International Journal of Materials
E-ISSN: 2313-0555
Volume 8, 2021
Notice: As of 2014 and for the forthcoming years, the publication frequency/periodicity of NAUN Journals is adapted to the 'continuously updated' model. What this means is that instead of being separated into issues, new papers will be added on a continuous basis, allowing a more regular flow and shorter publication times. The papers will appear in reverse order, therefore the most recent one will be on top.
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Volume 8, 2021
Title of the Paper: Qualitative and Quantitative Determination of Montmorillonite Using Infrared Spectrometry
Authors: A.F. Altzoumailis, V. N. Kytopoulos
Pages: 105-108
DOI: 10.46300/91018.2021.8.14 XML
Abstract: The present study investigates the various possibilities of qualitative and quantitative analysis of montmorillonite (1/2Ca, Na) 0.7 (Al, Mg, Fe) 4 (Si, Al) 8O20 (OH) 4. n H2O (MT), major constituent of Bendonite coming the island Milos-Greece, using infrared (IR) spectroscopy and preparing the samples with KBr. X-Ray diffraction diagrams were obtained for the determination of their mineralogical composition. Observation of IR spectra of sample with different MT content revealed that the Si-O-Si vibration band at 1038cm-1 sharpens with increasing MT content. The combination of the above techniques led to a convenient determination of the minerals, contained in the sample and to a discrimination of identical oscillations, observed in different minerals at the same wave number (1038cm-1)[1]. As far as the quantitative analysis concerns, in the case of MT, thirteen comparative samples of known composition were analysed. The obtained spectra were digitized and smoothed, within the area from 800 to 1200 cm-1, using the Savitzky – Golay method, followed by Lorentz function transformation. Due to overlap from other substances, the plot of a calibration curve for MT, and consequently the development of a model, describing the absorption / concentration correlation for a specific sample, were not satisfactory. So the calibration curve according to Lambert- Beer law [2, 3], required use of samples with high concentration of MT. To overcome this problem the calibration curve for MT was constructed using dilutions of standard samples containing more than 85% of the mineral, with SiO2, at the wave number of 1038cm-1. This curve was used for the determination of MT in unknown samples giving very good results compared with the mineralogical composition obtained by XRD.
Title of the Paper: On Modelling Approaches to the Influence of Mechanical Deformation on the Micromagnetic Activity in a Mild Steel
Authors: A. F. Altzoumailis, V. N. Kytopoulos
Pages: 95-104
DOI: 10.46300/91018.2021.8.13 XML
Abstract: In this study an attempt is made to develop a theoretical modelling by which the influence of certain mechanical deformation factors on the micromagnetic emission behavior of a low-carbon steel can reasonably be described and estimated. This modelling consists of a simple kinetics – kinematics – aided approach of the pinning state – controlled domain wall motion by which appropriate specific parameters are introduced. In this aspect the basic notion of specific micromagnetic activity (s.m.a.) is introduced by which the energetic strength of the activity is reflected. In this way, the synergetic effect of the quantitative (count rate) and qualitative (voltage) the detected micromagnetic Barkhausen emission (MBE) is taken into consideration. Thus it is possible, theoretically, to give a prediction of the general trend of changes in the s.m.a. under the influence of the tensile elastic as well as plastic deformation. For instance, one can demonstrate that tensile elastic deformation cannot influence the s.m.a. whereas plastic one leads to an increase in this. Furthermore, one can also predict that increasing permanent (residual) plastic deformation, obtained after unloading from prior tensile loading, leads to an obvious decrease in the s.m.a. Similar decrease in the s.m.a. can also be predicted for increasing rolling deformation by means of the same modelling approach used for the permanent tensile plastic deformation. Owing to the good agreement with the experimental results and the simplicity of the proposed theoretical approaches that can be seen as a promising valuable tool for further similar studies.
Title of the Paper: Energy Efficiency of DH System with Wood Chips Boiler Houses and Flue Gas Condensing Unit
Authors: Ăirts Vīgants, Gundars Galindoms, Ivars Veidenbergs, Dagnija Blumberga
Pages: 91-94
DOI: 10.46300/91018.2021.8.12 XML
Abstract: This study proposes a method for the evaluation of the efficiency of a heat supply system based on a correlation analysis of the data of the system's operations. The data from the system's operations have been analysed and a correlation equation has been applied to obtain the results of the analysis, which are then used for further calculations. The data can be divided into two groups: data characterising the condenser operations in the boiler house, and data characterising heating networks.
Title of the Paper: City Rhythms of Commuter Traffic Decarbonisation of Commuting in Vienna
Authors: Gerda Hartl
Pages: 84-90
DOI: 10.46300/91018.2021.8.11 XML
Abstract: Today’s distribution of residences and workplaces is a result of availability of cheap oil combined with human preferences for residence in low-density areas. Having reached Peak-Oil nowadays, common motorised mobility is under scrutiny: Not only its massive CO2 output but, most of all, its future scarcity demands urban and regional planning to anticipate the sustainable city of the future. In our work, we have looked at the city of Vienna, in which we have researched patterns of mobility regarding commuters. Our final goal is redensification as a means for transformation of the present state into a walkable city. To make that possible, our analysis provides insights into necessities of mode switching, according to the distances from workplaces. The model which we present is applicable not only to our research area, but to a variety of cities that want to achieve a sustainable settlement structure.
Title of the Paper: Environmental Performance Improvements and External Stakeholder Pressures in Companies with Certified Environmental Management System
Authors: Tiberio Daddi, Sara Tessitore, Francesco Testa, Fabio Iraldo
Pages: 76-83
DOI: 10.46300/91018.2021.8.10 XML
Abstract: The relationship between environmental performance and Environmental Management Systems has been widely investigated by international researches. Despite this, our paper adds new perspectives to the current literature framework. First, it is focused on companies with an Environmental Management System registered according to EMAS Regulation, while many previous studies considered also ISO14001 certified companies. Second, to achieve the objectives of this paper, a wide sample of Italian companies was considered, and the results of a questionnaire survey filled out by 143 organizations are reported. In addition, this study points out the relationship between environmental performance and stakeholder pressures which have not been thoroughly investigated in previous papers. The results show that EMAS positively influences performance on some environmental aspects such as water consumption and emissions into the atmosphere, while this positive influence is not confirmed for other aspects. The Public Authorities represent the stakeholder identified by the survey as the main external pressure to improve environmental performance.
Title of the Paper: Biological Potentiality to Remove Organic Solvents From Exhausted Air Emissions
Authors: Giovanni Cortella, Marcello Civilini
Pages: 70-75
DOI: 10.46300/91018.2021.8.9 XML
Abstract: The performance of an industrial prototype of a biological system was investigated during more than two years, for the treatment of exhaust gas from air emission of wooden painting activities. Two different type of VOCs mixture were treated at different weather conditions. Removal efficiencies were sufficiently high to maintain the outlet emissions within the legal thresholds. Particularly low costs for management were experienced, confirming the biofiltration a sustainable technology.
Title of the Paper: Study of Various Configurations of Hybrid PV/T System
Authors: H. Ben Cheikh El Hocine, M. Marir-Benabbas
Pages: 62-69
DOI: 10.46300/91018.2021.8.8 XML
Abstract: In this study, an attempt has been made to evaluate the theoretical performance and evaluation of a hybrid PV/thermal (PV/T) collector based on dual heat extraction operation a function of climatic and design parameters. On the first hand, the different configurations of hybrid collectors are considered for the present study which are defined as unglazed PV/T air heaters, with and without tedlar, PVT hybrid water collector, in the second hand two configurations with dual extraction operation (water and air as heat removal fluid) are presented which are defined as dual PV/T model with tedlar, dual hybrid PV/T without tedlar. Analytical expressions for the temperatures of solar cells, back surface of the module, outlet air, and outlet water of those configurations have been derived. Numerical computations have been carried out for composite climate and the results for different configurations have been compared. Our results clearly show the direct impact of various parameters, in particular the solar radiation, ambient temperature, mass flow rate on the variation of outlet and solar cell of the collector.
Title of the Paper: Dynamic Compressive Strength of Recycled Aggregate Concrete
Authors: Shamsoon Fareed, Asad-ur-Rehman Khan, Samra Masood
Pages: 56-61
DOI: 10.46300/91018.2021.8.7 XML
Abstract: Over the years the construction waste has enormously increased, this may be attributed to different factors such as (i) demolition (ii) accidents (iii) impact loads (iv) earthquakes. These activities have caused an increasing burden on already exhausted waste management system globally. As a result, the concrete waste produced in a large quantity has become a major issue to manage due to limited landfill sites. Therefore, the recycling of waste concrete can prove to be beneficial and necessary for the environmental preservation and effective utilization of natural resources. Number of studies have been conducted to study the static mechanical properties of recycled aggregate concrete; however, limited test data has been published which focused on the dynamic properties of the concrete prepared with recycled coarse aggregates. Therefore, in this investigation aim was to study the behavior of recycled aggregates concrete under increasing dynamic compressive loading. For this purpose, cylindrical specimens having a diameter of 100 mm and height of 200 mm were used. These specimens have been prepared with constant concrete mix ratio, having varying percentages of RA such as 0%, 30%, and 50% 70 % and 100%. The dynamic compressive behaviour was studied by using drop hammer system. The height drop hammer system consist of a frame having a maximum height of 15ft. Firstly, three samples (1, 1R, 2R) from each percentage replacement (0%, 30%, 50%, 70% and 100%) were tested on six different velocities of 2.44m/s, 3.45m/s, 4.23m/s, 4.89m/s, 5.46m/s and 7.45m/s with varying strain rates of 12.04/s, 17.00/s, 20.83/s, 24.08/s, 26.89/s and 36.73/s respectively. Weight of the drop hammer was 10 kg. Based on the detailed experimental investigation, it was found that the behaviour of the recycled aggregate concrete under dynamic loading differ significantly from the static loading.
Title of the Paper: Uncompleted Fullerenelike Structures: Synthesis and Chracteristics
Authors: Kasumov Mais
Pages: 48-55
DOI: 10.46300/91018.2021.8.6 XML
Abstract: The literature is considering completely formed fullerenes as usually. Without attentions have been left uncompleted ones, and their properties are practically unknown. Such structures may be received at arc discharge synthesis in the limited space with short time of synthesis. Here synthesis was made at arc discharge chamber with little radius and less gas flow. The time-of-flight mass spectrum synthesized product on m/z size showed containing of hydrated uncompleted-composite fullerene. They were like with structures: C54H4, C56H4, C56H8, C68H4 and other. A presence at mass spectrum of abnormal structures was manifested in form of doublet many-peaks lines. They also confirmed termperature-formating of new bonds with successive griping valence bonds with poliin structures at arc discharge. From mass spectrum, on base of Mendileive’s chemical plate was supposed the way forming conjectural structure. The MS-picture was confirmed with estimation for forming many-peaks abnormal poliin like structures.
Title of the Paper: Synthesis, Structure, and Radioprotective Activity of the Palladium (II) Complex with Mexidol
Authors: Kh.I.Gasanov, S.I.Nurullayeva, Z.H.Babayev
Pages: 43-47
DOI: 10.46300/91018.2021.8.5 XML
Abstract: New complex compounds of palladium (II) with biologically active ligand 2 - ethyl - 6 methyl - 3 - hydroxy-pyridine - mexidol in acidic medium (pH = 5,3) of the following composition have been synthesized – -abstract-image1.png)
. In this case, the ligand is protonated and as a single-charged cation occupies an external coordination sphere. The structure of the complex is proved by X-ray structure analysis. It is shown that the structure is constructed of an isolated complex anion – -abstract-image2.png)
and cation -abstract-image3.png)
The square planar coordination of the palladium atom is formed from three chlorine atoms and the formed tetraacidoanion ligand forms a hydrogen bond. The average length of Pd-Cl bond is 2, 3030 -abstract-image4.png)
, there are no deviations from 900 valence angles of Cl-Pd-Cl. The palladium atom is not shifted from the plane coordination polyhedron (square) and therefore trance angles of Cl-Pd-Cl are 1800. Two different lengths -2,289 and 2,713 of hydrogen bonds are related to the geometric location of the ligand functional group. The obtained 2 – ethyl – 6 – methyl – 3 -hydroxypyridinetrachloro - palladium - mexidazole was tested for radioprotective properties. Toxicity of the preparation is LD50 - 240 mg/kg of animal weight. Toxicological studies of mexidazole in mice, rats and dogs did not reveal cardiotoxic, immunotoxic, embryonic, nephrotoxic, hematoxic and other types of side effects. Mexidazole is removed from the body with urine 5-8 hours after intravenous injection. The carried out biological test showed that the compound, along with radioprotective properties, has some antitumor activity.
Title of the Paper: On Novel Aspects of Hydrogen Effects on Applied Stress - Coupled Micromagnetic Activity in a Mild Steel After Exposure to NaCl – Water Solution: A Combined Approach
Authors: Alexandros Altzoumails, Victor Kytopoulos
Pages: 30-42
DOI: 10.46300/91018.2021.8.4 XML
Abstract: Hydrogen produced after exposure of a low – carbon steel to corrosive NaCl – Water solution may affect various its tensile mechanical and magnetic microstructural behaviour in a complex manner. This was investigated by introducing a relevant micromagnetic specific emission (ME) - response of this ferromagnetic material, where related processes and parameters of micromagnetic activity and mechanical response were implemented. In this manner, it was demonstrated that an increase in the hydrogen accumulation with corrosion time leads to an associated increase in the embrittling effect expressed by a substantial loss in the ductility of material. The competive and opposing effects of cumulative hydrogen, applied stress and plastic strain – induced microstructural damage were related to the specific ME- response parameter by which an increased magnetic hardening tendency of material with corrosion time was possible to establish. In this fashion and by using a stress as well as strain mode of presentation- aided combined approach, the complex interplay between micromagnetic activity, hydrogen accumulation and applied stress-strain was better revieled and analysed. It was also shown that the embrittlement is a product of hydrogen accumulation introduced by two highly localized processes. As such, accumulation occurs in two characteristic parallel ways: one of a common lattice diffusion and one of hydrogen transport and redistribution by moving dislocation towards the affected sites. Concerning the highly localized effects the dominating role of hydrogen – induced damage in form void initiation and growth over the hydrogen – assisted stress relief was reasonably demonstrated by using a simple modelling approach. Based on a mechanism of moving dislocation – assisted interaction between commulative hydrogen and magnetic domain walls, a Portervin – Le Chatelier – type micromagnetic process of a cooperative-corelated domain wall transport was proposed to explain certain subtle, quasiperiodic behaviour of ME- response. In the frame of the above findings the superior sensivity of ME – response compared to the mechanical one in early detecting cumulative hydrogen – assisted microstructural damage changes can be d educed.
Title of the Paper: Characterization of a Mild Steel by Its Mutual Tensile Mechanical and Micromagnetic Emission Response after Corrosion in NaCl – Water Solution: A Combind Semiquantitive Approach
Authors: A. F. Altzoumailis, V. N. Kytopoulos
Pages: 11-29
DOI: 10.46300/91018.2021.8.3 XML
Abstract: In this work, the influence of corrosion – induced hydrogen accumulation on a stressed low- carbon steel after exposure to NaCl - water solution was investigated by means of its combined tensile mechanical and Micromagnetic emission (ME) - response. The investigation was conducted by employing certain relevant parameters and processes of mechanical and magnetic microstructural changes. The mechanical and Micromagnetic response data were reduced to the ultimate tensile strength as well as to maximum (ME) - response respectively where certain critical- characteristic microstructural- transitional changes take place. Under these conditions and by an appropriate procedure of “consecutive - selective discrimination steps” of the related affecting factors their differential influence on the mechanical and ME – response was better revealed, compared and analyzed. In this manner it was demonstrated that the detrimental influence of cumulative hydrogen arises in from of mechanical embrittlement which can be related to a parallel magnetic hardening trend of the material. The explanations are given on the basis of highly localized and competitive or opposing processes of void initiation- growth and stress relive, resulting by a common lattice diffusion, as well as moving dislocation- aided transport of hydrogen to the affected sites. Within the frame of the above findings it was shown that the ME-response presents, compared with mechanical response, an increased sensitivity making the first a superior technique in early detecting hydrogen- assisted microstructural damage in loaded steel components
Title of the Paper: Phenol Sulfonic Acid Oxidation in Aqueous Solution by UV, UV/H2O2 and Photo-Fenton Processes
Authors: N. Jamshidi, M. T. Jafarzadeh, A. Khoshgard, L. Talebiazar, R. Aslaniavali
Pages: 6-10
DOI: 10.46300/91018.2021.8.2 XML
Abstract: In this study, advanced oxidation processes (UV, UV/H2O2, UV/H2O2/Fe(II) and UV/H2O2/Fe(III)) were investigated in lab-scale experiments for degradation of phenol sulfonic acid (PSA) in aqueous solution. The study showed that the UV/H2O2 process has removal percentage 90.9, 93.0 and 94.4 for neutral, basic and acidic conditions in 20 minutes respectively. The experimental results showed that the optimum conditions were obtained at a pH value of 3, with 4 mmol/1 H2O2, and 0.25 mmol/1 Fe(II) for the UV/H2O2/Fe(II) system and 6 mmol/l H2O2 and, 0.4 mmol/1 Fe(III) for the UV/H2O2/Fe(III) system. The reaction was influenced by the pH, the input concentration of H2O2 and the amount of the iron catalyst and the type of iron salt. As for the UV processes, UV/H2O2 showed the highest degradation rate under acidic conditions
Title of the Paper: Solar Hydrogen from Glycerol-Water Mixture
Authors: Chong Fai Kait, Ela Nurlaela, Binay K. Dutta
Pages: 1-5
DOI: 10.46300/91018.2021.8.1 XML
Abstract: The photocatalytic activity of titania supported bimetallic Cu-Ni photocatalysts were assessed for hydrogen production from water and also a mixture of glycerol-water system under visible light illumination. Addition of 2.0 mL glycerol to 8.0 mL water enhanced the solar hydrogen production from 6.1 mL to 9.5 mL. If metal was not incorporated onto TiO2, the hydrogen production was minimal, 2.0 mL after 2 hr reaction. The band gap for bimetallic Cu-Ni/TiO2 was 2.78 eV compared to 3.16 eV for TiO2. Photooxidation of glycerol produced glyceraldehyde, glycolic acid and oxalic acid.
