SEARCH · Engineering Papers

Results for “Paper Based Procedures”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,369 records · Page 76

All sources NASA NTRS DOE OSTI

NASA NTRS2003

Performance Testing of Thermal Interface Filler Materials in a Bolted Aluminum Interface Under Thermal/Vacuum Conditions

A thermal interface material is one of the many tools that are often used as part of the thermal control scheme for space-based applications. These materials are placed between, for example, an avionics box and a cold plate, in order to improve the conduction heat transfer so that proper temperatures can be maintained. Historically at Marshall Space Flight Center, CHO-THERM@ 1671 has primarily been used for applications where an interface material was deemed necessary. However, there have been numerous alternatives come on the market in recent years. It was decided that a number of these materials should be tested against each other to see if there were better performing alternatives. The tests were done strictly to compare the thermal performance of the materials relative to each other under repeatable conditions and they do not take into consideration other design issues such as off-gassing, electrical conduction or isolation, etc. This paper details the materials tested, test apparatus, procedures, and results of these tests.

Glasgow, Shaun↗

NASA NTRS2011

Handling Qualities Flight Testing of the Stratospheric Observatory for Infrared Astronomy (SOFIA)

Airborne infrared astronomy has a long successful history, albeit relatively unknown outside of the astronomy community. A major problem with ground based infrared astronomy is the absorption and scatter of infrared energy by water in the atmosphere. Observing the universe from above 40,000 ft puts the observation platform above 99% of the water vapor in the atmosphere, thereby addressing this problem at a fraction of the cost of space based systems. The Stratospheric Observatory For Infrared Astronomy (SOFIA) aircraft is the most ambitious foray into the field of airborne infrared astronomy in history. Using a 747SP (The Boeing Company, Chicago, Illinois) aircraft modified with a 2.5m telescope located in the aft section of the fuselage, the SOFIA endeavors to provide views of the universe never before possible and at a fraction of the cost of space based systems. The modification to the airplane includes moveable doors and aperture that expose the telescope assembly. The telescope assembly is aimed and stabilized using a multitude of on board systems. This modification has the potential to cause aerodynamic anomalies that could induce undesired forces either at the cavity itself or indirectly due to interference with the empennage, both of which could cause handling qualities issues. As a result, an extensive analysis and flight test program was conducted from December 2009 through March 2011. Several methods, including a Lower Order Equivalent Systems analysis and pilot assessment, were used to ascertain the effects of the modification. The SOFIA modification was found to cause no adverse handling qualities effects and the aircraft was cleared for operational use. This paper discusses the history and modification to the aircraft, development of test procedures and analysis, results of testing and analysis, lessons learned for future projects and justification for operational certification.

Glaser, Scott T.↗

DOE OSTI2017

A business case for nuclear plant control room modernization - 352

This paper presents a generic business case for implementation of technology that supports Control Room Modernization (CRM) in existing nuclear power plants (NPPs). The business case is based on advanced digital instrumentation and control (I and C), human-system interface (HSI), and work process technologies that allow NPP operators to conduct control room operations with improved human factors and efficiency, and therefore operate with fewer operational events. Labor savings can be harvested in terms of reduced overtime and redistribution of work. Significant savings are also demonstrated as reduced time to bring the plant back on line after completion of outages. The benefits are quantified to a rough order of magnitude, providing directional guidance to NPPs that are interested in developing similar business cases. The technologies employed in CRM include large overview displays, task-based operator displays, computer-based procedures, advanced alarm systems, computerized operator support systems, and wireless networks, among others. The CRM business case is founded on the following categories of cost savings: - Integrated Computer-Based Procedures for Operators; - Reduction in Corrective Action Program Work Due to Operator Error; - Reduction in Outage Critical Path Time; - Operation of Local Control Panels; - Reduction in Control Room Support; - Reduction in Plant Events Resulting in Generation Loss; - Paperless Control Room Processes. In addition to cost savings, these technologies also offer improvements to indirect ways that have impact on key performance indicators of the plant. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

DOE OSTI2014

Electrostatics of proteins in dielectric solvent continua. I. An accurate and efficient reaction field description

We present a reaction field (RF) method which accurately solves the Poisson equation for proteins embedded in dielectric solvent continua at a computational effort comparable to that of an electrostatics calculation with polarizable molecular mechanics (MM) force fields. The method combines an approach originally suggested by Egwolf and Tavan [J. Chem. Phys. 118, 2039 (2003)] with concepts generalizing the Born solution [Z. Phys. 1, 45 (1920)] for a solvated ion. First, we derive an exact representation according to which the sources of the RF potential and energy are inducible atomic anti-polarization densities and atomic shielding charge distributions. Modeling these atomic densities by Gaussians leads to an approximate representation. Here, the strengths of the Gaussian shielding charge distributions are directly given in terms of the static partial charges as defined, e.g., by standard MM force fields for the various atom types, whereas the strengths of the Gaussian anti-polarization densities are calculated by a self-consistency iteration. The atomic volumes are also described by Gaussians. To account for covalently overlapping atoms, their effective volumes are calculated by another self-consistency procedure, which guarantees that the dielectric function ε(r) is close to one everywhere inside the protein. The Gaussian widths σ{sub i} of the atoms i are parameters of the RF approximation. The remarkable accuracy of the method is demonstrated by comparison with Kirkwood's analytical solution for a spherical protein [J. Chem. Phys. 2, 351 (1934)] and with computationally expensive grid-based numerical solutions for simple model systems in dielectric continua including a di-peptide (Ac-Ala-NHMe) as modeled by a standard MM force field. The latter example shows how weakly the RF conformational free energy landscape depends on the parameters σ{sub i}. A summarizing discussion highlights the achievements of the new theory and of its approximate solution particularly by comparison with so-called generalized Born methods. A follow-up paper describes how the method enables Hamiltonian, efficient, and accurate MM molecular dynamics simulations of proteins in dielectric solvent continua.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2026

A data-driven approach to real-time vertical position estimation for NSTX-U vertical stability control

In this paper, a database of 77 996 plasma equilibrium reconstructions from 727 discharges during the initial operation of the NSTX-U spherical tokamak is analyzed to develop a statistically robust model of the plasma vertical position for real-time control. A variety of regression models are developed and tested, ranging in complexity from linear models to deep neural networks, and including input signals ranging from the four pairs of flux loops used historically on NSTX-U up to the full set of 389 real-time signals available to the plasma control system. A linear model based on 140 real-time magnetics signals is found to offer excellent accuracy, with a coefficient of determination R 2 = 0.906. The robustness of this model to limited training data, new operating scenarios, and signal errors is tested, and a procedure is demonstrated to tune the model parameters to optimize its robustness. A time-dependent plasma equilibrium solver, TokaMaker, is used to simulate vertical stability control in NSTX-U, demonstrating that it should be possible to iteratively tune the parameters of a linear vertical position model to stabilize both positive and negative triangularity plasmas in future experiments.

magnetic diagnostics↗

NASA NTRS1976

Improvements in search and rescue distress alerting and locating using satellites

This paper describes a system concept for search and rescue which is capable of making a major contribution to saving lives and reducing the search time for downed aircraft. In addition, a beacon location experiment is described using the Amateur Radio Satellite Corporation Oscar-6 and Oscar-7 spacecraft. The purpose of this experiment was to demonstrate the system concept above by determining the geographical location of a low power 'distress beacon' via satellite based on a single pass of Doppler frequency measurements. Preliminary results are presented showing beacon location recovery on the order of 10 km with indications that an order of magnitude improvement is entirely possible. This experiment is in support of NASA's current exploration into the role satellites might play in providing much needed improvements in the reliability, coverage and accuracy of present search and rescue procedures.

Brandel, D. L.↗

NASA NTRS1985

Stochastic response analysis, order reduction, and output feedback controllers for flexible spacecraft

Real disturbances and real sensors have finite bandwidths. The first objective of this paper is to incorporate this finiteness in the 'open-loop modal cost analysis' as applied to a flexible spacecraft. Analysis based on residue calculus shows that among other factors, significance of a mode depends on the power spectral density of disturbances and the response spectral density of sensors at the modal frequency. The second objective of this article is to compare performances of an optimal and a suboptimal output feedback controller, the latter based on 'minimum error excitation' of Kosut. Both the performances are found to be nearly the same, leading us to favor the latter technique because it entails only linear computations. Our final objective is to detect an instability due to truncated modes by representing them as a multiplicative and an additive perturbation in a nominal transfer function. In an example problem it is found that this procedure leads to a narrow range of permissible controller gains, and that it labels a wrong mode as a cause of instability. A free beam is used to illustrate the analysis in this work.

Hablani, H. B.↗

NASA NTRS1997

External Boundary Conditions for Three-Dimensional Problems of Computational Aerodynamics

We consider an unbounded steady-state flow of viscous fluid over a three-dimensional finite body or configuration of bodies. For the purpose of solving this flow problem numerically, we discretize the governing equations (Navier-Stokes) on a finite-difference grid. The grid obviously cannot stretch from the body up to infinity, because the number of the discrete variables in that case would not be finite. Therefore, prior to the discretization we truncate the original unbounded flow domain by introducing some artificial computational boundary at a finite distance of the body. Typically, the artificial boundary is introduced in a natural way as the external boundary of the domain covered by the grid. The flow problem formulated only on the finite computational domain rather than on the original infinite domain is clearly subdefinite unless some artificial boundary conditions (ABC's) are specified at the external computational boundary. Similarly, the discretized flow problem is subdefinite (i.e., lacks equations with respect to unknowns) unless a special closing procedure is implemented at this artificial boundary. The closing procedure in the discrete case is called the ABC's as well. In this paper, we present an innovative approach to constructing highly accurate ABC's for three-dimensional flow computations. The approach extends our previous technique developed for the two-dimensional case; it employs the finite-difference counterparts to Calderon's pseudodifferential boundary projections calculated in the framework of the difference potentials method (DPM) by Ryaben'kii. The resulting ABC's appear spatially nonlocal but particularly easy to implement along with the existing solvers. The new boundary conditions have been successfully combined with the NASA-developed production code TLNS3D and used for the analysis of wing-shaped configurations in subsonic (including incompressible limit) and transonic flow regimes. As demonstrated by the computational experiments and comparisons with the standard (local) methods, the DPM-based ABC's allow one to greatly reduce the size of the computational domain while still maintaining high accuracy of the numerical solution. Moreover, they may provide for a noticeable increase of the convergence rate of multigrid iterations.

Tsynkov, Semyon V.↗

DOE OSTI2013

DETERMINATION OF STOCHASTIC ACCELERATION MODEL CHARACTERISTICS IN SOLAR FLARES

Following our recent paper, we have developed an inversion method to determine the basic characteristics of the particle acceleration mechanism directly and non-parametrically from observations under the leaky box framework. Earlier, we demonstrated this method for obtaining the energy dependences of the escape time and pitch angle scattering time. Here, by converting the Fokker-Planck equation to its integral form, we derive the energy dependences of the energy diffusion coefficient and direct acceleration rate for stochastic acceleration in terms of the accelerated and escaping particle spectra. Combining the regularized inversion method of Piana et al. and our procedure, we relate the acceleration characteristics in solar flares directly to the count visibility data from RHESSI. We determine the timescales for electron escape, pitch angle scattering, energy diffusion, and direct acceleration at the loop top acceleration region for two intense solar flares based on the regularized electron flux spectral images. The X3.9 class event shows dramatically different energy dependences for the acceleration and scattering timescales, while the M2.1 class event shows a milder difference. The discrepancy between the M2.1 class event and the stochastic acceleration model could be alleviated by a turbulence spectrum that is much steeper than the Kolmogorov-type spectrum. A likely explanation of the X3.9 class event could be that the escape of electrons from the acceleration region is not governed by a random walk process, but instead is affected by magnetic mirroring, in which the scattering time is proportional to the escape time and has an energy dependence similar to the energy diffusion time.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2018

Mechanical Characterization Study of Sintered Silver Pastes Bonded in a Double-Lap Configuration

Sintered silver-based bonded interfaces are a critical enabling technology for high-temperature, compact, high-performance, and reliable wide-bandgap packages and components. High-pressure (~40 MPa) sintered silver interfaces have been implemented commercially, most notably the commercial products offered by Semikron. To reduce manufacturing complexity, there is significant industry interest in pressure-less sintered silver interfaces. To this end, current formulations of sintered silver paste are comprised of purely nano-sized silver particles or a combination of nano- and micro-sized silver particles/flakes. It is essential to quantify the mechanical properties and determine the reliability of these interfaces prior to use in automotive power electronics applications. In this paper, research efforts at the National Renewable Energy Laboratory, in collaboration with Virginia Polytechnic Institute and State University and an industry partner, in optimizing the synthesis procedure and mechanical characterization of sintered silver double-lap samples are described. These double-lap samples were synthesized using pressure-less sintering techniques. Shear testing was conducted at multiple temperatures and displacement rates on these samples sintered using two types of sintered sintered silver pastes, one of them consisting of nano-silver particles and the other a hybrid paste or a combination of nano- and micron-sized silver flakes, employed in a double-lap configuration. Maximum values of shear stress obtained from the characterization study are reported.

33 ADVANCED PROPULSION SYSTEMS↗

DOE OSTI2017

Methodological approach to the sensitivity analysis of failure effects in modern digital I and C systems - 136

Modern I and C systems of nuclear power plants increasingly use digital equipment, software-based applications for I and C functions and different types and topologies of communication networks as well. The structure, operation and communication of digital safety-related I and C systems are strongly influenced by the implemented automatic fault detection and fault treatment procedures as barriers against failure propagation. Thus, these I and C systems can change their operating states automatically during the operation time, e.g. due to the detection and correction of certain failure types. Reasonably because of these dynamic properties of digital I and C systems the use of classical fault tree and event tree methods solely for the reliability analysis of modern I and C systems is less suitable. These methods basically apply static models and do not consider the temporal changes of the operating state of the I and C system or equipment appropriately. In this paper, a recently developed approach for the sensitivity analysis of digital I and C systems will be introduced that allows to investigate the dynamic behavior of such systems in cases of internal faults and to quantify the effects on the system reliability. The development and testing of the analysis methodology is carried out using models of generic I and C systems with different typical architectures of stepwise increased complexity. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

NASA NTRS1962

Fixed-Base Simulator Studies of the Ability of the Human Pilot to Provide Energy Management Along Abort and Deep-Space Entry Trajectories

A simulation study has been made to determine a pilot's ability to control a low L/D vehicle to a desired point on the earth with initial conditions ranging from parabolic orbits to abort conditions along the boost phase of a deep-space mission. The program was conducted to develop procedures which would allow the pilot to perform the energy management functions required while avoiding the high deceleration or skipout region and to determine the information display required to aid the pilot in flying these procedures. The abort conditions studied extend from a region of relatively high flight-path angles at suborbital velocities while leaving the atmosphere to a region between orbital and near-escape velocity outside the atmosphere. The conditions studied included guidance from suborbital and superorbital aborts as well as guidance following return from a deepspace mission. In this paper, the role of the human pilot?s ability to combine safe return abort procedures with guidance procedures has been investigated. The range capability from various abort and entry conditions is also presented.

PILOT↗

DOE OSTI2018

Fast Decomposition of Three-Component Spectra of Fluorescence Quenching by White and Grey Methods of Data Modeling

‘White’ and ‘grey’ methods of data modeling have been employed to resolve the heterogeneous fluorescence from a fluorophore mixture of 9-cyanoanthracene (CNA), 10-chloro-9-cyanoanthracene (ClCNA) and 9,10-dicyanoanthracene (DCNA) into component individual fluorescence spectra. The three-component spectra of fluorescence quenching in methanol were recorded for increasing amounts of lithium bromide used as a quencher. The associated intensity decay profiles of differentially quenched fluorescence of single components were modeled on the basis of a linear Stern-Volmer plot. These profiles are necessary to initiate the fitting procedure in both ‘white’ and ‘grey’ modeling of the original data matrices. ‘White’ methods of data modeling, called also ‘hard’ methods, are based on chemical/physical laws expressed in terms of some well-known or generally accepted mathematical equations. The parameters of these models are not known and they are estimated by least squares curve fitting. ‘Grey’ approaches to data modeling, also known as hard-soft modeling techniques, make use of both hard-model and soft-model parts. In practice, the difference between ‘white’ and ‘grey’ methods lies in the way in which the ‘crude’ fluorescence intensity decays of the mixture components are estimated. In the former case they are given in a functional form while in the latter as digitized curves which, in general, can only be obtained by using dedicated techniques of factor analysis. In the paper, the initial values of the Stern-Volmer constants of pure components were evaluated by both ‘point-by-point’ and ‘matrix’ versions of the method making use of the concept of wavelength dependent intensity fractions as well as by the rank annihilation factor analysis applied to the data matrices of the difference fluorescence spectra constructed in two ways: from the spectra recorded for a few excitation lines at the same concentration of a fluorescence quencher or classically from a series of the spectra measured for one selected excitation line but for increasing concentration of the quencher. The results of multiple curve resolution obtained by all types of the applied methods have been scrutinized and compared. In addition, the effect of inadequacy of sample preparation and increasing instrumental noise on the shape of the resolved spectral profiles has been studied on several datasets mimicking the measured data matrices. .

74 ATOMIC AND MOLECULAR PHYSICS↗

DOE OSTI2022

Optimizing power system restoration with damaged communications

Utility procedures for power system blackstart and restoration typically assume that energization decisions can be reliably communicated across the grid. In reality, the communications and control network would likely also be affected in power outages, such as those caused by extreme weather events or cyber-attacks. This paper studies the effect of damage to the power system communications and control infrastructure on restoration operations following a blackout. We model the communications infrastructure as a graph, overlaying the power grid, and imposing the requirement that every energized element in the power grid be observable from a control center. We expand on a specialized branch-and-bound algorithm from the literature to optimize the restoration process and devise an initialization heuristic and a rounding heuristic to improve solution speed. We perform numerical experiments on synthetic systems for Illinois and Texas with outages based on a solar flare or hurricane. We compare the results of our specialized branch-and-bound algorithm to the results from (i) the initialization heuristic alone, (ii) a variation of this heuristic that we use as a baseline, and (iii) the restoration optimization for the power system without communications constraints. Here, we find that damage to the communications infrastructure significantly increases the time required to re-energize the grid. Moreover, by simultaneously optimizing communications repairs and grid energization decisions, we are able to re-energize the grid significantly faster than if communications repairs and energization decisions were made independently or with partial coordination, motivating improvements to current industry practice.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2019

Prediction of atomization energy using graph kernel and active learning

Data-driven prediction of molecular properties presents unique challenges to the design of machine learning methods concerning data structure/dimensionality, symmetry adaption, and confidence management. In this paper, we present a kernel-based pipeline that can learn and predict the atomization energy of molecules with high accuracy. The framework employs Gaussian process regression to perform predictions based on the similarity between molecules, which is computed using the marginalized graph kernel. To apply the marginalized graph kernel, a spatial adjacency rule is first employed to convert molecules into graphs whose vertices and edges are labeled by elements and interatomic distances, respectively. We then derive formulas for the efficient evaluation of the kernel. Specific functional components for the marginalized graph kernel are proposed, while the effects of the associated hyperparameters on accuracy and predictive confidence are examined. We show that the graph kernel is particularly suitable for predicting extensive properties because its convolutional structure coincides with that of the covariance formula between sums of random variables. Using an active learning procedure, we demonstrate that the proposed method can achieve a mean absolute error of 0.62 ± 0.01 kcal/mol using as few as 2000 training samples on the QM7 dataset.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2021

Local rules for fabricating allosteric networks

Mechanical properties of disordered networks can be significantly tailored by modifying a small fraction of their bonds. This procedure has been used to design and build mechanical metamaterials with a variety of responses. A long-range “allosteric” response, where a localized input strain at one site gives rise to a localized output strain at a distant site, has been of particular interest. This work presents an approach to incorporating allosteric responses in experimental systems by pruning disordered networks in situ. Previous work has relied on computer simulations to design and predict the response of such systems using a cost function where the response of the entire network to each bond removal is used at each step to determine which bond to prune. It is not feasible to follow such a design protocol in experiments where one has access only to local response at each site. This paper presents design algorithms that allow determination of what bonds to prune based purely on the local forces in the network without employing a cost function; using only local information, allosteric networks are designed in simulations and then built out of real materials. The results show that some pruning strategies work better than others when translated into an experimental system. A method is presented to measure local stresses experimentally in disordered networks. This approach is then used to implement pruning methods to design desired responses in situ. Results from these experiments confirm that the pruning methods are robust and work in a real laboratory material.

36 MATERIALS SCIENCE↗

DOE OSTI2013

Simulation-Length Requirements in the Loads Analysis of Offshore Floating Wind Turbines: Preprint

The goal of this paper is to examine the appropriate length of a floating offshore wind turbine (FOWT) simulation - a fundamental question that needs to be answered to develop design requirements. To examine this issue, a loads analysis of an example FOWT was performed in FAST with varying simulation lengths. The offshore wind system used was the OC3-Hywind spar buoy, which was developed for use in the International Energy Agency Code Comparison Collaborative Project and supports NREL's offshore 5-megawatt baseline turbine. Realistic metocean data from the National Oceanic and Atmospheric Administration and repeated periodic wind files were used to excite the structure. The results of the analysis clearly show that loads do not increase for longer simulations. In regards to fatigue, a sensitivity analysis shows that the procedure used for counting half cycles is more important than the simulation length itself. Based on these results, neither the simulation length nor the periodic wind files affect response statistics and loads for FOWTs (at least for the spar studied here); a result in contrast to the offshore oil and gas industry, where running simulations of at least 3 hours in length is common practice.

17 WIND ENERGY↗

DOE OSTI2016

Assembly, Test and Launch Operations for a Nuclear-enabled NASA Mission: Considerations that are Specific to Use of a Nuclear Payload

For more than five decades, Radioisotope Power Systems (RPS) have played a critical role in the exploration of space, enabling missions of scientific discovery to destinations across the solar system by providing electrical power to explore remote, challenging and extreme environments. In particular, RPS enable deep space missions where increased heliocentric distances reduce the ability of solar power to adequately meet spacecraft and instruments power requirements. Some previous notable missions that were enabled by RPS include Nimbus III, the Apollo Surface Experiments, the Pioneers 10 and 11, the Viking Mars Landers, Galileo, Ulysses, Cassini, New Horizons and Curiosity. The current operating set of missions that are enabled by RPS are Voyagers 1 and 2, Cassini, New Horizons, and Curiosity. The Multi-Mission Radioisotope Thermal Generator (MMRTG) is the current RPS used for missions. An enhanced version of this generator outfitted with higher efficiency thermoelectrics is under development for potential use in the future. Other previously deployed power systems include the Multi-hundred Watt Radisotope Thermo-electric Generator (MHW RTG) and the General Purpose Heat Source Radisotope Thermo-electric Generator (GPHS RTG). The common thread for all of these power systems is that they are fueled with Pu-238. The use of this unique isotope involves additional planning activities and requires specific actions when the devices are delivered to Kennedy Space Center (KSC), launch site, and incorporated into the assembly, test and launch operations (ATLO) process to ensure mission success, met safety and security challenges. It has been forecasted that the use of a nuclear reactor system is on the horizon. This system could be used for either specifically powering S/C propulsion system or for surface power use once the mission arrived at its destina-tion. Since a nuclear-fission-based system has never been handled or integrated into a spacecraft at KSC, this nuclear reactor system would potentially require further challenges that must be accounted for in the ATLO process. This paper will explain ATLO considerations for the recent RTG-enabled launches that have occurred and planned in the near future (Mars 2020 NASA mission). It will also describe where further challenges that need to be met for the placement of a nuclear reactor (either for propulsion or transportation for surface power use) onto a space mission. Specifically, the following topics will be addressed: • Approach for nuclear safety planning for nuclear material use and its transportation to launch site • Planning for security posture for nuclear materials at launch site • Preparation for transportation of the nuclear power system from the fueling/testing location to the launch site • Preparation of documentation and procedures for nuclear material use at launch site • Planning for coordination between power system and space mission groups • Planning for appropriate staffing and scheduling of operations

07 ISOTOPE AND RADIATION SOURCES↗