3,446 research outputs found

    Economic Complexity Unfolded: Interpretable Model for the Productive Structure of Economies

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    Economic complexity reflects the amount of knowledge that is embedded in the productive structure of an economy. It resides on the premise of hidden capabilities - fundamental endowments underlying the productive structure. In general, measuring the capabilities behind economic complexity directly is difficult, and indirect measures have been suggested which exploit the fact that the presence of the capabilities is expressed in a country's mix of products. We complement these studies by introducing a probabilistic framework which leverages Bayesian non-parametric techniques to extract the dominant features behind the comparative advantage in exported products. Based on economic evidence and trade data, we place a restricted Indian Buffet Process on the distribution of countries' capability endowment, appealing to a culinary metaphor to model the process of capability acquisition. The approach comes with a unique level of interpretability, as it produces a concise and economically plausible description of the instantiated capabilities

    Experimental and numerical studies of thermoregulating textiles incorporated with phase change materials

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    Phase change materials (PCMs) provide thermal management solution to textiles for the protection of wearer from extreme weather conditions. PCMs are the substances which can store or release a large amount of energy in the form of latent heat at certain melting temperature. This research reports practical and theoretical studies of textiles containing PCMs. Mono and multifilament filaments incorporated with microencapsulated phase change material (MPCM) have been developed through melt spinning process. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) have been performed for the characterisation of MPCM polypropylene filaments. The parameters for optimum fibre processing and their effect on mechanical properties of filaments with respect to the amount of MPCM have also been studied. A plain woven fabric has been constructed using the developed MPCM multifilament yarn. The heat transfer property of the multifilament yarn and fabric has been investigated using finite element method. The time dependent thermoregulating effect of yarn and fabric incorporated with MPCM has also been predicted according to the validated models. The synthesis of Nanocapsules containing mixture of paraffins and Glauber’s salt as PCM and its characterisation using DSC and SEM has also been carried out. Polypropylene monofilament incorporated with the nanoencapsulated paraffins was developed and its properties have been compared to its MPCM counterpart. Furthermore the developed nanocapsules were applied on a cotton fabric via a pad-dry-cure process and the resultant fabric was evaluated using DSC and SEM in comparison with MPCM treated fabric. The research work described in this thesis has established a better understanding of use of phase change materials in textiles, the evaluation and application. It is anticipated that this research will broaden the understanding and potential use of encapsulated phase change materials in textiles especially in the field of active smart textiles

    Pakistan's cotton and textile economy: Intersectoral linkages and effects on rural and urban poverty

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    "Pakistan's economy relies heavily on its cotton and textile sectors. The cotton-processing and textile industries make up almost half of the country's manufacturing base, while cotton is Pakistan's principal industrial crop, supplying critical income to rural households. Altogether, the cotton-textile sectors account for 11 percent of GDP and 60 percent of export receipts. The future of this vital component of the national economy is uncertain, however. These industries face the challenges of unstable world prices and increased competition resulting from global liberalization of the multilateral textile and clothing trade. At the same time, Pakistan's macroeconomic situation is volatile. Given such challenges and volatility, this study investigates what the future might hold for Pakistan's cotton and textile industries and its implications for rural and urban poverty reduction in the country. The study uses a computable general equilibrium (CGE) model calibrated to a 2001–02 social accounting matrix of the Pakistan economy to conduct experimental simulations of possible economic changes. The CGE model results are linked to the nation-wide 2001–02 Pakistan Household Integrated Economic Survey to examine the implications the simulated developments have for Pakistani poverty. Simulation 1 examines the effects of a doubling of foreign capital inflows, as occurred from 2002 to 2006, before a subsequent financial crisis emerged in 2008. Simulation 2 analyzes the counterfactual effects of an increase in world prices of cotton lint and yarn and/or textiles which would have offset declines experienced in the late 1990s and early 2000s. Pakistan's strong textile association motivates Simulation 3, which examines the effects of a 5-percent increase in government production subsidies to the industry. Simulation 4 uses a dynamic-recursive version of the model to analyze the short- and long-run effects of a 5-percent increase of total factor productivity (TFP) in cotton, lint and yarn, and textile production." from textTextile industry, Rural-urban linkages, Poverty reduction,

    Effect of rotor spinning transfer channel modification on fiber orientation and yarn properties

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    The vortices are generated at the conventional transfer channel, having adverse effects on fiber configuration. In a former research, a conventional transfer channel was modified via rounding the transfer channel inlet corner and adding a bypass channel. The simulation results obtained with the modified transfer channel showed that the vortices were eliminated and the inlet air velocity increased. We present the impact of this modification on the yarn properties and fiber straightness. Four groups of yarn samples were spun using the conventional and modified spinning system. Yarn properties and fiber straightness along the rotor groove were evaluated. Results revealed that tenacities of the yarns spun on the modified system, increased in comparison to that of the conventionally spun yarns. The number of nearly straight fibers is increased by 25.55% by using the modified system, which was mainly attributed to the decrease in the number of fibers with trailing and leading hooks.Peer ReviewedPostprint (author's final draft

    Experimental investigation of the properties of electrospun nanofibers for potential medical application

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    Copyright © 2015 Anhui Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Polymer based nanofibers using ethylene-co-vinyl alcohol (EVOH) were fabricated by electrospinning technology. The nanofibers were studied for potential use as dressing materials for skin wounds treatment. Properties closely related to the clinical requirements for wound dressing were investigated, including the fluid uptake ability (FUA), the water vapour transmission rate (WVTR), the bacteria control ability of nanofibers encapsulated with different antibacterial drugs, and Ag of various concentrations. Nanofibre degradation under different environmental conditions was also studied for the prospect of long term usage. The finding confirms the potential of EVOH nanofibers for wound dressing application, including the superior performance compared to cotton gauze and the strong germ killing capacity when Ag particles are present in the nanofibers
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