Quantitative DBS LC-MS/MS assay for midazolam was used to compare two sample collection techniques (venipuncture and finger prick) and the midazolam concentrations measured in plasma samples, DBS and ...dried plasma spots.
Midazolam was extracted from DBS cards and compared with whole blood collected from usual venipuncture. Dried plasma spots were also compared with plasma. The blood volume used as well as the temperature impact during the blood and plasma deposits was evaluated. Midazolam was administrated to six healthy subjects during a clinical trial to obtained blood and plasma samples for the statistical comparison.
The method for midazolam using DBS was validated and showed an excellent performance. Excellent correlations were observed when the same collection procedures were used.
Die Prozessparameter sowie die Stabilisierung beeinflussen bei der Nasszerkleinerung in Rührwerkskugelmühlen die Produktivität von Nanopartikeln bzw. ‐suspensionen. Die Produkttemperatur spielte ...bisher bei der Untersuchung der Nanozerkleinerung nur eine untergeordnete Rolle. In der vorliegenden Arbeit lag der Fokus auf der Nanozerkleinerung von α‐Aluminiumoxid in Wasser bei verschiedenen Zerkleinerungstemperaturen. Durch Variation der Kühlwassertemperatur wurde der Einfluss der Prozesstemperatur auf die Fließeigenschaften analysiert. Es zeigt sich ein Zusammenhang zwischen der Produktaustrittstemperatur und dem Zerkleinerungsfortschritt auf der einen und den Fließeigenschaften auf der anderen Seite.
Wet grinding in stirred media mills enables high production outputs of nanoparticles and nanoparticular suspensions due to well chosen process parameters and stabilization additives. The effect of the process temperature during the nanogrinding process has not yet been considered in systematic studies. In this work grinding experiments were carried out using α‐alumina in water as feed material. By varying the temperature of the cooling fluid, the influence of process temperature on the flow properties was analyzed. The experimental results show a correlation of the temperature with the grinding performance and with the flow properties of suspensions.
Der Zusammenhang zwischen Prozesstemperatur und Zerkleinerungsfortschritt einerseits und Suspensionsstruktur andererseits ist für die industrielle Verarbeitung von Nanosuspensionen von starkem Interesse. Der Artikel beschäftigt sich mit dem Temperatureinfluss auf den Zerkleinerungsprozess und den Auswirkungen auf die Produktfeinheit bzw. die Stabilität.
Extraction of iron from copper-plant slag Lykasov, A. A.; Ryss, G. M.; Sharafutdinov, D. G. ...
Steel in translation,
09/2016, Letnik:
46, Številka:
9
Journal Article
Recenzirano
In the production of copper from sulfide ore, slag accumulates at the processing plant. In the present work, the phase transformations that occur in such slag during its reduction by the gasification ...products of carbon at 1100 and 1200°C are investigated. Experiments show that most of the iron present in such slag may be converted to metallic form by the gasification products of carbon in cupola furnaces at 1100°C. Subsequent increase in temperature to 1200°C improves the extraction of iron. In the indirect reduction of slag at temperatures above its melting point, metallic iron is mainly concentrated at the outer surface of the product, forming large inclusions that are easily extracted by magnetic separation. An expedient approach is to reduce laminar batch consisting of slag layers no thicker than 5 mm and interlayers of ground coal.
The purpose of depth measurement is to bring the altitude from the surface to the connected horizon (level) by means of a vertical mine. Points, for which the height is determined in this way, are ...part of the fundamental mining vertical control, and their height should therefore be determined as accurately as possible. There are several ways of this measurement and the temperature has influence on accuracy of each of them. The paper is dedicated to evaluation of influence of temperature, applying results of height connection measurement carried out at Karviná mine. Two measurements were performed in ČSA 2 shaft and the other in shaft Mír 5 of Darkov mine in Ostrava-Karviná Coal District, CZE. Height connection measurement by a vertical mining work was done in two ways: using the depth tape and using the electro-optical distance meter.
Model for concentration polarization enhanced by gel accumulated at membrane surface has been proposed. It provides distribution of concentration in the liquid phase and within the gel layer. Model ...allows analyzing the influence of thickness of fouling layer on the CP degree, surface concentration, osmotic pressure and membrane permeability. The model is based on the following assumptions: (1) the fluid is incompressible, continuous and isothermal with uniform density field under the steady-state conditions; (2) process is accompanied by accumulation of gel layer at membrane surface along with concentration polarization; (3) diffusion layer and deposited gel contains different components and are characterized by different values of diffusivity coefficients; (4) correlation for effective hindered back diffusion coefficient within deposited layer based on published data is used in the study; (5) transverse transport is based on the following mechanisms: convection due to the pressure difference and back diffusion owing to the concentration gradient.
The following conclusions have been drawn: (A) In the presence of gel layer the membrane surface concentration is enhanced due to the hindered back diffusion of salt ions that, in turn, results in growth of osmotic pressure at the membrane surface. The elevated surface concentration also results in elevated salt concentration in permeates and decreases of the net driving force; (B) For membranes with moderated degree of rejection the growth of temperature causes decrease of the CP degree at the surface.
The proposed model can be incorporated into the algorithm for calculation of longitudinal distribution of the CP degree, resistance and trans-membrane flux.
Gravity records include a wide spectrum of signals based on mass changes in the Earth's crust. Today, the detectable amplitudes of the signals of interest become smaller and smaller (e.g., ...hydrological effects). From this it follows that the accuracy and resolution of measurements must be very high and the noise level as low as possible. In this study, the influence of the temperature variations as noise signal in the gravity records was investigated. Therefore, two 215 day time series of the LaCoste and Romberg gravity meter ET18 in the broadband Geodynamical Observatory Moxa were analyzed and compared. Each time series was recorded in another room. The first room is characterized by a temperature variation of ±4°C per year. The second room has a constant temperature of 19°C. As reference data, the parallel recorded time series of the superconducting gravity meter (SG) CD‐034, installed in the temperature‐stabilized room were used. The result of this study shows a clear influence of temperature variation on the noise level in the spectra of the ET18 compared to the SG spectra. Depending on the frequency ranges, the ratios of the noise levels of the ET18 and SG spectra are between 2 and 5. In the frequency range up to 0.01 cph the ET18/SG factor is 2, between 0.01 cph and 0.09 cph the factor is 3, and above 0.09 cph the factor is 5.
Key Points
Influence of the temperature variations as noise signal in the gravity records
215 day time series of the ET18 and superconducting gravimeters were compared
In temperature‐stabilized room a high data quality of ET18 can be achieved
The
Candida antarctica lipase B catalyzed kinetic resolution of (
R/
S)-1-methoxy-2-propyl-acetate was studied as a model system for the biocatalytic production of chiral secondary alcohols. For this ...purpose, a kinetic model is proposed involving both enantiomers of this reaction using model discrimination and parameter identification. Starting from a ping–pong bi–bi mechanism, a simplified model with sensitive parameters was derived for the
R- and
S-enantiomer, respectively. It was validated at pH 7.0, using time-course measurements at varying temperatures (30–60
°C) and initial substrate conditions (0.05–1.5
M).
This model was then used for mechanistic interpretation of the kinetic resolution on a biochemical level. The effect of temperature on kinetic parameters and enantiomeric ratio was investigated and compared to findings from the field of molecular modeling to obtain a better understanding of the reaction system for process design. Values of 21.2 and 9.7
kJ
mol
−1 were determined for the enthalpic (Δ
R–
S
Δ
H
‡°) and the entropic (–
T·Δ
R–
S
Δ
S
‡°) contribution of the difference in transition state energy of both enantiomers at 30
°C.
High enantiomeric ratio's (
E of 47–110) especially at lower temperatures, in addition to enzyme activity at a wide pH range, indicate this biotransformation is a promising example for the industrial production of chiral secondary alcohols.
Data on the solubility of argon in water and aqueous solutions of L and D enantiomers of α-valine and α-phenylalanine at
T
= 283–328 K and partial pressure of argon
p
2
= 0.1 MPa are used to ...calculate the standard parameters of the Sechenov salt effect. Parameters of the solute-solute pair interaction are estimated within the formalism of the McMillan-Mayer theory. Evidence is provided for the presence of the chiral effect in the Sechenov parameters.
The influence of temperature on the product selectivity, aromatics distribution,
p-X/
o-X and
p-X/
m-X product ratios, aromatization/cracking and aromatization/dehydrogenation ratios have been ...exhaustively investigated on H-GaAlMFI at different iso-conversions of propane. These studies show a profound influence of temperature on the product selectivity/distribution of the propane aromatization reaction. The aromatization activity of the H-GaAlMFI zeolite decreases at higher temperatures relative to the cracking and dehydrogenation activities. The benzene selectivity increases whereas the toluene and C
8 selectivity decreases with increasing reaction temperature. The product selectivity and the formation of xylene isomers are kinetically controlled.
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