scholarly journals Maximum Bleaching of Vegetable Oils by Acid-Activated Bentonite: Influence of Nanopore Radius

2012 ◽  
Vol 30 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Müsęerref Önal ◽  
Yüksel Sarıkaya
Keyword(s):  
Vegetable Oils ◽  
Bleaching Earth ◽  
Nitrogen Adsorption ◽  
Mass Range ◽  
Acid Mixture ◽  
Acid Activation ◽  
Physicochemical Interaction ◽  
Activated Bentonite ◽  
The Mean ◽  
Bleaching Power

The optimum conditions necessary for preparing a bleaching earth (BE) with maximum bleaching power (BP) towards soybean oil (SO) and cottonseed oil (CSO) were investigated. BEs were obtained by H2SO4 activation of a white calcium bentonite (CaB) sample from the Kütahya region of Turkey. After drying for 4 h at 105 °C, the CaB samples were activated by heating their acidic aqueous suspensions for 6 h at 97 °C, the acid content of the dry bentonite/acid mixture being varied in the 0–70% mass range. The respective specific surface area (S) and specific nanopore volume (V) of the BEs were determined from nitrogen adsorption/desorption data obtained at −196 °C. For natural CaB, the values of S and V were 44 m2/g and 0.11 cm3/g, respectively. These values attained a maximum of 135 m2/g and 0.30 cm3/g for the BE sample prepared employing 40% H2SO4 for acid activation. Interestingly, the maximum BP was not associated with the maximum S and V values. The optimum values for the percentage H2SO4, S and V for attaining the maximum BP were 20%, 100 m2/g and 0.17 cm3/g, respectively. The mean nanopore radius (r) of each BE was calculated using the corresponding S and V values. Nanopores with a mean radius in the range 3.5–5.5 nm, which was close to the diameter of the coloured pigment, were found to be mostly responsible for the BP towards SO and CSO. The results obtained in the present study indicate that the value of r was more effective than the S and V values of BEs in the bleaching of vegetable oils. Adsorption of a pigment onto a BE was found to depend not only on the physicochemical interaction between the pigment molecule and the BE surface, but also on the mean nanopore size.

scholarly journals Aktivasi bentonit alam pacitan sebagai bahan penyerap pada proses pemurnian minyak sawit

2018 ◽  
Vol 5 (2) ◽  
pp. 429
Author(s):  
Ailen Tanjaya ◽  
S Sudono ◽  
Nani Indraswati ◽  
Suryadi Ismadji
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Palm Oil ◽  
Peroxide Value ◽  
Sensory Quality ◽  
Bleaching Earth ◽  
Activation Process ◽  
Acid Activation ◽  
Bleaching Process ◽  
Activated Bentonite

Application of pacitan's bentonite as adsorbent in purification process of palm oil. Bentonite is one of the widely use adsorbent which is usually used in the bleaching process of edible palm oil to remove pigments color and other impurities which can improve the sensory quality and the oxidative stability of the oil. Bleaching capacity from bentonite can be improved by acid activation, to modified the structure as well as to improve the sorptive surface area. The aim of this research was to determine the optimum acid concentration for the activation of bentonite from Pacitan, East Java. The bleaching capacity of activated bentonite was evaluated based on color, free fatty acid (FFA) and peroxide value (PV) contents of bleached palm oil. The activation was carried out using sulfitric acid (HSO) and hydrochloride acid (HCI) as activating agents at a ranges of concentrations from 1 N to 10 N. The bleaching process of crude palm oil was conducted at 100 C for 10 mins. The bleached palm oil were analyzed for its colur, free fatty acid (FFA) and peroxide value (PV) contents. From this study it can be concluded that the activation process using HCl 5 N gave the optimum bleaching capacity.Keywords: Bleaching earth; Acid activation; Bentonite; Color; Free fatty acid; Peroxide value AbstrakBentonit merupakan salah satu jenis adsorben yang sering digunakan pada proses bleaching minyak kelapa sawit untuk menyerap zat warna dan pengotor-pengotor dalam minyak. Kemampuan bleaching dari bentonit dapat ditingkatkan dengan aktivasi dengan asam untuk meningkatkan luas permukaan dan memodifikasi struktur bentonit. Tujuan dari penelitian ini adalah menentukan jenis dan konsentrasi asam yang optimum pada proses aktivasi bentonit Pacitan. Kemampuan bleaching bentonit dievaluasi berdasarkan parameter warna, kadar asam lemak bebas (Free Fatty Acid, FFA) dan bilangan peroksida (Peroxide Value, PV) pada bleached palm oil. Proses aktivasi bentonit dilakukan menggunakan asam sulfat (H2SO4) dan asam klorida (HCl) dengan variasi konsentrasi 1-10 N. Bentonit yang telah diaktivasi digunakan untuk proses bleaching degummed palm oil pad a suhu 100 C selama 10 menit. Bleached palm oil dianalisa warna (dengan lovibond tintometer), kadar FFA dan PV Dari hasil penelitian diperoleh bahwa bentonit Pacitan yang diaktivasi menggunakan HCl 5 N, memberikan hasil bleaching yang optimum.Kata kunci : Bleaching earth; Aktivasi asam; Bentonit; Wama; Asam lemak bebas; Bilangan peroksida

scholarly journals A study of stellar orbit fractions: simulated IllustrisTNG galaxies compared to CALIFA observations

2019 ◽  
Vol 489 (1) ◽  
pp. 842-854 ◽  
Author(s):  
Dandan Xu ◽  
Ling Zhu ◽  
Robert Grand ◽  
Volker Springel ◽  
Shude Mao ◽  
...  
Keyword(s):  
Observational Data ◽  
Mass Range ◽  
Stellar Mass ◽  
Model Uncertainties ◽  
Massive Galaxies ◽  
Hubble Sequence ◽  
Galaxy Sample ◽  
The Mean ◽  
Stellar Orbit

ABSTRACT Motivated by the recently discovered kinematic ‘Hubble sequence’ shown by the stellar orbit-circularity distribution of 260 CALIFA galaxies, we make use of a comparable galaxy sample at z = 0 with a stellar mass range of $M_{*}/\mathrm{M}_{\odot }\in [10^{9.7},\, 10^{11.4}]$ selected from the IllustrisTNG simulation and study their stellar orbit compositions in relation to a number of other fundamental galaxy properties. We find that the TNG100 simulation broadly reproduces the observed fractions of different orbital components and their stellar mass dependences. In particular, the mean mass dependences of the luminosity fractions for the kinematically warm and hot orbits are well reproduced within model uncertainties of the observed galaxies. The simulation also largely reproduces the observed peak and trough features at $M_{*}\approx 1\rm {-}2\times 10^{10}\, \mathrm{M}_{\odot }$ in the mean distributions of the cold- and hot-orbit fractions, respectively, indicating fewer cooler orbits and more hotter orbits in both more- and less-massive galaxies beyond such a mass range. Several marginal disagreements are seen between the simulation and observations: the average cold-orbit (counter-rotating) fractions of the simulated galaxies below (above) $M_{*}\approx 6\times 10^{10}\, \mathrm{M}_{\odot }$ are systematically higher than the observational data by $\lesssim 10{{\ \rm per\ cent}}$ (absolute orbital fraction); the simulation also seems to produce more scatter for the cold-orbit fraction and less so for the non-cold orbits at any given galaxy mass. Possible causes that stem from the adopted heating mechanisms are discussed.

scholarly journals Can an amino acid mixture alleviate gastrointestinal symptoms in neuroendocrine tumor patients?

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aman Chauhan ◽  
Satya Das ◽  
Rachel Miller ◽  
Laura Luque ◽  
Samuel N. Cheuvront ◽  
...  
Keyword(s):  
Amino Acid ◽  
Neuroendocrine Tumor ◽  
Gastrointestinal Symptoms ◽  
Retrospective Chart Review ◽  
Final Analysis ◽  
Acid Mixture ◽  
Tumor Patients ◽  
Short Gut Syndrome ◽  
Oral Rehydration ◽  
The Mean

Abstract Background Neuroendocrine tumors, although relatively rare in incidence, are now the second most prevalent gastrointestinal neoplasm owing to indolent disease biology. A small but significant sub-group of neuroendocrine tumor patients suffer from diarrhea. This is usually secondary to carcinoid syndrome but can also be a result of short gut syndrome, bile acid excess or iatrogenic etiologies. Recently, an amino acid based oral rehydration solution (enterade® Advanced Oncology Formula) was found to have anti-diarrheal properties in preclinical models. Methods A retrospective chart review of all NET patients treated with enterade® AO was performed after IRB approval. Results Ninety-eight NET patients who had received enterade® AO at our clinic from May 2017 through June 2019 were included. Patients (N = 49 of 98) with follow up data on bowel movements (BMs) were included for final analysis. Eighty-four percent of patients (41/49) had fewer BMs after taking enterade® AO and 66% (27/41) reported more than 50% reduction in BM frequency. The mean number of daily BMs was 6.6 (range, 3–20) at baseline before initiation of therapy, while the mean number of BMs at 1 week time point post enterade® AO was 2.9 (range, 0–11). Conclusions Our retrospective observations are encouraging and support prospective validation with appropriate controls in NET patients. This is first published report of the potential anti-diarrheal activity of enterade® AO in NET patients.

scholarly journals COMPOSITION, STRUCTURE AND TEXTURAL CHARACTERISTICS OF DOMESTIC ACID ACTIVATED BENTONITE

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Zоrаn Pеtrоvić ◽  
Pеrо Dugić ◽  
Vојislаv Аlеksić ◽  
Sаbinа Bеgić ◽  
Vlаdаn Мićić ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Low Temperature ◽  
Layered Structure ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Textural Characteristics ◽  
X Ray ◽  
Before And After ◽  
Activated Bentonite ◽  
Composition Structure

Bentonites are aluminosilicate minerals which, due to their porosity, layered structure and composition have a wide application. Structural and textural characteristics of bentonite may be improved by different modification procedures. The aim of this study was to investigate compositional, structural and textural characteristics of domestic bentonite in place Gerzovo, before and after the activation with sulfuric acid. These characteristics were investigated by analytical methods, X-ray diffraction (XRD) and the method of low-temperature nitrogen adsorption (BET). Characteristics of acid-activated bentonite were compared with the characteristics of commercial active clay. The obtained results showed that the activation of bentonite with sulfuric acid leads to a significant improvement in structural and textural characteristics. Using these results it can be assumed that this bentonite will have good adsorption characteristics and can serve as an alternative in comparison with imported commercial aluminosilicate-based adsorbents.

Effect of valence of copper on adsorption of dimethyl sulfide from liquid hydrocarbon streams on activated bentonite

2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Huan Huang ◽  
De-Zhi Yi ◽  
Yan-Nan Lu ◽  
Xiao-Lin Wu ◽  
Yun-Peng Bai ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Pore Volume ◽  
Dimethyl Sulfide ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Copper Cation ◽  
Liquid Hydrocarbon ◽  
Activated Bentonite ◽  
Better Than

AbstractSamples of activated bentonite and activated bentonite modified with CuCl and CuCl2, separately, were tested as dimethyl sulfide (DMS) adsorbents. The adsorption and desorption behaviours of DMS on the adsorbents were studied systematically. The adsorbents were characterised by nitrogen adsorption, XRD, and DMS-TPD tests. The addition of CuCl and CuCl2 to the activated carbon significantly enhanced the adsorption capacity of DMS, despite a notable decrease in the specific surface area and total pore volume of the activated bentonite. It is presumed that copper cation species may act as an adsorption site for DMS. The adsorption capacity of Cu(II)-bentonite was better than that of Cu(I)-bentonite. The DMS-TPD patterns indicate that the stronger electrophilicity of Cu(II) compared to that of Cu(I) caused it to interact with the DMS molecules more strongly, thus contributing to a better adsorptive performance. The Cu(II)-bentonite calcined at 150°C had the best DMS removal performance with a high sulphur capacity of 70.56 mg S g−1 adsorbent. The DMS removal performance became much lower with the increase in the calcination temperature, which appeared to be due to the decrease in the CuCl2·2H2O phase and the formation of the monoclinic Cu(OH)Cl phase.

scholarly journals Effect of the temperature in adsorption phenomena of water onto Sub-Bituminous coal

2016 ◽  
pp. 57-64
Author(s):  
Esteban Alberto Taborda Acevedo ◽  
William Jurado ◽  
Farid B. Cortés
Keyword(s):  
Bituminous Coal ◽  
Water Adsorption ◽  
Adsorption Process ◽  
Nitrogen Adsorption ◽  
Ft Ir ◽  
Industrial Use ◽  
The Mean ◽  
Technological Challenge ◽  
Adsorption Phenomena ◽  
Ft Ir Spectroscopy

The presence of water in coal presents a technological challenge for its industrial use in energetic processes. Therefore, this study aims to study the temperature effect on the water adsorption onto coals at 21, 30, 40 and 50°C. A Colombian bituminous coal was used as sample. The coal was characterized by nitrogen adsorption at 77 K (SBET), Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, elemental analysis (C-H-N elemental). The results showed that the water uptake increased as the vapor pressure increased. The Talu and Meunier model [1] was used to fit the adsorption isotherms, and the mean square root error (MSRE%) was lower than 10%. Additionally, the Gibbs free energy was found to have negative values, which corroborates the spontaneous adsorption process.

scholarly journals Study of sepiolite from Goles (Kosovo, Yugoslavia). II. Acid activation

2002 ◽  
Vol 67 (7) ◽  
pp. 499-506 ◽  
Author(s):  
Marina Radojevic ◽  
Vidojko Jovic ◽  
Dragomir Karaulic ◽  
Dragomir Vitorovic
Keyword(s):  
Specific Surface ◽  
Chemical Treatment ◽  
Acid Treatment ◽  
Nitrogen Adsorption ◽  
Adsorption Properties ◽  
Acid Activation ◽  
Surface Areas ◽  
Bet Method ◽  
Specific Surface Areas ◽  
Enhanced Adsorption

The changes in the pore structure and adsorption properties of sepiolite from Goles resulting from treatment with 4MHCl for various periods of time were investigated. The BET method specific surface areas, pore volumes and f ? plots were determined by nitrogen adsorption. The surface area progressively increased during the 70 hours of acid treatment, when a maximum was attained. The differences in the adsorption properties of the original and the acid treated sepiolite were evaluated by comparison of adsorption isotherms obtained with benzene, n-hexane, methanol and isooctane. The enhanced adsorption of isooctane was of great interest, since the sorption of this compound on natural sepiolites is generally very limited. The results suggest that chemical treatment of sepiolite with 4MHCl for 70 h produces an adsorbent of optimal porosity and other adsorption properties.

scholarly journals Tryptophan Requirement in School-Age Children Determined by the Indicator Amino Acid Oxidation Method is Similar to Current Recommendations

2019 ◽  
Vol 149 (2) ◽  
pp. 280-285 ◽  
Author(s):  
Abeer Al-mokbel ◽  
Glenda Courtney-Martin ◽  
Rajavel Elango ◽  
Ronald O Ball ◽  
Paul B Pencharz ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protein Intake ◽  
School Age Children ◽  
Acid Mixture ◽  
Acid Oxidation ◽  
School Age ◽  
Mixed Effect ◽  
Effect Change ◽  
Amino Acid Oxidation ◽  
The Mean

ABSTRACT Background The requirement for dietary tryptophan in school-age children has never been empirically derived. Objective The objective of our study was to determine the tryptophan requirement of school-age children using the indicator amino acid oxidation technique. Methods Volunteer healthy school-age children, between 8 and 12 y, were enrolled and the oxidation of l-[13C]-phenylalanine to 13CO2 measured in response to graded intakes of dietary tryptophan. Seven children (3 boys, 4 girls) participated in the study and received randomly assigned tryptophan intakes ranging from 0.5 to 9.75 mg.kg-1.d-1 for a total of 36 studies. The diets provided energy at 1.5 times each subject's resting energy expenditure and were isocaloric. Protein was provided as an amino acid mixture on the basis of the egg protein pattern, and phenylalanine and tyrosine were maintained constant across the protein intake concentrations at 25 and 40 mg.kg−1.d−1. All subjects were adapted for 2 d before the study day to a protein intake of 1.5 g.kg−1.d−1. The mean tryptophan requirement was determined by applying a mixed-effect change-point regression analysis to F13CO2 (label tracer oxidation in 13CO2 breath) which identified a breakpoint in the F13CO2 in response to graded amounts of tryptophan. Results The mean [estimated average requirement (EAR)] and upper 95% CI, (approximating the RDA) of tryptophan requirements were estimated to be 4.7 and 6.1 mg.kg−1.d−1, respectively. Conclusion Our results are similar to the current recommended EAR and RDA of 5 and 6 mg.kg−1.d−1 for healthy growing children based on the factorial calculation. Clinical Trials Registration No. NCT02018588.

scholarly journals 26. The flux of meteors and micrometeoroids in the neighborhood of the earth

1968 ◽  
Vol 33 ◽  
pp. 280-287 ◽  
Author(s):  
C. S. Nilsson ◽  
R. B. Southworth
Keyword(s):  
Detection System ◽  
Mass Range ◽  
Automatic Equipment ◽  
Correct Operation ◽  
Calculated Mass ◽  
Average Flux ◽  
The Mean ◽  
Particle Velocities ◽  
One Year ◽  
Image Position

1. Radio meteor rates for a calculated mass range 10−6 gm to 10−4 gm have been recorded semi-continuously at Havana, Ill., since July 1965. Automatic equipment samples the rate at four different levels of sensitivity each half hour. A flux vs. mass power law has been derived from these data for each of a number of different weeks of observation. Between September 1965 and December 1966 the mean cumulative influx I of meteors/m2/sec/2π ster can best be described by the equation: where m is the lower mass limit in grams.2. A micrometeoroid detection system, which hopefully was to have measured particle velocities and directions of arrival for masses greater than 10−12 gm, has been flown on the OGO-II satellite. A comprehensive in-flight calibration system has confirmed the correct operation of the experiment for more than one year in space. 700 hours of data have been analyzed and no micrometeoroid events have been observed. This excludes several hundred spurious events from the microphone sensors. The effective detection area of the instrument is 0·8 cm2 ster. Thus, to a probability of 0·86, the average flux of particles of mass greater than 10−12 gm must be less than 6 × 10−2 particles/m2/sec/2π ster.

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