Displacement Of Units Research Articles

A Model of Wafer Warpage for Trench Field‐Plate Power MOSFETs

A new wafer warpage model is proposed for the full process design of trench field‐plate (FP) power metal‐oxide‐semiconductor fileld‐effect transitors (MOSFETs) using large‐sized wafer. Trench FP power MOSFETs feature a deep trench and thick oxide at the wafer surface. Wafer warpage occurs due to the stress imbalance between the front and back sides of the wafer. This warpage leads to significant problems with transport errors in manufacturing equipment. This issue is expected to become even more crucial as lateral pitch narrowing is employed to reduce on‐resistance. In this study, two methods are compared to estimate the warpage of a 200 mm diameter Si‐wafer after trench etching and oxidation process. The mechanical stress generated by the oxidation process in several cell units is calculated using a 3D simulation. In the first approach, wafer warpage is converted from the displacement of the cell units. In the second approach, wafer warpage is estimated based on the surface film stress, which is calculated in the 3D simulation. The second approach shows good agreement with experimental results and is applicable to the 300 mm diameter Si process. This method yields more accurate measurements than the method using displacement.

РАСЧЕТ НДС РАМНЫХ УЗЛОВ СТРОИТЕЛЬНЫХ МЕТАЛЛОКОНСТРУКЦИИ ПРИ ИХ УСИЛЕНИИ

Experience in the operation of reinforced metal structures of industrial buildings has shown that under increased influence of static loads, units of frame elements rarely fail, which cannot be noted in the case of prolonged application of dynamic loads. As a rule, welded joints of fastenings of reinforcement elements are subject to destruction, which is the reason for conducting this study. During the work, the influence of residual welding stresses on the durability of reinforced frame assemblies under the influence of dynamic loads was revealed. The numerical modeling method was used using the Ansys SpaceClaim software package. The vibration strength of seams is determined by the height of the leg of welded joints associated with the transition of the material to the stage of deformation and displacement of structural units subjected to cyclic loading. It should be noted that fatigue failure is divided into two categories: high-cycle fatigue and low-cycle fatigue. High-cycle fatigue, when the number of cycles of load application is large (around 1e4 - 1e9). With this formulation, the stress level is usually lower in comparison with the ultimate strength of the material. Durability assessment, depending on the stress level, is usually used to calculate high-cycle fatigue. Low-cycle fatigue, when the number of cycles of the applied load is relatively small. Plastic deformation is often associated with low cycle fatigue calculations and results in reduced fatigue life. Assessment of durability depending on the level of deformation is more applicable to the calculation of low-cycle fatigue.

Garnet microstructures suggest ultra-fast decompression of ultrahigh-pressure rocks

Plate tectonics is a key driver of many natural phenomena occurring on Earth, such as mountain building, climate evolution and natural disasters. How plate tectonics has evolved through time is still one of the fundamental questions in Earth sciences. Natural microstructures observed in exhumed ultrahigh-pressure rocks formed during continental collision provide crucial insights into tectonic processes in the Earth’s interior. Here, we show that radial cracks around SiO2 inclusions in ultrahigh-pressure garnets are caused by ultrafast decompression. Decompression rates of at least 8 GPa/Myr are inferred independently of current petrochronological estimates by using thermo-mechanical numerical modeling. Our results question the traditional interpretation of fast and significant vertical displacement of ultrahigh-pressure tectonic units during exhumation. Instead, we propose that such substantial decompression rates are related to abrupt changes in the stress state of the lithosphere independently of the spatial displacement.

Production parameters of novel geopolymer masonry mortar in heritage buildings: Application in masonry building elements

The aim of this study is to develop an innovative high-strength restoration mortar using recycled materials as an alternative to the mortars used in historical buildings. Compressive strength tests were carried out on the samples and, according to the results, the mortar giving the highest strength was determined as the optimum mixture. The compressive strength, shear strength, displacement and load-carrying capacity values of the masonry units were tested by using the geopolymer mortar with the highest strength among the mortar samples produced. The novelty of this research is that geopolymer repair mortars were produced as an alternative to standard mortars and applied in masonry building units. The results showed that blast furnace slag and brick powder can effectively improve the compressive and bond strength of the geopolymer. In the compressive strength tests performed on the samples, much higher strength results were obtained with geopolymer historical building mortar than standard historical building mortar. In the compressive and shear strength performed on the masonry units, the geopolymer historical building mortar showed higher mechanical properties compared to the standard historical building mortars. When the compressive strength test results are compared, a strength of 1.8 times was observed in the masonry unit (GHB1) produced using geopolymer historical building mortar, compared to the masonry unit (HB1) produced with standard historical building mortar. As a result of the shear strength test, the masonry unit (GHK1) produced with geopolymer mortar demonstrated seven times more load carrying capacity than the masonry unit (HK1) elements produced with standard historical building mortar. Moreover, the masonry arch systems produced with standard historical building mortar showed close load bearing capacity with the geopolymer historical building mortar, but the masonry arch element produced with geopolymer mortar exhibited a more ductile behavior. It has been determined that the use of geopolymer mortars with recycled materials with increasing molarity in masonry arch elements improves the compressive strength and accelerates the geopolymerization mechanism. Innovative high-strength geopolymer mortars used in masonry walls provided good adhesion with the hollow brick, creating a compact structure.

Integrated digitalization at road transport enterprises: prospects for implementation

Modern opportunities for the introduction of digital technologies for enterprises of all industries in the Russian Federation are constrained by the fact that most software products are designed for certain areas of functional work blocks: corporate document management systems, accounting, finance and credit, personnel records management. With the displacement of management units by digital collection points, analysis, evaluation and solving problems of route optimization, cost of services, calculation of the level of logistics services, followed by the search for the most effective alternatives, the management structure is not just rationalized, it undergoes transformation, both regulations and the complete elimination of the structural management units themselves. In the future, only the chief specialist can remain from specialized management services with widespread digital support of management functions. Therefore, the most important condition for digital transformation at ATP enterprises should be integrated control systems based on automation, robotization and digitalization of most processes, the execution of which can be delegated to the plane of computerized execution on the ground. Keywords: digitalization, ATP enterprise, management structure, delegation, strategy, goal tree, efficiency, effectiveness, ATP workforce, management norm, quality of services, material incentives, personnel management, scientific labor organization, service produc

Analysis of the possibility of using additive technologies in basic parts manufacturing

The purpose of the article is to choose a selective laser sintering method suitable for basic parts manufacturing, as well as to analyze mechanical characteristics of parts obtained using selective laser sintering, depending on the technology of their production. Basic parts manufacturing is a complex and expensive process which includes casting or welding, milling of base surfaces, and boring of holes. As a rule, body is the largest part of the structure, and accuracy of its base surfaces manufacturing directly affects performance of the entire mechanism. Method of producing blank parts is of paramount importance in body manufacturing. Parts of this type must ensure precision of the relative position of individual elements, both at rest and in the dynamic mode of machine operation. At the same time, it is known that all methods of blank parts production are characterized by the presence of residual stresses in the blank part. Gradually relaxing, these stresses “come out” in the form of deformations, which leads to displacement of parts and units of the entire mechanism, and a change in their interaction. This directly affects performance and resource of the entire machine.

Simulation of Nondilute Dendrimer Systems with the Bond Fluctuation Model.

Using the bond fluctuation model, we performed Monte Carlo simulations for solutions of generation 4 and 5 dendrimers with only an intermediate unit between the branching points at different concentrations, ranging from moderately dilute solutions to concentrated systems close to the melt behavior. This model may represent different real types of dendrimer families. We obtained the mean sizes, asphericities, displacement of units, scattering functions, radial distribution functions and structure factors. We compared the results obtained for the last two properties with much faster Monte Carlo simulations of point-like dendrimers using global potentials obtained through the study of binary interactions. The latter procedure provided good reproductions of these properties but failed in the reproduction of the scattering functions in the range of higher concentrations. In this range, the scattering function cannot be described as the product of the structure function and the form factor, because the intensity decreases when the density of the dendrimer units becomes more homogenous.

Evidence of Active Quaternary Deformation on the Great Valley Fault System near Winters, Northern California

Abstract The Great Valley fault system defines the tectonic boundary between the Coast Ranges and the Central Valley in California, is active throughout the Quaternary, and has been the source of several significant (M > 6) historic earthquakes, including the 1983 M 6.5 Coalinga earthquake and the 1892 Vacaville–Winters earthquake sequence. However, the locations and geometries of individual faults in the Great Valley fault system are poorly constrained, and fault slip rates and paleoearthquake chronology are largely unknown. Here, we report geomorphic and subsurface geophysical evidence of surface-deforming displacement on a strand of the Great Valley fault system west of Winters, California. Detailed geomorphic mapping and a high-resolution seismic reflection and tomography survey along an ∼800 m profile across the Bigelow Hills document a fault, which we call the West Winters strand of the Great Valley fault system, with apparent east side-up displacement of surficial geologic units. These data together suggest that the West Winters strand is active in the latest Quaternary. Together with local reports from the time, this raises the possibility that the West Winters strand may have ruptured and deformed the surface during the 1892 M 6 Vacaville–Winters earthquake sequence. Future earthquakes with vertical displacement on this and Great Valley fault system structures could have significant hazard implications, given the region’s low relief and the presence of major water conveyance infrastructure.

Improvement of the Distribution Systems Resilience via Operational Resources and Demand Response

This article presents a restoration approach for improving the resilience of electric distribution systems (EDSs) by taking advantage of several operational resources. In the proposed approach, the restoration process combines dynamic network reconfiguration, islanding operation of dispatchable distributed generation units, and the prepositioning and displacement of mobile emergency generation (MEG) units. The benefit of exploring a demand response (DR) program to improve the recoverability of the system is also taken into account. The proposed approach aims to separate the in-service and out-of-service parts of the system while maintaining the radiality of the grid. To assist the distribution system planner, the problem is formulated as a stochastic-scenario-based mixed-integer linear programming model, where uncertainties associated with PV-based generation and demand are captured. The objective function of the problem minimizes the amount of energy load shedding after a fault event as well as PV-based generating curtailment. To validate the proposed approach, adapted 33-bus and 83-bus EDSs are analyzed under different test conditions. Numerical results demonstrate the benefits of coordinating the dynamic network reconfiguration, the prepositioning and displacement of MEG units, and a DR program to improve the restoration process.

Single and multi-vertices solitons in lattices of active Morse - van der Pol units

The dynamical evolution of one-dimensional lattice of active units (otherwise said particles) endowed with anharmonic Morse interactions and active–dissipative van der Pol negative friction is here studied both analytically and numerically. One of the directions of this evolution is the formation and stable propagation of dissipative soliton-like perturbations (in short solitons) against the background of some stationary displacement of units (pedestal). It is shown that the evolution of units at leading-front of the soliton is determined by mutual repulsive forces, while that of units at trailing-tail of the soliton is determined by the active–dissipative forces. Approximate analytically solvable models of the leading-front and the trailing-tail are obtained, which make it possible to predict soliton parameters and admissible range of pedestal values with high accuracy. There is also a scenario of N-vertices soliton formation emerging from a single soliton and (N-1)-vertices soliton. The possibility of controlling the number of vertices of multi-vertices solitons is offered, a feature which can be used in the problems of energy accumulation and transport in periodic structures.

3D quantification of in vivo orthodontic tooth movement in rats by means of micro-computed tomography.

(1) To test the accuracy of split-mouth models in rats for the study of orthodontic tooth movement (OTM) and (2) to propose an improved 3D model for quantification of OTM in rats. Eleven Wistar rats were split into group 1 (dental anchorage) and group 2 (skeletal anchorage). In both groups, no orthodontic force (OF) was applied on the contralateral hemi-maxilla. In vivo micro-CT images were taken before (T0) and 31days (T1) after OF. OTM was compared between time-points and experimental sides using conventional 2D analysis and a novel 3D model. Using incisors as anchorage leads to their distal displacement in both OF and no OF sides. In the OF side, movement of M1 is underestimated by incisor displacement. Mesial displacement of M1 was found in the no OF side of all groups 31days after the application of OF. The new 3D model yielded higher sensitivity for tooth displacement in planes other than sagittal and incisor displacement was reduced by using skeletal anchorage. Studies following split-mouth designs in orthodontic research in rats might be systematically underestimating the effects of techniques and/or medication on OTM, since there is tooth displacement on the control side. 3D quantification of OTM with skeletal anchorage is more sensitive and avoids displacement of the dental units used as anchorage.

Advanced Design and Optimal Sizing of Hydrostatic Transmission Systems

This paper presents a novel method for designing and sizing high-efficient hydrostatic transmissions (HTs) for heavy duty propulsion applications such as agricultural and construction machinery. The proposed method consists in providing cost effective HT architectures that maximizes efficiency at the most frequent operating conditions of the transmission, as opposed to the traditional HT design methods based on the most demanding requirements of the system. The sizing method is based on a genetic optimization algorithm for calculating the optimal displacement of the main units of the HT to maximizes the efficiency in the most frequent operating conditions of the vehicle. A simulation model for HTs is built in MATLAB/Simulink® environment to test three different circuit alternatives for basic HTs. Considering a particular 250 kW heavy-duty application for which drive cycle data were available, this study shows great improvement in energy efficiency (14%) and power saving (20.1%) at frequent operating conditions while still achieving the corner power condition.

Stability of caisson-type breakwater subjected to strong hydrodynamic impacts using discontinuous deformation analysis method

A numerical study using the Discontinuous Deformation Analysis (DDA) method is proposed to analyze the effect of the caisson sliding subjected to a hydrodynamic loading in the stability of the rear side of the caisson-type breakwater. The study takes into account the slope inclination of the breakwater as well as the contact between the armour units constituting the shoreward of the breakwater, where the contact stresses are imposed through a penalty method. A dimensionless displacement parameter, [Formula: see text], is defined to investigate the instability of armor units. The results of the simulation show that the shape of the armour units plays an important role in the stability of the breakwater, where the tetrapods and the acropods give better stability than the cubic shapes, with a clear superiority of the tetrapods. They also show that the reduction in the slope clearly contributes to the stability of caisson up to a slope of 1: 2, but below this ratio of 1: 2 this stability is no longer obvious. Furthermore, a new relation of the displacement of the armour units according to the slope is established.

3‐D Structure of the Variscan Thrust Front in Northern France: New Insights From Seismic Reflection Profiles

AbstractIn NW Europe, the late Carboniferous Variscan collision between the Laurussia and the Armorica‐Gondwana continental blocks led to the development of a crustal‐scale north‐verging thrust system along the southern Laurussian margin. In northern France, the 3‐D geometry and kinematics of the Variscan deformation front have been investigated on the basis of reprocessing and interpreting 532 km of industry‐level seismic reflection profiles. This extensive seismic imaging provides new constraints on the structural and kinematic features of the orogenic front. It particularly emphasizes the localization of displacement along the main frontal thrust zone that accommodated more than 50 km of total displacement of the allochthonous units above the foreland. It also highlights the induced large underthrusting of the foreland basin below the frontal thrust zone, and its truncation in a general out‐of‐sequence mode of thrust propagation. We built structural maps that led to better delineating a major NW‐SE lateral ramp along the main frontal thrust. The Mid‐Upper Devonian series within the flexured foreland were deformed at depth by N060–080° trending and N110–130° trending syn‐sedimentary normal faults that led to their south‐to southwestward thickening. These pre‐existing structures along the margin have exerted a primary control on the ensuing dynamics and geometry of the Northern Variscan Front by localizing both the frontal and lateral ramps during thrust wedge growth.

Conformational Changes of Uniformly Charged Polyelectrolyte Chains on the Surface of a Polarized Gold Nanoparticle: Molecular Dynamics Simulation and the Theory of a Gaussian Chain in a Field

The conformational changes of uniformly charged polypeptides adsorbed on the surface of a polarized gold nanoparticle are studied by means of molecular dynamics. The dependences of the average angular distributions and the radial density of polyelectrolyte atoms on the nanoparticle’s surface are calculated. A gradual displacement of the polyelectrolyte units into the hemisphere with the opposite charge is observed on the surface of a polarized gold nanoparticle, along with pronounced rarefaction of the outer layer of the adsorbed chain relative to the inner one in this hemisphere of the nanoparticle. An analytical model is presented of the conformational changes in the polyelectrolyte, based on the equation for the dynamics of a Gaussian chain in the potential field of a polarized nanoparticle. A picture of the deformed edge of the polyelectrolyte and the radial angular dependences of its unit density on the surface of a polarized nanoparticle is constructed according to the analytical model.

Gondwana fragments in the Eastern Alps: A travel story from U/Pb zircon data

We compare detrital U/Pb zircon age spectra of Carboniferous and Permian / Lower Triassic sedimentary rocks from different structural positions within the Austroalpine nappe pile with published ages of magmatic and metamorphic events in the Eastern Alps and the West Carpathians. Similarities between sink and possible sources are used to derive provenance of sediments and distinct frequency peaks in sink and source age pattern are used for paleogeographic plate tectonic reconstructions. From this, travel paths of Austroalpine and West Carpathian basement units are traced from the Late Neoproterozoic to the Jurassic. We place the ancestry of basement units on the northeastern Gondwana margin, next to Anatolia and the Iranian Luth-Tabas blocks. Late Cambrian rifting by retreat of the Cadomian Arc failed and continental slivers re-attached to Gondwana during a late Cambrian / early Ordovician orogenic event. In the Upper Ordovician crustal fragments of the Galatian superterrane rifted off Gondwana through retreat of the Rheic subduction. An Eo-Variscan orogenic event at ~390 Ma in the Austroalpine developed on the northern rim of Galatia, simultaneously with a passive margin evolution to the south of it. The climax of Variscan orogeny occurred already during a Meso-Variscan phase at ~350 Ma by double-sided subduction beneath Galatia fragments. The Neo-Variscan event at ~330 Ma was mild in eastern Austroalpine units. This orogenic phase was hot enough to deliver detrital white mica into adjacent basins but too cold to create significant volumes of magmatic or metamorphic zircon. Finally, the different zircon age spectra in today's adjacent Carboniferous to Lower Triassic sediments disprove original neighbourhood of basins. We propose lateral displacement of major Austroalpine and West-Carpathian units along transform faults transecting Apulia. The intracontinental transform system was released by opening of the Penninic Ocean and simultaneous closure of the Meliata Hallstatt Ocean as part of the Tethys.

Heat capacity, thermal expansion and sensitivity to hydrostatic pressure of [formula omitted] at successive structural phase transitions

Heat capacity, thermal dilatation, permittivity and sensitivity to external pressure of (NH4)3SiF7 were studied. Due to the absence of cubic phases Pm3¯m and Pa3¯, a strong decrease in the total entropy change ∑ΔSi=19 J/mol K associated with four successive transformations P4/mbm↔Pbam↔P21/c11↔P1¯↔P121/c1 was found in silicate in comparison with other double fluoride salts (NH4)3MeF7 (Me: Ge, Ti, Sn) Using analysis of the excess heat capacity in the framework of the thermodynamic theory, the entropies associated with each individual phase transition were determined. In accordance with the entropic parameters, the complete ordering of the structural elements occurs in the monoclinic phase P21/c11. Further change in symmetry is associated with small entropy changes which prove insignificant displacement of structural units. A T−p phase diagram was constructed and good agreement was found between measured and calculated baric coefficients.

Vertical-displacement history of an active Basin and Range fault based on integration of geomorphologic, stratigraphic, and structural data

Knowledge of the last reactivation age of faults in the western Basin and Range province (western North America) is key to understanding the recent evolution of the province in the context of the Pacific-North America plate boundary region. The Dixie Valley fault system (DVFS;Nevada, USA) is an important active normal fault in this region, but its slip history is not well known. Our goal is to determine the age of faulting initiation and the history of vertical displacement at the million-year time scale. We used well data from the Dixie Valley geothermal field and geologic maps to calculate offsets of geologic units. Tectonic events and their ages were determined from knickpoint analysis in the Stillwater Range. We then matched basin unconformities and knickpoints to obtain a vertical displacement history. The age of inception of the modern DVFS is likely between 13 and 7 Ma. The total vertical displacement of the geologic units is between 3 and 3.5 km, and most of it occurred in the last 2-3 Ma. Assuming an erosion rate between 0.03 and 0.07 m/ka, the maximum vertical displacement rate (similar to 1-2 mm/a) occurred between 3 and 0.5 Ma, and resulted in similar to 2 km of vertical displacement. Finally, the age-versus-distance profile of the Stillwater Range crest is tapered at both ends, as expected for a propagating range-bounding normal fault, but it also has two maxima matching the deepest parts of the Dixie Valley basin. This indicates that the present-day DVFS may have started out as two separate strands that connected within 2-3 Ma of inception. Our work shows that the combination of stratigraphic and structural data from the basin with geomorphological data from the adjacent mountain range is suitable for placing constraints on the displacement history at the million-year time scale of an active range-bounding normal fault. The resulting displacement-time paths for normal faults may not be as uniform as commonly assumed.

Frequency Dynamics Constrained Unit Commitment With Battery Energy Storage

The decline of system inertia due to the increasing displacement of synchronous units by renewable units has introduced a major challenge on the frequency dynamics management of a power system. This paper discusses how fast-response battery energy storages can be used to maintain the frequency dynamic security. Immediately following a generation loss, the injections of batteries are adjusted instantly to ensure minimum power imbalance in the system. This control strategy is included in a novel formulation of the frequency dynamics constrained unit commitment, in which the impact of wind uncertainty is dealt with using interval-based optimization. The reformulation-linearization technique is applied to reformulate the original nonlinear model as a mixed-integer linear programming problem. Case studies on a six-bus system and the modified RTS-79 system demonstrate that the proposed method guarantees frequency security while still preserving economy without curtailing wind generation.

Experience of an assessment of the vertical Francis hydroturbines vibration state at heads from 40 to 300 m

The article covers a choice of main vibration parameter at an assessment of a vibration state of vertical Francis hydroturbines. At present time vibration velocity and vibration displacement are adopted as main parameters of non-rotating parts vibration in the international standard ISO 10816-5:2000 «Mechanical vibration — Evaluation of machine vibration by measurements on non-rotating parts — Part 5: Machine sets in hydraulic power generating and pumping plants» (further ISO 10816-5:2000).The hydraulic turbines refer to the slow-speed machines with rotation speed from 60 to 600 rpm (∼ 1 - 10 Hz).So maximum vibration displacements and dynamic stresses in hydraulic turbines supporting parts are in low-frequency region of vibration spectrum.In this report comparative data of hydro units supporting parts vibration velocity and vibration displacement measurements are presented. Using these data assessment of hydro units vibration state has been done.It is shown that the assessment of a hydro unit vibration state using parameter "vibration displacement" corresponds to the fundamental principles of operational reliability and fatigue strength of hydro units supporting parts.It is noted that when hydro units operate at small and partial loads with high low-frequency unsteady flow (f < frot) we have the smallest vibration velocity and the greatest vibration displacement of hydro units supporting parts.Specialists of LMZ (Saint-Petersburg) have developed Russian standard RD 24.023.117-88 «Vibration measurement and evaluation vibration state of vertical hydraulic turbines» which was published in 1989. In this document vibration displacement was considered as a main parameter. Evaluation of turbine vibration was performed according to the effecrive value of turbine supporting parts vibration displacement.