Miracle-dz/UniFAR-FTUs huggingface dataset:
Flame imaging of gas-turbine relight

High-altitude relight inside a lean-direct-injection gas-turbine combustor is investigated experimentally by highspeed imaging. Realistic operating conditions are simulated in a ground-based test facility, with two conditions being studied: one inside and one outside the combustor ignition loop. The motion of hot gases during the early stages of relight is recorded using a high-speed camera. An algorithm is developed to track the flame movement and breakup, revealing important characteristics of the flame development process, including stabilization timescales, spatial trajectories, and typical velocities of hot gas motion. Although the observed patterns of ignition failure are in broad agreement with results from laboratory-scale studies, other aspects of relight behavior are not reproduced in laboratory experiments employing simplified flow geometries and operating conditions. For example, when the spark discharge occurs, the air velocity below the igniter in a real combustor is much less strongly correlated to ignition outcome than laboratory studies would suggest. Nevertheless, later flame development and stabilization are largely controlled by the cold flowfield, implying that the location of the igniter may, in the first instance, be selected based on the combustor cold flow. Copyright © 2010.
An Efficient Segregated Algorithm for Incompressible Fluid Flow and Heat Transfer Problems—IDEAL (Inner Doubly Iterative Efficient Algorithm for Linked Equations) Part I: Mathematical Formulation and Solution Procedure

An efficient segregated solution procedure for incompressible fluid flow and heat transfer problems is proposed. The new algorithm is called IDEAL (Inner Doubly Iterative Efficient Algorithm for Linked Equations). In the new algorithm there exist inner doubly iterative processes for the pressure equation, which almost completely overcome two approximations in the SIMPLE algorithm. Thus the coupling between velocity and pressure is fully guaranteed, greatly enhancing the convergence rate and stability of the iteration process. The mathematical formulation and solution procedure of the IDEAL algorithm are described in this article. In Part II, application examples are provided to show the features and feasibility of the new algorithm.
MAGNETIC RECONNECTION SITE IN THE MAGNETOTAIL DURING DIFFERENT SOLAR WIND STREAMS

In this work we discuss the problem of the magnetic reconnection site location in the magnetotail during substorms associated with different solar wind streams. It was shown recently that solar cycle variations of the solar wind control the location of magnetic reconnection in the tail. A well-known fact is that solar wind high-speed streams have different nature during different phases of solar activity. During the declining phase and minima of the solar cycle predominate the recurrent streams (RS) originating from coronal magnetic holes. During solar cycle maxima the flare streams connected with coronal mass ejections prevail. We analyze the relationship between the locations of the tail magnetic reconnection site during substorms connected with solar wind magnetic clouds (MC) and recurrent streams. We use data from Geotail spacecraft in the magnetotail and solar wind parameters from Wind spacecraft observations; the auroral bulge parameters were obtained by the Ultra Violet Imager onboard Polar. We show that magnetic reconnection in the magnetotail takes place closer to Earth when substorm is observed during MC, and further in radial distance for substorms during solar wind recurrent streams.
Search for satellites near comet 67P/Churyumov-Gerasimenko using Rosetta/OSIRIS images

The European Space Agency Rosetta mission reached and started escorting its main target, the Jupiter-family comet 67P/Churyumov-Gerasimenko, at the beginning of August 2014. Within the context of solar system small bodies, satellite searches from approaching spacecraft were extensively used in the past to study the nature of the visited bodies and their collisional environ- ment. Aims. During the approaching phase to the comet in July 2014, the OSIRIS instrument onboard Rosetta performed a campaign aimed at detecting objects in the vicinity of the comet nucleus and at measuring these objects’ possible bound orbits. In addition to the scientific purpose, the search also focused on spacecraft security to avoid hazardous material in the comet’s environment. Methods. Images in the red spectral domain were acquired with the OSIRIS Narrow Angle Camera, when the spacecraft was at a distance between 5 785 km and 5 463 km to the comet, following an observational strategy tailored to maximize the scientific outcome. From the acquired images, sources were extracted and displayed to search for plausible displacements of all sources from image to image. After stars were identified, the remaining sources were thoroughly analyzed. To place constraints on the expected displacements of a potential satellite, we performed Monte Carlo simulations on the apparent motion of potential satellites within the Hill sphere. Results. We found no unambiguous detections of objects larger than ∼ 6 m within ∼ 20 km and larger than ∼ 1 m between ∼ 20 km and ∼ 110 km from the nucleus, using images with an exposure time of 0.14 s and 1.36 s, respectively. Our conclusions are consistent with independent works on dust grains in the comet coma and on boulders counting on the nucleus surface. Moreover, our analysis Article number, page 1 of 9 shows that the comet outburst detected at the end of April 2014 was not strong enough to eject large objects and to place them into a stable orbit around the nucleus. Our findings underline that it is highly unlikely that large objects survive for a long time around cometary nuclei.
Regular and chaotic aspects of charged particle motion in a magnetotail‐like field with a neutral line

The motion of charged particles is studied numerically and analytically using a test particle approach. Acceleration near the X-type neutral line is described in terms of adiabatic invariants and separatrix crossings. The relation between regular and chaotic properties of the process is discussed for a realistic source in the plasma mantle.
A structure of the consumption function

It is claimed in the structural realism in philosophy of science that scientists aim to preserve the true structure, represented by the equations in their models. We reinterpret structural realism as a doctrine involving representation. Proving the existence of a representation theorem secures the problem of lacking independent criteria for identification between structure and non‐structure. This paper argues that a similar realist view of structure can be found in the theory of consumption in which the Fisherian framework of intertemporal choices is regarded as the true structure of the consumption function. Unlike the passive strategy of inducing the structure contained in structural realism, economists define structure in terms of invariance under intervention. Such a definition serves as a crucial device to examine and develop models for the adequacy of representing the structure of the consumption functions. JEL Classification: B22, B41, C50, E21
Turbulence measurements with inclined hot-wires Part 1. Heat transfer experiments with inclined hot-wire

The measurement of the turbulent shear stresses and normal and bi-normal intensities with a hot-wire anemometer requires that the directional sensitivity of the hot-wire be known. Normal component or cosine law cooling is generally assumed, although for finite wire lengths the non-uniform wire temperature must cause a deviation from the cosine law. Careful heat transfer measurements from wires inclined and normal to the flow were taken for several values of the Reynolds number, the length-to-diameter ratio of the wire, the overheat ratio and for several support configurations. All experiments were performed in air at low subsonic velocities, i.e. M < 0·1. The measurements indicate that the heat loss from an inclined wire is larger than that from a wire normal to the flow with the same normal component of velocity. The data were correlated by \[ U^2_E(\alpha) = U^2(0)(\cos^2\alpha + k^2\sin^2\alpha), \] where UE(α) is the effective cooling velocity at the angle α between the normal to the wire and the mean flow direction and U(0) is the velocity at α = 0. The value of k was found to depend primarily upon the length-to-diameter ratio ([lscr ]/d) of the wire. For platinum wires k is approximately 0·20 for [lscr ]/d = 200, decreases with increasing [lscr ]/d, and becomes effectively zero at [lscr ]/d = 600. To aid in interpreting the heat transfer data, measurements of the temperature distribution along inclined and normal wires were made with a high sensitivity infra-red detector coupled to a high resolution microscrope with reflective optics. The measurements indicate that inclined wires and normal wires have nearly identical end conduction losses, although the temperature distribution on an inclined wire is slightly asymmetrical. Therefore, the deviation from the cosine law is caused by an increase in the convection heat loss, and this increase is attributed to the tangential component of velocity.
Expandibility and collectionwise normality

In 1958 M. Katetov proved that in a normal space X, X is expandable if and only if X is collectionwise normal and countably paracompact. This result has since been used to answer many questions in various areas of general topology. In this paper Katetov's theorem is generalized for nonnormal spaces and various characterizations of collectionwise normality are shown. Results concerning metrization, paracompactness, sum theorems, product theorems, mapping theorems and M-spaces are then obtained as applications of these new theorems. Introduction. In [14] L. Krajewski investigated the property of expanding locally finite collections to open locally finite collections and obtained various results relating this property with certain topological covering properties, metrization theorems, sum theorems and product theorems. In ? 1 we summarize the known results concerning expandability, collectionwise normality and these topological covering properties; and then we show that every metacompact space is almost expandable. In ? 2 we introduce various generalizations of the notion of expandability and give characterizations for collectionwise normality. The theorem of Katetov [13] (Theorem 1.4 below) is then generalized. Characterizations of expandability properties in terms of open covers are given in ? 3; and in ? 4 we characterize the properties of paracompactness, subparacompactness, and metacompactness and establish equivalences in certain expandable spaces. Various mapping theorems are proved in ? 5, and product theorems are obtained in ? 6. We obtain results cQncerning subspaces and sum theorems in ? 7. As applications of the previous results, metrization theorems are observed in ? 8. Examples and unanswered questions are given in ? 9. REMARK. A space X is subparacompact (Fa-screenable) if every open cover has a a-discrete closed refinement. The symbol IAI will be used to denote the cardinality of the point set A. A space X will be a T1 topological space unless otherwise stated. 1. Preliminary results. The following definition is due to L. Krajewski [14]. DEFINITION 1.1. A space X is called m-expandable, where m is an infinite cardinal, if for every locally finite collection {F< a E A} of subsets of X with IAI < m, then Presented to the Society, January 24, 1971; received by the editors June 11, 1970 and, in revised form, November 3, 1970. AMS 1969 subject classifications. Primary 5423; Secondary 5435, 5450.
Search for sub-kilometre trans-Neptunian objects using CoRoT asteroseismology data

We present the search for sub-kilometre trans-Neptunian objects (TNOs) by re-examining the CoRoT ( Convection Rotation and Planetary Transits ) asteroseismology observations. The total observation time employed in this work is about 144 000 star hours with signal-to-noise ratio larger than 1000 computed on 30-s intervals. 13 Possible Occultation Events (POEs) were found from the deviation method. These detections gives a density in the ecliptic sky plane of TNOs larger than 400-m radius of N ( R > 400 m) = 1 . 4 + 4 . 2 − 0 . 7 × 10 7 deg − 2 . The ﬁt of the density of TNOs with the believed break r break = 45 km provides a power-law size distribution index q larger than 3.5. This value is consistent with the detection of two potential events from Hubble Space Telescope ( HST )/Fine Guidance Sensor (FGS) observations that found q = 3.8 ± 0.2. However, ﬁtting the 13 POEs with the HST /FGS result alone gives a power-law size distribution index of q = 4.5 ± 0.2 in the size range of 0.2–2.0 km. This value is then compared with evolution models of the Kuiper belt.
Pediatric AIDS in New York City: Estimating the Distributions of Infection, Latency, and Reporting Delay and Projecting Future Incidence

Abstract Maternal-to-infant transmission of the human immunodeficiency virus (HI V) accounts for most cases of acquired immune deficiency syndrome (AIDS) in children. In New York City more than 500 cases of AIDS attributed to such transmission were reported before the end of 1989; this accounts for 80% of the cases of pediatric AIDS in the United States. In addition to surveillance of AIDS cases, the New York State Health Department instituted a program to screen the blood of newborns for presence of HIV antibodies in December 1987. Such antibodies imply that the mother, although not necessarily the child, is infected with HIV. The new methods we propose in this article allow us to combine the two types of information to estimate the risk of AIDS for the first 10 years of life. They also make it possible to estimate the number of children born to infected mothers since the start of the epidemic and to project the future number of cases of pediatric AIDS. From these projections it appears that the case loa.
The characteristics of Hessian singular vectors using an advanced data assimilation scheme

Initial condition uncertainty is a significant source of forecast error in numerical weather prediction. Singular vectors of the tangent linear propagator can identify directions in phase‐space where initial errors are likely to make the largest contribution to forecast‐error variance. The physical characteristics of these singular vectors depend on the choice of initial‐time metric used to represent analysis‐error covariances: the total‐energy norm serves as a proxy to the analysis‐error covariance matrix, whereas the Hessian of the cost function of a 4D‐Var assimilation scheme represents a more sophisticated estimate of the analysis‐error covariances, consistent with observation and background‐error covariances used in the 4D‐Var scheme.
Performance and Calibration of an Acoustic Doppler Current Profiler Towed below the Surface

Abstract A towed acoustic Doppler current profiler (ADCP) system was tested. The instrument was deployed from ships of opportunity and towed at depths between 5 and 25 m. The towed system carries upward- and downward-looking ADCPs. The instrument platform is stable in most operating conditions at ship speeds up to 4.5 m s−1. Large discrepancies are found, however, between the ship's velocity obtained from bottom-tracking ADCP pulses and that from navigational data. These are explained with a magnetic compass bias that varies with the ship's heading direction. Both the ship and the tow platform induce magnetic fields that bias the ADCP compass. An in situ compass calibration scheme is thus necessary and requires accurate navigational data. In our main study area, it is found that the Global Position System provides absolute and relative positions to within 88 and 4 m, respectively. These accuracies are sufficient for calibration purposes. With our calibration scheme the towed ADCP system performs as well a.
A case series of autologous platelet-rich plasma injection in treating chronic ulcers conducted in Saudi Arabia

Objective: This is a case series study of 14 cases of chronic unhealed ulcers involving patients of 19–85 years, aimed to demonstrate the positive therapeutic outcomes of using autologous platelet rich plasma (PRP) in diabetic foot ulcer (DFU) and other chronic wound healing. Methods: This is a formal consecutive clinical case series. Patients with chronic unhealed ulcers were enrolled from the amputation prevention clinic by an interdisciplinary team includes podiatrist, general surgeon, orthopedic, vascular surgeon, and wound care nurses at Kahel Specialized Centre, a specialized center for managing foot and ankle diseases, located in Riyadh, Saudi Arabia. Those patients who presented with chronic wounds and showed no significant wound reduction despite following the standard wound care protocol were included in the study. There were no specific predetermined exclusion criteria when considering patients for treatment with this modality. Results: In this case series, majority (80%) of the patients were above 50 years of age, and 10 (66.7%) patients were male and 5 (33.3%) were female. Of all the cases presented to the amputation prevention clinic, majority (73.3%) reported suffering from type 2 diabetes mellitus (DM) and also, one reported type 1 DM [6.7%]). All the cases of DFU received a combination of hydrogel and autologous PRP treatment and were put of suitable offloading devices, except one case received a combination of Cadexomer iodine, hydrogel and PRP treatment. In the present case series involving 3–14 weeks of the treatment duration, only 2–3 doses of autologous PRP provided complete healing and or maximum wound closure. Conclusion: Autologous PRP therapy is efficacious in facilitating, enhancing wound healing and aids in complete wound closure. This case series was limited in term of the sample size which is the number patients enrolled for the study, hence, the study finding remain inconclusive to some extent and hence, further study is required with greater number of sample size. The strength of this study is that it is the first study in Saudi Arabia and gulf region, to report the beneficial effect of PRP in chronic unhealed ulcers including diabetic ulcers.
Association of serum hepcidin with prostate-specific antigen levels in men from high Andean cities of Peru

Objective: The prostate-specific antigen (PSA) is the primary biomarker to diagnose prostate cancer. Hepcidin has been reported as an alternative for this diagnosis; however, it is unclear how PSA and hepcidin function at high altitude (HA). This study aims to assess the association between hepcidin with PSA in HA residents chronically exposed to hypobaric hypoxia. Methods: We retrospectively examined data of 70 healthy males (aged 18–65-years-old) from four different altitudes cities in Peru: Lima (<150 m), Huancayo (2380 m), Puno (3800 m), and Cerro de Pasco (4320 m). Serum hepcidin, testosterone, and PSA were analyzed by chemiluminescence immunoassay. HA parameters (hemoglobin [Hb], pulse oxygen saturation [SpO2], and chronic mountain sickness [CMS] score) were also included in the study. Bivariate analyses and a multivariate linear mixed model were used to evaluate the association between hepcidin and PSA, adjusted by HA parameters, age, and body mass index (BMI). Results: Cases of excessive erythrocytosis (EE) (Hb >21 g/dL) were observed in the three highest cities. Hepcidin was positively correlated with Hb, CMS score, and BMI (P ≤ 0.05). Hepcidin was higher in Huancayo with respect to Puno, while PSA was lower in Cerro de Pasco in regard to Puno and Lima (P ≤ 0.05). Neither hepcidin nor PSA was increased by altitude in each city (P > 0.05). We did not find an association between hepcidin and PSA, even adjusted by age, BMI, Hb, and SpO2 (P ≤ 0.05). Conclusion: These findings showed no association between hepcidin and PSA levels in healthy residents at HA.
X-rays from SN 1986J : emission of a shocked clumpy wind

An alternative view on the origin of the powerful X-ray emission from SN 1986J is proposed. The model suggests that the supernova envelope is colliding with the clumpy circumstellar wind and the bulk of the observed X-rays is originated from the shocked dense wind clumps. The required mass loss rate for the clumpy component of the wind is M≃10 -4 M ○. yr -1 , while the filling factor ≃0.005. The homogeneous wind is relatively rarefied and contains significantly lower mass than the clumpy component. The model of the clumpy wind is qualitatively consistent with optical and radio data
Variability of midtropospheric moisture and its effect on cloud-top height distribution during TOGA COARE

The tropical western Pacific warm pool is often generalized to be a region of heavy precipitation. This concept is useful in constructing simplified models of the tropical circulation. However, the warm pool region is often punctuated by periods of little rain. Such drought periods may last up to 10 days over an area of at least 6 3 105 km2. Other common features of the drought periods include an extremely dry midtroposphere, few deep clouds typically associated with mesoscale convective systems, and a substantial amount of clouds that are too tall to be categorized as trade cumuli but too short to fall into the category of deep convective clouds. Midtropospheric moisture varies substantially (60% in relative humidity ,4gk g 21 in water vapor mixing ratio) between rainy and drought periods. The frequency distributions of humidity exhibit bimodal structures at certain levels above the freezing level. In either rainy or drought periods, or in a long period including both, the time-mean humidity above the boundary layer deviates substantially from the most frequent profile of humidity, defined as the relative humidity corresponding to the maximum frequency distribution at each level. Mean soundings, therefore, do not accurately represent the overall vertical structure of moisture in the warm pool. Calculations of a simple parcel model demonstrate that the warm pool atmosphere above the boundary layer can be dry enough to discourage the growth of deep convective clouds by depleting parcel buoyancy through entrainment. These results were drawn from an analysis of soundings collected during the Intensive Observing Period (1 November 1992‐28 February 1993) of the Tropical Ocean Global Atmosphere Coupled Ocean‐Atmosphere Response Experiment.
An exact perturbative formulation of the dielectric integral equations for lossy interfaces: Abstract

In modeling scattering from lossy surfaces, the surface is often approximated as a perfect electric conductor (PEC). However, when loss and wave penetration become important, the IBC model is typically employed and is adequate for many numerical simulations. However, the IBC's range of validity is considered unclear and an accurate quantification of its error is difficult. Consequently, other more exact implementations are necessary, such as integral equation methods. In this paper, a novel numerical implementation of the exact dielectric integral equations has been developed for scattering from a two-dimensional (2D), lossy dielectric interface. The formulation presented herein combines the coupled integral equations to form a single equation. This equation is easily interpreted as the magnetic field integral equation (MFIE) for a 2D, PEC surface with a perturbative term related to the finite conductivity of the surface. The advantage of this perturbation approach is that for ocean and other high loss surfaces, the solution is expected to be rapidly convergent with respect to other approaches and will reproduce the correct result even for surfaces with small curvature radii. Test cases demonstrate increased convergence with increased loss and increased contrast for perpendicular polarization. However with parallel polarization, convergence problems are uncovered and are associated with the Brewster angle effect.