Larger Ellipse Research Articles

Explaining supernova remnant G352.7-0.1 as a peculiar type Ia supernova inside a planetary nebula

I identify a point-symmetric morphology of the supernova remnant (SNR) G352.7-0.1 and propose that the outer axially-symmetric structure is the remnant of a common envelope evolution (CEE) of the progenitor system, while the inner structure is the ejecta of a thermonuclear explosion triggered by the merger of a white dwarf (WD) and the core of an asymptotic giant branch (AGB) star. The main radio structure of SNR G352.7-0.1 forms an outer (large) ellipse. The bright X-ray emitting gas forms a smaller ellipse with a symmetry axis inclined to the symmetry axis of the large radio ellipse. The high abundance of iron and the energy of its X-ray lines suggest a type Ia supernova (SN Ia). The massive swept-up gas suggests a relatively massive progenitor system. I propose a scenario with progenitors of initial masses of MZAMS,1≃5–7M⊙ and MZAMS,2≃4–5M⊙. At a later phase, the WD remnant of the primary star and the AGB secondary star experience a CEE that ejects the circumstellar material that swept up more ISM to form the large elliptical radio structure. An explosion during the merger of the WD with the core of the AGB star triggered a super-Chandrasekhar thermonuclear explosion that formed the inner structure that is bright in X-ray. A tertiary star in the system caused the misalignment of the two symmetry axes. This study adds to the wide variety of evolutionary routes within the scenarios of normal and peculiar SNe Ia.

Does the size of tracing actions affect learning outcomes?

ABSTRACT Objective Explicit instructions to students to use the index finger to trace out specified elements of mathematics worked examples have been shown to improve mathematics learning outcomes; however, there is limited research on whether the magnitude of tracing actions impacts these outcomes. Method Using an experimental design, 34 adults were randomly allocated to an experimental (tracing out larger ellipses) or control (tracing out smaller ellipses) condition. We hypothesised explicit instructions to make larger tracing actions on the surface of worked examples on a mental mathematics skill would support learning more than making smaller tracing actions. Video analysis established the two conditions differed in distance traced in the expected direction. Results Contrary to hypotheses, making larger tracing actions did not result in better post-lesson problem-solving. Instead, an aptitude–treatment interaction was established between multiplication expertise and experimental condition, with less expert students in particular solving more similar post-test problems after making smaller tracing actions. This interaction may reflect a split-attention effect generated by experimental materials. Conclusions Findings suggest there needs to be close consideration of how instructions to trace lesson elements are designed, so that visual processing following the index finger supports rather than hinders learning. Directions for future research are discussed.

Posterior lens capsule rupture in non‐diabetic canine cataracts: Pre‐operative, intra‐operative, and post‐operative findings

To describe clinical features of non-diabetic canine cataracts with presumed pre-existing posterior capsule rupture (PLCR) and their surgical outcomes. Clinical records of 497 non-diabetic canines that underwent elective cataract surgery were reviewed. Twelve canines met the inclusion criteria indicative of PLCR pre-dating surgery. The incidence of presumed pre-existing PLCR was 12/497 (2.4%). Cataracts included were unilateral in 10 out of 12 canines (83.3%) and bilateral in the remaining two (16.7%). Four eyes (28.6%) had clinically detectable pre-operative lens-induced uveitis. The mean age at cataract diagnosis for cases included was 6.6 years, and golden retrievers were the most common breed affected (28.6%). Phacoemulsification surgery was performed at a median time of 110 days (range 17-403 days) after presentation. Pre-existing PLCR was found intra-operatively as a large ellipse spanning the posterior capsule from equator to equator centrally in 12 eyes and peripherally in two eyes. The capsular defect in all eyes with PLCR incorporated a distinct "pseudo-capsule" preventing vitreal presentation and ruling out intraoperative surgeon rupture. Ten eyes (71.4%) received an intraocular lens implant (IOL), and 13 eyes (92.9%) maintained vision throughout a mean follow-up period of 12 months. Posterior lens capsule rupture of blunt trauma origin and associated cataract formation, as reported in humans, may also be an infrequent but distinct cause of some cases of non-diabetic canine cataracts. Medical management of phacolytic uveitis and delayed phacoemulsification surgery may be beneficial by allowing time for "pseudo-capsule" development, increasing the likelihood of IOL placement and improved visual outcomes.

Three-dimensional inversion of knot defects recognition in timber cutting

The comprehensive utilization of wood is the main goal of log cutting, but knot defects increase the difficulty of rationally optimizing cutting. Due to the lack of real shape data of knot defects in logs, it is difficult for detection methods to establish a correlation between signal and defect morphology. An image-processing method is proposed for knot inversion based on distance regularized level set segmentation (DRLSE) and spatial vertex clustering, and with the inversion of the defects existing relative board position in the log, an inversion model of the knot defect is established. First, the defect edges of the top and bottom images of the boards are extracted by DRLSE and ellipse fitting, and the major axes of the ellipses made coplanar by angle correction; second, the coordinate points of the top and bottom ellipse edges are extracted to form a spatial straight line; third, to solve the intersection dispersion of spatial straight lines and the major axis plane, K-medoids clustering is used to locate the vertex. Finally, with the vertex and the large ellipse, a 3D cone model is constructed which can be used to invert the shape of knots in the board. The experiment was conducted on ten defective larch boards, and the experimental results showed that this method can accurately invert the shapes of defects in solid wood boards with the advantages of low cost and easy operation.

CALCULATION SCHEME OF REINFORCED CONCRETE STRUCTURES OF CIRCULAR CROSS-SECTION UNDER BENDING WITH TORSION

The developed design diagram of the ultimate resistance of reinforced concrete structures in bending with torsion of circular cross-sections most fully reflects the features of their actual exploitation. For a spatial crack of a diagonal large ellipse, sections are taken in the form of a swirling propeller with concave and convex spatial parabolas from the first and second blocks between vertical transverse circular sections from the beginning to the end of the crack. For practical calculations in compressed and tensioned concrete, a polyline section of three sections is considered: two longitudinal trapezoids and the third middle section of the radius curve of a small ellipse close to forty-five degrees. When calculating unknown forces, solutions of the equations of equilibrium and deformations of the sections are made up to the end of the crack passing through the moment points for the resultant moments and the projections of internal and external forces. Shear torsional stresses along the linear longitudinal sections of the trapezoid were presented, as well as normal and shear stresses located on the end cross-sections at a distance x from the support. The height of the compressed area of concrete decreases with an increase in bending moments in the spatial section between the first and third cross-sections. It is found in their relationships and connections. The dowel action of reinforcement is determined using a special model of the second level with discrete constants. The static loading scheme was considered from the standpoint of an additional proportional relationship between the torques along the length of the bar in the spatial section and the first and third transverse sections. For a dangerous spatial crack, when projected onto the horizontal axis, the length C was found from a diagonal large ellipse of a round bar.

Modelling and simulation of novel liquid‐infiltrated PCF biosensor in Terahertz frequencies

The liquid-infiltrated photonic crystal fibre (LI-PCF) is proposed for guiding terahertz radiation. Geometrical asymmetry is achieved by introducing a large ellipse in the core. By filling the ellipse with liquid cocaine, the optical properties of the photonic crystal fibre (PCF) are theoretically examined using finite element method-based COMSOL multiphysics software. At an operating frequency of 1 THz, the proposed LI-PCF demonstrates a sensitivity of 87.02% and confinement loss in the order of 10 −4 cm −1 . The PCF also demonstrates extremely low effective material loss <0.01 cm −1 , a birefringence of 0.018, large effective mode area of 1.11 × 10 5 µm 2 , a high numerical aperture of 0.45 and near-zero ultra-flattened chromatic dispersion of 1.4351 ± 0.5883 ps/THz/cm. The design simplicity and high sensitivity, strong confinement factor, low material losses and high birefringence of the fibre suggest that the proposed fibre may be convenient for PCF-based cocaine sensing, for application in the security and defence industries.

MAXI/SSC all-sky maps from 0.7 keV to 4 keV

Abstract By accumulating data from the Solid-state Slit Camera (SSC) on board the MAXI mission from 2009 to 2011, diffuse X-ray background maps were obtained in energies of 0.7–1.0, 1.0–2.0, and 2.0–4.0 keV. They are the first to be derived with a solid-state instrument, and to be compared with the previous ROSAT all-sky survey result. While the SSC map in the highest energy band is dominated by point sources and the Galactic diffuse X-ray emission, that in 0.7–1.0 keV reveals an extended X-ray structure, of which the brightness distribution is very similar to that observed with ROSAT about 20 years before. As in the ROSAT result, the emission is dominated by a bright arc-like structure, which appears to be part of a circle of ∼50° radius centered at about (l,b) ∼ (340°, 15°). In addition, the SSC map suggests a fainter and larger ellipse, which is elongated in the north–south direction and roughly centered at the Galactic center. The spectrum of these structures is explained as thin thermal emission from a plasma, with a temperature of ∼0.31 keV and an abundance of ∼0.3 solar. Based on SSC observation conditions including low solar activity, the solar wind charge exchange signals are estimated to be negligible in the present SSC maps, as well as in the &amp;gt;0.56 keV ROSAT map. A brief discussion is given on the results obtained.

EXPRESS MONITORING OF THE MAIN PARAMETERS OF CLOUDS FROM THE EARTH’S SURFACE

Objectives The paper proposes a technique that allows the main types of clouds and cloud cover parameters (ceiling, direction and speed of cloud movement) to be determined at minimum cost via observations from the Earth’s surface. The aim is to avoid using meteorological information derived from official sources, which may not always be available for a specific place and time of observation.Method The method is based on the well-known Ippolitov formula that connects air humidity on the Earth’s surface with the cloud ceiling, whose empirical coefficients depend on the type of the cloud cover. In order to determine this type, a method based on elliptic cloud contour approximation is proposed.Results Additional classification features were the number of approximating ellipses in the image frame, the proximity of their mutual location, the total area that they occupy in the frame and the area occupied by the largest ellipse. The speed and direction of the clouds are determined through shifting the common key points in image frames obtained over a small fixed time interval. Each point is described by a descriptor calculated using the SURF method from the open image processing library OpenCV.Conclusion Despite the simplicity of the required software and hardware (web camera, humidity sensor, and OEM – Arduino module), this method provides a definition of these parameters with an error within 20%. Monitoring systems based on this method may be used in private automatic weather stations, such as the Wunderground, for obtaining more information that could improve the accuracy of weather forecasts, as well as for research in meteorology and climatology.

Movement detection on a concrete structure during traffic flow using Global Positioning System

Global Positioning System (GPS) monitoring has been interested in a sensing technology of the structural responses to monitor the movement of a concrete bridge because basic data are obtained by field measurements. Two stations as a base station with a long observation situated at the embankment of the bridge. The establishment stations observation has been cover from morning until night. This paper explores the possibility movement of Sultan Idris Shah Bridge structure using static signals to enhance the measurement of total static movement response of a bridge structure. The results are shows with the two epochs actual movement motions generated by the motion of real work. The determination of movement of measuring points installed on the bridge is dividing into two times frame namely peak and non-peak hour. Those of error ellipse explain relationship between movement and traffic flow. The largest ellipse was register at non-peak hour. This is caused by the low volume of traffic flow in which average speed of vehicle at this period of time is about 50-60km/h. The analysis of the bridge movements, the current operational safety, the cause of bridge cracks, sensitivity of GPS signals, and its movements were observed under traffic loads. The comparative results demonstrate that the proposed technique can significantly enhance the measurement of the total movement of a structure.

An efficiency improved recognition algorithm for highly overlapping ellipses: Application to dense bubbly flows

Image analysis is a widespread and performant tool for the characterization of particulate systems in chemical engineering. However, for bubbly flows, due to the wide range of particles size, shape and the appearance of large clusters resulting from particles projections overlapping at high hold-up, automatic particle detection remains a challenge. An efficient methodology for bubbly flow characterization based on pattern recognition is presented. The proposed algorithm provides an exhaustive, robust and computationally efficient way of analyzing complex images involving large ellipse clusters even in concentrated medium. The method is fully automated. A sub-clustering approach enables significant computation time reduction. Moreover, thanks to its ease of parallelization, it allows considering real time monitoring.

Comparing the Scour Upstream of Circular and Square Orifices

Scour pattern upstream of square and circular orifices with equal opening areas of 38.45 cm2 are compared experimentally. A total of 16 tests for four constant heads, two initial conditions of fixed bed versus mobile bed and two non-cohesive sediments used as the bed layer are performed. The bed profile is surveyed by an acoustic bed profiler and the velocity distribution is measured using an ADV instrument. In the fixed-bed tests the thickness of sediment layer below the orifices’ invert is 2 mm and the observations show that the influence zone, which is the zone exposed to excess shear stress in which particles are removed, is elliptically shaped in both orifices with larger ellipse radius in transverse direction. The influence zone area upstream of square orifice is 1.46 times larger than the circular orifice. Observations of the mobile-bed tests indicate that the geometrical scour parameters, namely maximum depth of scour, length and width of the scour hole increase with the head of water upstream of both orifices. It is also found that the maximum scour depth upstream of square orifice is approximately two times deeper than that of circular orifice. Meanwhile, scour length and width, upstream of square orifice are, respectively, 10–15 and 20–33% larger than those of circular orifice. Finally, the measurements of the longitudinal velocity profiles along the centrelines of the orifices for both orifices are performed. The results indicate the existence of three separate zones of velocity distribution upstream of the orifices.

TSS & TSB: Tensor scale descriptors within circular sectors for fast shape retrieval

We propose two novel region-based descriptors for shape-based image retrieval and analysis, which are built upon an extended tensor scale based on the Euclidean Distance Transform (EDT). First the tensor scale algorithm is applied to extract local structure thickness, orientation, and anisotropy as represented by the largest ellipse within a homogeneous region centered at each image pixel. In this work, we extend the local orientation to 360°. Then, for the first proposed descriptor, named Tensor Scale Sector descriptor (TSS), the local distributions of relative orientations within circular sectors are used to compose a fixed-length feature vector for a region-based representation. For the second method, named Tensor Scale Band descriptor (TSB), we consider histograms of relative orientations for each circular concentric band to compose a fixed-length feature vector with linear time matching. Experimental results with MPEG-7 and MNIST datasets are presented to illustrate and validate the methods. TSS can achieve high retrieval values comparable to state-of-the-art methods, which usually rely on time-consuming correspondence optimization algorithms, but uses a simpler and faster distance function, while the even faster linear complexity of TSB leads to a suitable and better solution for very large shape collections.

Imaging and spectroscopic observations of a strange elliptical bubble in the northern arm of the spiral galaxy NGC 6946

NGC 6946, known as the Fireworks galaxy because of its high supernova rate and high star formation, is embedded in a very extended HI halo. Its northern spiral arm is well detached from the galactic main body. We found that this arm contains a large (~300 pc in size) Red Ellipse, named according to a strong contamination of the H-alpha emission line on its optical images. The ellipse is accompanied by a short parallel arc and a few others still smaller and less regular; a bright star cluster is seen inside these features. The complicated combination of arcs seems to be unique, it is only a bit similar to some SNRs. However, the long-slit spectral data obtained with the Russian 6-m telescope did not confirm the origin of the nebula as a result of a single SN outburst. The emission-line spectrum corresponds to the photoionization by young hot stars with a small contribution of shock ionization. The most likely explanation of the Red Ellipse is a superbbuble created by a collective feedback of massive stars in the star cluster located in the NE side of the Red Ellipse. However, the very regular elliptical shape of the nebulae seems strange.

Growth requirements of different potato cultivars

A field trial with four potato cultivars (Faluka, Manitou, Madeleine and Stirling) was conducted in two consecutive years (2012 and 2013) at a laboratory field of Biotechnical Faculty in Ljubljana. The aim of the study was to evaluate different requirements of the selected cultivars in regard to the ridge and tuber cluster. The following parameters were defined and monitored: area of the form surrounding the tubers (ellipse), cross-sectional area of the ridge, vertical and horizontal tuber span in the ridge, the length of semi-axes (a) and (b) of the ellipse, minimum distance of tubers and ellipse from the outer ridge side. The results of 2012 trial indicated that the minimal ellipse method defining the ellipse was not satisfactory as statistical significance was limited due to a large volume of vacant space in the ridge not occupied by potato tubers. Therefore, the mathematical model was upgraded in 2013 and a physical parameter (tuber mass) was incorporated in the equation to better depict the tuber cluster. The trials were designed as a randomized block with five repetitions. The largest ellipse, horizontal tuber span in the ridge and the longest semi-axis (a) were recorded for the cv. Manitou resulting in the highest yield. However, no statistical differences were recorded in the horizontal tuber span, the length of the semi-axis (a) or cross-sectional area of the ridge among cultivars analysed. It was determined that different cultivars require specific growth space in the potato ridge. Moreover, the newly developed method proved efficient for determining growth requirements of potato tubers in the ridge.

CBD 시스템으로 보강된 비내진 RC 골조의 내진성능 평가

본 연구에서는 내진설계 이전에 지어진 학교 건물을 대상으로 내진보강효과를 알아보기 위하여 CBD 시스템을 설치하여 기존 비내진 설계된 보강 RC골조 실험결과와 비교 분석하였다. 실험결과, 비내진 설계된 실험체는 좌․우측 기둥의 상․하부에 피해가 집중되면서 급격한 강도저하와 함께 취성적인 전단파괴의 양상을 나타낸 반면, CBD 시스템을 보강한 실험체는 강도 및 강성의 증가와 함께 탄소성 거동을 보이면서 에너지 흡수 능력이 큰 타원형의 이력특성을 나타내었다. 또한, 두 실험체의 강성저하를 비교한 결과 CBD 시스템을 보강한 실험체가 강성저하를 방지하는데도 효과적임을 알 수 있었다. 에너지소산능력도 CBD 시스템을 보강한 실험체가 비보강 실험체에 비해 약 4.0배의 향상된 결과를 나타내었다. 이러한 에너지소산능력의 증진은 내력과 변형 능력의 증진에 따른 결과라고 사료된다. 본 연구에서 제안하는 CBD 시스템을 적용할 경우 비내진 상세를 갖는 철근콘크리트 골조의 내력 증진 및 안전성 확보를 위해 국내 내진기준에서 요구하는 허용층간변형각 기준을 만족하도록 보강하는데 용이하게 적용될 수 있을 것으로 판단된다.

더블 I형 감쇠장치로 보강한 비내진 RC 골조의 내진성능 평가

Abstract: In this study, to examine seismic reinforcement effect of a school building constructed prior to application of seismic design, a Double I-type damper supported by wall was installed to perform comparative analysis on existing non-seismic designed RC frame. As a result o f experiment, while non-seismic designed specimen showed rapid reduction in strength and brittle shear destruction as damages were focused on top a nd bottom of left and right columns, reinforced specimen showed hysteretic characteristics of a large ellipse with great energy absorption abilit y, exhibiting perfectly behavior with increased strength and stiffness from damper reinforcement. In addition, as a result of comparing stiffness reduc tion between the two specimens, specimen reinforced by shear wall type damper was effective in preventing stiffness reduction. Energy dissipation ability of specimen reinforced by Double I-type damper was about 3.5 times as high as energy dissipation ability of non-reinforced specimen. Such e nhancement in energy dissipation ability is considered to be the result of improved strength and deformation.Keywords: Double I-type Hysteretic damper, Strength degradation, Stiffness degradation, Energy dissipation, retrofitted

The effects of pronated foot posture and medial heel and sole wedge

Abstract Introduction: Aging has been associated with increasing foot pronation and changes in foot mobility which may influence standing balance. Orthotic interventions change foot posture and load distribution under the foot and therefore may have important effects on balance in older people. To investigate whether a pronated foot posture is associated with poorer standing balance in older people and whether medial heel and sole wedge orthoses affect their standing balance. Materials and Methods: Nine healthy older people with a pronated foot posture (age 67.1± 5.7 years) and Fourteen healthy elderly with normal foot posture (age 67.1± 6.4 years) were recruited.The Foot Posture Index was used to determine the pronated (FPI 7.5 ± 0.7) and normal (FPI 3.8 ± 1.5) foot posture. Static balance in double limb stance was assessed using Kistler force plate measures during four random shod conditions:1) 5° medial heel and sole wedge; 2) 8° medial heel and sole wedge; 3) 5°flat EVA base insole; 5) 8°flat EVA base insole. Each of the four cases was completed with eyes open (three trials) and eyes closed (three trials). The center-of-pressure (COP) mean excursion, total path length of COP, mean velocity of COP and area of 95% confidence ellipse were derived as measures of standing balance. Results: Participants with a pronated foot type demonstrated higher total and mean velocity excursion data in AP and ML directions, and larger ellipse, during normal standing, but this did not reach statistical significance (P>0.05). There were no statistically significant effects from the four orthoses designs in the pronated nor the normal foot types (P<0.05). Main effects for eye conditions were significant for center-of-pressure excursion and mean velocity in medial-lateral directions (P <0.001) also for total excursion and mean distance in anterior-posterior direction. Also there were no significant differences in interaction of all conditions (foot posture × eye condition × orthoses) (P<0.05). Conclusion: A trend towards less stable balance was observed in pronated foot type but this was not significant. Use of orthoses had no effect on balance parameters including negating the effects of eyes closed. Orthoses showed no negative effects on standing balance and therefore do not pose a threat to balance (e.g. if they are used for another purpose). Keywords: Aging, pronated foot posture, static balance, medial wedge orthoses

Myoelectrical Activity and Muscle Morphology in a Rat Model of Myofascial Trigger Points Induced by Blunt Trauma to the Vastus Medialis

To explore myoelectrical activity and muscle morphology of myofascial trigger points (MTrPs) in an injury model of rats. A total of 24 male SD rats were randomly divided into a control group (group A) and model group (group B). A blunt striking injury and eccentric exercise were applied to the vastus medialis (VM) of rats in group B for 8 weeks. Later, the palpable taut band (TB), local twitch response, myoelectrical activities and morphology in the two groups were examined. An average of 2.5 (30/12) palpable TBs were detected in the VM in group B compared with none in group A. The MTrPs had two types of abnormal potential. Their amplitudes were significantly higher than those in the control group (p<0.01) but their durations showed no significant differences. A series of reflex contractions appeared in groups A and B in response to external stimulation to the ear. Their amplitude and duration in group B were significantly lower than those in group A. A series of lower fibrillation potentials repeatedly occurred in model MTrPs in group B. The morphology of MTrPs showed abnormal muscle fibres with large round or ellipse shapes in cross-section and enlarged tapering shapes in longitudinal section. Active MTrPs can be provoked by repeated blunt injury. Active MTrPs are a group of muscle fibres with abnormal shapes and abnormal myoelectrical potentials. External stimulation provokes low-voltage responses in MTrPs, which is different from the response of normal muscle fibres.

Interrelationship of Micro- and Macrostructure with Nonlinear Optical Properties of Simple and Binary Acentric Niobate Crystals

On the plane of oxide bond lengths the rosette with three ellipses of acentricity have been displayed for noncentrosymmetric (NCS) niobate crystals distributed over 2 groups of paraelastic and ferroelastic crystals. Two small ellipses have perpendicular main axes and main axis of one large ellipse lie on bisector of other ellipses axis. Six characteristic regions and 12 sub-regions are found inside the ellipse rosette showing different crystal structure and χ(2) levels: 1) total crossing part of three ellipses; (2) four parts of two small ellipses outside crossing part, 3) one part of large ellipse outside other ellipses. The dependence of nonlinear optical susceptibility χ(2) on the shortest niobate bond length Nb‒O has been revealed.

Topographic ellipses in Finney and Sedgwick counties, Kansas may signal deep structures in Precambrian basement

Hillshade maps based on digitized topography and capable of detecting subtle changes in slope that are otherwise imperceptible, reveal two large and heretofore unrecognized topographic ellipses in Kansas here designated the Garden City ellipse (10 by 14 km dimensions) in Finney County and the Goddard ellipse (11 by 13 km) in Sedgwick County. Cheyenne Bottoms in Barton County, although long known, is a larger ellipse (22 by 32 km). All three are bounded by outlines that are remarkably elliptical, suggesting that they may represent the surface expressions of deeply buried bodies in the Precambrian basement perhaps the result of meteorite impact. Cheyenne Bottoms is controversial because it has been ascribed to subsidence caused by solution of the underlying Permian Hutchinson Salt. The Garden City and Goddard ellipses are not known to involve faulting, but it is hypothesized that fractures that bound deeply buried elliptical bodies that lie beneath them are propagated to the surface and perceptibly affect the topography. Support for the hypothesis that deep-seated fractures affect the landscape in the region also is provided by the pervasive influence of a “fine-scale fracture system” that may extend through the crust and influence the development of reticulate linear drainage patterns. Recurrent small up and down movements, perhaps in response to tectonic movements elsewhere and maintained by earth tides, may be responsible for the fine-scale fracture system. Paradoxically the fractures of the fine-scale system seem to be distinct from those that bound the ellipses, but they strengthen the hypothesis that deep-seated fractures of various configurations are basic aspects of the crust and are capable of revealing deep-seated features heretofore unrecognized.