Surface Penetration Research Articles

Whether the degradation of frying oil affects oil absorption: Tracking fresh and degraded oil in fried potato strips during frying and cooling and microstructure characterization

The effects of frying oil degradation on the oil absorption behavior of fried products remain ambiguous. This study aimed to clarify the effects of frying oil degradation on the oil absorption behavior and micromorphology changes of fried potato strips. Results showed during prolonged frying, oil degradation had a significant impact on the oil absorption and oil distribution of fried potato strips. Frying oil degradation caused the increase of surface oil content and the decrease of surface penetration oil content. The results of traditional methods, low-field nuclear magnetic resonance (LF NMR) technology and confocal laser scanning microscopy (CLSM) together confirmed the changes of oil absorption. CLSM 2D imaging showed starch in potato strips was more prone to combine with degraded oil. Scanning electron microscope and CLSM 3D imaging showed the surface micromorphology of strips fried by degraded oil suffered severe damage. The degradation degree of frying oil can be evaluated by using LF NMR. This paper may provide evidence for the effect of frying oil degradation on the oil absorption of fried foods.

Gapless-REMA100: A gapless 100-m reference elevation model of Antarctica with voids filled by multi-source DEMs

The digital elevation model (DEM) of Antarctica is a fundamental dataset for a wide range of glaciological applications, from fieldwork planning to ice sheet dynamics analysis. The DEM data at high spatial resolution provides a more detailed depiction of the topography. The reference elevation model of Antarctica (REMA) mosaic is a recently released high-resolution Antarctic DEM product with a high absolute vertical accuracy of 1 m or less. The REMA mosaic was generated using an optical photogrammetry technique and can reflect the surface elevation of the ice sheet. However, the REMA mosaic has a large number of data voids of various spatial sizes, which affects its wide glaciological application. Therefore, we propose the generation of a gapless 100-m reference elevation model of Antarctica (Gapless-REMA100) with the voids filled by combining multi-source DEMs. In this study, the best-fit fill DEMs were automatically selected between almost all available circum-Antarctica or regional DEMs. Targeting numerous voids in large areas of the 100-m REMA mosaic, we propose a novel hierarchical delta surface method for interpolating the created delta surface to achieve an efficient, unbiased, and continuous filled surface. High-precision laser altimetry data were used to evaluate the vertical accuracy of the REMA mosaic. To eliminate the influence of the temporal surface elevation change and penetration depth between the DEM and laser altimetry data, we developed a new local contrast evaluation method by calculating the vertical accuracy of the equal-area buffer as a control to that of the center void. The experimental results with the Ice, Cloud and Land elevation Satellite-2 (ICESat-2) laser altimetry data validate that the filled 100-m REMA mosaic of voids can reach an elevation accuracy similar to that of the original REMA dataset for the west and east Antarctic ice sheet as well as the entire continent. In the Antarctic Peninsula area, the vertical accuracy of the filled REMA mosaic by the proposed method is superior to that of the officially released version of the Polar Geospatial Center. This is the first time that a gapless, seamless, and accurate 100-m REMA mosaic has been released which has the potential to be extensively used in glaciological applications. The proposed methods can also be used in void-filling of different types of DEM products and their elevation accuracy evaluations.

Orthotropic wetting dynamics of wood: trade-off between surface spreading and penetration

Orthotropic wetting dynamics of wood: trade-off between surface spreading and penetration

Rock Dynamic Fracture Characteristics by Mini‐Linear Shaped Charge Jet Penetration: A Case Study

An insignificant number of studies have focused on employing penetration using mini‐linear shaped charge jets for directionally controlled splitting of massive rocks. In this study, we adopt a numerical calculation method to simulate the penetration and formation of the main splitting surface of a concrete specimen, considering a wedge angle of 45° in both processes. The surface on the principal axial plane is found to split first due to linear jet penetration. In the case of single primary‐plane splitting, cracks appear at both ends of the long axis of the penetration crack and the splitting surface extends diagonally from the center of the penetration. A transverse crack separates the splitting surface and the radial‐fracture surface, and the degree of fracture decreases along the direction of the height of the specimen. Finally, a realistic physical model demonstrating penetration using a mini‐linearshaped charge jet is established. It is a rapid and safe blasting technology to handle hazardous massive rocks during emergency rescuing or mining.

Sea Surface States Detection in Polar Regions Using Measurements of Ground-Based GNSS Interferometric Reflectometry

This article analyzes the interferometric measurements of ground-based global navigation satellite systems (GNSSs) stations and proposes a novel method for sea surface states detection. The novel technique benefits from a cost-effective data collection from a large number of global GNSS stations. In this study, we extend a traditional GNSS interferometry reflectometry (GNSS-IR) model so that it can be applied to a multilayer surface by considering the surface roughness, total reflectivity, and penetration loss in multilayer situations. Based on this model, the wavelet analysis is used to perform parameterization on the interferometric observations represented by the signal to noise ratio (SNR). An integration factor and power curve are also proposed to characterize the surface state transition. One-year data from an Arctic geodetic GNSS station in the north of Canada are collected for analysis to validate the proposed approach in comparison with the existing methods based on the amplitude and damping factors. The results show that the new method demonstrates good usability and sensitivity to detect surface state transitions, e.g., icing, snowfall, and snow melting. However, the amplitude and damping factor-based methods derived from the single-layer model are only able to detect the pure ice surface and cannot respond to thick snow conditions. Finally, the high-resolution spaceborne images confirm the reliability of this method, exhibiting a great potential for long-term coastal sea surface detection based on the global geodetic GNSS stations and later being expected to be applied to sense cryosphere surface states.

A Comparative Analysis of Surface Characteristics of Enamel after Conventional Acid Etching and Er,Cr:YSSG Laser Irradiation.

BackgroundTo evaluate the influence of Erbium, Chromium:Yttrium-Scandium-Gallium-Garnet (Er,Cr:YSGG) laser irradiation (2W 15Hz, 2W 25Hz) on Penetration Depth, Surface Roughness, Surface Morphology and Etching Pattern of enamel and to compare it with conventional acid etching. Material and MethodsSixty sound human premolars extracted for orthodontic reasons were used for this study. Penetration Depth and Surface Roughness between Acid Etched and Laser Etched Enamel were evaluated using Non-contact 3D- Profilometer .Surface Morphology and the Etching Pattern were evaluated using Field Emission - Scanning Electron Microscope. ResultsOn comparing the maximum depth and surface roughness values among all the three groups, highest was found in the acid-etched group, followed by the 2W 15Hz laser–etched group and the least was with the 2W 25Hz laser–etched group. The laser etching of enamel surface with an Er,Cr:YSGG laser system showed Type 3 etching pattern, whereas acid etched surface showed Type 1 etching pattern as described by Silverstone (1974). ConclusionsEr,Cr:YSGG laser irradiation produces favourable etching pattern and micro-irregularities that are suitable for resin penetration. Moreover, due to its decreased surface roughness and penetration depth, laser etching can significantly decrease the probability of formation of white spot lesions which is proved to be the potential disadvantage of conventional acid etching. Hence, laser etching can be preferred over the conventional phosphoric acid etching for orthodontic bonding. Key words:Laser, Er,Cr:YSGG, Surface Roughness, Etching Pattern,Penetration Depth,SEM, Laboratory Research, Acid etching.

Centrifuge experiment on the penetration test for evaluating undrained strength of deep-sea surface soils

Rapid advances in deep-sea mining engineering have created an urgent need for the accurate evaluation of the undrained strength of marine soils, especially surface soils. Significant achievements have been made using full-flow penetration penetrometers to evaluate marine soil strength in the deep penetration; however, a method considering the effect of ambient water on the surface penetration needs to be established urgently. In this study, penetrometers with multiple probes were developed and used to conduct centrifuge experiments on South China Sea soil and kaolin clay. First, the forces on the probes throughout the penetration process were systematically analyzed and quantified. Second, the spatial influence zone was determined by capturing the resistance changes and sample crack development, and the penetration depth for a sample to reach a stable failure mode was given. Third, the vane shear strength was used to invert the penetration resistance factor of the ball and determine the range of the penetration resistance factor values. Furthermore, a methodology to determine the penetration resistance factors for surface marine soils was established. Finally, the effect of the water cavity above various probes in the surface penetration was used to formulate an internal mechanism for variations in the penetration resistance factor.

The effect of beam oscillation on laser welding of AA2219-T87 under subatmospheric pressure

Aluminum alloy AA2219 is widely used in the aerospace industry due to its high specific strength, and corrosion resistance, especially for the production of propellant tanks of space rockets. With the rapid development of laser sources, the welding of metal materials changes gradually from arc welding to laser welding, but pore defect drags the application of laser welding of aluminum alloy. To solve this bottleneck problem, this paper investigates the effect of laser beam oscillation on welding of AA2219 under subatmospheric pressure (LOWSP). The experimental results showed that LOWSP has significantly improved the surface morphology, penetration depth, microstructure,and mechanical properties of the weld seam. The EBSD testing analysis shows that the low-angle grain boundaries (LAGBs) take up the largest proportion in the microstructure with the increased proportion of equiaxed grains, and the grain size is further refined in LOWSP. When welded at the optimal laser beam oscillation frequency of 80 Hz under the pressure of 102 Pa, the pore was almost inhibited and the tensile strength of the weld seam reached 388.62 MPa, up to 83.16% of the base metal (the current level of the industry is generally between 300 ∼ 360 MPa). It is believed that the reduced boiling point of the aluminum alloy under subatmospheric pressure accelerated the molten metal flow rate, the stirring effect of laser beam oscillation on weld microstructure within molten pool significantly eliminate porosity, therefore the LOWSP process generated the refined grain size and the improved mechanical properties of the weld seam.

7-Tesla MRI Evaluation of the Knee, 25 Years after Cartilage Repair Surgery: The Influence of Intralesional Osteophytes on Biochemical Quality of Cartilage.

ObjectiveTo evaluate the morphological and biochemical quality of cartilage transplants and surrounding articular cartilage of patients 25 years after perichondrium transplantation (PT) and autologous chondrocyte transplantation (ACT) as measured by ultra-high-field 7-Tesla (7T) magnetic resonance imaging (MRI) and to present these findings next to clinical outcome.DesignSeven PT patients and 5 ACT patients who underwent surgery on the femoral condyle between 1986 and 1996 were included. Patient-reported outcome measures (PROMs) were assessed by the clinical questionnaires: Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC), and Visual Analogue Scale (VAS) for knee pain. The morphological (MOCART score) and biochemical quality (glycosaminoglycans [GAGs] content and collagen integrity) of cartilage transplants and surrounding articular cartilage were analyzed by 7T MRI. The results of the PT and ACT patients were compared. Finally, a detailed morphological analysis of the grafts alone was performed.ResultsNo statistically significant difference was found for the PROMs and MOCART scores of PT and ACT patients. Evaluation of the graft alone showed poor repair tissue quality and high prevalence of intralesional osteophyte formation in both the PT and ACT patients. Penetration of the graft surface by the intralesional osteophyte was related to biochemically damaged opposing tibial cartilage; GAG content was significantly lower in patients with an osteophyte penetrating the graft surface.ConclusionsBoth PT and ACT patients have a high incidence of intralesional osteophyte formation 25 years after surgery. The resulting biochemical damage to the opposing tibial cartilage might be dependent on osteophyte morphology.

Combinational Fusion and Global Attention of the Single-Shot Method for Synthetic Aperture Radar Ship Detection

Synthetic Aperture Radar (SAR), an active remote sensing imaging radar technology, has certain surface penetration ability and can work all day and in all weather conditions. It is widely applied in ship detection to quickly collect ship information on the ocean surface from SAR images. However, the ship SAR images are often blurred, have large noise interference, and contain more small targets, which pose challenges to popular one-stage detectors, such as the single-shot multi-box detector (SSD). We designed a novel network structure, a combinational fusion SSD (CF-SSD), based on the framework of the original SSD, to solve these problems. It mainly includes three blocks, namely a combinational fusion (CF) block, a global attention module (GAM), and a mixed loss function block, to significantly improve the detection accuracy of SAR images and remote sensing images and maintain a fast inference speed. The CF block equips every feature map with the ability to detect objects of all sizes at different levels and forms a consistent and powerful detection structure to learn more useful information for SAR features. The GAM block produces attention weights and considers the channel attention information of various scale feature information or cross-layer maps so that it can obtain better feature representations from the global perspective. The mixed loss function block can better learn the positions of the truth anchor boxes by considering corner and center coordinates simultaneously. CF-SSD can effectively extract and fuse the features, avoid the loss of small or blurred object information, and precisely locate the object position from SAR images. We conducted experiments on the SAR ship dataset SSDD, and achieved a 90.3% mAP and fast inference speed close to that of the original SSD. We also tested our model on the remote sensing dataset NWPU VHR-10 and the common dataset VOC2007. The experimental results indicate that our proposed model simultaneously achieves excellent detection performance and high efficiency.

Comprehensive Analysis of the Stability and Design of a High Cutting Rock Slope

To realize the harmonious unification of safety and economy when designing slopes, we used geological analysis and performed a qualitative evaluation to investigate the controlling factors affecting slope stability. The finite element strength reduction method (SRM) and traditional limit equilibrium method were used to investigate the stability safety factor of a high and steep rock cutting slope in Northern Guangdong. The results showed that the influence of the structure surface on slope stability is determined by the combination of the structure surface, shape of the structure surface, filling between structure surfaces, penetration of the structure surface, and water content and sensitivity of the structure surface, the influence of only one factor on slope stability is limited. We analyzed the slope and design it optimally, the results showed after reinforcement of the second-level slope, the slope revealed an incompletely penetrated shallow slip zone and an evident deep potential slip zone. Compared to the reinforcement that was without an anchor cable, the safety factor increased when the potential slip zone moved down. Based on the SRM and traditional limit equilibrium method, the design scheme of this slope meets the safety requirements of permanent slopes, and the excavated stone can be used for roadbed filling. Thus, the optimized design scheme can coordinate safety and economic indicators. Moreover, the application of strong engineering measures to the joint development of slope in engineering practice is conservative and unreasonable. The design of these slopes can provide a reference for slope design and construction.

Lateral Translation of the Patella in MPFC Reconstruction: A Biomechanical Study of Three Surgical Techniques (210)

Objectives:Recurrent patellar instability (RPI) is a common knee disorder and can lead to chronic pain and functional disability. Surgically addressing recurrent patella instability has classically focused on reconstruction of the MPFL, which has widely become the standard of care either in isolation or concomitantly with other patellar realignment procedures. Complications following MPFL reconstruction include patellar fracture, articular surface penetration, and physeal injury in skeletally immature patients. In an effort to avoid these, other surgical techniques have been described. While these alternative MPFC reconstructions have anatomical support and the theoretical potential to reduce complications, it is unknown whether differences exist in lateral patellar translation and thus their effectiveness in adequately stabilizing the patella. The purpose of this study was to investigate whether differences exist in the ability to prevent lateral patellar translation between three distinct medial patellar stabilizing surgical procedures at varying knee flexion angles.Methods:Six cadaveric knee specimens were dissected, potted, and placed in a customized jig for testing. The quadricep muscle groups were separated into three components and loaded with a total of 175 N in anatomic directions using a weighted pulley system. Lateral patellar displacement was measured at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of knee flexion using a tensile testing machine with a 20 N lateral force applied to the patella. Each specimen was tested with the MPFC intact and sectioned, and after each of the three reconstruction techniques: medial patellofemoral ligament (MPFL) reconstruction, hybrid (proximal medial patellar restraints - PMPR) reconstruction, and medial quadriceps-tendon femoral (MQTFL) reconstruction. Statistical analysis used the Friedman and Wilcoxon rank sum tests due to non-normally distributed data.Results:There was significantly increased lateral patellar displacement following MPFC sectioning when compared to the intact state in early degrees of flexion (10° to 30°) (p<0.05). All three reconstruction groups adequately restored patella stability and reduced lateral patellar displacement following medial soft tissue sectioning by 42%, 41% and 33% following MPFL, Hybrid and MQTFL reconstruction, respectively, from 0° to 30° of knee flexion (p<0.05 for each reconstruction group). When compared to the native, intact medial restraints group, all three reconstruction groups demonstrated reduced patella translation at full knee extension, while the MPFL and Hybrid reconstruction groups additionally demonstrated significant reduction of patella translation at 10° of flexion as well (p<0.05). When comparing patella displacement between reconstruction groups, no significant difference was observed at any degrees of flexion between the three groups.Conclusions:This biomechanical cadaveric study demonstrates the efficacy of three different MPFC reconstruction techniques in restoring patella stability following MPFC sectioning, especially at lower knee flexion angles where the medial soft tissue restraints play a more important role. Although all three reconstruction groups demonstrated less patella translation than the native MPFL intact knee, MPFL reconstruction appears to provide the most robust patella stabilization, whereas MQTFL reconstruction may be the most forgiving construct. Future clinical studies are needed to investigate the clinical correlation of these findings.

Investigating the Effect of Waste Polystyrene Dissolved in Paint Thinner Product as an Admixture and Coating Sealer on Concrete Properties

Concrete is one of the major most widely used construction materials, due to its affordability, wide usability, and formability. Unfortunately, damages to concrete may occur over time causing structural and/or appearance defects. Concrete damage is mostly caused by surface water intrusion and penetration. Water intrusion can be caused by rainwater, poor drainage, and surrounding atmosphere humidity along with chloride ion ingress in marine structures and from de-icing salts in winter. If not prevented, water intrusion may lead to severe concrete deterioration, corrosion of reinforcement, and ultimately strength loss. Therefore, the main objective of this research has been to introduce and investigate the ability of a new type of admixture and coating material, by the use of waste material, on moisture sensitivity and chloride ion ingress of concrete. The polystyrene used in this research, as waste material, can be easily dissolved in paint thinner in order to produce a viscous solution. This viscous product is investigated in this study as an admixture to the fresh concrete and a coating sealer to the hardened concrete. The effect of the new material as an admixture or a coating sealer on permeability, porosity, absorption of the concrete, and the chloride ion effect have been all investigated. Specific tests per ASTM standards have been employed on the fresh and hardened concrete in order to achieve these objectives. Results have clearly showed that the new material has been very successful in reducing the permeability of the concrete when used as a coating sealer but not as an admixture. Therefore, a new type of coating sealer could be introduced in the construction market that can be easily produced by the use of a recycled/waste material.

The adjuvant effects of rosin and coconut oil on nicosulfuron and mesotrione to control weeds

Natural adjuvants are novel options to reduce the doses of chemical herbicides. The aim of the current study was to examine the compositions and adjuvant effects of rosin and coconut oil on herbicides using a combination of indoor experiment and field trial. The GC-MS results showed that the main component of rosin was abietic acid (40.02%), and the main components of coconut oil were 2-pentanone, 4-hydroxy-4-methyl- (21.45%) and dodecanoic acid (14.59%). In greenhouse experiment, rosin showed a significant adjuvant effect on nicosulfuron against Digitaria sanguinalis and Amaranthus retroflexus, with the GR50 ratios of 1.47 and 1.69, respectively. The GR50 values of nicosulfuron in the present of coconut oil were 3.99 and 10.13g a.i./hm2 against D. sanguinalis and A. retroflexus, lower than that of individual application. The adjuvant effect of rosin and coconut oil on mesotrione was also found. In field trial, the fresh weight control efficiency of nicosulfuron (45g a.i./hm2) and mesotrione (112.5g a.i./hm2) was significantly improved after the addition of rosin and coconut oil, similar with that of recommended dose. Rosin and coconut oil could reduce the contact angle of nicosulfuron, with the results of 56.68° and 53.90°, respectively, lower than that of individual application. Furthermore, rosin and coconut oil could decrease the surface tension, wetting and penetration time; and increase the spreading diameter and maximum retention. Both rosin and coconut oil have adjuvant effects on herbicides in the lab & field with multiple mechanisms. Thus, they have the potential to be developed into natural adjuvants for herbicide formulation to control weeds.

Cropping system and soil texture shape soil health outcomes and scoring functions

Inherent soil properties often define the soil's basic functions, but human management can have superimposing impacts on the quality of soil. It is therefore challenging to interpret Soil Health (SH) measurements in the context of a region's soils and cropping systems. We examined the effects of soil texture, a dominant inherent soil property, and cropping system on SH indicators for New York, USA soils. A dataset of 1,750 soil samples was analyzed for SH indicators including Soil Organic Matter (SOM), Permanganate-Oxidizable Carbon (POXC), Soil Respiration (Resp), soil protein (Protein), Available Water Capacity (AWC), Wet Aggregate Stability (WAS), surface and subsurface penetration resistance, and seven soil chemical properties. Measured physical and biological indicators were affected by both soil texture and cropping system. AWC measured on disturbed samples was mostly affected by texture (37.4% variance explained), while Resp, Protein, and WAS were mostly impacted by cropping system (11.7%, 14.7%, and 22.1% variance explained, respectively). POXC was equally affected by texture and cropping system. Pasture and Mixed Vegetable systems tended to have the highest biological and physical soil health, followed by Dairy Crop systems. Annual Grain and Processing Vegetable cropping systems tended to have the lowest soil health. The effects of cropping systems are presumably linked to differences in the carbon and nutrient balances and the amount of soil disturbance through tillage. New scoring functions based on soil texture classes and cropping systems were developed for New York State to facilitate interpretation of SH test results in the context of the production-specific environments.

Eye fluke effects on Danish freshwater fish: Field and experimental investigations.

Eye flukes in fish are common in freshwater lakes. Fish become infected by the penetration of cercariae released from freshwater snails, and high infection pressures may be associated with mortalities in a Danish lake. Examination of two other freshwater lakes, combined with laboratory study, supported the notion. We investigated 77 freshwater fish from two lakes and the infection level suggested the occurrence of a high cercarial infection pressure in the Danish lakes. Dominant genera were Tylodelphys and Diplostomum covering a range of species identified by PCR and sequencing of the 18S (partial)‐ITS1‐5.8S‐ITS2‐28S (partial) of the rDNA. Cercariae of the prevalent species Diplostomum pseudospathaceum were used to infect zebrafish Danio rerio for the elucidation of short‐term effects on the fish host. Zebrafish did not display abnormal behaviour when exposed to 200–400 cercariae, but a dosage of 600 and 1,000 cercariae/fish proved lethal. When fish were exposed to sublethal dosages, 19 out of 27 immune genes were significantly regulated and three genes encoding cytokine (IL 4/13B, IL‐6 and IL‐8) were upregulated at 3 hr post‐infection (hpi), whereas others were downregulated especially at a later time point. We suggest that direct massive cercarial penetration of fish surfaces may be detrimental and may represent a threat to fish populations.

Flexible High-Resolution Force and Dimpling Measurement System for Pia and Dura Penetration During In Vivo Microelectrode Insertion Into Rat Brain.

Objective:Understanding the in vivo force and tissue dimpling during micro-electrode implantation into the brain are important for neuro-electrophysiology to minimize damage while enabling accurate placement and stable chronic extracellular electrophysiological recordings. Prior studies were unable to measure the sub-mN forces exerted during in vivo insertion of small electrodes. Here, we have investigated the in vivo force and dimpling depth profiles during brain surface membrane rupture (including dura) in anesthetized rats.Methods:A µN-resolution cantilever beam-based measurement system was designed, built, and calibrated and adapted for in vivo use. A total of 244 in vivo insertion tests were conducted on 8 anesthetized rats with 121 through pia mater and 123 through dura and pia combined.Results:Both microwire tip sharpening and diameter reduction reduced membrane rupture force (insertion force) and eased brain surface penetration. But dimpling depth and rupture force are not always strongly correlated. Multi-shank silicon probes showed smaller dimpling and rupture force per shank than single shank devices.Conclusion:A force measurement system with flexible range and µN-level resolution (up to 0.032 µN) was achieved and proved feasible. For both pia-only and dura-pia penetrations in anesthetized rats, the rupture force and membrane dimpling depth at rupture are linearly related to the microwire diameter.Significance:We have developed a new system with both µN-level resolution and capacity to be used in vivo for measurement of force profiles of various neural interfaces into the brain. This allows quantification of brain tissue cutting and provides design guidelines for optimal neural interfaces.

Using PyC modified 3D carbon fiber to reinforce UHTC under low temperature sintering without pressure

Finding the optimum balance between strength and toughness, as well as acquiring reliable thermal shock resistance and oxidation resistance, has always been the most concerned topic in the discussion of ultra-high temperature ceramic composites. Herein, PyC modified 3D carbon fiber is used to reinforce ultra-high temperature ceramic (UHTC). The macroscopic block composite with large size is successfully fabricated through low temperature sintering at 1300 °C without pressure. The prepared PyC modified 3D Cf/ZrC-SiC composites simultaneously possess excellent physical and chemical stability under the synergistic effect of PyC interface layer and low temperature sintering without pressure. The fracture toughness is increased in magnitude to 13.05 ± 1.72 MPa·m1/2 accompanied by reliable flexural strength of 251 ± 27 MPa. After rapid thermal shock spanning from room temperature (RT) to 1200 °C, there are no visible surface penetrating cracks, spalling, or structural fragmentation. The maximum critical temperature difference reaches 875 °C, which is nearly three times higher than that of traditional monolithic ceramics. The haunting puzzle of intrinsic brittleness and low damage tolerance are resolved fundamentally. Under the protection of PyC interface layer, the carbon fibers around oxide layer and matrix remain structure intact after static oxidation at 1500 °C for 30 min. The oxide layer has reliable physical and chemical stability and resists the erosion from fierce oxidizing atmosphere, ensuring the excellent oxidation resistance of the composites. In a sense, the present work provides promising universality in designability and achievement of 3D carbon fiber reinforced ceramic composites.

TWC-Net: A SAR Ship Detection Using Two-Way Convolution and Multiscale Feature Mapping

Synthetic aperture radar (SAR) is an active earth observation system with a certain surface penetration capability and can be employed to observations all-day and all-weather. Ship detection using SAR is of great significance to maritime safety and port management. With the wide application of in-depth learning in ordinary images and good results, an increasing number of detection algorithms began entering the field of remote sensing images. SAR image has the characteristics of small targets, high noise, and sparse targets. Two-stage detection methods, such as faster regions with convolution neural network (Faster RCNN), have good results when applied to ship target detection based on the SAR graph, but their efficiency is low and their structure requires many computing resources, so they are not suitable for real-time detection. One-stage target detection methods, such as single shot multibox detector (SSD), make up for the shortage of the two-stage algorithm in speed but lack effective use of information from different layers, so it is not as good as the two-stage algorithm in small target detection. We propose the two-way convolution network (TWC-Net) based on a two-way convolution structure and use multiscale feature mapping to process SAR images. The two-way convolution module can effectively extract the feature from SAR images, and the multiscale mapping module can effectively process shallow and deep feature information. TWC-Net can avoid the loss of small target information during the feature extraction, while guaranteeing good perception of a large target by the deep feature map. We tested the performance of our proposed method using a common SAR ship dataset SSDD. The experimental results show that our proposed method has a higher recall rate and precision, and the F-Measure is 93.32%. It has smaller parameters and memory consumption than other methods and is superior to other methods.

Urethral Catheter Biofilms Reveal Plasticity in Bacterial Composition and Metabolism and Withstand Host Immune Defenses in Hypoxic Environment.

Biofilms composed of multiple microorganisms colonize the surfaces of indwelling urethral catheters that are used serially by neurogenic bladder patients and cause chronic infections. Well-adapted pathogens in this niche are Escherichia coli, Proteus, and Enterococcus spp., species that cycle through adhesion and multilayered cell growth, trigger host immune responses, are starved off nutrients, and then disperse. Viable microbial foci retained in the urinary tract recolonize catheter surfaces. The molecular adaptations of bacteria in catheter biofilms (CBs) are not well-understood, promising new insights into this pathology based on host and microbial meta-omics analyses from clinical specimens. We examined catheters from nine neurogenic bladder patients longitudinally over up to 6 months. Taxonomic analyses from 16S rRNA gene sequencing and liquid chromatography–tandem mass spectrometry (LC-MS/MS)–based proteomics revealed that 95% of all catheter and corresponding urinary pellet (UP) samples contained bacteria. CB biomasses were dominated by Enterobacteriaceae spp. and often accompanied by lactic acid and anaerobic bacteria. Systemic antibiotic drug treatments of patients resulted in either transient or lasting microbial community perturbations. Neutrophil effector proteins were abundant not only in UP but also CB samples, indicating their penetration of biofilm surfaces. In the context of one patient who advanced to a kidney infection, Proteus mirabilis proteomic data suggested a combination of factors associated with this disease complication: CB biomasses were high; the bacteria produced urease alkalinizing the pH and triggering urinary salt deposition on luminal catheter surfaces; P. mirabilis utilized energy-producing respiratory systems more than in CBs from other patients. The NADH:quinone oxidoreductase II (Nqr), a Na+ translocating enzyme not operating as a proton pump, and the nitrate reductase A (Nar) equipped the pathogen with electron transport chains promoting growth under hypoxic conditions. Both P. mirabilis and E. coli featured repertoires of transition metal ion acquisition systems in response to human host-mediated iron and zinc sequestration. We discovered a new drug target, the Nqr respiratory system, whose deactivation may compromise P. mirabilis growth in a basic pH milieu. Animal models would not allow such molecular-level insights into polymicrobial biofilm metabolism and interactions because the complexity cannot be replicated.