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Environmentally friendly lubricants are lubricants that are easily dissolved in the environment and are not harmful to the ecosystem. It uses to reduce the heat in the contact area so that the machinability of the workpiece and the ability of the chisel will increase. To minimize the use of bio-cutting fluids, lubrication is carried out by minimum drop lubrication in the lathe process. The purpose of this research is to comply with the surface roughness of the workpiece and the shape of the chip. The material used is aluminum 6061, the natural oil used are rubber seed oil, virgin coconut oil, sunflower seed oil, and castor oil. The turning parameters were the depth of cut 0.5 mm, spindle speed of 330 rpm, feed rate 0.231 mm/rev, tool angle 90o, drop lubrication 192 ml/hour, infeed length 100 mm. The results of the research showed that virgin coconut oil has the lowest surface roughness. This is because the viscosity value of virgin coconut oil is very small so that the flow rate is able to work perfectly to lubricate the contact area. It has a thin chip configuration, the tool also wears but did not experience cracks.

The novel controllable behaviour of magnetorheological (MR) fluid is the backbone of magnetorheological fluid-based finishing processes. MR fluid-based finishing processes facilitate better control over finishing forces as the stiffness of MR finishing fluid used in these processes can be controlled in accordance with the applied magnetic field and MR finishing fluid composition. Therefore, a detailed experimental investigation was carried out to find the effect of MR finishing fluid constituents on its yield stress through the Taguchi Design of Experiments. Rheological data obtained from a magneto-rheometer (MCR-102) was characterised by using Bingham plastic, Herschel–Bulkley and Casson’s fluid constitutive modelling. The coefficient of regression (R2) values of Herschel–Bulkley model were found to be best suited for all compositions of MR finishing fluid. Analysis of variance (ANOVA) has been used to find the contribution of selected parameters for improving the response characteristics. The optimized fluid has been then used for the finishing of biocompatible stainless steel AISI 316L, and the finishing results show that the average surface roughness value decreases down to 58 nm.

In this study, the effect of platinum-aluminide coating parameters on surface roughness of nickel-based superalloy Rene®80 was evaluated. For this purpose, different thicknesses of Pt-layer (2, 4, 6 and 8µm) were plated on the Samples. Then diffusion aluminide coating in two types, high tempeature-low activity and low temperature-high activity was performed. The results of structural investigations by scanning electron microscope and X-Ray diffraction indicated a three-zone structure of coating in all thicknesses of platinum layer, as well as in the two methods of aluminizing. Surface roughness of coatings was measured in three steps: 1-after Pt plating, 2-after Pt diffusion, and 3-after aluminizing and final aging. The results showed that the thickness of Pt and the final thickness of the coating directly affected the surface roughness. The minimum surface roughness was created by high temperature low activity with 2µ of Pt-layer (2.6μm) and the maximum of surface roughness was obtained in low-temperature high activity with 8µ of the Pt-layer (8.8 μm).

The particles used in magnetorheological polishing (MRP) fluid are the key components of the magnetorheological (MR) finishing processes. The rotational magnetorheological honing (R-MRH) process is recently developed as a highly productive MR finishing process which is used for finishing the internal surface of the industrial cylindric components. The involvement of micron-sized abrasive particles of MRP fluid in the finishing operation results in the invisible observation of the finishing mechanism which enables the urge of analyzing the motion of the particles during the present R-MRH process. Therefore, the effect of motions of the MRP-fluid's particles is analyzed for nano-finishing performance on the inside surface of the cylindric workpieces. The motions performed by active abrasive particles on the inside surface of the rotating hollow cylindric workpiece cause a higher finishing rate. The effects of particle motions on the reduction in surface roughness and improvement in surface morphology confirm the usefulness of the R-MRH process. The surface finish with the effect of the particles' motions of the MRP-fluid in the R-MRH process on the stationary workpiece's inner surface is achieved upto 100 nm from 420 nm of the initial ground surface in 60 min of finishing. Whereas, the same aforementioned surface of the rotating workpiece is finished upto 50 nm from the same initial ground surface in only 40 min of finishing with the effect of the particles' motions of the MRP-fluid. The improvement in the surface finish is also noticed through the scanning electron micrographs in this work. The significant change in surface finish obtained in experimentations confirms the integrity of the analytical study conducted for understanding the effects of motions of particles while finishing with the R-MRH process. [ABSTRACT FROM AUTHOR]

Background and aimsPolishing may increase the surface roughness of composites, with a possible effect on bacterial growth and material properties. This preliminary in vitro study evaluates the effect of three different polishing systems (PoGo polishers, Enhance, Venus Supra) on six direct resin composites (Gradia Direct, Venus, Venus Diamond, Enamel Plus HFO, Tetric Evoceram, Filtek Supreme XT).Materials and methodsFor each composite, 12 square specimens were prepared: 9 specimens were polished, three for each different method, while three specimens were used as controls. Surface roughness was determined with AFM by measuring Root Mean Square (RMS) of average height.ResultsPoGo polisher determined a significantly rougher surface, versus controls, in 5 out of 6 composites evaluated. Some significant differences from unpolished controls were observed also for Enhance polishing. Polishing with Venus Supra did not result in any significant difference in surface roughness versus controls. No differences were observed between different polishing systems.ConclusionsThese preliminary results suggest that Venus Supra polishing system could determine a smoother composite surface if compared to the other polishing systems tested. On this basis, we are conducting an in vivo study to evaluate bacterial colonization on some combinations of composites and polishing protocols.

Abstract. The narrow band gap lead chalcogenide semiconductors and related solid solutions are capable to detect effectively an infrared (IR) radiation in the wavelength range 3–25 μm. Due to the unique combination of the optimal dielectric permittivity, Seebeck coeffi cient, and high thermal conductivity, lead telluride is promising material for manufacturing of high-performance intermediate-temperature thermoelectric devices. By scanning electron microscopy (SEM), electron probe microanalysis (EPMA), X-ray analysis (XRD), and atomic force microscopy (AFM) the quantitative elemental composition, phase nature, surface morphology, and average surface roughness of homogeneous lead telluride fi lms synthesized by modifi ed «hot wall» technique on Si (100) substrates have been studied. The XRD patterns have shown that at condition of high condensation process rate, which was realized at substrate temperatures below T = 573 K and corresponded to the maximum deviation from the thermodynamic equilibrium, polycrystalline PdTe fi lms on Si (100) substrates were synthesized only. The increase in temperature Si (100) substrate to T = 593-613 K has led to fabrication of mosaic single-crystal PdTe fi lms with (100) texture. By SEM and AFM methods it has been found that under constant values of lead and tellurium vapour pressure synthesis an increase in the Si substrate temperature led to increase in crystallite average lateral dimension of PbTe fi lm on Si (100) substrates. By AFM method it has established the tendency of the average surface roughness value increasing with average thickness for both polycrystalline and mosaic single crystal PbTe/Si (100) fi lms. At the same average thickness values polycrystalline PbTe/Si (100) fi lms are characterized by higher surface roughness compared to mosaic single-crystal PbTe (100) samples. It is suggested that of average surface roughness-to-fi lm thickness ratio it can be used as a criterion of evaluation of surface contribution to functional properties of PbTe fi lms. It has been shown that with optimum values of average roughness-to-thickness ratio mosaic single-crystal PdTe (100) fi lms with thickness over 1.2 μm are characterized.

Background: Minimally invasive dentistry aims to prevent progression of caries and treats non-cavitated lesions through non-invasive approaches to preserve the integrity of tooth structure. The aim of this research was to investigate the possible biomimetic effect of agarose hydrogel in remineralizing a human demineralized enamel model. Methods: Mandibular third molars were distributed into three groups (G1, G2 and G3) according to the follow up time (2, 4 and 6 days respectively). Caries like lesion was prepared by applying 37% phosphoric acid gel for 1 minute and then remineralization was performed through applying agarose hydrogel on the demineralized surfaces. The specimens were placed in phosphate solution at 37˚C for 2, 4 & 6 days. Scanning electron microscope (SEM), surface microhardness (SMH) and surface roughness analysis (SR) were performed to assess the regenerated tissue. Results: SEM revealed mineral depositions on the demineralized enamel surface that increased in density by time resulting in a relatively smooth surface in G3. SR and SMH analysis revealed significant differences between the remineralized enamel surfaces of different groups (p< 0.00001) with the highest SR in G1 and the highest SMH in G3. Conclusions: Agarose hydrogel application is a promising approach to treat early carious lesion. Further studies are needed to clarify the stability of agarose hydrogels in clinical application.

In the present study, the impact of raw material grown region on the physical, mechanical, surface properties and formaldehyde emission of the particleboard was investigated. Ailanthus altissima wood grown in Trabzon had longer fiber length and thicker fiber and trachea cell wall than those of the wood grown in Artvin. The highest amounts of lignin, ash, condensed tannin and solubility values were found in wood grown in Artvin. Ailanthus altissima wood grown in Trabzon had higher amounts of cellulose and hemicellulose than those of the wood grown in Artvin. Particleboards made from wood grown in Artvin had worse surface quality and mechanical strength properties than those of panels made from wood grown in Trabzon. On the other hand, the results showed that particleboards produced from wood grown in Artvin had lower thickness swelling and formaldehyde emision values than those of the panels produced from wood grown in Trabzon.

The present paper investigates the application of traditional Taguchi method with fuzzy logic for multi objective optimization of the turning process of Al-5Cu alloy in CNC Lathe machine. The cutting parameters are optimized with considerations of the multiple surface roughness characteristics (Centre line average roughness Ra, Average maximum height of the profile Rz, Maximum height of the profile Rt, Mean spacing of local peaks of the profile Sa ). Experimental results are demonstrated to present the effectiveness of this approach. The parameters used in the experiment were cutting speed, depth of cut, feed rate. Other parameters such as tool nose radius, tool material, workpiece length, workpiece diameter, and workpiece material were taken as constant.

Amaç: Bu çalışma, süt dişi dentini yüzeyindeki çürüğün kemo-mekanik olarak Carisolv™ multimix jeli ve geleneksel döner aletler ile temizlenmesi sonrası fiziko-kimyasal etkilerini karşılaştırmak amacıyla yapıldı. Gereç ve Yöntem: Carisolv™ jeli ve döner aletlerle temizlenen dentin yüzey özellikleri taramalı elektron mikroskobuyla, pürüzlülükler ise yüzey profilometresi ile değerlendirildi. Bu amaçla, okluzal çürüklü çekilmiş 30 adet süt azı dişi dikey eksenine paralel olarak ikiye bölündü ve tek tarafındaki çürük lezyonu Carisolv™ jeli, diğeri ise geleneksel döner aletler ile temizlendi. Bulgular: Carisolv™ jeli ile temizlenen dentin yüzeylerinde, döner aletlere göre pürüzlülük değerlerinde azalma olduğu fakat bu azalmanın anlamlı olmadığı saptandı. Döner aletlerle temizlendikten sonra alınan SEM görüntüsünde, dentin yüzeylerindeki kollajen liflerin yer yer devamlılıklarını yitirdiği, smear tabakası ile dentin tübüllerinin tıkandığı ve uniform, düz bir yüzeyin oluştuğu gözlendi. Carisolv™ jeli ile temizledikten sonra SEM görüntüsünde dentin yüzeylerinde kollajen yapının devamlılığını sürdürdüğü, dentin tübüllerinde bir tıkanma olmadığı ve döner aletlerle temizlenen dentine göre yüzeyin daha pürüzlü ve poröz bir yapıda olduğu gözlendi. Sonuç: Bu sonuçlar ışığında Carisolv™ jeli ile çürük temizlemenin ardından yapılacak olan rezin bazlı restorasyonun tutuculuğunun, geleneksel döner aletlere göre daha iyi olacağı ileri sürülmektedir.

Bu çalışmada sıcak iş takım çeliklerinden Dievar derece çeliği üzerinde çeşitli matkaplar ile delik delme esnasında meydana gelen eksenel kuvvetler, kesme momentleri, yüzey pürüzlülükleri, ölçü tamlığı ve dairesellikten sapma değerleri araştırılmıştır. Deneyler dik işleme tezgâhında soğutma sıvısı ile Ø16 mm çaplarında kaplamasız karbür matkap ve kendinden raybalı TiAlN kaplamalı matkap kullanılarak yapılmıştır. Deneylerde ilerleme hızı 0,16 mm/dev, kesme hızı ise 36, 40, 44, 48 m/dak hızları kullanılmıştır. Çıkan sonuçlar doğrusal regresyon metodu ile modellenmiş ve polinom regresyon eğrisi eşitliği anlamlılık değerleri mukayese edilmiştir. Aynı zamanda varyans analizi yapılarak kesme hızı ve matkap tipinin eksenel ilerleme kuvveti, kesme momenti, yüzey pürüzlülüğü ölçü tamlığı ve dairesellikten sapma değeri sonuçları üzerine etkileri incelenmiştir.

Bu çalışmada sıcak iş takım çeliklerinden Dievar derece çeliği üzerinde çeşitli matkaplar ile delik delme esnasında meydana gelen eksenel kuvvetler, kesme momentleri, yüzey pürüzlülükleri, ölçü tamlığı ve dairesellikten sapma değerleri araştırılmıştır. Deneyler dik işleme tezgâhında soğutma sıvısı ile Ø16 mm çaplarında kaplamasız karbür matkap ve kendinden raybalı TiAlN kaplamalı matkap kullanılarak yapılmıştır. Deneylerde ilerleme hızı 0,16 mm/dev, kesme hızı ise 36, 40, 44, 48 m/dak hızları kullanılmıştır. Çıkan sonuçlar doğrusal regresyon metodu ile modellenmiş ve polinom regresyon eğrisi eşitliği anlamlılık değerleri mukayese edilmiştir. Aynı zamanda varyans analizi yapılarak kesme hızı ve matkap tipinin eksenel ilerleme kuvveti, kesme momenti, yüzey pürüzlülüğü ölçü tamlığı ve dairesellikten sapma değeri sonuçları üzerine etkileri incelenmiştir.

Planing properties of seven Australian plantation-grown eucalypts were evaluated to provide recommendations on how these species should be machined and considered for the manufacture of high quality furniture and furnishings. The surface quality produced for each species was evaluated using eight planing conditions. All species performed well producing equivalent or better results than mature traditional furniture species, and could be used for high value furniture manufacturing. Tungsten carbide cutters produced better results than high-speed steel for most eucalypts and the grinding of a small chip-breaker usually produced improving results as the size of the chip-breaker was reduced. Grain orientation did not affect the planed surfaces for some species but planing with the grain usually produced better surface. Recovery and presence of torn grain could not be related to the wood density.

Bu çalışmada, üniversal torna tezgahında işlenebilirlik deneyleri yapılmıştır. İş parçasının tornalanması sırasında kesme kuvvetleri ölçülmüştür. Kesme kuvvetlerinin ölçülmesinde, standart bir dinamometre kullanılmıştır. Dinamometrenin üniversal torna tezgahına uygun bir şekilde bağlanması için, bir bağlama aparatı tasarlanarak imalatı yapılmıştır. Yapılan işlenebilirlik deneylerinde, AISI 316Ti paslanmaz çelik malzeme, TiAlN kaplamalı, farklı kesici takım uç yarıçapına sahip karbür uçlar kullanılarak tornalanmıştır. Takım uç yarıçapının kesme kuvvetlerine ve yüzey pürüzlülüğüne etkisi araştırılmıştır. Deneylerden elde edilen kesme kuvvetleri ve işlenen yüzeylerin yüzey pürüzlülükleri değerlendirilmiştir. Değerlendirmeler sonucunda, ilerleme miktarı artıkça, kesme kuvvetlerinin arttığı, takım uç yarıçapının büyümesi ile de yüzey pürüzlülüğünün düştüğü görülmüştür.

Bu çalışmada, üniversal torna tezgahında işlenebilirlik deneyleri yapılmıştır. İş parçasının tornalanması sırasında kesme kuvvetleri ölçülmüştür. Kesme kuvvetlerinin ölçülmesinde, standart bir dinamometre kullanılmıştır. Dinamometrenin üniversal torna tezgahına uygun bir şekilde bağlanması için, bir bağlama aparatı tasarlanarak imalatı yapılmıştır. Yapılan işlenebilirlik deneylerinde, AISI 316Ti paslanmaz çelik malzeme, TiAlN kaplamalı, farklı kesici takım uç yarıçapına sahip karbür uçlar kullanılarak tornalanmıştır. Takım uç yarıçapının kesme kuvvetlerine ve yüzey pürüzlülüğüne etkisi araştırılmıştır. Deneylerden elde edilen kesme kuvvetleri ve işlenen yüzeylerin yüzey pürüzlülükleri değerlendirilmiştir. Değerlendirmeler sonucunda, ilerleme miktarı artıkça, kesme kuvvetlerinin arttığı, takım uç yarıçapının büyümesi ile de yüzey pürüzlülüğünün düştüğü görülmüştür.

Bu çalışmanın amacı; nano-dolduruculu bir kompozit Filtek Supreme XT , bir nano-seramik kompozit CeramX ve bir nano-hibrit kompozitin Grandio yüzey pürüzlülüğü üzerine iki farklı bitirme frezi ve iki farklı cila sisteminin etkisini araştırmaktır. Her kompozit rezin için paslanmaz çelik kalıplar kullanılarak disk şeklinde 5 mm çap-2 mm kalınlık 35 örnek hazırlandı. Örnekler bitirme ve cila prosedürlerine göre rastgele gruplara ayrıldı. Grup 1: Şeffaf bant control , Grup 2: Elmas bitirme frezleri, Grup 3: Elmas bitirme frezleri +Optidisc, Grup 4: Elmas bitirme frezleri +HiLuster, Grup 5: Tungsten karbit frez, Grup 6: Tungsten karbit frez +Optidisc, Grup 7: Tungsten karbit frez +Hi-Luster. Tüm örneklerin ortalama yüzey pürüzlülük değerleri Ra profilometre ile ölçüldü. Bulguların istatistiksel değerlendirmeleri P

In the present study, electric discharge deep hole drilling of Inconel 718 was experimented with three different commercial tube electrodes viz., copper, copper-tungsten and graphite. The pertinent process parameters selected for the study were peak current, pulse on-time, duty factor and electrode rotational speed. The machining performance was investigated by analysing Material Removal Rate (MRR), Electrode Wear Ratio (EWR) and Surface Roughness (SR). The experiments were planned according to Response Surface Method (RSM) and Central Composite Design (CCD). Through holes of diameter around 3.0mm and 25mm depth were drilled. Experimental data was fitted and regression analysis was done. The experimental results indicated that copper electrode outperformed copper-tungsten and graphite electrodes with regard to MRR and SR. Further, the EWR was high in copper electrode followed by copper-tungsten and graphite electrodes. Among the three electrode materials tested, copper is the best choice of electrode material with respect to high MRR and low SR. [ABSTRACT FROM AUTHOR]

In this study, the optimization of machining parameters and the effect of polycrystalline diamond (PCD) grain sizes on machining characteristics in micro electrical discharge machining (μEDM) are analyzed. There are four experimental factors, each parameter is set at three levels: current (0.5A, 2A and 4A), pulse-on time (2 μs, 4 μs and 8 μs), pulse-off time (2 μs, 4 μs and 8 μs) and PCD grain size (1.7 μm, 4 μm and 6 μm). Voltage is fixed at 140 V. Base on L9 orthogonal array and signal to noise ratio through Taguchi method, analysis of variance (ANOVA) is used to validate the significant experimental parameters. The results suggest that the PCD in grain size of 6 μm is the best choice for maximum material removal rate and minimum for electrode wear ratio, meanwhile, the optimum condition of surface roughness is obtained at 1.7 μm. The current and pulse on-time play as significant roles that affect machining performance. The discharge energy (current and pulse on-time) increases leading to the decrease of the material removal rate and the increase of the electrode wear ratio and the surface roughness. In addition to, the PCD grain size has a minor influence on electrode wear ratio and material removal rate and relatively affects surface roughness. The surface roughness increases as increasing the diamond particle size. [ABSTRACT FROM AUTHOR]

The performance of a 3-lobe bearing is investigated by means of three-dimensional computational fluid dynamics analysis. Surface roughness effects were included in the computation of unsteady transient analysis of 3-lobe bearing, taking into account gravity. Each of the lobes is placed at a distance of 120 degree. In this paper K-Epsilon turbulence model is used. The 3-lobe bearing is designed in Gambit software, the journal is modeled as a “moving wall” with an absolute rotational speed of 6000 rpm. Design parameters like L/D ratio, total pressure distribution, surface roughness and lubricant flow properties like turbulent viscosity and velocity magnitude are considered for the analysis The flow is simulated using Ansys Fluent software. [ABSTRACT FROM AUTHOR]

Use of cutting fluids in machining processes can reduce the cutting temperature and provides lubrication to tool and workpiece. These translate to longer tool life and improved surface quality. Due to the issues of using fluids in machining related to environment, health, and manufacturing cost that need to be solved, options to reduce their use. A technique called minimal quantity lubrication (MQL), which sprays small amount of cutting fluid (in the range of approximately 10 – 100 ml/h) to the cutting zone area with the aid of compressed air, was developed to merge the advantages of both dry cutting and flood cooling. For the type of cutting fluids, vegetable oils are common cutting fluids used in MQL because of its superior lubrication and high-pressure performance. This study evaluates the performance of MQL using castor oil as cutting fluid. The workpiece is hardened stainless steel 48 HRC. Results are compared with dry cutting. It was found that using small amount of lubricant of 50 ml/h during the particular turning process produces better results compared to dry cutting, in terms of longer tool life. Surface roughness and cutting forces were also enhanced albeit slightly. From the results, MQL can be a good technique for turning hardened stainless steel using coated carbide cutting tools for cutting parameters of up to 170 m/min cutting speed and 0.24 mm/rev feed. [ABSTRACT FROM AUTHOR]

Surface roughness plays an important role in manufacturing process and is a factor of great significance in the evaluation of cutting performance. In this paper an attempt was made to develop a model based on Artificial Neural Network to simulate hard turning of AISI H13 steel with minimal cutting fluid application. This model is expected to predict the surface roughness in terms of cutting parameters. Networks with different architecture were trained using a set of training data for a fixed number of cycles and were tested using a set of input /output data reserved for this purpose. The root mean square error was determined for the selected architectures. The model with 3-7-7-1 architecture gave the minimum RMSE value. The ability of ANN model to predict surface roughness (R a ) was analyzed. It was found that the predictions made by the ANN model matched well with the experimental results. [ABSTRACT FROM AUTHOR]

This paper focused on optimizing deep drilling parameters based on Taguchi method for minimizing surface roughness. The experiments were conducted on CNC lathe machine using solid carbide cutting tool on material AISI 321 austenitic stainless steel. Four cutting parameters such as cutting fluid, speed, feed and hole-depth, each at three levels except the cutting fluid at two levels were considered. Taguchi L 18 orthogonal array was used as design of experiment. The signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) was carried out to determine which machining parameter significantly affects the surface roughness and also the percentage contribution of individual parameters. Confirmation test was conducted to ensure validity of the test result. The results revealed that the combination of factors and their levels A 2 B 3 C 2 D 1 i.e. the machining done in the presence of cutting fluid, at a speed of 500 r.p.m. with a feed of 0.04 mm/s and hole-depth of 25 mm yielded the optimum i.e. minimum surface roughness. Further, the results of ANOVA indicated that all four cutting parameters significantly affected the surface roughness with maximum contribution from speed (27.02%), followed by cutting fluid (25.10%), feed (22.99%), and hole-depth (14.29%). It is also observed that the surface finish for deep drilling process can be improved effectively through this approach. [ABSTRACT FROM AUTHOR]

This paper describes the application of the fuzzy logic integrated with Taguchi method for minimizing the surface roughness and maximizing the material removal rate simultaneously, in CNC end milling of Al 7075 T6 aerospace aluminium alloy. The input parameters taken into consideration are speed, feed, depth of cut and nose radius. Al 7075 T6 is one of the highest strength aluminium alloys in 7000 series family. In Taguchi method, L 27 orthogonal array with 4 factors and 3 levels are chosen and S/N ratios are calculated. The S/N ratios of roughness and material removal rate are fed as inputs to fuzzy logic system and output received is Multi response performance index (MRPI). With application of ANOVA, the nose radius and depth of cut are identified as the most significant parameters contributing about 31% of the variance. Further a confirmation test showed that, there was a significant improvement in MRPI of optimal process parameters as compared to MRPI of initial process parameters. [ABSTRACT FROM AUTHOR]

Surface roughness plays an important role in manufacturing process and is a factor of great importance in the evaluation of cutting performance. Performance parameters such as cutting force, cutting temperature, acoustic emission signals etc. can be used to predict surface roughness. It is expected that more accurate prediction would be possible if these factors are considered collectively with cutting parameters since each of these factors predict surface roughness in their own characteristic fashion. In this present work, an attempt was made to fuse cutting temperature along with cutting parameters to predict surface roughness during turning of H13 tool steel having a hardness of 43 HRC. An artificial neural network model was developed exclusively with cutting parameters then it was compared with another ANN model developed by fusing cutting temperature with cutting parameters and their ability to predict surface roughness (Ra) was analyzed. The fusion model developed based on the artificial neural network was found to be superior to ANN model without sensor fusion. [ABSTRACT FROM AUTHOR]

Titanium alloys are some of the recently developed advanced materials having excellent mechanical properties including high strength to weight ratio and are finding extensive applications in many industries including aerospace industries. But these alloys have poor machinability. Certain non conventional machining techniques have been found to be useful in machining these alloys. Wire-Electro Discharge Machining (WEDM) is one such advanced technique employed to generate intricate shapes when hard metals like titanium is to be cut. The efficient titanium alloy machining involves a proper selection of process parameters to optimize the performance characteristics including material removal rate (MRR) and surface roughness (Ra). In the present research work, the effects of certain process parameters such as peak current (Ip), pulse on time (Ton), pulse off time (Toff) and servo reference voltage (SV) on MRR and Ra were investigated. The experimental plan was based on Taguchi method using four factors each at three levels. In addition, analysis of variance (ANOVA) was implemented to identify the significant WEDM process parameters. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this research was to investigate the effect of the main factors of the surface roughness in aluminum semi-solid 2024 face milling. The results of the research could be applied in the manufacture of automotive components and mold industries. This study was conducted by using computer numerical controlled milling machine with 63 millimeter diameters fine type carbide tool with twin cutting edge. The controlled factors were the speed, the feed rate and the depth of cut which the depth of cut was not over 1mm. For this experiment, we used factorial designs and the result showed that the factors effected of surface roughness was the feed rate and the speed while the depth of cut did not effect with the surface roughness. Furthermore, the surface roughness was likely to reduce when the speed was 3,600rpm and the feed rates was 1,000mm/min. The result of the research led to the linear equation measurement value which was Ra = 0.205 - 0.000022 Speed + 0.000031 Feed rate. The equation formula should be used with the speed in the range of 2,400 - 3,600rpm, feed rate in the range of 1,000 - 1,500mm/min and the depth of cut not over 1mm. The equation was used to confirm the research results, it was found that the mean absolute percentage error (MAPE) of the surface roughness obtained from the predictive comparing to the value of the experiment was 3.48%, which was less than the specified error and it was acceptable. [Copyright &y& Elsevier]

Stabilizing the copper interconnect process is the key to improving yield and reliability. A stable process for forming adequate grains in a copper film is important, but there is no proper method for monitoring the grains in that film. We introduce the micro-haze method, an advanced method for monitoring grain size using scattering light. We experimentally verified the effectiveness of the method and concluded that the method enables the monitoring the grains in a copper film. [ABSTRACT FROM AUTHOR]

The approach of two spheres along their line of centres is analyzed assuming that each sphere is covered by a porous layer. The slip of the fluid at the surface of the porous layers then permits the spheres to touch without a singularity in the associated force. In a corresponding analysis for flat surfaces, an analytical formula for the force is obtained. This force is also finite for vanishing gap width. It is shown how the properties of the porous layers can be related to the statistics of spatial distributions of surface asperities. Finally, it is emphasised that a finite force is associated with a finite asperity height. [ABSTRACT FROM AUTHOR]

A semiempirical polarimetric backscattering model for bare soil surfaces is inverted directly to retrieve both the volumetric soil moisture content Mv and the rms surface height s from multipolarized radar observations. The rms surface height s and the moisture content Mv can be read from inversion diagrams using the measurements of the cross-polarized backscattering co- efficient σvh0 and the copolarized ratio p( = σhh0/σvv0). Otherwise, the surface parameters can be estimated simply by solving two equations (σvh0 and p) in two unknowns (Mv and s). The inversion technique has been applied to the polarimetric backscattering coefficients measured by ground-based polarimetric scatterometers and the Jet Propulsion Laboratory airborne synthetic aperture radar. A good agreement was observed between the values of surface parameters (the rms height s, roughness parameter κs, and the volumetric soil moisture content Mv) estimated by the inversion technique and those measured in situ. [ABSTRACT FROM AUTHOR]

In this paper, we discuss in detail the modeling of surface roughness (SR) scattering in single- and double-gate silicon-on-insulator (SOI)MOSFETS, where the conventional formulation based on the expected value of the electric field cannot be used. By reconsidering the Ando's original approach, we show that a model based on the eigenfunction derivatives at the Si-oxide interface can be naturally extended to SOI MOSFETs, and, further- more, we also derive a formulation based on appropriate integrals of the eigenfunctions in the silicon film, which must replace the expected value of the field used in bulk MOSFETs. All the analytical identities used in the derivation of the model have been verified by using numerically calculated eigenvalues and wavefunctions. Our results indicate that, in ultrathin-film SOI MOSFETs, the effective field is no longer a good metric for the SR scattering and, furthermore, SR scattering affects the total mobility even at lower inversion densities than it does in bulk transistors. [ABSTRACT FROM AUTHOR]

We have studied the coercivity of magnetic nanonetworks as a function of thickness, nominal pore diameter, and surface/interface roughness in the thickness range of approximately 2 to 45 nm where a Néel-type domain wall has been theoretically predicted. Such magnetic nanonetworks have been prepared by sputtering iron on the walls of commercially available porous nano-channel alumina (NCA) membranes. The thickness dependence of coercivity has also been studied on films deposited on surface-oxidized Si and glass subtrates. These substrates are essentially non-porous and much smoother than NCAs. Our investigation shows that the coercivity of films deposited on Si and glass depends on the spatial fluctuation of thickness which arises from the roughness of the apparently smooth substrates. On the other hand, NCAs are found to be inherently quite rough, and films on NCAs show a complex thickness dependence which arises from the interplay between surface/interface roughness, domain pinning due to porosity, surface anisotropy, surface torques, and oxidation of the iron films. It was found that the growing films on NCA substrates led to partial filling up of the pore entrance, thereby reducing its effective diameter. The film growth also affects the roughness of the film, which in turn affects its coercivity. We propose a model for the thickness dependence of coercivity based on the pore fill-up geometry considering the effective pore diameter and the critical thickness at which the pore will be completely filled up. Experimental results on coercivity with thickness variation of iron network deposited on NCA generally agree with the suggested model. [ABSTRACT FROM AUTHOR]

An analytical model for the fatigue probability of abrasive waterjet cut high strength steel as a function of surface roughness, surface residual stress, tensile strength and number of cycles to failure is presented. Based on the model, which is valid in the finite and infinite-life high cycle fatigue regime, the influence of the aforementioned parameters on the fatigue strength at different probability levels is studied. For validation, fatigue tests are performed on abrasive waterjet-cut dog-bone specimens manufactured from high-strength steel with a yield strength of 700 MPa. Residual stresses are measured parallel to the loading direction at the inlet, middle and outlet of the cut surface. Surface roughnesses are measured with laser line triangulation as well as a traditional contact stylus method, showing good agreement between both measurement techniques. The proposed probabilistic model shows good agreement with the experimental results with less than 4% error in the predicted mean fatigue limit. Furthermore, the applicability of the presented analytical expression in a probabilistic design framework is demonstrated. An engineering example is introduced demonstrating the implementation of the model in a finite-element simulation, accounting for both multiaxial loading and the statistical size effect. Unlabelled Image • Experimental investigation of the fatigue performance and surface properties of abrasive waterjet cut high strength steel. • Probability of failure model valid in both finite and infinite-life High Cycle Fatigue regime. • Model of the influence of surface roughness, residual stress and tensile strength on the fatigue failure probability. • Finite-element implementation of weakest-link probability assessment of engineering steel structures. • Novel fatigue design guidelines for abrasive waterjet cut steel structures. [ABSTRACT FROM AUTHOR]

• Algorithm for perfecting the envelope method for characterization of a thin film. • It has a capacity for providing utmost accurate characterization of thin films. • It accounts implicitly for light scattering in the film. • It accounts implicitly for scattering due to roughness of the surface film/air. An algorithm is proposed for perfecting the envelope method (EM) for characterization of a thin film on a substrate specimen from its normal incidence interference transmittance spectrum T (λ). It takes into account the partial coherence of light propagating through the film, due to light scattering mainly associated with roughness of the surface film/air, in the computations of both the smoothed transmittance spectrum T sm (λ) and the extinction coefficient k (λ) of the film. The algorithm includes enhanced computation of the envelopes T + (λ) and T - (λ) of T sm (λ), and adjustment of points T + (λ t) and T - (λ t) in spectral regions of substrate non-transparency as λ t are the wavelengths of the tangency points between T sm (λ) and its envelopes. The average thickness d ¯ and the non-uniformity ∆d of the film are computed by EM based optimization procedure, followed by obtaining the refractive index n (λ) of the film by optimized curve fitting over approximated values n 0 (λ t) of n (λ t) without employing a dispersion model. It is demonstrated that k (λ) is determined more accurately from T sm (λ), based on computing its coherent light approximation k 0 (λ) and partially coherent light correction Δ k (λ), rather than the commonly used computation of k (λ) from T + (λ). Two a-Si films with dissimilar thicknesses are characterized by the proposed algorithm; as there are published characterization results for the same films computed by two spectroscopic ellipsometry related methods, and two EMs, selected as most likely to provide accurate characterization of the films. Comparing the characterization accuracy for the proposed algorithm with the characterization accuracy for the best of these published results shows that using the proposed algorithm leads to significantly more accurate characterization of both a-Si films. Accurate characterization is achieved even in a case of T (λ) influenced by residual gas absorption during its measurement, by employing both T sm (λ) and T + (λ) in the computation of k (λ). The presented results indicate that using the proposed algorithm has a capacity for providing most accurate characterization of almost every dielectric or semiconductor film with d ¯ = [300,5000] nm on a substrate, only from T (λ), compared to all the other methods for characterization of such films only from T (λ). [ABSTRACT FROM AUTHOR]

Background : Minimally invasive dentistry aims to prevent progression of caries and treats non-cavitated lesions through non-invasive approaches to preserve the integrity of tooth structure. The aim of this research was to investigate the possible biomimetic effect of agarose hydrogel in remineralizing a human demineralized enamel model. Methods : Mandibular third molars were distributed into three groups (G1, G2 and G3) according to the follow up time (2, 4 and 6 days respectively). Caries like lesion was prepared by applying 37% phosphoric acid gel for 1 minute and then remineralization was performed through applying agarose hydrogel on the demineralized surfaces. The specimens were placed in phosphate solution at 37˚C for 2, 4 & 6 days. Scanning electron microscope (SEM), surface microhardness (SMH) and surface roughness analysis (SR) were performed to assess the regenerated tissue. Results : SEM revealed mineral depositions on the demineralized enamel surface that increased in density by time resulting in a relatively smooth surface in G3. SR and SMH analysis revealed significant differences between the remineralized enamel surfaces of different groups (p< 0.00001) with the highest SR in G1 and the highest SMH in G3. Conclusions : Agarose hydrogel application is a promising approach to treat early carious lesion. Further studies are needed to clarify the stability of agarose hydrogels in clinical application., Competing Interests: No competing interests were disclosed.