Reflection Intensity Research Articles

How Well Does 4‐km WRF Model Predict Three‐Dimensional Reflectivity Structure Over China as Compared to Radar Observations?

AbstractThe performance of 4‐km Weather Research and Forecasting model in predicting reflectivity structure in China over three summer months is investigated using three‐dimensional (3D) reflectivity observations. Three verification domains, namely Southern China (SC), Central and Eastern China , and North China, that correspond to the three major rainfall centers of mainland China are selected. Results show that the forecasts reproduce the distribution and diurnal variation of precipitation well, but significant differences exist in the vertical distributions of the predicted and observed reflectivities. In observations, the highest frequency (of reflectivity ≥35 dBZ) occurs between 3 and 6 km, whereas it is at the surface in the forecast. The forecasts tend to over‐predict reflectivity intensity at the lower levels, especially in SC. Further evaluation using object‐based verification methods show that the forecasts greatly underestimate the afternoon peak frequency of precipitation clouds with reflectivity >30 dBZ. The forecasts fail to reproduce the diurnal variation of 35 dBZ mean and maximum height of the objects, producing less variation than observations. Analyses show that the failure in properly reproducing small‐scale reflectivity objects (with diameter <100 km) is primarily responsible for the underestimation of the mean and maximum object heights. Evaluation using additional 3D information show that the forecasts tend to produce a greater proportion of faster‐moving small‐scale objects. This study reveals that the simulation of the 3D structure of precipitation clouds in terms of reflectivity remains a great challenge, especially for smaller convective cells.

High-Angle Structural Color Scattering Features from Polymeric Photonic Structures

Three-dimensional goniometric measurements of structural color from melt-sheared polymer nanoparticle composites is presented revealing high-angle features arising from Bragg scattering. These features are presented in terms of ‘scattering cones’ from full 180° hemispherical scans showing the spectroscopic and angular properties of these scattering spots. This work identifies the Miller indices of the photonic crystal planes responsible for these features and makes further observations as to the appearance of this scattering in the context of these structures as quasi-ordered systems. We probe structural color metrics such as peak wavelength and the tunability of reflectance intensities. As such, this report contributes towards an improved understanding of Bragg scattering and structural color from structures with inherent disorder. The complexity and specificity of color quality across the scattering hemisphere is an important consideration for practical uses such as in sensing applications, and we suggest that soft photonics, in particular, are strong candidates in high-angle color uses.

Research on Reflection Mechanism of Nonuniform Plasma

The surface of the near-space hypersonic vehicle is covered with a plasma sheath (PSh) with fluid properties. During the radar detection of hypersonic vehicles, the spatial distribution characteristics of PSh parameters affect the reflected wave intensity and the position of the maximum reflection layer of plasma in the vehicle’s different areas, resulting in significant differences in the intensity and frequency offset of echo signals in various areas. In order to further study the reflection characteristics of nonuniform plasma, this article uses the equivalent wave impedance method to calculate the reflection and transmission coefficients of each layer of plasma, analyzes the reflection intensity distribution mechanism of nonuniform plasma, and reveals the EM shielding effect (ES-effect) of plasma. Based on the typical carrier frequency, collision frequency, electron density, and electron density distribution gradient, the variation law of maximum reflection position and maximum reflection intensity in nonuniform plasma is revealed. The research results lay a theoretical foundation for analyzing echo signal characteristics of the PSh-covered target, radar detection anomaly suppression, and EM stealth.

Research on the Spatial Distribution Mechanism of the EM Reflection Intensity of a Plasma-Sheath-Covered Target

A plasma sheath forms on the surface of a hypersonic vehicle due to aerodynamic thermal ionization. Due to the distribution characteristics of plasma-sheath parameters, the reflection intensity at different positions of the plasma sheath is different, affecting the vehicle’s electromagnetic (EM) scattering characteristics. Based on the numerical calculation results of the plasma flow field at typical altitudes and velocities, this article solves the reflection intensity of a typical reference area. It obtains the spatial distribution characteristics of the EM reflection intensity from the stagnation-point to tail-end areas of the plasma-sheath-covered target. By analyzing the influence of different flight altitudes and different carrier frequencies on the reflection intensity of each area, the variation law of the spatial distribution of the EM reflection intensity of the plasma-sheath-covered target is revealed. The research results provide a theoretical basis for radar detection, the measurement of EM scattering characteristics, and the active EM-control stealth of plasma-sheath-covered targets.

An Edge-Filtered Optical Fiber Interrogator for Thermoplastic Polymer Analysis.

The present paper deals with the determination of thermodynamic quantities of thermoplastic polymers by using an optical fiber interrogator. Typically, laboratory methods such as differential scanning calorimetry (DSC) or thermomechanical analysis (TMA) are a reliable state-of-the-art option for thermal polymer analysis. The related laboratory commodities for such methods are of high cost and are impractical for field applications. In this work, an edge-filter-based optical fiber interrogator, which was originally developed to detect the reflection spectrum of fiber Bragg grating sensors, is utilized for the detection of the boundary reflection intensities of the cleaved end of a standard telecommunication optical fiber (SMF28e). By means of the Fresnel equations, the temperature-dependent refractive index of thermoplastic polymer materials is measured. Demonstrated with the amorphous thermoplastic polymers polyetherimide (PEI) and polyethersulfone (PES), an alternative to DSC and TMA is presented as the glass transition temperatures and coefficients of thermal expansion are derived. A DSC alternative in the semi-crystalline polymer analysis with the absence of a crystal structure is shown as the melting temperature and cooling-rate-dependent crystallization temperatures of polyether ether ketone (PEEK) are detected. The proposed method shows that thermal thermoplastic analysis can be performed with a flexible, low-cost and multipurpose device.

Drag force modification model for turbulent suspended-load sediment solid–liquid two-phase flow

The calculation accuracy of a solid–liquid two-phase flow numerical simulation is related directly to the reliability of the results obtained. The interphase drag force significantly affects the calculation results of the solid concentration distribution of suspended-load sediment solid–liquid two-phase flow. However, the conventional Wen–Yu drag force model is obtained by adding solid concentration to the standard drag force coefficient curves. The model does not consider the influence of turbulence, which is a comprehensive reflection of particle inertia and liquid turbulence intensity. To improve the calculation accuracy of the Wen–Yu model, the particle inertia and turbulence intensity factors are introduced to express the comprehensive influence of the particle inertia and liquid turbulent intensity on the drag force coefficient for the suspended-load sediment solid–liquid two-phase flow. The turbulence modification function preliminary expression is determined and further modified to improve the calculation accuracy for a particle Reynolds number of less than 100 by combining experimental data and the least square method through experiments and theoretical research. Then, the final expression of the turbulence modification function is proposed to help modify the drag force coefficient of the Wen–Yu model, and finally establish the modified turbulence effect (MTE)-Wen–Yu drag force modification model. The calculations for the suspended-load sediment solid–liquid two-phase flow in the circular tubes show that the solid-phase concentration values calculated by the MTE-Wen–Yu drag force model are considerably closer to the experimental results than those obtained by the Wen–Yu drag force model in the suspended-load sediment solid–liquid two-phase flow calculation for different inlet velocities, inlet solid concentrations, and particle diameters. Hence, the calculation accuracy of the MTE-Wen–Yu model is higher than that of the Wen–Yu drag force model. The calculation precision of the solid-phase concentration distribution calculated using the MTE-Wen–Yu drag force model decreases with the increase in particle diameter owing to the high quality and large inertia of large particles. Therefore, it is more suitable for the numerical simulation of suspended-load sediment solid–liquid two-phase flow with a small particle diameter.

Use of Reflectometer Optipen to assess the preventive effect of a sugarcane cystatin on initial dental erosion in vivo

The sugarcane cystatin 5 (CaneCPI-5) showed protection against erosion and erosive tooth wear (ETW) under several protocols. However, evaluating these conditions in vivo is hard due to the lack of a suitable device. The aim of this study was to use clinically the relative surface reflection intensity (%SRI) by the Reflectometer Optipen to assess the acquired pellicle engineering with CaneCPI-5 rinse for the prevention of initial erosion in vivo. Nine volunteers were distributed in three cross-over phases, according to the rinse used, as follows: 1) Deionized water (negative control); 2) Elmex® (800 ppm Sn2+, 500 ppm F-; positive control); 3) 0.1 mg/mL CaneCPI-5. The following experimental steps were performed: Initially, the volunteers received prophylaxis and the initial %SRI was performed. Subsequently, they rinsed with the solutions (10 mL; 1min), followed by the formation of the acquired enamel pellicle (AEP; 120min). After, the erosive challenge with citric acid 1%, pH 2.5 (10 μL; 10s) was performed (in isolation) on the buccal surface of the maxillary central incisors (right and left). The calcium present in the acid was analyzed by Arsenazo III method. Finally, the final %SRI was performed. Data were analyzed by Kruskal-Wallis/Dunn's tests and Spearman's correlation were used (p < 0.05). For both variables, the negative control led to significantly less protection (lower reflectivity and higher calcium release) in comparison with the other groups. The best protection (higher reflectivity and lower calcium release) was observed for the Elmex® and the CaneCPI-5 groups, with no significant differences between them (p < 0.05). There was a significant correlation between both analyzes. The Reflectometer Optipen demonstrated to be a good device to assess clinically. Moreover, CaneCPI-5 rinse proved effective through acquired pellicle engineering against initial erosion in vivo.

An efficient optical diffuser fabricated from fungal mycelium

Scattering of light from randomly textured materials is ubiquitous and of great interest in biology and for diverse applications—including filtering, light trapping in solar cells, and speckle photography. One attractive means to build these materials is by harnessing the complexity present in structures of biological origin. Here, we report on the development of a random phase diffuser based on intertwined filamentous cells (hyphae) of the fungus Trichoderma atroviride. A fungal colony (mycelium) is grown on the surface of a gel medium, and then removed, fixated, and dehydrated, resulting in a free-standing, two-dimensional random mesh (1 cm × 1 cm × 5 μm) composed of rigid hyphae separated by air gaps. A laser beam incident on the bioplate results in speckle patterns of nearly equal intensity in transmission and reflection. By modeling the bioplate as composed of optical phase elements and computing Fraunhofer diffraction, we recover the overall shape of the observed diffuse light spot. As the hyphal density composing the sample is increased, all optical power is in the speckle pattern, and approximate Lambertian transmissivity is reached. Altogether, our observations suggest that a planar fungal colony can scatter light efficiently by imparting a random phase. These results underscore the potential of a biological structure to develop optical elements and to use light scattering to evaluate morphology in complex structures—such as filamentous mycelia.

Enlarged rete pegs with excessive accumulation of melanosomes leading to darker aging spots revealed by histomorphological measurements of internal structures of the epidermis.

Various histological studies of facial pigmented spot sites such as solar lentigo have been reported, but few studies have used quantitative indices by histomorphometric analysis of the internal structure of pigmented spot sites using non-invasive methods. In the present study, to quantitatively elucidate morphological changes in the epidermis in male, darker-pigmented spots and female, light-pigmented spots, indices that characterize the internal structure of the epidermis in pigmented spot sites were measured using in vivo confocal laser scanning microscopy (CLSM). The darkness of pigmented spots on the cheeks of 69 women and 43 men was analysed using image analysis software. The L* value was calculated from RGB values obtained from facial images. The internal structures of pigmented spots on the cheeks of 13 subjects were observed by CLSM. Various parameters were measured using CLSM images from the surface of the stratum corneum to the bottom of the dermal papillae, including the thickness of the epidermis, melanosome content, and shape of the dermal papillae. Mean ΔL* values between pigmented spots and non-pigmented areas of male subjects were significantly increased in the 40s and 50s compared with those of female subjects. Conspicuous pigmented spots increased in the 40s in male subjects and the 50s in female subjects. In CLSM observations, significant increases in the thickness of the epidermis and melanosome content were confirmed in pigmented spots compared with surrounding non-pigmented areas. In particular, melanosome content in the male subject group with dark-coloured pigmented spots increased significantly to about eight times that of non-pigmented areas, and more than double that of the male subject group with light-coloured pigmented spots. From the measurements of quantitative parameters, morphological changes in the epidermis were clearly related to the surface colour tone of pigmented spots. Darker pigmented spot sites tended to show longer rete pegs in the epidermis. Accumulation of melanosomes in epidermal basal cells could be considered to increase with the degree of elongation of rete pegs at pigmented spot sites and, thus, induce darker pigmented spots.

Effects of Microphysics Parameterizations on Forecasting a Severe Hailstorm of 30 April 2021 in Eastern China

On the evening of 30 April 2021, a severe hailstorm swept across eastern China, causing catastrophic gale and damaging hailstones. This hailstorm event was directly caused by two mesoscale convective systems associated with strong squall lines, with mid-level cold advection from the northeast cold vortex, and strong low-level convergence associated with the low-level vortex and wind shear line. Double nesting of the high-resolution weather research and forecasting model (9–1 km) is utilized to simulate this hailstorm with five microphysics schemes. The radar-based maximum estimated size of hail (MESH) algorithm, differential reflectivity and fractions skill scores were used to quantitatively evaluate the precision. All schemes basically captured the two squall lines that swept through eastern China, although they appeared one or two hours earlier than observation. Particularly, Goddard and Thompson performed better in the MESH swath and fractions skill scores among the five different schemes. However, Thompson most realistically captured the reflectivity pattern, intensity and vertical structure of mesoscale convective systems. Its high-reflectivity column corresponded to the maximum center of the hail mixing ratio within the updraft region, which is consistent with the characteristics of a pulse-type hailstorm in its mature phase.

Empirical Analysis of Autonomous Vehicle's LiDAR Detection Performance Degradation for Actual Road Driving in Rain and Fog.

Light detection and ranging (LiDAR) is widely used in autonomous vehicles to obtain precise 3D information about surrounding road environments. However, under bad weather conditions, such as rain, snow, and fog, LiDAR-detection performance is reduced. This effect has hardly been verified in actual road environments. In this study, tests were conducted with different precipitation levels (10, 20, 30, and 40 mm/h) and fog visibilities (50, 100, and 150 m) on actual roads. Square test objects (60 × 60 cm2) made of retroreflective film, aluminum, steel, black sheet, and plastic, commonly used in Korean road traffic signs, were investigated. Number of point clouds (NPC) and intensity (reflection value of points) were selected as LiDAR performance indicators. These indicators decreased with deteriorating weather in order of light rain (10-20 mm/h), weak fog (<150 m), intense rain (30-40 mm/h), and thick fog (≤50 m). Retroreflective film preserved at least 74% of the NPC under clear conditions with intense rain (30-40 mm/h) and thick fog (<50 m). Aluminum and steel showed non-observation for distances of 20-30 m under these conditions. ANOVA and post hoc tests suggested that these performance reductions were statistically significant. Such empirical tests should clarify the LiDAR performance degradation.

Preparation and evaluation of astaxanthin-loaded 2-hydroxypropyl-beta-cyclodextrin and Soluplus® nanoparticles based on electrospray technology.

Astaxanthin is a type of food-derived active ingredient with antioxidant, antidiabetic and non-toxicity functions, but its poor solubility and low bioavailability hinder further application in food industry. In the present study, through inclusion technologies, micellar solubilization and electrospray techniques, we prepared astaxanthin nanoparticles before optimizing the formulation to regulate the physical and chemical properties of micelles. We accomplished the preparation of astaxanthin nanoparticle delivery system based on single needle electrospray technology through use of 2-hydroxypropyl-β-cyclodextrin and Soluplus® to improveme the release behavior of the nanocarrier. Through this experiment, we successfully prepared astaxanthin nanoparticles with a particle size of approximately 80 nm, which was further verified with scanning electron microscopy and transmission electron microscopy. Furthermore, the encapsulation of astaxanthin molecules into the carrier nanoparticles was verified via the results of attenuated total reflectance intensity and X-ray powder diffraction techniques. The in vitro release behavior of astaxanthin nanoparticles was different in media that contained 0.5% Tween 80 (pH1.2, 4.5 and 6.8) buffer solution and distilled water. Also, we carried out a pharmacokinetic study of astaxanthin nanoparticles, in which it was observed that astaxanthin nanoparticle showed an effect of immediate release and significant improved bioavailability. 2-hydroxypropyl-β-cyclodextrin and Soluplus® were used in the present study as a hydrophilic nanocarrier that could provide a simple way of encapsulating natural function food with repsect to improving the solubility and bioavailability of poorly water-soluble ingredients. © 2023 Society of Chemical Industry.

Enhancing Wireless Capsule Endoscopy images from intense illumination specular reflections using the homomorphic filter

Wireless Capsule Endoscopy (WCE) is a non-invasive medical imaging device that gastroenterologists use to investigate gastrointestinal tract disorders. WCE images often suffer from specular reflections (SRs). SR is an outcome of the rigorous light and luminous regions emerging in WCE images, impacting the performance of abnormality detection approaches and physician analysis. The current study aims to invent a method that can automatically segment and eliminate SRs in WCE images to increase the accuracy of abnormality detection approaches and help physicians to make a potent diagnosis. In this study, we introduce a novel method for SR elimination with a negligible damage to the image texture using a homomorphic filter. The proposed method encompasses three steps. Initially, we utilize a robust segmentation technique using the U-Net model to segment SRs based on semantic segmentation. Then, we use the homomorphic filter to separate the illumination and reflection components. Damage caused by SR has different effects on these two components. Our proposed method enhances each of these components separately instead of enhancing the whole image uniformly. Eventually, we reconstruct SR regions using the Navier-Stokes inpainting technique based on fluid dynamics. Our experiments were conducted on three different types of WCE datasets. The evaluations were performed with the following criteria accuracy, false negative rate, false positive rate, precision, recall, and F-Measure. The results show that our proposed method eliminates SRs admirably and quantitatively increases the accuracy of the state-of-the-art abnormality detection methods in WCE and improves their performance.

Development of a dye nanoparticle-loaded test strip for the Zn(II) determination in metal plating wastes.

Zincon/Latex-NR3+ nanocomposite-loaded dye nanoparticle coated test strip (Zincon/Latex-NR3+ DNTS) was fabricated to detect Zn(II) in plating wastewater by a unique color change from red-purple to deep blue and evaluated its detection performance in actual plating samples. The 5 × 5mm square-cut DNTS attached sticks were immersed into 10mL aliquots of aqueous solutions containing Zn(II) ion and 0.01M TAPS buffer at pH 8.4 with stirring at 250rpm for 60min. The calibration curve for Zn(II) was prepared based on the integrated area intensity of reflectance by TLC at 620nm with the 3σ detection limit was 48.61ppb, and the quantitative range was approximately up to 1000ppb. Although Cu(II), Mn(II), Ni(II), and Co(II) showed competitive interference due to complex formation with Zincon, a mixture of masking reagent including thiourea, 2-aminoethanthiol, and o-phenanthroline was effective in removing the contamination. To eliminate Cr(III) interference based on the incorporation of Zn(II) into Cr(III) hydrolyzed polymer, adding KBrO3 and H2SO4 under boiling for several minutes was required. With appropriate pretreatment, all results of actual plating water samples by Zincon/LatexNR3+ DNTS were close to those of ICP-OES.

How woodcocks produce the most brilliant white plumage patches among the birds.

Until recently, and when compared with diurnal birds that use contrasting plumage patches and complex feather structures to convey visual information, communication in nocturnal and crepuscular species was considered to follow acoustic and chemical channels. However, many birds that are active in low-light environments have evolved intensely white plumage patches within otherwise inconspicuous plumages. We used spectrophotometry, electron microscopy, and optical modelling to explain the mechanisms producing bright white tail feather tips of the Eurasian woodcock Scolopax rusticola. Their diffuse reflectance was approximately 30% higher than any previously measured feather. This intense reflectance is the result of incoherent light scattering from a disordered nanostructure composed of keratin and air within the barb rami. In addition, the flattening, thickening and arrangement of those barbs create a Venetian-blind-like macrostructure that enhances the surface area for light reflection. We suggest that the woodcocks have evolved these bright white feather patches for long-range visual communication in dimly lit environments.

Research on EM Shielding Mechanism of the Plasma-Sheath-Covered Target

When a near-space hypersonic vehicle flies at a velocity of several Machs, a plasma sheath is created on its surface. The plasma sheath is a complex electromagnetic (EM) medium composed of many charged particles, producing a series of EM effects on EM waves. In this article, based on the numerical calculation results of the plasma sheath flow field at typical altitudes, the spatial distribution characteristics of the reflection intensity of the typical reference area on the vehicle surface are solved. The EM shielding effect of the plasma-sheath-covered target is revealed by the incident depth and the maximum reflection position of the EM wave in the plasma. By analyzing the influence of different flight altitudes and carrier frequencies on the reflection characteristics of each typical vehicle area, the variation law of the EM shielding effect of the plasma-sheath-covered target is obtained. The research results reveal the EM shielding mechanism of plasma sheath and provide a theoretical basis for radar detection and radar cross section (RCS) measurement of the plasma-sheath-covered target.

Peripapillary Subretinal Space of the Blunt Traumatic Optic Neuropathy: RPE/Bruch’s Membrane Complex Micro-Rips - The Novel SD-OCT Findings

Aim: To report the unusual SD-OCT findings in peripapillary subretinal space of the blunt traumatic optic neuropathy (TON). Methods: All patients underwent a comprehensive eye examination included color fundus photography, ultrasonography, fundus fluorescein angiography, visual field, PVEP if patient’s vision was allowed to examine. An orbital CT scan was performed for all of patients and no orbital fracture was found. However, we did not assess them here and assessed the results of SD-OCT examination only. Results: Peripapillary subretinal spaces of four contused eyes were abnormal that showed a flat, localized hyperreflection due to hemorrhages. It was adjacent to optic disc. The intensities of reflection could be nonuniform due to the blood concentration or contained serous liquid. It could be observed that RPE/Bruch’s membrane complex micro-rips, but ELM were normal that were not involved in the peripapillary subretinal space. Choroid rupture of macula was observed at times. Conclusion: For TON patients, to examine the peripapillary subretinal space by SD-OCT at first time might have valuable for diagnosis. The results suggested that the hemorrhages of peripapillary subretinal space might come from the peripapillary choriocapillaris.

Adsorption of direct red 79 in wastewater on Fe2Fe1-xMnxO4 (x = 0 - 1) nanoparticles prepared by co-precipitation method

Magnetic spinel ferrite nanoparticles Fe2Fe1-xMnxO4 were synthesized by a simple co-precipitation method. The morphology and structures of the synthesized samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), Raman spectroscopy, and infrared spectroscopy (FTIR). The magnetic properties of the materials were studied using VMS measurement. The results showed that the spinel ferrite nanoparticles formed a single phase of packed face-centered cubic spinel structure. When replacing Mn2+ ions with Fe2+, the crystal structure shifted from the Fe3O4 crystal structure to the MnFe2O4 crystal structure assigned with an increased lattice constant from 6.30 nm to 26.33 nm. Raman and FTIR spectrum analysis showed that when replacing Mn2+ ions with Fe2+, the Mn-O and Fe-O bonds changed significantly. Specifically, the intensity of the Raman spectrum's reflection and the FTIR spectrum's absorption decreased gradually. All the samples exhibited uniform spherical shapes, and particle size varied from 9.8 nm to 30 nm, depending strongly on the substituted concentration. The magnetization curves confirm the soft ferromagnetic behavior with close superparamagnetic properties of Fe2Fe1-xMnxO4 nanoparticles. The material used to study the adsorption of Direct Red 79 (DR79) in water has good adsorption capacity. The adsorption process obeys pseudo-second-order kinetics and also shows compliance with Langmuir, Freundlich and Temkin isotherms.

Ship Instance Segmentation Based on Rotated Bounding Boxes for SAR Images

Ship instance segmentation in synthetic aperture radar (SAR) images is a hard and challenging task, which not only locates ships but also obtains their shapes with pixel-level masks. However, in ocean SAR images, because of the consistent reflective intensities of ships, the appearances of different ships are similar, thus making it far too difficult to distinguish ships when they are in densely packed groups. Especially when ships have incline directions and large aspect ratios, the horizontal bounding boxes (HB-Boxes) used by all the instance-segmentation networks that we know so far inevitably contain redundant backgrounds, docks, and even other ships, which mislead the following segmentation. To solve this problem, a novel ship instance-segmentation network, called SRNet, is proposed with rotated bounding boxes (RB-Boxes), which are taken as the foundation of segmentation. Along the directions of ships, the RB-Boxes can surround the ships tightly, but a minor deviation will corrupt the integrity of the ships’ masks. To improve the performance of the RB-Boxes, a dual feature alignment module (DAM) was designed to obtain the representative features with the direction and shape information of ships. On account of the difference between the classification task and regression task, two different sampling location calculation strategies were used in two convolutional kernels of the DAM, making these locations distributed dynamically on the ships’ bodies and along the ships’ boundaries. Moreover, to improve the effectiveness of training, a new adaptive Intersection-over-Union threshold (AIoU) was proposed based on the aspect-ratio information of ships to raise positive samples. To obtain the masks in the RB-Boxes, a new Mask-segmentation Head (MaskHead) with the twice sampling processes was explored. In experiments to evaluate the RB-Boxes, the accuracy of the RB-Boxes output from the Detection Head (DetHead) of SRNet outperformed eight rotated object-detection networks. In experiments to evaluate the final segmentation masks, compared with several classic and state-of-the-art instance-segmentation networks, our proposed SRNet achieved more accurate ship instance masks in SAR images. The ablation studies demonstrated the effectiveness of the DAM in the SRNet and the AIoU for our network training.

Effect of synthetic zeolite on tobermorite synthesis

This paper presents the results of a study of the effect of synthetic zeolite addition on the formation of tobermorite in a burnt lime-quartz mixture. Synthetic zeolite was obtained by thermal activation of halloysite followed by boiling in sodium hydroxide solution. In this study, the formation of tobermorite was investigated at a constant CaO/SiO2 molar ratio of 0.86 under autoclaving conditions corresponding to saturated steam pressure at 180ºC. The synthesis times were 4 and 12 hours. Synthetic zeolite was added at 5%, 15% and 30%. Studies have shown that synthetic zeolite infl uences the formation of hydrated calcium silicates with poor crystallinity. After 4 hours of autoclaving for samples with synthetic zeolite, a small peak of tobermorite can be found on the XRD pattern. In samples where the molar ratio of Al/(Al+Si) &gt; 0.15 was exceeded, hydrogarnets of the hibschite-katoite group appear. The paper shows that hydrogarnets of the hibschite-katoite group appear for samples with 15% and 30% zeolite after 4 hours of hydrothermal treatment. The intensity of the katoite reflection decreases with increasing autoclaving time and disappears for the sample with 15% zeolite after 12 hours of autoclaving. The presence of portlandite was also demonstrated in these samples.