Elaboration and characterization of humidity sensors for environmental monitoring

The water content in surrounding air is an important factor for the well-being of humans and animals, as the level of comfort is determined by a combination of two factors: relative humidity and ambient temperature. Humidity is also an important factor for operating certain equipment such as high-impedance electronic circuits, electrostatic-sensitive components, high-voltage devices, fine mechanisms, etc. Nonetheless, moisture is the ingredient common to most manufactured goods and processed materials. Thus, humidity sensors have been receiving wide attentions since decades. Yet, despite the high request, major advances in these sensors in terms of simple structure, lower cost, better selectivity, durability and reliability are always needed. Throughout the years, a large number of materials based on polymers, composite and ceramics have been tested, due to their own features and specific operating conditions. However, great attention has been paid to ceramic materials due to their chemical inertness which allow them to operate in harsh conditions. Amongst the different studied humidity sensors, impedance-based ones are used most commonly. The operation principle of the impedance sensors is based on the dependence of the impedance (or either capacitance or resistance) of the sensor element recognizing the nature and amount of water molecules on the surface or in the bulk. The resistance or impedance of the resistive-type sensor decreases as the relative humidity (RH)increases. Ions or electrons, or both of them, are the conduction carriers for resistive-type humidity sensors. The common construction of the resistive-type ceramic humidity sensors consists of a ceramic substrate with noble metal interdigitated electrodes coated with humidity sensing ceramic materials, both deposited by screen-print technique [1]. Metal oxides and metal oxide based composites are the most popular materials to be used as resistive sensing elements: TiO2, TiO2–SnO2, TiO2–WO3, TiO2–Cu2O–Na2O, KTaO3//TiO2(bilayered), TiO2/KTaO3 (bilayered), TiO2–K2O–LiZnVO4, Al2O3, AlO(OH), SiO2, WO3, Cr2O3–WO3, SnO2, a noble metal doped SnO2, SnO2: ZrO2 (bilayered), single Sb doped SnO2, K+-dopedSnO2–LiZnVO4, MnO2 –Mn3O4, Li+-doped Fe2O3, Au3+ and Li+ co-doped Fe2O3, Li+, Zn2+ and Au3+ co-doped Fe2O3, NiMoO4–MoO3, Li+-doped NiMoO4–MoO3, CuMoO4–MoO3 and PbMoO4–MoO3 [1]. Spinel-type oxides and composites based on spinel-type oxides are also used for humidity resistive sensing elements: MgAl2O4, Sr2+-doped CoAl2O4, Sr2+-doped BaAl2O4, Sr2+-doped ZnAl2O4, MgFe2O4, MgAl2O4–MgFe2O4, Mg0.8Li0.2Fe2O4, Mg0.9Sn0.1Fe2O4, MgFe2O4–CeO2, MgCr2O4–TiO2, Zn2SnO4–LiZnVO4 and ZnCr2O4–K2CrO4 [1]. Finally, Perovskite-type oxides and composites based on perovskites have been used for humidity sensing elements too: NaH2PO4 doped BaTiO3, MnTiO3, Li+ doped Ca0.35Pb0.65TiO3, BaNbO3, LaFeO3, K+-doped nanocrystalline LaCo0.3Fe0.7O3 (La0.93K0.07Co0.3Fe0.7O3) and Sr-doped SmCrO3 (Sm0.90Sr0.10CrO3) [1]. Preparation techniques can considerably affect the physical, chemical and gas sensing properties of the metal oxide sensors. Developments of new preparative routes, as well as compositional variations, are two perspective approaches for the design of highly sensitive and selective gas sensor materials.Reference: [1] T.A. Blanka, L.P. Eksperiandova, K.N. Belikov, Recent trends of ceramic humidity sensors development: A review. Sensors and Actuators B, 228 (2016) 416–442

3rd International Conference on Nanomaterials Science and Mechanical Engineering: book of abstracts

Sem resumo disponível.publishe

Microstructural evolution of epitaxial dielectric films derived from chemical precursors

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1995.Includes bibliographical references (leaves 138-150).by Man Fai Ngg.Ph.D

Прва међународна конференција о електронској микроскопији наноструктура ELMINA 2018, 27-29 август 2018. Београд, Србија

ELMINA2018 International Conference organized by the Serbian Academy of Sciences and Arts and the Faculty of Technology and Metallurgy, University of Belgrade, as the first in a series of electron microscopy conferences: Electron Microscopy of Nanostructures. The scope of ELMINA2018 will be focused on electron microscopy, which provides structural, chemical and electronic information at atomic scale, applied to nanoscience and nanotechnology (physics, chemistry, materials science, earth and life sciences), as well as advances in experimental and theoretical approaches, essential for interpretation of experimental data and research guidance. It will highlight recent progress in instrumentation, imaging and data analysis, large data set handling, as well as time and environment dependent processes

Application of hydroxyapatite granules in posterolateral intertransverse lumbar spinal fusion

In many clinical disciplines used of bone graft is unavoidable such as to replace bone loss due to trauma, to fill in bone defect after tumour excision, for reconstructive surgery or spinal fusion. Calcium phosphate based hydroxyapatite is widely used bone graft substitute due to its similarity with the mineral components of bone matrix. This study was conducted to evaluate bone formation effect of this biomaterial in posterolateral intertransverse lumbar fusion, a novel site for its application. Twelve adult New Zealand white rabbits underwent bilateral intertransverse lumbar spinal fusion at L5-L6 vertebrae. One site of the animals was implanted with hydroxyapatite granules (HA group) while the contralateral sides received autograft and served as the control (AUTO group). Bone formation was assessed at 6 and 16 weeks by undecalcified histology and scanning electron microscopy. New bone was formed on the surface of hydroxyapatite granules and continually formed even at 16 weeks. Close contact between new bone and hydroxyapatite granules was demonstrated by scanning electron microscopy

Program and the Book of abstracts / Nineteenth Young Researchers' Conference Materials Science and Engineering, December 1-3, 2021, Belgrade, Serbia

Young Researchers' meetings are held annually late in December since 2002 and they are organized by the Materials Research Society of Serbia. Originally conceived as seminars, since 2007 these meetings were transformed into conferences. The previous eleven meetings featured presentations based on the research of various young scientists from Serbia, Bosnia and Herzegovina, Montenegro, Slovenia, Brazil, Germany, United States of America, China, Poland, Belgium, Spain, Romania, United Kingdom, Austria, Italy, Hungary, Russia, Canada, etc. At the Conference, young researchers, students of doctoral, master and undergraduate studies, are given the opportunity to make an overview of their research into materials science and engineering through oral and poster presentations. As for the scientific content of the conference, we have given full priority to research topics that are currently considered as being on the frontier of the field. Nanotechnology and Advanced Materials, Synthesis and Engineering of Biomaterials, Application of Biomaterials, Theoretical Modeling of Materials and Advanced Methods for Synthesis and Processing present only some of those exciting topics that will be given the central stage and most attention during this meeting. The 19th Young Researchers' Conference Materials Science and Engineering was held in Belgrade, Serbia on December 1-3, 2021, Belgrade, Serbia. It was organized by the Materials Research Society of Serbia and Institute of Technical Sciences of the Serbian Academy of Sciences and Arts

Program and the Book of abstracts / Twenty-first Young Researchers' Conference Materials Science and Engineering, November 29 – December 1, 2023, Belgrade, Serbia

Young Researchers' meetings are held annually late in December since 2002 and they are organized by the Materials Research Society of Serbia. Originally conceived as seminars, since 2007 these meetings were transformed into conferences. The previous eleven meetings featured presentations based on the research of various young scientists from Serbia, Bosnia and Herzegovina, Montenegro, Slovenia, Brazil, Germany, United States of America, China, Poland, Belgium, Spain, Romania, United Kingdom, Austria, Italy, Hungary, Russia, Canada, etc. At the Conference, young researchers, students of doctoral, master and undergraduate studies, are given the opportunity to make an overview of their research into materials science and engineering through oral and poster presentations. As for the scientific content of the conference, we have given full priority to research topics that are currently considered as being on the frontier of the field. Nanotechnology and Advanced Materials, Synthesis and Engineering of Biomaterials, Application of Biomaterials, Theoretical Modeling of Materials and Advanced Methods for Synthesis and Processing present only some of those exciting topics that will be given the central stage and most attention during this meeting