Masses of constituent quarks confined in open bottom hadrons

We apply color-spin and flavor-spin quark-quark interactions to the meson and baryon constituent quarks, and calculate constituent quark masses, as well as the coupling constants of these interactions. The main goal of this paper was to determine constituent quark masses from light and open bottom hadron masses, using the fitting method we have developed and clustering of hadron groups. We use color-spin Fermi-Breit (FB) and flavor-spin Glozman-Riska (GR) hyperfine interaction (HFI) to determine constituent quark masses (especially $b$ quark mass). Another aim was to discern between the FB and GR HFI because our previous findings had indicated that both interactions were satisfactory. Our improved fitting procedure of constituent quark masses showed that on average color-spin (Fermi-Breit) hyperfine interaction yields better fits. The method also shows the way how the constituent quark masses and the strength of the interaction constants appear in different hadron environments.Comment: 15 pages, 6 tables, 1 figure. Accepted for publication in Mod. Phys. Lett.

Optimization of the preparation of novel polymer/clay nanocomposites

Recent advances in material technologies have resulted in the preparation of novel polymer/clay composites with improved thermal, mechanical, optoelectronic/ magnetic properties and increased biodegradability [1]. In this study, six samples of poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (PGME) nanocomposites with organically-modified montmorillonite clay Cloisite 30B® (C30B), were prepared via suspension copolymerization. In order to obtain nanocomposites with fine spherical beads of regular shape and satisfying thermal stability the optimization of the synthesis conditions was performed. Firstly, the influence of the poly(N-vinyl pyrrolidone) (PVP) quantity in the aqueous phase was varied (1, 3 and 5 wt.%) at a constant stirring rate of 250 rpm and constant clay content C30B (10 wt.%). In the second phase of the optimization of the preparation, samples with a constant composition of the composite reaction mixture (5 wt.% PVP and 10 wt.% C30B) at a stirring rate of 250, 325 and 400 rpm, were prepared. According to the obtained results, it was concluded that the optimal conditions for preparation of these composites are 5 wt.% of PVP and 400 rpm. The prepared nanocomposites were characterized with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) in air. The structure of the prepared nanocomposites was confirmed with FTIR spectroscopy. According to the obtained SEM microphotographs the fine spherical beads, with desired size and homogeneous morphology, were prepared. Furthermore, SEM analysis was also showed that clay nanoparticles are homogeneously dispersed both inside surface and cross-section area. The incorporation of C30B clay increased the thermal stability of the prepared polymer/clay nanocomposites in comparison to the pure PGME copolymer

Optimization of the preparation of novel polymer/clay nanocomposites

Recent advances in material technologies have resulted in the preparation of novel polymer/clay composites with improved thermal, mechanical, optoelectronic/ magnetic properties and increased biodegradability [1]. In this study, six samples of poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (PGME) nanocomposites with organically-modified montmorillonite clay Cloisite 30B® (C30B), were prepared via suspension copolymerization. In order to obtain nanocomposites with fine spherical beads of regular shape and satisfying thermal stability the optimization of the synthesis conditions was performed. Firstly, the influence of the poly(N-vinyl pyrrolidone) (PVP) quantity in the aqueous phase was varied (1, 3 and 5 wt.%) at a constant stirring rate of 250 rpm and constant clay content C30B (10 wt.%). In the second phase of the optimization of the preparation, samples with a constant composition of the composite reaction mixture (5 wt.% PVP and 10 wt.% C30B) at a stirring rate of 250, 325 and 400 rpm, were prepared. According to the obtained results, it was concluded that the optimal conditions for preparation of these composites are 5 wt.% of PVP and 400 rpm. The prepared nanocomposites were characterized with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) in air. The structure of the prepared nanocomposites was confirmed with FTIR spectroscopy. According to the obtained SEM microphotographs the fine spherical beads, with desired size and homogeneous morphology, were prepared. Furthermore, SEM analysis was also showed that clay nanoparticles are homogeneously dispersed both inside surface and cross-section area. The incorporation of C30B clay increased the thermal stability of the prepared polymer/clay nanocomposites in comparison to the pure PGME copolymer

Influence of process parameters of simultaneous anodization/anaphoretic electrodeposition synthesis of hydroxyapatite/titanium oxide composite coatings on adhesion

In-situ synthesis of hydroxyapatite/titanium oxide (HAp/TiO2) coating on titanium was performed via anaphoretic deposition of hydroxyapatite (HAp) and simultaneous anodization of Ti to produce highly adherent and strengthened composite coating. The influence of electric potential, time, electrolyte concentration and pH value of the anodization process on titanium surface roughness and anodization of titanium was examined, as well as influence of same process parameters on adhesion strength and compactness of composite HAp/TiO2 coatings was investigated. Prior to novel in situ method of synthesis of hydroxyapatite/titanium oxide composite coatings by simultaneous anodization/anaphoretic electrodeposition described in this manuscript, optimization of anodization process of titanium was performed. Anodization was executed under different electric potentials and different distances of counter electrodes from working electrodes, but all anodization processes had constant quantity of electric charge. Characterization of titanium samples, prepared from grade 6 Ti, and having rectangular contact surfaces of 10×10×0.89 mm included SEM/EDS analyses, X-ray diffraction analyses, AFM surface topography, morphology and roughness analyses and linear measurements of roughness. A chemical precipitation method was used to prepare hydroxyapatite powder by the reaction of calcium oxide (obtained by calcination of CaCO3 for 5 h at 1000 °C in air) and phosphoric acid. A stoichiometric amount of the calcium oxide was stirred in distilled water and phosphoric acid was added drop wise to the suspension in order to obtain hydroxyapatite powder, Ca10(PO4)6(OH)2. Two types of HAp coatings were prepared, in order to compare the adhesion, morphology and consistency of the HAp and composite HAp/TiO2 on Ti, namely cathaphoretic and anaphoretic coatings, respectively [1,2]. The prepared coatings were characterized by field emission scanning electron microscopy, X-ray diffraction and electron dispersive spectroscopy. Adhesion was investigated by ASTM D 3359 – 97 Test method B. Uniform and adherent HAp/TiO2 composite coating on Ti was obtained. Since smaller size of HAp crystals within highly porous coating structures is of improved binding ability to various biomolecules, our coating is expected to be of excellent coverage and compactness. The obtained coating can be good candidate for bone implants due to improved adhesion

The process of obtaining quartz sand size fraction -0.4 + 0.05 mm for use in water glass production

The paper presents the process of quartz sand processing from the „Bijela Stijena“-Skočić deposit in the plant „Kesogradnja d.o.o.“ at Kozluk near Zvornik, Republic of Srpska. Bearing in mind the fact that this quartz sand is used for water glass production in the company „Birač“ - Zvornik or „Alumina“ Zvornik, it was necessary to meet the quality requirements prescribed by that industrial production. Thus, the required size was -0.4+0.05 mm and the Fe2O3 content was maximum of 0.04%. Based on the laboratory tests, a technological scheme for the quartz raw material valorization was conceived in the separation of the company „Kesogradnja d.o.o.“. The obtained results showed that quartz sand for water glass size fraction -0.4+0.05 mm could be obtained in the plant. Also, by introducing a magnetic concentration after washing and grading, the Fe2O3 content was reduced from 0.131% as it is in the initial sample to 0.038% which meets the required conditions from the water glass producers

Novel in-situ synthesis of hydroxyapatite/titanium oxide composite coatings on titanium by simultaneous anodization/anaphoretic electrodeposition

In-situ synthesis of HAp/TiO2 coating on titanium was performed via anaphoretic deposition of HAp and simultaneous anodization of Ti to produce highly adherent and strengthened composite coating. The prepared coatings were characterized by field emission scanning electron microscopy, X-ray diffraction and electron dispersive spectroscopy. HAp on anodized titanium was prepared at constant voltage of 60 V and deposition time of 45 s, which provided uniform and adherent HAp/TiO2 composite coating on Ti. Since smaller size of HAp crystals within highly porous coating structures is of improved binding ability to various biomolecules, our coating is expected to be of excellent coverage and compactness. The obtained coating can be good candidate for bone implants due to reduced brittleness and improved adhesion

Surface modification of titanium implants by adherent hydroxyapatite/titanium oxide composite coatings using novel in-situ synthesis

The medical devices based on titanium and its alloys are widely used in the repair and replacement of a degraded or inhibited func-tion of locomotor system [1]. Ti and its alloys exhibit high mechanical strength, good workability, resistant to corrosion and low cost. Although, they are widely used as orthopedic and dental implants their inability to interact with living tissue will inhibit their biological fixation and osseoin-tegration [2]. Therefore, to improve the hard-tissue compatibility of Ti various sur-face treatments have been developed for the inorganic coating formation [3]. The hyd-roxyapatite (HAp, Ca10(PO4)6(OH)2) with superior osteogenic activity is a competitive approach to make novel coatings for titanium implants applications. HAp is a calcium phosphate very similar to the inorganic part of the human bone and hard tissues both in morphology and compo-sition. Herein, in-situ synthesis of HAp/TiO2 coating on titanium was performed via ana-phoretic deposition of HAp and simulta-neous anodization of Ti to produce highly adherent and strengthened composite coating. It can be seen that morphology of Ti substrate of anHAP/TiO2 coating is of tubular shape, and tube formation occurs mainly due to competing processes of anodization and electrophoretic deposition of HAp. anHAp/TiO2 coating does not need sintering process, and simultaneous Ti anodization and HAp deposition occur, where HAp crystals incorporate in the anodized Ti surface. From the presented results it can be concluded that novel suggested process of in situ simultaneous anHAp/TiO2 deposition with Ti surface anodization gives much better results that cathaphoretic deposition regarding adhesion

Comparison of bioactivity, cytotoxicity, antimicrobial and corrosive behavior of ceramic coatings with and without polymer on titanium

Kalcijum fosfati (CP), među kojima su amorfni kalcijum fosfat (ACP) i hidroksiapatit (HAp), zajedno sa slojevima Ti i TiO2, pronašli su ogromnu primenu u preventivnoj i regenerativnoj medicini zbog svoje odlične biokompatibilnosti, netoksičnih svojstava i sposobnosti da učestvuju u metaboličnim procesima organizama. U ovom radu je prikazana citotoksičnost multifunkcionalnih i hibridnih kompozitnih prevlaka amorfnog kalcijum fosfata (ACP) i hitozan laktata (ChOL) na ćelijskoj liniji humanih fibroblasta pluća MRC-5. ACP/TiO2 i ACP/TiO2/ChOL prevlake su taložene novim procesom in situ anodizacije/anaforetske depozicije pri konstantnom naponu od 60 V tokom 180 s na 25 ° C. Testovi citotoksičnosti pokazali su da nije bilo značajnog smanjenja preživljavanja zdravih ćelija MRC-5 u kompozitnim uzorcima Ti i ACP/TiO2, dok je došlo do povećanja broja viabilnih ćelija u uzorku ACP/TiO2/ChOL. Pokazano je poboljšanje ćelijske proliferacije, diferencijacije i viabilnosti ćelija. Uzorak koji sadrži ACP/TiO2/ChOL prevlaku pokazao je negativnu citotoksičnost u DET i u MTT testovima. Zabeležen je veći oporavak humanih ćelija fibroblasta pluća MRC-5 u poređenju sa kontrolnim uzorkom posle 48 h oporavka. Iz ovih rezultata može se zaključiti da multifunkcionalna kompozitna prevlaka ACP/TiO2/ChOL nije samo necitotoksična, već prisustvo ChOL-a u prevlaci poboljšava ćelijsku proliferaciju, diferencijaciju i viabilnost ćelija. Na osnovu dobijenih rezultata može se zaključiti da oba kompozitna materijala koji su korišćeni u studijama nisu citotoksični za korišćene ćelijske linije, te da 5 tež.% ChOL-a ima pozitivan efekat na netoksičnost materijala. Na osnovu prikazanih rezultata u ovom radu i prethodnih objavljenih rezultata fizičko-hemijskih i bioaktivnih svojstava kompozitnog materijala ACP/TiO2/ChOL, može se zaključiti da bi dalji razvoj, kao i potencijalne pretkliničke studije bili u velikoj meri opravdani.Calcium phosphates (CP), amongst which amorphous calcium phosphate (ACP) and hydroxyapatite (HAp), along with Ti and TiO2 layers, have found vast applications in preventive and regenerative medicine due to their excellent biocompatibility, nontoxic properties and ability to participate in the normal metabolism of organisms. In this paper cytotoxicity of amorphous calcium phosphate (ACP) and chitosan lactate (ChOL) multifunctional and hybrid composite coatings on MRC-5 human lung fibroblast cell line is presented. ACP/TiO2 and ACP/TiO2/ChOL are deposited by coatings new in situ anodization/anaphoretic deposition process at constant voltage of 60 V for 180 s at 25 °C. Cytotoxicity tests showed that there was no significant decrease in the survival of healthy MRC-5 cells in the Ti and ACP/TiO2 composite samples, while there was an increase in the number of viable cells in the ACP/TiO2/ChOL sample. There is improved cell proliferation, differentiation and cell viability in the later. Sample containing ACP/TiO2/ChOL coating showed negative cytotoxicity in both DET and MTT tests. Greater recovery of MRC-5 human lung fibroblasts cells was observed compared to the control sample after 48 h of recovery. From these results, it can be concluded that not only the ACP/TiO2/ChOL multifunctional composite coating is non-cytotoxic, but the presence of ChOL in the coating improves cell proliferation, differentiation and cell viability. Based on the obtained results, it can be concluded that both composite materials used in the studies are non-cytotoxic to the cell lines used, and that 5 wt.% of ChOL has a positive effect on the non-toxicity of the material. Based on presented results in this paper and previous published results of the physicochemical and bioactive properties of the ACP/TiO2/ChOL composite material, it can be concluded that further development as well as potential preclinical studies would be largely justified

Comparison of bioactivity, cytotoxicity, antimicrobial and corrosive behavior of ceramic coatings with and without polymer on titanium

Kalcijum fosfati (CP), među kojima su amorfni kalcijum fosfat (ACP) i hidroksiapatit (HAp), zajedno sa slojevima Ti i TiO2, pronašli su ogromnu primenu u preventivnoj i regenerativnoj medicini zbog svoje odlične biokompatibilnosti, netoksičnih svojstava i sposobnosti da učestvuju u metaboličnim procesima organizama. U ovom radu je prikazana citotoksičnost multifunkcionalnih i hibridnih kompozitnih prevlaka amorfnog kalcijum fosfata (ACP) i hitozan laktata (ChOL) na ćelijskoj liniji humanih fibroblasta pluća MRC-5. ACP/TiO2 i ACP/TiO2/ChOL prevlake su taložene novim procesom in situ anodizacije/anaforetske depozicije pri konstantnom naponu od 60 V tokom 180 s na 25 ° C. Testovi citotoksičnosti pokazali su da nije bilo značajnog smanjenja preživljavanja zdravih ćelija MRC-5 u kompozitnim uzorcima Ti i ACP/TiO2, dok je došlo do povećanja broja viabilnih ćelija u uzorku ACP/TiO2/ChOL. Pokazano je poboljšanje ćelijske proliferacije, diferencijacije i viabilnosti ćelija. Uzorak koji sadrži ACP/TiO2/ChOL prevlaku pokazao je negativnu citotoksičnost u DET i u MTT testovima. Zabeležen je veći oporavak humanih ćelija fibroblasta pluća MRC-5 u poređenju sa kontrolnim uzorkom posle 48 h oporavka. Iz ovih rezultata može se zaključiti da multifunkcionalna kompozitna prevlaka ACP/TiO2/ChOL nije samo necitotoksična, već prisustvo ChOL-a u prevlaci poboljšava ćelijsku proliferaciju, diferencijaciju i viabilnost ćelija. Na osnovu dobijenih rezultata može se zaključiti da oba kompozitna materijala koji su korišćeni u studijama nisu citotoksični za korišćene ćelijske linije, te da 5 tež.% ChOL-a ima pozitivan efekat na netoksičnost materijala. Na osnovu prikazanih rezultata u ovom radu i prethodnih objavljenih rezultata fizičko-hemijskih i bioaktivnih svojstava kompozitnog materijala ACP/TiO2/ChOL, može se zaključiti da bi dalji razvoj, kao i potencijalne pretkliničke studije bili u velikoj meri opravdani.Calcium phosphates (CP), amongst which amorphous calcium phosphate (ACP) and hydroxyapatite (HAp), along with Ti and TiO2 layers, have found vast applications in preventive and regenerative medicine due to their excellent biocompatibility, nontoxic properties and ability to participate in the normal metabolism of organisms. In this paper cytotoxicity of amorphous calcium phosphate (ACP) and chitosan lactate (ChOL) multifunctional and hybrid composite coatings on MRC-5 human lung fibroblast cell line is presented. ACP/TiO2 and ACP/TiO2/ChOL are deposited by coatings new in situ anodization/anaphoretic deposition process at constant voltage of 60 V for 180 s at 25 °C. Cytotoxicity tests showed that there was no significant decrease in the survival of healthy MRC-5 cells in the Ti and ACP/TiO2 composite samples, while there was an increase in the number of viable cells in the ACP/TiO2/ChOL sample. There is improved cell proliferation, differentiation and cell viability in the later. Sample containing ACP/TiO2/ChOL coating showed negative cytotoxicity in both DET and MTT tests. Greater recovery of MRC-5 human lung fibroblasts cells was observed compared to the control sample after 48 h of recovery. From these results, it can be concluded that not only the ACP/TiO2/ChOL multifunctional composite coating is non-cytotoxic, but the presence of ChOL in the coating improves cell proliferation, differentiation and cell viability. Based on the obtained results, it can be concluded that both composite materials used in the studies are non-cytotoxic to the cell lines used, and that 5 wt.% of ChOL has a positive effect on the non-toxicity of the material. Based on presented results in this paper and previous published results of the physicochemical and bioactive properties of the ACP/TiO2/ChOL composite material, it can be concluded that further development as well as potential preclinical studies would be largely justified

Deflection control for reinforced recycled aggregate concrete beams: Experimental database and extension of the fib Model Code 2010 model

Recycled aggregate concrete (RAC) has emerged as a viable solution for solving some of the environmental problems of concrete production. However, design guidelines for deflection control of reinforced RAC members have not yet been proposed. This study presents a comprehensive analysis of the applicability of the fib Model Code 2010 (MC2010) deflection control model to reinforced RAC beams. Three databases of long-term studies on natural aggregate concrete (NAC) and RAC beams were compiled and meta-analyses of deflection predictions by MC2010 were performed. First, the MC2010 deflection control model was tested against a large database of long-term tests on NAC beams. Second, a database of RAC and companion NAC beams was compiled and initial and long-term deflections were calculated using the MC2010 model. It was shown that deflections of RAC beams are significantly underestimated relative to NAC beams. Previously proposed modifications for MC2010 equations for shrinkage strain and creep coefficient were used, and new modifications for the modulus of elasticity and empirical coefficient β were proposed. The improved MC2010 deflection control model on RAC beams was shown to have equal performance to that on companion NAC beams. The proposals presented in this paper can help engineers to more reliably perform deflection control of reinforced RAC members.This is the peer-reviewed version of the article: N. Tošić, S. Marinković, and J. de Brito, ‘Deflection control for reinforced recycled aggregate concrete beams: Experimental database and extension of the fib Model Code 2010 model’, Structural Concrete, vol. 20, no. 6, pp. 2015–2029, 2019 [https://doi.org/10.1002/suco.201900035