Abstract: The material selection in the design of the sandwich
structures is very crucial aspect because of the positive or negative
influences of the base materials to the mechanical properties of the
entire panel. In the literature, it was presented that the selection of the
skin and core materials plays very important role on the behavior of
the sandwich. Beside this, the use of the correct adhesive can make
the whole structure to show better mechanical results and behavior.
In the present work, the static three-point bending tests were
performed on the sandwiches having an aluminum alloy foam core,
the skins made of three different types of fabrics and two different
commercial adhesives (flexible polyurethane and toughened epoxy
based) at different values of support span distances by aiming the
analyses of their flexural performance in terms of absorbed energy,
peak force values and collapse mechanisms. The main results of the
flexural loading are: force-displacement curves obtained after the
bending tests, peak force and absorbed energy values, collapse
mechanisms and adhesion quality. The experimental results presented
that the sandwiches with epoxy based toughened adhesive and the
skins made of S-Glass Woven fabrics indicated the best adhesion
quality and mechanical properties. The sandwiches with toughened
adhesive exhibited higher peak force and energy absorption values
compared to the sandwiches with flexible adhesive. The use of these
sandwich structures can lead to a weight reduction of the transport
vehicles, providing an adequate structural strength under operating
conditions.
Abstract: This article discusses issues related to the System of
Innovation: Comparing economies of Brazil and South Africa.
Having as this study aimed at comparing the Innovation System of
the countries mentioned. Then briefly describe the process of Venture
Capital and present the industry innovation in Brazil and South
Africa. The methodological approach described in this article is
descriptive and the approach is qualitative, taking as a basis
secondary data relating to research articles. The main results are
related to the different forms of financing of Venture Capital used by
countries compared, in addition to the training and economic policy.
And finally, it was highlighted the importance of implementation of
policy reforms for the Brazil and Africa in the innovation process.
Abstract: In the scope of application of technical textiles, Non-
Crimp Fabrics are increasingly used. In general, NCF exhibit
excellent load bearing properties, but caused by the manufacturing
process, there are some remaining disadvantages which have to be
reduced. Regarding to this, a novel technique of processing NCF was
developed substituting the binding-thread by an adhesive. This stitchfree
method requires new manufacturing concept as well as new basic
methods to prove adhesion of glue at fibres and textiles. To improve
adhesion properties and the wettability of carbon-fibres by the
adhesive, oxy-fluorination was used. The modification of carbonfibres
by oxy-fluorination was investigated via scanning electron
microscope, X-ray photoelectron spectroscopy and single fibre
tensiometry. Special tensile tests were developed to determine the
maximum force required for detachment.
Abstract: This paper conducts a comparison study using KES-FB and PhabrOmeter to measure 58 selected warp knitted fabric hand properties. Fabric samples were selected and measured by both KES-FB and PhabrOmeter. Results show differences between these two measurement methods. Smoothness and stiffness values obtained by KES-FB were found significant correlated (p value = 0.003 and 0.022) to the PhabrOmeter results while softness values between two measurement methods did not show significant correlation (p value = 0.828). Disagreements among these two measurement methods imply limitations on different mechanism principles when facing warp knitted fabrics. Subjective measurement methods and further studies are suggested in order to ascertain deeper investigation on the mechanisms of fabric hand perceptions.
Abstract: The design of an optimised horizontal axis 5-meter-long wind turbine rotor blade in according with IEC 61400-2 standard is a research and development project in order to fulfil the requirements of high efficiency of torque from wind production and to optimise the structural components to the lightest and strongest way possible. For this purpose, a research study is presented here by focusing on the structural characteristics of a composite wind turbine blade via finite element modelling and analysis tools. In this work, first, the required data regarding the general geometrical parts are gathered. Then, the airfoil geometries are created at various sections along the span of the blade by using CATIA software to obtain the two surfaces, namely; the suction and the pressure side of the blade in which there is a hat shaped fibre reinforced plastic spar beam, so-called chassis starting at 0.5m from the root of the blade and extends up to 4 m and filled with a foam core. The root part connecting the blade to the main rotor differential metallic hub having twelve hollow threaded studs is then modelled. The materials are assigned as two different types of glass fabrics, polymeric foam core material and the steel-balsa wood combination for the root connection parts. The glass fabrics are applied using hand wet lay-up lamination with epoxy resin as METYX L600E10C-0, is the unidirectional continuous fibres and METYX XL800E10F having a tri-axial architecture with fibres in the 0,+45,-45 degree orientations in a ratio of 2:1:1. Divinycell H45 is used as the polymeric foam. The finite element modelling of the blade is performed via MSC PATRAN software with various meshes created on each structural part considering shell type for all surface geometries, and lumped mass were added to simulate extra adhesive locations. For the static analysis, the boundary conditions are assigned as fixed at the root through aforementioned bolts, where for dynamic analysis both fixed-free and free-free boundary conditions are made. By also taking the mesh independency into account, MSC NASTRAN is used as a solver for both analyses. The static analysis aims the tip deflection of the blade under its own weight and the dynamic analysis comprises normal mode dynamic analysis performed in order to obtain the natural frequencies and corresponding mode shapes focusing the first five in and out-of-plane bending and the torsional modes of the blade. The analyses results of this study are then used as a benchmark prior to modal testing, where the experiments over the produced wind turbine rotor blade has approved the analytical calculations.
Abstract: The calcarenites carbonate rocks of the Quaternary ridges, which extend along the northwestern Mediterranean coastal plain of Egypt, represent an excellent model for the transformation of loose sediments to real sedimentary rocks by the different stages of meteoric diagenesis. The depositional and diagenetic fabrics of the rocks, in addition to the strata orientation, highly affect their ultimate compressive strength and other geotechnical properties.
There is a marked increase in the compressive strength (UCS) from the first to the fourth ridge rock samples. The lowest values are related to the loose packing, weakly cemented aragonitic ooid sediments with high porosity, besides the irregularly distributed of cement, which result in decreasing the ability of these rocks to withstand crushing under direct pressure. The high (UCS) values are attributed to the low porosity, the presence of micritic cement, the reduction in grain size and the occurrence of micritization and calcretization processes.
The strata orientation has a notable effect on the measured (UCS). The lowest values have been recorded for the samples cored in the inclined direction; whereas the highest values have been noticed in most samples cored in the vertical and parallel directions to bedding plane. In case of the inclined direction, the bedding planes were oriented close to the plane of maximum shear stress. The lowest and highest anisotropy values have been recorded for the first and the third ridges rock samples, respectively, which may attributed to the relatively homogeneity and well sorted grainstone of the first ridge rock samples, and relatively heterogeneity in grain and pore size distribution and degree of cementation of the third ridge rock samples, besides, the abundance of shell fragments with intraparticle pore spaces, which may produce lines of weakness within the rock.
Abstract: Rubric is a very important tool for teachers and students for a variety of purposes. Teachers use the rubric for evaluating student work while students use rubrics for self-assessment. Therefore, this paper was emphasized scoring rubric as a scoring tool for teachers in an environment of Competency Based Education and Training (CBET) in Malaysia Vocational College. A total of three teachers in the fields of electrical and electronics engineering were interviewed to identify how the use of rubrics practiced since vocational transformation implemented in 2012. Overall holistic rubric used to determine the performance of students in the skills area.
Abstract: Based on different experiences in the historic centers
of Spain, we propose an global strategy for the regeneration of the
pre-tertiary fabrics and its application to the specific case of San
Mateo neighborhood, in Jerez de la Frontera (Andalusia), through a
diagnosis that focus particularly on the punishments the last-decade
economic situation (building boom and crisis) and shows the tragic
transition from economic center to an imminent disappearance with
an image similar to the ruins of war, due to the loss of their
traditional roles. From it we will learn their historically-tested
mechanisms of environment adaptation, which distill the vernacular
architecture essence and that we will apply to our strategy of action
based on a dotacional-and-free-space rhizome which rediscovers its
hidden character. The architectural fact will be crystallized in one of
the example-pieces proposed: The Artistic Revitalization Center.
Abstract: Circular knitting machine makes the fabric with more than two knitting tools. Variation of yarn tension between different knitting tools causes different loop length of stitches duration knitting process. In this research, a new intelligent method is applied to control loop length of stitches in various tools based on ideal shape of stitches and real angle of stitches direction while different loop length of stitches causes stitches deformation and deviation those of angle. To measure deviation of stitch direction against variation of tensions, image processing technique was applied to pictures of different fabrics with constant front light. After that, the rate of deformation is translated to needed compensation of loop length cam degree to cure stitches deformation. A fuzzy control algorithm was applied to loop length modification in knitting tools. The presented method was experienced for different knitted fabrics of various structures and yarns. The results show that presented method is useable for control of loop length variation between different knitting tools based on stitch deformation for various knitted fabrics with different fabric structures, densities and yarn types.
Abstract: Banyan networks are really attractive for serving as
the optical switching architectures due to their unique properties of
small depth and absolute signal loss uniformity. The fact has been
established that the limitations of blocking nature and the nonavailability
of proper connections due to non-rearrangeable property
can be easily ruled out using electro-optic MZI switches as basic
switching elements. Combination of the horizontal expansion and
vertical stacking of optical banyan networks is an appropriate scheme
for constructing non-blocking banyan-based optical switching
networks. The interconnected banyan switching fabrics (IBSF) have
been considered and analyzed to best serve the purpose of optical
switching with electro-optic MZI basic elements. The cross/bar state
interchange for the switches has been facilitated by appropriate
voltage switching or the by the switching of operating wavelength.
The paper is dedicated to the modification of the basic switching
element being used as well as the architecture of the switching
network.
Abstract: In this paper a novel method was presented for
evaluating the fabric pills using digital image processing techniques. This work provides a novel technique for
detecting pills and also measuring their heights, surfaces and
volumes. Surely, measuring the intensity of defects by human vision is an inaccurate method for quality control; as a result, this problem became a motivation for employing digital image processing techniques for detection of defects of fabric
surface. In the former works, the systems were just limited to measuring of the surface of defects, but in the presented
method the height and the volume of defects were also
measured, which leads to a more accurate quality control. An algorithm was developed to first, find pills and then measure their average intensity by using three criteria of height, surface
and volume. The results showed a meaningful relation
between the number of rotations and the quality of pilled fabrics.
Abstract: In this research, the main aim is to investigate the
antimicrobial effectiveness of ammonyx solutions finishing on
Sweatshirt Sport with immersion method. 60 Male healthy subjects
(football player) participated in this study. They were dressed in a
Sweatshirt for 14 days and some microbes found on them were
investigated. The antimicrobial effect of different ammonyx
solutions(1/100, 1/500, 1/1000, 1/2000 v/v solutions of Ammonyx)
on the identified microbes was studied by the zone inhabitation
method in vitro. In the next step the Sweatshirt Sports were treated
with the same different solutions of ammonyx and the antimicrobial
effectiveness was assessed by colony count method in different times
and the results were compared whit untreated ones. Some mechanical
properties of treated cotton/polyester yarn that used in Sweatshirt
Sport were measured after 30 days and were compared with
untreated one. Finally after finishing, scanning electron microscopy
(SEM) was used to compare the surfaces of the finished and
unfinished specimens. The results showed the presence of five
pathogenic microbes on Sweatshirt Sports such as Escherichia coli,
Staphylococcus aureus, Aspergillus, Mucor and Candida. The
inhalation time for treated on Sweatshirt Sports improved. The
amount of colony growth on treated clothes reduced considerably
and moreover the mechanical tests results showed no significant
deterioration effect of studies properties in comparison to the
untreated yarn. The visual examination of the SEM indicated that the
antimicrobial treatments were applied usefully to fabrics.
Abstract: This paper investigates the problem of automated defect
detection for textile fabrics and proposes a new optimal filter design
method to solve this problem. Gabor Wavelet Network (GWN) is
chosen as the major technique to extract the texture features from
textile fabrics. Based on the features extracted, an optimal Gabor filter
can be designed. In view of this optimal filter, a new semi-supervised
defect detection scheme is proposed, which consists of one real-valued
Gabor filter and one smoothing filter. The performance of the scheme
is evaluated by using an offline test database with 78 homogeneous
textile images. The test results exhibit accurate defect detection with
low false alarm, thus showing the effectiveness and robustness of the
proposed scheme. To evaluate the detection scheme comprehensively,
a prototyped detection system is developed to conduct a real time test.
The experiment results obtained confirm the efficiency and
effectiveness of the proposed detection scheme.
Abstract: This paper presents a novel approach to assessing textile porosity by the application of the image analysis techniques. The images of different types of sample fabrics, taken through a microscope when the fabric is placed over a constant light source,transfer the problem into the image analysis domain. Indeed, porosity can thus be expressed in terms of a brightness percentage index calculated on the digital microscope image. Furthermore, it is meaningful to compare the brightness percentage index with the air permeability and the tightness indices of each fabric type. We have experimentally shown that there exists an approximately linear relation between brightness percentage and air permeability indices.
Abstract: Concerning the measurement of friction properties of
textiles and fabrics using Kawabata Evaluation System (KES), whose
output is constrained to the surface friction factor of fabric, and no
other data would be generated; this research has been conducted to
gain information about surface roughness regarding its surface
friction factor. To assess roughness properties of light nonwovens, a
3-dimensional model of a surface has been simulated with regular
sinuous waves through it as an ideal surface. A new factor was
defined, namely Surface Roughness Factor, through comparing
roughness properties of simulated surface and real specimens. The
relation between the proposed factor and friction factor of specimens
has been analyzed by regression, and results showed a meaningful
correlation between them. It can be inferred that the new presented
factor can be used as an acceptable criterion for evaluating the
roughness properties of light nonwoven fabrics.
Abstract: The purpose of this study is to identify and evaluate
the scale of implementation of Just-In-Time (JIT) in the different industrial sectors in the Middle East. This study analyzes the empirical data collected by a questionnaire survey distributed to
companies in three main industrial sectors in the Middle East, which
are: food, chemicals and fabrics. The following main hypotheses is formulated and tested: (The requirements of JIT application differ
according to the type of industrial sector).Descriptive statistics and Box plot analysis were used to examine the hypotheses. This study indicates a reasonable evidence for accepting the main hypotheses. It
reveals that there is no standard way to adopt JIT as a production system. But each industrial sector should concentrate in the
investment on critical requirements that differ according to the nature
and strategy of production followed in that sector.
Abstract: The stab resistance performance of newly developed
fabric composites composed of hexagonal paper honeycombs, filled
with shear thickening fluid (STF), and woven Kevlar® fabric or
UHMPE was investigated in this study. The STF was prepared by
dispersing submicron SiO2 particles into polyethylene glycol (PEG).
Our results indicate that the STF-Kevlar composite possessed lower
penetration depth than that of neat Kevlar. In other words, the
STF-Kevlar composite can attain the same energy level in
stab-resistance test with fewer layers of Kevlar fabrics than that of the
neat Kevlar fabrics. It also indicates that STF can be used for the
fabrication of flexible body armors and can provide improved
protection against stab threats. We found that the stab resistance of the
STF-Kevlar composite increases with the increase of SiO2
concentration in STF. Moreover, the silica particles functionalized
with silane coupling agent can further improve the stab resistance.
Abstract: The aim of study was to evaluate pressure distribution characteristics of the elastic textile bandages using two instrumental techniques: a prototype Instrument and a load Transference. The prototype instrument which simulates shape of real leg has pressure sensors which measure bandage pressure. Using this instrument, the results show that elastic textile bandages presents different pressure distribution characteristics and none produces a uniform distribution around lower limb.
The load transference test procedure is used to determine whether a relationship exists between elastic textile bandage structure and pressure distribution characteristics. The test procedure assesses degree of load, directly transferred through a textile when loads series are applied to bandaging surface. A range of weave fabrics was produced using needle weaving machine and a sewing technique. A textile bandage was developed with optimal characteristics far superior pressure distribution than other bandages. From results, we find that theoretical pressure is not consistent exactly with practical pressure. It is important in this study to make a practical application for specialized nurses in order to verify the results and draw useful conclusions for predicting the use of this type of elastic band.
Abstract: The major objective of this study is to understand the
potential of a newly fabricated equipment to study the thermal
properties of nonwoven textile fabrics treated with aerogel at subzero
temperatures. Thermal conductivity was calculated by using the
empirical relation Fourier’s law, The relationship between the
thermal conductivity and thermal resistance of the samples were
studied at various environmental temperatures (which was set in the
clima temperature system between +25oC to -25oC). The newly
fabricated equipment was found to be a suitable for measuring at
subzero temperatures. This field of measurements is being developed
and will be the subject of further research which will be more suitable
for measurement of the various thermal characteristics.
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.