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Physical Integrity (physical + integrity)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Inherent flammability parameters,Room corner test application

FIRE AND MATERIALS, Issue 8 2009
J. G. Quintiere
Abstract It has been hypothesized that four parameters are solely responsible for a material's performance in a flammability scenario. This excludes effects of material physical integrity, i.e. melting, delamination, etc. They are (1) the critical heat flux below which piloted ignition cannot occur (CHF), (2) the ratio of heat of combustion to heat of gasification (HRP), (3) the thermal response parameter related to the thermal inertia and the ignition temperature (TRP), and (4) the available energy per unit area (AEP). The fire scenario controls the process by its initial heat flux and region of ignition. The hypothesis is applied to 54 tests of the ISO Room Corner Test to assess its validity. It is shown that these four parameters give good correlations in predicting the time to flashover and whether it occurs. In principle, different correlations could be developed for other scenarios of tests and fire configurations. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Capillary Force Lithography: A Versatile Tool for Structured Biomaterials Interface Towards Cell and Tissue Engineering,

ADVANCED FUNCTIONAL MATERIALS, Issue 17 2009
Kahp-Yang Suh
Abstract This Feature Article aims to provide an in-depth overview of the recently developed molding technologies termed capillary force lithography (CFL) that can be used to control the cellular microenvironment towards cell and tissue engineering. Patterned polymer films provide a fertile ground for controlling various aspects of the cellular microenvironment such as cell,substrate and cell,cell interactions at the micro- and nanoscale. Patterning thin polymer films by molding typically involves several physical forces such as capillary, hydrostatic, and dispersion forces. If these forces are precisely controlled, the polymer films can be molded into the features of a polymeric mold with high pattern fidelity and physical integrity. The patterns can be made either with the substrate surface clearly exposed or unexposed depending on the pattern size and material properties used in the patterning. The former (exposed substrate) can be used to adhere proteins or cells on pre-defined locations of a substrate or within a microfluidic channel using an adhesion-repelling polymer such as poly(ethylene glycol) (PEG)-based polymer and hyaluronic acid (HA). Also, the patterns can be used to co-culture different cells types with molding-assisted layer-by-layer deposition. In comparison, the latter (unexposed substrate) can be used to control the biophysical surrounding of a cell with tailored mechanical properties of the material. The surface micropatterns can be used to engineer cellular and multi-cellular architecture, resulting in changes of the cell shape and the cytoskeletal structures. Also, the nanoscale patterns can be used to affect various aspects of the cellular behavior, such as adhesion, proliferation, migration, and differentiation. [source]

Organic and aqueous compatible polystyrene,maleic anhydride copolymer ultra-fine fibrous membranes

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2009
Corine Cécile
Abstract Polystyrene,maleic anhydride copolymer (PSMA, Mv= 700 kDa) was synthesized and efficiently processed into 400 to 600 nm diameter fibers via electrospinning from either 20 wt % dimethylformamide or 25 wt % dimethylsulfoxide solution. Crosslinking of PSMA was effective by adding glycerol and poly(vinyl alcohol) (PVA) (Mw = 31,50 kDa) in the dimethylformamide and dimethylsulfoxide solutions, respectively. The PSMA fibers containing glycerol at 29.4 mol% were auto-crosslinked whereas those with 12.9 mol% (2 wt %) glycerol and 15.4 mol% (0.75 wt %) PVA required heating to induce intermolecular esterification. Heat-induced crosslinking with glycerol was more effective in rendering the PSMA fibrous membranes insoluble in all solvents whereas that with PVA remained soluble in most solvents except for acetone and tetrahydrofuran. The crosslinked fibrous membranes had improved thermally stability and retained physical integrity upon exposure (2 hr at 40°C) to carbon disulfide, the solvent for Friedel-Craft reactions of the styrene moiety. Hydrolysis (0.01N NaOH) of the auto-crosslinked fibrous membrane significantly improved its hydrophilicity by reducing the water contact angles from 90.6° to 62.5° in a matter of seconds. These ultra-high specific surface PSMA fibrous membranes have shown superior organic and aqueous solvent compatibility to be used as highly reactive and easily retrievable supports for solid-phase synthesis. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]

Maintaining the integrity of older patients in long-term institutions: relatives' perceptions

JOURNAL OF CLINICAL NURSING, Issue 5 2007
Sari Teeri MSc
Aim., To study relatives' views on how the integrity of older patients is maintained in long-term institutions in Finland. Background., Maintaining patient integrity is considered a key prerequisite for good quality care and treatment and a characteristic of ethical care. Institutionalization, dependence on others and vulnerability may all threaten the integrity of the older patient and, in this sense, pose ethical problems. Design/methods., The data for this descriptive and explorative survey were collected by questionnaires from 213 relatives of older patients in four long-term institutions in Finland. The response rate was 78%. Data were analysed using statistical methods. Results., Relatives rated the maintenance of patient integrity quite highly. The highest ratings were recorded for the maintenance of physical integrity and the lowest to the maintenance of psychological integrity. The main source of problems were patients' and/or relatives' wishes concerning elimination. There were also shortcomings in the provision of intimacy. Relatives who thought that admission to the long-term institution had been problematic, either for the patient or for themselves, felt that patient integrity was poorly maintained. Conclusion., The findings highlight the importance of nurses' efforts in long-term care facilities to preserve the integrity of patients and to maintain close contact and cooperation with relatives. Although relatives generally were quite pleased with how patient integrity was maintained, the results also provide evidence on problems that may threaten patient integrity. Relevance to clinical practice., Greater emphasis should be placed on the need for cooperation between older patients, their relatives and nursing staff, especially before admission to long-term care. Furthermore, increased efforts are needed in maintaining the integrity of older patients and in reducing ethically problematic situations. [source]