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Mechanical Impact (mechanical + impact)

Distribution by Scientific Domains

Polymers and Materials Science	40%

Selected Abstracts

Comparison of the washing efficiencies of a laboratory washing device (Launder-Ometer) and of automatic household washing machines with horizontal drums

INTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 6 2007
Hanna-Riitta Kymäläinen
Abstract The objective of this study was to compare the cleaning result of a laboratory washing machine , Launder-Ometer (LOM) , with that of drum-type household washing machines, using detergent without bleaching agent, standard soiled fabrics and a colorimeter for assessing the washing result. The mechanical effect applied to the laundry in the household washers was not obtained in the LOM by increasing mechanical impact or the number of metal balls. Extended washing time did not improve removal of blood soil in the LOM, although it did increase removal of mayonnaise soil containing chlorophyll. However, in practice a washing time of 60,85 min is relatively long for a laboratory device considering the claimed time-saving nature of these devices. None of the examined parameters affected removal of a red wine soil containing tannins, which was poor in all test combinations both in the household machines and in the laboratory washing machine. Bleaching agent is recommended for removal of this type of soil. In conclusion, conformity between washing results of the laboratory washing machine and the drum-type household washing machines depends on the type of soiled test fabrics and other parameters in the washing process. Removal of blood soil differed most between the household machines and the LOM. [source]

Effect of molecular relaxation of acrylic elastomers on impact toughening of polybutylene terephthlate

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2007
Nafih Mekhilef
Abstract In this study, we examined the performance of two core-shell acrylic-based impact modifiers (AIM) prepared by emulsion polymerization. The rubber core was prepared from ethyl hexyl acrylate (EHA) and n -octyl acrylate (n -OA). In such as process, the particle size and particle-size distribution of the modifiers were precisely controlled, so that performance differences observed in polybutylene terephthlate (PBT), used as matrix resin, could only be interpreted in terms of the nature of the elastomeric component of the modifiers. When isolated, the rubber core of the modifiers showed identical glass transition temperatures (Tg) by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) despite the fact that they were made from two different acrylic monomers. Temperature-frequency superposition principle inferred from the classical WLF equation showed that the rubber components exhibit the same Tg at all frequencies including at the time scale at which mechanical impact typically occurs. However, significant differences in low temperature impact performance measured at ,30°C using notched Izod impact test according to ASTM D 256 were obtained even though their rubber components had identical Tg. Such differences were attributed to the dynamic relaxation behavior of the rubber components and identified as inherent properties of the elastomers due to the structure of the monomers' repeat units. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [source]

Brain damage in pigs produced by impact with a nonpenetrating captive bolt pistol

AUSTRALIAN VETERINARY JOURNAL, Issue 3 2003
JW FINNIE
Objective To assess the effect of impact with a nonpene-trating captive bolt pistol in pigs by studying the resulting traumatic brain injury (TBI) and to compare the pathological changes with those found previously in the brains of sheep using a similar experimental paradigm. Procedure The unrestrained heads of six, anaesthetised, 7- to 8-week-old, Large White pigs were impacted in the temporal region with a nonpenetrating captive bolt pistol. Four hours postimpact, brains were perfusion-fixed with 4% paraformaldehyde. Coronal sections from six levels along the brain were cut and stained with haematoxylin and eosin and immunohistochemically for amyloid precursor protein, a sensitive marker of axonal injury (AI) in the brain after trauma. Results TBI in pigs was characterised only by very mild AI, whereas AI in sheep after captive bolt impact to the same head region was much more severe and widely distributed and often associated with vascular damage such as contusions, subarachnoid and intraparenchymal haemorrhage. Conclusions TBI in pigs was much less severe than in sheep after non-penetrating mechanical impact of similar magnitude, confirming the importance of interspecies differences in determining an appropriate physical method of euthanasia. [source]

Plasma assisted LED wafer scribing and fabrication of Ag nanoparticle-embedded LED

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7-8 2010
Jong-Moo Lee
Abstract Two applications of plasma effects in fabrication of LEDs are introduced. One is scribing LED wafer by mechanical impacts of plasma, which is induced by laser ablation, to the bottom of LED wafer. The other one is the surface plasmon effect on light emission. Ag nano-particles are formed on about 50-nm thick p-GaN epitaxial layer over multi-quantum wells (MQWs) and an additional 150-nm thick p-GaN layer is grown again over the surface. As the result, the Ag nano-particles are located within the overall p-GaN epitaxial layer, very near to MQWs. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

The effect of biological studies of polyester composites filled carbon black and activated carbon from bamboo (Gigantochloa scortechinii)

POLYMER COMPOSITES, Issue 1 2007
H.P.S. Abdul Khalil
The development of composites using various filler material increased significantly nowadays. Composite materials need to implement the biological and mechanicals impact in their life cycle. The carbon black (CB) and activated carbon (AC) from bamboo (Gigantochloa scortechinii) were used as filler in polyester composites. CB and AC were pyrolized to 700°C and activated with ZnCl2. The composites were prepared with 40% filler loading. The degradation of the composites CB and AC (mechanical properties) to the soil burial test was determined. Tensile, flexural, impact and mass changes of the buried samples were investigated. The deterioration of the samples affected by the biological attack was confirmed by SEM studies. The assessment was done after 0, 3, 6, and 12 months of the biological exposure and the results were compared with the composites filled CaCO3 (commercial filler) and cast polyester resin (as control). POLYM. COMPOS. 28:6,14, 2007. © 2007 Society of Plastics Engineers [source]