PubMed Health⌕ Search

Biomedical subjects

A Shenhar

Publications and source records attributed to A Shenhar.

9 recordsLinked to original sources
PubMed2001

Corrosion behavior of PIRAC nitrided Ti-6Al-4V surgical alloy.

Hard titanium nitride (TiN) coatings were obtained on the surface of Ti-6Al-4V alloy using an original PIRAC nitriding method, based on annealing the samples under a low pressure of monatomic nitrogen created by selective diffusion of N from the atmosphere. PIRAC nitrided samples exhibited excellent corrosion resistance in Ringer's solution in both potentiodynamic and potentiostatic tests. The anodic current and metal ion release rate of PIRAC nitrided Ti-6Al-4V at the typical corrosion potential values were significantly lower than those of the untreated alloy. This, together with the excellent adhesion and high wear resistance of the TiN coatings, makes PIRAC nitriding an attractive surface treatment for Ti-6Al-4V alloy surgical implants.

Journal Article↗
PubMed1996

Microcell for anodic stripping voltammetry of trace metals.

A microcell for batch injection stripping voltammetry of trace metals with the use of a rotating disk working electrode has been developed and tested for samples of 0.2-0.3 mL. The detection limits for Pb(2+), Cd(2+) and Zn(2+) are 0.03 ppb and 0.3 for a deposition time of 5.0 and 0.5 min, respectively.

Journal Article↗
PubMed1986

The fusion of pressing situation and releasing writing: on adolescent suicide poetry.

The poetry of adolescents in despair may provide us with early signs of suicide; hence referral to professional help may result at an early stage. The present study concentrated on two adolescents who wrote poetry and committed suicide. The words used in these adolescents' poetry and in the poetry of two nonsuicidal adolescents were analyzed and classified into semantic fields. Significant differences were found between the suicide and the control groups. These differences showed themselves in the vigor and intensity of the loaded words in the suicide group, as well as in the more extreme occurrence of two major foci, "Death" and "Bad Situation." These foci are demonstrated in a constructed model that may guide parents and professionals in early detection of suicide.

Adolescent↗
PubMedDate not supplied

Simultaneous determination of water and enediols or thiols in chemical products and drugs not amenable to direct Karl Fischer titration.

A method proposed for determining water and enediols or thiols is based on consecutive titration of the enediols or thiols by a novel reagent and of water by the conventional Karl Fischer reagent in the same cell. The time for both titrations is 8-20 min. The novel reagent consists of iodine, sodium acetate as a base, and potassium iodide in a nonaqueous solvent system. The method is applicable for quality control of chemical products and drugs during their production and trade.

Ascorbic Acid↗
PubMedDate not supplied

pH-metric determination of acid numbers of petroleum oils without titration.

A pH-metric method was developed for determination of the acid numbers of oils containing organic and inorganic acids at levels <0.1 mg KOH/g oil. The method is based on rapid and complete extraction of acids from a test portion of oil into a special reagent, and measurement of the conditional pH of the mixture "oil-reagent" by a glass electrode. The method uses nontoxic reagents, is not time and labor consuming, and is cheap and simple enough for automation.

Electrodes↗
PubMedDate not supplied

pH-metric determination of the acid value of vegetable oils without titration.

The acid value (AV) of vegetable oils is determined without titration by using a new reagent consisting of triethanolamine in a solution of water and isopropyl alcohol. When the oil sample is mixed with the reagent in the pH-metric cell, free fatty acids from the sample are extracted into the reagent (3-4 min). The initial pH, called conditional pH'1, is measured, a standard acid (HCl) is added, and the final pH, pH'2, is measured. AV is calculated from the difference between pH'1 and pH'2. The method is applicable for quality control of vegetable oils during their production, trade, and use.

2-Propanol↗