Cognitive bearing of techno-advances in Kashmiri carpet designing

The design process in Kashmiri carpet weaving is a distributed process encompassing a number of actors and artifacts. These include a designer called naqash who creates the design on graphs, and a coder called talim-guru who encodes that design in a specific notation called talim which is deciphered and interpreted by the weavers to weave the design. The technological interventions over the years have influenced these artifacts considerably and triggered major changes in the practice, from heralding profound cognitive accomplishments in manually driven design process causing major alterations in the overall structure of the practice. The recent intervention is by the digital technology: on the one hand, it has brought precision and speedy processing in the design process, and on the other, it has eliminated some of the crucial actors from the practice. This paper, which forms part of a larger study on the situated and distributed cognitive process in Kashmiri carpet-weaving practice, describes the technological makeover of the design artifacts involved in this practice over the years and their resultant cognitive impact on the design process as well as on the practice

Microfluidic Synthesis of Microfibers for Magnetic-Responsive Controlled Drug Release and Cell Culture

This study demonstrated the fabrication of alginate microfibers using a modular microfluidic system for magnetic-responsive controlled drug release and cell culture. A novel two-dimensional fluid-focusing technique with multi-inlets and junctions was used to spatiotemporally control the continuous laminar flow of alginate solutions. The diameter of the manufactured microfibers, which ranged from 211 µm to 364 µm, could be well controlled by changing the flow rate of the continuous phase. While the model drug, diclofenac, was encapsulated into microfibers, the drug release profile exhibited the characteristic of a proper and steady release. Furthermore, the diclofenac release kinetics from the magnetic iron oxide-loaded microfibers could be controlled externally, allowing for a rapid drug release by applying a magnetic force. In addition, the successful culture of glioblastoma multiforme cells in the microfibers demonstrated a good structural integrity and environment to grow cells that could be applied in drug screening for targeting cancer cells. The proposed microfluidic system has the advantages of ease of fabrication, simplicity, and a fast and low-cost process that is capable of generating functional microfibers with the potential for biomedical applications, such as drug controlled release and cell culture

An experimental study on hulk and solution polymerization of methyl methacrylate with responses to step changes in temperature

Several important polymerizations [e.g., polymethylmethacrylate (PMMA), polystyrene (PS), etc.] exhibit the gel, glass and cage effects during polymerization. These are associated with the decrease of the diffusivities of the macroradicals, monomer molecules and primary radicals with increasing viscosities of the reaction mass. The recent model of Seth and Gupta [ V. Seth, S.K. Gupta, J. Polym. Eng., 15 (1995) 283.] has been used to explain these results. The model parameters are tuned using experimental data on near-isothermal bulk and solution polymerizations of methyl methacrylate (MMA) in a 1-1 stainless steel, computer controlled reactor. A series of bulk and solution polymerizations (at 10%, 20% and 30% solvent concentrations) have been carried out at two different temperatures (50 degrees C and 70 degrees C) using benzoyl peroxide (BPO) as initiator at one initiator concentration (41.5 mol/m(3)). Two important process variables, e.g., monomer conversion and viscosity average molecular weights were measured using gravimetric analysis and dilute solution viscometry, respectively. The results obtained from this study are in excellent agreement with those reported earlier in the literature. Experiments have also been carried out with step changes in temperature. Thus, the present study establishes the applicability of the model for the more general non-isothermal reactor operations with bulk as well as solution polymerizations along with semi-batch reactor operations. (C) 1998 Elsevier Science.