scholarly journals The influence of electric ARC activation on the speed of heating and the structure of metal in welds

2016 ◽  
Vol 20 (1) ◽  
pp. 239-246 ◽  
Author(s):  
Oleksandr Savytsky ◽  
Mychailo Savytsky ◽  
Darko Bajic ◽  
Yuriy Shkrabalyuk ◽  
Tomaz Vuherer
Keyword(s):  
Chemical Composition ◽  
Electric Arc ◽  
Martensitic Structure ◽  
Activating Flux ◽  
Metal Thickness ◽  
Structure Of Metal ◽  
Speed Up ◽  
The Impact ◽  
Welding Productivity ◽  
Metal Weld

This paper presents the results of a research related to the impact of electric arc activation onto drive welding energy and metal weld heating speed. It is confirmed that ATIG and AMIG methods, depending on metal thickness, single pass weldability and chemical composition of activating flux, enable the reduction of welding energy by 2-6 times when compared to conventional welding methods. Additionally, these procedures create conditions to increase metal weld heating speed up to 1,500-5,500?C/s-1. Steel which can be rapidly heated, allows for a hardened structure to form (with carbon content up to 0.4%), together with a released martensitic structure or a mixture of bainitic-martensitic structures. Results of the research of effectiveness of ATIG and AMIG welding showed that increase in the penetration capability of electric arc, which increases welding productivity, is the visible side of ATIG and AMIG welding capabilities.

Plasma parameters in atomic-emission spectral analysis of phosphate concentrates of the fission products

2019 ◽  
Vol 85 (2) ◽  
pp. 17-22
Author(s):  
M. I. Khamdeev ◽  
E. A. Erin
Keyword(s):  
Spectral Analysis ◽  
Chemical Composition ◽  
Reference Materials ◽  
Fission Products ◽  
Atomic Emission ◽  
Electric Arc ◽  
Physical Parameters ◽  
Arc Plasma ◽  
Atomic Emission Spectral Analysis ◽  
Excitation Processes

Physical parameters of electric arc plasma as well as their time dependences are calculated when analyzing phosphate precipitates of the fission products of irradiated nuclear fuel. Phosphate concentrates of the fission products are known for their complex chemical composition and high thermal and chemical stability. Hence, direct atomic emission spectral analysis of phosphate powders without transferring them into solutions is advisable. Different conditions of sample preparation and synthesis of the reference materials determine the different chemical forms of the elements to be determined. This, in turn, affects the kinetics of their evaporation in the electrode crate and excitation processes in the plasma. The known mechanisms of those processes cannot always be transferred to specific conditions of the given method of analysis thus entailing the necessity of studying the effect of the samples chemical composition on the results of determination, proper choice of spectroscopic carriers, detailed study of spectra excitation processes in spectral analysis, and analysis of the physical parameters of the electric arc plasma. We used the lines Zn I 307.206 nm and Zn I 307.589 nm to measure the effective temperature of the central hot sections of the arc in a range of4500 - 6500 K. NaCl, BaCl2 and NaCl + T1C1 were studied to reduce the effect of the sample elemental composition on excitation conditions of the spectra and their stabilization as a spectroscopic carrier. In control experiments we used carrier-free samples. The coincidence of the values of the plasma physical parameters within the measurement error not exceeding 20%, as well as the identity of the nature of the kinetic curves for samples of phosphate precipitates and synthetic reference materials prove their correctness. The result of the study substantiate correctness of the direct atomic-emission spectral procedure in analysis of phosphate concentrates of fission when using synthetic reference materials.

Population Study on the Impact Food Chemical Composition on Patients with Non-Alcoholic Fatty Liver Diseases

2018 ◽  
Vol 69 (4) ◽  
pp. 961-964
Author(s):  
Andrei Vasile Olteanu ◽  
Georgiana Emmanuela Gilca Blanariu ◽  
Gheorghe Gh. Balan ◽  
Dana Elena Mitrica ◽  
Elena Gologan ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Fatty Liver ◽  
Nutritional Value ◽  
Liver Steatosis ◽  
Saturated Fat ◽  
Control Group ◽  
Healthy Population ◽  
Alcoholic Fatty Liver ◽  
Major Interest ◽  
The Impact

Non-alcoholic fatty liver disease (NAFLD) has become of major interest worldwide, it is estimated that more than 20% of the general population suffer from liver steatosis. NAFLD is highly associated with metabolic risk factors like type 2 diabetes mellitus, obesity and dyslipidemia, the patients diagnosed with NAFLD should adopt a high fiber low calorie diet, with reduced saturated fat and carbohydrates content, leading to weight loss and improvement of metabolic profile. Our study is aiming to shape the profile of the patient interested in being informed related to food quality and chemical composition and to evaluate the aspects on the food products label which are important for the customer. Between June 2017 and December 2017, 83 patients diagnosed with NASH were included in the study, representing the study group, while 33 subjects, without metabolic syndrome or digestive diseases, selected from patient list belonging to two general practitioners, constituted the control group. Related to the interest of being informed about the chemical composition and nutritional value of the products bought, the study showed a low interest for the provided information on nutritional value. lack of confidence in the provided information and complexity of the information are understandable, the high number of subject reasoning through lack of immediate clinical benefit is surprising. Among the healthy population the willingness to pay attention to this aspect is extremely low.

Chemical Composition and Antimicrobial Activity of Bark and Leaf Extracts of Cupressus sempervirens and Juniperus phoenicea Grown in Al- Jabel Al-Akhdar Region, Libya

2019 ◽  
Vol 9 (4) ◽  
pp. 268-279
Author(s):  
Mohamed E.I. Badawy ◽  
Ibrahim E.A. Kherallah ◽  
Ahmed S.O. Mohareb ◽  
Mohamed. Z.M. Salem ◽  
Hameda A. Yousef
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Sea Level ◽  
Plant Extracts ◽  
Complex Mixture ◽  
Biologically Active ◽  
Cupressus Sempervirens ◽  
Leaf Extracts ◽  
Juniperus Phoenicea ◽  
The Impact

Background:Plant extracts are important products in the world and have been widely used for isolation of important biologically active products. Because of their significant environmental impact, extensive research has been explored to determine the antimicrobial activity of plant extracts.Methods:Acetone extracts of the bark and leaf of Cupressus sempervirens and Juniperus phoenicea, collected from three different altitudes (125, 391, and 851 m high of sea level) at Al- Jabel Al-Akhdar area, Libya were obtained and analyzed by GC/MS. The antimicrobial activity of the extracts was further evaluated against plant bacteria Rhizobium radiobacter, Erwinia carotovora, Rhodococcus fascians and Ralstonia solanacearum and fungus Botrytis cinerea.Results:The impact of the altitude from the sea level on the quantity and chemical constituents of the extracts was investigated. The yield was largely dependent on tree species and the highest yield (6.50%) was obtained with C. sempervirens L bark of altitude III (851 m of the sea level), while the lowest (1.17%) was obtained with the leaf extract of C. sempervirens L from altitude I (125 m). The chemical composition analyzed by GC/MS confirmed that the leaf extracts of C. sempervirens and J. phoenicea contained a complex mixture of monoterpene hydrocarbons, sesquiterpenes, diterpenes, diterpenoids, terpenophenolic, steroids and phthalates. However, the bark extracts of both trees contained a mixture of sesquiterpenes, diterpenes, diterpenoids, terpenophenolics, phthalates, retinol and steroids. These constituents revealed some variability among the extracts displaying the highest interesting chemotype of totarol (terpenophenolic) in all extracts (14.63-78.19% of the total extract). The extracts displayed a noteworthy antifungal potency with varying degrees of inhibition of growth with EC50 values ranged from 78.50 to 206.90 mg/L. The extracts obtained from the leaves of C. sempervirens showed that the highest inhibitory activity was obtained with the extract of altitude II (391 m) with MIC 565, 510, 380 and 710 mg/L against E. carotovora, R. fascians, and R. radiobacter and R. solanacearum, respectively.Conclusion:Based on antimicrobial activity, raw plant extracts can be a cost-effective way to protect crops from microbial pathogens. Because plant extracts contain several antimicrobial compounds, the development of resistant pathogens can be delayed.

scholarly journals Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

2011 ◽  
Vol 2 ◽  
pp. 152-161 ◽  
Author(s):  
Hans J Ensikat ◽  
Petra Ditsche-Kuru ◽  
Christoph Neinhuis ◽  
Wilhelm Barthlott
Keyword(s):  
Chemical Composition ◽  
Water Repellency ◽  
Contact Angles ◽  
Dense Layer ◽  
Lotus Effect ◽  
Nano Structure ◽  
Lotus Leaf ◽  
Water Drops ◽  
The Impact ◽  
Unique Chemical

Lotus leaves have become an icon for superhydrophobicity and self-cleaning surfaces, and have led to the concept of the ‘Lotus effect’. Although many other plants have superhydrophobic surfaces with almost similar contact angles, the lotus shows better stability and perfection of its water repellency. Here, we compare the relevant properties such as the micro- and nano-structure, the chemical composition of the waxes and the mechanical properties of lotus with its competitors. It soon becomes obvious that the upper epidermis of the lotus leaf has developed some unrivaled optimizations. The extraordinary shape and the density of the papillae are the basis for the extremely reduced contact area between surface and water drops. The exceptional dense layer of very small epicuticular wax tubules is a result of their unique chemical composition. The mechanical robustness of the papillae and the wax tubules reduce damage and are the basis for the perfection and durability of the water repellency. A reason for the optimization, particularly of the upper side of the lotus leaf, can be deduced from the fact that the stomata are located in the upper epidermis. Here, the impact of rain and contamination is higher than on the lower epidermis. The lotus plant has successfully developed an excellent protection for this delicate epistomatic surface of its leaves.

Methods for Defining the Concentration of Nanostructured Powders in Protective Gas and its Effect on the Microstructure of Deposit Metal

2015 ◽  
Vol 770 ◽  
pp. 28-33 ◽  
Author(s):  
M.A. Kuznetsov ◽  
Svetlana A. Barannikova ◽  
Evgeniy A. Zernin ◽  
A.V. Filonov ◽  
D.S. Kartcev
Keyword(s):  
Chemical Composition ◽  
Austenitic Steel ◽  
Arc Welding ◽  
Metal Structure ◽  
Structure Of Metal ◽  
Deposited Metal ◽  
Protective Gas ◽  
Equilibrium Microstructure ◽  
Positive Effect ◽  
Nanostructured Powders

The effect on the deposited metal structure of nanostructured modifiers introduced into the weldpool has been studied. Methods have been developed for determining the concentration of nanostructured powders of tungsten, molybdenum and Al2O3 in protective gas and for defining their optimal concentration. The influence of nanopowders on the structure of deposited metal was examined in consumable electrode arc welding employing the austenitic steel (chemical composition: C – 0,12%, Cr – 18%, Ni – 10%,Ti – 1%) as deposit and 1.2-mm welding wire manufactured from the austenitic steel (chemical composition: C – 0,12%, Cr – 18%, Ni – 9%,Ti – 1%). Addition of nanostructured powders of tungsten, molybdenum and Al2O3 to the weldpool has shown positive effect on the structure of metal in arc welding. It is shown that introducing the powders decreases dendrite size and leads to the formation of a more equilibrium microstructure of the weld.

scholarly journals Towards a better understanding of the origins, chemical composition and aging of oxygenated organic aerosols: case study of a Mediterranean industrialized environment, Marseille

2013 ◽  
Vol 13 (15) ◽  
pp. 7875-7894 ◽  
Author(s):  
I. El Haddad ◽  
B. D'Anna ◽  
B. Temime-Roussel ◽  
M. Nicolas ◽  
A. Boreave ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Organic Aerosols ◽  
Industrial Emissions ◽  
Aerosol Mass Spectrometer ◽  
Statistical Confidence ◽  
Aerosol Mass ◽  
Novel Approach ◽  
Organic Markers ◽  
The Impact ◽  
First Time

Abstract. As part of the FORMES summer 2008 experiment, an Aerodyne compact time-of-flight aerosol mass spectrometer (cToF-AMS) was deployed at an urban background site in Marseille to investigate the sources and aging of organic aerosols (OA). France's second largest city and the largest port in the Mediterranean, Marseille, provides a locale that is influenced by significant urban industrialized emissions and an active photochemistry with very high ozone concentrations. Particle mass spectra were analyzed by positive matrix factorization (PMF2) and the results were in very good agreement with previous apportionments obtained using a chemical mass balance (CMB) approach coupled to organic markers and metals (El Haddad et al., 2011a). AMS/PMF2 was able to identify for the first time, to the best of our knowledge, the organic aerosol emitted by industrial processes. Even with significant industries in the region, industrial OA was estimated to contribute only ~ 5% of the total OA mass. Both source apportionment techniques suggest that oxygenated OA (OOA) constitutes the major fraction, contributing ~ 80% of OA mass. A novel approach combining AMS/PMF2 data with 14C measurements was applied to identify and quantify the fossil and non-fossil precursors of this fraction and to explicitly assess the related uncertainties. Results show with high statistical confidence that, despite extensive urban and industrial emissions, OOA is overwhelmingly non-fossil, formed via the oxidation of biogenic precursors, including monoterpenes. AMS/PMF2 results strongly suggest that the variability observed in the OOA chemical composition is mainly driven in our case by the aerosol photochemical age. This paper presents the impact of photochemistry on the increase of OOA oxygenation levels, formation of humic-like substances (HULIS) and the evolution of α-pinene SOA (secondary OA) components.

scholarly journals Comparison of Different Methods for Extracting the Astaxanthin from Haematococcus pluvialis: Chemical Composition and Biological Activity

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3569
Author(s):  
Yicheng Tan ◽  
Zhang Ye ◽  
Mansheng Wang ◽  
Muhammad Faisal Manzoor ◽  
Rana Muhammad Aadil ◽  
...  
Keyword(s):  
High Pressure ◽  
Biological Activity ◽  
Chemical Composition ◽  
Haematococcus Pluvialis ◽  
Activity Analysis ◽  
Cell Disruption ◽  
Dependent Manner ◽  
Dpph Activity ◽  
The Impact ◽  
Dose Dependent

In this study, the impact of different cell disruption techniques (high-pressure micro fluidization (HPMF), ionic liquids (ILs), multi-enzyme (ME), and hydrochloric acid (HCl)) on the chemical composition and biological activity of astaxanthin (AST) obtained from Haematococcus pluvialis was investigated. Results indicated that all cell disruption techniques had a significant effect on AST composition, which were confirmed by TLC and UPC2 analysis. AST recovery from HCl (HCl-AST) and ILs (ILs-AST) cell disruption techniques was dominant by free and monoesters AST, while AST recovery from HPMF (HPMF-AST) and ME (ME-AST) cell disruption techniques was composed of monoesters, diesters, and free AST. Further biological activity analysis displayed that HCl-AST showed the highest ABTS and DPPH activity, while ILs-AST showed better results against the ORAC assay. Additionally, ILs-AST exhibits a stronger anti-proliferation of HepG2 cells in a dose-dependent manner, which was ascribed to AST-induced ROS in to inhibit the proliferative of cancer cells.

Construction and survey of changes in electric arc furnace parameters based on energy conservation model using Pscad software

2021 ◽  
Vol 15 (1) ◽  
pp. 75-83
Author(s):  
Ngoc Toan Luong ◽  
◽  
Duc Tung Doan
Keyword(s):  
Energy Conservation ◽  
Power Quality ◽  
Power Level ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
Electricity Grid ◽  
Power Quality Improvement ◽  
Conservation Model ◽  
The Impact

Actual analysis showed that the arc furnace current contains many harmonics that adversely affect the power quality. There are many domestic and foreign reports on modeling and assessing the impact of EAF on the grid based on different models. However, EAF's selection of capacity for research and application of power quality improvement devices suitable to the power level has not been mentioned, these models are mainly built on Matlab Simulink software. should be primarily academic. PSCAD is one of the widely used software for electrical system simulation and is used by large companies such as ABB, Korean power corporation Kepco. Building EAF model with PSCAD software will increase the ability to apply simulation results into practice. The objective of the paper is to build an electric arc furnace model based on the energy conservation model with PSCAD software, thereby assessing the change of parameters in the model and the effect of this load on electricity grid during operation.

Influence of flour from oilseed meal on sugars content in rye bread

2021 ◽  
Vol 9 (16) ◽  
pp. 57-68
Author(s):  
Halyna Voloshchuk ◽  
Keyword(s):  
Chemical Composition ◽  
Mass Fraction ◽  
Raw Materials ◽  
Sugar Content ◽  
Jerusalem Artichoke ◽  
Oilseed Meal ◽  
Rye Bread ◽  
Rye Flour ◽  
Pumpkin Seeds ◽  
The Impact

Subject of research – sugar content in rye bread with fractionally defatted flour from walnuts, pumpkin seeds, sesame and Jerusalem artichoke powder. The purpose – to investigate the chemical composition of sugars in flour from oilseed meal and to explain the impact of new raw materials upon the sugar content in bread made from rye flour. Materials and methods. For the production of pilot of bread used: rye flour; fermented rye malt; table salt; drinking water; ready liquid rye sourdough (composition: Lactobacillus plantarum 30, L .casei 26, L. fermenti 34, L .brevis and Saccharomyces minor "Chernorichenskaya", S. cerevisiae L1); fractionally defatted flour from walnuts, pumpkin seeds and sesame produced by PE "Research and Production Company "Elitfito"; Jerusalem artichoke powder "Dar". The dough was prepared in a three-phase way: liquid sourdough – saccharified choux – dough. Jerusalem artichoke powder and oilseed meal were added to the dough. The chemical composition of sugars in raw materials and bread was determined by high-performance liquid chromatography. The effect of fractionally defatted flour on the course of processes in rye dough was performed on a farinograph and amylograph of Brabender. The intensity of gas formation of the dough was determined on the device AG-1. Changes in the crystal structure of the bread crumb were performed using X-ray phase analysis on the device DRON UM-1 in the range of angles 2θ from 5 to 60 degrees. Results. It is established that the share of sugars in flour from oilseed meal is 2 ... 8 times higher than the content of sugars in rye flour. The content of sugars in fractionally defatted flour from walnuts is 43.0 %, from pumpkin seeds – 14.2 %, from sesame – 12.8% by weight of dry matter. Up to 80% of all sugars in fractionally defatted flour are sucrose and maltose. The ratio of fructose to glucose in fractionally defatted flour from walnuts is 1:1.25; from pumpkin seeds – 1:0.73; of sesame seeds – 1:0.5. The addition of 7.0 % fractionally defatted flour mixed with 3 % of the Jerusalem artichoke powder reduces the mass fraction of sugars in bread compared to the bread made with Jerusalem artichoke only. It has been studied that fractionally defatted flour from walnuts, pumpkin seeds and sesame reduces the hydrolytic decomposition of rye flour starch and promotes the process of fermentation of sugars. Scope. A mixture of fractionally defatted flour from oilseed meal in the amount of 7 % should be used for the production of bread from rye flour with 3 % Jerusalem artichoke powder to the mass fraction of flour to reduce the content of high glycemic starch sugars.

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