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1

Seasonal and Qualitative Approach of the Oued Mellègue Basin (Algeria)

Samai Ibtissem, Nebbache Saloua, Aounallah Ouafia, Ayat Somia Lakehal

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 3

184--191

EN

Water holds a particularly important place in our lives; it is a precious resource called: blue gold. Unfortunately, pollutants and pollution in general are the main causes of the degradation of the quality of water resources in the world. In this intention we have focused our research on a qualitative study of surface waters of the Oued Mellègue watershed (North East of Algeria), which is a tributary of Oued Medjerda (Souk-Ahras), whose objective is to estimate the intensity as well as the origin of the pollution that has contaminated this water course However, the results obtained reveal that the waters of this wadi are totally polluted and deteriorated, and they have lost all their physical and chemical qualities. And they become contaminated to the point that they have become harmful for the public and for the fauna and flora that shelter. So the research of solutions to the pollution of water resources must be in full swing, because the future of water is intimately linked to that of humanity. It must therefore be preserved and protected rigorously and with great accuracy.

2

Effect of Physico-Chemical Properties of Submerged Arc Welding Fluxes on Pipeline Steel - A Brief Review

Sharma Lochan, Chhibber Rahul

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

409-421

EN

Pipeline welding is an integral part of oil and gas exploration industries. Often the welded joint failures were due to lack of weld quality, improper heat treatment and even poor workmanship. Further, the use of new material in pipeline industry puts focus on a better understanding of qualifying requirements of welding for reducing the failures in future. This necessitates the need for development and design of suitable welding fluxes for joining these materials. In this paper an attempt is made to study the effects of submerged arc welding fluxes on weldability as well as structural integrity issues in pipeline steels. Physicochemical and thermophysical properties of submerged arc fluxes widely affects the mechanical behaviour of pipeline steels. This paper presents an overview of the role of welding parameters, flux composition, cooling rate, slag behaviour and physicochemical properties of slag on final welded joint properties such as tensile strength, impact toughness etc. during submerged arc welding.

3

Evaluation of the microbial, cytotoxic and physico-chemical properties of the stainless steel crowns used in pediatric dentistry

Sztyler Klaudia, Pajączkowska Magdalena, Nowicka Joanna, Rusak Agnieszka, Chodaczek Grzegorz, Nikodem Anna, Wiglusz Rafał J., Watras Adam, Dobrzyński Maciej

Acta of Bioengineering and Biomechanics

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2022

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Vol. 24, no. 4

127--137

EN

Preformed stainless steel crowns are used in pediatric dentistry to obtain full crown restoration of primary molar teeth. They are consider the best restoration in terms of durability and effectiveness. The purpose of this study is to evaluate microbial, cytological and physio-chemical properties to determine whereas stainless steel crown are biocompatible, safe for surrounding tissue and helpful in avoiding micro-organisms influence on the tooth tissue. Based on the results, it was determined that stainless steel crowns used in pediatric dentistry represent no cytotoxic risk to the surrounding tissues, have a low probability of developing hypersensitivity to the coronal material and also that their biological properties make them suitable to use in pediatric dentistry for the reconstruction of damaged primary molar tissue.

4

Analiza właściwości oleju pirolitycznego pod kątem jego magazynowania, transportu i użytkowania

Czardybon Agata, Ignasiak Karina

Przemysł Chemiczny

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2021

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T. 100, nr 5

436--444

PL

Przeprowadzono testy stabilności oleju pirolitycznego, polegające na analizie zmian jego lepkości dynamicznej, zawartości wody oraz składu lotnych związków organicznych. Badania wykazały stosunkowo ograniczoną stabilność oleju podczas przechowywania, zwłaszcza w podwyższonych temperaturach, objawiającą się wzrostem lepkości oraz zawartości wody. Po okresie przechowywania oleju zaobserwowano spadek stężenia reaktywnych związków tlenowych odpowiadających za jego stabilność. Ze względu na znaczną zawartość wody w badanym biooleju podjęto próby jego waloryzacji metodą wirowania, ekstrakcji oraz inwersji faz emulsji. Przeprowadzono także testy mieszalności biooleju z olejem napędowym i RME w celu waloryzacji oleju pirolitycznego jako potencjalnego paliwa silnikowego.

EN

Pyrolysis oil produced from pine wood by rapid biomass pyrolysis was tested for water content, dynamic viscosity, and oil volatile organic fraction compn. The oil showed relatively limited storage stability, especially at elevated temp. A decrease in the concn. of reactive O compds. responsible for the oil stability was observed after its storage period. The miscibility of pyrolysis oil with diesel fuel and rapeseed methyl esters was tested to develop a method of pyrolysis oil valorization as a potential engine fuel.

5

Badanie fizyczno-chemicznych właściwości stałych produktów pirolizy zanieczyszczonych i zmieszanych tworzyw sztucznych

Ścierski Waldemar

Przemysł Chemiczny

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2020

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T. 99, nr 9

1366--1368

PL

Przedstawiono wyniki badań podstawowych właściwości fizyczno-chemicznych stałego produktu procesu pirolizy niskotemperaturowej. Badaniom poddano karbonizaty pochodzące z pirolizy zanieczyszczonych folii, prowadzonej w temp. 425°C, 450°C lub 475°C, oraz karbonizaty pochodzące z pirolizy tworzyw zmieszanych prowadzonej w takich temperaturach. Przeprowadzono badania gęstości nasypowej i wartości opałowej, zawartości chloru, azotu ogólnego, siarki, węgla, wodoru, części lotnych, części palnych oraz popiołu. Oznaczenia przeprowadzono zgodnie z obowiązującymi normami.

EN

Two types of plastic wastes, foils and plasic bags as well as materials from the recycling of worn-out vehicles were processed by low-temp. pyrolysis at 425°C, 450°C, 475°C. The carbonizates were tested for the contents of C, Cl, N, S and H. Their bulk d., heat of combustion, calorific value, volatile and flammable parts and ash content were detd.

6

Radiological and health hazards resulting from radioactivity and elemental composition of some soil samples

Al-Khawlany Abdu Hamoud, Khan A. R., Pathan J. M.

Polish Journal of Medical Physics and Engineering

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2020

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Vol. 26, Iss. 2

97--110

EN

Inspection of the radioactivity level in the soil is very important for human health and environmental protection. This study aims at evaluating the radiological hazards and pollution risks related to natural radionuclides and elements in the selected soil samples. Ten samples of soil were collected from different sites of Aurangabad-India and the level of radioactivity was measured using gamma-ray spectrometry with NaI (Tl) detector. Furthermore, the Physico-chemical properties such as pH, organic matter, electrical conductivity, moisture, soil texture, etc., and elemental composition of soils have been decided on using various standard techniques. The mean concentrations of 226Ra, 232Th, and 40K were 8.178, 17.408, and 96.496 Bq/kg, respectively, which are lower than the global average values of 35, 30, and 400 Bq/kg, respectively (UNSCEAR, 2000). The radiological hazard indices such as radium equivalent, absorbed dose, annual effective dose, internal index, external index, gamma index, excess lifetime cancer risk, etc., were calculated to assess the radiation hazards and compared with internationally recommended values which found to be lower than the permissibility limits.

7

Structural, optical, morphological and SHG studies on 8 MeV electron beam irradiated Sr(HCOO)2·2H2O crystal

Muthupoongodi S., Manickam S. Theodore David, Mahadevan C. K., Greena J. Angel Mary, Balakumar S., Ananthapadmanabhan P. V., Shajan X. Sahaya

Materials Science Poland

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2020

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Vol. 38, No. 2

236--247

EN

Strontium formate dihydrate single crystals have been grown by the slow solvent evaporation method and subjected to 8 MeV electron beam (EB) irradiation at different doses, viz. 1 kGy, 10 kGy, 50 kGy and 100 kGy. The irradiated crystals have been studied by various techniques such as FT-IR, Raman, and UV-Vis-NIR spectral analyses, powder, and high resolution X-ray diffraction, thermogravimetric analysis (TG/DTA) and second harmonic generation (SHG) measurements. The morphological features of the non-irradiated and irradiated crystals were analyzed by SEM and optical microscopy studies. It has been noticed that the SHG efficiency increases while the crystalline perfection and thermal stability of the irradiated crystals decrease with the increase of EB irradiation dose. The results indicate a significant overall tuning of physical properties of strontium formate dihydrate crystals due to irradiation.

8

Properties of Reactive Materials for Application in Runoff Water Treatment Systems

Fronczyk Joanna

Journal of Ecological Engineering

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2020

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Vol. 21, nr 8

185--197

EN

The emissions related to urbanized areas, including communication routes and accompanying facilities, are considered as essential sources of subsoil pollution. Enhancement of the naturally occurring removal processes in infiltration systems, e.g. through placing the appropriately selected materials (treatment zones) on the flow path of runoff water, prevents the spread of undesirable components. The article presents the analysis of tests checking the properties of selected low-cost mineral materials, activated carbon and zero-valent iron in terms of their applicability in the runoff water treatment zones. Their physical features, surface structure, and chemical and hydraulic properties were analysed. The test results indicate a well-developed surface area of active carbon and halloysite, as well as an extensive pore volume of active carbon, halloysite, zeolite and diatomite. Nevertheless, the average pore diameters indicated the potential limited access of pollutants to the inner structure of all analyzed materials. The chemical parameters point to the stimulation potential of precipitation processes by limestone sand and silica spongolite, ion exchange by zeolite and silica spongolite, and oxidation-reduction processes by zero-valent iron. The value of the material hydraulic conductivity may potentially limit their application in infiltration systems. Taking into account all analyzed parameters, activated carbon together with silica spongolite and zeolite have the best application potential.

9

Physico-chemical characterization and biological tests of silk fibroin/collagen/chitosan materials, cross-linked by glyoxal solution

Grabska-Zielińska Sylwia, Sionkowska Alina, Monteiro Fernando J., Coelho Catarina C., Lewndowska Katarzyna

Engineering of Biomaterials

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2020

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Vol. 23, no. 158 spec. iss.

20

10

Synthesis of new carbon-nitrogen composites based on waste sweet drinks

Kaźmierczak-Raźna Justyna, Pietrzak Robert, Nowicki Piotr

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1366--1374

EN

The materials under investigation were new carbon-nitrogen composites obtained via pyrolysis and CO2 activation of sweet drinks destined for utilization. Waste Pepsi Cola® has been examined as an alternative and renewable carbon source for composite materials. Nitrogen was introduced into the Pepsi Cola® solution via the addition of guanidine carbonate, before the pyrolysis process. The physicochemical properties of the materials studied were characterized by low- temperature nitrogen adsorption (using BET and BJH methods), elemental analysis, FTIR spectroscopy, scanning electron microscopy (SEM) as well as determination of pHPZC and the number of surface functional groups. Additionally, thermal properties of the samples were investigated by thermogravimetric analysis (TG) and differential thermogravimetry (DTG). The final products were new carbon-nitrogen composites characterized by a very high content of nitrogen (11.2 - 21.6 wt.%) as well as relatively low surface area and pore volume reaching 198 m2/g and 0.16 cm3/g, respectively. Results of FT-IR study and Boehm titration indicated that the composites surface has clearly basic character, which was confirmed by pHpzc values above 8.0.

11

Characterization of the reactivity of mineral additions by different microstructural and mechanical approaches

Bouglada M. S., Naceri A., Baheddi M.

Mining Science

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2018

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Vol. 25

129--146

EN

This paper presents an experimental study aimed at evaluating the reactivity of natural and industrial local mineral additions (pozzolan, slag and limestone) by different microstructural and mechanical approaches. Binary, ternary and quaternary cement compositions were prepared with partial replacement of the clinker by additions limited to 20%, according to CEM II / A cement specifications. The reactivity during the hydration process is characterized by the hydraulic power of the additions to react with the water and the hydrates of the cement and the pozzolanic capability of fixing the portlandite to form new mineral phases which contribute to the resistance as much as the hydrated products of cement. An experimental methodology was established for the reactivity illustration of the additions by a microstructural approach based on a study of the physicochemical and microstructural properties realized by X-ray diffraction (XRD), the scanning electron microscopy (SEM) on pastes. Further, thermogravimetric analysis (TGA), mercury microporosity (MIP) on mortars at 28 days of age was performed. A mechanical approach based on compressive strength at 2, 7 and 28 days to determine the activity index according to ASTM C 618 has been undertaken. The results obtained show a good correlation between the microporosity, X-ray diffraction and the resistance activity index, in particular for the slag, as for the thermogravimetric analysis that clearly confirms the pozzolanic activity of the pozzolan addition. As for mechanical performance, a binary mortar with 20% slag showed a better compressive strength at 28 days (49.40 MPa) with a reactivity index (87.90%) compared to the control mortar. Further, the slag developed better resistance (49.53 MPa) in combination with the other additions for quaternary mortars (pozzolan, limestone and slag) with an optimal rate of 5, 5 and 10%, respectively. Nevertheless, the pozzolan showed better compressive strength values compared to the slag for the binary mortars at young age 2 and 7 days of 25.67 and 32.07 MPa, respectively.

12

Influence of Sterilization and Exposure to the Ringer's Solution on Mechanical and Physicochemical Properties of Nitrocarburized 316 LVM Steel

Kajzer A., Rabij K., Basiaga M., Nowińska K., Kaczmarek M., Borowski T., Wierzchoń T.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 3

1257--1266

EN

Studies on biocompatibility of AISI 316LVM steel indicate the need to eliminate the nickel from the surface and replace it with other elements of improved biocompatibility. Therefore, in the presented work selected physicochemical and mechanical properties of the diffusive nitrocarburized layer formed by plasma potential by means of an active screen made of the Fe-Cr-Ni were studied. In the paper we present results of microstructure and phase composition of the layers, roughness, and surface wettability, potentiodynamic pitting corrosion resistance, penetration of ions into the solution as well as mechanical properties. The studies were conducted for the samples of both mechanically polished and nitrocarburized surfaces, after sterilization, and exposure to the Ringer’s solution. Deposition of the nitrocarburized layer increased the contact angle, surface roughness, surface hardness, and corrosion resistance with respect to the polished surfaces. The nitrocarburized layer is a barrier against the ions release into the solution and sterilization and exposure to Ringer solution. The obtained results showed beneficial increase of both mechanical and electrochemical properties of the deposited layer, and thus the applicability of the proposed method of surface treatment of the 316 LVM steel for short-term implants after sterylization.

13

Wybrane technologie wzbogacania fizykochemicznego materiałów bardzo drobno uziarnionych

Blaschke Z.

Inżynieria Mineralna

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2002

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nr S. 1

145--155

PL

W procesie wzbogacania ziaren drobnych wykorzystuje się różnice w fizykochemicznych właściwościach minerałów użytecznych i skały płonnej. Przemysłową metodą wzbogacania ziaren drobnych jest metoda flotacji. Od wielu lat, w kraju i za granicą prowadzi się badania nad wzbogacaniem ziaren drobnych i skrajnie drobnych innymi metodami, np. aglomeracji olejowej, flokulacji selektywnej, koagulacji hydrofobowej. Wykład ograniczono do omówienia tych procesów w zastosowaniu do wzbogacania węgla.

EN

In the process of fine grains beneficiation, the differences in physical-chemical properties of usable minerals and waste rock are used. Flotation is an industrial method of fine grains beneficiation. For many years, in the country and abroad, the research on beneficiation processes of fine and very fine grains using other methods like oil agglomeration, selective flocculation, hydrophobic coagulation, is conducted. The lecture is limited to discussing these methods in relation to coal beneficiation.