Coordinate Grid Research Articles

КОНЦЕПТУАЛІЗАЦІЯ ЛОКАЛЬНОГО ПРОСТОРУ КИЄВА В МОВІ ХУДОЖНЬОЇ ПРОЗИ ХХ СТОЛІТТЯ

The article examines the linguistic features of the conceptualization of the local space of the “Kyiv” mindset in the language of artistic prose by two outstanding Ukrainian writers of the 20th century. – V. Pidmohylnyi and P. Zahrebelnyi. Emphasis is placed on the fact that the local-spatial constant of the linguistic-cultural concept of the proper name “Kyiv”, reflected in the artistic discourses of artists, captures many urban and natural objects, which partially reflect the extremely complex topographical and coordinate grid of the real city. The system of urbanonyms, which represent the specifics of the individual and linguistic pictures of the world of novelists in terms of fixing the realities of the same city in different historical periods of its life, is studied. From the point of view of linguistic stylistics, a comparative analysis of expressive and figurative means of addressing the “Kyiv” mindset in the novel “The City” by V. Pidmohylnyi and in a number of historical novels and works about modernity by P. Zahrebelnyi was carried out. It is noted that the study of the verbalized constant of the local space of the city is an important issue not only for integrative linguistic stylistics, but also for cognitive linguistics, conceptology, linguistic and cultural studies, etc. The semantic-stylistic and logical-cognitive transformations of the internal forms of a number of proper names, which in P. Zahrebelnyi's artistic discourse have consistently evolved from an urbanonym to a concept have been traced. It was concluded that V. Pidmohylnyi, having “immersed” Stepan Radchenko, a rural man, in the urbanized space with its anthropogenic landscape, was one of the first Ukrainian writers of the beginning of the 20th century. conceptualized the city as a determining factor in the civilizational and historical development of society. In the artistic discourse of P. Zahrebelnyi, numerous linguistic units that nominate the real landscape of the city reflect the philosophy of the author's vision of Kyiv as a unique, originally Ukrainian city, as it appears in the national-linguistic picture of the world.

A Novel Renewable Smart Grid Model to Sustain Solar Power Generation

The stability performance of smart grid power systems is critical and requires special attention. Additionally, the combination of Battery Energy Storage (BES) systems, Solar Photovoltaic (SPV), and wind systems in the intelligent grid model provides utilities with excellent efficiency and dependability. However, a coordination grid with PV and other resources frequently results in severe issues, such as outages or power disruptions. A power outage in the grid might result in a power loss in the delivery system. As a result, the distributed grid model’s dependable performance is intended for integrated wind energy, SPV arrays, and BE systems. This paper proposes a renewable intelligent grid model to sustain solar power generation. The model incorporates a boost converter to optimize the performance of solar panels by converting the DC power generated by the panels into AC power for use in the grid. The boost converter is optimized using a novel Horse Herd Optimization Algorithm (HOA) method. In this case, the HOA method is used to optimize the control parameters of the boost converter, such as the duty cycle and the inductor and capacitor values. According to the final results, the proposed method has reduced the Total Harmonic Deformation (THD) and power loss. Additionally, the proposed method outperformed existing strategies related to the Expected Energy Not Supplied (EENS), Loss of Load Probability (LOLP), and Loss of Load Expected (LOLE), indicating the sustainability of power generation.

Technique Evaluates Polymer Injectivity in High-Salinity/High-Temperature Carbonates

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 211451, “Assessment of World-First Two-Polymer Injectivity Tests Performed in Two Giant High-Salinity/High-Temperature Carbonate Reservoirs Using Single-Well Simulation Models and Pressure-Falloff Analysis,” by Juan M. Leon, Shehadeh K. Masalmeh, SPE, and Ali M. Al-Sumaiti, SPE, ADNOC, et al. The paper has not been peer reviewed. _ The complete paper presents the interpretation of two polymer injectivity tests (PITs) performed in two giant light-oil high-salinity/high-temperature (HS/HT) carbonate reservoirs onshore Abu Dhabi. The detailed data acquired in both tests were used to evaluate both polymer injectivity at representative field conditions and in-depth mobility reduction. The interpretation of the pressure transient analysis (PTA) of the pressure falloffs (PFOs) and the mechanistic 3D simulation models of the two PITs confirmed the generation of polymer banks and demonstrated effective propagation of the polymer into the reservoirs at target concentrations and representative rates of future interwell pilots. Introduction The reservoirs tested in the PITs can be described as heterogeneous carbonate reservoirs divided into upper and lower zones. Upper-zone porosities range between 20 and 30%; permeability ranges from 10 to 1000 md. In contrast, the lower zone has porosities and permeabilities ranging from 10 to 30% and from 1 to 20 md, respectively. The main production mechanisms in the reservoirs are peripheral water injection, middip-pattern water injection, and crestal hydrocarbon gas injection in the gas cap. The reservoirs have been developed through long horizontal wells oriented into the lower zones to allow a more-homogeneous sweep. However, the injected fluids in the lower zone travel quickly through the upper zone not far from the injection wells and around the producers into the lower zone. This water or gas inverse coning results in bypassed oil in the lower zone. To face this challenge, the operator has investigated simultaneous injection of miscible CO2 gas and polymer (SIMGAP) for reservoirs with an approximately 10-fold permeability contrast between the lower and upper zones and simultaneous injection of water and polymer (SIWAP) for reservoirs with a permeability contrast of 100-fold or greater between the lower and upper zones. These techniques rely on reducing mobility by polymer injection in the upper zone to provide a pressure barrier and reduce crossflow of the higher-mobility fluid injected into the lower zone. PIT Simulation Model Setup A single-well radial simulation model was built for PIT 1 to assess near-wellbore phenomena by minimizing in-situ velocity and shear-rate calculation errors compared with Cartesian coordinate grids. For interpretation of PIT 2, a mechanistic Cartesian 3D thermal black-oil simulation model was built by extracting a subsector from the last available static geomodel, preserving well architecture and grid resolution in the extracted subsector. The radial simulation model was found unsuitable for PIT 2 because the injector well presented a very high deviated section in the target reservoir, while the long string presented a long horizontal section. Therefore, the polymer injectivity and polymer bank propagation in the upper reservoir might not be represented properly using a vertical well. Different local-grid-refinement (LGR) levels were implemented around the perforation length (upper zone), while the lower zone was in the root grid. The minimum cell radius in the model was determined to be 1.3 ft to avoid errors in well-index calculations considering the well-flow model. Thus, three LGR levels were applied.

Short-term operation of cascade hydropower system sharing flexibility via high voltage direct current lines for multiple grids peak shaving

The escalating pressure for peak shaving presents a significant challenge for the power grid's operation, particularly with the rapid growth of renewable energies. Huge cascade hydropower stations (CHS) send power to the local power grid and multiple power grids via long-distance high voltage direct current (HVDC) transmission lines, how to share hydropower flexibility for multiple power grids in peak shaving while considering constraints of hydropower and HVDC lines challenges power dispatching management. This study proposed a multiple power grids peak shaving model of cascade hydropower stations with HVDC sharing flexibility for receiving power grids. Firstly, the objective of minimizing the peak-valley difference of multiple power grids is adopted. The model then takes into account the operation constraints of CHSs and HVDC tie-lines to share hydropower flexibility. Finally, the model is transformed into a Mixed-Integer Linear Programming problem through piecewise linearization. The case studies of practical examples in southwest China show that the proposed model reduces peak-valley differences by 23.3%, 46.9%, 99.1% and 19.6%, 34.3%, 99.5% for three receiving power grids in two typical days by sharing hydropower flexibility. Moreover, adjusting the HVDC daily power regulation times and electricity deviation tolerance helps coordinate power grids to improve their peak shaving performance.

Iterative image reconstruction with polar coordinate discretized system matrix for optical CT radiochromic gel dosimetry.

Gel dosimeters are a potential tool for measuring the complex dose distributions that characterize modern radiotherapy. A prototype tabletop solid-tank fan-beam optical CT scanner for readout of gel dosimeters was recently developed. This scanner does not have a straight raypath from source to detector, thus images cannot be reconstructed using filtered backprojection (FBP) and iterative techniques are required. Iterative image reconstruction requires a system matrix that describes the geometry of the imaging system. Stored system matrices can become immensely large, making them impractical for storage on a typical desktopcomputer. Here we develop a method to reduce the storage size of optical CT system matrices through use of polar coordinate discretization while accounting for the refraction in optical CTsystems. A ray tracing simulator was developed to track the path of light rays as they traverse the different mediums of the optical CT scanner. Cartesian coordinate discretized system matrices (CCDSMs) and polar coordinate discretized system matrices (PCDSMs) were generated by discretizing the reconstruction area of the optical CT scanner into a Cartesian pixel grid and a polar coordinate pixel grid, respectively. The length of each ray through each pixel was calculated and used to populate the system matrices. To ensure equal weighting during iterative reconstruction, the radial rings of PCDSMs were asymmetrically spaced such that the area of each polar pixel was constant. Two clinical phantoms and several synthetic phantoms were produced and used to evaluate the reconstruction techniques under known conditions. Reconstructed images were analyzed in terms of spatial resolution, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), signal nonuniformity (SNU), and Gamma map passpercentage. A storage size reduction of 99.72% was found when comparing a PCDSM to a CCDSM with the same total number of pixels. Images reconstructed with a PCDSM were found to have superior SNR, CNR, SNU, and Gamma (1mm, 1%) pass percentage compared to those reconstructed with a CCDSM. Increasing spatial resolution in the radial direction with increasing radial distance was found in both PCDSM and CCDSM reconstructions due to the outer regions refracting light more severely. Images reconstructed with a PCDSM showed a decrease in spatial resolution in the azimuthal directions as radial distance increases, due to the widening of the polar pixels. However, this can be mitigated with only a slight increase in storage size by increasing the number of projections. A loss of spatial resolution in the radial direction within 5mm radially from center was found when reconstructing with a PCDSM, due to the large innermost pixels. However, this was remedied by increasing the number of radial rings within the PCDSM, yielding radial spatial resolution on par with images reconstructed with a CCDSM and a storage size reduction of 99.26%. Discretizing the image pixel elements in polar coordinates achieved a system matrix storage size reduction of 99.26% with only minimal reduction in the imagequality.

ГЕОМЕТРИЯ ПРЯМЫХ КОНОИДОВ С ОРТОГОНАЛЬНОЙ СИСТЕМОЙ КООРДИНАТ.

The geometry and methods of forming right conoids are considered in the article. Right conoids are formed by the movement of a rectilinear generatrix perpendicular to a fixed straight line – the axis of the conoid, along which the rectilinear generatrix moves. When moving, the rectilinear generatrix rotates according to a given law around the directrix curve. Usually, the generatrix line is connected to some reference curve that the generatrix line touches. The coordinate grid along the generatrix lines is also connected with the reference curve. In this case, a non-orthogonal coordinate system of a right conoid is formed. Coefficients of quadratic forms of surfaces with a non-orthogonal coordinate system, usually are complex. Methods for analyzing shells with a non-orthogonal coordinate system of the middle surface of the shell are becoming more complicated. The article considers the possibility of forming right conoids with an orthogonal coordinate system, including with directrix reference curves. A vector equation is given for specifying right conoids with an orthogonal nonconjugate coordinate system. Formulas of coefficients of quadratic forms characterizing the internal geometry and curvature of right conoidal surfaces in space with the help of this vector equation are obtained. Based on the vector equations of the surface assignment, drawings of right conoids with various geometric parameters are constructed in the MathCAD program. The difference in the construction of right conoids with orthogonal and non-orthogonal curved coordinate systems is clearly demonstrated, so with different methods of specifying the angles of inclination of rectilinear generatrix of surfaces.

A Global–Regional-Unified Atmospheric Dynamical Core on the Yin–Yang Grid

Abstract A global–regional-unified nonhydrostatic dynamical core was constructed on the Yin–Yang grid using a semi-implicit semi-Lagrangian solver. Arbitrary coordinate rotation was possible for both global and limited-area models with a multilevel nesting capability. Significant flexibility is available when configuring the model’s horizontal mesh using coordinate rotation. The performance of the dynamical core was assessed using a series of numerical tests in Cartesian and spherical coordinates. The results illustrate the reasonable ability of the piecewise rational method to manage sharp gradient advection and the capability of the dry dynamical core to simulate fine structures in target systems in the Cartesian and spherical configurations. An average convergence rate of 2.43 was confirmed for the dry dynamical core in the balanced flow test. The nested grid improved the fine structure simulation of the baroclinic wave development without affecting wave propagation. The propagating speed of the vortex remained unchanged in the nested grid in the colliding modons test, although the vorticity amplitude decayed more slowly than that in the coarse grid. Proper development of topographic waves was achieved for both large- and small-scale mountains with a clear damping effect in association with the off-center semi-implicit average. A deepened trough in the nesting region, in comparison with that in the parent grid, was simulated in a topographic Rossby wave test. The implementation of coordinate rotation and grid nesting improved the numerical performance when managing atmospheric dynamical problems at relatively low cost.

Combinatorial Properties and Recognition of Unit Square Visibility Graphs

Unit square visibility graphs (USV) are described by axis-parallel visibility between unit squares placed in the plane. If the squares are required to be placed on integer grid coordinates, then USV become unit square grid visibility graphs (USGV), an alternative characterisation of the well-known rectilinear graphs. We extend known combinatorial results for USGV and we show that, in the weak case (i.e., visibilities do not necessarily translate into edges of the represented combinatorial graph), the area minimisation variant of their recognition problem is {{,mathrm{{textsf{N}}{textsf{P}}},}}-hard. We also provide combinatorial insights with respect to USV, and as our main result, we prove their recognition problem to be {{,mathrm{{textsf{N}}{textsf{P}}},}}-hard, which settles an open question.

A methodology for transformation between geodetic datums used in Syria

The Global Navigation Satellite System (GNSS) provides geodetic coordinates referenced to the world ellipsoid WGS84, whereas positions are computed on the local ellipsoid adopted for geodetic computation in various countries. Thus, to take advantage of GNSS in geodetic applications, the need arises to transform coordinates from the global ellipsoid to the local ellipsoid. This is usually carried out by applying geometric transformation models to convert coordinates from The Global Geodetic System WGS84 into the local systems used in each country of the world and into the grid coordinates of local systems. Over the past years, with the increase in the utilization of GNSS in several geodetic projects, numerous methodologies are available for the solution of transformation issues. These methods can be classified into three categories, the first is based on direct mathematical formulas, the second on iteration approaches, and the last category depends on direct transformation from the global system to the local system based on the calculation of transformation parameters (three, seven, nine …etc.). In this study, a methodology has been proposed for direct transformation from global geodetic coordinates to local geodetic coordinates for a limited area in Syria. It is based on the properties of the ratio and proportion between the geometric elements of points on global and local ellipsoids without the calculation of transformation parameters. The results are compared with some studied methods (Bursa-Wolf, Molodensky Abridge, and Cassini). The resulting accuracy is about ± 3.5 cm. The main conclusion drawn is that the proposed method provides a promising alternative approach in coordinates transformation. Therefore, the capability of the suggested methodology as a powerful method for converting geodetic coordinates from one referenced frame to another has been demonstrated in this present study.

Adoption of Local Peer-to-Peer Energy Markets: Technical and Economical Perspectives for Utilities

Peer-to-peer (P2P) energy markets constitute a promising approach for locally coordinating the increasing amount of distributed energy resources (DERs) in the distribution system. Although the benefits of P2P markets for the prosumers are already well understood, their impact on utilities is not well discussed nor well understood. This hinders the development of regulatory frameworks, which are still needed to allow for the widespread adoption of decentralized energy markets in any interested country. So far, research has been conducted in specific isolated aspects, making it difficult to understand the overall implications for utilities. The present study aims to tackle this research gap by comprehensively evaluating P2P markets’ effects, considering utilities as primary stakeholders. A qualitative roadmap with the overall benefits and challenges of adopting P2P by utilities is outlined to reach this purpose. Technical and economic criteria are assigned for comparing a P2P market to the current regulatory framework. Each criterion is evaluated in a co-simulation platform connecting a market model to a power flow model. Market performance is assessed by revenue analysis, and grid operation indicators evaluate grid performance. Furthermore, network fees are introduced as compensation mechanisms for the net revenue loss. Comparison scenarios encompass network fees and the number of agents, PV, and storage penetration. Results demonstrate that there is no possible benefit for both utilities and prosumers simultaneously if looking exclusively at the financial balance of the market. An equilibrium in benefits for all stakeholders is achievable if non-financial metrics are considered in an integrated market and fee structure analysis. Moreover, results demonstrate that the design of market structures must be sensitive to network configurations and DER penetration changes. This study contributes toward comprehending how the utilities could embrace P2P markets as a feasible solution for grid coordination challenges, opening a new set of questions for further research.

Trajectories of principal stresses after plastic deformation

Improving research efficiency of mechanical stresses in metals can be achieved by studying and taking into account the fields of the trajectories of the main stresses (isostats), which qualitatively characterize the stress state. The purpose of the work was to determine the possibility of detecting the isostates in a St3 steel sample, following its plastic deformation. The methodology is based on the magnetoelastic method, manifested by the dependence of magnetic permeability of ferromagnetic materials upon mechanical stresses, acting in them. The method is implemented using the IMN-4M monophase magnetoelastic meter of mechanical stress: the base of the device gage is 5 mm, the angle meter error is ± 2°. The sample is a plate with dimensions of 150 x 150 x 4 mm. Coordinate grids with 10 x 10 mm cells were applied to its front and back surfaces. Using the IMN-4M device, we measured the values of tilt angles for tangents to principal stress trajectories in all nodes, then we created isostates by consecutive adjustment of the direction and radius of curvature for a raised curve. The plastic deformation of a plate was performed by shooting small lead pellets with kinetic energy of 1916 J. The maximum plate curvature in the impact zone of main charge equaled 7 mm. After a shot, the measurements were repeated in the same nodes of coordinate grids, and the isostates were plotted again. The experiment has shown that: the magnetoelastic method makes it possible to detect the isostates even after plastic deformation; the trajectories are present both on front and back surfaces of the deformed plate; isotropic points and parallel isostates are available in fields, formed by the shot. Izotropic zones were formed on front and back surfaces, in which isostates can not be plotted due to random orientation of tangents. The "disturbances" of fields with disruption of regular trajectory flows were detected. The results of the work may be useful for researchers and technical engineers, engaged in the study of elastic and plastic deformations.

Listening to the Soviet Union’s “Silent” Majority: The Evasion of Labor Obligations on the Home Front, 1941–45

AbstractLarge‐scale evasion of the requirements of the law is a substantial part of the interaction between citizen and state under authoritarian regimes. Forced to exist within a coordinate grid established against their will, people routinely play games with the state with the goal of minimizing the hardships of life. Tactics of covert resistance are not necessarily politically motivated by conscious opposition to the regime. Instead, these are a matter of accommodation and survival. It is precisely these popular illegalities that, paradoxically, do not so much weaken a system intended to achieve full implementation of its instructions, but instead strengthen it to a certain degree. Evasion serves as a safeguard against social burnout, replete with unpredictable reactions born of desperation. This article examines practices of mass illegality via examples of evasion of labor obligations in the Soviet Union during the war with Nazi Germany. It analyzes instances that primarily involved peasants, especially women, who predominated in the Soviet rear areas after the men were conscripted into the army. This discriminated‐against and uneducated majority rarely enters historians’ field of vision, which concentrates on the diaries and memoirs of the educated, urban part of the Soviet population.

A two-stage optimization method for Vehicle to Grid coordination considering building and Electric Vehicle user expectations

The formulation of the Vehicle to Grid (V2G) scheme should ideally consider both Electric Vehicle (EV) and building owners’ viewpoints. From the building owner’s viewpoint, the EVs should be present in the building and participate consistently to deliver the required power. From the EV owners’ viewpoint, participating in the V2G scheme should provide economic incentives while not compromising their travel needs. However, those proposed V2G algorithms up to this point in time had not considered any corrections required in response to unplanned changes in the EV travel plan. In this paper, a Two-stage optimization technique is proposed to determine the charging and discharging schedule for EVs participating in a vehicle-to-grid (V2G) programme at an office building. The EV owners’ travel convenience is focused with more attention in the proposed model by giving them two V2G options. Firstly, day-ahead optimization (DAO) is applied, based on the expected building load profile and EV behaviour, the optimal charging or discharging control of the EVs is obtained in order to save electricity bills by minimizing the maximum demand of the building. Subsequently, a real-time optimization (RTO) is performed to adjust the V2G operation based on actual vehicle behaviours which usually deviate from their estimations. Simulations are conducted and the preliminary results show that the proposed technique is able to adjust the EV charging or discharging in real-time with the aid of the day-ahead stage. The proposed model manages to capture a new ideal optimal maximum demand point and maintain the EV SOC profile as planned from the DAO stage in real-time when prediction deviation occurs. In addition, a comprehensive cost–benefit analysis in utilizing V2G in peak load reduction is also performed to gain insight into the potential savings and discharging rewards attributable to the building and EV owner respectively.

Transmission Network Loss Reduction and Voltage Profile Improvement Using Network Restructuring and Optimal DG Placement

This paper introduced a method using hybrid combination of network restructuring and optimal placement of optimally sized distributed generators (DG) to reduce loss and improve voltage profile in a practical transmission network for scenario of high load demand for a period of ten years. A study is performed for four study cases which includes the test transmission network without considering optimal DG placement and network restructuring, considering network restructuring, optimal placement of DG units using proposed grid parameter oriented harmony search algorithm (GPOHSA) and considering hybrid combination of network restructuring and DG placement using GPOHSA. Network restructuring is achieved by addition of a new 400 kV Grid-substation (GSS) and a 220 kV GSS along with associated transmission system. GPOHSA is obtained by a modification in the conventional harmony search algorithm (HSA) where grid coordinates are used for locating the individuals in an objective space. Performance Improvement Indicators such as real power loss reduction indicator (SPLRI), reactive power loss reduction indicator (SQLRI) and summation of node voltage deviation reduction indicator (SNVDRI) are proposed to evaluate performance of each case of study. The period of investment return is assessed to evaluate the pay back period of the investments incurred in network restructuring and DG units. It is established that hybrid combination of network restructuring and DG units placement using GPOHSA is effective to meet the increased load demand for time period of ten years with reduced losses and improved voltage profile. Investment incurred on the network restructuring and DG units placement will be recovered in a time period of 4 years. Effectiveness of the GPOHSA is better relative to the conventional genetic algorithm (GA) for DG unit placement. The study is performed using the MATLAB software on a practical transmission network in India.

On the Buildings and Location of Armagh Observatory

We consider the buildings of Armagh Observatory and present their location to a few tens of centimetres or approximately 0.01 arcsecond in latitude and longitude, referred to the position of the Ordnance Survey (OS) benchmark (OSBM) inscribed on the historic eighteenth-century building. This has Irish Grid (IG) coordinates (287829.309BM, 345757.815BM) and a height above mean sea level of 61.08 m. It lies approximately 12.1 ± 0.15 m west and 7.9 ± 0.1 m south of the Observatory’s earliest transit telescopes and 1.5 ± 0.05 m east and 1.7 ± 0.1 m south of the 1795 Troughton telescope. Ground level at the Observatory has an orthometric height of 61.9 ± 0.1 m, approximately 2 metres below that given in the Astronomical Almanac. Accurate measurements of height have implications for values of atmospheric pressure reduced to mean sea level, for precise comparisons between weather stations, and for weather forecasting. Our position for the Observatory’s earliest transit telescopes lies within ~0.4 m of the coordinate origin of the 1835 OS 6-inch County Armagh maps, highlighting the link between astronomy and the first high-accuracy maps of Ireland. An 1834 plan and measurements of the surviving north meridian marks suggest that the transit room’s east windows were moved ∼0.8 m east when the sector tower was added around 1840. This resolves an unexplained discrepancy between the present distance (3.0 m) between the centres of the west and east windows of the transit room and the original distance (~2.2 m) inferred by other means. We suggest that we may havefound parts of early transit instruments believed lost and give improved coordinates for the meridian marks. This work has applications to the history of astronomy, geodesy, meteorology, and climate change.

Kamodo’s model-agnostic satellite flythrough: Lowering the utilization barrier for heliophysics model outputs

Heliophysics model outputs are increasingly accessible, but typically are not usable by the majority of the community unless directly collaborating with the relevant model developers. Prohibitive factors include complex file output formats, cryptic metadata, unspecified and often customized coordinate systems, and non-linear coordinate grids. Some pockets of progress exist, giving interfaces to various simulation outputs, but only for a small set of outputs and typically not with open-source, freely available packages. Additionally, the increasing array of tools built upon these sporadic interfaces are typically model-specific. We present Kamodo’s model-agnostic satellite flythrough capabilities as the solution to the utilization barrier for heliophysics model outputs. Developed at the Community Coordinated Modeling Center, these flythrough capabilities are built in Python upon a network of model-agnostic interfaces developed in collaboration with model developers, providing interpolation results the community can trust. Kamodo’s flythrough capabilities present the user with a growing variety of flythrough tools based upon a rapidly expanding library of heliophysics model outputs in several domains, currently including a variety of Ionosphere-Thermosphere-Mesosphere and global magnetosphere model outputs. Each capability is designed to be easily accessible via simplistic model-agnostic syntax, with the entire package freely available in the cloud on Github. Here, we describe the tools developed, include several sample applications for common science questions, demonstrate interoperability with selected packages, and summarize ongoing developments.

The Baltic Sea Model Intercomparison Project (BMIP) – a platform for model development, evaluation, and uncertainty assessment

Abstract. While advanced computational capabilities have enabled the development of complex ocean general circulation models (OGCMs) for marginal seas, systematic comparisons of regional ocean models and their setups are still rare. The Baltic Sea Model Intercomparison Project (BMIP), introduced herein, was therefore established as a platform for the scientific analysis and systematic comparison of Baltic Sea models. The inclusion of a physically consistent regional reanalysis data set for the period 1961–2018 allows for standardized meteorological forcing and river runoff. Protocols to harmonize model outputs and analyses are provided as well. An analysis of six simulations performed with four regional OGCMs differing in their resolution, grid coordinates, and numerical methods was carried out to explore intermodel differences despite harmonized forcing. Uncertainties in the modeled surface temperatures were shown to be larger at extreme than at moderate temperatures. In addition, a roughly linear increase in the temperature spread with increasing water depth was determined and indicated larger uncertainties in the near-bottom layer. On the seasonal scale, the model spread was larger in summer than in winter, likely due to differences in the models' thermocline dynamics. In winter, stronger air–sea heat fluxes and vigorous convective and wind mixing reduced the intermodel spread. Uncertainties were likewise reduced near the coasts, where the impact of meteorological forcing was stronger. The uncertainties were highest in the Bothnian Sea and Bothnian Bay, attributable to the differences between the models in the seasonal cycles of sea ice triggered by the ice–albedo feedback. However, despite the large spreads in the mean climatologies, high interannual correlations between the sea surface temperatures (SSTs) of all models and data derived from a satellite product were determined. The exceptions were the Bothnian Sea and Bothnian Bay, where the correlation dropped significantly, likely related to the effect of sea ice on air–sea heat exchange. The spread of water salinity across the models is generally larger compared to water temperature, which is most obvious in the long-term time series of deepwater salinity. The inflow dynamics of saline water from the North Sea is covered well by most models, but the magnitude, as inferred from salinity, differs as much as the simulated mean salinity of deepwater. Marine heat waves (MHWs), coastal upwelling, and stratification were also assessed. In all models, MHWs were more frequent in shallow areas and in regions with seasonal ice cover. An increase in the frequency (regionally varying between ∼50 % and 250 %) and duration (50 %–150 %) of MHWs during the last 3 decades in all models was found as well. The uncertainties were highest in the Bothnian Bay, likely due to the different trends in sea ice presence. All but one of the analyzed models overestimated upwelling frequencies along the Swedish coast, the Gulf of Finland, and around Gotland, while they underestimated upwelling in the Gulf of Riga. The onset and seasonal cycle of thermal stratification likewise differed among the models. Compared to observation-based estimates, in all models the thermocline in early spring was too deep, whereas a good match was obtained in June when the thermocline intensifies.

Optimal Scheduling of Neural Network-Based Estimated Renewable Energy Nanogrid

In developing countries, many areas are deprived of electrical energy. Access to cleaner, more affordable energy is critical for improving the poor’s living conditions in developing countries. With the advent of smart grid technology, the integration and coordination of small grids, known as nanogrids, has become very easy. The purpose of this research is to propose a nanogrid model that will serve the purpose of providing the facility of electrical power to the poor rural community in Pakistan using hybrid renewable energy sources. This paper targets the electrification of a poor rural community of Akora Khatak, a small district located in Pakistan. The mathematical modeling of solar and wind energy, neural network-based forecasting of solar irradiance and wind velocity, and the social analysis to calculate the payback period for the community have been discussed in this paper.

PREDICTION OF THE TENSILE STRENGTH OF STEEL FORGINGS

Great attention is paid to the issues of improving the methods of product quality prediction, in particular, a comprehensive approach to its evaluation is being developed based on the principles of qualimetry. The example of experimental approach is provided to predict one of the mechanical properties ‒ tensile strength which is an important indicator of the steel forgings quality. The investigation has been carried out to estimate the accumulated strain degree, chemical composition, friction conditions at contact surface influencing on temporal resistance distribution in the forging volume. The accumulation of strain degree was carried out by crimping of cubic billets in three mutually perpendicular directions with different number of crimping cycles according to cube‒cube scheme. The distribution of strain degree over the volume of a deformed billet was experimentally determined for lead samples by coordinate grid technique. The lead cubic billets were cut in half. A square grid was applied to one of the halves, and then the halves were fused with a fusible Wood alloy and subjected to the first upsetting. After upsetting the sample was unsoldered and the Λ value in each cell was calculated from the curvature of the coordinate grid. The forging of steel billets was carried out in a similar way. After forging the steel billets, the specimens were cut out for mechanical testing. As a result of experimental data processing, the equation of regression has been received, which enables to predict the level of forgings’ tensile strength at the known technological parameters. Significance of the coefficients of the obtained equation was validated by the Student's criterion and the adequacy by the Fisher's criterion. The developed technique can be applied for selection of rational mode of deformation during forging for maintenance of the given level of mechanical properties.

Numerical analysis of passive safety injection driven by natural circulation in floating nuclear power plant

The traditional energy supply paradigm has been difficult to meet the demands of ocean resources development. As a combination of small nuclear reactors and offshore platforms, the floating nuclear power plant(FNPP) can be well used in offshore energy supply. Considering passive safety injection of FNPP will be deeply affected by the ocean environment, the present study brings a CFD customization model to assess the injection process. The additional inertial force is implanted into the momentum equation to simulate motion conditions. The combination of coordinate transformation and grid traversal is used to output critical parameters. Therefore, it can be seen the overall evolution process and the local flow characteristics of natural circulation intuitively apart from quantitative analysis, making up for the deficiency of the previous analysis code. Results suggested the injection process can be divided into several stages. Affected by ocean conditions, the flow rate in FNPP will decrease with periodic fluctuation after a linear increase, so the safety injection can be completed in 180 s under static conditions while needing more than 240 s under rolling. However, although additional acceleration weakens the driving force of natural circulation, liquid sloshing and disturbed flow will make the reactor core cool more effectively.