Improved Surface Smoothness Research Articles

Functionalization of reverse osmosis membrane with graphene oxide and polyacrylic acid to control biofouling and mineral scaling

The polyamide reverse osmosis (RO) membrane was modified with graphene oxide (GO), followed by polymerization of acrylic acid (used as an antiscalant) for the reduction of both biofouling and mineral scaling. After functionalization, the water contact angle reduced from 41.7 ± 4.5° for unmodified RO membrane to 24.4 ± 1.3° for the modified RO membranes, which showed that membrane hydrophilicity was significantly enhanced, in addition to the improvement in surface smoothness. The modified membranes were tested for their anti-scaling and anti-biofouling characteristics. When the mineral scaling test was performed using CaSO4 solution as feedwater, the permeate flux was reduced by only 3% as compared to the unmodified RO membrane which encountered up to 22% decline in flux by the end of the experiment. After the scaling test, the membrane surface was characterized by Scanning electron microscopy – energy-dispersive X-ray spectroscopy, Fourier transform infrared, and X-ray diffraction techniques. The results showed that the unmodified RO membrane was fully covered with gypsum precipitates. Whereas, the precipitates were detected only at the highly saturated zones of the water channel i.e. towards the exit of water flow. Additionally, the anti-bacterial test was performed through bacteriostasis rate determination, which showed that the modified membranes inhibited the growth of nearly 95% of the bacterial cells. Further experiments were also performed to investigate the inhibition of both scaling and biofouling by modified RO membranes. Thus, it was found that the polymer-modified GO coated RO membranes were able to diminish both gypsum scaling and biofilm formation demonstrating their potential to control different types of membrane fouling.

Effect of Softeners on Smoothness Behavior of Cotton Fabrics

Cotton woven fabrics were treated with three different silicone softeners. These softeners were applied on the fabric using the pad- dry-cure method. The hand value of treated fabrics was analyzed by determining bending length, crease recovery angle, and surface roughness and smoothness properties. With increased silicone softener concentration, an improvement in surface smoothness of the fabric was observed at a certain level, beyond which there were no significant changes in smoothness. Statistical analysis (ANOVA) was carried out to establish a relationship between the application of softeners at different concentrations on the bending length, smoothness, and crease recovery angle properties. A correlation was established between subjective and Kawabata analyses.

Influence of Molar Concentration: Sol-Gel Synthesized Magnesium Oxide Thin Films for High Power Light Emitting Diode Thermal Management

Sol-gel technique was used to synthesize 0.6 M and 0.8 M molar concentrations of magnesium oxide thin on aluminium substrate and enforced into heat spreader material in thermal management of lighting devices. X-ray diffraction analysis confirm the films to be polycrystalline cubic in nature with (200), (220) and (222) orientations. 20 layers from 0.8 M showed higher intensity from the X-ray analysis. Relative thermal conductivity measurement of 20 layers from 0.6 M showed a value of (26.3 W/mK) which appears to improve over other layers. At 700 mA operating current, 20 layers from 0.6 M showed higher junction temperature difference of 37.16 °C as well as higher thermal resistance difference of 5.9 K/W when compared to bare aluminium substrate. All coated films are within the accepted color correlated temperature safe operating range (< 3300 K) of light emitting diodes, addition to this, 20 layers MgO thin films from 0.6 M displayed a recommendable illuminance as well as color correlate temperature performance from optical characterization. Atomic force microscope surface analysis for both molar concentrations showed an improvement in surface smoothness over bare substrate. Overall, magnesium oxide thin films can be perfectly enforced as heat spreader for high power light emitting diodes.

Effect of additional polishing methods on the physical surface properties of different nanocomposites: SEM and AFM study.

This evaluated the arrangement of filler particles in depth of nanocomposites, and surface roughness, wettability, microtopography, and micromorphology following additional polishing step. Forty samples of each composite tested [Filtek Z350XT (FZ), IPS Empress Direct (IP)] were fabricated and finished/polished/additionally polished using one of the following methods (n = 10/group): no finishing/polishing (NFP), Sof-Lex Pop-On + no additional polishing (SP), Sof-Lex Pop-On + Astropol rubber polisher (SP+A), and Sof-Lex Pop-On + felt disc with polishing paste (SP+FP). Surface roughness (Ra) and contact angles were measured using a profilometer and goniometer, respectively. Microtopography and micromorphology were evaluated using atomic force microscopy and scanning electron microscopy, respectively. Ra and contact angle data were examined by two-way analysis of variance and Tukey's test (p < .05). Organic matrix, lower and larger filler particles were disposed in depth. Mean Ra values were lowest and contact angles were smallest in the NFP group for both composite resins. SP+A and SP+FP decreased mean Ra in comparison with SP for FZ, whereas only SP+FP decreased mean Ra in comparison with SP for IP. Only SP+FP increased contact angles in comparison with SP for FZ, whereas contact angles in the SP+A, SP+FP, and SP groups were similar for FZ. Both composites presented more uniform topography and smother surfaces following SP+A and SP+FP in comparison with SP. Therefore, additional polishing improved surface smoothness and decreased wettability of the composite resins studied. SP+FP produced smoother and less wettable surfaces for FZ and IP.

Influence of Additives on Surface Smoothness and Polytype Stability in Solution Growth of n-Type 4H-SiC

We have investigated the dependence of the macrostep height on various additives in solution growth of n-type 4H-SiC. Surface modification by adding transition elements in periods 4‒6 (Sc, Ti, V, Mn, Fe, Co, Ni, Cu, Y, Nb, Mo, Ce, and W) and group 13‒14 elements (B, Al, Ga, Ge, Sn) was systematically studied to find additives improving smoothness of the growth surface. We found that Sc, Co, Mo, and Ge improved surface smoothness in addition to the already-known additives, such as Al, B, and Sn. Besides, these additives (Sc, Co, Mo, Ge) give no measurable influence on the conductivity of n-type grown crystals. These results demonstrated that Sc, Co, Mo, Ge and Sn are useful additives for solution growth of n-type 4H-SiC.

Upgrading the Ti/TiN Film Depositions on KP-1 Steel by Using the Anode Ring Bias Voltage

By newly adopting of a two-step bias voltage-sustained nitrification of the plasma process the titanium nitride films which applied to the mold base steel KP-1 are manufactured. The two-step process of biased voltages was introduced in order to consider microscopic kinematics of Ti ion bombardments which lead to a deep study on the plasmas including surface temperature of substrates associated with nitrification the KP-1 surface. For supplying of the additional biased voltage to the conventional coater, an anode-biased ring was installed near the plasma source and it ultimately upgraded the typical method of physical vapor depositions which uniquely adopted one bias voltage applied to the substrates because the additional ring controlled both ions and electrons effectively in order to improve surface smoothness and to increase surface hardness with various values of surface temperatures of substrate and deposition times. The discharge ionic current of titanium flux was measured as functions of both the ring bias voltage and the substrate voltage using single probe. By using plasma physics for the two-step bias voltages the discrete mean-free-times, due to cyclonic motions of ions by magnetic field, were studied to show the effects of two bias voltages. The maximal hardness increase of Ti/TiN films deposited on KP-1 was 370% when the surface temperature was 370 °C, the substrate bias voltage of 800volts, and the deposition time was 55 minutes after ring bias was applied. The 2000 times-magnified cross-sectional morphologies of TiN films deposited on the carbon mold base KP-1 were taken as a function of the ring anode bias. The 1000 times-magnified photograph of the TiN-filmed surface deposited on KP-1 mold base was taken to investigate the surface morphology. In order to examine the two-step bias test with respect to both the corrosion problem and the surface hardness, the 2000 times-magnified morphological photograph of a cross-sectional Ti/TiN film which was deposited on the KP-1steel mold was taken.

The evaluation of surface sealants' effect on the surface roughness of Nano-hybrid composite after polishing with One-Step system (in-vitro).

BackgroundThe clinical use of composite resins has increased substantially due to increased esthetic demands by patients, improvements in formulation, and simplification of bonding procedures. Use of surface sealants is recommended to improve surface smoothness of composite restorations. The aim of this study was to evaluate the effect of surface sealants on the surface roughness of nano-hybrid composite after polishing with One-Step system.Material and MethodsUsing a silicon mold, 56 specimens of 10 mm diameter and 2 mm height were prepared from Grandio nano-hybrid composite (Voco, Cuxhaven, Germany) with A2 shade. Specimens were randomly divided in 2 groups. The surface of specimens were polished with VOCO One-step system. One group of specimens assigned as control group and received no more surface treatment. Surface sealant PermaSeal (Ultradent, USA) was applied on the surface of specimens of the other group as experimental group. Specimens were stored in Ringer’s solution at 37°C for 24 hours. The specimens were subjected to artificial accelerated aging with thermocycling method (3000 cycles, between 5 and 55°C) and then 100000 cycles of tooth brushing. A Profilometer was used to measuring the surface roughness of specimens before and after aging procedures.ResultsThe surface roughness changes of control group were significant before and after aging (P<0.05). The mean final surface roughness of control group was unacceptable clinically while it was acceptable in experimental group.ConclusionsThe use of surface sealants on nano-hybrid composite causes noticeable reduces in surface roughness of composite. Key words:Surface-penetrating sealant, surface roughness, nano-hybrid, composites, one-step polishing.

Hydrophobization and smoothing of cellulose nanofibril films by cellulose ester coatings

The Cellulose nanofibrils (CNF), also referred to as nanocellulose, is one of the most studied bio-based material in recent year, which has good potential in the future for packaging applications due to its excellent mechanical strength and oxygen barrier properties. In the future, CNF films may also find new applications for example in printed electronics, if the surface smoothness of CNF films can be improved. One way to improve surface smoothness is to use thin coating solutions with zero porosity, such as molar mass controlled cellulose ester coatings. In this study, we have coated CNF films using molar mass controlled cellulose esters with different side chain lengths forming 3-layer film (ester-CNF-ester). These coatings improved significantly the smoothness of CNF films. The 3-layer films have also good water vapor barrier and mechanical properties and the films are heat-sealable, which enable various new applications in the future.

The Effects of Deposition Time and Surface Temperature on the TiN Films for KP-4 Steel Mold

In order to improve surface smoothness and increase its surface hardness of the PK-4 steel mold the dependencies of the surface temperatures of substrate, deposition times, and bias voltages applied to the substrate on the TiN film made by the physical vapor deposition were studied. Six main steps of the synthesis process were introduced to improve the robustness. Double applications of the bias voltages increased the surface hardness. The rotating substrates increased the uniformity of the films. 1000 times-magnified pictures were taken to analyze the micro-grains of TiN. SEM pictures were taken to confirm the surface smoothness. Both the surface temperature of substrates and deposition time were affecting factors. The maximal hardness of TiN film deposited on KP-4 was increased by 20%. The surface temperature of substrates contributed to 13% in the increase of hardness. The deposition time also contributed to 6% in the increase of hardness respectively.

Programmable Bidirectional Folding of Metallic Thin Films for 3D Chiral Optical Antennas.

3D structures with characteristic lengths ranging from nanometer to micrometer scale often exhibit extraordinary optical properties, and have been becoming an extensively explored field for building new generation nanophotonic devices. Albeit a few methods have been developed for fabricating 3D optical structures, constructing 3D structures with nanometer accuracy, diversified materials, and perfect morphology is an extremely challenging task. This study presents a general 3D nanofabrication technique, the focused ion beam stress induced deformation process, which allows a programmable and accurate bidirectional folding (-70°-+90°) of various metal and dielectric thin films. Using this method, 3D helical optical antennas with different handedness, improved surface smoothness, and tunable geometries are fabricated, and the strong optical rotation effects of single helical antennas are demonstrated.

Impact of CeO2 incorporation in electrodeposited Ni-Fe on structure and physical properties of multifunctional nanocomposites

A new type of nanocomposite, Ni-Fe/CeO2 (∼40nm) was prepared by cathodic co-deposition at several current densities (1.0–5.0Adm−2) from an ethylene glycol bath. Coatings obtained from optimized bath were characterized by field emission scanning electron microscope (FESEM), energy dispersed X-ray analyzer (EDAX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Electrochemical and physical properties of the coatings were studied as a function of variation in current density and in CeO2 particle content. Compared to Ni-Fe alloy, these nanocomposites exhibited finer grains, higher microhardness, better electrical conductivity, improved corrosion resistance and enhanced soft magnetic properties. The effect of annealing temperature on surface morphology, microstructure, texture and microhardness was also studied. CeO2 particles were found involved in managing textural evolution of Ni-Fe growth resulting in a shift in preferred orientation from (111) to (220) crystallographic plane with increasing current density. The incorporation of CeO2 particles (up to 5wt%) also results in improvement in surface smoothness, and physical and electrochemical properties.

Dermal Remodeling of Burn Scar by Fractional CO2 Laser.

Ablative CO2 fractional lasers have recently been introduced for burn scar treatment because of pronounced clinical outcomes with fewer treatment sessions than nonablative fractional laser. This study was conducted to observe clinical as well as histologic changes of burn scars after treatment with CO2 fractional laser. Eleven patients (one female and 10 males, aged 31-59years) with skin phototypes III to V with burn scars received 10 sessions of fractional CO2 laser treatments (UltraPulse(®) Encore; Lumenis, Santa Clara, CA, USA) over an average 5-week interval. Two passes were performed using the following parameters: deep FX mode, 12.5-30mJ, with a density setting of 5-10%. Clinical evaluations by three blinded dermatologists were obtained at baseline and at 6months after the final treatment via photographs using the Vancouver scar scale (VSS). Skin biopsies were done on four patients before and after treatment. All patients showed clinical improvement in their scars with significant decrease in VSS. Histologic findings showed the changes in the upper dermis with newly formed dermal papilla. This characteristic upper dermis change was presented as improvement in surface smoothness and skin tension clinically. Postinflammatory hyperpigmentation and itching sensation were the most common adverse effects. Burn scar treatment by fractional CO2 laser is effective by forming new collagen fibers mainly in the upper dermis. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A two-step thermal annealing and HNO3 doping treatment for graphene electrode and its application in small-molecule organic solar cells

The transferred chemical vapor deposition (CVD)-grown graphene from copper foils to other desired substrates by using poly(methyl methacrylate) (PMMA) as supporter, suffers from problems of rough surface, low conductivity and poor wettability, which hinders its applications in optoelectronic devices. In this work, a combined thermal annealing and HNO3 doping treatment for graphene electrode has been employed to simultaneously improve its smoothness, conductivity and wettability. The thermal annealing process results in the improved surface smoothness by removing the PMMA residue. HNO3 doping treatment for the graphene enhances its conductivity and surface wetting to PEDOT:PSS. Furthermore, the work function (WF) of two-step treated graphene increased from ∼4.4 eV to ∼5.1 eV. Small-molecule organic solar cells (OSCs) based on the two-step treated graphene anodes exhibit a power conversion efficiency (PCE) of 2.43%, which is comparable to that of ITO electrode (2.48%). This work demonstrates the bright future of graphene transparent electrodes as a replacement for ITO.

Characterization of grafted jute fiber using acrylate monomers pretreated with alkali

AbstractThe reactivity of lingocellulosic jute fiber to sunlight (UV) and atmospheric gases and chemicals was reduced by grafting jute with acrylate monomers, such as ethyl acrylate (EA) and 2-hydroxy ethyl methacrylate (HEMA). The grafting reaction sufficiently blocked the reactive groups of jute and thus, physically- and chemically-bound cellulosic units and on the fiber surface. The grafting gave additional strength, higher thermal stability and improved surface smoothness. Though the modified fibers showed better color fastness properties in sunlight, the dyeability of the modified fibers somewhat decreased. Grafting reaction and other characteristics of modified fibers were investigated with FT-IR, tensile tester, thermogravimeric analyser, and grey scale respectively. The change of surface morphology of the jute fiber on modification was also observed with a scanning electron microscopy. Modification of bleached jute and alkali-activated bleached jute with HEMA gave higher graft yield (26.6, 29.4 %) than that of EA modification (22.5, 24.7 %). Due to the different chemical features, HEMA-modified fiber exhibited better chemical, thermal and physical properties.

Experimental and numerical study of microchannel formation in rubber-assisted hot embossing with an open-channel mold

In comparison to conventional hot embossing with a precisely aligned pair of hard mold plates, the rubber-assisted hot embossing process with a modified embossing tool that employs only one hard mold plate containing through-thickness open microchannels was investigated both experimentally and numerically. The numerical process dynamics model was constructed using a hyperelastic constitutive model to describe the large deformation behavior of the embossing film at an embossing temperature near the glass transition temperature. Both experimental and numerical results showed that excellent replication of microchannel patterns can be achieved using the simplified tool setup and an embossing temperature slightly above Tg is suitable for achieving a uniform embossing thickness. Additional advantages from the use of open channels on the embossing mold include reduced diesel effect in the mold cavity and improved surface smoothness of the embossed film. The simulation results agreed very well with the experimental observations for the effects of the main process parameters on the replication quality, and this study demonstrated that the hyperelastic process model is capable of predicting the basic characteristics of the rubber-assisted embossing process with an open-channel embossing mold.

Effect of additives and steaming on quality of air dried noodles.

Texture is the most important property for consumer acceptance in cooked noodles. The air dried noodles are known to have higher cooking loss and cooking time, to that of instant fried noodles. But the fat content of instant fried noodles is more. In the present work attempts were made to optimize the moisture content so as to obtain a smooth dough for extruded noodle preparation and develop air dried noodles of low fat content with lesser cooking loss and cooking time. To meet the objectives, the effect of various additives and steaming treatment on cooking quality, sensory attributes, textural properties and microstructure of noodles were studied. Dough prepared by addition of 40ml water to 100g flour resulted into formation of a soft dough, leading to production of noodles of improved surface smoothness and maximum yield. The use of additives (5g oil, 0.2g guar gum, 2g gluten and 1ml of 1% kansui solution for 100g of flour) and steaming treatment showed significant effect on noodles quality, with respect to cooking characteristics, sensory attributes and textural properties. The microstructure images justified the positive correlation between the effects of ingredients with steaming and quality parameters of noodles. Air dried noodles with reduced cooking loss (~50% reduction) with marginal reduction in cooking time was developed, which were having similar characteristics to that of instant fried noodles. Compared to the instant fried noodle, the prepared air dried noodle was having substantially reduced fat content (~70% reduction). Thus the present study will be useful for guiding extrusion processes for production of air dried noodles having less cooking time and low fat content.

Improving Surface Smoothness of Aluminium Alloys Multi-Bead Weld for Welding Rapid Forming Application

Understanding the interference of multi-bead parameters on surface smoothness is essential for accuracy of the formed parts made by welding rapid forming. This paper presents an investigation on surface smoothness of multi-bead aluminium alloys. Deposition path planning and overlap ratio is manipulated in order to improve surface smoothness. Observation on bead cross section indicates that deposition path planning has remarkable effect on the surface smoothness. Multi-bead that developed using continuous path planning has surface smoothness of 0.46 mm – 1.34 mm and most bead present wavy type surfaces. The surface smoothness is improved by increasing the overlap ratio. Meanwhile, skip path planning produced good surface smoothness of 0.11 mm – 0.28 mm. An improved surface smoothness featuring flat surface type is obtained with this path planning.

Fully automated whole-head segmentation with improved smoothness and continuity, with theory reviewed.

Individualized current-flow models are needed for precise targeting of brain structures using transcranial electrical or magnetic stimulation (TES/TMS). The same is true for current-source reconstruction in electroencephalography and magnetoencephalography (EEG/MEG). The first step in generating such models is to obtain an accurate segmentation of individual head anatomy, including not only brain but also cerebrospinal fluid (CSF), skull and soft tissues, with a field of view (FOV) that covers the whole head. Currently available automated segmentation tools only provide results for brain tissues, have a limited FOV, and do not guarantee continuity and smoothness of tissues, which is crucially important for accurate current-flow estimates. Here we present a tool that addresses these needs. It is based on a rigorous Bayesian inference framework that combines image intensity model, anatomical prior (atlas) and morphological constraints using Markov random fields (MRF). The method is evaluated on 20 simulated and 8 real head volumes acquired with magnetic resonance imaging (MRI) at 1 mm3 resolution. We find improved surface smoothness and continuity as compared to the segmentation algorithms currently implemented in Statistical Parametric Mapping (SPM). With this tool, accurate and morphologically correct modeling of the whole-head anatomy for individual subjects may now be feasible on a routine basis. Code and data are fully integrated into SPM software tool and are made publicly available. In addition, a review on the MRI segmentation using atlas and the MRF over the last 20 years is also provided, with the general mathematical framework clearly derived.

Adjusting dental ceramics: An in vitro evaluation of the ability of various ceramic polishing kits to mimic glazed dental ceramic surface

Statement of problemDuring the insertion appointment, the practitioner is often faced with the need to adjust ceramic surfaces to fit a restoration to the adjacent or opposing dentition and soft tissues. PurposeThe purpose of this study was to assess the ceramic surface smoothness achieved with various commercially available ceramic polishing kits on different commonly used ceramic systems. The reliability of the cost of a polishing kit as an indicator of improved surface smoothness was assessed. Material and methodsA total of 350 ceramic surfaces representing 5 commonly available ceramic systems (IPS Empress Esthetic, IPS e.max Press, Cergo Kiss, Vita PM 9, Imagine PressX) were treated with 5 types of ceramic polishing systems (Cerapreshine, 94006C, Ceramiste, Optrafine, Zenostar) by following the manufacturers’ guidelines. The surface roughness was measured with a profilometer (Taylor Hobson; Precision Taylor Hobson Ltd). The effects of ceramic systems and polishing kits of interest on surface roughness were analyzed by 2-way ANOVA, paired t test, and Bonferroni corrected significance level. ResultsThe ceramic systems and polishing kits statistically affected surface roughness (P<.001).The polishing kit Zenostar on IPS e.max Press created the smoothest ceramic surface. No correlation could be established between the high cost of the polishing kit and low surface roughness. None of the commonly used ceramic polishing kits could create a surface smoother than that of glazed ceramic (P<.001). ConclusionsThe inclusion of a diamond polishing paste step is recommended to improve surface smoothness (P<.001). The cost of ceramic polishing kits is not recommended as a reliable indicator of better performance of ceramic polishing kits (P>.30).

The differences in potential corrosive effects of sulfides and disulfides in insulating oils

This paper describes work performed in an attempt to bring more clarity regarding the differences in potential corrosive effect between sulfides and disulfides at specified reaction conditions as defined in ASTM 1275 B. SEM/EDS was used to further evaluate testing results. The results show that Dibenzyl disulfide (DBDS) has a strong tendency to form copper sulfides while Dibenzyl sulfide (DBS) display no tendency at all to form copper sulfides in the virgin insulating oils, but the reactivity of DBS increase if in the thermally degraded oils. In addition, the insulating paper decrease the oxidation of the copper surface due to that oxygen is adsorbed and consumed when migrating through the cellulose phase. With the improvement of surface smoothness, the specific surface area accessible for reactions will decrease and consequently it is more difficult for the copper to be corroded by DBDS.