Profilometer Results Research Articles

Dopamine-assisted sustainable antimicrobial peptide coating with antifouling and anticorrosion properties

Surface biofouling will seriously affect the performance of solid–liquid contact surfaces. Antimicrobial peptides (AMPs) are considered as potential agents for surface antifouling due to its broad-spectrum antimicrobial capacity. In this study, a derived AMP was synthesized by the reaction between a marine originated AMP and monomolecular dopamine, which was then used to modify 304 stainless steel. Mass spectrometry analysis confirmed the synthesis reaction of DP, and the co-culture essays with E11 and 293 T cells proved DP’s excellent compatibility. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis confirmed that DP was grafted on surface successfully, meanwhile, atomic force microscope, contact angle and 3D optical profilometer results demonstrated that surface morphology and wettability changed remarkably after modification. The results of Vibrio natriegens and Phaeodactylum tricornutum adhesion assays illustrated that DP treated surface possessed great antifouling capacity, and the antibacterial and anti-algal properties of the DP modified surface can reach 97.78% and 90.01%, respectively. Electrochemical results indicated that DP modified surface exhibited superior anticorrosion. The stability test results showed that DP modified surface possessed long-lasting properties in antifouling and anticorrosion. These findings may provide a useful tethering process for producing excellent antifouling surfaces in marine equipment, medical devices and other relevant fields.

Synthesis and Research of Rare Earth Nanocrystal Luminescent Properties for Security Labels Using the Electrohydrodynamic Printing Technique

YVO4:Eu3+ nanoparticles were successfully synthesized by two methods, namely the sonochemical method and hydrothermal method. The X-ray diffraction (XRD) patterns showed the tetragonal phase of YVO4 (JCPDS 17-0341) was indexed in the diffraction peaks of all samples. The samples synthesized by the sonochemical method had a highly crystalline structure (X-ray diffraction results) and luminescence intensity (photoluminescence results) than those synthesized by the hydrothermal method. According to the results of field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM), the average size of YVO4:Eu3+ nanoparticles was around 25–30 nm for the sonochemical method and 15–20 nm for the hydrothermal method. YVO4:Eu3+ nanoparticles in the case of the sonochemical method had a better crystalline structure and stronger emissivity at 618 nm. The Eu3+ ions’ average lifetime in YVO4:Eu3+ at 618 nm emission under 275 nm excitation were at 0.955 ms for the sonochemical method and 0.723 ms for the hydrothermal method. The security ink for inkjet devices contained YVO4:Eu3+ nanoparticles, the binding agent as polyethylene oxide or ethyl cellulose and other necessary solvents. The device used for security label printing was an inkjet printer with an electrohydrodynamic printing technique (EHD). In the 3D optical profilometer results, the width of the printed line was ~97–167 µm and the thickness at ~9.1–9.6 µm. The printed security label obtained a well-marked shape, with a size at 1.98 × 1.98 mm.

Corrosion response of ultra-high strength steels used for automotive applications

The corrosion resistance properties of two ultra-high strength steels, Docol 1200 and 1400 were studied in 3.5 wt% NaCl solution using chemical and electrochemical techniques supported by surface characterization techniques namely scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), atomic force microscope (AFM), and optical profilometer. The mechanical properties of both Docol 1200 and Docol 1400 uncorroded and corroded were determined by tensile test. Results obtained reveal that the two alloys exhibit similar mechanical properties. Corrosion has effect on the mechanical properties of the alloys. Corrosion studies reveal that both Docol 1200 and 1400 are prone to corrosion in NaCl environment. A corrosion rate of 30.6 mpy and 49.6 mpy was recorded for a Docol 1200 at 25 °C and 60 °C, respectively. For Docol 1400, the corrosion rate obtained at 25 °C and 60 °C was 32.7 mpy and 52.4 mpy, respectively. Docol 1200 is adjudged to exhibit superior corrosion resistance property than Docol 1400. The optical profilometric results disclose that Docol 1200 and Docol 1400 suffered pitting corrosion in NaCl solution. Pitting corrosion was more severe with Docol 1400 than 1200.

Injectable profiloplasty: Forehead, nose, lips, and chin filler treatment

We propose a medical filler treatment algorithm of the profile which includes forehead, nose, and chin and to evaluate profilometric results and complications. 83 case reviews of associated liquid forehead, nose, and chin plasty performed consecutively from 2014 to 2016. We monitored the horizontal and vertical sagittal stability into two age group: <40 y.o. and >40 y.o. using profilometric Arnett analysis measurements on the F, Gb, Na, Nd, Nt, Sn, ULA, LLA, B, Pg, and Gn soft-tissue points. The results at both 3 and 6 months were consistent with the normal ranges indicated by Arnett, with a 0.8 mm maximum of defect/excess. Forehead treatment was performed in 51 (61.4%) patient. Patients >40 y.o. always needed a global correction of the forehead profile. We performed nasal treatment in 83 (100%) patient, acute nasolabial angles was the more frequent nasal defect. The lips were injected in 59 patients (71.1) more frequently >40 y.o. In 83 (100%) patients we perform a chin augmentation. The average advancement of the chin was 3 mm. The correction of the projection of the forehead, of the profile and shape of the nose, of the lips and chin as well as an overall improvement in face aesthetics and harmony gives a good solution in patients avoiding the need for a surgical intervention, scars and cost of general anesthesia, thus providing the optimum in patient satisfaction.

Improved HER activity of Ni and stainless steel electrodes activated by NiCoMo ionic activator – A combined DFT and experimental study

In this paper we discussed various factors contributing to the improvement of hydrogen evolution reaction (HER) activity of Ni and stainless steel electrodes activated by in situ addition of NiCoMo activators, using a combination of experimental techniques and DFT calculations. By comparing energy consumption of stainless steel (SS) electrodes in a lab scale alkaline electrolyzer with and without ionic activation, we obtained reduction of energy consumption by 21% at industrial conditions (high current density and temperature). We recorded U–I curves for activated and non-activated stainless steel electrodes in the current density range from 40 to 500 mA cm2 and in the temperature range 298–343 K, and the obtained results were used in an electrochemical model of the laboratory alkaline electrolyzer. Increase of the electrode surface upon addition of ionic activators was confirmed by profilometric measurements and SEM analysis. Finally, we applied density functional theory (DFT) to discuss partial roles of applied ionic activators (Ni, Co and Mo) in the modification and improvement of the intrinsic properties of the cathode towards the HER in alkaline medium. From the combination of profilometric, SEM and DFT results, we conclude that the main factor contributing to the improvement of HER activity of Ni electrodes upon NiCoMo activation is the increase of electrode surface area.

Structural and morphological characterization of Al2O3 coated macro-porous silicon by atomic layer deposition

In the present study, Al2O3 coated on macro-porous silicon (m-PS) is prepared by atomic layer deposition (ALD) whereas m-PS is prepared by electrochemical anodization of P type silicon (100) with current density of 15mA/cm2. Field emission scanning electron microscopy analysis shows Al2O3 nanoparticles with size of ~100nm are conformally coated on m-PS. The surface chemistry and formation mechanism of ALD of Al2O3 (ALD-Al2O3) on m-PS are demonstrated in detail. Optical profilometer results of Al2O3/m-PS confirm conformality of Al2O3 coating on m-PS because the surface amplitude parameter values of m-PS are decreased after ALD-Al2O3. Fourier Transform Infrared analysis confirms that unstable Si-H species of m-PS are replaced with stable Si-Al species. X-ray photoelectron spectroscopy (XPS) analysis of Al2O3/m-PS is carried out for chemical analysis and band gap energy measurement of Al2O3. The XPS survey spectrum shows that fluorine peak is also evolved along with Al, O and C elements which confirm that m-PS surface consists of fluorine. The band gap energy of Al2O3 coating is calculated as 6.91eV from analysis of high resolution O 1s spectrum.

Tribological behavior of borided AISI 1018 steel under linear reciprocating sliding conditions

In this study, the wear behavior of AISI 1018 borided steel is characterized. The boriding thermochemical treatment was carried out at 1273K for 6h, and different thicknesses of the boriding agent surrounding the samples were examined. The layer structure was composed of FeB and Fe2B layers.The tribological properties at the surface of borided and unborided steel were evaluated employing the ball-on-flat method with sliding reciprocating wear tests, using an Al2O3 ball as the counterpart. The applied load and the sliding speed remained constant at 5N and 5mm/s, respectively, with sliding distances of 81m, 108m and 135m.The coefficients of friction (CoFs) on the boride layers from the sliding reciprocating wear tests for dry and lubricated conditions were evaluated. The CoFs are independent of the boriding potential expressed as the powder thickness. Surface wear for longer sliding distances in lubricated conditions was neglected; there was no difference between the wear track and the original surface roughness in the profilometer results. The wear scar diameter and the worn surfaces of borided and unborided steels in both experimental conditions were characterized by SEM to understand the wear mechanisms.

The role of matrix metalloproteinases and cysteine-cathepsins on the progression of dentine erosion

ObjectiveTo evaluate in vitro the effect of the inhibition of endogenous dentinal enzymes (matrix metalloproteinases-MMPs and cysteine cathepsins-CCs) on dentine erosion. DesignDentine blocks (4mm×4mm×2mm) from sound human teeth were randomly divided into 7 groups (n=17) according to the treatment: MMP- and CC-inhibitor chlorhexidine digluconate (CHX, 10mM); MMP-inhibitor galardin (G, 0.2mM); specific cathepsin B inhibitor (CCB, 0.2mM); non-specific CC inhibitor (CCE-64, 0.5μM); fluoride (F, 1.23% NaF); placebo (P) and untreated (UT). Inhibitors were applied as gels once for 1min. Specimens were submitted to 5 days of pH cycling including the erosive challenge (Coke, pH 2.64, 90s/day) and remineralisation (artificial saliva). Demineralised organic surface loss was determined profilometrically. Demineralised organic matrix (DOM) was removed with collagenase and the profile was re-evaluated in the absence of collagen fibrils. The differences in profilometric results and DOM thickness among the groups were analysed with ANOVA and Tukey's test (p<0.05). ResultsLoss of demineralised tissue (μm, mean±SD) was: CHX 8.4±1.7 b, G 8.6±1.9 b, CCB 9.6±1.4 a, CCE-64 9.9±1.3 a, F 9.9±1.7 a, P 10.9±2.2 a, UT 11.0±1.5 a. Loss of mineralised tissue was: CHX 15.4±2.2 b, G 16.0±1.8 b, CCB 17.6±2.4 a, CCE-64 17.6±2.0 a, F 17.3±2.8 a, P 19.1±2.1 a, UT 18.9±2.4 a. MMP-inhibitors significantly reduced organic matrix and mineral loss in comparison to all the other groups (p<0.05). No statistically significant differences were found in the thickness of the remaining DOM (p=0.845). ConclusionDentine endogenous MMPs seem to be the main enzymes responsible for DOM loss and erosion.

The Corrosion Processes Effect on Surface Roughness of Bonded Magnetic Material Based on Nd-(Fe,Co)-B Powder Type

This paper presents an analysis of the Nd-(Fe,Co)-B bonded magnetic materials surface before and after corrosion tests. In the technological process of bonded magnetic materials the main difficulty is the fact that in the presence of small amounts of oxygen magnetic powders (having in their composition a highly active, a rare earth element) the particle surface easily cover with an oxide layer. The oxides phases are creating and furthermore the presence of this kind of paramagnetic phase on the powder particles surface adversely affects on the properties of the final product. Important is to protect the surface against spontaneously oxidation of the magnetic materials. One of the activities way to surface isolation is creating the additional protection coating (biencapsulation). Biencapsulation is a protection process in which not only set resin layer, but also an additional protective coating has been applied. The powder particles are coated with protective coatings: Ni-P/epoxy resin and phosphate/epoxy resin. In the paper the roughness measurement (2D) with profilometer (Taylor Hobson) results were presented. Also the effect of corrosion process evaluation on the bonded magnets surface roughness were determined (sulfate solution pH = 3, the exposure time 4h). It has been found that the application of powder particles biencapsulation with phosphate/epoxy resin coating (in comparison with Ni-P/epoxy resin biencapsulation) leads to a more effective corrosion protection of the final bonded magnets.

Scratch behavior of glass fiber reinforced polyester matrix composite after solid particle erosion

In current study, the tested material is a glass fiber reinforced polyester matrix composite with one stacking sequence namely [0/90]s. First of all, the solid particle erosion behavior of composite samples was investigated under various impingement angles (15°, 30°, 45°, 60°, 75°, and 90°, respectively). Eroded composite samples were examined by non-contact optical profilometer and 3D surface roughness maps were obtained. From optical profilometer results, it was clearly shown that values of erosion crater hole volumes were well suited with erosion rate values versus impingement angles. Maximum and minimum erosion crater hole volumes observed at 60° and 15° impingement angles due to semi-ductile characteristic of the target material, respectively. After erosion tests, the scratch behavior of composite samples was examined. The results showed that the coefficient of friction was decreased by the increase in impingement angles of 45° and 60°. The maximum scratch hardness value was determined at 60° impingement angle. Scratch damage morphologies were determined by using optical microscope and scanning electron microscope. It was observed that low (15° and 30°) and high (75° and 90°) impingement angles result in remarkably severe surface deformation on the samples. POLYM. COMPOS., 36:1958–1966, 2015. © 2014 Society of Plastics Engineer

Evaluation of the Activity and Tolerability of a Cosmetic Treatment for the Periocular Area on the Aging Face: Controlled Clinical and Instrumental Evaluation vs. Placebo

The aim of this study was to evaluate clinically and by non invasive instrumental evaluations the efficacy and tolerability of a cosmetic treatment containing an innovative active ingredient, ethyl ximenynate, in the prevention of dark circles under the eyes and blemishes of skin aging on the eye profile. Evaluations were performed at baseline and after 2 and 4 weeks of treatment on 22 volunteers; the study was planned as a double blind half-face trial. Data showed a trend towards a lifting of the eyelid skin; all investigator scores (eye puffiness, skin smoothness, roughness and dryness) decreased. In addition, profilometric results confirmed the anti-wrinkles efficacy of the active product and its lifting action, while those related to spectrophotometry underlined the decongestant effect on dark circles that appeared, at the end of the study, to be less marked. The improvement of skin microcirculation and capillary resistance and vascular tone in the eye area underlines a general mitigation of all relevant skin imperfections and blemishes of skin aging on the eye profile. The active ingredient was shown to be effective for the cosmetic treatment of the periocular area.

The use of a profilometer for both quantitative and qualitative measurements of toothpaste abrasivity

To evaluate the abrasivity of different toothpastes both quantitatively and qualitatively with a profilometer technique and to correlate these findings to the radioactive dentin abrasivity (RDA) value. Acrylic plates were exposed to brushing in a brushing machine with 11 different toothpastes. The results were evaluated using a profilometer. A surface roughness value (Ra-value), that is, a qualitative measurement, and also a volume value, that is, a quantitative measurement, were calculated from the profilometer results. These values were then correlated to each other and to the RDA-value. A comparison between RDA, Ra and volume measurements was performed using linear fitting procedure. The results showed that the correlation between RDA and Ra measurements was low (R(2) = 0.04) and also that the correlation between RDA and volume measurements was low (R(2) = 0.00002). Correlation between Ra and abraded volume was high (R(2) = 0.87). It is important to consider not only the RDA-value when evaluating toothpaste abrasivity. From the profilometer results both a quantitative (volume) and qualitative (roughness) measurement of the abrasivity of a toothpaste can be obtained.

Effect of acidic fluoride treatments on early enamel erosion lesions—A comparison of calcium and profilometric analyses

Objective The protective effect of fluoride solutions against acidic challenge on enamel was tested in vitro using calcium- and profilometer analyses. Methods HF-, SnF 2-, TiF 4- and NaF solutions (0.1 M F −, with a pH of 2.0, 2.9, 1.5, 7.3, respectively) and H 2O were tested on a total of 60 enamel specimens divided into 10 groups. Prior to and after F-treatment five groups were exposed for 1 min to 0.01 M citric acid, and the other five groups for 10 min to 0.1 M citric acid. Enamel specimens were measured by profilometry at baseline and before and after each acidic challenge. [Ca] in the collected citric acid samples was measured by atom absorption spectroscopy (AAS). ΔCa and Δ surface height were calculated for each specimen and the data were analysed using one-way ANOVA, Tukeys test and Pearson r correlation. Results AAS showed that the acidic F-treatments significantly reduced enamel dissolution for both the 1 min and 10 min acidic challenge. Profilometry showed no significant differences between the F-solutions for the 1 min groups. Significant differences could be seen between the fluorides for the 10 min groups and there was a large correlation between the profilometric and AAS results. In conclusion, all fluoride solutions reduced enamel dissolution when specimens were exposed to citric acid. Conclusions The profilometer was not sensitive enough to measure the effects of the different fluorides against a low acidic challenge. AAS was able to show these differences and for the 10 min acidic challenge there was a good correlation between the results from the two methods.

Langmuir−Schaeffer Films from a π−π Stacking Perylenediimide Dye: Organization and Charge Transfer Properties

The organization of pi-pi stacking perylenediimide (PDI) derivative, PDI12, was studied in solution and in thin films. Films were prepared with the Langmuir-Schaeffer (LS) method and characterized by means of AFM, optical profilometry, steady-state absorption, emission, fluorescence lifetime, and transient photovoltage measurements. The columnar aggregates observed previously in PDI12 solutions and in spin-coated films persist also in LS films. Because of the specific conditions during the preparation of the LS film, i.e., hydrophobic interactions and lateral compression, the columnar aggregates seem to organize with their long axis perpendicular to the layer plane whereas in spin-coated films the columns were oriented parallel to the layer plane. According to AFM and profilometer results, the thickness of LS monolayer of PDI12 is 10 nm, indicating that it consists mainly of aggregates, each containing approximately 30 monomers. Intermolecular photoinduced energy and electron transfer processes in C(60)|PDI12 double layer junction were studied. The fluorescence lifetime of PDI12 film is exceptionally long, but the quenching is very efficient in the presence of C(60). In charge transfer studies, long-lived photovoltage signal was observed for the double layer. Results of this work indicate that PDI12 acts as an electron acceptor and fullerene C(60) as an electron donor.

Clinical trial of a novel non‐thermal LED array for reversal of photoaging: Clinical, histologic, and surface profilometric results

Photomodulation has been described as a process which modifies cell activity using light sources without thermal effect. The objective of this study was to investigate the use of a non-thermal low dose light emitting diode (LED) array for improving the appearance of photoaged subjects. This prospective study investigated a random cohort of patients (N = 90) with a wide range of photoaged skin treated by LED photomodulation using a full panel 590 nm non-thermal full face LED array delivering 0.1 J/cm(2) with a specific sequence of pulsing. Subjects were evaluated at 4, 8, 12, 18 weeks and 6 and 12 months after a series of 8 treatments delivered over 4 weeks. Data collected included stereotactic digital imaging, computerized optical digital profilometry, and peri-ocular biopsy histologic evaluations for standard stains and well as collagen synthetic and degradative pathway immunofluorescent staining. Digital imaging data showed a reduction of signs of photoaging in 90% of subjects with smoother texture, reduction of peri-orbital rhytids, and reduction of erythema and pigmentation. Optical profilometry showed a 10% improvement by surface topographical measurements. Histologic data showed markedly increased collagen in the papillary dermis of 100% of post-treatment specimens (N = 10). Staining with anti-collagen I antibodies demonstrated a 28% (range: 10%-70%) average increase in density while staining with anti-matrixmetalloproteinase (MMP)-1 showed an average reduction of 4% (range: 2%-40%). No side effects or pain were noted. Photomodulation to reverse photoaging is possible with a specific array of LEDs with a specific fluence using a precise pulsing or "code" sequence. Skin textural improvement by digital imaging and surface profilometry is accompanied by increased collagen I deposition with reduced MMP-1 (collagenase) activity in the papillary dermis. This technique is a safe and effective non-painful non-ablative modality for improvement of photoaging.

A double-sideband transmitted carrier amplitude modulation method for laser texture characterization

A technique based on double-sideband transmitted carrier amplitude modulation is presented in this study to characterize the laser texture on a magnetic disk. This method can be used to accurately determine the laser texture zone locations, circumferential and radial pitches, and frequency components. It is easy to implement, fast to characterize a surface, and has up to sub-micron lateral resolution. Laser texture is also characterized by using a profilometer, and the frequency response of the laser texture can be predicted well using the profilometer results.

A study of the surface parameters of ground and lapped metal surfaces, using specular and diffuse reflection of laser light

Laser light, with a photocell giving a logarithmic response, is used to measure the specular and diffuse reflection from ground and ground and lapped metal surfaces. Theory suggests that the probability distribution of roughness heights determines the specular reflection, while the distribution of surface slopes determines the diffuse reflection. For specular reflection the theory gives useful results even in the range of grazing incidence (70° or 80°) which must be used for the roughness range 0.2 to 1.5 μm. The optical and profilometer results suggest skewed non-Gaussian probability distributions, and a theoretical model which may account for such distributions is suggested. The diffuse light results show that, except for the roughest specimens, the slope distribution is also non-Gaussian. The standard deviation of the slopes increases with roughness, and the relation between them is obtained.