Abstract: The fractal-shaped orifices are assumed to have a
significant effect on the pressure drop downstream pipe flow due to
their edge self-similarity shape which enhances the mixing
properties. Here, we investigate the pressure drop after these fractals
using a digital micro-manometer at different stations downstream a
turbulent flow pipe then a direct comparison has been made with the
pressure drop measured from regular orifices with the same flow
area. Our results showed that the fractal-shaped orifices have a
significant effect on the pressure drop downstream the flow. Also
the pressure drop measured across the fractal-shaped orifices is
noticed to be lower that that from ordinary orifices of the same flow
areas. This result could be important in designing piping systems
from point of view of losses consideration with the same flow
control area. This is promising to use the fractal-shaped orifices as
flowmeters as they can sense the pressure drop across them
accurately with minimum losses than the regular ones.
Abstract: Domain-specific languages describe specific solutions to problems in the application domain. Traditionally they form a solution composing black-box abstractions together. This, usually, involves non-deep transformations over the target model. In this paper we argue that it is potentially powerful to operate with grey-box abstractions to build a domain-specific software system. We present parametric code templates as grey-box abstractions and conceptual tools to encapsulate and manipulate these templates. Manipulations introduce template-s merging routines and can be defined in a generic way. This involves reasoning mechanisms at the code templates level. We introduce the concept of Neurath Modelling Language (NML) that operates with parametric code templates and specifies a visualisation mapping mechanism for target models. Finally we provide an example of calculating a domain-specific software system with predefined NML elements.
Abstract: Two-phase frictional pressure drop data were
obtained for condensation of carbon dioxide in single horizontal
micro tube of inner diameter ranged from 0.6 mm up to 1.6 mm over
mass flow rates from 2.5*10-5 to 17*10-5 kg/s and vapor qualities
from 0.0 to 1.0. The inlet condensing pressure is changed from 33.5
to 45 bars. The saturation temperature ranged from -1.5 oC up to 10
oC. These data have then been compared against three (two-phase)
frictional pressure drop prediction methods. The first method is by
Muller-Steinhagen and Heck (Muller-Steinhagen H, Heck K. A
simple friction pressure drop correlation for two-phase flow in pipes.
Chem. Eng. Process 1986;20:297–308) and that by Gronnerud R.
Investigation of liquid hold-up, flow-resistance and heat transfer in
circulation type evaporators, part IV: two-phase flow resistance in
boiling refrigerants, Annexe 1972. Then the method used by
FriedelL. Improved friction pressures drop in horizontal and vertical
two-phase pipe flow. European Two-Phase Flow Group Meeting,
Paper E2; 1979 June, Ispra, Italy. The methods are used by M.B Ould
Didi et al (2001) “Prediction of two-phase pressure gradients of
refrigerant in horizontal tubes". Int.J.of Refrigeration 25(2002) 935-
947. The best available method for annular flow was that of Muller-
Steinhagen and Heck. It was observed that the peak in the two-phase
frictional pressure gradient is at high vapor qualities.
Abstract: The current trend of increasing quality and demands
of the final product is affected by time analysis of the entire
manufacturing process. The primary requirement of manufacturing is
to produce as many products as soon as possible, at the lowest
possible cost, but of course with the highest quality. Such
requirements may be satisfied only if all the elements entering and
affecting the production cycle are in a fully functional condition.
These elements consist of sensory equipment and intelligent control
elements that are essential for building intelligent manufacturing
systems. The intelligent manufacturing paradigm includes a new
approach to production system structure design. Intelligent behaviors
are based on the monitoring of important parameters of system and
its environment. The flexible reaction to changes. The realization and
utilization of this design paradigm as an "intelligent manufacturing
system" enables the flexible system reaction to production
requirement as soon as environmental changes too. Results of these
flexible reactions are a smaller layout space, be decreasing of
production and investment costs and be increasing of productivity.
Intelligent manufacturing system itself should be a system that can
flexibly respond to changes in entering and exiting the process in
interaction with the surroundings.
Abstract: The aim of this paper is to present current and future
procedures in castings procurement. Differences in procurement are
highlighted. The supplier selection criteria used in practice is
compared to literature findings. Different trends related to supply
chains are presented and it is described how they are reflected in
reality to castings procurement. To fulfil the aim, interviews were
conducted in nine companies using castings. It was found that largest
casting users have the most subcontractor foundries and it is more
typical that they have multiple suppliers for the same parts. Currently
only two companies out of nine purchase castings outside Europe,
but the others are also progressing in the same direction. The main
reason is the need to lower purchasing costs. Another trend is that all
companies want to buy cast components or sub-assemblies instead of
raw castings from foundries. It was found that price is a main
supplier selection criterion. All companies use competitive bidding in
supplier selection.
Abstract: The shortest path routing problem is a multiobjective nonlinear optimization problem with constraints. This problem has been addressed by considering Quality of service parameters, delay and cost objectives separately or as a weighted sum of both objectives. Multiobjective evolutionary algorithms can find multiple pareto-optimal solutions in one single run and this ability makes them attractive for solving problems with multiple and conflicting objectives. This paper uses an elitist multiobjective evolutionary algorithm based on the Non-dominated Sorting Genetic Algorithm (NSGA), for solving the dynamic shortest path routing problem in computer networks. A priority-based encoding scheme is proposed for population initialization. Elitism ensures that the best solution does not deteriorate in the next generations. Results for a sample test network have been presented to demonstrate the capabilities of the proposed approach to generate well-distributed pareto-optimal solutions of dynamic routing problem in one single run. The results obtained by NSGA are compared with single objective weighting factor method for which Genetic Algorithm (GA) was applied.
Abstract: Dynamic location referencing method is an important technology to shield map differences. These method references objects of the road network by utilizing condensed selection of its real-world geographic properties stored in a digital map database, which overcomes the defections existing in pre-coded location referencing methods. The high attributes completeness requirements and complicated reference point selection algorithm are the main problems of recent researches. Therefore, a dynamic location referencing algorithm combining intersection points selected at the extremities compulsively and road link points selected according to link partition principle was proposed. An experimental system based on this theory was implemented. The tests using Beijing digital map database showed satisfied results and thus verified the feasibility and practicability of this method.
Abstract: This paper presents a research agenda on the SCOR
model adaptation. SCOR model is designated to measure supply
chain performance and logistics impact across the boundaries of
individual organizations. It is at its growing stage of its life cycle and
is enjoying the leverage of becoming the industry standard. The
SCOR model has been developed and used widely in developed
countries context. This research focuses on the SCOR model
adaptation for the manufacturing industry in developing countries.
With a necessary understanding of the characteristics, difficulties and
problems of the manufacturing industry in developing countries-
supply chain; consequently, we will try to designs an adapted model
with its building blocks: business process model, performance
measures and best practices.
Abstract: There have been many variations of technologies that helped educators in teaching & learning. From the past research it is evident that Information Technology significantly increases student participation and interactivity in the classrooms. This research started with a aim to find whether adoption of Wi-Fi environment by Malaysian Higher Educational Institutions (HEI) can benefit students and staff equally. The study was carried out in HEI-s of Klang Valley, Malaysia and the data is gathered through paper based surveys. A sample size of 237 units were randomly selected from 5 higher educational institutions in the Klang Valley using the Stratified Random sampling method and from the analysis of the data, it was found that the implementation of wireless technologies in HEIs have created lot of opportunities and also challenges.
Abstract: In this study, communities of ammonia-oxidizing
archaea (AOA) and ammonia-oxidizing bacteria (AOB) in nitrifying
activated sludge (NAS) prepared by enriching sludge from a
municipal wastewater treatment plant in three continuous-flow
reactors receiving an inorganic medium containing different
ammonium concentrations of 2, 10, and 30 mM NH4
+-N (NAS2,
NAS10, and NAS30, respectively) were investigated using molecular
analysis. Results suggested that almost all AOA clones from NAS2,
NAS10, and NAS30 fell into the same AOA cluster and AOA
communities in NAS2 and NAS10 were more diverse than those of
NAS30. In contrast to AOA, AOB communities obviously shifted
from the seed sludge to enriched NASs and in each enriched NAS,
communities of AOB varied particularly. The seed sludge contained
members of N. communis cluster and N. oligotropha cluster. After it
was enriched under various ammonium loads, members of N.
communis cluster disappeared from all enriched NASs. AOB with
high affinity to ammonia presented in NAS 2, AOB with low affinity
to ammonia presented in NAS 30, and both types of AOB survived in
NAS 10. These demonstrated that ammonium load significantly
influenced AOB communities, but not AOA communities in enriched
NASs.
Abstract: The dynamic model of a drill in drilling process was
proposed and investigated in this study. To assure a good drilling quality, the vibration variation on the drill tips during high speed
drilling is needed to be investigated. A pre-twisted beam is used to
simulate the drill. The moving Winkler-Type elastic foundation is used to characterize the tip boundary variation in drilling. Due to the
variation of the drill depth, a time dependent dynamic model for the drill is proposed. Results simulated from this proposed model indicate that an abrupt natural frequencies drop are experienced as the drill tip
tough the workpiece, and a severe vibration is induced. The effects of parameters, e.g. drilling speed, depth, drill size and thrust force on the
drill tip responses studied.
Abstract: For a long time as a result of accommodating car
traffic, planning ideologies in the past put a low priority on public
space, pedestrianism and the role of city space as a meeting place for
urban dwellers. In addition, according to authors such as Jan Gehl,
market forces and changing architectural perceptions began to shift
the focus of planning practice from the integration of public space in
various pockets around the contemporary city to individual buildings.
Eventually, these buildings have become increasingly more isolated
and introverted and have turned their backs to the realm of the public
space adjoining them. As a result of this practice, the traditional
function of public space as a social forum for city dwellers has in
many cases been reduced or even phased out. Author Jane Jacobs
published her seminal book “The Death and Life of Great American
Cities" more than fifty years ago, but her observations and
predictions at the time still ring true today, where she pointed out
how the dramatic increase in car traffic and its accommodation by the
urban planning ideology that was brought about by the Modern
movement has prompted a separation of the uses of the city. At the
same time it emphasizes free standing buildings that threaten urban
space and city life and result in underutilized and lifeless urban cores.
In this discussion context, the aim of this paper is to showcase a
reversal of just such a situation in the case of the Dasoupolis
neighborhood in Strovolos, Cyprus, where enlightened urban design
practice has see the reclamation of pedestrian space in a car
dominated area.
Abstract: In this study, the adhesion of ice to solid substrates
with different surface properties is compared. Clear ice, similar to
atmospheric in-flight icing encounters, is accreted on the different
substrates under controlled conditions. The ice adhesion behavior is
investigated by means of a dynamic vibration testing technique with
an electromagnetic shaker initiating ice de-bonding in the interface
between the substrate and the ice. The results of the experiments
reveal that the affinity for ice accretion is significantly influenced by
the water contact angle of the respective sample.
Abstract: This paper is focused on issues of process modeling
and two model based control strategies of a fed-batch sugar
crystallization process applying the concept of artificial neural
networks (ANNs). The control objective is to force the operation into
following optimal supersaturation trajectory. It is achieved by
manipulating the feed flow rate of sugar liquor/syrup, considered as
the control input. The control task is rather challenging due to the
strong nonlinearity of the process dynamics and variations in the
crystallization kinetics. Two control alternatives are considered –
model predictive control (MPC) and feedback linearizing control
(FLC). Adequate ANN process models are first built as part of the
controller structures. MPC algorithm outperforms the FLC approach
with respect to satisfactory reference tracking and smooth control
action. However, the MPC is computationally much more involved
since it requires an online numerical optimization, while for the FLC
an analytical control solution was determined.
Abstract: For Seismic design, it is important to estimate,
maximum lateral displacement (inelastic displacement) of the
structures due to sever earthquakes for several reasons. Seismic
design provisions estimate the maximum roof and storey drifts
occurring in major earthquakes by amplifying the drifts of the
structures obtained by elastic analysis subjected to seismic design
load, with a coefficient named “displacement amplification factor"
which is greater than one. Here, this coefficient depends on various
parameters, such as ductility and overstrength factors. The present
research aims to evaluate the value of the displacement amplification
factor in seismic design codes and then tries to propose a value to
estimate the maximum lateral structural displacement from sever
earthquakes, without using non-linear analysis. In seismic codes,
since the displacement amplification is related to “force reduction
factor" hence; this aspect has been accepted in the current study.
Meanwhile, two methodologies are applied to evaluate the value of
displacement amplification factor and its relation with the force
reduction factor. In the first methodology, which is applied for all
structures, the ratio of displacement amplification and force reduction
factors is determined directly. Whereas, in the second methodology
that is applicable just for R/C moment resisting frame, the ratio is
obtained by calculating both factors, separately. The acquired results
of these methodologies are alike and estimate the ratio of two factors
from 1 to 1.2. The results indicate that the ratio of the displacement
amplification factor and the force reduction factor differs to those
proposed by seismic provisions such as NEHRP, IBC and Iranian
seismic code (standard no. 2800).
Abstract: Among the many promising nanomaterials with antifungal properties, metal nanoparticles (silver nanoparticles) stand out due to their high chemical activity. Therefore, the aim of this study was to evaluate the effect of silver nanoparticles (AgNPs) against Phomopsis sp. AgNPs were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. The synthesized AgNPs have further been characterized by UV/Visible spectroscopy, Biophysical techniques like Dynamic light scattering (DLS) and Scanning Electron Microscopy (SEM). The average diameter of the prepared silver colloidal nanoparticles was about 52 nm. Absolute inhibitions (100%) were observed on treated with a 270 and 540 µg ml-1 concentration of AgNPs. The results from the study of the AgNPs antifungal effect are significant and suggest that the synthesized silver nanoparticles may have an advantage compared with conventional fungicides.
Abstract: This study investigates the in-situ regeneration of deactivated Pt-Pd catalyst in a laboratory-scale catalysis reactor. Different regeneration conditions are tested and the activity and characteristics of regenerated catalysts are analyzed. Experimental results show that the conversion efficiencies of C3H6 by different regenerated Pt-Pd catalysts were significantly improved from 77%, 55% and 41% to 86%, 98% and 99%, respectively. The best regeneration conditions was 52ppm ozone, 500oC, and 10min. Regeneration temperature has more influences than ozone concentration and regeneration time. With the comparisons of characteristics of deactivated catalyst and regenerated catalyst, the major poison species (carbon, metals, chloride, and sulfate) on the spent catalysts can be effectively removed by ozone regeneration.
Abstract: This paper presents two different sequential switching hybrid-modulation strategies and implemented for cascaded multilevel inverters. Hybrid modulation strategies represent the combinations of Fundamental-frequency pulse width modulation (FFPWM) and Multilevel sinusoidal-modulation (MSPWM) strategies, and are designed for performance of the well-known Alternative Phase opposition disposition (APOD), Phase shifted carrier (PSC). The main characteristics of these modulations are the reduction of switching losses with good harmonic performance, balanced power loss dissipation among the devices with in a cell, and among the series-connected cells. The feasibility of these modulations is verified through spectral analysis, power loss analysis and simulation.
Abstract: The world is entering a new path of development which is becoming the driving force of globalization. It is seen as an irreversible process of the present reality and has a significant impact on the transformation of economic, social and cultural rights. This also applies to changes in the rural environment which while emphasizing the global development should also maintain its identity and locality, and a rural community should do more to recognize the globalization of an opportunity than a threat to the Polish countryside. The paper discusses theoretical problems of rural development and the importance of diversification in rural areas and preserving the countryside life and there werepresente the opinions of residents of the Polish countryside on the impact of globalization on the development.
Abstract: A Picard-Newton iteration method is studied to accelerate the numerical solution procedure of a class of two-dimensional nonlinear coupled parabolic-hyperbolic system. The Picard-Newton iteration is designed by adding higher-order terms of small quantity to an existing Picard iteration. The discrete functional analysis and inductive hypothesis reasoning techniques are used to overcome difficulties coming from nonlinearity and coupling, and theoretical analysis is made for the convergence and approximation properties of the iteration scheme. The Picard-Newton iteration has a quadratic convergent ratio, and its solution has second order spatial approximation and first order temporal approximation to the exact solution of the original problem. Numerical tests verify the results of the theoretical analysis, and show the Picard-Newton iteration is more efficient than the Picard iteration.