Pi Angle Research Articles

Predictability of MKG Angle and Comparison with ANB Angle, W Angle, Yen Angle, Beta Angle and Pi Angle A Cephalometric Study

Predictability of MKG Angle and Comparison with ANB Angle, W Angle, Yen Angle, Beta Angle and Pi Angle A Cephalometric Study

Predictability of Wits appraisal, ANB, Beta, Yen, W, µ and Pi angle as indicators of anteroposterior dysplasia in Jharkhand population

: The measurements for assessing the antero-posterior discrepancy between the apical bases are many with their individual benefits and shortcomings. So, it is very important to categorize the reliability of the major diagnostic criteria for successful planning of treatment and to fore see the outcome. The present study assesses the predictability of Wits appraisal, ANB, Beta, Yen, W, µ and Pi angles as an indicators of anteroposterior dysplasia. A total of 120 lateral cephalograms of skeletal Class I, II and III patients were selected based on Down’s facial angle and then tracing was carried out manually to measure Wits appraisal, ANB, Beta, Yen, W, µ and Pi angles. Analysis of variance and correlation coefficient analysis were done to assess the significance of association between these variables. Yen angle is highly predictable and a homogenously distributed angular parameter used to assess sagittal discrepancy. The most desirable differentiation results among the three skeletal relationship were represented by Beta angle followed by Yen angle. Statistically significant correlation among the seven parameters for skeletal Class I relationship were shown by Yen and W angle, for skeletal Class II relationship by Beta angle and µ angle and for skeletal Class III relationship by Beta angle and W angle. No statistically significant correlation existed between Yen Angle and Beta Angle in all the three groups. Yen angle was found to have the most homogenous and predictable parameter. A statistically significant correlation for skeletal Class I relationship were observed between Yen and W angle, for skeletal Class II relationship between Beta and µ angle and for skeletal Class III relationship between Beta angle and W angle and they can be used interchangeably in assessing skeletal jaw relationship.

Spreading Equilibria Under Mildly Singular Potentials: Pancakes Versus Droplets

We study global minimizers of a functional modeling the free energy of thin liquid layers over a solid substrate under the combined effect of surface, gravitational, and intermolecular potentials. When the latter ones have a mild repulsive singularity at short ranges, global minimizers are compactly supported and display a microscopic contact angle of pi /2. Depending on the form of the potential, the macroscopic shape can either be droplet-like or pancake-like, with a transition profile between the two at zero spreading coefficient for purely repulsive potentials. These results generalize, complete, and give mathematical rigor to de Gennes’ formal discussion of spreading equilibria. Uniqueness and non-uniqueness phenomena are also discussed.

Evaluation of Reliability of Various Cephalometric Angles for Assessing Sagittal Jaw Dysplasia in Different Skeletal Pattern: A Cephalometric Study

Objective: The study aimed to compare the reliability of different cephalometric angles like the Beta, Yen, W and Pi angles to evaluate sagittal dysplasia in various skeletal patterns and assess the correlation between the variables.
 Materials and Methods: 135 pre-treatment lateral cephalograms were taken and further divided into Class I, Class II and Class III groups. Each group had equal samples of 45 (n=45), based on ANB angle using Nemoceph software. Cephalometric landmarks Pi, Yen, Beta and W angle were identified and measured. Statistical analysis was done using the ANOVA test followed by Correlation coefficient analysis.
 Results: Pi angle was highly predictable for differentiating class I cases, with 91.1% accuracy. Whereas in class II cases Pi and Beta angle were found to be most predictable with 73% and 66% accuracy respectively, while in class III cases Yen angle was found to be most predictable with 88% accuracy.
 Conclusion: Overall Pi angle is considered the most reliable for assessing anteroposterior jaw relationship, followed by Beta and Yen angle.

A heuristic model for cephalometric diagnosis of sagittal dysplasia.

To identify the best-suited cephalometric parameter for assessing the sagittal skeletal discrepancy in the Indian population. An in vitro, observational, single-blinded, retrospective study. Department of Orthodontics and Dentofacial Orthopaedics. A total of 94 lateral cephalograms were used in this study. The study involved one key person and two examiners. The key person collected the radiographs, coded, analysed and classified them into three groups (skeletal classes I, II and III). Subsequently, the coded radiographs were independently analysed by the two examiners. They classified the cases by matching a minimum of 6 out of 11 parameters. On completion of diagnosis by the examiners, the samples were decoded and matched with the original diagnosis given by the key person. The samples in which identification of a particular cephalometric parameter matched the original evaluation as given by the key person was regarded as correctly diagnosed. The number of correctly assessed cases was used to judge the diagnostic performance of all the parameters in all the cases. Cross-validation of the method was performed, and a diagnostic algorithm was developed for diagnosis. β angle and Pi angle showed a positive predictive value of 1 in both skeletal class I and II cases. ANB angle, W angle and HBN angle showed a positive predictive value of 1 in skeletal class III cases. No single cephalometric parameter can independently be used to diagnose sagittal skeletal discrepancy in all cases. However, a conclusive diagnosis on the type of sagittal skeletal malocclusion can be made by using a simple and easy to use diagnostic algorithmic process having a combination of cephalometric parameters.

Biomechanical analysis of accuracy penalties-kicking performance for Turkish Soccer players: Group-based analysis without goalkeeper

Background and Study Aim. It is stated that kinetic performance factors are important in the successful execution of accurate kick-penalties, thus, its offer excellent performance despite a substantial kinetic method change in their implementation. The aim of the study is to biomechanical analysis of accuracy penalties-kicking performance for Turkish soccer players. Material and Methods. The study group consisted 15 male students of Turkish Regional Amateur League players (Age: 21.08± 1.56 years old). Two video cameras placed at optical axes X&Y filmed penalty-kick performance of the subjects. we analysed the best three scores by video analysis Dartfish 9.0 software. Standard statistical methods were used for the calculation of mean±SD. the Statistical significance at p<.05 for Pearson product—moment correlations. Results. Accurate penalty-kicks showed significant positive relationship of knee Pi angle value in backswing, ball Contact phases, trunk angle value in ball contact with the accuracy at p<.01. Significant negative relationship of inclination_body angle value, time of foot contact at p<.01, and distance pivot foot&ball value at p<.05 in the follow-through phase. Conclusion. Such knowledge should aid in clarify the relationships between variables of penalty kicking during The performance phases and accuracy. the present preliminary investigation of accurate penalty-kicks performance indicates Support-leg characteristics demonstrated in knee angle values an important factor in Backswing, Ball Contact phases with the accuracy of penalty kicking. also, the Foot Contact time and Inclination_Body angle in that.

Thoracolumbar Junction Orientation: A Novel Guide for Sagittal Correction and Proximal Junctional Kyphosis Prediction in Adult Spinal Deformity Patients.

Novel radiographic sagittal parameters of the thoracolumbar junction orientation (TLJO, thoracolumbar slope [TLS] and thoracolumbar tilt [TLT]) have been introduced and correlated with lumbopelvic parameters and thoracic kyphosis. To determine a predictive model for reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) based on the TLJO. A total of 127 patients who had fusion from sacrum to T10-L2 from 2004 to 2014 were reviewed. TK (T5-T12), PI, SS, PT, LL, and proximal junctional angle (PJA) were measured preoperatively, 6 wk postoperatively, and at final follow-up. TLJO was measured by TLS and TLT. Changes between time points were determined (preop-6 wk = ΔParameterPre6wk and preop-final follow/up = ΔParameterPreFinal). Scoliosis Research Society (SRS) and Oswestry Disability Index (ODI) questionnaires were evaluated at final follow-up. Patients were divided into 2 groups based on the presence of PJK (ΔPJAPreFinal >15°). Independent t-tests and receiver operating characteristic (ROC) curves were used to investigate the significance of differences and cut-off values. Pearson correlations and linear regressions were used to analyze the entire cohort to determine the relationship between the changes in parameters. Compared to patients without PJK (n=100), those with PJK (n=27) had significantly lower SRS scores and significantly greater ΔTKPreFinal, ΔLLPre6wk, and ΔTLSPre6wk. To maintain in the nonPJK group, ROC curves demonstrated a cut-off value of -9.4° for ΔTLSPre6wk. PJK was significantly correlated with ΔTKPreFinal and ΔTLSPre6wk. The linear correlation revealed that ΔTLSPre6wk < -25.3° is the risk factor of PJK >15°. As change of TLS reflects lumbopelvic realignment and influences reciprocal TK, reducing the change of TLS may be a sagittal realignment guideline to reduce the risk of PJK.

Experimental study on engine parameters variation in CRDI engine fuelled with palm biodiesel

The present research emphasizes on performance, combustion and emission parameters generated by palm oil methyl ester by means of multiple fuel injection strategies. Initially 20% of transesterified palm oil in diesel was tested with varying split injection quantities at 10%, 20% and 30% with a PI angle of 33° bTDC and MI angle of 23° bTDC. Superior performance with respect to fuel consumption, efficiency and emissions was achieved at 30% pilot-injection mass of POME20. At peak load condition, brake thermal efficiency of diesel@10% PI quantity, POME20 at 10%, 20% and 30% PI quantities was observed as 26.15%, 27.95%, 28.45% and 30.42% respectively. The combustion characteristics also enhanced for POME20@30% PI quantity. In emission perspective, NOx emissions for POME20 at 30% pilot-injection mass were 7.19% higher than the diesel fuel at 10% pilot-injection mass. In an effort to decrease NOx emissions for POME20@30% PI mass while retaining the same performance, three methodologies was investigated, such as usage of 10% EGR, decreasing injection pressure from 600 bar to 500 bar, advancing pre-injection timing from 33° bTDC to 53° bTDC. While comparing the outcomes, POME20-30% PI mass@10% EGR showed 2.4% and 0.55% more brake thermal efficiency than diesel and POME20 with a PI quantity of 10%@0% EGR. Nitrogen oxide outflows for POME20-30% PI mass@10% EGR were nearly equivalent to diesel-10% PI mass@0% EGR and 1.28% lesser than POME20-10% PI mass@0% EGR. Finally it was concluded that POME20-30% PI quantity@10% EGR would be a best potential strategy with respect to performance and emission viewpoint.

Modelling and control of a new differential steering concept

ABSTRACTThis paper presents a new steer-by-wire concept using an all-wheel drive vehicle layout with in-wheel motors while completely omitting the application of any dedicated steering device. Steering is based on the so-called differential steering principle which generates the necessary steering moment about the kingpins by a traction force difference between left and right sides of the vehicle. In order to investigate the behaviour of the vehicle and to design the underlying control algorithms, a planar vehicle model is presented, where the vehicle is described as constrained non-holonomic system requiring a special treatment. A state feedback linear controller for controlling of the lateral dynamics of the vehicle at higher speeds and a simple PI angle controller for low-speed manoeuvring are developed. The resulting behaviour of the system is investigated by various simulation experiments demonstrating a comparable steering performance of the new steering concept as that of conventional passenger cars.

Predictability of Pi Angle and Comparison with ANB Angle, W Angle, Yen Angle, and Beta Angle in South Indian Population

Predictability of Pi Angle and Comparison with ANB Angle, W Angle, Yen Angle, and Beta Angle in South Indian Population

Predictability of Pi Angle and Comparison with ANB Angle, W Angle, Yen Angle, and Beta Angle in South Indian Population

Predictability of Pi Angle and Comparison with ANB Angle, W Angle, Yen Angle, and Beta Angle in South Indian Population

A “new vista” in the assessment of antero-posterior jaw relationship

Aim The purpose of this investigation was to (1) compare the credibility of four recently introduced cephalometric measurements in assessing the antero-posterior jaw relationship; (2) To assess the correlation between various measurements used for assessment of antero-posterior discrepancy, including Yen linear, Yen angle, W angle and Pi angle. Materials and Methods The sample size for the study consisted of 45 subjects with age group of 15-19 years (mean age 17 ± 2.1) and was subdivided into Skeletal Class I, II and III groups of 15 each based upon the ANB angle derived from the pre treatment lateral cephalogram. Landmarks were located and Yen angle, Yen linear, W angle and Pi angle were assessed for each group. All the lateral cephalograms were traced by a single examiner. Intra examiner reliability was assessed by Intraclass co-efficient correlation (ICC) test. Correlation coefficients were obtained for each of parameters to compare their relationship with other parameters in Class I group. Receiver operating characteristics (ROC) curves were run to examine sensitivity and specificity of all the angles. Results The results showed that ICC for all the groups were ≥0.90 showing good repeatability of the measurements. There was statistically significant correlation between Yen angle and ANB angle, Yen linear and Yen angle for Class I group, between W angle and Yen angle for Class II group, between Yen angle, Yen linear and ANB for Class III group. ROC curves showed that Pi angle had 100% sensitivity and specificity to discriminate a Class II and a Class III group from a Class I and a Class III group from a Class II. Yen linear and W angle showed very low specificity to differentiate a Class II from a Class I group. Interpretation and Conclusion The new parameters considered in the study were found to be equally reliable and are not affected much by local remodeling due to tooth movements or by occlusal or Frankfurt horizontal plane. These parameters measure the antero-posterior discrepancy more consistently and accurately, with Pi angle being the most accurate.

TIDAL TORQUES ON MISALIGNED DISKS IN BINARY SYSTEMS

We extend previous studies of the tidal truncation of coplanar disks in binary systems to the more general case of noncoplanar disks. As in the prograde coplanar case, Lindblad resonances play a key role in tidal truncation. We analyze the tidal torque acting on a misaligned nearly circular disk in a circular orbit binary system. We concentrate on the 2:1 inner Lindblad resonance associated with the m=2 tidal forcing (for azimuthal wavenumber m) that plays a major role in the usual coplanar case. We determine the inclination dependence of this torque, which is approximately cos^8(i/2) for misalignment angle i. Compared to the prograde coplanar case (i=0), this torque decreases by a factor of about 2 for i = pi/6 and by a factor of about 20 for i=pi/2. The Lindblad torque decreases to zero for a tilt angle of pi (counter-rotation), consistent with previous investigations. The effects of higher order resonances associated with m>2 tidal forcing may contribute somewhat, but are much more limited than in the i=0 case. These results suggest that misaligned disks in binary systems can be significantly extended compared to their coplanar counterparts. In cases where a disk is sufficiently inclined and viscous, it can overrun all Lindblad resonances and overflow the Roche lobe of the disk central object.

Fluorene based donor-acceptor polymer electrets for nonvolatile organic transistor memory device applications

Fluorene based donor-acceptor polyimides, including poly[bis-(4-aminophenyl)fluorene-hexanediamide] [PA(BAP F-AC)], poly[bis-(4-aminophenyl)fluorene-hexafluoroisopropylidenediphthalimide] [PI(BAPF-6FDA)], poly[bis-(4-aminophenyl)fluorene-oxydiphthalimide] [PI(BAPF-ODPA)], and poly[bis-(4-aminophenyl)fluorene-1,2,4,5-cyclohexanetetracarboxylic diimide] [PI(BAPF-HPMDA)], as charge storage layer (electret) are employed for nonvolatile memory device applications. The polyimides are consisted of electron-donating fluorene diamine moiety (BAPF) and neutral (AC and HPMDA) or electron-accepting (6FDA and ODPA) moieties, respectively. The memory characteristics of these devices can be tuned from the EORM (erase once and read many times) behavior [PA(BAPF-AC)], semi-flash [PI(BAPF-ODPA)], [PI(BAPF-HPMDA)], to a flash type memory [PI(BAPF-6FDA)]. The PI(BAPF-6FDA) devices show the largest memory window of 77 V and a long retention time over 104 s with a high Ion/Ioff current ratio of 108. This is attributed to the largest torsion angle of PI(BAPF-6FDA) stabilizing charge transfer (CT) complexes. The write-read-erase-read cycles were stably operated over 100 cycles. This work provides a new insight into the relationship between the CT effect and the nonvolatile memory behavior. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 602–614

An evaluation of the Pi analysis in the assessment of anteroposterior jaw relationship

This study has investigated two new cephalometric variables, the Pi angle and Pi linear in the evaluation of anteroposterior skeletal discrepancy. Retrospective cross-sectional study. Manipal College of Dental Sciences, Manipal, India A sample of 155 subjects (mean age 19·7 years) were subdivided into skeletal class I, II and III groups based upon ANB angle. Descriptive data were calculated for each variable and group. Receiver operating characteristics curves were used to examine sensitivity and specificity of the Pi angle in the discrimination between different skeletal groups. Correlation coefficients were obtained for each of the parameters to compare their relationship with other parameters in the class I group. Coefficient of determination, regression coefficient, regression equation and standard error of estimate were also calculated from the parameters showing significant correlation with the Pi angle. Mean values for the Pi angle in skeletal class I, II and III subjects were 3·40 (±2·04), 8·94 (±3·16) and -3·57 (±1·61) degrees, respectively. For the Pi linear they were 3·40 (±2·20), 8·90 (±3·56) and -3·30 (±2·30) mm for class I, II and III subjects, respectively. Receiver operating characteristic curves showed that a Pi angle greater than 5 degrees had 89% sensitivity and 82% specificity for discriminating a skeletal class II group from class I. A Pi angle of less than 1·3 degrees had 100% sensitivity and 84% specificity in discriminating skeletal class III groups from class I. The overall accuracy for discriminating class II groups from class I was 85% and for class III from class I, 90%. Thus, a cut-off point between class I and II groups could be considered a Pi angle of approximately 5 degrees and between class I and class III, approximately 1·3 degrees. There were no statistically significant correlations found between Pi angle and ANB (0·07), Beta angle (-0·04) and WITS analysis (0·19). The highest level of correlation was obtained for the Pi angle and Pi linear (0·96). The anglar and linear components of the Pi analysis are a suitable method for assessing anteroposterior jaw discrepancy in daily clinical practice.

Creation and Detection of Skyrmions in a Bose-Einstein Condensate

We present the first experimental realization and characterization of two-dimensional Skyrmions and half-Skyrmions in a spin-2 Bose-Einstein condensate. The continuous rotation of the local spin of the Skyrmion through an angle of pi (and half-Skyrmion through an angle of pi/2) across the cloud is confirmed by the spatial distribution of the three spin states as parametrized by the bending angle of the l vector. The winding number w = (0,1,2) of the internal spin states comprising the Skyrmions is confirmed through matter-wave interference.

Superhydrophilic polymer surface modification by low energy reactive ion beam irradiation using a closed electron Hall drift ion source

A gridless closed electron Hall drift plasma accelerator with very low energy (< 200 eV) and high current density (∼ 1 mA/cm 2) was adopted for polymer surface modification. Ar, N 2, O 2, and N 2O gases were used for the generation of plasma and the ions were irradiated on polyimide and polyvinylidene fluoride with the ion fluence of 5 × 10 15/cm 2–1 × 10 18/cm 2. By the irradiation of O 2 + at the very low ion fluence of 5 × 10 15/cm 2 corresponding to 1 s treatment time, the wetting angle of PI and PVDF were greatly reduced from 78° and 61° to less than 2° and N 2O + ion irradiation showed analogous results. The attainment of superhydrophilic polymer surface can be explained by the formation of hydrophilic group induced by low energy reactive ion beam irradiation. From the results, it is revealed that the very low energy ion beam irradiation can be used as an effective and productive ion source compared with conventional gridded ion source for the enhancement of surface energy of polymer.

Living specimen tomography by digital holographic microscopy: morphometry of testate amoeba

This paper presents an optical diffraction tomography technique based on digital holographic microscopy. Quantitative 2-dimensional phase images are acquired for regularly-spaced angular positions of the specimen covering a total angle of pi, allowing to built 3-dimensional quantitative refractive index distributions by an inverse Radon transform. A 20x magnification allows a resolution better than 3 microm in all three dimensions, with accuracy better than 0.01 for the refractive index measurements. This technique is for the first time to our knowledge applied to living specimen (testate amoeba, Protista). Morphometric measurements are extracted from the tomographic reconstructions, showing that the commonly used method for testate amoeba biovolume evaluation leads to systematic under evaluations by about 50%.

N-Cinnamoylsaccharin

The title compound [systematic name: 2-cinnamoyl-1,2-benzisothiazol-3(2H)-one 1,1-dioxide], C16H11NO4S, contains both saccharin and cinnamoyl groups. The molecule is approximately planar in the solid state, and adjacent molecules are connected by C-H...O and C-H...pi(phenyl) interactions. In the C-H...pi interaction, the C...CgA distance is 3.916 (4) A (CgA is the non-fused benzene ring centroid) and the C-H...pi angle is 156 (2) degrees . A feature of the molecular geometry is the narrow C-S-N angle of 92.51 (9) degrees in the five-membered ring. This angle relieves strain from the ring and makes it possible for the whole saccharin group to become quite planar.

N-(o-chlorophenyl)-2,5-dimethylpyrrole-3-carbaldehyde.

Crystal structure analysis of the title compound, C(13)H(12)ClNO, reveals three crystallographically independent molecules in the asymmetric unit. The main conformational difference between these molecules is the orientation of the phenyl rings with respect to the pyrrole rings. The coplanar arrangement of the aldehyde groups attached to the pyrrole rings influences the pyrrole-ring geometry. The C2-C3 and N1-C5 bonds are noticeably longer than the C4-C5 and N1-C2 bonds. Two independent molecules of the title compound form dimers via intermolecular C-H.O hydrogen bonds [D.A = 3.400 (3) A and D-H.A = 157 degrees ]. The perpendicular orientation of the phenyl and pyrrole rings of one independent molecule and its symmetry-related molecule allows C-H.pi interactions, with an H.centroid distance of 2.85 A and a C-H.pi angle of 155 degrees. The distances between the H atom and the pyrrole-ring atoms indicate that the C-H bond points towards one of the bonds in the pyrrole ring.