Abstract: Transmission shafts are affected by various forces, for
example, during acceleration or sudden breaks, bending during
transportation, vertical forces that lead to cuts. One of the main
failures in combines is breaking shaft which repairmen refer it.
Structural resistance of canal against torque is very important in the
beginning of the movement. For analyzing stress, a typical sample
from a type of combine was selected, called JD955 combine. Long
shaft in this combine was analyzed with finite element method by
Ansys13 generic package under static load. Conducted analysis
showed that there is a maximum stress in contact surfaces of
indentations and also in place of changing diameter. Safety factor
value is low in parts of the shaft and this increases the probability of
failure at these points. To improve the conditions with the least cost
and an approach of product improvement, using alternative alloy is
important.
Abstract: The aims of this study were to determine the factor
structure and psychometric properties (i.e., reliability and convergent
validity) of the Malaysian Multi-Ethnic Discrimination Scale
(MMEDS). It consists of 71-items measure experience, strategies
used and consequences of ethnic discrimination. A sample of 649
university students from one of the higher education institution in
Malaysia was asked to complete MMEDS, as well as Perceived
Ethnic and Racial Discrimination. The exploratory factor analysis on
ethnic discrimination experience extracted two factors labeled ‘unfair
treatment’ (15 items) and ‘Denial of the ethnic right’ (12 items)
which accounted for 60.92% of the total variance. The two sub scales
demonstrated clear reliability with internal consistency above .70.
The convergent validity of the Scale was supported by an expected
pattern of correlations (positive and significant correlation) between
the score of unfair treatment and denial of the ethnic right and the
score of Perceived Ethnic and Racial Discrimination by Peers Scale.
The results suggest that the MMEDS is a reliable and valid measure.
However, further studies need to be carried out in other groups of
sample as to validate the Scale.
Abstract: The efficiency of the actuation system of exoskeletons
and active orthoses for lower limbs is a significant aspect of the
design of such devices because it affects their efficacy. The F-IVT is
an innovative actuation system to power artificial knee joint with
energy recovery capabilities. Its key and non-conventional elements
are a flywheel that acts as a mechanical energy storage system, and
an Infinitely Variable Transmission (IVT). The design of the F-IVT
can be optimized for a certain walking condition, resulting in a heavy
reduction of both the electric energy consumption and of the electric
peak power. In this work, by means of simulations of level ground
walking at different speeds, it is demonstrated that the F-IVT is still
an advantageous actuator which permits to save energy consumption
and to downsize the electric motor even when it does not work in
nominal conditions.
Abstract: This study is about the structural transformations of
aluminium examining with the Dynamic Mechanical Thermal
Analyzer (DMTA). It is a faster and simpler measuring method to
make consequence about the metal’s structural transformations. The
device measures the changing of the mechanical characteristics
depending on the heating rate, and concludes certain transformations.
This measuring method fast and shows clean-cut results comparing
the conventional ways.
Applying polymer measuring devices for metal investigations is
not widespread method. One of the adaptable ways is shown in this
study. The article compares the results of the small specimen test and
the DMTA method, considering the temperature and the forming
dependence of recrystallization temperature.
Abstract: An Australian manufacturer has fabricated an
innovative GFRP sandwich panel made from E-glass fiber skin and a
modified phenolic core for structural applications. Debonding, which
refers to separation of skin from the core material in composite
sandwiches, is one of the most common types of damage in
composites. The presence of debonding is of great concern because it
not only severely affects the stiffness but also modifies the dynamic
behaviour of the structure. Generally it is seen that the majority of
research carried out has been concerned about the delamination of
laminated structures whereas skin-core debonding has received
relatively minor attention. Furthermore it is observed that research
done on composite slabs having multiple skin-core debonding is very
limited. To address this gap, a comprehensive research investigating
dynamic behaviour of composite panels with single and multiple
debonding is presented. The study uses finite-element modelling and
analyses for investigating the influence of debonding on free
vibration behaviour of single and multilayer composite sandwich
panels. A broad parametric investigation has been carried out by
varying debonding locations, debonding sizes and support conditions
of the panels in view of both single and multiple debonding.
Numerical models were developed with Strand7 finite element
package by innovatively selecting the suitable elements to diligently
represent their actual behavior. Three-dimensional finite element
models were employed to simulate the physically real situation as
close as possible, with the use of an experimentally and numerically
validated finite element model. Comparative results and conclusions
based on the analyses are presented. For similar extents and locations
of debonding, the effect of debonding on natural frequencies appears
greatly dependent on the end conditions of the panel, giving greater
decrease in natural frequency when the panels are more restrained.
Some modes are more sensitive to debonding and this sensitivity
seems to be related to their vibration mode shapes. The fundamental
mode seems generally the least sensitive mode to debonding with
respect to the variation in free vibration characteristics. The results
indicate the effectiveness of the developed three dimensional finite
element models in assessing debonding damage in composite
sandwich panels.
Abstract: In this study, out-of-plane free vibrations of a circular
rods is investigated theoretically. The governing equations for
naturally twisted and curved spatial rods are obtained using
Timoshenko beam theory and rewritten for circular rods. Effects of
the axial and shear deformations are considered in the formulations.
Ordinary differential equations in scalar form are solved analytically
by using transfer matrix method. The circular rods of the mass matrix
are obtained by using straight rod of consistent mass matrix. Free
vibrations frequencies obtained by solving eigenvalue problem. A
computer program coded in MATHEMATICA language is prepared.
Circular beams are analyzed through various examples for free
vibrations analysis. Results are compared with ANSYS results based
on finite element method and available in the literature.
Abstract: The Aptima® HIV-1 Quant Dx Assay is a fully
automated assay on the Panther system. It is based on Transcription-
Mediated Amplification and real time detection technologies. This
assay is intended for monitoring HIV-1 viral load in plasma
specimens and for the detection of HIV-1 in plasma and serum
specimens.
Nine-hundred and seventy nine specimens selected at random
from routine testing at St Thomas’ Hospital, London were
anonymised and used to compare the performance of the Aptima
HIV-1 Quant Dx assay and Roche COBAS® AmpliPrep/COBAS®
TaqMan® HIV-1 Test, v2.0. Two-hundred and thirty four specimens
gave quantitative HIV-1 viral load results in both assays. The
quantitative results reported by the Aptima Assay were comparable to
those reported by the Roche COBAS AmpliPrep/COBAS TaqMan
HIV-1 Test, v2.0 with a linear regression slope of 1.04 and an
intercept on -0.097.
The Aptima assay detected HIV-1 in more samples than the
COBAS assay. This was not due to lack of specificity of the Aptima
assay because this assay gave 99.83% specificity on testing plasma
specimens from 600 HIV-1 negative individuals. To understand the
reason for this higher detection rate a side-by-side comparison of low
level panels made from the HIV-1 3rd international standard
(NIBSC10/152) and clinical samples of various subtypes were tested
in both assays. The Aptima assay was more sensitive than the
COBAS assay.
The good sensitivity, specificity and agreement with other
commercial assays make the HIV-1 Quant Dx Assay appropriate for
both viral load monitoring and detection of HIV-1 infections.
Abstract: Technology, multimedia in Open Educational
Resources, can contribute positively to student performance in an
online instructional environment. Student performance data of past
four years were obtained from an online course entitled Applied
Calculus (MA139). This paper examined the data to determine
whether multimedia (independent variable) had any impact on
student performance (dependent variable) in online math learning,
and how students felt about the value of the technology. Two groups
of student data were analyzed, group 1 (control) from the online
applied calculus course that did not use multimedia instructional
materials, and group 2 (treatment) of the same online applied calculus
course that used multimedia instructional materials. For the MA139
class, results indicate a statistically significant difference (p = .001)
between the two groups, where group 1 had a final score mean of
56.36 (out of 100), group 2 of 70.68. Additionally, student
testimonials were discussed in which students shared their experience
in learning applied calculus online with multimedia instructional
materials.
Abstract: 600 schools going adolescents and 100 teachers from
16 schools of Dhemaji and Lakhimpur district of Assam, India were
surveyed to assess and compare their awareness regarding AIDS and
AIDS Education. An awareness test was administered containing 38
items for adolescents and 40 items for teachers in the test.
Observations revealed that the majority of school-going adolescents
are poor in their HIV/AIDS and AIDS education awareness. It shows
that the school going adolescents of Dhemaji district are better in
HIV/AIDS and AIDS education awareness than the school going
adolescents of Lakhimpur district while comparing the gender,
settlement, steam and district wise variables.
Abstract: The main objective of incorporating natural fibers such as Henequen microfibers (NF) into the High Density Polyethylene (HDPE) polymer matrix is to reduce the cost and to enhance the mechanical as well as other properties. The Henequen microfibers were chopped manually to 5-7mm in length and added into the polymer matrix at the optimized concentration of 8 wt %. In order to facilitate the link between Henequen microfibers (NF) and HDPE matrix, coupling agent such as Glycidoxy (Epoxy) Functional Methoxy Silane (GPTS) at various concentrations from 0.1%, 0.3%, 0.5%, 0.7%, 0.9% and 1% by weight to the total fibers were added. The tensile strength of the composite increased marginally while % elongation at break of the composites decreased with increase in silane loading by wt %. Tensile modulus and stiffness observed increased at 0.9 wt % GPTS loading. Flexural as well as impact strength of the composite decreased with increase in GPTS loading by weight %. Dielectric strength of the composite also found increased marginally up to 0.5wt % silane loading and thereafter remained constant.
Abstract: Image enhancement is a challenging issue in many applications. In the last two decades, there are various filters developed. This paper proposes a novel method which removes Gaussian noise from the gray scale images. The proposed technique is compared with Enhanced Fuzzy Peer Group Filter (EFPGF) for various noise levels. Experimental results proved that the proposed filter achieves better Peak-Signal-to-Noise-Ratio PSNR than the existing techniques. The proposed technique achieves 1.736dB gain in PSNR than the EFPGF technique.
Abstract: The principle of the seismic performance evaluation methods is to provide a measure of capability for a building or set of buildings to be damaged by an earthquake. The common objective of many of these methods is to supply classification criteria. The purpose of this study is to present a method for assessing the seismic performance of structures, based on Pushover method; we are particularly interested in reinforced concrete frame structures, which represent a significant percentage of damaged structures after a seismic event. The work is based on the characterization of seismic movement of the various earthquake zones in terms of PGA and PGD that is obtained by means of SIMQK_GR and PRISM software and the correlation between the points of performance and the scalar characterizing the earthquakes will developed.
Abstract: Introduction: Researchers globally have strived to explore diverse factors that augment the continuation and uptake of family planning methods. Clients’ satisfaction is one of the core determinants facilitating continuation of family planning methods. There is a major debate yet scanty evidence to contrast public and private sectors with respect to client satisfaction. The objective of this study is to compare quality-of-care provided by public and private sectors of Pakistan through a client satisfaction lens. Methods: We used Pakistan Demographic Heath Survey 2012-13 dataset on 3133 women. Ten different multivariate models were made. to explore the relationship between client satisfaction and dependent outcome after adjusting for all known confounding factors and results are presented as OR and AOR (95% CI). Results: Multivariate analyses showed that clients were less satisfied in contraceptive provision from private sector as compared to public sector (AOR 0.92, 95% CI 0.63-1.68) even though the result was not statistically significant. Clients were more satisfied from private sector as compared to the public sector with respect to other determinants of quality-of-care follow-up care (AOR 3.29, 95% CI 1.95-5.55), infection prevention (AOR 2.41, 95% CI 1.60-3.62), counseling services (AOR 2.01, 95% CI 1.27-3.18, timely treatment (AOR 3.37, 95% CI 2.20-5.15), attitude of staff (AOR 2.23, 95% CI 1.50-3.33), punctuality of staff (AOR 2.28, 95% CI 1.92-4.13), timely referring (AOR 2.34, 95% CI 1.63-3.35), staff cooperation (AOR 1.75, 95% CI 1.22-2.51) and complications handling (AOR 2.27, 95% CI 1.56-3.29). Discussion: Public sector has successfully attained substantial satisfaction levels with respect to provision of contraceptives, but it contrasts previous literature from a multi country studies. Our study though in is concordance with a study from Tanzania where public sector was more likely to offer family planning services to clients as compared to private facilities. Conclusion: In majority of the developing countries, public sector is more involved in FP service provision; however, in Pakistan clients’ satisfaction in private sector is more, which opens doors for public-private partnerships and collaboration in the near future.
Abstract: The paper presents the trends of Georgian hazelnut market development and analyses the competitive advantages which will help Georgia to enter international hazelnut market using modern technologies. The history of hazelnut crop development and hazelnut varieties in Georgia are discussed. For hazelnut supply analysis trends in hazelnut production are considered, trends in export and import development is evaluated, domestic hazelnut market is studied and analysed based on expert interviews and initial accounting materials. In order to achieve and strengthen its position in international market, potential advantages and disadvantages of Georgian hazelnut are revealed, analysis of export and import possibilities of hazelnut is presented. Recommendations are developed based on the conclusions, which are made through identifying the key factors that hinder development of Georgian hazelnut market.
Abstract: Reflux condensation occurs in vertical channels and tubes when there is an upward core flow of vapour (or gas-vapour mixture) and a downward flow of the liquid film. The understanding of this condensation configuration is crucial in the design of reflux condensers, distillation columns, and in loss-of-coolant safety analyses in nuclear power plant steam generators. The unique feature of this flow is the upward flow of the vapour-gas mixture (or pure vapour) that retards the liquid flow via shear at the liquid-mixture interface. The present model solves the full, elliptic governing equations in both the film and the gas-vapour core flow. The computational mesh is non-orthogonal and adapts dynamically the phase interface, thus produces a sharp and accurate interface. Shear forces and heat and mass transfer at the interface are accounted for fundamentally. This modeling is a big step ahead of current capabilities by removing the limitations of previous reflux condensation models which inherently cannot account for the detailed local balances of shear, mass, and heat transfer at the interface. Discretisation has been done based on finite volume method and co-located variable storage scheme. An in-house computer code was developed to implement the numerical solution scheme. Detailed results are presented for laminar reflux condensation from steam-air mixtures flowing in vertical parallel plate channels. The results include velocity and gas mass fraction profiles, as well as axial variations of film thickness.
Abstract: A chromium-loaded ash originating from incineration of tannery sludge under anoxic conditions was mixed with low grade soda-lime glass powder coming from commercial glass bottles. The relative weight proportions of ash over glass powder tested were 30/70, 40/60 and 50/50. The solid mixtures, formed in green state compacts, were sintered at the temperature range of 800o C up to 1200o C. The resulting products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDXS) and micro-indentation. The above methods were employed to characterize the various phases, microstructure and hardness of the produced materials. Thermal treatment at 800o C and 1000o C produced opaque ceramic products composed of a variety of chromium-containing and chromium-free crystalline phases. Thermal treatment at 1200o C gave rise to composite products, where only chromium-containing crystalline phases were detected. Hardness results suggest that specific products are serious candidates for structural applications.
Abstract: Freelancing in IT has seen an increased popularity
during the last years mainly because of the fast Internet adoption in
the countries with emerging economies, correlated with the
continuous seek for reduced development costs as well with the rise
of online platforms which address planning, coordination and various
development tasks. This paper conducts an overview of the most
relevant Freelance Marketplaces available and studies the market
structure, distribution of the workforce and trends in IT freelancing.
Abstract: Family has a crucial role in maintaining the
physical, social and mental health of the children. Most of the
mental and anxiety problems of children reflect the complex
interpersonal situations among family members, especially parents.
In other words, anxiety problems of the children are correlated
with deficit relationships of family members and improper
childrearing styles. The parental child rearing styles leads to
positive and negative consequences which affect the children’s
mental health. Therefore, the present research was aimed to
compare the parental childrearing styles and anxiety of children
with stuttering and normal population. It was also aimed to study
the relationship between parental child rearing styles and anxiety
of children. The research sample included 54 boys with stuttering
and 54 normal boys who were selected from the children (boys) of
Tehran, Iran in the age range of 5 to 8 years in 2013. In order to
collect data, Baum-rind Childrearing Styles Inventory and Spence
Parental Anxiety Inventory were used. Appropriate descriptive
statistical methods and multivariate variance analysis and t test for
independent groups were used to test the study hypotheses.
Statistical data analyses demonstrated that there was a significant
difference between stuttering boys and normal boys in anxiety (t =
7.601, p< 0.01); but there was no significant difference between
stuttering boys and normal boys in parental childrearing styles (F =
0.129). There was also not found significant relationship between
parental childrearing styles and children anxiety (F = 0.135, p<
0.05). It can be concluded that the influential factors of children’s
society are parents, school, teachers, peers and media. So, parental
childrearing styles are not the only influential factors on anxiety of
children, and other factors including genetic, environment and
child experiences are effective in anxiety as well. Details are
discussed.
Abstract: Hydrothermal liquefaction (HTL) is a technique for obtaining clean biofuel from biomass in the presence of heat and pressure in an aqueous medium which leads to a decomposition of this biomass to the formation of various products. A role of operating conditions is essential for the bio-oil and other products’ yield and also quality of the products. The effects of these parameters were investigated in regards to the composition and yield of the products. Chlorellaceae microalgae were tested under different HTL conditions to clarify suitable conditions for extracting bio-oil together with value-added co-products. Firstly, different microalgae loading rates (5-30%) were tested and found that this parameter has not much significant to product yield. Therefore, 10% microalgae loading rate was selected as a proper economical solution for conditioned schedule at 250oC and 30 min-reaction time. Next, a range of temperature (210-290oC) was applied to verify the effects of each parameter by keeping the reaction time constant at 30 min. The results showed no linkage with the increase of the reaction temperature and some reactions occurred that lead to different product yields. Moreover, some nutrients found in the aqueous product are possible to be utilized for nutrient recovery.
Abstract: Lignocellolusic material is a substance that is resistant to be degraded by microorganisms or hydrolysis enzymes. To be used as materials for biofuel production, it needs pretreatment process to improve efficiency of hydrolysis. In this work, chemical pretreatments on rice straw using three diluted organic acids, including acetic acid, citric acid, oxalic acid, were optimized. Using Response Surface Methodology (RSM), the effect of three pretreatment parameters, acid concentration, treatment time, and reaction temperature, on pretreatment efficiency were statistically evaluated. The results indicated that dilute oxalic acid pretreatment led to the highest enhancement of enzymatic saccharification by commercial cellulase and yielded sugar up to 10.67 mg/ml when using 5.04% oxalic acid at 137.11 oC for 30.01 min. Compared to other acid pretreatment by acetic acid, citric acid, and hydrochloric acid, the maximum sugar yields are 7.07, 6.30, and 8.53 mg/ml, respectively. Here, it was demonstrated that organic acids can be used for pretreatment of lignocellulosic materials to enhance of hydrolysis process, which could be integrated to other applications for various biorefinery processes.