Search results for "Extraction"
showing 10 items of 2072 documents
Supercritical CO2 extraction of essential oil from orange peel. Effect of operation conditions on the extract composition
1999
Abstract The supercritical fluid extraction (SFE) of orange essential oil was studied using dehydrated orange peel (0.0538 kg H2O/kg dm) from naveline cultivars as raw material and CO2 as solvent. The effect of operation conditions was analyzed in a series of experiments at temperatures between 293 and 323 K and pressures between 8 and 28 MPa. The collected extracts were analyzed and the relative composition of the essential oil was determined. Limonene was the principal component extracted, the optimum conditions for limonene extraction were 12.5 MPa and 308 K, in these conditions limonene represents more than 99.5% of the essential oil. Within the operating range conditions, the optimum f…
Aroma Profiling of Leaf, Flower, Peel and In Vitro Embryo Tissues of “Ciaculli Late” Mandarin
2003
Abstract Volatile compounds released from leaf, flower and peel as well as from somatic (nucellar) embryo tissues of “Tardivo di Ciaculli” or “Ciaculli late” mandarin have been collected/ concentrated by headspace solid phase microextraction, HS-SPME, and analyzed by GC-MS. The tehnique allowed the rapid comparison of the volatiles from the various sources; in particular, 19 compounds were identified for the embryos, 16 for leaf and flower and 13 for peel. Limonene was the most abundant volatile component of the embryo and peel while γ-terpinene was the major compound among volatiles from leaf and flower. Relatively high amounts of methyl N-methyl anthranilate and β-caryophyllene were also …
Solubilities of Essential Oil Components of Orange in Supercritical Carbon Dioxide
2000
The solubilities of pure limonene and linalool in compressed carbon dioxide have been measured using a flow apparatus at 318.2 K and 328.2 K and pressures ranging from 69 bar to 111 bar. The solubilities were successfully modeled using equations of state (Peng−Robinson, Soave−Redlich−Kwong, 3P1T, Dohrn and Prausnitz nopolar) and a semiempirical equation (Chrastill model). The generalized parameters for the Peng−Robinson EOS were obtained for each system. These parameters were independent of temperature, and they reproduce successfully all data available in the literature. The results show that the solubility of limonene in supercritical carbon dioxide was bigger than the solubility of linal…
Cohesive explicitness and explicitation in an English-German translation corpus
2007
Explicitness or implicitness as assumed properties of translated texts and other texts in multilingual communication have for some time been the object of speculation and, at a later stage, of more systematic research in linguistics and translation studies. This paper undertakes an investigation of explicitness/implicitness and related phenomena of translated texts on the level of cohesion. A corpus-based research architecture, embedded in an empirical research methodology, will be outlined, and first results and possible explanations will be discussed. The paper starts with a terminological clarification of the concepts of ‘explicitness’ and ‘explicitation’ in terms of dependent variables …
Stir bar sorptive-dispersive microextraction for trace determination of triphenyl and diphenyl phosphate in urine of nail polish users
2018
Abstract This work describes a new analytical method useful for monitoring the human exposure to the endocrine-disrupting plasticizer triphenyl phosphate (TPP) via nail polish use. The method allows trace determination of this parent compound and its main metabolite, namely diphenyl phosphate (DPP), in urine samples of nail polish users. The method is based on a novel microextraction technique termed stir bar sorptive-dispersive microextraction (SBSDME) using a magnetic composite made of CoFe2O4 magnetic nanoparticles embedded into a mixed-mode weak anion exchange polymer (Strata™-X-AW), followed by liquid chromatography-tandem mass spectrometry (LC–MS/MS). The main parameters involved in t…
Wine analysis: Study and comparison of techniques developed for the study of volatile constituents
1986
A number of headspace techniques have been compared, using a standard solution containing 12 compounds and a wine sample, viz.: (1) purge and cold trap injection; (2) dynamic headspace combined with liquidliquid extraction; (3) static headspace with and without preconcentration; (4) direct liquid injection. The sensitivity, reproducibility and speed of analysis were determined. Considering the results obtained and dependent on the purpose of the experiments and the number of samples to be examined the appropriate technique can be selected. ?? 1980 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.
Phase I metabolites (organic acids) of gamma‐hydroxybutyric acid–validated quantification using GC–MS and description of endogenous concentration ran…
2020
Gamma-hydroxybutyric acid (GHB) is a sedative drug used in drug-facilitated crimes. Its detection window is very short. GHB undergoes intensive phase I metabolism to organic acids (glycolic acid, succinic acid, dihydroxybutyric acids). These could be potential analytical targets to broaden the detection window. The aim of the present study was to enable the detection of endogenous levels of these metabolites in biological samples (blood and urine). A gas chromatographic-mass spectrometric method using liquid-liquid extraction and derivatization with N-methyl-N-tri-methylsilyltrifluoracetamide was developed for the quantification. Validation results were consistent with international guideli…
Volume and effectiveness assessment of articain 4% versus mepivacaine 2% used in third molar surgery : randomized, double-blind, split-mouth controll…
2020
Made available in DSpace on 2021-06-25T11:06:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Background: The different indications for extraction of the lower third molars, require resources to manage pain and discomfort, such as, for example, adequate anesthetic techniques, and the type of anesthetic used can in-fluence the management of pain in tooth extractions. Few studies in the literature compare the anesthetics 4% articaine hydrochloride and 2% mepivacaine hydrochloride showing evidence that both allow for successful pain management. This study sought to compare the volume, efficacy and safety of these two anesthetic drugs, both associated with epinephrine at a ratio …
Bupivacaine 0.5% versus articaine 4% for the removal of lower third molars. A crossover randomized controlled trial.
2012
Objective: To compare the anesthetic action of 0.5% bupivacaine in relation to 4% articaine, both with 1:200,000 epinephrine, in the surgical removal of lower third molars. As a secondary objective hemodynamic changes using both anesthetics were analyzed. Study Design: Triple-blind crossover randomized clinical trial. Eighteen patients underwent bilateral removal of impacted lower third molars using 0.5% bupivacaine or 4% articaine in two different appointments. Preoperative, intraoperative and postoperative variables were recorded. Differences were assessed with McNemar tests and repeated measures ANOVA tests. Results: Both solutions exhibited similar latency times and intraoperative effic…
Video-Based Depression Detection Using Local Curvelet Binary Patterns in Pairwise Orthogonal Planes
2016
International audience; Depression is an increasingly prevalent mood disorder. This is the reason why the field of computer-based depression assessment has been gaining the attention of the research community during the past couple of years. The present work proposes two algorithms for depression detection, one Frame-based and the second Video-based, both employing Curvelet transform and Local Binary Patterns. The main advantage of these methods is that they have significantly lower computational requirements, as the extracted features are of very low dimensionality. This is achieved by modifying the previously proposed algorithm which considers Three-Orthogonal-Planes, to only Pairwise-Ort…