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Studies of fretting processes in titanium implantation alloys from the Ti-Al-V group KLEKOTKA Marcin1,a*, DĄBROWSKI Jan Ryszard1,b, KALSKA-SZOSTKO Beata2,c, KLEKOTKA Urszula2,d 1 Department of Materials and Biomedical Engineering, Białystok University of Technology Wiejska 45C, 15-351 Białystok, Poland 2Institute of Chemistry, University of Bialystok, Ciolkowskiego 1K, 15-245 Bialystok, Poland a m.klekotka@pb.edu.pl, b j.dabrowski@pb.edu.pl, c kalska@uwb.edu.pl, d u.wykowska@uwb.edu.pl Keywords: fretting, implants, saliva substitute, wear, biomaterials Abstract.
Fretting processes are a significant problem concerning the operating lifetime of components of kinematic pairs operating in both technical and medical structures.
Dental implants and elements of prosthetic structures are particularly exposed to fretting processes.
Meyers ed., Interpretation of Infrared Spectra, A Practical Approach in Encyclopedia of Analytical Chemistry John Wiley & Sons Ltd, Chichester, (2000) 10815-10837.

Gustavo Pasquale's group studied heteropolyacids of Keggin and Wells-Dawson structures  esterification catalysts [25].
Rataboul, Synthesis and applications of alkyl levulinates, ACS Sustainable Chemistry & Engineering, 2 (2014), 1338-1344 [18] E.
Burton, Chemical and performance properties of levulinate esters as fuel blend components, American Chemical Society, Division of Fuel Chemistry, 56 (2011) 501-502 [19] J.
Fujitani, Esterefication of levulinic acid with ethanol over sulfated Si-doped ZrO2 solid acid catalyst: Study of the structure – activity relationships, Appl.

Effective Impregnation of SiO2 Sol-Gel Solution in Pine Wood and Following Gel Localization in Free Cell Volume Janis Locs 1, a , Liga Berzina-Cimdina1,b , Aivars Zhurinsh2,c and Dagnija Loca 1,d 1 Riga Technical University, Riga Biomaterials Innovation and Development Centre, Pulka street 3/3, Riga, LV-1007, Latvia 2 Latvian State Institute of Wood Chemistry, Dzerbenes street 27, Riga, LV-1006, Latvia a janis.locs@rtu.lv, b liga@ktf.rtu.lv, caivarsz@edi.lv, d dagnija.loca@apollo.lv Keywords: wood, SiO2, localization, impregnation Abstract.
Introduction Advantage of the wood as structural material is its structure durability, combined with low bulk density.
Naturally grown and chemically modified structure is their common feature.
[12] R.M.Rowell: Handbook of wood chemistry and wood composites (Taylor & Francis, Boca Raton, Florida 2005)

Assessment of Hydrophilic Biochar Effect on Sandy Soil Water Retention Ramida Rattanakam1,a *, Pinitpon Pituya2,b, Mantana Suwan3,c and Sitthisuntorn Supothina3,d 1Department of Chemistry, Kasetsart University, Bangkok, Thailand 2Huaysai Royal Development Study Center, Petchburi, Thailand 3National Metal and Materials Technology Center, NSTDA, Patumthani, Thailand afscirdr@ku.ac.th, bbiocharhuaysai@gmail.com, cmantanas@mtec.or.th, dsitthis@mtec.or.th Keywords: biochar, water retention, hydrophilicity, FTIR.
However, evidently published results can be contradictory as some studies showed no significant effects of biochar application on hydrological function of sandy soil.[10-11] Gray et al.[12] and Jeffery et al.[11] have postulated that the hydrophobicity biochar surface may hinder uptake of water into the pores of biochar regardless of pore size and structure, causing soil repellency to water which subsequently affects infiltration and water retention and also plant growth.
This particular observation could be explained by the changes in surface chemistry of biochars after oxidation.
Kleber, Dynamic molecular structure of plant biomass-derived black carbon (biochar), Environ.

This research can provide an avenue of guiding energy saving preparation and maintaining working effectiveness of PCE from the aspect of polymer chemistry, giving a useful insight into exploring novel energy-conservation manner for eco-building materials.
The adsorption behavior of these polymers was related to their surface chemistry, and thus it is necessary to further investigate the adsorption kinetics of PCE on the surfaces of cement particles.
Impact of molecular structure on zeta potential and adsorbed conformation of α-allyl-ω-methoxy polyethylene glycol-maleic anhydride superplasticizers, J.
Effects of polycarboxylate superplasticizers with different molecular structure on the hydration behavior of cement paste, J.

Chemical Constituents and their Nanoemulsion Properties of Ethyl Acetate Crude Extract from Black Galingale Rhizome Nuttacha Boonkert1,a, Chanikan Sonklin1,b, Cherdchai Laongtiparos1,c Siriporn Pranee2,d, Samitthichai Seeyangnok1,e, Nisalak Trongsiriwat1,f* 1Department of Industrial Chemistry of Applied Science, King Mongkut’s University of Technology North Bangkok, 10800, Thailand 2Department of Veterinary Technology, Faculty of Veterinary Technology, Kasetsart University, Thailand as6404011810024@email.kmutnb.ac.th, bchanikan.s@sci.kmutnb.ac.th, ccherdchai.l@sci.kmutnb.ac.th, dcvtspp@ku.ac.th, esamitthichai.s@sci.kmutnb.ac.th, fnisalak.t@sci.kmutnb.ac.th Keywords: Kaempferia parviflora, Flavonoids, Antioxidants, Antimicrobial, Nanoemulsion.
The main flavonoid structure consists of 15 carbon atoms arranged in the form C6-C3-C6 (aryl-propyl-aryl), corresponding to Two aromatic rings linked by units of three carbon atoms [4].
These fractions were combined based on the same TLC profiles, which the structures of these compounds to identify by their spectral data of UV-vis spectrophotometry (range 200-800nm) (SPECORD 210 PLUS, Analytic Jena, Germany), FT-IR (Perkin Elmer, Spectrum 100, USA), and 1H-NMR and 13C-NMR spectra were recorded in CDCl3 (Karlsruhe, Germany; 1H 400 MHz; 13C 75.5 MHz).
Acknowledgment The research was supported by the Department of Industrial Chemistry, Faculty of Applied Sciences, King Mongkut's University of Technology North Bangkok, Thailand for providing tools and equipment for the workplace.

Room Temperature Synthesis of Magnetite Particles by an Oil Membrane Layer-Assisted Reverse Co-Precipitation Approach URIPTO Trisno Santoso1,a*, ABDULLAH1,b, DWI Rasy Mujiyanti1,c, DAHLENA Ariyani1,d, JOYO Waskito1,e 1Department of Chemistry, Faculty of Mathematics and Natural Sciences, Lambung Mangkurat University, Jalan Jendral Ahmad Yani Km. 36 Banjarbaru, South Kalimantan 70714, Indonesia auriptotrisnosantoso@gmail.com, babdullahunlam@gmail.com, cdwirasy@gmail.com, ddahlena.ariyani579@gmail.com, ejoyowaskito.jw@gmail.com Keywords: magnetite; maghemite; nanoparticles; co-precipitation; reverse co-precipitation.
When reaching the pH to 3, Fe3+ ions are precipitated as ferrihydrite, which at that point reacts with the Fe2+ ions in the arrangement structure for magnetite formation.
However, this technique usually yields particles with a wide size distribution, most likely due to the high possible arrangement of pathways that lead to the development of magnetite structure [7].
The factors of the complicated aqueous Fe2+/Fe3+ ion chemistry and the fluctuating kinetic in co-precipitation process make controlling the exact reaction route is not easy, obtaining particles with narrow size distribution and high magnetization become be a challenging.

This is because the phosphorus (P) atom is reduced due to the replacement of phosphate ions by carbon ions in the CHA crystal structure.
Procedia Chemistry 19 (2016) 539–545
Coordination Chemistry Reviews 347 (2017) 48–76
Journal of Molecular Structure 1147 (2017) 594–602

Introduction Positron interactions with matter and materials provide a unique tool to non-destructively probe lattice defects in materials science, solid state physics, chemistry and electronics.
Positrons therefore serve as highly sensitive and mobile probes for non-destructive studies, bridging the gap between fundamental studies and technological applications where defect engineering leads to tailored material properties and enhanced performance, e.g. in CMOS circuits (low-k materials), magnetic switching, surface chemistry and catalysis, membranes, high-entropy alloys, radiation-hard materials, and solar cell materials.
Due to the growing need for time-dependent phenomena, e.g. in defect annealing [1,2], considerable efforts are being made to increase the intensity of the positron beams, their temporal structure and the combination of sample treatment and sample modification (such as high and low temperatures, (laser) light illumination, ion irradiation and in-situ thin film growth).
For energies above roughly 10 MeV the radiation length is given as: rl-1=4αr02 Z2NAAln183Z1/3+18 cm2g with the fine structure constant a, the classical Bohr radius r0, and Avogadro’s number NA.

Schematic of the gas sensing system Results and Discussion Structure Characterization.
L'Vov: Carbon crooked nanotube layers of polyethylene: Synthesis, structure and electron emission, Carbon Vol. 36(1998), p. 713-715
Chapline: Controlled chemical routes to nanotube architectures, physics, and devices, Journal of Physical Chemistry B Vol. 103(1999), p. 11246-11255
Gabriel: Gas sensor array based on metal-decorated carbon nanotubes, Journal of Physical Chemistry B Vol. 110(2006), p. 21014-21020