Search Results (20)

To address the issues of low efficiency, high labor intensity, and susceptibility to damage during the manual harvesting of Volvariella volvacea, a mechanized harvesting device was developed to accommodate the growth characteristics of Volvariella volvacea. Thin-film sensors were used to measure the harvesting force values under both the bending method and the rotating method, incorporating two-finger and three-finger operation modes. The results indicated that the maximum force for the bending method was 4.60 N, while that for the twisting method was 2.91 N (peak values, n = 20 per method). The twisting method required less effort and posed a lower risk of damage. A four-suction-cup flexible end-effector was designed using silicone rubber material and equipped with a rotary cylinder. ANSYS 2022 R1 finite element simulation verified that under an applied force of 8 N, the surface stress on the Volvariella volvacea was less than 1.1489 MPa, meeting low-damage requirements. A Volvariella volvacea harvesting test rig was constructed, and performance tests were conducted. The results showed that the overall harvesting success rate was 96.65%, the damage rate was 2.03%, and the average time per harvest by the end-effector was 5.9 s. This study provides a theoretical foundation and technical support for the mechanized and intelligent harvesting of Volvariella volvacea, and is significant for promoting the high-quality development of the Volvariella volvacea industry. Full article

Percentage depth–dose (PDD) distributions are fundamental to characterizing radiation beams in radiotherapy. This review provides an overview of both methods and sensor technologies for measuring PDD in photon, electron, proton, and carbon-ion beams. We summarize conventional dosimetry techniques, including water-phantom scanning with ionization chambers (cylindrical and parallel-plate) and radiochromic film, and discuss their strengths (established accuracy, calibration traceability) and limitations (volume averaging, delayed readout). We then examine emerging sensor technologies designed to improve spatial resolution, speed, and radiation hardness: multi-layer ionization chambers and Faraday cups for one-shot PDD acquisition; scintillator-based detectors (liquid, plastic, and fiber-optic) enabling real-time and high-resolution depth–dose measurements; advanced semiconductor detectors including silicon carbide diodes; as well as novel approaches such as ionoacoustic range sensing for proton beams. For each modality and detector type, we emphasize clinical relevance, measurement accuracy, spatial resolution, radiation durability, and suitability for high dose-per-pulse environments (e.g., FLASH radiotherapy). Current challenges, such as detector response in regions of steep dose gradient, saturation or recombination at ultra-high dose rates, and energy-dependent sensitivity in mixed radiation fields, are analyzed in detail. We also highlight the limitations of each technique and discuss ongoing improvements and prospects for clinical implementation. In summary, no single detector technology fully satisfies all requirements for fast, high-accuracy, high-resolution, radiation-hard PDD measurement, but the integration of emerging sensor innovations into clinical dosimetry promises to enhance the precision and efficiency of radiotherapy quality assurance. Full article

With regard to space telescopes, the processing of large optical mirrors has always been a highlight in the field of optical processing. These mirrors are typically made of hard and brittle materials such as quartz glass, microcrystalline glass, and silicon carbide. These materials have long been considered challenging to work with due to their processing efficiency and propensity for damage. This study proposes a trochoid model considering the actual motion trajectory of the cup wheel with discrete consolidated abrasive grains. Through the establishment of a process parameter–mathematical model to establish the multi-grain coupled motion trajectory, the uniformity of the trajectory is optimized to increase the material removal rate and reduce the surface damage caused by abrasive interference. The results show that the process parameter optimization using this model can effectively reduce the surface roughness of quartz glass grinding. The surface and sub-surface damage caused by grinding stress are significantly reduced, and the edge fracture area of quartz glass is decreased. The large contact area at the end face of the cup-grinding wheel enables a larger grinding depth while ensuring that cracks do not extend to the sub-surface, improving the overall surface integrity of the mirror. Full article

The paper presents a follow-up on the subject of the use of thermal analysis for the generation of fraction solid evolution in cast alloys, particularly in aluminum—silicon alloys. It discusses in detail the importance of correctly determining the characteristic temperatures of the cooling curve, including the beginning of solidification, the eutectic temperature, and the end of solidification. It demonstrates the importance of the smoothing techniques applied to the experimentally recorded temperature (cooling curve). Newtonian and Fourier analyses are used to generate the evolution of fraction of solid and the latent heat on cups of different diameters, to assess the effect of cooling rate for Al-7.5%Si alloys. Calculation results are compared with the literature data. It was found that the maximum temperature of the alloy in the cup affected the overall results. Full article

We report a low-cost protocol and platform for whole-abdomen 3D dynamic contrast-enhanced ultrasound (DCE-US) imaging in mice using a clinical matrix-array transducer. Background/Objectives: This platform addresses common limitations of preclinical ultrasound systems. In particular, these systems often lack real-time volumetric and molecular imaging capabilities. Methods: Using a modified silicone cup and water bath configuration, mice with dual subcutaneous tumors were imaged in vivo on a clinical EPIQ 7 system equipped with an X6-1 transducer. Results: Intravenous administration of targeted microbubbles enabled high-resolution, contrast-mode 3D imaging at multiple time points. Volumetric reconstructions captured both tumors and surrounding anatomy in a single scan, while time–intensity curves and Differential Targeted Enhancement (DTE) analysis revealed greater microbubble uptake in irradiated tumors, consistent with elevated P-selectin expression. Conclusions: This standardized imaging platform enables whole-abdomen molecular DCE-US in preclinical studies, facilitating intra-animal comparisons of vascular and molecular features across lesions or organs. Full article

Paeonia suffruticosa Andr. (tree peony) and Paeonia lactiflora Pall. (herbaceous peony) are traditional Chinese flowers with great ornamental value. To maintain the aesthetic value and show the characteristics of these species, preserved flowers named ‘germplasm display balls’ were developed. Firstly, dried flowers were obtained by vacuum freeze-drying. Secondly, to embed dried flowers and develop germplasm display balls, highly transparent crystal glue (in wrapped display balls type 1 and drop-type display balls type 2) and highly transparent silicone gel (in wrapped display balls, type 3) were used. Finally, the first pass yield (FPY), labor productivity (LP), average cost (AC), and popularity of three kinds of germplasm display balls were compared. The results showed that with the support of a paper cup, the deformation rate of flowers significantly decreased by 91.11%. The FPY of dried flowers was as high as 98.89% at 18 °C. The optimal process for type 1 and type 2 was a glue dosage of 20 g, stirring time of 3 min, and room temperature of 25 °C. Although there was a higher AC in type 3 display ball process, moderate LP and higher FPY and popularity than in other two types, accompanied by high durability, render it the best choice. Full article

A conformal cooling channel (CCC) follows the mold core or cavity profile to carry out uniform cooling in the cooling stage. However, the significant pressure drop along the cooling channels is a distinct disadvantage of the CCC. In this study, an innovative waterfall cooling channel (WCC) was proposed and implemented. The WCC cools the injected products via surface contact, replacing the conventional line contact to cool the injected products. The WCC was optimized using numerical simulation software. Silicone rubber molds with two kinds of cooling channels were designed and implemented. The cooling time of the molded part was evaluated using a low-pressure wax injection molding machine. The experimental results of the cooling time of the molded part were compared with the simulation results from numerical simulation software. The results showed that the optimal mesh element count was about 1,550,000 with a mesh size of 1 mm. The simulation software predicted the filling time of the water cup injection-molded product to be approximately 2.008 s. The cooling efficiency for a silicone rubber mold with a WCC is better than that of the silicone rubber mold with a CCC since the core and cavity cooling efficiency is close to 50%. The pressure drop of the WCC is smaller than that of the CCC, which reduces the pressure drop by about 56%. Taking a water cup with a mouth diameter of 70 mm, a height of 60 mm, and a thickness of 2 mm as an example, the experimental results confirmed that the use of the WCC can save the cooling time of the product by about 265 s compared with the CCC. This shows how a WCC can increase cooling efficiency by approximately 17.47%. Full article

A rapidly developing area of ceramic science and technology involves research on the interaction between implanted biomaterials and the human body. Over the past half century, the use of bioceramics has revolutionized the surgical treatment of various diseases that primarily affect bone, thus contributing to significantly improving the quality of life of rehabilitated patients. Calcium phosphates, bioactive glasses and glass-ceramics are mostly used in tissue engineering applications where bone regeneration is the major goal, while stronger but almost inert biocompatible ceramics such as alumina and alumina/zirconia composites are preferable in joint prostheses. Over the last few years, non-oxide ceramics—primarily silicon nitride, silicon carbide and diamond-like coatings—have been proposed as new options in orthopaedics in order to overcome some tribological and biomechanical limitations of existing commercial products, yielding very promising results. This review is specifically addressed to these relatively less popular, non-oxide biomaterials for bone applications, highlighting their potential advantages and critical aspects deserving further research in the future. Special focus is also given to the use of non-oxide ceramics in the manufacturing of the acetabular cup, which is the most critical component of hip joint prostheses. Full article

For the purpose of minimizing the damage to apples during the operation of an apple-picking robot, improving the stability of an apple-harvesting mechanical hand and reducing the use and operation cost of the robot, a novel biomimetic apple mechanical hand based on negative pressure air suction is purposely designed based on the physical characteristics of apples by imitating octopus predation. The mechanical hand has four suction cups evenly distributed in the hand, which produce concave deformation under negative vacuum pressure to fit the apple surface and adsorb the apple; the fruit stalk is separated by wrist rotation and dragging in a compound way to complete the picking operation. This paper firstly determines the key parameters of the mechanical hand based on the characteristics of silicone material and the three growth postures of apples, tries to make a physical prototype of the mechanical hand and conducts relevant performance tests on the picking platform built in the laboratory to explore the best combination of parameters and further optimize the manipulator. The results show that the success rate of the biomimetic nondestructive apple picker with the best combination of parameters is 100%, 76% and 68% for three different apple-growth postures and the operation is smooth, reliable, safe and non-invasive. Full article

Background: We sought to determine the effectiveness of common cleaning procedures in eliminating S. aureus from silicone menstrual cups. Methods: In this in vitro study, we tested four cleaning techniques: (1) cold water; (2) cold water and liquid soap; (3) cold water followed by steeping the cup in boiled water for 5 min in a ceramic mug covered with a small plate; and (4) cold water and soap followed by steeping the cup in boiled water as in (3). Human blood was coated to the inner and outer surface of each cup, dried, and incubated with 10⁶S. aureus colony-forming units (CFU/mL). All tests were performed in triplicate. Viable bacterial abundance was measured with decadic dilution and drop plate or surface plating. Results: Bacteria were most effectively eliminated by cleaning cups with soap and water and then steeping in boiled water (0 CFU/cup vs. 2.075 × 10⁸/cup no cleaning, p = 0.005). This was not statistically significantly different from washing cups with water only and steeping 5 min in boiled water (14 CFU/cup). Raised lettering on the outer surface of the menstrual cups resulted in more bacterial recovery from pieces with lettering than without lettering. Conclusions: These results advance knowledge of between-period menstrual cup cleaning recommendations, suggesting that the logistical challenges of continuous boiling may be eliminated with steeping at least 5 min. Full article

The acquisition and analysis of EEG signals of dolphins, a highly intelligent creature, has always been a focus of the research of bioelectric signals. Prevailing cable-connected devices cannot be adapted to data acquisition very well when dolphins are in motion. Therefore, this study designs a novel, light-weighted, and portable EEG acquisition device aimed at relatively unrestricted EEG acquisition. An embedded main control board and an acquisition board were designed, and all modules are encapsulated in a 162 × 94 × 60 mm³ waterproof device box, which can be tied to the dolphin’s body by a silicon belt. The acquisition device uses customized suction cups with embedded electrodes and adopts a Bluetooth module for wireless communication with the ground station. The sampled signals are written to the memory card on board when the Bluetooth communication is blocked. A limited experiment was designed to verify the effectiveness of the device functionality onshore and underwater. However, more rigorous long-term tests on dolphins in various states with our device are expected in future to further prove its capability and study the movement-related artifacts. Full article

Low-cost, environmentally friendly and easily applicable coating for Mg alloys, able to resist in real world conditions, are studied. Coatings already used for other metals (aluminum, steel) and never tested on Mg alloy for its different surface and reactivity were deposited on AM60 magnesium alloys to facilitate their technological applications, also in presence of chemically aggressive conditions. A biobased PA11 powder coating was compared to synthetic silicon-based and polyester coatings, producing lab scale samples, probed by drop deposition tests and dipping in increasingly aggressive, salty, basic and acid solutions, at RT and at higher temperatures. Coatings were analyzed by SEM/EDX to assess their morphology and compositions, by optical and IR-ATR microscopy analyses, before and after the drop tests. Migration analyses from the samples were performed by immersion tests using food simulants followed by ICP-OES analysis of the recovered simulant to explore applications also in the food contact field. A 30 μm thick white lacquer and a 120 μm PA11 coating resulted the best solutions. The thinner siliconic and lacquer coatings, appearing brittle and thin in the SEM analysis, failed some drop and/or dipping test, with damages especially at the edges. The larger thickness is thus the unique solution for edgy or pointy samples. Finally, coffee cups in AM60 alloy were produced, as real word prototypes, with the best performing coatings and tested for both migration by dipping, simulating also real world aging (2 h in acetic acid at 70° and 24 h in hot coffee at 60 °C): PA11 resulted stable in all the tests and no migration of toxic metals was observed, resulting a promising candidate for many real world application in chemically aggressive environments and also food and beverage related applications. Full article

High-silicon spheroidal graphite (SG) irons present higher changes of density during the solidification process when compared to normal SG irons. This special behavior is particularly significant in the last stages of solidification, where the graphite expansion may become insufficient to compensate the contraction of the austenite and the risk of microporosity formation increases. The goal of this laboratory research was to establish correlations between the different levels of nodule count obtained using five commercial inoculants, the cooling rate at the end of solidification, and the shrinkage porosity propensity. The analysis was conducted on thermal analysis cups that were sectioned and evaluated for microstructure by optical metallography and by 2D analysis with the Image J software to quantify the size of the microporosity region. It was found that a higher nodule count, associated with higher cooling rate at the end of solidification, generates lower porosity. SEM analysis was conducted to study the nature of nuclei. Complex (MgSiAl)N nitrides were found as the main nucleation sites for graphite. Full article

Background: Large recurrent phyllodes breast tumors are often malignant. Therefore, when taking the surgical decision, a simple mastectomy and immediate reconstruction must be considered. Case presentation: The patient, aged 40 years, with a benign phyllodes tumor in the left breast, having a recurrence 2 years after, with 4–7 cm conglomerate tumor masses, was subjected to skin-reducing mastectomy, breast reconstruction with a silicone mammary implant in the left breast, and symmetrization of the right breast. Discussion and conclusions: In the case of patients with breast hypertrophy and gigantomastia (cup size D–F), skin-reducing mastectomy and immediate reconstruction with an implant can be the option. It is important for the resection specimen to include the skin tissue above the tumor. After 14 months of follow-up, there was no recurrence of the lesions on a clinical examination, ultrasonography, or MRI. Full article

Silicon carbide (SiC) is a promising material for the fabrication of ceramic shell molds due to its high mechanical strength, hardness, thermal shock resistance, and thermal conductivity compared with commonly used slurries. This article describes the test results of casting materials, i.e., SiC-based powders and aqueous binders with aluminum oxide nanoparticles, as well as the parameters of slurries used for prime coats and structural layers. Tests were also performed to evaluate the physical and mechanical properties of SiC-based shell molds for the manufacture of aircraft turbine components. Two SiC-based slurries with solid concentrations of 65 and 70 wt.% were prepared, and their viscosity, density, pH, quantity, thickness, and copper plate adhesion (plate weight test) were investigated. Fourteen days were required to prepare and evaluate the slurry parameters. The results showed that SiC-based slurries had a Zahn cup #4 outflow time of 33.1 s to fabricate the first two coats and 14.8 s to fabricate the shell mold structural layers. Three series of SiC-based shell mold samples were prepared: after dewaxing (PW1), after burnout preheating at 700 °C (PW2), and after annealing at 1200 °C (PW3). The bending mechanical strength, Young’s modulus, and Weibull’s modulus of the samples were calculated, and the roughness (Ra and Rq) and microstructures of samples were also analyzed (SEM). Inner defects were evaluated by CMT (µCT). The Ra and Rq values of the prime coat of the SiC-based shell mold did not exceed 5 µm. The fabricated SiC shell molds had bending mechanical strengths from 1.21–2.28 MPa, Young’s modulus of 102.97–207.66 MPa, and a Weibull’s modulus from 5.36–9.94. The shell molds fabricated on the technical scale met the requirements specified for industrial shell molds. Full article