The phase behaviour of binary mixtures containing hydrogen

1983 ◽  
Vol 36 (10) ◽  
pp. 2005 ◽  
Author(s):  
AK Burgess ◽  
CL Young
Keyword(s):  
Small Molecules ◽  
Equations Of State ◽  
Fluid Model ◽  
Phase Behaviour ◽  
Critical Temperatures ◽  
Higher Hydrocarbons ◽  
The One ◽  
Hydrogen Systems ◽  
Permanent Gases ◽  
Best Fit

The solubility and gas-liquid critical temperatures of mixtures of hydrogen with the permanent gases has been discussed in terms of the one-fluid model and 'hard sphere + attractive term' equations of state as proposed by Carnahan and Starling and Guggenheim. The solubilities of hydrogen and 'moderately-sized' hydrocarbons such as benzene and cyclohexane and higher hydrocarbons such as decalin and bicyclohexyl have also been discussed in terms of the one-fluid model. Finally, examples of the solubilities of other small molecules, methane, nitrogen and carbon dioxide, in both 'moderately sized' and higher hydrocarbons are considered in terms of the one-fluid model. It is concluded that : (A) The best fit values of the interaction parameter, ζ, for all mixtures, except the permanent gas+ hydrogen systems, are considerably smaller than predicted by the Hudson and McCoubrey rule. (B) The values of ζ for the hydrogen+ hydrocarbon mixtures are considerably smaller than those for similar hydrocarbons + other small molecules. (c) Often the best fit value of ζ decreases with an increase in temperature.

Gas-liquid critical temperatures of mixtures containing an organosilicon compound

1978 ◽  
Vol 31 (5) ◽  
pp. 957 ◽  
Author(s):  
SD Waterson ◽  
CL Young
Keyword(s):  
Critical Temperature ◽  
Equation Of State ◽  
Hard Sphere ◽  
Organosilicon Compound ◽  
Composition Dependence ◽  
Fluid Model ◽  
Iterative Solution ◽  
Critical Temperatures ◽  
Temperature And Pressure ◽  
The One

The gas-liquid critical temperatures of 16 binary mixtures containing an organosilicon compound have been measured by the sealed-tube method, together with the gas-liquid critical temperature and pressure of tetramethoxysilane, tetraethoxysilane and tetrapropoxysilane.��� The results for the mixtures have been used to calculate a parameter characterizing the interactions between unlike molecules. An iterative solution to the criticality condition was used together with the one-fluid model and a 'hard sphere+attractive term' equation of state. ��� The interaction parameters are discussed briefly. The one-fluid model in the form used here, at least, appears to be unsatisfactory for predicting the composition dependence of the gas-liquid critical temperatures within 5 K for mixtures of molecules of widely differing sizes (i.e. size ratios as estimated from molar volumes of greater than 1 : 4).

Upper critical solution temperatures of perfluoro-n-hexane + alkane, sulfur hexafluoride + siloxane and perfluoropropane + siloxane mixtures

1980 ◽  
Vol 33 (9) ◽  
pp. 1987 ◽  
Author(s):  
SD Waterson ◽  
J Semmens ◽  
CL Young
Keyword(s):  
Chain Length ◽  
Sulfur Hexafluoride ◽  
Fluid Model ◽  
Phase Behaviour ◽  
Interaction Parameters ◽  
Type Ii ◽  
Type Iii ◽  
The One ◽  
Behaviour Type ◽  
Critical Solution Temperatures

Upper critical solution temperatures of perfluorohexane+alkanes (C5 to C18), sulfur hexafluoride+siloxanes (Si2 to Si8) and perfluoropropane+siloxanes (Si2 to Si8) mixtures are reported. In each of the three groups of mixtures the phase behaviour type changes from type II to type III (in terms of the Scott classification). The interaction parameters, ξ, calculated by using the one-fluid model change more or less smoothly with increasing chain length of the siloxane (or alkane) even when the phase behaviour type changes.

Phase-Behavior of Carbon-Dioxide and Hydrocarbon Mixtures

1985 ◽  
Vol 38 (12) ◽  
pp. 1739 ◽  
Author(s):  
RJ Sadus ◽  
CL Young
Keyword(s):  
Carbon Dioxide ◽  
Phase Behavior ◽  
Equations Of State ◽  
Fluid Model ◽  
Van Der Waals ◽  
Solubility Data ◽  
Critical Temperatures ◽  
Hydrocarbon Mixtures ◽  
Critical Solution Temperatures

Upper critical solution temperatures, gas-liquid critical temperatures and solubility data of carbon dioxide and hydrocarbon mixtures have been used to obtain a parameter, ξ, characterizing the interaction between pairs of unlike molecules in the mixture. The calculation of ξ values involved the use of the van der Waals one-fluid model together with the Guggenhiem and Redlich-Kwong equations of state. There is a discrepancy of several percent between ξ values calculated from the three sources of data. Trends in the value of ξ are discussed briefly.

scholarly journals BIOSIMILARS IN INFLAMMATORY BOWEL DISEASES: an important moment for Brazilian gastroenterologists

2015 ◽  
Vol 52 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Fábio Vieira TEIXEIRA ◽  
Paulo Gustavo KOTZE ◽  
Aderson Omar Mourão Cintra DAMIÃO ◽  
Sender Jankiel MISZPUTEN
Keyword(s):  
Small Molecules ◽  
Inflammatory Bowel Diseases ◽  
Generic Drugs ◽  
Specific Data ◽  
Chemical Structures ◽  
Bowel Diseases ◽  
Original Product ◽  
Inflammatory Bowel ◽  
The One ◽  
Extrapolation Of Indications

ABSTRACT Biosimilars are not generic drugs. These are more complex medications than small molecules, with identical chemical structures of monoclonal antibodies that lost their patency over time. Besides identical to the original product at the end, the process of achieving its final forms differs from the one used in the reference products. These differences in the formulation process can alter final outcomes such as safety and efficacy of the drugs. Recently, a biosimilar of Infliximab was approved in some countries, even to the management of inflammatory bowel diseases. However, this decision was based on studies performed in rheumatologic conditions such as rheumatoid arthritis and ankylosing spondylitis. Extrapolation of the indications from rheumatologic conditions was done for Crohn’s disease and ulcerative colitis based on these studies. In this article, the authors explain possible different mechanisms in the pathogenesis between rheumatologic conditions and inflammatory bowel diseases, that can lead to different actions of the medications in different diseases. The authors also alert the gastroenterological community for the problem of extrapolation of indications, and explain in full details the reasons for being care with the use of biosimilars in inflammatory bowel diseases without specific data from trials performed in this scenario.

scholarly journals Bottom-Up Generation of Peak Demand Scenarios in Water Distribution Networks

2020 ◽  
Vol 13 (1) ◽  
pp. 31
Author(s):  
Enrico Creaco ◽  
Giacomo Galuppini ◽  
Alberto Campisano ◽  
Marco Franchini
Keyword(s):  
Water Distribution ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Peak Demand ◽  
Long Time ◽  
Cross Correlations ◽  
User Demand ◽  
One Year ◽  
The One ◽  
Best Fit

This paper presents a two-step methodology for the stochastic generation of snapshot peak demand scenarios in water distribution networks (WDNs), each of which is based on a single combination of demand values at WDN nodes. The methodology describes the hourly demand at both nodal and WDN scales through a beta probabilistic model, which is flexible enough to suit both small and large demand aggregations in terms of mean, standard deviation, and skewness. The first step of the methodology enables generating separately the peak demand samples at WDN nodes. Then, in the second step, the nodal demand samples are consistently reordered to build snapshot demand scenarios for the WDN, while respecting the rank cross-correlations at lag 0. The applications concerned the one-year long dataset of about 1000 user demand values from the district of Soccavo, Naples (Italy). Best-fit scaling equations were constructed to express the main statistics of peak demand as a function of the average demand value on a long-time horizon, i.e., one year. The results of applications to four case studies proved the methodology effective and robust for various numbers and sizes of users.

scholarly journals A Study on the Feasibility of Anaerobic Co-Digestion of Raw Cheese Whey with Coffee Pulp Residues

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3611
Author(s):  
Sandra Gonzalez-Piedra ◽  
Héctor Hernández-García ◽  
Juan M. Perez-Morales ◽  
Laura Acosta-Domínguez ◽  
Juan-Rodrigo Bastidas-Oyanedel ◽  
...  
Keyword(s):  
Methane Production ◽  
Kinetic Models ◽  
Cheese Whey ◽  
Maximum Yield ◽  
Gompertz Model ◽  
Coffee Pulp ◽  
The One ◽  
The Cost ◽  
Best Fit ◽  
Cheese Production

In this paper, a study on the feasibility of the treatment of raw cheese whey by anaerobic co-digestion using coffee pulp residues as a co-substrate is presented. It considers raw whey generated in artisanal cheese markers, which is generally not treated, thus causing environmental pollution problems. An experimental design was carried out evaluating the effect of pH and the substrate ratio on methane production at 35 °C (i.e., mesophilic conditions). The interaction of the parameters on the co-substrate degradation and the methane production was analyzed using a response surface analysis. Furthermore, two kinetic models were proposed (first order and modified Gompertz models) to determine the dynamic profiles of methane yield. The results show that co-digestion of the raw whey is favored at pH = 6, reaching a maximum yield of 71.54 mLCH4 gVSrem−1 (31.5% VS removed) for raw cheese whey and coffee pulp ratio of 1 gVSwhey gVSCoffe−1. The proposed kinetic models successfully fit the experimental methane production data, the Gompertz model being the one that showed the best fit. Then, the results show that anaerobic co-digestion can be used to reduce the environmental impact of raw whey. Likewise, the methane obtained can be integrated into the cheese production process, which could contribute to reducing the cost per energy consumption.

scholarly journals Helium, [Fe/H] Abundances and the HR (Log TEFF, MBol) Diagram With Hipparcos Data of The Four Nearest Open Clusters: Hyades, Coma Berenices, The Pleiades and Praesepe

1998 ◽  
Vol 11 (1) ◽  
pp. 565-565
Author(s):  
G. Cayrel de Strobel ◽  
R. Cayrel ◽  
Y. Lebreton
Keyword(s):  
Main Sequence ◽  
Open Clusters ◽  
Main Sequence Stars ◽  
Spectroscopic Analyses ◽  
Solar Metallicity ◽  
Metal Abundances ◽  
The Mean ◽  
The Moment ◽  
The One ◽  
Best Fit

After having studied in great detail the observational HR diagram (log Teff, Mbol) composed by 40 main sequence stars of the Hyades (Perryman et al.,1997, A&A., in press), we have tried to apply the same method to the observational main sequences of the three next nearest open clusters: Coma Berenices, the Pleiades, and Praesepe. This method consists in comparing the observational main sequence of the clusters with a grid of theoretical ZAMSs. The stars composing the observational main sequences had to have reliable absolute bolometric magnitudes, coming all from individual Hipparcos parallaxes, precise bolometric corrections, effective temperatures and metal abundances from high resolution detailed spectroscopic analyses. If we assume, following the work by Fernandez et al. (1996, A&A,311,127), that the mixing-lenth parameter is solar, the position of a theoretical ZAMS, in the (log Teff, Mbol) plane, computed with given input physics, only depends on two free parameters: the He content Y by mass, and the metallicity Z by mass. If effective temperature and metallicity of the constituting stars of the 4 clusters are previously known by means of detailed analyses, one can deduce their helium abundances by means of an appropriate grid of theoretical ZAMS’s. The comparison between the empirical (log Teff, Mbol) main sequence of the Hyades and the computed ZAMS corresponding to the observed metallicity Z of the Hyades (Z= 0.0240 ± 0.0085) gives a He abundance for the Hyades, Y= 0.26 ± 0.02. Our interpretation, concerning the observational position of the main sequence of the three nearest clusters after the Hyades, is still under way and appears to be greatly more difficult than for the Hyades. For the moment we can say that: ‒ The 15 dwarfs analysed in detailed in Coma have a solar metallicity: [Fe/H] = -0.05 ± 0.06. However, their observational main sequence fit better with the Hyades ZAMS. ‒ The mean metallicity of 13 Pleiades dwarfs analysed in detail is solar. A metal deficient and He normal ZAMS would fit better. But, a warning for absorption in the Pleiades has to be recalled. ‒ The upper main sequence of Praesepe, (the more distant cluster: 180 pc) composed by 11 stars, analysed in detail, is the one which has the best fit with the Hyades ZAMS. The deduced ‘turnoff age’ of the cluster is slightly higher than that of the Hyades: 0.8 Gyr instead of 0.63 Gyr.

scholarly journals Unbinding of Hyaluronan Accelerates the Enzymatic Activity of Bee Hyaluronidase

2011 ◽  
Vol 286 (41) ◽  
pp. 35699-35707 ◽  
Author(s):  
Attila Iliás ◽  
Károly Liliom ◽  
Brigitte Greiderer-Kleinlercher ◽  
Stephan Reitinger ◽  
Günter Lepperdinger
Keyword(s):  
Experimental Data ◽  
Quartz Crystal ◽  
Surface Loop ◽  
X Ray ◽  
Site Model ◽  
Substrate Interaction ◽  
Close Proximity ◽  
Binding Groove ◽  
The One ◽  
Best Fit

Hyaluronan (HA), a polymeric glycosaminoglycan ubiquitously present in higher animals, is hydrolyzed by hyaluronidases (HAases). Here, we used bee HAase as a model enzyme to study the HA-HAase interaction. Located in close proximity to the active center, a bulky surface loop, which appears to obstruct one end of the substrate binding groove, was found to be functionally involved in HA turnover. To better understand kinetic changes in substrate interaction, binding of high molecular weight HA to catalytically inactive HAase was monitored by means of quartz crystal microbalance technology. Replacement of the delimiting loop by a tetrapeptide interconnection increased the affinity for HA up to 100-fold, with a KD below 1 nm being the highest affinity among HA-binding proteins surveyed so far. The experimental data of HA-HAase interaction were further validated showing best fit to the theoretically proposed sequential two-site model. Besides the one, which had been shown previously in course of x-ray structure determination, a previously unrecognized binding site works in conjunction with an unbinding loop that facilitates liberation of hydrolyzed HA.

Analysis of the industrial quality of three sugarcane cultivars at “santa rosalía de la chontalpa” sugarcane mill

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Samuel Córdova-Sánchez ◽  
José Izquierdo-Hernández ◽  
Sergio Salgado-García ◽  
Luz del Carmen Lagunes-Espinoza ◽  
David Jesús Palma-López ◽  
...  
Keyword(s):  
Design Methodology ◽  
Reducing Sugars ◽  
Environmental Friendly ◽  
Linear Polynomial ◽  
Sugar Mills ◽  
Standard Values ◽  
Santa Rosalia ◽  
The One ◽  
Best Fit

Objective: To evaluate the industrial quality of three sugarcane cultivars in a template cycle at the supply area of “Santa Rosalía de la Chontalpa” sugarcane mill. Design / Methodology / Approach: An experiment was established under a factorial design 3x3 (3 cultivars: CP 72-2086, MEX 79-431 and MEX 69-290; x 3 sampling dates: 330, 390 and 450 DDS, Spanish equivalent for days after sowing) on an Eutric Fluvisol soil. In each plantation, a sample of 10 stems with three replications was collected to determine the industrial quality by polarimetry. Results: The industrial quality of the evaluated cultivars only differed statistically in terms of the percentage of purity, MEX 79-431 was the one that presented the lowest value for this variable. At 450 DDS, the highest value was observed for °Brix (17.28), POL percentage (14.92), purity (86.44%). The values obtained in the present study for the quality of juice in the evaluated cultivars are within the range of the standard values established for Mexico. Limitations / Implications: Polarimetry is still the method used by most of the sugar mills in Mexico, even if other more environmental-friendly methodologies exist. Findings / Conclusions: The trend line that best fit to MEX 69-290 and MEX 79-431, for °Brix, POL and purity, was a linear polynomial and to CP 72-2086, a polynomial quadratic. Fresh stems and reducing sugars showed best fit with an inverse polynomial. °Brix presented strong and positive correlation with POL (R = 0.99**); and strong and negative with reducer sugars (R = -0.95**) and fresh stem humidity (R = -0.91**).

Operational Time and Melt Fraction Based Optimization of a Phase Change Material Longitudinal Fin Heat Sink

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
D. Jaya Krishna
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Heat Sink ◽  
Fluid Model ◽  
Melting Behavior ◽  
Base Temperature ◽  
Critical Temperatures ◽  
Volume Of Fluid Model ◽  
Change Material ◽  
Operational Time

Abstract In the present study, the numerical investigation has been performed for a phase change material (PCM)-based longitudinal fin heat sink. The fins are taken as an integral part of the heat sink and are made up of aluminum. The PCM considered in the study is RT44HC. Heat is transferred to the heat sink through its horizontal base. In order to simulate the melting behavior of the PCM, volume of fluid model has been used. To attain the best configuration with optimum operational time, Taguchi method has been used followed by analysis of melt fraction and maximum base temperature. The optimized heat sink configuration with maximum operational time has been obtained at the critical temperatures of 54.8 °C, 63 °C, and 72.6 °C.

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