Asymmetric Type Research Articles

Characteristic Analysis and Experimental Verification of the Axially Asymmetric Structured Outer-Rotor Type Permanent Magnet Motor

In this study, we have dealt with a design characteristic of outer-rotor type permanent magnet (PM) motor applied for Engine Cooling Fan (ECF). When we design a motor with structure like this type, it is required as a requisite to consider 3-Dimensional (3-D) effect by implementing a non-linear Finite Element Analysis (FEA) due to a yoke-ceiling, which is perpendicular to the axis of rotation. We have analyzed identical models under three different conditions. The analysis has been performed through a non-linear 2-Dimensional (2-D) and 3-D FEA. Finally, the results have been compared with Back Electro-Motive Force (BEMF) value of actual motor model. As a result, a yokeceiling function as an additional flux path and the operating point on B-H curve of rotor material is shifted to non-saturation region relatively. Accordingly, magnetic flux linkage can be increased and motor size can be decreased under same input condition to satisfy ECF specification, such as torque.

A cross-sectional study for the development of growth of patients with pectus excavatum.

Pectus excavatum is one of the most common congenital chest wall deformities, and is thought to be one of the musculoskeletal diseases. There have been few studies on the development of growth of patients with pectus excavatum. The objectives of the present study were to present the development of growth of patients with pectus excavatum and to investigate the effects of the Nuss procedure on the development of growth. Data from 1371 patients who were treated for pectus excavatum (411 patients for only the Nuss procedure, 316 patients for only bar removal and 322 patients for both the Nuss procedure and the bar removal) at the Department of Thoracic and Cardiovascular Surgery in a single tertiary Korean Hospitals from March 2011 to December 2014 were assessed with respect to body measurements [height, weight and body mass index (BMI)]. Anthropometric measurements and developmental data and deviations of a reference population were analysed by the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-3), 2011-2013, Korea Centers for Disease Control and Prevention. To analyse the development of growth in patients with pectus excavatum, we performed (i) comparisons of body measurements between patients with pectus excavatum and the normal population, (ii) analyses of postoperative changes in the body measurements and (iii) analyses of the body measurements with respect to age at surgery, morphology and severity. (i) Body measurements of the preoperative group (PreG, patients for the Nuss procedure) were significantly smaller than those of the normal control group (NCG) (height 139.2 ± 0.4 vs 140.7 ± 0.0, weight 37.4 ± 0.3 vs 39.6 ± 0.0, BMI 17.5 ± 0.1 vs 18.6 ± 0.0, all P < 0.001). Weight and BMI of the postoperative group (PostG, patients for pectus bar removal) were also significantly smaller than those of NCG (weight 36.6 ± 0.4 vs 39.6 ± 0.0, BMI 17.4 ± 0.1 vs 18.6 ± 0.0, both P < 0.001). However, height of PostG was not significantly different from that of NCG. In addition, height and BMI of PostG were larger than those of PreG (height 131.2 ± 0.3 vs 130.4 ± 0.3, P < 0.001; BMI 16.7 ± 0.1 vs 16.6 ± 0.1, P = 0.143). However, weight of PostG was significantly smaller than that of PreG (30.4 ± 0.2 vs 30.9 ± 0.2, P = 0.005). (ii) The severity of pectus excavatum was defined by the Haller index and the patients were divided into two groups by the mean value of the Haller index (4.3 ± 1.53). Preoperatively, weight and BMI of the high severity group (HG) were significantly smaller than those of the low severity group (LG) (weight 28.2 ± 0.3 vs 29.1 ± 0.2, P = 0.029; BMI 16.2 ± 0.1 vs16.6 ± 0.1, P = 0.008); however, height of HG was not significantly different from that of LG. Postoperatively, body measurements of HG were not significantly different from those of LG. In addition, severity of pectus excavatum was not correlated to age. (iii) Preoperatively, body measurements of the symmetric group (SG) were not different from those of the asymmetric group (AG). However, asymmetric type was more common in the older group (10.8 ± 5.7 vs 6.7 ± 5.0 years, P < 0.001). In addition, body measurements of SG were not different from those of AG postoperatively. (iv) Body growth after the surgery was more prominent in the early (age <10 years: height 112.4 ± 0.3 vs113.1 ± 0.4, P = 0.016, weight 20.2 ± 0.1 vs 20.2 ± 0.3, P = 0.053, BMI 15.7 ± 0.2 vs 15.8 ± 0.1, P = 0.007) than the late operation group (age ≥10 years: height 167.7 ± 0.5 vs 167.0 ± 0.6, P < 0.001, weight 51.2 ± 0.5 vs 51.8 ± 0.5, P = 0.536, BMI 18.1 ± 0.1 vs 18.3 ± 0.1, P = 0.078). Development of growth in patients with pectus excavatum is retarded and appears to be related to the severity of pectus excavatum. The development of growth can be recovered by early correction of the deformity.

Interaction Dynamics of Gap Solitons in Dual-Core Bragg Gratings With Cubic-Quintic Nonlinearity

Interactions between quiescent gap solitons in dual-core Bragg gratings with cubic-quintic nonlinearity are systematically investigated. In a previous work, it was found that the model supports symmetric and asymmetric soliton solutions. For each of these categories, there exist two disjoint families of quiescent gap solitons. One family can be regarded as the generalization of the quiescent gap solitons in dual-core Bragg gratings with Kerr nonlinearity (called Type 1). On the other hand, the other family is found in the region, where the quintic nonlinearity is dominant (called Type 2). The interactions of in-phase Type 1 asymmetric solitons result in a range of outcomes, namely, fusion into a single zero-velocity soliton, asymmetrical separation of solitons, symmetrical separation of solitons, formation of three solitons, and the destruction of solitons. In the case of symmetric solitons, interactions of in-phase Type 1 solitons may lead to fusion in the form of a quiescent soliton, asymmetrically separating solitons, or the formation of three solitons. It is also found that the interaction of in-phase asymmetric Type 2 solitons results in their destruction. Also, the effects of the quintic nonlinearity, coupling coefficients, initial separation, and initial phase difference on the outcomes of the interactions are analyzed. Also, in the case of asymmetric solitons, the outcomes of the soliton-soliton interactions for specular-symmetric and cross-symmetric initial configurations are compared.

Suzuki type theorems for asymmetric type mappings

Suzuki type theorems for asymmetric type mappings

Interaction of sine‐Gordon solitons in the model with attracting impurities

We study properties of the localized solutions to the sine‐Gordon equation excited on the attractive impurity by a moving kink. The cases of one‐dimensional and two‐dimensional spatially extended impurities are considered. For the case of one‐dimensional impurity the possibility of excitation of the first even and odd high‐amplitude impurity modes by the moving kink is demonstrated. By linearizing the sine‐Gordon equation the dispersion relations for the small‐amplitude localized impurity modes were obtained. The numerically obtained dispersion relations in the case of low oscillation amplitudes are in a good agreement with the results of analytical calculations. For the case of two‐dimensional impurity we show the possibility of excitation of the nonlinear high‐amplitude waves of new type called here a breathing pulson and a breathing 2D soliton. We suggest analytical expressions to model these nonlinear excitations. The breathing pulson and breathing 2D soliton are long‐lived and can be of both symmetric and asymmetric type depending on the impurity type. The range of the impurity parameters where the breathing pulson and breathing 2D soliton can be excited was determined. The dependencies of the oscillation frequency and the amplitude of the excited impurity modes on the impurity parameters are reported. Copyright © 2016 John Wiley &amp; Sons, Ltd.

A survey on Neyman‐Pearson classification and suggestions for future research

In statistics and machine learning, classification studies how to automatically learn to make good qualitative predictions (i.e., assign class labels) based on past observations. Examples of classification problems include email spam filtering, fraud detection, market segmentation. Binary classification, in which the potential class label is binary, has arguably the most widely used machine learning applications. Most existing binary classification methods target on the minimization of the overall classification risk and may fail to serve some real‐world applications such as cancer diagnosis, where users are more concerned with the risk of misclassifying one specific class than the other. Neyman‐Pearson (NP) paradigm was introduced in this context as a novel statistical framework for handling asymmetric type I/II error priorities. It seeks classifiers with a minimal type II error subject to a type I error constraint under some user‐specified level. Though NP classification has the potential to be an important subfield in the classification literature, it has not received much attention in the statistics and machine learning communities. This article is a survey on the current status of the NP classification literature. To stimulate readers' research interests, the authors also envision a few possible directions for future research in NP paradigm and its applications. WIREs Comput Stat 2016, 8:64–81. doi: 10.1002/wics.1376This article is categorized under: Statistical Learning and Exploratory Methods of the Data Sciences &gt; Clustering and Classification

Probing the early stages of solvation of cis-pinate dianions by water, acetonitrile, and methanol: a photoelectron spectroscopy and theoretical study.

cis-Pinic acid is one of the most important oxidation products of α-pinene--a key monoterpene compound in biogenic emission processes. Molecular level understanding of its interaction with water in cluster formation is an important and necessary prerequisite for ascertaining its role in the aerosol formation processes. In this work, we studied the structures and energetics of the solvated clusters of cis-pinate (cis-PA(2-)), the doubly deprotonated dicarboxylate of cis-pinic acid, with H2O, CH3OH, and CH3CN by negative ion photoelectron spectroscopy and ab initio theoretical calculations. We found that cis-PA(2-) prefers being solvated alternately on the two -CO2(-) groups with increase of solvent coverage, a well-known solvation pattern that has been observed in microhydrated linear dicarboxylate dianion (DCn(2-)) clusters. Experiments and calculations further reveal an intriguing feature for the existence of the asymmetric type isomers for cis-PA(2-)(H2O)2 and cis-PA(2-)(CH3OH)2, in which both solvent molecules interact with only one of the -CO2(-) groups, a phenomenon that has not been observed in DCn(2-) water clusters and exhibits that the subtle effect of the rigid four-membered carbon ring brought on the cis-PA(2-) solvation. The dominant interactions between cis-PA(2-) and solvent molecules form bidentate O(-)...H-O H-bonds for H2O, O(-)...H-O and O(-)...H-C H-bonds for CH3OH, and tridentate O(-)...H-C H-bonds for CH3CN. The formation of inter-solvent H-bonds between H2O and CH3CN is found to be favorable in mixed solvent clusters, different from that between H2O and CH3OH. These findings have important implications for understanding the mechanism of cluster growth and the formation of atmospheric organic aerosols, as well as for rationalizing the nature of structure-function relationship of proteins containing carboxylate groups in various solvent environments.

Comparison of placement for tibial component in total knee arthroplasty with symmetric type versus asymmetric type

Comparison of placement for tibial component in total knee arthroplasty with symmetric type versus asymmetric type

CARDIAC ABNORMALITIES IN YOUNG MALE ELITE HOCKEY PLAYERS PRESELECTED BY THE NATIONAL HOCKEY LEAGUE (NHL) : DETECTION BY SCREENING TRANATHORACIC ECHOCARDIOGRAPHY

BACKGROUND: Bicuspid aortic valves (BAV) are commonly classified according to the absence (type 0), presence of 1 (type 1) or 2 (type 2) raphes. Type 1, however, encompasses a wide spectrum of anatomically distinct patterns that are addressed by different repair techniques depending on the behaviour of the raphe, the commissural orientation, the quantity of leaflet tissue and the dimensions of the ventricular-arterial junction (VAJ), among other characteristics. PURPOSE: To establish whether transesophageal echocardiography (TEE) correlates with the surgical findings that modulate the repair approach in BAV patients. METHODS: Pre-operative TEEs of 78 consecutive patients who underwent BAV repair/sparing at our institution between June 2010 and January 2015 were reviewed by one echocardiographer blinded to the surgical findings and procedures. Two surgeons, blinded to TEE data, reviewed the operative videos to determine the anatomical features of the diseased valves and describe the surgical techniques. In our center, type 0 and type 1 BAV with a complete, prolapsing raphe (type 1A) and excess tissue are repaired with free margin plication triangular resection. In symmetrical (commissural orientation 150 ) restrictive type 1 BAV (type 1B), central plication for gap closure and maintenance of bicuspid configuration is usually performed, while asymmetrical (120 ) BAV are considered for tricuspidization with patch, depending on the quantity of tissue. Root-replacement valve-sparing with reimplantation is chosen to stabilize the VAJ when the root is dilated, and subcommissural annuloplasty is used when root dimensions are normal. RESULTS: TEE correctly identified the raphe presence and behaviour (ie. prolapsing vs restrictive) determined at surgical inspection in 84.6% of cases (table). Tricupidization with commissural patch was performed in 4 cases, which had all been appropriately categorized as type 1B with asymmetrical (z120 ) orientation at TEE. Bicuspid configuration was restored in 5 asymmetrical type 1B BAV patients, in whom relatively large VAJ (mean 14.4 1.5 mm/m) and sinuses of Valsalva (18.8 1.3 mm/m) allowed sufficient tissue for bicuspid restoration after aortic root remodelling. CONCLUSION: TEE has the potential to accurately classify BAV according to specific structural and functional patterns that guide the surgical repair approach and that the currently accepted anatomical classifications of BAV do not take into account.

Firm-level effects of asymmetric intervention in foreign exchange markets: Evidence from the Swiss currency floor

In January 2015, the Swiss National Bank (SNB) abandoned the Swiss franc's exchange rate floor against the Euro. This paper is the first to study the firm-level effects of this asymmetric type of central bank intervention in foreign exchange markets. Using weekly stock returns for a sample of Swiss non-financial firms, I find significant reductions in total stock return volatility as well as market risk following the introduction of the currency floor. Accounting for the asymmetric nature of the intervention, I show that the enforcement of this policy solely manifests in a significant reduction of incremental EUR/CHF exchange rate risk exposures of exporting firms, while importing firms experience reductions in proportion to the market portfolio only. Thus, the asymmetric policy design is reflected in asymmetric responses of firm-level currency exposures. All effects, however, do not depend on the extent of business activity in the Eurozone. The overall results suggest that the currency floor was successful in supporting the performance of the Swiss economy by effectively reducing stock return sensitivities to market fluctuations and EUR/CHF exchange rate volatility.

Typology of the antegonial notch in the human mandible.

Surgical treatment for serious malocclusions and fractures of the organ of mastication is a golden standard in medicine. Procedures performed on the mandible require detailed knowledge of the anatomy of the organ. Antegonial notching constitutes a serious technical challenge for surgeons. Therefore, a detailed anatomical description of this structure, which is the subject of this paper, is essential. We analysed 251 human Caucasian mandibles of identified sex and took measurements of all sections describing the mandibular antegonial notch. Depending on the proportion between sections we classified the shape of the antegonial notch into three types. The surface area of the notch was calculated. We analysed the dimorphic and bilateral differences for each of the three types of notch. We used variance analysis for the assessment of statistical difference. The analysis revealed that in both men and women, regardless of body side, the type 3 antegonial notch was the most frequent. Type 3 occurred with a frequency of between 38% in men on the right side and 55.9% in women on the left side of the body. Type 1 was the least frequent. Dimorphic differences in the presence of individual types of antegonial notch were statistically significant only for the left side of the body. The symmetrical type (type 2) occurred more frequently in men (by 11%) than in women. Type 3 was found more frequently in women (by 10%) than in men. Bilateral differences in men were revealed for the frequencies of types 1 and 3. On the right side type 1 was more frequent (by 8%), and on the left side type 3 was also more frequent (by 8%). The greatest surface area was found for the asymmetrical posterior type (type 1). The smallest surface area was found for the asymmetrical anterior type 3. This difference was statistically significant with respect to the surface area of types 1 and type 2 and found for both sexes for both sides of the body. However, no statistically significant differences were found between the surface areas of types 1 or 2. Knowledge of the preangular notch anatomy can be useful for surgeons during reconstructive and plastic procedures on the body of the mandible.

Morphological evidence for dopamine interactions with pallidal neurons in primates.

The external (GPe) and internal (GPi) segments of the primate globus pallidus receive dopamine (DA) axonal projections arising mainly from the substantia nigra pars compacta and this innervation is here described based on tyrosine hydroxylase (TH) immunohistochemical observations gathered in the squirrel monkey (Saimiri sciureus). At the light microscopic level, unbiased stereological quantification of TH positive (+) axon varicosities reveals a similar density of innervation in the GPe (0.19 ± 0.02 × 106 axon varicosities/mm3 of tissue) and GPi (0.17 ± 0.01 × 106), but regional variations occur in the anteroposterior and dorsoventral axes in both GPe and GPi and along the mediolateral plane in the GPe. Estimation of the neuronal population in the GPe (3.47 ± 0.15 × 103 neurons/mm3) and GPi (2.69 ± 0.18 × 103) yields a mean ratio of, respectively, 28 ± 3 and 68 ± 15 TH+ axon varicosities/pallidal neuron. At the electron microscopic level, TH+ axon varicosities in the GPe appear significantly smaller than those in the GPi and very few TH+ axon varicosities are engaged in synaptic contacts in the GPe (17 ± 3%) and the GPi (15 ± 4%) compared to their unlabeled counterparts (77 ± 6 and 50 ± 12%, respectively). Genuine synaptic contacts made by TH+ axon varicosities in the GPe and GPi are of the symmetrical and asymmetrical type. Such synaptic contacts together with the presence of numerous synaptic vesicles in all TH+ axon varicosities observed in the GPe and GPi support the functionality of the DA pallidal innervation. By virtue of its predominantly volumic mode of action, DA appears to exert a key modulatory effect upon pallidal neurons in concert with the more direct GABAergic inhibitory and glutamatergic excitatory actions of the striatum and subthalamic nucleus. We argue that the DA pallidal innervation plays a major role in the functional organization of the primate basal ganglia under both normal and pathological conditions.

Effect of hydrostatic pressure on the kinetics of the ordering of ferroelectrics upon second-order phase transitions

The effect of hydrostatic pressure on the kinetics of the formation of electrical domains in ferroelectric materials that undergo second-order phase transitions has been considered. It has been shown using the example of triglycine sulfate ferroelectric crystals undergoing an order-disorder phase transition that the applied pressure increases the ordering temperature and thus accelerates the ordering process. It has been found that, by increasing the hydrostatic pressure applied to the sample after quenching, it is possible to obtain a single-domain state, instead of the multi-domain type of ordering. The evolution curves for the average value of the order parameter and its dispersion have been obtained by numerical integration. These curves indicate that quasi-stationary multi-domain structures of the asymmetric type can be formed at specially selected pressures. It has been established that the kinetics of the formation of electrical domains in ferroelectrics depends significantly on the initial relaxation conditions, which are determined by the technological prehistory of the quenching.

Step-length control analysis with a multi-staged clutch damper model in a torsional vibration problem using harmonic balance method

This study focuses on a step-length control method to investigate piecewise type nonlinearities such as multi-staged clutch dampers in a practical system. In general, step-length control techniques are employed to overcome at least two difficulties with respect to examining the nonlinear dynamic responses of a physical system. Such techniques first reduce the calculation time, which increases the efficiency of simulation in many case studies. Then, the employment of step-length control resolves strongly stiff problems which often occur in the asymmetrical piecewise type nonlinearities. In order to overcome these difficulties, this study suggests a newly developed step-length control method based on the employment of two different adaptive step sizes from prior steps to the next steps, when simulation is conducted using an arc-length continuation method. The simulation results using the step-length control method show much improvement with respect to reducing the calculation times and number of steps compared with the ones without step-length control method. Thus, this study provides clear understanding of the objectives of using step-length control such that it increases the efficiency of simulation as well as resolves the convergence problems in a nonlinear dynamic system.

Influence of parental social status on intrauterine fetal growth restriction development

Aim. To study the role of parental social status on the chance of intrauterine growth restriction.Methods. We observed 315 mothers who delivered off children with intrauterine growth restriction, of which 172 mothers gave birth to children with asymmetric type, and 143 mothers - with symmetric type of intrauterine growth restriction. Control group included 119 mothers who delivered off babies with normal growth. All mothers filled in a questionnaire addressing parental education, occupation, age, living conditions and area of residence. Dispersion analysis was performed to determine the influence of the studied factors on the chance of intrauterine growth restriction.Results. Mother’s employment had the most influence - 8.93%. Mother’s education level effect on the chance of intrauterine growth restriction was 5.51%, followed by father’s employment, which had 4.24% of impact. Living conditions influence on the chance of intrauterine growth restriction was assessed as 2.53%, followed by the family area of residence and mother’s age, which were 2.12 and 1.52%, respectively.Conclusion. Conducted analysis of parental social status influence on the chance of intrauterine growth restriction revealed that mother’s unemployment and low educational level are the major risk factors for this condition, which might further help to develop preventive and therapeutic approaches to decrease the effects of intrauterine growth restriction consequences.

Angular and polarization dependence of all optical diode in one-dimensional photonic crystal

The effect of the incident angle on all-optical diode (AOD) efficiency in a one-dimensional photonic crystal structure (1DPC) for TE and TM polarizations was studied. An asymmetric hybrid Fabry Perot resonator type 1DPC structure composed of linear and nonlinear materials was considered in this communication. The nonlinear transmission curves around the defect mode resonant frequency inside the photonic band gap for both TE and TM polarizations at different incident angles, from left to right (L-R) and right to left (R-L) incidences, are illustrated. Results showed that with increasing the incident angle, AOD performance efficiency increases only for TM polarization. The AOD efficiency increased to 80% for an incident angle of 60 degrees because of the dynamical shifting of the defect mode peak frequency caused by the intensity-dependency of the nonlinear layer refractive index along the z-axes. For TE polarization, the z-component of the electric field remained constant for all incident angles. The results of this study can be important in optical data communications and information analysis in all-optical integrated circuits.

Firm-Level Effects of Asymmetric Intervention in Foreign Exchange Markets: Evidence from the Swiss Currency Floor

In January 2015, the Swiss National Bank (SNB) abandoned the Swiss franc's exchange rate floor against the Euro. This paper is the first to study the firm-level effects of this asymmetric type of central bank intervention in foreign exchange markets. Using weekly stock returns for a sample of Swiss non-financial firms, I find significant reductions in total stock return volatility as well as market risk following the introduction of the currency floor. Accounting for the asymmetric nature of the intervention, I show that the enforcement of this policy solely manifests in a significant reduction of incremental EUR/CHF exchange rate risk exposures of exporting firms, while importing firms experience reductions in proportion to the market portfolio only. Thus, the asymmetric policy design is reflected in asymmetric responses of firm-level currency exposures. All effects, however, do not depend on the extent of business activity in the Eurozone. The overall results suggest that the currency floor was successful in supporting the performance of the Swiss economy by effectively reducing stock return sensitivities to market fluctuations and EUR/CHF exchange rate volatility.

The Prevalence and Characteristics of Psoriatic Arthritis in Patients With Psoriasis in a Tertiary Hospital

Objectives: This study aims to investigate psoriatic arthritis (PsA) prevalence in patients with psoriasis (Ps), and compare clinical and laboratory characteristics of patients with or without PsA. Patients and methods: A total of 126 patients (59 males, 67 females; mean age 45.6±13.8 years; range 18 to 82 years) with Ps who applied to Dermatology Outpatient Clinic between October 2009 and September 2010 were included in this study. The patients were screened for PsA using Classification of Psoriatic Arthritis criteria. The patients classified as PsA were grouped according to Moll and Wright criteria. Enthesopathy was evaluated according to Maastricht Ankylosing Spondylitis Enthesis score. Psoriasis Area and Severity Index scores were calculated by the same dermatologist. Results: The prevalence of PsA was 25.4%. Ps duration was significantly longer in the group with PsA. The most common type was asymmetrical oligoarticular type (53.1%). Compared to previous studies, the rate of isolated spondyloarthropahty was higher in our study (21.9%). Nail involvement, Psoriasis Area and Severity Index score, mean erythrocyte sedimentation rate, and C-reactive protein values were significantly higher in the group with PsA. Conclusion: High rate of isolated spondyloarthropahty in patients with PsA indicates that PsA must be kept in mind in the differential diagnosis of seronegative spondyloarthropathies. The fact that nail involvement is seen more frequently in patients with arthritis may assist in screening of PsA in patients with Ps. In addition, our results showing a higher probability of PsA development in patients with more severe skin lesions and a higher probability of arthritis development in patients with long lasting Ps may guide clinicians in terms of the probability of arthritis development in patients with Ps.

Micro–computed Tomographic Analysis of Mandibular Second Molars with C-shaped Root Canals

IntroductionThe goal of the present study was to evaluate the morphometric aspects of the internal anatomy of the root canal system of mandibular second molars with C-shaped canals. MethodsFifty-two extracted second mandibular molars with C-shaped canals, fused roots, and radicular grooves were selected from a Brazilian population. The samples were scanned with a micro–computed tomographic scanner at a voxel size of 19.6 μm. The root canal cross sections were recorded as C1, C2, C3, and C4 root canal configurations according to the modified Melton classification. Morphometric parameters, including the major and minor diameters of the root canals, the aspect ratio, the roundness, and the tridimensional configuration (merging, symmetric, and asymmetric), were evaluated. ResultsThe 3-dimensional reconstruction images of the teeth indicated an even distribution within the sample. The analysis of the prevalence of the different cross-sectional configurations of the C-shaped molars revealed that these were predominantly of the C4 and C3 configurations (1 mm from the apex) and the C1 and C2 configurations in the cervical third. According to the morphometric parameters, the C1 and the distal aspect of the C2 configurations exhibited the lowest roundness values and higher values for the area, major diameter, and aspect ratio in the apical third. ConclusionsMandibular molars with C-shaped root canals exhibited similar distributions of symmetric, asymmetric, and merging type canals. The C1 configuration and the distal aspect of the C2 configuration exhibited the highest area values, low roundness values, and large apical diameters.

Synchronization between two coupled direct current glow discharge plasma sources

Experimental results on the nonlinear dynamics of two coupled glow discharge plasma sources are presented. A variety of nonlinear phenomena including frequency synchronization and frequency pulling are observed as the coupling strength is varied. Numerical solutions of a model representation of the experiment consisting of two coupled asymmetric Van der Pol type equations are found to be in good agreement with the observed results.