Exact Angle Research Articles

How to Calculate the Exact Angle for Two-level Osteotomy in Ankylosing Spondylitis?

A prospective case series study. To describe and assess a two-level osteotomy method for the management of severe thoracolumbar kyphosis (TLK) in patients with ankylosing spondylitis (AS). To achieve better postoperative outcomes in these patients, a sophisticated preoperative surgical plan is required. Most deformities are managed using a one-level osteotomy and a two-level osteotomy is seldomly reported. Till date, no study has described a two-level osteotomy for these cases. From January 2011 to December 2012, 10 consecutive patients with ankylosing spondylitis who underwent two-level spinal osteotomy were studied. Pre- and postoperative full-length free-standing radiographs, including the whole spine and pelvis, were available for all patients. Pre- and postoperative radiological parameters, including T5-S1 Cobb angles, TLK, lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope, and sagittal vertical axis were measured. Health related quality of life , including Oswestry Disability Index and Scoliosis Research Society-22 surveys were administered before surgery and at 1-year follow up. The preoperative and postoperative T5-S1 Cobb angles was 51.3° and -7.1°, respectively (P < 0.001). All patients demonstrated changes in postoperative radiographic parameters including decreased pelvic tilt (from 37.1° to 14.3°, P < 0.001), TLK (from 36.9° to 12.6°, P < 0.001), and sagittal vertical axis (from 21.4 cm to 7.1 cm, P < 0.001), increased lumbar lordosis (from -5.1° to -47.1°, P < 0.001), sacral slope (from 13.4° to 37.7°, P < 0.001), but no significant change in pelvic incidence. Health related quality of life scores at 1-year follow up were significantly improved compared to those before surgery. This calculation of two-level osteotomy provides an accurate and reproducible method for ankylosing spondylitis correction. By which, we can obtain satisfactory radiological parameters and clinical outcomes. 4.

An Enhanced fall detection system with GSM and GPS Technology

Fall-related accident and injury are a standout among the most widely recognized motivations to reason for death and hospitalization among elderly. Falls among older people become a major problem facing hospitals and nursing homes. An enhanced fall detection system is proposed for elderly person monitoring that is based on-body sensor. Various fall-detection solutions have been previously proposed to create a reliable surveillance system for elderly people with high requirements on accuracy. In this paper, an enhanced fall detection system is proposed for elderly person monitoring that is based on smart sensors worn on the body and operating through long distance as well as consumer home networks. The principle behind this work is the detection of changes in the motion and position using the sensor which tracks the acceleration changes in three orthogonal directions. By using MEM's accelerometer sensor is used for determining exact angle of an elderly person with the help of signal magnitude vector (SMV). When the fall is detected the GPS locates the exact fall location and GSM modem is used to transmit the message to the mobile phone of caretakers/relatives of the fallen subjects at that time also send their latitude and longitude value by using GPS. This alert message helps to provide immediate assistance and treatment.

Calculation of the angle required during pedicle subtraction osteotomy for fixed sagittal deformity: a literature review

Sagittal spinal deformity is one of the common reasons of sagittal disequilibrium which can cause torso forward, cardiopulmonary dysfunction, flat back syndrome, intractable low back pain and a series of cases, affecting the patients' life quality and increasing huge economic burden on society. The treatment of sagittal spinal deformity has been a hot spot in the field of clinical spinal surgery and its main purpose is to reconstruct the overall balance of the body, which would relieve pain and improve life quality. Pedicle subtraction osteotomy is considered to be one of the most effective and safe method for correcting spinal deformity with excellent reconstruction of sagittal plane balance. However, the calculation of the angle required during surgery is still a problem, because insufficient or excessive correction will lead to the secondary sagittal disequilibrium. Therefore, an accurate calculation of the angle required during pedicle subtraction osteotomy is particularly important. In recent years, scholars believe that the sagittal equilibrium depends on a fragile balance among spinal curvature, pelvic shape and position of the lower limbs. Scholars have developed a standard of sagittal equilibrium based on their own research, and proposed a variety of quantitative analysis methods to calculate the angle required during pedicle subtraction osteotomy: trigonometric method, exact angle calculation method, overall balance method, spine femoral angle measurement method, digital virtual method, graphic method, acoustic meati to hip axis method and hilus pulmonis to hip axis method, which provide important theoretical bases for the treatment of sagittal spinal deformity.

改进的精密测角法标定面阵摄像机参数

改进的精密测角法标定面阵摄像机参数

UV–VIS depolarization from Arizona Test Dust particles at exact backscattering angle

In this paper, a controlled laboratory experiment is performed to accurately evaluate the depolarization from mineral dust particles in the exact backward scattering direction (ϴ=180.0±0.2°). The experiment is carried out at two wavelengths simultaneously (λ=355nm, λ=532nm), on a determined size and shape distribution of Arizona Test Dust (ATD) particles, used as a proxy for mineral dust particles. After validating the set-up on spherical water droplets, two determined ATD-particle size distributions, representative of mineral dust after long-range transport, are generated to accurately retrieve the UV–VIS depolarization from ATD-particles at exact backscattering angle, which is new. The measured depolarization reaches at most 37.5% at λ=355nm (35.5% at λ=532nm), and depends on the particle size distribution. Moreover, these laboratory findings agree with T-matrix numerical simulations, at least for a determined particle size distribution and at a determined wavelength, showing the ability of the spheroidal model to reproduce mineral dust particles in the exact backward scattering direction. However, the spectral dependence of the measured depolarization could not be reproduced with the spheroidal model, even for not evenly distributed aspect ratios. Hence, these laboratory findings can be used to evaluate the applicability of the spheroidal model in the backward scattering direction and moreover, to invert UV–VIS polarization lidar returns, which is useful for radiative transfer and climatology, in which mineral dust particles are strongly involved.

Strong gravitational lensing by Kiselev black hole

We investigate the gravitational lensing scenario due to Schwarzschild-like black hole surrounded by quintessence (Kiselev black hole). We work for the special case of Kiselev black hole where we take the state parameter $w_{q}=-\frac{2}{3}$. For the detailed derivation and analysis of the bending angle involved in the deflection of light, we discuss three special cases of Kiselev black hole: non-extreme, extreme and naked singularity. We also calculate the approximate bending angle and compare it with exact bending angle. We found the relation of bending angles in the decreasing order as: naked singularity, extreme Kiselev black hole, non-extreme Kiselev black hole and Schwarzschild black hole. In the weak field approximation, we compute the position and total magnification of relativistic images as well.

How best to study the function of consciousness?

How best to study the function of consciousness?

A new dynamic model of a planar rotating hub–beam system based on a description using the slope angle and stretch strain of the beam

A new dynamic model of a planar rotating hub–beam system is developed, where the beam is of an Euler–Bernoulli type and the deformation of the beam is described by the slope angle and stretch strain of the centroid line of the beam. The nonlinear partial differential equations of the system and associated boundary conditions are derived using Hamilton׳s principle. Four corresponding spatially discretized models are obtained based on the new modeling method: (1) the spatially discretized exact slope angle (ESA) model that considers stretch of the beam by using the finite element method (FEM); (2) the spatially discretized fourth-order slope angle (FOSA) model by neglecting the fifth- and higher-order nonlinear terms from a quadratic Taylor expansion of the slope angle by using Galerkin׳s method; (3) the second-order slope angle (SOSA) model by neglecting the third- and higher-order nonlinear terms in the FOSA model; and (4) the simplified second-order slope angle (SSOSA) model without considering stretch of the beam. Dynamic responses of the rotating hub–beam system are studied using the new models for two cases: (I) the angular velocity of the hub is given, and (II) an external torque is applied on the hub. Dynamic responses from the four slope angle models are compared with those from previous models in the literature. Results show that when the angular velocity of the hub is small, dynamic responses from the four models and previous models are close to each other. The ESA model has lower computational efficiency compared with the other three slope angle models. Compared with the ESA and FOSA models, the SOSA model is sufficiently accurate for engineering applications. By linearizing the SOSA model, natural frequencies and mode shapes of the rotating hub–beam system with a constant angular velocity with and without the chordwise bending and stretching coupling effect are calculated and compared. Curve veering and mode shift phenomena occur when the bending and stretching coupling effect is included. Natural frequencies calculated from the new model are in excellent agreement with those from previous models. The FOSA and SOSA models can have better computational accuracy and efficiency than previous models.

Tris(tri-o-tolyl phosphite-κP)nickel: a coordinatively unsaturated nickel(0) complex.

A previously reported complex, [Ni(C(21)H(21)O(3)P)(3)] or Ni[P(O-o-tolyl(3))(3)] [Gosser & Tolman (1970). Inorg. Chem. 9, 2350-2353], crystallized in the monoclinic space group C2/c, and its solid-state structure was determined. The Ni(0) atom adopts an essentially trigonal-planar geometry as a consequence of the steric congestion of the ligands. Three of the phenoxy rings on two phosphite ligands were modelled as being disordered over two sets of sites, and the occupancy factors were set at 0.5 after trial refinement and intramolecular contact considerations. The exact ligand cone angle has been calculated to be 163.6°.

2D MEMS scanner integrating a position feedback

An integrated position sensor for a dual-axis electromagnetic tilting mirror is presented. This tilting mirror is composed of a silicon based mirror directly assembled on a silicon membrane supported by flexible beams. The position sensors are constituted by 4 Wheatstone bridges of piezoresistors which are fabricated by doping locally the flexible beams. A permanent magnet is attached to the membrane and the scanner is mounted above planar coils deposited on a ceramic substrate to achieve electromagnetic actuation. The performances of the piezoresistive sensors are evaluated by measuring the output signal of the piezoresistors as a function of the tilt of the mirror and the temperature. White light interferometry was performed for all measurement to measure the exact tilt angle. The minimum detectable angle with such sensors was 30μrad (around 13bits) in the range of the minimum resolution of the interferometer. The tilt reproducibility was 0.0186%, obtained by measuring the tilt after repeated actuations with a coil current of 50mA during 30 min and the stability over time was 0.05% in 1h without actuation. The maximum measured tilt angle was 6° (mechanical) limited by nonlinearity of the MEMS system.

High-frequency video capture and a computer program with frame-by-frame angle determination functionality as tools that support judging in artistic gymnastics.

The main aim of this study was to verify the usefulness of selected simple methods of recording and fast biomechanical analysis performed by judges of artistic gymnastics in assessing a gymnast's movement technique. The study participants comprised six artistic gymnastics judges, who assessed back handsprings using two methods: a real-time observation method and a frame-by-frame video analysis method. They also determined flexion angles of knee and hip joints using the computer program. In the case of the real-time observation method, the judges gave a total of 5.8 error points with an arithmetic mean of 0.16 points for the flexion of the knee joints. In the high-speed video analysis method, the total amounted to 8.6 error points and the mean value amounted to 0.24 error points. For the excessive flexion of hip joints, the sum of the error values was 2.2 error points and the arithmetic mean was 0.06 error points during real-time observation. The sum obtained using frame-by-frame analysis method equaled 10.8 and the mean equaled 0.30 error points. Error values obtained through the frame-by-frame video analysis of movement technique were higher than those obtained through the real-time observation method. The judges were able to indicate the number of the frame in which the maximal joint flexion occurred with good accuracy. Using the real-time observation method as well as the high-speed video analysis performed without determining the exact angle for assessing movement technique were found to be insufficient tools for improving the quality of judging.

Insights gained from three-dimensional imaging modalities for closure of ventricular septal defects.

Ventricular septal defects (VSDs) are the commonest group of congenital heart lesions, accounting for ≈30% of congenital heart defects in liveborn infants.1 Defects in the ventricular septum are classified according to their position when the ventricular septum is viewed from the right ventricle and these may vary in their location, size, and number.2,3 VSDs can occur as isolated lesions or as part of more complex disease, for example, transposition of the great arteries or double outlet right ventricle, where the location and size of such defects assume great importance in planning the optimal mode of surgical repair.4 In most cases, surgical closure remains the mainstay treatment for VSDs, but selected lesions may be amenable to catheter closure.5,6 Cross-sectional echocardiography is the most commonly used noninvasive diagnostic method to delineate the position of a VSD before surgery.7 Multiple sonographic cuts and cross-sectional sweeps of the region of interest are used to build a virtual reconstruction of the three-dimensional (3D) anatomy in the mind of the echocardiographer. However, for the surgeon who deals solely with 3D images there can remain an element of uncertainty when called to operate on the patient. The number, size, location of VSDs, and their relationship to adjacent structures are central for selecting whether the defects might be best closed via the tricuspid valve, via the semilunar valves, or via a ventriculotomy or whether these might not be readily approachable and a palliative pulmonary artery banding is desirable.8,9 In this review, we present key 3D echocardiographic projections and examples of different types of VSDs where the images have a direct effect on the approach taken to VSD closure. Comparison of 3D echocardiography (3DE) with other 3D imaging modalities is also described. Images are presented in an …

Consequence of various wrist angulations at impact on the severity of Colles’ fractures (922.4)

A Colles’ fracture, eponymously named after Irish surgeon Abraham Colles, is a transverse break of the distal radius (2.5 cm from the radio‐carpal joint) with dorsal displacement of the carpus and hand. It is most commonly a consequence of falling onto outstretched hands. As the exact angle of the wrist changes with each fall, this study tested for correlation between wrist angulation at impact and the severity of the resulting Colles’ fracture. A sample of 15 cadaveric upper limbs exhibiting no evidence of traumatic injuries on gross observation was used to study this relationship. Specimens were cut transversely at mid‐forearm and randomly assigned to either the 90 degree wrist extension group (n=7) or the 45 degree wrist extension group (n=8). Specimens were secured and a drop‐weight impactor was used to apply force to the extended palms, recreating a scenario of falling. After impact, each specimen was radiographed and assessed for evidence and severity of fracture graded via Frykman’s classification system. Results showed that falling with the wrist extended 90 degrees was more likely to produce a Colles’ fracture while falling onto a wrist extended 45 degrees produced extensive damage to the ulna and carpus. Better understanding of the relationship between carpal angulation and likelihood/severity of fractures may aid preventative approaches for populations at high‐risk for falls such as the elderly and athletes.Grant Funding Source: Supported by SUNY Downstate Alumni Association

Exact solution of shear problem for inclined cracked bending reinforced concrete elements

In spite of a wide experimental and theoretical data on shear that forms a basis for modern design approaches, exact solution of shear problem for inclined cracked bending reinforced concrete elements is still not found. It yields high dispersion in the bearing capacity of concrete according to the main compression stresses. A similar problem appears with the internal forces carried by shear reinforcement. The above mentioned problem is related to two parameters: the angle of the main compression stresses and that of the inclined links. Corresponding internal forces together with the force in the tensile reinforcement form a commonly used design model (truss model), therefore each force depends on the other. This fact is practically not considered in modern design provisions hence there are no tools to express the shear capacity accurately. The two angles should be considered simultaneously in every case, when the links section is taken according to the calculated value (but not to the minimum one). The present study is one of the first attempts, focused on considering the interaction between the internal forces in concrete and inks according to the design model. It allows calculation of an exact angle, defining the inclined cracks and forces in links within the known experimentally investigated limits of this angle.

Dynamometric Indicators of Fatigue From Repeated Maximal Concentric Isokinetic Plantar Flexion Contractions Are Independent of Knee Flexion Angles and Age but Differ for Males and Females

Sex and age are reported to influence the maximal dynamometric performance of major muscle groups, inclusive of ankle plantar flexors. Knee flexion (KF) also impacts plantar flexion function from where stems use of 0° and 45° angles of KF for clinical assessment of gastrocnemius and soleus, respectively. The influence of KF, sex, and age on dynamometric indicators of plantar flexion fatigue was examined in 28 males and 28 females recruited in 2 different age groups (older and younger than 40 years). Each subject performed 50 maximal concentric isokinetic plantar flexions at 60-degree angle per·second with 0° and 45° angles of KF. Maximal voluntary isometric contractions were determined before and after isokinetic trials and maximal, minimal, and normalized linear slopes of peak power during testing. Main effects of and 2-way interactions between KF, sex, age, and order of testing were explored using mixed-effect models and stepwise regressions. At angles of 0° and 45°, the fatigue indicators in younger and older individuals were similar and not influenced by testing order. However, peak isokinetic power and isometric torque declined to greater extents in males than females and, moreover, KF exerted greater impacts on the absolute plantar flexion performance and maximal-to-minimal reduction in isokinetic power in males. Because KF wielded no pronounced effect on fatigue indicators, this test may perhaps be used over time with no major concern regarding the exact knee angle. Our findings indicate that sex, rather than age, should be considered when interpreting dynamometric indicators of fatigue from repeated maximal concentric isokinetic plantar flexions, for example, when establishing normative values or comparing outcomes.

Exact Ligand Solid Angles.

Steric demands of a ligand can be quantified by the area occluded by the ligand on the surface of an encompassing sphere centered at the metal atom. When viewed as solid spheres illuminated by the metal center, the ligand atoms generally cast a very complicated collective shadow onto the encompassing sphere, causing mathematical difficulties in computing the subtended solid angle. Herein, an exact, analytic solution to the ligand solid angle integration problem is presented based on a line integral around the multisegmented perimeter of the ligand shadow. The solution, which is valid for any ligand bound to any metal center, provides an excellent method for analyzing geometric structures from quantum chemical computations or X-ray crystallography. Over 275 structures of various metals bound to diverse mono- and multidentate ligands were optimized using B3LYP density functional theory to exhibit exact solid angle (Ω°) computations. Among the intriguing Ω° solutions, Pd(xantphos) and ferrocene exhibit holes in their ligand shadows, and Fe(EDTA)(2-) has a surprisingly simple shadow defined by only four arcs, despite having a multitude of overlaps among individual shadow cones.

Heat flux characteristics of spray wall impingement with ethanol, butanol, iso-octane, gasoline and E10 fuels

Future fuel stocks for spark-ignition engines are expected to include a significant portion of bio-derived components with quite different chemical and physical properties to those of liquid hydrocarbons. State-of-the-art high-pressure multi-hole injectors for latest design direct-injection spark-ignition engines offer some great benefits in terms of fuel atomisation, as well as flexibility in in-cylinder fuel targeting by selection of the exact number and angle of the nozzle’s holes. However, in order to maximise such benefits for future spark-ignition engines and minimise any deteriorating effects with regards to exhaust emissions, it is important to avoid liquid fuel impingement onto the cylinder walls and take into consideration various types of biofuels. This paper presents results from the use of heat flux sensors to characterise the locations and levels of liquid fuel impingement onto the engine’s liner walls when injected from a centrally located multi-hole injector with an asymmetric pattern of spray plumes. Ethanol, butanol, iso-octane, gasoline and a blend of 10% ethanol with 90% gasoline (E10) were tested and compared. The tests were performed in the cylinder of a direct-injection spark-ignition engine at static conditions (i.e. quiescent chamber at 1.0bar) and motoring conditions (at full load with inlet plenum pressure of 1.0bar) with different engine temperatures in order to decouple competing effects. The collected data were analysed to extract time-resolved signals, as well as mean and standard deviation levels of peak heat flux. The results were interpreted with reference to in-cylinder spray formation characteristics, as well as fuel evaporation rates obtained by modelling. In addition, high-speed images of single droplets of fuel impinging onto the array of the heat flux sensor were acquired with simultaneous sampling of the heat flux signal in an attempt to provide further interpretation. The single droplet tests showed ability of the signals to quantify droplet mass impinged on the sensor. Analysis of the peak heat flux at static engine conditions quantified values of fuel temperature at impingement in agreement with the wet bulb temperatures predicted by the droplet evaporation model. Comparison of the static and motoring engine heat flux signals around the bore showed the effect of the intake flow on the spray’s pattern at impingement and demonstrated fuel presence on the liner that survived at exhaust valve open timing. The general behaviour was different for the alcohols to that of the hydrocarbons, with ethanol exhibiting the effect of its high latent heat on the signals and butanol exhibiting effects related to poor atomization and slow evaporation.

The influnence of an accurate incident angle in magneto-optical ellipsometry system

In all of the techniques based on magneto-optical materials, generalized magneto-optical ellipsometry is chosen for its surface sensitivity and high magnetic field compatibility. While recent research in this technique does not pay enough attention to the accuracy of the incident angle. This text analyzes the importance of an accurate incident angle in the magneto-optical ellipsometry system. Result shows that the precisely determined incident angle has a strong impact on the system accuracy. This conclusion can be seen as an warning to other workers that, in generalized magneto-optical ellipsometry test, accuracy of the incident angle should be raised to minute level. If the incident angle error changes 1o, the changes of refraction index, extinction coefficient, real and imaginary part of the magneto-optical coupling constant will be 5% 5.4% 8.2% and 9%. So the spectrometer is used to give an accurate incident angle which can accurate to minute level. Then the 200nm Fe film magneto-optical ellipsometry experiment is performed under exact incident angle. The experiment data confirms the importance of accurate incident angle in GME experiment.

A New Method for Calculating the Exact Angle Required for Spinal Osteotomy

Prospective study. To assess a new method for determining the exact angle required for spinal osteotomy in patients with ankylosing spondylitis (AS). The ideal method for maintaining sagittal balance is to shift the center of gravity of the trunk over the hip axis when pelvic and lower extremity joints are in the neutral position. For patients with AS, various methods have been explored to calculate the required corrective angle. However, these methods carry some limitations. Twenty patients with AS who underwent spinal osteotomy for correcting kyphotic deformity were studied. Pre- and postoperative full-length freestanding radiographs of the whole spine and pelvis were obtained for all patients. We calculated the ideal postoperative pelvic tilt according to pelvic incidence, and chose the plumbline of the hilus pulmonis rather than C7 as gravity axis of the trunk. Then, the necessary angular correction at the level of osteotomy was calculated. Pre- and postoperative radiological parameters, including Cobb T1-S1, pelvic incidence, pelvic tilt, sacral slope, and sagittal vertical axis were measured. Health related quality of life, including Oswestry Disability Index and Scoliosis Research Society outcomes instrument-22, were administered before surgery and at 6-month follow-up. The preoperative and postoperative Cobb T1-S1 were 52° and 3°, respectively (P < 0.001). All patients demonstrated changes in preoperative to postoperative radiographical parameters including decreased pelvic tilt (from 30° to 11°, P < 0.001) and sagittal vertical axis (from 18 cm to 7 cm), increased sacral slope (from 16° to 35°, P < 0.001), but no significant change in pelvic incidence. Health related quality of life scores at 6-month follow-up had significantly improved compared with those before surgery. This method provides an accurate and reproducible calculation for AS correction. 2.

Exact ligand cone angles

Many properties of transition-metal complexes depend on the steric bulk of bound ligands, usually quantified by the Tolman (θ) and solid (Θ) cone angles, which have proven utility but suffer from various limitations and coarse approximations. Here, we present an improved, mathematically rigorous method to determine an exact cone angle (θ°) by solving for the most acute right circular cone that contains the entire ligand. The procedure is applicable to any ligand, planar or nonplanar, monodentate or polydentate, bound to any metal center in any environment, and it is ideal for analyzing structures from quantum chemical computations as well as X-ray crystallography experiments. Exact cone angles were evaluated for a wide array of phosphine and amine ligands bound to palladium, nickel, or platinum by optimizing structures using B3LYP/6-31G* density functional theory with effective core potentials for the transition metals. The mean absolute deviations of the standard θ and Θ parameters from the exact cone angles were 15-25°, mostly caused by distortions from the assumed idealized structures.