Search

Objectives: To compare marginal gap width and depth with different cementation systems, excess removal, and after polishing. Method and materials: In total, 80 composite crowns were milled, divided into ten groups, and cemented on identical artificial teeth. Eight crowns per group were fixed with (i) zinc phosphate cement (ZnOPh), (ii) glass-ionomer cement (GIC), (iii) resin-reinforced glass-ionomer cement (GIC mod), (iv) dual-curing adhesive composite (Comp dual), or (v) dual-curing self-adhesive composite (Comp SE dual). Excess removal was performed with a scaler after brief light-cure (tack-cure), final light-cure, during rubber or gel phase or by wiping with foam pellet. Curing was completed in chemical, dark cure, or light-curing modus. The specimens were polished and stored in water (37°C). The margins were digitized using a 3D laser-scanning microscope (VK-X100 series, Keyence). The width and the depth of the marginal gap were measured at 10 points between the crown margin and the preparation margin. Results: The width after excess removal varied between 65.1 ± 15.7 µm (Comp dual, wipe, with polishing) and 208.6 ± 266.7 µm (Comp SE dual, dark cure, without polishing). The depth varied between 29.8 ± 22.2 µm (Comp dual, wipe, with polishing) and 89.5 ± 45.2 µm (Comp SE dual, dark cure, without polishing). The impact on gap width and depth was detected for fixation material, excess removal, and polishing. Conclusion: The gap depth and width depend on the luting material and the mode of access removal. Polishing can improve the gap quality, especially for GIC and resin-based systems. [ABSTRACT FROM AUTHOR]

In order to achieve a high-quality superfine surface on K9 glass, a novel algorithm was developed for addressing optimisation challenges in high-precision machining using magnetised liquid solution. This algorithm employs a collective global exploration developed based on AI (Artificial Intelligence) inspiration, which effectively coordinates various nonlinear systems encountered during the machining process. By integrating multiple nonlinear systems and utilising straightforward physical techniques, the goal is to create a powerful artificial intelligence algorithm in optimising nonlinear systems (AIONS). This algorithm aims to achieve the same level of versatility and rapid convergence observed in enhancing surface quality during the burnishing of optical material K9. To demonstrate the effectiveness of the AIONS algorithm, benchmark functions were analysed in conjunction with optimising the K9 optical glass polishing process. Polishing experiments were conducted to determine the ideal technical parameters using the new algorithm and a straight permanent magnetic yoke surface finishing approach. The analysis and experimental results revealed that when polishing K9 optical glass materials with a permanent-magnetic yoke field and employing a magnetised liquid solution (MLS) with technological parameters guided by the AIONS algorithm, exceptionally smooth surface finish with an Ra value of 0.480 nm was achieved, leaving no scratches on the polished surface. The objective of this study is to provide valuable insights into optimising the surface polishing of challenging materials like K9 optical glass and other materials used in the optical industry. [ABSTRACT FROM AUTHOR]

Phase separation was observed in silica glass following low‐temperature heat treatment in high water vapor pressure through the formation of bubbles. Although the 6 day diffusion treatment in saturated water vapor pressure at 250°C does not normally cause phase separation, the reactive fracture surface and subsurface damage caused by polishing with cerium oxide (CeO2) allowed for an increase in water absorption during treatment and heterogeneous nucleation of the bubbles at damaged sites. The sub‐surface damage, characteristic of blunt contact damage, was only revealed when the polished sample was etched. The formation of bubbles and polishing damage were observed in two silica glasses—one containing chlorine impurities and the other containing OH impurities. Raman spectra collected after fracture or polishing and water diffusion treatment demonstrated an increase in the abundance of –OH species including silanol (SiOH) groups and an evolution in the glass structure in the bubble regions compared with the bubble‐free regions. These results indicate an increase in the reactivity between water and glass fracture surfaces relative to the bulk. [ABSTRACT FROM AUTHOR]

This study aimed to reduce more protein by combining the physical treatment, polishing, and high-pressure enzymatic treatment in a sequence. To understand the mechanism of accelerated hydrolysis during the high-pressure enzymatic treatment process, the effects of pressure on the enzyme and substrate were independently examined, the higher the pressure, the better the enzyme stability. The substrate, rice, also showed increased sensitivity to the enzyme when soaked under high pressure. Although there was no significant difference in the protein content of rice by degree of polishing, greater protein hydrolysis was observed in 130% polished rice than in white rice during the high-pressure enzymatic treatment. As a result, it is expected that the process utilizing the synergistic effect between polishing and high-pressure enzymatic treatment can be applied to a new low-protein rice production method to help improve the diet and quality of life of patients with kidney disease.Please confirm if the author names are presented accurately and in the correct sequence. Also, kindly confirm the details in the metadata are correct.YesPlease check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.YesPlease confirm the section headings are correctly identified.Yes [ABSTRACT FROM AUTHOR]

Objective: This in vitro study aimed to investigate the effect of five polishing systems on the surface roughness (SR) and color change (CC) of novel bulk-fill composite resins. Methods: Fifty composite resin samples were prepared for each of the five groups: Stark Bulk Fill, SDR Plus, SonicFill 3, Charisma Bulk Flow One, and Filtek Z250. Each group of composite resins was further subdivided into five subgroups based on the polishing method applied: OptraGloss (OG), OptraGloss combined with Diapolisher paste (OGD), OptiDisc (OD), OptiDisc combined with Diapolisher paste (ODD), and Occlubrush (OCC) (n = 10). Surface roughness was measured using a profilometer following the polishing procedures, while surface morphology was assessed through atomic force microscopy and scanning electron microscopy. Subsequently, the samples were divided into two further subgroups for aging in distilled water and coffee (n = 5). The initial color parameters and those measured after 7 days were recorded to evaluate color change. Statistical analysis was performed using two-way ANOVA, followed by Tukey's post-hoc tests (α = 0.05). Results: SR significantly varied based on the composite resin and polishing system (p < 0.001). OCC polishing yielded the smoothest surface for STARK and SDR composites, while Charisma exhibited the lowest roughness in the ODD group (p < 0.05). OGD group consistently produced lower SR across multiple composites compared to the OG group (p < 0.001). Significant color changes (ΔE00) were found, with SonicFill and Filtek showing the greatest color stability when polished with OGD and OCC. For all polishing systems, except ODD, the SDR composite showed the greatest CC in coffee storage (p < 0.003). Conclusion: This study demonstrated that both the polishing technique and composite resin type significantly influenced SR. SR was notably affected by the interaction between the polishing method and resin type, with the OCC system consistently producing the lowest SR values. Additionally, Charisma exhibited surface properties similar to Filtek. Variations in color change were also observed based on both the polishing method and resin type, highlighting the critical role these factors play in determining the color stability of restorative materials. [ABSTRACT FROM AUTHOR]

Introduction: To evaluate topographic changes of enamel surface in 3-dimensional after different debonding methods of aligner attachments formed with 2 different composite resins. Methods: Vertical rectangular attachments were created on 88 premolar teeth and divided into two composite resin groups (Group 1:flowable, Group 2:packable) (N = 44). These were then divided into two subgroups (N = 22) using different debonding methods. In Group A, the attachments were firstly removed using an attachment debonding plier and then with white fiberglass. Following, the tooth surfaces were polished with blue fiberglass. In Group B, the excess attachment composite was removed with a 12-blade carbide bur, followed by a 24-blade carbide bur, and tooth surfaces were polished with Renew stone. The remaining composite volume was measured using Geomagic Control X software. Enamel surface roughness and morphological change were compared between the groups. Results: Residual composite resin volume did not show a statistically significant difference between composite resin groups (1–2 A). The enamel demineralization volume and area changes in Group 2 A were significantly higher than observed in 2B (p < 0.05). Roughness parameters Ra (T1-T0), Ra (T2-T0), Rq (T1-T0), and Sa (T1-T0) were significantly higher in Group 1B compared to Group 1 A (p < 0.05). Similarly, Ra (T1-T0), Sa (T1-T0), and Sq (T1-T0) parameters were significantly higher in Group 2B compared to Group 2 A (p < 0.05). Conclusions: Fiberglass with a debonding plier produced a smoother enamel surface compared to carbide burs, but caused significantly more enamel demineralization, as seen in micro-CT evaluations after polishing. [ABSTRACT FROM AUTHOR]

luorescence of natural teeth and its alterations due to environmental factors should also be taken into account in restorations. This study aims to assess fluorescence changes of three types of dental ceramics. 36 Ceramics of Feldspathic, Emax, and Enamic in 10 mm diameter and the thicknesses of 0.5 and 1mm with glaze and polish finishes were studied. Fluorescence was measured before and after aging and were analyzed using Anova test. The results showed that ceramics became opaque as the result of aging. This was more noticeable for Enamic ceramic with the lightness increase of 4.10 and 4.86 for the UV excited and non-excited measurements, respectively. Moreover, Enamic ceramic experienced significant changes in its fluorescence due to aging (Average Fluoresence ChangeEnamic=-10.2) while Emax (Average Fluoresence ChangeEmax=-3.6) and feldspathic (Average Fluoresence ChangeFeldspathic=-0.4) ceramics were superior to Enamic in this respect. In Feldspathic ceramic, due to the presence of feldspar phase, high resistance to aging process was observed. While, severe shifts in fluorescence due to aging were observed in Enamic ceramic. Several factors affect color and fluorescence change of ceramics due to aging. Preparations stresses, adhesion of glazes and the formation of micro cracks on the ceramic surfaces are among the factors can influence on this behavior. In case on Enamic ceramic caveat should be taken as it can change its appearance due to fluorescence hue shift probably as a result of surface scattering of UV light. According to the findings of this study Feldspathic, Emax and Enamic are respectively preferable in terms of fluorescence stability during aging process. [ABSTRACT FROM AUTHOR]

Highlights: The SG flexible tool has been developed, which is a combination of a sol–gel polishing pad and a multilayer fiber pad. The microscopic yielding and the macroscopic yielding are the main properties of SG flexible tools. The problem of polishing complex curved surface by robot has been solved effectively by SG flexible tools. Complex marble surfaces with high gloss, low roughness and good surface consistency can be achieved by using SG flexible tools to polish. Newly developed Sol–gel (SG) flexible tools are used to polish complex marble surfaces with a robot to achieve a high-gloss, low-roughness, and scratch-free surface. The SG tool is composed of semi-solid abrasive and flexible fiber pads, which can realize a dual yielding effect at both the micro and macro levels so that the SG flexible tool can better fit the complex curved surface. Through the simulation analysis of the contact of SG flexible tools, the relationship between different curvature surfaces and polishing forces was obtained. Based on the Preston material removal theory, constant-pressure polishing of surfaces of different curvatures was achieved by simulating the contact force distribution between the SG flexible tool and the marble surface, as well as the constant-pressure material removal profile. By optimizing the space of the polishing trajectory, the uniformity of the material removal depth was improved, and the consistency of surface quality after polishing was enhanced. By establishing a model that correlates the optimum polishing trajectory space with curvature for surfaces of different curvatures, the effective prediction of material removal profiles for robotic polishing of surfaces of different curvatures was achieved. These strategies aim to ensure surface consistency after polishing complex curved surfaces under different conditions, thereby increasing the product's added value. This research provides initial theoretical guidance for the application of SG flexible tools in the robotic polishing of marble with complex curved surfaces. [ABSTRACT FROM AUTHOR]

Many industrial components, especially those realized through 3D printing undergo surface finishing processes, predominantly, in the form of mechanical polishing. The polishing processes for custom components remain manual and iterative. Determination of the polishing endpoints, i.e., when to stop the process to achieve a desired surface finish, remains a major obstacle to process automation and in the cost-effective custom/3D printing process chains. With the motivation to automate the polishing process of 3D printed materials to a desired level of surface smoothness, we propose a dynamic model of surface morphology evolution of 3D printed materials during a polishing process. The dynamic model can account for both material removal and redistribution during the polishing process. In addition, the model accounts for increased material flow due to heat generated during the polishing process. We also provide an initial random surface model that matches the initial surface statistics. We propose an optimization problem for model parameter estimation based on empirical data using KL-divergence and surface roughness as two metrics of the objective. We validate the proposed model using data from polishing of a 3D printed sample. The procedures developed makes the model applicable to other 3D printed materials and polishing processes. We obtain a network formation model as a representation of the surface evolution from the heights and radii of asperities. We use the network connectivity (Fiedler number) as a metric for surface smoothness that can be used to determine whether a desired level of smoothness is reached or not. [ABSTRACT FROM AUTHOR]

Diamond is an excellent material for applications in acoustics, optics, electronics, and thermal management. However, their extremely low material removal rate results in very long processing durations. Therefore, it is essential to improve polishing efficiency while maintaining excellent polishing quality. In this study, a comparative experiment on the polishing of polycrystalline diamonds using diamond wheels under normal and oxygen-enriched environments has been conducted. It is found that the material removal rate reaches 2. 29 μm/h under oxygen-enriched environment, which is over nine times the removal rate of 0. 25 μm/h under normal condition, while maintaining good surface quality. The characterization results of atomic force microscopy indicate that, within a 30 μm × 30 μm measurement area, the surface roughness Sa of the polished diamond under the oxygen-enriched environment could reach below 2 nm. Meanwhile, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations reveal no significant structural damage. Furthermore, the material removal mechanism during diamond polishing was analyzed by X-ray photoelectron spectroscopy (XPS), the results indicate that the diamond during polishing undergoes a phase transition from sp3 to sp2 structures under mechanical action, with the resultant phase transition layer being removed under both mechanical and oxidative effects. Additionally, it is observed that in the oxygen-enriched environment, the phase transition layer is removed more rapidly, indicating that oxidation plays a more significant role in the diamond material removal process. [ABSTRACT FROM AUTHOR]

The basic design parameters and operational conditions of an enhanced vibratory lapping machine are considered. The main purpose of the research is to define the influence of different machining regimes on the roughness parameters of flat surfaces of parts made of C22 steel. The experiments are carried out at different controllable conditions of the vibratory lapping process: amplitudes of vibrations of the upper lap, forced frequencies, machining durations, and lapping paste types. The obtained results are shown in the form of bar charts describing the dependencies of the surface roughness on the machining conditions mentioned above. The major scientific novelty consists in the further development of the technologies of lapping and polishing of flat surfaces using vibratory machines with an electromagnetic drive. The presented research can be used by engineers and technologists while improving existent designs of vibratory lapping- polishing machines, as well as enhancing the corresponding machining processes. [ABSTRACT FROM AUTHOR]

In this paper, the polishing mechanism of polycrystalline tungsten has been studied, focusing on the reasons for the appearance of grain steps and the effects of different polishing factors on the polishing effect. The surface morphology and mechanical properties after polishing were analyzed by electron backscatter diffraction, scanning electron microscope, nanoindentation and other characterization tools. Effects of different polishing factors on the polishing effect were also analyzed by orthogonal and single factor experiments. Results show that the effects of abrasive size, polishing pressure, polishing speed, and abrasive concentration on the polishing effectiveness decrease in turn. The optimal polishing parameters obtained by orthogonal experiments are 60 rpm polishing speed, 5.0 μm abrasive size, 5 wt% abrasive concentration, and 30 kPa polishing pressure. In the single factor experiment, with the increase of abrasive size, the height of grain step decreased from 0.5 μm to 0.11 μm, and the surface roughness (Ra) decreases from 11.3 nm to 5.2 nm. Grain anisotropy is the main reason for the appearance of grain steps on the surface after polishing. Different grain orientations lead to different surface mechanical properties. The hardness of high grain step is higher than that of low grain step. In addition, the increase of abrasive size can effectively suppress the grain step phenomenon, thereby improving the surface polishing effect. • Surface morphology after polishing is analyzed, and influence of different polishing factors on polishing effect is studied. • The grain anisotropy leads to the appearance of grain steps on the surface of material after polishing. • The influence of abrasive size, polishing pressure, speed, abrasive concentration on polishingeffect decreases in turn. [ABSTRACT FROM AUTHOR]

Technological recommendations for polishing of workpieces with a thickness of up to 0.25 mm and linear size of up to 9.0 mm are presented. A method for fastening workpieces is developed and equipment that allows for fixing and simultaneously processing five or more parts is tested. Technological modes that ensure the required surface roughness with satisfactory polishing productivity are established. [ABSTRACT FROM AUTHOR]

Finishing and polishing dental ceramics after chairside adjustments is necessary to regain the original surface topography. Though highly subjective, visual and tactile assessment are the most practical ways to assess surface roughness clinically. Several manufacturers recommend polishing kits for specific ceramic materials that differ in efficacy. Proper polishing protocols require the use of sequential polishing instruments that reduce the size of the adjustment abrasions, improve aesthetics and reduce plaque accumulation. If polishing systems are interchanged, stepwise use of a zirconia polishing system may have a "universal" effect on different ceramic substrates. Adjusting zirconia restorations could result in phase transformation and potentially compromise flexural strength. The extent of this degradation is dependent on the yttria content of the zirconia. This may be reduced by appropriate finishing and polishing. Continuing Education Credit Available: A CDA Continuing Education quiz is online for this article: The practice worksheet is available online: [ABSTRACT FROM AUTHOR]

Hollow cylindrical components of longer length are a crucial necessity in industries catering to products like gun barrels, cylinder liners of ship and locomotive engines, pneumatic and hydraulic cylinders, etc. A highly finished inner surface improves resistance to corrosion, wear, and friction. Conventional magnetorheological (MR) finishing techniques typically use axis-based CNC setups, which are limited in their ability to finish longer components (>30 cm) due to the Z-axis tool restriction. In this work, a novel MR finishing method has been designed and developed that is based on the pneumatic cylinder and has extremely high reach for the length of the hollow cylindrical workpiece thereby successfully mitigating the limitation of conventional CNC-based MR finishing techniques. Using mild steel as the material, the new technique achieved a significant reduction in surface roughness, with a minimum average roughness of 0.059 µm after 150 minutes of finishing. [ABSTRACT FROM AUTHOR]

Abstract Objective This in vitro study aimed to investigate the effect of five polishing systems on the surface roughness (SR) and color change (CC) of novel bulk-fill composite resins. Methods Fifty composite resin samples were prepared for each of the five groups: Stark Bulk Fill, SDR Plus, SonicFill 3, Charisma Bulk Flow One, and Filtek Z250. Each group of composite resins was further subdivided into five subgroups based on the polishing method applied: OptraGloss (OG), OptraGloss combined with Diapolisher paste (OGD), OptiDisc (OD), OptiDisc combined with Diapolisher paste (ODD), and Occlubrush (OCC) (n = 10). Surface roughness was measured using a profilometer following the polishing procedures, while surface morphology was assessed through atomic force microscopy and scanning electron microscopy. Subsequently, the samples were divided into two further subgroups for aging in distilled water and coffee (n = 5). The initial color parameters and those measured after 7 days were recorded to evaluate color change. Statistical analysis was performed using two-way ANOVA, followed by Tukey’s post-hoc tests (α = 0.05). Results SR significantly varied based on the composite resin and polishing system (p

A laser-assisted magnetorheological polishing device was used, which achieved flat polishing of SLM formed 316 L stainless steel by rotating the polishing head. Through orthogonal experiments, the effects of laser power, nozzle flow rate, polishing time, polishing gap, and spindle speed on polishing performance are comprehensively considered. The surface roughness of the samples before and after the experiment is measured, and signal-to-noise ratio analysis is utilized to determine the impact of independent variables on the polishing effect and to derive the optimal parameter combination. Experimental findings indicate that polishing time significantly influences surface roughness, followed by spindle speed, laser power, nozzle flow rate, and polishing gap; The optimal parameter combination is: polishing time of 40 min, spindle speed of 3600 rpm, laser power of 3 W, nozzle flow rate of 100 mL/min and polishing gap of 2 mm. Under this parameter combination, the sample exhibits the smoothest surface post-experiment. [ABSTRACT FROM AUTHOR]

This paper proposes a reverse growth surface planarization mechanism for achieving high-efficiency precision processing of the potassium dihydrogen phosphate (KDP) crystal. The KDP crystal reverse growth has ordered and controllable characteristics similar to growth, which differs from the disordered and random dissolution in the natural state. Experiments are conducted using a high-precision annular polisher to investigate the surface characteristics, material removal, and surface planarization of different crystallographic planes in reverse growth. The repeat utilization of polishing liquids is studied to reduce processing costs. The difference in material removal and surface roughness of different crystallographic planes obtained from the same reverse growth polishing process is within 8%. The suitable undersaturation range for reverse growth surface planarization is 0.01–0.18, with a maximum material removal rate of 90 μm/min, 50 times that of the microemulsion polishing methods. Finally, a mirror-like KDP crystal surface is obtained with a surface roughness Ra of 0.00975 μm. [ABSTRACT FROM AUTHOR]

A novel approach to enhancing the efficacy and surface quality of magnetic polishing involves the incorporation of a magnetic liquid circulation system for abrasive particle regeneration in conjunction with a circular Halbach array. The continuous renewal of abrasive particles within the polishing zone is realised through a conveyor belt that transports new abrasive particles into the polishing liquid solution. This formation of a continuously circulating polishing system ensures uninterrupted magnetic finishing processes and maintains stability throughout the polishing operation. This study extensively explores polishing force distribution, magnetic field distribution and abrasive grain behaviour in the polishing area facilitated by the magnetic liquid solution. The application of the proposed polishing processes to polymethyl methacrylate, an optical lens material, aims to comprehend the characteristics and validate the feasibility of the polishing method. Key influencing factors in the magnetic polishing process, including abrasive grain size, magnetic particle, polishing distance and conveyor speed to surface quantity, are examined through experimental analysis. Results of the experimental polishing processes demonstrate that the utilisation of circular Halbach arrays with circulating abrasives produces a nanometric surface finish. Even in the polishing of polymethyl methacrylate with an initial rough surface (Ra = 464.895 nm), the process achieves an ultra-fine level with Ra below 9 nm without disruption in the material polishing processes of optical lenses.

Mechanical polishing of a product makes it possible to decrease the roughness of its surface to Ra = 0.001 µm by rubbing it with a fine abrasive contained in a fabric or other soft material. This method takes too much time and is associated with abrasive particles and microscopic scratches remaining after the processing. As such, a non-contact treatment with plasma and accelerated particles has been chosen in the present work to study polishing of ceramic samples. The small angular divergence of fast argon atoms made it possible to obtain the dependence of the sample roughness on the angle α of the atom’s incidence on its surface. It was found that the roughness weakly depends on the angle α, if not exceeding the threshold value αo ~ 50°, and rapidly decreases with increasing α > αo. Polishing with fast argon atoms leads to a noticeable decrease in friction of ceramic samples.

The infrared conformal window is one of the most critical components in aircraft. Conformal windows with high performance bring low aberrations, high aerodynamic performance, reliability in extreme working environments, and added value for aircraft. Through the past decades, remarkable advances have been achieved in manufacturing technologies for conformal windows, where the machining accuracy approaches the nanometer level, and the surface form becomes more complex. These advances are critical to aircraft development, and these manufacturing technologies also have significant reference values for other directions of the ultra-precision machining field. In this review, the infrared materials suitable for manufacturing conformal windows are introduced and compared with insights into their performances. The remarkable advances and concrete work accomplished by researchers are reviewed. The challenges in manufacturing conformal windows that should be faced in the future are discussed.

The demand for optical glass has been rapidly increasing in various industries, where an ultra-smooth surface and form accuracy are critical for the functional elements of the applications. To meet the high surface-quality requirements, a polishing process is usually adopted to finish the optical glass surface to ensure an ultra-smooth surface and eliminate sub-surface damage. However, current ultra-precision polishing processes normally polish workpieces individually, leading to a low production efficiency and high polishing costs. Current mass-finishing methods cannot be used for optical glasses. Therefore, magnetic-field-assisted batch polishing (MABP) was proposed in this study to overcome this research gap and provide an efficient and cost-effective method for industrial use. A series of polishing experiments were conducted on typical optical components under different polishing parameters to evaluate the polishing performance of MABP on optical glasses. The results demonstrated that MABP is an efficient method to simultaneously polish multiple lenses while achieving a surface roughness, indicated by the arithmetic mean height (Sa), of 0.7 nm and maintained a sub-micrometer surface form for all the workpieces. In addition, no apparent sub-surface damage was observed, indicating the significant potential for the high-quality rapid polishing of optical glasses. The proposed method is highly competitive compared to the current optical polishing methods, which has the potential to revolutionize the polishing process for small optics.

Dwell time plays a vital role in determining the accuracy and convergence of the computer-controlled optical surfacing process. However, optimizing dwell time presents a challenge due to its ill-posed nature, resulting in non-unique solutions. To address this issue, several well-known methods have emerged, including the iterative, Bayesian, Fourier transform, and matrix-form methods. Despite their independent development, these methods share common objectives, such as minimizing residual errors, ensuring dwell time's positivity and smoothness, minimizing total processing time, and enabling flexible dwell positions. This paper aims to comprehensively review the existing dwell time optimization methods, explore their interrelationships, provide insights for their effective implementations, evaluate their performances, and ultimately propose a unified dwell time optimization methodology.

Millets are widely recognized for their nutritional significance; however, the methods employed for their processing are currently lacking. This article primarily focuses on the advanced technologies and progressions in millet dehulling and polishing. These technologies operate based on the fundamental principles of compression-shearing, abrasion-friction, and centrifugal-impact forces. Processing of millets can be challenging because of the physical characteristics and tight attachment of hull and bran to the endosperm. However, several dehullers have been designed to solve this problem for different kinds of millets. In addition, the nutritional and anti-nutritional characteristics undergo alterations due to both dehulling and polishing processes. These alterations are thoroughly examined and discussed in this article. Specifically, anti-nutrients such as tannins and phytate are predominantly found in the outer pericarp of the grain and experience a reduction after undergoing dehulling and polishing. The nutritional properties are also subjected to a reduction; however, this reduction can be mitigated by subjecting the grains to certain pretreatments before dehulling and polishing. These treatments serve to enhance dehulling efficiency and nutrient digestibility while simultaneously reducing the presence of anti-nutrients. Novel thermal and non-thermal methodologies such as microwave, hydrothermal, high-pressure processing, and ohmic heating can be employed for processing millets, thereby diminishing the loss of nutrients. Additional research can be carried out to investigate their impact on the dehulling and polishing of millets.

ABSTRACT Objective Materials and Methods Results Conclusion Clinical Significance To evaluate the effect of staining, glazing, and polishing of stabilized zirconia with 5 mol% of yttrium oxide (5Y‐TZP) on the wear behavior of opposing tooth enamel.The plane specimens of 5Y‐TZP were divided into 6 groups (n = 10), according to surface treatment: as sintered, staining, glazing, polishing, staining followed by glazing, and staining followed by polishing, and positioned against tooth enamel during the two‐body wear test (20 N, 2 Hz, until completing 300,000 cycles). The wear rates of tooth enamel were evaluated using a profile projector and a digital pachymeter as a measure of vertical height loss. The data were analyzed by one‐way ANOVA and a Tukey post hoc test (α = 0.05).Polishing reduced the vertical height loss (p < 0.001) while there was no difference among other groups.Polishing is recommended as a finishing procedure to reduce the wear rates of tooth enamel, and finishing procedures (glazing or polishing) performed after staining did not affect the vertical height loss of tooth enamel.Polishing is the recommended finishing procedure for preshaded 5Y‐TZP to reduce the wear rates of opposing tooth enamel. Staining is applied to the occlusal surface to reproduce the pigmented groove appearance, and glazing or polishing performed after staining did not affect the wear rates of opposing tooth enamel. [ABSTRACT FROM AUTHOR]

The positive effect of plasma electrolytic treatment on CrWMn tool steel to increase the wear resistance of its surface is shown. The effect of plasma electrolytic nitriding and subsequent polishing on the structure, phase and elemental composition, microhardness of the surface layer, and surface morphology is established. Steel nitriding leads to the formation of a modified surface layer including Fe2–3N iron nitride and nitrogen martensite, below which hardening martensite is formed, reaching a microhardness value of 1200 HV. Subsequent polishing leads to a decrease in surface roughness by 42–68%. Tribological tests were carried out according to the shaft-bushing scheme. A decrease in the friction coefficient and weight wear of up to 2.6 and 30.1 times, respectively, is shown. The formed structure of the surface layer compensates for the effect of the counter body and determines the destruction of friction bonds by plastic displacement. The wear mechanism has been established and is defined as fatigue wear under dry friction and plastic contact. [ABSTRACT FROM AUTHOR]

ABSTRACT A considerable number of different tools and operating materials are used in classical optics manufacturing. Moreover, further parameters such as environmental and process conditions contribute to material removal and surface smoothing in the course of production. A large potential variety of the final surface state of optics can thus be expected. Against this background, nominally identical fused silica optics surfaces purchased from different suppliers were investigated in the present work via x‐ray photoelectron spectroscopy, laser‐induced breakdown spectroscopy, infrared spectroscopy, ellipsometry, and atomic force microscopy. It is shown that the surfaces under consideration feature quite different types and degrees of contamination that can be attributed to the particularly used water and polishing agent. Moreover, slight differences in index of refraction and surface roughness were detected. The presented data thus confirm the expectation that the surface state of an optical component might depend on its origin. The findings are intended to sensitize users regarding such a potential impact, for example, when switching to other suppliers for bought‐in parts and outsourced precision optics items. [ABSTRACT FROM AUTHOR]

During polishing tasks, it is critical to guarantee that the contact force applied at the terminus of the robot manipulator is accurate and stable. However, conventional impedance control methods struggle to perfectly track the desired force signals due to the uncertainties and errors present in the environment. In this paper, a super-twisting sliding mode adaptive impedance control is proposed to overcome the issues mentioned. Firstly, the overshooting of the force signal that occurs during the initial contact phase is solved by establishing a tracking differentiator. This allows the system to apply force from zero smoothly, enabling a seamless transition from a step function to a predetermined force value, reducing the risk of damage to the workpiece or robot due to force overload. Then,for adjustment to an uncertain environment, an exponential update factor based impedance control approach is developed. In addition, super-twisting sliding mode control (STSMC) is introduced, which can effectively suppress the fluctuation of the contact force and enhance the robustness of the whole system. Eventually, simulation and strategy comparison trials show that the proposed method is effective and superior. [ABSTRACT FROM AUTHOR]

A new method of machining ultrasonic cavitation abrasive flow based on phase control technology was proposed for improving the machining efficiency of the inner wall of TC4 (Ti-6Al-4V) titanium alloy tubes. According to ultrasonic phase control theory and Hertzian contact theory, a model of ultrasonic abrasive material removal rate under phase control technology was established. Using COMSOL Multiphysics 6.1 software, the phase control deflection effect, acoustic field distribution, and the size of the phase control cavitation domain on the inner wall surface were examined at different transducer frequencies and transducer spacings. The results show that the inner wall polishing has the most excellent effect at a transducer frequency of 21 kHz and spacing of 100 mm. In addition, the phased deflection limit was explored under the optimal parameters, and predictive analyses were performed for voltage control under uniform inner wall polishing. Finally, the effect of processing time on polishing was experimented with, and the results showed that the polishing efficiency was highest from 0 to 30 min and stabilized after 60 min. In addition, the change in surface roughness and material removal of the workpiece were analyzed under the control of the voltage applied, and the experimental results corresponded to the voltage prediction analysis results of the simulation, which proved the viability of phase control abrasive flow polishing for the uniformity of material removal of the inner wall of the tube. [ABSTRACT FROM AUTHOR]

Untethered magnetic actuation is an attractive technique for controlling a batch of micrometer‐sized soft robots. Recent advancements have enabled each robot to follow its path independently using a single magnetic device. However, applications of magnetic soft microrobots are mostly biased toward the biomedical field. In this study, thermoplastic polyurethane–Fe3O4 nanocomposite soft spinning microrobots, that is, spinbots that actuate on a tabletop magnetic stirrer, were utilized as innovative precision manufacturing tools for spatially selective precision polishing and cleaning. The pivot motion of the revolving spinbots, which involves repetitive sweeping during rotation cycles, is explored. This sweeping action physically removes nanometer‐sized surface contaminants from the workpiece, achieving a cleaning efficiency of 99.6%. Multiple spinbots, up to 42 in total, simultaneously operated along their own orbital pathways on three vertically stacked wafers, thereby demonstrating an unprecedented cleaning method. In addition, the spinbots precisely removed materials from the workpiece using a three‐body abrasion mechanism. Furthermore, the spinbots contributed to precise material removal, resulting in remarkable surface polishing (Ra ≈ 1.8 nm). This novel polishing system, which uses the collective behavior of multiple spinbots on a tabletop magnetic stirrer, is 1000‐fold lighter than current state‐of‐the‐art equipment aimed at achieving similar levels of fine finishing. [ABSTRACT FROM AUTHOR]

A large variety of ultrafast laser‐matter interaction regimes and different processed surface finishing qualities of stainless steel can be achieved by varying the laser processing parameters. The optimization of the laser fluence to the most efficient ablation also leads to the lowest surface roughness of the ablated material. High laser fluence together with a high pulse repetition rate leads to heat accumulation, which results in the formation of microstructures with various morphology and scales. The use of GHz bursts allows a rough stainless‐steel surface to be smoothed and even polished. In this work, the fast and high‐quality milling of 2.5D cavities is demonstrated. Laser beam spot optimization is used to increase the throughput of the high‐power femtosecond laser (67.8 W), resulting in an ablation rate of 13 mm3 min−1. The complex cavities are produced by laser milling and cutting in layers. The formation of surface structures on stainless steel because of laser irradiation has been demonstrated. The possibilities of further GHz burst polishing are examined on previously laser‐milled stainless steel using with lowest possible surface roughness. The ability to polish the surface with microstructures below the original roughness is demonstrated by bursts of ultrashort pulses with a repetition rate in the GHz range. It has been demonstrated that mold milling in stainless steel designed for LED diffusers can be fabricated using a modern femtosecond laser source together with beam size optimization technique for efficient ablation with low surface roughness, layer‐by‐layer milling techniques, and GHz burst polishing techniques. [ABSTRACT FROM AUTHOR]

Abstract—As a result of studying the mechanism of polishing with a disperse system from micro- and nanopowders for polystyrene scintillators, sludge nanoparticles (SP) and polishing powder wear particles (PP) were established to form due to Förster resonance energy transfer (FRET) occurring in a four-mode regime in the open microresonator formed by the surfaces of a treated material and a polishing powder particle. The disperse phase particles in the polishing disperse system were demonstrated to wear twice faster as compared to treated material removal. The total cross section of SPs scattering on PPs (31.1 Mb) during the scattering of quantum nanoparticles in the open resonator formed by the treated material and lap surfaces was shown to be much larger than the total cross section of PPs scattering on SPs to result in the absence of a deposit from polishing powder wear nanoparticles on the treated surface and the presence of a deposit from sludge nanoparticles on the lap surface. The results of calculating the material removal rate were established to agree with the data of experimental polystyrene polishing rate measurements at a deviation up to 4%, and SP deposit fragments on the lap surface were from 0.2 to 1.0 mm in size and discretely arranged within an annular zone with a radius of 24.5 mm. The polishing of polystyrene based scintillation elements with a disperse system from micro- and nanoparticles was shown to improve the pulse shape discrimination of fast neutrons and gamma quanta by high aspect ratio detectors by 14%. [ABSTRACT FROM AUTHOR]