Determination of the Stability of Asphaltenes Through Physicochemical Characterization of Asphaltenes

2016 ◽  
Author(s):  
Andreas Prakoso ◽  
Abhishek Punase ◽  
Kristina Klock ◽  
Estrella Rogel ◽  
Cesar Ovalles ◽  
...  
Keyword(s):  
Physicochemical Characterization ◽  
The Stability

scholarly journals Chemical and Physicochemical Characterization of Faveleria (Cnidoscolus phyllacanthus) Oil - It Use of Determination of Enzymatic Activity of Extract of Fungi rhizopus sp.

2020 ◽  
Vol 12 (5) ◽  
pp. 1319-1333
Author(s):  
Carla Verônica Rodarte de Moura ◽  
Haroldo Luis Sousa Neres ◽  
Edmilson Miranda de Moura ◽  
Maria Christina Sanches Muratori ◽  
Tiago Linus Silva Coelho ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Physicochemical Characterization ◽  
It Use ◽  
Rhizopus Sp

scholarly journals Structure and Stability of Gas Adsorption Complexes in Periodic Porous Solids as Studied by VTIR Spectroscopy: An Overview

2020 ◽  
Vol 10 (23) ◽  
pp. 8589
Author(s):  
Montserrat R. Delgado
Keyword(s):  
Gas Adsorption ◽  
Variable Temperature ◽  
Spectroscopic Technique ◽  
Porous Solids ◽  
Large Temperature ◽  
Adsorption Complexes ◽  
The Stability ◽  
Standard Enthalpy Change

Variable-temperature infrared (VTIR) spectroscopy is an instrumental technique that enables structural characterization of gas-solid adsorption complexes by analysis of meaningful vibrational modes, and simultaneous determination of the standard enthalpy change (ΔH0) involved in the gas adsorption process, which allows one to quantify the stability of the corresponding complex. This is achieved by a van’t Hoff analysis of a set of IR spectra recorded over a sufficiently large temperature range. Herein, the use of this versatile spectroscopic technique is demonstrated by reviewing its application to the study of carbon monoxide, carbon dioxide and dinitrogen adsorption on several (alkaline) zeolites, which can be regarded as the archetype of periodic porous solids.

Characterization and Oil Recovery Observations on a Series of Synthetic Petroleum Sulfonates

1982 ◽  
Vol 22 (02) ◽  
pp. 226-236 ◽  
Author(s):  
Earl W. Malmberg ◽  
Carolyn C. Gajderowicz ◽  
F. David Martin ◽  
Jill S. Ward ◽  
J.J. Taber
Keyword(s):  
New Mexico ◽  
Oil Recovery ◽  
Optimal Salinity ◽  
Aqueous Dispersions ◽  
R And D ◽  
Recovery System ◽  
Characterization Studies ◽  
The Stability

Abstract Synthetic sulfonates for application in enhanced oilrecovery are of increasing interest. Because of the needto explore the range of candidates potentially available atvarious costs from the petrochemical industry, a series ofnine samples was prepared for distribution with financial suppose of the U.S. DOE. This paper briefly describesthe samples and, in more detail, the characterization ofthe samples for oil recovery. The characterization included determination of optimal salinity, stability ofaqueous dispersions in brines containing sodium chlorideand calcium ion, and oil recovery and loss of sulfonate in1-ft (0.305-m) Berea cores. Introduction Most current work in surfactant systems for enhanced oilrecovery is based on sulfonates, either petroleum(natural) or synthetic. The synthetic sulfonates discussedin this paper are those made by alkylation of an aromatic hydrocarbon with a selected olefin, followed by sulfonationof this alkylate. Interest in these synthetic sulfonatesis evident from numerous patents and publications fromseveral laboratories. The major published work in this area, by Reed andHealy, stems from earlier studies that generated seriousquestions as to the effect of fractionation of petroleumsulfonates when used in reservoirs. Interest in andwork with synthetic sulfonates has increased steadily inthe Sun Co. laboratories over the past years because offavorable experimental results. However, availablesamples of synthetic sulfonates have been limited; theydid not include agents that probably would be thelowest cost materials available from current petrochemicaloperations. With the question of cost effectiveness inmind and with the expressed interest of a number of oilrecovery laboratories, Sun approached the Energy R and DAdmin. with the following proposal:Sun wouldprepare large samples of a representative set of syntheticsulfonates,the New Mexico Petroleum RecoveryResearch Center would distribute the samples tointerested laboratories and would receive and distributeinformation from these groups, andthis informationwould include characterization studies on the sampleswith preliminary studies by the New Mexico and Sun laboratories. This work has now been completed. The Sun Applied R and D group in Marcus Hook, PA, did the preparative work. The samples are describedbriefly in a following section; complete description isavailable in Ref. 5. This paper describes characterization of the synthetic sulfonates by optimal salinityexperiments, studies of aqueous dispersions in selectedsodium chloride and calcium chloride concentrations, and oil-recovery experiments in 1-ft (0.305-m) Bereacores. Plans for this work required a decision on the levelof concentration of sulfonate to use. One philosophyexemplified in published work is that the level should below so that, for an acceptable total amount of sulfonate, the %PV of the slug could be as large as possible. Thisapproach is an advantage in efforts to improve theoverall conformance of the recovery system in areservoir. Some interesting results have been obtained with synthetic sulfonates at the level of 2% active concentration.In studies of the stability of aqueous dispersions asin the salinity grids, 1.5% sulfonate was used. Thisvalue is expressed in terms of the aqueous phase; nosignificant oil phase was present. SPEJ P. 226^

scholarly journals Cyclosporine CsA—The Physicochemical Characterization of Liposomal and Colloidal Systems

2020 ◽  
Vol 4 (4) ◽  
pp. 46
Author(s):  
Agnieszka Ewa Wiącek ◽  
Małgorzata Jurak ◽  
Agata Ładniak ◽  
Kacper Przykaza ◽  
Klaudia Szafran
Keyword(s):  
Particle Size ◽  
Lipid Membranes ◽  
Physicochemical Characterization ◽  
Colloidal Systems ◽  
Drug Bioavailability ◽  
Individual Variations ◽  
The Stability ◽  
The Individual ◽  
Formulation Stability

This paper presents an overview of the possibilities of testing various cyclosporine (CsA) formulations with an emphasis on parameters that may be key to improving the stability and biocompatibility. The feasibility of CsA colloidal systems for oral (injection) administration were investigated using different techniques and compared with similar investigations of other researchers. The chosen CsA systems were developed using dipalmitoylphosphocholine (DPPC) and/or cholesterol as a lipid matrix, stabilized with ethanol, with soybean oil or n-tetradecane as oil phase in emulsions, under natural pH, room and physiological temperature. Their integrity was found to be strictly dependent on the stabilizers. The highest CsA penetrability with the system containing phospholipid in the context of its interactions with lipid membranes was shown. Also, the bioavailability of CsA can be enhanced with the biopolymer antibacterial chitosan. This mini-review suggests the suitability of liposome/microemulsion as promising vehicles for CsA delivery. The most hopeful proved to be formulation with the smaller particle size facilitating absorption, but when safety is assessed, relying on just the particle size cannot be the only criteria. Reassumed, the CsA formulation stability known on the basis of the size and zeta potential measurements guarantees a decrease of the individual variations in the drug bioavailability, toxicity and minimizes rejection.

scholarly journals PHYSICOCHEMICAL CHARACTERIZATION OF PITUITARY FOLLICLE-STIMULATING HORMONE

1952 ◽  
Vol 35 (4) ◽  
pp. 629-637 ◽  
Author(s):  
Choh Hao Li ◽  
Kai O. Pedersen
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Follicle Stimulating Hormone ◽  
Physicochemical Characterization ◽  
Single Protein ◽  
Pituitary Glands ◽  
The Stability ◽  
Stimulating Hormone

The physiochemical characteristics of the follicle-stimulating hormone (FSH) from whole sheep pituitary glands have been studied. The hormone behaves as a single protein in electrophoresis, diffusion, and ultracentrifugation. It has an isoelectric point at pH 4.5 and a molecular weight of 67,000 and contains 1.23 per cent hexose and 1.51 per cent hexosamine. The amino acid composition has also been determined in large part. The stability of the hormone to acid and heat has been investigated.

Determination of inorganic constituents and physicochemical characterization of functional flour samples

2017 ◽  
Vol 132 ◽  
pp. 112-118 ◽  
Author(s):  
Anna Luiza B. Brito ◽  
Aline F. Oliveira ◽  
Ana Rita A. Nogueira ◽  
Amália G.G. Pessoa ◽  
Liliana F.B.L. Pontes
Keyword(s):  
Physicochemical Characterization ◽  
Inorganic Constituents

scholarly journals Extraction and Physicochemical Characterization of Oil from Unripe Plantain (Musa Paradisiaca) Peels

2020 ◽  
pp. 151-155
Author(s):  
Orodu Victor Enearepuadoh ◽  
Igara Evawere Abigail
Keyword(s):  
Physicochemical Properties ◽  
Physicochemical Characterization ◽  
Iodine Content ◽  
Acid Value ◽  
Physicochemical Analysis ◽  
Human Consumption ◽  
Musa Paradisiaca ◽  
The Mean ◽  
The Stability

Extraction and physicochemical analysis of oil from unripe plantain (Musa paradisiaca) peels was carried out using cold extraction method. The peels were washed with distilled water, sun dried for 3 hours and oven dried for 6 hours at 85oC. It was then ground thoroughly. 700g of the sample was weighed and 1.20 liter of n-hexane was added for 72 hours. It was placed in a water bath for the evaporation of the solvent. The physicochemical properties determined were Saponification Value (SV), Iodine Value (IV), Free Fatty Acid Value (FFA), Peroxide Value (PV), Acid Value (AV) the mean results obtained SV 335.18mg/KOH/g, IV 7.16gI2/100g, FFA 338.76mg/KOH/g, AV 696.35mg/KOH/g and PV 328.46meq/kg. In comparing these physicochemical properties with the standard given by WHO/FAO, it was observed that IV and PV were below the range, SV, AV and FFA was above the range. Hence, the oil obtained from unripe plantain (Musa paradisiaca) peels is not fit for human consumption because AV, SV and FFA are higher than the standard given by WHO/FAO rather it can be used for making of soap and shampoos, PV showed the stability of the oil and IV indicates it’s nondrying quality which will not be suitable for ink and paint making due to its low iodine content.

Physicochemical Characterization of Canola Oil/Water Nano‐emulsions Obtained by Determination of Required HLB Number and Emulsion Phase Inversion Methods

2006 ◽  
Vol 27 (1) ◽  
pp. 109-115 ◽  
Author(s):  
Jacqueline Moreira de Morais ◽  
Orlando David Henrique dos Santos ◽  
Tatiani Delicato ◽  
Ricardo Azzini Gonçalves ◽  
Pedro Alves da Rocha‐Filho
Keyword(s):  
Canola Oil ◽  
Phase Inversion ◽  
Physicochemical Characterization ◽  
Emulsion Phase ◽  
Inversion Methods ◽  
Oil Water
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