows that the compression ratio
and computation time is reduced.
Abstract: The objective of the paper is a numerical study of heat
transfer between perforated metal plates and the surrounding air
flows. Different perforation structures can nowadays be found in
various industrial products. Besides improving the mechanical
properties, the perforations can intensify the heat transfer as well. The
heat transfer coefficient depends on a wide range of parameters such
as type of perforation, size, shape, flow properties of the surrounding
air etc. The paper was focused on three different perforation
structures which have been investigated from the point of the view of
the production in the previous studies. To determine the heat
coefficients and the Nusselt numbers, the numerical simulation
approach was adopted. The calculations were performed using the
OpenFOAM software. The three-dimensional, unstable, turbulent and
incompressible air flow around the perforated surface metal plate was
considered.
Abstract: NiFe2O4 (nickel ferrite), ZnFe2O4 (zinc ferrite) and
Ni0.5Zn0.5Fe2O4 (nickel-zinc ferrite) were prepared by
mechanochemical route in a planetary ball mill starting from mixture
of the appropriate quantities of the Ni(OH)2/Fe(OH)3,
Zn(OH)2/Fe(OH)3 and Ni(OH)2/Zn(OH)2/Fe(OH)3 hydroxide
powders. In order to monitor the progress of chemical reaction and
confirm phase formation, powder samples obtained after 25 h, 18 h
and 10 h of milling were characterized by X-ray diffraction (XRD),
transmission electron microscopy (TEM), IR, Raman and Mössbauer
spectroscopy. It is shown that the soft mechanochemical method, i.e.
mechanochemical activation of hydroxides, produces high quality
single phase ferrite samples in much more efficient way. From the IR
spectroscopy of single phase samples it is obvious that energy of
modes depends on the ratio of cations. It is obvious that all samples
have more than 5 Raman active modes predicted by group theory in
the normal spinel structure. Deconvolution of measured spectra
allows one to conclude that all complex bands in the spectra are made
of individual peaks with the intensities that vary from spectrum to
spectrum. The deconvolution of Raman spectra allows to separate
contributions of different cations to a particular type of vibration and
to estimate the degree of inversion.
Abstract: This research tested the performance of alternative
warehouse designs concerning the picking process. The chosen
performance measures were Travel Distance and Total Fulfilment
Time. An explanatory case study was built up around a model
implemented with SIMUL8. Hypotheses were set by selecting
outcomes from the literature survey matching popular empirical
findings. 17.4% reductions were found for Total Fulfilment Time and
Resource Utilisation. The latter was then used as a proxy for
operational efficiency. Literal replication of theoretical data-patterns
was considered as an internal validity sign. Assessing the estimated
changes benefits ahead of implementation was found to be a
contribution to practice.