Width Of Zone Research Articles

Determination of Solubility and Metastable Zone of Sodium Hypophosphite and Nucleation Kinetics

AbstractTo obtain thermodynamic and kinetic data of sodium hypophosphite, such as solubility and metastable zone, respectively, the solubility data for sodium hypophosphite in the temperature range of 298.15–373.15 K were obtained using a dynamic method. These data were then fitted to the Apelblat and Van't Hoff equations, and the corresponding model parameters were determined. The effects of stirring intensity and cooling rate on the width of the metastable zone of sodium hypophosphite in water were studied. The findings indicated that an increase in stirring intensity reduced the width of the metastable zone, whereas an increase in cooling rate resulted in its widening. The self‐consistent NýVlt and Sangwal metastable zone models were employed to calculate nucleation dynamic parameters in conjunction with classical nucleation theory. The results showed that the nucleation order was 2.311–3.361 over the investigated temperature range. 316.15 K is the critical temperature point at which sodium hypophosphite transforms into a dominant nucleation mode. The solid–liquid interface tension decreased rapidly with the increase of saturation temperature, and the solid–liquid interface tension is 1.167–2.638 mJ m−2.

Influence of arc energy on the microstructure and corrosion behavior of ER2209 duplex stainless steel deposited on Q345B low-alloy steel by GMAW

In order to eliminate the complex effects of thermal cycling and the thermal effects of the next pass on multi-layer multi-pass welding of low-alloy steel and duplex stainless steel, ER2209 welding wire was single-layer single-pass deposited on the surface of Q345B hot-rolled plate by gas metal arc welding (GMAW). The microstructure and corrosion resistance of welded joints were studied by different arc energies. The results showed that the arc energy had a significant impact on the “tongue-shaped” morphology and the width of heat affect zone in the welded joint, which in turn affected the corrosion performance of the welded joints. Due to the least distribution of “tongue-shaped” morphology and minimum width of heat affected zone in the welded joint with arc energy of 0.645kJ/mm, it owned the best corrosion resistance. The weld metals of the welded joints were composed of ferrite and austenite phases. The ferrite phases were distributed along grain boundaries and intergranular. As the heat input increases, the distribution of ferrite phase along grain boundaries gradually decreased. The corrosion products and corrosion morphology of the welded joint were also investigated and the corrosion mechanism was discussed in detail. The research results of this article provide a theoretical basis for improving the corrosion performance of multi-layer multi-pass welded joints of low-alloy and duplex stainless dissimilar steels.

Specialization of a new flux-based approach to thermal problems. Numerical study of glass façades of buildings with cast shadows

Uneven temperature distributions in the glass panes of building façades can induce thermal stresses exceeding material strength, a critical condition usually referred to as “thermal shock”. Here, we specialize in architectural glazing a recently-proposed flux-based variational approach to thermal problems, by considering heat exchanges resulting from climatic actions, in particular the variability of environmental temperatures and solar radiation, influenced by the shielding of cast shadows. The finite element implementation is facilitated because the unknown field is the heat displacement, whose time derivative is the heat flux, which is much smoother than the temperature field, on which the classical approach via Fourier’s law is based. A custom in-house-made FEM code is used to determine the effect of size and shape of cast shadows on temperature distribution in monolithic and laminated glass panes, also coupled in insulating glass units. We find that the temperature difference between irradiated and shadowed regions is only mildly influenced by the shape and size of the shadows, but the glass thickness determines the width of the transition zone and, hence, the temperature gradient. Practical rules for the design of glass façades are tentatively proposed.

Seismic and outcrop-based 3D characterization of fault damage zones in sandstones, Rio do Peixe Basin, Brazil

Fault damage zones, composed of sub-seismic deformation structures, are difficult to detect using seismic data. Still, they can be related to fault throw, which is widely measured in the subsurface. This research employs a multiscale approach that integrates outcrop studies with seismic reflection data to investigate the attributes of fault damage zones affecting porous sandstones. We provide an in-depth understanding of the 3D fault zone volume, investigating correlations between geometric attributes of faults (width of damage zone, frequency of subsidiaries structures, and fault termination) in the outcrop and the fault throw in the subsurface, with insights from deformation mechanisms within the fault zone. The methods encompass 1D scanlines to constrain the damage zone width on the outcrop. At the same time, the subsurface analysis uses 3D seismic data, seismic attributes, and deep learning neural network (DNN) fault volumes to interpret fault geometries and quantify fault throw at different depths. Results show that the area presents a complex fault zone with multiple fault sets, deformation bands, and fracture corridors trending mainly NE-SW, NW-SE, and E-W. The integration of surface and subsurface fault data enabled the identification of two portions in each fault set outcropping at the fault tip for E-W/ESE-WNW-striking faults and the central part of the fault for NE-SW-striking faults. Faults with the greatest length do not outcrop with the largest damage zone width since they are outcropping the tip of the fault. The parallel faults overlap their damage zones, increasing the deformation zones in the affected sandstones. Fault throw and damage zone width present a positive correlation. This relation is affected by fault segments and subsidiary faults.

Flow analysis of steady state forward flow of aortic valve prostheses using Particle Image Velocimetry

Abstract Transcatheter aortic valve replacement (TAVR) has become the standard therapy for aortic valve stenosis in patients with high surgical risk. Understanding the flow dynamics in TAVR is crucial for its evaluation and optimization. Experimental flow measurement by means of Particle Image Velocimetry (PIV) is increasingly applied alongside numerical analyses. This study introduces a novel test rig concept enabling the determination of velocity fields using Stereo-PIV under steady forward flow conditions through a TAVR during the peak systole matching the ISO 5840-1:2021 requirements. The experimental setup utilized an impeller pump to generate steady forward flow through a silicone aortic root model with implanted TAVR. A Stereo-PIV setup captured velocity fields in both ventricular inflow and aortic outflow regions. Test conditions were based on physiological flow rates determined from pulsatile measurements. Illumination of the added particles in the test fluid was achieved using an Nd:YAG laser. Fluorescent polystyrol particles (size: 50 μm) were used for flow visualization. Results showed characteristic flow patterns: a central jet flow entering the TAVR in the ventricular flow field. A jet flow directed towards the sinus side and a recirculation zone forming on the opposite side of the sinus could be detected in the aortic outflow. The width of the recirculation zone increases with distance from the TAVR. Maximum flow velocities were detected at 0.78 m/s for the ventricular flow field and 0.94 m/s for the aortic flow field. This study provides a comprehensive approach for fluid dynamic analysis of TAVR under steady flow conditions, offering insights into flow mechanics performance crucial for device optimization. Further investigations could enhance the PIV - measurement procedure by increasing both the spatial resolution and the tracer particle density within the acquired images for a comprehensive characterization of TAVR flow dynamics.

Supersaturation Behavior: Investigation of Polymers Impact on Nucleation Kinetic Profile for Rationalizing the Polymeric Precipitation Inhibitors.

Although nucleation kinetic data is quite important for the concept of supersaturation behavior, its part in rationalizing the crystallization inhibitor has not been well understood. This study aimed to investigate the nucleation kinetic profile of Dextromethorphan HBr (as an ideal drug, BCS-II) by measuring liquid-liquid phase segregation, nucleation induction time, and Metastable Zone width. Surfeit action was examined by a superfluity assay of the drug. The concentration was scrutinized by light scattering techniques (UV spectrum (novel method) and Fluorometer (CL 53)). The drug induction time was 20 min without polymer and 90 and 110 min with polymers, such as HPMC K15M and Xanthan Gum, respectively. Therefore, the order of the polymer's ability to inhibit nucleation was Xanthan Gum > HPMC K15M in the medium (7.4 pH). Similarly, the drug induction time was 30 min without polymer and 20, 110, and 90 min with polymers, such as Sodium CMC, HPMC K15M, and Xanthan Gum, respectively. Therefore, the order of the polymer's ability to inhibit nucleation was HPMC K15M > Xanthan Gum > Sodium CMC in SIFsp (6.8 pH), which synchronizes the polymer's potentiality to interdict the drug precipitation. The HPMC K15M and xanthan Gum showed the best crystallization inhibitor effect for the maintenance of superfluity conditions till the drug absorption time. The xanthan gum is based on the "glider" concept, and this shows the novelty of this preliminary research. The screening methodology used for rationalizing the best polymers used in the superfluity formulations development successfully.

Visiting the microstructures, mechanical properties and corrosion resistance of hot-rolled Al-Cu(-Mg) alloys with and without T6 treatment

It is important to optimize the microstructures of Al-Cu based alloys for expanding their practical applications. In this work, the effects of Mg additions and T6 treatment on the microstructures, mechanical properties and corrosion resistance of hot-rolled Al-Cu alloy were investigated. The hot-rolled Al-4Cu, Al-4Cu-0.25Mg and Al-4Cu-0.5Mg (wt.%) alloys with and without T6 treatment were prepared. Experimental results indicated that the grain size of the as-rolled samples was decreased by adding Mg because of the introduction of S′-Al2CuMg phases, and the T6 treatment also obviously reduced the grain size with the help of static recrystallization regardless of alloy composition. However, the grain size of the Mg-free sample was smaller than that of the Mg-containing samples after T6 treatment, which might be resulted from the more nucleation sites provided by stored energy. The combination of Mg additions and T6 treatment could significantly enhance the mechanical properties with the help of increased second phases and decreased precipitate free zone widths, and the yield strength, ultimate tensile strength and fracture elongation were 333.5MPa, 397.1MPa and 24.5% for the T6-treated Al-4Cu-0.5Mg alloy. In addition, the corrosion resistance in 3.5wt.% NaCl solution was obviously enhanced by adding Mg, which was attributed to the narrow PFZs. Differently, the amounts of second phases were increased after T6 treatment, which induced more PFZs and damaged the corrosion resistance. As a result, the hot-rolled Al-4Cu-0.5Mg alloy with corrosion potential of -0.667V and corrosion current density of 2.668×10-7 A/cm2 exhibited the highest corrosion resistance. It is believed that this work can offer referenced information to design and process the high-performance Al-Cu based alloys in various service conditions.

Improving the performance of crumb rubber concrete using waste ultrafine glass powder

Due to its superior toughness and environmental benefits over traditional concrete, crumb rubber (CR) concrete (CRC) gained considerable attention in both research and practical engineering fields. However, the static mechanical characteristics of CRC exhibit a certain level of decline as CR demonstrates a lower elastic modulus and less effective bonding capabilities with mortar when compared to natural aggregates. Consequently, this study explores the potential of substituting cement with ultra-fine waste glass powder (WGP) to enhance the mechanical characteristics and microstructure of CRC. The impact of varying WGP substitution rates on workability, wet packing density (WPD) in the fresh phase is examined. Moreover, analyses on compressive strength, flexural-tensile strength, ductility index, dynamic elastic modulus, damping ratio, and impermeability post-hardening are presented. The use of scanning electron microscopy (SEM), X-ray diffraction (X-RD), and mercury intrusion piezometry (MIP) provided insights into the influence of WGP on the micromorphology, mineral composition, and pore structure characteristics. The results revealed that WGP introduction enhanced the fresh properties of CRC, notably in terms of workability and WPD. The slump and slump-flow increased to 270 mm and 630 mm for WGP dosing increased to 30 %. A gradual enhancement in strength, dynamic elastic modulus, and impermeability was observed with increased WGP content, alongside a significant improvement in toughness. The compressive and flexural strengths of 30 % WGP were mentioned to be about 11 % and 62 %, respectively, and the permeability coefficient was reduced to 0.78 × 10−12 m2/s. The damping ratio initially decreases, then rises to a peak of 1.6 % at a WGP content of 30 %. Integration of WGP resulted in a progressive decrease in interfacial frictional zone width, average pore diameter, and porosity, while the fraction of harmless pores increased, likely aiding the strength and dynamic elastic modulus.

Sun Glints and Underwater Caustics in Remote Sensing of Seas and Oceans

The Sun glints that are observed on the water surface have different radiances, shapes, and color shades, depending on the positions of the Sun and the observer, the water surface statement, and the transparency of the water and atmosphere. The texture, radiance, and color characteristics of Sun glints carry information about the state of the water and atmosphere. Therefore, Sun glints play an important role in remote sensing of seas and oceans, being a useful signal in some problems and noise in others. Bright stripes (underwater caustics) on the bottom of the water basin that are caused by the waves are also an indicator of the water surface shape. The application of the wave theory of light is used to study the intensity distribution in the vicinity of the caustic (i. e., where the geometric-optical approximation is inapplicable), which arises when light is refracted on a wavy water surface.A formula, which determines the parameters of the waves from the width of the caustic zone is obtained. The correctness of the method has been verified by experiments carried out in the pool. Also, here we give a brief overview of our investigations related to sun glints and underwater caustics.

Enhanced material flow and joint formation of FSWed AA2024 by using protruding cylinder tool

The optimization mechanism of the protruding cylinder on the modified tool for the performance of friction stir welding (FSW) joints in 2024 aluminum alloy was investigated. The results indicate that the presence of a protruding cylinder on the modified tool significantly improves the surface quality of the weld, increases the width and area of the weld nugget zone(WNZ), and refines the grain size. Additionally, the size of the precipitated phases is reduced, and their distribution becomes more uniform, which in turn enhances the tensile strength and hardness of the joint. Furthermore, the presence of a protruding cylinder facilitated material flow, stabilized the welding process, and contributed to the formation of uniform welds.

Computed tomography-based anatomic suitability of an Endo-Bentall prosthesis for ascending aortic aneurysms

IntroductionThis study aimed to evaluate the suitability of a coronary-branched ascending aortic endograft, paired with aortic valve (AV) prosthesis (Endo-Bentall), for the endovascular repair of ascending aortic aneurysms. MethodsPre-operative ≤1mm computed tomography angiographies of consecutive patients managed with Bentall procedure or ascending aortic replacement and AV reconstruction/replacement, in a single institution (01.01.2008-31.12.2023), were retrospectively analyzed. Dedicate software was used to assess: (1) vascular access, (2) proximal landing zone, (3) coronary artery anatomy and (4) distal landing. Eligibility criteria for Endo-Bentall were: ≥8mm iliac arteries, without severe calcification/tortuosity, proximal landing with 18-29mm aortic annulus diameter, ≥10mm annulus-coronary ostium distance, no mechanical AV, absence of coronary grafts in the ascending aorta, no left ventricle thrombus, coronary arteries ≥3mm wide and ≥10mm long, with no anatomic abnormalities, ostial stent or stenosis and ≥20mm long and ≤38mm wide distal landing zone within the ascending aorta or applicability of branched endovascular arch repair. ResultsTwenty-nine patients (55.2% females) were included. All patients had adequate proximal landing zone in terms of annulus diameter (median: 25mm, IQR: 5mm). Two (6.8%) had inadequate iliac access (external iliac artery <8mm). Two patients (6.8%) had a mechanical AV. Twenty-six patients (89.6%) had adequate landing zone for stenting of the left main coronary artery (LMCA; median diameter: 5.2mm, IQR: 1.8mm) and 28 (96.6%) had adequate right coronary artery (RCA) landing (median diameter: 4.1, IQR: 1mm). The LMCA and RCA were located at 5:00' and 10:50’ clock positions, respectively. Three patients (20.7%) had an adequate distal landing zone within the ascending aorta. The remaining were suitable for extension with a branched arch device. According to the predefined criteria, 75.9% of patients were anatomically suitable for Endo-Bentall. ConclusionThree out of four patients with ascending aortic aneurysms may be considered as anatomically eligible for endovascular treatment with an Endo-Bentall prosthesis.

Design and Verification of Continuous Tube Forming Process Parameters for PEEK-Based Rod Aimed at Space Manufacturing Applications

To meet the in-orbit construction needs of super-large spacecraft for ultra-long rod structures, this paper proposes an innovative on-orbit roll forming method for polyetheretherketone (PEEK)-based rod stock. This method ingeniously integrates temperature gradient control into a continuous deformation surface cavity design to achieve an efficient forming of resin rod components. A parametric model of the forming die cavity was established based on the comprehensive bending and downhill methods, and the boundary conditions for the temperature distribution gradient within the cavity were determined. Through the simulation and analysis of the PEEK rod curling and stitching forming process, the influence of the cavity configuration parameters on the forming load was determined. By constructing a test platform for the roll forming characteristics of resin rod components, the effects of different forming methods, stitching temperatures, and feed rates on forming quality and load were verified, and the main factors affecting the width of the welding zone, the roundness of the rod, and the straightness of the weld were analyzed. Experimental results show that the proposed continuous roll forming scheme can achieve an efficient and continuous forming of resin rod structures. When the length of the member is processed to 300 mm, at a formed rod diameter of 20 mm, by employing a cavity deformation zone length of 210 mm, a cavity clearance of 0.1 mm, a sheet width of 61 mm, a feed rate of 1 mm/s, and a sealing zone temperature setting of 335 °C, optimal rod forming quality can be achieved, characterized by a straightness error of 0.0133 ± 0.005 mm and a roundness error of 0.19 ± 0.07 mm. The proposal of this scheme provides a reliable basis for the continuous manufacturing of rod structures in the on-orbit construction of large space structures in terms of both the scheme and the parameter selection.

The influence of secondary aging on the microstructure and corrosion resistance of Al-Zn-Mg-Cu alloy

In this study, through process optimization, we successfully identified a 7-day T6I4 secondary low-temperature aging treatment that significantly enhances the corrosion resistance of Al-Zn-Mg-Cu alloys. Microstructural analysis revealed that the Guinier-Preston (GP) zones and η' phases, are uniformly dispersed within the aluminum matrix after this treatment, effectively reducing the width of the precipitate-free zone (PFZ), thereby significantly lowering the risk of intergranular corrosion. Electrochemical testing results indicate that the alloy treated with this process exhibits superior electrochemical corrosion resistance, characterized by the highest charge transfer resistance (Rct) and the lowest corrosion current density (Icorr). Furthermore, long-term corrosion experiments have provided an in-depth understanding of the alloy's corrosion durability mechanisms under optimal process conditions. Density Functional Theory (DFT) calculations have further elucidated the work function and surface energy of the precipitates, providing a theoretical foundation for the enhancement of alloy performance.

Damage Characteristics of Blasting Surrounding Rock in Mountain Tunnel in Fault Fracture Zones Based on the Johnson–Holmquist-2 Model

Blasting is a widely employed technique for tunnel construction in mountainous regions; however, it often causes damage to the surrounding rock mass, particularly in fault fracture zones, which can lead to hazards such as rockfalls and collapses. This study examines the characteristics of damage to surrounding rock due to tunnel blasting through fault fracture zones. Based on an actual tunnel blasting construction project, we conducted a finite element analysis using the JH-2 material model, taking into account the width of the fault fracture zone. Results indicate that as the width of the fault fracture zone increases, the disturbance effect of tunnel blasting on the surrounding rock becomes more pronounced. Compared to the arch bottom and arch waist of the tunnel, the tunnel vault primarily absorbs the slip deformation and compressive forces resulting from blasting disturbances in the fault fracture zone. The findings of this paper contribute a valuable methodology for analyzing the mechanical mechanisms in mountain tunnel blasting and provide essential theoretical parameters to inform the design and construction of tunnel blasting projects.

Testing of a multi-energy complementary absorption heat pump prototype for combined cooling and heating with large temperature range from − 20 to 90 °C

In the process of carbon neutrality, the comprehensive utilization of clean and renewable energy, including solar, geothermal and biomass, is a potential solution to the low-carbon cooling and heating in distributed areas with weak power grids, such as countryside and suburban. In this paper, an absorption heat pump with multi-energy complementary was built to provide combined cooling and heating. Solar energy was collected through an evacuated tube collector using heat conduction oil, and a gas boiler was adopted to further heat the oil and balance the solar thermal fluctuations. Heat collected in the oil circulation was used to drive an ammonia-water absorption heat pump. A control strategy was proposed to achieve stable energy supply under different weather condition, and efficient operation in wide temperature zone. Environmental test of the prototype was performed in Jinan. The results showed that the prototype ran stably to provide 5-15 kW cooling at −20 to 10 °C, and 20-35 kW heating at 40 to 90 °C, with solar thermal ratio of 20–35 % in different weather conditions, and the renewable energy ratio in heating mode could exceed 55 % through further recovery of ambient heat. Furthermore, the COP for cooling reached 0.30–0.43 at −20 °C cold supply, and 0.70–0.78 at 7 °C cold supply, with cooling water temperatures varied from 30 to 20 °C; and the COP of heating reached 1.40–1.90 at 45 °C heat supply, and 1.35–1.56 at 80 °C heat supply, with evaporation temperature varied from −15 to 20 °C. Results demonstrated that the proposed prototype has significant energy and carbon reduction potential, and is a solution for combined cooling and heating in distributed areas.

Field and numerical investigation of groundwater flow and dissolved inorganic nitrogen (DIN) dynamics in a sandy nearshore aquifer

Nutrients delivered to the coastal ocean via submarine groundwater discharge (SGD) can have a major impact on marine ecosystems. The flux of nutrients delivered via this pathway can be modified by biogeochemical processes occurring in coastal nearshore aquifers. This study combines field investigations with numerical simulations to characterize patterns of groundwater flow, salinity and dissolved inorganic nitrogen (DIN) in a permeable nearshore aquifer and to quantify SGD and associated DIN fluxes to the ocean. At the field study site, an upper saline plume (USP) and saltwater wedge with low DIN concentrations were observed together with a fresh groundwater zone with high DIN concentrations. Seawater infiltration predominantly occurred in the intertidal zone, contributing 85% of the total infiltration, with the greatest infiltration occurring in the upper-middle intertidal zone. The simulations indicate that the USP expanded and contracted through the tidal cycle, and the width of the high-DIN freshwater discharge zone also varying. The freshwater discharge zone was narrower around the high tide period due to expansion of the overlying low-DIN zone associated with the USP. Over the simulated period, only approximately 30% of the DIN entering the nearshore aquifer ultimately discharged to the ocean. The findings of this combined field and numerical study are needed to inform future field and numerical investigations examining the fate of DIN in nearshore aquifers.

Effects of nano-modification on the microstrfuctural evolution and mechanical properties of AA7075/AA6061 aluminum alloy joints fabrica ted by laser-MIG hybrid welding technique

In this study, a rigorous comparative analysis is conducted to assess the implications of 7075 welding wire and 7075 welding wire fortified with 1.0 wt% of TiC nanoparticles on the microstructural characteristics, distribution patterns of secondary phases, grain refinement, and mechanical properties of AA7075/AA6061 dissimilar aluminum alloy joints produced via laser-MIG hybrid welding. The experimental results show that: The introduction of TiC nanoparticles prompts a transformation in the weld microstructure, transitioning from coarse dendritic morphologies to finer equiaxed dendritic structures. The grain size and the strengthening phases have both undergone a process of refinement. Notably, a marked increase in high-angle grain boundaries (HAGBs) and a concomitant decrease in low-angle grain boundaries (LAGBs) are observed in the nano-modified weld. Nano-modification yields substantial improvements in the mechanical properties of the welded joint. Specifically, the softening width of the AA6061 heat-affected zone (HAZ) is reduced by approximately half (from 8 mm to 4 mm), while the minimum microhardness of the joint has been increased from 34.1 Hv to 62.4 Hv. Moreover, the average ultimate tensile strength (UTS) of the joint has been enhanced from 95.7 MPa to 208.9 MPa, while the average yield strength (YS) has been increased from 57.1 MPa to 155.1 MPa.

Processing characteristics of C/C composites with nanosecond pulse laser

This study investigates the effects of the nanosecond pulse laser parameters on the processing characteristics of carbon fiber-reinforced carbon matrix (C/C) composites through a series of laser cutting experiments. It compares the cutting width, depth, heat-affected zone (HAZ) width, processed surface micro-morphology, as well as the oxidation characteristics of the material under different processing parameters. The HAZ width is analyzed in relation to the variations in the oxygen content. The results indicate that both the cutting width and depth initially increase and then decrease with increasing repetition frequency. Moreover, increasing the laser power and pulse width gradually increases the cutting width, depth, and HAZ width, whereas a higher scanning speed tends to reduce the cutting width and depth. Since changes in the processing power, scanning speed, and pulse width affect the HAZ, the oxygen content exhibits a proportional relationship with the HAZ width. In addition, an increase in the repetition frequency can expand the HAZ while reducing the oxygen content. A careful increase in the repetition frequency aids in lowering the ablation threshold of the material, leading to more material removal. Nevertheless, a continuous increase in energy density can trigger a fiber pull-out phenomenon and cause degradation of the matrix.

Evaluation of retinal arterioles in retinitis pigmentosa: Arterial lumen diameter reduced with retinal degeneration and wall thickness related to systemic condition

Purpose: Retinal arterioles are attenuated in eyes with retinitis pigmentosa (RP), but dimensions such as lumen diameter (LD) and wall thickness (WT) have not been thoroughly investigated. This study aimed to determine the dimensions of reduced retinal arterioles in eyes with RP. Methods: The study included 66 patients with RP (66 eyes) and 36 control participants (36 eyes) for whom adaptive optics (AO) recordings of the retinal arteries were available. LD and WT were measured on the AO images. The correlations between arteriole dimensions and clinical parameters were determined. Results: The mean LD was significantly smaller in patients with RP than in controls, while the mean WT did not differ significantly. LD was significantly and positively correlated with the mean deviation (MD) of the Humphrey 10-2 field analyzer and ellipsoid zone (EZ) width. The WT and wall-to-lumen ratio were significantly and positively correlated with age and systolic blood pressure but not with MD and EZ width. Conclusion: Retinal arteriole dimensions were significantly correlated with retinal degeneration and systemic factors.

Convergence Zone Width Analysis Based on Ray Cluster Theory and Its Application in the Array Depth Optimization of Active Sensors

Convergence Zone Width Analysis Based on Ray Cluster Theory and Its Application in the Array Depth Optimization of Active Sensors