@article{kim_pourdeyhimi_desai_abhiraman_2001, title={Anisotropy in the mechanical properties of thermally spot-bonded nonwovens: Experimental observations}, volume={71}, ISSN={["0040-5175"]}, DOI={10.1177/004051750107101106}, abstractNote={ Anisotropy is evaluated for in-plane mechanical properties, such as tensile modulus, maximum stress in tension, elongation at maximum stress, shear modulus, and bending rigidity, of three designed sets of spot-bonded nonwoven fabrics. Image analysis is used to quantify the fiber orientation distribution and identify failure mechanisms. The non-woven fabrics in this study have been produced specifically to explore the effects of different processing conditions (temperature, pressure, and bond area) on mechanical performance. The results show that, within a typical window of processing conditions, bond area and bonding temperature have a significant influence on all the mechanical properties. The data also suggest that failure of thermally bonded nonwoven structures is likely to be governed by critical stress-based criteria. An important inference from this work is the recognition that the mechanical properties of thermally spot-bonded nonwoven structures can be described quantitatively through a simple composite model. The results also suggest that the azimuthal properties of the bonded and nonbonded regions, and thus the nonwoven, are likely to be amenable to continuum models of materials with ortho-tropic symmetry. }, number={11}, journal={TEXTILE RESEARCH JOURNAL}, author={Kim, HS and Pourdeyhimi, B and Desai, P and Abhiraman, AS}, year={2001}, month={Nov}, pages={965–976} }
 @article{latifi_kim_pourdeyhimi_2001, title={Characterizing fabric filling due to fabric-to-fabric abrasion}, volume={71}, ISSN={["1746-7748"]}, DOI={10.1177/004051750107100713}, abstractNote={ This paper describes a cylindrical lighting system and its applications for objectively assessing fabric pilling. This cylindrical lighting system allows easy isolation and measurement of pills by illuminating only the pills and suppressing the background. Using this new lighting scheme, the pilling properties in two knitted fabrics are successfully explored as a function of fiber type and abrasion cycles. }, number={7}, journal={TEXTILE RESEARCH JOURNAL}, author={Latifi, M and Kim, HS and Pourdeyhimi, B}, year={2001}, month={Jul}, pages={640–644} }
 @article{kim_deshpande_pourdeyhimi_abhiraman_desai_2001, title={Characterizing structural changes in point-bonded nonwoven fabrics during load-deformation experiments}, volume={71}, ISSN={["0040-5175"]}, DOI={10.1177/004051750107100211}, abstractNote={ Current efforts to establish links between processing conditions and the structure and properties of nonwoven fabrics in general, and for point-bonded (spot-bonded) nonwovens in particular, would be served significantly by in situ experimental visualization and measurement of the structural changes that occur during controlled deformation experiments. The features of a simultaneous “tensile testing/image acquisition” instrument that can serve this critical need are described in this report. The instrument is effective in providing quantitative measures of the orientation distribution function (ODF) of the fibers, the bond spot strain, the unit bond repeat pattern strain, and the shear deformation of this unit cell as a function of applied macroscopic deformation. It is also useful in determining the failure mode as a function of the method of applying deformation to the nonwoven fabric. These features are exemplified through analysis of a point-bonded carded nonwoven, which is anisotropic in its fiber orientation distribution and in the geometry and distribution of its patterned thermal bond spots. }, number={2}, journal={TEXTILE RESEARCH JOURNAL}, author={Kim, HS and Deshpande, A and Pourdeyhimi, B and Abhiraman, AS and Desai, P}, year={2001}, month={Feb}, pages={157–164} }
 @article{seyam_mohamed_kim_1998, title={Signal analysis of dynamic forces experienced by individual needles in high speed needle punching}, volume={68}, ISSN={["1746-7748"]}, DOI={10.1177/004051759806800408}, abstractNote={ Dynamic forces experienced by individual needles are measured and investigated in time and frequency domains to deduce the needle force signal due to fiberweb resistance during penetration and withdrawal of the needles from the fiberweb. A technique de veloped to deduce a needle force signal due to fiberweb resistance for the entire nee dling cycle for any number of cycles enables the determination of peak penetration force, peak stripping force, and penetration and stripping energies due to fiberweb resistance. The force parameters are essential to loom and needle manufacturers for design purposes. Equally important, the force parameters are related to needled fabric end use performance. This relationship can be used to produce consistent fabric prop erties by controlling the process variables that influence needle force parameters. }, number={4}, journal={TEXTILE RESEARCH JOURNAL}, author={Seyam, AM and Mohamed, A and Kim, H}, year={1998}, month={Apr}, pages={296–301} }
 @article{kim_reisman_williams_1997, title={Low-field trap generation dependence on the injection current density in gate insulators - How valid are accelerated hot electron measurements?}, volume={144}, ISSN={["0013-4651"]}, DOI={10.1149/1.1837847}, abstractNote={Continuous low gate insulator field (1 MV/cm) electron injection in insulated gate field effect transistors using a pulsed injection technique (PIT) was conducted in the dose range 10 -3 to 10 17 e/cm 2 over the range of current densities from 1.5 x 10 -7 to 3.4 x 10 -5 A/cm 2 . PIT enables independent control of insulator fields and injection current densities, while not causing optically induced shallow trap depopulation. As is generally the case, the threshold voltage shift, AV D varies monotonically with dose, and can be modeled using a defect generation power law requiring fewer adjustable parameters than is necessary using a first order trapping model. It was also found that for a given dose the injection current density has a profound effect on the observed magnitude of trap generation. Previously, the total dose and insulator field were thought to be the only determining factors in trap generation. Based on these results, it appears that when the intrinsic defect concentration(s) is to be determined, a very low current density (injection rate) should be used to minimize trap generation effects which would confuse the issue. It is reported also for the first time that the expected in-use lifetime of the devices, calculated from the injection data, also exhibits a power law dependency on the injection current density. These results raise serious questions about the validity of aggressive injection techniques (such as avalanche injection and Fowler-Nordheim approaches), of the existence of ultrasmall cross section electron traps based on such methods, and of aggressive accelerated aging conclusions, based on the extrapolation of high injection current density data to end-of-life threshold voltage shifts.}, number={7}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Kim, HS and Reisman, A and Williams, CK}, year={1997}, month={Jul}, pages={2517–2521} }