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Electrical discharge machining (EDM) has demonstrated its promising potential for surface modification. The integration of materials from tool electrode or powder that is mixed into the dielectric fluid has proven to modify the workpiece surface to enhance its mechanical properties, realize antibacterial effects, or increase biocompatibility. Recent EDM studies showed that due to non-contact forces, properties of the modified surface such as roughness values and the thickness of modified layer were significantly influenced when using magnetic field assisted EDM. Consequently, in this study, an external magnetic field with a strength of 0.66 T is used to assist the material transfer from tool electrode to workpiece surfaces during the EDM process. Pure silver and copper tools with a diameter of 2 mm are used to modify surfaces of Ti6Al4V workpieces at a discharge energy of 125 µJ with different polarities. Results show that the assistance by magnetic field significantly increases the content of transferred material from tool electrode to the workpiece surface. Additionally, it increases material removal rate and reduces the modified layer thickness. Magnetic field assisted EDM is a potential technology for improving the efficacy of the EDM surface modification. [ABSTRACT FROM AUTHOR]

A unique method for synthesizing a surface modifier for metallic hydrogen permeable membranes based on non-classic bimetallic pentagonally structured Pd-Pt nanoparticles was developed. It was found that nanoparticles had unique hollow structures. This significantly reduced the cost of their production due to the economical use of metal. According to the results of electrochemical studies, a synthesized bimetallic Pd-Pt/Pd-Ag modifier showed excellent catalytic activity (up to 60.72 mA cm−2), long-term stability, and resistance to COads poisoning in the alkaline oxidation reaction of methanol. The membrane with the pentagonally structured Pd-Pt/Pd-Ag modifier showed the highest hydrogen permeation flux density, up to 27.3 mmol s−1 m−2. The obtained hydrogen flux density was two times higher than that for membranes with a classic Pdblack/Pd-Ag modifier and an order of magnitude higher than that for an unmodified membrane. Since the rate of transcrystalline hydrogen transfer through a membrane increased, while the speed of transfer through defects remained unchanged, a one and a half times rise in selectivity of the developed Pd-Pt/Pd-Ag membranes was recorded, and it amounted to 3514. The achieved results were due to both the synergistic effect of the combination of Pd and Pt metals in the modifier composition and the large number of available catalytically active centers, which were present as a result of non-classic morphology with high-index facets. The specific faceting, defect structure, and unusual properties provide great opportunities for the application of nanoparticles in the areas of membrane reactors, electrocatalysis, and the petrochemical and hydrogen industries. [ABSTRACT FROM AUTHOR]

This article presents the results of a study on the effect of electrolyte-plasma cementation on the phase composition of the surface-modified layer and the mechanical properties of 20X steel using different solutions. It has been determined that electrolyte-plasma cementation followed by quenching in solutions containing (a) 10% calcined soda (Na2CO3), 10% urea (CH4N2O), 10% glycerin (C3H8O3) and 70% distilled water and (b) 10% calcined soda (Na2CO3), 20% urea (CH4N2O) and 70% distilled water, results in the formation of a modified structure on the surface of 20X steel. This structure mainly consists of the α-Fe phase, along with separate particles of reinforcing phases, Fe3C and Fe3C7 carbides and martensitic αx-Fe phase. The plasma of the electrolyte was used to heat the samples. Then these samples were partially immersed in the electrolyte and held at a temperature of 950 ℃ for 5 min, followed by quenching. As a result of this process, it was found that 20X steel exhibits higher hardness. After the electrolyte plasma cementation, it was observed that the friction coefficient of the modified surface of the steel samples significantly decreased. Additionally, the wear volume was reduced by more than 6.5 times compared to the initial state. The average microhardness after the electrolyte-plasma cementation is 660 HV, which is nearly four times higher than that of the initial material.

This article presents the results of a study on the effect of electrolyte-plasma cementation on the phase composition of the surface-modified layer and the mechanical properties of 20X steel using different solutions. It has been determined that electrolyte-plasma cementation followed by quenching in solutions containing (a) 10% calcined soda (Na2CO3), 10% urea (CH4N2O), 10% glycerin (C3H8O3) and 70% distilled water and (b) 10% calcined soda (Na2CO3), 20% urea (CH4N2O) and 70% distilled water, results in the formation of a modified structure on the surface of 20X steel. This structure mainly consists of the &#945-Fe phase, along with separate particles of reinforcing phases, Fe3C and Fe3C7 carbides and martensitic α'-Fe phase. The plasma of the electrolyte was used to heat the samples. Then these samples were partially immersed in the electrolyte and held at a temperature of 950 °C for 5 min, followed by quenching. As a result of this process, it was found that 20X steel exhibits higher hardness. After the electrolyte plasma cementation, it was observed that the friction coefficient of the modified surface of the steel samples significantly decreased. Additionally, the wear volume was reduced by more than 6.5 times compared to the initial state. The average microhardness after the electrolyte-plasma cementation is 660 HV, which is nearly four times higher than that of the initial material. [ABSTRACT FROM AUTHOR]

A unique method for synthesizing a surface modifier for metallic hydrogen permeable membranes based on non-classic bimetallic pentagonally structured Pd-Pt nanoparticles was developed. It was found that nanoparticles had unique hollow structures. This significantly reduced the cost of their production due to the economical use of metal. According to the results of electrochemical studies, a synthesized bimetallic Pd-Pt/Pd-Ag modifier showed excellent catalytic activity (up to 60.72 mA cm−2), long-term stability, and resistance to COads poisoning in the alkaline oxidation reaction of methanol. The membrane with the pentagonally structured Pd-Pt/Pd-Ag modifier showed the highest hydrogen permeation flux density, up to 27.3 mmol s−1 m−2. The obtained hydrogen flux density was two times higher than that for membranes with a classic Pdblack/Pd-Ag modifier and an order of magnitude higher than that for an unmodified membrane. Since the rate of transcrystalline hydrogen transfer through a membrane increased, while the speed of transfer through defects remained unchanged, a one and a half times rise in selectivity of the developed Pd-Pt/Pd-Ag membranes was recorded, and it amounted to 3514. The achieved results were due to both the synergistic effect of the combination of Pd and Pt metals in the modifier composition and the large number of available catalytically active centers, which were present as a result of non-classic morphology with high-index facets. The specific faceting, defect structure, and unusual properties provide great opportunities for the application of nanoparticles in the areas of membrane reactors, electrocatalysis, and the petrochemical and hydrogen industries.

In this paper, an experimental study investigating the effect of the geometrical shape of the circular and rectangular pin fins on the heat transfer performance and the boiling phenomenon is presented. A pool boiling experiment in the HFE-7100 dielectric working fluid under atmospheric pressure was conducted. Boiling curves and boiling heat transfer coefficients of different test cases were plotted to evaluate the heat transfer performance as well as the captured images of the boiling phenomenon on the test samples. Two quantities, flow resistance and wetted perimeter, were calculated to understand the behaviour of the boiling physics due to variation of fin geometrical shape and, hence, their effect on the heat transfer performance. It was found that the cooling performance of the rectangular pin fins was higher than that of the circular pin fins, despite having a slightly higher flow resistance of 4% and 7%, respectively. This is believed to be the result of the longer wetted perimeter up to 27%, whereby the nucleation site has a higher probability of generating more bubbles in the same boiling surface area. For the tested modified boiling surface with 196 and 144 pin fins, the average heat transfer performances were found to have differences of up to 3.54 and 1.58 times larger, respectively.

The effect of thermohydrogen treatment and vacuum ion–plasma nitriding on the determination of the volume and surface structure of ball heads made of Ti–6Al–4V alloy was studied. It was found that the submicrocrystalline structure formed in the head during thermohydrogen treatment makes it possible to achieve hardness values of 39–41 units HRC and a surface roughness of 0.02 μm. It was shown that the creation of a modified layer consisting of ε (TiN) and δ (Ti2N) titanium nitrides on the surface of a ball head and the solid interstitial solution of nitrogen in α-titanium makes it possible to completely eliminate material wear when testing for friction on ultra-high-molecular-weight polyethylene. The equivalent analysis was also conducted with a ball head that had been implanted in a human body for 12 years. It was found that the change in the color of the head, from slightly golden after nitriding to metallic, is due to the formation of an oxynitride nanoscale layer on the surface. It was shown that in contrast with films made of titanium oxide, the film developed in this study has high wear resistance.

• A magnetic field changes the ferrofluid droplet-surface interaction and cooling performance. • Ferrofluid cooling with a magnet is from 28% to 263% higher than that without it. • A silicon substrate under a magnetic field shows the best heat transfer performance. • Superhydrophobic surfaces do not foul after ferrofluid droplet impact and evaporation. [Display omitted] This paper documents the spreading characteristics and heat transfer of a single ferrofluid droplet impinging onto dry solid surfaces with and without a magnetic field. Three surfaces were investigated: a pure silicon substrate, a silicon substrate with a thin titanium film, and a superhydrophobic coating. Fluid dynamics and cooling results of a ferrofluid droplet were compared to that of pure water and water-surfactant droplets for the same Weber number (We = 61) and initial surface temperature (T 0 = 95 ∘ C). Our results show that the magnetic field (magnetic Bond number Bo m = 2186) increased the droplet spreading diameter up to 12% and suppressed droplet rebound, thus improving the cooling performance of a ferrofluid droplet. The highest heat transfer rates were measured for the pure silicon substrate under a magnetic field with an average value of 14 W. The lowest cooling performance was observed for the superhydrophobic surface without a magnetic field with a peak value of 0.82 W. However, using the magnetic field, the superhydrophobic surface achieved 263% higher heat transfer rate than the non-magnetic case because of the suppression of droplet rebound. Moreover, the surface did not foul from ferrofluid deposition, an advantage for spray cooling applications when using any nanofluid. [ABSTRACT FROM AUTHOR]

In this study, nitrate (NO3-) removal from aqueous solutions was investigated using granular activated carbon (GAC) modified with CaCl2. Batch sorption studies were performed as a function of sorbent dose, initial nitrate concentration and pH. Sorption was maximized between pH 3 and 9. Studies on the effect of pH showed that the ion exchange mechanism might be involved in the sorption process. The percentage of nitrate removed increased with increasing sorbent concentration, and the ideal sorbent dose was found to be 20 g•L-1. Four isotherm models-Langmuir, Freundlich, Redlich-Peterson and Sips-were used to fit the experimental data. The Redlich-Peterson isotherm model explained the sorption process well and showed the best coefficient of determination (0.9979) and Chi-square test statistic (0.0079). Using the Sips isotherm model, the sorption capacity (qe) was found to be 1.93 mg nitrate per g of sorbent. Kinetic experiments indicated that sorption was a fast process, reaching equilibrium within 120 min. The nitrate sorption kinetic data were successfully fitted to a pseudo-second-order kinetic model. The overall results demonstrated potential applications of modified GAC for nitrate removal from aqueous solutions.

Cocondensation and postfunctionalization methods were employed to synthesize a mesoporous silica with large surface area (795.1 ± 1.1 m2 g-1) modified with 4-amino-5-hydrazino-1,2,4-triazole-3-thiol, which was successfully applied to adsorb and preconcentrate Cu(II), Co(II), and Cd(II) from aqueous media. Infrared spectroscopy of the adsorbent material demonstrated N-H stretching bonds related to primary amines existing in the ligand molecule, elemental analysis revealed the presence of 0.132 mmol g-1 of nitrogen, scanning electron microscopy indicated globularly shaped particles with average size of 10 μm, and the point of zero charge was found to be 7.2. Kinetic data were applied to the pseudo-second-order model, indicating that a chemisorption mechanism is probably involved in the uptake of metal ions from aqueous solutions. According to the Langmuir model, the adsorption capacities for the different ions obey the following order: Cu(II) > Co(II) > Cd(II). Through a preconcentration system, a preconcentration factor of 18-, 15-, and 20-fold was attained for Cu(II), Cd(II), and Co(II), respectively. The proposed method was applied in the determination of trace metals in natural river water (Tietê River) and the results were validated through standard reference material analysis. The results also indicated that the packed column proved to be stable over 24 adsorption/desorption cycles, demonstrating that the developed material is potentially suitable for the determination of trace-level metal ions in aqueous samples. [ABSTRACT FROM AUTHOR]

The aim of this study is to undertake a clinical and radiographic evaluation between two different patient groups: machined versus modified surface, to find out if there is statistically significant difference that support the use of implants with different surface properties. Sixty screw, external hex connection implants were examined: one group with 30 machined surface implants (SuperCAT®), and a second group with 30 implants with modified surface (RBM®), for restoring a single tooth. The surgical procedure was performed according with the manufacturer’s protocol. After six months the second phase surgery was performed and the temporary restoration was placed. At this point, the first radiographic evaluation was made. The Roos et al (1997) parameters were followed for the clinical and radiographic evaluation. A 100% of osseointegration was accomplished in both groups. The average marginal bone loss was 0.78 mm, without significant differences between the groups. All implants were reported as success grade 1, with no complications. There are not significant differences between the two groups of machined and modified implant surfaces for single tooth restoration.

The structure of the low-alloy steel after plasma electrolytic nitriding (PEN) in electrolyte containing ammonium nitrate was investigated. The cross-sectional microstructure, composition, and phase constituents of modified layer under different processing conditions were characterized. It is shown that anode PEN provides the saturation of steel with nitrogen and formation of α-FeO, FeO, and FeO oxides, FeN nitride, and martensite. The aqueous solution that contained 15 wt.% NHCl and 5 wt.% NHNO allows one to obtain the hardened layer with a thickness of 80 μm and a microhardness up to 740 HV during 5 min at 850 °C. Surface roughness decreases from 1.5 to 0.8 μm after 5-min PEN at 650 °C. The proposed electrolyte and processing mode (750 °C, 10 min) enable to obtain the decrease in the weight loss after lubricate wear testing by a factor of 2.7. The base-nitrate electrolyte conditioned a decrease in the corrosion current density by a factor of 9 due to passivating effect of the oxide and nitride of iron. [ABSTRACT FROM AUTHOR]

Deposition of bioactive coatings composed of zinc oxide, cyclodextrin and cefepime (ZnO/CD/Cfp) was performed by the Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The obtained nanostructures were characterized by X-ray diffraction, IR microscopy and scanning electron microscopy. The efficient release of cefepime was correlated with an increased anti-biofilm activity of ZnO/CD/Cfp composites. In vitro and in vivo tests have revealed a good biocompatibility of ZnO/CD/Cfp coatings, which recommend them as competitive candidates for the development of antimicrobial surfaces with biomedical applications. The release of the fourth generation cephalosporin Cfp in a biologically active form from the ZnO matrix could help preventing the bacterial adhesion and the subsequent colonization and biofilm development on various surfaces, and thus decreasing the risk of biofilm-related infections. [ABSTRACT FROM AUTHOR]

In this study, nitrate removal from aqueous solutions was investigated using granular activated carbon (GAC) modified with CaCl2. Batch sorption studies were performed as a function of sorbent dose, initial nitrate concentration and pH. Sorption was maximized between pH 3 and 9. Studies on the effect of pH showed that the ion exchange mechanism might be involved in the sorption process. The percentage of nitrate removed increased with increasing sorbent concentration, and the ideal sorbent dose was found to be 20 g•L-1. Four isotherm models -- Langmuir, Freundlich, Redlich-Peterson and Sips -- were used to fit the experimental data. The Redlich-Peterson isotherm model explained the sorption process well and showed the best coefficient of determination (0.9979) and Chi-square test statistic (0.0079). Using the Sips isotherm model, the sorption capacity (qe) was found to be 1.93 mg nitrate per g of sorbent. Kinetic experiments indicated that sorption was a fast process, reaching equilibrium within 120 min. The nitrate sorption kinetic data were successfully fitted to a pseudo-second-order kinetic model. The overall results demonstrated potential applications of modified GAC for nitrate removal from aqueous solutions. [ABSTRACT FROM AUTHOR]

Deposition of bioactive coatings composed of zinc oxide, cyclodextrin and cefepime (ZnO/CD/Cfp) was performed by the Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The obtained nanostructures were characterized by X-ray diffraction, IR microscopy and scanning electron microscopy. The efficient release of cefepime was correlated with an increased anti-biofilm activity of ZnO/CD/Cfp composites. In vitro and in vivo tests have revealed a good biocompatibility of ZnO/CD/Cfp coatings, which recommend them as competitive candidates for the development of antimicrobial surfaces with biomedical applications. The release of the fourth generation cephalosporin Cfp in a biologically active form from the ZnO matrix could help preventing the bacterial adhesion and the subsequent colonization and biofilm development on various surfaces, and thus decreasing the risk of biofilm-related infections.

Surface-modified silica nanoparticles have a plenty of applications, such as coatings, dyes or biomarkers, catalysts and encapsulated products. When modified with 3-(trimethoxysilyl)propyl methacrylate (SiO 2 -MPS) or covered with a polymeric shell obtained from a reaction between divinylbenzene and styrene (SiO 2 -Pol), these SiO 2 nanoparticles induced distinct arrangements in polymer nanocomposites (PNC) prepared with commercial carboxylated nitrile rubber (XNBR). The hydrophilicity character of the modified SiO 2 nanoparticles was also altered, improving their interaction with the XNBR macromolecules. Consequently, choosing the PNC properties for different conditions and applications became possible due to the adjustment of the nanoparticle surface characteristics. Although the final characteristics of the nanocomposites films varied according to the nanoparticle used, the PNC prepared with SiO 2 -Pol presented better homogeneity than those with SiO 2 -MPS. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the method of decreasing the size of heat exchanger surfaces by increasing the heat transfer coefficients and the importance of heat transfer enhancement for vaporization. We report an experimental study on surfaces modified by passive methods applied to heat transfer surfaces mechanically processed, covered with sleeves made by metallic tissues or covered with metallic porous layers performed using welding procedures. Experiments are made to investigate the heat transfer coefficient on copper tubes with a 22mm external diameter using heat from inner source to outer vaporizing liquid. There are developed specific heat transfer correlations for each group of enhanced surfaces. The experimental data and new proposed correlations are compared with well known correlations. The results are in best agreement with the Cornwell–Houston correlation. [Copyright &y& Elsevier]

• Successive droplet impingement cooling on hydrophilic (uncoated) and superhydrophobic (coated) surfaces is investigated experimentally. • A new hybrid heat transfer solution using the integral transform technique is explained and used. • Single droplet impingement onto the uncoated surface showed higher heat transfer rates than for the coated surface. • Successive droplet impingement onto the coated heated surface allows surface refreshing with potential benefits for spray cooling. New high-performance electronic components generate a massive amount of heat per unit of area, and spray cooling is a field of interest for this application. Spray cooling achieves higher heat transfer coefficients than commonly used forced air convection cooling systems. In this study, we performed multiple droplet impingement experiments over heated surfaces in the non-boiling regime, a scenario that is closer to the phenomena of spray cooling than individual droplet impact. This paper focuses on the effects of droplet interactions with surfaces exhibiting distinct wettabilities. A surface thermocouple was used concomitantly as the impact surface and the temperature sensor. The surface thermocouple was originally hydrophilic (uncoated), which later we treated with a low cost commercial superhydrophobic coating (coated). High-speed imaging showed the droplet motion during impact. We proposed a one-dimensional inverse heat conduction semi-analytical solution, adopting a time-dependent droplet heat flux as one of the boundary conditions to represent the droplet cooling effect. We compared the heat transfer performances of both uncoated and coated surfaces for different droplet velocities but same initial temperature. The results showed higher heat transfer rates on uncoated surface relative to the coated one. Also, higher droplet velocities showed higher heat transfer mainly due to the increase in the droplet spreading diameter in contact with the solid. Successive droplets showed lower heat flow for the uncoated surface because of the low thermal effusivity and thickness of the heated solid, where most of the heat is removed by the first droplet. The first droplet thermal resistance and damping effects for the subsequent droplets, reduced the overall cooling performance. On the other hand, for the coated surface we found that the consecutive droplets continued to transfer heat with a similar rate as the previous one, which is desirable for spray cooling. However, the reduced overall heat transfer performance for the coated surface can be explained by the air pockets within the coating structure. [ABSTRACT FROM AUTHOR]

In this paper, an experimental study investigating the effect of the geometrical shape of the circular and rectangular pin fins on the heat transfer performance and the boiling phenomenon is presented. A pool boiling experiment in the HFE-7100 dielectric working fluid under atmospheric pressure was conducted. Boiling curves and boiling heat transfer coefficients of different test cases were plotted to evaluate the heat transfer performance as well as the captured images of the boiling phenomenon on the test samples. Two quantities, flow resistance and wetted perimeter, were calculated to understand the behaviour of the boiling physics due to variation of fin geometrical shape and, hence, their effect on the heat transfer performance. It was found that the cooling performance of the rectangular pin fins was higher than that of the circular pin fins, despite having a slightly higher flow resistance of 4% and 7%, respectively. This is believed to be the result of the longer wetted perimeter up to 27%, whereby the nucleation site has a higher probability of generating more bubbles in the same boiling surface area. For the tested modified boiling surface with 196 and 144 pin fins, the average heat transfer performances were found to have differences of up to 3.54 and 1.58 times larger, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Topotecan, a novel anticancer drug, has been widely used in the treatment of ovarian and cervical cancers. Herein, acetylene black (AB) nanoparticles were used to modify the electrode surface, and the electrochemical behavior of topotecan was examined. At the AB film surface, an irreversible oxidation peak was observed for topotecan, and the response signal greatly increased. The influences of pH value, amount of AB, accumulation potential and time were investigated. As a result, a novel electrochemical method with high sensitivity and rapid response was developed for the detection of topotecan. The linear range is from 2μgL−1 to 0.4mgL−1, and the limit of detection is 1.45μgL−1 (or 3.17×10−9 M). The method was successfully used to detect topotecan in blood serum, and the results consisted with the values that obtained by high performance liquid chromatography. [Copyright &y& Elsevier]

The effect of thermohydrogen treatment and vacuum ion–plasma nitriding on the determination of the volume and surface structure of ball heads made of Ti–6Al–4V alloy was studied. It was found that the submicrocrystalline structure formed in the head during thermohydrogen treatment makes it possible to achieve hardness values of 39–41 units HRC and a surface roughness of 0.02 μm. It was shown that the creation of a modified layer consisting of ε (TiN) and δ (Ti2N) titanium nitrides on the surface of a ball head and the solid interstitial solution of nitrogen in α-titanium makes it possible to completely eliminate material wear when testing for friction on ultra-high-molecular-weight polyethylene. The equivalent analysis was also conducted with a ball head that had been implanted in a human body for 12 years. It was found that the change in the color of the head, from slightly golden after nitriding to metallic, is due to the formation of an oxynitride nanoscale layer on the surface. It was shown that in contrast with films made of titanium oxide, the film developed in this study has high wear resistance. [ABSTRACT FROM AUTHOR]

Abstract: Elaboration and charaterization of a new dialysis membrane by sorption of polyelectrolytes nanolayers. This work aims at improving dialysis membrane selectivity and adaptability to the media to be treated by surface modifications using a polyelectrolyte. The poly(acrylonitrile-co-methallyl sulfonate) membrane, denoted AN69, has been modified by sorption of a cationic polyelectrolyte, the poly(allyldimethylammonium chloride), denoted PDADMA, on the membrane from its dilute solution. The modified membrane was characterized by measuring the selectivity towards lithium ions (Li+) in dialysis by measuring its transport number, the diffusional flow of few electrolytes, the hydraulic permeability and the streaming potential. The results showed that the membrane charge is reversed upon sorption of the PDADMA, indicating a drastic change in the membrane charge. The combination of Li+ transport numbers and streaming potential measurements show with a good evidence some modifications of the membrane on the surface and inside their pores; although the adsorption is reversible, it is so strong – due to multiple membrane–polyelectrolyte electrostatic interactions – that the layer is only removed by conditioning in NaCl aqueous solutions with ionic strength higher than 2 mol/L. The modified membrane appeared to be more selective toward ions Li+, Na+, K+, Ca2+, and Mg2+. Finally, this kind of surface modification can be easily engaged in order to better adapt the membrane surface to its end use. Furthermore, in the present article, we have described in detail, for the first time, a new streaming potential apparatus especially designed for this study. To cite this article: M. Pontié et al., C. R. Chimie 08 (2005) . [Copyright &y& Elsevier]

Successful water treatment is one of the most important aspects for a healthy human life and environmental protection. This study deals with the investigation of a modified catalytic material that is used in water treatment as one of the most promising filter media for water deironing. The activated carbon granules were coated with iron oxide by solution combustion synthesis (SCS) method in a muffle furnace oven. We investigated obtained samples using different diffraction and spectroscopic methods. The elemental composition of the surface and phases of produced materials and the results of comparative analysis with initial samples of the raw material used for the underground water deironing were presented. Using the SCS method, active coal granules were modified with a formation of fine dispersed and crystalline structures of magnetite on their surface. This had a positive effect on the catalytic capacity of the material for deironing of underground water as well as for the specific surface area increase. The residual concentration of total iron in the first portions of the filtrate when using modified samples was almost 3 times lower than for initial material. Image 1 • Active coal was modified for deironing of underground water. • The modification resulted in treatment efficiency. • Perspective on a method of materials modification for water treatment. [ABSTRACT FROM AUTHOR]

Modifying the surface of the transmucosal area is a key research area because this process positively affects the three functions of implants: attachment to soft tissue, inhibiting bacterial biofilm adhesion, and the preservation of the crestal bone. To exploit the potential of titania nanotube arrays (TNTs) with or without using bovine serum albumin (BSA) to modify the surface of a dental implant in contact with the transmucosal area, BSA was loaded into TNTs that were fabricated by anodizing Ti sheets; the physical characteristics of these arrays, including their morphology, chemical composition, surface roughness, contact angle, and surface free energy (SFE), were assessed. The effect of Ti surfaces with TNTs or TNTs-BSA on human gingival fibroblasts (HGFs) was determined by analyzing cell morphology, early adhesion, proliferation, type I collagen (COL-1) gene expression, and the extracellular secretion of COL-1. The results indicate that early HGF adhesion and spreading behavior is positively correlated with surface characteristics, including hydrophilicity, SFE, and surface roughness. Additionally, TNT surfaces not only promoted early HGF adhesion, but also promoted COL-1 secretion. BSA-loaded TNT surfaces promoted early HGF adhesion, while suppressing late proliferation and COL-1 secretion. Therefore, TNT-modified smooth surfaces are expected to be applicable for uses involving the transmucosal area. Further study is required to determine whether BSA-loaded TNT surfaces actually affect closed loop formation of connective tissue because BSA coating actions in vivo are very rapid.