Search results for "dilution"

Bestimmung der molekularen konstanten von naturkautschuk III. Molekulargewicht trägheitsradius und thermodynamische eigenschaften von cyclohexan-kaut…

1960

Lichtstreuungsmessungen an Crepekautschuk in Cyclohexan ergeben Mw = 1,85·106. In Verbindung mit Diffusions- und Sedimentationsmessungen ergibt sich als wahrscheinlichster Wert Mw = 1,7·10−6. Unter Verwendung der Messungen von CARTER, SCOTT und MAGAT wird als Molekulargewichts-Viskositatsbeziehung die Gleichung fur Losungen von Naturkautschuk in Cyclohexan vorgeschlagen. Der 2. Virialkoeffizient und der STAUDINGER-Index nehmen in der Reihenfolge Benzol, Cyclohexen, Cyclohexan zu. Die beiden ersten Losungsmittel sind endotherm, Cyclohexan ist exotherm. Der Tragheitsradius der Molekulknael nach Lichtstreuungsmessungen ist etwa Rw = 1000 A. Der wahrscheinlichste Wert unter Mitberucksichtigung …

1984

By means of data from critical demixing and vapour pressure measurements and by inverse gas chromatography, including the results of published light scattering measurments, a consistent picture is obtained for the entire dependence of the Flory-Huggins parameter χ on the weight fraction w2 of the polymer and on the temperature T for the system tert-butyl acetate/polystyrene. Within the entire T-range (ca. 0°C – 140°C), χ increases stronger than exponentially with w2, the rise being the larger the larger χH (the enthalpy contribution to χ) becomes in the limit of infinite dilution. At sufficiently high temperatures (≳ 50°C), χH changes its sign from negative to positive as w2 is raised. This…

Stability of topotecan infusion solutions in polyvinylchloride bags and elastomeric portable infusion devices

1999

Purpose. The purpose of this study was to determine the physicochemical stability of topotecan after reconstitution and after further dilution in two commonly used infusion fluids (0.9% sodium chloride, 5% dextrose) in both polyvinylchloride (PVC) bags and elastomeric portable infusion devices. Methods. Each vial of topotecan (Hycamtin®) was reconstituted with sterile water for injection, yielding a nominal concentration of 1 mg/mL. Topotecan infusion solutions were aseptically prepared by further dilution of reconstituted topotecan solutions with either 0.9% sodium chloride or 5% dextrose in both PVC bags and portable elastomeric infusion devices, in amounts yielding topotecan concentrati…

Physical properties of aerosol particles measured from a bubbling fluidized bed boiler

2015

Abstract Increased use of biomass and waste fuels, and the consequent corrosion problem have led to an increased need to study and monitor the combustion processes. This study presents an extensive physical characterization of aerosol particles measured from a bubbling fluidized bed boiler with different fuel mixtures and optional ferric sulfate feeding. The fuel mixtures included bark, sludge, peat and solid recovered fuel. Previously, the characterization of the particles analyzed from a fluidized bed reactor has mainly focused on chemical off-line analysis of collected impactor samples, large coarse mode particles or laboratory-scale reactors. In this study, the focus is in the particle …

Effect of electric currents on antibacterial effect of chlorhexidine against Entrococcus faecalis biofilm : An in vitro study

2018

Background This in vitro study was mainly aimed to evaluate the effect of high-frequency alternating currents (AC) applied by an electronic apex locator (EAL) on the antibacterial properties of chlorhexidine (CHX) on E. faecalis biofilm. Material and Methods The root canals of 120 extracted human single-rooted teeth were prepared using Gates-Glidden drills and hand K-files. After contaminating the root canals with E. faecalis, they were incubated for 60 days. Then, the teeth were randomly divided into six experimental groups (n=20). Group 1, 2% CHX; group 2, normal saline (NS) with direct current (DC); group 3, normal saline (NS) with high-frequency alternating current (AC); group 4, 2% CHX…

Cytotoxicity of a new hemostatic agent on human pulp fibroblasts in vitro

2011

Objective: The objective of this study was to evaluate the cytotoxicity of the plant extract ankaferd blood stopper (ABS) in vitro. Study Design: ABS was eluted with fresh Dulbecco's Modified Eagle's Medium (DMEM) without serum for 72 h, at 37°C. The cells treated with various dilutions of ABS were seeded into 96-well microplate at 10 4 /well in triplicates. Cells without treatment served as a control group. The number of viable cells after 48 h incubation was determined by a modified 3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay. The relative viability of pulp cells was expressed as color intensity of the number in the experimental wells relative to that of t…

Towards a representation of halogen chemistry within volcanic plumes in a chemistry transport model

2014

Volcanoes are a known source of halogens to the atmosphere. HBr volcanic emissions lead rapidly to the formation of BrO within volcanic plumes as shown by recent work based on observations and models. BrO, having a longer residence time in the atmosphere than HBr, is expected to have a significant impact on tropospheric chemistry, at least at the local and regional scales. The objective of this paper is to prepare a framework that will allow 3-D modelling of volcanic halogen emissions in order to determine their fate within the volcanic plume and then in the atmosphere at the regional and global scales. This work is based on a 1-D configuration of the chemistry transport model MOCAGE whose …

Vitesse, accessibilité et étalement urbain ; analyse et application à l'aire urbaine dijonnaise

2003

The set of themes of the city is approached primarily by the means of the residential density. This concept is analyzed from a purely conceptual point of view, then more theoretical (thus making use of rather traditional econometric models: Clark, Newling) for finally being applied to the agglomeration dijonnaise like with its urban surface. One releases the great urban structures thus revealing an intermediate city between the model monocentric and polycentric. The two components are analyzed successively starting from the concept of residential density. Taking as assumption that the cities are dynamic, the second stage is that of urban sprawl out. A first introductory approach attempts to…

The impact of wildlife and environmental factors on hantavirus infection in the host and its translation into human risk

2023

Identifying factors that drive infection dynamics in reservoir host populations is essential in understanding human risk from wildlife-originated zoonoses. We studied zoonotic Puumala orthohantavirus (PUUV) in the host, the bank vole ( Myodes glareolus ), populations in relation to the host population, rodent and predator community and environment-related factors and whether these processes are translated into human infection incidence. We used 5-year rodent trapping and bank vole PUUV serology data collected from 30 sites located in 24 municipalities in Finland. We found that PUUV seroprevalence in the host was negatively associated with the abundance of red foxes, but this process did no…

High-frequency filtering for low-temperature thermal transport studies in nanostructures

2012

Filtering of external unwanted RF-noise and thermal noise generated at the high-temperature parts of the measuring circuit is essential for successful measurements of thermal transport of nanostructures at low temperatures. This is because of thermal decoupling of the systems, i.e. the extreme weakness of thermal conduction at sub-Kelvin temperatures, leading easily to overheating even with excess power in sub pW range. We have started to improve the noise filtering in our cryogenic dilution refrigerators, which can reach a base temperature of ~ 50 mK. The miniature low-pass filters were made from special RF sealing compound Eccosorb CR124, stainless steel powder of grain size 50 micrometer…