Multidimensional Analysis of Copper Ore Flotation in Terms of Applied Hydrophobizing Agents

Flotation is a method of enrichment used to distribute particles, which differ in their surface properties. Hydrophobic solids intrinsically create contact at the solid-liquid-gas interface. However, not all minerals, including copper minerals, can be characterized by this crucial ability. In that case it is necessary to use the collector reagents which guarantees a high efficiency of the enrichment process. The main aim of the paper was to examine the impact of selected collector types and dosages on the results of Polish sandstone copper ore flotation and to find optimal parameter values for products that meet quality and quantity requirements. The laboratory tests were carried out with an application of two types of collectors (Hostaflot, sodium ethyl xanthate aqueous solution) in dosages 100 and 150 g/Mg. Data analysis was based on the use of the taxonomy methods in order to select optimal conditions of collector dosage and type. Based on the indexes, it was found that the best enrichment effects were obtained with a sodium ethyl xanthate aqueous solution 150 g/Mg.

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MEMS Accelerometer Design Optimization Using Genetic Algorithm

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.705.288 ◽

2013 ◽

Vol 705 ◽

pp. 288-294 ◽

Cited By ~ 3

Author(s):

V.S. Krushnasamy ◽

A. Vimala Juliet

Keyword(s):

Genetic Algorithm ◽

Design Optimization ◽

High Efficiency ◽

Microelectromechanical Systems ◽

Optimal Parameter ◽

Low Cost ◽

Complex Nature ◽

Mems Accelerometer ◽

Mems Technology ◽

Parameter Values

MEMS (Microelectromechanical Systems) refers to the technology integrating electrical and mechanical components with feature size of 1~1000 microns. Due to its small size, low cost, low power consumption and high efficiency, MEMS technology has been widely used in many fields.In this paper,the design optimization of MEMS accelerometer is discussed.The main objective of this investigation is to find a optimum design of MEMS,which satisfies a set of given constraints. The accelerometer employs a double folded beam flexure system and the mass being displaced is the proof mass.Due to the complex nature of the problem,a genetic algorithm (GA) is developed for the optimization of MEMS.The GA attempts to minimize the die area and so the four optimal parameter values can be determined. MEMS accelerometers can be used in air-bag deployment systems in automobiles.The experimental results will show the optimal design of MEMS.

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Parameter Optimization of Vibrating and Comb-Brushing Harvesting of Lycium barbarum L. Based on FEM and RSM

Horticulturae ◽

10.3390/horticulturae7090286 ◽

2021 ◽

Vol 7 (9) ◽

pp. 286

Author(s):

Jian Zhao ◽

Te Ma ◽

Tetsuya Inagaki ◽

Yun Chen ◽

Guangrui Hu ◽

...

Keyword(s):

Field Experiments ◽

High Efficiency ◽

Optimal Parameter ◽

Ripe Fruit ◽

Lycium Barbarum ◽

Unripe Fruit ◽

Rotating Speed ◽

Damage Rate ◽

Materials Used ◽

Parameter Values

The current mechanical harvesting methods of Lycium barbarum L. are labor intensive and cause too much damage, but vibrating and comb-brushing harvesting can increase the efficiency while minimizing the damage. However, optimizing the main factors and their parameter values of vibrating and comb-brushing harvesting is challenging. To achieve the high-efficiency and low-damage harvesting of L. barbarum, firstly, the mechanical models of the materials used in the experiments were established based on the physical tests. Then, the vibrating and comb-brushing harvesting simulations were conducted based on FEM to acquire the ranges of the parameter values. The effects of the rotating speed, material, and amplitude on the harvesting rate of ripe fruit and harvesting rate of unripe fruit, as well as the damage rate of ripe fruit were determined based on RSM. Finally, the optimized parameters were obtained and verified using the field experiments. The field experiments showed that the harvesting rate of ripe fruit was 85.8%, the harvesting rate of unripe fruit was 10.5%, and the damage rate of ripe fruit was 9.7%. The findings provided the optimal parameter values, which were a design basis for the vibrating and comb-brushing harvesters of L. barbarum.

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An Evaluation of Sodium Ethyl Xanthate for the Froth Flotation Upgrading of a Carbonatitic Copper Ore

Journal of Physical Science ◽

10.21315/jps2016.27.2.2 ◽

2016 ◽

Vol 27 (2) ◽

pp. 13-21

Author(s):

Meso Florence Mokgethwa ◽

◽

Abraham Adewale Adeleke ◽

Peter Mendonidis ◽

Mosobalaje Oyebamiji Adeoye ◽

...

Keyword(s):

Froth Flotation ◽

Copper Ore ◽

Ethyl Xanthate ◽

Sodium Ethyl

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The Impact of Exogenous Insulin Input on Calculating Hepatic Clearance Parameters

Journal of Diabetes Science and Technology ◽

10.1177/1932296820986878 ◽

2021 ◽

pp. 193229682098687

Author(s):

Alexander D. McHugh ◽

J. Geoffrey Chase ◽

Jennifer L. Knopp ◽

Jennifer J. Ormsbee ◽

Diana G. Kulawiec ◽

...

Keyword(s):

Optimal Parameter ◽

Hepatic Clearance ◽

Intravenous Glucose Tolerance Test ◽

Accurate Identification ◽

Kinetics Parameters ◽

Intravenous Glucose ◽

Insulin Kinetics ◽

First Pass ◽

Parameter Values ◽

The Impact

Objective: Model-based metabolic tests require accurate identification of subject-specific parameters from measured assays. Insulin assays are used to identify insulin kinetics parameters, such as general and first-pass hepatic clearances. This study assesses the impact of intravenous insulin boluses on parameter identification precision. Method: Insulin and C-peptide data from two intravenous glucose tolerance test (IVGTT) trials of healthy adults ( N = 10 × 2; denoted A and B), with (A) and without (B) insulin modification, were used to identify insulin kinetics parameters using a grid search. Monte Carlo analysis ( N = 1000) quantifies variation in simulation error for insulin assay errors of 5%. A region of parameter values around the optimum was identified whose errors are within variation due to assay error. A smaller optimal region indicates more precise practical identifiability. Trial results were compared to assess identifiability and precision. Results: Trial B, without insulin modification, has optimal parameter regions 4.7 times larger on average than Trial A, with 1-U insulin bolus modification. Ranges of optimal parameter values between trials A and B increase from 0.04 to 0.12 min-1 for hepatic clearance and from 0.07 to 0.14 for first-pass clearance on average. Trial B’s optimal values frequently lie outside physiological ranges, further indicating lack of distinct identifiability. Conclusions: A small 1-U insulin bolus improves identification of hepatic clearance parameters by providing a smaller region of optimal parameter values. Adding an insulin bolus in metabolic tests can significantly improve identifiability and outcome test precision. Assay errors necessitate insulin modification in clinical tests to ensure identifiability and precision.

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Analysis of the Impact of Randomization of Search-Control Parameters in Monte-Carlo Tree Search

Journal of Artificial Intelligence Research ◽

10.1613/jair.1.12065 ◽

2021 ◽

Vol 72 ◽

pp. 717-757

Author(s):

Chiara F. Sironi ◽

Mark H. M. Winands

Keyword(s):

Monte Carlo ◽

Optimal Parameter ◽

Parameter Tuning ◽

Tree Search ◽

Control Parameters ◽

Monte Carlo Tree Search ◽

The One ◽

Parameter Values ◽

Search Control ◽

The Impact

Monte-Carlo Tree Search (MCTS) has been applied successfully in many domains, including games. However, its performance is not uniform on all domains, and it also depends on how parameters that control the search are set. Parameter values that are optimal for a task might be sub-optimal for another. In a domain that tackles many games with different characteristics, like general game playing (GGP), selecting appropriate parameter settings is not a trivial task. Games are unknown to the player, thus, finding optimal parameters for a given game in advance is not feasible. Previous work has looked into tuning parameter values online, while the game is being played, showing some promising results. This tuning approach looks for optimal parameter values, balancing exploitation of values that performed well so far in the search and exploration of less sampled values. Continuously changing parameter values while performing the search, combined also with exploration of multiple values, introduces some randomization in the process. In addition, previous research indicates that adding randomization to certain components of MCTS might increase the diversification of the search and improve the performance. Therefore, this article investigates the effect of randomly selecting values for MCTS search-control parameters online among predefined sets of reasonable values. For the GGP domain, this article evaluates four different online parameter randomization strategies by comparing them with other methods to set parameter values: online parameter tuning, offline parameter tuning and sub-optimal parameter choices. Results on a set of 14 heterogeneous abstract games show that randomizing parameter values before each simulation has a positive effect on the search in some of the tested games, with respect to using fixed offline-tuned parameters. Moreover, results show a clear distinction between games for which online parameter tuning works best and games for which online randomization works best. In addition, the overall performance of online parameter randomization is closer to the one of online parameter turning than the one of sub-optimal parameter values, showing that online randomization is a reasonable parameter selection strategy. When analyzing the structure of the search trees generated by agents that use the different parameters selection strategies, it is clear that randomization causes MCTS to become more explorative, which is helpful for alignment games that present many winning paths in their trees. Online parameter tuning, instead, seems more suitable for games that present narrow winning paths and many losing paths.

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Piezoelectric β-polymorph formation of new textiles by surface modification with coating process based on interfacial interaction on the conformational variation of poly (vinylidene fluoride) (PVDF) chains

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200158 ◽

2020 ◽

Vol 91 (3) ◽

pp. 31301

Author(s):

Nabil Chakhchaoui ◽

Rida Farhan ◽

Meriem Boutaldat ◽

Marwane Rouway ◽

Adil Eddiai ◽

...

Keyword(s):

High Efficiency ◽

Vinylidene Fluoride ◽

Research Work ◽

Research Area ◽

Interfacial Interaction ◽

Tetraethyl Orthosilicate ◽

Poly Vinylidene Fluoride ◽

Carbon Nanofillers ◽

The Impact ◽

Advanced Applications

Novel textiles have received a lot of attention from researchers in the last decade due to some of their unique features. The introduction of intelligent materials into textile structures offers an opportunity to develop multifunctional textiles, such as sensing, reacting, conducting electricity and performing energy conversion operations. In this research work nanocomposite-based highly piezoelectric and electroactive β-phase new textile has been developed using the pad-dry-cure method. The deposition of poly (vinylidene fluoride) (PVDF) − carbon nanofillers (CNF) − tetraethyl orthosilicate (TEOS), Si(OCH2CH3)4 was acquired on a treated textile substrate using coating technique followed by evaporation to transform the passive (non-functional) textile into a dynamic textile with an enhanced piezoelectric β-phase. The aim of the study is the investigation of the impact the coating of textile via piezoelectric nanocomposites based PVDF-CNF (by optimizing piezoelectric crystalline phase). The chemical composition of CT/PVDF-CNC-TEOS textile was detected by qualitative elemental analysis (SEM/EDX). The added of 0.5% of CNF during the process provides material textiles with a piezoelectric β-phase of up to 50% has been measured by FTIR experiments. These results indicated that CNF has high efficiency in transforming the phase α introduced in the unloaded PVDF, to the β-phase in the case of nanocomposites. Consequently, this fabricated new textile exhibits glorious piezoelectric β-phase even with relatively low coating content of PVDF-CNF-TEOS. The study demonstrates that the pad-dry-cure method can potentially be used for the development of piezoelectric nanocomposite-coated wearable new textiles for sensors and energy harvesting applications. We believe that our study may inspire the research area for future advanced applications.

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REMOVAL OF HEAVY METAL Cr (II), Ni (II), Cu (II), Zn (II), Cd (II), Pb (II) IONS FROM AQUEOUS SOLUTION BY MENTHA PIPERITA EXTRACT

10.32006/eeep.2020.2.1520 ◽

2020 ◽

pp. 15-20

Author(s):

Ersin Yucel ◽

Mine Yucel

Keyword(s):

Aqueous Solution ◽

Metal Ions ◽

High Efficiency ◽

Correlation Coefficients ◽

Langmuir Model ◽

Mentha Piperita ◽

Freundlich Model ◽

Biosorption Capacity ◽

Peppermint Extract ◽

The Stability

In this study, the usage of the peppermint (Mentha piperita) for extracting the metal ions [Mg (II), Cr (II), Ni (II), Cu (II), Zn (II), Cd (II), Pb (II)] that exist at water was investigated. In order to analyze the stability properties, Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms were used at removing the metal ions and the highest correlation coefficients (R2) were obtained at Langmuir isotherm. Therefore, it is seen that the Langmuir model is more proper than the Freundlich model. However, it was found that the correlation coefficients of removing Ni and Cd is higher at Freundlich model than Langmuir and low at Dubinin-Radushkevich isotherm. It is established that the biosorption amount increase depends on the increase of biosorbent and it can be achieved high efficiency (95%) even with small amount (0.6 mg, peppermint extract) at lead ions. It is also determined that the peppermint extracted that is used at this study shows high biosorption capacity for metal ions and can be used for immobilization of metals from polluted areas.

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Heterotrophic Kinetic Parameter Estimation for Enhanced Biological Phosphorus Removal Processes Operated in Conventional and Membrane-Assisted Modes

Water Quality Research Journal ◽

10.2166/wqrj.2006.008 ◽

2006 ◽

Vol 41 (1) ◽

pp. 72-83 ◽

Cited By ~ 2

Author(s):

Zhe Zhang ◽

Eric R. Hall

Keyword(s):

Parameter Estimation ◽

Phosphorus Removal ◽

Growth Yield ◽

Pilot Scale ◽

Enhanced Biological Phosphorus Removal ◽

Biological Phosphorus Removal ◽

Nitrogen And Phosphorus ◽

Parameter Values ◽

The Impact ◽

Biological Phosphorus

Abstract Parameter estimation and wastewater characterization are crucial for modelling of the membrane enhanced biological phosphorus removal (MEBPR) process. Prior to determining the values of a subset of kinetic and stoichiometric parameters used in ASM No. 2 (ASM2), the carbon, nitrogen and phosphorus fractions of influent wastewater at the University of British Columbia (UBC) pilot plant were characterized. It was found that the UBC wastewater contained fractions of volatile acids (SA), readily fermentable biodegradable COD (SF) and slowly biodegradable COD (XS) that fell within the ASM2 default value ranges. The contents of soluble inert COD (SI) and particulate inert COD (XI) were somewhat higher than ASM2 default values. Mixed liquor samples from pilot-scale MEBPR and conventional enhanced biological phosphorus removal (CEBPR) processes operated under parallel conditions, were then analyzed experimentally to assess the impact of operation in a membrane-assisted mode on the growth yield (YH), decay coefficient (bH) and maximum specific growth rate of heterotrophic biomass (µH). The resulting values for YH, bH and µH were slightly lower for the MEBPR train than for the CEBPR train, but the differences were not statistically significant. It is suggested that MEBPR simulation using ASM2 could be accomplished satisfactorily using parameter values determined for a conventional biological phosphorus removal process, if MEBPR parameter values are not available.

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Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽

10.3390/min11020213 ◽

2021 ◽

Vol 11 (2) ◽

pp. 213

Author(s):

Hamid Ait Said ◽

Hassan Noukrati ◽

Hicham Ben Youcef ◽

Ayoub Bayoussef ◽

Hassane Oudadesse ◽

...

Keyword(s):

Molecular Weight ◽

Compressive Strength ◽

Mechanical Strength ◽

Bone Repair ◽

Mechanical Stability ◽

Three Dimensional ◽

Processing Parameters ◽

Composite Effect ◽

Solid Liquid ◽

The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

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Modeling and Experiments of Laser Cladding With Droplet Injection

Journal of Heat Transfer ◽

10.1115/1.2005273 ◽

2005 ◽

Vol 127 (9) ◽

pp. 978-986 ◽

Cited By ~ 48

Author(s):

J. Choi ◽

L. Han ◽

Y. Hua

Keyword(s):

Fluid Flow ◽

Laser Cladding ◽

Dynamic Motion ◽

Cladding Layer ◽

Melt Pool ◽

Material Deposition ◽

Modeling And Experiments ◽

Solid Liquid Interface ◽

Solid Liquid ◽

The Impact

Laser aided Directed Material Deposition (DMD) is an additive manufacturing process based on laser cladding. A full understanding of laser cladding is essential in order to achieve a steady state and robust DMD process. A two dimensional mathematical model of laser cladding with droplet injection was developed to understand the influence of fluid flow on the mixing, dilution depth, and deposition dimension, while incorporating melting, solidification, and evaporation phenomena. The fluid flow in the melt pool that is driven by thermal capillary convection and an energy balance at the liquid–vapor and the solid–liquid interface was investigated and the impact of the droplets on the melt pool shape and ripple was also studied. Dynamic motion, development of melt pool and the formation of cladding layer were simulated. The simulated results for average surface roughness were compared with the experimental data and showed a comparable trend.

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