Abstract: In this work, the condensation fraction and transition
temperature of neutral many bosonic system are studied within the
static fluctuation approximation (SFA). The effect of the potential
parameters such as the strength and range on the condensate fraction
was investigated. A model potential consisting of a repulsive step
potential and an attractive potential well was used. As the potential
strength or the core radius of the repulsive part increases, the
condensation fraction is found to be decreased at the same
temperature. Also, as the potential depth or the range of the attractive
part increases, the condensation fraction is found to be increased. The
transition temperature is decreased as the potential strength or the
core radius of the repulsive part increases, and it increases as the
potential depth or the range of the attractive part increases.
Abstract: The present work was conducted for the synthesis of
nano size zerovalent iron (nZVI) and hexavalent chromium (Cr(VI))
removal as a highly toxic pollutant by using this nanoparticles. Batch
experiments were performed to investigate the effects of Cr(VI),
nZVI concentration, pH of solution and contact time variation on
the removal efficiency of Cr(VI). nZVI was synthesized by
reduction of ferric chloride using sodium borohydrid. SEM and
XRD examinations applied for determination of particle size and
characterization of produced nanoparticles. The results showed that
the removal efficiency decreased with Cr(VI) concentration and pH
of solution and increased with adsorbent dosage and contact time.
The Langmuir and Freundlich isotherm models were used for the
adsorption equilibrium data and the Langmuir isotherm model was
well fitted. Nanoparticle ZVI presented an outstanding ability to
remove Cr(VI) due to high surface area, low particle size and high
inherent activity.
Abstract: One of the basic concepts in marketing is the concept
of meeting customers- needs. Since customer satisfaction is essential
for lasting survival and development of a business, screening and
observing customer satisfaction and recognizing its underlying
factors must be one of the key activities of every business.
The purpose of this study is to recognize the drivers that effect
customer satisfaction in a business-to-business situation in order to
improve marketing activities. We conducted a survey in which 93
business customers of a manufacturer of Diesel Generator in Iran
participated and they talked about their ideas and satisfaction of
supplier-s services related to its products. We developed the measures
for drivers of satisfaction first by as investigative research (by means
of feedback from executives and customers of sponsoring firm). Then
based on these measures, we created a mail survey, and asked the
respondents to explain their opinion about the sponsoring firm which
was a supplier of diesel generator and similar products. Furthermore,
the survey required the participants to mention their functional areas
and their company features.
In Conclusion we found that there are three drivers for customer
satisfaction, which are reliability, information about product, and
commercial features. Buyers/users from different functional areas
attribute different degree of importance to the last two drivers. For
instance, people from buying and management areas believe that
commercial features are more important than information about
products. But people in engineering, maintenance and production
areas believe that having information about products is more
important than commercial aspects. Marketing experts should
consider the attribute of customers regarding information about the
product and commercial features to improve market share.
Abstract: In this study the mixed convection heat transfer in a
coil-in-shell heat exchanger for various Reynolds numbers and
various dimensionless coil pitch was experimentally investigated.
The experiments were conducted for both laminar and turbulent flow
inside coil and the effects of coil pitch on shell-side heat transfer
coefficient of the heat exchanger were studied. The particular
difference in this study in comparison with the other similar studies
was the boundary conditions for the helical coils. The results indicate
that with the increase of coil pitch, shell-side heat transfer coefficient
is increased.
Abstract: The present investigation was undertaken to explore the biogas potentiality of Jatropha (Jatropha curcas, Euphorbiaceae) Fruit Coat (JFC) alone and in combination with cattle dung (CD) in various proportions at 15 per cent total solids by batch phase anaerobic digestion for a period of ten weeks HRT (Hydraulic Retention Time) under a temperature of 35°C+1°C. The maximum biogas production was noticed in Cattle dung and Jatropha Fruit Coat in 2:1 ratio with 403.84 L/kg dry matter followed by 3:1,1:2, 1:1 and 1:3 having 329.66, 219.77, 217.79, 203.64 L /kg dm respectively as compared to 178.49 L/kg dm in CD alone. The JFC alone found to produce 91 per cent of total biogas that obtained from Cattle dung. The per cent methane content of the biogas in all the treatments was found on par with Cattle dung.
Abstract: Urbanization and regionalization are two different
approaches when it comes to economical structures and development,
infrastructure and mobility, quality of life and living, education,
social cohesion and many other topics. At first glance, the structures
associated with urbanization and regionalization seems to be
contradicting. This paper discusses possibilities of transfer and
cooperation between rural and urban structures. An empirical
investigation contributed to reveal scenarios of supposable forms of
exchange and cooperation of remote rural areas and big cities.
Abstract: Following the laser ablation studies leading to a
theory of nuclei confinement by a Debye layer mechanism, we
present here numerical evaluations for the known stable nuclei where
the Coulomb repulsion is included as a rather minor component
especially for lager nuclei. In this research paper the required
physical conditions for the formation and stability of nuclei
particularly endothermic nuclei with mass number greater than to
which is an open astrophysical question have been investigated.
Using the Debye layer mechanism, nuclear surface energy, Fermi
energy and coulomb repulsion energy it is possible to find conditions
under which the process of nucleation is permitted in early universe.
Our numerical calculations indicate that about 200 second after the
big bang at temperature of about 100 KeV and subrelativistic region
with nucleon density nearly equal to normal nuclear density namely,
10cm all endothermic and exothermic nuclei have been
formed.
Abstract: A method based on the power series solution is proposed to solve the natural frequency of flapping vibration for the rotating inclined Euler beam with constant angular velocity. The vibration of the rotating beam is measured from the position of the corresponding steady state axial deformation. In this paper the governing equations for linear vibration of a rotating Euler beam are derived by the d'Alembert principle, the virtual work principle and the consistent linearization of the fully geometrically nonlinear beam theory in a rotating coordinate system. The governing equation for flapping vibration of the rotating inclined Euler beam is linear ordinary differential equation with variable coefficients and is solved by a power series with four independent coefficients. Substituting the power series solution into the corresponding boundary conditions at two end nodes of the rotating beam, a set of homogeneous equations can be obtained. The natural frequencies may be determined by solving the homogeneous equations using the bisection method. Numerical examples are studied to investigate the effect of inclination angle on the natural frequency of flapping vibration for rotating inclined Euler beams with different angular velocity and slenderness ratio.
Abstract: A Matlab based software for logistic regression is developed to enhance the process of teaching quantitative topics and assist researchers with analyzing wide area of applications where categorical data is involved. The software offers an option of performing stepwise logistic regression to select the most significant predictors. The software includes a feature to detect influential observations in data, and investigates the effect of dropping or misclassifying an observation on a predictor variable. The input data may consist either as a set of individual responses (yes/no) with the predictor variables or as grouped records summarizing various categories for each unique set of predictor variables' values. Graphical displays are used to output various statistical results and to assess the goodness of fit of the logistic regression model. The software recognizes possible convergence constraints when present in data, and the user is notified accordingly.
Abstract: Turbulent forced convection flow in a 2-dimensional channel over periodic grooves is numerically investigated. Finite volume method is used to study the effect of turbulence model. The range of Reynolds number varied from 10000 to 30000 for the ribheight to channel-height ratio (B/H) of 2. The downstream wall is heated by a uniform heat flux while the upstream wall is insulated. The investigation is analyzed with different types of nanoparticles such as SiO2, Al2O3, and ZnO, with water as a base fluid are used. The volume fraction is varied from 1% to 4% and the nanoparticle diameter is utilized between 20nm to 50nm. The results revealed 114% heat transfer enhancement compared to the water in a grooved channel by using SiO2 nanoparticle with volume fraction and nanoparticle diameter of 4% and 20nm respectively.
Abstract: Deep cold rolling (DCR) is a cold working process, which easily produces a smooth and work-hardened surface by plastic deformation of surface irregularities. In the present study, the influence of main deep cold rolling process parameters on the surface roughness and the hardness of AISI 4140 steel were studied by using fractional factorial design of experiments. The assessment of the surface integrity aspects on work material was done, in terms of identifying the predominant factor amongst the selected parameters, their order of significance and setting the levels of the factors for minimizing surface roughness and/or maximizing surface hardness. It was found that the ball diameter, rolling force, initial surface roughness and number of tool passes are the most pronounced parameters, which have great effects on the work piece-s surface during the deep cold rolling process. A simple, inexpensive and newly developed DCR tool, with interchangeable collet for using different ball diameters, was used throughout the experimental work presented in this paper.
Abstract: Numerical calculations of flow around a square cylinder are presented using the multi-relaxation-time lattice Boltzmann method at Reynolds number 150. The effects of upstream locations, downstream locations and blockage are investigated systematically. A detail analysis are given in terms of time-trace analysis of drag and lift coefficients, power spectra analysis of lift coefficient, vorticity contours visualizations and phase diagrams. A number of physical quantities mean drag coefficient, drag coefficient, Strouhal number and root-mean-square values of drag and lift coefficients are calculated and compared with the well resolved experimental data and numerical results available in open literature. The results had shown that the upstream, downstream and height of the computational domain are at least 7.5, 37.5 and 12 diameters of the cylinder, respectively.
Abstract: The main aim of this study was to examine whether
people understand indicative conditionals on the basis of syntactic
factors or on the basis of subjective conditional probability. The
second aim was to investigate whether the conditional probability of
q given p depends on the antecedent and consequent sizes or derives
from inductive processes leading to establish a link of plausible cooccurrence
between events semantically or experientially associated.
These competing hypotheses have been tested through a 3 x 2 x 2 x 2
mixed design involving the manipulation of four variables: type of
instructions (“Consider the following statement to be true", “Read the
following statement" and condition with no conditional statement);
antecedent size (high/low); consequent size (high/low); statement
probability (high/low). The first variable was between-subjects, the
others were within-subjects. The inferences investigated were Modus
Ponens and Modus Tollens. Ninety undergraduates of the Second
University of Naples, without any prior knowledge of logic or
conditional reasoning, participated in this study.
Results suggest that people understand conditionals in a syntactic
way rather than in a probabilistic way, even though the perception of
the conditional probability of q given p is at least partially involved in
the conditionals- comprehension. They also showed that, in presence
of a conditional syllogism, inferences are not affected by the
antecedent or consequent sizes. From a theoretical point of view these
findings suggest that it would be inappropriate to abandon the idea
that conditionals are naturally understood in a syntactic way for the
idea that they are understood in a probabilistic way.
Abstract: In this paper, the torsion capacity of ultimate point on rectangular beams with spiral reinforcements in the torsion direction and its anti-direction are investigated. Therefore, models of above-mentioned beams have been numerically analyzed under various loads using ANSYS software. It was observed that, spirallyreinforced prismatic beam and beam with spiral links, show lower torsion capacity than beam with normal links also in anti-direction. The result is that the concrete regulations are violated in this case.
Abstract: One of the most challengeable issues in ESL
(Electronic System Level) design is the lack of a general modeling
scheme for on chip communication architecture. In this paper some
of the mostly used methodologies for modeling and representation of
on chip communication are investigated. Our goal is studying the
existing methods to extract the requirements of a general
representation scheme for communication architecture synthesis. The
next step, will be introducing a modeling and representation method
for being used in automatically synthesis process of on chip
communication architecture.
Abstract: An investigation of the process of deformation hardening and evolution of deformation defect medium in dispersion-hardened materials with face centered cubic matrices and nanoparticles was done. Mathematical model including balance equation for the deformation defects was used.
Abstract: Composite steel-concrete slabs using thin-walled
corrugated steel sheets with embossments represent a modern and
effective combination of steel and concrete. However, the design
of new types of sheeting is conditional on the execution of expensive
and time-consuming laboratory testing. The effort to develop
a cheaper and faster method has lead to many investigations all over
the world. In our paper we compare the results from our experiments
involving vacuum loading, four-point bending and small-scale shear
tests.
Abstract: An Ad hoc wireless network comprises of mobile
terminals linked and communicating with each other sans the aid of
traditional infrastructure. Optimized Link State Protocol (OLSR) is a
proactive routing protocol, in which routes are discovered/updated
continuously so that they are available when needed. Hello messages
generated by a node seeks information about its neighbor and if the
latter fails to respond to a specified number of hello messages
regulated by neighborhood hold time, the node is forced to assume
that the neighbor is not in range. This paper proposes to evaluate
OLSR routing protocol in a random mobility network having various
neighborhood hold time intervals. The throughput and delivery ratio
are also evaluated to learn about its efficiency for multimedia loads.
Abstract: This paper numerically investigates the effects of input
speed on the overall dynamic characteristics of a multi-body system
with differently located revolute clearance joints without friction. A
typical planar slider-crank mechanism is used as a demonstration case
in which the effects of the input speed on the dynamic performance
of the mechanism with a revolute clearance joint between the crank
and connecting rod, and between the connecting rod and slider are
separately investigated with comprehensive observations numerically
presented. It is observed that, changing the driving speed of a multibody
system makes the behavior of the system to change from
either periodic to chaotic, or chaotic to periodic depending on which
joint has clearance. The location of the clearance revolute joint and
the operating speed of a multi-body system play a crucial role in
predicting accurately the dynamic responses of the system. Therefore
the dynamic behavior of one clearance revolute joint cannot be used
as a general case for a mechanical system.
Abstract: A comparative evaluation of acute toxicity of
synthesized nano silvers using two different procedures (biological
and chemical reduction methods) and silver ions on bacteria
Vibrio fischeri was investigated. The bacterial light inhibition test as
a toxicological endpoint was used by applying of a homemade
luminometer. To compare the toxicity effects as a quantitative
parameter, a nominal effective concentrations (EC) of chemicals and
a susceptibility constant (Z-value) of bacteria, after 5 min and 30 min
exposure times, were calculated. After 5 and 30 min contact times,
the EC50 values of two silver nanoparticles and the EC20 values were
about similar. It demonstrates that toxicity of silvers was independent
of their procedure. The EC values of nanoparticles were larger than
those of the silver ions. The susceptibilities(Z- Values) of V.fischeri
(L/mg) to the silver ions were greater than those of the nano silvers.
According to the EC and Z values, the toxicity of silvers decreased in
the following order: Silver ions >> silver nanoparticles from
chemical reduction method ~ silver nanoparticles from biological
method.