Sharp Edges Research Articles

Controlled Fracture‐Based Micropatterning of Ruddlesden–Popper Halide Perovskite for Ultra High‐Density Arrays of Micro Light Emitting Diodes

AbstractQuasi‐2D Ruddlesden–Popper perovskite (RPP) have surfaced as a promising candidate for light emitting diodes (LEDs) due to its outstanding optoelectronic properties. However, a reliable approach for patterning RPPs remains elusive due to the use of polar solvents in lithographic processes, which can damage the RPP. Here, a reliable and damage‐free dry micropatterning method of RPPs is reported, which also offers a cost/time advantage compared to conventional patterning methods. The sharp edges of high aspect ratio silicon micropillars are used to cut RPPs to a pre‐defined shape and then the cut RPPs are delaminated to obtain a patterned array of RPPs. The resultant patterned array exhibits no sign of degradation or discernable difference between adjacent pixels, achieving a ≈100% yield. The obtained array is utilized to fabricate a pixelated LED where a sharp electroluminescence (EL) spectrum peaking at 410 nm with full‐width‐at‐half‐maximum (FWHM) of 10 nm is observed. The pixelated devices demonstrate the potential to suppress EQE drops as the pixel size decreases, attributed to both the damage‐free micropatterning process and the defect tolerance of RPPs. Moreover, further improvements of the patterning method are demonstrated to avoid parasitic emission and suggest a promising strategy to fabricate pixel‐accessible micro‐LEDs.

Low tube voltage and deep-learning reconstruction for reducing radiation and contrast medium doses in thin-slice abdominal CT: a prospective clinical trial.

To investigate the feasibility of low-radiation dose and low iodinated contrast medium (ICM) dose protocol combining low-tube voltage and deep-learning reconstruction (DLR) algorithm in thin-slice abdominal CT. This prospective study included 148 patients who underwent contrast-enhanced abdominal CT with either 120-kVp (600 mgL/kg, n = 74) or 80-kVp protocol (360 mgL/kg, n = 74). The 120-kVp images were reconstructed using hybrid iterative reconstruction (HIR) (120-kVp-HIR), while 80-kVp images were reconstructed using HIR (80-kVp-HIR) and DLR (80-kVp-DLR) with 0.5 mm thickness. Size-specific dose estimate (SSDE) and iodine dose were compared between protocols. Image noise, CT attenuation, and contrast-to-noise ratio (CNR) were quantified. Noise power spectrum (NPS) and edge rise slope (ERS) were used to evaluate noise texture and edge sharpness, respectively. The subjective image quality was rated on a 4-point scale. SSDE and iodine doses of 80-kVp were 40.4% (8.1 ± 0.9 vs. 13.6 ± 2.7 mGy) and 36.3% (21.2 ± 3.9 vs. 33.3 ± 4.3 gL) lower, respectively, than those of 120-kVp (both, p < 0.001). CT attenuation of vessels and solid organs was higher in 80-kVp than in 120-kVp images (all, p < 0.001). Image noise of 80-kVp-HIR and 80-kVp-DLR was higher and lower, respectively than that of 120-kVp-HIR (both p < 0.001). The highest CNR and subjective scores were attained in 80-kVp-DLR (all, p < 0.001). There were no significant differences in average NPS frequency and ERS between 120-kVp-HIR and 80-kVp-DLR (p ≥ 0.38). Compared with the 120-kVp-HIR protocol, the combined use of 80-kVp and DLR techniques yielded superior subjective and objective image quality with reduced radiation and ICM doses at thin-section abdominal CT. Scanning at low-tube voltage (80-kVp) combined with the deep-learning reconstruction algorithm may enhance diagnostic efficiency and patient safety by improving image quality and reducing radiation and contrast doses of thin-slice abdominal CT. Reducing radiation and iodine doses is desirable; however, contrast and noise degradation can be detrimental. The 80-kVp scan with the deep-learning reconstruction technique provided better images with lower radiation and contrast doses. This technique may be efficient for improving diagnostic confidence and patient safety in thin-slice abdominal CT.

A boundary element analysis of quasi-potential inviscid incompressible flow in multiply connected airfoil wing

AbstractThe quasi-potential flow in a doubly linked airfoil wing with a sharp trailing edge can be solved using a high-order boundary-element method (BEM). A bicubic Hermite spline interpolation is used to express the unknown, with node derivatives given by finite difference method. The revolutionary traits apply to bleeding-edge settings; specifically, challenges relating to the three-dimensional problem of multiply connected domains are investigated. Numerical validation examples were utilized to assess the implemented BEM approach.

Dynamic Regularized Adaptive Cluster Optimization (DRACO) for Quantitative Cardiac Cine MRI in Complex Arrhythmias.

Irregular cardiac motion can render conventional segmented cine MRI nondiagnostic. Clustering has been proposed for cardiac motion binning and may be optimized for complex arrhythmias. To develop an adaptive cluster optimization method for irregular cardiac motion, and to generate the corresponding time-resolved cine images. Prospective. Thirteen with atrial fibrillation, four with premature ventricular contractions, and one patient in sinus rhythm. Free-running balanced steady state free precession (bSSFP) with sorted golden-step, reference real-time sequence. Each subject underwent both the sorted golden-step bSSFP and the reference Cartesian real-time imaging. Golden-step bSSFP images were reconstructed using the dynamic regularized adaptive cluster optimization (DRACO) method and k-means clustering. Image quality (4-point Likert scale), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), edge sharpness, and ventricular function were assessed. Paired t-tests, Friedman test, regression analysis, Fleiss' Kappa, Bland-Altman analysis. Significance level P < 0.05. The DRACO method had the highest percent of images with scores ≥3 (96% for diastolic frame, 93% for systolic frame, and 93% for multiphase cine) and the percentages were significantly higher compared with both the k-means and real-time methods. Image quality scores, SNR, and CNR were significantly different between DRACO vs. k-means and between DRACO vs. real-time. Cardiac function analysis showed no significant differences between DRACO vs. the reference real-time. DRACO with time-resolved reconstruction generated high quality images and has early promise for quantitative cine cardiac MRI in patients with complex arrhythmias including atrial fibrillation. Stage 2.

Spatially resolved work-function manipulation of azobenzene-functionalized self-assembled monolayers by optical stimulation

Strongly differing static dipole moments of the trans and cis isomers of photochromic azobenzene allow for optical switching of the work function of azobenzene-functionalized self-assembled monolayers (SAMs). We apply these properties in a fundamental experiment to manipulate the area size of the switched SAM. Azobenzene molecules were excited by ultraviolet laser illumination, and the transient isomerization profile of the SAM was spatially resolved recording photoemission electron microscopy images. Thereby, we demonstrate the spatial tuning of the SAM's work function and discuss the role of the laser spot profile in generating sharp edges or gradual changes of the work function.

Ultra-stable foam enabled by nano silica engineering for foam concrete improvement

Foam concrete is increasingly applied in construction due to its lightweight, good thermal insulation and fire resistance, and environmental sustainability, while its low strength limits its further popularization and applications. To enhance the stability and performance of foam concrete, amphiphilic nano silica (ANS) was employed in this study to modify the sodium dodecyl sulphate (SDS) based foaming agent. Then, the designed foam was utilized to fabricate foam concrete, of which the micro/macro performance was analysed in detail. The results showed that ANS-modified foam exhibited superior stability with a thicker foam wall thickness, contributing to the enhancement of foam stability within the cement matrix. The foam concrete with ANS exhibited higher strength compared to the control groups. The analysis of pore structures revealed that the ANS modification led to a more rounded and homogeneous pore configuration, characterized by an increased proportion of small and medium-sized pores and a decreased average pore size. The increase in pore roundness was accompanied by a reduction in the number of sharp edges of the pores and therefore a reduction in the stress concentration factor, while the moderately sized pore also was more conducive to increasing strength due to its lower stress concentration. As a result, the strength of the concrete is significantly increased. These findings demonstrate the potential of ANS as an effective foam stabilizer for foam concrete production, leading to enhanced foam stability and improved mechanical properties of concrete.

Arbitrary engineering of spatial caustics with 3D-printed metasurfaces

Caustics occur in diverse physical systems, spanning the nano-scale in electron microscopy to astronomical-scale in gravitational lensing. As envelopes of rays, optical caustics result in sharp edges or extended networks. Caustics in structured light, characterized by complex-amplitude distributions, have innovated numerous applications including particle manipulation, high-resolution imaging techniques, and optical communication. However, these applications have encountered limitations due to a major challenge in engineering caustic fields with customizable propagation trajectories and in-plane intensity profiles. Here, we introduce the “compensation phase” via 3D-printed metasurfaces to shape caustic fields with curved trajectories in free space. The in-plane caustic patterns can be preserved or morphed from one structure to another during propagation. Large-scale fabrication of these metasurfaces is enabled by the fast-prototyping and cost-effective two-photon polymerization lithography. Our optical elements with the ultra-thin profile and sub-millimeter extension offer a compact solution to generating caustic structured light for beam shaping, high-resolution microscopy, and light-matter-interaction studies.

Design and development of square stub loaded band pass filter with quality factor analysis

In this paper, a compact square stub-loaded band pass filter (BPF) is designed and investigated for quality factor improvement analysis. A detailed analysis has been presented to demonstrate the superior power handling capability of the proposed microstrip bandpass filter without any degradation in its electrical performance parameters. For this purpose, square-type stubs are incorporated in the proposed bandpass filter which reduced the maximum peak voltage and increased the high peak threshold, instead of using sharp edges. Also, an in-depth analysis of peak voltage with a center frequency of 2.1 and 4.2 have been carried out by considering some parameters like pressure and quality. The proposed bandpass filter shows minimum peak voltage of 1.61 V and 1.59 V across the frequency of 2.1 GHz and 4.2 GHz which covers the application of mobile and radio altimeters. The designed BPF shows the minimum heat generation of 0.29 and 0.89 per watt at the resonating frequencies of 2.1 and 4.2 GHz. Furthermore, the proposed bandpass filter presents an in-depth analysis of several characteristic parameters such as return loss, insertion loss, power loss, delay in group and phase, current distribution, H and E field distribution and maximum power loaded and unloaded quality factor.

A novel hybrid SBM-MFS methodology for acoustic wave propagation problems

In this paper, a novel hybrid meshless approach that combines the singular boundary method (SBM) and the method of fundamental solutions (MFS) to deal with two-dimensional (2D) exterior acoustic wave propagation problems is proposed and studied. The methodology is particularly devised to solve problems with complex boundary geometries containing geometric singularities such as corners and sharp edges. It employs the SBM to model intricate segments of these geometries and the MFS for the smooth ones. The proposed hybrid SBM-MFS method is studied in a 2D context in the framework of three benchmark examples involving acoustic radiation problems of circular-, square- and L-shaped objects in a full-space acoustic medium. In addition, the applicability of the proposed hybrid SBM-MFS methodology to predict the acoustic performance of a T-shaped thin barrier is also investigated. These examples are specifically designed to assess the feasibility, validity and accuracy of the hybrid SBM-MFS approach in comparison with the available analytical solutions and alternative numerical strategies such as the MFS, the SBM and the boundary element method (BEM). Numerical simulations demonstrate that the proposed method can match the level of accuracy of the MFS while keeps the robustness of the SBM when dealing with complex geometries, overcoming one the most important drawbacks of the traditional MFS. Moreover, the proposed hybrid SBM-MFS naturally avoids the non-uniqueness problem arising at the fictitious eigenfrequencies associated with the corresponding interior problems, a feature that neither the SBM nor the BEM inherently possesses.

Heat transfer and flow analysis of a novel particle heater using CFD-DEM

CFD-DEM coupled simulations of a unique gravity-fed particle heater are performed. Physical and heat transfer properties of the solid particles and walls are varied to determine their relative impact on the local heat transfer coefficient along the heater surfaces. The varied parameters are the coefficient of restitution, particle-particle and particle-wall friction coefficients, particle size distribution, normal spring constant, particle conductivity, particle specific heat, and the numerical lens radius. The local heat transfer coefficient increases when the local void fraction along the heater surface decreases. In addition to analyzing thermal performance, flow instabilities are also identified under certain conditions. The outlet particle flow oscillates when the top of each heater is rounded. For heaters with sharp top edges, the local heat transfer coefficient and void fraction profiles change dramatically. The sharp corners remove the particle stagnation point, and the particles adhere to the surface better which increases the heat transfer.

Micro-cracking on the surface of zinc metal improves the cycle performance of aqueous zinc ion batteries

The notorious zinc dendrite is a severe constraint to the practical application of zinc-based batteries, as the metal tips growing vertically in two dimensions on the surface of the electrodes during cycling and loosely packed sharp edges may pierce through the diaphragm, posing a safety hazard. In this study, physical stress extrusion was used to generate micron- or submicron-sized cracks on zinc metal anodes, which significantly increased the specific surface area of the electrodes and mitigated the local current density of the electrodes. Zinc ion fluxes were significantly dispersed, producing a dense Zn2SO4(OH)6-xH2O (ZHS) layer, which differed distinctly from the by-products of the loose upright growth on the surface of Raw Zn (RZn). Additionally, three-dimensional structure of cracked zinc composition allows it to adjust the zinc volume variations during electroplating/stripping, and the abundance of nucleation sites significantly reduces the Zn polarization voltage, resulting in uniform Zn deposition. The average cycle life of the symmetric cell was >400 h at 1 mA cm−2 current density, and nearly 500 cycles at 5 mA cm−2 current density for the asymmetric cell, with an average Coulombic efficiency of 99.3 %. The activation energy substantially declined with the increase in Zn ion flux per unit time (29.615 KJ mol−1 vs. 44.041 KJ mol−1), demonstrating efficient desolvation kinetics. Furthermore, the Crack Zn || V2O5 full cell also exhibits outstanding self-discharge performance, with 85 % capacity retention in a 48 h resting charge/discharge testing, superior to the raw zinc foil anode (78.3 %). Herein, a method of creating microcrack configurations on the surface of zinc anodes using stress extrusion was presented, sparing the current density while optimizing the undesirable growth patterns of ZHS by-products.

An Experimental Study on Light Emitting Concrete

The study of light emitting concrete which has the property of transmitting light from concrete by using optical fibers. Since years concrete has a low impression because of its dirty greyish color, opaqueness and sharp edge but this concept has been changed after the development of light emitting concrete, which gives the increased strength, better looks and light transmitting features. Plastic optical fibers are used because of its total internal reflection as its working principle as it gives maximum efficiency in transmitting light. The percentages of optical fiber added in this experimental study are 3%, 4%, 5%. This paper gives the structure a good aesthetic look without loss of strength parameters and serves as a eco-friendly building material and is also a energy efficient which reduces energy consumption by 30% by allowing the natural light by transmitting light through optical fibers and will also have a good scope in future. This experiment will be a series of initiatives to look closely at new and emerging advanced construction in future

Compressive Strength of Concrete Containing Merapi Cold Lava Sand

Reports from the literature state that Merapi sand is a good material as a filler in concrete to replace some of the fine aggregate because it has a high content of silica (SiO&lt;sub&gt;2&lt;/sub&gt;) and the sharp edges of the silica form angular particles. The potential function of Merapi sand as a filler and its use as a waste material prompted this study to be carried out. The objective of this study is to determine the potential of Merapi Sand in terms of concrete compressive strength as an effective replacement for local sand in the Cikarang area. In this study, Merapi cold lava was crushed to the size of fine aggregate by passing a 2.26 mm sieve. The percentages of Merapi sand used as a partial substitute for local sand are 10%, 20%, and 30%. The results of this study show that Merapi sand concrete (MSC) 30% at age of 7 days and 28 days provides the highest increase in compressive strength of 17.4% and 15.8% respectively compared to normal concrete (NC). The addition of a percentage of Merapi sand as a partial replacement for local sand tends to increase the compressive strength of the concrete. Based on this study, Merapi sand has the potential to be used as a partial replacement for local sand in increasing the compressive strength of concrete and reducing cold lava waste.

Anisotropic Fracture of Two-Dimensional Ta2NiSe5.

Anisotropic two-dimensional materials present a diverse range of physical characteristics, making them well-suited for applications in photonics and optoelectronics. While mechanical properties play a crucial role in determining the reliability and efficacy of 2D material-based devices, the fracture behavior of anisotropic 2D crystals remains relatively unexplored. Toward this end, we herein present the first measurement of the anisotropic fracture toughness of 2D Ta2NiSe5 by microelectromechanical system-based tensile tests. Our findings reveal a significant in-plane anisotropic ratio (∼3.0), accounting for crystal orientation-dependent crack paths. As the thickness increases, we observe an intriguing intraplanar-to-interplanar transition of fracture along the a-axis, manifesting as stepwise crack features attributed to interlayer slippage. In contrast, ruptures along the c-axis surprisingly exhibit persistent straightness and smoothness regardless of thickness, owing to the robust interlayer shear resistance. Our work affords a promising avenue for the construction of future electronics based on nanoribbons with atomically sharp edges.

New suture probe canaloplasty combined with suprachoroidal collagen implantation.

To present the modified surgery technique of new suture probe canaloplasty with a specially prepared monofilament 4.0 polypropylene suture combined with suprachoroidal drainage (ScD) and collagen sheet implantation for non-penetrating glaucoma surgery. Prospective study with a twelve months follow-up. A standard 4/0 polypropylene suture (ProleneTM by Ethicon; thickness: approximately 250m) is cut and shaped with an ophthalmic knife (MANI® Crescent Knife, Mani Inc 8-3 Kiyohara Industrial Park, Utsunomiya, Tochigi 321-3231, Japan) to create a blunt end without sharp or compressed edges. This improves suture probe canaloplasty by providing a more stable and smoother probing device. Schlemm's canal is prepared using the standard technique of canaloplasty with suprachoroidal drainage. Then, instead of using the canaloplasty microcatheter or the previously published 6/0 double-helix suture, Schlemm's canal is probed with the blunt ending of the 4/0 Prolene suture. After successful 360-degree probing, a doubled 10/0 polypropylene tension suture is threaded through the tip of the 4/0 suture. The 4/0 suture is then pulled back and the 10/0 tension sutures are tied at both ends to tension Schlemm's canal. A special collagen sheet (Ologen®) is placed in suprachoroidal space, and the scleral flap is firmly sewed. 115 eyes were included in this prospective study. In 113 cases the Schlemm's canal could completely be probed with the suture probe and canaloplasty with ScD and collagen sheet implantation succeeded. In two cases the intervention was transformed to 360-degree suture trabeculotomy due to an intraoperative cheese-wiring. Twelve months after successful new suture probe canaloplasty with ScD and Collagen Implantation the IOP had decreased by 37.1% (from 21.6 ± 6.0mmHg with 3.3 different IOP lowering eye drops to 13.5 ± 3.5mmHg with 1.0 eye drops). 16 Patients did not achieve sufficient IOP levels and underwent 360-degree suture trabeculotomy during the follow-up. One patient had to be treated with further glaucoma surgery to achieve a sufficient IOP level. Complications were hyphema, postoperative IOP elevation and transient hypotony. No serious or sight-threatening complications occurred. New suture probe canaloplasty with ScD and collagen sheet implantation yields the opportunity to conduct a cost-effective canaloplasty easier and less complicated than with the previously described method with the twisted 6/0 suture. The safety profile and IOP lowering effect is comparable. In cases where complete probing fails, there is still the opportunity to switch to suture trabeculotomy over the majorly probed part of Schlemm's canal. The pressure lowering effect of the deep sclerectomy with ScD and suprachoroidal collagen sheet implant seems to have an additional impact on the sufficient pressure lowering procedure.

Room Temperature Polariton Condensation from Whispering Gallery Modes in CsPbBr3 Microplatelets.

Room temperature (RT) polariton condensate holds exceptional promise for revolutionizing various fields of science and technology, encompassing optoelectronics devices to quantum information processing. Using perovskite materials, like all-inorganic cesium lead bromide (CsPbBr3) single crystal, provides additional advantages, such as ease of synthesis, cost-effectiveness, and compatibility with existing semiconductor technologies. In this work, the formation of whispering gallery modes (WGM) in CsPbBr3 single crystals with controlled geometry is shown, synthesized using a low-cost and efficient capillary bridge method. Through the implementation of microplatelets geometry, enhanced optical properties and performance are achieved due to the presence of sharp edges and a uniform surface, effectively avoiding non-radiative scattering losses caused by defects. This allows not only to observe strong light matter coupling and formation of whispering gallery polaritons, but also to demonstrate the onset of polariton condensation at RT. This investigation not only contributes to the advancement of the knowledge concerning the exceptional optical properties of perovskite-based polariton systems, but also unveils prospects for the exploration of WGM polariton condensation within the framework of a 3D perovskite-based platform, working at RT. The unique characteristics of polariton condensate, including low excitation thresholds and ultrafast dynamics, open up unique opportunities for advancements in photonics and optoelectronicsdevices.

Use of Dixon in magnetic resonance breast contrast-enhanced T1 weighted high-resolution imaging for mastectomy patients at 3T: A prospective study in single center

BackgroundFor patients with complete breast resection, conventional contrast-enhanced T1-weighted imaging (CE-T1WI) with frequency-selective spectral attenuated inversion recovery (SPAIR) provides limited fat suppression on the postoperative side due to the uneven skin surface, inhomogeneous tissue environment, and frequency-selective feature of the SPAIR scheme, leading to difficulties in precise diagnosis. This study aimed to investigate the image quality and performance of the Dixon method compared with SPAIR in breast high-resolution CE-T1WI for mastectomy patients. Materials and methodsSixty female patients who had not performed any breast surgeries were randomly selected retrospectively as the control group. Postmastectomy female patients were enrolled to undergone high-resolution CE-T1WI with SPAIR and Dixon breast scans. Subjective scores were rated using a 5-point scale. Objective parameters, including contrast-to-noise ratio (CNR), edge sharpness, and signal uniformity were measured and calculated. The Wilcoxon rank-sum test and Kappa statistic were used. ResultsA total of 114 consecutive postmastectomy patients were included. Subjective scores of T1WI-SPAIR in the control group were all significantly better than those with SPAIR on the postoperative side of mastectomy patients (P < 0.01). Dixon outperformed SPAIR with significantly better subjective scores in regards to uniformity and degree of fat-suppression, anatomical structures depiction, lesion conspicuity, and axillary visibility (p < 0.05) in both post- and non-operative sides and bilateral axillary areas through the paired comparison. The objective parameters of Dixon were significantly better than those of SPAIR. ConclusionThe Dixon method provided better image uniformity and higher fat suppression efficiency, and showed significant advantages in delineating the anatomical structures, with better axillary and lesion visibilities, especially on the completely removed breast side.

Generated realistic noise and rotation-equivariant models for data-driven mesh denoising

3D mesh denoising is a crucial pre-processing step in many graphics applications. However, existing data-driven mesh denoising models, primarily trained on synthetic white noise, are less effective when applied to real-world meshes with the noise of complex intensities and distributions. Moreover, how to comprehensively capture information from input meshes and apply suitable denoising models for feature-preserving mesh denoising remains a critical and unresolved challenge. This paper presents a rotation-Equivariant model-based Mesh Denoising (EMD) model and a Realistic Mesh Noise Generation (RMNG) model to address these issues. Our EMD model leverages rotation-equivariant features and self-attention weights of geodesic patches for more effective feature extraction, thereby achieving SOTA denoising results. The RMNG model, based on the Generative Adversarial Networks (GANs) architecture, generates massive amounts of realistic noisy and noiseless mesh pairs data for data-driven mesh denoising model training, significantly benefiting real-world denoising tasks. To address the smooth degradation and loss of sharp edges commonly observed in captured meshes, we further introduce varying levels of Laplacian smoothing to input meshes during the paired training data generation, endowing the trained denoising model with feature recovery capabilities. Experimental results demonstrate the superior performance of our proposed method in preserving fine-grained features while removing noise on real-world captured meshes.

First report of basal stem rot caused by three Fusarium species on Chinese yam in China.

The cultivated variety of Chinese yam (Dioscorea polystachya Turcz. cv. Tiegun) is an economically important plant, capable of producing tubers that are used as food and traditional Chinese medicine. The basal stem rot was found on approximately 65% of yam (tuber expansion stage) in a total of 10 ha field in Wuzhi, Wen, and Hua counties, Henan, China (Sep 2021). Dark brown fusiform lesions initially occurred at the stems basal, irregularly extending to join together and leading to loop-stem necrotic indentation. Three diseased samples from Wuzhi county were collected, cut into 5 × 5 mm pieces, surface sterilized in 75% ethanol (30 s) and 1% NaClO (1 min), washed in sterile water 3 times, and placed on PDA in the dark for 3 days at 28℃. A total of 44 isolates forming three groups of Fusarium colonies were obtained using monosporic isolation, of which 19, 8, and 17 isolates were identified as F. oxysporum, F. solani, and F. proliferatum based on colony morphology, respectively. Typical isolates SYJJ6, 9, and 10 for each group were further studied. The SYJJ6 colonies showed gray white abundant fluffy aerial mycelium with rough edges, formation of ellipsoid, unicellular microconidia without septa, 5.6 to 13.4 × 2.4 to 4.7 μm (n = 50), and sickle-shaped, slightly curved macroconidia with 2 to 4 septa, 14.0 to 23.9 × 3.4 to 5.1 μm (n = 50). Isolate SYJJ9 produced flocculent white colonies, grew in a circular pattern with a sharp edge, forming oval or oblong microconidia with zero or one septum, 11.2 to 18.8 × 3.4 to 6.2 μm (n = 50), and slightly curved macroconidia with 2 to 3 septa, 27.6 to 44.0 × 3.9 to 7.4 μm (n = 50). SYJJ10 produced whitish or pinkish white colonies with fluffy aerial mycelium and a red pigmentation, produced renal or oval microconidia with no septa, 5.1 to 11.8 × 1.8 to 4.2 μm (n = 50), and falcate, slightly curved macroconidia with 3 to 4 septa, 16.1 to 30.2 × 3.1 to 5.9 μm (n = 50). Additionally, TUB, EF-1α, and RPB2 genes were amplified with primers BT2a/BT2b, EF1/EF2, and 5f2/-7cr, respectively (Glass and Donaldson 1995; O'Donnell et al. 1998, 2010). BLASTn analysis on SYJJ6 (OR047663, OR047666, OR047669), SYJJ9 (OR047665, OR047667, OR047670), and SYJJ10 (OR047664, OR047668, OR047671) gene sequences were over 99% identical to those of F. oxysporum (100%, MK432917; 100%, MN417196; 99.61%, MN457531), F. solani (100%, MF662662; 100%, MN223440; 99.80%, CP104055), and F. proliferatum (100%, ON557521; 100%, ON458137; 99.90%, LT841266), respectively. Pathogenicity tests of three isolates were separately performed on 60-day-old yam seedlings. The basal stems were wounded using needle, and the wounds were wrapped with cotton balls soaked with conidial suspension (1 mL, 3×106 conidia/mL) or water (control). Each isolate treated three plants and repeated three times. All plants were grown at 28℃ under a 16/8-h light/dark cycle. Typical symptoms emerged on basal stems at 16, 13, and 17 days after inoculation with the conidia of isolates SYJJ6, 9, and 10, while the control basal stems appeared healthy. The re-isolated fungi were identical to the original three isolates. Fusarium species (F. oxysporum, F. commune, F. humuli, etc.)were previously reported to cause wilt or stem rot on different D. polystachya cultivars (Fang et al. 2020; Li et al. 2023; Zhao et al. 2013), or basal stem rot on Panax ginseng (Ma et al. 2020). This is the first report of Chinese yam basal stem rot caused by Fusarium species, which threatens the production of Chinese yam 'Tiegun' and should be further studied.

Measuring Device Detecting Impact Forces on Impact Rollers

This paper presents laboratory devices on which measurements were carried out to prove the validity of the assumption about the reduction in vibrations transmitted to the conveyor belt structure generated by the impact forces of falling material grains in the places of transfer or on the hoppers of conveyor belts. In order to limit damage to the conveyor belts caused by the impact of the sharp edges of material grains, conveyor belts are supported by impact rollers or impact rubber rods. A special modification of the fixed conveyor idler is presented, which consists of inserting plastic brackets into the structurally modified roller axle holders of the fixed conveyor idler. Measurements showed that the specially modified fixed conveyor idler resulted in a higher damping of up to 15% of the impact forces of the falling weight on the rubberized hoop of the impact roller shell compared to the conventional fixed conveyor idler design. Measurements carried out show that the effective vibration velocity values detected at the points where the impact roller axis fits into the fixed roller table holder are higher than when using plastic brackets, up to 6% for a 108-mm-diameter roller, compared to steel impact roller brackets.