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This study aims to deal with the dyeing of nylon-/cotton-blended fabric in one bath using direct and acid dyes.

The cellulose in cotton/nylon-blended fabric was chemically modified using 3-chloro-2-hydroxypropyl tri-methyl ammonium chloride (CHPTAC) as cationizing agent to impart positive charge on the cellulose. The modified and unmodified blended fabrics were dyed in a single bath with direct and acid dyes under various concentrations of 0.5, 1, 2, 4 and 6 per cent on the weight of fabric by exhaust method. The dyeing of modified and unmodified fabrics was characterized through the properties such as K/S and colorfastness to washing, rubbing and light.

The modified fabric exhibited higher color yield, comparable rubbing fastness and good washing fastness.

The dye uptake was maximum in a single-bath dyeing process of nylon-/cotton-blended fabrics without electrolyte addition, which minimizes the impact of dyes on environment.

This paper aims to evaluate the effect of plasma treatment on the performance and color strength of pigment printed polypropylene nonwovens fabrics.

Melt spun nonwoven fabrics have been treated with plasma discharge using oxygen as a reactive gas to activate their surfaces for better interfacial interactions. The untreated and plasma treated fabrics are printed using pigment print pastes to investigate the print properties of nonwoven fabrics that are correlated to surface characteristics. The printed fabrics are characterized through FTIR, color fastness to washing and rubbing, flexural rigidity and moisture management observations.

The fabrics treated with oxygen plasma exhibited higher wettability, higher overall moisture management capability, enhanced color strength and superior color fastness to washing. However, bending length and flexural rigidity have been increased.

This study offers promising findings regarding the surface activation of polypropylene nonwovens for enhanced performance, comfort and color fastness characteristics.

This study aims to evaluate the dyeing of the p-aramid fibre with cationic dyes and investigate the effect of dyeing in the protection of the fibre from ultraviolet (UV) light.

P-aramid fabric has been dyed with cationic dyes using benzyl alcohol as swelling agent to promote the penetration of dye molecules into the fibre. The fabrics were evaluated against colour strength (K/S) value and colour fastness properties after dyed with cationic dyes using full factorial design. This design was used to study the effect of factors that affect the response variables as well as to study the interactions among the factors on response variable. The bursting strength, scanning electron microscopy analysis and X-ray diffraction analysis of undyed and dyed p-aramid fabric were performed before and after exposure to UV light to investigate the changes in mechanical behaviour.

The results show that the p-aramid fabric dyed with cationic dyes has good K/S values and good fastness properties. The exposure of undyed p-aramid fabric to UV light causes serious loss in strength over short duration i.e. 40 h. Dyeing of p-aramid fabric enhances the resistance to UV light which reduces the loss in strength.

Most of the work is patented and no one has done the process optimization for the industry, so this study offers promising outcomes concerning the dyeing of p-aramid fabric with enhanced shade depth and good colour fastness characteristics.

This review deals with the pros and cons of ultraviolet (UV) radiation on human beings and the role of textile clothing and the chemicals used for textiles to protect from their harmful effects.

UV radiation (UVR) which has further divided into UVA, UVB, and UVC. Almost 100% of UVC and major portion of UVB are bounced back to stratosphere by ozone layer while UVA enters the earth atmosphere. Excessive exposure of solar or artificial UVR exhibit potential risks to human health. UVR is a major carcinogen and excessive exposure of solar radiation in sunlight can cause cancer in the lip, skin squamous cell, basal cell and cutaneous melanoma, particularly in people with the fair skin.

This article aims to provide a comprehensive overview of the harmful effects of UVR on human skin, factors affecting UV irradiance and factors affecting UV protection offered by textile clothing.

Effect of fiber properties, yarn properties, fabric construction, fabric treatments and laundering has been reviewed along with the identification of gaps in the reported research. A comparison of inorganic and organic UV absorbers has also been given along with different testing and evaluation methods for UV protective clothing.

The purpose of this paper is to present a new cubic B-spline (CBS) approximation technique for the numerical treatment of coupled viscous Burgers’ equations arising in the study of fluid dynamics, continuous stochastic processes, acoustic transmissions and aerofoil flow theory.

The system of partial differential equations is discretized in time direction using the finite difference formulation, and the new CBS approximations have been used to interpolate the solution curves in the spatial direction. The theoretical estimation of stability and uniform convergence of the proposed numerical algorithm has been derived rigorously.

A different scheme based on the new approximation in CBS functions is proposed which is quite different from the existing methods developed (Mittal and Jiwari, 2012; Mittal and Arora, 2011; Mittal and Tripathi, 2014; Raslan et al., 2017; Shallal et al., 2019). Some numerical examples are presented to validate the performance and accuracy of the proposed technique. The simulation results have guaranteed the superior performance of the presented algorithm over the existing numerical techniques on approximate solutions of coupled viscous Burgers’ equations.

The current approach based on new CBS approximations is novel for the numerical study of coupled Burgers’ equations, and as far as we are aware, it has never been used for this purpose before.

The purpose of this paper is to investigate and minimize the printing-related defects in the surface mount assembly (SMA) process.

This paper uses an experimental approach to explore process parameter and printing defects during the SMA process. Increasing printing performance, various practices of solder paste (Ag3.0/Cu0.5/Sn) storage and handling are suggested. Lopsided paste problem is studied by varying squeegee pressure and the results are presented. Unfilled pads problems are observed for ball grid array (BGA) and quad flat package (QFP) which is mitigated by proper force tuning. In this paper, a comparative study is conducted which evaluates the manifestation of printing offset due to low-grade stencil. The input/output (I/O) boards were oxidized when the relative humidity was maintained beyond 70 per cent for more than 8 h. This pad oxidation problem is overcome by proper printed circuit board (PCB) handling procedures. When the unoptimized line is used, the paste wedged in the stencil and influences the performance of the screen printer, for this reason, an optimized line is proposed that minimize the printing defects.

The key findings are as follows: in the SMA process, printing quality is directly associated with solder paste quality. Experimentally, it is observed that a considerable variance in solder deposition occurred when the front and rear squeegee have different configurations. High-grade and unsoiled stencil results in superior paste deposition and less distinction. Insufficient solder paste and bridge problems also occur in printing when PCB pads are oxidized. Optimized line resolves solder paste clog issues, associated with stencil’s aperture. The cooling arrangement on the conveyor, after reflow, explicates hot jig problem. Control environmental conditions minimized static charges and printing defects.

The preceding studies emphasis mostly on the squeegee pressure, while other important parameters are not completely investigated. Moreover, it is very imperative to concurrently measure all parameters while varying the environmental conditions. This study highlights and provides an experimental approach to various PCB printing defects, and a comparative study has been conducted that concurrently measure all process parameters.

Low relative humidity (RH) effect surface mount devices in numerous ways. The smaller size (0201) capacitor and resistor start wasting when RH is low. Due to low RH, electrostatic charges built-up on the surface of surface mount devices (SMDs) and component’s reel. The positive charged SMDs stick with the negatively charged reel tape and are wasted. This paper comprehensively explores the environmental effects on 0201 size surface mount devices during mounting process. Different type and size of surface mount devices are tested in low and desired RH to validate the effectiveness of the proposed approach. This paper will also highlight high electrostatic discharge (ESD) due to low RH which can be detrimental for small size surface mount devices. The experimental and graphical illustrations will stipulate the results of success rate for mounting components. The effect on ESD, subsequently varying temperature and humidity will also be analyzed.

In this paper, 0201 SDMs will be considered for analysis. The surface mount technology (SMT) plant temperature and humidity has been varied to examine the properties of small size SMDs. Total 5 hours production data are collected from Laptop motherboard production environment. This approach is applicable to all SMT environment.

The authors reduced the wastage of 0201 chip size resistor and capacitor. Total 11 components are selected of this size, and there success rate is observed during mounting. These components are first observed in harsh environment where the temperature is first set to 20ºC and RH is set to 25 per cent. The success rate of these components is very low due to component’s wastage. When the plant temperature is set to 25ºC and RH is set to 45 per cent, the success rate of mounting increased up to 100 per cent. A single component placement success rate with respect to RH is observed for one month. The results are shown in Table IV. It can be seen that the success rate is near 100 per cent when RH and temperature is maintained in production environment. To eliminate the ESD build-up in material and equipment in manufacturing environment humidification is a very effective way. When the RH is kept to 45 per cent, the moisture content of the air is a natural conductor and earths any ESD in environment.

Experimental data have been obtained from Laptop motherboard manufacturing process to validate the effectiveness of proposed approach.

In surface mount assembly (SMA) process, small components are subjected to high temperature variations, which result in components’ deformation and cracking. Because of this phenomenon, cracks are formed in the body of carbonyl powder ceramic inductor (CPCI) in the preheat and cooling stages of the reflow oven. These cracks become the main cause of board failure in the ageing process. The purpose of this paper is to ascertain the thermal stress, thermal expansion of carbonyl iron ceramics and its effects on crack commencement and proliferation in the preheat stage of reflow oven. Moreover, this paper also categorized and suggested important parameters of reflow profile that could be used to eliminate these thermal shock failures.

In this paper, two different reflow profiles were studied that evaluate the thermal shock of CPCI during varying ΔT at the preheat zone of the reflow oven. In the first profile, the change in temperature ΔT at preheat zone was set to 3.26°C/s, which has resulted in a number of device failures because of migration of micro cracks through the CPCI. In the second profile, this ΔT at preheat stage is minimized to 2.06°C/s that eliminated the thermal stresses; hence, the failure rates were significantly reduced.

TMPC0618H series lead (Pb)-free CPCI is selected for this study and its thermal expansion and thermal shock are observed in the reflow process. It is inferred from the results that high ΔT at preheat zone generates cracks in the carbonyl powder-type ceramics that cause device failure in the board ageing process. Comparing materials, carbonyl powder ceramic components are less resistant to thermal shock and a lower rate of temperature change is desirable.

The proposed study presents an experimental analysis for mitigating the thermal shock defects. The realization of the proposed approach is validated with experimental data from the printed circuit boards manufacturing process.

Existing models of gift applied to religious charities are either abstract or sometimes very limited in their applicability to understand the reciprocal relationships throughout the interconnected chain of giving and receiving charities. The paper contributes to this debate by asking: How gift economy explains the circulation of charities across interconnected spheres of local governance? And what are the implications of these inter-linkages for social welfare provisions where states are ineffective in the provision of these services? To answer these questions, the study presents the case of Zakat in Islam and Dasvandh in Sikhism in the northwest of Pakistan. In both the cases, charity is an important element of the social welfare provision within local governance structure. The findings suggest that conceptualizations of the religious charities as a triad including God, the rich and the poor are unsuitable gift models for grasping the role of charities in the local governance of social welfare provision.

Purpose: Through globalization, financial markets have become more integrated and their tendency to act together has increased. The majority of the literature states that there is a cointegration between developed and emerging markets. How do positive or negative shocks in developed markets affect emerging markets? And how do positive or negative shocks in emerging markets affect developed markets? For this reason, the aim of the study is to investigate the asymmetric causality relationship between developed and emerging markets with Hatemi-J asymmetric causality test.

Design/methodology/approach: In this study, the Dow Jones Industrial Average (DJIA) index was used to represent developed markets and the Morgan Stanley Capital International (MSCI) Emerging Market Index was used to represent emerging markets. The asymmetric causality relationship between the DJIA Index and the MSCI Emerging Market Index was investigated using monthly data between January 2009 and April 2019. In the first step of the study, the Johansen Cointegration Test was used to determine whether there is a cointegration between the markets. In the next step, the Hatemi-J asymmetric causality test was applied to see the asymmetric causality relationship between the markets.

Findings: There is a weak correlation between developed and emerging markets. This result is important for international investors who want to diversify their portfolios. As a result of the Johansen Cointegration Test, it was found that there is a long-term relationship between the MSCI Emerging Market Index and the DJIA Index. Therefore, investors who make long-term investment plans should not forget that these markets act together and take into account the causal relationship between them. According to the asymmetric causality test results, a unidirectional causality relationship from the MSCI Emerging Market Index to the DJIA Index was determined. This causality shows that negative shocks in the MSCI Emerging Market Index have positive effects on the DJIA Index.

Originality/value: This study contributes to the literature as it is one of the first studies to examine the asymmetrical relationship between developed and emerging markets. This study is also useful in predicting the short- and long-term relationship between markets. In addition, this study helps investors, portfolio managers, company managers, policymakers, etc., to understand the integration of financial markets.