Tube Angle Research Articles

AI-Supported Autonomous Uterus Reconstructions: First Application in MRI Using 3D SPACE with Iterative Denoising

T2-weighted imaging in at least two orthogonal planes is recommended for assessment of the uterus. To determine whether a convolutional neural network-based algorithm could be used for the re-constructions of uterus axes derived from a 3D SPACE with iterative denoising. 50 patients aged 18-81 (mean: 42) years who underwent an MRI examination of the uterus participated voluntarily in this prospective study after informed consent. In addition to a standard MRI pelvis protocol, a 3D SPACE research application sequence was acquired in sagittal orientation. Reconstructions for both the cervix and the cavum in the short and long axes were performed by a research trainee (T), an experienced radiologist (E), and the prototype software (P). In thenext step, the reconstructions were evaluated anonymously by two experienced readers according to 5-point-Likert-Scales. In addition, the length of the cervical canal, the length of the cavum and the distance between the tube angles were measured on all reconstructions. Interobserver agreement was assessed for all ratings. For all axes, significant differences were found between the scores of the reconstructions by research T, E and P. P received higher scores and was preferred significantly more often with the exception of the comparison of the reconstruction Cervix short of E (Cervix short: P vs. T: p=0.02; P vs. E: p=0.26; Cervix long: P vs. T: p=0.01; P vs. E: p<0.01; Cavum short: P vs. T: p=0.01; P vs. E: p=0.02; Cavum long: P vs. T: p<0.01; P vs. E: p<0.01). Regarding the measured diameters, (length of cervical canal/cavum/distance between tube angles) significantly larger diameters were recorded for P compared to E and T (Cervix long (mm): T: 25.43; E: 25.65; P: 26.65; Cavum short (mm): T: 26.24; E: 25.04; P: 27.33; Cavum long (mm): T: 31.98; E: 32.91; P: 34.41; P vs. T: p<0.01); P vs. E: p=0.04). Moderate to substantial agreement was found between Reader 1 and Reader 2 (range: 0.39-0.67). P was able to reconstruct the axes at least as well as or better than E and T. P could thereby lead to workflow facilitation and enable more efficient reporting of uterine MRI.

Influence of powder stream density on near infrared measurements upon scale-up of a simulated continuous process

Near-infrared (NIR) spectroscopy is a powerful process analytical tool for monitoring chemical constituents in continuous pharmaceutical processes. However, the density variation introduced when quantitative NIR measurements are performed on powder streams at different flow rates is a potential source of a lack of model robustness. Since different flow rates are often required to meet the production requirements (e.g., during scale-up) of a continuous process, the development of efficient strategies to characterize, understand, and mitigate the impact of powder density on NIR measurements is highly desirable. This study focused on assessing the effect of powder physical variation on NIR by enabling the in-line characterization of powder stream density in a simulated continuous system. The in-line measurements of powder stream density were facilitated through a unique analytical interface to a flowing process. Powder streams delivered at various design levels of flow rate and tube angle were monitored simultaneously by NIR diffuse reflectance spectroscopy, live imaging, and dynamic mass characterization. Statistical analysis and multivariate modeling confirmed powder density as a significant source of spectral variability due to flow rate. Besides providing broader process understanding, results elucidated potential mitigation strategies to facilitate effective continuous process scale-up while ensuring NIR model robustness against density.

CFD simulations for flashing pressurized slurry in metallurgical processing

A compressible multiphase CFD model has been developed to simulate the flashing process of the three-phase slurry at high temperatures and pressures. The model is validated with the gas-water flash process in the literature. A comparison of simulation results for gas-liquid and gas-liquid-solid systems indicates that the presence of solids changes important physical characteristics of these systems, including velocity, pressure, and shock location. The simulations indicate that changing the deflection angle, length, and diameter of the blast tube will significantly influence the flashing process. Increased blast tube length can reduce the velocity of the outlet significantly. The performance of the blast tube will be impaired if the deflection angle is too large. Increased tube diameter boosts mass flow rate while decreasing shock strength and increasing velocity at the outlet. These simulation results would be beneficial for the design and operation of flashtubes.

The difference in rotation angle of the distal endotracheal tube through nasal approach

BackgroundNasal intubation using a fiberoptic scope is a useful technique. In clinical practice, we have experienced difficulty in advancing the endotracheal tube (ETT) over the fiberoptic scope because of resistance to the passage of the ETT against rotation in the nasal cavity, when it gets hung up on structures of the laryngeal inlet. Several maneuvers have been proposed to overcome this difficulty. The gap between the tip of the ETT and the fiberoptic scope can be reduced using a thicker fiberoptic scope and a thinner ETT. Moreover, simultaneous rotation of the fiberoptic scope and ETT could lead to successful intubation by reducing impingement on the ETT. However, the discrepancy between these rotation angles is unclear. This observational prospective study aimed to investigate the discrepancy in the rotation angle between the ETT and fiberoptic scope during nasal intubation.MethodsThe patients (aged 20–80 years) who underwent nasal intubation for oral and maxillofacial surgery participated in three sizes of preformed nasal ETT and were intubated using a fiberoptic scope. They were divided into three groups; the ETT internal diameter (ID) 6.5 mm (6.5 group), ID 7.0 mm (7.0 group), and ID 7.5 mm (7.5 group). The ETT was then inserted through the nasal cavity into the pharynx. After the fiberoptic scope was advanced through the ETT above the glottis, simultaneous rotation by both the proximal end of the fiberoptic scope and ETT was performed in 90° and 180° in both right (clockwise) and left (counterclockwise) directions, and the rotation angle at the distal end of the ETT was monitored using a video laryngoscope (Pentax-AWS).ResultsA total of 39 patients were included in the study. When both the proximal end of the fiberscope and ETT were simultaneously rotated by 90°, in the 6.5 group (n = 13), the distal end of the ETT rotated by 47.8 ± 1.5°. In the 7.0 °group (n = 13), the distal end of the ETT rotated by 45.5 ± 1.0°. In the 7.5 group (n = 13), the distal end of the ETT rotated by 39.9 ± 1.0°. When the proximal end of the fiberscope and ETT were rotated by 180°, in the 6.5 group, the distal end of the ETT rotated by 166.2 ± 2.5°. In the 7.0 group, the distal end of the ETT rotated by 145.7 ± 2.2°. In the 7.5 group, the distal end of the ETT rotated by 115.1 ± 2.0°. All rotation angles in the distal end of the ETT were significantly lower than those in both the proximal end of the fiberscope and ETT (p < 0.05). Rotating right by 180° was significantly different among the three groups (p < 0.05), although rotating right by 90° was not significantly different. Similar results were obtained for the left rotation.ConclusionSimultaneous rotation by the proximal end of the ETT and fiberscope above the glottis for the nasal approach induced significant differences in the distal end of the ETT. The larger tube lagged by the resistance of the nasal passages during rotation. Therefore, the ETT does not rotate as much as the rotation angle.Trial registrationThis prospective observational study was conducted after receiving approval from the Ethics Review Board of Kyushu University Hospital (Approval No. 30–447).

Comparison between Eustachian tube angle and length in chronic otitis media and contralateral ear

Background: Chronic suppurative otitis media (CSOM) is still a significant public health problem, especially in developing countries. Eustachian tube dysfunction is one of the factors that influence the occurrence of CSOM. The pathogenesis of acute and chronic otitis media is initiated by negative pressure in the middle ear. One theory of the event of CSOM is the continuum theory. The eustachian tube as one of the factors that influence the occurrence of CSOM has been proven from various studies comparing CSOM patients and the average population and CSOM with and without cholesteatoma. With the advanced technology, CT scan helps diagnose pathological conditions in the ear as a diagnostic tool and evaluation modality. CT scan imaging with a multiplanar reconstruction technique can provide a clear image of the anatomical shape of the Eustachian tube. Objective: This study aims to determine the relationship between the angle and length of the Eustachian tube in the ear with CSOM and the contralateral ear's angle and length. Method: An analytic study with a cross-sectional design involving 30 samples of CSOM patients with the contralateral ear. The measurement of the angle and length of the Eustachian tube using the multiplanar HRCT temporal reconstruction technique. Result: Statistical analysis with paired t-test showed that the Eustachian tube angle was significantly more horizontal in the CSOM ear than the contralateral ear (p&lt;0.05). Eustachian tube length was shorter in CSOM than contralateral (p&lt;0.05). Conclusion: The angle of the eustachian tube in the CSOM ear is smaller (more horizontal) and shorter than the contralateral ear.

Design optimization and experiment of corn U-shaped fertilization device

Aiming at the problems of low utilization rate of corn fertilizer, low precision of fertilization ratio, and time-consuming and laborious topdressing in the later stage, an U-shaped fertilization device with uniform fertilizer mechanism was designed. The device was mainly composed of uniform fertilizer mixing mechanism, fertilizer guide plate and fertilization plate. Compound fertilizer was applied on both sides and slow/controlled release fertilizer was applied at the bottom to form an U-shaped distribution of fertilizer around corn seeds. Through theoretical analysis and calculation, the structural parameters of the fertilization device were determined. Through the simulated soil tank test, the quadratic regression orthogonal rotation combination design was carried out on the main factors affecting the spatial stratification effect of fertilizer. The optimal parameters were obtained as follows: the stirring speed of the stirring structure was 300 r/min, the bending angle of the fertilization tube was 165°, and the operating speed of the fertilization device was 3 km/h. The results of bench verification test showed that under the optimized stirring speed and bending angle, the fertilizer particles were stirred evenly, and the average values of fertilizer flowing out of the fertilization tubes on both sides were 299.5 g and 297.4 g, respectively. The average fertilizer amounts of the three fertilizer outlets were 200.4 g, 203.2 g and 197.7 g, respectively, which met the agronomic requirements of 1:1:1 fertilization, and the variation coefficients of fertilizer amounts on both sides of the fertilizer pipe and each layer were less than 0.1% and 0.4%, respectively. The simulation results of the optimized U-shaped fertilization device can achieve the expected U-shaped fertilization effect around corn seeds. The results of field experiment showed that the U-shaped fertilization device could realize the U-shaped proportional application of fertilizer in soil. The distance between the upper end of fertilization on both sides and the distance between the base fertilizer and the surface were 87.3–95.2 mm and 197.8–206.0 mm, respectively. The transverse distance between the fertilizers on both sides was 84.3–99.4 mm, and the error with the designed theoretical fertilization was within 10 mm. Compared with the traditional side fertilization method, the number of corn roots increased by 5–6, the root length increased by 30–40 mm, and the yield increased by 9.9–14.8%.

Anatomical tilt lateral wrist X-ray – Not always 22°

IntroductionOpen Reduction and Internal Fixation (ORIF) with volar locking plates are commonly used to manage distal radial fractures. The anatomical tilt lateral (ATL) wrist X-ray is often required for evaluation of intra-articular screw penetration due to the screw position. This study aims to evaluate the correlation between the tube angulation given by performing radiographers for the ATL projection and the post-examination measurement of radial inclination (RI) on the Posterior Anterior (PA) wrist image. MethodsA retrospective review was performed for 36 patients. A standardised method developed by Kreder et al. (1996) was used to measure the RI on the PA wrist image. All ATL images sent into Picture Archiving and Communications System (PACS) have the tube angulation applied annotated on the image. Pearson's correlation was used to analyse the co-relationship between the RI and the tube angle applied for ATL projection. ResultsThe average angle of RI measured by the four observers was 19. Normality of 0.385 was established. A positive correlation (p = 0.792) between the RI and the tube angle applied for ATL was found. ConclusionOur study found a strong positive correlation between the tube angulation applied by performing radiographers for the ATL projection and the post-examination RI measured on the PA wrist image by the independent reviewers. This suggests that radiographers can use the measured RI to apply the tube angulation when performing the ATL wrist X-ray, instead of estimating the tube angulation to be applied. Implications for practiceUsing the measured RI to apply the tube angulation when performing the ATL wrist X-ray will ensure a more reliable and reproducible way that could reduce the number of repeated images and, thus, unnecessary radiation dose to patients.

Effect of tubular heater structures on the thermal behaviors of waxy crude oil

In this paper, we research the temperature field, flow field and melting law of gelled crude oil with different diameters, locations and inclination angles of heating tube by numerical simulation method. Using the synergy angle, temperature variance and effective heating ratio as evaluation indices, the effect of the heating tube and distribution homogeneity of the temperature field were examined. The simulation results show that the temperature field and velocity field of waxy crude oil and the melting law of gelled crude oil are basically the same under different conditions. The most important factor affecting average temperature and temperature variance is the location of heating tube, which can increase the average temperature by 1.252 °C and decrease the temperature variance by 9.019°C2. The most important factor affecting the synergy angle is the inclination angle of heating tube, which can be reduced by 4.104°. In the 8 cases, when the inclination angle of the heating tube is 45°, the temperature maintaining effect of tubular heating is the best, and the synergy angle is the smallest. The least temperature variance is the uniform arrangement of heating tube. The results of this study will provide theoretical guidance for the optimization design of tubular heater structure.

Effect of curvature radius and angle on aerodynamic characteristics of a sphere travelling in a branched tube system

Compressible flow through a branched duct and the motion of a sphere through a high blockage ratio pipe are two important and engaging topics throughout the years. The results of studies on these topics are of practical relevance to many fields such as the gas pipeline technology, air transport systems in gas turbines technology, and tube transportation, etc. However, studies on the motion of a sphere in a branched duct are scarce. Studies of the motion of a sphere in a near-vacuum tube could contribute to the development of a branched Hyperloop system in the future. In this study, we investigated the effect of the tube curvature radius and angle on the aerodynamic characteristics of a sphere during its motion in a branched tube. We examined, quantified, and compared the variation of the drag, side force, and pressure waves for the cases where a sphere enters a branch considering six curvature radii (from 500 to 3000 m), three angles (10°, 15°, and 20°), three speeds (100, 200, and 300 m s-1), and two initial pressures (1/1000 and 1 atm) in simulations. The results indicated that the drag and side force vary only in the intersection region (region where the straight tube and branched tube intersect); before and after the intersection region, they are similar. With an increase in the curvature radius, the rate of drag reduction (FD/max(FD)) decreases, while the changes in the angle do not affect variation of drag and side forces. Furthermore, we compared the motion of a sphere in straight and branched directions and found out that the flow in front and behind the sphere was similar for both directions.

Numerical analysis of the influence iron type on Von Mises Stress and safety parameters for compost processing machine frame construction

The installation of other engine parts, such as the engine, transmission, shaft, blade, and cover, includes the engine frame. The engine frame must be developed and constructed with the strength to support other components. The building of the waste processing machine frame with variants of square tube type and angle bar type will be analyzed in this study, with a focus on the analysis of von Mises’s stress and safety aspects. Using Solidworks software, finite element analysis is the research methodology used. The examination of the waste processing machine’s frame modelling using square tubes and angular bars yielded maximum von Mises stress values of 3.77e+7 N/m2 and 3.162e+4 N/m2, respectively. The maximum deformation values for the square tube iron and angular bar used in the modelling analysis of the waste processing machine frame are 2,499e+1mm and 9,725e+1mm, respectively . and 8.5 and 1 is the required minimum safety factor value for modelling the frame of a waste processing machine made of square tube iron. The safety factor value of 2-3 is the primary criterion for a suitable design. It is safe and advised to utilize the waste processing machine frame made of square tube iron for this purpose.

Compressive behavior of circular GFRP tube-confined UHPC-filled steel-encased stub columns

Using ultra-high-performance concrete with coarse aggregate (UHPC-CA) instead of plain concrete, the mechanical performance of FRP tube-confined concrete-filled steel-encased columns (FUSCs) can be significantly improved with controllable cost. In this study, the axial compressive behavior of FUSCs was investigated, in which the thickness and fiber winding angle of FRP tube, section size of profile steel, and substitution rate of coarse aggregate were the variables considered. The failure mode and the load-deformation relation were analyzed, upon which the interaction mechanism between the profile steel, UHPC, and FRP tube was uncovered. The results showed that FUSCs mainly failed in two distinct failure modes, i.e., shear failure and crush failure respectively, depending on the magnitude of FRP confinement and the size of profile steel. Meanwhile, the incorporation of coarse aggregate could enhance the constraint effect of FRP tube, resulting in an increase in the strength index and peak strain up to 16.2% and 38.2%, respectively. With extra restraint after the peak load, the profile steel provided a significant contribution to the FUSCs’ ductility, leading to a transition of FRP confinement effect from non-uniform to uniform. The research outcome serves as a reference for design of FUSCs and promotes the application of FUSC structure.

Contrast-enhanced magnetic resonance angiography in the identification of prostatic arterial anatomy in patients with benign prostatic hyperplasia: prospective comparison with digital subtraction angiography

To evaluate the utility of contrast-enhanced magnetic resonance angiography (CE-MRA) for identifying prostatic artery (PA) anatomy in patients with benign prostatic hyperplasia (BPH) before PA embolisation (PAE), using digital subtraction angiography (DSA) as the reference standard. A total of 176 patients underwent pelvic CE-MRA at 3 T. DSA was performed within the following 7 days. Two interventional radiologists compared the CE-MRA findings with DSA findings to assess the anatomy of the PAs. The rates of correct identification of the origins and collaterals of the PAs by CE-MRA were calculated. The utility for predicting the optimal X-ray tube angle obliquity for visualising the origins of the PAs by CE-MRA was evaluated. An exact McNemar's test was used to compare the detection rates of the PAs and the collaterals with DSA versus CE-MRA. A two-sided p-value of <0.05 was considered statistically significant. Of the 376 PAs identified by DSA, CE-MRA correctly identified the origins of 369 vessels (98.1%), with a 1.9% false-negative rate and no false-positive results. Of the 57 total collaterals identified by DSA, CE-MRA identified 50 vessels correctly (87.7%), with a 12.3% false-negative rate and no false-positive results. No significant differences were observed between CE-MRA and DSA in the identification of the PA origins (p=0.824) and the collaterals (p=0.327). The optimal degree for an oblique projection to visualise the origins of the PAs could be predicted accurately (100%) by pre-procedural CE-MRA. CE-MRA before PAE can reliably predict the PA anatomy and facilitate procedural planning.

Method for Measuring Noise Power Spectrum Depending on X-ray Tube Angle in Spiral Orbit of Helical CT Scan

The noise power spectrum (NPS) in computed tomography (CT) images potentially varies with the X-ray tube angle in a spiral orbit of the helical scan. The purpose of this study was to propose a method for measuring the NPS for each angle of the X-ray tube. Images of the water phantom were acquired using a helical scan. As a conventional method, we measured the two-dimensional (2D) NPS from each image and averaged them; the obtained 2D-NPS was referred to as NPSconventional. In the proposed method, we made the X-ray tube angle θ (0°≤θ<360°) to correspond to the image according to each slice position of the images that located within the travel distance of the CT scan table per 360° rotation of the X-ray tube. We obtained the 2D-NPS from each image and assigned the θ (0°, 30°, 60°, 90°, 120°, 150°, 180°); the obtained 2D-NPS was referred to as NPSsθ. The NPSsθ was compared to the NPSconventional. Also, we investigated the dependency of the NPSsθ on the θ. The NPSconventional was found to be isotropic, and in contrast, the NPSsθ was anisotropic. The NPSsθ showed a continuously rotational change while increasing the θ. There was an excellent correlation (R2>0.999) between the rotation angle of NPSθ and the θ. The proposed method was demonstrated to be effective for evaluating anisotropic noise characteristics depending on the X-ray tube angle.

Radiological Anatomy of Eustachian Tube and its Correlation with Graft Uptake in Type I Tympanoplasty

Introduction: Eustachian tube (ET) also known as pharyngotympanic tube connects nasopharynx with the middle ear. Evaluation of ET anatomy is aimed in patients with chronic otitis media. Materials and Methods: In a study of 53 patients, HRCT Temporal bone was done on 128 dual source simens somatom definition flash machine on 5mm cut section and tympanoplasty was carried out. Results: ET angle is one of the important factors for middle ear aeration. Outcome of tympanoplasty at 12th week was 88.7%. In the patients with vertical Eustachian Tube (i.e., more Eustachian Tube angle with the horizontal plane), better graft uptake in tympanoplasty was observed which was statistically significant. However, graft uptake did not correlate with the length of the Eustachian tube. Conclusion: It was concluded that on measuring ET length on HRCT, majority of the patients had bony length of 10-12 mm, cartilaginous length of 15-19 mm and total ET length of 28-32 mm. Majority of the patients had ET angle of 21-30 degrees with the hard palate.

Feasibility study of deep learning-based markerless real-time lung tumor tracking with orthogonal X-ray projection images.

The feasibility of a deep learning-based markerless real-time tumor tracking (RTTT) method was retrospectively studied with orthogonal kV X-ray images and clinical tracking records acquired during lung cancer treatment. Ten patients with lung cancer treated with marker-implanted RTTT were included. The prescription dose was 50Gy in four fractions, using seven- to nine-port non-coplanar static beams. This corresponds to 14-18 X-ray tube angles for an orthogonal X-ray imaging system rotating with the gantry. All patients underwent 10 respiratory phases four-dimensional computed tomography. After a data augmentation approach, for each X-ray tube angle of a patient, 2250 digitally reconstructed radiograph (DRR) images with gross tumor volume (GTV) contour labeled were obtained. These images were adopted to train the patient and X-ray tube angle-specific GTV contour prediction model. During the testing, the model trained with DRR images predicted GTV contour on X-ray projection images acquired during treatment. The predicted three-dimensional (3D) positions of the GTV were calculated based on the centroids of the contours in the orthogonal images. The 3D positions of GTV determined by the marker-implanted RTTT during the treatment were considered as the ground truth. The 3D deviations between the prediction and the ground truth were calculated to evaluate the performance of the model. The median GTV volume and motion range were 7.42 (range, 1.18-25.74) cm3 and 22 (range, 11-28) mm, respectively. In total, 8993 3D position comparisons were included. The mean calculation time was 85ms per image. The overall median value of the 3D deviation was 2.27 (interquartile range: 1.66-2.95) mm. The probability of the 3D deviation smaller than 5mm was 93.6%. The evaluation results and calculation efficiency show the proposed deep learning-based markerless RTTT method may be feasible for patients with lung cancer.

A gas distributor capable of multiple injection directions to improve the gas–liquid dispersion performance in the airlift loop reactor

As the gas supply equipment, the gas distributor is one of the core components in the airlift loop bioreactor. The gas injection direction and the dynamic behavior of the bubbles significantly affect the gas–liquid dispersion performance in the bioreactor. Therefore, based on the previously designed airlift loop reactor, a new type of tubular convex gas distributor (TCD) with multi-angle gas injection capability was developed. Under the conditions of different superficial gas velocities, the gas–liquid flow in the reactor was numerically simulated by computational fluid dynamics. The results showed that TCD had better gas–liquid dispersion and mass transfer performance in this reactor than several other traditional types of distributors. Under the experimental conditions, the optimal gas–liquid two-phase flow in the reactor was observed when the angle of the TCD vent tube was 15°, the number was 12, and the diameter was 1 mm. It was found that the error between the experimental results and the simulation results was controlled within 10 %, which verified the accuracy of the simulation. The application of TCD in the airlift loop bioreactor improved the wastewater treatment and biomass accumulation, significantly. The TCD can provide design ideas for gas distributors in other types of bioreactors, and is beneficial to improving the process of biological wastewater treatment for industrial application.

Simulation study on charging performance of the latent energy storage heat exchanger with a novel conical inner tube

The application of a latent heat thermal energy storage (LHTES) system can effectively solve the problem of the mismatch between the energy supply and demand. However, most studies focus on the traditional cylindrical configuration with a low heat storage rate, which limits the wide application of LHTES systems. The configuration optimization of a vertical shell-and-tube LHTES unit is carried out in this paper to enhance heat storage rate, and the effects of cone angle values (0–10°) in the conical shell and conical tube configurations on the heat storage performance are explored by numerical simulations. The results show that these two kinds of conical configurations both significantly improve the melting rate of the phase change material (PCM) compared with the cylindrical unit. However, when the cone angle is the same, the heat transfer enhancement effect of the latter is found to be superior to that of the former. Moreover, the complete melting time is shortened by 46 % as the cone angle of the inner tube increases from 0° to 10°. More importantly, a novel conical tube configuration design is proposed to eliminate the hard-to-melt zone at the bottom of the LHTES unit with the conical tube, then the effects of different tilting heights (60–170 mm) and bottom annulus distances (0–10 mm) are investigated. The results demonstrate that the melting rate increases with the increase in the tilting height, but the increased amplitude of that gradually reduces. Besides, the average heat storage rate shows a trend of first increasing and then decreasing with the increase in the distance of the bottom annulus. When the bottom annulus distance is 2 mm, the average heat storage rate reaches the maximum value, which is 94.84 W. The research results can provide a reference for the engineering design and configuration optimization of the vertical shell-and-tube phase change heat exchanger.

Design of Automatic Correction System for UAV’s Smoke Trajectory Angle Based on KNN Algorithm

Unmanned aerial vehicles (UAVs) have evolved with the progress of science and technology in recent years. They combine high-tech, such as information and communications technology, mechanical power, remote control, and electric power storage. In the past, drones could be flown only via remote control, and the mounted cameras captured images from the air. Now, UAVs integrate new technologies such as 5G, AI, and IoT in Taiwan. They have a great application value in a high-altitude data acquisition, entertainment performances (such as night light shows and UAV shows with smoke), agriculture, and 3D modeling. UAVs are susceptible to the natural wind when spraying smoke into the air, which leads to a smoke track offset. This study developed an autocorrect system for UAV smoke tracing. An AI model was used to calculate smoke tube angle corrections so that smoke tube angles could be immediately corrected when smoke is sprayed. This led to smoke tracks being consistent with flight tracks.

Effects of full transient Injection Rate and Initial Spray Trajectory Angle profiles on the CFD simulation of evaporating diesel sprays- comparison between singlehole and multi hole injectors

This paper investigates experimental and computational diesel sprays of single hole and multi hole injectors under vaporizing conditions. Two single hole and two ten-hole injectors with the same nozzle hole size are tested with the 120 MPa injection pressure. Experiments implement Laser Absorption Scattering technique. This method utilizes two wavelengths (Visible and Ultraviolet) of light and fuel's mixture concentrations are measured by attenuations of these lights. On the other hand, sprays are simulated in the Eulerian Langrangian two-phase fluid framework where KHRT and Multicomponent models are used as droplet breakup and evaporation models respectively. Full transient profiles of Injection Rate and Initial Spray Trajectory Angle are used as input boundary conditions for the spray simulation and effects on the spray characteristics are observed. Injection rates are measured with Bosch Long Tube and Initial Spray Trajectory Angles are extracted from the near nozzle field spray images. Experiments reveal that multi-hole injectors (0.101 mm and 0.133 mm) injectors depict longer liquid and shorter vapor penetrations. However, longer simulation liquid and vapor penetrations are seen for single hole injectors due to increased initial ramp-up phase. Sprays of Multi-hole injectors are diffused radially which promote air entrainment, better mixture formation, improved combustion, and lower exhaust emissions. Overall, simulated sprays using unfiltered injection rate profile as an input parameter showed an excellent agreement with experiments. While sprays using low-pass filtered injection rates showed a clear disagreement. Parameters including Liquid Length, Vapor Penetration and Evaporation ratios were found to be influenced by the IR profile rather than ISTA. Whereas vapor equivalence ratios depend on both input parameters plus breakup model constants.

Flexural behaviour of hollow reinforced concrete-filled fibreglass tubular beams

An experimental and numerical study of hollow reinforced concrete-filled glass-fibre-reinforced polymer tubular beams was carried out. Based on bending tests, the working mechanism and failure modes were studied. A finite-element model was established and the validity was assessed by comparing the experimental and numerical results. The main parameters included the wall thickness of the fibreglass tube, reinforcement ratio, hollow ratio, concrete strength and fibre winding angle. The results indicated that the composite beams failed gradually with considerable ductility. The bending capacity increased by about 12% with every 1 mm increment of the fibreglass tube thickness, increased by about 40% as the reinforcement ratio increased from 2.28% to 4.56%, and increased by about 6% with every 5 MPa increment of the concrete strength. The bending capacity decreased and then increased as the fibre winding angles ranged from 10° to 90°, and a small fibre winding angle was preferable for the flexural member. A hollow ratio of 0.375 is proved to be applicable to obtain lighter member self-weight with minimal decrease in strength.