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1

Reducing Tannery Wastewater Pollutants through a Magnetic-Field and Ozone-Treatment Electrocoagulation System using Response Surface Methodology

Aguilar Ascon Edwar, Marrufo Saldaña Liliana, Neyra Ascón Walter

Journal of Ecological Engineering

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2024

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Vol. 25, nr 1

74--83

EN

This study assessed the effectiveness of integrating electrocoagulation, magnetic fields, and ozonation technologies to remove chemical oxygen demand (COD) and total suspended solids (TSS) from tannery wastewater. Furthermore, the effects of their key operating factors were determined. To achieve this goal, an electrocoagulation reactor coupled with a magnetic-field generator was used and the response surface methodology was applied through a Box-Behnken experimental design. Here, current intensity (I), treatment time (T), and ozone concentration (O3) are considered the influencing factors. Likewise, the removal percentages of COD and TSS serve as response indicators. The results indicate that T, I, and O3 are significant for the removal of COD and TSS at a confidence level of p-value < 0.05. For COD, the optimal operating conditions are I = 6.8 A, T = 30 min, and O3 = 10 mg/l; and for TSS, the optimal conditions are I = 5.72 A, T = 28 min, and O3 = 7.8 mg/l. These conditions yield removal efficiencies of 41.8% for COD and 97.9% for TSS. The findings suggest that integrating these technologies is a viable alternative for mitigating the pollution issues caused by the tannery industry.

2

Desulfurization of Crude Oil by Laboratory Developed Multipumping Flow Injection Analysis System with Optimization by Response Surface Methodology

Hadi Ahmed Abdulrazzaq, Ali Ali Abdulkhabeer, Khathi Mohammed Turki

Journal of Ecological Engineering

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2023

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Vol. 24, nr 2

328--339

EN

Sour crude oil is the crude oil that contains a high level of sulfur impurity. It can be toxic and corrosive. Before this lower-quality crude can be processed into other crude oil derivatives, the sulfur content must be reduced, raising the processing cost. A homemade semi-automated multipumping flow analysis system was constructed, consisting of several parts available on the local markets and at low economic costs to decrease the sulfur content of crude oil samples collected. The central composite design (CCD) and response surface methodology (RSM) have been used for modeling and optimization. The effects of the operational parameters, including polar and nonpolar solvent types, solvent flow rates (10–40 ml/min), mixing coil lengths (120–200 min), temperature (30–60 °C), and solvent entry time to the system (0–60 sec) were studied. Experimental and theoretical applications were made to determine the optimal sulfur content, which came out to be 1.438 and 1.395 wt.%, respectively. This system evaluated the effectiveness of the sulfur removal content for actual heavy crude oil by experimentally and theoretically to be 65.73 and 66.75% respectively. The semi-automated system was applied successfully to reduce the sulfur content in a highly sensitive and accurate way.

3

Granular computational homogenisation of composite structures with imprecise parameters

Beluch W., Hatłas M., Ptaszny J.

Archives of Mechanics

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2023

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Vol. 75, nr 3

271--300

EN

The paper presents the formulation of a granular computational homogenisation problem and the proposition of a method to solve it, which enables multiscale analysis of materials with uncertain microstructure parameters. The material parameters and the geometry, represented by the interval and fuzzy numbers, are assumed to be unprecise. An _-cut representation of fuzzy numbers allows the use of interval arithmetic for epistemic uncertainties. Directed interval arithmetic is used to reduce the effect of interval widening during arithmetic operations. Response surfaces of diverse types, including Artificial Neural Networks, are used as model reduction methods. The finite element method is employed to solve the boundary value problem on a micro scale. Numerical examples are provided to demonstrate the effectiveness of the proposed approach.

4

Effect of rise in temperature (250°C) on the physico-mechanical properties of rubber mortars

Assia Aidoud, Messaouda Boutahir Born Bencheikh, Salima Boukour, Ouassila Bahloul

Advances in Materials Science

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2023

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Vol. 23, nr 3(77)

47--60

EN

The recovery and use of waste in the field of civil engineering, particularly in construction materials, is one of the most prominent solutions for preserving the environment. In order to evaluate the results obtained, it is necessary to study the evolution of the properties of these new materials in the different environments where they can live or be exposed, and why not develop an effective method of treatment of such materials for the possibility of their use even in the field of precast concrete.The objective of this work is to study the effect of the increase in temperature as a living environment or as a treatment on the physico-mechanical properties of a crumbled mortar, a potential source of many environmental and economic problems.Hence the screening and the possibility of using these new mortars with sufficient physico-mechanical properties for masonry and why not for prefabrication.The formulation of the mixturesbased on the substitution of dune sand by crumb rubber, at different weight contents 10, 20 and 30%. Consequently, prismatic specimens (4x4x16) cm3subjected to the temperature (250°C), with a speed of 2°C/min followed by a one-hour plateau at the target temperature then cooling to the ambient temperature.The results obtained show that the maximum mass loss is 5% for 30% substitution and that for 10% substitution the absorption by total immersion decreased by more than two thirds and the porosity accessible to water decreased by more than half. The compressive strength increases by 8.9% for 10% substitution and the minimum decrease in tensile strength by bending is at the same substitution of an order of 26.9%.Using the analysis of variance, the influence of the substitution of dune sand by rubber crumbs and of the rise in temperature to 250°C on the behavior of the mortar acquired. Patterns developed by response surface methodology were significant for all p-value substitutions <5%. The results of the numerical optimization showed that the best mixture couldobtained by replacing 30% of dune sand with rubber crumb and subjecting the hardened mortar obtained from this mixture to the temperature of 135°C.

5

Practical guidelines for predicting the proper conditions of high-energy mixing in a planetary ball mill towards powder flow improvement

Leś Karolina M., Opaliński Ireneusz

Chemical and Process Engineering

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2022

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Vol. 43, nr 3

419-–433

EN

In this work Response Surface Methodology and Central Composite Rotatable Design were applied to find high-energy mixing process parameters enabling flow properties of highly cohesive Disulfiram powder to be improved. Experiments were conducted in a planetary ball mill. The response functions were created for an angle of repose and compressibility index as measures of powder flowability. To accomplish an optimisation procedure of mixing process parameters according to a desirability function approach, the results obtained earlier for potato starch, as another cohesive coarse powder, were also employed. Coupling these results with those achieved in a previous work, it was possible to develop some guidelines of practical importance allowing mixing conditions to be predicted towards flow improvement of fine and coarse powders.

6

Optimization of oil extraction process from blended sludge and algae for biodiesel production

Abdissa Desalegn

Production Engineering Archives

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2021

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Vol. 27, Iss. 3

203--211

EN

Sewage sludge is one of the most polluting wastes that affect the environment, which contains organic and inorganic pollutants released into the surroundings. Using non-renewable energy for the engine also releases large amounts of pollutants results from combustion products was other issues to the environment. The decline of non-renewable energy sources, such as natural gas, fossil fuel, and petroleum made the world increase the production of alternative fuels like waste-derived fuels. Recently, biodiesel production developed from edible oil to cover the depilation of non-renewable energy supply. But it has also become a significant challenge for food security. Therefore, finding other potential opportunities for lipid extraction is crucial. Algae and sludge conversion presented by recent studies seem to be a promising method. The paper presents the extraction and optimization of lipids from blended sludge and algae for biodiesel production. The procedure of the study was a characterization of algal and sludge wastes, the extraction of the lipid component by Soxhlet extraction, and the parameters optimization for maximum oil yield obtain. Temperature, extraction time, and solvents were the basic factor affect oil extraction yield. In the optimization 80 temperature, 6hrs time and hexane solvent results in 61% oil extraction yield which maximum point. Algae and wastewater sludge high potential of lipid and can be substitute edible oil supplies for biodiesel production.

7

Optimization of cutting parameters on surface roughness and productivity when milling wood materials

Loc Nguyen Huu, Hung Trinh Quoc

Journal of Machine Engineering

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2021

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Vol. 21, No. 4

72--89

EN

The quality of the machined surface is one of the most important criteria when products are processed. For different materials, there are differentially fitting processing technologies and cutting modes to ensure that the parts have surface roughness in the allowed value range. In this paper, the research on surface roughness of machining tropical wood by milling method is presented. It is necessary to establish and solve the optimal problems with such aims as the highest surface quality, minimum cutting power and the highest productivity in the optimal cutting mode. Using a great amount of experimental planning and many constrained nonlinear optimization problem solving methods, the authors built a process and solved the problem to determine the optimal cutting parameters such as feed per tooth Sz, tool tip radius ρ, depth of cut h, etc. that satisfy the above object. Research object is tropical wood chukrasia and this is the database to design woodworking machines by milling method and choose a reasonable working mode when processing on CNC machines.

8

An approach towards parametric optimization of construction frames for Cartesian industrial robots

Gwardecki Filip, Falkowski Piotr

Journal of Automation Mobile Robotics and Intelligent Systems

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2021

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Vol. 15, No. 3

15--28

EN

The paper presents an approach to parametric optimization with response surface methodology. This process was performed based on the design of a construction frame for a Cartesian industrial robot. The presented installation is dedicated to the real industrial pick‐and place application. Firstly, the case study was described with relevant information about the components invol‐ ved. Then, the finite element model with constraints and loads, as well as the settings of the response surface op‐ timization were discussed. The simulation was presented to the reader within all the stages with necessary details. Into consideration were taken six methods of creating response surfaces. Influence on the final optimization result and prediction accuracy of each one was presented. In the end, to validate the outcomes of the process, the static structural analysis of the setup was computed. The paper compares the impact of applying different methods of response surface generation on the results of parametric optimization. Moreover, it indicates the most vulnerable fragments of dynamically loaded elements made of construction profiles. Its results may be used to select appropriate settings in similar applications, mainly for frame structures.

9

Investigation of filtration capacity of surface wastewater filters by mathematical modelling

Marčiulaitienė Eglė, Meškauskaitė Laura, Pozniak Natalija, Sakalauskas Leonidas

Ecological Chemistry and Engineering. S

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2020

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Vol. 27, nr 2

241--255

EN

As the urbanisation level increases, due to intensification of car traffic and increased areas of impermeable surfaces, pollution of surface wastewater and a negative impact on water bodies are increasing. Due to the increasing pollution of surface water bodies, the eutrophication process is taking place intensively. One of the technologies of surface wastewater treatment allowing reduction in the amounts of suspended solids (SS), heavy metals and other pollutants is surface wastewater filters. Filters with different fillers have been designed for the treatment of principal surface wastewater pollutants: suspended solids, heavy metals (zinc, cadmium, copper, lead), BOD5, total carbon and nitrogen. The Kriging method was adapted to test the efficiency of filters filled with construction waste and wood waste-derived biochar using distance matrices. The method developed makes it possible to model the characteristics of filters in relation to different fillers, using experimental results. The mathematical model is suitable for other filtrate characteristics, not only the ratio of fillers, but also the length of the filter life, its durability calculations, which allows optimizing filter cleaning efficiency up to 96.93 %.

10

Reduction of Total Chromium Levels from Raw Tannery Wastewater via Electrocoagulation using Response Surface Methodology

Aguilar-Ascón Edwar, Marrufo-Saldaña Liliana, Neyra-Ascón Walter

Journal of Ecological Engineering

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2019

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Vol. 20, nr 11

217--224

EN

This study focused on reducing total chromium levels in raw wastewater from the leather tanning industry via electrocoagulation to comply with maximum permissible limits (MPL) and to determine the effects of main process parameters. An electrocoagulation reactor was built using aluminum electrodes as an anode and cathode. Then, the response surface methodology was applied using a 3k factorial design considering three factors, namely current intensity, treatment time, and pH. The total chromium removal percentage was considered as a response variable. 99% of the total chromium found in wastewater could be removed after 14-min treatment at 2-A current intensity and pH 5.5. Similar amount of chromium was removed at pH of 8.5 and 7. Statistical analysis performed at a confidence level of p < 0.05 revealed that all three factors influenced electrocoagulation. Total chromium could be efficiently removed from raw wastewater at a current intensity of 2.9 A, a pH of 8.4, and a treatment time of 21 min, suggesting that electrocoagulation using aluminum electrodes is an efficient method for total chromium removal. Thus, this process must be considered as a solution to the problems caused by the leather tanning industry and for better compliance with the MPL established in the Peruvian environmental standards.

11

Response surfaces in the numerical homogenization of non-linear porous materials

Beluch Witold, Hatłas Marcin

Engineering Transactions

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2019

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Vol. 67, iss. 2

213--226

EN

The paper deals with the numerical homogenization of structures made of non-linear porous material. Material non-linearity causes a significant increase in computational costs for numerical homogenization procedure. An application of the response surface methodology allows a significant reduction of the computational effort providing good approximation precision. Finite element method commercial software is employed to solve the boundary-value problem in both scales. Due to the significant reduction in computing time, the proposed attitude may be applied for different optimization and identification tasks for inhomogeneous, non-linear media, especially with the use of global optimization methods.

12

The use of mathematical experiments planning in building materials quality research

Dvorkin Leonid, Prokopski Grzegorz, Marchuk Vitaliy, Huts Andriy

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2019

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z. 66, nr 4

5--16

EN

The issue of ensuring the construction of materials and products, necessary quality characteristics and durability, is associated with the solution of many problems arising both in the construction industry enterprises and in the conditions of a construction site. Most of these (construction-technological) problems are solved due to the rational choice of raw materials, changes in the ratio between the main components, as well as production modes. The method of solving such problems assumes simultaneous consideration of many factors (composition, consumption of components, formation conditions, hardening, etc.) and providing many parameters (workability, strength, frost resistance, water resistance, etc.), which in practice is difficult to implement by traditional methods of experimentation because of high labor intensity of the work and the need for complex analysis. The article considers using methods of system analysis and mathematical planning of experiments in the study of building materials quality. Methods of obtaining mathematical models of various types, their interpretation and analysis, as well as the basic principles of using system analysis for solving the problems of building materials technology are presented. The technique of mathematical planning of experiments is presented. The main types of tasks solved with this method are analyzed, optimization criteria for solving problems of concrete technology are formulated. Methods for constructing linear and nonlinear models, their statistical analysis, and typical plans for carrying out experiments are presented.

13

Case study about economic order quantities and comparison of results from conventional EOQ model and response surface-based approach

Yıldız R., Yaman R.

Management and Production Engineering Review

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2018

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Vol. 9, No. 3

23--32

EN

This study involves the implementation of an economic order quantity (EOQ) model which is an inventory control method in a ceramic factory. Two different methods were applied for the calculation of EOQs. The first method is to determine EOQ values using a response surface method-based approach (RSM). The second method uses conventional EOQ calculations. To produce a ceramic product, 281 different and additive materials may be used. First, Pareto (ABC) analysis was performed to determine which of the materials have higher priority. Because of this analysis, the value of 21 items among 281 different materials and additives were compared to the ratio of the total product. The ratio was found to be 70.4% so calculations were made for 21 items. Usage value for every single item for the years 2011, 2012, 2013 and 2014, respectively, were obtained from the company records. Eight different demand forecasting methods were applied to find the amount of the demand in EOQ. As a result of forecasting, the EOQ of the items were calculated by establishing a model. Also, EOQ and RSM calculations for the items were made and both calculation results were compared to each other. Considering the obtained results, it is understood that RSM can be used in EOQ calculations rather than the conventional EOQ model. Also, there are big differences between the EOQ values which were implemented by the company and the values calculated. Because of this work, the RSM-based EOQ approach can be used to decide on the EOQ calculations as a way of improving the system performance.

14

Analysis and synthesis of complex spatial thin-walled structures

Marchenko A., Chepurnoy A., Sen'ko V., Makeev S., Litvinenko O., Sheychenko R., Graborov R., Tkachuk M., Bondarenko M.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2017

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z. 1/110

17--29

EN

The new approach to solve the problems of analysis and synthesis of complex spatial thin-walled structures is proposed. It is based on generalized parametric modeling of complex mechanical systems. Generalized parameters are structure, design and technological solutions for the structures, design parameters and operating conditions. Beside the solution of problems of a single analysis, and multivariate studies, and studies of rational design and technological solutions are provided. In addition, it is possible to justify parameters of finite element models for accurate calculation of stress-strain state by the finite element method. Also, it becomes possible to model boundary conditions and loading effort, not only for one, but for a number of similar designs. As the result a tool for quick and accurate solutions of totality of tasks justification of design solutions for complex spatial thin-walled structures by strength and stiffness criteria is created.

PL

Zaproponowano nowe podejście do rozwiązania problemów analizy i syntezy skomplikowanych przestrzennych i cienkościennych struktur. Jest on oparty na uogólnionym parametrycznym modelowaniu złożonych układów mechanicznych. Parametry są uogólnione budową, konstrukcją i rozwiązaniem technologicznym dla struktury, parametrów konstrukcyjnych i warunków pracy. Oprócz rozwiązania problemów pojedynczej analizy oraz badań i analiz wielowymiarowych, prezentowane są racjonalne projekty i rozwiązania technologiczne. Ponadto istnieje możliwość uzasadnienia parametrów modeli elementów skończonych dla dokładnego obliczenia stanu rozciągania metodą elementów skończonych. Ponadto istnieje możliwość modelowania warunków brzegowych i wysiłku załadunków, nie tylko dla jednego, ale dla wielu podobnych wzorów. W rezultacie powstaje narzędzie do szybkich i dokładnych rozwiązań całości zadań uzasadniających rozwiązania projektowe dla złożonych przestrzennych cienkościennych konstrukcji według kryteriów wytrzymałości i sztywności.

15

Effect of lubricant contamination on EHL rolling contact: response surface methodology

Maatallah S., Saric M. R., Khochemane L.

Engineering Transactions

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2016

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Vol. 64, iss. 1

69--88

EN

In this research the failure of EHL rolling contact in highly contaminated media is investigated. The conducted study uses an original experimental device to predict the effects of operating parameters, namely, surface hardness, contaminant concentration, rotational velocity, and the applied load on wear and roughness components. The planning of the experiments was based on Taguchi’s L9 orthogonal array. The statistical significance of the above mentioned parameters on the results was explored using the analysis of variance (ANOVA). The relationship between responses’ factors and the operating parameters is also established employing the multiple linear regression method. ANOVA results show clearly that the surface hardness (H) and contaminant concentration (C) are the most significant factors that influence wear and surface roughness of machine elements.

16

The soft rock socketed monopile with creep effects – a reliability approach based on wavelet neural networks

Kozubal J., Tomanovic Z., Zivaljevic S.

Archives of Mining Sciences

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2016

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Vol. 61, no. 3

571--585

EN

In the present study the numerical model of the pile embedded in marl described by a time dependent model, based on laboratory tests, is proposed. The solutions complement the state of knowledge of the monopile loaded by horizontal force in its head with respect to its random variability values in time function. The investigated reliability problem is defined by the union of failure events defined by the excessive horizontal maximal displacement of the pile head in each periods of loads. Abaqus has been used for modeling of the presented task with a two layered viscoplastic model for marl. The mechanical parameters for both parts of model: plastic and rheological were calibrated based on the creep laboratory test results. The important aspect of the problem is reliability analysis of a monopile in complex environment under random sequences of loads which help understanding the role of viscosity in nature of rock basis constructions. Due to the lack of analytical solutions the computations were done by the method of response surface in conjunction with wavelet neural network as a method recommended for time sequences process and description of nonlinear phenomenon.

PL

W niniejszym studium zaprezentowany jest problem pojedynczego pala osadzonego w miękkiej skale, zastosowano wiskoplastyczny model materiału bazujący na wynikach badań laboratoryjnych zespołu z Uniwersytetu Montenegro. Rozwiązanie uzupełnia stan wiedzy dla pali obciążonych poziomą siłą w głowicy zmienną w sposób losowy w czasie. Badany problem niezawodności został określony przez sumę zdarzeń – awarii – zdefiniowanych jako przekroczenie maksymalnie dopuszczalnego poziomego przemieszczenia głowicy pala niezależnie w wszystkich stanach obciążenia. Zastosowano program metody elementów skończonych, ABAQUS, do budowy trójwymiarowego modelu z dwuwarstwowym wiskoplastycznym modelem dla margla. Parametry mechaniczne modelu zarówno w części plastycznej i reologicznej zostały skalibrowane na podstawie wyników badań laboratoryjnych wykonanych na przestrzeni ostatnich czterech lat na próbkach z jednorodnego złoża margla w Montenegro. Ważnym aspektem problemu jest analiza niezawodności pojedynczego pala dla złożonego mechanicznie środowiska w ramach sekwencji losowych obciążeń. Przedstawione zadanie pozwala dostrzec istotę lepkiej części modelu. Ze względu na brak rozwiązań analitycznych oraz długotrwałość procesu obliczeniowego obliczenia niezawodnościowe przeprowadzono metodą powierzchni odpowiedzi bazując na sieciach falkowo-neuronowych. Sieć poprzez nadanie jej struktury rejestru została dostosowana do opisu procesu o nieliniowym charakterze zjawiska i dla obciążeń zmiennych w czasie.

17

Strukturalna optymalizacja wektorowa narzędzia robota medycznego z wykorzystaniem metody elementów skończonych

Ilewicz G., Nawrat Z.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

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2016

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Vol. 22, nr 4

234--244

PL

Praca przybliża analizy strukturalne z wykorzystaniem algorytmu metody elementów skończonych, która a priori daje prawidłowe wyniki dla układów o skomplikowanej geometrii, dla której trudno jest uzyskać rozwiązanie analityczne lub dla której przeprowadzenie testów fizycznych jest utrudnione. Eksperymenty numeryczne zostały przeprowadzone dla narzędzia robota kardiochirurgicznego Robin Heart 1, który został przetestowany podczas operacji na zwierzętach. W artykule pokazano wyniki analizy deformacji, częstotliwości drgań własnych oraz optymalizację wektorową mającą na celu określenie ekstremum w oparciu o algorytm genetyczny. Wykorzystano również metodę powierzchni odpowiedzi, globalny front Pareto i metodę elementów skończonych. Zaprezentowany model optymalizacji wielokryteralnej umożliwia uzyskiwanie struktury o minimalnej masie i maksymalnej sztywności oraz odstrajanie układu od częstotliwości bliskich rezonansowym. Przy minimalnym wzroście masy, co skutkuje minimalizacją amplitudy drgań podczas ruchu narzędzia. Celem pracy jest wyjaśnienie zjawiska rezonansu dla wyznaczonych częstotliwości drgań własnych narzędzia do serwisowania sztucznego narządu i wektorów własnych, które przedstawiają kształty deformacji przy pojawieniu się tego negatywnego zjawiska.

EN

The work explains structural analysis using algorithm of finite element method, which gives a priori correct results for systems with complicate geometry for which it is difficult to obtain analytical solution or when conducting physical tests is hampered. Numerical experiments were performed for endoscopic tool of cardiosurgical robot Robin Heart 1, which was tested during the operating experiment on animals. The article shows the results of the analysis of deformation, natural frequency of vibrations, and vectorial optimization aiming at calculations of extremum on the basis of genetic algorithm. Response surface method, global Pareto front, and finite element method were also used. The presented model of vectorial optimization allows to obtain the structure with minimal mass and maximal stiffness and tuning away from frequency that are close to resonant frequency. At minimum mass increase which results in minimizing the amplitude of vibration during movement of the tool. The aim of the work is also to explain of the phenomenon of resonance for the designated vibration natural frequencies of the tool for servicing an artificial organ and eigenvectors which show shapes of deformation as a result of this negative phenomenon.

18

Effect of Weave Structure on Thermo-Physiological Properties of Cotton Fabrics

Ahmad S., Ahmad F., Afzal A., Rasheed R., Mohsin M., Ahmad N.

Autex Research Journal

|

2015

|

Vol. 15, no. 1

30--34

EN

This paper aims to investigate the relationship between fabric weave structure and its comfort properties. The two basic weave structures and four derivatives for each selected weave structure were studied. Comfort properties, porosity, air permeability and thermal resistance of all the fabric samples were determined. In our research the 1/1 plain weave structure showed the highest thermal resistance making it suitable for cold climatic conditions. The 2/2 matt weave depicted the lowest thermal resistance which makes it appropriate for hot climatic conditions.

19

Wpływ warunków ogrzewania roztworów koncentratu soku z buraka ćwikłowego na parametry barwy i zawartość barwników betalainowych

Gościnna K., Walkowiak-Tomczak D., Czapski J.

Aparatura Badawcza i Dydaktyczna

|

2014

|

T. 19, nr 2

183-189

PL

Celem pracy było określenie wpływu ogrzewania roztworów koncentratu soku z buraka ćwikłowego rozcieńczonego do zawartości ekstraktu 14%, na zmiany parametrów barwy i barwników betalainowych. Zmiany te badano w zależności od pH roztworu, czasu i temperatury ogrzewania. Badania przeprowadzono z zastosowaniem metody płaszczyzn odpowiedzi wykorzystując układ doświadczalny Box-Behnkena. W czasie ogrzewania następowała degradacja fioletowych barwników betalainowych, tym większa, im dłuższy był czas i temperatura ogrzewania. Na zawartość żółtych barwników betalainowych największy wpływ miało pH. Największą stabilność barwników betalainowych stwierdzono w próbach o pH 4,5. Wartości składowych barwy X, Y, Z wzrastały w czasie ogrzewania, co związane jest ze spadkiem zawartości barwników fioletowych. Parametr L* określający jasność, a* określający udział barwy czerwonej oraz parametr b* określający udział barwy żółtej wzrastały w czasie ogrzewania. Największy wpływ na zmianę tych wyróżników miał czas ogrzewania, a najmniejszy wpływ miało pH. Wartość tonu barwy h* wzrastała w czasie ogrzewania, co wskazuje na zmianę barwy w kierunku żółtej.

EN

The aim of this study was to determine the changes of colour parameters and betalain pigments contents in solutions of red beet juice concentrate (14% extract) during heating in dependence on pH, time and temperature of heating. Analyses were conducted in model systems using the response surface method according to Box-Behnken design. During heating of solutions, violet betalain contents decreased with an increase in time and temperature of heating. The pH value had the greatest effect on yellow betalain pigment contents. The highest stability of betalains was determined in pH 4,5. Values of the X, Y and Z components increased during heating, what was associated with decreasing of violet pigment contents. Lightness of colour L*, the share of the red colour a* and share of the yellow colour b* increased during heating. The time of heating had the greatest effect on these responses, the effect of pH value was relatively small. Values of hue angle h* increased, what indicate a change in colour tone towards yellow.

20

Zmiany aktywności przeciwutleniającej, zawartości barwników betalainowych i polifenoli w roztworach koncentratu soku z buraka ćwikłowego podczas ogrzewania

Gościnna K., Czapski J., Walkowiak-Tomczak D.

Aparatura Badawcza i Dydaktyczna

|

2013

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T. 18, nr 4

373-379

PL

Celem badań było określenie wpływu czasu, temperatury i pH roztworów koncentratu z soku buraka ćwikłowego rozcieńczonego do zawartości ekstraktu 14% na zmiany zawartości barwników betalainowych, polifenoli i aktywności przeciwutleniającej. Doświadczenie zaplanowano z zastosowaniem metody płaszczyzn odpowiedzi, w układzie doświadczalnym Box-Behnkena przy trzech poziomach zmiennych niezależnych: temperatury ogrzewania (70-90°C), czasu ogrzewania (0-120 min) i wartości pH (3-6). Największą stabilność barwników stwierdzono w próbach o pH 4,5. Istotny wpływ na zmianę zawartości barwników, na podstawie współczynników równań płaszczyzn odpowiedzi, miała temperatura i czas ogrzewania oraz interakcje między nimi. Temperatura i czas ogrzewania nie miały istotnego wpływu na zawartość polifenoli. Istotny był natomiast wpływ pH. Zaobserwowano wysoką korelację pomiędzy zawartością barwników betalainowych, a zdolnością przeciwutleniającą badanych prób. Największy wpływ na zdolność przeciwutleniającą miała temperatura ogrzewania. Dla większości zmiennych zależnych uzyskano dobre dopasowanie dla płaszczyzn drugiego stopnia. Metoda płaszczyzn odpowiedzi w badanym zakresie czynników doświadczalnych umożliwia dobre przewidywanie zmian zawartości związków biologicznie aktywnych oraz zdolności przeciwutleniającej w roztworach koncentratu soku z buraka ćwikłowego, w zależności od warunków ogrzewania.

EN

The aim of this study was to determine the effect of temperature, time and pH values on changes in betalain and polyphenol contents and antioxidant capacity in solutions (14% extract) of red beet juice concentrate during heating. Analyses were conducted in model systems with the use of response surface methodology, according to the Box-Behnken design for three independent variables: temperature (70-90°C), time (0-120 min) and pH (3-6). The highest stability of betalain pigments was determined in pH 4,5. The time and temperature of heating and interactions between them had the greatest effect on betalain pigments. pH value had the greatest effect on polyphenol contents, while temperature and time of heating had no significant effect on them. The temperature of heating had the strongest effect on antioxidant capacity. The pigment contents was significantly correlated with antioxidant capacity. The goodness of fit for quadratic equations was obtained for the most responses. Within the tested range of experimental factors the response surface method makes it possible to predict changes in bioactive compound contents and antioxidant activity, dependent on heating conditions.