Saturation Kinetics of Iopanoate in Dogs with an Intact Enterohepatic Circulation Before and After Phenobarbital Induction

1976 ◽  
Vol 11 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Richard J. Herzog ◽  
James A. Nelson ◽  
Alfred E. Staubus
Keyword(s):  
Enterohepatic Circulation ◽  
Saturation Kinetics ◽  
Before And After ◽  
Kinetics Of ◽  
Phenobarbital Induction

STUDY OF THE KINETICS OF DRYING BREWER’S SPENT GRAIN

2020 ◽  
Author(s):  
Т.Г. КОРОТКОВА ◽  
А.С. ДАНИЛЬЧЕНКО ◽  
Н.Ю. ИСТОШИНА
Keyword(s):  
Matter Content ◽  
Dry Matter Content ◽  
Drying Time ◽  
Brewer’S Spent Grain ◽  
Average Value ◽  
Free Moisture ◽  
Before And After ◽  
Spent Grain ◽  
Kinetics Of ◽  
Two Temperature

Исследована кинетика сушки сырой пивной дробины – вторичного продукта ООО «Белореченский пивоваренный завод» (Россия, Краснодарский край). Сушка проведена в двух температурных режимах – 60 и 55°С. Скорость сушильного агента при вынужденной конвекции составляла 4,5 м/с. Содержание сухого вещества определено по ГОСТ 31640–2012 в лабораторных условиях и составило 12,9%. Измерение убыли массы при сушке проведено с интервалом 5 мин. Общее время сушки навески пивной дробины в количестве 50 г – 420 мин при режиме 50°С, 360 мин – при 60°С. Среднее значение конечной влажности пивной дробины составило 11,85%. Построены кривые сушки и скорости сушки. Скорость сушки при удалении свободной влаги в первом периоде сушки, мин–1: при 60°С – 3,5, при 55°С – 3,0. Установлено, что содержание связанной влаги составляет в среднем 57% от массы влаги в навеске пивной дробины, свободной влаги – 43%. Анализ структуры навески пивной дробины под микроскопом до сушки и после нее подтвердил факт, что в исследованном материале количество связанной влаги больше, чем свободной. Наличие частиц размером 5–7 мм свидетельствует о значительном количестве клеточной влаги в неразрушенных капиллярах. Дальнейшее совершенствование технологии переработки пивной дробины должно быть направлено на разрушение клеточной структуры материала после его механического обезвоживания. The kinetics of drying of the crude brewer’s spent grain – a secondary product of LLC «Belorechensky brewery» (Russian Federation, Krasnodarregion) has been studied. Drying is carried out in two temperature modes – 60 and 55°C. The speed of the drying agent under forced convection was 4,5 m/s. The dry matter content was determined according to GOST 31640–2012 in laboratory conditions and was 12,9%. Measurement of mass loss during drying was performed at an interval of 5 min. The total drying time of the brewer’s spent grain sample in the amount of 50 gis 420 min at 50°C, 360 min – at 60°C. The average value of the final moisture content of brewer’s spent grain made up 11,85%. Curves of drying and drying speed are constructed. Drying speed when removing free moisture in the first drying period, min–1: at 60°C – 3,5, at 55°C – 3,0. It was found that the content on average of bound moisture is 57% of the mass of moisture in brewer’s spent grain, free moisture – 43%. Analysis of the structure sample of brewer’s spent grain a microscope before and after drying confirmed the fact that the amount of bound moisture in the studied material is greater than the amount of free moisture. The presence of particles of 5–7 mm in size indicates a significant amount of cellular moisture in undisturbed capillaries. Further improvement of the technology for processing brewer’s spent grain should be aimed at destroying the cellular structure of the material after its mechanical dehydration.

scholarly journals Enhanced removal of hexavalent chromium by different acid-modified biochar derived from corn straw: behavior and mechanism

2020 ◽  
Vol 81 (10) ◽  
pp. 2270-2280
Author(s):  
Yonggang Xu ◽  
Tianxia Bai ◽  
Yubo Yan ◽  
Yunfeng Zhao ◽  
Ling Yuan ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hydrogen Ion ◽  
Corn Straw ◽  
Order Model ◽  
Freundlich Model ◽  
X Ray ◽  
Modified Biochar ◽  
Before And After ◽  
Pseudo Second Order ◽  
Kinetics Of

Abstract It is of great significance to remove Cr(VI) from water as a result of its high toxicity. Biochar from corn straw was modified by different acids (HNO3, H2SO4 and H3PO4) to remove Cr(VI) from aqueous solution. To estimate the removal mechanisms of Cr(VI) by the acid-modified biochars, batch experiments were performed in the light of contact time, Cr(VI) concentration, and pH, and the characteristics of acid-modified biochars before and after Cr(VI) adsorption were investigated by Fourier transform infrared spectra (FTIR) and X-ray photoelectron spectroscopy (XPS). The adsorption kinetics of Cr(VI) by acid-modified biochars were consistent with the pseudo-second-order model, and the adsorption isotherm obeyed the Freundlich model. Furthermore, the acid- modified biochars could supply more oxygen-containing functional groups (-COOH and -OH) as electron donor (e−) and hydrogen ion (H+) to enhance the reduction of Cr(VI) to Cr(III), resulting in enhanced removal of Cr(VI). HNO3-modified biochar exhibited the highest removal efficiency of Cr(VI). In general, the acid modifition of biochar was an effective method to increase the removal of Cr(VI).

Kinetics of hepatic alanine uptake and urea synthesis in pigs

1988 ◽  
Vol 254 (4) ◽  
pp. G602-G609
Author(s):  
H. Vilstrup ◽  
L. T. Skovgaard
Keyword(s):  
Maximum Rate ◽  
Maximum Likelihood Method ◽  
Blood Flow Rate ◽  
Likelihood Method ◽  
Synthesis Rate ◽  
Urea Synthesis ◽  
Half Maximum ◽  
Concentration Gradients ◽  
Saturation Kinetics ◽  
Kinetics Of

The kinetics of hepatic alanine uptake and urea synthesis in relation to sinusoid alanine concentration was investigated in seven anesthetized pigs weighing 63 kg, using liver vein catheterizations. Each experiment consists of four steady-state periods of 40 min with alanine concentrations in the range of 0.4-27 mmol/l. The process rates were measured as the products of transhepatic concentration gradients and hepatic blood flow rate, determined by indocyanine green. The data suggest that both processes follow saturation kinetics, that there exists a sinusoidal concentration of alanine below which net removal is limited, and that urea synthesis consists of two components: one alanine independent and one depending on alanine concentration according to Michaelis-Menten kinetics. The kinetic parameters were estimated iteratively by the maximum likelihood method. The maximum rate of alanine uptake was 1.13 +/- 0.74 mmol.min-1.kg liver wt-1 (mean +/- SD), the alanine concentration resulting in half-maximum alanine uptake rate was 1.69 +/- 0.99 mmol/l, and the removal-limiting alanine concentration was 0.27 +/- 0.09 mmol/l. The maximum rate of urea-N synthesis was 1.49 +/- 0.87 mmol.min-1.kg liver wt-1, the alanine concentration resulting in half-maximum urea-N synthesis rate was 2.32 +/- 1.11 mmol/l, and the alanine concentration-independent urea-N synthesis rate was 0.13 +/- 0.10 mmol.min-1.kg liver wt-1.

Proximal Renal Tubular Peptide Catabolism, Ammonia Excretion and Tubular Injury in Patients with Proteinuria: Before and after Lisinopril

1998 ◽  
Vol 94 (4) ◽  
pp. 425-430 ◽  
Author(s):  
Rana Rustom ◽  
J. Steve Grime ◽  
Michael Costigan ◽  
Paul Maltby ◽  
Anthony Hughes ◽  
...  
Keyword(s):  
Ammonia Excretion ◽  
Protein Catabolism ◽  
Tubular Injury ◽  
Mild Renal Impairment ◽  
Heavy Proteinuria ◽  
Before And After ◽  
51Cr Edta ◽  
Renal Tubular ◽  
Kinetics Of ◽  
Nephrotic Range Proteinuria

1. Progression to renal failure may be linked to the degree of proteinuria through tubulo-interstitial mechanisms. However, there are no data in man on the kinetics of proximal renal tubular protein catabolism or markers of tubular injury before and after lisinopril. We developed a method to allow such studies, and found increased tubular catabolism of 99mTc-labelled aprotinin (Trasylol) in patients with nephrotic range proteinuria which was associated with increased ammonia excretion. 2. In this study, 10 patients with mild renal impairment (51Cr-EDTA clearance 63.7 ± 8.3 ml · min−1 · 1.73 m−2) and heavy proteinuria (8.2 ± 2.3 g/24 h) were given lisinopril (10–20 mg) for 6 weeks. Renal tubular catabolism of intravenous aprotinin was measured before and after lisinopril by renal imaging and urinary excretion of the free radiolabel over 26 h. Fractional degradation was calculated from these data. Fresh timed urine collections were also analysed for ammonia excretion every fortnight from 6 weeks before treatment. Total urinary N-acetyl-β-d-glucosaminidase and the more tubulo-specific N-acetyl-β-d-glucosaminidase ‘A2’ isoenzyme were also measured. 3. After lisinopril proteinuria fell significantly as expected (from 9.5 ± 1.6 to 4.5 ± 1.0 g/24 h, P < 0.01). This was associated with a reduction in metabolism over 26 h (from 1.7 ± 0.1 to 1.2 ± 0.1% dose/h, P < 0.01) and in fractional degradation of aprotinin (from 0.08 ± 0.02 to 0.04 ± 0.007/h, P < 0.04). Ammonia excretion also fell significantly (from 1.2 ± 0.1 to 0.6 ± 0.1 mmol/h, P < 0.0001), as did both total urinary N-acetyl-β-d-glucosaminidase (P < 0.0001) and the N-acetyl-β-d-glucosaminidase ‘A2’ isoenzyme (P < 0.015). These observations after lisinopril treatment have not been described previously. There was no significant change in blood pressure nor in glomerular haemodynamics.

Acid dissolution of synthetic aluminous goethite before and after transformation to hematite by heating

Clay Minerals ◽  
1995 ◽  
Vol 30 (1) ◽  
pp. 55-65 ◽  
Author(s):  
H. D. Ruan ◽  
R. J. Gilkes
Keyword(s):  
Surface Area ◽  
Heating Temperature ◽  
Dissolution Kinetics ◽  
Frequency Factor ◽  
Dissolution Time ◽  
Unit Surface Area ◽  
Acid Dissolution ◽  
Al Substitution ◽  
Before And After ◽  
Kinetics Of

AbstractMeasurements of the kinetics of acid dissolution of synthetic aluminous goethites and corresponding hematites produced by heating of parent Al-goethites at various temperatures were carried out in 1 M HC1 at 30, 40 and 50°C. Dissolution-time curves show sigmoidal shapes for the goethites (110°C), whereas deceleratory shapes were obtained for most of the partly and fully dehydroxylated samples. The dissolution rate for all materials decreased with increasing Al substitution and increased with increasing dissolution temperature, specific surface area and heating temperature. On a unit surface area basis, hematite dissolved ∼ 2–8 times faster than goethite. Dissolution kinetics of most heated goethite samples (200–260°C) were quite well described (R2 > 0.96) by the modified first-order Kabai equation. The activation energy and frequency factor for dissolution increased with increasing Al substitution.

scholarly journals Effect of Post Weld Heat Treatment on the Microstructure and Electrochemical Characteristics of Dissimilar Material Welded by Butter Method

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4512
Author(s):  
Umer Masood Chaudry ◽  
Hafiz Waqar Ahmad ◽  
Muhammad Rehan Tariq ◽  
Ameeq Farooq ◽  
Muhammad Kashif Khan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Parameters ◽  
Post Weld Heat Treatment ◽  
Dissimilar Material ◽  
Electrochemical Characteristics ◽  
Corrosion Kinetics ◽  
Before And After ◽  
C 50 ◽  
Kinetics Of ◽  
Weld Heat

In the present study, the effect of post weld heat treatment (PWHT) on the microstructure and corrosion kinetics of butter welded Nickel Alloy 617 and 12Cr steel was investigated. Buttering was carried out on the 12Cr side with the Thyssen 617 filler metal. Furthermore, post weld heat treatment (PWHT) was conducted at 730 °C with a holding time of 4 h followed by furnace cooling. Optical Microscopy (OM) was conducted to study the microstructural evolution in dissimilar material welding as a result of PWHT. Moreover, Scanning Electron Microscopy with energy dispersive spectroscopy (SEM-EDS) was employed to determine the elemental concentrations in all important regions of the butter weld before and after the PWHT. In addition, the effect of PWHT on the corrosion kinetics of the butter weld was also investigated by potentiodynamic polarization measurements in 5 wt.% NaCl + 0.5 wt.% CH3COOH electrolyte at room temperature, 30 °C, 50 °C and 70 °C. The corrosion activation parameters were also determined for both the samples by using Arrhenius plots. The results revealed the higher susceptibility of corrosion of the butter weld after PWHT, which was attributed to the reduced Cr content in the heat affected zone of the 12Cr region due to the sensitization effect of the heat treatment, resulting in higher corrosion rates.

Evaluation of Nanostructured Coatings for the Protection of Apuan Marble Stone

2019 ◽  
Vol 286 ◽  
pp. 105-116
Author(s):  
Silvia Germinario ◽  
Federica Fernandez ◽  
Giovanni Baldi ◽  
Valentina Dami ◽  
Andrea Cioni
Keyword(s):  
Sample Surface ◽  
Test Methods ◽  
Historical Materials ◽  
Uva Irradiation ◽  
Preliminary Validation ◽  
Before And After ◽  
Environmental Agents ◽  
And Behavior ◽  
Kinetics Of ◽  
Over Time

Nowadays the use of multifunctional nanomaterials has significantly increased with interesting applications for the cultural heritage conservation sector, leading to the definition and use of products with innovative properties. Therefore, a preliminary validation of the performances and behavior over time of these treatments becomes an unavoidable key point for a correct use of these products before being applied to historical materials, in order to avoid irreparable damage over time. In this direction, the aim of this study was to evaluate the effectiveness of the treatment with multifunctional nanostructured products on Apuan marble. The focus of the work was to test methods to accelerate aging, in order to simulate different environmental agents of degradation to which marble in historical buildings can be exposed. Stone samples were examined after exposition to high temperature cycles in a muffle furnace, treatments in saline solution, cycles of thermal shock and aging by SO2 action in presence of humidity. After each artificial aging cycle, changes in appearance were noted and chemical-physical properties were measured in order to compare differences between fresh and treated samples. The protective qualities of the coatings were evaluated using the following tests: contact angle; photocatalytic properties by methylene blue degradation tests; photodegradation kinetics of pollutants under UVA irradiation. Before and after the treatments, scanning electron microscopy equipped by microanalysis detector (SEM-EDS) was also used to evaluate changes in the surface morphology of the samples. The results showed effects of degradation in the rock samples due to aging after each test and all the products applied to the sample surface seemed to be very efficient in relation to their functions.

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