scholarly journals Optimasi Proses Ozonasi pada Depolimerisasi κ-Karagenan dengan Metode Respon Permukaan

REAKTOR ◽  
2017 ◽  
Vol 17 (1) ◽  
pp. 1
Author(s):  
Aji Prasetyaningrum ◽  
Ratnawati Ratnawati ◽  
Bakti Jos
Keyword(s):  
Experimental Data ◽  
Molecular Weight ◽  
Optimum Parameter ◽  
Ozone Treatment ◽  
Operating Parameters ◽  
Distilled Water ◽  
Optimum Conditions ◽  
Ozonation Time ◽  
Abstract Optimization ◽  
Ozonation Process

Abstract OPTIMIZATION OF OZONATION PROCESS FOR κ-CARRAGEENAN DEPOLYMERIZATION USING RESPONSE SURFACE METHODOLOGY. The objective of this research is to optimize the operating parameters in depolymerization of κ-carrageenan by ozone treatment. The optimization is done by using Box-Bhenken Design (BBD) model with ozonation time (5-15 minute), pH (3-11) and temperature (20-40oC) as the independent variables.The response of ozonation process is the degree of depolymerization of κ-carrageenan (DP). The initial molecular weight of refined κ-karagenan was 271 kDa. The κ-carrageenans powder was completely dissolved in distilled water to form 1% (weight/volume). The experiments were carried out in a 2000 ml of a glass reactor with an ozone gas sparger. The inlet ozone concentration was 80±2 ppm. The result shows that ozonation time, pH and temperature have significant effects during ozonation process (p< 0.05). Analysis of variance shows that the experimental data fit the model very well with the R2 value of 0.98. The optimum conditions during ozonation process are achieved at the reaction time of 15 min, ozonation pH of 3 and reaction temperature of 25oC. Under these optimum conditions the DP of κ-carrageenan is 91.513%. Keywords: depolymerization; κ-carrageenan;optimization; ozonation process   Abstrak Tujuan penelitian ini adalah menentukan kondisi optimum parameter operasi depolimerisasi κ-karagenan dengan perlakuan ozonasi. Optimasi dilakukan dengan menggunakan model statistika Box-Bhenken Design (BBD) dengan variabel yang digunakan yaitu waktu ozonasi (5-15 menit), pH (3-11), dan suhu (20-40oC). Respon dari proses ozonasi adalah derajat depolimerisasi κ-karagenan (DP). Berat molekul awal refined κ-karagenan adalah 271 kDa. Sampel κ-karagenan dilarutkan secara sempurna dalam air distilasi dan konsentrasi diatur 1% (berat/volume). Percobaan dilakukan dalam reaktor gelas volume 2000 ml yang dilengkapi dengan sparger gas ozon. Konsentrasi gas ozon yang masuk adalah 80±2 ppm. Hasil penelitian menunjukkan bahwa waktu ozonasi, pH, dan suhu berpengaruh secara signifikan terhadap proses ozonasi (p<0,05). Analisis varian menghasilkan ketelitian yang tinggi antara data eksperimen dan prediksi, dengan nilai koefisien R2 = 0,98. Kondisi optimum diperoleh pada waktu ozonasi 15 menit, pH ozonasi 3 dan temperatur reaksi 25oC. Pada kondisi optimum ini diperoleh DP κ-karagenan sebesar 91,513%. Kata kunci:depolimerisasi; κ-carrageenan;optimasi; proses ozonasi 

scholarly journals Assessment of coagulation pretreatment of leachate by response surface methodology

2017 ◽  
Vol 76 (9) ◽  
pp. 2321-2327 ◽  
Author(s):  
Ridha Lessoued ◽  
Fatiha Souahi ◽  
Leonor Castrillon Pelaez
Keyword(s):  
Experimental Data ◽  
Response Surface ◽  
Simple Technique ◽  
Operating Parameters ◽  
Optimum Conditions ◽  
Turbidity Removal ◽  
Surface Method ◽  
Model Predictions ◽  
Initial Ph ◽  
Central Composite

Abstract Coagulation-flocculation is a relatively simple technique that can be used successfully for the treatment of old leachate by poly-aluminum chloride (PAC). The main objectives of this study are to design the experiments, build models and optimize the operating parameters, dosage m and pH, using the central composite design and response surface method. Developed for chemical organic matter (COD) and turbidity responses, the quadratic polynomial model is suitable for prediction within the range of simulated variables as it showed that the optimum conditions were m of 5.55 g/L at pH 7.05, with a determination coefficient R² at 99.33%, 99.92% and adjusted R² at 98.85% and 99.86% for both COD and turbidity. We confirm that the initial pH and PAC dosage have significant effects on COD and turbidity removal. The experimental data and model predictions agreed well and the removal efficiency of COD, turbidity, Fe, Pb and Cu reached respectively 61%, 96.4%, 97.1%, 99% and 100%.

Reconstruction of Two-Dimensional Projections of GP 32*I

1981 ◽  
Vol 39 ◽  
pp. 38-39
Author(s):  
H.A. Cohen ◽  
W. Chiu ◽  
J. Hosoda
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Uranyl Acetate ◽  
Distilled Water ◽  
Acetate Solution ◽  
Two Dimensional ◽  
Parent Molecule ◽  
T4 Bacteriophage ◽  
Electron Imaging ◽  
Better Than

GP 32 (molecular weight 35000) is a T4 bacteriophage protein that destabilizes the DNA helix. The fragment GP32*I (77% of the total weight), which destabilizes helices better than does the parent molecule, crystallizes as platelets thin enough for electron diffraction and electron imaging. In this paper we discuss the structure of this protein as revealed in images reconstructed from stained and unstained crystals.Crystals were prepared as previously described. Crystals for electron microscopy were pelleted from the buffer suspension, washed in distilled water, and resuspended in 1% glucose. Two lambda droplets were placed on grids over freshly evaporated carbon, allowed to sit for five minutes, and then were drained. Stained crystals were prepared the same way, except that prior to draining the droplet, two lambda of aqueous 1% uranyl acetate solution were applied for 20 seconds. Micrographs were produced using less than 2 e/Å2 for unstained crystals or less than 8 e/Å2 for stained crystals.

scholarly journals Effect of Ozone Treatment on the Quality of Sea Buckthorn (Hippophae rhamnoides L.)

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 847
Author(s):  
Anita Zapałowska ◽  
Natalia Matłok ◽  
Miłosz Zardzewiały ◽  
Tomasz Piechowiak ◽  
Maciej Balawejder
Keyword(s):  
Mechanical Properties ◽  
Volatile Compounds ◽  
Sea Buckthorn ◽  
Hippophae Rhamnoides ◽  
Ozone Treatment ◽  
Aerobic Bacteria ◽  
Hippophaë Rhamnoides ◽  
Hippophae Rhamnoïdes L ◽  
Ozonation Process

The aim of this research was to show the effect of the ozonation process on the quality of sea buckthorn (Hippophae rhamnoides L.). The quality of the ozonated berries of sea buckthorn was assessed. Prior to and after the ozone treatment, a number of parameters, including the mechanical properties, moisture content, microbial load, content of bioactive compounds, and composition of volatile compounds, were determined. The influence of the ozonation process on the composition of volatile compounds and mechanical properties was demonstrated. The ozonation had negligible impact on the weight and moisture of the samples immediately following the treatment. Significant differences in water content were recorded after 7 days of storage. It was shown that the highest dose of ozone (concentration and process time) amounting to 100 ppm for 30 min significantly reduced the water loss. The microbiological analyses showed the effect of ozone on the total count of aerobic bacteria, yeast, and mold. The applied process conditions resulted in the reduction of the number of aerobic bacteria colonies by 3 log cfu g−1 compared to the control (non-ozonated) sample, whereas the number of yeast and mold colonies decreased by 1 log cfu g−1 after the application of 100 ppm ozone gas for 30 min. As a consequence, ozone treatment enhanced the plant quality and extended plant’s storage life.

Research on Chemical Modification of Wood of Fast-Growing Poplar

2013 ◽  
Vol 749 ◽  
pp. 461-465
Author(s):  
De Jun Shen ◽  
Chang Hai Yu ◽  
Zhen Xing
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Structural Material ◽  
Chemical Modification ◽  
Orthogonal Test ◽  
Low Molecular Weight ◽  
Wood Structure ◽  
Optimum Conditions ◽  
Fast Growing ◽  
Performance Requirements

This topic is considered to modify the fast-growing Poplar to improve the properties, in order to fully meet the performance requirements for the structural material. This study aims to improve the dimensional stability and some other mechanical properties through impregnated with the low-molecular-weight PF resin. Through design orthogonal test in different mole ratio of Formaldehyde and Phenol, different amount of NaOH and PVA, we make PF resin to impregnate Poplar and pressing into laminated timber to measure bonding strength, MOR, MOE. The study indicated that: the optimum conditions of the low molecular weight PF resin for modify Poplar are: mole ratio of Formaldehyde and Phenol is 2.4, mole ratio of NaOH and phenol is 0.05, amount of PVA is 3% of the phenol. Under this condition Poplar specimen got the biggest increase in various properties and it can satisfy the requirements of the outdoor wood structure.

scholarly journals A preliminary study of the degradation of selected commercial packaging materials in compost and aqueous environments

2011 ◽  
Vol 13 (1) ◽  
pp. 55-57 ◽  
Author(s):  
Marta Musioł ◽  
Joanna Rydz ◽  
Wanda Sikorska ◽  
Piotr Rychter ◽  
Marek Kowalczuk
Keyword(s):  
Molecular Weight ◽  
Weight Loss ◽  
Terephthalic Acid ◽  
Packaging Materials ◽  
Distilled Water ◽  
Abiotic Degradation ◽  
Aqueous Environments ◽  
Preliminary Study ◽  
Industrial Composting ◽  
Surface Changes

A preliminary study of the degradation of selected commercial packaging materials in compost and aqueous environmentsThe paper presents the results of the degradation of two commercial packaging materials CONS-PET and BioPlaneta in the compost and distilled water at 70°C. The materials containing polylactide (PLA), CONS-PET 13% and BioPlaneta 20%, aliphatic-aromatic copolyester terephthalic acid/adipic acid/1,4-butanediol (BTA) and commercial additives degraded under the industrial composting conditions (composting pile or container) and in distilled water at 70°C in the laboratory holding oven. Distilled water provided the conditions for the hydrolytic (abiotic) degradation of the materials. Weight loss, changes of molecular weight, dispersity monitored via the GPC technique and the macroscopic surface changes of the tested materials were monitored during the experiments. The investigated systems show similar trends of degradation, however on the last day of the incubation the decrease of the molecular weight was higher in water than under the industrial composting conditions. The results indicate that commercial packaging materials can be degraded both while composting ((bio)degradation) and during the incubation in distilled water at 70°C (abiotic hydrolysis).

Decolorization of Reactive Black 5 using Peroxymonosulfate in Fentonlike Process

2013 ◽  
Vol 16 (2) ◽  
Author(s):  
Gülin Ersöz ◽  
Süheyda Atalay
Keyword(s):  
Advanced Oxidation Processes ◽  
Catalytic Effect ◽  
Industrial Effluents ◽  
Operating Parameters ◽  
Reactive Black 5 ◽  
Process Performance ◽  
Optimum Conditions ◽  
Oxidation Processes ◽  
Wide Availability ◽  
Initial Ph

AbstractOne of the advanced oxidation processes, the Oxone process, was studied to determine its effects on the decolorization of Reactive Black 5 (RB5) in an aqueous solution. Ferrous ion was chosen as the transition metal due to its potential catalytic effect and wide availability in dye containing industrial effluents. The effects of the operating parameters such as Fe(II) and Oxone concentration, initial pH, and temperature on the process performance were investigated. The optimum conditions were determined as: 0.5 mM of Oxone concentration, 0.5 mM of Fe

scholarly journals DEVELOPMENT AND TESTING OF ALGORITHM FOR CALCULATION OF OPERATING PARAMETERS OF TRAWLING SYSTEMS

2019 ◽  
Vol 198 ◽  
pp. 221-229 ◽  
Author(s):  
E. A. Zakharov ◽  
O. N. Kruchinin ◽  
D. L. Shabelsky
Keyword(s):  
Experimental Data ◽  
Visual Basic ◽  
Educational Process ◽  
Resistance Force ◽  
Operating Parameters ◽  
Calculation Algorithm ◽  
Model Application ◽  
Bottom Trawling ◽  
Good Convergence ◽  
Expansion Force

Numerical model of trawling system is developed on the base of equilibrium principle, using F.I. Baranov’s scheme of its power and geometric parameters interdependence. The model application to bottom trawling takes into account the effect of bottom grounds on the resistance force and expansion force of the trawling system. Algorithm is proposed for calculation of operating parameters of bottom and midwater trawls, with an operation to minimize the error of iteration. The model and the calculation algorithm were tested in MS Office Excel environment, using Visual Basic programming, and showed good convergence of the calculated and experimental data that indicates reliability of the model. This algorithm and the program for calculation of operating parameters could be used for trawl designing, in accounting surveys to determine the trawl opening, and in educational process for training the industrial fishery scholars.

CATIONIC COPOLYMERIZATION OF ISOBUTYLENE WITH ISOPRENE: KINETICS OF THE PROCESS AND DETERMINATION OF KINETIC CONSTANTS

2015 ◽  
Vol 88 (4) ◽  
pp. 574-583 ◽  
Author(s):  
N. V. Ulitin ◽  
K. A. Tereshchenco ◽  
D. A. Shiyan ◽  
G. E. Zaikov
Keyword(s):  
Experimental Data ◽  
Molecular Weight ◽  
Cationic Polymerization ◽  
Methyl Chloride ◽  
Theoretical Description ◽  
Kinetic Constants ◽  
Molecular Weight Characteristics ◽  
Cationic Copolymerization ◽  
Kinetics Of

ABSTRACT A theoretical description has been developed of the kinetics of isobutylene with isoprene (IIR) cationic polymerization in the environment of methyl chloride on aluminum trichloride as the catalyst. Based on experimental data on the kinetics of copolymerization (isobutylene conversion curve) and the molecular weight characteristics of the copolymer of IIR, kinetic constants for the process were found. Adequacy of the developed theoretical description of the kinetics of the IIR copolymerization process was confirmed by comparing the experimental molecular-weight characteristics calculated by this description, independent characteristics, and IIR unsaturation.

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