scholarly journals Determination of emission of iron oxides from the welding process on the basis of mathematical models

2021 ◽  
Vol 93 (2) ◽  
pp. 35-42
Author(s):  
Jarosław Mikołajczyk ◽  
Karolina Pikulik
Keyword(s):  
Mathematical Models ◽  
Iron Oxides ◽  
Welding Process ◽  
Welding Current ◽  
Test Results ◽  
Negative Effects ◽  
Average Value ◽  
Harmful Emission ◽  
R Program

Oxygen in metals is most often present in the form of oxides, including: FeO, Fe2O3, Fe3O4. The complexity of the welding process means that oxygen compounds can enter both the liquid metal and the atmosphere, causing negative effects. A welder is exposed to harmful emission of oxides entering the human body through the respiratory system or pores in the skin. The essence of the problem is so serious that standards for air purity and determination of amount of oxides at workplaces have been introduced. The article presents the results of research on the influence of the welding current intensity on the emission of air pollutants (in particular the emission of iron oxides) of the inhalable and respirable fractions. The bench tests were carried out on the basis of the applicable standards for air quality at welding stations. Based on the test results, on the basis of the R program, mathematical models of the emission of iron oxides generated during the welding process were developed. It was observed that with the increase of the welding current, the average value of the emission of iron oxides – both the inhalable and respirable fractions – increases. For both fractions, it was also noted that the model values ​​are closer to the values measured in the model No. 1.

scholarly journals Electric current effect on mechanical properties of SMAW-3G on the stainless steel AISI 304

2018 ◽  
Vol 197 ◽  
pp. 12003
Author(s):  
Edi Widodo ◽  
Iswant Iswanto ◽  
Mirtza Adi Nugraha ◽  
Karyanik Karyanik
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Tensile Test ◽  
Electric Current ◽  
Welding Process ◽  
Welding Current ◽  
Test Results ◽  
Aisi 304 ◽  
Steel Aisi ◽  
Stainless Steel Aisi

Parameters in the welding need to be known because the effect on the mechanical properties of the material after the welding process. This research purposes to find out the influence of variation of SMAW welding current on Stainless Steel AISI 304, with variation of electric current equal to 70A, 80A and 90A.The electrode of AWS A5.4 E308-16 with diameter of 2.6 mm is used. Dye penetrant test, tensile test and metallographic test applied to analysis the characteristic. Based on data from tensile test results obtained the highest value on the specimen welding current 90A is equal to 632 MPa. The lowest tensile strength value recorded on the specimens of current 70A is 498.66 MPa.

scholarly journals Conditionings of decision of foreign investors on Ukraine in regional expression

Equilibrium ◽  
2010 ◽  
Vol 4 (1) ◽  
pp. 175-187
Author(s):  
Mykola Vashchenko
Keyword(s):  
Economic Development ◽  
Data Analysis ◽  
Concentration Index ◽  
Foreign Capital ◽  
Regional Distribution ◽  
Test Results ◽  
Negative Effects ◽  
Foreign Investors ◽  
Source Materials

The purpose of the article is determination of influence of FDI on Ukrainian regional development. On the basis of theoretical grounds there will be presented question of heterogeneity in the sphere of regional distribution of FDI and also the influence of this phenomenon on development of host country. Methods of statistic data analysis and source materials will be used for this purpose. Induction will allow todraw the conclusions. In turn, the concentration index of Herfindahl-Hirschman indicates the situation in the distribution of foreign capital in Ukrainian regions. Test results indicate a substantial level of concentration of foreign capital invested in the Ukrainian economy. This has negative effects manifested in the stratification of society and creating gaps in economic development.

DETERMINATION OF THE BEHAVIOR OF 6063 ALUMINUM IN THE FRICTION WELDING PROCESS USING MATHEMATICAL MODELS

2012 ◽  
Vol 1381 ◽  
Author(s):  
F. García ◽  
P. del C. Zambrano Robledo ◽  
M.P. Guerrero ◽  
F. García-Vazquez
Keyword(s):  
Mechanical Strength ◽  
Mathematical Models ◽  
Strain Rate ◽  
Friction Welding ◽  
Welded Joint ◽  
Welding Process ◽  
Plastic Model ◽  
Rate Dependent ◽  
Ideal Process

AbstractIn this work, it was used a Johnson-Cook elastic-plastic model to represent the behavior in the friction welding process of 6063 aluminum. Temperature and strain rate dependent laws were used to determine the behavior of the material. The results determined that the amount of heat transferred into the material dictates the quality and the microstructure of the welding and the mechanical strength of the welded joint in an ideal process.

Description of Cyclic Properties of Steel in Variability Conditions of Mean Values and Amplitudes of Loading Cycles

2012 ◽  
Vol 726 ◽  
pp. 69-76 ◽  
Author(s):  
Grzegorz Szala ◽  
Bogdan Ligaj
Keyword(s):  
Mechanical Properties ◽  
Mathematical Models ◽  
Experimental Test ◽  
Point Of View ◽  
Test Results ◽  
Mean Values ◽  
Fatigue Characteristics ◽  
Verification Test

The work includes description of determination of two-parametric fatigue characteristics (TFC) on the base of experimental test results and description of mathematical models of these characteristics. Mathematical models were verified in C45 and 41Cr4 tests that are essentially different from the point of view of mechanical properties. On the base of analysis of verification test results there were determined ranges of applications of TFC models described in the work.

scholarly journals Kandungan Antioksidan Daun Mahang Damar (Macaranga triloba (Bl.) Muell Arg.)

2018 ◽  
Vol 3 (2) ◽  
pp. 122-131
Author(s):  
Pienyani Rosawanti ◽  
Dewi Sari Mulia ◽  
Syahrida Dian Ardhany
Keyword(s):  
Antioxidant Activity ◽  
Economic Value ◽  
Ethyl Acetate Fraction ◽  
Hexane Extract ◽  
Flavonoid Compound ◽  
Test Results ◽  
Average Value ◽  
Dpph Method ◽  
Similar Content

In the year 2015, the plants that initially grow a lot of wild is increasing in popularity because many contested by the citizens. The reason is because the plant has an economic value. Based on the literature review it is known that apigenin, a flavonoid compound has been isolated from the ethyl acetate fraction of methanolic extract of Macaranga gigantia leaf. Compounds that have potential as antioxidants are generally compounds of flavonoids, phenolics, and alkaloids. Flavonoid and polyphenolic compounds are antioxidant, antidiabetic, anticancer, antiseptic, and anti-inflammatory, while alkaloids have antineoplastic properties that also inhibit the growth of cancer cells. Phenol content, antioxidant activity and antibacterial activity were also found in Macaranga gigantea, M. hosei, M. hypoleuca, M. kingii, M. pruinosa and M. triloba (Lim et.al., 2014). This leads to the notion that mahang leaves were obtained and collected from the Central Kalimantan region where this study carried out also contained similar content and activity. Determination of the value of antioxidant activity in this study using DPPH method performed on n-hexane extract ofmahang leaf obtained by maceration. N-hexane extract of mahang leaf have antioxidant activity, this can be seen from the preliminary TLC test results where the spots produced when sprayed with DPPH fluoresce when viewed at 366 nm uv. The average value of IC50n-hexane extract of mahang leaves was 141.3 ppm.

scholarly journals Selected Aspects of the FEM-Based Numerical Modelling of Current Propagation in the Resistance Multispot Cruciform Welding of Bars

2021 ◽  
pp. 7-14
Author(s):  
Mariusz Stępień ◽  
Zygmunt Mikno
Keyword(s):  
Power Supply ◽  
Software Package ◽  
Research Work ◽  
Three Dimensional ◽  
Welding Process ◽  
Welding Current ◽  
Welding Machine ◽  
Dc Power ◽  
Welding Processes

The article presents selected aspects of the FEM-based analysis concerning resistance welding processes performed using multispot welding systems. The analysis was based on a three-spot welding machine used for the joining bars in the cruciform configuration. Both two and three-dimensional modelling was performed as the comparative analysis of two computing software packages, i.e. the commercial ANSYS Mechanical software package and the ARTAP software package, available on an open access basis. The research work involved the determination of current propagation in various welding process configurations as well as the identification of the percentage loss of welding current and power resulting from the bridging of current by neighbouring welds. The article discusses the effect of the method of the power supply and the earthing of the system of electrodes along with the welded material on the manner of current propagation. The analyses presented in the article were performed in relation to the DC power supply (inverter welding machine). Related calculations were performed using averaged (in terms of heat and resistance) material parameters.

DIP quality influenced by process water quality

TAPPI Journal ◽  
2014 ◽  
Vol 13 (9) ◽  
pp. 51-60
Author(s):  
DENNIS VOSS ◽  
HANS-JOACHIM PUTZ ◽  
SAMUEL SCHABEL
Keyword(s):  
Water Quality ◽  
Surface Tension ◽  
Ph Value ◽  
Water Hardness ◽  
Process Water ◽  
Test Results ◽  
Negative Effects ◽  
Water Parameters ◽  
Effects Of Ph ◽  
Contamination Levels

The need for deinking mills to reduce their fresh water consumption has resulted in higher loads of various contaminants in the process water. Lower recovered paper quality also leads to higher contamination levels in the mills. This higher load has an influence on achievable target brightness. The objective of the work was to determine and explain the main reasons for relatively poor deinked pulp quality or poor deinking potential based on the influence of recovered paper composition and process water quality. The process water parameters significantly affect the deinking potential of recovered paper. The test results showed the negative effects of increased water hardness. For standard recovered paper mixtures, flotation selectivity is higher with increasing flotation pH-value. Good results were realized for standard recovered paper with low hardness, low surface tension, and high pH-value. The results for recovered paper containing flexo newsprint could be slightly improved with low hardness, low surface tension, and low pH-value. The results of the test program using design of experiments showed interacting effects of pH-value and surface tension on luminosity and flotation selectivity.

DETERMINATION OF THE JUICE EVAPORATION MATHEMATICAL MODELS EFFICIENCY FOR AUTOMATED PROCESS CONTROL SYSTEMS

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
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Keyword(s):  
Process Control ◽  
Mathematical Models ◽  
Control Systems ◽  
Process Control Systems ◽  
Automated Process

New approaches for the determination of dextran in the sugar production process

2018 ◽  
pp. 138-146 ◽  
Author(s):  
Karin Abraham ◽  
Eckhard Flöter
Keyword(s):  
Molecular Mass ◽  
Mass Distribution ◽  
Molecular Mass Distribution ◽  
Molecular Size ◽  
Mass Variation ◽  
Negative Effects ◽  
New Approaches ◽  
Precise Knowledge ◽  
Enzyme Application

The presence of polysaccharides in cane and beet raw juices causes several negative effects during the sugar manufacture. These are usually mitigated by enzymatic decomposition of dextrans. Such effects not only depend on the content, but also on the molecular mass distribution. This means that the different dextran fractions specifically affect the process. An accurate process control hence requires the most precise knowledge about the existing content and the molecular mass distribution present. A detailed understanding of the specific processing problems and also a targeted enzyme application hence requires the determination of a total dextran content and also its characterization including the differentiation between the different dextran fractions. An accurate analytical tool which equally satisfies industrial applicability is still lacking. To improve on this situation, two new approaches for the determination of dextran were developed and benchmarked against the commonly used and established Haze Method, which is rather inaccurate and also sensitive to molecular mass variation. The two new approaches are both based on polarimetry. These two methods indicate to be superior over the Haze Method with respect two molecular mass variation and hence enable the determination of a broader molecular size range including also low molecular mass dextrans.

PENGARUH MODEL PEMBELAJARAN KELILING KELOMPOK (ROUND CLUB) TERHADAP KETERAMPILAN MENULIS LAPORAN PERJALANAN SISWA KELAS V SDN 01 NAGARI BUKIK SIKUMPA

2020 ◽  
Author(s):  
Wirda Linda
Keyword(s):  
Standard Deviation ◽  
Performance Test ◽  
Writing Skills ◽  
Learning Model ◽  
Homogeneity Test ◽  
Test Results ◽  
Class V ◽  
Average Value ◽  
Normality Test ◽  
Lecture Method

This research is motivated by the low desire of students in writing travel reports. The lack of students' knowledge of the report concept, the lack of students' knowledge of the 5W + 1H report points of good and correct language, the lack of students' knowledge of the spatial, time and topic pattern and not yet reached KKM 75. The method used by the teacher has not been interesting, lecture method. The purpose of this study is to describe the skills of writing travel reports by using Round Club learning model which is viewed from the aspect of understanding the report concept, the use of 5W +1H report points, the spatial, time, and topic pattern.The population of this study is the students of class V Lessons Year 2017/2018 which amounted to 2 classes with the number 80. The sample of research as much as two classes taken by the sample of propotional.Class V.1 as experimental class and class V.2 as control class. The research instrument used is performance test. Provide an assessment by specifying the subject of the 5W + 1H report, as well as the spatial, time and topic pattern. Data were analyzed by 't' test by first testing normality, homogeneity, and hypothesis testing.The results showed that the average control class 68 with more than enough qualifications with standard deviation 16.96. 83 experimental class with good qualification and standard deviation of 15.42 and there is a significant influence on the result of writing skill of class V SDN 01 Nagari Bukik SikumpaSubdistrict, Lima Puluh Kota. This is evidenced by the average value of writing skills in the experiment class higher than the average value in the control class. Normality test results indicate that the two sample classes of  Lo  values in the control class -0.2141 are smaller than the normal 0.190 Lt distributed. Homogeneity test results that the variation of this study is homogeneous at a real level of 0.05, because Ftable 2.16 > Fhitung 1.21 and the results of data analysis then obtained = 2.78 > 1.70 t table, so H0 rejected and H1 accepted. It can be concluded that there is Influence. Using  Learning  Model of Student Group Writing  Skills Travel Report of students of class V SDN 01 Nagari Bukik Sikumpa Subdistrict, Kabupaten Lima Puluh Kota.KeyWords: model pembelajaran round club, menulis laporan perjalanan.

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