Change Of Inclination Angle Research Articles

ENSURING SPEED STABILITY OF THE UNMANNED AERIAL VEHICLE IN DIF-FERENT FLIGHT MODES

The publication deals with the issue of ensuring the stability of an unmanned aerial vehicle flight by speed. An analysis of the physical essence of the process of ensuring the unmanned aerial vehicle stability by speed is presented. Attention is paid to the flight modes in which the operator (external pilot) may encounter difficulties in the practical piloting of the unmanned aerial vehicle. The possible causes of abnormal situations when flying the unmanned aerial vehicle at speeds close to the borderline low are analyzed. Possible actions of the operator (external pilot) to return the unmanned aerial vehicle to the operating speed range from the area of instability are considered. The article shows the features of stability and controllability of an unmanned aerial vehicle in a route flight mode. Attention is paid to the complexity of piloting and safety of flight in the second modes. The article demonstrates the method of determining the boundary between the first and second flight modes. The features of unmanned aerial vehicle management and ensuring stability in the first and second modes are shown. The issue of dynamic stability of the unmanned aerial vehicle is investigated. Numerical modeling of the longitudinal movement of the unmanned aerial vehicle in free, uncontrolled flight was carried out, trajectories for the unmanned aerial vehicle of the selected configuration with a change in speed and angle of inclination of the trajectory in time were obtained. Graphs of movement trajectories with changes in speed and height over time were constructed, graphs of transient processes were constructed for cases of stable and unstable flight modes. An analysis of the external factors that most affect the flight parameters in various conditions of unmanned aerial vehicle use was carried out.

Testing a Method Based on an Improved UNet and Skeleton Thinning Algorithm to Obtain Branch Phenotypes of Tall and Valuable Trees Using Abies beshanzuensis as the Research Sample.

Sudden changes in the morphological characteristics of trees are closely related to plant health, and automated phenotypic measurements can help improve the efficiency of plant health monitoring, and thus aid in the conservation of old and valuable tress. The irregular distribution of branches and the influence of the natural environment make it very difficult to monitor the status of branches in the field. In order to solve the problem of branch phenotype monitoring of tall and valuable plants in the field environment, this paper proposes an improved UNet model to achieve accurate extraction of trunk and branches. This paper also proposes an algorithm that can measure the branch length and inclination angle by using the main trunk and branches separated in the previous stage, finding the skeleton line of a single branch via digital image morphological processing and the Zhang-Suen thinning algorithm, obtaining the number of pixel points as the branch length, and then using Euclidean distance to fit a straight line to calculate the inclination angle of each branch. These were carried out in order to monitor the change in branch length and inclination angle and to determine whether plant branch breakage or external stress events had occurred. We evaluated the method on video images of Abies beshanzuensis, and the experimental results showed that the present algorithm has more excellent performance at 94.30% MIoU as compared with other target segmentation algorithms. The coefficient of determination (R2) is higher than 0.89 for the calculation of the branch length and inclination angle. In summary, the algorithm proposed in this paper can effectively segment the branches of tall plants and measure their length and inclination angle in a field environment, thus providing an effective method to monitor the health of valuable plants.

Accurate Phase Modulation Scheme in a Micropixel Liquid Crystal on Silicon with Multiple Polymer Walls

In the micropixel liquid crystal on silicon (LCoS), the fringe electric field seriously affects the phase modulation accuracy of the adjacent pixels. In this paper, we propose an accurate phase modulation scheme in micropixel LCoS with multiple polymer walls. The multiple polymer walls are fabricated between aluminum (Al) electrodes to block the crosstalk of the fringe electric field between adjacent pixel arrays and reduce the change of liquid crystal (LC) molecular inclination angle. Therefore, the phase can be accurately controlled by the driving voltage. The change in LC molecular inclination angle in the edge of the driving Al electrode is simulated, and the improvement effect of the multiple polymer walls on light leakage is also analyzed. The simulation results show that the change in the LC molecular inclination angle and light leakage in the edge of the driving Al electrodes can be ignored. In addition, we also fabricate the multiple polymer walls in the LC cell, which are made of a photoresist on the oriented glass substrate. The experimental results indicate that the LC cell with multiple polymer walls shows good bright and dark states, which proves that the phase can be accurately adjusted.

Influence of Installation Deviation of Thrust Bearing on Oil Film Flow of 1000 MW Hydraulic Turbine Unit

The thrust bearing, as the only part bearing the axial load, is extremely important in vertical hydroelectric generating units. Its working condition directly affects the safe and reliable operation of the hydroelectric generating unit. However, during operation, the oil film is easily damaged under the influence of complex factors. Installation deviation is a key point that can cause temperature and pressure changes in the oil film, affecting the force on the bearing. This article takes the thrust bearing model of the 1000 MW Francis turbine unit of the Baihetan Power Station as the research object. Based on the fluid–solid coupling theory and CFD technology, the oil film characteristics of thrust bearings are analyzed, and the influence of inclination angles and installation deviation on the oil film flow performance of thrust bearings is discussed. The results show that as the inclination angle changes from 0.0030° to 0.0048°, the axial force changes from 856 t to 368 t, and there is an approximate linear correlation between them. The radial installation deviation has an effect on the axial force. Under the optimal working condition of an inclination angle of 0.0039°, when the radial deviation of the pad changes from 0 mm to 1 mm, the axial force changes from 1573 t to 1275 t. In the process of unit installation, it is necessary to pay attention to the installation deviation of the pad. The results provide guidance for the installation of the bearing, which helps to ensure the safe and stable operation of the station.

Numerical study on cyclic driving force of enhanced refrigeration wave rotor based on optimized passage structure

Gas wave refrigeration technology is a new type of technical means to realize cold energy recovery by utilizing shock wave propagation characteristics. As the principal place for energy transfer, the shape of the oscillating tube directly determines the energy efficiency expression of the refrigeration equipment. In this paper, the differences in flow characteristics and loss patterns due to different passage shapes are numerically simulated. The optimized passage can not only improve the guiding effect of the wall on the gas flow but also bring about the self-excited ability of the circulating exhaust process, significantly reducing the external driving force demand. The shape of the rotor passage directly determines the expression of the pressure energy in the oscillating tube. The inclination angle of the high-temperature side represents the availability of static pressure energy, and the static pressure is more sensitive to the change of the high-pressure inclination angle. The calculation results show that reasonable passage length and intermediate radius will broaden the expansion depth and static pressure conversion rate and comprehensively improve the efficiency of the gas wave refrigeration system.

Effects of Pipe Inclination on Global Two-Phase Flow Parameters

Inclined two-phase flow geometries can be found in advanced nuclear reactor systems, such as the helical coil steam generators being considered for use in current integral steam generator designs. While this geometry includes inclination and centrifugal effects coupled together on two-phase flow, there have been limited studies to separate these effects to develop robust models. The majority of two-phase flow research is conducted on vertical channels, with recent work being conducted in a horizontal orientation and limited work in inclined pipes. In the current work, experiments are conducted in an adiabatic two-phase flow test facility to investigate the inclination effect on an air-water flow in straight pipes near atmospheric pressure. The pipe is made of clear acrylic with an inner diameter of 25.4 mm. The inclination of the flow loop can be adjusted in increments of 0.1 deg. Measurement capabilities are included to obtain local two-phase flow parameters such as void fraction, interfacial area concentration, bubble velocity, and Sauter-mean diameter using a local multisensor conductivity probe, local two-phase flow static pressure and pressure drop using a pressure transducer, and flow visualization using a high-speed video camera system. The experimental studies performed in the current work demonstrate how changes in inclination angle can affect the gas distribution flow regime transition and two-phase frictional pressure drop. Based on these experimental results, existing correlations for frictional pressure drop are evaluated, and the modified Lockhart-Martinelli correlation is found to predict the two-phase frictional pressure drop for inclined two-phase flows. This method agrees with experimental data within 7% on average.

Condition Monitoring of Horizontal Sieving Screens—A Case Study of Inertial Vibrator Bearing Failure in Calcium Carbonate Production Plant

Predictive maintenance is increasingly popular in many branches, as well as in the mining industry; however, there is a lack of spectacular examples of its practice efficiency. Close collaboration between Omya Group and Wroclaw University of Science and Technology allowed investigation of the failure of the inertial vibrator's bearing. The signals of vibration are captured from the sieving screen just before bearing failure and right after repair, when it was visually inspected after replacement. The additional complication was introduced by the loss of stable attachment of the vibrator's shield, which produced great periodical excitation in each place of measurement on the machine. Such anomalies in the signals, in addition to falling pieces of material, made impossible the diagnostics by standard methods. However, the implementation of advanced signal processing techniques such as time-frequency diagrams, envelope spectrum, cyclic spectral coherence, orbits analysis, and phase space plots allowed to undermine defects (pitting on the inner ring). After repair, the amplitudes of vibration from the damaged bearing side were reduced by five times, while sound pressure was only two times lower. The quantitative parameters of vibrations showed significant changes: time series RMS (-68%) median energy of spectrograms (89%), frequencies ratio of cyclic spectral coherence (-85%), and average amplitude of harmonics in envelope spectrum (-80%). The orbits demonstrated changes in inclination angle (16%) and sizes (-48, … -96%), as well as phase space plots sizes (-28, … -67%). Directions of further research are considered.

Comparison of heat transfer enhancement between open and closed cell porous metal structures for solid–liquid phase change

PurposeThe purpose of this study is to analyze heat transfer for solid–liquid phase change in two inclined cavities assisted with open cell and closed cell porous structures for enhancement of heat transfer and compare them.Design/methodology/approachThe heat transfer analysis is done numerically. The set of conservation equations for mass, momentum and energy for phase change material (PCM) and conduction heat transfer equation for metal frame are solved. Furthermore, temperature and solid–liquid fraction distributions for a cavity filled only with PCM are also obtained for comparison. The porosity is 0.9 for both porous structures. Rayleigh number and inclination angle change from 1 to 108, and from −90° to 90°, respectively.FindingsThe present study reveals that the use of closed cell structures not only can make phase change faster than open cell structure (except for Ra = 108 and = 90°) but also provide more stable process. The use of a closed cell porous structure in a cavity with PCM can reduce melting period up to 55% more than a cavity with an open cell porous structure. The rate of this additional enhancement depends on Rayleigh number and inclination angle.Originality/valueTo the best of the authors’ knowledge, this is the first time that the comparison between closed cell and open cell porous structures for heat transfer enhancement in a solid/liquid phase change process is reported. Authors believe that the present study will lead more attentions on the use of closed cell porous structures.

The Decay Process of an α-configuration Sunspot

The decay of sunspot plays a key role in magnetic flux transportation in solar active regions (ARs). To better understand the physical mechanism of the entire decay process of a sunspot, an α-configuration sunspot in AR NOAA 12411 was studied. Based on the continuum intensity images and vector magnetic field data with stray light correction from Solar Dynamics Observatory/Helioseismic and Magnetic Imager, the area, vector magnetic field and magnetic flux in the umbra and penumbra are calculated with time, respectively. Our main results are as follows: (1) The decay curves of the sunspot area in its umbra, penumbra, and whole sunspot take the appearance of Gaussian profiles. The area decay rates of the umbra, penumbra and whole sunspot are −1.56 MSH day−1, −12.61 MSH day−1 and −14.04 MSH day−1, respectively; (2) With the decay of the sunspot, the total magnetic field strength and the vertical component of the penumbra increase, and the magnetic field of the penumbra becomes more vertical. Meanwhile, the total magnetic field strength and vertical magnetic field strength for the umbra decrease, and the inclination angle changes slightly with an average value of about 20°; (3) The magnetic flux decay curves of the sunspot in its umbra, penumbra, and whole sunspot exhibit quadratic patterns, their magnetic flux decay rates of the umbra, penumbra and whole sunspot are −9.84 × 1019 Mx day−1, −1.59 × 1020 Mx day−1 and −2.60 × 1020 Mx day−1, respectively. The observation suggests that the penumbra may be transformed into the umbra, resulting in the increase of the average vertical magnetic field strength and the reduction of the inclination angle in the penumbra during the decay of the sunspot.

Performance of Rock-like Materials Containing Filled Kinked Fissures under Uniaxial Tension at Failure

To investigate the tensile failure phenomenon of rock masses with filled natural defects, the mechanical behavior of 3D printed rock-like materials containing filled kinked fissures under uniaxial tension was identified. Different inclination angles of branch fissure were considered, and cement and gypsum slurry were selected as the infilling materials. It was found that filling materials enhanced the strength of the specimen, which presented to be cement filling > gypsum filling > no filling. The change of inclination angle of branch fissure had significant influence on the strength and failure mode of the specimen and the strength order was −135° > −45° > 90° and +45° > 90° > +135°. Two types of failure pattern, namely tip failure and non-tip failure, were observed in the experiment. Three types of newborn cracks were identified using a high-speed camera. The result achieved by using the digital image correlation technology indicated that different filling conditions led to the position change of high-strain zone. The displacement field of the filled specimen developed from being continuous to being discontinuous. Furthermore, the extended finite element method was adopted to simulate the filled and unfilled specimens, consistent with the experimental results. This study can provide a reliable reference for studying the tensile stress zones in rock exploration.

Numerical Investigation on the Hydrodynamic Response of Pentamaran—Resistance Analysis of Different Outrigger Inclination Angles

Due to the interference between the main hull and the outrigger of the pentamaran, resistance is greatly affected. Therefore, research on the pentamaran front outrigger inclination angle has further practical significance for reducing resistance. In this study, the pentamaran front outrigger inclination angle was analyzed by CFD method, the ship motion in waves was simulated by overlapping grid technology, and the resistance of the pentamaran in static water and waves was predicted by using the unsteady RANS equation. First, a series of validation studies were carried out for the numerical methods used in the study. Then, the influence of the front outrigger inclination angle on the pentamaran resistance performance under different working conditions is calculated and discussed. In order to analyze the influence of the change of the front outrigger inclination angle on the resistance, free surface wave-making and hull pressure are further discussed. The results show that the influence of the front outrigger inclination angle change on the resistance of the pentamaran has a certain rule, and the resistance of the pentamaran can be reduced by adjusting the front outrigger inclination angle.

A short review on the pulsar magnetic inclination angles

AbstractThe inclination angle χ between the magnetic and rotation axes of pulsars is an important parameter in pulsar physics. The changes in the inclination angle of a pulsar would lead to observable effects, such as changes in the pulse beam width and braking index of the star. In this paper, we perform a short review on the evolution of a pulsar's magnetic inclination angle, as well as the latest research progress. Using an alignment rotator model in a vacuum, we investigate the magnetic inclination angle change rates for 12 high‐braking index pulsars without a glitch, whose timing observations are obtained using the Nanshan 25‐m Radio Telescope at Xinjiang Astronomical Observatory. For our purpose, three representative pulsars J0157+6212, J1743−3150, and J1857+0526 are chosen and their rotation and inclination angle evolutions are further investigated. In the future, radio and x‐ray polarimetric observations will provide more information about the inclination angles of pulsars, which could help us understand the origin of the variations in χ of pulsars and shed light on the range of possibilities of pulsar magnetic field configuration. A continuous study of the pulsar inclination angle will provide an important window into additional physical processes at work in the young and highly magnetized pulsars.

Inclination Sensor With a Wide Angle Measurement Range Using Half-Wavelength Microstrip Resonator

In this article, a new inclinometer concept based on an angular half-wavelength microstrip resonator is presented. The inclinometer has a wide dynamic range of 84° (±42°) which can be extended to 180° through a simple modification. The inclinometer is composed of a microstrip transmission line resonator on printed circuit board and a second transmission line on an overlapping circuit board that rotates according to the inclination angle. As the inclination angle changes, the overall length of the resonator varies and leads to resonance frequency shift, which is transformed into inclination variation. The sensor measurements results determined the sensitivity of the sensor as 0.384 mm/° and the resolution as 0.035°. The proposed sensor is also quite simple, cost-effective, compact, and robust.

Relationship between Pelvic Inclination and Quadriceps Angle in Middle Aged Obese Individuals

Context: Many studies have engrossed on correlating one or two biomechanical parameters related to the lower limb alignment factors but not many have taken into account the effect of increased body weight on the relationship between Q-angle and pelvic tilt. Aim: The present study aims to assess the changes in pelvic inclination angle (PIA) and quadriceps angle (Q-angle) in the different categories of body mass index (BMI). Furthermore, to find an association between PIA, Q-angle, and waist-hip ratio (WHR) in different categories of BMI. Setting and Design: The Observational case control study was conducted on community dwelling individuals from Delhi NCR. Subjects and Methods: Two hundred and forty participants (120 participants of BMI score 18.5–22.9 kg/m2 (normal weight healthy individuals) and 120 participants of BMI score >25 kg/m2 (obese healthy individuals) were recruited on the basis of inclusion and exclusion criteria. BMI, PIA, Q-angle, and WHR were assessed in the standing position. Statistical Analysis: Intra-class correlations of analysis was done using the Pearson correlation coefficient calculation for all the measured variables. Results: Significant higher mean values of PIA and Q-angle were observed in obese participants when compared with normal weight participants (P < 0.01). BMI was significantly positively correlated with PIA (P = 0.011) and Q-angle (P = 0.014) for obese population, whereas no significant association was found to normal weight healthy population. Similarly, statistically significant positive correlation was found between PIA and Q-angle (P < 0.01). Conclusion: The study concluded that increase in body weight is an important factor which influences the biomechanical alignment of kinematic chain segments of the lower quadrant of the body. Hence, it is very important to focus on proper biomechanical alignment and the whole lower extremity should be considered rather than a single segment as a factor, because one mechanical factor has the potential to compensate for or affected by another when functioning in the weight bearing position.

Effect of the sagittal osteotomy inclination angle on the posterior tibial slope change in high tibial osteotomy: three-dimensional simulation study

In performing medial open-wedge high tibial osteotomy, it is recommended not to alter the posterior tibial slope. However, it remains unclear whether the osteotomy inclination angle affects the posterior tibial slope in the sagittal plane. This study aimed to verify how anterior or posterior osteotomy inclination angle affects the tendency of change in the posterior tibial slope and to conduct quantitative analysis of the extent to which the posterior tibial slope changes according to the degree of the osteotomy inclination angle change in MOWHTO. Computed tomography images of 30 patients who underwent MOWHTO were collected. Three-dimensional models of preoperative original tibia were reconstructed, and virtual osteotomies were performed. The sagittal osteotomy inclination angles formed by the osteotomy line and the medial tibial plateau line were classified as positive in case of anteriorly inclined osteotomy and negative in case of posteriorly inclined osteotomy. Thirteen osteotomies were performed for each tibial model at intervals of 5° from − 30° to 30°. The posterior tibial slope was assessed, and the proportional relationship between the sagittal osteotomy inclination angle and the posterior tibial slope change was analyzed. The posterior tibial slope changed significantly after osteotomy (p < 0.001), except for the cases where the sagittal osteotomy inclination angles were 5°, 0°, and − 5°. Anteriorly and posteriorly inclined osteotomy caused increase and decrease in the posterior tibial slope, respectively. As the inclination angle increased by 1°, the posterior tibial slope increased by 0.079° in anterior inclination osteotomy, while in posterior inclination osteotomy, as the inclination angle decreased by 1°, the posterior tibial slope decreased by 0.067°. The osteotomy inclination angle in the sagittal plane significantly affected the posterior tibial slope. When there was an inclination angle occurred between the osteotomy line and the medial tibial plateau line in the sagittal plane, the posterior tibial slope changed after MOWHTO. The posterior tibial slope tended to increase in anteriorly inclined osteotomy and decrease in posteriorly inclined osteotomy. The change in the posterior tibial slope was proportionally related to the absolute value of the osteotomy inclination angle.

Limb accelerations during sleep are related to measures of strength, sensation, and spasticity among individuals with spinal cord injury

BackgroundTo evaluate the relationship between measures of neuromuscular impairment and limb accelerations (LA) collected during sleep among individuals with chronic spinal cord injury (SCI) to provide evidence of construct and concurrent validity for LA as a clinically meaningful measure.MethodsThe strength (lower extremity motor score), sensation (summed lower limb light touch scores), and spasticity (categorized lower limb Modified Ashworth Scale) were measured from 40 adults with chronic (≥ 1 year) SCI. Demographics, pain, sleep quality, and other covariate or confounding factors were measured using self-report questionnaires. Each participant then wore ActiGraph GT9X Link accelerometers on their ankles and wrist continuously for 1–5 days to measure LA from movements during sleep. Regression models with built-in feature selection were used to determine the most relevant LA features and the association to each measure of impairment.ResultsLA features were related to measures of impairment with models explaining 69% and 73% of the variance (R²) in strength and sensation, respectively, and correctly classifying 81.6% (F1-score = 0.814) of the participants into spasticity categories. The most commonly selected LA features included measures of power and frequency (frequency domain), movement direction (correlation between axes), consistency between movements (relation to recent movements), and wavelet energy (signal characteristics). Rolling speed (change in angle of inclination) and movement smoothness (median crossings) were uniquely associated with strength. When LA features were included, an increase of 72% and 222% of the variance was explained for strength and sensation scores, respectively, and there was a 34% increase in spasticity classification accuracy compared to models containing only covariate features such as demographics, sleep quality, and pain.ConclusionLA features have shown evidence of having construct and concurrent validity, thus demonstrating that LA are a clinically-relevant measure related to lower limb strength, sensation, and spasticity after SCI. LA may be useful as a more detailed measure of impairment for applications such as clinical prediction models for ambulation.

Radiative thermal analysis for four types of hybrid nanoparticles subject to non-uniform heat source: Keller box numerical approach

The advancement in the thermal engineering presented the idea of nanomaterials with stable thermal consequences and performances. The importance of hybrid nanomaterials attributes importance in solar energy production, electronics devices, heating systems, mechanical processes etc. The hybrid model is classified as a distinct thermal phenomenon with different tiny particles. The thermal evaluation of hybrid nanofluid containing four types of nanoparticles subject to the non-uniform heat source/sink and inclined magnetic field for two-dimensional unsteady flow due to permeable stretched surface has been numerically investigated. Four different types of nanoparticles, copper, titanium dioxide, silver and aluminum oxide have been considered with water base fluid. With the help of similarity transformation, we convert the governing partial differential equation into the ordinary differential equation. To solve these similarity equations a numerical technique known as Keller box method is used. The results are shown graphically and in tabular form. For special cases, comparison of numerical results to the previous results is presented with excellent agreement. The physical onset of parameters due to fluctuated heat transfer rate, wall shear force and Nusselt number is observed. It is observed that change in magnetic field inclination angle declines the velocity profile. The temperature profile can be effectively controlled with interaction of titanium oxide nanoparticles. The presence of heat source enhanced the nanoparticles temperature more effectively.

Study on the tensile-shear mechanical behavior of sandstone using a simple auxiliary apparatus

Mixed failure of rock by tension and shear occurs frequently in underground openings, rock slopes, and transtension faults. In this study, a simple auxiliary device (which consists of an indenter and a hollowed base) is proposed to implement tension-shear tests of rock samples combined with a servo-controlled uniaxial compression machine. Experimental and numerical tension-shear tests are carried out on red sandstones using the proposed auxiliary device and particle flow code. The effects of sample height H and base hollow diameter D on the mechanical behaviors are analyzed in detail, including the peak load, fracture characteristics, and AE characteristics. The results show that peak load increases with the sample height while decreases with hollow diameter due to the change of inclination angle of the failure surface. The initial crack and dominant cracks changed from shear cracks to tensile cracks as D increase from 2 cm to 4 cm, which suggests the transition from shear failure to hybrid tension-shear failure.

Thermo-fluid characteristics and second law analysis of an inclined two-fluid system with variable surface roughness

The present numerical study focuses on the analysis of thermodynamic characteristics of an inclined two-fluid system (Al2O3-water and CuO-water nanofluids) having a heat conducting partition wall of variable surface roughness with constant geometric orientation. A further level of thermal control that results in an optimum system orientation for greater thermo-physical transport along with less entropy generation and thermal optimization is explored by examining the effect of system inclination. Based on the second law of thermodynamics, the quantitative results include the variation of average Nusselt number, average fluid temperature, average entropy generation, and average Bejan number for a wide range of Rayleigh number and inclination angle. Current study realizes that the mean quantitative properties of the system are significantly affected by the change of Rayleigh number and inclination angle, despite having a weak dependency on the partition roughness. The variation of average Bejan number with Rayleigh number assumes a reverse trend compared to the same for average Nusselt number and entropy generation and decreases continuously as the flow circulation strengthens. The rate of thermal transport is significantly regulated by the system orientation. Each Rayleigh number conforms to a critical angle of the system inclination for highest thermal transport and entropy generation.

&lt;strong&gt;The increasing risk of temporomandibular disorder and articular eminence inclination due to tooth loss&lt;/strong&gt;

ABSTRACTIntroduction: Tooth loss leads to increased biomechanical pressure in the temporomandibular joint due to changes in the functional movement pattern of the jaw, resulting in joint structure damage specifically change of the articular eminence inclination (AEI) angle, which is one of the increased risks of the temporomandibular disorder (TMD). This study aimed to analyze the relationship between the number and quadrants of tooth loss on TMD and the AEI. Methods: It was descriptive-analytic study using a cross sectional design. The study was done in Universitas Sumatera Utara (USU) Dental hospital, conducted questionnaires and panoramic radiographic on 42 subjects aged over 18-64 years with tooth loss. Data analyzed used Chi-square analysis. Results: The prevalence of TMD on the ≥3 tooth loss group by 82.6% and the four-quadrant group by 93.8%. The prevalence of change in the AEI on the ≥3 tooth loss group was 34.8% on the flat right side, while on the left side of 26.1% was flat, and 13% was steep. Based on the number of quadrants tooth loss, the highest was on the four-quadrant group by 50% on flat right side, and on the three-quadrant group was 25% flat, 25% steep on the left side. There was a significant relationship between the number of tooth loss (p=0.023), the number of tooth loss quadrants, and TMD (p=0.016). There was no relationship between the number of tooth loss and the AEI, except for the number of tooth loss quadrants and the AEI on the right side with a significant result (p=0.017). Conclusion: There was relationship between the number of tooth loss, the number of tooth loss quadrants, and TMD and there was no relationship between the number of tooth loss and the AEI, except for the number of tooth loss quadrants and the AEI on the right side.Keywords: Edentulous; tooth loss; temporomandibular disorder; inclination of articular eminence.