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At least 37 records · Page 2Linked to original sources
PubMed2006

Effect of vacuum-steam-vacuum treatment on microbial quality of whole and fresh-cut cantaloupe.

Minimally processed fruits and vegetables have a limited shelf life because of deterioration caused by spoilage microflora and physiological processes. Cutting may increase microbial spoilage of fruits through transfer of microflora on the outer surfaces to the interior tissue. The objectives of this study were to use the vacuum-steam-vacuum (VSV) process to reduce indigenous spoilage microflora on the surface of cantaloupes and to investigate the effects of such treatments on transfer of spoilage microflora from the cantaloupe surface to the fresh-cut melon during rind removal and cutting. Whole cantaloupes were treated in the VSV processor, and fresh-cut pieces prepared from treated and control samples were stored at 5 and 10 degrees C for up to 9 days. Presence and growth of mesophilic bacteria, yeasts and molds, and Pseudomonas spp. were determined in fresh-cut samples during storage. Texture and color (CIE L*, a*, and b*) also were measured during storage. VSV treatment resulted in a 1.0-log reduction of aerobic mesophilic bacteria, a 2.0-log reduction of yeasts and molds, and a 1.5-log reduction of Pseudomonas spp. on cantaloupe surfaces. VSV treatment significantly reduced transfer of yeasts and molds and Pseudomonas spp. from whole cantaloupe surface to fresh-cut pieces during preparation (P < 0.05). Texture and color of the fresh-cut pieces prepared from the VSV-treated whole melons were similar to those of the controls. The results of this study indicate that the use of the VSV process to reduce the surface populations of yeasts and molds and Pseudomonas spp. on whole cantaloupes will reduce subsequent transfer of these microbes to fresh-cut pieces and enhance the microbial quality of the fresh-cut product.

Colony Count, Microbial↗
PubMed2001

Comparing the acceptability of manual vacuum aspiration and electric vacuum aspiration as methods of early abortion.

OBJECTIVE: to compare the acceptability of manual vacuum aspiration (MVA) and electric vacuum aspiration (EVA) as methods of early (< or = 77 days' gestation) abortion. METHODS: We interviewed 42 women who had been randomly assigned to either MVA or EVA and compared their perceptions of the two procedures. RESULTS: The experiences and perceptions of women in the two groups were similar in many ways. The majority of women in both procedure groups were very satisfied with the method used, and most indicated that they would prefer the same method if they were to have another abortion. CONCLUSION: This study found no major differences in the acceptability of MVA and EVA among women undergoing early abortions.

Abortion, Induced↗
PubMed1980

[The effect of vacuum vibration investing and vacuum mixing on the properties of "LAW-Modellguss investment" and the fit of cast structures from cobalt-chromium-molybdenum alloys. 1. Technologic-experimental tests].

Using materials-scientific test methods, the author studied the effect of vacuum mixing and vibration on the setting and the thermal expansion and contraction behaviour of the investment compound "LAW-Modellgusseinbettmasse" as well as on its hardness and structure after setting. The results obtained show that vacuum processing may considerably improve the properties which are of importance in model casting.

Chromium↗
PubMed1999

The response of SiC fibres to vacuum plasma spraying and vacuum hot pressing during the fabrication of titanium matrix composites

Vacuum plasma spraying (VPS) and vacuum hot pressing (VHP) have been used to fabricate Ti-6Al-4V matrix composite material reinforced longitudinally with DERA Sigma C coated SiC 1140+ fibres. VPS of Ti-6Al-4V onto Sigma 1140+ SiC fibres caused no fibre/matrix interfacial reaction. During VHP a fibre/matrix reaction occurred, producing a mixture of fine (< 50 nm) TiCx (x </= 1) adjacent to the fibre coating and coarse-grained (0.3-0.5 &mgr;m) equiaxed TiCx adjacent to the Ti matrix. A decrease in C concentration with increasing distance from the C coating is proposed, and is consistent with the evidence presented. A similar thickness and morphology of reaction product arose from conventional foil-fibre foil processing, but the matrix coated fibre/hot isostatic pressing process led to a slightly thicker reaction layer. The TiCx reaction product acted as a diffusion barrier, inhibiting further reaction more effectively than in experiments on earlier SiC fibres having a C coating. Surface damage was shown to be a factor in lowering 1140+ SiC fibre failure stress. Surface damage to 1140+ fibres resulted from both VPS and VHP, the former causing a slight reduction in mean ultimate tensile strength (UTS), and a large reduction in the bend strain to failure Weibull modulus. This damage was caused by both fibre winding and by deposition of metal during VPS, giving rise to coating flaws, and is not in itself considered to be a major problem. Surface damage increased after VHP, reducing the mean UTS and tensile Weibull modulus, and the mean bend strain to failure. This damage arose from bending and flattening of the rough monotapes, and from the fibre/matrix reaction caused by thermal exposure. The level of damage to 1140+ SiC fibre from VHP was reduced by modification of the process path. Increasing the VHP temperature and lowering the pressure ramp rate reduced fibre damage sufficiently to enable a macroscopic composite UTS of 95% of the theoretical maximum to be achieved.

Journal Article↗
PubMed2006

Scattering of vacuum states by dynamic plasmon singularities: generating photons from vacuum.

A metallic nanoparticle surrounded by an amplifying medium results in a boundary condition that creates a singularity in the particle's dynamic polarizability at a critical value of the gain. When this boundary condition is time dependent, parametric excitation of the electromagnetic vacuum results in photon emission. Estimates of the vacuum emission from nanostructures embedded in high-gain laser dyes excited by femtosecond lasers predict energies nearly 2 orders of magnitude larger than the spontaneous emission background.

Journal Article↗
PubMed1995

[Wound drainage with a continuous high vacuum drainage system and a drainage system with variable vacuum].

A study of 120 total hip replacements showed the advantages of the variable vacuum drainage system over the continuous high vacuum drainage system. Better wound healing, less severe hematomas and less occlusion of drains confirmed the higher effectiveness of secretion draining. With regard to hygienic aspects, and especially to wound infection, the continuous closed drainage system is an improvement of the intermittent closed drainage system.

Adult↗