scholarly journals Adsorption of cellulases onto sugar beet shreds and modeling of the experimental data

2014 ◽  
pp. 119-128
Author(s):  
Darjana Ivetic ◽  
Radovan Omorjan ◽  
Mirjana Antov
Keyword(s):  
Experimental Data ◽  
Sugar Beet ◽  
Langmuir Model ◽  
Steam Pretreatment ◽  
Dilute Acid ◽  
Adsorption Parameters ◽  
Adsorption Models ◽  
Adsorbed Proteins ◽  
Process Productivity

This study investigated the adsorption of cellulases onto sugar beet shreds. The experiments were carried out using untreated, as well as dried and not dried dilute acid and steam pretreated sugar beet shreds at different initial enzyme loads. Both dilute acid and steam pretreatment were beneficial in respect of cellulases adsorption providing 8 and 9 times higher amounts of adsorbed proteins, respectively, in comparison to the results obtained with the untreated substrate. Although the use of higher solids load enabled by drying of pretreated substrates, could be beneficial for process productivity, at the same time it decreases the adsorption of enzymes. The obtained experimental data were fitted to five adsorption models, and the Langmuir model having the lowest residual sum of squares was used for the determination of adsorption parameters which were used to calculate the strength of cellulases binding to the substrates.

Studi Komparasi Model Langmuir, Freundlich dan Emzha untuk Biosorpsi Beberapa Ion Logam

2019 ◽  
Vol 4 (2) ◽  
pp. 141
Author(s):  
Rahmiana Zein ◽  
Zulfi Zulfi ◽  
Riza Nurafni
Keyword(s):  
Experimental Data ◽  
Metal Ions ◽  
Research Method ◽  
Langmuir Model ◽  
Coefficient Of Determination ◽  
Original Form ◽  
Adsorption Model ◽  
Average Coefficient ◽  
Two Stages

<p><em>Telah dilakukan studi komparasi untuk menguji keandalan model EMZHA dibandingkan model Langmuir dan Freunlich dalam penyerapan ion logam Cu(II), Cd(II) dan Pb(II) oleh beberapa biosorben. Model EMZHA adalah model adsorbsi baru yang diusulkan oleh peneliti Indonesia sebagai upaya mendapatkan model yang lebih bersifat universal (berlaku untuk semua tipe data) sehingga dapat digunakan untuk mengungkap mekanisme adsorbsi secara lebih lengkap dan mendasar. Model Langmuir dan Freunlich dipillih sebagai pembanding karena kedua model ini paling banyak digunakan dan memiliki karakter yang cenderung berlawanan. Penelitian ini digunakan data ekperimen dalam bentuk aslinya,  tidak diubah kedalam bentuk linier terlebih dahulu, dengan tujuan untuk menghindari error yang timbul akibat proses linierisasi. Regresi yang digunakan adalah regresi non linier. Metode penelitian ini dibagi dalam dua tahapan yaitu tahap pengumpulan data eksperimen yang berasal dari berbagai penelitian adsorbsi ion logam berat oleh berbagai biosorben dan pengolahan data komparasi model. Pengusul model EMZHA telah melaporkan keandalan prediksi model ini untuk penyerapan beberapa ion logam tapi hanya menggunakan satu jenis biosorben, yaitu kulit buah atap, sedangkan penelitian ini menggunakan 11 biosorben yang berbeda. Pada penelitian ini berhasil dibuktikan bahwa model EMZHA memiliki koefisien determinasi rata-rata 0,9034 yang lebih tinggi dari rata-rata koefisien determinasi model Langmuir (0,8485) dan Freundlich (0,8483).</em></p><p><em><br /></em></p><p><em><em>Comparative studies have been conducted to test the reliability of the EMZHA model compared to the Langmuir and Freunlich models in the absorption of Cu (II), Cd (II) and Pb (II) metal ions by several biosorbents. The EMZHA model is a new adsorption model proposed by Indonesian researchers in an effort to obtain a more universal model (applicable to all types of data) so that it can be used to uncover the mechanism of adsorption more fully and fundamentally. Langmuir and Freunlich's models are chosen as a comparison because these two models are the most widely used and have opposing characters. This study used experimental data in its original form, not converted into linear form first, with the aim of avoiding errors arising from the linearization process. The regression used is non linear regression. This research method is divided into two stages, namely the stage of collecting experimental data derived from various studies of adsorption of heavy metal ions by various biosorbents and the processing of comparative data models. Proponents of the EMZHA model have reported the reliability of the prediction of this model for the absorption of several metal ions but only use one type of biosorbent, namely the skin of the roof, while this study uses 11 different biosorbents. In this study successfully proved that the EMZHA model has an average determination coefficient of 0.9034 which is higher than the average coefficient of determination of the Langmuir model (0.8485) and Freundlich (0.8483).</em></em></p>

scholarly journals Inhibition of Aluminium Corrosion in 1.0 M HCl by Caffeine: Experimental and DFT Studies

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
R. H. B. Beda ◽  
P. M. Niamien ◽  
E. B. Avo Bilé ◽  
A. Trokourey
Keyword(s):  
Experimental Data ◽  
Hydrochloric Acid ◽  
Quantum Chemical ◽  
Inhibition Efficiency ◽  
Langmuir Model ◽  
Dft Studies ◽  
Metal Dissolution ◽  
Adsorption Model ◽  
Adsorption Parameters ◽  
Insight Into

Aluminium corrosion inhibition in 1.0 M hydrochloric acid solution by caffeine has been studied using mass loss technique and quantum chemical calculations based on DFT. The inhibition efficiency was found to increase with increasing concentration of caffeine but decreases with a rise in temperature. The molecule shows the highest inhibition efficiency of 74% at 10−2 M for T=303 K. The experimental data were used to fit isotherms including Langmuir, Temkin, Freundlich, and El-Awady. The best fits were obtained with the Langmuir model and the kinetic-thermodynamic adsorption model of El-Awady. However, it was found that the adsorption parameters suit well with the isotherm of El-Awady which was chosen as the appropriate isotherm. To distinguish between physisorption and chemisorption, the Dubinin-Radushkevich adsorption model was used. The thermodynamic parameters governing the adsorption of caffeine onto aluminium and that of the metal dissolution were calculated and discussed. DFT study gave further insight into the mechanism of the inhibiting action of caffeine.

Method development for the determination of textural properties of sugar beet roots

2019 ◽  
pp. 392-400 ◽  
Author(s):  
Gunnar Kleuker ◽  
Christa M. Hoffmann
Keyword(s):  
Sugar Beet ◽  
Compression Test ◽  
Storage Period ◽  
Textural Properties ◽  
Small Sample ◽  
Root Tip ◽  
Flexural Test ◽  
Sample Distribution ◽  
The Impact

The harvest of sugar beet leads to root tip breakage and surface damage through mechanical impacts, which increase storage losses. For the determination of textural properties of sugar beet roots with a texture analyzer a reliable method description is missing. This study aimed to evaluate the impact of washing, soil tare, storage period from washing until measurement, sample distribution and number of roots on puncture and compression measurements. For this purpose, in 2017 comprehensive tests were conducted with sugar beet roots grown in a greenhouse. In a second step these tests were carried out with different Beta varieties from a field trial, and in addition, a flexural test was included. Results show that the storage period after washing and the sample distribution had an influence on the puncture and compression strength. It is suggested to wash the roots by hand before the measurement and to determine the strength no later than 48 h after washing. For reliable and comparable results a radial distribution of measurement points around the widest circumference of the root is recommended for the puncture test. The sample position of the compression test had an influence on the compressive strength and therefore, needs to be clearly defined. For the puncture and the compression test it was possible to achieve stable results with a small sample size, but with increasing heterogeneity of the plant stand a higher number of roots is required. The flexural test showed a high variability and is, therefore, not recommended for the analysis of sugar beet textural properties.

Determination of microbiological activity during the processing of frost damaged sugar beets

2014 ◽  
pp. 228-231 ◽  
Author(s):  
Maciej Wojtczak ◽  
Aneta Antczak-Chrobot ◽  
Edyta Chmal-Fudali ◽  
Agnieszka Papiewska
Keyword(s):  
Sugar Beet ◽  
Microbiological Activity ◽  
Microbiological Contamination ◽  
Sugar Beets ◽  
Bacterial Metabolites ◽  
Kinetics Of

The aim of the study is to evaluate the kinetics of the synthesis of dextran and other bacterial metabolites as markers of microbiological contamination of sugar beet.

Equilibrium Sorptions in Heterogeneous Ion Exchange Membranes

1992 ◽  
Vol 57 (9) ◽  
pp. 1905-1914
Author(s):  
Miroslav Bleha ◽  
Věra Šumberová
Keyword(s):  
Experimental Data ◽  
Ion Exchange ◽  
Total Content ◽  
Distribution Coefficients ◽  
Exchange Capacity ◽  
Ion Exchange Membranes ◽  
Ion Exchange Capacity ◽  
Equilibrium Sorption ◽  
Inhomogeneity Factor

The equilibrium sorption of uni-univalent electrolytes (NaCl, KCl) in heterogeneous cation exchange membranes with various contents of the ion exchange component and in ion exchange membranes Ralex was investigated. Using experimental data which express the concentration dependence of equilibrium sorption, validity of the Donnan relation for the systems under investigation was tested and values of the Glueckauf inhomogeneity factor for Ralex membranes were determined. Determination of the equilibrium sorption allows the effect of the total content of internal water and of the ion-exchange capacity on the distribution coefficients of the electrolyte to be determined.

Numerical evaluation of hydrodynamic characteristics of planing hulls by using a hybrid method

2021 ◽  
pp. 147509022199024
Author(s):  
Emre Kahramanoglu ◽  
Silvia Pennino ◽  
Huseyin Yilmaz
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Design Stage ◽  
Hydrodynamic Characteristics ◽  
Calm Water ◽  
Preliminary Design Stage ◽  
Reduction Function ◽  
Hull Forms ◽  
Good Agreement

The hydrodynamic characteristics of the planing hulls in particular at the planing regime are completely different from the conventional hull forms and the determination of these characteristics is more complicated. In the present study, calm water hydrodynamic characteristics of planing hulls are investigated using a hybrid method. The hybrid method combines the dynamic trim and sinkage from the Zarnick approach with the Savitsky method in order to calculate the total resistance of the planing hull. Since the obtained dynamic trim and sinkage values by using the original Zarnick approach are not in good agreement with experimental data, an improvement is applied to the hybrid method using a reduction function proposed by Garme. The numerical results obtained by the hybrid and improved hybrid method are compared with each other and available experimental data. The results indicate that the improved hybrid method gives better results compared to the hybrid method, especially for the dynamic trim and resistance. Although the results have some discrepancies with experimental data in terms of resistance, trim and sinkage, the improved hybrid method becomes appealing particularly for the preliminary design stage of the planing hulls.

A Technique for the Laboratory Determination of Recirculation in Single Needle Dialysis

1993 ◽  
Vol 16 (2) ◽  
pp. 63-70 ◽  
Author(s):  
N.A. Hoenich ◽  
P.T. Smirthwaite ◽  
C. Woffindin ◽  
P. Lancaster ◽  
T.H. Frost ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Experimental Results ◽  
New Technique ◽  
Treatment Efficiency ◽  
Single Lumen ◽  
Theoretical Predictions ◽  
Lumen Catheter ◽  
A New Technique

Recirculation is an important factor in single needle dialysis and, if high, can compromise treatment efficiency. To provide information regarding recirculation characteristics of access devices used in single needle dialysis, we have developed a new technique to characterise recirculation and have used this to measure the recirculation of a Terumo 15G fistula needle and a VasCath SC2300 single lumen catheter. The experimentally obtained results agreed well with those established clinically (8.5 ± 2.4% and 18.4 ± 3.4%). The experimental results have also demonstrated a dependence on access type, pump speeds and fistula flow rate. A comparison of experimental data with theoretical predictions showed that the latter exceeded those measured with the largest contribution being due to the experimental fistula.

The determination of betaine in sugar beet by-products

The Analyst ◽  
1936 ◽  
Vol 61 (729) ◽  
pp. 829 ◽  
Author(s):  
J. W. Blood ◽  
H. T. Cranfield
Keyword(s):  
Sugar Beet ◽  
By Products

Theoretical determination of the structures of CaSiO3 perovskites

2006 ◽  
Vol 62 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
Razvan Caracas ◽  
Renata M. Wentzcovitch
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Determination ◽  
Functional Theory ◽  
Starting Point ◽  
Atomic Coordinates ◽  
The Ideal

Density functional theory is used to determine the possible crystal structure of the CaSiO3 perovskites and their evolution under pressure. The ideal cubic perovskite is considered as a starting point for studying several possible lower-symmetry distorted structures. The theoretical lattice parameters and the atomic coordinates for all the structures are determined, and the results are discussed with respect to experimental data.

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