Academic literature on the topic 'Curvature per meter'

The Hancheng block in the southeastern Ordos Basin is one of the earliest and the most important areas for coalbed methane exploration and development in China. However, there are significant production variations in different wells or even some adjacent wells in the Hancheng block. To reveal the reasons of production differences in such a small scale, further detailed studies of coalbed methane productivity in the Hancheng pilot test area, a precursor trial area in Hancheng block with mature, well-characterized coalbed methane reservoirs and long-term production database, were conducted. The influence of nine factors (including engineering and geological factors) on gas production was analyzed. By introducing the rough set theory, which is applicable to the vague, imprecise, and incomplete information system, this paper presents a method for quantitative evaluation of the influencing factors on gas production. The results indicate that there are certain distribution characteristics of productivity in Hancheng pilot test area, which can be partitioned into four zones. The degressive order of the influencing degree of these nine factors is (i) the distance between the well and the fault, (ii) the structure curvature of the coal seams, (iii) the gas content, (iv) the critical reservoir ratio, (v) the volume of the fracturing liquids per meter, (vi) the volume of the fracturing sand per meter, (vii) the dynamic liquid level drop rate, (viii) the depth, and (ix) the thickness. Geological factors, especially the influence of fault, structural curvature of the coal seams and gas content, play a major role in controlling long-term gas production. Engineering factors (effect of fracturing and dynamic liquid level drop rate) have always been integral parts of coalbed methane development.

Abstract. Based on assumptions that substorm field line dipolarization at geosynchronous altitudes is associated with the arrival of high-velocity magnetotail flow bursts referred to as bursty bulk flows, the following sequence of field line dipolarization is proposed: (1) slow magnetoacoustic wave excited through ballooning instability by enhanced inflows in pre-onset intervals towards the equatorial plane; (2) in the equatorial plane, slow magnetoacoustic wave stretching of the flux tube in dawn–dusk directions resulting in spreading plasmas in dawn–dusk directions and reduction in the radial pressure gradient in the flux tube. As a consequence of these processes, the flux tube assumes a new equilibrium geometry in which the curvature radius of new field lines increased in the meridian plane, suggesting an onset of field line dipolarization. The dipolarization processes associated with changing the curvature radius preceded classical dipolarization caused by a reduction of cross-tail currents and pileup of the magnetic fields. Increasing the curvature radius induced a convection surge in the equatorial plane as well as inductive westward electric fields of the order of millivolts per meter (mV m−1). Electric fields transmitted to the ionosphere produce an electromotive force in the E layer for generating a field-aligned current system of Bostrom type. This is also equivalent to the creation of an incomplete Cowling channel in the ionospheric E layer by the convection surge.

Abstract. In this study, high-resolution bathymetric multibeam and optical image data, both obtained within the Belgian manganese (Mn) nodule mining license area by the autonomous underwater vehicle (AUV) Abyss, were combined in order to create a predictive random forests (RF) machine learning model. AUV bathymetry reveals small-scale terrain variations, allowing slope estimations and calculation of bathymetric derivatives such as slope, curvature, and ruggedness. Optical AUV imagery provides quantitative information regarding the distribution (number and median size) of Mn nodules. Within the area considered in this study, Mn nodules show a heterogeneous and spatially clustered pattern, and their number per square meter is negatively correlated with their median size. A prediction of the number of Mn nodules was achieved by combining information derived from the acoustic and optical data using a RF model. This model was tuned by examining the influence of the training set size, the number of growing trees (ntree), and the number of predictor variables to be randomly selected at each node (mtry) on the RF prediction accuracy. The use of larger training data sets with higher ntree and mtry values increases the accuracy. To estimate the Mn-nodule abundance, these predictions were linked to ground-truth data acquired by box coring. Linking optical and hydroacoustic data revealed a nonlinear relationship between the Mn-nodule distribution and topographic characteristics. This highlights the importance of a detailed terrain reconstruction for a predictive modeling of Mn-nodule abundance. In addition, this study underlines the necessity of a sufficient spatial distribution of the optical data to provide reliable modeling input for the RF.

The compressibility, bending, weight, friction, tensile and shear properties of wool fabrics and yarns are of vital importance in the hung shape and virtual fitting of end-use textile products. A new apparatus has been developed for characterizing the above mechanical properties of wool fabrics and yarns through a single testing, and the corresponding modeling analysis for compressing, bending, weighting, friction, stretching and shearing properties were conducted and the corresponding characteristics were all measured just through one pulling out testing based on a three-point bending in principal. The compressing measurements for fabric and transversal cross-section yarn were conducted and could obtain the thickness under certain pressure and the low load and thickness curve. The bending modeling for small deflection was developed and adapted to the nonlinear relationship of bending moment and curvature, and the governing differential equation for bending rigidity was found. The weight of fabric in Gram per square meter and the linear density of yarn in Tex per unit length were both effectively and accurately calculated. The friction method was developed based on the Amonton’s Law, and the static and dynamic frictional coefficients were found. The tensile and shear properties under low stress were investigated and the corresponding characteristics, such as elastic modulus and shearing modulus, were obtained. Moreover, the fuzzy clustering analysis for handle of fabrics or yarns was utilized to classify and further verify the measured fabrics or yarns based on the mechanical properties mentioned above. Thereof, the comprehensive handle system for fabrics and yarns (briefly named CHS-FY) was necessarily self-designed and utilized to characterize the mechanical properties, which played a crucial role in quickly classifying the fabrics and yarns with different style. Meanwhile, the verifications of the comprehensive handle system for fabric and yarn was conducted, and indicated that there were in good agreement between theoretical and experimental results of mechanical properties of wool fabric and yarn, and showed that there existed high accuracy in classification with the fuzzy clustering analysis. Thereby, the comprehensive handle system for wool fabrics and yarns is effective and accurate in measuring the compressibility, bending, weight, friction, tensile and shear properties and fast classifying the handle of wool fabrics and yarns.

Consecutive replanting of peach (Prunus persica) trees on the same orchard site can result in various replant problems and diseases, including armillaria root disease (Armillaria spp.), which develops upon contact between the roots of newly planted trees and infested residual root pieces in the soil. There is little information regarding the quantity of roots remaining in stone fruit orchards following tree removal and land clearing. We investigated the utility of ground-penetrating radar (GPR) to characterize reflector signals from peach root fragments in a controlled burial experiment and to quantify the amount of residual roots remaining after typical commercial orchard clearing. In the former experiment, roots ranging from 2.5 to 8.2 cm in diameter and buried at depths of 11 to 114 cm produced characteristic parabolic reflector signals in radar profiles. Image analysis of high-amplitude reflector area indicated significant linear relationships between signal strength (mean pixel intensity) and root diameter (r = -0.517; P = 0.0097; n = 24) or the combined effects of root diameter and burial depth, expressed though a depth × diameter term (r = -0.630; P = 0.0010; n = 24). In a peach orchard in which trees and roots had been removed following typical commercial practice (i.e., trees were pushed over, burned, and tree rows subsoiled), a GPR survey of six 4 × 8-m plots revealed that the majority of reflector signals indicative of root fragments were located in the upper 30 to 40 cm of soil. Based on ground-truth excavation of selected sites within plots, reflectors showing a strong parabolic curvature in the radar profiles corresponded to residual root fragments with 100% accuracy, whereas those displaying a high amplitude area represented roots in 86.1% of the cases. By contrast, reflectors with both poor curvature and low amplitude yielded roots for less than 10% of the excavated sites, whereas randomly selected sites lacking reflector signals were devoid of any roots or other subsurface objects. A high level of variability in the number of residual roots was inferred from the radar profiles of the six plots, indicating an aggregated distribution of root fragments throughout the field. The data further indicated that at least one residual root fragment would be present per cubic meter of soil, and that many of these fragments have diameters corresponding to good to excellent inoculum potential for armillaria root disease. Further GPR surveys involving different levels of land clearing, combined with long-term monitoring of armillaria root disease incidence in replanted trees, will be necessary to ascertain the disease threat posed by the levels of residual root biomass observed in this study.

Over the last hundred years, shaft spillways have become widely used in hydraulic engineering practice due to their undeniable advantages: high discharge capacity, maximal water consumption per one cubic meter of concrete, point structure compactness. The modern theory of hydraulic calculations was formed based on works on the study of the operation of a circular spillway with a sharp edge carried out by Wagner in 1954. Although numerous hydraulic studies have not proved many of the statements Wagner's calculation methodology was based on, the materials of his studies have been presented in special hydraulic literature for hydraulic calculations up to date. The accepted design conditions of the drainage surface of the spillway shaft, which is round-cylindrical in the cross-section and in the form of a convex parabolic line in the longitudinal section, do not correspond to the possibilities of work. As a result, the drainage surface is replaced by a system of truncated cones, the joints of which cause flow separation from the drainage surface and the formation of vacuum zones. It results in approximate hydraulic calculations. To eliminate these disadvantages of hydraulic calculations and bring design developments in line with technological possibilities of works, it is possible to replace a round-cylindrical cross-section of the inner surface of the shaft with a polygonal one. In this case, the drainage surface will consist of a system of longitudinal wedges with one-dimensional curvature, for which the formwork can be made of flat sheets. This paper presents materials on the calculation and design of a shaft spillway of a hydroelectric complex with a dodecagonal cross-section for Algeria, and four shafts with an octagonal cross-section and two shafts with a tetragonal cross-section for Syria. The receiving hopper head is round-cylindrical, and the drainage surface is elliptical, which allows adapting the drainage surface to any initial design parameters of shaft spillways.

Objective. The aim of this study was to validate a survival analysis assessing the effect of type of rotary system, canal curvature, and instrument size on cyclic resistance.Materials and Methods. Cyclic fatigue testing was carried out in stainless steel artificial canals with radii of curvature of 3 or 5 mm and the angle of curvature of 60 degrees. All the instruments were new and 25 mm in working length, and ISO colour coding indicated the instrument size (yellow for size 20; red for size 25).Wizard Navigatorinstruments,Mtwoinstruments,ProTaperinstruments, andRevo-Sinstruments were passively rotated at 250 rotations per minute, and the time fracture was being recorded. Subsequently, fractographic analysis of broken tips was performed by scanning electron microscope. The data were then analysed by the Kaplan-Meier estimator of the survival function, the Cox proportional hazards model, the Wald test for regression covariates, and the Wald test for significance of regression model.Conclusion. The lifespan registered for the tested instruments wasMtwo>Wizard Navigator>Revo-S>ProTaper; 5 mm radius > 3 mm radius; and yellow > red in ISO colour coding system.

La práctica deportiva sistemática puede conllevar adaptaciones en el morfotipo raquídeo. Varios estudios han mostrado diferentes morfotipos raquídeos en función de la disciplina practicada, así como mejoras en la movilidad global de la columna en bailarinas de flamenco o asimetrías posturales entre jugadores adolescentes de voleibol y sedentarios. Por lo que se pretende describir el morfotipo raquídeo de tenistas adolescentes en diferentes posiciones. La muestra estuvo compuesta por 40 tenistas varones entre los 14 y 18 años (media de edad: 16,35 ± 1,82 años; talla media: 1,71± 0,14 metros; masa media: 67,45 ± 10,11 kilogramos) y una frecuencia de entrenamiento de 3 sesiones por semana durante al menos 4 años. Se exploró la disposición angular del raquis torácico y lumbar y el ángulo de inclinación pélvica mediante el Spinal Mouse. Los resultados mostraron en la bipedestación relajada, un 79,5% de los sujetos dentro los valores de normalidad; en la sedentación relajada, más de la mitad de los sujetos presentaron cifosis leves y moderadas, tanto en la zona lumbar como torácica; y en los test de distancia DD-S y DD-P se observó una cifosis moderada en la zona lumbar en un 94,9% y un 71,8% de los casos respectivamente. Por lo tanto, en bipedestación, la mayoría de los tenistas presentan unos valores angulares torácicos y lumbares normales, mientras que en la sedentación relajada los valores de normalidad se reducen a la mitad en ambas curvaturas. Por su parte, en la flexión máxima del tronco, se presentan morfotipos cifóticos en ambas curvaturas evidenciando una cifosis funcional. Abstract. Systematic sports practice can provoke adaptations in the spinal morphotype. Several studies have shown different spinal morphotypes depending on the discipline practiced, as well as improvements in the overall mobility of the spine in flamenco dancers, or postural asymmetries among adolescent volleyball players and sedentary youth. Therefore, we intend to describe the spinal morphotype of adolescent tennis players in different positions. The sample consisted of 40 male tennis players between 14 and 18 years old (mean age: 16.35 ± 1.82 years, average height: 1.71 ± 0.14 meters, average weight: 67.45 ± 10.11 kilograms) and a training frequency of 3 sessions per week for at least 4 years. The angular disposition of the thoracic and lumbar spine, as well as the pelvic tilt angle, were measured using Spinal Mouse. Results showed that in relaxed standing, 79.5% of the subjects laid within normal values; in slumped sitting, more than half of the subjects presented mild and moderate kyphosis, both in the lumbar and thoracic curvatures; and in the DD-S and DD-P distance tests, a moderate kyphosis was observed in the lumbar spine in 94.9% and 71.8% of the cases respectively. Therefore, most tennis players present normal thoracic and lumbar angle values while standing, whereas in slumped sitting normality values are reduced by half in both curvatures. On the other hand, kyphotic morphotypes appear in both curvatures during maximum flexion of the trunk, evidencing a functional kyphosis

A neurological disorder is a, structural, biochemical or electrical abnormalities in the brain or spinal cord and peripheral nerves. Neurological disorders include mental retardation, cerebralpalsy, autism and down’ syndrome. Children with neurological disorders have a high incidence of respiratory problems. Many children with cerebral palsy have scoliosis, an irregular curvature of spine that can interfere with lungs ability to expand. Genetic condition including cerebral palsy and muscular dystrophy can be associated with congenital airway abnormalities. The aim of the study is to find out peak expiratory flow rate in children with multiple neurological disorder. Study design non-experimental,15 subjects with age group of 7-17years was selected based on the inclusion and exclusion criteria.(subjects:3-cerebral palsy,3-down syndrome,2-autism,7-mental retardation) were selected Maithree special school, East Tambaram. An informed consent was obtained from the parents and children with detailed explanation of the procedure. First the participant was asked to breath in and breath out normally and then breath in deeply as much as possible followed by quick expiration to the maximum into the device. Three trials have been done and best of the three is adopted as PEFR. The value on the meter was monitored and recorded. The training was stopped whenever the subject feels dizziness. The data on height, age, sex, weight, were registered. The peak expiratory flow rate of normal children ranges from 182-565 l/min.The mean value of PEFR in children with multiple neurological disorder was found to be cerebral palsy-121 l/ min, Down’s syndrome-130 l/min, autism-77.5 l/min, mentally retarded-145 l/min. For the data, complete action of PEFR measurement were performed in children with multiple neurological disorder. The PEFR values clearly depicts that the children with multiple neurological disorder have decreased PEFR. Our findings confirm that the peak expiratory flow meter is a well functioning instrument for measuring PEFR in children, giving reliable results, and an inexpensive tool. The study conclude that there was a decreased PEFR in children with cerebral palsy, down’s syndrome, autism and mentally retarded. The study was made simple and this can be done by giving interventions like respiratory muscle training.

AbstractIn this paper we review some theoretical aspects of the dynamics of the mesoscale filaments extending along the magnetic field lines in the edge plasma, which are often called ‘blobs’. We start with a brief historical survey of experimental data and the main ideas on edge and SOL plasma transport, which finally evolved into the modern paradigm of convective very-intermittent cross-field edge plasma transport. We show that both extensive analytic treatments and numerical simulations demonstrate that plasma blobs with enhanced pressure can be convected coherently towards the wall. The mechanism of convection is related to an effective gravity force (e.g. owing to magnetic curvature effects), which causes plasma polarization and a corresponding E× B convection. The impacts of different effects (e.g. X-point magnetic geometry, plasma collisionality, plasma beta, etc.) on blob dynamics are considered. Theory and simulation predict, both for current tokamaks and for ITER, blob propagation speeds and cross-field sizes to be of the order of a few hundred meters per second and a centimeter, respectively, which are in reasonable agreement with available experimental data. Moreover, the concept of blobs as a fundamental entity of convective transport in the scrape-off layer provides explanations for observed outwards convective transport, intermittency and non-Gaussian statistics in edge plasmas, and enhanced wall recycling in both toroidal and linear machines.

Final thesis describes two variants of computational models to simulate cross-roll leveling of rods, which are based on the Lagrangian approach to describe the continuum. Implementation of both variants was performed in ANSYS software, and their main difference lies in the choice of the type of elements for the discretization. An integral part of this thesis is the description of the principle, which is an evaluation of the curvature of the rod after completion of the simulation leveling. In the other part of the work are presented the results, which are then compared with realized experiment and simulation algorithm for cross-roll leveling based on the Euler approach. The final part is dedicated to the optimal settings of the leveller.

Several national guidelines set the non-linear horizontal spring values between the railway track and a railway bridge. In Finland that is not the case. Consequently, one of the objectives of the research funded by the Finnish Rail Administration was to determine the spring values both during the elastic phase in the beginning of displacement and during the plastic phase. These values are needed, for example, to calculate the behaviour of an integral bridge-track structure. In autumn 2007 researchers from the Department of Civil Engineering at Tampere University of Technology performed field tests to measure the track resistance at a railway yard in Mellila¨, Finland. The main objectives of the experimental study were 1) to determine the longitudinal track resistance and the load-displacement relation, 2) to compare the measured values to those reported by the International Union of Railways (UIC), and 3) to determine the transverse track resistance and the load-displacement relation. The railway yard had three track test locations, two for longitudinal loading and one for transverse loading. At each location the rails were cut to a length of six to seven metres. During the longitudinal loading the track was loaded with two adjacent hydraulic jacks. Altogether eight longitudinal tests were conducted, three without a vertical load and five with a vertical load. The vertically unloaded track reached the plastic phase due to the axial load. The vertically loaded rails moved axially in their fasteners while the sleepers moved only a little in relation to them. Consequently, the track did not reach the plastic phase. The results of the longitudinal tests were reported as horizontal and vertical displacements and axial rail stresses along the rail at different phases of the axial loading. The results were presented also in tables where initial stage stiffness was presented as an elastic value [kN/m/m] and plastic track resistance in kN/m. The maximum forces per metre affecting the track without a vertical load were 13 to 15 kN/m. The maximum forces per metre affecting the track with a vertical load were 26, 15 and 31 kN/m. During transverse loading the track was loaded horizontally with an excavator bucket. Altogether five loadings with three different arrangements were performed. The loadings clearly caused curvature of the track. The results of the transverse tests were reported as displacements at different locations during different phases of loading.