Angle Parameters Research Articles

No‐organic solvent, no‐fluorinated waterborne superhydrophobic coatings based on SiO2 and IBTS

AbstractWaterborne superhydrophobic coatings have attracted widespread attention. However, organic solvents, fluorine‐containing compounds, and complex operational technologies hinder superhydrophobic coatings development severely. Herein, A simple method of preparing water‐based superhydrophobic coatings by one‐step spraying without organic solvent and fluorine is reported. The particles of silicon dioxide (SiO2) was modified by isobutyltriethoxysilane (IBTS), then combined with waterborne acrylic polyurethane (WPUA) and phenolic resin (PF), baked at 110°C to fabricate superhydrophobic coatings. According to the contact Angle (CA), hardness, adhesion, and other parameters, the ratio of SiO2 and PF of the composite coatings was optimized. Results showed that the superhydrophobicity and physical properties of the coating are the most exceptional at the content of SiO2 is 0.6 g, and the PF is 25%. In addition, related experimental results show that the coatings have good water resistance and self‐cleaning ability, the special nano/micro structure of the coatings also endows it excellent abrasion resistance. Exceptional hydrophobicity and physical properties meeting the actual application conditions of superhydrophobic coatings. Therefore, the simple method for preparing superhydrophobic coatings has great application prospects.

Development and validation of sloped ground pressure prediction model for a tracked tractor in hilly and mountainous environments

Tracked tractors are better suited for agricultural production in hilly environments because of their excellent stability and flotation. The ground pressure in these environments is highly irregular owing to the ground slope, which has led to a lack of theoretical foundation and data support for the development of hillside tracked tractors (HTTs). Therefore, accurate prediction of the ground pressure at the track-soil interface on inclined terrain is important. In this study, sloped ground pressure prediction model composed of sloped terrain soil pressure-sinkage model was developed to analyse the distribution characteristics of the ground pressure of tracked tractors in agricultural operations on hillside slopes. Considering the influence of the slope angle, soil conditions, operating conditions, and important parameters of the tracked tractors (including mass, centre of gravity, and track gauge), the ground pressure prediction model used harmonic oscillator functions and peak-valley control primitive functions. To validate the proposed model, ground pressure tests of the experimental tracked tractor were conducted at different slope angles and operating conditions in an experimental platform integrating a "soil-machine-crop" system. The results showed that the maximum error between the predicted results and the test data under various slopes and operating conditions was approximately 6.3%, with an average error of approximately 4.7%; the consistency between the test results and the simulated results indicate that the model established in this study is accurate and credible. Based on the ground pressure model, the developed tractive performance prediction model for HTTs had high prediction accuracy for the slip rate and traction force in the climbing traction test. The developed theoretical model and results provide practical guidance for the structural design of advanced HTTs and manoeuvrability optimization.

A novel harmonic movable tooth drive with almost surface contact conjugate tooth profiles: Parametric design, modification and analysis

This paper focuses on a novel harmonic movable tooth drive as an alternative of currently used harmonic gear drives. Different from the harmonic gear drives, the novel drive removes small module teeth from thin-walled flexible rim, instead, adopts several rigid movable teeth with logarithmic spiral tooth profile. Such tooth geometry makes almost surface contact possible under load condition, in comparison with the conventional involute tooth profile creating a linear contact. Aiming at the issue of cusp meshing between movable tooth and ring gear during the meshing process, this paper proposes a modification design method for the conjugate tooth profiles. First, the radial motion law of movable tooth is modified, in order to avoid rigid impacts at the exchange point of the rise travel and return travel. Then, the tooth profile of ring gear is generated by the envelope of the modified profile of movable tooth. Based on the formulated modification scheme, the equations of the conjugate tooth profiles are derived, and the influences of spiral angle and modification parameters on the meshing characteristics are systematically investigated. Finally, the wave generator cam profile and pivoted segment profile are established considering the strength consistency. The outcomes can provide significance guidance for the parametric design and optimization of this novel drive.

A numerical study of heterogeneous nucleation of ice crystals and frost layer growth on horizontal cold surfaces

In engineering applications, the formation and growth of frost layers can significantly affect the normal operation of equipment, leading to undesirable influences. Therefore, it is imperative to understand the frost formation mechanisms as a basis for developing effective anti-frosting and defrosting methodologies. This study proposes a model for the growth of horizontal cold surface frost layers using the classical nucleation theory and the Eulerian multiphase flow model. Compared to numerous models that investigate the frost formation issues using the computational fluid dynamics (CFD) method, our proposed model takes into account the crystal growth period (the heterogeneous nucleation process of ice). The predicted results of the proposed model were found to be in good agreement with the data collected from five related experimental studies. In this regard, the maximum frost layer thickness error was 23.9 % with a mean error of 5.1 %, and the maximum density error was 22.8 % with a mean error of 8.1 %. Compared to existing models in the literature, the proposed model can reduce the maximum thickness and density uncertainties by 17.4 % and 10.2 %, respectively. Additionally, the effects of the surface contact angle and environmental parameters on the nucleation process were analyzed using the established model. It was found that a larger contact angle, higher cold surface temperature, and lower air temperature, humidity, and velocity were unfavorable conditions for supporting the formation and growth of ice crystals. Moreover, the nucleation completion time was shortened with the increase in the moist air supersaturation degree, varying as an exponential function. The findings of this study provide an important theoretical basis for the development of optimizing strategies for anti-frosting and defrosting.

Basal and dentoalveolar transverse parameters in different sagittal and vertical malocclusions in adults: a comparative study.

This study sought to three-dimensionally (3D) evaluate the maxillomandibular basal bone and dentoalveolar widths using cone-beam computed tomography (CBCT) scans in adult Chinese populations with different vertical and sagittal facial skeletal patterns whilst no apparent posterior dental crossbite. The retrospective cross-sectional comparative study enrolled CBCT images of 259 adult patients (125 males and 134 females). The subjects were divided into the hyperdivergent(n = 82), hypodivergent(n = 88), and normodivergent(n = 89) groups based on the Jarabak ratio (S-GO/N-Me), which were further divided into three subgroups of skeletal Class I, II and III, based on both the ANB angle and AF-BF parameters. ANOVA was used to analyze the extracted data of the studied groups. The intra- and inter-observer reliability was analyzed using the intra-class correlation coefficient (ICC). In all three vertical facial skeletal patterns, the skeletal Class II had significantly smaller mandibular basal bone width compared to skeletal Class I and Class III, both at the first molar and first premolar levels. The skeletal Class III seemed to have smaller maxillary basal bone width compared to skeletal Class I and Class II malocclusions; however, a significant difference was found only in the normodivergent pattern. As for the dentoalveolar compensation, it was most notable that in the hypodivergent growth pattern, the skeletal Class II had significantly smaller maxillary dentoalveolar width compared to the Class I and Class III groups, both at the first molar and first premolar levels. Based on the sample in the present study, skeletal Class II has the narrowest mandibular basal bone regardless of the vertical facial skeletal pattern. For Chinese adults with no apparent transverse discrepancy, the maxillomandibular basal bone and dentoalveolar widths are revealed in specific categories based on different vertical and sagittal facial skeletal patterns. In diagnosis and treatment planning, particular attention should be paid to skeletal Class II for possibly existing mandibular narrowing.

Phase angle at bioelectric impedance analysis is associated with detrimental sperm quality in idiopathic male infertility: a preliminary clinical study.

In 2020, 38% of adults were affected by obesity, while infertility globally affected 1 in 6 people at some stage of their lives.Body mass index (BMI) provides an easy but occasionally inaccurate estimation of body composition. To achieve a more precise assessment, bioelectric impedance analysis serves as a validated tool that administers electrical energy through surface electrodes. Phase angle as a function of the relationship between tissues resistance and reactance, is a trustworthy predictor of body composition and cell membrane integrity. We aim to assess whether there is an association between phase angle and seminal parameters, as well as sperm DNA fragmentation percentage. Semen samples of 520 idiopathic infertile patients were analyzed according to 2021 World Health Organization guidelines and evaluated for sperm DNA fragmentation rate. Each participants underwent bioelectric impedance analysis. Median age was 40 years old, median BMI was 26.3 kg/m2, median phase angle was 6.2°. In the logistic regression analysis adjusted for age and total intracorporeal water, phase angle (continuous) was significantly associated with oligozoospermia (odds ratio [OR]:0.4; p<0.01) and sperm morphology (OR: 0.65; p=0.05) and slightly with sperm DNA fragmentation (OR: 0.98; p=0.07). In subgroup analysis, the logistic regression analysis adjusted for the mentioned parameters showed that a phase angle between 6.2 and 7 (°) (OR: 0.63; p=0.02) and >7 (°) (OR: 0.12; p<0.01) were associated with a reduced risk of oligozoospermia compared to values <6.2 (°). Similarly, a phase angle between 6.2 and 7 (°) (OR: 0.57; p< 0.01 and OR: 0.58; p= 0.01) and PA > 7 (°) (OR: 0.12; p= 0.03 and OR: 0.21; p< 0.01) were associated with a reduced risk of lower sperm concentration and lower total sperm count, respectively, compared to a phase angle < 6.2 (°). Our study suggests a negative association between phase angle and detrimental sperm parameters in male idiopathic infertility.

In-situ EBSD tensile revealing the evolution mechanism of high angle grain boundaries in Al–Zn–Mg alloy profile with heterogeneous structures

The evolution of grain boundary (GB) of an Al–Zn–Mg alloy profile with heterogeneous structures is studied based on in-situ EBSD tensile. This evolution is not only related to its grain boundary misorientation angle (GBMA) and slip transfer parameter (m'/(Δb/b)) but also to the behavior of the geometrically necessary dislocation (GND) tensor in the deformation. The effect of GBMA and m'/(Δb/b) for three types of high angle grain boundary (HAGB) on GND density and back stress has been revealed. The increase of GND density is not obvious near the HAGBs with 45°–55° GBMA of neighboring coarse grains or neighboring fibrous grains. The optimal grain boundary for forming back stress is the HAGBs between coarse grain and fibrous grain, which has 35°–45° GBMA and a low m'/(Δb/b). The back stress is hard to form near these HAGBs with 25°–35° GBMA and a low m'/(Δb/b). Combined with the neighboring grain type, slip transfer and GBMA, the new criterion is proposed to predict GND behavior near HAGBs.

Supercritical heat transfer of Novec 649 refrigerant in a minichannel with various inclination angles: Horizontal to vertically downward flows

The study of organic fluids under supercritical conditions has been less extensive than that of supercritical carbon dioxide and water. In addition, most studies on supercritical heat transfer have focused on horizontal or vertical channels, with limited research on inclination angles. Therefore, the focus of this study was to investigate the supercritical heat transfer of organic fluid (Novec 649) in a miniaturized channel across various inclination angles. The experimental findings reveal that the heat transfer coefficient (HTC) increases with an increase in the fluid's bulk temperature at a given mass flux and with an increase in the mass flux at a given bulk temperature. Notably, the HTC in horizontal flow channels marginally surpasses that in non-horizontal channels. The buoyancy effect, found to be non-dominant in a studied channel, does not lead to heat transfer deterioration. In vertical flow channels, under the experimental conditions, the acceleration parameters exceeded the threshold values, suggesting a potential significance of the acceleration effect. Particularly at higher mass fluxes, the acceleration parameter peaked as the film temperature approached the fluid's pseudocritical value. We further developed the supercritical heat transfer correlation by introducing an inclination angle parameter, achieving a mean absolute error of 12.7 %.

Validity Verification of Human Pose-Tracking Algorithms for Gait Analysis Capability.

Two-dimensional (2D) clinical gait analysis systems are more affordable and portable than contemporary three-dimensional (3D) clinical models. Using the Vicon 3D motion capture system as the standard, we evaluated the internal statistics of the Imasen and open-source OpenPose gait measurement systems, both designed for 2D input, to validate their output based on the similarity of results and the legitimacy of their inner statistical processes. We measured time factors, distance factors, and joint angles of the hip and knee joints in the sagittal plane while varying speeds and gaits during level walking in three in-person walking experiments under normal, maximum-speed, and tandem scenarios. The intraclass correlation coefficients of the 2D models were greater than 0.769 for all gait parameters compared with those of Vicon, except for some knee joint angles. The relative agreement was excellent for the time-distance gait parameter and moderate-to-excellent for each gait motion contraction range, except for hip joint angles. The time-distance gait parameter was high for Cronbach's alpha coefficients of 0.899-0.993 but low for 0.298-0.971. Correlation coefficients were greater than 0.571 for time-distance gait parameters but lower for joint angle parameters, particularly hip joint angles. Our study elucidates areas in which to improve 2D models for their widespread clinical application.

Andreev reflections in deformed semi-Dirac material superconducting junctions

Besides the strong anisotropy, another unique feature of the semi-Dirac materials (SDMs) is the evolution of its dispersion with gap parameter from a merging semi-Dirac point to two Dirac points. In this study, we study the superconducting coherent transport at the SDM superconducting junction and focus on the influence of evolution of the SDM dispersion on the Andreev reflection. We found that the coexistence of peculiar quadruple reflections, including double specular normal reflection and double retro Andreev reflection, can occur within a wide range of parameters. We in detail discuss the dependence of reflection probabilities on the incident angle, incident energy, and gap parameter. By modulating these parameters, we also observe rich double reflection scenarios. These results enrich our understanding of the superconducting coherent transport and facilitate the probing of the intrinsic gap parameter in SDMs experimentally.

AFDet: alignment and focusing for aerial object detection

ABSTRACT Object detection in aerial images has become a focus in recent years due to the expansion of its application fields. Aerial objects have the characteristics of multi-scale, arbitrary angle and dense arrangement, which brings considerable challenges to the task. Based on the efficient one-stage detectors, most methods design modules to adaptively align the feature receptive field with the anchors to improve the accuracy of the bounding box regression and calculate loss according to parameter bias. Current methods are not adequately data-driven in feature optimization and the angle parameter regression faces boundary problems. To handle these problems, in this letter, we propose an Align-Focus detector (AFDet) for aerial image object detection. We introduce the ideology of deformable multi-head self-attention to feature optimization and design a new Align-Focus Module (AFM) which can sensitively focus feature encoding response to the real texture area of the objects. In addition, we apply KF-IOU Loss to solve the boundary problem. We conduct necessary experiments on DOTA and HRSC2016 datasets, and AFDet achieves the highest mAP performance compared to the existing methods.

Entropy generation due to MHD Falkner–Skan flow of Casson fluid over a wedge: A numerical study

AbstractThis study highlights the significance of entropy generation in the Falkner–Skan flow of Casson fluid past a wedge. To investigate the energy analysis, the governing equations include the heat transport equation in the presence of internal heat source, and the energy transport accounts for heat dissipation using viscous dissipation and Joule heating effect. The mathematical formulation of the problem leads to a set of nonlinear coupled partial differential equations. To obtain a similarity solution, similarity variables are introduced. The resulting differential equations are solved numerically using the shooting technique in conjunction with the Runge–Kutta–Fehlberg 45 (RKF‐45) method. Graphical representations are utilized to demonstrate the physical significance of the relevant parameters. The study analyzes the impact of various parameters on the velocity, temperature, and entropy distributions for three wedge positions: stationary, forward‐moving, and backward‐moving. The results show that an increase in the wedge angle parameter and Casson parameter leads to an increase in fluid velocity, while fluid entropy increases rapidly with an increase in the Brinkmann number, power law Falkner–Skan parameter, and Reynolds number. Moreover, with an increment in the Prandtl and Eckert number, the Nusselt number coefficient decelerates for both static and moving wedge.

THREE-DIMENSIONAL MODEL OF EQUIVALENT ROLL GAP OF CVC MILL UNDER CONDITIONS OF ROLL CROSSING AND NO LOAD

Traditional roll technologies focus solely on the contour of the roll gap at the outlet under ideal conditions. However, upon roll crossing, the three-dimensional distribution of the deformation zone becomes asymmetrical, leading to an adverse impact on the rolling pressure in the deformation zone. To study the screw-down load deviation of plate mills, it is necessary to accurately calculate the equivalent three-dimensional roll gap in the deformation zone under roll-crossing conditions. In this paper a model for calculating the equivalent three-dimensional roll gap under the conditions of roll crossing and no load was established based on the method of the coordinate nonlinear transformation of the spatial rectangular coordinate system. Based on this model, the influences of roll-crossing angles and translation parameters on the symmetry of the equivalent three-dimensional roll gap were analyzed. The distribution of the three-dimensional equivalent roll gap was calculated with different roll lengths, roll radii, and the roll gap’s nominal thickness. The intuitive contour map reveals that under the same condition of crossing angle and translation parameters, the larger the roll length and roll radii and the smaller the roll gap’s nominal thickness are, the greater the influence of the roll crossing on the asymmetrical distribution of roll gap is. It put forward a quantitative calculation method for evaluating the symmetrical distribution of the roll gap, and the calculation results can provide the equivalent roll profile for the roll-deformation model.

Model Predictive Control of Magnetic Helical Swimmers in Two-Dimensional Plane

Magnetic micro/mini-swimmers have a great potential application in biomedical research and have gained broad attention. Recent research studies focus on the automatic control methods of magnetic micro/mini-swimmers, such as artificial intelligence methods. However, their autonomous manipulation remains a challenge since they are subject to various disturbances from the external environment and model uncertainties. The current methods employ a status observer to estimate these disturbances and uncertainties. In this paper, we apply a data-driven technique that utilizes the nonlinear approximation ability of neural networks (NNs). To be specific, a flexible structure of NNs, Broad Learning System (BLS), is employed to model the input-output mapping relationship between the direction of the rotating magnetic field and the swimming direction of the helical miniature swimmer. Then, according to the dual-variable decoupling control, a levitation controller is formulated and a path following controller is proposed based on a planar three-degree-of-freedom model of magnetic helical swimmers, which is inspired by the model of wheeled mobile robots. Simulations and experiments are conducted to quantitatively validate the proposed control method using different planar paths. The experiment results show that the mean absolute error of the path following control is about 3 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\%$</tex-math> </inline-formula> of the body length which is less than 0.5 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$mm$</tex-math> </inline-formula> . Our proposed control method provides a preliminary study to alleviate the impact of disturbances and uncertainties on the control performance of magnetic micro/mini-swimmers. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —This paper is mainly motivated by the potential application of artificial intelligence methods in magnetic micro/mini-robot community, especially for the applications that reject disturbances and uncertainties. In practice, a path planner is employed to compute a pre-defined reference path that connects the start and the targeted locations. Then our control method is applied to the magnetic helical swimmer and it is guided to follow the reference path. Tackling external disturbances and model uncertainties is still challenging during the control progress. Neural network-based technique is an intuitive approach since their nonlinear modeling ability and generalization are suitable for estimating these disturbances and uncertainties. As for training the neural-network model, the training data about the angle parameters should be recorded by manual control of the helical swimmer. These angle parameters define the rotating axis of the uniform rotating magnetic field and the self-rotating axis of the magnetic helical swimmer. According to the planar motion model, the optimal controller is formulated using the feedback distance error and angle error, and the sum of the control signal and the prediction of the compensating model is used as the final control input. Our electromagnetic coil system features easy operation and configuration of cameras or other sensors. Simulations and experiments validate the performance of the neural network-based compensating method and the proposed optimal control method using magnetic micro/mini-swimmers.

Inverse design of twisted bilayer graphene metasurface for terahertz absorption broadening based on artificial neural network

With the development of terahertz (THz) technology, achieving ultra-wideband absorption of THz waves has become a significant challenge that researchers are striving to address. Different from the complex stacking of multiple graphene layers in the traditional design, inspired by the twisted magic angle of graphene structures, a twisted bilayer graphene metasurface absorber (TBGMA) is innovatively investigated for THz wave absorption broadening inverse design based on artificial neural network (ANN). Compared with the traditional manual parameter tuning, the ANN-based inverse design method can quickly accomplish the selection of the structural parameters and twist angles of the TBGMA, realizing the ultra-wideband absorption of THz waves (6.046 THz). The relationship between twisted SGLs and broadened effective absorption bandwidths is thoroughly analyzed through a combination of the electric field distribution and effective medium theory (EMT). Additionally, the tunability and absorption spectra of TBGMA under different incidence conditions have been discussed. The study of the twisted angle of SGLs can provide a unique idea for expanding the absorption bandwidth, and the inverse design of structural and angle parameters in conjunction with ANN is expected to be extended to the design of other precision structures in nanophotonics.

Anterior Knee Pain (AKP) and its Relationship to Quadriceps Angle and Anthropometric Parameters: A Hospital-Based Cross-Sectional Study from Iraq

Abstract Background: Anterior knee pain (AKP) is a common condition, especially among physically active adults who present a clinical challenge. Patellar malalignment is thought to be an important cause. Measuring quadriceps (Q) angle significant test used in the assessment of patellar alignment and hence used in the assessment of AKP. Objectives: To assess the relationship between AKP and Q angle among ample Iraqi patients. Materials and Methods: The right and left Q angles of 100 participants were measured using a universal goniometer. The participants were divided into three groups: controls, patients with left AKP (LAKP), and patients with right AKP (RAKP). The relationship between Q angles and different groups was tested using appropriate statistical tests. Results: The left Q angles for males measure 14.1 ± 1.9 in controls, 17.7 ± 1.6 in LAKP cases and 16.1 ± 1.8 in RAKP cases, and for the females 16.1 ± 1.8 in controls, 18.1 ± 1.8 in LAKP cases and 17.1 ± 2.5 in RAKP cases. The right Q angles for males measure 15.6 ± 2.2 in controls, 15.1 ± 2.7 in LAKP cases and 19 ± 1.6 in RAKP cases, and for the females were 17.7 ± 2.4 in controls, 17.9 ± 2.2 in LAKP cases and 19.9 ± 2 in RAKP cases. Both Q angles (right and left) were greater in females than in males and both were greater in cases than in controls. Conclusion: The study concluded that there is a significant association between AKP and quadriceps femoris angle measurement in both genders. Therefore, clinical and/or radiological demonstration of quadriceps angle can be used as a means for initial detection of AKP.

A study of mydriatic effect on intraocular pressure and anterior chamber angle morphology by anterior segment optical coherence tomography

Context Pharmacological mydriasis possibly is associated with intraocular pressure (IOP) rise and anterior chamber angle changes. Hence, this study is focused on pressure analysis with anterior segment optical coherence tomography measurements of angle parameters during various dilation phases. Aims Purpose is to investigate IOP variations during dilation phases and to discover association of anterior segment optical coherence tomography measurements. Settings and design Observational study. Patients and methods Thirty-two participants were recruited and IOP measured by rebound tonometer in pre, mid, and full pupillary dilation phases. Lens vault (LV at horizontal and vertical), angle opening distance (AOD at 500 and 750 μm) and trabecular iris space area (TISA at 500 and 750 μm) in temporal and nasal scans were quantified. Paired t test performed to establish a statistical significance P value less than or equal to 0.05. Statistical analysis used MS Excel. Results A total of 32 participants with mean age of 47.5±10.94 years consisting of 17 (53.13%) males and 15 (46.87%) females with 20 (62.5%) right and 12 (37.5%) left eyes were investigated. Mean IOP in pre, mid, and full-dilation phases were 14.86±2.87, 15.94±2.72, and 15.63±2.69 mmHg. Predilation IOP with IOP in mid and full dilation showed statistical significance (P=0.0001, 95% confidence interval 0.56–1.56) and 0.88 and 0.85 Pearson’s coefficients, respectively. IOP analysis with LV, AOD, and TISA in pre, mid, and full-dilation phases exhibited a significant difference (P&lt;0.0001). Conclusion This research highlights an increase in IOP alongside a noteworthy decrease in the average LV by 30.94 μm during mid-dilation compared to the predilation phase. Likewise, the AOD at 750 μm demonstrated a significant reduction by 0.40 and 0.45 μm in temporal scans during mid and full dilation, respectively, while TISA remained unchanged.

Performance of anterior segment OCT-based algorithms in the opportunistic screening for primary angle-closure disease

PurposeThis study aimed to investigate the performance of deep learning algorithms in the opportunistic screening for primary angle-closure disease (PACD) using combined anterior segment parameters. MethodsThis was an observational, cross-sectional hospital-based study. Patients with PACD and healthy controls who underwent comprehensive eye examinations, including gonioscopy and anterior segment optical coherence tomography (ASOCT) examinations under both light and dark conditions, were consecutively enrolled from the Department of Ophthalmology at the Beijing Tongren Hospital between November 2020 and June 2022. The anterior chamber, anterior chamber angle, iris, and lens parameters were assessed using ASOCT. To build the prediction models, backward logistic regression was utilized to select the variables to discriminate patients with PACD from normal participants, and the area under the receiver operating characteristic curve was used to evaluate the efficacy of the opportunistic screening. ResultsThe data from 199 patients (199 eyes) were included in the final analysis and divided into two groups: PACD (109 eyes) and controls (90 eyes). Angle opening distance at 500 μm, anterior chamber area, and iris curvature measured in the light condition were included in the final prediction models. The area under the receiver operating characteristic curve was 0.968, with a sensitivity of 91.74 % and a specificity of 91.11 %. ConclusionASOCT-based algorithms showed excellent diagnostic performance in the opportunistic screening for PACD. These results provide a promising basis for future research on the development of an angle-closure probability scoring system for PACD screening.

Effect of Rotational Angle of Discrete Inclined Ribs on Horizontal Flow and Heat Transfer of Supercritical R134a

This work numerically studied the heat transfer and flow characteristics of supercritical R134a in horizontal pipes equipped with DDIR, considering variations in the rotation angle of DDIR. The aim is to improve the effects of the DDIR configuration on the heat transfer of supercritical flow. After validation with experimental data, the AKN model was employed to examine the effects of four sets of rotation angles (0°, 30°, 45°, and 60°) on the axial and circumferential heat transfer characteristics of DDIR horizontal tubes under the influence of strong (q1/G1 = 0.1 kJ/kg) and medium (q2/G2 = 0.056 kJ/kg) buoyancy. Results show that variations in the rotation angle do not induce significant alterations in the flow field, thus exerting minimal influence on the axial heat transfer characteristics. Meanwhile, the rotation angle determines the relative positioning of the circumferential inner wall temperatures and heat flux distribution, although the magnitude of this effect remains inconspicuous. The rotational angle parameter can be reasonably neglected in the future design and installation of heat exchangers.

Estimation of angle parameters by ASOCT and biometric parameters by optical biometer in eyes with occludable angles and open angles.

To compare anterior chamber angle (ACA) parameters measured by Anterior Segment Optical Coherence Tomography (ASOCT) and biometric parameters measured by Swept-Source (SS) OCT-based biometry among patients with suspected occludable angles and open angles. An analytical, cross-sectional study was performed on subjects attending our ophthalmology outpatient department with suspected occludable angles (van Herick grades 0, 1, and 2) in group 1, and with open angles (van Herick grades 3 and 4) in group 2. Each subject underwent a complete ophthalmic examination to exclude any intraocular pathology like cataract. We recruited 128 eyes of 64 subjects, 34 in group 1 and 30 in group 2. Each eye was henceforth subjected to ASOCT (Spectralis, Heidelberg Engineering, Heidelberg) and SS-OCT-based optical biometry (IOL Master 700, Carl Zeiss Meditec AG). Anatomical parameters were recorded and compared between the two groups. The main outcome measures of the study included nine ASOCT parameters (central corneal thickness [CCT], lens vault, AOD750, ACA, TISA750 [nasal and temporal], and ACW) and five optical biometric parameters (CCT, ACD, WTW, LT, and axial length). We found a significant difference (p < 0.05) among all the anatomical parameters between the two groups, except CCT which was not significantly different (p = 0.297). ASOCT and SSOCT biometry overcome the challenges of gonioscopy and allow screening for angle closure disease in otherwise normal subjects. ASOCT may serve as an alternative to gonioscopy as it clearly separates occludable angles from open angles in a non-invasive and objective manner.