RESEARCH NOTE SHEARING PROPERTIES OF THE SKEWED WOVEN FABRICS

Abstract This experimental work deals with the effects of skewness on the shearing properties of the worsted woven fabric. Shearing properties of 160 samples are measured by two methods (KES and concentrated loading methods) and the results are compared. Both methods show a positive correlation between skewness and shear rigidity indicating, as the skewness goes up the shear rigidity also increases. Correlation between shear rigidity evaluated by KES and skewness was 0.725, but new parameter (EML) extracted from the concentrated loading curve (Extension at 200 gram-load) showed more sensitivity to fabric skewness and gave a higher correlation (-0.866) to it. In other words, the concentrated loading method shows the relationship between skewness and the shear rigidity (G)

The State, Entrepreneur, and Labour in the Establishment of the Iranian Copper Mining Industry: The Sarcheshmeh Copper Mine 1966-1979

The Sarcheshmeh Copper Mine was the world’s second largest open pit copper deposit in the 1970s. Currently, it is the largest in the Middle East and retains its place as one of the biggest copper processing complexes in the world. This thesis examines the formation of the modern copper mining industry in Iran, with particular focus on the establishment of Sarcheshmeh Copper Mine. It is elaborated within the theory of developmental state and accentuates an assortment of factors including political stability, relatively autonomous institutions with equitable performance, conversant technocrats committed to the national interest, a development-oriented state, and the growth of oil revenue.It then aimed to highlight the significance of the structure of mine ownership and the presence of the state in transforming the social policy, industrial relations, and mode of management in the Sarcheshmeh Copper Mine. These factors were instrumental in the formation of a working class, which was inspired by working-class power to indicate the role of the workers’ background and the company’s welfare policy in the workers’ response to the political unrest during the 1979 Revolution.Middle Eastern Studie

Effects of Kevlar® 29 yarn twist on tensile and tribological properties of self-lubricating fabric liner

Yarn twist in textile technology is an important characteristic since it considerably affects the properties of knitted or woven fabrics. Many researchers have investigated the effect of staple-spun yarn twist on the properties of the yarns and fabrics. However, the effects of twist level of Kevlar® 29 filament yarn on the properties of yarn and its resin-impregnated self-lubricating fabric liner are not fully known yet. In this study, we have investigated the effects of Kevlar® 29 twist level on the tensile and tribological properties of the fabric liner (Kevlar® 29/polytetrafluoroethylene fabric-resin composite). Two unexpected findings about the effect of yarn twist have been observed, namely (1) asynchronous twist effect on the yarn’s and the liner’s tensile strength and (2) dissimilar yarn twist effect on the liner’s performance. These findings are mainly attributed to the synergic contributions of the yarn twist and strength and the interaction of the resin with the yarn orientation in the woven fabric structure of the liner

Ischemia-Reperfusion Injury and Pregnancy Initiate Time-Dependent and Robust Signs of Up-Regulation of Cardiac Progenitor Cells

To explore how cardiac regeneration and cell turnover adapts to disease, different forms of stress were studied for their effects on the cardiac progenitor cell markers c-Kit and Isl1, the early cardiomyocyte marker Nkx2.5, and mast cells. Adult female rats were examined during pregnancy, after myocardial infarction and ischemia-reperfusion injury with/out insulin like growth factor-1(IGF-1) and hepatocyte growth factor (HGF). Different cardiac sub-domains were analyzed at one and two weeks post-intervention, both at the mRNA and protein levels. While pregnancy and myocardial infarction up-regulated Nkx2.5 and c-Kit (adjusted for mast cell activation), ischemia-reperfusion injury induced the strongest up-regulation which occurred globally throughout the entire heart and not just around the site of injury. This response seems to be partly mediated by increased endogenous production of IGF-1 and HGF. Contrary to c-Kit, Isl1 was not up-regulated by pregnancy or myocardial infarction while ischemia-reperfusion injury induced not a global but a focal up-regulation in the outflow tract and also in the peri-ischemic region, correlating with the up-regulation of endogenous IGF-1. The addition of IGF-1 and HGF did boost the endogenous expression of IGF and HGF correlating to focal up-regulation of Isl1. c-Kit expression was not further influenced by the exogenous growth factors. This indicates that there is a spatial mismatch between on one hand c-Kit and Nkx2.5 expression and on the other hand Isl1 expression. In conclusion, ischemia-reperfusion injury was the strongest stimulus with both global and focal cardiomyocyte progenitor cell marker up-regulations, correlating to the endogenous up-regulation of the growth factors IGF-1 and HGF. Also pregnancy induced a general up-regulation of c-Kit and early Nkx2.5+ cardiomyocytes throughout the heart. Utilization of these pathways could provide new strategies for the treatment of cardiac disease

Genetic sequencing for surveillance of drug resistance in tuberculosis in highly endemic countries: a multi-country population-based surveillance study

BACKGROUND : In many countries, regular monitoring of the emergence of resistance to anti-tuberculosis drugs is hampered by the limitations of phenotypic testing for drug susceptibility. We therefore evaluated the use of genetic sequencing for surveillance of drug resistance in tuberculosis. METHODS : Population-level surveys were done in hospitals and clinics in seven countries (Azerbaijan, Bangladesh, Belarus, Pakistan, Philippines, South Africa, and Ukraine) to evaluate the use of genetic sequencing to estimate the resistance of Mycobacterium tuberculosis isolates to rifampicin, isoniazid, ofloxacin, moxifloxacin, pyrazinamide, kanamycin, amikacin, and capreomycin. For each drug, we assessed the accuracy of genetic sequencing by a comparison of the adjusted prevalence of resistance, measured by genetic sequencing, with the true prevalence of resistance, determined by phenotypic testing. FINDINGS : Isolates were taken from 7094 patients with tuberculosis who were enrolled in the study between November, 2009, and May, 2014. In all tuberculosis cases, the overall pooled sensitivity values for predicting resistance by genetic sequencing were 91% (95% CI 87–94) for rpoB (rifampicin resistance), 86% (74–93) for katG, inhA, and fabG promoter combined (isoniazid resistance), 54% (39–68) for pncA (pyrazinamide resistance), 85% (77–91) for gyrA and gyrB combined (ofloxacin resistance), and 88% (81–92) for gyrA and gyrB combined (moxifloxacin resistance). For nearly all drugs and in most settings, there was a large overlap in the estimated prevalence of drug resistance by genetic sequencing and the estimated prevalence by phenotypic testing. INTERPRETATION : Genetic sequencing can be a valuable tool for surveillance of drug resistance, providing new opportunities to monitor drug resistance in tuberculosis in resource-poor countries. Before its widespread adoption for surveillance purposes, there is a need to standardise DNA extraction methods, recording and reporting nomenclature, and data interpretation.The Bill & Melinda Gates Foundation, the United States Agency for International Development, and the TB Alliance.www.thelancet.com/infectionhttp://www.thelancet.com/infectionam2018Medical Microbiolog

Updating the approaches to define susceptibility and resistance to anti-tuberculosis agents: implications for diagnosis and treatment

11 páginas, 2 figuras, 1 tablaInappropriately high breakpoints have resulted in systematic false-susceptible AST results to anti-TB drugs. MIC, PK/PD and clinical outcome data should be combined when setting breakpoints to minimise the emergence and spread of antimicrobial resistance.I. Comas was supported by PID2019-104477RB-I00 from the Spanish Science Ministry and by ERC (CoG 101001038)Peer reviewe

A new method to evaluate low-stress shearing behaviour of woven fabrics

333-338The ability of extraction and concentrated loading methods for measuring the shearing properties of woven fabrics has been studied. Forty light weight woven fabrics of different varieties have been tested by three methods, viz KES, extraction and a new suggested method, and the results compared. Correlation between the KES quantitative parameters and the measured features extracted from the curves of extraction and new methods indicates better ability of the new method to measure the shearing properties. It is observed that the buckling zone of fabrics is the key point to evaluate the shearing rigidity. In addition, the new method is capable of yielding the effect of changing production parameters

Wpływ kierunku skrętu przędzy na właściwości mechaniczne tkanin

This work deals with the role that twist directions at the contact point of warp and weft play in the mechanical behaviour of fabrics. Two sets of 100 percent combed cotton yarns (20 tex) of different twist directions (Z & S) and six twist levels were produced and then used as wefts on an old type Dornier loom (weft insertion of 120 picks/min), in which the warp was 100% combed cotton yarns with 870 Z twist per meter. Hereby we obtained two sets of fabrics in which the warps were all the same but the wefts were different in the twist directions and twist levels. Then the fabrics were compared with respect to the yarn pullout (two adjacent yarns were pulled out at the same time), the fabric formability (product of bending rigidity and reverse value of initial modulus) and fabric buckling (200-g tensile concentrated force was applied to the fabrics). The results show that the yarn pull-out force, fabric formability and fabric buckling force were greater in the fabrics in which the warp and wefts were unidirectional in the twist directions. In addition, in the group in which the warp and weft twist directions were the same, the maximum pull-out force, maximum formability and maximum buckling force belonged to the fabrics in which the nesting angle was around zero.W pracy rozważono wpływ skrętu na właściwości mechaniczne wzajemnie krzyżujących się przędz osnowy i wątku. Wyprodukowano dwa zestawy przędz bawełnianych o rożnych kierunkach skrętu (Z i S) i rożnych jego wartościach. Uzyskano tkaniny o jednakowej osnowie i wątkach o różnym kierunku skrętu i jego wartościach. Następnie tkaniny badano oceniając efekt wyciągania nitek, odkształcalność i wyboczenie tkaniny. Wybrane parametry badano przy różnej wzajemnej konfiguracji skrętów osnowy i wątku

Wytrzymałość na ścieranie przędz krzyżujących się pod kątem prostym

This paper investigates yarn abrasion behaviour based on the yarn structure, twist factor and fibre alignment at the rubbing contact points (twist direction at contact points). First yarns arranged at right angle (utilized with a high resolution camera) were introduced on a yarn abrasion tester and then the abrasion behaviour of the ring (R) and open-end rotor (O.E.) spun yarns were compared and analysed. Comparison of the yarns indicates that the abrasion resistance thereof is affected by the twist factor in a way that as the twist increases, the yarn on yarn abrasion cycles to failure follows the same trend as the effect of twist on the yarn strength (first an increase and then a decrease); that is, yarn on yarn abrasion resistance increases up to a certain degree (a=140 in ring spun yarn and a=156 in open-end rotor spun yarn), and then as the twist increases, the yarn on yarn abrasion resistance decreases. It also shows that the yarn abrasion cycle to failure is lower when the fibre alignments of the contact yarns are in the same direction. Close observation of the yarn rubbing also indicates that as the fibres are removed from the outer layers, the rotor spun yarn shows higher yarn on yarn abrasion resistance; that is, moving from the outer side to the interlayer of the rotor spun yarn, the relative yarn on yarn abrasion resistance (abrasion cycles to failure/yarn count) increases. This phenomenon indicates the fact that in open-end rotor spun yarn the compactness of the interlayer fibres are higher than the compactness of the outer layer fibres.Analizowano różne właściwości mechaniczne przy zrywaniu lnianych przędz łączonych różnymi węzłami, stosując test na rozciąganie dla czterech węzłów o różnej strukturze - węzeł prosty, zwykły, tkacki i rybacki. Zastosowano cztery próbki: 50 tex (A - bielona, B - surowa) i 68 tex (C - bielona, D - surowa), każda wyprzędziona z lnu. W pracy przedstawiono wartości siły zrywającej, wytrzymałości przy zerwaniu, wydłużenia przy zerwaniu, pracy do zerwania oraz jednostkowej pracy do zerwania dla przędz łączonych węzłami. Ponadto, przeanalizowano współczynnik retencji dla siły zrywającej, wydłużenia przy zerwaniu i pracy przy zerwaniu. Stwierdzono, że wytrzymałość przędz łączonych węzłami zależy w dużym stopniu od struktury węzłów, podczas gdy przędze surowe i bielone wykazały podobne właściwości wytrzymałościowe