Plate Junction Research Articles

POLA SESAR SADDANG BERDASARKAN TINGKAT SEISMISITAS DAN FOKAL MEKANISME (Studi Kasus Januari 2010 - Juli 2020)

The research of the Saddang fault pattern based on the level of seismicity and focal mechanism (a case study in January 2010- July 2020) aims to determine the level of seismicity in the Saddang fault area and the Saddang fault focal mechanism in the 2010-2020 earthquake. The data which were used were secondary data from the BMKG catalog from January 2010 - July 2020. The coordinating limit is 118.50 ° East Longitude 120.60 ° East Longitude and (-2.60 ° South Latitude) - (-5.70 ° South Latitude) there were 1425 earthquakes. This research used ArcGis application to measure seismicity distribution map and seiscomp3 to measure focal mechanism. Furthermore, the focal mechanism divides the region into three regions. The results which obtained from the seismicity map obtained a high level of seismicity with a shallow depth. Which was caused by the lack of factors from the active Saddang fault and Sulawesi who had four plate junctions. The results of the focal mechanism in each region had the whole type of shear fault or horizontal. Keywords: Earthquake, geology software ArcGis, software seisco

PENENTUAN TIPE FLUIDA DAN GUGUS FUNGSI MANIFESTASI PANAS BUMI KAWAH TUA GUNUNG API SOPUTAN

Indonesia is a country that has the largest geothermal resources in the world which is directly proportional to the number of volcanoes. Indonesia is an archipelagic country located at three junction of active mountain plates, namely the Eurasia, Indo-Australia and Pacific plates. Where Indonesia is also located in an active ring of fire that is associated with active volcanoes in Indonesia. North Sulawesi is one of the provinces in Indonesia which has several active volcanoes, one of which is the object of research is Mount Soputan. This volcano is located in South Minahasa and Southeast Minahasa Districts, North Sulawesi Province. The method used in this research is descriptive method and analysis of geothermal fluid chemical data. Analysis of the ion content in the fluid using a SpectroDirect Photometer. As well as functional group analysis using the FTIR Spectroscopy method (Fourier Transform Infra Red), this method is an infrared spectroscopy method equipped with Fourier transform for its spectrum analysis. Geothermal manifestation fluid in the Old Crater of Mount Soputan Volcano is a bicarbonate type of fluid with an HCO3 content of 479 ppm. The high HCO3 content is thought to be associated with the increase in geothermal fluids containing gas, especially CO2, which then experiences condensation in shallow aquifers.

Simplifying Access to the Lateral Sphenoid Recess: A Modification of the Transpterygoid Approach.

Meningoencephaloceles originating in the lateral recess of the sphenoid sinus can be difficult to access. Historically, the endoscopic transpterygoid approach was advocated, which carries additional morbidity given the dissection of the pterygopalatine fossa (PPF) contents to provide a direct line approach to the defect. Given our increased facility with angled endoscopes and instrumentation, we now approach this region in a less invasive manner. We describe the endoscopic modified transpterygoid approach (MTPA), a quicker approach to the lateral sphenoid recess which preserves the PPF contents through a single nostril corridor. In the MTPA, the face of the sphenoid and anterior junction of the pterygoid plates are removed, allowing for mobilization of the PPF contents with the periosteum intact. Angled instrumentation is then used to resect the meningoencephalocele and repair the skull base defect in the lateral recess. If increased exposure is needed, this can be gained by sacrificing the sphenopalatine artery and even the vidian nerve, although this is rarely required. The MTPA obviates the need for PPF dissection and simplifies access to the lateral sphenoid recess while minimizing postoperative morbidity. This approach should be considered for accessing meningoencephaloceles and other benign lesions in this challenging location.

Transmission and reflection of waves at structural junctions connecting thin orthotropic plates

We present a semi-analytical method for computing the reflection and transmission coefficients at joints connecting an arbitrary number of semi-infinite orthotropic plates based on the line-junction approximation. We use a wave approach and describe reflection, transmission and mode conversion between eigenmodes of the vibro-acoustic equations for orthotropic plates. A detailed derivation is presented here for the first time for an arbitrary number of plates meeting at the junction and without restrictions on the orientation of the principal material axes both with respect to the junction and with respect to the orientation in different plates. The approach is discussed for two specific example configurations, namely an L- and a T-shaped orthotropic plate junction. Furthermore, the scattering coefficients for a rib-stiffened orthotropic plate are derived, and the occurrence of resonance phenomena is discussed.

Electrical Conductivity of the Basement of East European Platform in the Southeastern Ladoga Region from Magnetotelluric Data

Abstract—The paper presents the results of magnetotelluric soundings conducted in 2018–2019 in the southeastern Ladoga region for studying the deep geoelectric structure of the basement of the East European platform at the junction of the Russian plate with the Fennoscandinavian shield. The results of noise suppression processing of the observations on the 180-km Tikhvin–Vinnitsa profile and the invariant analysis of the obtained magnetotelluric and magnetovariational transfer operators are discussed. A geoelectrical model of the Earth’s crust along the profile down to a depth of 50 km is constructed by two-dimensional inversion. The model clearly reflects the structures of the southeastern segment of the Ladoga crustal conductivity anomaly confined to the extended Ladoga-Bothnian tectonic zone at the boundary of the Archaean (AR) and Proterozoic (PR) domains of the shield. Fundamental features of the similarity between the new 2D model of the Ladoga anomaly and the similar model previously constructed for the Vyborg–Suojarvi profile on the northern coast of Lake Ladoga are revealed: the general southwestward dip of the crustal conductive structures and a significant increase in their integral conductivity at the depths of 15–20 km within the southern segments of the profiles. A preliminary geological interpretation of the constructed resistivity section along the Tikhvin–Vinnitsa line is presented.

Low prevalence of end plate junction failure in danish patients with lumbar disc herniation

The present study was undertaken to determine the prevalence of endplate junction failure in a smaller cohort of Danish patients with lumbar disk herniation and compare this to the previously published data from India. Consecutive patients seen in a large regional hospital spine-care unit, with a clinical presentation suggesting a lumbar disk herniation with concomitant radiculopathy and confirmatory recent MRI were included. Additional imaging by CT was performed as part of the study and these were analyzed with specific attention to endplate junction failures. For ethical reasons, the number of participants was kept to a minimum and a total of 26 patients were included. The prevalence (n = 5) of endplate junction failure was found to be statistically significantly lower than that previously reported. Our findings do not echo those previously reported in an Indian population: Endplate junction failure was indeed observed, but at a significantly lower rate. We discuss potential reasons for the difference in findings with due attention to the weaknesses of the current study.

A theoretical solution of the axial stiffness of a cylindrical shell with a circular plate

A structure of a cylindrical shell with a circular plate end cap is usually used in connect different shaft system and it is necessary to estimate the axial stiffness in order to analyze the vibration of the rotor system. This paper builds the model of this structure. The theoretical solution of the bending deflection of the circular plate and the cylindrical shell are deduced by using the classic theory of plates and shells, and the continuity boundary conditions at the junction of the circular plate and the cylindrical shell. Furthermore, the axial stiffness of the structure is solved through considering the relationship between the external force-bending deformation. Two different boundary conditions for the left side of the cylindrical shell is considered and their axial stiffness varying with the length of the cylindrical shell is calculated. For verification, a finite element model of the structure is built and analyzed. The theoretical results fairly coincide with the finite element ones.

Developing a New Type of Jointing the Metal Plates of a Heat Exchanger

This paper proposes using a new composition of the metal polymer compound to joint heat exchanger plates. This composition makes it possible to improve the factors of plate junction, such as the cost, safety, efficiency, and rate of the junction procedure. We consider the benefits and drawbacks of the two main ways to joint metal plates of brazed steel plate heat exchangers (BPHE), namely, copper brazing and laser beam welding; propose to joint plates using a metal polymer compound consisting of the metal powder of steel 316L and binding agents; show the metal polymer compound production process; provide the results of the component mixing process depending on the parameters, such as duration and rate of mixing; as well as present the resulting density of the specimens made of the metal polymer compound, depending on the mixing conditions.

Compressibility effect on heat transfer intensified by horseshoe vortex structures in turbulent flow past a blunt-body and plate junction

Results of numerical simulation of turbulent heat and mass transfer in the 3D problem of flow past a blunt-body and plate junction are presented. Comparison with the known experimental data is given; solution grid sensitivity is discussed. Numerical solutions obtained for incompressible fluid flows with different Prandtl numbers, and for the compressible gas flow with the Mach number ranging from 0.01 to 0.5 are analyzed. The effect of compressibility on heat transfer intensification in the region occupied by horseshoe-shaped vortex structures is investigated.

Effect of general boundary and coupling conditions on the vibration and power flow characteristics of a coupled H-shaped three-plate structure

Coupled H-shaped three-plate structures are extensively used as support platforms for machinery structures in engineering applications. These structures are constructed with various types of real engineering boundaries and coupling mechanisms. This investigation presents a numerical analysis of the effect of finitely varying boundary and coupling conditions on the vibration and power flow characteristics of a coupled H-shaped three-plate system. Modified Fourier series approximation of out-of-plane and in-plane displacement along with the Rayleigh–Ritz energy minimising procedure has been utilised for theoretical analysis, and different cases of variation of boundary and coupling spring stiffnesses have been taken to numerically analyse its effect on the vibration and power flow characteristics of the plate system. The numerical results indicate the presence of three different zones of finite coupling stiffness combinations at the coupled junction wherein the natural frequency and mode shapes undergo a major alteration. The decay or amplification of power flow characteristics across the plate junctions has been found to be highly dependent on the coupling stiffness values at the junctions. The consideration of general boundaries and coupling conditions in coupled plate systems is an essential design necessity for accurate prediction of the dynamic behaviour of coupled plate structures as their finite variations greatly influence the vibration and power flow characteristics of the coupled system.

Estimation of coupling loss factors for rectangular plates with different materials and junctions

In statistical energy analysis, coupling loss factor is the essential parameter for vibro-acoustic analysis of complicated structures. The coupling loss factors have been estimated using energy-level difference method. The tightening torque applied at structural junction has been varied. Higher values of coupling loss factor have been observed for higher tightening torque on bolted junction. The coupling loss factors have been determined for various structural junctions of rectangular composite plates. The riveted and bolted junctions have been examined for composite plates in same plane and size. The coupling loss factors for bolted junction are relatively higher than that for riveted junction of composite plates. The values of coupling loss factors are found to increase with increasing tightening torque applied at structural junctions of composite plates. It is also noted that the experimental results of coupling loss factors for point junctions vary with changes in fiber orientations of composite plates. It is firmly believed that the various findings of the coupling loss factors in this article help for vibro-acoustic analysis of complicated structures.

Seismic hazard at a triple plate junction: the state of Chiapas (México)

The state of Chiapas (SE Mexico) conforms a territory of complex tectonics and high seismic activity. The interaction among the Cocos, North American and Caribbean tectonic plates, as well as the active crustal deformation inside Chiapas, determines a variety of seismogenic sources of distinct characteristics and particular strong ground motion attenuation. This situation makes the assessment of seismic hazard in the region a challenging task. In this work, we follow the methodology of probabilistic seismic hazard analysis, starting from the compilation of an earthquake catalogue, and the definition of seismogenic source-zones based on the particular seismotectonics of the region: plate-subduction-related sources (interface and intraslab zones), active crustal deformation zones and the shear zone between the North American and Caribbean plates formed by the Motagua, Polochic and Ixcan faults. The latter source is modelled in two different configurations: one single source-zone and three distinct ones. We select three ground motion prediction equations (GMPEs) recommended for South and Central America, plus two Mexican ones. We combine the GMPEs with the source-zone models in a logic tree scheme and produce hazard maps in terms of peak ground acceleration and spectral acceleration for the 500-, 1000- and 2500-year return periods, as well as uniform hazard spectra for the towns of Tuxtla Gutierrez, Tapachula and San Cristobal. We obtain higher values in comparison with previous seismic hazard studies and particularly much higher than the output of the Prodisis v.2.3 software for seismic design in Mexico. Our results are consistent with those of neighbouring Guatemala obtained in a recent study for Central America.

Simulation of Hypersonic-Shock-Wave–Laminar-Boundary-Layer Interaction over Blunt Fin

Shock-wave–boundary-layer interaction is one of the most important phenomena in hypersonic flights due to its ubiquitous presence and its extreme effects on the aerothermodynamic loads on the aircraft surfaces. Low-frequency oscillations in separated flows in addition to high localized pressure and heat transfer as a result of such interactions make the ability to predict the flow with shock-wave–boundary-layer interaction highly essential in design of any hypersonic aircraft. To further investigate three-dimensional shock-wave–hypersonic-boundary-layer interaction, a cylindrically blunt fin–plate junction with three different sweep angles, 0, 22.5, and 45 deg, of the fin relative to the plate is chosen to numerically simulate. An MPI code written by the authors was used to solve the unsteady Navier–Stokes and ideal gas equations. The blunt fin shock wave with strength depending on the sweep angle of the fin interacts with the boundary layer on the plate and creates a separated region with a complex flow structure. The extent of the separated region decreases with increase in the sweep angle of the fin and decrease in the strength of the blunt fin shock wave. Localized high pressure forms at the reattachment point of the boundary layer by formation of a reattachment shock wave, with its maximum peak decreasing by increase in the sweep angle of the fin. The boundary-layer thickness on the blunt fin reaches its minimum at the reattachment point, where the heat transfer rate reaches its maximum value. Unsteady oscillations are observed in the 0 deg sweep angle configuration. The unsteady oscillations significantly subside with increase in the sweep angle of the fin. Time-averaged normalized heat transfer of the numerical simulations shows good agreement with the experimental data, except for the peak heat transfer for the 0 deg sweep angle case.

Study on bidirectional fluid-solid coupling characteristics of reactor coolant pump under steady-state condition

The AP1000 reactor coolant pump is a vertical shielded-mixed flow pump, is the most important coolant power supply and energy exchange equipment in nuclear reactor primary circuit system, whose steady-state and transient performance affect the safety of the whole nuclear island. Moreover, safety demonstration of reactor coolant pump is the most important step to judge whether it can be practiced, among which software simulation is the first step of theoretical verification. This paper mainly introduces the fluid-solid coupling simulation method applied to reactor coolant pump, studying the feasibility of simulation results based on workbench fluid-solid coupling technology. The study found that: for the unsteady calculations of the pure liquid media, the average head of the reactor coolant pump with bidirectional fluid-solid coupling decreases to a certain extent. And the coupling result is closer to the real experimental value. The large stress and deformation of rotor under different flow conditions are mainly distributed on impeller and idler, and the stress concentration mainly occurs at the junction of front cover plate and blade outlet. Among the factors that affect the dynamic stress change of rotor, the pressure load takes a dominant position.

Eigenvalue asymptotics of long Kirchhoff plates with clamped edges

Asymptotic expansions are constructed for the eigenvalues and eigenfunctions of the Dirichlet problem for the biharmonic operator in thin domains (Kirchhoff plates with clamped edges). For a rectangular plate the leading terms are asymptotically determined from the Dirichlet problem for a second-order ordinary differential equation, while for a -junction of plates they are determined from another limiting problem in an infinite waveguide formed by three half-strips in the shape of a letter and describing a boundary-layer phenomenon. Open questions are stated for which the method developed gives no answer. Bibliography: 33 titles.

Treatment of hypospadias in children with urethral plate combined with one crescent flap

Objective To investigate the clinical effect of urethral plate combined with unilateral crescent flap in the treatment of hypospadias in children. Methods The clinical data of 14 cases of hypospadias treated from March 2017 to March 2018 were retrospectively analyzed, with average age of (3.3±2.1) years.The external urethral orifice was located in the middle and distal part of the ventral side of the penis, with mild and moderate bends of the penis.The prepuce was piling up on the penile dorsal side, the ventral skin was deficient, and there was no concomitant disease such as penis scrotum transposition or cryptorchidism.All children were primarily treated with urethroplasty with urethral plate and one crescent flap.One side of the free urethral plate had a crescent superficial fascia, which was used as the new urethral material together with the urethral plate. By design, the urethra sutured deviating from the midline.The external urethral orifice was formed by trimming the anterior opening of urethra in the form of shallow V shape, and the new urethra was covered with the dorsal fleshy vascular pedicle. The pterygoid flap of the penis was sutured to form the penile head, and the foreskin was cut to cover the body of the penis.The specimens were taken for HE staining. Results The operation was successfully completed in 14 children.The length of the penis was measured before it is stretched out.The penile length was(3.5±0.5)cm, the penile diameter was(1.2±0.3) cm at the coronal sulcus, and the diameter of the tortoise head was(1.5±0.3)cm at the pterygoid.The width of urethral plate was(0.6±0.1)cm.Remeasurement was performed after complete correction of penile bending deformity.The length of the penis was(3.5±0.5)cm, and the urethral defect was(1.7±0.7)cm.According to Barcat method, there were 2 cases of coronal sulcus type, 7 cases of anterior penile type and 5 cases of middle penile type. The results of HE staining showed that the number of blood vessels in the dorsal prepuce and fascia was(8.5±2.1), dorsal foreskin plate was (5.1±1.6), ventral prepuce internal plates was(7.6±1.8), and ventral outer prepuce plates was(4.8±1.6). The number of superficial fascia vessels and deep fascia vessels were(10.3±1.4)and (4.2±1.7). The analysis of variance showed that there was significant difference in the mean number among groups(P=0.036), which was compared with each other by SNK-q test.The number of fasciae in dorsal prepuce was the most abundant, there was significant difference between dorsal and outer prepuce(P=0.033), and there was also significant difference with ventral prepuce(P=0.047). But there was no significant difference between the two groups(P=0.326). There was no significant difference in the number of blood vessels between the dorsal and ventral prepuce(P=0.682). The number of superficial fascia vessels near the skin was significantly more than that of deep fascia(P=0.037). On the transverse plane, there are more branches of the superficial fascia to the urethral plate at the junction of the ventral external plate and the urethral plate.All 14 cases were followed up for 3 to 9 months with an average of(5.4±2.1)months.The penis was straight and satisfactory, urethral orifice was not cracked, urination was laborious and not forked, and there was no fistula.One patient with middle penile type developed postoperative infection and was controlled after anti-infective treatment.One patient with anterior penile type had slight urination after operation, but had no difficulty in urination. F6 metal urethral dilator was used to dilate for 2 months, and the urination was normal. Conclusion Urethral plate combined with crescent flap urethroplasty for hypospadias has a satisfactory appearance and fewer complications.It provides an optional operative method for the children who need no transection of urethra plate to straighten the penis, especially for the poor development of the penis and the insufficiency of the new urethral materials.The superficial fascia tissue on both sides of the urethral plate is an ideal material for the new urethra because of its abundant blood supply adjacent to the urethral plate and direct vascular connection. Key words: Urethral plate; Flap; Crescent; Hypospadias

A Trench LDMOS Improved by Quasi Vertical Super Junction and Resistive Field Plate

An improved trench lateral double-diffused MOSFET (T-LDMOS) is proposed. It has a quasi vertical super junction (QVSJ) drift region and adopts a resistive field plate (RFP) to help QVSJ satisfy charge-balance. The realization of RFP barely complicates the device fabrication, but it motivates QVSJ to significantly improve the relationship between breakdown voltage (BV) and specific on-state resistance ( ${R} _{\mathrm{ON,SP}}$ ). The simulation results show that compared with the conventional QVSJ T-LDMOS, the proposed one gains the ${R} _{\mathrm{ON,SP}}$ reduced by about 79% under the same BV requirement of about 500 V. It therefore presents an excellent figure of merit (FOM) (FOM = BV2/ ${R} _{\mathrm{ON,SP}}$ , Baliga’s FOM) up to 29.8 MW/cm2, which is superior to the prior art and exhibits a bright prospect of saving energy.

Analysis of Anti-Collapse Performance of Beam–Column Substructure with Welded Flange-Bolted Web Connection in Minor-Axis Direction Under Different Span Ratios

The failure modes, mechanical properties, and resistance mechanisms of beam–column substructures with welded flange-bolted web connection in the minor-axis direction under different span ratios (1:0.6, 1:1.0, 1:1.4) were compared and analyzed under the condition of progressive collapse. The beam–column substructures included three columns and two beams, and monotonic static loading tests were conducted using the alternate load path method. The test results indicated that the specimens began to fracture at the beam tension flange; and then, part of the main internal force was transferred by the bolts on the web, followed by buckling of the compression flange at the beam end. Finally, specimens were deactivated by the shear failure of bolt holes or the fracturing of the web and junction plate. The joint with a welded flange-bolted web connection was found to have high redundancy, with sufficient rotational capacity after the fracture of the tension flange. As a result of the effective pulling force between the beam and column, combined with sufficient rotation of the beam end, the remaining structure could give full play to the catenary effect, which would play a leading role in the later stage of large deformation. The deformation of the beam–column joint increased rapidly, which was conducive to the beam–column substructure to bear the load by collaboration between the beam and column. The simplified model and the numerical simulation are proved to be reliable by test results. The results of numerical simulations and analyses of anti-collapse performances of beam–column substructures under different span ratios showed that the large beam-span ratio was beneficial to the development of ultimate failure displacement of the substructure and increase the ratio of ultimate to initial failure load. The resistance provided by catenary mechanism also increased, and the short beam developed a better catenary effect than the long one.

Energy-absorption characteristics of a bionic honeycomb tubular nested structure inspired by bamboo under axial crushing

Geometric configurations in nature could be mimicked in order to develop novel materials and structures with desirable properties. Lots of bio-inspired configurations had been introduced to tubal structures in promoting the energy-absorption performance of thin-walled structures. Nevertheless, these existing studies largely focused on hierarchical hexagonal honeycombs, and the bio-inspired hierarchical circular thin-walled structures under the out-of-plane crushing loads had not been well studied experimentally, numerically and analytically for energy absorption to date. In this study, the bionic honeycomb tubular nested structure (BHTNS) was first inspired by the micro-architecture of bamboo vascular bundles, which could be mimicked by connecting a central circular tube to other six circular tubes in a hexagonal arrangement, regardless of size or choice of materials. The energy-absorption characteristics of BHTNS under axial crushing were systematically studied by drop-weight experiment, numerical simulation, and theoretical analysis. Dynamic drop-weight impact experiments were conducted and the results showed that the specific energy absorption (SEA) of BHTNS was as high as 29.3 J/g. Furthermore, the parametric numerical simulation revealed the influence of diverse mean diameter D of the circular tube and length L of the junction plate on the energy-absorption characteristics. Finally, a theoretical model was also developed to predict the mean crush force Pm, which was in good agreement with the numerical simulation. This work could provide a reference for an energy-absorber design with high efficiency.

Effect of the hydrothermal activity in the Lower Yangtze region on marine shale gas enrichment: A case study of Lower Cambrian and Upper Ordovician-Lower Silurian shales in Jiangye-1 well

Abstract Finding favorable sites for the exploration of shale gas, is still one of the important areas of research that needs immediate attention. The content of organic matter in shale plays a crucial role in the hydrocarbon generation potential, reservoir space and gas-bearing capacity of shales. Therefore, studying the sedimentary environment of organic shale can provide a scientific basis for locating favorable exploration areas for shale gas. The article takes the Lower Cambrian and the Upper Ordovician-Lower Silurian shales in the Yangtze region as the research object and selects representative wells to quantitatively calculate the existence of excess silicon in shale siliceous minerals and the content of excess silicon. Then, the origin of excess silicon can be clarified by the Al, Fe and Mn elemental analysis. Finally, the sedimentary organic matter enrichment mechanism is analyzed from water oxidation-reduction environments and biological productivity. The results of the study show that the excess silicon in the Lower Cambrian and Upper Ordovician-Lower Silurian shales in the Lower Yangtze region is of hydrothermal origin. The hydrothermal activity improves biological fertility on the one hand; whereas on the other hand, it can enhance the reducing capacity of the bottom water conducive for the preservation of organic matter thereby enriching the sedimentary organic matter. The place near the junction of Yangtze plate and Cathaysian plate, where hydrothermal activities were more intense, provided favorable loci for shale gas exploration in the Lower Yangtze region. It was observed that, since the hydrothermal activity was stronger in the Early Cambrian than in the Late Ordovician-Early Silurian times, the total organic carbon (TOC) content of the Lower Cambrian shale was higher than that of the Upper Ordovician-Lower Silurian shales.