Impact Of Surface Treatment Research Articles

Humus condition under different systems of basic cultivation of dark gray forest soil

Studies, were conducted in a stationary experiment between 1988 and 2018 on dark gray forest heavy loam soil in Scientific Research Institute of Agriculture for Northern Trans-Ural Region - Branch of Federal State Institutions Federal Research Centre Tyumen Scientific Centre of Siberian Branch of the Russian Academy of Sciences. The aim of the study is to determine the effect of long-term (30 years) impact of different systems of basic cultivation of dark gray forest soils in the cultivation of grain crops on the humus content. Observations were made according to generally accepted methods during 6 rotations of grain and fallow crop rotation: bare fallow, winter rye, spring wheat, spring vetch, spring barley, unfolded in time and space. The impact of the combined system of tillage with alternation of plowing and no-tillage at 20-22 cm during 6 rotations of a 5-pole grain and steam crop rotation (30 years), increased the humus content in the 0-40 cm layer of dark gray forest soil compared with the initial content by 0.42%. The systems of main tillage - differentiated, without sowing, and mouldboard provided in general a relatively favorable dynamics of the humus state of the soil. The content of humus in the 0-40 cm layer of soil by differentiated and unswept systems during the study period remained close to the initial condition. По отвальной системе содержание гумуса снижалось на 0,22% или в среднем 0,37т/га в год. The greatest loss of humus in the 0-40 cm layer of soil by 0.80% in relation to the initial was the impact of surface treatment with annual discing BDT-2,5 (heavy disc harrows) on 10-12 cm or an average annual loss of 1.33 t / ha.

Impact of Surface Treatments and Hybrid Flame Retardants on Flammability, and Thermal Performance of Bamboo Paper Composites

ABSTRACT In this article, bamboo nonwoven fabric (BF) is introduced as reinforcement into the vinyl ester (VE) matrix for the manufacturing of BF/VE composites through Vacuum Assisted Resin Transfer Mold process. Eco-friendly (NaHCO3) and other common treatments (NaOH and Silane) are applied to BF to modify the surface chemistry, thereby improving the mechanical strength (tensile modulus 10(NHTB), 11(NCTB) and 11% (SiTB); flexural modulus 11(NHTB) and 90% (SiTB) and impact strength 23% (SiTB)) and thermal properties. Besides, the three flame retardants (FRs) (chitosan (CS), ammonium polyphosphate (APP), and zinc borate) are incorporated with various percentages (3 and 6) for the improvement of flame retardancy of the BF composites and the experiments are proceeded by Taguchi L9 orthogonal array (OA) through the layup method. The nature of pure and modified BF is analyzed using Fourier transform infrared spectroscopy, x-ray diffraction and scanning electron microscopy exhibited the removal of the constituents and formation of reactive sites, etc. The effect of treatment on the thermal and flame retardant properties is analyzed by thermogravimetric analysis, horizontal burning test, and microcalorimeter, respectively. The thermal stability, burning rate, and peak heat release rate were significantly changed than that of pure BF composites.

Impact of Surface Treatment on the Functional Properties Stainless Steel for Biomedical Applications.

The main goal of the carried out tests was to analyze the influence of the surface modification of a substrate by depositing composite ZnO layers by the Atomic Layer Deposition (ALD) method. The samples were subjected to preliminary surface modification consisting of being sandblasted and electropolished. A ZnO layer was applied to the prepared substrates by the ALD method. As a precursor of ZnO, diethylzinc (DEZ) was used, which reacted with water, enabling the deposition of the thin films. The chamber temperature was as follows: T = 100–300 °C. The number of cycles was 500 and 1500. As part of the assessment of the physicochemical properties of the resulting surface layers, the tests of chemical composition of the layer, pitting corrosion, impedance corrosion, adhesion to the metal substrate, morphology surface, and wettability were carried out. On the basis of the obtained research, it was found that a composite ZnO layer deposited onto a substrate previously subjected to the electrochemical polishing process has more favorable physicochemical properties. Moreover, an influence of temperature and the number of cycles of the deposition process on the obtained properties was observed, where the ZnO layer was characterized by more favorable properties at a temperature of 200–300 °C at 1500 cycles of the deposition process.

Impact of Surface Treatment of Historic Bricks on the Process of Water Vapours Diffusion

The article is dealing with impact of selected types of surface finish of historic bricks on their diffusion properties, i.e. on the process of their spontaneous self-drying. Within the pilot experiment was monitored diffusion flow of water vapours going from humid brick fragment through its surface finish to the surrounding environment. Brick fragment was saturated with water to a degree usually corresponding to common humidity of uninsulated underground brickwork of historic buildings. Surrounding environment had parameters of common heated object for residential or administrative purpose or an object for storage of things sensitive to impact of high relative air humidity. Test results proved that any surface finish of the brickwork, even its hydropohobisation is significantly slowing down process of drying of the masonry compared to the speed of drying of the untreated brickwork. It is evident from the course of lines of diffusion flows that the process of water vapours diffusion is most intense at the beginning of the period (about 5 to 10 days) and after this period the diffusion flow speed goes to a long-term stabilisation of diffusion flow speed, in such a way that its course is in average corresponding to linear functional dependence on time. In conclusion of the article we introduce on practical example calculation of real time of drying up of the masonry in historic building selected space flooded with flood water where is now running process of natural drying without additional humidity sources.

Impact of Surface Treatments and Hybrid Flame Retardants on Flammability, and Thermal Performance of Bamboo Fabric Composites

ABSTRACT In this article, bamboo nonwoven fabric (BF) is introduced as reinforcement into the vinyl ester (VE) matrix for the manufacturing of BF/VE composites through Vacuum Assisted Resin Transfer Mold process. Eco-friendly (NaHCO3) and other common treatments (NaOH and Silane) are applied to BF to modify the surface chemistry, thereby improving the mechanical strength (tensile modulus 10(NHTB), 11(NCTB) and 11% (SiTB); flexural modulus 11(NHTB) and 90% (SiTB) and impact strength 23% (SiTB)) and thermal properties. Besides, the three flame retardants (FRs) (chitosan (CS), ammonium polyphosphate (APP) and zinc borate) are incorporated with various percentages (3 and 6) for the improvement of flame retardancy of the BF composites and the experiments are proceeded by Taguchi L9 orthogonal array (OA) through the layup method. The nature of pure and modified BF is analyzed using Fourier transform-infrared spectroscopy, x-ray diffraction and scanning electron microscopy exhibited the removal of the constituents and formation of reactive sites, etc. The effect of treatment on the thermal and flame retardant properties is analyzed by thermogravimetric analysis, horizontal burning test, and microcalorimeter, respectively. The thermal stability, burning rate, and peak heat release rate were significantly changed than that of pure BF composites.

The Impact of Surface Treatment on the Structure and Chemistry of Protective Oxide-Scale in High-Temperature Oxidation-Resistant Nickel Alloys

The Impact of Surface Treatment on the Structure and Chemistry of Protective Oxide-Scale in High-Temperature Oxidation-Resistant Nickel Alloys

Impact of Surface Treatments and Post-Deposition Annealing Upon Interfacial Property of ALD-Al₂O₃ on a-Plane GaN

Optimization of interface characteristics between dielectric and non-polar GaN surface is very important and urgent for vertical GaN MOS device whose channel is perpendicular to the conventional cplane. In this work, the effects of piranha cleaning and N2 post deposition annealing (PDA) to the interface between atomic-layer-deposited (ALD)-Al 2 O 3 and a-plane GaN samples were comprehensively investigated by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and photo-assisted capacitance-voltage (C-V) measurements. The piranha cleaning and N2 annealing can improve interface characteristics through the reduction in surface roughness and Ga-O bonds, respectively. Therefore, the frequency dispersion and hysteresis are nearly suppressed with a low interface trap quantity (Qit) of 4.1 x 10 11 cm -2 and a low average interface state density (Dit) of 2.04 x 10 11 cm -2 ·eV -1 from photoassisted C-V measurements, showing the great promise of utilizing piranha pretreatment, buffered oxide etch (BOE) dip, and N 2 annealing as an effective route to improve the vertical GaN MOS interface properties.

Impact of Surface Treatment with Different Repair Acrylic Resin on the Flexural Strength of Denture Base Resin: An In Vitro Study

The aim and objective of the present study was to assess the flexural strength of denture base resin based on surface treatment with different acrylic resin repair materials. Totally, 120 heat-polymerized polymethyl methacrylate denture base resin materials which are rectangular shaped with the size of 65 mm × 10 mm × 2.5 mm were fabricated. 150 μm-sized alumina used for surface treatment. All the 120 heat-cured, surface-treated acrylic denture base resin samples were randomly divided into three groups. Group I: glass-fiber-reinforced auto-polymerizing acrylic resin, group II: auto-polymerizing acrylic resin, and group III: light-cured acrylic resin. A universal testing machine was used to test the flexural strength of the repaired specimens. A highest mean flexural strength (88.96 ± 0.31) was demonstrated by group I, followed by group II (72.18 ± 1.86) and group III (66.30 ± 1.02). ANOVA demonstrated a statistically significant inter-group difference. On multiple comparisons, using Tukey's post hoc test a statistically significant difference between groups I and II and between groups I and III was found. After considering the limitations, the present study concluded that the highest flexural strength is shown by glass-fiber-reinforced auto-polymerizing acrylic resin than by auto-polymerizing acrylic resin and light-cured acrylic resin. Denture repair comprises of joining two fractured parts of a denture with a denture repair material. The success of denture repair depends on the adhesion phenomenon. The treatment of the surface can be accomplished using a suitable material which changes chemically and morphologically and thus promotes better adhesion.

Defect formation in N* LCs via photovoltaic fields: impact of surface treatment

ABSTRACTField-induced defect creation was investigated in chiral nematic liquid crystal test cells, where a Fe-doped lithium niobate thin-cut was applied as field generating substrate. These photo responsive test cells were exposed to focused continuous wave laser light, which resulted in the formation of localised defects. The covering indium tin oxide coated glass of the test cells was treated with a polyvinyl alcohol alignment layer. This alignment layer was either applied with a doctor blade technique or by spin casting of a polyvinyl solution, which was thermally annealed, subsequently. The surface roughness of the alignment layers was investigated with atomic force microscopy, which was interesting to understand how defects and locally lying helices were supported or suppressed in various samples. Well-confined circular defects were formed in test cells with spin-casted alignment layers and the appearance and unwanted interaction with oily streaks could be efficiently reduced in these samples. The results are promising. Samples with an oily streak-free homogenous standing helix orientation of the chiral nematic liquid crystal are an ideal canvas for rewritable pattern formation in a chiral nematic LC: Such samples have high potential as reconfigurable diffractive elements such as rewritable diffraction gratings.

Mitigation of Soot Deposition on Modified Surfaces of Exhaust Gas Recirculation Coolers

A common approach for lower emission of NOx from diesel engines is to use exhaust gas recirculation (EGR) coolers where part of the exhaust gas is returned to the cylinder to reduce the combustion temperature. Nonetheless, the deposition of various species, i.e. soot particles, on surfaces deteriorates the thermal efficiency of EGR coolers. This study investigated the impact of surface treatment on particulate fouling of a rectangular EGR cooler. An experimental setup was assembled through which the uncoated and coated plates were exposed to the flow of exhaust flue gases. The cooler surfaces were coated by ceramic-based materials with resistance to high temperatures by spraying. The results showed that surface modification abated soot deposition to some extent and the deposit layer was easily flaked off with a force of 0.8 N when it was scratched with a nano-intender. Contrariwise, the deposit formed on the uncoated surface did not result in similar propensity and instead it required a larger force of 2.25 N. This implies weaker stickiness of soot deposit on the investigated coatings compared to baseline stainless steel surface. It was also found that the electron donor component of surface energy would determine the tendency of a surface to foul or not.

Impact of surface treatment on metal-work-function dependence of barrier height of GaN-on-GaN Schottky barrier diode

The impact of surface treatment on Schottky contacts on a GaN-on-GaN epitaxial layer was comprehensively investigated by combining X-ray photoelectron spectroscopy (XPS) at each step of the treatment process and electrical measurements on Schottky barrier diodes. XPS showed that a photolithography process on a GaN surface reduced the surface oxide and band bending and that the subsequent HCl-based treatment reduced them further. Electrical measurements indicated that HCl treatment after photolithography affected the metal-work-function, ϕM, dependence of the Schottky barrier height, ϕB, resulting in an increase in the slope factor compared with that of the samples without HCl treatment. It is highly likely that the reduction in interface disorder by the chemical treatment led to a reduction in the interface state density at the metal/GaN interface. On the basis of the obtained ϕB–ϕM plots, the charge neutrality level was measured experimentally to be 5.0 eV from the vacuum level and 0.9 eV from the conduction band edge, while the electron affinity was measured to be 4.1 eV.

The Impact of Surface Treatment and Degree of Vacuum on the Interface and Mechanical Properties of Stainless Steel Clad Plate.

In this study, the impact of different surface treatment and degree of vacuum on the interface and mechanical properties of 304/Q345 stainless steel clad plate was investigated. The study indicated that more continuous or aggregated Al2O3 and Si-Mn composite oxides were formed at the interface after brush grinding. However, less inclusions such as Al2O3, MnS and Ca-Mg-Al-Si composite oxides were formed at the interface after pickling treatment. For the vacuum degrees of 10−2 Pa, 1 Pa and 105 Pa, the oxidation reaction became more intense with the decrease in vacuum degree. The interface inclusions were gradually changed from Al2O3 and Si-Mn complex oxides to oxide scale and MnCr2O4 spinel oxide. The interfacial bonding strength of stainless steel clad plate was improved with the increase in degree of vacuum. The bonding strength was 55 MPa at vacuum of 105 Pa, but it was 484 MPa at vacuum of 10−2 Pa, which is far greater than that of the national standard, and an excellent performance was obtained.

Correlating the Microstructure and Surface Morphology of Additively Manufactured 304L Series Stainless Steel to Its Corrosion Response

In recent years a desire to rapidly prototype complex metallic parts has driven the advancement of metal additive manufacturing (AM). Powder bed selective laser melting (SLM) and laser engineered net shape (LENS) have emerged as prevalent techniques for producing a wide range of complex metal components. That said, the non-equilibrium processes associated with SLM and LENS techniques lead to microstructural heterogeneity and irregular surface structures throughout components, which can be cause for corrosion behavior considerably different from conventionally processed materials. This presentation will investigate and compare the corrosion behavior of 304L stainless steel produced by the SLM and LENS processes. An emphasis will be on how the heterogeneous microstructures of the AM components influence breakdown of passivity and repassivation in aqueous solutions. The impact of surface treatments, such as laser surface modification, have on AM component roughness and subsequently the corrosion response will be explored.

Impact of surface treatment on the mechanical properties of sisal and jute reinforced with epoxy resin natural fiber hybrid composites

ABSTRACTNatural fiber composites (NFCs) are gaining importance in various fields of engineering due to their ecofriendly nature and low cost. The present work is aimed in studying the mechanical properties such as tensile strength, flexural strength, impact strength, and hardness for natural fiber/epoxy resin composites reinforced with sisal and jute. The composites are prepared by hand lay-up method by varying the proportion of jute fiber. One set of fibers is surface treated with NAOH solution and its impact on mechanical strength was studied. From the results obtained, it was observed that the tensile strength increases by 20%, flexural strength by 25%, impact strength increases by 27.27%, and hardness by 5% for surface treated composites. Scanning electron microscope was used to study the morphology of prepared specimen and fractured specimen. The results indicate that surface-treated composites perform better than the untreated fiber composites.

Surface Nanobubbles Studied by Time-Resolved Fluorescence Microscopy Methods Combined with AFM: The Impact of Surface Treatment on Nanobubble Nucleation.

The impact of surface treatment and modification on surface nanobubble nucleation in water has been addressed by a new combination of fluorescence lifetime imaging microscopy (FLIM) and atomic force microscopy (AFM). In this study, rhodamine 6G (Rh6G)-labeled surface nanobubbles nucleated by the ethanol-water exchange were studied on differently cleaned borosilicate glass, silanized glass as well as self-assembled monolayers on transparent gold by combined AFM-FLIM. While the AFM data confirmed earlier reports on surface nanobubble nucleation, size, and apparent contact angles in dependence of the underlying substrate, the colocalization of these elevated features with highly fluorescent features observed in confocal intensity images added new information. By analyzing the characteristic contributions to the excited state lifetime of Rh6G in decay curves obtained from time-correlated single photon counting (TCSPC) experiments, the characteristic short-lived (<600 ps) component of could be associated with an emission at the gas-water interface. Its colocalization with nanobubble-like features in the AFM height images provides evidence for the observation of gas-filled surface nanobubbles. While piranha-cleaned glass supported nanobubbles, milder UV-ozone or oxygen plasma treatment afforded glass-water interfaces, where no nanobubbles were observed by combined AFM-FLIM. Finally, the number density of nanobubbles scaled inversely with increasing surface hydrophobicity.

Influence of surface treatment on adhesion of iCVD PGMA thin films for wafer-level bonding

ABSTRACTThis work demonstrates wafer bonding using initiated chemical vapor deposition (iCVD) poly(glycidylmethacrylate) (PGMA) thin films, and studies the impact of surface treatment to manipulate adhesion energy between polymer film and silicon substrate. Substrates were modified with organosilanes or nitrogen plasma prior to iCVD and bonding. Adhesion was characterized by measuring critical energy release rate (Gc) using a 4-point bend technique. Results demonstrate a correlation between substrate surface energy and polymer-substrate adhesion energy where, depending on the functional group, close to an order of magnitude variation in adhesion energy was observed. These results point to minimal covalent interaction between polymer and substrate for these samples. Exposing the bonded wafers to a thermal anneal step led to an improved grafting of PGMA to substrate. For grafted films, the sample failure mode shifted from adhesive to cohesive, with drastic increase in Gc. These findings demonstrate that the adhesion energy and failure mode of iCVD-PGMA bonded wafers can be manipulated through surface functionalization and thermal treatment, which enable both temporary and permanent chip-bonding applications using iCVD polymer films as adhesives.

Impact of surface treatments on high-κ dielectric integration with Ga-polar and N-polar GaN

Gallium- and nitrogen-polar GaN surfaces are subjected to a variety of pretreatments, including oxidation, before the application of high-κ dielectrics by atomic layer deposition (ALD) in order to assess the “best” preparation of smooth, clean, and electrically high-performing dielectric semiconductor interfaces. In terms of topographical and chemical cleanliness, a pretreatment with a wet chemical piranha etch (H2SO4:H2O2) was found to be optimum for both surfaces, and additionally, (NH4)2S is effective for N-polar surfaces. Both thermal and plasma oxidations were employed for controlled growth of native oxides. For Ga-polar surfaces, all native oxides were as smooth as pretreated surfaces, while for N-polar surfaces, all native oxides are much rougher except for very short, high temperature oxidations. ALD Al2O3 films on Ga-polar surfaces are smoother for pretreated surfaces than for as-received surfaces, whereas for N-polar surfaces the opposite is true. In general, ALD HfO2 films on Ga-polar surfaces are rougher (0.8 nm rms) than Al2O3 films (0.1 nm rms), whereas for piranha treated N-polar surfaces, HfO2 films are smoother than Al2O3 films. For Ga-polar surfaces, capacitance–voltage measurements of simple Al2O3 (measured κ = 9) capacitors show the smallest hysteresis for unintentionally oxidized surfaces (0.37 V), whereas simple HfO2 (measured κ = 14) capacitors show the smallest hysteresis for a thermal GaOx at the interface (0.1 V). In both cases, the thicker the GaOx at the interface the larger the negative threshold voltage shift—suggesting an electron trap. Calculated total trapped charges associated with the dielectrics range from 3.2 × 1011 cm−2 (for HfO2 on thermally oxidized GaN) to 1 × 1012 cm−2 for Al2O3 on thermally oxidized GaN and HfO2 on plasma oxidized GaN. Finally, the leakage current density for nearly all capacitors is &amp;lt;10−5 A-cm−2 at +8 V bias.

Impact of Surface Treatment on the Structural and Electronic Properties of Polished CdZnTe Surfaces for Radiation Detectors

We present the effects of surface treatments on the structural and electronic properties of chemomechanically polished Cd0.9Zn0.1Te before contact deposition. Specifically, polished CdZnTe (CZT) samples were treated with four distinct chemical etchants: (1) bromine methanol (BM), (2) bromine in lactic acid, (3) bromine in methanol followed by bromine–20% lactic acid in ethylene glycol, and (4) hydrochloric acid (HCl). The surface structure and surface electronic properties were studied with atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). AFM images showed that three of the four etchants significantly altered the surface morphology and structure of CZT. All etchants created smoother surfaces; however, all except HCl also introduced high densities of defects. HCl was found to not affect the surface structure. XPS measurements indicated that a thick, ∼3 nm to 4 nm, TeO2 layer formed about 1 h after etching; hence, it is very important to process devices immediately after etching to prevent oxide formation.

Impact of Surface Treatment on the Corrosion Resistance of ASTM F138-F139 Stainless Steel for Biomedical Applications

AISI 316 LVM stainless steel type considered in ASTM F138 and F139 standards for implant devices is widely used, in particular for orthopedic surgery, because it combines good biofunctionality and acceptable biocompatibility at low costs. Adequate interaction of these materials with the human body and its capability to reach the desired service level are determined by the surface preparation. The goal of the present work is to relate the surface roughness parameters with the localized corrosion resistance of AISI 316 LVM stainless steel grit blasted for different times and passivated with nitric acid. At intermediate blasting times the roughness parameters attain an extreme value and this surface condition corresponds with the maximum pitting corrosion resistance.

Effect of surface treatments on interfacial characteristics and band alignments of atomic‐layer‐deposited Al2O3 films on GaAs substrates

AbstractThe GaAs surfaces were passivated by two kinds of chemical pretreatments (using NH4OH and (NH4)2S as passivation agents) for atomic layer deposited (ALD) Al2O3 dielectric film growth. The chemical information at Al2O3/GaAs interfaces was carefully characterized. The impact of surface treatments on the band alignments of ALD Al2O3 films on nGaAs (100) substrates was also investigated. After postdeposition annealing, the NH4OH passivated samples not only have a slight increase of the AsAs peaks with an appearance of As suboxide (AsOx) feature at Al2O3/GaAs interfaces but also exhibit a serious interfacial interdiffusion between Al2O3 and GaAs. However, the (NH4)2S passivated samples produce the GaS and AsS overlayers on GaAs, effectively preventing from the intermixed diffusion between Al2O3 films and GaAs substrates with a sharper interface. Both NH4OH and (NH4)2S passivated Al2O3 samples show the same band gap of 6.67 eV. The conduction band offset at Al2O3/GaAs interface for the (NH4)2S passivated samples have a slight enhancement of 0.14 eV in comparison to NH4OH passivated ones. Copyright © 2010 John Wiley &amp; Sons, Ltd.