Helmholtz vibrations in bowed strings.

For almost 160 years, it has been known that Helmholtz oscillations, unique to vibrating strings in bowed instruments (violin, cello, etc.), have two distinct regimes: "slip" and "stick." During the slip regime, the force at the bow-string interaction is attributed to friction between the sliding bow hair and the vibrating string, with a friction coefficient that decreases with increasing relative velocity.

Adverse Events in the Efficacy of Crotalidae Polyvalent Immune Fab Antivenom vs Placebo in Recovery from Copperhead Snakebite Trial.

Objective: To compare the incidence of hypersensitivity reactions following copperhead envenomation treated with Fab antivenom (FabAV) or placebo.

Methods: Patients with copperhead snakebites received treatment and follow-up in a prospective, randomized, double-blind, placebo-controlled trial of FabAV or placebo. The treatment allocation ratio was 2:1 (FabAV:placebo).

Remote Video Auditing to Verify OR Cleaning: A Quality Improvement Project.

There are many sources of contamination in the perioperative environment. Patient experience can be negatively affected by the presence of environmental contamination, especially if it is the cause of a surgical site infection. Perioperative and environmental services staff members and leaders are tasked with ensuring a clean and safe environment for their patients while maintaining an awareness of time and budgetary constraints.

Composition dependence of the elastic constants of beta-phase and (alpha+beta)-phase PdHx.

We have measured the composition and temperature dependence of the shear moduli C' and C(44) for two-phase (alpha+beta)- and single-phase beta-PdH(x). In the two-phase region, the alpha- and beta-phases are coherent. Here, the composition dependence of C(44) and C' deviate negatively from a Vegard-type volume average.

Exploring the next neighbourhood relationship in amorphous alloys utilizing atom probe tomography.

A new algorithm is developed to explore the next neighbourhood atomic vicinity from the analysed data obtained using the tomographic atom probe (TAP) technique. The presented algorithm allows to calculate the atomic distances among different next neighbours of different elements as applied to bulk amorphous alloys. The results obtained for Pd55 Cu23 P22 bulk amorphous alloys show reasonable consistency to already available data from different diffraction techniques.

Similarities in the Cp/T3 peaks in amorphous and crystalline metals.

A low-temperature peak in C(p)/T(3) vs is ubiquitous to glasses. It arises from an abundance of low-frequency vibrations, the origin of which remains unclear. A comparable C(p)/T(3) vs peak is observed in crystals due to the dispersion of acoustic phonons and/or the excitation of optical phonons.

The structure of a metallic glass system using EXELFS and EXAFS as complementary probes.

The short-range atomic order around all three constituent atoms in a prototypical bulk metallic glass (BMG) system was probed in a complementary way, using extended X-ray absorption fine structure for neighborhood of the higher atomic number elements, and extended energy loss fine structure (EXELFS) for the lower atomic number ones. The Pd(x)Ni((80-x))P((20)) system is a prototype for a whole class of BMG formers which are 80% transition metal and 20% metalloid. We find that the structure of these BMGs could be explained in terms of those of glasses at the end of the BMG range, namely, Pd(60)Ni(20)P(20) and Pd(30)Ni(50)P(20).

Elastic constants of an aluminum-alumina unidirectional composite.

The five independent second-order elastic constants of a transversely isotropic aluminum/alumina fiber composite have been measured for the first time using a resonant ultrasound spectroscopy technique. These data were used to deduce the elastic constants and engineering moduli for off-axis loading conditions.

Electron microscopy study of twin behavior in GdBa2Cu3Ox and YBa2Cu3Ox.

Twins are ubiquitous in the perovskite superconductors. They form during cooling from high temperatures through the tetragonal-to-orthorhombic phase transformation. Their behavior has been studied by transmission electron microscopy using a liquid-nitrogen-cooled specimen holder.