Miracle-dz/UniFAR-FTUs huggingface dataset:
The structure of the Cepheus E protostellar outflow: The jet, the bowshock, and the cavity

Context. Protostellar outflows are a crucial ingredient of the star-formation process. However, the physical conditions in the warm outflowing gas are still poorly known. Aims. We present a multi-transition, high spectral resolution CO study of the outflow of the intermediate-mass Class 0 protostar Cep E-mm. The goal is to determine the structure of the outflow and to constrain the physical conditions of the various components in order to understand the origin of the mass-loss phenomenon. Methods. We have observed the J = 12–11, J = 13–12, and J = 16–15 CO lines at high spectral resolution with SOFIA/GREAT and the J = 5–4, J = 9–8, and J = 14–13 CO lines with HIFI/Herschel towards the position of the terminal bowshock HH377 in the southern outflow lobe. These observations were complemented with maps of CO transitions obtained with the IRAM 30 m telescope (J = 1–0, 2–1), the Plateau de Bure interferometer (J = 2–1), and the James Clerk Maxwell Telescope (J = 3–2, 4–3). Results. We identify three main components in the protostellar outflow: the jet, the cavity, and the bowshock, with a typical size of 1.7′′ × 21′′, 4.5′′, and 22′′ × 10′′, respectively. In the jet, the emission from the low-J CO lines is dominated by a gas layer at Tkin = 80–100 K, column density N(CO) = 9 × 1016 cm−2, and density n(H2) = (0.5−1) × 105 cm−3; the emission of the high-J CO lines arises from a warmer (Tkin = 400–750 K), denser (n(H2) = (0.5−1)× 106 cm−3), lower column density (N(CO) = 1.5× 1016 cm−2) gas component. Similarly, in the outflow cavity, two components are detected: the emission of the low-J lines is dominated by a gas layer of column density N(CO) = 7 × 1017 cm−2 at Tkin = 55–85 K and density in the range (1−8) × 105 cm−3; the emission of the high-J lines is dominated by a hot, denser gas layer with Tkin = 500–1500 K, n(H2) = (1−5) × 106 cm−3, and N(CO) = 6 × 1016 cm−2. A temperature gradient as a function of the velocity is found in the high-excitation gas component. In the terminal bowshock HH377, we detect gas of moderate excitation, with a temperature in the range Tkin ≈ 400–500 K, density n(H2) (1−2) × 106 cm−3 and column density N(CO) = 1017 cm−2. The amounts of momentum carried away in the jet and in the entrained ambient medium are similar. Comparison with time-dependent shock models shows that the hot gas emission in the jet is well accounted for by a magnetized shock with an age of 220–740 yr propagating at 20–30 km s−1 in a medium of density n(H2) = (0.5−1) × 105 cm−3, consistent with that of the bulk material. Conclusions. The Cep E protostellar outflow appears to be a convincing case of jet bowshock driven outflow. Our observations trace the recent impact of the protostellar jet into the ambient cloud, produing a non-stationary magnetized shock, which drives the formation of an outflow cavity.
Graphitization of n-type polycrystalline silicon carbide for on-chip supercapacitor application

Synthesis of silicon carbide-derived carbon films with excellent supercapacitor characteristics is demonstrated by a process that is fully compatible with standard microfabrication technology. NiTi alloy deposited on nitrogen-doped polycrystalline SiC films is shown to result in the growth of a rough, porous, high conductivity, nanocrystalline graphitic carbon film upon rapid thermal annealing to 1050 °C. Electrodes fabricated in this manner exhibit high charge/discharge rates with a time constant of about 0.062 s. Analysis shows that the incorporated nitrogen in the carbon electrode may induce pseudo-capacitance, and the electrodes exhibit the capacitance/area values comparable to those reported on carbon nanotube-based supercapacitors.
Refinery Pre-Heat Train Network Simulation Undergoing Fouling: Assessment of Energy Efficiency and Carbon Emissions

Fouling in crude preheat trains in oil refineries causes additional fuel and production costs, operating difficulties, CO2 emissions, and safety issues. Crude oil fouling deposition mechanisms are still not well understood. Current exchanger design methodologies (based on empirical fouling factors), operating practices, and mitigation solutions (ranging from the use of chemical additives to tube inserts) do not prevent efficiency losses or disruption of operations. Moreover, current analysis and design methodologies neglect local effects and dynamics of fouling, in favor of lumped, steady-state, “averaged” heuristic models. In this paper, a dynamic and distributed model recently developed that accounts for localized fouling growth as a function of process conditions is used to simulate the dynamic behavior of the hot end of a refinery preheat train. The network is simulated by a simultaneous solution of all exchangers, combined according to a desired configuration, within gPROMS, a commercial dynamic simulation environment. The overall network model allows capturing some complex interactions within the network over time and enables the rigorous computation of several key indicators which are highly dependent on fouling. These include throughput reduction, additional energy requirements, and overall economic and CO2 emission impacts.
Numerical Simulation of Unsteady Flow around Three Dimensional Bluff Bodies by an Advanced Vortex Method

Recently, the present authors have developed a vortex method for analyses of various two and three-dimensional unsteady flows, aiming its application to various engineering problems. In this paper, a new scheme is proposed for the vorticity creation at a solid surface of a three-dimensional body, in which a number of nascent vortices are introduced in the flow field according to the diffusion and the convection of the vorticity near the solid surface. As an example, the new scheme is applied to the analyses of starting flows around two kinds of bodies : a sphere and a prolate spheroid. As a result of this calculation, the boundary layer separation from the body surface and the development of vortical wake have been reasonably simulated.
A stable single-longitudinal-mode dual-wavelength erbium-doped fiber ring laser with superimposed FBG and an in-line two-taper MZI filter

A simple approach to fabricate a stable single-longitudinal-mode (SLM) dual-wavelength erbium-doped fiber ring laser with one superimposed fiber Bragg grating (FBG) is proposed and demonstrated. The superimposed FBG is fabricated by the dual-exposure method for wavelength selection. A home-made in-line two-taper Mach–Zehnder interferometer is incorporated to balance the intra-cavity loss for the wavelengths. The SLM operation is guaranteed by a feedback fiber loop and saturable absorber. A stable dual-wavelength SLM fiber ring laser with a wavelength spacing of approximately 8.53 nm is experimentally realized. The optical signal-to-noise ratio of the laser output is over 50 dB and the linewidth of each wavelength measured by the delayed self-heterodyne method is 9.67 kHz and 9.07 kHz, respectively. The proposed scheme offers the possibility for difference frequency generation of terahertz radiation.
Finite groups whose subnormal subgroups permute with all Sylow subgroups

As a generalization of (t)-groups and of (q)-groups, a group G is called a (i7 q)-group if every subnormal subgroup of G permutes with all Sylow subgroups of G. It is shown that if G is a finite solvable (i7 q)-group, then its hypercommutator subgroup D(G) is a Hall subgroup of odd order and every subgroup of D(G) is normal in G; conversely, if a group G has a normal Hall subgroup N such that G/N is a (i7 q)-group and every subnormal subgroup of N is normal in G, then G is a (iT q)-group. Let G be a finite group. Following Ore [6], a subgroup of G is called quasinormal in G if it permutes with all subgroups of G. As a generalization of this concept we say, following Kegel, that a subgroup of G is 77-quasinormal in G if it permutes with all Sylow subgroups of G. Kegel [5] proved that a i7-quasinormal subgroup is always a subnormal subgroup. Since a subnormal subgroup is not necessarily a i7-quasinormal subgroup, it seems natural to ask: "What can be said about the structure of a group if all of its subnormal subgroups are i7-quasinormal in the group? " We call such a group a (T q)-group and, in this paper, we study finite (Tq)groups. We especially study and characterize, in ? 2, finite solvable (iT q)-groups. Theorems 2.3, 2.4, and 2.5 establish the characterization. The (q)-groups and the (t)-groups (see the definitions below) have been studied by Zacher [8] and Gaschutz [2], respectively, and they have characterized such finite solvable groups. We extend their results to finite solvable (iT q)-groups and give the conditions under which a (U q)-group is either a (q)-group or a (t)-group. Throughout the paper, the groups are finite. Received by the editors June 26, 1973 and, in revised form, January 11, 1974. AMS (MOS) subject classifications (1970). Primary 20D10, 20D35.
GaAs metal–oxide–semiconductor field-effect transistor with nanometer-thin dielectric grown by atomic layer deposition

A GaAs metal–oxide–semiconductor field-effect transistor (MOSFET) with thin Al2O3 gate dielectric in nanometer (nm) range grown by atomic layer deposition is demonstrated. The nm-thin oxide layer with significant gate leakage current suppression is one of the key factors in downsizing field-effect transistors. A 1 μm gate-length depletion-mode n-channel GaAs MOSFET with an Al2O3 gate oxide thickness of 8 nm, an equivalent SiO2 thickness of ∼3 nm, shows a broad maximum transconductance of 120 mS/mm and a drain current of more than 400 mA/mm. The device shows a good linearity, low gate leakage current, and negligible hysteresis in drain current in a wide range of bias voltage.
Global solutions of adiabatic accretion flows with isothermal shocks in Kerr black hole geometry

This paper presents global solutions of adiabatic accretion flows with isothermal shocks in Kerr black hole geometry. It is known that in the previously studied cases, where the flow including the shock is either entirely adiabatic or entirely isothermal, there can be no more than one stable shock solution, and the solution can only be of α–x type. However, the solution topology in the present case shows remarkable new characteristics: for the same flow parameters there can be two stable shock solutions satisfying physical boundary conditions, and the solution can be of three types, namely α–x, x–α and α–α type. In addition, shocks in the present case occur for a parameter region different from that for Rankine–Hugoniot shocks. These results greatly increase the possibilities of shock formation in astrophysical flows. It is also significant that the effects of frame-dragging of a rapid Kerr black hole on the shock formation are discovered. Finally, a brief comparison is made between shocked inviscid flows and two types of shock-free viscous flows, namely those of Shakura & Sunyaev and Narayan & Yi, and some comments are made about the fact that numerous authors who have studied transonic global solutions of accretion flows have found no shocks.
Influence of long-term regional and large-scale atmospheric circulation on the Baltic sea level

The connection between variations in the North Atlantic Oscillation (NAO) index and theBaltic sea level has been investigated for the period 1825—1997. The association between theNAO and the strength of the zonal geostrophic wind stress over the Northwest Atlantic suggestsan NAO impact on Baltic sea level variations, because the monthly mean sea level mainly isdetermined by externally driven variations caused by wind conditions over the North Sea.Several period bands were found to have high correlation between oscillations in the winter(JFM) NAO index and the Baltic Sea winter mean sea level. The correlation was, however, higher in the 20th century than in the 19th. During the last two decades, the correlation betweenthe NAO index and the sea level has been exceptionally high. The winter mean of a regionalatmospheric circulation index had a correlation with the Kattegat winter mean sea level of 0.93. With the Baltic sea level the correlation was 0.91, compared with the NAO index correlationfor the same period of 0.74. The regional index also showed a high correlation with the meansummer and mean autumn sea levels, when the corresponding seasonal NAO indices showeda weak connection. The temporal variation of the connection with the NAO index implies aregional atmospheric circulation occasionally differing from the large-scale circulation associatedwith the NAO. Seasonal means of the sea level in Stockholm do, however, reflect theregional wind climate to a large extent, and the Baltic sea level is a useful proxy for identificationsof climatic dependencies in the region.
DIFFUSIVE CUT-OFF SCALE OF FRACTAL SURFACES IN CHAOTIC MIXING

Results concerning the fractal properties of isovalue surfaces of a passive, diffusive scalar field being advected by a three-dimensional, steady flow exhibiting chaotic streamlines are presented. For all the Peclet numbers and the flow fields studied, the mixing efficiency is shown to be related to the extent of the so-called advective zone for which the similarity dimension Ds is optimal in the sense of mixing (Ds=3). For global chaos, the effective mixing time can be related to the diffusive cut-off scale which bounds this zone. For partial chaos, this cut-off scale corresponds to the size of the regular region which limits asymptotically the mixing.
Far Ultraviolet Spectroscopic Explorer Atlas of OB Stars in the Magellanic Clouds

An atlas of the 900-1200 Å region in the spectra of 47 OB stars in the Large and Small Magellanic Clouds, observed at high resolution by the Far Ultraviolet Spectroscopic Explorer (FUSE), is presented and discussed. The systematic trends in the numerous stellar-wind features in this region, some from species (and ionizations) not represented at longer wavelengths, are charted as a function of the optical spectral types. The FUSE sample is by far the most powerful to date for that purpose. A special effort has been made to verify the spectral types of all stars included in the atlas, in a number of cases with new optical observations that are also illustrated, to avoid uncertainties from that source in the stellar-wind trends. A new O2 star has been found in the process. Most of these stars have been previously observed at longer ultraviolet wavelengths by the Hubble Space Telescope and in the optical from the ground with high-resolution, digital instruments; thus very comprehensive physical modeling of these OB atmospheres and winds now becomes possible. This atlas will serve as a guide to the FUSE Magellanic Cloud OB database for that purpose. The Magellanic Cloud sample provides a very important complement to the FUSE database of Galactic OB counterparts (Pellerin et al. 2002), both because the lower extinction and interstellar H2 absorption toward the Cloud stars allow a much clearer view of the stellar spectra below 1100 Å, and because of the metallicity differences among the three galaxies. In particular, most wind features in the SMC spectra are seen to be significantly weaker than those in the LMC at the same spectral types.
A Passive Microwave Technique for Estimating Rainfall and Vertical Structure Information from Space. Part I: Algorithm Description

Abstract This paper describes a multichannel physical approach for retrieving rainfall and vertical structure information from satellite-based passive microwave observations. The algorithm makes use of statistical inversion techniques based upon theoretically calculated relations between rainfall rates and brightness temperatures. Potential errors introduced into the theoretical calculations by the unknown vertical distribution of hydrometeors are overcome by explicitly accounting for diverse hydrometcor profiles. This is accomplished by allowing for a number of different vertical distributions in the theoretical brightness temperature calculations and requiring consistency between the observed and calculated brightness temperatures. This paper will focus primarily on the theoretical aspects of the retrieval algorithm, which includes a procedure used to account for inhomogeneities of the rainfall within the satellite field of view as well as a detailed description of the algorithm as it is applied over bo.
A pruned dual-tree discrete wavelet transform

This paper describes a new pruned dual-tree discrete wavelet transform (DWT), which is designed to reduce the redundancy while maintaining the orientations. The new transform is based on the dual-tree wavelet transform introduced by Kingsbury. The number of wavelets associated with the transform is reduced substantially for both 2D and 3D cases. Wavelets generated from the pruned dual-tree DWT have direction/motion selectivity and are free of the checkerboard artifact, which are efficient for signal applications, such as image and video processing. This paper also describes an algorithm to compute the Matching Pursuit decomposition with this transform. Examples are shown to illustrate the performance of the matching pursuit algorithm and the 2D and 3D pruned dual-tree wavelet transforms.
In vivo functional imaging of embryonic chick heart using ultrafast 1310nm-band spectral domain optical coherence tomography

During the cardiac development, the cardiac wall and the blood flow actively interact with each other, and determine the biomechanical environment to which the embryonic heart exposes. Employing an ultrafast 1310nm-band dual-camera spectral domain optical coherence tomography (SDOCT), the radial strain rate of the myocardial wall can be extracted with high signal-to-noise ratio, at the same time the Doppler velocity of the blood flow can also be displayed. The ability to simultaneously characterize these two cardiac tissues provides a powerful approach to better understand the interaction between the cardiac wall and the blood flow, which is important to the investigation of cardiac development.
A gradient and offset compensated Ioffe–Pritchard trap for Bose–Einstein condensation experiments

The Ioffe–Pritchard trap is the workhorse of modern cold atom physics. Here, we present a novel Ioffe–Pritchard trap coil configuration based purely on circular coils. By eliminating the traditional Ioffe bars one can increase the gradient and thus the radial trapping frequency by almost a factor 2. We also present a method to achieve minimal coupling between the gradient, curvature and offset fields of the trap, thus facilitating the dynamic control of the trapping frequencies and aspect ratio.
Attacking a Defended Optical Flow Network

Deep Neural Networks for optical flow estimation achieve exceeding performances on published datasets. However successful and practically applicable patch attacks in the past and the lack of robustness guarantees for published networks demonstrate the importance to further study their resilience against manipulated inputs. The recent desire to deploy optical flow networks in security-critical applications like autonomous driving or robot navigation further amplifies this problem. Recently, the suitability of localized pre-processing defenses against adversarial patch attacks for optical flow networks was examined and a specialized defense was proposed. However an extensive robustness assessment of the defended systems using adaptive attacks was missing. Furthermore results about adaptive attacks on defended networks are currently rather restricted to classification networks. In this thesis we devise adaptive adversarial patch attacks against the optical flow network FlowNetC when it is defended by the specialized defenses Inpainting with Laplacian Prior (ILP) and Local Gradients Smoothing (LGS). We provide empirical evidence that our adaptive whitebox attacks increase the efficiency of injected patches significantly compared to the attacks considered in their initial evaluation. Our attacks introduce serious distortions in the flow field estimation of defended networks. Additional contributions are the implementation of a flexible training pipeline and the reimplementation of the Inpainting with Laplacian Prior defense according to its description in the original publication.
Image Authentication Using Self-Supervised Learning to Detect Manipulation Over Social Network Platforms

Social media nowadays has a direct impact on people's daily lives as many edge devices are available at our disposal and controlled by our fingertips. With such advancement in communication technology comes a rapid increase of disinformation in many kinds and shapes; faked images are one of the primary examples of misinformation media that can affect many users. Such activity can severely impact public behavior, attitude, and belief or sway the viewers' perception in any malicious or benign direction. Mitigating such disinformation over the Internet is becoming an issue with increasing interest from many aspects of our society, and effective authentication for detecting manipulated images has become extremely important. Perceptual hashing (pHash) is one of the effective techniques for detecting image manipulations. This paper develops a new and a robust pHash authentication approach to detect fake imagery on social media networks, choosing Facebook and Twitter as case studies. Our proposed pHash utilizes a self-supervised learning framework and contrastive loss. In addition, we develop a fake image sample generator in the pre-processing stage to cover the three most known image attacks (copy-move, splicing, and removal). The proposed authentication technique outperforms state-of-the-art pHash methods based on the SMPI dataset and other similar datasets that target one or more image attacks types.
CAMBRIDGE WORKING PAPERS IN ECONOMICS Is Affirmative Action in Employment Still Effective in the 21st Century?

We study Executive Order 11246, an employment-based affirmative action policy targeted at firms holding contracts with the federal government. We find this policy to be ineffective in the 21st century, contrary to the positive effects found in the late 1900s (Miller, 2017). Our novel dataset combines data on federal contract acquisition and enforcement with US linked employer-employee Census data 2000– 2014. We employ an event study around firms’ acquiring a contract, based on Miller (2017), and find the policy had no effect on employment shares or on hiring, for any minority group. Next, we isolate the impact of the affirmative action plan, which is EO 11246’s preeminent requirement that applies to firms with contracts over $50,000. Leveraging variation from this threshold in an event study and regression discontinuity design, we find similarly null effects. Last, we show that even randomized audits are not effective, suggesting weak enforcement. Our results highlight the importance of the recent budget increase for the enforcement agency, as well as recent policies enacted to improve compliance. Reference Details CWPE 2262 Published 1 November 2022