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1.
PLoS One ; 17(1): e0261427, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35085239

RESUMO

Cost and safety are critical factors in the oil and gas industry for optimizing wellbore trajectory, which is a constrained and nonlinear optimization problem. In this work, the wellbore trajectory is optimized using the true measured depth, well profile energy, and torque. Numerous metaheuristic algorithms were employed to optimize these objectives by tuning 17 constrained variables, with notable drawbacks including decreased exploitation/exploration capability, local optima trapping, non-uniform distribution of non-dominated solutions, and inability to track isolated minima. The purpose of this work is to propose a modified multi-objective cellular spotted hyena algorithm (MOCSHOPSO) for optimizing true measured depth, well profile energy, and torque. To overcome the aforementioned difficulties, the modification incorporates cellular automata (CA) and particle swarm optimization (PSO). By adding CA, the SHO's exploration phase is enhanced, and the SHO's hunting mechanisms are modified with PSO's velocity update property. Several geophysical and operational constraints have been utilized during trajectory optimization and data has been collected from the Gulf of Suez oil field. The proposed algorithm was compared with the standard methods (MOCPSO, MOSHO, MOCGWO) and observed significant improvements in terms of better distribution of non-dominated solutions, better-searching capability, a minimum number of isolated minima, and better Pareto optimal front. These significant improvements were validated by analysing the algorithms in terms of some statistical analysis, such as IGD, MS, SP, and ER. The proposed algorithm has obtained the lowest values in IGD, SP and ER, on the other side highest values in MS. Finally, an adaptive neighbourhood mechanism has been proposed which showed better performance than the fixed neighbourhood topology such as L5, L9, C9, C13, C21, and C25. Hopefully, this newly proposed modified algorithm will pave the way for better wellbore trajectory optimization.


Assuntos
Conservação de Recursos Energéticos/métodos , Algoritmos , Simulação por Computador , Indústria de Petróleo e Gás
2.
ACS Omega ; 6(40): 26519-26532, 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34661007

RESUMO

Ionic liquids (ILs) can play a vital role in clay swelling inhibition during hydraulic fracturing. Previous studies highlighted the effect of side-chain length attached to the cationic core and different anions possessing almost the same chemical properties on inhibition performance. However, polyatomic anions have the potential to superiorly inhibit swelling compared to monoatomic anions. In this study, three ILs, namely, 1-butyl-3-methylimidazolium chloride (BMIMCl), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), were utilized to assess the effects of polyatomic anions on clay swelling inhibition. These performances were compared with the performances of a conventional inhibitor, potassium chloride (KCl). X-ray diffraction (XRD) testing was applied to check the mineral components present in the bentonite clay sample studied in this research. Clay swelling inhibition performance and rheological properties of these ILs were evaluated by the bentonite plate soaking test, linear swelling test, and rheological test. The swelling inhibition mechanisms were investigated through ζ-potential measurement, Fourier transform infrared (FT-IR) spectroscopy, and contact angle measurement. Moreover, COSMO-RS computer simulation was conducted to explain the inhibition mechanisms theoretically. The results demonstrated that BMIMPF6 showed superior inhibition performance and reduced the swelling by 21.55%, while only 9.26% reduction was attained by potassium chloride (KCl). The adsorption ability on the bentonite surface through electrostatic attraction, higher activity coefficient, and less electronegativity of PF6 - anion played a vital role in attaining such superior inhibition performance by BMIMPF6.

3.
J Med Toxicol ; 9(1): 9-15, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23143832

RESUMO

2,3-Dimercaptopropane-1-sulfonate (DMPS) is a metal chelator approved in Europe for oral or intravenous use for heavy metal poisoning. Transdermally applied DMPS (TD-DMPS) is used by some alternative practitioners to treat autism, despite the absence of evidence for its efficacy. We found no literature evaluating the pharmacokinetics of the transdermal route of delivery or the ability of TD-DMPS to enhance urinary mercury elimination. We hypothesized that TD-DMPS is not absorbed. Eight adult volunteers underwent application of 1.5-3 drops/kg of TD-DMPS. Subjects provided 12-h urine collections the day before and day of application. Subjects underwent blood draws at 0, 30, 60,90, 120, and 240 min after TD-DMPS application. Plasma and urine were assayed for the presence of DMPS. Urine was assayed for any change in urinary mercury excretion after DMPS. One control subject ingested 250 mg of oral DMPS and underwent the same urine and blood collections and analyses. No subject had detectable urine DMPS or increased urine mercury excretion after TD-DMPS. One subject had detectable levels of DMPS in the 30-min plasma sample, suspected to be contamination. All other samples for that subject and the other seven subjects showed no detectable plasma DMPS. The control subject had detectable urine and plasma DMPS levels and increased urine mercury excretion. These results indicate that TD-DMPS is not absorbed. There was no increase in urine mercury excretion after TD-DMPS. Our results argue that TD-DMPS is an ineffective metal chelator.


Assuntos
Quelantes/farmacocinética , Unitiol/farmacocinética , Administração Cutânea , Administração Oral , Adulto , Quelantes/administração & dosagem , Feminino , Humanos , Masculino , Compostos de Mercúrio/urina , Pessoa de Meia-Idade , Unitiol/administração & dosagem
4.
J Pharm Biomed Anal ; 49(3): 692-701, 2009 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-19181471

RESUMO

The development and utility of an efficient HPLC method screening strategy using only four columns for the separation of pharmaceutical compounds and related impurities is presented. The strategy established a two-column approach to enable rapid early method development, along with a four-column approach for commercial method development of the analytical methods utilized to verify the quality of drug substance or drug product. Mobile phases consisted of acetonitrile or methanol with aqueous trifluoroacetic acid for low pH screening, and ammonium hydroxide for high pH screening. Examples are provided to demonstrate the practicality and orthogonality of the method screening process. A unique system suitability check, using commercially available compounds, was incorporated as a tool for troubleshooting and for ensuring adequate system performance prior to screening. Initial testing of the strategy revealed that the columns chosen were successful in leading to assay and impurity methods for 40 pharmaceutical compounds.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Preparações Farmacêuticas/análise , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Espectrometria de Massas , Modelos Estatísticos , Reprodutibilidade dos Testes , Bibliotecas de Moléculas Pequenas , Software , Espectrofotometria Ultravioleta , Temperatura
5.
J Chromatogr A ; 1101(1-2): 122-35, 2006 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-16236292

RESUMO

A general procedure is proposed for the rapid development of a reversed-phase liquid chromatographic (RP-LC) separation that is "orthogonal" to a pre-existing ("primary") method for the RP-LC separation of a given sample. The procedure involves a change of the mobile-phase organic solvent (B-solvent), the replacement of the primary column by one of very different selectivity, and (only if necessary) a change in mobile phase pH or the use of a third column. Following the selection of the "orthogonal" B-solvent, column and mobile phase pH, further optimization of peak spacing and resolution can be achieved by varying separation temperature and either isocratic %B or gradient time. The relative "orthogonality" of the primary and "orthogonal" RP-LC methods is then evaluated from plots of retention for one method versus the other. The present procedure was used to develop "orthogonal" methods for nine routine RP-LC methods from six pharmaceutical analysis laboratories. The relative success of this approach can be judged from the results reported here.


Assuntos
Cromatografia Líquida/métodos , Simulação por Computador , Contaminação de Medicamentos , Matemática , Preparações Farmacêuticas/isolamento & purificação , Sensibilidade e Especificidade , Solventes/química
6.
J Chromatogr A ; 1000(1-2): 637-55, 2003 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-12877193

RESUMO

The concept of hydrophobicity has been addressed by researchers in all aspects of science, particularly in the fields of biology and chemistry. Over the past several decades, the study of the hydrophobicity of biomolecules, particularly amino acids has resulted in the development of a variety of hydrophobicity scales. In this review, we discuss the various methods of measuring amino acid hydrophobicity and provide explanations for the wide range of rankings that exist among these published scales. A discussion of the literature on amino acid interactions is also presented. Only a surprisingly small number of papers exist in this rather important area of research; measuring pairwise amino acid interactions will aid in understanding structural aspects of proteins.


Assuntos
Aminoácidos/química , Sequência de Aminoácidos , Aminoácidos/genética , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida
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