Blisters

About: Blisters is a research topic. Over the lifetime, 980 publications have been published within this topic receiving 16229 citations.

Blistering and deuterium retention in Nb-doped W exposed to low-energy deuterium plasma

Abstract: Tungsten and tungsten-niobium alloy with niobium concentration of 5 wt% were exposed to deuterium plasma at ~470 – 506 K, with flux of ~1.8 × 1021 D/m2/s, an ion energy of 100 eV and fluence of 1.3 × 1025 D/m2 – 5.2 × 1025 D/m2. Before exposure, the hardness and Young's modulus as well as lattice parameter of W are improved due to Nb doping. After exposure, the TDS spectra can be deconvoluted into two major Gaussian peaks located at ~700–800 K and ~900–1000 K for all samples. At low fluence (1.3 × 1025 D/m2) and low temperature (470 K), only sparse and small blisters are formed on the pure W surface, while the strip-like surface structures are observed on the W-5Nb surface. The total D retention is significantly reduced due to the Nb doping, where the D retention in W-5Nb is 1.34 times lower than that of in pure W. With increasing fluence up to 2.6 × 1025 D/m2, both the blister size of pure W and W-5Nb alloy continue to increase. The blister size of W-5Nb alloy is slightly bigger than that of pure W, but the opposite trend is observed in blister density. The total D retention in W-5Nb alloy is also observed to be 1.38 times higher than that of pure W. Further increase of irradiation fluence (5.2 × 1025 D/m2) and temperature (506 K) at the same time lead to the significant increase of blister size and D retention for the pure W. However, whether the blister size or D retention are greatly suppressed in W-5Nb alloy. Moreover, the deuterium retention in W-5Nb is about 3 times less than that in pure W, implying that niobium alloying suppress the surface blistering and reduce the deuterium retention in tungsten exposed to D plasma with a fluence of 5.2 × 1025 D/m2 at 506 K.

A bottom-up approach for controlled deformation of carbon nanotubes through blistering of supporting substrate surface

Abstract: Tuning the band structure and, in particular, gap opening in 1D and 2D materials through their deformation is a promising approach for their application in modern semiconductor devices. However, there is an essential breach between existing laboratory scale methods applied for deformation of low-dimensional materials and the needs of large-scale production. In this work, we propose a novel method which is potentially well compatible with high end technological applications: single-walled carbon nanotubes (SWCNTs) first deposited on the flat surface of a supporting wafer, which has been pre-implanted with H+ and He+ ions, are deformed in a controlled and repetitive manner over blisters formed after subsequent thermal annealing. By using resonant Raman spectroscopy, we demonstrate that the SWCNTs clamped by metallic stripes at their ends are deformed over blisters to an average tensile strain of 0.15 ± 0.03%, which is found to be in a good agreement with the value calculated taking into account blister's dimensions. The principle of the technique may be applied to other 1D and 2D materials in perspective.

Fiducial mark and nanocrack zone formation during thin-film delamination

Abstract: Carbon fiducial marks are formed during thin-film local delamination processes induced either by superlayer indentation forming circular blisters, or by residual stress relief through telephone cord blister formation. Hydrocarbons are sucked into the crack tip during the delamination process, outlining the crack-tip-opening angle, which can be used to back calculate thin-film adhesion using either elastic or plastic analyses presented here. Fiducial marks have been observed in two different thin-film systems, namely Cu/SiO2 and TiW x N y /GaAs. Cu/SiO2 delamination blisters have been cross-sectioned using the focused-ion-beam method, and high-resolution scanning electron microscopy of the cross-sections revealed crack renucleation ahead of the original crack tip. This is attributed to the stress redistribution process due to the dislocation shielding mechanism. At stress intensity levels of 0.33 MPa m½, it is found that four emitted dislocations can account for crack arrest, with renucleation of ...

A retrospective analysis of the aspiration of fracture blisters

Abstract: Introduction Fracture blisters are frequently encountered in orthopaedic trauma. Fracture blisters are associated with increased infection rates and wound breakdown. This study was performed to determine whether fluid aspirate from blisters is sterile or colonized. Materials and methods This is a retrospective review of a prospectively gathered cohort of patients. Patients with fracture blisters were recruited from a U.S. level I trauma center between 2011 and 2017. The blisters were aspirated under sterile conditions. Fluid was analyzed for gram stain and quantitative culture. Medical history obtained included blister location, presence of blood in blister, injury mechanism, gender, diabetes status and tobacco use. The demographic and behavioral descriptors were compared across positive aspirate or infection status using chi-square and Fisher’s exact tests. Results We enrolled 64 patients in the study, seven of which had colonized aspirates (10.9%). None of the potential risk factors were significantly associated. Tobacco use trended towards significance for a positive aspirate (p = 0.09), but not for infection (p = 0.61). We followed patients for an average of 4.6 months. Four patients went on to have surgical site infections and none of them had positive aspirates. Conclusion Fracture blisters cannot be assumed to be sterile with more than 10% of our sample being colonized. Blister rupture during surgery or prepping for surgery could represent a contamination of the sterile field. No risk factors were significantly associated with colonization in our sample. However, colonized aspirates may not predispose patients to increased infection rates.

Pharmacokinetic studies of antibacterial agents using the suction blister method.

Abstract: The suction blister technique was used for pharmacokinetic studies with sulfonamides and trimethoprim. Blisters produced by suction (-0.3 kg/cm2) for 1.5 h contained approximately 0.15 ml fluid with a protein content of 40-50% of that in plasma, the main protein fractions being present in the same ratio as in plasma. 2 g sulfaisodimidine was given as bolus injection, i.v. infusion or orally to groups of 4 volunteers. The peak blister fluid concentrations after oral administration (120 +/- 18 mmol/l) was only marginally lower than the concentrations after i.v. infusion (122 +/- 28 mmol/l) and i.v. bolus injections (134 +/- 37 mmol/l). The total drug blister fluid concentration started to decrease before the plasma level was reached. However the relative concentration increased from 53% of that in plasma at 8 h to 66% at 12 h after drug administration. Considering the protein binding of the drugs, the interstitial fluid levels of free drug were presumably higher than the plasma level after 8 h. Comparison of drug concentrations in blisters produced before and after the drugs were given showed higher concentrations in the latter for the first 2-6 h. However, after 8-12 h the concentrations of the drugs in the two types of blisters were similar. The suction blister method produces blisters of uniform size. The drug concentrations in different experiments showed the coefficient of variation for blister fluid concentrations to be no greater than for plasma levels. The consistent results of the standardized suction blister method makes this method useful for studying drug penetration to extravascular compartments in humans.