Simple Ring Research Articles

Features of repair welding of power hydrocylinder elements

At present, the use of power hydraulic cylinders is an integral part of most industrial equipment. They provide translational and horizontal movements, replacement of goods, fixation, etc. These devices are necessary elements of the equipment where application of the corresponding level of effort is applied. Often hydraulic cylinders are created specialized to perform certain types of work. It should be noted that part of the elements of the power cylinder in the manufacture is combined with welding. Such integral connections provide rigidity of installation, tightness of a design, fatigue strength at multicycle loadings. Difficult operating conditions, significant workloads, the presence of various external factors often leads to the destruction of individual elements of the cylinder. At the same time, the cost of repairing equipment that involves replacement with new power devices is quite high. This causes the implementation of repair and restoration work carried out at specialized enterprises. However, in the case of repairs, there are often a number of problems that require prompt resolution in the production environment. These should include the provision of basic materials with similar physical and chemical properties, the establishment of welding modes, the selection of the necessary welding materials, the use of appropriate techniques for conducting the arc process, etc. Therefore the repaired welded design of the case of the power hydraulic cylinder needs additional studying for weldability of separate elements among themselves, formation of a zone of thermodeformation influence. In general, the repaired hydraulic cylinder should meet the installation operating requirements depending on the purpose. The design of the considered hydraulic cylinder of the press installation is rather technological from the point of view of maintenance of automation of welding process. It contains long welds of a simple ring configuration. At the same time, the significant linear dimensions and the presence of a cylindrical surface cause some complexity in the implementation of processes. The construction material of the power hydraulic cylinder is low-carbon low-alloy steels. The analysis of technological weldability indicates a tendency to crack due to the thermal cycle of welding. The simulation of welds of the power hydraulic cylinder is performed in the work. The number of rollers was taken into account when obtaining butt welds. A comparative analysis of different electrode materials with different doping systems is done. The most applicable welding materials by chemical composition and properties of the weld metal are determined. According to the literature data and the results of comparative analysis, the optimal range of cooling rate of the main material of the hydraulic cylinder was established. The properties and structure of the zone of thermal influence of the butt welds of the power hydraulic cylinder have been studied. The magnitude of deformations and stresses caused by the thermal cycle of welding of the shell structure of the hydraulic cylinder liner is investigated. The admissible parameters of the zone of plastic deformations during butt welding are determined.

Phosphorous Acid-Catalyzed Alkylation of Phenols with Alkenes.

A H3PO3-catalyzed alkylation of phenols with alkenes is achieved in a facile, efficient, and selective manner. The reaction shows a unique selectivity, i.e., excellent regioselectivity, thorough suppression of overalkylation, without alkylation of a simple phenyl ring, and can selectively provide ortho-, meta-, or para-alkylated phenol derivatives in good to excellent yields. This feature along with mild reaction conditions, sensitive functional group tolerance, and scale-up synthesis and late modification of phenolic bioactive compounds make it an ideal and practical alternative for the modification of phenols.

Fully on-chip clock jitter and skew measurement scheme via incoherent subsampling

An incoherent subsampling scheme for on-chip measurement of high-speed clock jitter and skew is presented. A simple inverter-based ring oscillator with frequency selection multiplexers is used to generate uniform and uncorrelated sampling events when binned in the unit period of the clock. The measurement results are directly reflected in the on-chip counters which are proportional to the injected jitter and skew. The measurement errors can be reduced with increasing sampling numbers. Theories of ring oscillator period suitability, sampling number requirement and jitter measurement are analyzed in detail. Behavioral simulations using MATLAB are performed to verify the proposed theories. The measurement circuit is implemented using a 55 ​nm CMOS process and the maximum measurement errors in skew mode and jitter mode from SPICE simulations are 0.121ps and 0.123 ​ps, respectively. The implemented measurement circuit has good immunity to PVT variations after proper tuning and the influence of supply noise is also investigated.

Performance Evaluation of Visual Noise Imposed Stochastic Resonance Effect on Brain-Computer Interface Application: A Comparison Between Motion-Reversing Simple Ring and Complex Checkerboard Patterns.

Adding noise to a weak input signal can enhance the response of a non-linear system, a phenomenon known as stochastic resonance (SR). SR has been demonstrated in a variety of diverse sensory systems including the visual system, where visual noise enhances human motion perception and detection performance. The SR effect has not been extensively studied in brain-computer interface (BCI) applications. This study compares the performance of BCIs based on SR-influenced steady-state motion visual evoked potentials. Stimulation paradigms were used between a periodically monochromatic motion-reversing simple ring and complex alternating checkerboard stimuli. To induce the SR effect, dynamic visual noise was masked on both the periodic simple and complex stimuli. Offline results showed that the recognition accuracy of different stimulation targets followed an inverted U-shaped function of noise level, which is a hallmark of SR. With the optimal visual noise level, the proposed visual noise masked checkerboard BCI paradigm achieved faster and more stable detection performance due to the noise-enhanced brain responses. This work demonstrates that the SR effect can be employed in BCI applications and can achieve considerable performance improvements.

Contribution of public squares to the reduction of urban flooding risk

Urbanization is directly linked to the process of impermeabilization of the soil in urban areas that contributes to the emergence of flood risks. The purpose of this study was to determine the hydrodynamic properties of the public squares in a flood-prone Brazilian city and determine to what extent they could contribute to the reduction of flooding. The Beerkan method was used to determine the hydrodynamic properties of the soil in nine squares located at critical flooding points in the city of Recife. This method uses simple ring infiltration and the collection of soil samples to obtain the soil granulometric distribution, thereby generating the soil water retention curve θ(h) and the hydraulic conductivity K(θ). The squares studied have similar hydrodynamic characteristics because of their similar soil texture classes, such as Loamy Sand and Sandy Loam. This made it possible for eight of the nine squares studied to be able to contribute positively to the reduction of flood risks by adapting them into micro infiltration basins that can receive the surface flows that overload the drainage network.

Correlations between multiplicities and transverse momenta in nucleus-nucleus collisions from model with cluster of fused color strings

The long-range rapidity correlations between the multiplicities (n-n) and the transverse momentum and the multiplicity (pT-n) of charged particles are analyzed in the framework of the simple string inspired model with two types of sources. The sources of the first type correspond to the initial strings formed in a hadronic collision. The sources of the second type imitate the appearance of the emitters of a new kind resulting from interaction (fusion) of the initial strings. The model enabled to describe effectively the influence of the string fusion effects on the strength both the n-n and the pT-n correlations. Modification of the model to the analogue of the “core-corona” mechanism allows to take into account event selection criteria based on centrality and perform a comparison with existing experimental data on correlation measurements in nucleus-nucleus collisions at LHC energies. It is shown that string fusion effects in the model with the core-corona mechanism lead to the change of a sign of the pT-n correlation coefficient with a decrease of a centrality interval width.

Simulative Study of Simple Ring Resonator Based Brewster Plate for Power System operation Stability

<span>This study has outlined the simulative study of simple ring resonator based Brewster plate in the air. The obtained results are achieved with the variations of space length, curvature radius and phase angle of the </span><span>spherical mirror</span><span>. Beam radius criterion and stability parameters are measured with the variations of </span><span>refractive index</span><span> and thickness of Brewster plate in the air. The negative and positive effects of increasing operating parameters are observed on the performance of ring resonator system efficiency. </span>

On Minimisation of Earthing System Touch Voltages

Finding cost efficient earthing system design with acceptable level of safety might be quite tedious work. Thus, many earthing system engineers try to find the most suitable design either by employing only their best experience or taking advantage of some more complex optimisation programs. Although both approaches might work well under certain circumstances, they might fail either due to counter-intuitiveness of the specific situation or by misunderstanding of the applied optimisation method, its limitations etc. Thus, in this paper, the earthing system design optimisation problem was addressed by analysing optimisation simulation results together with conducted sensitivity analysis. In the paper, a simple double ring earthing system was optimised while using five different optimisation methods. The earthing system was placed in different horizontally stratified soil models and the earthing system was optimised by minimising touch voltages instead of commonly minimised earth potential rise. The earthing system was modelled by Ansys Maxwell software. Apart from using Ansys Maxwell built-in optimisers, the possible solution space has also been mapped by performing sensitivity analysis with changing the earthing system design dimensions and the results of optimisation were compared and validated. It was found out that the Sequential Non-Linear Programming Optimisation technique was quite superior to the other techniques. Additionally, in most cases, the Ansys Maxwell optimiser was able to found optimal solution; however, in some cases, based on the initial conditions, it might get stuck in local minima or the results might be influenced by the solution noise. Additionally, some quite non intuitive dependencies of earthing system electrodes positions had been found when different spatial dimensions constraints are used.

Pulse train stability in passively Mode-locked Erbium-doped fiber laser with a nonlinear polarization rotation

<span>A nonlinear polarization rotation technique-based mode-locked erbium-doped fiber laser has been experimentally demonstrated using a 0.75 m long highly concentrated erbium-doped fiber as the gain medium. With unintentional polarization dependent loss induced by twisting single-mode fiber in an intracavity polarization controller, the optical output of the laser shifts from continuous wavelength to modelocked soliton pulse. A stable and cleaner pulse with a repetition rate of 15.32 MHz laser wavelengths and a pulse energy of 0.496 nJ with optical signal-to noise ratio of more than 33 dB are successfully obtained using a simple ring cavity.</span>

Quantum fine-tuning in stringy quintessence models

We investigate the extent to which quintessence models for dark energy are fine-tuned in the context of recent swampland conjectures. In particular, the issue is whether there is a double fine-tuning in which both V and |∇V| are fine-tuned, or whether there is only a single fine-tuning due to the relation |∇V|∼V/MPl arising naturally. We find that indeed this relation arises naturally in simple string compactifications for some scalars, such as the dilaton and volume modulus, when treated classically. However, we find that quantum effects can spoil this natural relation, unless the scalar is conformally coupled to the matter sector. Furthermore, it is well known that such conformal couplings are generically ruled out by fifth force tests. To avoid these fifth forces, an interesting proposal is to assume the scalar (quintessence) only couples to the hidden sector. However, we then find quantum corrections to V from visible sector Standard Model particles generically spoil the relation. A possible way out of all these problems is to have the scalar conformally coupled to a dark sector that is an exact copy of the Standard Model. This ensures the relation |∇V|∼V/MPl is maintained naturally even when matter particles run in the loop. However, we find that quantum corrections from quintessons or gravitons in the loop spoil the relation if the effective theory has a cutoff greater than ∼0.1GeV.

Finite-element analysis of turbine generator using homogenization method taking account of magnetic anisotropy

PurposeThis paper aims to propose a homogenization method considering magnetic anisotropy for a magnetic field analysis of a turbine generator. To verify the validity of the proposed method, the effects of magnetic anisotropy and a space factor on a no-load saturation curve and no-load iron loss of the turbine generator are discussed.Design/methodology/approachThe proposed method was derived from the combination of the homogenization of microscopic fields in a laminated iron core with the modelling of two-dimensional magnetic properties based on free energy. To verify the validity, the proposed method was applied to a finite-element analysis of a simple ring core model. Finally, a no-load saturation curve and iron loss of the turbine generator was investigated by using the proposed method.FindingsThe computational accuracy of the homogenization method considering magnetic anisotropy is almost the same as that of the detailed modelling of the laminated structure in the magnetic field analysis of the laminated iron core. Furthermore, it is clarified that magnetic anisotropy does not have a large influence on the no-load saturation curve of the turbine generator because of the large air gap. On the other hand, the space factor affects the shape of the no-load saturation curve.Originality/valueThis paper verifies the validity of the homogenization method considering magnetic anisotropy method and elucidates the effects of magnetic anisotropy and a space factor on no-load characteristics of the turbine generator.

Isomorphism between endomorphism rings of modules over a semi simple ring

Our question is what ring R which all modules over R are determined, up to isomorphism, by their endomorphism rings? Examples of this ring are division ring and simple Artinian ring. Any semi simple ring does not satisfy this property. We construct a semi simple ring R but R is not a simple Artinian ring which all modules over R are determined, up to isomorphism, by their endomorphism rings.

Automated Organ-Level Classification of Free-Text Pathology Reports to Support a Radiology Follow-up Tracking Engine.

To evaluate the performance of machine learning algorithms on organ-level classification of semistructured pathology reports, to incorporate surgical pathology monitoring into an automated imaging recommendation follow-up engine. This retrospective study included 2013 pathology reports from patients who underwent abdominal imaging at a large tertiary care center between 2012 and 2018. The reports were labeled by two annotators as relevant to four abdominal organs: liver, kidneys, pancreas and/or adrenal glands, or none. Automated classification methods were compared: simple string matching, random forests, extreme gradient boosting, support vector machines, and two neural network architectures-convolutional neural networks and long short-term memory networks. Three methods from the literature were used to provide interpretability and qualitative validation of the learned network features. The neural networks performed well on the four-organ classification task (F1 score: 96.3% for convolutional neural network and 96.7% for long short-term memory vs 89.9% for support vector machines, 93.9% for extreme gradient boosting, 82.8% for random forests, and 75.2% for simple string matching). Multiple methods were used to visualize the decision-making process of the network, verifying that the networks used similar heuristics to a human annotator. The neural networks were able to classify, with a high degree of accuracy, pathology reports written in unseen formats, suggesting the networks had learned a generalizable encoding of the salient features. Neural network-based approaches achieve high performance on organ-level pathology report classification, suggesting that it is feasible to use them within automated tracking systems.© RSNA, 2019Supplemental material is available for this article.See also the commentary by Liu in this issue.

Maximal zero product subrings and inner ideals of simple rings

Let Q be a (not necessarily unital) simple ring or algebra. A nonempty subset S of Q is said to have zero product if S2=0. We classify all maximal zero product subsets of Q by proving that the map R↦R∩LeftAnn(R) is a bijection from the set of all proper nonzero annihilator right ideals of Q onto the set of all maximal zero product subsets of Q. We also describe the relationship between the maximal zero product subsets of Q and the maximal inner ideals of its associated Lie algebra.

Techniques for Data Extraction from Heterogeneous Sources with Data Security

Data Extraction is the process of mining or fetching relevant information from unstructured data or the heterogeneous sources of data. This paper aims at mining data from three different sources such as online website, flat files and database and the extracted data are even analyzed in terms of precisions, recall and accuracy. In the environment of heterogeneous sources of data, data extraction is one of the crucial issue and therefore considering the present scenario, we can observe that the heterogeneity is expanding widespread. So this paper focus on the different sources for the data extraction and provides a single framework to perform the required tasks. In this paper, healthcare data are considered in order to show the processing starting from data extraction using three different sources to dividing them in to two clusters based on the thresholds value which has been calculated using cosine similarity and finally calculations of parameters like precisions, recall and accuracy for analyzation purpose. Fetching data online is the task in which we cannot fetch simple string from any website. The backend of each page is html and hence this paper focus on extracting that html of the page while mining data from any web server. The webpage contains a lot of html tags and all of these cannot be removed because they are complex tags which cannot be removed by regular expressions. But still 60% filtered data can be attained as demonstrated in this paper as most of the waste html will be removed. While filtration of the data, we should also note that the content containing Google APIs cannot be removed. So filtered data will contain the contents and tags which does not contain Google APIs. In order to provide data security while extraction, the connection string is being used to avoid tampering of data. This paper also focuses on one of the arguable concepts present in the generation of big data which is Data Lake. In originality, the origin about the idea of Data Lake appears from the field of business. An architectural approach which is specially designed in order to store all the data which are potentially relevant in a repository located centrally is referred to as Data Lake. The data which are stored in the central based repository are fetched from the sources belonging to public as well as enterprises and these data are further used for the purpose of organization, discovery of hidden facts, understanding of new concepts, analyzation of stored information etc. Many challenges and concerns related to privacy are faced during the adoption of Data Lake as it is a new concept which brings revolutionization. This paper also highlights some of the issues imposed by Data Lake.

A GENERALIZATION OF SIMPLE-INJECTIVE RINGS

A ring R is called right 2-simple J-injective if, for every 2-generated right ideal I < J(R), every R-linear map from I to R with simple image ex tends to R. The class of right 2-simple J-injective rings is broader than that of right 2-simple injective rings and right simple J-injective rings. Right 2-simple J-injective right Kasch rings are studied, several conditions under which right 2-simple J-injective rings are QF-rings are given.

Catalytic Ring Expansions of Cyclic Alcohols Enabled by Proton-Coupled Electron Transfer.

We report here a catalytic method for the modular ring expansion of cyclic aliphatic alcohols. In this work, proton-coupled electron transfer activation of an allylic alcohol substrate affords an alkoxy radical intermediate that undergoes subsequent C-C bond cleavage to furnish an enone and a tethered alkyl radical. Recombination of this alkyl radical with the revealed olefin acceptor in turn produces a ring-expanded ketone product. The regioselectivity of this C-C bond-forming event can be reliably controlled via substituents on the olefin substrate, providing a means to convert a simple N-membered ring substrate to either n+1 or n+2 ring adducts in a selective fashion.

Heterogeneous High-Loading Hyperbranched Polyglycidol with Peripheral NHC–Pd Complex: Synthesis and Application as Catalyst in Suzuki Coupling Reaction

A new polymer-supported highly functionalized dendritic polyether with peripheral NHC–Pd complex was developed by the simple anionic ring opening polymerization of glycidol on bis(3-hydroxypropyl) amine grafted Merrifield resin and its subsequent functional modification of hydroxyl group to NHC–Pd complex. The polymeric material had high stability and swelling capacity in a wide range of solvents, even in water. Similar to supported higher generation dendrimer, the newly developed system showed high palladium content with uniformly distributed and well isolated metal nanocentres. The palladium content was found to be 2.02 mmol/g which was comparatively higher than other heterogeneous NHC–Pd based catalysts and the polymer was used as heterogeneous palladium catalyst for Suzuki coupling reaction. Various factors affecting the catalyst’s performance were studied. The high availability and increased accessibility of catalytic sites, stability and dendrimer like property of the polymeric support, reusability, better resistance to metal leaching, easy synthesis etc. are the important features of this newly synthesized catalytic system.

A new and simple split series strings approach for adding bypass diodes in shingled cells modules to reduce shading loss

Overlapping solar cells in shingled cells modules create series strings, making it difficult to connect bypass diodes across the modules. A new, simple split strings approach is proposed in this paper, where copper foil tapes are attached to the back of the cells. A module can be bridged by two bypass diodes with this approach, and the effects of shading area and orientation on the electrical performance of the module were investigated. The current-voltage and power-voltage curves of the module were measured in three different shading cases. It was found that the output performance declines critically as the shading area increases along the vertical direction. Moreover, the obtained results were compared with results from shaded modules without split strings in order to justify the benefits of the new split strings approach for reducing shading loss.

Latossolo húmico sob pastagem com diferentes intensidades de usos: atributos químicos e físico-hídricos

The municipality of Brejao has special conditions with cooler and rainy weather and deeper soils and well structured, with occurrence horizon latosols with the humic. So the aim of this study was to investigate the changes in chemical, physical and water attributes of the surface horizon of a humic Oxisol subjected to different forms of use in the South Agreste Pernambuco, and investigate the repellency of the soil water. The disturbed and undisturbed samples were collected in a native forest (MN), pasture 5 years (PA5) and grazing 30 (PA30) in three layers 0 to 10 cm, 10 to 20 cm and 20 to 30 cm and evaluated the chemical, physical and water attributes, and realized an infiltration test with simple ring. Chemical attributes presented typicality dystrophic yellow latosols, and attributes related to the acidity showing significant results mainly in the surface layer. Have the physical attributes that most change with inadequate management are the bulk density (Ds) and porosity. For the infiltration test it is clear the presence of soil water repellency.