Search results for "ash"
showing 10 items of 1718 documents
Dosimetric characterization of an ultra-high dose rate beam for FLASH radiotherapy through alanine EPR dosimetry
2022
Experimental evidence is growing, supporting the evidence of a considerable normal tissue sparing effect when treatments are delivered with dose rates much larger with respect to the conventional ones [1]. In particular, an increasing of the therapeutic window has been demonstrated for dose rates over 50 Gy/s, over a large variety of in-vivo experiments [2]. If confirmed, the ‘FLASH effect’ has the potential to re-shape the future of radiation treatments, with a significant impact on many oncology patients [3]. Ultra-high dose rate (UHDR) beams for FLASH radiotherapy present significant dosimetric challenges [4]. Ionization chambers are affected by ion recombination effects, although novel …
Staged Wrecks: The Railroad Crash Between Infrastructural Lesson and Amusement
2019
To explore infrastructures and publics from a historical perspective, in this paper I will focus on the entangled development of transport infrastructures in the nineteenth century on the one hand and the rise of amusement cultures on the other. More specifically, I will examine a phenomenon that became popular at US State Fairs at the end of the century, namely staged railroad crashes with two steam locomotives.
Ready Access to Proquinazid Haptens via Cross-Coupling Chemistry for Antibody Generation and Immunoassay Development.
2015
17 pages, 4 tables, 5 figures.-- Publisher's PDF
The determination of trace element concentrations in fly ash samples using ultrasound-assisted digestion followed with inductively coupled plasma opt…
2009
Abstract A method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of trace element (chromium, copper, lead, nickel, vanadium and zinc) concentrations in fly ash samples was developed. All the measurements were performed in robust plasma conditions. Ultrasound-assisted digestion procedures using digestion solutions of aqua regia and hydrofluoric acid (HF) resulted in recovery rates of over 80% for all the analyte elements. Ultrasound-assisted two-step digestion with digestion solutions of 6 mL of HNO3 (Step 1) and 3 mL of HNO3 + 3 mL of HF (Step 2) resulted in recovery rates of over 92% for all the ana…
Control of matrix interferences by multiple linear regression models in the determination of arsenic and lead concentrations in fly ashes by inductiv…
2010
A multiple linear regression technique was used to evaluate and correct the matrix interferences in the determination of As and Pb concentrations in fly ashes by inductively coupled plasma optical emission spectrometry. The direct determination of As and Pb in SRM 1633b by ICP-OES failed to obtain the certified concentrations, except in a couple of cases. However, it proved possible to use the multiple linear regression (MLR) technique to correct the determined concentrations to a satisfactory level. This method of correction is based on the multiple regression line obtained from the analysis of 19 synthetic mixtures of matrix and analyte elements (Al, As, Ca, Fe, Pb, and Si) at five concen…
Combined Adsorption/Photocatalytic dye removal by copper-titania-fly ash composite
2020
Abstract Achieving both photocatalytic efficiency and adsorption capacity is essential to produce a highly efficient photocatalyst. This study fabricated a new photocatalyst by combining copper (Cu) doped titanium dioxide (TiO2) with fly ash (FA). The photocatalysts were synthesized using mild acid (acid-FA/Cu/TiO2), base (base-FA/Cu/TiO2), and deionized water (rFA/Cu/TiO2) activated FA. EDX confirmed the inclusion of Cu in both Cu/TiO2 and FA/Cu/TiO2 composites. XRD analysis indicated the presence of the anatase form of TiO2 after Cu doping and incorporation into modified FA. All three FA/Cu/TiO2 composites demonstrated high absorption (UV and visible region) compared to their TiO2 and Cu/…
Atomic fluorescence determination of total and inorganic arsenic species in beer
2001
A simple and nearly direct procedure has been developed for the determination of As in beers, based on hydride generation and atomic fluorescence detection. Using 2 mol l−1 HCl with a carrier flow of 6 ml min−1, 3% m/v NaBH4 with a flow of 1.3 ml min−1, a reaction coil of 200 cm and an argon flow of 400 ml min−1, total arsenic in beer could be determined in samples diluted 1∶10 with a final concentration of 2 mol l−1 HCl, 1% m/v KI and 0.08% v/v of an antifoam agent. For the estimation of AsIII and AsV concentrations in beer samples, the difference between the analytical sensitivities of the fluorescence signals obtained for As hydride, without and with previous treatment of samples with KI…
Diversity and Evolution of the Phenazine Biosynthesis Pathway
2010
ABSTRACT Phenazines are versatile secondary metabolites of bacterial origin that function in biological control of plant pathogens and contribute to the ecological fitness and pathogenicity of the producing strains. In this study, we employed a collection of 94 strains having various geographic, environmental, and clinical origins to study the distribution and evolution of phenazine genes in members of the genera Pseudomonas , Burkholderia , Pectobacterium , Brevibacterium , and Streptomyces . Our results confirmed the diversity of phenazine producers and revealed that most of them appear to be soil-dwelling and/or plant-associated species. Genome analyses and comparisons of phylogenies inf…
In vitro antifungal properties of mouthrinses containing antimicrobial agents
1997
The purpose of this study was to investigate the in vitro antifungal properties of seven commercial mouthrinses containing antimicrobial agents. These included cetylpyridinium chloride (CPC), chlorhexidine digluconate (CHX), hexetidine (HEX), sanguinarine (SNG), and triclosan (TRN). The minimum fungicidal concentration (MFC) against six species of yeasts was determined by a broth macrodilution method. The kill-time of mouthrinses at half the concentration of the commercial formulations was also determined. MFCs were achieved with each mouthrinse, except the SNG-containing mouthrinse, against all the organisms being tested. However, the CPC-containing mouthrinse appeared more active than the…
The determination of antimony and arsenic concentrations in fly ash by hydride generation inductively coupled plasma optical emission spectrometry
2011
Abstract Hydride generation inductively coupled plasma optical emission spectrometry (HG-ICP-OES) was used in the determination of As and Sb concentrations in fly ash samples. The effect of sample pre-treatment reagents and measurement parameters used for hydride generation was evaluated. Due to memory effects observed, the appropriate read delay time was adjusted to 60 s resulting in RSDs 0.6% and 2.3% for As and Sb, respectively. The most suitable volumes of pre-reduction reagents for 10 mL of sample were 4 mL of KI/ascorbic acid (5%) and 6 mL of HCl (conc.). The determination of Sb was significantly interfered by HF, but the interference could be eliminated by adding 2 mL of saturated bo…