scholarly journals Effects of mixtures containing chlordecone and a dechlorinated by-product on hydra regeneration capacity: use of experimental design to evaluate the toxicity risk associated with remediation programs in long-lasting polluted areas

2022 ◽  
Author(s):  
Xavier Moreau ◽  
Magalie Claeys-Bruno ◽  
Jean-Pascal Andraud ◽  
Hervé Macarie ◽  
Daniel E Martínez ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Experimental Design ◽  
West Indies ◽  
Endocrine Disruptor ◽  
Regeneration Capacity ◽  
Hydra Vulgaris ◽  
Persistent Organochlorine ◽  
Environmental Concentrations ◽  
Erosion Processes ◽  
Toxicity Risk

Abstract Chlordecone (CLD), an obsolete insecticide, used in the French West Indies between 1972 and 1993, is persistent in the environment but can be dechlorinated either chemically or under the action of microorganisms. Therefore, if soil remediation programs based on these processes are implemented in areas still contaminated today, those will see their concentrations of dechlorinated derivatives increase and these compounds will be also found in freshwater by streaming, leaching and erosion processes. The purpose of the present study was to evaluate, at environmental concentrations, the toxic effects of mixtures of chlordecone and a three-chlorine substituted byproduct. A hydra clone, which has been confirmed to be Hydra vulgaris Pallas, 1766 has been retained for bioassays where the toxicity has been evaluated by regeneration capacity during exposure. Exposure to mixtures is complex to investigate by classical methods, therefore, an experimental design associated to a mathematical model has been used to predict the effects of all the mixtures and to detect the toxic influence of each compound. The predictive model is discussed regarding the stochastic “endocrine disruptor effect” of CLD. At probable environmental concentrations of the compounds in the mixture, results show that impairment of regeneration capacity is explained mostly by the presence of CLD in the mixtures and support the implementation of remediation programs aimed at dechlorination of this persistent organochlorine pesticide.

Mathematical modeling of the influence of cutting mode parameters on the quality of machined surfaces from aluminum alloys

2020 ◽  
pp. 55-57
Author(s):  
M.G. Galkin ◽  
A.S. Smagin ◽  
A.S. Pupyireva
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Surface Roughness ◽  
Aluminum Alloys ◽  
Experimental Design ◽  
Manufacturing Process ◽  
Machined Surfaces

An algorithm for the development of a mathematical model of cutting processing, as a multifactorial process, which determines the influence of significant parameters of the cutting mode on the roughness of the processed surface, is proposed. In the development of the algorithm, the method of extreme experimental design is used. Keywords cutting, mode, manufacturing process, surface roughness, mathematical model. [email protected]

The Identification and Decomposition of Hierarchical Tasks

1977 ◽  
Vol 14 (3) ◽  
pp. 189-212 ◽  
Author(s):  
John W. Cotton ◽  
John P. Gallagher ◽  
Sandra P. Marshall
Keyword(s):  
Mathematical Model ◽  
Experimental Design ◽  
Experimental Evidence ◽  
Hierarchical Structure ◽  
Alternate Route ◽  
Component Task ◽  
Two Component ◽  
Hierarchical Ordering ◽  
Definition Of

The definition of hierarchical structure is reviewed, together with psychometric and experimental evidence regarding the existence of specific structures. Exceptions to hierarchical ordering are frequent enough to merit consideration of an assumption that skill on an item may simply transfer to the next higher item rather than being fully prerequisite to it. In some cases an alternate route hierarchy may occur, with persons either learning an item and then the next item or learning both at the same time. A mathematical model including hierarchical and nonhierarchical options fir a two-component task is presented; an experimental design appropriate to testing the model and related transfer hypotheses is also presented.

scholarly journals Catalytic Benzylation of o-Cresol with Benzyl Alcohol: A Mathematical Model

2012 ◽  
Vol 47 (1) ◽  
pp. 137-142
Author(s):  
AA Rana ◽  
M Kamruzzaman ◽  
M Saha
Keyword(s):  
Mathematical Model ◽  
Experimental Design ◽  
Benzyl Alcohol ◽  
Reaction Temperature ◽  
Molar Ratio ◽  
Single Factor ◽  
Suggested Model

Benzylation of o-cresol with benzyl alcohol (Bz-OH) in presence of 94% H2SO4 as catalyst was studied statistically with a two-levels threefactored   experimental design to study the effects of single factor and effects of their interactions on the yield of benzylated product. Reaction   temperature, molar ratio of o-cresol to Bz-OH and amount of 94% H2SO4 were considered as the major variables. A mathematical model   was derived to calculate the predicted yield of benzyl o-cresol as y = 0.419T+12.4055m+16.17w-0.0525Tm-2.606mw-   0.094Tw+0.0175Tmw-6.25; where, T = temperature (oC), m = o-cresol to Bz-OH molar ratio, w = amount of catalyst (% by wt. of o-cresol)   and y = yield. The adequacy of the suggested model was checked up and the discrepancies between the experimental and calculated values   did not exceed ± 0.79%. DOI: http://dx.doi.org/10.3329/bjsir.v47i1.10727 Bangladesh J. Sci. Ind. Res. 47(1), 137-142, 2012

Tribological study of a polymer bushing wear with a steel axle for an automatic car tensioner

2021 ◽  
pp. 135065012110535
Author(s):  
Rafael Rodrigues Fortes ◽  
José Rubens de Camargo ◽  
Giorgio Eugenio Oscare Giacaglia ◽  
Wendell de Queiróz Lamas
Keyword(s):  
Mathematical Model ◽  
Experimental Design ◽  
Transfer Film ◽  
Wear Behaviour ◽  
Factorial Experimental Design ◽  
Tribological Study ◽  
Adhesion Wear ◽  
Report Analysis ◽  
Polyamide Film ◽  
Significant Factors

This paper aims to show through a factorial experimental design significant factors on the polymeric bushing wear PA66, including their amplitude, frequency and spring height, when interacting with a steel axle SAE1018 (from Society of Automotive Engineers - SAE) in a tension belt applied. It was verified that factors as amplitude and frequency are significant and it was possible to propose a mathematical model to predict this wear behaviour for the proposed test. Moreover, an adhesion wear behaviour was verified, whereof a polyamide film was observed on the axle transferred by the bushing. Through the microscopy report analysis, it was possible to see the transfer film topology characterisation for a better comprehension of the adhered polyamide film from the bushing to the axle surface.

Modeling and optimization of sand crushing plant using experimental design methodology

2019 ◽  
Vol 16 (4) ◽  
pp. 487-496
Author(s):  
Djamel Benyessad ◽  
Hamid Arkoub ◽  
Abdelghani Seghir
Keyword(s):  
Mathematical Model ◽  
Experimental Design ◽  
Design Methodology ◽  
Operating Conditions ◽  
Experimental Program ◽  
Operating Parameters ◽  
Content Type ◽  
Modeling And Optimization ◽  
Crushing Plant

Purpose The purpose of this paper is to present results of an experimental program conducted on manufacturing process of crushed sand. The aim of the research is to propose an optimized approach which allows to fix, directly at the process stage, the rate of fines in the produced crushed sand. Design/methodology/approach In the first step of the study, samples of crushed sand are collected in situ, at each adjustment of the identified operating parameters. They are then analyzed in laboratory to retrieve especially the fines contents for each adjustment. These adjustments are conducted for all possible combinations of the extremum operating conditions of the parameters. In the second step of the study, the experimental design technique is applied to study the influence of the different factors, and to model the interaction between them. An expression is obtained and subjected to statistical tests, and then it is confronted to other experimental measures. Findings Parameters influencing the fines rates are identified and their effects are analyzed. The domain of variation of three predominant parameters is defined allowing to conduct in situ experiments with minimal incidence on the manufacturing disturbance. A mathematical model is proposed to quantify the crushed sand fines by analytical expression that takes into account the interaction between influencing parameters. Practical implications The conducted experiments provided new data that will help to enhance and to better set up the settings of the parameters influencing the rate of filler. The proposed expression constitutes a practical tool for the manufacturer to fix the operating parameters values that results in a desired target fines contents. Originality/value Modeling and optimization of the sand crushing plant, considered here as a case study, has not been attempted previously. The conducted experiments and the proposed mathematical model constitute an original work of this study.

scholarly journals Mathematical Model and Experimental Design of Nanocomposite Proximity Sensors

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 153087-153097 ◽  
Author(s):  
Reza Moheimani ◽  
Abdolreza Pasharavesh ◽  
Mangilal Agarwal ◽  
Hamid Dalir
Keyword(s):  
Mathematical Model ◽  
Experimental Design

Modeling and Optimization of Mask Assisted Laser Transmission Micro Joining Process

2014 ◽  
Vol 620 ◽  
pp. 10-16
Author(s):  
Zhen Guan Zhao ◽  
Hui Xia Liu ◽  
Ye Cai ◽  
Yan Wei Wu ◽  
Xiao Wang
Keyword(s):  
Mathematical Model ◽  
Response Surface Methodology ◽  
Experimental Design ◽  
Process Parameters ◽  
Joint Strength ◽  
Slit Width ◽  
Joint Width ◽  
The Mathematical Model ◽  
The Relationship ◽  
Joining Process

This article uses semiconductor laser for mask assisted laser transmission micro joining PET and PET with clear weld absorbents, the mask slit width is 0.3mm, using CCD to plan experimental design. The mathematical model of joining process parameters with joint strength and joint width was established using response surface methodology. Experimental verification was also done. The actual joint width was compared to mask slit width and the process parameters were optimized. The results show that the mathematical model can response the relationship between process parameters and joining quality, the mask can effectively control the joint width, reasonable process parameters can obtain high-precision, high-intensity joining quality.

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