Abstract: This work presents a numerical model developed to
simulate the dynamics and vibrations of a multistage tractor gearbox.
The effect of time varying mesh stiffness, time varying frictional
torque on the gear teeth, lateral and torsional flexibility of the shafts
and flexibility of the bearings were included in the model. The model
was developed by using the Lagrangian method, and it was applied to
study the effect of three design variables on the vibration and stress
levels on the gears. The first design variable, module, had little effect
on the vibration levels but a higher module resulted to higher bending
stress levels. The second design variable, pressure angle, had little
effect on the vibration levels, but had a strong effect on the stress
levels on the pinion of a high reduction ratio gear pair. A pressure
angle of 25o resulted to lower stress levels for a pinion with 14 teeth
than a pressure angle of 20o. The third design variable, contact ratio,
had a very strong effect on both the vibration levels and bending
stress levels. Increasing the contact ratio to 2.0 reduced both the
vibration levels and bending stress levels significantly. For the gear
train design used in this study, a module of 2.5 and contact ratio of
2.0 for the various meshes was found to yield the best combination
of low vibration levels and low bending stresses. The model can
therefore be used as a tool for obtaining the optimum gear design
parameters for a given multistage spur gear train.
Abstract: This paper presents the impact study of apparent
reactance injected by series Flexible AC Transmission System
(FACTS) i.e. Thyristor Controlled Series Reactor (TCSR) on the
measured impedance of a 400 kV single electrical transmission line
in the presence of phase to earth fault with fault resistance. The study
deals with an electrical transmission line of Eastern Algerian
transmission networks at Group Sonelgaz (Algerian Company of
Electrical and Gas) compensated by TCSR connected at midpoint of
the line. This compensator used to inject active and reactive powers
is controlled by three TCSR-s. The simulations results investigate the
impacts of the TCSR on the parameters of short circuit calculation
and parameters of measured impedance by distance relay in the
presence of earth fault for three cases study.
Abstract: The present work deals with thermodynamic analysis
of cascade refrigeration system using ozone friendly refrigerants pair
R507A and R23. R507A is azeotropic mixture composed of HFC
refrigerants R125/R143a (50%/50% wt.). R23 is a single component
HFC refrigerant used as replacement to CFC refrigerant R13 in low
temperature applications. These refrigerants have zero ozone
depletion potential and are non-flammable and as R507A an
azeotropic mixture there is no problem of temperature glide. This
study thermodynamically analyzed R507A-R23 cascade refrigeration
system to optimize the design and operating parameters of the
system. The design and operating parameters include: Condensing,
evaporating, subcooling and superheating temperatures in the high
temperature circuit, temperature difference in the cascade heat
exchanger, Condensing, evaporating, subcooling and superheating
temperatures in the low temperature circuit.
Abstract: This study proposes novel hybrid social network analysis and collaborative filtering approach to enhance the performance of recommender systems. The proposed model selects subgroups of users in Internet community through social network analysis (SNA), and then performs clustering analysis using the information about subgroups. Finally, it makes recommendations using cluster-indexing CF based on the clustering results. This study tries to use the cores in subgroups as an initial seed for a conventional clustering algorithm. This model chooses five cores which have the highest value of degree centrality from SNA, and then performs clustering analysis by using the cores as initial centroids (cluster centers). Then, the model amplifies the impact of friends in social network in the process of cluster-indexing CF.
Abstract: This study aimed to develop and initially validate an instrument that measures social competency among tertiary level faculty members. A review of extant literature on social competence was done. The review of extant literature led to the writing of the items in the initial instrument which was evaluated by 11 Subject Matter Experts (SMEs). The SMEs were either educators or psychologists. The results of the evaluations done by the SMEs served as bases for the creation of the pre-try-out instrument used in the first trial-run. Insights from the first trial-run participants led to the development of the main try-out instrument used in the final test administration. One Hundred Forty-one participants from five private Higher Education Institutions (HEIs) in the National Capital Region (NCR) and five private HEIs in Central Luzon in the Philippines participated in the final test administration. The reliability of the instrument was evaluated using Cronbach-s Coefficient Alpha formula and had a Cronbach-s Alpha of 0.92. On the other hand, Factor Analysis was used to evaluate the validity of the instrument and six factors were identified. The development of the final instrument was based on the results of the evaluation of the instrument-s reliability and validity. For purposes of recognition, the instrument was named “Social Competency Inventory for Tertiary Level Faculty Members (SCI-TLFM)."
Abstract: Polymeric microreactors have emerged as a new
generation of carriers that hold tremendous promise in the areas of
cancer therapy, controlled delivery of drugs, for removal of
pollutants etc. Present work reports a simple and convenient
methodology for synthesis of polystyrene and poly caprolactone
microreactors. An aqueous suspension of carboxylated (1μm)
polystyrene latex particles was mixed with toluene solution followed
by freezing with liquid nitrogen. Freezed particles were incubated at
-20°C and characterized for formation of voids on the surface of
polymer microspheres by Field Emission Scanning Electron
Microscope. The hollow particles were then overnight incubated at
40ºC with unfunctionalized quantum dots (QDs) in 5:1 ratio. QDs
Encapsulated polystyrene microcapsules were characterized by
fluorescence microscopy.
Likewise Poly ε-caprolactone microreactors were prepared by
micro-volcanic rupture of freeze dried microspheres synthesized
using emulsification of polymer with aqueous Poly vinyl alcohol and
freezed with liquid nitrogen. Microreactors were examined with Field
Emission Scanning Electron Microscope for size and morphology.
Current study is an attempt to create hollow polymer particles which
can be employed for microencapsulation of nanoparticles and drug
molecules.
Abstract: This paper mainly proposes an efficient modified
particle swarm optimization (MPSO) method, to identify a slidercrank
mechanism driven by a field-oriented PM synchronous motor.
In system identification, we adopt the MPSO method to find
parameters of the slider-crank mechanism. This new algorithm is
added with “distance" term in the traditional PSO-s fitness function to
avoid converging to a local optimum. It is found that the comparisons
of numerical simulations and experimental results prove that the
MPSO identification method for the slider-crank mechanism is
feasible.
Abstract: A Finite Volume method based on Characteristic Fluxes for compressible fluids is developed. An explicit cell-centered resolution is adopted, where second and third order accuracy is provided by using two different MUSCL schemes with Minmod, Sweby or Superbee limiters for the hyperbolic part. Few different times integrator is used and be describe in this paper. Resolution is performed on a generic unstructured Cartesian grid, where solid boundaries are handled by a Cut-Cell method. Interfaces are explicitely advected in a non-diffusive way, ensuring local mass conservation. An improved cell cutting has been developed to handle boundaries of arbitrary geometrical complexity. Instead of using a polygon clipping algorithm, we use the Voxel traversal algorithm coupled with a local floodfill scanline to intersect 2D or 3D boundary surface meshes with the fixed Cartesian grid. Small cells stability problem near the boundaries is solved using a fully conservative merging method. Inflow and outflow conditions are also implemented in the model. The solver is validated on 2D academic test cases, such as the flow past a cylinder. The latter test cases are performed both in the frame of the body and in a fixed frame where the body is moving across the mesh. Adaptive Cartesian grid is provided by Paramesh without complex geometries for the moment.
Abstract: Group contribution methods such as the UNIFAC are
of major interest to researchers and engineers involved synthesis,
feasibility studies, design and optimization of separation processes as
well as other applications of industrial use. Reliable knowledge of
the phase equilibrium behavior is crucial for the prediction of the fate
of the chemical in the environment and other applications. The
objective of this study was to predict the solubility of selected
volatile organic compounds (VOCs) in glycol polymers and
biodiesel. Measurements can be expensive and time consuming,
hence the need for thermodynamic models. The results obtained in
this study for the infinite dilution activity coefficients compare very
well those published in literature obtained through measurements. It
is suggested that in preliminary design or feasibility studies of
absorption systems for the abatement of volatile organic compounds,
prediction procedures should be implemented while accurate fluid
phase equilibrium data should be obtained from experiment.
Abstract: ZnO+Ga2O3 functionally graded thin films (FGTFs)
were examined for their potential use as Solar cell and organic light
emitting diodes (OLEDs). FGTF transparent conducting oxides (TCO)
were fabricated by combinatorial RF magnetron sputtering. The
composition gradient was controlled up to 10% by changing the
plasma power of the two sputter guns. A Ga2O3+ZnO graded region
was placed on the top layer of ZnO. The FGTFs showed up to 80%
transmittance. Their surface resistances were reduced to < 10% by
increasing the Ga2O3: pure ZnO ratio in the TCO. The FGTFs- work
functions could be controlled within a range of 0.18 eV. The
controlled work function is a very promising technology because it
reduces the contact resistance between the anode and Hall transport
layers of OLED and solar cell devices.
Abstract: The aim of this study is to compare the innovativeness, risk taking, and focusing on opportunity of the nurse managers and nurses. The data are collected from nurse managers and nurses in Ondokuz Mayıs University, Faculty of Medicine Hospital and Karadeniz Technical University, Faculty of Medicine Hospital. The study sample consisted of 151 participants, 76 nurse managers (50.3%) and 75 nurses (49.7%). All participants have been assessed by Participant Information Form and Corporate Entrepreneurship Scale. In data analysis, independent t-test has applied. The results show that there are significant differences between nurse managers and nurses on innovativeness (t = 2.42, p < 0.05), risk taking (t = 3.62, p < 0.01), and focusing on opportunity (t = 2.16, p < 0.05). Consequently, it can be said that nurse managers have more innovativeness than nurses and tend to take more risks and focus more on opportunities.
Abstract: In this study, single nozzle method used for
electrospinning technique which composite polymer solution with
cellulose nanowiskers (CNW) was treated by ultrasonic sonificator
have been compared with coaxial (double) nozzle method, in terms of
mechanical, thermal and morphological properties of composite
nanofiber. The effect of water content in composite polymer solution
on properties of nanofiber has also been examined. It has been seen
that single nozzle method which polymer solution does not contain
water has better results than that of coaxial method, in terms of
mechanical, thermal and morphological properties of nanofiber.
However, it is necessary to make an optimization study on setting
condition of ultrasonic treatment to get better dispersion of CNW in
composite nanofiber and to get better mechanical and thermal
properties
Abstract: The draft Auckland Unitary Plan outlines the future land used for new housing and businesses with Auckland population growth over the next thirty years. According to Auckland Unitary Plan, over the next 30 years, the population of Auckland is projected to increase by one million, and up to 70% of total new dwellings occur within the existing urban area. Intensification will not only increase the number of median or higher density houses such as terrace house, apartment building, etc. within the existing urban area but also change mean housing design data that can impact building thermal performance under the local climate. Based on mean energy consumption and building design data, and their relationships of a number of Auckland sample houses, this study is to estimate the future mean housing energy consumption associated with the change of mean housing design data and evaluate housing energy efficiency with the Auckland Unitary Plan.
Abstract: In this paper, a new Genetic Algorithm (GA) based
methodology is proposed to optimize the Degree of Hybridization
(DOH) in a passenger parallel hybrid car. At first step, target
parameters for the vehicle are decided and then using ADvanced
VehIcle SimulatOR (ADVISOR) software, the variation pattern of
these target parameters, across the different DOHs, is extracted. At
the next step, a suitable cost function is defined and is optimized
using GA. In this paper, also a new technique has been proposed for
deciding the number of battery modules for each DOH, which leads
to a great improvement in the vehicle performance. The proposed
methodology is so simple, fast and at the same time, so efficient.
Abstract: 115 samples of Labeo calbasu ranged 8.0-17.9cm
length with mean11.90±1.96 and 4.9-68.5g weight with mean
22.25±12.54 from the River Chenab, Southern Punjab, Pakistan were
analyzed to investigate length-weight relationships (LWR) of fish in
relation to condition factor (K). Standard length (SL), fork length
(FL), head length (HL) head width (HW), body girth (BG), dorsal fin
length (DFL), dorsal fin base (DFB), pectoral fin length (PcFL),
pelvic fin length (PvFL) and anal fin length (AFL) are found to be
highly correlated with increasing total length and wet body weight (r
> 0.500). Wet body weight has positive (r=0.540) and total length
has no correlation (r=0.344) with calculated Condition factor (K).
The slope “b" in the relationship is 3.27 and intercepts -2.2258.
Abstract: Data mining and knowledge engineering have become a tough task due to the availability of large amount of data in the web nowadays. Validity and reliability of data also become a main debate in knowledge acquisition. Besides, acquiring knowledge from different languages has become another concern. There are many language translators and corpora developed but the function of these translators and corpora are usually limited to certain languages and domains. Furthermore, search results from engines with traditional 'keyword' approach are no longer satisfying. More intelligent knowledge engineering agents are needed. To address to these problems, a system known as Multilingual Word Semantic Network is proposed. This system adapted semantic network to organize words according to concepts and relations. The system also uses open source as the development philosophy to enable the native language speakers and experts to contribute their knowledge to the system. The contributed words are then defined and linked using lexical and semantic relations. Thus, related words and derivatives can be identified and linked. From the outcome of the system implementation, it contributes to the development of semantic web and knowledge engineering.
Abstract: In textile industry, besides the conventional textile
products, technical textile goods, that have been brought external
functional properties into, are being developed for technical textile
industry. Especially these products produced with weaving
technology are widely preferred in areas such as sports, geology,
medical, automotive, construction and marine sectors. These textile
products are exposed to various stresses and large deformations under
typical conditions of use. At this point, sufficient and reliable data
could not be obtained with uniaxial tensile tests for determination of
the mechanical properties of such products due to mainly biaxial
stress state. Therefore, the most preferred method is a biaxial tensile
test method and analysis. These tests and analysis is applied to fabrics
with different functional features in order to establish the textile
material with several characteristics and mechanical properties of the
product. Planar biaxial tensile test, cylindrical inflation and bulge
tests are generally required to apply for textile products that are used
in automotive, sailing and sports areas and construction industry to
minimize accidents as long as their service life. Airbags, seat belts
and car tires in the automotive sector are also subject to the same
biaxial stress states, and can be characterized by same types of
experiments. In this study, in accordance with the research literature
related to the various biaxial test methods are compared. Results with
discussions are elaborated mainly focusing on the design of a biaxial
test apparatus to obtain applicable experimental data for developing a
finite element model. Sample experimental results on a prototype
system are expressed.
Abstract: The contribution is dealing with the influence of high speed parameters on the quality of machined surface. In general the principle of high speed cutting lies in achieving faster machine times with concurrent increase in accuracy and quality of the machined areas in largely irregular, mathematically hard to define shapes. High speed machining is a highly effective method of machining with the following goals: increasing of machining productivity, increasing of quality of the machined surface, improving of machining economy, improving of ecological aspects of machining. This article is based on an experiment performed by the Department of Machining and Assembly of the Faculty of Mechanical Engineering of VŠBTechnical University of Ostrava.
Abstract: Load managing method on road became necessary
since overloaded vehicles occur damage on road facilities and existing
systems for preventing this damage still show many
problems.Accordingly, efficient managing system for preventing
overloaded vehicles could be organized by using the road itself as a
scale by applying genetic algorithm to analyze the load and the drive
information of vehicles.Therefore, this paper organized Ubiquitous
sensor network system for development of intelligent overload vehicle
regulation system, also in this study, to use the behavior of road, the
transformation was measured by installing underground box type
indoor model and indoor experiment was held using genetic algorithm.
And we examined wireless possibility of overloaded vehicle
regulation system through experiment of the transmission and
reception distance.If this system will apply to road and bridge, might
be effective for economy and convenience through establishment of
U-IT system..
Abstract: The migration-environment nexus has gained increased interest from the social research field over the last years. While straightly connected to human security issues, this theme has pervaded through the media to the public sphere. Therefore, it is important to observe how did the discussions over environmentally induced migrations develop from the scientific basis to the media attention, passing through some political voices, and in which ways might these messages be interpreted within the broader public discourses. To achieve this purpose, the analysis of the press entries between 2004 and 2010 in three of the main Portuguese newspapers shall be presented, specially reflecting upon the events, protagonists, topics, geographical attributions and terms/expressions used to define those who migrate due to environmental degradation or disasters.