Wide Angle Research Articles

Ultra-broadband polarization-insensitive versatile solar thermal harvester

Sustainable and Renewable Energy is essential because it's non-polluted and available in nature. Solar energy is the most important of them all as its the essential of them all. Sun energy is a clean and finest alternative to renewable energy sources. The slotted cylinder-shaped Mxene-based resonator solar absorber (SCMRSA) achieved an average of 95.06 % efficient absorption. The MXene material is used as a resonating material above the titanium oxide layer based on the MXene layer. The wide angle of incidence is achieved which is analyzed by changing the different angles of incidence. The E-field response is also observed for the TE and TM modes. The results show a similar response for both TE and TM modes. The optimization of the structure is also observed for different variable variations and the final optimized design is used for the highly efficient absorptance results. The SCMRSA is also applicable for various solar thermal applications and energy harvesters.

Determining Chin Dimensions for Feminizing Genioplasty: An Anatomic Study.

Feminizing genioplasty warrants chin modification to achieve feminine characteristics. This study compared female and male facial skeletal dimensions and shape to guide feminizing genioplasty. Skulls stored at the Cleveland Museum of Natural History were analyzed. Sex, age, and race were documented. Heights and widths of the face and chin were measured, normalized, and compared. Forty-three male (43.58±12.52-y-old) and 43 female (40.48±12.04-y-old) skulls were included. Within each group, 25 skulls were of African American (AA) origin and 18 were of Caucasian (C) origin. Absolute chin heights were larger in AA and C males compared with females (P<0.05). After normalization to lower facial height, there was a trend toward greater chin height in AA males compared with females (P=0.07). Parasagittal chin width in AA males was significantly larger than AA females (P=0.0006). Interforaminal chin width in C males trended toward being significantly larger than females (P=0.08). Following normalization of chin widths, no significant sex-based differences were noted for AA skulls except for the interforaminal/intergonial ratio, which was smaller in AA males (P=0.04). For C skulls, most normalized ratios were significantly smaller in males (P<0.05). C females had wider angles at the point of maximum chin projection (P=0.007) and wider symphyseal inclinations (P<0.0001). These differences were not present in AA skulls (P>0.05). Regardless of race, male chins appeared square, whereas female chins were round. While chin width reduction is not needed for most patients, height reduction could be considered. Chin contouring is the most central component of feminizing genioplasty.

Development of ITER first wall heat load feedback control

Real-time monitoring and control of thermal loads on tungsten plasma-facing components is mandatory for ITER to avoid their overheating during plasma discharges. For the Start of Research Operations (SRO) phase, dedicated First Wall Heat Load Control (FWHLC) functions are included in the ITER Plasma Control System (PCS) to prevent the development of excessive plasma heat loads on the inertially cooled first wall (FW). In this work, we propose a FWHLC design with a model-based approach, which features a simplified thermal model for the FW armour. This control-oriented model simulates the thermal response of ITER FW to slow changes in plasma equilibrium and energy, which during ITER operation will be monitored by the real-time wide angle infrared camera system. This allows computationally efficient runs for rapid controller performance assessment but can also assist operation scenario design by pre-empting potential heat load issues. FWHLC is designed to react to measured and predicted FW temperatures overcoming predesigned limits with real-time variations of the plasma shape or auxiliary power references, aiming to reduce thermal loads before a premature plasma termination is required to protect the FW. The new scheme is tested in closed loop simulations, where perturbations to nominal ITER low current scenarios are introduced in the wall thermal model to trigger the response of FWHLC, supporting the effectiveness of the proposed policy.

Preparation of Panchromatic Silver Halide Emulsion to Fabricate High Efficiency Multiplexed Volume Phase Holograms for Solar Concentration Application

Volume Phase Gratings (VPG) are often recorded using holographic emulsions such as photopolymer, Dichromated Gelatin (DCG), and silver halide. We employed silver halide emulsion to record the VPG in monochromatic red wavelength for solar concentration purposes. According to the Braggs condition, the recorded VPG's diffraction efficiency reaches its peak at the recorded angle and wavelength. For solar applications, we needed high diffraction efficiency over a wide angle and wavelength range. So, we captured multiplexed single VPG in our own panchromatic silver halide emulsion. The procedure of making panchromatic silver halide emulsion is described in depth. This technique is unique in that it achieves peak diffraction efficiency at broad wavelength and wide angle in a single multiplexed VPG. The panchromatic multiplexed VPG produced a high diffraction efficiency in wide-angle response with overall visible wavelengths. This study describes the high diffraction efficiency multiplexed VPG in its own manufactured panchromatic silver halide emulsion for solar concentrating applications.

Differences in structural optical coherence tomography and infrared enface images between non-exudative macular neovascularizations secondary to AMD and pachychoroid disease.

To provide an analysis of structural optical coherence tomography (OCT) and enface infrared reflectance (IR) differences between non-exudative macular neovascularizations (NE MNVs) secondary to age-related macular degeneration (AMD) and NE MNVs secondary to pachychoroid spectrum. Patients diagnosed with NE-MNV documented by OCTA and dye angiography in the context of either AMD or pachychoroid spectrum were retrospectively included in AMD group and PACHY group respectively. Only treatment-naïve NE MNVs showing persistence of non-exudative status for at least 1 year after diagnosis were considered. Availability of good quality structural OCT B scan and IR enface acquisitions both at baseline and at 1 year follow up was also required. The study population included 15 eyes of 15 patients in AMD group and 13 eyes of 13 patients in PACHY group. AMD group showed at baseline a significantly wider pigment epithelium detachment (PED) apex angle (p = 0.02), higher homogeneity of the PED (p = 0.015), higher PED shadowing(p = 0.03). Both groups experienced a widening of apex angle (flattening of the PED) during follow-up. Ten (76.9%) patients in PACHY group showed a hyporeflective halo at the margins of the PED at baseline compared to 3/15 (20.0%) patients in AMD group (0.007), with no significant changes at 1 year follow up (p = 0.47). NE-MNVs in pachychoroid eyes are characterized by sharper and more inhomogeneous PEDs with a lighter choroidal shadowing compared to NE-MNVs in AMD eyes. Moreover, they often show a hyporeflective halo around the lesion with IR imaging.

The location of cationic substitutions in carbonated biomimetic apatites significantly affects crystal nanomechanics

Bone and teeth are comprised of carbonate-substituted apatites with cationic substitutions, like sodium and potassium. Cations substitute for calcium in the apatite lattice but it is unclear whether they substitute for Ca(1) or Ca(2). Additionally, although we know that anionic substitutions affect the mineral mechanics, it is unclear how cationic substitutions affect mineral stiffness. Here, a combined experimental and theoretical approach using in situ fluid-mediated hydrostatic loading with synchrotron Wide Angle X-ray Scattering (WAXS) and Density Functional Theory (DFT) is used to elucidate the role of CO32− and Na+ or K+ co-substitutions on the atomic structure and mechanics of biomimetic apatites. Comparison of WAXS and DFT results showed that preferential substitutions at the Ca(1) and Ca(2) sites depended on cationic type and concentration, with a preference for Ca(1) at higher levels of co-substitution. Substitution levels and location of the cationic substitution both significantly affected the modulus of the minerals. This presents a new paradigm for the development of biomimetic apatites with multi-property tunability by considering composition and atomic organization.

Enhancing bending strength in continuous drive friction welding of PEEK polymer cylinders through the innovative progressively increased welding area method

The continuous drive friction welding (CDFW) stands out for its low energy consumption within the welding realm. Polyetheretherketone (PEEK) represents a high-performance engineering thermoplastic, falling under the polyaryletherketone family. Renowned for its outstanding mechanical, thermal, and chemical attributes, PEEK finds utility across a diverse array of industries. However, the discovery of numerous voids at the weld interface has revealed limitations in the mechanical properties of PEEK welded samples. This study introduces an innovative approach named progressively increased welding area (PIWA) method, to mitigate voids within the weld interface. In general, the Taguchi method was used to optimize the process parameters of CDFW of dissimilar PEEK round rods to reduce random efforts by the trial-and-error method. It was found that the proposed PIWA method can definitely enhance the bending strength of rotational friction welded samples due to reduction of voids inside the weld interface. The optimal process parameters for the CDFW with the PIWA method involve a rotational speed of 2500 rpm, a cone angle of 120°, a cone top width of 8 mm, and a feed rate of 0.1 mm/s. The most influential factor affecting the bending strength of the PEEK welded samples is the feed rate, followed by cone angle, rotational speed, and cone top width. Specifically, the contribution ratios for feed rate, cone angle, rotational speed, and cone top width are about 71 %, 20 %, 7 %, and 2 %, respectively. The confirmation tests showed that the bending strength of the PEEK welded samples using optimal process parameters can be increased by approximately 68 % compared with the maximum bending strength of 180 MPa using the conventional method with a cone angle of 180° The proposed PIWA method has industrial applicability and practical value because this technique can enhance the mechanical properties of PEEK welded samples under low environmental pollution and energy consumption.

Impact of Acute Short-term Hypobaric Hypoxia on Anterior Chamber Geometry

Précis: Hypobaric hypoxia, the major environmental factor at high altitudes, has been observed to induce pupil miosis and widening of the anterior chamber angle. This environment may be safe for individuals with narrow angle and deserves further study. Purpose: This study aimed to quantify anterior chamber biometric parameters before and after acute short-term, effortless exposure to hypobaric hypoxia (HH) in healthy lowlanders using swept-source anterior segment optical coherence tomography (SS AS-OCT). Methods: This prospective study included 25 healthy young lowlanders (50 eyes) who underwent SS AS-OCT measurements and intraocular pressure (IOP) assessments under baseline sea-level conditions (T1).They were then passively exposed to simulated 4000 m above sea level for 3 hours and underwent Acute mountain sickness (AMS) symptoms evaluation and IOP measurement after 2-hours exposure to HH (T2).Repeat SS AS-OCT measurements and IOP assessments were taken within 15 minutes after leaving the hypobaric chamber (T3). Anterior segment parameters including anterior chamber depth (ACD),lens vault (LV),angle opening distance (AOD500), trabecular-iris space area (TISA500), angle recess area (ARA500) at 500 μm from the scleral spur, iris curvature (IC), iris volume (IV), pupil diameter (PD), and central corneal thickness (CCT) were obtained through SS AS-OCT. These repeated measurements were compared using linear mixed model analysis. Results: In comparison to sea level, both IOP (16.4±3.4 vs. 14.9±2.4 mm Hg, P=0.029) and PD (5.36±0.77 vs. 4.78±0.89 mm, P=0.001) significantly decreased after exposure to HH. Significant post-HH changes (Mean difference (95% CI)) were observed in AOD500 (0.129 (0.006, 0.252), P=0.04), TISA500 (0.059 (0.008, 0.11), P=0.025), ARA500 (0.074 (0.008, 0.141), P=0.029), IV (1.623 (0.092, 3.154), P=0.038), and IC (−0.073 (−0.146, 0.001), P=0.047), while CCT, ACD, and LV remained stable. After adjusting for age, post-HH variations in AOD500 (Beta=0.553, 95% CI: 0.001, 1.105, P=0.048) and TISA500 (Beta=0.256, 95% CI: 0.02, 0.492, P=0.034) were associated with decreased IC but were not related to lowered arterial oxygen pressure or IV increase per millimeter of pupil miosis (IV/PD). These differences in anterior segment parameters were neither correlated with differences in IOP nor AMS. Conclusion: After short-term, effortless exposure to hypobaric hypoxia, pupil miosis occurred with widening of the anterior chamber angle and decreased IC. These changes in anterior chamber angle parameters were associated with decreased IC but did not correlate with the post-hypobaric variations in IV/PD, IOP, or AMS.

Incidence Angle Effect: Validation of New Measurement Methods for IEC 61853‐2

ABSTRACTThe incidence angle effect causes a decrease in the photogenerated current of PV modules when they are subject to incident irradiance at wide angles: Its relevance should be quantified for accurate energy yield purposes and has recently gained significance due to the rising interest in novel integrated PV applications, where vertical or nonoptimal tilt are favored (e.g., in urban structures, in agrivoltaics, and vehicles). The international standard IEC 61853‐2 presents both outdoor and indoor measurement methods: However, the indoor measurement method for commercial‐size modules is often impractical due to irradiance uniformity limitations on the volume spanned by the tested module upon rotation in most of the solar simulators available on the market. In recent years, new solutions have been proposed to overcome these limitations and allow wider adoption of this standard: However, method validations and interlaboratory comparisons have been conducted so far only on small‐area samples, and a real validation on commercial‐size modules is still missing. In this work, we aim at filling this gap, reporting the results of an interlaboratory comparison conducted within the international project team that is currently working at the new edition of IEC 61853‐2. The results show a remarkable agreement between different measurement methods, thus validating more options for the evaluation of this important effect.

Symmetric engineered central cross-shaped broadband metamaterial absorber with high absorption and stability for solar sailing and solar energy applications

We propose a theoretical design and analysis of a broadband metamaterial absorber (MMA) with significant potential for solar sailing applications which is a method of spacecraft propulsion that usages the momentum of sunlight to propel a spacecraft through space. The absorber features a metal-dielectric-metal configuration with a tungsten (W) based resonator and ground plane, and a Silicon-dioxide (SiO₂) substrate. Addressing the critical need for materials that can efficiently harness solar radiation for propulsion in space, our design achieves an average absorption of 99.15 % over a broad spectrum from 250 nm to 1200 nm, covering the UV–Visible–NIR regions, with near-unity absorption peaks at 362 nm and 915.8 nm. It maintains high absorptions of 84.9 % and 86 % under transvers electric and transvers magnetic modes respectively, demonstrating excellent wide incident angle stability and polarization insensitivity due to its symmetric design. PCR values close to zero confirm its functionality as an absorber rather than a polarizer. The MMA shows minimal deformation across temperatures from 500 K to 1750 K and remains stable under various mechanical stresses, proving its durability and efficiency in space. Additionally, in solar thermophotovoltaic (STPV) systems, the MMA demonstrates high photothermal conversion efficiency (PTCE) over a wide temperature range (500 °C to 1500 °C) and different concentration factors. This dual functionality highlights its potential for both efficient space exploration and terrestrial solar energy harvesting, making it a versatile tool for future technological applications.

Effect of nozzles on disease control with spraying fungicides in soybean crops

ABSTRACT The productivity of the soybean crop (Glycine max) can be limited by several factors, including diseases. In the integrated management of diseases, one of the strategies used is chemical control. The aim of this experiment was to evaluate the influence of spray nozzle types on the chemical control of fungal diseases in soybean plants. The experimental design was randomised blocks, with six treatments and four replications. The treatments consisted of control (without fungicide application on soybean plants) and application of fungicides with different spray nozzles: hollow cone jet, double flat jet, extended range flat jet, wide angle flat jet and air induction flat jet. The sprayer used was the backpack pressurised by carbon dioxide CO2. The experiment was installed in the Campos Gerais region (Paraná, Brazil); during three cropping seasons. The evaluated variables were incidence and severity, spray quality (covered area, droplet density, and relative amplitude) and yield components. It was concluded that the chemical control of fungal diseases in soybean plants reduced the proliferation of pathogens and losses in crop yield. There were significant changes in spraying quality in all analysed variables. There were no differences among the spray nozzle types regarding the analysis of incidence, severity and soybean yield components.

A wide angle beam scanning CRLH leaky-wave antenna with non-identical elements per unit-cells

In this research article, a wide-angle scanning leaky-wave antenna (LWA) based on the composite right/left-handed (CRLH) metamaterial (MTM) operating over the C-band spectrum for mobile applications is proposed, investigated, and realized. The proposed LWA includes nine CRLH-MTM-based unit-cells. The properties of CRLH-MTM have been applied using series slots and shunt metallic via-holes. Each unit cell consists of three patches, two external patches, and one smaller middle patch implemented between them. One slot has been etched on each external patch; the width of these two slots is unequal. Moreover, the distance of the middle patch with each side patch is different. The results show that using this method of realizing non-identical elements caused the achievement of proper return-loss at the transition frequency and provided the balanced CRLH metamaterial condition. Additionally, using CRLH-MTM properties by realizing series capacitance (slot) and shunt inductance (via-holes) made the wide-angle scant from backward to forward radiation pattern. The results demonstrate that the LW antenna with small dimensions of 251.5 × 30 × 1.575 mm3 operates over a frequency range of 4.8–6.13 GHz covering a wide beam scanning range from −63° to +65° with broadside radiation at the center frequency of 5.46 GHz. The radiation gain of the proposed antenna varies from 6.2–13.1 dB. The achievements confirm the effectiveness of the proposed methods to realize a high-performance LW-antenna with the advantages of simple design, low profile, low cost, and easy of manufacture for mobile applications.

The high-Q THz stereo metasurface sensor based on double toroidal dipole with wide operating angle bandwidth

A highly sensitive terahertz stereo metasurface sensor, characterized by a high quality factor (Q-factor) and based on dual toroidal dipole (TD) resonance, has been proposed. The optimal structural parameters are ascertained by comparing the pertinent parameters of the stereo and planar structures in relation to TD modal excitation. The effective excitation of the TD mode is demonstrated using the calculations of multipole scattered power, reflection spectra, surface currents, electric fields, and magnetic field distributions. It is crucial that the stereo metasurface exhibits simplicity and that the dual TD resonance can be readily excited through simple adjustments in the distance and height of the intermediate gap. It also demonstrates exceptionally high sensitivity and Q-factor, both of which are essential for sensing applications. Moreover, the proposed stereo terahertz metasurface sensor still shows excellent sensing performance in a wide range of incidence angles (±40°), which is of great significance for practical applications. In conclusion, this structure offers a novel design framework for high-performance terahertz sensors based on the TD mode.

GdWN3 is a nitride perovskite

Nitride perovskites ABN3 are an emerging and highly underexplored class of materials that are of interest due to their intriguing calculated ferroelectric, optoelectronic, and other functional properties. Incorporating novel A-site cations is one strategy to tune and expand such properties; for example, Gd3+ is compelling due to its large magnetic moment, potentially leading to multiferroic behavior. However, the theoretically predicted ground state of GdWN3 was a non-perovskite monoclinic structure. Here, we experimentally show that GdWN3−y crystallizes in a perovskite structure. High-throughput combinatorial sputtering with activated nitrogen is employed to synthesize thin films of Gd2−xWxN3−yOy with oxygen content y &amp;lt; 0.05. Ex situ annealing crystallizes a polycrystalline perovskite phase in a narrow composition window near x = 1. LeBail fits of synchrotron grazing incidence wide angle x-ray scattering data are consistent with a perovskite ground-state structure. Refined density functional theory calculations that included antiferromagnetic configurations confirm that the ground-state structure of GdWN3 is a distorted Pnma perovskite with antiferromagnetic ordering, in contrast to prior predictions. Initial property measurements find that GdWN3−y is paramagnetic down to T = 2 K with antiferromagnetic correlations and that the absorption onset depends on cation stoichiometry. This work provides an important path toward both the rapid expansion of the emerging family of nitride perovskites and understanding their potential multiferroic properties.

Investigation of the effect of elbow pipes of Ti6Al4V, 304 stainless steel, AZ91 materials on erosion corrosion by finite element analysis

Corrosion is the degradation of metals caused by chemical or electrochemical reactions with their environment. As a result of these reactions, undesirable conditions occur in the physical, chemical, mechanical and electrical properties of metals. These conditions cause parts made of metallic materials to become unusable. Erosion corrosion is one of the most common types of corrosion in fluid transfer. There are several methods for preventing erosion corrosion. First of all, some precautions should be taken to prevent wear. Intervention is very important in terms of cost, especially at the design stage. Measures such as wide angle bends, wall thickness of wear-resistant material and corrosion allowance can be taken, especially in applications where the flow direction needs to be changed. The aim of this study was to determine the effect of liquid fluid on erosion corrosion in Ti6Al4V, 304 stainless steel and MgAz91 elbow pipes by using the computer aided and finite element based AnsysWorkbench Explicit Dynamics module. For the design of the elbow pipe, SolidWorks was used for 3D studies. In the analysis of the pipe, the suitability of the pipe for the 3D model was examined. The effect of fluid rotation on the pipe walls and the effect of the pipe material on the flow along the pipe were determined. The standard k-e model based on the velocity-pressure relationship in continuous and steady flow was used for the flow calculations. The flow simulation showed that for all models the flow accumulation after rotation was more concentrated on the opposite walls of the pipe, as expected. The results obtained showed that the deformation in MgAZ91 material had the highest value at 9.14 × 10−8 mm. This situation has been interpreted to mean that it may vary depending on the flow rate automation. Designs on the old designs in the erosion structure of the liquid that occurs in the pipes with a new product design in the analysis design.

Assessing the effect of offline topography on electrical resistivity measurements: insights from flood embankments

Summary Electrical resistivity tomography (ERT), a geophysical imaging method, is commonly used on flood embankments (dykes or levees) to characterise their internal structure and look for defects. These surveys often use a single line of electrodes to enable 2D imaging through the embankment crest, an approach that enables rapid and efficient surveying compared to 3D surveys. However, offline variations in topography can introduce artefacts into these 2D images, by affecting the measured resistivity data. Such topographic effects have only been explored on a site-specific basis. If the topographic effects can be assessed for a distribution of embankment geometries (e.g. slope angle and crest width) and resistivity variations, it would allow for targeted correction procedures and improved survey design. To investigate topographic effects on ERT measurements, we forward-modelled embankments with different trapezoidal cross-sections sat atop a flat foundation layer with contrasting resistivity values. Each was compared to a corresponding flat model with the same vertical resistivity distribution. The modelling workflow was designed to minimise the effect of forward modelling errors on the calculation of topographic effect. We ran 1872 unique embankment forward models, representing 144 geometries, each with 13 different resistivity contrasts. Modelling results show that offline topography affects the tested array types (Wenner-Schlumberger, Dipole-Dipole, and Multiple-Gradient) in slightly different ways, but the magnitudes are similar, so all are equally suitable for embankment surveys. Three separate mechanisms are found to cause topographic effects. The dominant mechanism is caused by the offline topography confining the electrical current flow, increasing the measured transfer resistance from the embankment model. The two other mechanisms, previously unidentified, decrease the measured transfer resistances from the embankment model compared to a layered half-space but only affect embankments with specific geometries and resistivity distributions. Overall, we found that for typical embankment geometries and resistivity distributions, the resistivity distribution has a greater control on the magnitude of the topographic effect than the exact embankment geometry: the subsurface resistivity distribution cannot be neglected. 2D inversions are suitable when both the embankment is more resistive than the foundations and when the embankment's cross-sectional area is greater than 4 m2/m2 (area scaled to an embankment with a height of 1 m). Topographic corrections, 3D data acquisition or 3D forward models are required when these conditions are not met. These are demonstrated using field data from an embankment at Hexham, Northumberland, UK. Improving the accuracy of the resistivity values in ERT models will enable more accurate ground models, better integration of resistivity data with geotechnical datasets, and will improve the translation of resistivity values into geotechnical properties. Such developments will contribute to a better characterised and safer flood defence network.

The nano-organization structure of triple fluorocopolymer

Three nanostructures with size 37–130 nm discovered in the triple fluorocopolymer with different temperature past by X-ray pattern at small and wide angles. Two level of order nano-organization are determined which change with phase transitions above glass transition. The conformation TGTG′ of vinyledenfluoride microblockes passage in conformation zigzag at the ρ3′–ρ5′ transitions in triple fluorocopolymer different from polyvinyldifluoride.

Do anomalously dense hot Jupiters orbit stealth binary stars?

ABSTRACT The Wide Angle Search for Planets (WASP) survey used transit photometry to discover nearly 200 gas-giant exoplanets and derive their planetary and stellar parameters. Reliable determination of the planetary density depends on accurate measurement of the planet’s radius, obtained from the transit depth and photodynamical determination of the stellar radius. The stellar density and hence the stellar radius are typically determined in a model-independent way from the star’s reflex orbital acceleration and the transit profile. Additional flux coming from the system due to a bright, undetected stellar binary companion can, however, potentially dilute the transit curve and radial velocity signal, leading to underestimation of the planet’s mass and radius, and to overestimation of the planet’s density. In this study, we cross-check the published radii of all the WASP planet-host stars, determined from their transit profiles and radial velocity curves, against radiometric measurements of stellar radii derived from their angular diameters (via the infrared flux method) and trigonometric parallaxes. We identify eight systems showing radiometric stellar radii significantly greater than their published photodynamical values: WASPs 20, 85, 86, 103, 105, 129, 144, and 171. We investigate these systems in more detail to establish plausible ranges of angular and radial velocity separations within which such ‘stealth binaries’ could evade detection, and deduce their likely orbital periods, mass ratios, and flux ratios. After accounting for the dilution of transit depth and radial velocity amplitude, we find that, on average, the planetary densities for the identified stealth binary systems should be reduced by a factor of 1.3.

A comprehensive study on active mixer performance using liquid metal droplets: an experimental approach

In this experimental study, we delve into the performance of an active mixer that utilizes liquid metal droplets. Our mixer configuration follows an innovative Y-type design, where two liquid metal-based pumping mechanisms operate within the minichannel inlet branches. By applying alternating current voltage to both sides of the liquid metal, we induce a surface tension gradient, propelling the fluid from the reservoirs toward the minichannel. Notably, the two entering liquids are distinctly colored, allowing us to quantify mixing using a Mixing Index (MI) definition and image processing techniques. Our investigation centers on four key variables governing mixer performance: applied voltage, liquid metal droplet diameter, input angle between the branches, and minichannel width. Given the experimental nature of our research, we employ a central composite design method within the framework of design of experiments (DoE). From our obtained experimental results, we establish correlations between MI and the other variables. Our examination of the four mentioned parameters revealed that liquid metal droplet diameter exerts the most significant influence on the mixing index. Following this, in descending order of impact, we find applied voltage, input angle, and channel width. In the optimal dimensions of our mixer, we achieve a remarkable maximum MI of 0.867.

Wheel path planning for flute grinding of non-cylindrical solid end-mills based on circular arc projection

Flute grinding is a crucial process in solid end-mill manufacturing, because the generated flute parameters, i.e. helix angle, rake angle, core radius, and flute width, have significant effects on the cutting performance of end-mills. However, the flute grinding of non-cylindrical solid end-mills is still challenging due to the variation of the flute parameters along the tool axis. This paper proposes an accurate and efficient method of wheel path planning for flute grinding of non-cylindrical solid end-mills based on circular arc projection. The wheel path determined by the new method can accurately generate the designed helix angle, rake angle, core radius, and flute width, even if all of these parameters vary along the tool axis. The helix angle and rake angle are ensured by the conjugate condition between the wheel surface and the cutting-edge curve. Based on circular arc projection, equivalent errors of the core radius and flute width are introduced to quantify the machining errors of the two parameters, without the need to predict the flute profile. Simulations and experiments are conducted to validate the proposed method. Three types of non-cylindrical end-mills i.e. tapered end-mill, tapered barrel end-mill, and barrel end-mill, are considered in the validation. The measured results indicate that the generated flute parameters coincide well with the designed ones at different axial positions of the end-mills.