Gold and silver diffusion in germanium: a thermodynamic approach

Diffusion properties are technologically important in the understanding of semiconductors for the efficent formation of defined nanoelectronic devices. In the present study we employ experimental data to show that bulk materials properties (elastic and expansivity data) can be used to describe gold and silver diffusion in germanium for a wide temperature range (702–1177 K). Here we show that the so-called cBΩ model thermodynamic model, which assumes that the defect Gibbs energy is proportional to the isothermal bulk modulus and the mean volume per atom, adequately metallic diffusion in germanium

The separation-preconcentration and determination of ultra-trace gold in water and solid samples by dispersive liquid-liquid microextraction using 4-ethyl-1(2-(4-(4-nitrophenyl)piperazin-1-yl)acetyl)thiosemicarbazide) as chelating agent and flame atomic absorption spectrometry

Soylak, Mustafa/0000-0002-1017-0244WOS: 000431928200014A selective separation and preconcentration method for the determination of gold ions in water and ore samples has been developed using dispersive liquid-liquid microextraction, followed by flame atomic absorption spectrometry. 4-Ethyl-1(2-(4-(4-nitrophenyl)piperazin-1-yl)acetyl)thiosemicarbazide) (NPPTSC) has been used for the first time as new chelating reagent. A mixture of ethanol (dispersive solvent) and carbon tetrachloride (extraction solvent) was used. Some parameters affecting the extraction procedure including the type and volume of the extracting and dispersive solvents, HNO3 concentration, the chelating agent amount, volume of sample, and foreign ions have optimized. Also, the complex formation between gold ions and the ligand has been investigated in a methanol-water solution (1:1) using UV-visible spectrometry. The spectrophotometric titration data showed that of Au-NPPTSC complex composition was found to be 3:2. After optimizing the instrumental and experimental parameters, we achieved a detection limit of 1.5 mu g L-1, a preconcentration factor of 50, and a linear dynamic range of 10.0-400.0 mu g L-1. The relative standard deviation obtained 2.1% at 50 mu g L-1 for gold ions (n = 10). The proposed method was successfully performed for the determination of gold in certified reference material, environmental water, and ore samples.Scientific Research Projects of Giresun University [101016-131]The financial support of the unit of the Scientific Research Projects of Giresun University (Project No.: 101016-131) (Giresun Turkey) is gratefully acknowledged and also gratitude to Karadeniz Technical University (Trabzon, Turkey) for laboratory facilities

The outcome of decompression surgery for lumbar herniated disc is influenced by the level of concomitant preoperative low back pain

Decompression surgery is a common and generally successful treatment for lumbar disc herniation (LDH). However, clinical practice raises some concern that the presence of concomitant low back pain (LBP) may have a negative influence on the overall outcome of treatment. This prospective study sought to examine on how the relative severity of LBP influences the outcome of decompression surgery for LDH. The SSE Spine Tango System was used to acquire the data from 308 patients. Inclusion criteria were LDH, first-time surgery, maximum 1 affected level, and decompression as the only procedure. Before and 12 months after surgery, patients completed the multidimensional Core Outcome Measures Index (COMI; includes 0–10 leg/buttock pain (LP) and LBP scales); at 12 months, global outcome was rated on a Likert scale and dichotomised into “good” and “poor” groups. In the “good” outcome group, mean baseline LP was 2.8 (SD 3.1) points higher than LBP; in the “poor” group, the corresponding value was 1.1 (SD 2.9) (p < 0.001 between groups). Significantly fewer patients with back pain as their “main problem” had a good outcome (69% good) when compared with those who reported leg/buttock pain (84% good) as the main problem (p = 0.04). In multivariate regression analyses (controlling for age, gender, co-morbidity), baseline LBP intensity was a significant predictor of the 12-month COMI score, and of the global outcome (each p < 0.05) (higher LBP, worse outcome). In conclusion, patients with more back pain showed significantly worse outcomes after decompression surgery for LDH. This finding fits with general clinical experience, but has rarely been quantified in the many predictor studies conducted to date. Consideration of the severity of concomitant LBP in LDH may assist in establishing realistic patient expectations before the surgery