Quality Management in Pakistan's Knitwear Industry

Although quality is a critical success factor for all types of business, its salience is to be driven home in Pakistan's business environment in general and its export-oriented business segment in Pakistan in particular. As a first part of this effort, we chose to study quality management in Pakistan's knitwear industry, whose combined share with readymade garments in Pakistan's total exports rose to 16.7% by 1997/1998. We mailed a postal self-completion questionnaire to 59 members of the Pakistan Knitwear and Sweaters Exporters Association. The response rate was 29%. It was found that Pakistan's knitwear industry was in various stages of development in quality management, with greater concentration in the quality inspection mode. Although there are attempts to graduate to quality assurance and beyond, it was found that considerable distance has yet to be traversed before Pakistan's knitwear industry acquires a quality philosophy as a part of its overall business approach industrywide. As part of a statistical test, however, advanced quality management concepts were found applicable in Pakistan, although the application is currently limited. These concepts must gain in popularity.     

Molecular dynamics simulations of transport and separation of supercritical carbon dioxide-alkane mixtures in supported membranes

The results of extensive nonequilibrium molecular dynamics (MD) simulations of flow and transport of several binary mixtures of CO₂ and an n-alkane chain, from CH₄ to C₄H₁₀, through a model porous membrane composed of three pores in series with significantly different sizes and in the presence of an external pressure gradient, are reported. The technique that we use for the simulations is a combination of the configurational-bias Monte Carlo method (used for efficient generation of molecular models of n-alkane chains) and the dual control-volume grand-canonical MD method. The selectivity of the membrane changes qualitatively as the length of the alkane chain increases, resulting in high separation factors in favor of the alkanes. Moreover, we find that, under supercritical conditions, unusual phenomena occur that give rise to direction- and pressure-dependent permeabilities for the fluids. The results, which are also in agreement with a continuum formulation of the problem, indicate that the composite nature of the membrane gives rise to the direction-dependent permeabilities. Hence, modeling flow and transport of supercritical fluid mixtures in porous materials with the type of morphology considered in this paper (such as supported porous membranes) would require using effective permeabilities that depend on both the external pressure drop and the direction along which it is applied to the materials.     

Secure FSM-based arithmetic codes

Recently, arithmetic coding has attracted the attention of many scholars because of its high compression capability. Accordingly, in this paper, a method that adds secrecy to this well-known source code is proposed. Finite state arithmetic code is used as source code to add security. Its finite state machine characteristic is exploited to insert some random jumps during source coding process. In addition, a Huffman code is designed for each state to make decoding possible even in jumps. Being prefix-free, Huffman codes are useful in tracking correct states for an authorized user when he/she decodes with correct symmetric pseudo-random key. The robustness of our proposed scheme is further reinforced by adding another extra uncertainty by swapping outputs of Huffman codes in each state. Several test images are used for inspecting the validity of the proposed Huffman finite state arithmetic coding (HFSAC). The results of several experimental key space analyses, statistical analyses, key and plaintext sensitivity tests show that HFSAC with a little effect on compression efficiency provides an efficient and secure method for real-time image encryption and transmission.     

Removal of malachite green (a toxic dye) from water by cobalt ferrite silica magnetic nanocomposite: Herbal and green sol-gel autocombustion synthesis

Cobalt ferrite-silica nanocomposites were synthesized in the presence of various amounts of Salix alba bark extract via the self-propagating sol-gel process. The structure, morphology and magnetic property of nanostructures was investigated and the adsorbent ability for the removal of malachite green (MG) dye from water through CoFe₂O₄SiO₂ has been reported. The products were characterized by XRD, SEM, TEM, FTIR and VSM techniques. The samples that were synthesized in the presence of more extract (20 mg extract) revealed no trace of impurity in XRD pattern and indicated more spherical and agglomerated particles on SEM images; in contrast other samples indicated Co₃O₄ as impurity besides rough and irregular spherical shapes. TEM images for sample SA20 (15.41 ± 0.65 nm size) illustrated narrow size distribution which is consistent with the SEM analysis. The saturation magnetization values continuously increase with the increasing Salix alba bark extract amount and reaches to 2.89 emu/g for SA20 sample. Investigation on MG adsorption isotherm and kinetic onto the nanocomposites were carried out as well. The experimental data best fitted to the Langmuir model and revealed a monolayer adsorption capacity of 75.5 ± 1.21 mg g^?1. The adsorption kinetic was found to follow pseudo-second-order kinetic model. Consequently, prepared nanocomposite can be used as an effective magnetic adsorbent for the MG removal from water.     

Decreased expression and activity of P-glycoprotein in rat liver during acute inflammation

PURPOSE: Drug disposition is often altered in inflammatory disease. Although the influence of inflammation on hepatic drug metabolism and protein binding has been well studied, its impact on drug transport has largely been overlooked. The multidrug resistance (MDR) gene product, P-glycoprotein (P-gp) is involved in the active secretion of a large variety of drugs. Our goal was to ascertain the influence of acute inflammation (AI) on the expression and functional activity of P-gp. METHODS: AI was induced in rats through turpentine or lipopolysaccharide (LPS) administration. Expression of P-gp in liver was detected at the level of protein on Western blots using the monoclonal antibody C-219 and at the level of mRNA using an RNase protection assay. P-gp mediated transport activity was assessed by measuring the verapamil-inhibitable efflux of rhodamine 123 (R123) in freshly isolated hepatocytes. RESULTS: Turpentine-induced AI significantly decreased the hepatic protein expression of P-gp isoforms by 50-70% and caused a significant 45-65% reduction in the P-gp mediated efflux of R123. Diminished mRNA levels of all three MDR isoforms were seen. LPS-induced AI similarly resulted in significantly reduced levels and activity of P-gp in liver. Although differences in the constitutive levels of P-gp were seen between male and female rats, the influence of AI on P-gp expression and activity was not gender specific. CONCLUSIONS: Experimentally-induced inflammation decreases the in vivo expression and activity of P-gp in liver. This is the first evidence that expression of P-gp is modulated in response to experimentally-induced inflammation.     

Robust adaptive actuator failure compensation for a class of uncertain nonlinear systems

This paper presents a robust adaptive state feedback control scheme for a class of parametric-strict-feedback nonlinear systems in the presence of time varying actuator failures. The designed adaptive controller compensates a general class of actuator failures without any need for explicit fault detection. The parameters, times, and patterns of the considered failures are completely unknown. The proposed controller is constructed based on a backstepping design method. The global boundedness of all the closed-loop signals is guaranteed and the tracking error is proved to converge to a small neighborhood of the origin. The proposed approach is employed for a two-axis positioning stage system as well as an aircraft wing system. The simulation results show the correctness and effectiveness of the proposed robust adaptive actuator failure compensation approach.     

Development and characterization of a Persian gum–sodium caseinate biocomposite film accompanied by Zingiber officinale extract

Nowadays, instead of synthetic polymers, ecofriendly biopolymers are being widely used as packaging materials; this minimizes packaging waste and environmental pollution. In this study, we aimed to characterize edible films based on sodium caseinate (SC) with the simultaneous use of Zingiber officinale extract (ZOE) and Persian gum (PG). The functional, structural, morphological, and physicochemical aspects of manufactured samples were investigated. Response surface methodology was used to optimize the use of PG (0–1%) and ZOE (0–500 ppm) in the production of the edible films. Fourier transform infrared spectroscopy analysis was carried out to confirm the SC–PG–ZOE interactions. Statistical analysis revealed that the addition of ZOE led to a significant increase in the tensile strength and elongation at break (EB). However, the addition of PG, regardless of ZOE addition, decreased EB. In addition, the incorporation of ZOE into the biopolymer matrix improved the water resistance, water vapor permeability (WVP), and water solubility (WS), whereas the incorporation of PG reduced the transparency. Our findings indicated that minimum of transparency and EB and minimum of WVP and WS were obtained at 0.6% for PG and 360 ppm for ZOE. Therefore, the results of this study suggest a new biocomposite with desirable characteristics and promising potential for producing edible films. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47215.     

An Experimental and Finite Element Study of Cold Spray Copper Impact onto Two Aluminum Substrates

The effect of cold spray temperature and substrate hardness on particle deformation and adhesion has been studied, with particular emphasis on adiabatic shearing leading to melting. Copper particles were cold sprayed onto commercial purity (CP) aluminum and alloy 7050-T7451, with stagnation temperatures 200, 400, and 600 °C. Deposition efficiency, assisted by particle embedding, increased with temperature and was higher on the softer CP substrate. Crater surfaces, adhered particles, and interfaces were characterized by scanning electron microscopy, focused ion beam, and transmission electron microscopy. For comparison, the impact of 15 μm Cu particles was simulated using finite element modeling. A thin layer of material on the substrate-side of the interface was predicted to reach melting point on both substrates at higher impact velocities. Formation of a molten layer was found experimentally. At 600 °C, the effect of substrate heating by the gas jet could not be ignored.     

Correlations of SPT,CPT and pressuremeter test data in alluvial soils. Case study: Tabriz Metro Line 2, Iran

Bulletin of Engineering Geology and the Environment - The Menard pressuremeter modulus (Em), limit pressure (PL), shear modulus (G) and subgrade reaction modulus (Ks) can be obtained by using the...     

Application of Conducting Polymer Layer for Measurement of Ag Nanoparticle Concentration Using Surface Plasmon Resonance

An application of polypyrrole and polypyrrole–chitosan were presented to measure the concentration of silver ion and silver nanoparticles using surface plasmon resonance sensor. These results were compared to those for atomic absorption spectroscopy method. The sensing layers were prepared using an electrodeposition on gold layer with the sensor limitation at about 1mg/L, and well correlated to prior atomic absorption spectroscopy results. The sensor with a polypyrrole-chitosan layer was more sensitive and accurate than the sensor with just a polypyrrole layer.