Degree Angle Research Articles

Investigation of Tactile and Strain Sensing Utilizing Carbon-Fiber Network in Silicone Elastomer Matrix

Abstract As the popularity of immersive and interactive technology continues to grow, there is demand for wearable or conformable tactile and strain sensors for human-computer-interaction (HCI). A major challenge in current conformable sensors is durability, tremendously limiting their applications in the market. This study utilizes long carbon-fiber networks in silicone elastomer matrix as electrodes for sensing, which consequently strengthens the sensors. Row and column pattern of long carbon-fiber was used to create projected capacitive touch sensors at every intersection and demonstrate multi-touch and spatial mapping capabilities. Similarly, these intersections were also demonstrated as piezoresistive force sensor where deformation from pressure on the intersection decreases the resistance between the row and column electrodes by altering the electrical network among the carbon-fibers. Lastly, piezoresistive strain sensors were manufactured by impregnating a pre-woven carbon-fiber fabric with silicone. Deformation in the 45-degree angle relative to the fabric caused changes in the electrical interactions between carbon-fibers and therefore the resistance along the sensor as well. These strain sensors showed an interesting behavior of increasing then decreasing resistance as the tensile load shifted from the silicone matrix to the carbon-fibers. The ultimate strength of properly bonded strain sensors using Smooth-On Sil-Poxy was significantly greater than the strength of pure two-part silicone. An intricately designed carbon-fiber network within a silicone matrix could combine these sensing mechanisms to potentially create a durable and compact multifunctional sensor that expands wearable sensing technology to rugged environments.

Modeling the Emission and Polarization Properties of Pulsating Ultraluminous X‐Ray Sources

ABSTRACTPulsating Ultraluminous X‐ray Sources (PULXs) are a class of extragalactic sources with high X‐ray luminosity, in excess of erg , and showing pulsations that associate them with neutron stars accreting at a super‐Eddington rate. A simplified model is presented, which describes the thermal emission from an accreting, highly magnetized neutron star and includes the contributions from an accretion disk and an accretion envelope surrounding the star magnetosphere. Through numerical calculations, we determine the flux, pulsed fractions, polarization degree, and polarization angle considering various viewing geometries. The model is confronted with the XMM‐Newton spectra of M51 ULX‐7, and the best fitting viewing geometries are estimated. A measurement of the polarization observables, which will be available with future facilities, along with spectroscopic data obtained with XMM‐Newton, will provide considerable additional information on these sources.

Non-Linear Hyperelastic Model Analysis and Numerical Validation of 3D Printed PLA+ Material Incorporating Various Infill Densities

Additive manufacturing (AM) or 3D printing technology creates a tangible object by adding successive layers of materials. Nowadays, 3D printing is used for developing both metal and non-metal products. In the advancement of 3D printing technology, material specimen design, modification, and testing become very simple, especially for non-metal materials, such as hyperelastic, thermoplastic, or rubber-like materials. However, proper material modeling and validation are required for the analysis of these types of materials. In this study, 3D printed poly lactic acid (PLA+) material behavior is analyzed numerically for validation in the counterpart of experimental analysis to evaluate their behavior in both cases. The specimen was designed in SolidWorks by following ASTM D638 dimension standards with proper infill densities and raster angle or infill orientation angle. These infill layer densities and angles of orientation play an important role in the mechanical behavior of the specimen. This paper aims to present a numerical validation of five infill densities (20%, 40%, 60%, 80%, and 100%) for a ±45-degree infill angle orientation by incorporating a nonlinear hyperelastic model. Results indicate that infill densities affect the mechanical behavior of PLA+ material. The result also suggested that neo-Hookean and Mooney–Rivlin are the best-fitted hyperelastic material models for these five separate linear infill densities. However, neo-Hookean is easier to analyze, as it has only one parameter and a new equation is developed in this study for determining the parameter for different infill densities.

Resistance of Resin-Bonded Ceramic Endocrowns of Different Intracoronal Depths.

This in-vitro study was conducted to assess the fracture resistance of resin-bonded ceramic endocrowns with different designs at varying intracoronal depths. Forty-eight (n = 48) extracted mandibular first molar teeth were randomly divided into four groups (n = 12). In the control group, the specimens remained untreated. Whereas the specimens in the test groups A, B, and C were decapitated 2 mm above the cementoenamel junction (CEJ) and endodontically treated. The test groups were prepared with a butt-joint design in a standardised manner with varying intracoronal depths. Groups A, B, and C were prepared to receive lithium disilicate endocrown with intracoronal cores at 0 mm, 2 mm, and 4 mm, respectively. Crowns were fabricated as a non-anatomical design with a thickness of 3 mm. After ceramic bonding procedures, specimens underwent thermocyclic ageing prior to the fracture resistance test. Specimens were loaded at a 15-degree angle using the Universal Testing Machine and the failure modes were observed. One-way analysis of variance (ANOVA) and Chi-square were utilised for data statistical analyses. Significant statistical results in fracture resistance tests were found in all experimental groups. The highest load was found in group B, followed by group C, and lastly group A (P 0.05). Although endocrowns with no extension had the lowest fracture resistance, they showed a favourable cohesive failure with statistically no significant difference from the control group. In bonded ceramic endocrowns, the fracture resistance is not newcessarily proportional to the intracanal depth. The intrcoronal cores of 4 mm did not show the highest fracture resistance, and their mode of failure was catastrophic compared to endocrowns with no intracoronal extensions.

Advanced IoT-integrated parking systems with automated license plate recognition and payment management

Urban parking management is a growing challenge with increasing vehicle numbers and limited parking space. Traditional methods often fail during peak hours, leading to inefficiencies, unauthorized usage, and revenue losses. For instance, a parking lot designed for 300 vehicles often exceeds 90% occupancy during peak times, creating congestion and billing inaccuracies. This research proposes an automated system integrating sensors, image processing, and database management to address these issues. A single camera monitors multiple parking slots, with predefined coordinates linked to IR sensors for dual verification. Image processing algorithms, including Optical Character Recognition (OCR), enable accurate license plate recognition. Testing under real-world conditions showed 95% accuracy in daylight, 90% in low light, and 93% for plates at 45-degree angles. Detection accuracy reached 88% at distances of 1.5–3 m, ensuring reliable operation even at the camera’s range limits. Occupancy tracking achieved less than a 5% error margin compared to manual methods, while the fare calculation module reduced billing errors by 90%, enhancing efficiency and revenue. The system’s scalable design supports applications in parking management, toll collection, and traffic monitoring. By improving vehicle detection, occupancy tracking, and billing accuracy, this solution addresses critical challenges in urban parking and contributes to smarter city infrastructure.

Detached Eddy Simulation of Micro-Vortex Generators Mounted on NACA 4412 Airfoil

Abstract Micro Vortex Generators (MVGs) are simple vane-type devices installed on surfaces i.e. aircraft wing and tail, to control boundary layer flow separation. They are cost-effective and require an efficient numerical method to resolve the embedded longitudinal vortical structure, as the flow behind them is highly unsteady. This numerical study aims at analyzing the effect of MVGs on the NACA 4412 airfoil performance using the detached eddy simulation (DES) at 60,000 Reynolds number based on the free stream velocity of 11 m/s and the wing chord of 0.1 meter. The MVGs are installed in a row in counter-rotating configuration at 10% chord of the airfoil. The DES is utilized to resolve the high energetic scales of the vortex behind the MVGs which Reynolds Averaged Navier-Stokes (RANS) is not likely to resolve properly. A comparison of DES simulations with the RANS simulations shows that RANS modeling is not sufficient to capture the airfoil flow characteristics at higher angles of attack. The DES simulations resolve the turbulent scales downstream of the MVGs effectively and produce significant improvement in NACA 4412 wing performance. It has been observed that airfoil lift coefficient at 10 degree angle of attack with the MVGs is 5% higher than the airfoil without MVGs. MVGs along the airfoil chordwise location demonstrate that MVGs at 25% chord are more effective in managing separation over the airfoil compared to those at 10% chord location.

Top-down and emotional attention in blind and sighted individuals.

There is evidence that congenitally blind individuals possess superior auditory perceptual skills compared to sighted people. However, relatively little is known about the auditory-specific cortical correlates of spatial attention in the blind and how task-irrelevant emotional stimulus features could further modulate such neural processes. This study tested blind and sighted participants in a challenging auditory discrimination task. All participants were blindfolded and seated between loudspeakers at 45-degree angles, while pseudowords were randomly presented. The task was to identify target sounds from either the left or the right speaker while ignoring nontarget stimuli, the irrelevant loudspeaker, and irrelevant speaker identity. Emotional valence-neutral, happy, fearful, threatening-of pseudowords was task-irrelevant, focusing solely on syllable detection. Our focus was on measuring the moment-to-moment deployment of auditory-selective attention. This was achieved using the lateralized N2ac event-related potential component characterised by greater negativity at anterior electrodes on the side contralateral to an attended auditory stimulus and observed 75 to 250 ms after stimulus onset. We observed that blind individuals showed better behavioural performance and reduced N2ac amplitudes than sighted individuals. Furthermore, for both groups, N2ac amplitudes were increased for the target compared to nontarget stimuli and stimuli appearing at spatially relevant versus irrelevant locations. Our study highlights the superiority of auditory processing capabilities in blind individuals. The results also highlight the N2ac component's sensitivity to top-down attentional engagement and emotional attention, offering new insights into how blind and sighted individuals process auditory information.

Improvement of Physical Ability to Children Gymnasts in Tirana of Albania

Balance is one of the main physical components of the sport of gymnastics. This study aims to determine the improvement effect of balance in female gymnasts aged 6-8 years. Methodology: The study lasts for 16 weeks and includes 5 gymnasts of 6-8 years old. Training sessions take place six times a week, with duration of 2 hours for each session. The measurement of balance parameters is done at before and after of the experiment using the GRFP "Leonardo". Balance tests include the Romberg stand with eyes open and closed, semi-tangent stand with eyes open and closed, tangent stand with eyes open and eyes closed, one-legged stand with eyes open and with eyes closed. Results: The results are obtained for each test from GRFP; Std. Ellipse Area (cm 2); Std. Ellipse Angle (degree); Num. Eccentricity; dominant Freq (Hz); rel. Path length (mms); abs. Path length (mm); EQ(AP); Total Duration (s). Conclusion: The findings suggest that engaging in regular “Core Training” sessions can contribute to the development and improvement of balance skills in gymnasts of this age. Specific exercises aimed at core training have a direct impact on postural control and stability, which are essential for maintaining balance during various physical activities.

Experimental study on high fatty acid WCO biodiesel effects on RCCI engine performance, and emissions, considering fuel oxygen level

One of the significant challenges of RCCI engines is increasing the amount of UHC and combustion phasing control. On the other hand, a substantial challenge for biodiesel fuel is increasing NOx production. The low-temperature combustion (LTC) strategy is an effective method of reducing NOx. In this experimental study, an RCCI engine with diesel-gasoline dual fuel was experimentally evaluated under medium load conditions (BMEP = 20 bar) with a waste cooking oil (WCO) biodiesel mixture. The effect of changing WCO biodiesel fuel to diesel ratio (with different volume ratios of 0, 5, 10, and 20%) was investigated. The results showed that with a 5% increase in WCO fuel volume share, due to the higher cetane number of WCO fuel, the start of combustion (SOC) occurred about 4 crank angle degrees earlier. By increasing the volume ratio of biodiesel from 5 to 10% (B10), the amount of CO emissions suddenly increased by 33%; due to the increase in the viscosity of the high reactivity fuel (HRF), the fuel is not well atomized, causing poor cold combustion. In the case of using B20 fuel, the amount of unburned hydrocarbons (UHC) is greatly reduced due to the high pressure inside the cylinder.

Pulse duration dependent effects of ultrafast laser induced damage on a 1030 nm multi-layer dielectric mirror for high repetition rate, high average power laser systems

High repetition rate, high peak, and average power laser systems are crucial for next-generation particle accelerators, inertial confinement fusion, and secondary particle sources. These applications demand durable laser optics, particularly interference coatings on optics lasting millions of shots at high fluence. This study focuses on designing, testing, and simulating multi-layer dielectric (MLD) mirrors for pulse durations of 260 fs, 77 fs, and 25 fs at 1030 nm wavelength and 45-degree incidence angle with p-polarization. S-on-1 laser-induced damage thresholds (LIDT) for varying pulse numbers were determined, with single-shot LIDT values of 0.98 Jcm-2, 1.63 Jcm-2, and 2.3 Jcm-2 for 25 fs, 77 fs, and 260 fs respectively. A strong correlation between blister shape and local fluence was observed, implying that the layer expansion in a blister depends on local fluence. We have also examined mechanisms responsible for laser-induced stress generation and energy release rates in blister formation. Damage mechanisms are further explored by finite-difference time-domain (FDTD) simulations, incorporating Keldysh strong field ionization, whose predictions were in excellent agreement with the onset of damage determined experimentally. These findings offer insights for enhancing MLD coating technology, promising more efficient and resilient laser systems for diverse scientific and industrial applications.

Urogenital Anomalies Identified on Examination of Pediatric Patients Before Circumcision

Abstract Object: Circumcision is included in European urology guidelines as a treatment choice only for severe phimosis, while it is a procedure routinely performed for socio-cultural reasons in many different countries. Parents bring their children to urology clinics requesting circumcision. Before circumcision, it is very important to perform full urogenital examination because many urogenital anomalies that require treatment may be identified so. In this study, we aimed to determine the urogenital anomalies identified in children before circumcision. Method: This study retrospectively investigated findings of 190 pediatric cases attending our urology for circumcision between September 2015 and September 2021. Each child had standard examinations of penis, urethra, testis and scrotum. The presence and laterality of undescended testis, presence and laterality of retractile testis, presence and degree of phimosis, presence and localization of hypospadias, presence and degree of buried penis, presence direction, and angle of penis chordee-curvature, presence of penoscrotal web, presence and laterality of hydrocele, presence of urethral stenosis, and presence of urethral duplication were recorded. Results: In our study assessing the examination findings of 190 pediatric cases attending our urology clinic for circumcision between September 2015 and September 2021, a total of 127 children had urogenital anomalies (66%). Buried penis (46 cases, 24%) was the most frequently encountered urogenital anomaly. Undescended testis was the second most common (19 cases, 10%), while retractile testis (15 cases, 7%) was the third most common anomaly. Accordingly, phimosis was identified in 11 cases, penile curvature in 6 cases, hypospadias in 3 cases, hydrocele in 3 cases, penoscrotal web in 1 cases and urethral meatus duplication in 1 case. Conclusion: Circumcision is performed for both medical reasons and socio-cultural reasons in many countries. However, these patients may have serious urogenital anomalies . Careful physical examination is very important for patients attending for circumcision.

Comparison of the primary stability of orthodontic mini-screws manufactured by the Computer Numerically Control and Selective Laser Melting manufacturing methods: An exploratory study

Background: This study was to assess the primary stability of orthodontic mini-screws of the same design produced by a conventional and a novel manufacturing method. Methods: A total of 150 orthodontic mini-screws with a body length of 8 mm, a diameter of 1.6 mm, a button head, and a self-drilling feature were used in the study. Mini-screws were manufactured through computer numerically controlled (CNC) and selective laser melting (SLM) manufacturing methods. Titanium (T) and stainless steel (SS) alloys were used as manufacturing materials. The study was conducted on three groups; CNC-T, SLM-T and SLM-SS. Mini-screws were placed at 60- and 90-degree angles in fresh bovine femur bones, where the cortical bone thickness was 2 mm. With the radiofrequency analysis (RFA) technique, the stability of the mini-screws was determined immediately after they were placed (F0), immediately after applying orthodontic force to the mini-screw (F1), after six hours (F6), and after 24 hours (F24). Three-way robust ANOVA was used to compare the data, and the Bonferroni correction was statistically applied. Results: Except for the insertion angle of the mini-screw, the group and time factors had statistically significant effects on the RFA values. The highest RFA value was detected in the SLM-T group. Conclusion: Orthodontic mini-screws manufactured from titanium or stainless steel alloys using the SLM technology can be an alternative to mini-screws manufactured using the traditional manufacturing method. The mini-screws manufactured using the SLM technology demonstrated adequate primary stability when subjected to an orthodontic force. Keywords: Orthodontic mini-screw, Primary stability, Selective laser melting, Computer numerical control, Radiofrequency analysis

A Feasibility Study of a Controlled Standing Fulcrum Side-Bending Test in Adolescent Idiopathic Scoliosis.

Background/Objectives: Spinal flexibility radiographs are important in adolescent idiopathic scoliosis (AIS) for clinical decision-making. In this study, we introduce a new method, the 'quantitatively controlled standing fulcrum side-bending' test (CSFS test). This is a feasibility study; we aimed to quantify the applied force and track the temporospatial changes in the spine specifically by measuring the continuous change in the Cobb angle (in degrees) during lateral bending. Methods: In this cross-sectional study, we included patients with AIS. Using a low-dose cinematic fluoroscopic technique, we captured the lateral bending of the thoracolumbar vertebral spine while inducing quantified lateral force on the ribs by a force gauge in a three-point fixation setup of controlled lateral bending. Trial registration number: H-1703423. Results: Twenty-one patients with small-curve AIS were included as subjects. All subjects performed the CSFS test adequately. They had small curves with a mean Cobb angle of 12.0 (range: 0.0-26.0, SD: 7.1). The measured median stiffness was 3.66 N/degrees (°) of the Cobb angle (range: 0.02-11.81) with a median coefficient of determination R2 of 0.58 (range: 0.002-0.92) by regression analyses. When analysed concerning the median-term clinical outcome of either progression/regression or stationary curves, various Cobb angle measurements and the other experimental parameters, there were no significant relationships. Conclusions: The CSFS test is feasible to quantify the force applied and the temporospatial changes in the spine during lateral bending. The CSFS test has been utilised in basic research for mechanical characterisation of the scoliotic spine and has the potential of being implemented directly in patient-specific bracing to estimate the forces needed for brace correction and adjustment so as not to supersede the allowed skin pressure.

EXPERIMENTAL STAND FOR STUDYING LOCAL CONDITIONS OF TRANSIENT HEAT TRANSFER

An experimental setup has been designed to study local conditions of non-stationary heat exchange during cooling of a high-temperature surface with a sprayed liquid: from nozzles of various modifications (including sprayers); water-air; steam-air; steam-water; superheated liquid; water with different concentrations of surfactants. An analysis of scientific sources has determined a research methodology that will allow the study of the influence of irrigation density, surface temperature, degree of liquid underheating, its velocity and angle of flow onto the surface, taking into account the possibility of implementing a change in the determining factors in the range of their corresponding real values ​​in natural energy and metallurgy facilities and the task of selecting a method for identifying the boundary conditions of heat exchange. We have not come across any studies of heat exchange intensity as a function of underheating of sprayed liquid – water with different concentrations of surfactants at different local irrigation densities and surface temperatures in scientific publications. Therefore, these studies, as well as the development of effective cooling systems or determination of the thermal state of objects under various external influences, are of primary importance to us. In order to implement our planned research program, in addition to developing a method for identifying the boundary conditions of heat exchange, it was necessary to solve a number of special problems associated with determining the operating parameters of the cooling medium. These include the local irrigation density and the velocity of the dispersed medium at the surface of the thermal probe. For reliable determination of local irrigation flow rate, as well as determination of the dispersed composition of drops, the pulse counting method, which has the possibility of practical implementation in our country, should be used. To determine local conditions of non-stationary heat exchange, we have developed a scheme for measuring the EMF of temperature detectors installed in the body of the rod of the thermal probe, and also selected high-speed digital recording equipment. The solution of the inverse problem of heat conduction will allow us to establish the degree of influence of practically all factors indicated as determining ones.

INTEGRATION OF HIGH-TEMPERATURE SURFACE HEAT EXCHANGE

Despite the discrete nature of the interaction of droplets of sprayed liquid with a high-temperature surface, the inevitable formation of a liquid film leads to the fact that the main qualitative laws of the heat exchange that occurs in this case are characteristic of the known process of heat exchange during boiling. At the same time, the presence of extensive theoretical and experimental studies of “large-volume boiling” and the process of steam generation in channels does not allow us to establish the conditions of heat exchange during the thermal interaction of a dispersed liquid - water with different concentrations of surfactants with a high-temperature surface. We did not find any materials about this process in the scientific literature. With a number of features common to the above two cases of heat exchange (the presence of boiling crises, film and bubble modes, etc.), cooling a high-temperature surface with a droplet medium containing various concentrations of surfactants has significant distinctive features due to the hydrodynamics of the process, which is the subject of further study. To fully explore the above task, the following must be done: Develop a methodology for experimental study of local conditions of non-stationary heat exchange of sprayed water with different concentrations of surfactants. Develop and manufacture an experimental setup on which to conduct research on the effects of irrigation density, surface temperature, degree of liquid underheating, its speed and angle of impingement on the surface. Develop a mathematical model for calculations of heat flows, heat transfer coefficients, dynamics of hydraulic methods of liquid dispersion – water with different concentrations of surfactants, critical heat flows and surface temperatures in the transition region from film to bubble boiling as a function of determining factors. Establish the independent influence of the degree of non-stationarity of the process on the heat exchange conditions.

Immediate Effects of Whole Body Vibration on Proprioception and Upper Extremity Reaction Speed in Young Adult Students.

There is limited information on the immediate effects of whole-body vibration (WBV) on the upper limb. This study aims to determine the immediate effects of WBV on reaction speed and proprioception in young adult students' upper extremities. In total, 62 students participated in the study. WBV was applied to the participants, and its immediate effects on proprioception and upper extremity reaction speed were examined. Participants' proprioception and perception of joint position at 30-60 degrees of shoulder flexion, shoulder abduction, and elbow flexion angles were measured with absolute error degrees. Reaction rates were evaluated with the Ruler-Drop Test and the mobile application SWAY. A decrease was observed in the absolute error level of the participants' joint position perception at 30-60 elbow and shoulder position degrees, measured after immediate WBV application (p <0.05). After the RDT application, a decrease in the length of catching the target was observed (p <0.05). The SWAY test determined that they moved the smartphone in a shorter time (p <0.05). Right and left RDT scores showed that the distance to catch the ruler was significantly lower in male individuals before the application. In comparison, the distance to catch the ruler was lower after the application (right/left p<0.05). The study found that applying WBV improved upper extremity proprioception perception and reaction speed in young adults. This information can guide clinicians in applying WBV to healthy individuals and those with symptoms.

Analytical study of some kinematics variables for the last steps in the javelin event and their relationship with performance

Kinematics is one of the branches of biomechanics used in the field of sports, and it is one of the important tools that aid in the diagnosis of faults and virtues of the technical performance of the movement. javelin. This effectively goes through multiple stages the require continuous biomechanical evaluation in order to accomplish advance achievement. This study's primary objective was to determine the values of some kinematic variables of the last three steps of the javelin throw by senior throwers from Erbil provence clubs. The the research population consists of senior throwers in Erbil governarate clubs who participated in the Erbil competition numbered (12) individuals, furthermore, the sample of (5) players intentionally selected from population. The results show that there is a correlation between the length of the second-to-last and last step in addition to correlation between vertical velocity in the third step with javalin achievement. The researchers concluded that the optimal extrusion angle (45 degrees) is not optimal for all events; although the javelin is a projectile, a 45-degree angle is not commonly used in the javelin (angle younger had a correlation with the best achievement of the angle 45).

OPTIMIZATION OF URBAN THERMAL ENVIRONMENT FOR INDONESIA COASTAL-CLIMATE URBAN AREA: A MICROCLIMATIC MODELING

Coastal urban areas, one of which is the PIK 2, Tangerang Regency, Indonesia, as the study case, have distinctive climate characteristics: changes in land and sea breezes during different seasons and high humidity and wind speed levels, which affect thermal comfort. The optimal building mass needs to be studied to achieve ideal thermal comfort conditions, which can effectively respond to climate characteristics different from those of other urban areas. This paper investigates the existing urban thermal environment and models the impact of building orientation, form, and H/W ratio simulated in ENVI-met. Based on the study findings, it has been determined that positioning a building diagonally towards the sea at a 45-degree angle effectively reduces excessive wind speeds, resulting in a favorable PMV score. Additionally, incorporating a sky bridge into the building form design provides adequate shading and contributes to achieving optimal thermal comfort in coastal-climate urban areas. Moreover, the optimal H/W ratio is 0.5, which can reduce wind speed without significantly lowering the temperature, thereby maintaining thermal comfort.

Verification of how to distinguish between male and female seedlings of date palm seeds

A method has been developed to distinguish between male and female date palm seeds. The (Apocole) emergence from the hilum bends towards gravity to the right or left of the seed head in a ratio of 1:1. To ensure that it is a genetically controlled phenomenon in date palms, 400 seeds were mixed randomly.100 seeds were planted with their dorsal surface up (as a control treatment) which germinated 52% towards the right and 48% towards the left of the seed’s head. 50 seeds were planted inverted in deep dishes and then germinated at the same ratio. 100 seeds were planted by tilting the embryo axis at a 45-degree angle to the right or the left. Half of them bent in the direction of gravity, and the other half delayed germination for several days, rising 2 mm above the surface of the seeds. Then 100 seeds were planted on a rotating clinostat placed on the plate's circumference to push the Apocole by the centrifugal force to bend towards the right or the left. Half of the seeds (which oppose the centrifugal force) germination were delayed for several days. 50 seeds were planted in the rotation axis center, so the Apocole germinated several days later before bending in its inherited direction. These confirmed that this bending is an inherited trait that distinguishes the sex of the seedling. After 5 years it confirmed our discovery of the distinction between male and female trees. Keywords: Date palm, sex determination, date palm seedlings, germination method, Apocole growth.

Observation Angle Effect of Near-Ground Thermal Infrared Remote Sensing on the Temperature Results of Urban Land Surface

During the process of urbanization, a large number of impervious land surfaces are replacing the biologically active surface. Land surface temperature is a key factor reflecting the urban thermal environment and a crucial factor affecting city livability and resident comfort. Therefore, the accurate measurement of land surface temperature is of great significance. Thermal infrared remote sensing is widely applied to study the urban thermal environment due to its distinctive advantages of high sensitivity, wide coverage, high resolution, and continuous measurement. Low-altitude remote sensing, performed using thermal infrared sensors carried by unmanned aerial vehicles (UAVs), is a common method of land surface observation. However, thermal infrared sensors may experience varying degrees of sway due to wind, affecting the quality of the data. It is still uncertain as to what degree angle changes affect thermal infrared data in urban environments. To investigate this effect, a near-ground remote sensing experiment was conducted to observe three common urban land surfaces, namely, marble tiles, cement tiles and grasses, at observation angles of 15°, 30°, 45°, and 60° using a thermal infrared imager. This is accompanied by synchronous ground temperature measurements conducted by iButton digital thermometers. Our results suggest that the temperature differences between the remote sensing data of the land surface and the corresponding ground truth data increase as a function of the increasing observation angle of the three land surfaces. Furthermore, the differences are minor when the observation angle changes are not more than 15° and the changes are not the same for different land surfaces. Our findings increase the current understanding of the effects of different angles on thermal infrared remote sensing in urban land surface temperature monitoring.