Search Results (839)

Barrel tools are increasingly used in high-precision machining of free-form surfaces. However, limited studies evaluate their performance specifically on spherical geometries, where tool–surface contact characteristics differ significantly. Understanding how tool geometry and process parameters influence surface quality and cutting forces in such cases remains underexplored. This study evaluates how barrel cutter radius and varying machining parameters affect cutting forces and surface roughness when milling internal and external spherical surfaces. Machining tests were conducted on structural steel 1.1191 using two barrel cutters with different curvature radii (85 mm and 250 mm) on a 5-axis CNC machine. Feed per tooth and radial depth of cut were systematically varied. Cutting forces were measured using a dynamometer, and surface roughness was assessed using the Rz parameter, which is more sensitive to peak deviations than Ra. Novelty lies in isolating spherical surface shapes (internal vs. external) under identical path trajectories and systematically correlating tool geometry to force and surface metrics. The larger curvature tool (250 mm) consistently generated up to twice the cutting force of the smaller radius tool under equivalent conditions. External surfaces showed higher Rz values than internal ones due to less favorable contact geometry. Radial depth of the cut had a linear influence on force magnitude, while feed rate had a limited effect except at higher depths. Smaller-radius barrel tools and internal geometries are preferable for minimizing cutting forces and achieving better surface quality when machining spherical components. The aim of this paper is to determine the actual force load and surface quality when using specific cutting conditions for internal and external spherical machined surfaces. Full article

This study aimed to optimize the inoculation dosage and fermentation duration to enhance the protein content and reduce soluble oligosaccharides in soybean meal using Aspergillus oryzae and assessed its performance in dog food extrusion. A 3 × 5 factorial design was used to determine the optimal fermentation conditions. These conditions were applied to ferment soybean meal in bulk for nutritional analysis. Finally, the impact of fermentation on extrusion processing was assessed by formulating and extruding four diets: SBM (30% soybean meal), AMF (30% soybean meal with 1% Amaferm^®—A. oryzae biomass), FSBM (30% fermented soybean meal), and SPI (18% soy protein isolate). Diets were extruded with a single-screw extruder, and physical characteristics of kibbles, particle size distribution, and viscosity of raw mixes were analyzed. The optimal fermentation conditions were 1 × 10⁴ spore/g substrate for 36 h, which increased the crude protein content by 4.63% DM, methionine and cysteine total content by 0.15% DM, and eliminated sucrose, while significantly reducing stachyose, raffinose, and verbascose (95.22, 87.37, and 41.82%, respectively). The extrusion results showed that FSBM had intermediate specific mechanical energy (SME), in-barrel moisture requirements, and sectional expansion index (198.7 kJ/kg, 28.2%, and 1.80, respectively) compared with SBM (83.7 kJ/kg, 34.5%, and 1.30, respectively) and SPI (305.3 kJ/kg, 33.5%, and 2.55, respectively). The FSBM also exhibited intermediate particle size distribution and the least raw mix viscosity. These findings demonstrate that A. oryzae fermentation enhances the nutrient profile of soybean meal while improving extrusion efficiency and kibble quality, supporting its potential use as a sustainable pet food ingredient. Full article

Compared with biocompatibility, osteoconductivity, and mechanical properties, the poor injectability of calcium phosphate bone cements (CPCs) is always ignored, which actually hinders the development of CPC clinical transfer in minimally invasive orthopedic surgeries. Moreover, currently, CPC preparation in the clinic is labor-intensive and requires well-trained technicists, which might also result in the unstable quality of CPCs. In this work, we focused on three research objectives: (i) introducing a standardized preparation method for CPCs; (ii) studying the effects of preparation parameters on CPC injectability and compressive strength; and (iii) studying the injecting condition effects on CPC injectability, aiming to overcome CPCs’ disadvantages in minimally invasive surgeries. Firstly, two strategies, named “variable mixing barrel control (VMBC)” and the “nested blade–baffle stirring rod (NBBSR)”, were proposed in this study to solve the problems in the preparation of CPCs, which involved blending CPC powder and an agent to generate a paste, by enhancing the mixing performance and mimicking human manual stirring actions. Secondly, although the grinding parameter could significantly generate differences in the microstructure of CPCs, the compressive strength remained relatively stable. However, it was found to significantly affect the injectability of CPCs, leading to the inefficient injection of CPCs. Finally, the effects of syringe design, dimensions, and injecting conditions on CPC injectability were studied, and the results showed that the optimization of these factors enables the injection of CPCs, which has otherwise always been infeasible to implement in minimally invasive orthopedic surgeries. Full article

As the core component of ultra-precision machine tools, the manufacturing errors of aerostatic spindles are inevitable due to the limitations of machining and assembly processes, and these errors significantly affect the spindle’s static and dynamic performance. To address this issue, a force model of the unbalanced air film, considering the straightness errors of the rotor’s radial and thrust surfaces, was constructed. Unlike conventional studies that rely solely on idealized error assumptions, this research integrates actual straightness measurement data into the simulation process, enabling a more realistic and precise prediction of bearing performance. Rotors with different tolerance specifications were fabricated, and static performance simulations were carried out based on the measured geometry data. An experimental setup was built to evaluate the performance of the aerostatic spindle assembled with these rotors. The experimental results were compared with the simulation outcomes, confirming the validity of the proposed model. To further quantify the influence of straightness errors on the static characteristics of aerostatic spindles, ideal functions were used to define representative manufacturing error profiles. The results show that a barrel-shaped error on the radial bearing surface can cause a load capacity variation of up to 46.6%, and its positive effect on air film load capacity is more significant than that of taper or drum shapes. For the thrust bearing surface, a concave-shaped error can lead to a load capacity variation of up to 13.4%, and its enhancement effect is superior to those of the two taper and convex-shaped errors. The results demonstrate that the straightness errors on the radial and thrust bearing surfaces are key factors affecting the radial and axial load capacities of the spindle. Full article

Non-Newtonian debris flows represent a critical challenge for hydraulic infrastructure in mountainous regions, often causing significant damage and service disruption. However, current models typically simplify these flows as Newtonian, leading to inaccurate design assumptions. This study addresses this gap by comparing the hydraulic behavior of Newtonian and non-Newtonian flows in an alluvial fan, using the Amoray Gully in Apurímac, Peru, as a case study. This gully intersects the Interoceánica Sur national highway via a low-water crossing (baden), making it a relevant site for evaluating debris flow impacts on critical road infrastructure. The methodology integrates hydrological analysis, rheological characterization, and hydraulic modeling. QGIS 3.16 was used for watershed delineation and extraction of physiographic parameters, while a high-resolution topographic survey was conducted using an RTK drone. Rainfall-runoff modeling was performed in HEC-HMS 4.7 using 25 years of precipitation data, and hydraulic simulations were executed in HEC-RAS 6.6, incorporating rheological parameters and calibrated with the footprint of a historical event (5-year return period). Results show that traditional Newtonian models underestimate flow depth by 17% and overestimate velocity by 54%, primarily due to unaccounted particle-collision effects. Based on these findings, a multi-barrel circular culvert was designed to improve debris flow management. This study provides a replicable modeling framework for debris-prone watersheds and contributes to improving design standards in complex terrain. The proposed methodology and findings offer practical guidance for hydraulic design in mountainous terrain affected by debris flows, especially where infrastructure intersects active alluvial fans. Full article

Neuroactive steroids (NAS) have long been recognized for their hypnotic and anesthetic properties in both clinical and preclinical settings. While sex differences in NAS sensitivity are acknowledged, the underlying mechanisms remain poorly understood. Here, we examined sex-specific responses to an endogenous NAS epipregnanolone (EpiP) in wild-type mice using behavioral assessment of hypnosis (loss of righting reflex, LORR) and in vivo electrophysiological recordings. Specifically, local field potentials (LFPs) were recorded from the central medial thalamus (CMT) and electroencephalogram (EEG) signals were recorded from the barrel cortex. We found that EpiP-induced LORR exhibited clear sex differences, with females showing increased sensitivity. Spectral power analysis and thalamocortical (TC) and corticocortical (CC) phase synchronization further supported enhanced hypnotic susceptibility in female mice. Our findings reveal characteristic sex-dependent effects of EpiP on the synchronized electrical activity in both thalamus and cortex. These results support renewed exploration of endogenous NAS as clinically relevant anesthetic agents. Full article

A key feature that differentiates Gram-positive and Gram-negative bacteria is the outer membrane, an asymmetric membrane composed of lipopolysaccharides, phospholipids, lipoproteins and integral proteins, including the outer-membrane proteins (OMPs). By being in direct contact with the extracellular milieu, the outer membrane and OMPs participate in multiple functions in Gram-negative bacteria, including controlling nutrient and molecule access to the cytoplasm, membrane vesicle formation and resistance to environmental stresses. OMPs have a characteristic barrel shape formed by antiparallel β-strands, with or without channels that allow diffusion of substrates through the outer membrane. The marine bacterium Vibrio cholerae is responsible for non-invasive gastroenteritis and cholera disease by consumption of contaminated water or food. Its OMPs, besides having a porin function, contribute to resistance to osmotic pressure and antimicrobial agents, intracellular signaling, adhesion to host cells and biofilm formation, amongst other functions. In this review, in addition to quickly reviewing the general structure of the outer membrane, the OMPs and how they reach the outer membrane, the functions attributed to these proteins are compiled. The mechanisms used by each of the described OMP to accomplish these functions in the marine pathogenic bacterium V. cholerae are discussed. Potential clinical and bioengineering applications of OMPs, such as diagnostic tools, vaccine development, and targeted antimicrobial or anti-virulence strategies are presented. What is known about the OMPs of V. cholerae is presented below. Full article

This paper presents the design and validation of a novel specialized fixture device for machining inclined planes with barrel cutters on 3-axis CNC machine tools. Barrel milling, also known as Parabolic Performance Cutting (PPC), is extensively used on 5-axis machines to enhance the efficiency of machining complex surfaces. While significant research has focused on optimizing barrel milling for aspects such as surface roughness and cutting forces, implementing this technique on 3-axis machines poses a challenge due to limitations in tool orientation. To overcome this, an innovative adaptable device was designed, enabling precise workpiece orientation relative to the barrel cutter. To overcome this limitation, an adaptable device was designed that enables precise workpiece orientation relative to the barrel cutter. The device utilizes interchangeable locating elements for different cutter programming angles (such as 18°, 20°, and 42.5°), thereby ensuring correct workpiece positioning. Rigid workpiece clamping is provided by the device’s mechanism to maintain precise workpiece positioning during machining, and probing surfaces are integrated into the device to facilitate the definition of the coordinate system necessary for CNC machine programming. Device control was performed using a Hexagon RA-7312 3D measuring arm. Inspection results indicated minimal dimensional deviations (e.g., surface flatness between 0.002 mm and 0.012 mm) and high angular accuracy (e.g., angular non-closure of 0.006°). The designed device enables the effective and precise use of barrel cutters on 3-axis CNC machines, offering a previously unavailable practical and economical solution for cutting tool tests and cutting regime studies. Full article

Wine aroma is the result of the association of numerous volatile and non-volatile compounds belonging to the grapes, the fermentation, and aging process. During aging, wines complete their complex composition, and many aromas emerge. Therefore, aging represents a fundamental step to obtaining high-quality wines. Aromas belong directly to the odorless precursor in grapes or to the aging technology used. Analyses have been performed on wines obtained from the cv Carignano subjected to four aging technologies: stainless-steel tank, plastic vat, concrete vat, and oak barrel. GC/FID and GC/MS analysis allowed the identification of 78 significant compounds belonging to eight different chemical classes. Volatile composition in the various containers was assessed at two levels: chemical classes and individual compounds. At 12 months, plastic vats had the highest increase in the total VOC concentration (p < 0.05), followed by concrete and stainless steel. In contrast, oak barrels showed a decrease, although the difference was not statistically significant (p > 0.05). Unsupervised principal component analysis (PCA) demonstrated that the container exerts a more substantial influence at 6 months, while at 12 months, the samples were categorized irrespective of the container. In the loading plot, several esters, acids, lactones, and aldehydes showed negative loadings on PC1 (associated with time), indicating a correlation with the 12-month collection time. Full article

This study proposes a deflection-based criterion for the assessment of barrel support brackets to ensure the structural stability of large fire shutters installed in large-scale buildings such as logistics facilities. While the current extended application method in the BS EN 15269 standard allows for the evaluation of the structural adequacy of the barrel—primarily based on stress analysis—this research aims to establish a more reliable design guideline by additionally considering the deflection of barrel support brackets, which may become structurally vulnerable under high-temperature conditions. To achieve this, the bracket was modeled as a cantilever beam, and deflection equations were applied. The deflection and stress were analyzed for various rectangular hollow sections. Furthermore, the support capacities at ambient temperature and at 700 °C were compared, and regression analysis was conducted to assess the Accuracy and error rates associated with different deflection limits (L/180 to L/480). The results indicate that setting the deflection limit to L/180 yields the most favorable outcome in terms of structural safety and error minimization across most conditions. It is expected that the adoption of deflection criteria for barrel support brackets in the design of large fire shutters will contribute significantly to preventing the spread of fire and ensuring structural safety. Full article

Belle II is a particle physics experiment working at an high luminosity collider within a hard irradiation environment. The Time-Of-Propagation detector, aimed at the charged particle identification, surrounds the Belle II tracking detector on the barrel part. This detector is composed by 16 modules, each module contains a finely fused silica bar, coupled to microchannel plate photomultiplier tube (MCP-PMT) photo-detectors and readout by high-speed electronics. The MCP-PMT lifetime at the nominal collider luminosity is about one year, this is due to the high photon background degrading the quantum efficiency of the photocathode. An alternative to these MCP-PMTs is multi-pixel photon counters (MPPC), known as silicon photomultipliers (SiPM). The SiPMs, in comparison to MCP-PMTs, have a lower cost, higher photon detection efficiency and are unaffected by the presence of a magnetic field, but also have a higher dark count rate that rapidly increases with the integrated neutron flux. The dark count rate can be mitigated by annealing the damaged devices and/or operating them at low temperatures. We tested SiPMs, with different dimensions and pixel sizes from different producers, to study their time resolution (the main constraint that has to satisfy the photon detector) and to understand their behavior and tolerance to radiation. For these studies we irradiated the devices to radiation up to $5\times {10}^{11}1$ MeV neutrons equivalent (neq) per cm² fluences; we also started studying the effect of annealing on dark count rates. We performed several measurements on these devices, on top of the dark count rate, at different conditions in terms of overvoltage and temperatures. These measurements are: IV-curves, amplitude spectra, time resolution. For the last two measurements we illuminated the devices with a picosecond pulsed laser at very low intensities (with a number of detected photons up to about twenty). We present results mainly on two types of SiPMs. A new SiPM prototype developed in collaboration with FBK with the aim of improving radiation hardness, is expected to be delivered in September 2025. Full article

Toxoplasma gondii, a pathogen of significant concern in animal production, companion animal health, and public health, particularly affects immunocompromised individuals and pregnant women. Current diagnostic techniques employ both direct and indirect methods, with serological assays widely used for detecting T. gondii infections in humans and animals. In this study, the TIM-barrel structure of Br2 β-glucosidase was engineered to create 10 chimeric multi-epitope proteins for T. gondii serological detection. Indirect ELISA screening identified three promising candidate proteins, V4Z, SFF, and S7V-V4Z-SFF, with sensitivities ranging from 71–86% and specificities ranging from 68–76%. Among these, ELISA-V4Z achieved the highest concordance with the reference IFAT method (Kappa = 0.58, 95% CI = 0.32–0.84) and demonstrated a moderate positive predictive value (PPV, 67%) and strong negative predictive value (NPV, 90%). These results suggest that the V4Z chimeric protein demonstrated the strongest performance among the tested candidates for T. gondii detection, exhibiting the highest sensitivity and specificity along with moderate agreement with the reference IFAT. However, its overall diagnostic performance remains limited. These findings highlight the need for further refinement and validation to enhance its diagnostic potential and assess its applicability for broader serological testing. Full article

This paper introduces SmartBarrel, an innovative IoT-based sensory system that monitors and forecasts wine fermentation processes. At the core of SmartBarrel are two compact, attachable devices—the probing nose (E-nose) and the probing tongue (E-tongue), which mount directly onto stainless steel wine tanks. These devices periodically measure key fermentation parameters: the nose monitors gas emissions, while the tongue captures acidity, residual sugar, and color changes. Both utilize low-cost, low-power sensors validated through small-scale fermentation experiments. Beyond the sensory hardware, SmartBarrel includes a robust cloud infrastructure built on open-source Industry 4.0 tools. The system leverages the ThingsBoard platform, supported by a NoSQL Cassandra database, to provide real-time data storage, visualization, and mobile application access. The system also supports adaptive breakpoint alerts and real-time adjustment to the nonlinear dynamics of wine fermentation. The authors developed a novel deep learning model called V-LSTM (Variable-length Long Short-Term Memory) to introduce intelligence to enable predictive analytics. This auto-calibrating architecture supports variable layer depths and cell configurations, enabling accurate forecasting of fermentation metrics. Moreover, the system includes two fuzzy logic modules: a device-level fuzzy controller to estimate alcohol content based on sensor data and a fuzzy encoder that synthetically generates fermentation profiles using a limited set of experimental curves. SmartBarrel experimental results validate the SmartBarrel’s ability to monitor fermentation parameters. Additionally, the implemented models show that the V-LSTM model outperforms existing neural network classifiers and regression models, reducing RMSE loss by at least 45%. Furthermore, the fuzzy alcohol predictor achieved a coefficient of determination ($R^2$) of 0.87, enabling reliable alcohol content estimation without direct alcohol sensing. Full article

The barrel jellyfish (Rhizostoma pulmo), like other cnidarians, shows cnidocytes containing cnidae, responsible for the jellyfish’s stinging properties. The sting of R. pulmo can cause contact dermatitis or urticaria and even systemic symptoms. Recent studies have identified stinging-cell structures in the mucous secretion released in the water column by Cassiopea xamachana, belonging to the same order as R. pulmo. The present paper verifies the release of stinging-cell structures in the water by R. pulmo and reports the case of two 17-year-old adolescents (one male and one female) who were affected by epidermal rashes consistent with the irritating sensations of stinging water. The reaction happened twice in the Ionian Sea; the patients were in proximity to R. pulmo but, on both occasions, there had been absolutely no direct contact with the jellyfish’s tentacles. To test the hypothesis of stinging water caused by R. pulmo, samples of sea water and mucous harvested in close proximity to a living jellyfish were taken and analyzed under a microscope at different magnifications. The microscopic analysis showed the presence of free and aggregated nematocysts in both the samples of water and mucous. It is likely that the free and aggregated nematocysts observed were discharged in the water by the jellyfish and were dispersed by water currents that led them to come into contact with the patients’ skin. At present, it is not known what predisposes humans to the perception of stinging water, and it is reasonable to affirm that caution should be advised for people with an allergic history when entering the water in the presence of jellyfish. Further investigations are required to better understand both the pathophysiological pathways underlying the stinging water phenomenon and the minimum concentration of urticating elements that is able to trigger the onset of stinging water. Full article

In recent decades, the use of wood pieces has been promoted as a viable alternative to barrels to improve the quality of white wines. However, most available studies have focused on red wines. Given that white and red wines present significant oenological differences that affect their development and final characteristics, it is necessary to expand research specifically to the case of white wines. For this reason, this study evaluates the impact of using pieces of traditional oak wood (Quercus petraea (two origins: French and Romanian) and Quercus alba), other oaks (Quercus humboldtti and Quercus candicans) and other genera (Robinia pseudoacacia, Acacia dealbata, Prunus avium and Nothofagus pumilio) on the quality of white wine during the short period of contact with the wood. The results show that aging with the different woods has little effect on the oenological parameters of the wine; however, it does lead to a change in the phenolic composition and in the final chromatic characteristics of the white wines. From a sensory point of view, the wines showed different sensory profiles depending on the type of wood used. In general, the tasting panel preferred the white wine aged with French Quercus petraea wood pieces, followed by the wine aged with Quercus humboldtti wood pieces and the wine aged with Robinia speudoacacia wood pieces. This research improves our understanding of the potential impact of using pieces of different woods in white wines, describing the potential interest of some that have not been studied before, such as Quercus humboldtti. Full article