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Composite structures are used mainly two types of reinforcement materials: woven glass fabric and the chopped strand mat, each contributing either to increase the resistance of the composite whole or in isotropic distribution of stresses. This paper presents a comparison of the visco-elastic characteristics of composites reinforced with glass fabric and the chopped strand mat and the breaking mode of the two types of the composite. The first type of samples contain three layers of chopped strand mat known as MAT with density of 450g/m2 and 225g/m2) and the second type is composed of four layers of woven glass fabric type RT500 (density of 500g/m2). Both specimens were cut in accordance with EN ISO 527-2 SR. Characteristic curve of the two types of specimens highlights visco-elastic-plastic behavior which largely depends on the type of reinforcement used as the matrix resin is the same in both cases (orthophthalic polyester resin). Breaking mode of those types of specimens were observed and analyzed by electronic microscope.

-Nearly 17 percent of the world‟s total commodity trade is accounted by BRICS countries. BRICS countries,categorised as leading emerging economies and political powers at the regional and international level, are causing changes in the architecture of international development cooperation. Keeping in view the increasing international importance of BRICS countries both economically and politically and increasing efforts by leaders of BRICS countries to enhance mutual trade and strengthen BRICS as a group financially and politically, one of the major objectives of present study is to find out how intense the trade is among BRICS countries so as to determine whether the value of trade among BRICS countries is greater or smaller than expected value on the basis of their importance in world trade. The share of BRICS countries in total world commodity trade has persistently increased from 7.33%i n 2 0 0 1 to17.25% in 2015. During 2001-2015, intraBRICS trade as percent of Total BRICS trade is almost doubled, increasing from 6.03 to 12.12. However it is worth mentioning that China is the dominant contributor in both cases. Out of total BRICS share in world trade (17.25), 12.08 percent is accounted by China only. India‟s share is just 2% while Brazil, Russia and South Africa have only 1.11, 1.56 and 0.51 % share in world trade. Further, the findings of the present study also reveals that the Intra-BRICS trade of major BRICS countries (China, India and Russia) became less intense as intra-BRICS trade intensities decreased in 2015 compared to that in 2001. Intra-BRICS trade intensity of BRICS as a group decreased from 0.82 in 2001 to 0.70 in 2015. For India and Russia it is 0.84 and 0.85 respectively and for China, it is just 0.59 in 2015, implying that China‟s trade with other BRICS countries is far less than expected, given its importance in world trade. However for Brazil and South Africa, trade flows between these two countries and other BRICS countries is more than expected given their importance in world trade, as the figures for intra-BRICS trade intensity are greater than one.

Abstract In this work, the effects of variables such as initial carded web mass, needle penetration depth, punch density, and the frequency of incident sound wave on transmission of sound through polypropylene needle-punched nonwovens were investigated. Fibrous carded webs using commercially available 17 dtex, 90 mm staple length polypropylene fibers were prepared with different mass per unit area using carding machine. Samples were needled at various punch-densities and needle penetration depths were produced. Design points of experiments were set up using Taguchi experimental design method. Sound transmission loss (STL) of needled samples was measured using an impedance tube equipped with four microphones. Minitab software was used to analyze the sound transmission ability of the samples. Results indicated that all of the considered controllable factor have significant effects on STL values determined for the needled nonwovens. Also, initial carded web mass was found to be the most influential factor affecting sound transmission through the samples. It was concluded that an increase in thickness of the samples as well as mass per unit area of nonwovens results in higher sound transmission loss by the samples.

The influence of roller temperature and treatment rate of fabrics of various surface densities based on a mixture of poly(ethylene terephthalate) and bicomponent fibers on the air permeability of the materials was investigated. The permeability decreased for fabrics with surface densities from 0.15 to 0.25 kg/m2 for various roller temperatures if the treatment rate was decreased from 10 to 2-4 m/min although it began to increase if the rate was reduced further. The permeability of fabrics with surface density 0.4 kg/m2 decreased constantly if the treatment rate at various roller temperatures was decreased. The dependence of the permeability on the structure of a modified layer of fabric in which the fibers reoriented with increasing filtration resistance during the treatment was determined from the relationship between the change of permeability and porosity of treated materials. Defects in the layer with increased permeability appeared for fabrics of low surface density at slow treatment rates.

This paper presents a numerical study of the calendering mechanism. The calendered material is represented using the Carreau-Yasuda fluid model. The governing flow equations in the calendering process are made first dimensionless then the lubrication approximation theory (LAT) is used to simplify them. The simplified flow equations are transformed into stream function and then are numerically solved. A numerical method is constructed with Matlab’s built-in-bvp4c routine to find the stream function and pressure gradient. We use the Runge-Kutta algorithm to calculate the pressure and mechanical quantities related to the calendering process. In this analysis the pressure distribution increases with increasing Weissenberg number, however the pressure domain length decreases as the Weissenberg number increases. The pressure inside the nip region decreases from its Newtonian value when the power law index is less than one (shear thinning), and the pressure profile increases from its Newtonian pressure when the power law index is greater than one(shear thickening). How the Carreau-Yasuda fluid model parameters influence the velocity and related calendering process quantities are also discussed via graphs.

Bi-directional corrugated honeycomb aluminum has two-way energy absorption performance intended to be used as impact limiter filling material for nuclear spent fuel transport casks. It is made of a...

Introduction: Proper protective gear sizing is an important factor both for civilian and defence population. This is much more so in the defence sector as a well fitted personal protective ensemble...

Poly(γ-glutamic acid) (PGA) is a biopolymer produced by Bacillus spp. via the γ-amide linkages of D- and/or L-glutamate. Although high-molecular-weight (HMW) PGA possesses many attractive properties, such as flocculating, wound healing, and immune-stimulating effects, no studies have reported factors useful for increasing the molecular weight of PGA during microbial production. PgsB, PgsC, and PgsA are the minimum protein sets required for PGA production in B. subtilis, and PgsE improves PGA productivity. Analysis by size-exclusion chromatography combined with multiangle laser light scattering revealed that the molecular weight of PGA was M_w = 2,900,000 g mol^−1 and predominantly M_w = 47,000 g mol^−1 in preparations derived from B. subtilis cells with and without pgsE, respectively. PgsE may be required to increase the molecular weight of PGA. 納豆のネバネバの主因であるポリグルタミン酸(PGA)は、枯草菌の一種である納豆菌が分泌生産する高分子です。これまで、PGA生合成に必須なタンパク質は、PGA合成関連pgsオペロンから翻訳されるPgsB、PgsC、およびPgsAと報告されてきました。本研究では、pgsオペロンにおいてpgsAの下流に位置するpgsE遺伝子に着目し、PgsEタンパク質がPGAの生合成に与える影響を動的粘度法や多角度光散乱検出器による分子量解析を通して調べました。その結果、PgsB、PgsC、およびPgsAの3つのタンパク質で生産されたPGAは、ほとんど粘性を示さず、47,000の分子量でした。一方、PgsB、PgsC、PgsA、およびPgsEの4つのタンパク質で生産されたPGAは高粘性を示し、その分子量も2,900,000であることが判明しました。以上の結果より、PgsEは、PGAの分子量を大幅に向上させ、納豆をネバネバにさせる主因である可能性が示唆されました。

ABSTRACTOwing to their interesting mechanical behavior and their diversity, rubberlike materials are more and more used in the industry. Previous works (Poisson et al.) presented an important experimental investigation on the multiaxial fatigue of polychloroprene rubber, with both proportional and non-proportional combinations of tension and torsion loads (with a large range of loads and three different phase angles: 0°; 90°, 180°). A fatigue criterion, based on the dissipated energy density (DED) was introduced. Comparing this parameter to the most important criteria available on literature—which are the strain energy density (SED), the cracking energy density (CED), and the Eshelby tensor—in their accuracy allows one to predict fatigue life of rubberlike material. All the predictors are computed with an analytical viscoelastic model based on the kinematics of a combined tension and torsion loading applied on a cylinder. This cylinder represents the central part of the axisymetric dumbbell specimen, and the model was identified with a polychloroprene rubber. It is finally shown that the DED and CED reach more conclusive results, provided the structure, the material, and the loads investigated.

This paper is the second part of a series reporting the recent development of a computerised method for automatic mosaic sequential yarn images. In our earlier work, an effective method for stitching sequence slub yarn images automatically was developed based on image processing and the normalised cross correlation (NCC) method. 100 image pairs of two kinds of slub yarn were measured in certain specific conditions, such as the frame rate, size of stitching template, etc., and the measurement results were evaluated with the manual method. In this paper, the effects of various influencing factors are numerically examined, including the stitching template size, threshold value, frame rate, and computing time of the mosaic algorithm. The feasibility and accuracy of the fully computerized method were evaluated further under the various influencing parameters. One hundred percent cotton ring spun single slub yarns of 27.8, 15.6, and 9.7 tex were prepared and used for the evaluation. The measurement results obtained by the method proposed are analysed and compared with those measured manually by Adobe Photoshop. The experimental results show that the method proposed can accurately find the stitch position and has a high consistency with the manual method when the matching template is 100 × N pixels, the threshold value T1 ∈ [20, 40] and T2 ∈ [51, 80], and the frame rate is greater than 40 fps.