Abstract: There is an evident trend to elevate pressure ratio of a
single stage of a turbo compressors - axial compressors in particular.
Whilst there was an opinion recently that a pressure ratio 1,9 was a
reasonable limit, later appeared information on successful modeling
tested of stages with pressure ratio up to 2,8. The authors recon that
lack of information on high pressure stages makes actual a study of
rational choice of design parameters before high supersonic flow
problems solving. The computer program of an engineering type was
developed. Below is presented a sample of its application to study
possible parameters of the impeller of the stage with pressure ratio
3,0. Influence of two main design parameters on expected efficiency,
periphery blade speed and flow structure is demonstrated. The results
had lead to choose a variant for further analysis and improvement by
CFD methods.
Abstract: Universal modeling method well proven for industrial
compressors was applied for design of the high flow rate supersonic
stage. Results were checked by ANSYS CFX and NUMECA Fine
Turbo calculations. The impeller appeared to be very effective at
transonic flow velocities. Stator elements efficiency is acceptable at
design Mach numbers too. Their loss coefficient versus inlet flow
angle performances correlates well with Universal modeling
prediction. The impeller demonstrates ability of satisfactory operation
at design flow rate. Supersonic flow behavior in the impeller inducer
at the shroud blade to blade surface Φ des deserves additional study.
Abstract: Parameters of flow are calculated in vaneless diffusers
with relative width 0,014–0,10. Inlet angles of flow and similarity
criteria were varied. There is information on flow separation,
boundary layer development, configuration of streamlines.
Polytrophic efficiency, loss coefficient and recovery coefficient are
used to compare effectiveness of diffusers. The sample of
optimization of narrow diffuser with conical walls is presented. Three
wide diffusers with narrowing walls are compared. The work is made
in the R&D laboratory “Gas dynamics of turbo machines” of the TU
SPb.
Abstract: Construction cost estimation is one of the most
important aspects of construction project design. For generations, the
process of cost estimating has been manual, time-consuming and
error-prone. This has partly led to most cost estimates to be unclear
and riddled with inaccuracies that at times lead to over- or underestimation
of construction cost. The development of standard set of
measurement rules that are understandable by all those involved in a
construction project, have not totally solved the challenges. Emerging
Building Information Modelling (BIM) technologies can exploit
standard measurement methods to automate cost estimation process
and improve accuracies. This requires standard measurement
methods to be structured in ontological and machine readable format;
so that BIM software packages can easily read them. Most standard
measurement methods are still text-based in textbooks and require
manual editing into tables or Spreadsheet during cost estimation. The
aim of this study is to explore the development of an ontology based
on New Rules of Measurement (NRM) commonly used in the UK for
cost estimation. The methodology adopted is Methontology, one of
the most widely used ontology engineering methodologies. The
challenges in this exploratory study are also reported and
recommendations for future studies proposed.
Abstract: This paper presents modeling of an Alternating
Current (AC) Photovoltaic (PV) module using Matlab/Simulink. The
proposed AC-PV module model is simple, realistic, and application
oriented. The model is derived on module level as compared to cell
level directly from the information provided by the manufacturer data
sheet. DC-PV module, MPPT control, BC, VSI and LC filter, all
were treated as a single unit. The model accounts for changes in
variations of both irradiance and temperature. The AC-PV module
proposed model is simulated and the results are compared with the
datasheet projected numbers to validate model’s accuracy and
effectiveness. Implementation and results demonstrate simplicity and
accuracy, as well as reliability of the model.
Abstract: Managing and improving efficiency in the current
highly competitive global automotive industry demands that those
companies adopt leaner and more flexible systems. During the past
20 years the domestic automotive industry in North America has been
focusing on establishing new management strategies in order to meet
market demands. The lean management process also known as
Toyota Manufacturing Process (TPS) or lean manufacturing
encompasses tools and techniques that were established in order to
provide the best quality product with the fastest lead time at the
lowest cost. The following paper presents a study that focused on
improving labor efficiency at one of the Big Three (Ford, GM,
Chrysler LLC) domestic automotive facility in North America. The
objective of the study was to utilize several lean management tools in
order to optimize the efficiency and utilization levels at the “Pre-
Marriage” chassis area in a truck manufacturing and assembly
facility. Utilizing three different lean tools (i.e. Standardization of
work, 7 Wastes, and 5S) this research was able to improve efficiency
by 51%, utilization by 246%, and reduce operations by 14%. The
return on investment calculated based on the improvements made
was 284%.
Abstract: The 6th version of Universal modeling method for
centrifugal compressor stage calculation is described. Identification
of the new mathematical model was made. As a result of
identification the uniform set of empirical coefficients is received.
The efficiency definition error is 0,86 % at a design point. The
efficiency definition error at five flow rate points (except a point of
the maximum flow rate) is 1,22 %. Several variants of the stage with
3D impellers designed by 6th version program and quasi threedimensional
calculation programs were compared by their gas
dynamic performances CFD (NUMECA FINE TURBO).
Performance comparison demonstrated general principles of design
validity and leads to some design recommendations.
Abstract: Logistics processes of perishable food in the supply
chain include the distribution activities and the real time temperature
monitoring to fulfil the cold chain requirements. The paper presents
the use of RFID (Radio Frequency Identification) technology as an
identification tool of receiving and shipping activities in the cold
store. At the same time, the use of RFID data loggers with
temperature sensors is presented to observe and store the
temperatures for the purpose of analyzing the processes and having
the history data available for traceability purposes and efficient recall
management.
Abstract: Stator elements «Vane diffuser + crossover + return
channel» of stages with different specific speed were investigated by
CFD calculations. The regime parameter was introduced to present
efficiency and loss coefficient performance of all elements together.
Flow structure demonstrated advantages and disadvantages of design.
Flow separation in crossovers was eliminated by its shape
modification. Efficiency increased visibly. Calculated CFD
performances are in acceptable correlation with predicted ones by
engineering design method. The information obtained is useful for
design method better calibration.
Abstract: Recently, universities are increasingly consuming
energy to support various activities. A large population of staff and
students in Malaysian universities has led to excessive energy
consumption which directly gives an impact to the environment. The
key question then ascended “How well is an energy management
(EM) been practiced in universities without taking the Critical
Success Factors (CSFs) into consideration to ensure the management
of university achieves the goals in reducing energy consumption.
Review on past literature is carried out to establish CSFs for EM best
practices. Thus, this paper highlighted the CSFs which have to be
focused on by management of university to successfully measure the
EM implementation and its performance. At the end of this paper, a
theoretical framework is developed for EM success factors towards
sustainable university.
Abstract: This research was conducted in the Mae Sot
Watershed where located in the Moei River Basin at the Upper
Salween River Basin in Tak Province, Thailand. The Mae Sot
Municipality is the largest urban area in Tak Province and situated in
the midstream of the Mae Sot Watershed. It usually faces flash flood
problem after heavy rain due to poor flood management has been
reported since economic rapidly bloom up in recent years. Its
catchment can be classified as ungauged basin with lack of rainfall
data and no any stream gaging station was reported. It was attached
by most severely flood events in 2013 as the worst studied case for
all those communities in this municipality. Moreover, other problems
are also faced in this watershed, such shortage water supply for
domestic consumption and agriculture utilizations including a
deterioration of water quality and landslide as well. The research
aimed to increase capability building and strengthening the
participation of those local community leaders and related agencies to
conduct better water management in urban area was started by mean
of the data collection and illustration of the appropriated application
of some short period rainfall forecasting model as they aim for better
flood relief plan and management through the hydrologic model
system and river analysis system programs. The authors intended to
apply the global rainfall data via the integrated data viewer (IDV)
program from the Unidata with the aim for rainfall forecasting in a
short period of 7-10 days in advance during rainy season instead of
real time record. The IDV product can be present in an advance
period of rainfall with time step of 3-6 hours was introduced to the
communities. The result can be used as input data to the hydrologic
modeling system model (HEC-HMS) for synthesizing flood
hydrographs and use for flood forecasting as well. The authors
applied the river analysis system model (HEC-RAS) to present flood
flow behaviors in the reach of the Mae Sot stream via the downtown
of the Mae Sot City as flood extents as the water surface level at
every cross-sectional profiles of the stream. Both models of HMS and
RAS were tested in 2013 with observed rainfall and inflow-outflow
data from the Mae Sot Dam. The result of HMS showed fit to the
observed data at the dam and applied at upstream boundary discharge
to RAS in order to simulate flood extents and tested in the field, and
the result found satisfying. The product of rainfall from IDV was fair
while compared with observed data. However, it is an appropriate
tool to use in the ungauged catchment to use with flood hydrograph
and river analysis models for future efficient flood relief plan and
management.
Abstract: This paper proposes a mathematical model and
examines the performance of an exact algorithm for a location–
transportation problems in humanitarian relief. The model determines
the number and location of distribution centers in a relief network,
the amount of relief supplies to be stocked at each distribution center
and the vehicles to take the supplies to meet the needs of disaster
victims under capacity restriction, transportation and budgetary
constraints. The computational experiments are conducted on the
various sizes of problems that are generated. Branch and bound
algorithm is applied for these problems. The results show that this
algorithm can solve problem sizes of up to three candidate locations
with five demand points and one candidate location with up to twenty
demand points without premature termination.
Abstract: Absorptive capacity generally facilitates the adoption
of innovation. How does this relationship change when economic
return is not the sole driver of innovation uptake? We investigate
whether absorptive capacity facilitates the adoption of green
innovation based on a survey of 79 construction companies in
Scotland. Based on the results of multiple regression analyses, we
confirm that existing knowledge utilisation (EKU), knowledge
building (KB) and external knowledge acquisition (EKA) are
significant predictors of green process GP), green administrative
(GA) and green technical innovation (GT), respectively. We discuss
the implications for theories of innovation adoption and knowledge
enhancement associated with environmentally-friendly practices.
Abstract: Diminished antioxidant defense or increased
production of reactive oxygen species in the biological system can
result in oxidative stress which may lead to various
neurodegenerative diseases including Alzheimer’s disease (AD).
Microglial activation also contributes to the progression of AD by
producing several proinflammatory cytokines, nitric oxide (NO) and
prostaglandin E2 (PGE2). Oxidative stress and inflammation have
been reported to be possible pathophysiological mechanisms
underlying AD. In addition, the cholinergic hypothesis postulates that
memory impairment in patient with AD is also associated with the
deficit of cholinergic function in the brain. Although a number of
drugs have been approved for the treatment of AD, most of these
synthetic drugs have diverse side effects and yield relatively modest
benefits. Marine algae have great potential in pharmaceutical and
biomedical applications as they are valuable sources of bioactive
properties such as anticoagulation, antimicrobial, antioxidative,
anticancer and anti-inflammatory. Hence, this study aimed to provide
an overview of the properties of Malaysian seaweeds (Padina
australis, Sargassum polycystum and Caulerpa racemosa) in
inhibiting oxidative stress, neuroinflammation and cholinesterase
enzymes. These seaweeds significantly exhibited potent DPPH and
moderate superoxide anion radical scavenging ability (P
Abstract: The present work analyses different parameters of end
milling to minimize the surface roughness for AISI D2 steel. D2 Steel
is generally used for stamping or forming dies, punches, forming
rolls, knives, slitters, shear blades, tools, scrap choppers, tyre
shredders etc. Surface roughness is one of the main indices that
determines the quality of machined products and is influenced by
various cutting parameters. In machining operations, achieving
desired surface quality by optimization of machining parameters, is a
challenging job. In case of mating components the surface roughness
become more essential and is influenced by the cutting parameters,
because, these quality structures are highly correlated and are
expected to be influenced directly or indirectly by the direct effect of
process parameters or their interactive effects (i.e. on process
environment). In this work, the effects of selected process parameters
on surface roughness and subsequent setting of parameters with the
levels have been accomplished by Taguchi’s parameter design
approach. The experiments have been performed as per the
combination of levels of different process parameters suggested by
L9 orthogonal array. Experimental investigation of the end milling of
AISI D2 steel with carbide tool by varying feed, speed and depth of
cut and the surface roughness has been measured using surface
roughness tester. Analyses of variance have been performed for mean
and signal-to-noise ratio to estimate the contribution of the different
process parameters on the process.
Abstract: Part and parcel of building green homes (GHs) with
favorable thermal comfort (TC) is to design and build with reduced
carbon footprint (CF) from embodied energy in the building envelope
and reduced operational CF overall. Together, the environmental
impact of GHs can be reduced significantly. Nevertheless, there is
still a need to identify the base CF value for Malaysian GHs and this
can be done by assessing existing ones which can then be compared
to conventional and vernacular houses which are built differently
with different building materials. This paper underlines the research
design and introduces the case studies. For now, the operational CF
of the case studies is beyond the scope of this study. Findings from
this research could identify the best building material and
construction technique combination to build GHs depending on the
available skills, financial constraints and the condition of the
immediate environment.
Abstract: Carbon Deposits are often occurred inside the
industrial coke oven during coking process. Accumulation of carbon
deposits may cause a big issue, which seriously influences the coking
operation. The carbon is burning off by injecting fresh air through
pipes into coke oven which is an efficient way practically operated in
industries. The burning off carbon deposition in coke oven performed
by Computational Fluid Dynamics (CFD) method has provided an
evaluation of the feasibility study. A three dimensional, transient,
turbulent reacting flow simulation has performed with three different
injecting air flow rate and another kind of injecting configuration. The
result shows that injection higher air flow rate would effectively
reduce the carbon deposits. In the meantime, the opened charging
holes would suck extra oxygen from atmosphere to participate in
reactions. In term of coke oven operating limits, the wall temperatures
are monitored to prevent over-heating of the adiabatic walls during
burn-off process.
Abstract: In this paper, we used data mining to extract
biomedical knowledge. In general, complex biomedical data
collected in studies of populations are treated by statistical methods,
although they are robust, they are not sufficient in themselves to
harness the potential wealth of data. For that you used in step two
learning algorithms: the Decision Trees and Support Vector Machine
(SVM). These supervised classification methods are used to make the
diagnosis of thyroid disease. In this context, we propose to promote
the study and use of symbolic data mining techniques.
Abstract: A well designed and executed Production Planning
and Control (PPC) system is one of the key levers for superior
performance in the current manufacturing set-up. Hence, measuring
the PPC system performance has become a necessity for long term
success. The present study examined PPC related issues which
impact the production capacity and productivity of leather companies
with special focus on Kombolcha Tannery Share Company (KTSC),
Ethiopia. Physical observation, interview, and questionnaire were
used to generate necessary information from the respondents and
reach valid conclusions. Company annual reports were referred and
analyzed to triangulate primary data. Consequently, the study
revealed that KTSC runs below its capacity due to its inefficient PPC
system being in use for which the root causes were identified. The
study thereby conceptualizes a PPC system improvement framework
comprising three pillars viz., management culture, internal capability
and performance measurement together with key considerations in
each case. The study findings enable the company to recognize the
importance of efficient PPC system as a source of competitive
advantage. It also aid managers in evaluating various PPC execution
schemes to enhance productivity.
Abstract: Despite the highly touted benefits, emerging
technologies have unleashed pervasive concerns regarding unintended
and unforeseen social impacts. Thus, those wishing to create safe and
socially acceptable products need to identify such side effects and
mitigate them prior to the market proliferation. Various methodologies
in the field of technology assessment (TA), namely Delphi, impact
assessment, and scenario planning, have been widely incorporated in
such a circumstance. However, literatures face a major limitation in
terms of sole reliance on participatory workshop activities. They
unfortunately missed out the availability of a massive untapped data
source of futuristic information flooding through the Internet. This
research thus seeks to gain insights into utilization of futuristic data,
future-oriented documents from the Internet, as a supplementary
method to generate social impact scenarios whilst capturing
perspectives of experts from a wide variety of disciplines. To this end,
network analysis is conducted based on the social keywords extracted
from the futuristic documents by text mining, which is then used as a
guide to produce a comprehensive set of detailed scenarios. Our
proposed approach facilitates harmonized depictions of possible
hazardous consequences of emerging technologies and thereby makes
decision makers more aware of, and responsive to, broad qualitative
uncertainties.