96/01789 ‘The impact of source separation, recycling and mechanical processing on MSW conversion to energy’ activity

The effects of cutting fluids to health, environment, productivity, and quality in machining operations have been discussed. MQL is a green technology that is gradually applied in mechanical processing. The article has introduced about MQL cooling lubrication method in mechanical processing. Some previous research results have been made to clarify the meaning of this method. In addition, the comparison of the outputs of MQL, dry, and wet methods has also been shown to show the effectiveness of the MQL method. Then, based on the MQL equipment being used at Tran Dai Nghia University, the authors designed the experiment to evaluate the impact of MQL parameters on the process outputs. Machining and optimization of that parameter. This paper presents the MQL parameters optimization approach in which the multi-response outputs based on Taguchi's L9 orthogonal array method is used. During the turning AISI-1045 steel, the cutting temperature, the maximum of tool wear, and the surface roughness were measured. The MQL parameters, which are the ratio of soluble lubricant and water, pressure of spray head, the flow volume of the emulsion was simultaneously optimized by taking the multi-response outputs using Taguchi based grey relational analysis (GRA) into consideration. In turning experiments, three different flow volume of emulsion Q (40, 60, 80 ml/h), three different levels pressure of spray head P (3, 5, 7 bar) and three different levels ratio of soluble lubricant and water R (4, 6, 8%) were used. Here, three mathematical models were created using response surface regression methodology. The experiments had been done to investigate the effect of the MQL parameters to the turning process. As a result, the set of optimal MQL parameters had been pointed out to simultaneously minimize the cutting temperature, the tool wear, and surface roughness. The Flow volume of emulsion 80 ml/h, Pressure of spray head 7 bar, Ratio of soluble lubricant, and water 6% was observed to be the most effective.

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The structure and phase composition of the cermet charge in the Al‒Al2O3 system obtained using mechanical processing of aluminum powder in a planetary ball mill

NOVYE OGNEUPORY (NEW REFRACTORIES) ◽

10.17073/1683-4518-2021-6-31-38 ◽

2021 ◽

pp. 31-38

Author(s):

D. A. Ivanov ◽

G. E. Val'yano ◽

T. I. Borodina

Keyword(s):

Aluminum Powder ◽

Amorphous Carbon ◽

Ball Mill ◽

Bending Strength ◽

Exothermic Reaction ◽

Planetary Ball Mill ◽

Mechanical Processing ◽

Aluminum Particles ◽

Industrial Grade ◽

The Impact

The cermet charge in the Al‒Al2O3 system was obtained by mechanical processing (MP) in a planetary ball mill of aluminum powder of the industrial grade PAP-2 (GOST 5494‒95), consisting of flake particles of submicron thickness with a coating of stearin. Depending on the MP modes used, 4 types of charge were obtained, the bulk density of which varied from 0,33 to 1,1 g/cm3. For all types of charge, the synthesis of the α-Al2O3 phase was observed as a result of the exothermic reaction of the interaction of air oxygen with the surface of aluminum particles during the MP. It is also possible to form boehmite and gibbsite when the activated surface of Al particles interacts with atmospheric water vapor. The local X-ray spectral analysis (EDX) was used to detect X-ray amorphous carbon in the composition of the charge, the appearance of which is associated with the impact- shearing effect of grinding bodies, leading to the nucleation of X-ray amorphous carbon inclusions due to the termal destruction of stearin. The maximum bending strength of the sintered cermet was 550 MPa. This cermet is characterized by a discrete fracture: the formation of dimples as a result of the shear of layered packets under the action of tangential stresses. The revealed mechanisms cermet’s fractures allow us to establish the optimal modes of MP of powder compositions for obtaining various constructional elements from them.

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Determination of phytotoxicity of wastes of mechanical processing of polymer mixtures with their mechanical activation

Biological Systems: Theory and Innovation ◽

10.31548/biologiya2021.01.006 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

O. Malyshevska ◽

Keyword(s):

Heavy Metals ◽

Household Waste ◽

Mechanical Processing ◽

Polymer Mixtures ◽

Phytotoxic Effect ◽

Contamination Levels ◽

Complex Relationships ◽

Living Organisms ◽

The Impact

Biotesting to assess the complex relationships between soil, contaminants and living organisms and to determine the impact on ecosystems of pollutants whose concentrations may be beyond the sensitivity of the methods of determination and the composition of which cannot be determined. The aim is to establish the level of phytoxicity of wastes of mechanical processing of polymer mixtures, which are extracted from solid household waste with the help of indicator plants. Methods. Evaluation of phytotoxic effects was performed by vegetation methods according to ISO: 17402-2008, 17126-2005a, 11269-1: 2012a, 11269-2: 2012b. Contamination levels of the test samples were assessed according to ISO 16198.Objects of research: watercress seeds, mustard, wheat, corn, soybeans, barley and sludge from the processing of polymer mixtures composed of polymer particles of different composition and quantity, along with the remnants of paper labels. Studies of the content of heavy metals (Pb, Cu, Cd, Zn, Ni) were performed by atomic absorption method on a spectrophotometer type CAS-120.1 in accordance with generally accepted methods. Results. The studied sludge does not negatively affect the process of germination of watercress, mustard, corn. The level of phytotoxic effect of sludge on the germination of soybeans and barley was within acceptable limits and did not exceed 3.33%. The study of migration of heavy metals present in the sludge and their accumulation during the growth and development of plants showed their insignificant content regardless of the sludge content. Only the lead content was higher than in the control 2.13 times and 1.83 times higher than in "relatively clean soil". Conclusions. Determination of phytotoxicity of this type of sludge on the process of germination and vegetation changes of plants should be carried out on the most sensitive crops - watercress and mustard. A study of the migration of heavy metals present in the sludge and their accumulation during plant growth showed the presence of bound forms of heavy metals copper, nickel, cadmium and zinc - the migration of which has not been established. However, mobile forms of lead that migrate from the sludge and accumulate in plants have been identified.

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Risk assessment of negative effects on population health from the process of mechanical processing of secondary polymers

Reports of Vinnytsia National Medical University ◽

10.31393/reports-vnmedical-2021-25(1)-27 ◽

2021 ◽

Vol 25 (1) ◽

pp. 152-156

Author(s):

O. S. Malyshevska

Keyword(s):

Risk Assessment ◽

Air Pollution ◽

Mechanical Activation ◽

Raw Materials ◽

Statistical Processing ◽

Polymer Processing ◽

Mechanical Processing ◽

Mechanical Recycling ◽

Mean Values ◽

The Impact

Annotation. The most hygienically safe process of recycling polymers is mechanical recycling, which does not cause the destruction of polymers, which dangerously affect all components of the environment and man. The purpose of the study is to assess the level of risk of adverse effects on the health of the population living under the influence of mechanical processing of secondary polymers, depending on the presence or absence of the stage of mechanical activation in the processing process. Research methods: sanitary-epidemiological examination; risk assessment of dangerous factors for public health; instrumental assessment methods; statistical processing of results – determination of arithmetic mean values, standard error, quadratic deviation. It was found that the total indicators of air pollution, calculated on the maximum concentrations of specific pollutants at distances for the processing of polymers without the stage of mechanical activation of 15 m – the level of pollution was assessed as alarming, and at distances of 25 and 50 m as acceptable. For the process of processing polymers with a stage of mechanical activation, at all distances from the emission source (15, 25 and 50 m) the level of contamination was assessed as acceptable. To assess the impact of air pollution in the area of impact of polymer processing on the health of the population, the risk factors for the development of non-carcinogenic effects are more informative than the indicators of pollution. The critical human organs and systems most affected by polymer processing are: the respiratory system, the cardiovascular system, the liver, the kidneys, the central nervous system, and the blood. In order to reduce the man-caused load of enterprises for mechanical processing of secondary polymer raw materials, it is necessary to introduce in-depth purification units for air emitted into the atmosphere and switch to safer fuels.

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Modeling of the impact of hold-down forces on the accuracy of the workpiece shape using the finite element method

10.33920/pro-2-2102-01 ◽

2021 ◽

pp. 9-20

Author(s):

A.V. Zaitsev ◽

A.N. Izosimov

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Cross Section ◽

The Body ◽

Machining Process ◽

Mechanical Processing ◽

The Finite Element Method ◽

The Cross ◽

The Impact ◽

Element Method

In the article, the modeling of the impact of hold-down forces on the accuracy of the shape of the workpiece using the finite element method was carried out. The operation of mechanical processing (turning cut) of a workpiece of the body of rotation type on a milling machine with basing and fixing along the inner cylindrical surface of the workpiece is considered. The study was conducted for four different types of machine retaining devices used on machines of this group. A consistent description and illustration of the method of modeling the process of the impact of hold-down forces on the workpiece is made for each type of the device under consideration. The force constraints and effects imposed on the model are described and illustrated, the parameters of the finite element grid used in modeling are presented, the displacement profiles obtained in the modeling process and the stages of modeling the machining process are described, and the values of the largest deviations from the shape of the workpiece are determined. The results of the modeling are presented: a qualitative picture of the shape errors obtained as a result of mechanical processing — the values of the largest deviation from the roundness and the largest deviation from the cross-section profile of the workpiece to be processed, as well as the shape of the cutting obtained in the cross-section of the workpiece for each type of the devices under consideration. On the basis of the obtained results, estimates of the degree of accuracy of the shape and the relative geometric accuracy provided by the considered devices were made in accordance with GOST 24643–81. The conclusion is made about the suitability of using the considered variants of machine retaining devices for the proposed technological process according to the criterion of the provided accuracy of the shape of the processed surface. English version of the article is available at URL: https://panor.ru/articles/modeling-the-influence-of-the-fastening-forces-on-the-accuracy-of-the-workpiece-shape-using-the-finite-element-method/65043.html

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Does China’s Municipal Solid Waste Source Separation Program Work? Evidence from the Spatial-Two-Stage-Least Squares Models

Sustainability ◽

10.3390/su12041664 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1664 ◽

Cited By ~ 1

Author(s):

Liange Zhao ◽

Jianfeng Zou ◽

Zhijian Zhang

Keyword(s):

Municipal Solid Waste ◽

Solid Waste ◽

Spatial Interaction ◽

Source Separation ◽

Spillover Effect ◽

Absolute Amount ◽

Waste Generation ◽

Solid Waste Generation ◽

The Absolute ◽

The Impact

This paper evaluates the impact of the second municipal solid waste (MSW) source separation program on municipal solid waste generation (MSWG) in China. Without considering the spatial interactions between cities, the second MSW source separation program has a nonsignificant adverse effect on the per capita municipal solid waste generation (PMSWG). Relaxing the stable-unit-treatment-value assumption (SUTVA), which holds in most of the previous estimation literature on treatment effects, involving the spatial spillover effect among cities, as well as correcting the endogenous local policy has a significantly negative but not robust impact on the PMSWG. The estimation results of the generalized nesting spatial regression models (GNS) imply that the spatial interaction characteristics among Chinese prefecture-level cities may, if neglected, lead to underestimation of the reduction effects of the second MSW source separation policy on the absolute amount of PMSWG. More importantly, our study indicates that although not all the spatial econometric models support the significant reduction effect of source separation on the absolute amount of PMSWG, the source separation program significantly reduces the relative amount of PMSWG, and this result is robust in all spatial models.

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A Novel Method to Estimate the Unknown Mixing-Matrix for Blind Source Separation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.605-607.2206 ◽

2012 ◽

Vol 605-607 ◽

pp. 2206-2210

Author(s):

Ning Chen ◽

Hong Yi Zhang

Keyword(s):

Sparse Representation ◽

Blind Source Separation ◽

Membership Function ◽

Optimization Algorithm ◽

Source Separation ◽

Reliable Data ◽

Mixing Matrix ◽

Novel Method ◽

Effectiveness And Efficiency ◽

The Impact

The blind source separation (BSS) using a two-stage sparse representation approach is discussed in this paper. We presented the algorithm based on linear membership function to estimate the unknown mixing matrix precisely, and then, the optimization algorithm based on integral to get the max value of the function is proposed. Another contribution described in this paper is the discussion of the impact of noise on the estimating the mixing matrix. Given the impact of noise, we set weights to put more emphasis on the more reliable data. Several experiments involving speech signals show the effectiveness and efficiency of this method.

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