Abstract: Circular tubes have been widely used as structural
members in engineering application. Therefore, its collapse behavior
has been studied for many decades, focusing on its energy absorption
characteristics. In order to predict the collapse behavior of members,
one could rely on the use of finite element codes or experiments.
These tools are helpful and high accuracy but costly and require
extensive running time. Therefore, an approximating model of tubes
collapse mechanism is an alternative for early step of design. This
paper is also aimed to develop a closed-form solution of thin-walled
circular tube subjected to bending. It has extended the Elchalakani et
al.-s model (Int. J. Mech. Sci.2002; 44:1117-1143) to include the
rate of energy dissipation of rolling hinge in the circumferential
direction. The 3-D geometrical collapse mechanism was analyzed by
adding the oblique hinge lines along the longitudinal tube within the
length of plastically deforming zone. The model was based on the
principal of energy rate conservation. Therefore, the rates of internal
energy dissipation were calculated for each hinge lines which are
defined in term of velocity field. Inextensional deformation and
perfect plastic material behavior was assumed in the derivation of
deformation energy rate. The analytical result was compared with
experimental result. The experiment was conducted with a number of
tubes having various D/t ratios. Good agreement between analytical
and experiment was achieved.
Abstract: The present work describes an experimental
investigation concerning the determination of viscosity behavior with
shear rate and temperature of edible oils: canola; sunflower; corn;
soybean and the no edible oil: Jatropha curcas. Besides these, it was
tested a blend of canola, corn and sunflower oils as well as sunflower
and soybean biodiesel. Based on experiments, it was obtained shear
stress and viscosity at different shear rates of each sample at 40ºC, as
well as viscosity of each sample at various temperatures in the range
of 24 to 85ºC. Furthermore, it was compared the curves obtained for
the viscosity versus temperature with the curves obtained by
modeling the viscosity dependency on temperature using the Vogel
equation. Also a test in a stationary engine was performed in order to
study the energy generation using blends of soybean oil and soybean
biodiesel with diesel.
Abstract: This paper explores the use of project work in a
content-based instruction in a Rajabhat University, a teacher college,
where student teachers are instructed to perform teaching roles
mainly in basic education level. Its aim is to link theory to practice,
and to help language teachers maximize the full potential of project
work for genuine communication and give real meaning to writing
activity. Two research questions are formulated to guide this study:
a) What is the academic achievement of the students- writing skill
against the 70% attainment target after the use of project to enhance
the skill? and b) To what degree is the development of the students-
writing skills during the course of project to enhance the skill? The
sample of the study comprised of 38 fourth-year English major
students. The data was collected by means of achievement test,
student writing works, and project diary. The scores in the summative
achievement test were analyzed by mean score, standard deviation,
and t-test. Project diary serves as students- record of the language
acquired during the project. List of structures and vocabulary noted in
the diary has shown students- ability to attend to, recognize, and
focus on meaningful patterns of language forms.
Abstract: In recent years, the underground water sources in
southern Taiwan have become salinized because of saltwater
intrusions. This study explores the adsorption characteristics of
activated carbon on salinizing inorganic salts using isothermal
adsorption experiments and provides a model analysis. The
temperature range for the isothermal adsorption experiments ranged
between 5 to 45 ℃, and the amount adsorbed varied between 28.21 to
33.87 mg/g. All experimental data of adsorption can be fitted to both
the Langmuir and the Freundlich models. The thermodynamic
parameters for per chlorate onto granular activated carbon were
calculated as -0.99 to -1.11 kcal/mol for DG°, -0.6 kcal/mol for DH°,
and 1.21 to 1.84 kcal/mol for DS°. This shows that the adsorption
process of granular activated carbon is spontaneously exothermic. The
observation of adsorption behaviors under low ionic strength, low pH
values, and low temperatures is beneficial to the adsorption removal of
perchlorate with granular activated carbon.
Abstract: The product development process (PDP) in the
Technology group plays a very important role in the launch of any
product. While a manufacturing process encourages the use of certain
measures to reduce health, safety and environmental (HSE) risks on
the shop floor, the PDP concentrates on the use of Geometric
Dimensioning and Tolerancing (GD&T) to develop a flawless design.
Furthermore, PDP distributes and coordinates activities between
different departments such as marketing, purchasing, and
manufacturing. However, it is seldom realized that PDP makes a
significant contribution to developing a product that reduces HSE
risks by encouraging the Technology group to use effective GD&T.
The GD&T is a precise communication tool that uses a set of
symbols, rules, and definitions to mathematically define parts to be
manufactured. It is a quality assurance method widely used in the oil
and gas sector. Traditionally it is used to ensure the
interchangeability of a part without affecting its form, fit, and
function. Parts that do not meet these requirements are rejected
during quality audits.
This paper discusses how the Technology group integrates this
quality assurance tool into the PDP and how the tool plays a major
role in helping the HSE department in its goal towards eliminating
HSE incidents. The PDP involves a thorough risk assessment and
establishes a method to address those risks during the design stage.
An illustration shows how GD&T helped reduce safety risks by
ergonomically improving assembling operations. A brief discussion
explains how tolerances provided on a part help prevent finger injury.
This tool has equipped Technology to produce fixtures, which are
used daily in operations as well as manufacturing. By applying
GD&T to create good fits, HSE risks are mitigated for operating
personnel. Both customers and service providers benefit from
reduced safety risks.
Abstract: Bionanotechnology deals with nanoscopic interactions between nanostructured materials and biological systems. Polymer nanocomposites with optimized biological activity have attracted great attention. Nanoclay is considered as reinforcing nanofiller in manufacturing of high performance nanocomposites. In current study, organomodified-nanoclay with negatively charged silicate layers was incorporated into biomedical grade silicone rubber. Nanoparticle loading has been tailored to enhance cell behavior. Addition of nanoparticles led to improved mechanical properties of substrate with enhanced strength and stiffness while no toxic effects was observed. Results indicated improved viability and proliferation of cells by addition of nanofillers. The improved mechanical properties of the matrix result in proper cell response through adjustment and arrangement of cytoskeletal fibers. Results can be applied in tissue engineering when enhanced substrates are required for improvement of cell behavior for in vivo applications.
Abstract: The hydrodynamic processes in bubbly liquid flowing
in tubes and nozzles are studied theoretically and numerically. The
principal regularities of non-stationary processes of boiling liquid
outflow are established under conditions of experiments when the
depressurization of a tube with high pressure inside occurs. The
steady-state solution of bubbly liquid flow in the nozzle of round
cross section with high pressure and temperature conditions inside
bubbles is studied accounting for phase transition and chemical
reactions.
Abstract: Recent research result has shown that two multidelay
feedback systems can synchronize each other under different
schemes, i.e. lag, projective-lag, anticipating, or projectiveanticipating
synchronization. There, the driving signal is significantly
complex due that it is constituted by multiple nonlinear transformations
of delayed state variable. In this paper, a secure communication
model is proposed based on synchronization of coupled multidelay
feedback systems, in which the plain signal is mixed with a complex
signal at the transmitter side and it is precisely retrieved at the receiver
side. The effectiveness of the proposed model is demonstrated and
verified in the specific example, where the message signal is masked
directly by the complex signal and security is examined under the
breaking method of power spectrum analysis.
Abstract: The wave function at the origin is an important quantity in studying many physical problems concerning heavy quarkonia. This is because that it is using for calculating spin state hyperfine splitting and also crucial to evaluating the production and decay amplitude of the heavy quarkonium. In this paper, we present the variational method by using the single-parameter wave function to estimate the WFO for the ground state of heavy mesons.
Abstract: Databases have become ubiquitous. Almost all IT applications are storing into and retrieving information from databases. Retrieving information from the database requires knowledge of technical languages such as Structured Query Language (SQL). However majority of the users who interact with the databases do not have a technical background and are intimidated by the idea of using languages such as SQL. This has led to the development of a few Natural Language Database Interfaces (NLDBIs). A NLDBI allows the user to query the database in a natural language. This paper highlights on architecture of new NLDBI system, its implementation and discusses on results obtained. In most of the typical NLDBI systems the natural language statement is converted into an internal representation based on the syntactic and semantic knowledge of the natural language. This representation is then converted into queries using a representation converter. A natural language query is translated to an equivalent SQL query after processing through various stages. The work has been experimented on primitive database queries with certain constraints.
Abstract: The density estimates considered in this paper comprise
a base density and an adjustment component consisting of a linear
combination of orthogonal polynomials. It is shown that, in the
context of density approximation, the coefficients of the linear combination
can be determined either from a moment-matching technique
or a weighted least-squares approach. A kernel representation of
the corresponding density estimates is obtained. Additionally, two
refinements of the Kronmal-Tarter stopping criterion are proposed
for determining the degree of the polynomial adjustment. By way of
illustration, the density estimation methodology advocated herein is
applied to two data sets.
Abstract: Recently, with the appearance of smart cards, many
user authentication protocols using smart card have been proposed to
mitigate the vulnerabilities in user authentication process. In 2004,
Das et al. proposed a ID-based user authentication protocol that is
secure against ID-theft and replay attack using smart card. In 2009,
Wang et al. showed that Das et al.-s protocol is not secure to randomly
chosen password attack and impersonation attack, and proposed an
improved protocol. Their protocol provided mutual authentication and
efficient password management. In this paper, we analyze the security
weaknesses and point out the vulnerabilities of Wang et al.-s protocol.
Abstract: Nuts are part of a healthy diet such as Mediterranean diet. Benefits of nuts in reducing the risk of heart disease has been reasonably attributed to their composition of vitamins, minerals, unsaturated fatty acids, fiber and phytochemicals such as polyphenols, tocopherols, squalene and phytosterols. More than 75% of total fatty acids of nuts are unsaturated. α- tocopherol is the main tocopherol isomer present in most of the nuts. While walnuts, Brazil nut, cashew nut, peanut, pecan and pistachio nuts are rich in γ- tocopherol. β- sitosterol is dominant sterol in nuts. Pistachio and pine nut have the highest total phytosterol and Brazil nut and English walnut the lowest. Walnuts also contain large amount of phenolic compounds compared with other nuts. Nuts are rich in compounds with antioxidant properties and their consumption can offer preventing from incidence of many diseases including cardiovascular.
Abstract: The present work describes a computational study of
aerodynamic characteristics of GLC305 airfoil clean and with 16.7
min ice shape (rime 212) and 22.5 min ice shape (glaze 944).The
performance of turbulence models SA, Kε, Kω Std, and Kω SST
model are observed against experimental flow fields at different
Mach numbers 0.12, 0.21, 0.28 in a range of Reynolds numbers
3x106, 6x106, and 10.5x106 on clean and iced aircraft airfoil
GLC305. Numerical predictions include lift, drag and pitching
moment coefficients at different Mach numbers and at different angle
of attacks were done. Accuracy of solutions with respect to the
effects of turbulence models, variation of Mach number, initial
conditions, grid resolution and grid spacing near the wall made the
study much sensitive. Navier Stokes equation based computational
technique is used. Results are very close to the experimental results.
It has seen that SA and SST models are more efficient than Kε and
Kω standard in under study problem.
Abstract: In this paper, we study the existence, the boundedness and the asymptotic behavior of the positive solutions of a fuzzy nonlinear difference equations xn+1 = A + k i=0 Bi xn-i , n= 0, 1, · · · . where (xn) is a sequence of positive fuzzy numbers, A,Bi and the initial values x-k, x-k+1, · · · , x0 are positive fuzzy numbers. k ∈ {0, 1, 2, · · ·}.
Abstract: This paper makes a contribution to the on-going
debate on conceptualization and lexicalization of cutting and
breaking (C&B) verbs by discussing data from Telugu, a language of
India belonging to the Dravidian family. Five Telugu native speakers-
verbalizations of agentive actions depicted in 43 short video-clips
were analyzed. It was noted that verbalization of C&B events in
Telugu requires formal units such as simple lexical verbs, explicator
compound verbs, and other complex verb forms. The properties of
the objects involved, the kind of instruments used, and the manner of
action had differential influence on the lexicalization patterns.
Further, it was noted that all the complex verb forms encode 'result'
and 'cause' sub-events in that order. Due to the polysemy associated
with some of the verb forms, our data does not support the
straightforward bipartition of this semantic domain.
Abstract: Gas condensate Reservoirs show complicated thermodynamic behavior when their pressure reduces to under dew point pressure. Condensate blockage around the producing well cause significant reduction of production rate as well bottom-hole pressure drops below saturation pressure. The main objective of this work was to examine the well test analysis of naturally fractured lean gas condensate reservoir and investigate the effect of condensate formed around the well-bore on behavior of single phase pseudo pressure and its derivative curves. In this work a naturally fractured lean gas condensate reservoir is simulated with compositional simulator. Different sensitivity analysis done on Corry parameters and result of simulator is feed to analytical well testing software. For consideration of these phenomena eighteen compositional models with Capillary number effect are constructed. Matrix relative permeability obeys Corry relative permeability and relative permeability in fracture is linear. Well testing behavior of these models are studied and interpreted. Results show different sensitivity analysis on relative permeability of matrix does not have strong effect on well testing behavior even most part of the matrix around the well is occupied with condensate.
Abstract: As a part of routine oesophageal HDR Brachytherapy procedure, treatment planning takes about 45 minutes while patients are under light sedation. Some patients may suffer gagging and/or spasms before the 90-minute brachytherapy procedure complete, and the treatment may need to be aborted. A pre-prepared plan generated before patient’s sedation may reduce the brachytherapy procedure time by 40 minutes. This paper reports rationality and evidence of pre-prepared treatment plans. A retrospective study of 28 patients confirms that pre-prepared plans would be acceptable for all reviewed patients. The rationality is further confirmed by a systemic study with a wide range of applicator curvature and treatment volume. Detailed comparison between CT based treatment plans and pre-prepared plans are discussed. The argument holds for endobronchial HDR brachytherapy too. With the above evidence, pre-prepared plans have been used for all oesophageal and endobronchial HDR brachytherapy cases in our clinic.
Abstract: This paper explains the cause of nonlinearity in floor
attenuation hither to left unexplained. The performance degradation
occurring in air interface for GSM signals is quantitatively analysed
using the concept of Radiating Columns of buildings. The signal
levels were measured using Wireless Network Optimising Drive Test
Tool (E6474A of Agilent Technologies). The measurements were
taken in reflected signal environment under usual fading conditions
on actual GSM signals radiated from base stations. A mathematical
model is derived from the measurements to predict the GSM signal
levels in different floors. It was applied on three buildings and found
that the predicted signal levels deviated from the measured levels
with in +/- 2 dB for all floors. It is more accurate than the prediction
models based on Floor Attenuation Factor. It can be used for
planning proper indoor coverage in multi storey buildings.
Abstract: This paper presents a comparative study of statistical methods for the multi-response surface optimization of a cryogenic freezing process. Taguchi design and analysis and steepest ascent methods based on the desirability function were conducted to ascertain the influential factors of a cryogenic freezing process and their optimal levels. The more preferable levels of the set point, exhaust fan speed, retention time and flow direction are set at -90oC, 20 Hz, 18 minutes and Counter Current, respectively. The overall desirability level is 0.7044.