Surface Roughness Loss Research Articles

Evaluation of the Loss of Surface Roughness Following the Use of Four Different Instruments for Mechanical Debridement of Dental Implants: An In-vitro Pilot Study

To compare the dental implant surface properties such as mean surface roughness, roughness depth, and the surface loss produced by different prophylactic instrument types. Twenty-four surfaces of twelve dental implants were treated using titanium curettes, titanium-coated curettes, an air abrasion unit, and titanium brushes. The dental implants were inserted partially into a Styrofoam base, exposing one-third to simulate cases of peri-implantitis. The exposed surface was coated with artificial dental calculus (ADC) and divided into four groups for treatment. The arithmetic mean surface roughness (Ra) and the mean roughness depth (Rz) were assessed using the confocal microscope, and the surface loss (SL) area was calculated from the scanning electron microscopic images using an image analysis software. The Ra value varied between 1.08 to 0.29 µm, the Rz value between 10.3 to 70.5 µm, and the mean surface loss area between 154 to 9410 µm2. The One-way ANOVA analysis showed a statistically significant difference between the four groups (P < 0.05). The air abrasion unit showed the highest mean roughness value of 1.08 ± 0.14 µm, mean roughness depth of 70.5 ± 2.21 µm, and a minor surface area loss of 154 ± 132 µm2. In comparison, the titanium brushes showed the least Ra and Rz of 0.29 ± 0.05 µm and 10.3 ± 2.32 µm, respectively, whereas the titanium-coated curettes showed the highest loss of surface area 9410 ± 91.6 µm2. The air abrasion unit was shown to have the least detrimental effect on the implant surface when removing the artificial dental calculus compared to the other three methods.

Comparative Evaluation on the Effects of Three Pediatric Syrups on Microhardness, Roughness and Staining of the Primary Teeth Enamel: An In-Vitro Study.

​​​​​Introduction One of the most prevalent oral diseases is dental caries. Syrups are commonly used by children who have difficulty swallowing tablets and capsules. Some medications can make dental caries worse and cause the enamel to erode. Most of the time, parents are unaware that a number of foods, drinks, and syrup-formulated pediatric drugs include sugar, whichcan cause erosion of primary teeth, resulting in plaque accumulation and dental caries.Henceforth, theaim of this study is to assess the effects of pediatric syrups on the microhardness, roughness, and staining ability of primary tooth enamel as a result of daily intake of syrup. Methods Eighty primary teeth, including both anterior and posterior, that required extraction due to pre-shedding mobility were randomly divided into four groups of twenty samples each. Samples were exposed to multivitamin syrup (Rudimin), iron syrup (C Pink), and diuretic syrup (Furosemide). The samples were submerged in 10 mL of the respective medication once daily for five minutes for 21 days. On days 0 and 21, enamel surfaces were assessed for changes in microhardness, roughness, and staining. The microhardness was assessed using a Micro Vickers microhardness tester machine; the roughness was assessed using a Mitutoyo surface roughness tester; and the staining ability was assessed using a spectrophotometer, and data processing was done using the analysis of variance (ANOVA) test andTukey's post hoc analysis. Results The changes in enamel surface for microhardness, roughness, and staining were assessed twice, at days 0 and 21. Group 4 (Furoped) showed a significant difference in surface microhardnessand staining ability of enamel surfaces with a statistically significant p-value (<0.05). When roughness was compared, allthree interventions had a significant difference from the control group, whereas there was no statistically significant difference between the intervention groups. Conclusion This study concludes that pediatric syrups can significantly weaken the enamel of primary teeth, resulting in loss of enamel surface microhardness and roughness making them vulnerable to caries. Since frequent consumption of these syrups is correlated with tooth decay, certain precautions like oral hygiene maintenance and rinsingwith water after taking the syrup should be done to prevent dental caries, as consumption of medicinal syrups by children cannot be avoided.

Polymer-Based 3-D Printed 140 to 220 GHz Metal Waveguide Thru Lines, Twist and Filters

This paper demonstrates the current state-of-the-art in low-cost, low loss ruggedized polymer-based 3-D printed G-band (140 to 220 GHz) metal-pipe rectangular waveguide (MPRWG) components. From a unique and exhaustive up-to-date literature review, the main limitations for G-band split-block MPRWGs are identified as electromagnetic (EM) radiation leakage, assembly part alignment and manufacturing accuracy. To mitigate against leakage and misalignment, we investigate a ‘trough-and-lid’ split-block solution. This approach is successfully employed in proof-of-concept thru lines, and in the first polymer-based 3-D printed 90° twist and symmetrical diaphragm inductive iris-coupled bandpass filters (BPFs) operating above 110 GHz. An inexpensive desktop masked stereolithography apparatus 3-D printer and a commercial copper electroplating service are used. Surface roughness losses are calculated and applied to EM (re-)simulations, using two modifications of the Hemispherical model. The 7.4 mm thru line exhibits a measured average dissipative attenuation of only 12.7 dB/m, with rectangular-to-trapezoidal cross-sectional distortion being the main contributor to loss. The 90° twist exhibits commensurate measured performance to its commercial counterpart, despite the much lower manufacturing costs. A detailed time-domain reflectometry analysis of flange quality for the thru lines and 90° twists has also been included. Finally, a new systematic iris corner rounding compensation technique, to correct passband frequency down-shifting is applied to two BPFs. Here, the 175 GHz exemplar exhibits only 0.5% center frequency up-shifting. The trough-and-lid assembly is now a viable solution for new upper-mm-wave MPRWG components. With this technology becoming less expensive and more accurate, higher frequencies and/or more demanding specifications can be implemented.

Generalized theory of optical resonator and waveguide modes and their linear and Kerr nonlinear coupling

We derive a general theory of linear coupling and Kerr nonlinear coupling between modes of dielectric optical resonators from first principles. The treatment is not specific to a particular geometry or choice of mode basis, and can therefore be used as a foundation for describing any phenomenon resulting from any combination of linear coupling, scattering, and Kerr nonlinearity, such as bending and surface roughness losses, geometric backscattering, self- and cross-phase modulation, four-wave mixing, third-harmonic generation, and Kerr frequency comb generation. The theory is then applied to a translationally symmetric waveguide in order to calculate the evanescent coupling strength to the modes of a microresonator placed nearby, as well as the Kerr self- and cross-phase modulation terms between the modes of the resonator. This is then used to derive a dimensionless equation describing the symmetry-breaking dynamics of two counterpropagating modes of a loop resonator and prove that cross-phase modulation is exactly twice as strong as self-phase modulation only in the case that the two counterpropagating modes are otherwise identical.

Evaluation of the Disintegration in Water of Tissue Papers Distributed in Korea

In this study, water disintegration was evaluated according to ISO 12625-17 for a total of 51 types of tissue products, primarily bathroom tissue distributed in Korea. Moreover, the strength, surface, and softness properties of tissue were measured to investigate the effect of each property on the water disintegration of tissue. As a result of the water disintegration of bathroom tissue distributed in Korea, most products showed 100% disintegration within 30 s, and all of them showed 100% disintegration except for D8 (P600= 94.5%) in the 600 s test. The water disintegration results of facial tissue, paper towel, travel tissue, and hanky tissue were very low. Therefore, it is difficult to determine if the quality of the bathroom tissue is the reason for the clogging issue. As a result of mechanical, surface, and softness, it was found that wet strength, loss of strength, surface roughness and friction, and surface softness affect water disintegration. The results of this study are expected to solve user confusion, to be used as a basis for the management of sewage systems, and to be used as data for the development of tissue products with excellent water disintegration.

AFM Study of Nanoscale Membrane Perturbation Induced by Antimicrobial Lipopeptide C14 KYR.

Lipopeptides have been extensively studied as potential antimicrobial agents. In this study, we focused on the C14-KYR lipopeptide, a modified version of the KYR tripeptide with myristic acid at the N-terminus. Here, membrane perturbation of live E. coli treated with the parent KYR and C14-KYR peptides was compared at the nanoscale level using AFM imaging. AFM analyses, including average cellular roughness and force spectroscopy, revealed the severe surface disruption mechanism of C14-KYR. A loss of surface roughness and changes in topographic features included membrane shrinkage, periplasmic membrane separation from the cell wall, and cytosolic leakage. Additional evidence from synchrotron radiation FTIR microspectroscopy (SR-FTIR) revealed a marked structural change in the membrane component after lipopeptide attack. The average roughness of the E. coli cell before and after treatment with C14-KYR was 129.2 ± 51.4 and 223.5 ± 14.1 nm, respectively. The average rupture force of the cell treated with C14-KYR was 0.16 nN, four times higher than that of the untreated cell. Our study demonstrates that the mechanistic effect of the lipopeptide against bacterial cells can be quantified through surface imaging and adhesion force using AFM.

Influence of the acid erosion associated with dental bleaching in bovine enamel: In vitro study

Objective: To evaluate the influence of acid erosion caused by the daily intake of lemon juice or apple cider vinegar, associated with immediate dental whitening, on bovine enamel. Materials and Methods: 30 bovine teeth were sectioned to obtain enamel blocks and were distributed into three groups (n = 10): G1- Tooth whitening with 35% hydrogen peroxide; G2- Tooth whitening with 35% hydrogen peroxide + lemon juice and G3 - Tooth whitening with 35% hydrogen peroxide + apple cider vinegar. Treatments were performed for 21 days, the varnish was removed and the analysis of loss of structure and surface roughness were performed by means of non-contact 3D Confocal Chromatic Profilometer. The roughness data obtained were analyzed by Kruskal-Wallis and Mann-Whitney non-parametric tests. Results: All groups exhibited greater roughness (Sa) on the side exposed to the treatments (G1 = 3.17b; G2 = 4.17b; G3 = 3.99b) compared to the unexposed side (G1 = 2.55a; G2 = 3.94a; G3 = 2.40a). There was a statistically significant difference among the groups evaluated, being G1 (3.17A) &lt;G3 (3.99C) &lt;G2 (4.17B). Conclusion: 35% hydrogen peroxide has the least erosive potential when compared to its association with vinegar and to lemon juice.

Influence of scaler tip design on root surface roughness, tooth substance loss and patients\u2019 pain perception: an in vitro and a randomised clinical trial

BackgroundThe influence of scaler tip design on root surface roughness, tooth substance loss and patients’ pain perception is investigated.MethodsThis article was divided into the following parts: Part 1 Surface roughness and substance loss: an in vitro study, which involves intact extracted teeth sectioned and treated using a piezoelectric ultrasonic device (PM200 EMS Piezon, Switzerland) with a conventional scaler tip (FS-407) and a Perio Slim (PS) scaler tip (Perio Slim DS-016A). All sectioned samples for tooth surface roughness (n = 20) and tooth substance loss (n = 46) analyses were measured and compared using a 3D surface texture analyser and scanning electron microscope (SEM) respectively, at baseline and following scaling. Part 2 Pain Perception: a clinical study, which was a split mouth study design including 30 participants with gingivitis and/or mild chronic periodontitis; treated with supra-gingival scaling from teeth #13 to #23. Subjects were randomised to group A or group B. Group A was treated first with PS scaler tips, whereas group B was treated first with conventional scaler tips. Pain perception was recorded using the visual analogue scale (VAS).ResultsIn vitro study: both scaler tips caused significant reduction in root substance roughness after scaling (p < 0.05), but no significant difference between the two scaler tips (p > 0.05) was observed. The PS scaler tip caused statistically significantly less root substance loss (p < 0.05) when the initial thickness of the tooth was < 1000 µm. Clinical study: the participants reported significantly lesser pain score during scaling using the PS scaler tip (median: 3) than when using the conventional scaler tip (median: 5) (p < 0.05).ConclusionsIn the in vitro study, using a slim scaler tip design causes less tooth substance loss compared to a wider scaler tip design. In the clinical study, less pain was observed compared than a wide (conventional) scaler tip design.

IMPATT Efficiency Extraction Using On-Chip Antenna Radiation

IMPATT diodes were designed and integrated with microstrip patch antenna on–chip in standard CMOS technology to extract the efficiency beyond avalanche frequency. By comparing the on-chip simulations and measurements of an IMPATT diode integrated in a CPW to an integrated one with a microstrip patch antenna at the same biasing conditions, the results demonstrated an efficiency ranging from ~ 0.01% to 0.016% without and with the added surface roughness losses, respectively. Such variation is strongly associated with the uncertainty provided by the increase of conduction losses ranging between 40%~80% beyond the avalanche frequency.

A physics-based framework for online surface roughness assessment for high-pressure turbines

Surface roughness is a critical health parameter of a turbine blade due to its implications on blade surface heat transfer and structural integrity. This paper proposes a physics-based online framework for Gas Turbine Engines (GTE), in order to assess the blade surface roughness in a high-pressure turbine without engine shutdown. The framework consolidates Gas Path Analysis (GPA) based performance monitoring models and meanline turbomachinery analysis, using a novel GPA-meanline matching process. This extracts meaningful performance deviation trends from GPA, while addressing the uncertainties associated with the measurements and modelling. To relate efficiency loss to surface roughness severity, a meanline-based system-identification process has been developed to establish the meanline representation of the turbine stage, and to incorporate the empirical surface roughness loss correlations. The roughness loss correlations have been evaluated against recent transonic test data in the literature. A modification to the compressibility correction factor has been made according to the evaluation outcome, which improved loss predictions compared to the experimental measurements. The framework was tested on the three-year operational data of a cogeneration GTE, and the results verified the framework's potential for online surface roughness monitoring. The predicted surface roughness showed agreement in both trend and the magnitude-level with the measurements reported in the literature.

Approximate Solutions for Surface Reflection Loss Inclusive of a Practical Model of Refraction in the Wind-Driven Bubbly Layer

The authors previously prepared a model of coherent acoustic reflection loss at the ocean surface by combining a model of surface roughness loss with determination of surface incidence angle that accounted for the refractive effects of a uniformly stratified distribution of wind-driven bubbles. Originally, the surface roughness loss was based on a second-order small-slope approximation and the surface incidence angle was obtained using an exact solution for propagation of the incident acoustic plane wave in a layer of particular sound-speed variation. In this paper, the previous solution for surface incidence angle is simplified with the assumption that the grazing angle at the bottom of the layer is small. An approximate solution for the surface grazing angle is found in terms of grazing angle below the layer and a polynomial series in a derived parameter, which in turn is a function of wind speed and acoustic frequency. This determination of surface angle is combined with a simplified model of surface roughness loss to produce a complete model suitable for use with ray-type transmission calculations or hand calculations. The resulting model permits the prediction of the coherent surface reflection loss with only wind speed and frequency as input parameters. Results from the use of this approximated model with a Gaussian beam acoustic propagation code are compared with predictions based on Monte Carlo parabolic equation transmission calculations for surface ducted scenarios including various levels of roughness. The zones of validity of the model are considered at length.

Wear Behavior of Spheroidal Graphite Cast Iron in Biodiesel Blends

Biodiesel as an alternative fuel is overcoming to replace petroleum diesel partially. The tribological performance of biodiesel is crucial with respect to application in automobiles. Cast iron is widely used in for manufacturing of many automobile engine parts such as piston, valves, piston rings, etc. This research article evaluates the wear behavior of spheroidal graphite cast iron which is used for the manufacturing of piston rings with respect to different blends of biodiesel. Many experiments were carried out under metal to metal contact and lubricated sliding condition on, pin on disc wear testing machine. This shows the metallographic changes due to wear damage. Previous experimental result shows that friction coefficient and wear loss decreases significantly due to decrease in lubrication percentage of palm biodiesel. The test parameters used under this work were 8 kg, 10 kg, 12 kg, 14 kg and 16 kg loads for 1 h, at speed 300 rpm and at ambient temperature. Wear behavior of spheroidal graphite cast iron is evaluated using five different blends of biodiesel, B0 (100% petroleum diesel), B5 (5% biodiesel), B10 (10% biodiesel), B20 (20% biodiesel), B100 (100% palm biodiesel)).The period for which cast iron can sustain is determined by its wear and abrasion resistance. Due to formation of lubrication layer of ester compounds in palm biodiesel wear resistance of nodular cast iron increases as biodiesel percentage increase in the blend. Therefore, high wear resistance is critical for ensuring a long life of the cast iron in biodiesel environment. The results showed that the B100 has higher coefficient of friction and lowest surface roughness and wear volume loss as compared with petroleum diesel (B0). It also shows that wear and friction decrease as percentage of biodiesel increases. Scanning electron microscopy (SEM) investigations used to analyze the structure and surface morphology. Wear scar diameter (WSD) was investigated using optical microscopy in tested specimen. The wear rate was found to be more in petroleum diesel compared with palm biodiesel than other blends.

The preparation, characterization and application of ultra-smooth, low-loss plasmonics noble metal films

Since its discovery, plasmonics has become one of the most popular topics in the field of nano-optics due to its unprecedented capability of harvesting and localizing electromagnetic fields down to diffraction-unlimited length scales. However, the application of plasmonic effects has long been hindered by the difficulties in controlling the surface morphology and reducing the optical loss of noble metal films, which not only hinders the progress of its experimental research, but also cast a shadow on its application prospects in many fields. With the fast development of nanofabrication technologies, the surface roughness and optical loss of noble metal films is getting closer the theoretical expectation, while the preparation technology is becoming precisely controllable, which lets it play an important role not only in the traditional field, but in may emerging fields as well. In this review, we systematically summarize the recent progress in preparation, characterization and application of ultra-smooth, low-loss noble metal films.

Guided wave analysis of fractional TIR-QPM-based broadband SHG in the MIR region in a reverse tapered isotropic slab

This paper is a numeric-analytical work on generating second harmonic by using guided wave optics in lieu of plane ray optics for the reason that guided wave optics gives a more accurate representation of the nonlinear optical phenomena. In this analysis we have taken a reverse tapered isotropic semiconductor slab where the effects of the nonlinear law of reflection are minimized. Other lossy factors like surface roughness, Goos-Hänchen shift and absorption losses are also incorporated in the computer-aided simulation results. The effects of the parametric changes are also explained in the results section to give a better perspective of the whole analysis. The results are obtained in terms of efficiency and 3 dB bandwidth and are superior compared to tapered structure of semiconductor slab.

Effect of sensitization on tribological behavior of AISI 304 austenitic stainless steel

AbstractThis paper aims to evaluate the dry sliding wear of AISI 304 austenitic stainless steel as a function of the applied load. Samples of AISI 304 were heat treated (sensitized) to precipitate Cr23C6carbides in the grain boundaries, and the resulting microstructure was compared to that of the non-sensitized samples. Wear testing was carried out at room temperature of 25°C and a relative humidity of about 60% using a pin-on-disk apparatus. The load applied was varied from 10 to 30 N at a constant sliding velocity of 0.5 m s–1. Wear particles were analyzed by means of scanning electron microscopy and X-ray diffraction. The results showed that the dynamic friction coefficient remained effectively constant with increasing applied load. The surface hardness measured after the wear process generally increased at higher loads due to subsurface strain-hardening, and deformation-induced martensitic transformation occurred during the wear process. Surface roughness and weight losses were found to increase with increasing the load for both sensitized and non-sensitized samples. In addition, a great amount of Cr23C6carbides in the grain boundaries favored a size reduction of the debris generated due to wear.

Mathematical simulation of the influence of surface roughness and mass loss on thermal protection

A mathematical model of the thermochemical destruction of carbon fiber-reinforced plastic in the presence of surface roughness and composite ablation is refined based on known theoretical results. It is shown that mass loss through rough surface ambiguously influences the intensity of heat exchange processes in thermal protective material. Results of numerical calculations are compared with known data.

Recent advances in tissue conditioners for prosthetic treatment: A review.

Tissue conditioners (TCs) are short-term soft liners, formed in situ from a mixture of a polymer powder and a liquid plasticizer. This article reviews the recent advances in the composition, functions, clinical use, gelation process, and physical properties of TCs and their effects on denture bases and oral mucosa. TCs are used to improve the fit and function of an ill-fitting denture. They can also be used to treat abused mucosal tissues underlying ill-fitting acrylic dentures as temporary expedients. TCs are recommended as provisional liners to maintain the fit of removable dentures and to prevent mechanical irritation from the denture. TCs may also be used to rehabilitate cancer patients. The polymer powder, used in the formulation of TCs generally consists of polyethyl methacrylate (PEMA) and the liquid plasticizer is ester-based in ethyl alcohol solution without an acrylic monomer. The plasticizers are low molecular weight aromatic esters. Mixing of the powder and liquid results in polymer chain entanglement and the formation of a coherent gel characterized by viscoelastic behavior appropriate to its intended clinical use. The loss of surface integrity and surface roughness of TCs are regarded as the main problems in the denture bearing oral mucosa conditions resulting in inflammation of oral mucosa of the denture-bearing area - denture stomatitis. TCs provide an even distribution of masticatory force, accurately modeling itself to the changes which occur during the healing of lesion of substrate and can act therapeutically by incorporating antifungal or antibacterial agents.

Interaction of land use, slope gradient and rain sequence on runoff and soil loss from weakly aggregated semi-arid soils

The effects of land use, tillage methods and slope gradient on soil erosion have been widely investigated. However, there is limited information about their effects on very weakly aggregated soils that can be found in semi-arid, nutrient limited regions of low productivity. This study was carried out to investigate the interaction of land use, tillage method and slope gradient on runoff and soil loss in a weakly aggregated soil in the north-west of Iran. Plots (3m×10m) with three treatments and two replicates were installed in each of four slopes gradient categories (12.6, 15.3, 17.0, 19.4%). The three treatments were pasture with poor vegetation cover (27%) and rainfed wheat either cultivated up to down slope or along the contour. Wheat was sown in early autumn and runoff and soil loss was measured under natural rainfall during the eight months long growing period. Out of 53 precipitation events, 8 storms were classified erosive. The susceptibility of all plots to produce runoff and soil loss increased pronouncedly and highly significantly with subsequent rainfalls. The potential of a rainfall to produce runoff and soil loss was thus highly dependent on preceding rainfalls. Wheat cultivation increased runoff 13 times and soil loss 60 times compared to pasture. Runoff and soil loss increased about 5.5 and 35 times in plots cultivated up to down slope as compared with contour cultivated plots. The effects of land use increased pronouncedly with increasing slope gradient. These results showed that erosivities of rainfalls separated by several months were not independent from each other and that the effects of land use and slope gradient interacted. Also the effect of slope gradient on soil loss was much larger than estimated by current equations. All effects could be explained by the extremely weak aggregates. Soil erosion was thus not detachment limited but transport limited. Transport limitation decreased in the sequence of rainfalls due to loss of surface roughness and with increasing slope gradient due to increasing failure of roughness elements. Under conditions leading to extremely weak soil aggregates, land use and slope gradient thus exert a much larger impact on runoff and soil loss than what is commonly assumed. This should be better considered in soil conservation efforts but also in runoff and erosion modelling.

Effects of monomer compositions on physicochemical properties of composite resins

The aim of this study was to evaluate the cohesive strength (CS), surface roughness (Ra), and weight loss (WL) of different composite resins. Three composite resins (Filtek Z100; Filtek Z350; Filtek P90, 3M ESPE) were tested. To evaluate CS, an hourglass silicone mold (11 × 2 × 1 mm) was used (n = 10). The Ra and WL tests were performed using a circular mold (5 × 2 mm, n = 10). The composite resins were light-cured with an LED light curing device (FreeLight 2, 3M ESPE) for 40 s and 1000 mW/cm2. The CS test was performed using a universal testing machine (Instron 4411, Instron) at a crosshead speed of 0.5 mm/min and cell load of 500 N. The initial mass weight was registered (analytical digital balance) and the initial Ra reading evaluated using a profilometer (Surftest 211, Mitutoyo). The specimens were submitted to 30,000 brushing cycles. The WL and the final Ra were evaluated. All data were subjected to one-way ANOVA, followed by Tukey’s test (p < 0.05). Filtek Z100 showed the highest values of Ra and Filtek Z350 the lowest values of Ra. When considering CS, Filtek Z350 and Z100 had the highest mean values. Filtek P90 had the highest mean value of WL. The organic matrix and the type, shape, and size of fillers may influence the physicochemical properties of composite resins.

Electrical Characterization of Low-Profile Copper Foil for Reduced Surface Roughness Loss

Abstract Signal attenuation in transmission lines is a major issue for reliable transmission in high frequency range. Knowledge of the electrical parameters of printed circuit board (PCB), including dielectric constant and loss tangent, is critical. Moreover, surface roughness has a great effect on loss in high frequency. This paper demonstrates an effective simulation fitting method for electrical material characterization. Cavity resonator is chosen as the circuit for characterization. A methodology is presented to measure surface roughness from cross sections, and compared with values extracted from resonator measurements. Several materials and copper foils treatments, including low-profile, are analyzed in this paper.