Experimental and Mathematical Optimization of the β-Sitosterol extraction from Mechanically Activated Pine Bark

The optimization of the process of β-sitosterol extraction from the original and activated with two different methods (drum mill, explosive autohydrolysis) pine bark was carried out. The effect of the duration of the extraction process and the concentration of NaOH in the saponification solution on the yield of β-sitosterol was explored. The concentration of NaOH in the saponification solution appeared to have the highest effect on the β-sitosterol yields from activated pine bark. Mechanical activation of pine bark significantly increased the yield of β-sitosterol and reduced the duration of the isolation process. The highest yield of β-sitosterol was achieved with the use of pine bark activated by explosive autohydrolysis. According to the proposed mathematical model, the maximum predicted value of the β-sitosterol yield from this sample is 0.078 (wt%). This could be achieved using the process duration 10.3 hours and a 0.5 N solution of NaOH. This yield is close to the content of β-sitosterol in the original pine bark

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Simulation of fuel bed ignition by wildland firebrands

International Journal of Wildland Fire ◽

10.1071/wf17083 ◽

2018 ◽

Vol 27 (8) ◽

pp. 550 ◽

Cited By ~ 3

Author(s):

O. V. Matvienko ◽

D. P. Kasymov ◽

A. I. Filkov ◽

O. I. Daneyko ◽

D. A. Gorbatov

Keyword(s):

Mathematical Model ◽

Pinus Sylvestris ◽

Mathematical Modelling ◽

Thermal Energy ◽

Ignition Time ◽

Pine Bark ◽

Bark Sample ◽

Airflow Velocity ◽

Experimental Conditions ◽

Series Of Experiments

A 3-D mathematical model of fuel bed (FB) ignition initiated by glowing firebrands originating during wildland fires is proposed. In order to test and verify the model, a series of experiments was conducted to determine the FB ignition time by a single pine bark and twig firebrand (Pinus sylvestris). Irrespective of the pine bark sample sizes and experimental conditions, the ignition of the FB was not observed. Conversely, pine twigs, under certain parameters, ignited the FB in the range of densities (60–105 kg m−3) and with the airflow velocity of ≥2 m s−1. The results of the mathematical modelling have shown that a single pine bark firebrand ≤5 cm long with a temperature of T ≤ 1073 K does not ignite in the flaming mode the FB, and only the thermal energy of larger particles is sufficient for flaming ignition of the adjacent layers of the FB. The analysis of the results has shown that the firebrand length is a major factor in the initiation of ignition. Comparison of the calculated and observed FB ignition times by a single firebrand have shown that our modelling accords well with the experimental results.

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Effect of Extraction Solvent on Tannin-Formaldehyde Adhesives for Plywood Production

Journal of Energy and Natural Resource Management ◽

10.26796/jenrm.v1i0.27 ◽

2018 ◽

Vol 1 (2) ◽

pp. 120-126 ◽

Cited By ~ 2

Author(s):

N.S.A. Derkyi

Keyword(s):

Aqueous Ethanol ◽

Sugar Content ◽

Extraction Process ◽

Poor Quality ◽

Pine Bark ◽

Formaldehyde Resin ◽

Extraction Solvent ◽

High Sugar Content ◽

Very High

Pine bark is a good source of natural polyphenolic compounds for wood adhesives. The objective of this study was to obtainthe most suitable solvent for extracting pine tannins in the preparation of tannin-formaldehyde plywood adhesives. Aqueousacetone, aqueous ethanol, aqueous NaOH and water as solvents were used to obtain crude tannins from pine bark. Thetannin content, sugar content and Stiasny number of the extracts were determined. Using the extracts from the solventextractions, synthesis of tannin-formaldehyde resin was carried out. Plywood panels were made using the synthesized resinsand the quality of the resins in plywood application determined. The quality of tannin-formaldehyde resins produced from thetannins were generally in close agreement with the chemical characteristics of the extracts obtained from the various solventextractions. The aqueous NaOH extraction although gave very high tannin yield (16.1%), its associated high sugar content(33.8%) and very low Stiasny number (49) resulted in poor quality resin. Similarly, although aqueous extraction gave a veryhigh Stiasny number (91), its low tannin yield (8.7%) might not be of commercial interest. The extraction process that gave ahigh tannin yield (12.9%) and a very good Stiasny number (81.5) with a corresponding good quality resin (shear strength =1.9 MPa, 22% delamination) was found for 60% aqueous ethanol extraction.

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USE OF MECHANICAL ACTIVATION OF POLYVINYL CHLORIDE IN THE PRODUCTION OF TENT MATERIALS

АГРАРНЫЙ ВЕСТНИК ВЕРХНЕВОЛЖЬЯ ◽

10.35523/2307-5872-2019-28-3-83-88 ◽

2019 ◽

Keyword(s):

Mathematical Model ◽

Mechanical Activation ◽

Polyvinyl Chloride ◽

Raw Materials ◽

Viscosity Change ◽

Number Of Factors ◽

Conformational Transformations ◽

Minimum Number ◽

Number Of Treatment

Physical and mechanical characteristics of tent materials depend on the quality of raw materials, which varies depending on its mechanical processing. A mathematical model of the process of dispersed materials activation is proposed, which describes the kinetics of change both during processing and dur-ing the further storage of the product of one or a number of factors characterizing physicochemical prop-erties of the material. The process of mechanical activation and verification of the adequacy of mathe-matical model proposed was carried out on emulsion polyvinyl chloride in a disintegrator unit. When processing PVC-E in a disintegrator, physicochemical processes take place, leading both to an increase and to a decrease in the viscosity of PVC-E solutions. The processes of dehydrochlorination breaking molecules, lead to a decrease in viscosity, and the formation of organic acids and copolymers - to in-crease. And these processes are irreversible. Conformational transformations of macromolecules con-tribute to the growth of viscosity of PVC-E solutions and are reversible. The adequacy of the proposed mathematical model describing the process of mechanical activation of dispersed materials is shown on the example of viscosity change of PVC-E solutions. Calculations show that increasing the loading speed, it is possible to maximize viscosity of PVC-E solutions in the minimum number of treatment cycles. If the number of processing cycles is more than one, then the rate of each subsequent loading should increase. The use of PVC-E, treated once in a disintegrator at a speed of 140 m / s, allows increasing physical and mechanical parameters of tent materials.

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MODELING OF COMPETITIVE HORTICULTURAL INNOVATIVE ENTERPRISES

Ukrainian Journal of Applied Economics ◽

10.36887/2415-8453-2019-4-21 ◽

2019 ◽

Vol 4 (4) ◽

pp. 183-190

Author(s):

Oleksandr YERMAKOV ◽

Lyudmila SLYEPTSOVA

Keyword(s):

Mathematical Model ◽

High Efficiency ◽

Mathematical Optimization ◽

Production Optimization ◽

Research Station ◽

Innovative Development ◽

Foreign Markets ◽

Economic Entity ◽

Proposed Model ◽

Berry Crops

The article is devoted to organizational and economic aspects of the creation and functioning of horticultural innovation-oriented enterprises and substantiates scientific approaches to the development of such production and economic structures. The objective of every economic entity in the competitive economy is to maximize the profit that may be achieved not only by producing fruitful products, but by its successful sale in certain terms and markets. This is primarily due to the fact that, under market conditions for horticultural enterprises, agrobiological potential is already insufficient to effectively grow fruit and berry crops. Therefore, innovation’s activity and its results are a prerequisite for successful management of the horticulture industry in Ukraine, namely: the transition to models of horticultural innovation-oriented enterprises which will be able to ensure the competitiveness of grown fruit products in both its domestic and foreign markets. The object of the investigations was the process of innovative development of horticultural enterprises and the construction of an economic and mathematical model of optimization of pome fruits (apples) sales – the basis of the industry in most regions of Ukraine. On the research basis of organizational and economic features of innovative development in the article the economic-mathematical optimization model of production and sale (apples) in a horticultural innovation-oriented enterprise is grounded. This is the experimental farm of the Podilsky Horticultural Research Station as a testing ground for innovative developments in fruitful production. Optimization of the structure of production and sales of products on the basis of the proposed model in this horticultural enterprise allows to significantly increase the profitability of growing apple’s orchards (from 0.9 million to 35.4 million UAH). Due to its high efficiency, this innovative project can be extended to other horticultural enterprises of Ukraine, in particular in the Podillya. Keywords: simulation, competitiveness, innovative development, horticultural enterprises, economic and mathematical model, realization, maximum profit, optimization, innovation-oriented enterprises.

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A multi-factorial mathematical model for the selection of electropolishing parameters with a view to reducing the environmental impact

Scientific Reports ◽

10.1038/s41598-021-88731-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Paweł Lochyński ◽

Sylwia Charazińska ◽

Maciej Karczewski ◽

Edyta Łyczkowska-Widłak

Keyword(s):

Mathematical Model ◽

Weight Loss ◽

Stainless Steel ◽

Current Density ◽

Quality Parameters ◽

Important Goal ◽

Process Duration ◽

Metal Processing ◽

Selection Of

AbstractElectrochemical metal processing is a process that generates harmful pollution. An important goal often disregarded by researchers is not only the achievement of the best possible quality of electropolished surface, but also minimising the load of metal ions in the wastewater generated in the process. The conducted experiments on the electropolishing of stainless steel in laboratory conditions, varied time, temperature and current density conditions, as well as process bath contamination (ranging from 0 to 6% Fe mass) allowed us to develop a multi-factorial mathematical model. This model offers the possibility of being able to select the process parameters recommended for achieving the desired effects. It takes into account such surface quality parameters as roughness and gloss, process duration and current density that determine power consumption, as well as the weight loss of the electropolished element that influence the rate of contamination in processing baths and wastewater. The study presents the composition of a passive film of stainless steel after the electropolishing process at the initial and final stages of the process bath’s exploitation. The results obtained from XPS tests were then correlated with the results of corrosion tests and resistance to pitting corrosion in the environment of 0.1 M NaCl.

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OPTIMIZATION TECHNIQUE FOR MANPOWER TRAINING IN TECHNICAL COLLEGE

International Journal of Students Research in Technology & Management ◽

10.18510/ijsrtm.2020.824 ◽

2020 ◽

Vol 8 (2) ◽

pp. 21-24

Author(s):

Manoj Kumar Mandal ◽

Arun Prasad Burnwal ◽

Avinash Kumar

Keyword(s):

Mathematical Model ◽

Technical College ◽

Optimization Technique ◽

Mathematical Formulation ◽

Mathematical Optimization ◽

Sample Problem ◽

Technical Institute ◽

Engineering Department ◽

Optimal Values ◽

Modern Era

Purpose: In the modern era, the number of technical colleges increases rapidly due to the huge growth of the students. But the number of teachers is less compare to the number of students. So, there is a need for optimization of manpower in the institutes. Methodology: In this paper, mathematical optimization is used with the help of linear programming by using permanent, contractual, and adjunct faculties with the help of three objectives for the engineering department, general department, and non-teaching staffs. Main Finding: Finally, the outcome of the paper is different optimal values for three stated objectives. Implication: The proposed method is the mathematical formulation of the optimization in a technical institute. The novelty of Study: This paper deals with a mathematical model of manpower problem. A sample problem has solved to illustrate the procedure.

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Mathematical model of steel consumption minimization considering the two-stage billets cutting

Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu ◽

10.33271/nvngu/2021-2/118 ◽

2021 ◽

pp. 118-124

Author(s):

V.V Hnatushenko ◽

T.A Zheldak ◽

L.S Koriashkina

Keyword(s):

Mathematical Model ◽

Mathematical Optimization ◽

Optimal Size ◽

Multi Stage ◽

Distribution Process ◽

Steel Consumption ◽

Rolling Production ◽

Mathematical Optimization Model ◽

The Moment ◽

Cutting Plan

Purpose. To achieve a decrease in energy and resource costs in the multi-stage production of rolled products within a given plan through the development of appropriate mathware. Methodology. The multi-stage problem mathware for producing rolling steel products is developed on the basis of system approach applying fundamental principles of the optimization and operation research theory. Realization of the developed mathematical model allows discovering such a strategy of using steel during the whole manufacturing process, which minimizes not only the steel waste at the moment of its casting in a mold, but also the offcuts in the process of cutting the obtained ingots into the billets. Findings. A mathematical task model is built to minimize the amount of steel for producing a certain order of size of one cast volume only. The developed model specifies the possibility to pre-evaluate the billet optimal size, based on the necessary cutting along the final product length, appropriate for the certain billet form of section, and ingot weight limits. Originality. A mathematical model is provided for the optimal metal distribution process when implementing the plan of manufacturing rolling products. The model, in contrast to the existing ones, shifts the emphasis on forming the optimal ingot weight, which has a pre-calculated optimal cutting plan. Practical value. The use of the developed mathematical optimization model (minimizing the amount of steel for producing a certain order) as part of an automated decision support system for management of rolling production will reduce the number of cutting machine changeover and minimize resources use and stock balance.

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STUDY ON MATHEMATICAL MODEL IN SIMULATING CYMBOPOGON WINTERIANUS ESSENTIAL OIL EXTRACTION BY STEAM DISTILLATION

Journal of Applied Science & Process Engineering ◽

10.33736/jaspe.170.2016 ◽

1970 ◽

Vol 3 (1) ◽

Author(s):

Nik ‘Amirah Farhana Nik Ahmad Lutfi ◽

Mohd Farid Atan ◽

Nazeri Abdul Rahman ◽

Shanti Faridah Salleh ◽

Noraziah Abdul Wahab

Keyword(s):

Mathematical Model ◽

Essential Oil ◽

Steam Distillation ◽

Maximum Yield ◽

Process Variable ◽

Extraction Process ◽

Oil Extraction ◽

Raw Material ◽

Extraction Time ◽

Cymbopogon Winterianus

The main objective of this study is to improve the mathematical modelling of Cymbopogon winterianus essential oil extraction by steam distillation proposed by Cassel and Vargas by minimum 5% error reduction. Two process variable of steam distillation which are extraction time and raw material state (dry or natural) has been optimized by using factorial experimental planning to obtain high yields of citronella essential oil from twig and leaves of lemongrass species Cymbopogon winterianus (C.winterianus). The optimal condition for maximum yield (0.942%) were found to be an extraction time, 4 hr, state, natural plant. The study of Cassel and Vargas was subsequently continued with five proposed kinetics model of the extraction process. The modelling of the extraction process is optimized by using one adjustable parameter of the model and the adequacy of the fit of the models to the experimental data are analyzed by using three statistical criteria that are correlation coefficient (r) ,the root mean square error (RMSE) and the mean relative deviation modulus (E). The result has shown that the mathematical model developed by Ana based on mass transfer fundamentals is the optimum mathematical model for the extraction of Cymbopogon winterianus essential oil by steam distillation.

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