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Precision grinding is a promising method for machining microstructured surfaces. Controlling microstructured surface geometries provides interesting insights into the optimisation of their usage based on the application fields. This requires an understanding of the effects of the factors influencing the grinding process. The effects of the designed process parameters on the geometries of microstructured surfaces machined using precision grinding is investigated herein. The investigated parameters include the velocity ratio between the workpiece feed rate and wheel cutting velocity, in addition to the grinding depth of cut. First, a mathematical model is developed to correlate the designed grinding parameters and the resultant geometry of the ground microstructured surfaces; furthermore, the geometrical parameters of the surface microstructures are defined. Subsequently, an algorithm and a simulation method are used to illustrate the change in the microstructure geometries with varying operating parameters. Subsequently, precision grinding experiments under various conditions are performed on the surfaces of TC4 titanium alloys for experimental investigations. The obtained microstructure geometries are analysed and compared with those predicted via simulation. The results confirmed the accuracy and ability of proposed strategy in designing and machining the microstructured surfaces with controlled geometry via precision grinding. Finally, the behaviour of the geometrical parameters of the microstructured surfaces based on the investigated operating parameters is discussed.

This study investigates the effects of the structured wheels’ geometrical parameters on the geometries of structured surfaces machined by grinding operations. First, the geometrical parameters of the structured wheels were determined. The resultant geometrical parameters of structured surfaces were defined and related to the designed operating condition, including the structured wheel and grinding process by mathematical and simulation models. The results showed that each wheel’s geometrical parameter affects the structured surface geometry at different rates. Grinding experiments were then performed to explore experimentally how the geometrical parameters of the structured wheel affect the geometry of structured surfaces and verify the modeling and simulation results and explanations. The results showed a remarkable compatibility between the predicted and machined surfaces and reflected the accuracy of the presented method for machining the structured surfaces by grinding.

Recently hydrogels and the treatment of skin wounds based on hydrogel dressings have become one of the research hotspots in the field of skin trauma. In this chapter, we focus on the materials and methods of hydrogel preparation, and discuss the properties that hydrogels should possess for the treatment of wounds. Moreover, we discuss the potential of non-invasive optical imaging techniques in the assessment of cutaneous wound healing. The research results of the application of non-invasive optical techniques such as diffuse reflectance spectroscopy (DRS) and optical coherence tomography (OCT) in scar identification, skin bruising, and skin and vascular structure identification are reviewed. Furthermore, we further discuss the superiority and potential of current artificial intelligence (AI) technology in dermatological diagnosis, and analyze the application status of hydrogel in skin wound treatment. Finally, we believe that the combination of AI and optical imaging technology in the development and efficacy monitoring of hydrogels will be a promising research direction in the future.

Diamond turning, fly-cutting, and milling are the primary manufacturing technologies for generating free-form surfaces; however, they are not sufficiently effective in machining free-form optics on hard and brittle materials. Ultra-precision grinding has been demonstrated to have an outstanding capability in machining difficult-to-cut materials. Therefore, we proposed a novel surface generation technique for free-form optics based on a slow tool servo with diamond grinding wheels (STS-DGW). First, the generation strategies of the wheel path for grinding biconical optics were explored. Subsequently, the generation process of surface topography was theoretically analysed, and the interference between the diamond wheel and biconical optics in the process of surface generation was checked. Eventually, typical biconical free-form optics were fabricated on single-crystal silicon. Submicron profile accuracy and nanometer surface roughness were achieved, and the influence of the processing parameters on the surface topography and material removal mechanism was investigated.

Indium, a low melting point metal, is well-known for constructing eutectic gallium-indium liquid metal. However, unlike liquid metal nanoparticles, the biomedical applications of metallic indium nanoparticles (In NPs) remain in their infancy. Herein, an ultrasound-assisted liquid-reduction synthesis strategy was developed to prepare PEGylated In NPs, which were then used as a high-performance contrast agent for enhancing multiwavelength photoacoustic imaging and second near-infrared (NIR-II) photothermal therapy of the 4T1 breast tumor. The obtained In NPs depicted remarkable optical absorption from the first near-infrared (NIR-I) to NIR-II region and a high photothermal conversion efficiency of 41.3% at 1064 nm, higher than the majority of conventional NIR-II photothermal agents. Upon injection into the tumor, the photoacoustic intensities of the tumor section post-injection were obviously increased by 2.59-, 2.62-, and 4.27-fold of those of pre-injection by using excitation wavelengths of 750, 808, and 970 nm, respectively, depicting an excellent multiwavelength contrast capability of photoacoustic imaging. In addition, efficient ablation of the 4T1 tumor was achieved through the photothermal performance of PEGylated In NPs under NIR-II laser irradiation. Importantly, as the widely used element in the clinic, In NPs were highly biocompatible in vitro and in vivo. Therefore, this work pioneered the biomedical applications of PEGylated In NPs for cancer diagnosis and treatment.

Direct interspecies electron transfer (DIET) has been received tremendous attention, recently, due to the advantages of accelerating methane production via organics reduction during anaerobic digestion (AD) process. DIET-based syntrophic relationships not only occurred with the existence of pili and some proteins in the microorganism, but also can be conducted by conductive materials. Therefore, more researches into understanding and strengthening DIET-based syntrophy have been conducted with the aim of improving methanogenesis kinetics and further enhance methane productivity in AD systems. This study summarized the mechanisms, application and microbial structures of typical conductive materials (carbon-based materials and iron-based materials) during AD reactors operation. Meanwhile, detail analysis of studies on DIET (from substrates, dosage and effectiveness) via conductive materials was also presented in the study. Moreover, the challenges of applying conductive materials in boosting methane production were also proposed, which was supposed to provide a deep insight in DIET for full scale application.

Optical coherence tomography angiography (OCTA) images suffer from inevitable micromotion (breathing, heartbeat, and blinking) noise. These image artifacts can severely disturb the visibility of results and reduce accuracy of vessel morphological and functional metrics quantization. Herein, we propose a multiple wavelet-FFT algorithm (MW-FFTA) comprising multiple integrated processes combined with wavelet-FFT and minimum reconstruction that can be used to effectively attenuate motion artifacts and significantly improve the precision of quantitative information. We verified the fidelity of image information and reliability of MW-FFTA by the image quality evaluation. The efficiency and robustness of MW-FFTA was validated by the vessel parameters on multi-scene in vivo OCTA imaging. Compared with previous algorithms, our method provides better visual and quantitative results. Therefore, the MW-FFTA possesses the potential capacity to improve the diagnosis of clinical diseases with OCTA.

A novel bioelectrochemical reactor assembled with cooperative cathodes of chemical cathode and bio-cathode (BERCC) and excess sludge as the anodic substrate obtained continuous and effective Cr(VI) reduction. Cooperative cathodes in BERCC stimulated the growth of electrochemically active microorganisms such as Geobacter sp. and Shewanella sp. in the anodic biofilm and produced 8.21 ± 0.64 mg C/(L·h) more electrons than the dual chemical cathodes in the bioelectrochemical reactor with dual chemical cathodes, which enhanced the electrons for electricity generation and Cr(VI) reduction by approximately 58.3% and 56.1 ± 5.6%, respectively.

In this study, micro-grooves were fabricated on a chemical vapour deposition (CVD) diamond coating using spray-mist-assisted laser machining. In this paper, the advantages and characteristics of spray-mist-assisted laser machining are analysed through comparison with other forms of laser machining based on morphology and composition. Meanwhile, the effects of process parameters (laser power, scanning speed, defocusing quantity, air pressure, spray angle, and offset distance) on the machining characteristics were investigated using the Taguchi method, and the optimal parameter range of spray-mist-assisted laser-machined CVD diamond coating was obtained. The results indicate that spray-mist-assisted laser machining can effectively remove the recast layer and ensure the precision and continuity of laser machining. The most significant factor affecting the cross-sectional area of the grooves is laser power, while laser power and scanning speed significantly affect depth-to-width (D/W) ratio of grooves. The spray parameters had no significant effect on the characteristics of ablative grooves because the thickness of the water film formed by spray-wall impingement was relatively thin and stabilised.

In a proton exchange membrane fuel cell (PEMFC), effective GDL surface water elimination is significant to water management. This paper used the volume-of-fluid method (VOF) method to carry out simulation research on transferring liquid water in the flow channel with a hydrophilic pipe. The findings indicated that compared with a straight channel, a hydrophilic pipe structure could effectively remove water from the gas diffusion surface (GDL) and reduce the surface water coverage of the GDL. With the increase in the diameter and height of the pipe structure, the GDL surface's water coverage first increased and then decreased, and it was less with the pipe structure than with the direct flow channel. The removal rate of water on the GDL surface was accelerated. The spacing of hydrophilic pipes has a significant impact on the transportation of water. As the spacing increases, the removal rate of water on the GDL surface slowed. A hydrophilic pipe structure with a diameter of 75 μm, a height of 400 μm, and spacing of 300 μm has good water removal performance on the GDL surface. This research work proposes a new internal structure design of the flow channel, which has specific implications for removing water on the GDL surface.

Biconical optics with excellent profile accuracy and bright surface finish are increasingly applied in the fields of aviation, aerospace, biology, consumer electronics, etc. However, the extreme demand of micron/sub-micron scaled profile accuracy of the biconical optics poses a great challenge for the manufacturing process. In this study, a novel compensation strategy was developed based on the on-machine non-contact laser displacement sensor and wavelet decomposition technique for depressing the final profile error of biconical optics machined by raster grinding. Firstly, a profile error evaluation model was established to restructure the error surface measured by the laser sensor, and the low-frequency profile error was separated successfully from the reconstructed errors using the proposed technology. Secondly, the momentous error sources that affect the profile accuracy were identified and analyzed, and a wheel-error model was established based on the correspondence between the error sources and the profile errors, which is then applied for the wheel path compensation. Finally, the compensation experiments were undertaken. The profile errors along the workpiece length (220 mm) and workpiece height (105 mm) decreased from 15.425 μm to 1.678 μm and 18.6 μm to 1.6948 μm, respectively. The PV-values of the machined surface with profile error compensation reduced from 21.6 μm to 1.5486 μm in a 220m × 105 mm measurement area. This demonstrates the effectiveness of the proposed profile error compensation methods for the biconical surface.

Optical coherence tomography (OCT) is a non-invasive imaging technique which has become the “gold standard” for diagnosis in the field of ophthalmology. However, in contrast to the eye, nontransparent tissues exhibit a high degree of optical scattering and absorption, resulting in a limited OCT imaging depth. And the progress made in the past decade in OCT technology have made it possible to image nontransparent tissues with high spatial resolution at large (up to 2mm) imaging depth. On the one hand, OCT can be used in a rapid, noninvasive way to detect diseased tissues, organs, blood vessels or glands. On the other hand, it can also identify the optical characteristics of suspicious parts in the early stage of the disease, which is of great significance for the early diagnosis of tumor diseases. Furthermore, OCT imaging has been explored for imaging tumor cells and their dynamics, and for the monitoring of tumor responses to treatments. This review summarizes the recent advances in the OCT area, which application in oncological diagnosis and treatment in different types: (1) superficial tumors:OCT could detect microscopic information on the skin’s surface at high resolution and has been demonstrated to help diagnose common skin cancers; (2) gastrointestinal tumors: OCT can be integrated into small probes and catheters to image the structure of the stomach wall, enabling the diagnosis and differentiation of gastrointestinal tumors and inflammation; (3) deep tumors: with the rapid development of OCT imaging technology, it has shown great potential in the diagnosis of deep tumors such in brain tumors, breast cancer, bladder cancer, and lung cancer.

Three new chlorinated compounds, including two propenylphenol derivatives, chlorophenol A and B (

In this study, carbon emissions in three full-scale wastewater treatment plants were determined by the emission factor method. Moreover, the correlation between basic parameters (influent water parameters and pollutant removal efficiency) and carbon emissions was examined via a structural equation model (SEM). The results showed a significant variation in the total carbon emission intensity of plants over time. The average total carbon emission intensity of plants A, B and C were 0.314, 0.404 and 0.363 kg eqCO2/m³, respectively. Meanwhile, the indirect carbon emission caused by energy and chemical agent consumption accounts for the majority of total carbon emissions (about 85%). Generally, statistical analysis results show that carbon emission intensity is positively correlated with pollutant removal efficiency. Notably, RTN showed the highest positive correlation with Eind, followed by RTN > RCODCr > RTP > TN > RNH3-N > NH3-N > TP. Moreover, capacity showed the greatest negative contribution to Eind, followed by CODCr. In contrast, the positive contribution to Edir was followed by the sequence of RTN > RCODCr > TN > RNH3-N > NH3-N. Notably, CODCr showed a significantly negative correlation with Edir, while TP and its removal showed little correlation with Edir.

Sludge treatment wetland-microbial fuel cells (STW-MFCs) are a unique sludge treatment process that produces bioelectricity, but its technology is still in its infancy. This study investigated the electrochemical properties, organic matter characteristics, leachate purification, and microbial community structure of STW-MFCs as affected by electrode location. When electrodes were placed in the filler layer, the STW-MFC system presented a higher power generation capacity (maximum output power density: 0.498 W/m

In this research, a strategy to design structured grinding wheels to machine designed structured surfaces in micro-scale through the grinding process is investigated. Firstly, the geometry of the microstructured surface is defined. A mathematical model to describe the geometry of the structured grinding wheel and the grinding parameters is presented according to the geometry of the designed microstructures on the workpiece surface. And then, several operating conditions for the grinding operation are mathematically determined and kinematically simulated using a proper programming language to produce the designed geometry of the microstructured surface. The errors in the simulated geometries of the machined microstructures are calculated and analyzed. Finally, the reasons for deviation and ability to minimize error sources are investigated.

In order to achieve high-efficiency machining of Fresnel microstructure, an improved laser scanning contour ablation (LSCA) method with continuously variable feedrate was proposed based on the theoretical model of the material removal depth. The silicon carbide (SiC) Fresnel microstructure was machined by the improved LSCA method and characterized by multiple means. The experimental results showed that the crystallinity of SiC decreased and amorphous Si and SiO2 were generated on the SiC Fresnel microstructure. The form profile error PV was less than 5 μm, the average verticality error of the step sidewall was 34.6°, the surface roughness was Sa 0.237 μm–0.343 μm, the subsurface cracks depth was 1–1.5 μm. The material removal rate (MRR) of machining SiC Fresnel microstructure by using the improved LSCA method could achieve 0.2875 mm3/min, which was much higher than the MRR of mechanical machining and reflected the efficiency advantage of laser to process hard and brittle materials.

Input-series-output-parallel (ISOP) converter system is suitable for high-input voltage applications owing to the reduced voltage stress of power switches. This article proposes an ISOP converter system with two-stage dc–dc converter as the basic module, which is composed by a non-isolated dc–dc converter and an isolated dc–dc converter. The isolated dc–dc converter functions as a dc transformer (DCX), and the non-isolated dc–dc converter serves as the pre- or post-regulator to regulate the output voltage. With this arrangement, a common duty ratio is applied to all the pre-or postregulators, and natural input-voltage sharing (IVS) and output-current sharing (OCS) can be achieved. The LLC resonant converter is adopted as the DCX, and the design considerations are given for achieving a nearly constant voltage gain even if there is parameters drift. Meanwhile, the non-isolated converter has simple topology and the parameters are easy to be identical. Thus, the proposed ISOP converter system realizes excellent IVS and OCS even the constituent modules are not well matched. Furthermore, the improved ISOP converter system employing boost+ LLC resonant converter is proposed. Two 12-kW ISOP converter systems have been fabricated and tested in the lab, and the experimental results are provided to verify the natural voltage sharing of the proposed ISOP converter system.

Diamond micro/nano-pillar is widely applied in quantum transportation and nanomechanics, but it is very difficult to be machined by conventional mechanical methods, duo to its feature of high hardness, wear-proof and extremely small scale. Thus, a novel strategy of galvanometer-assisted femtosecond laser milling (GFM) was proposed to overcome the difficulty of fabricating the micro-pillar with high aspect ratio on monocrystalline diamond. Through numeric calculation, it is found that GFM trajectory possesses the special distribution consisting of separate pulse-concentrated regions and expanded flat-distributed region, which was then experimentally proved beneficial for improving the energy consumption and highly promoting the material removal rate. Moreover, the GFM was found to be much easier to generate micro-pillar, whereas in the case of conventional non-galvanometer milling (NGM) micro-pillar underwent severe degeneration or height loss under various average laser powers. Through optimizing the machining parameters, the micro-pillar was successfully prepared with an aspect ratio of as high as 42.25 by GFM. A 5 × 5 micro-pillar array of monocrystalline diamond was also fabricated with consistent diameter, height and aspect ratio. With Raman spectroscopy, the graphitization induced by GFM was slight, though it was unavoidably introduced with relatively high average laser power. Besides, the graphitizing level on the lateral face of the machined micro-pillar was found to non-linearly change with different machining parameters, because the material removal mode underwent a transformation from graphitization dominated to sublimation dominated with the increasing of applied energy density.

Inadequate mixing has been proven to be a major cause of anaerobic digester failure. This study revealed the mechanism of mixing intervals on high-solids anaerobic co-digestion (HS-AcoD) of food waste (FW) and sewage sludge (SS). Optimized intermittent mixing time (15 min/h) was determined through computational fluid dynamics (CFD) simulation. Experimental results indicated that the simulated intermittent mixing could shorten digestion time and increase cumulative methane output (366.8 mL/gVS) compared with continuous mixing and unmixing. Mixing could considerably accelerate substrate solubilization and hydrolysis. Maximum rates of acidogenesis (53.35 %) and methanogenesis (49.41 %) were observed with an optimized intermittent mixing (15 min/h). Vigorous mixing induced apoptosis and disrupted syntrophic metabolism, whereas intermittent mixing promoted the syntrophic metabolism between Syntrophomonas and Methanobacterium, and led to an enrichment of genes involved in acidogenic and methanogenic pathways. These findings have important implications for the development of an optimized intermittent mixing strategy for maximizing HS-AcoD efficiency of FW and SS.

Dissolved organic matter (DOM) plays a pivotal role in the biogeochemical cycles of elements and the regulation of forest ecosystem functions. However, studies on the regional and seasonal characteristics of DOM in cold-temperate montane forests are still not comprehensive. In this study, samples of water, soil, and sediment from different sites in the forest drainage basin were collected, and their DOM was characterized by an excitation-emission matrix and parallel factor analysis (EEM-PARAFAC). The results showed that terrestrial-sourced humic-like substances were the dominant DOM in the studied reservoir and inflowing rivers. The quality and quantity of DOM exhibited spatiotemporal variations with the influence of terrain and monsoonal precipitation. The average concentration of dissolved organic carbon (DOC) in the wet season was 11.62 mg/L, which was higher than that in the dry season (8.18 mg/L). Higher humification index (HIX) values were observed in the wet season and upstream water than in the dry season and reservoir water. Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) was used to further develop a molecular-level understanding of the in situ degradation process of DOM. The results indicated that photodegradation rather than biodegradation may play a dominant role in the in situ degradation of terrestrial-sourced humic-like substances under natural conditions. The biodegradability of DOM was enhanced after the in situ degradation process. Additionally, a significant decrease in the precursors of disinfectant byproducts in DOM was observed after in situ degradation. To our knowledge, this is the first study of the sources, characteristics, and in situ degradation of DOM in a reservoir in a cold-temperate forest. These findings help better understand the quality, quantity, and biogeochemical process of DOM in the studied reservoir and may contribute to the selection of drinking water treatment technologies for water supply.

Two-dimensional transition metal dichalcogenides have attracted widespread attention in cancer theranostics due to their high specific surface area and excellent photothermal conversion properties. However, their dimensions and biodegradability have limited the exploration of the therapeutic properties of transition metal dichalcogenides. Herein, we explore the mechanism of the keratin α-helix-to-random coil transition, as an actuation mechanism for the controllable design and precise synthesis of two-dimension copper sulfide nanoflakes (CuS NFs) with high absorption in the NIR-II window. Upon mixing keratin and Cu