New Materials and Advanced Procedures of Obtaining and Processing II

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Materials Science and Engineering".

Deadline for manuscript submissions: closed (31 December 2023) | Viewed by 10187

Special Issue Editors


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Guest Editor
Faculty of Material Science and Engineering, Technical University of Iasi Gheorghe Asachi, 700050 Iasi, Romania
Interests: material science; biomaterials; surface; aerosols; coatings; chemical and physical deposition

Special Issue Information

Dear Colleagues,

After our successful Special Issue “New Materials and Advanced Procedures of Obtaining and Processing”, we have decided to establish a second volume, which will continue to publish state-of-the-art research in the field of new materials and their understanding.

This second volume, similarly to its predecessor, is focused on highlighting the most recent contributions in the field of materials and procedures from a broad range of applications, from medical to civil engineering.

The main applications are related to materials involved in environmental engineering, medicine, dentistry, and civil engineering as well as the procedures for the processing and treatment of various materials.

The studied materials can be from nano to macro scale and involve alloys, ceramics, composites, biomaterials, polymers, and more. We welcome the submission of a variety of manuscripts, from theoretical approaches (modeling or simulation) to advanced insights into materials and procedures.

For this Special Issue of Applied Sciences, it is my pleasure to invite you to submit reviews and articles addressing the abovementioned areas.

Prof. Dr. Andrei Victor Sandu
Dr. Ioan-Gabriel Sandu
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (5 papers)

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Research

14 pages, 2530 KiB  
Article
Alkaline-Activation Technique to Produce Low-Temperature Sintering Activated-HAp Ceramic
by Wan Mohd Arif W. Ibrahim, Mohd Mustafa Al Bakri Abdullah, Noorina Hidayu Jamil, Hasmaliza Mohamad, Mohd Arif Anuar Mohd Salleh, Andrei Victor Sandu, Petrica Vizureanu, Madalina Simona Baltatu and Patimapon Sukmak
Appl. Sci. 2023, 13(4), 2643; https://doi.org/10.3390/app13042643 - 18 Feb 2023
Viewed by 1172
Abstract
The fabrication of hydroxyapatite (HAp) ceramics prepared by existing conventional sintering requires high-temperature sintering of 1250 °C to 1300 °C. In this paper, the activated metakaolin (MK)/HAp specimens were prepared from varied mix design inputs, which were varied solid mixtures (different amounts of [...] Read more.
The fabrication of hydroxyapatite (HAp) ceramics prepared by existing conventional sintering requires high-temperature sintering of 1250 °C to 1300 °C. In this paper, the activated metakaolin (MK)/HAp specimens were prepared from varied mix design inputs, which were varied solid mixtures (different amounts of MK loading in HAp) and liquid-to-solid (L/S) ratios, before being pressed and sintered at 900 °C. Phase analysis, thermal analysis, surface morphology, and tensile strength of the specimens were investigated to study the influences of the Al, Si, Fe, Na, and K composition on the formation of the hydroxyapatite phase and its tensile strength. XRD analysis results show the formation of different phases was obtained from the different mix design inputs HAp (hexagonal and monoclinic), calcium phosphate, sodium calcium phosphate silicate and calcium hydrogen phosphate hydrate. Interestingly, the specimen with the addition of 30 g MK prepared at a 1.25 L/S ratio showed the formation of a monoclinic hydroxyapatite phase, resulting in the highest diametrical tensile strength of 12.52 MPa. Moreover, the increment in the MK amount in the specimens promotes better densification when sintered at 900 °C, which was highlighted in the microstructure study. This may be attributed to the Fe2O3, Na2O, and K2O contents in the MK and alkaline activator, which acted as a self-fluxing agent and contributed to the lower sintering temperature. Therefore, the research revealed that the addition of MK in the activated-HAp system could achieve a stable hydroxyapatite phase and better tensile strength at a low sintering temperature. Full article
(This article belongs to the Special Issue New Materials and Advanced Procedures of Obtaining and Processing II)
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22 pages, 7078 KiB  
Article
Technological and Functional Approaches Applied to Miniature Vessels with Pigment Traces: Two Middle Bronze Age Case Studies from Eastern Subcarpathians of Romania
by Ana Drob, Viorica Vasilache and Neculai Bolohan
Appl. Sci. 2023, 13(4), 2093; https://doi.org/10.3390/app13042093 - 06 Feb 2023
Viewed by 1256
Abstract
Vessels with a special shape have always been a point of interest for pottery studies, especially from the perspective of the distinct functionality that these pots would have had. The ceramic typologies made for the miniature finds specific to the Middle Bronze Age [...] Read more.
Vessels with a special shape have always been a point of interest for pottery studies, especially from the perspective of the distinct functionality that these pots would have had. The ceramic typologies made for the miniature finds specific to the Middle Bronze Age in the Eastern Carpathian area include a series of such vessels attributed to the Costișa communities. Currently, the role of these pots is still under debate, being classified as ritual or special, which led to two case studies focused on investigating these miniatures. The analyzed vessels come from the Piatra Neamț—Bâtca Doamnei and Siliștea—Pe Cetățuie settlements (Neamț County), where these containers were discovered with traces of pigment or in association with colored minerals. These findings led to a series of questions related to their use, as it is known that in the Middle Bronze Age there are not many archaeological discoveries that explain the presence of pigments in the studied area. In this sense, multiplication of information was achieved by performing detailed analyses, such as optical microscopy (texture and surface details), colorimetry CIE L*a*b* (color investigation), SEM-EDX (elemental composition) and µ-FTIR (chemical compounds). The results of the interdisciplinary study led to new data on the nature of the pigment and the method of preparation, and also clues on the source of the raw material. Thus, these items illustrate the special use of miniature vessels and their probable functions. Full article
(This article belongs to the Special Issue New Materials and Advanced Procedures of Obtaining and Processing II)
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16 pages, 3072 KiB  
Article
Assessment of Persistence of Gunshot Residues Produced by Firearms from Criminal Cases in the Republic of Kosovo
by Milazim Tahirukaj, Andriana Surleva, Petrica Vizureanu, Blerim Olluri and Andrei Victor Sandu
Appl. Sci. 2022, 12(20), 10477; https://doi.org/10.3390/app122010477 - 17 Oct 2022
Cited by 2 | Viewed by 2280
Abstract
Gunshot residue (GSR) is a material formed during firearm discharge with a specific spheroidal/noncrystalline morphology and chemical composition. The examination of gunshot residue by SEM/EDS is an important tool in forensic studies and presents supporting evidence in criminal investigations. This study is aimed [...] Read more.
Gunshot residue (GSR) is a material formed during firearm discharge with a specific spheroidal/noncrystalline morphology and chemical composition. The examination of gunshot residue by SEM/EDS is an important tool in forensic studies and presents supporting evidence in criminal investigations. This study is aimed at exploring the number of particles characteristic of GSR identified by SEM/EDS as a function of time, gun caliber, the number of shots, and weather conditions. Firearms typically used in criminal cases in Kosovo were studied, and the experiments were conducted outdoors in the summer and winter seasons. Nine people made different numbers of shots from one to nine and followed a common office routine. An optimized and validated SEM/EDS protocol was applied with a sensitivity of 95%, a bias of −5%, a repeatability of 2% (RSD), a within-lab reproducibility of 2% (RSD), and an expanded uncertainty of the number of GSR particles of 6% at coverage factor k = 2. The results showed that GSR particles could be identified by SEM/EDS five to seven hours after shooting, depending on the weapon used and number of produced shots. The results will benefit forensic scientists by providing a supportive tool for hypothesizing the time interval between firearm discharge and GSR sampling. Full article
(This article belongs to the Special Issue New Materials and Advanced Procedures of Obtaining and Processing II)
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18 pages, 3802 KiB  
Article
In Vitro Antibacterial Activity of Some Plant Essential Oils against Four Different Microbial Strains
by Daniela Gheorghita, Alina Robu, Aurora Antoniac, Iulian Antoniac, Lia Mara Ditu, Anca-Daniela Raiciu, Justinian Tomescu, Elena Grosu and Adriana Saceleanu
Appl. Sci. 2022, 12(19), 9482; https://doi.org/10.3390/app12199482 - 21 Sep 2022
Cited by 9 | Viewed by 3332
Abstract
This study evaluates the antimicrobial and antioxidant activities of five essential oils (EO): pine oil, thyme oil, sage oil, fennel oil, and eucalyptus essential oils. To identify the chemical composition of the essential oils, we used gas chromatography coupled to a mass spectrometer [...] Read more.
This study evaluates the antimicrobial and antioxidant activities of five essential oils (EO): pine oil, thyme oil, sage oil, fennel oil, and eucalyptus essential oils. To identify the chemical composition of the essential oils, we used gas chromatography coupled to a mass spectrometer (GC-MS). EO are predominantly characterized by the presence of monoterpene hydrocarbons and oxygenated monoterpenes, except in the case of fennel essential oil which contains phenylpropanoids as its main components. The antimicrobial activity of the EO was highlighted on four standard microbial strains (two Gram-negative strains-Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853; one Gram-positive strain Staphylococcus aureus ATCC 25923, and one yeast strain-Candida albicans ATCC 10231). Antimicrobial activity was assessed by measuring the diameter of the inhibition zone, and by determining the values of the minimum inhibitory concentration (MIC) and minimum concentration of biofilm eradication (MCBE). Analyzing the diameter values of the inhibition zones we observed increased efficiency of thyme essential oil, which showed the highest values for all tested microbial species. The results of tests performed in a liquid confirm the high sensitivity of the standard strain Escherichia coli ATCC 25922 to the action of all essential oils, the lowest values of MIC being recorded for sage and thyme essential oils. For the most essential oils tested in this study, the MCBE values are close to the MIC values, except for the pine EO which seems to have stimulated the adhesion of the yeast strain at concentrations lower than 5%. The study highlights the antimicrobial activity of the tested essential oils on Gram-positive and Gram-negative strains. Full article
(This article belongs to the Special Issue New Materials and Advanced Procedures of Obtaining and Processing II)
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10 pages, 2335 KiB  
Article
Experimental Analysis on the Impact of Current on the Strength and Lifespan of a Ni-Ti Element
by Cernusca Dumitru, Laurențiu Dan Milici, Radu Dumitru Pentiuc, Pavel Atănăsoae, Constantin Ungureanu and Eugen Hopulele
Appl. Sci. 2022, 12(6), 3185; https://doi.org/10.3390/app12063185 - 21 Mar 2022
Cited by 1 | Viewed by 1304
Abstract
Intelligent materials, especially materials with shape memory, are an important discovery, with technical applications in the medical and aerospace field, among others, which led to the development of systems and applications with multiple advantages and disadvantages due to ignorance about their functionality. This [...] Read more.
Intelligent materials, especially materials with shape memory, are an important discovery, with technical applications in the medical and aerospace field, among others, which led to the development of systems and applications with multiple advantages and disadvantages due to ignorance about their functionality. This paper presents an application developed in the research laboratory for determining and monitoring the behavior of a material element with Ni-Ti shape memory, and its lifespan. The application allows the stress level of the Ni-Ti element subjected to numerous repeated cycles of deformation to be determined by supplying it to a constant electric current. Thus, the results show the variation of the Ni-Ti element force, in the form of a spring, at the ambient temperature variations as well as force variations at different numbers of attempts. The Ni-Ti alloy has both shape retention and superelasticity properties, being the most common in the fields of applicability. Due to its unique properties, it can be used in the most demanding applications in the medical field, usually involving difficult conditions of resistance to fatigue. Full article
(This article belongs to the Special Issue New Materials and Advanced Procedures of Obtaining and Processing II)
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