cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Continual Robot Learning: Benchmarks and Modular Methods
Creators: name: Powers, Samantha
Publisher: name: Carnegie Mellon University
Year: 2023
Subjects: Adaptive Agents and Intelligent Robotics

description: Humans adapt continuously to the world around us, allowing us to acquire new skills and explore diverse environments seamlessly. Current AI methods, however, cannot attain this versatility. Instead, they are typically trained with vast datasets, and learn all tasks simultaneously. However, the trained models have limited ability to adapt to changing contexts, and are limited by available data. This challenge is particularly pronounced in robotics, where real world interaction data is scarce. Instead, we envision a robot capable of continuously learning from both the environment and human interactions, quickly acquiring new information without overwriting past knowledge, and capable of adapting to a user’s specific needs. In this thesis, we apply continual learning to robotics, with the goal of enabling crucial capabilities, including: the ability to apply prior information to new settings, maintain old information, sustain capacity for new skills, and understand context. We explore these across two learning modes: continual reinforcement learning (CRL), where the agent learns from experience, and continual imitation learning (CIL), where it learns from demonstrations. However, substantial barriers hinder progress, including limited open-source resources, resource-intensive benchmarks, and impractical metrics for robotics. To address these challenges, we present CORA (COntinual Reinforcement Learning Agents), an open-source toolkit with benchmarks, baselines, and metrics to enhance CRL accessibility. CORA extends beyond catastrophic forgetting, evaluating models for forward transfer and generalization. With this foundation, we introduce SANE (Self-Activating Neural Ensembles) to create a dynamic library of adaptable skills. SANE’s ensemble of independent modules learns and applies skills as needed, reducing forgetting. We demonstrate this method on several Procgen reinforcement learning task sets. We then adapt SANE to a physical robot, the Stretch, with SANER (SANE for Robotics) using CIL. Leveraging our novel Attention-Based Interaction Policies (ABIP), SANER excels in few-shot learning, showcasing its effectiveness at generalization across various tasks. SANERv2 further advances this capability, integrating natural language and achieving strong performance over a diverse set of 15 manipulation tasks in a simulated environment, RLBench. Remarkably, SANERv2 was also able to display the potential of independent modules, demonstrating that a node could be moved between agents without loss of performance, promising possible future composable ensembles.
Aloha Games with Spatial Reuse
Creators: name: Lyu, Jiangbin
name: Chew, Yong Huat
name: Wong, Wai-Choong
Publisher: name: arXiv
Year: 2013
Subjects: subject: Computer Science and Game Theory (cs.GT)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Aloha games study the transmission probabilities of a group of non-cooperative users which share a channel to transmit via the slotted Aloha protocol. This paper extends the Aloha games to spatial reuse scenarios, and studies the system equilibrium and performance. Specifically, fixed point theory and order theory are used to prove the existence of a least fixed point as the unique Nash equilibrium (NE) of the game and the optimal choice of all players. The Krasovskii's method is used to construct a Lyapunov function and obtain the conditions to examine the stability of the NE. Simulations show that the theories derived are applicable to large-scale distributed systems of complicated network topologies. An empirical relationship between the network connectivity and the achievable total throughput is finally obtained through simulations.
description: 26 pages, 9 figures, 1 table, accepted by IEEE Transactions on Wireless Communications, June 15, 2013
title: Management of autonomous power supply system with priority connection of consumers
Creators: name: Matveev, Yu.V.
Publisher: name: Scientific Research Centre "MachineStructure"
Year: 2019

description: In some cases, when consumers are powered by an autonomous power supply system, the problem arises of their priority connection to electric power sources. Such tasks can be solved on the basis of a queuing system operating in priority mode without interruption. To this end, the possibility of using a digital control system with an assessment of the main parameters of the system’s functioning is being considered.
Intramuscular Inflammation, Exercise and Muscle Wasting in Chronic Kidney Disease
Creators: name: O’Sullivan, Thomas F.
Publisher: name: University of Leicester
Year: 2021
Subjects: Uncategorized

description: Chronic kidney disease (CKD) patients suffer from skeletal muscle wasting. This is a debilitating complication that has a significant impact on morbidity, mortality and quality of life. Despite these severe consequences, our understanding of why CKD patients lose muscle mass is incomplete, hindering preventative measures. Therefore, mechanistic research is of paramount importance to develop effective preventative interventions.In the thesis, low muscle mass was demonstrated in non-dialysis CKD patients (Chapter 4). This was associated with reduced physical function and was concurrent with systemic and intramuscular inflammation, potentially representing a mechanism for muscle loss in CKD. Within this field, there is a reliance on immortalised cell lines which lack translation to human physiology. To address this limitation, a cell culture model of human primary skeletal muscle cells derived from biopsies collected from CKD patients was characterised (Chapter 5) and used to demonstrate that CKD derived myoblasts and myotubes do not retain in vivo characteristics of muscle wasting and dysfunction. Alternatively, recreation of the in vivo systemic environment by culturing human derived cells in serum from CKD patients increased myoblast proliferation and decreased myotube diameter (Chapter 6). There was also evidence of reduced Akt phosphorylation in response to CKD derived serum (Chapter 7). However similar, but less pronounced, effects were also seen in response to serum derived from healthy controls. Therefore, further work is required to delineate the effect of the systemic CKD environment on human skeletal muscle cells in vitro.The work presented in this thesis is the first example of the use of human primary skeletal muscle cells in renal research, thereby providing a novel contribution to the literature. Further development of this model and research studying the effect of the systemic and intramuscular uraemic environment on human derived skeletal muscle cells will expand our understanding of why CKD patients experience muscle loss, highlighting avenues for potential therapies.
Atmosphere-ocean dynamics of persistent cold states of the tropical Pacific Ocean
Creators: name: Seager, Richard
name: Henderson, Naomi L.
name: Cane, Mark A.
name: Zhang, Honghai
name: Nakamura, Jennifer A.
Publisher: name: Columbia University
Year: 2021
Subjects: Ocean-atmosphere interaction
Thermoclines (Oceanography)
Thermodynamics

description: Persistent multiyear cold states of the tropical Pacific Ocean drive hydroclimate anomalies worldwide, including persistent droughts in the extratropical Americas. Here, the atmosphere and ocean dynamics and thermodynamics of multiyear cold states of the tropical Pacific Ocean are investigated using European Centre for Medium-Range Weather Forecasts reanalyses and simplified models of the ocean and atmosphere. The cold states are maintained by anomalous ocean heat flux divergence and damped by increased surface heat flux from the atmosphere to ocean. The anomalous ocean heat flux divergence is contributed to by both changes in the ocean circulation and thermal structure. The keys are an anomalously shallow thermocline that enhances cooling by upwelling and anomalous westward equatorial currents that enhance cold advection. The thermocline depth anomalies are shown to be a response to equatorial wind stress anomalies. The wind stress anomalies are shown to be a simple dynamical response to equatorial SST anomalies as mediated by precipitation anomalies. The cold states are fundamentally maintained by atmosphere-ocean coupling in the equatorial Pacific. The physical processes that maintain the cold states are well approximated by linear dynamics for ocean and atmosphere and simple thermodynamics.
Mechanisms of winter precipitation variability in the European-Mediterranean region associated with the North Atlantic Oscillation
Creators: name: Seager, Richard
name: Liu, Haibo
name: Kushnir, Yochanan
name: Osborn, Timothy J.
name: Simpson, Isla R.
name: Kelley, Colin R.
name: Nakamura, Jennifer A.
Publisher: name: Columbia University
Year: 2020
Subjects: Rain and rainfall
Hydrometeorology
North Atlantic oscillation
Climatic changes

description: The physical mechanisms whereby the mean and transient circulation anomalies associated with the North Atlantic Oscillation (NAO) drive winter mean precipitation anomalies across the North Atlantic, Europe and the Mediterranean are investigated using the European Centre for Medium Range Weather Forecasts Interim Reanalysis. A moisture budget decomposition is used to identify the contribution of the anomalies in evaporation, the mean flow, storm tracks and the role of moisture convergence and advection. Over the eastern North Atlantic, Europe and the Mediterranean, precipitation anomalies are primarily driven by the mean flow anomalies with, for a positive NAO, anomalous moist advection causing enhanced precipitation in the northern British Isles and Scandinavia and anomalous mean flow moisture divergence causing drying over continental Europe and the Mediterranean region. Transient eddy moisture fluxes work primarily to oppose the anomalies in precipitation minus evaporation generated by the mean flow but shifts in storm track location and intensity help explain regional details of the precipitation anomaly pattern. The extreme seasonal precipitation anomalies that occurred during the two winters with the most positive (1988/89) and negative (2009/10) NAO indices are also explained by NAO-associated mean flow moisture convergence anomalies.
Transfer reaction experiments with radioactive beams: from halos to the r-process
Creators: name: Jones, Kate L.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Transfer reactions are a powerful probe of the properties of atomic nuclei. When used in inverse kinematics with radioactive ion beams they can provide detailed information on the structure of exotic nuclei and can inform nucleosynthesis calculations. There are a number of groups around the world who use these reactions, usually with particle detection in large silicon arrays. Sometimes these arrays are coupled to gamma-ray detectors, and occasionally smaller arrays of silicon detectors are mounted within a solenoid magnet. Modern techniques using transfer reactions in inverse kinematics are covered, with specific examples, many from measurements made with beams from the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory.
description: From the proceedings of Nobel Symposium 152: Physics with Radioactive Beams, Goteborg, Sweden, Spring 2012
Global Southerners in the North
Creators: name: Francis, Ama R.
Publisher: name: Columbia University
Year: 2021
Subjects: International law
Capitalism
Environmental justice--Political aspects
Climatic changes--Political aspects
Climatic changes

description: Third World Approaches to International Law (TWAIL) scholarship contends that international law privileges nation-states in the Global North over those in the Global South. The literature primarily draws on a Westphalian conception of the North-South divide in analyzing asymmetrical issues of power in the global political economy. Given the expansion of global capitalism, however, the nation-state-based mode of analysis misses the fact that there are Global Souths in the geographic North and Global Norths in the geographic South. This Essay makes two theoretical claims. First, it argues that racial capitalism renders expendable populations across the geographic North and South, destabilizing the Westphalian North-South structure. Global Southerners, defined by their positionality as capitalism’s externalities, exist across the North-South schema. The Essay uses climate displacement as an example. The adverse effects of carbon pollution combine with postcolonial legacy and contemporary imperialism to transmogrify the lives, livelihoods, and homelands of Black, Indigenous, and People of Color (BIPOC) around the world into the hidden cost of industrialization. Climate change, an issue that challenges strict notions of national borders, serves as germane material in the Essay’s work to deterritorialize the notion of the North-South divide. Second, this Essay names the existence of Global Southerners in the geographic North as a heretofore unnamed site of resistance for reordering the North-South divide in international law. It leverages the author’s deterritorialized view of the Global South to claim that Global Southerners are political agents with the capacity to shift the global political economy of international law. Although others have begun to reimagine the Global South beyond geographical lines in order to articulate a theory of resistance in international law, this Essay seeks to break new ground by highlighting the particular power of Global Southerners residing in the geographic North. As such, this Essay reinvigorates the central TWAIL question of how to shift power along the North-South divide.
Developing organizational learning for scaling-up community-based primary health care in Ghana
Creators: name: Awoonor-Williams, John Koku
name: Phillips, James F.
Publisher: name: Columbia University
Year: 2021
Subjects: Organizational learning
Primary health care
Community health services

description: Introduction: Achieving effective community-based primary health care requires evidence for guiding strategic decisions that must be made.. However, research processes often limit data collection to particular organizational levels or disseminate results to specific audiences. Decision-making that emerges can fail to account for the contrasting perspectives and needs of managers at each organizational level. The Ghana Health Service (GHS) addressed this problem with a multi-level and sequential research and action approach that has provided two decades of implementation learning for guiding community-based primary health care development. Methods: The GHS implementation research initiatives progressed from i) a participatory pilot investigation to ii) an experimental trial of strategies that emerged, to iii) replication research for testing scale-up, culminating in iv) evidence-based scale-up of a national community-based primary health care program. A reform process subsequently repeated this sequence in a manner that involved stakeholders at the community, sub-district, district and regional levels of the system. The conduct, interpretation, and dissemination of results that emerged comprised a strategy for achieving systems learning by conducting investigations in phases in conjunction with “bottom up” knowledge capture, lateral exchanges for fostering peer learning at each system level, and top-down processes for communicating results as policy. Continuous accumulation of qualitative data on stakeholder reactions to operations at each organizational level was conducted in conjunction with quantitative monitoring of field operations. Results: Implementation policies were enhanced by results associated with each phase. A quasi-experiment for testing the reform process showed that scale-up of community-based primary health care was accelerated, leading to improvements in childhood survival and reduced fertility. Conclusion: Challenges to system learning were overcome despite severe resource constraints. The integration of knowledge generation with ongoing management processes institutionalized learning for achieving evidence-driven program action.
New Diluted Ferromagnetic Semiconductor isostructural to 122 type iron pnictide superconductor with TC up to 180 K
Creators: name: Zhao, K.
name: Deng, Z.
name: Wang, X. C.
name: Han, W.
name: Zhu, J. L.
name: Li, X.
name: Liu, Q. Q.
name: Yu, R. C.
name: Goko, T.
name: Frandsen, B.
name: Liu, Lian
name: Ning, Fanlong
name: Uemura, Y. J.
name: Dabkowska, H.
name: Luke, G. M.
name: Luetkens, H.
name: Morenzoni, E.
name: Dunsiger, S. R.
name: Senyshyn, A.
name: Böni, P.
name: Jin, C. Q.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Diluted magnetic semiconductors (DMS) have received much attention due to its potential applications to spintronics devices. A prototypical system (Ga,Mn)As has been widely studied since 1990s. The simultaneous spin and charge doping via hetero-valence (Ga3+,Mn2+) substitution, however, resulted in severely limited solubility without availability of bulk specimens. Previously we synthesized a new diluted ferromagnetic semiconductor of bulk Li(Zn,Mn)As with Tc up to 50K, where isovalent (Zn,Mn) spin doping was separated from charge control via Li concentrations. Here we report the synthesis of a new diluted ferromagnetic semiconductor (Ba1-xKx)(Zn1-yMny)2As2, isostructural to iron 122 system, where holes are doped via (Ba2+, K1+), while spins via (Zn2+,Mn2+) substitutions. Bulk samples with x=0.1-0.3 and y=0.05-0.15 exhibit ferromagnetic order with TC up to 180K, comparable to that of record high Tc for Ga(MnAs), significantly enhanced than Li(Zn,Mn)As. Moreover the (Ba,K)(Zn,Mn)2As2 shares the same 122 crystal structure with semiconducting BaZn2As2, antiferromagnetic BaMn2As2, and superconducting (Ba,K)Fe2As2, which makes them promising to the development of multilayer functional devices.
description: 12 pages, 3 Figures, 3 tables
Wittgenstein in the Machine
Creators: name: Liu, Lydia H.
Publisher: name: Columbia University
Year: 2021
Subjects: Artificial intelligence
Ordinary-language philosophy
Machine translating

description: This article brings to light how AI research has benefited from post-Wittgensteinian philosophy. My research shows that Wittgenstein’s work began to engage the attention of AI researchers not only in the 1970s down to the present but right from the early beginnings of computational research in the 1950s. More specifically, his later philosophy inspired a group of researchers called the Cambridge Language Research Unit (CLRU) to start one of the first programs in machine translation, information retrieval, mechanical abstracting, and knowledge representation technologies in the early 1950s, all of which have later been claimed for AI and cognitive science. I focus on the philosophical work of CLRU founder Margaret Masterman and her extraordinary but forgotten contributions to ordinary language philosophy.
Transonic wind tunnel for investigation of turbomachinery blades
Creators: name: Dolait, Jean-Pierre
Publisher: name: California Institute of Technology
Year: 1972
Subjects: Aeronautics

description: The design of a two-stream wind tunnel was undertaken to allow
the simulation and study of certain features of the flow field around
the blades of high-speed axial-flow turbomachineries. The mixing of
the two parallel streams with designed Mach numbers respectively
equal to 1.4 and 0.7 will simulate the transonic Mach number distribution
generally obtained along the tips of the first stage blades in
large bypass-fan engines.

The GALCIT hypersonic compressor plant will be used as an
air supply for the wind tunnel, and consequently the calculations contained
in the first chapter are derived from the characteristics and
the performance of this plant.

The transonic part of the nozzle is computed by using a method
developed by K. O. Friedrichs. This method consists essentially of
expanding the coordinates and the characteristics of the flow in power
series. The development begins with prescribing, more or less arbitrarily,
a Mach number distribution along the centerline of the nozzle.
This method has been programmed for an IBM 360 computer to define
the wall contour of the nozzle.

A further computation is carried out to correct the contour for
boundary layer buildup. This boundary layer analysis included geometry,
pressure gradient, and Mach number effects. The subsonic nozzle
is calculated {including boundary layer buildup) by using the same
computer programs. Finally, the mixing zone downstream of the splitter
plate was investigated to prescribe the wall contour correction necessary
to ensure a constant-pressure test section.
Monte-Carlo study of the semimetal-insulator phase transition in monolayer graphene with realistic inter-electron interaction potential
Creators: name: Ulybyshev, M. V.
name: Buividovich, P. V.
name: Katsnelson, M. I.
name: Polikarpov, M. I.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We report on the results of the first-principle numerical study of spontaneous breaking of chiral (sublattice) symmetry in suspended monolayer graphene due to electrostatic interaction, which takes into account the screening of Coulomb potential by electrons on $σ$-orbitals. In contrast to the results of previous numerical simulations with unscreened potential, we find that suspended graphene is in the conducting phase with unbroken chiral symmetry. This finding is in agreement with recent experimental results by the Manchester group \cite{Elias et al, 2011}. Further, by artificially increasing the interaction strength we demonstrate that suspended graphene is quite close to the phase transition associated with spontaneous chiral symmetry breaking, which suggests that fluctuations of chirality and nonperturbative effects might still be quite important.
description: 5 pages, 2 figures, minor corrections, accepted for publication in PRL
Organizational learning—COVID-19 experience: innovative global practices for improving patient care in crisis response
Creators: name: Muskopf, Jamie H.
name: Sudan, Nimit
name: Verdooner, Elise
name: Nair, Murali D.
Publisher: name: Columbia University
Year: 2021
Subjects: COVID-19 (Disease)
Emergency management
Medical care
Organizational learning

description: Across human history, civilizations have responded to disasters and outbreaks of disease with increasingly complex, systematic approaches as a means of organizing chaos and protecting human life. The SARS-CoV-2 coronavirus (COVID-19) pandemic provides a unique opportunity to learn from the practice of disaster management and crisis-driven changes to patient care processes in hospital and emergent care environments worldwide. COVID-19 acts as an accelerant for process change and the need for redesign in systems where classical, linear evaluation methods most often inform carefully implemented service improvements. Strikingly, many innovative approaches and valuable lessons come from all over the globe where technology and access to resources have been most limited. This article answers the question, what can we learn about how to respond to future disasters from the evolution of disaster management as performed by helping professionals and policymakers during the past hundred-plus years and best practices seen today? Macro practitioners have co-created unique approaches within several global communities to help cope with COVID-19 and other disasters despite limited resources and seemingly unlimited needs. Referencing existing case studies of patient care responses during COVID-19 in Italy, Nigeria, South Africa, South Korea, and the United States, the authors document innovative practices and use of diverse technologies in local patient care systems. The article concludes by suggesting best practices for designing more robust, adaptive, and crisis ready responses to patient care, as well as the use of developmental evaluation as an agile approach to evaluating and improving patient services. It also suggests roles that helping professionals can play in the translation of big data systems of disaster management from organizations such as the Center for Disease Control, World Health Organization, non-governmental organizations (NGOs), and selected think tanks, among others.
A magnetic survey of Sand Canyon for placer deposits, San Gabriel Mountains, California
Creators: name: Dehlinger, Peter
Publisher: name: California Institute of Technology
Year: 1943
Subjects: subject: San Gabriel Mountains
subject: Sand Canyon
subject: Geology
subject: FOS: Earth and related environmental sciences
subject: placer deposits

description: A magnetic survey was made in Sand Canyon, which
is in the northwestern part of the San Gabriel Mountains,
the object being to locate possible placer deposits. The
bedrock in this area is an iron rich igneous rock which
has been intruded by numerous dikes. The stream gravels
consist of large boulders interspersed with highly magnetic
sands.

Over 200 stations were involved in the survey in which vertical magnetic intensity was measured using a Schmidt-type vertical magnetometer. Magnetic anomalies found were
so large that all instrument corrections were ignored.

Results of the survey show that the magnetic intensity readings are due to both the basement and the gravels, though the gravels have a greater effect. The location of the largest anomalies, thus the most probable placers, is at the eastern end of the area. Downstream from this site the intensity decreases rather uniformly; upstream it decreases very sharply where the canyon narrows suddenly. Geologically, this is the expected picture. It is thought that a fault has been located, which strikes up the canyon, but this has not been confirmed by surface evidence.

Data and profiles of the traverses, and a detailed map of the magnetic intensities of the region are included in this paper.
S^2 x S^3 geometries in ABJM and giant gravitons
Creators: name: Lozano, Yolanda
name: Prinsloo, Andrea
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We construct a new NS5-brane solution in AdS_4 x CP^3 with S^2 x S^3 topology. This solution belongs to the general class of non-Einstein N_{11} metrics to which T^{1,1} belongs, and carries a non-vanishing D0-brane charge. In eleven dimensions it gives rise to a squashed S^2 x S^3 M5-brane giant graviton which is now of the N_{10} type. The energies of both solutions satisfy the BPS bound E=kQ/2, indicating supersymmetric configurations, where Q is interpreted as D0-brane charge for the NS5-brane and as angular momentum for the dynamically stable M5-brane giant graviton. The ground state is degenerate with a spherical D2 or M2-brane, rather than with a point-like object. Moreover, while the charge of the spherical 2-brane can be arbitrary, the charge of the S^2 x S^3 5-brane is bounded by N/2, with N the rank of the ABJM gauge group, a manifestation of the stringy exclusion principle. A microscopic description, suitable for the study of the finite 't Hooft coupling region, is provided in terms of spherical D2 or M2-branes expanding into fuzzy 3-spheres.
description: 30 pages; 2 figures; change to JHEP3 style; minor revisions
“Internally Wicked”: Investigating How and Why Essentialism Influences Punitiveness and Moral Condemnation
Creators: name: Martin, Justin
name: Heiphetz, Larisa A.
Publisher: name: Columbia University
Year: 2021
Subjects: subject: Essentialism (Philosophy)
subject: Ethics
subject: Social perception
subject: Punishment
subject: Law
subject: FOS: Law
subject: Criminal justice, Administration of--Public opinion

description: Kant argued that individuals should be punished “proportional to their internal wickedness,” and recent work has demonstrated that essentialism—the notion that observable characteristics reflect internal, biological, unchanging “essences”—influences moral judgment. However, these efforts have yielded conflicting results: essentialism sometimes increases and sometimes decreases moral condemnation. To resolve these discrepancies, we investigated the mechanisms by which essentialism influences moral judgment, focusing on perceptions of actors’ control over their behavior, the target of essentialism (particular behaviors versus actors’ character), and the component of essentialism (biology versus immutability). Participants punished people described as having a criminal essence more than those with a non-criminal essence or no essence. Probing potential mechanisms underlying this effect, we found a mediating role for perceptions of control and weak influences of essentialism focus (behavior versus character) and component of essentialism (biology versus immutability). These results extend prior work on essentialism and moral cognition, demonstrating a causal link between perceptions of “internal wickedness” and moral judgment. Our findings also resolve discrepancies in past work on the influence of essentialism on moral judgment, highlighting the role that perceptions of actors’ control over their behavior play in moral condemnation.
Pathways for minimal and zero liquid discharge with enhanced reverse osmosis technologies: Module-scale modeling and techno-economic assessment
Creators: name: Atia, Adam Ahmed
name: Yip, Ngai Yin
name: Fthenakis, Vasilis M.
Publisher: name: Columbia University
Year: 2021
Subjects: subject: Saline water conversion
subject: Saline water conversion--Reverse osmosis process
subject: Saline water conversion--Reverse osmosis process--Costs
subject: Environmental engineering
subject: FOS: Environmental engineering

description: While mechanical vapor compression is typically applied for the concentration of brine, new approaches that are less costly and less energy intensive are needed to facilitate minimal and zero liquid discharge. Several variations of reverse osmosis for high-salinity desalination and increasing recovery rates beyond the pressure limitation of conventional RO have been proposed in the literature. The promise of these enhanced RO approaches entails a reduction in energy consumption when compared with thermal desalination methods. In this paper, low-salt rejection reverse osmosis (LSRRO), cascading osmotically mediated reverse osmosis (COMRO), and osmotically assisted reverse osmosis (OARO) were comparatively assessed via module-scale, cost optimization models to gain an accurate perspective of the performance differences between each of these configurations. We quantified the optimal levelized cost of water (LCOW) of each technology for the case of desalinating feedwater at 70 g/L at 75% recovery, which would result in a brine concentration near 250 g/L, a level that allows further treatment with crystallizers. For baseline scenarios, LCOW results for LSRRO, COMRO, and OARO were 6.63, 7.90, and 5.14 $/m3 of product water, respectively, while the corresponding specific energy consumption (SEC) values were 28.9, 12.8, and 10.3 kWh/m3. A sensitivity analysis is also presented.
Superflares on Solar-Type Stars Observed with Kepler II. Photometric Variability of Superflare-Generating Stars : A Signature of Stellar Rotation and Starspots
Creators: name: Notsu, Yuta
name: Shibayama, Takuya
name: Maehara, Hiroyuki
name: Notsu, Shota
name: Nagao, Takashi
name: Honda, Satoshi
name: Ishii, Takako T.
name: Nogami, Daisaku
name: Shibata, Kazunari
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We performed simple spot-model calculations for quasi-periodic brightness variations of solar-type stars showing superflares, by using Kepler photometric data. Most of superflare stars show quasi-periodic brightness modulations with the typical period of one to a few tens of days. Our results indicate that these brightness variations of superflare stars can be explained by the rotation of the star with fairly large starspots. Using the result of the period analysis, we investigated the relation between the energy and frequency of superflares and the rotation period. Stars with relatively slower rotation rates can still produce flares that are as energetic as those of more rapidly rotating stars, although the average flare frequency is lower for more slowly rotating stars. We found that the energy of superflares are related to the total coverage of starspots. The correlation between the spot coverage and the flare energy in superflares is similar to that in solar flares. These results suggest that the energy of superflares can be explained by the magnetic energy stored around starspots.
description: 34 pages, 10 figures, Published. (2013, ApJ, 771, 127)
Sound Absorption and Dispersion in Dilute Polyatomic Gases: A Generalized Kinetic Approach
Creators: name: Fischer, Sebastian
name: Marques, Wilson
Publisher: name: arXiv
Year: 2013
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: A generalized kinetic model equation which takes into account the frequency depence of the thermal conductivity is used to analyze the problem of sound propagation in dilute polyatomic gases. By comparing the theoretical results with some available experimental data we infer that our model equation provides a precise transition between low and high-frequency limits.
description: 16 pages, 2 figures
The performance of jet propelled space vehicles
Creators: name: Fischer, Charles Fink
Publisher: name: California Institute of Technology
Year: 1941
Subjects: Aeronautics
Aeronautical Engineering

description: This thesis presents an investigation of the steady state performance of space vehicles partially propelled by jets, the acceleration period required to reach the steady state, the use of jets for the assisted take off of flying boats, and the general economic aspects of jet propulsion applied to aircraft.
Nodes having a major influence to break cooperation define a novel centrality measure: game centrality
Creators: name: Simko, Gabor I.
name: Csermely, Peter
Publisher: name: arXiv
Year: 2013
Subjects: subject: Molecular Networks (q-bio.MN)
subject: Computer Science and Game Theory (cs.GT)
subject: Social and Information Networks (cs.SI)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Biological sciences
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Cooperation played a significant role in the self-organization and evolution of living organisms. Both network topology and the initial position of cooperators heavily affect the cooperation of social dilemma games. We developed a novel simulation program package, called 'NetworGame', which is able to simulate any type of social dilemma games on any model, or real world networks with any assignment of initial cooperation or defection strategies to network nodes. The ability of initially defecting single nodes to break overall cooperation was called as 'game centrality'. The efficiency of this measure was verified on well-known social networks, and was extended to 'protein games', i.e. the simulation of cooperation between proteins, or their amino acids. Hubs and in particular, party hubs of yeast protein-protein interaction networks had a large influence to convert the cooperation of other nodes to defection. Simulations on methionyl-tRNA synthetase protein structure network indicated an increased influence of nodes belonging to intra-protein signaling pathways on breaking cooperation. The efficiency of single, initially defecting nodes to convert the cooperation of other nodes to defection in social dilemma games may be an important measure to predict the importance of nodes in the integration and regulation of complex systems. Game centrality may help to design more efficient interventions to cellular networks (in forms of drugs), to ecosystems and social networks. The NetworGame algorithm is downloadable from here: www.NetworGame.linkgroup.hu
description: 18 pages, 2 figures, 3 Tables + a supplement containing 8 pages, 1 figure, 2 Tables and the pseudo-code of the algorithm, the NetworGame algorithm is downloadable from here: http://www.NetworGame.linkgroup.hu
Influence of Solute Molecular Diameter on Permeability-Selectivity Tradeoff of Thin-Film Composite Polyamide Membranes in Aqueous Separations
Creators: name: Chen, Xi
name: Boo, Chanhee
name: Yip, Ngai Yin
Publisher: name: Columbia University
Year: 2021
Subjects: subject: Membranes (Technology)
subject: Thin films
subject: Polymers--Permeability
subject: Water chemistry
subject: Reverse osmosis
subject: Environmental engineering
subject: FOS: Environmental engineering

description: Fundamental understanding of the reverse osmosis (RO) transport phenomena is necessary for quantitative prediction of contaminant rejection and development of more selective membranes. The solution-diffusion (S-D) model predicts a tradeoff relationship between permeability and selectivity, and this tradeoff trend was recently reported for RO. But the first principles governing the relationship are not well understood for aqueous separation membranes. This study presents a framework to elucidate the underlying factors of the permeability-selectivity tradeoff relationship in thin-film composite polyamide (TFC-PA) membranes. Water and solute permeabilities of membranes with a range of selectivities are examined using six nonelectrolyte solutes of various sizes and dimensions. The permeability-selectivity tradeoff trend, as defined by S-D, was observed for all six solutes. Crucially, the slopes of the tradeoff lines, λ, are found to be related to the solute and solvent (i.e., water) diameters, ds and dw, respectively, by λ = (ds/dw)^2 – 1, consistent with the S-D framework established for gas separation membranes. Additionally, the intercepts of the tradeoff lines are shown to be also influenced by ds. These results highlight that solute molecular diameter is a primary influence on the permeability-selectivity tradeoff for the permeants investigated in this study. Furthermore, a transport regime where solute permeation is only very weakly coupled to water transport, in addition to the conventional S-D, is identified for the first time. We demonstrate that the boundary delineating the two transport regimes can be determined by the solute diameter. The relationship between characteristic features of the “additional regime” and solute dimensions are analyzed. The study shows that the general principles of the S-D framework are applicable to TFC-PA membranes and the analysis quantified the principal role of solute size in governing RO transport. The experimental and analytical evidence suggest that nonelectrolyte solute transport can, in principle, be a priori predicted using molecular diameter. Findings of this investigation provide new insights for understanding the transport mechanisms in osmotic membrane processes.
Unique continuation from conical boundary points for fractional equations
Creators: name: De Luca, Alessandra
name: Felli, Veronica
name: Vita, Stefano
Publisher: name: arXiv
Year: 2024
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 31B25, 35R11, 35C20, 35J75, 35A16

description: We provide fine asymptotics of solutions of fractional elliptic equations at boundary points where the domain is locally conical; that is, corner type singularities appear. Our method relies on a suitable smoothing of the corner singularity and an approximation scheme, which allow us to provide a Pohozaev type inequality. Then, the asymptotics of solutions at the conical point follow by an Almgren type monotonicity formula, blow-up analysis and Fourier decomposition on eigenspaces of a spherical eigenvalue problem. A strong unique continuation principle follows as a corollary.
description: 33 pages, 3 figures
Access to thermostable enzymes and their application in flow biocatalysis
Creators: name: Stoeckle, Marius
Publisher: name: Karlsruher Institut für Technologie (KIT)
Year: 2022

description: The immobilization of biocatalysts in a continuous fluidic setup is one way to achieve compartmentalization and thus precise control over artificial reaction cascades for synthetic chemistry. We recently demonstrated the encapsulation of unmodified thermostable enzymes in a 3D printed, agarose-based thermoreversible hydrogel to enable multi-step sequential biotransformations.[1] To test the feasibility of the encapsulation strategy, we used a naturally thermostable alcohol dehydrogenase (ADH) as well as a ketoisovalerate decarboxylase (KIVD) from a mesophile organism as exemplary biocatalysts. KIVD was thermostabilized by different computational or evolutionary methods to increase the T50 value by up to 9°C.[1,2] After the successful proof-of-concept study, we further expanded the scope of this system by integrating phenacrylate decarboxylases (PAD) into this microfluidic system.[3] As an alternative for the hydrogel based immobilization strategy, thermostable enzymes can be covalently attached onto beads in a packed-bed reactor. In this context thermostable enzymes offer improved process stability and we selected a benzaldehyde lyase (BAL) as an example, since only one enzyme had been biochemically characterized before, which was rather instable.[4] To this end, we employed a computational prediction tool[5] for the identification of a novel thermostable benzaldehyde lyase and employed the enzyme for the continuous production of α-hydroxy-ketones. A homology-model based approach was used to create enzyme variants with altered substrate scope, which also showed further increased thermal stability.
Effect of Reynolds number on the flow about a finite cone of 70 degrees
Creators: name: Bottenberg, William R.
Publisher: name: California Institute of Technology
Year: 1949
Subjects: Aeronautics

description: An investigation was made to determine the effect of Reynolds number on the flow about a cone of 70 degrees apex angle with free stream Mach numbers close to the Mach number for shock attachment.

Conditions existing on the forward half of a one-half inch diameter cone were investigated at two Mach numbers, one giving a slightly detached shock and one giving a slightly attached shock, at Reynolds numbers from 150,000 to 1,300,000 based on model diameter.

Close to the apex the static pressure on the surface of the cone divided by the stagnation pressure before the shock was found to be dependent upon the Reynolds number at the lowest Reynolds number when the shock was detached but not when the shock was attached.  In both cases at a distance half way back on the cone there was a continuous increase in this ratio with increasing Reynolds number.  All of these Reynolds number effects were small in magnitude.

The investigation was conducted in the GALCIT 2.5” Supersonic Wind Tunnel.
Crossover from adiabatic to antiadiabatic phonon-assisted tunneling in single-molecule transistors
Creators: name: Eidelstein, Eitan
name: Goberman, Dotan
name: Schiller, Avraham
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The crossover between two customary limits of phonon-assisted tunneling, the adiabatic and antiadiabatic regimes, is studied systematically in the framework of a minimal model for molecular devices: a resonant level coupled by displacement to a localized vibrational mode. Conventionally associated with the limits where the phonon frequency is either sufficiently small or sufficiently large as compared to the bare electronic hopping rate, we show that the crossover between the two regimes is governed for strong electron-phonon interactions primarily by the polaronic shift rather than the phonon frequency. In particular, the perturbative adiabatic limit is approached only as the bare hopping rate Γexceeds the polaronic shift, leaving an extended window of couplings where Γwell exceeds the phonon frequency and yet the physics is basically that of the antiadiabatic regime. We term this intermediate regime the extended antiadiabatic regime. The effective low-energy Hamiltonian in the traditional and the extended antiadiabatic regime is shown to be the (purely fermionic) interacting resonant-level model, with parameters that we extract from numerical renormalization-group calculations. The extended antiadiabatic regime is followed in turn by a true crossover region where the polaron gets progressively undressed. The renormalized tunneling rate, which serves as the low-energy scale in the problem and thus sets the width of the tunneling resonance, is found to follow an approximate scaling form on going from the adiabatic to the antiadiabatic regime. Charging properties are governed by two distinct mechanisms at the extended antiadiabatic and into the crossover region, giving rise to distinctive shoulders in the low-temperature conductance as a function of gate voltage.
description: 19 pages, 14 figures
Squatting in New South Wales 1880-1905 : the pastoral finance company view
Creators: name: Cain, Neville G.
Publisher: name: Canberra, ACT : The Australian National University
Year: 1961
Subjects: subject: Land settlement Australia New South Wales
subject: Corporations Finance Australia New South Wales
subject: New South Wales Economic conditions

description: The following is an essay in one phase of Australian economic development; the advance of squatting into the more arid and unfamiliar regions of New South Wales and its subsequent retreat therefrom. It is an essay in the acquisition of Knowledge; the costs of that acquisition and the way in which they were shared by all involved in western squatting.
U.S. Climate Litigation in the Age of Trump: Full Term
Creators: name: Silverman-Roati, Korey G.
Publisher: name: Columbia University
Year: 2021
Subjects: Climatic changes
Environmental law
Deregulation
Trials, litigation, etc.

description: In response to a presidential administration uniquely committed to climate deregulation, hundreds of litigants turned to the judiciary. At least 378 cases filed in courts across the United States responded to or interacted with the Trump administration’s agenda of climate deregulation. Of those, 89% aimed at climate protection or weakening climate deregulation and 11% aimed at furthering climate deregulation or undermining those seeking climate protection. Pro-climate protection plaintiffs filed the greatest number of cases aiming to integrate climate change into environmental review and permitting, but also filed cases in significant numbers to defend climate policies, demand transparency, and advance climate protections. The most common plaintiffs/petitioners in “pro” cases were NGOs, followed next by government entities, and the most common filing parties in “con” cases were industry actors. The federal government was by far the most common defendant in all cases, with the Department of Interior the most sued agency. In terms of the sectors implicated in the cases, the highest number raised claims based on the climate impacts on the environment, and the second highest number involved fossil fuel development. Litigants based their suits on federal environmental statutes and administrative law in high numbers, and cited the National Environmental Policy Act most often in their suits. Many of these trends reflect high numbers of cases filed by NGOs against the federal government alleging unlawful failure to consider climate change in their permitting of fossil fuel projects, or in their decisions regarding endangered species.