scholarly journals General Tendencies of the Behaviour of Vegetables Developed in a Soil Contaminated with Heavy Metals

2020 ◽  
Vol 71 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Augustina Pruteanu ◽  
Valentin Vladut ◽  
Petru Cardei ◽  
Despina Bordean
Keyword(s):  
Heavy Metals ◽  
Life Cycle ◽  
Mathematical Models ◽  
Research Program ◽  
Accumulation Rate ◽  
Experimental Results ◽  
Extensive Research Program ◽  
Rate Behaviour ◽  
Plant Behaviour

The paper presents experimental results obtained in the study of heavy metals transfer from soil to vegetables. The experiments for which the raw and statistically processed data are presented in this paper are preliminary experiments within an extensive research program of plant behaviour in soils contaminated with heavy metals. These experiments underlie the development of primary statistical mathematical models that are also presented in the paper. These experiments will also form the basis for far more consistent experiments that follow plants throughout the life cycle. The statistical mathematical models presented in this paper facilitate extracting important conclusions about how plants accumulate heavy metals as well as about the accumulation rate behaviour during experiments. Both experiments and mathematical models will form the basis of complex experiments and dynamic mathematical models in the next stage of research.

Methodology of Research in Micropollutants – Heavy Metals

1982 ◽  
Vol 14 (12) ◽  
pp. 107-125 ◽  
Author(s):  
Roland Wollast
Keyword(s):  
Heavy Metals ◽  
Mathematical Models ◽  
Aqueous Phase ◽  
Suspended Matter ◽  
Solid Phase ◽  
Aquatic Organisms ◽  
Biological Processes ◽  
Particulate Phase ◽  
Sources Of Pollution ◽  
Adsorption Desorption

A comparison of the concentration of dissolved and of particulate heavy metals in the aquatic system indicates that these elements are strongly enriched in the suspended matter. The transfer between the aqueous phase and the solid phase may be due to dissolution-precipitation reactions, adsorption-desorption processes or biological processes. When these processes are identified, it is further possible to develop mathematical models which describe the behaviour of these elements. The enrichment of heavy metals in the particulate phase suspended or deposited and in aquatic organisms constitutes a powerful tool in order to evaluate sources of pollution.

RELIABILITY ASSESSMENT OF AXIALLY COMPRESSED COMPOSITE CYLINDRICAL SHELLS WITH RANDOM IMPERFECTIONS

2011 ◽  
Vol 11 (02) ◽  
pp. 215-236 ◽  
Author(s):  
MATTEO BROGGI ◽  
ADRIANO CALVI ◽  
GERHART I. SCHUËLLER
Keyword(s):  
Mathematical Models ◽  
Axial Compression ◽  
Cylindrical Shells ◽  
Reliability Assessment ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Experimental Results ◽  
Drastic Decrease ◽  
Different Types ◽  
Probability And Statistics

Cylindrical shells under axial compression are susceptible to buckling and hence require the development of enhanced underlying mathematical models in order to accurately predict the buckling load. Imperfections of the geometry of the cylinders may cause a drastic decrease of the buckling load and give rise to the need of advanced techniques in order to consider these imperfections in a buckling analysis. A deterministic buckling analysis is based on the use of the so-called knockdown factors, which specifies the reduction of the buckling load of the perfect shell in order to account for the inherent uncertainties in the geometry. In this paper, it is shown that these knockdown factors are overly conservative and that the fields of probability and statistics provide a mathematical vehicle for realistically modeling the imperfections. Furthermore, the influence of different types of imperfection on the buckling load are examined and validated with experimental results.

A Collaborative Filtering Recommendation Algorithm Incorporated with Life Cycle

2013 ◽  
Vol 765-767 ◽  
pp. 630-633 ◽  
Author(s):  
Chong Lin Zheng ◽  
Kuang Rong Hao ◽  
Yong Sheng Ding
Keyword(s):  
Life Cycle ◽  
Collaborative Filtering ◽  
Recommendation Systems ◽  
Experimental Results ◽  
User Interest ◽  
Recommendation Algorithm ◽  
Time Information ◽  
Successful Technology

Collaborative filtering recommendation algorithm is the most successful technology for recommendation systems. However, traditional collaborative filtering recommendation algorithm does not consider the change of time information. For this problem,this paper improve the algorithm with two new methods:Predict score incorporated with time information in order to reflect the user interest change; Recommend according to scores by adding the weight information determined by the item life cycle. Experimental results show that the proposed algorithm outperforms the traditional item in accuracy.

A Database Tool for Managing Customer and Design Information During Product Definition

1994 ◽  
Author(s):  
Dileep V. Khadilkar ◽  
John A. Gershenson ◽  
Larry A. Stauffer
Keyword(s):  
Life Cycle ◽  
Design Process ◽  
Research Program ◽  
New Product ◽  
Design Engineering ◽  
Ongoing Research ◽  
Design Information ◽  
Product Definition

Abstract We developed a new database tool to manage information during the product definition process. This tool is a result of an ongoing research program to coordinate marketing and design engineering efforts in new product developments, and consider the related life cycle issues early in the design process. The database tool facilitates a methodology that integrates customer and design information, and allows reuse of this information during redesign problems. This paper presents the development, implementation, and an example use of the database tool.

Experimental Research to Evaluate Thermal Behavior of a Brushless Driving Servomotor for Linear Motion NC Axis Experimental Stand

2015 ◽  
Vol 762 ◽  
pp. 55-60
Author(s):  
Georgia Cezara Avram ◽  
Florin Adrian Nicolescu ◽  
Radu Constantin Parpală ◽  
Constantin Dumitrascu
Keyword(s):  
Thermal Behavior ◽  
Mathematical Models ◽  
Experimental Research ◽  
Infrared Imaging ◽  
Experimental Results ◽  
Ball Screw ◽  
Linear Motion ◽  
Functional Optimization ◽  
Thermal Infrared Imaging ◽  
Experimental Stand

This paper presents the works carried out by the authors in the field of structural and functional optimization of industrial robot's numerically controlled (NC) axes. The study includes the results obtained in the research stage of the experimental measurements performed to evaluate the electrical servomotor's thermal behavior using a thermal (infrared) imaging camera. The analyzed servomotor is a brushless servomotor integrated in an experimental stand for linear motion NC axis experimental research, existing in the MMS department from EMTS faculty. Supplementary to the driving servomotor, the experimental stand includes a belt drive transmission, a ball screw - bearings assembly and a driven element guided by ball rail system. This experimental research phase is part of the doctoral thesis of first author and was conducted in order to validate the mathematical models developed in the PhD thesis. Thus, experimental results presented in the paper have been used to validate first mathematical models for electric motor's preliminary selection and checking, (performed by determining the total reflected inertia of the mechanical system on motor shaft level) as well as the mathematical models for final selection and checking (by evaluating the servomotor's thermal energy dissipation, and servomotor's internal and external maximum operating temperature). Second, the experimental results have been used to validate the assisted simulation for structural and functional optimization of industrial robot's NC axes based on both servomotor and drive's thermal behavior analysis, performed in the thesis by means of a dedicated commercial software package.

scholarly journals The influence of soil microorganisms on heavy metal content in the substrate of waste rock dumps

2021 ◽  
Vol 31 ◽  
pp. 00017
Author(s):  
Natalia Makeeva ◽  
Olga Neverova
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Content ◽  
Soil Microorganisms ◽  
Accumulation Rate ◽  
Heavy Metal Content ◽  
Waste Rock ◽  
Soil Reclamation ◽  
The Impact ◽  
Concentration Limits

The environmental effects of mining and its impact on natural resources are of a holistic nature. One of the modern methods employed for the remediation of technogenically disturbed soils is the application of microorganisms. This paper studies the impact made by soil microorganisms on the accumulation rate of heavy metals in the substrate of waste rock dumps in the process of soil reclamation. Suspensions of soil microorganisms (microorganisms utilising mineral nitrogen forms / MUMN; microorganisms decomposing silicates / MDS; microscopic fungi / MF) were applied to the rock dump surface. Separate groups as well as their combinations were applied. The heavy metal content analysis did not indicate a significant exceedance of the maximum allowable concentration limits (MACL) in the soil of the waste rock. The only metal whose content exceeded the maximum admissible concentration limits was nickel. It has found that the application of microorganisms influences the concentration of several heavy metals due to pH level changes of the rock dump soil.

A Study of Multiple Hole Extrusion

1979 ◽  
Vol 101 (2) ◽  
pp. 135-138
Author(s):  
Amit Bagchi ◽  
John G. Lenard
Keyword(s):  
Velocity Field ◽  
Mathematical Models ◽  
Maximum Power ◽  
Experimental Results ◽  
Significant Parameter ◽  
Area Reduction

Two mathematical models proposed by Avitzur and valid for axially symmetrical square extrusion are tested for their ability to predict the maximum power required in single as well as multiple hole extrusion. Comparison to experimental results obtained using plumber’s lead shows good correlation. The most significant parameter is shown to be the total area reduction. The velocity field in multiple hole extrusion—which by necessity must be nonaxially symmetrical—appears not to affect the power required for extrusion.

scholarly journals Influence of Gamma Prime Evolution on the Creep Behaviour of SX Nickel Base Superalloys

2011 ◽  
Vol 278 ◽  
pp. 351-356 ◽  
Author(s):  
Maurizio Maldini ◽  
Valentino Lupinc ◽  
Giuliano Angella
Keyword(s):  
Strain Rate ◽  
Creep Behaviour ◽  
Experimental Results ◽  
Morphology Evolution ◽  
Shape Evolution ◽  
Strain Accumulation ◽  
Gamma Prime ◽  
Single Crystal Turbine Blade ◽  
Nickel Base ◽  
Rate Behaviour

The objective of this paper is to critically analyse the effect of the ’ morphology evolution on the creep strain rate behaviour in the temperature range 900 - 1100°C where rafts form in superalloys for single crystal turbine blade and vane applications. A close examination of the experimental results has shown different regimes of strain accumulation depending on the value of the applied stress and temperature. The experimental results have been rationalised in terms of the ’ shape evolution during creep.

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