Kinetics Study Using Solvent-Free Microwave Extraction of Essential Oil from Allium sativum L.

2020 ◽  
Vol 840 ◽  
pp. 186-192
Author(s):  
Yeni Variyana ◽  
Mahfud Mahfud
Keyword(s):  
Essential Oil ◽  
Allium Sativum ◽  
Extraction Process ◽  
Second Order ◽  
Solvent Free ◽  
Order Kinetic ◽  
Microwave Extraction ◽  
Order Model ◽  
First Order ◽  
Best Fit

Extraction of Allium sativum L. using Solvent-Free Microwave Extraction (SFME) without the addition of solvents in the process has been carried out. SFME is an alternative technique and method to produce essential oil and it has several advantages in terms of product quality. In this study, the essential oil was extracted from Allium sativum used extraction time from 10 to 90 min and microwave power in the range of 300-600 W. The result showed that SFME could produce the highest yield of 0.2636 g oil/100 g fresh garlic at 450 W and 90 min. In addition, the kinetic study of SFME model appears to be the best fit to explain with second-order than first-order model. It was proved by a good correlation between the experimental data and model achieved (R2>0.99) and (RMSE=0.0021). Based on the results obtained, second-order kinetic models could actually describe the kinetics model of extraction process from Allium sativum L. using SFME.

scholarly journals Solvent-free microwave extraction of essential oil from Melaleuca leucadendra L.

2018 ◽  
Vol 156 ◽  
pp. 03007
Author(s):  
Aviarina Widya Ismanto ◽  
Heri Septya Kusuma ◽  
Mahfud Mahfud
Keyword(s):  
Kinetic Model ◽  
Essential Oil ◽  
Extraction Method ◽  
Solvent Free ◽  
Order Kinetic ◽  
Microwave Extraction ◽  
First Order ◽  
Kinetics Modelling ◽  
Order Kinetic Model ◽  
Melaleuca Leucadendra

Cajuput (Melaleuca leucadendra L.) oil is one of potential commodity that provides an important role for the country’s foreign exchange but the extraction of these essential oil is still using conventional method such as hydrodistillation which takes a long time to produce essential oil with good quality. Therefore it is necessary to optimize the extraction process using a more effective and efficient method. So in this study the extraction is done using solvent-free microwave extraction method that are considered more effective and efficient than conventional methods. The optimum yield in the extraction of cajuput oil using solvent-free microwave extraction method is 1.0674%. The optimum yield is obtained on the feed to distiller (F/D) ratio of 0.12 g/mL with microwave power of 400 W. In the extraction of cajuput oil using solvent-free microwave extraction method is performed first-order and second-order kinetics modelling. Based on kinetics modelling that has been done, it can be said that the second-order kinetic model (R2 = 0.9901) can be better represent experimental results of extraction of cajuput oil that using solvent-free microwave extraction method when compared with the first-order kinetic model (R2 = 0.9854).

scholarly journals Examining the Impostor-Profile—Is There a General Impostor Characteristic?

2021 ◽  
Vol 12 ◽  
Author(s):  
Fabio Ibrahim ◽  
Johann-Christoph Münscher ◽  
Philipp Yorck Herzberg
Keyword(s):  
Convergent Validity ◽  
Factor Model ◽  
Second Order ◽  
Model Fit ◽  
Impostor Phenomenon ◽  
General Factor ◽  
Order Model ◽  
First Order ◽  
Order Factor ◽  
Best Fit

The Impostor-Profile (IPP) is a six-dimensional questionnaire measuring the Impostor Phenomenon facets. This study aims to test (a) the appropriateness of a total score, (b) measurement invariance (MI) between gender, (c) the reliability of the IPP, and (d) the convergent validity of the IPP subscales. The sample consisted of N = 482 individuals (64% female). To identify whether the scales of the IPP form a total score, we compared four models: (1) six correlating subscales, (2) a general factor model, (3) a second-order model with one second-order factor and six first-order factors, and (4) a bifactorial model with six group factors. The bifactorial model obtained the best fit. This supports the assumption of a total impostor score. The inspection of structural validity between gender subgroups showed configural, metric, and partial scalar MI. Factor mean comparisons supported the assumption that females and males differ in latent means of the Impostor Phenomenon expressions. The omega coefficients showed sufficient reliability (≥0.71), except for the subscale Need for Sympathy. Overall, the findings of the bifactor model fit and construct validity support the assumption that the measurement through total expression is meaningful in addition to the theoretically formulated multidimensionality of the Impostor Phenomenon.

scholarly journals Kinetics of scandium recovery by TVEX-TBP from the solution formed after the salt chlorinator cake leaching

2020 ◽  
Vol 168 ◽  
pp. 00050
Author(s):  
Vadym Korovin ◽  
Yurii Pohorielov ◽  
Yurii Shestak ◽  
Oleksandr Valiaiev ◽  
Jose Luis Cortina
Keyword(s):  
Chemical Interaction ◽  
Extraction Process ◽  
Second Order ◽  
Order Kinetic ◽  
Order Model ◽  
Elovich Equation ◽  
Diffusion Phase ◽  
Leaching Solution ◽  
Pseudo Second Order ◽  
Kinetics Of

Kinetics of scandium recovery by TVEX containing tributyl phosphate was studied from the clarified leaching solution of salt chlorinator cake. To assess the contribution of each diffusion phase, experimental data were analyzed using a graphic method. To define the contribution of chemical interaction into the scandium extraction process, recovery kinetics was quantitatively described using pseudo-first order, pseudo-second order kinetic models and Elovich equation in linearized form. It was established that recovery kinetics was most accurately described with the pseudo-second-order model.

scholarly journals ZnO Nanoparticles for Photocatalytic Application in Alkali-Activated Materials

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5519
Author(s):  
Hector R. Guzmán-Carrillo ◽  
Alejandro Manzano-Ramírez ◽  
Ines Garcia Lodeiro ◽  
Ana Fernández-Jiménez
Keyword(s):  
Zinc Oxide Nanoparticles ◽  
Second Order ◽  
Order Kinetic ◽  
Order Model ◽  
First Order ◽  
Photocatalytic Application ◽  
Vis Spectroscopy ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
Alkali Activated

This paper reports an Alkali-Activated Materials (AAM) using two different precursors, metakaolin and a metallurgical slag with photocatalytic zinc oxide nanoparticles, as novel photocatalytic composites. The photodegradation performance of the composites using methylene blue (MB) dye as a wastewater model was investigated by ultraviolet radiations (UV-vis) spectroscopy. Adsorption in dark conditions and photodegradation under UV irradiation are the mechanisms for removing MB dye. The pseudo-first-order kinetic and pseudo-second-order kinetic models were employed, and the experimental data agreed with the pseudo-second-order model in both cases with UV and without UV irradiations. As new photocatalytic materials, these composites offer an alternative for environmental applications.

Transient changes in muscle high-energy phosphates during moderate exercise

1993 ◽  
Vol 75 (2) ◽  
pp. 648-656 ◽  
Author(s):  
G. D. Marsh ◽  
D. H. Paterson ◽  
J. J. Potwarka ◽  
R. T. Thompson
Keyword(s):  
Oxygen Consumption ◽  
Steady State ◽  
Recovery Period ◽  
High Energy ◽  
Second Order ◽  
Moderate Intensity ◽  
High Energy Phosphates ◽  
Order Model ◽  
Time Constants ◽  
First Order

The purpose of this study was to use 31P-nuclear magnetic resonance spectroscopy to examine changes in wrist flexor muscle metabolism during the transitions from rest to steady-state exercise (on-transient) and back to rest (off-transient). Five healthy young males (mean age 25 +/- 2 yr) performed a series of square-wave exercise tests, each consisting of 5 min of moderate-intensity work followed by a 5-min recovery period. The subjects repeated this protocol six times, and each individual's results were pooled before analysis. ATP and intracellular pH did not change significantly during exercise or recovery. Phosphocreatine (PCr) declined progressively at the onset of exercise, reaching a plateau after approximately 2 min. A reciprocal increase in Pi occurred during the onset of exercise. During the recovery period PCr was resynthesized, whereas Pi returned to resting levels. The data were plotted as a function of time and fit with both first- and second-order exponential growth or decay models; however, the second-order model did not significantly improve the fit of the data. Time constants for the first-order model of the on- and off-transient responses for both PCr and Pi were approximately 30 s. These values are nearly identical to the time constants for oxygen consumption during submaximal exercise that have been reported previously by several authors. The results of this study show that the metabolism of muscle PCr during steady-state exercise and recovery can be accurately described by a monoexponential model and, further, suggest that a first-order proportionality exists between metabolic substrate utilization and oxygen consumption.

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