3,920 research outputs found
Implicit large-eddy simulation of the stratocumulus-topped boundary layer: A grid sensitivity study
No full textA range of implicit large-eddy simulations of the stratocumulus-topped boundary layer is performed to study the influence of grid resolution on selected parameters including liquid water path and second and third moments of vertical velocity fluctuations. The simulations are based on two sets of aircraft measurements, which are also used to evaluate the results of the simulations. The specific case presented here indicates that simulations with a grid aspect ratio accounting for the anisotropic nature of the turbulence near the surface and at the top of the boundary layer lead to better agreement with measurements than simulations with an isotropic grid
Entrainment and detrainment rates from the piv measurements at the top of laboratory analogs of stratocumulus and cumulus clouds
No full textWe analyze mixing at the top of laboratory analogs of convective clouds: stratocumulus and cumulus to investigate entrainment of environmental air into the cloud. We retrieve two components of air velocity using Particle Image Velocimetry technique. Suitable image processing allows to determine cloud–clear air interface. Using velocity differences between cloudy and clear sides of the interface we calculate entrainment / detrainment rates
Prof. S.P. Fedorov — founder of urology in Russia (150th anniversary of the birthday)
Full text linkThis article presents the important scientific achievements of S.P. Fedorov as a urologist. S.P. Fedorov is the author of over 120 scientific papers. It was noted that in 1892 he was the first in Russia to prepare and use cholera antitoxin for the treatment of patients, then tetanus toxin and antitoxin, found that antitoxin protects against tetanus if it is administered simultaneously with the toxin. Abroad S.P. Fedorov studied the system of aseptic mode of operation from K. Schimmelbush, and L. Casper studied the method of cystoscopy and catheterization of the ureters and other endoscopic methods that appeared at that time. It was shown that S.P. Fedorov developed new surgeries — in situ pyelotomy, subcapsular nephrectomy, and new surgical instruments were proposed. He is rightly called the father of Russian urology. The circumstance is analyzed that the main direction of S.P. Fedorov's scientific activity was the problems of surgery of the urinary and biliary tracts. He summarized the extensive experience of the surgeon in the Atlas of Cystoscopy and Rectoscopy (1911), the Surgery of the Kidneys and Ureters (1923-1925), and others. Galpernom edition of the surgical journal «New Surgical Archive», essentially the first Soviet surgical journal, created in the difficult years of the Civil War and post-war devastation. He was the editor of the 1st edition of the BME, together with S.S. Girgolavom and A.V. Martynov was the editor of the multivolume Guide to Practical Surgery. S.P. Fedorov created a major domestic surgical school, from which dozens of specialists, heads of surgical departments of medical universities in various cities of the USSR graduated. The name of S.P. Fedorov was given to the department of hospital surgery of the Military Medical Academy. S.M. Kirov. It is noted that he was the first of the Soviet surgeons to be awarded the Order of Lenin (1933)
Measurements of turbulence at stratocumulus top
No full textUsing 1m resolution airborne data from research flights we divide stratocumulus top region into sublayers and characterize properties of turbulence in each sublayer. Results indicate, that there are no clear differences of turbulence properties between thermodynamically different "calassical" and "non-classical" stratocumulus regimes, but there are clear signs of turbulence ainsotropy in stably stratified sublayers in the cloud top region
Compressive Sensing for Near-field Source Localization
No full textNear-field source localization is an important aspect in many diverse areas such as acoustics, seismology, to list a few. The planar wave assumption frequently used in far-field source localization is no longer valid when the sources are in the near field. Near-field sources can be localized by solving a joint direction-of-arrival and range estimation problem. The original near-field source localization problem is a multi-dimensional non-linear optimization problem which is computationally intractable. In this thesis we study address two important questions related to near-field source localization: (i) Sparse reconstruction techniques for joint DOA and range estimation using a grid-based model. (ii) Matching the sampling grid for off-grid sources. In the first part of this thesis, we use a grid-based model and by further leveraging the sparsity, we can solve the aforementioned problem efficiently using any of the off-the-shelf l1_-norm optimization solvers. When multiple snapshots are available, we can also exploit the cross-correlations among the symmetric sensors of the array and further reduce the complexity by solving two sparse reconstruction problems of lower dimensions instead of a single sparse reconstruction problem of a higher dimension. In the second part of this thesis, we account scenarios where the true source locations are not on the grid resulting in a grid mismatch. Using the first-order Taylor approximation, we model the grid mismatch as a perturbation around the sampling grid. Based on the grid mismatch model, we propose a bounded sparse and bounded joint sparse recovery algorithms to localize near-field sources.Electrical EngineeringTelecommunicationsElectrical Engineering, Mathematics and Computer Scienc
Application of improved interferometry on low SNR data to auto-pick first arrivals
No full textThree improvements are added to the traditional super-virtual refraction interferometry. Inverse correlation functions are used to enhance the quality of near-offset traces. Interferometry in common-receiver gathers increases the stacking fold. Wavelet shaping effectively suppresses spurious events. The improved interferometry increases the SNR of first arrivals on both synthetic data and real exploration data. We then add two methods to distinguish the spurious events and real events on super-virtual data by event consecutiveness and inexistence of spurious events in raw data. With improved interferometry and improved auto-picking process, we can accurately auto-pick first arrivals over an expanded aperture of low SNR data.EI
Agelosus auricomus Smetana & Hu 2019, sp. nov.
No full textAgelosus auricomus sp. nov. (Figs 1–5, 19, 23, 26) Type locality. TAIWAN: Taipei City. Type material. Holotype, male “ 28-V-2016 ♂ TAIWAN: Taipei City, oldTianmu Trail [in Chinese] Y. H. Ho leg.” (In NMNS). Allotype, female: “ 30-V-2015 TAIWAN. Taipei City, Jinshan village B.H. Ho leg.” (FSHC). Paratypes: “ 02-V-218 ♂ TAIWAN: Taipei City, Fuyang S.W. Zhang leg., 1 ♂ (FSHC); “ 09-VI-2016 TAIWAN: Taipei City, Shanzhuhu B.H. Ho leg., 1 ♂ (CNC); “ 26-V-2018 TAIWAN: New Taipei City, Xindian District, Nankan Mt. S.P. Lin leg. By hand collecting / Fang-Shuo collection”, 1 ♂ (FSHC); “ TAIWAN: Taipei City, Erzihping Trail, Erziping Trail [in Chinese], Beitou. 17.VI.2016. leg. Y.H. Ho / Fang-Shuo collection”, 1♀ (FSHC); “ 04-III-2018 TAIWAN: Yilan County, Jiaoxi Township, Linwei Road [in Chinese], F.S. Hu leg. / 24 49’14.4”N 121 43’17.2”E (alt. 510 m)”, 1 ♀ (CNC). Diagnosis. Species similar to A. nigricollis Smetana, 2018, but with golden yellow tomentose pubescence on the head limited to middle portion and present also on the neck. Description. Black, head with golden yellow tomentose pubescence on middle portion, rest of head with black pubescence; neck with golden yellow tomentose pubescence; pronotum with uniform black pubescence; each elytron with black pubescence and with more or less triangular patch of golden-yellow tomentose pubescence below humerus; abdomen with black pubescence, but tergites 6 to 8 each with a basal pair of spots of golden yellow tomentose pubescence, those on tergite 8 small; maxillary and labial palpi brunneous to piceous; antennae piceous-black to black, first three segments more or less paler; legs variably brunneous. Head of rounded quadrangular shape with rounded posterior angles, wider than long (ratio 1.20), eyes small, moderately convex, slightly shifted dorsad, tempora longer than length of eyes seen from above (ratio 1.38); disc of head moderately finely and densely punctate, punctation becoming gradually finer and denser posteriad and posteriolaterad; linear impunctate midline present; interspaces between punctures without microsculpture. Antennae moderately long, hardly thickened toward apex, segment 3 longer than segment 2 (ratio 1.23), segments 4–9 longer than wide, gradually becoming shorter, segment 10 as long as wide, last segment small, asymmetrically emarginated, along lateral margin shorter than penultimate segment. Pronotum about as long as wide, moderately convex, narrow marginal groove disappearing downwards at about anterior third of pronotal length; punctation on disc about the same as that on disc of head, interspaces between punctures without microsculpture; quite fine impunctate line present mostly on posterior half of pronotum. Prescutum moderately densely punctate-setose, interspaces with distinct microsculpture of transverse and oblique striae. Scutellum densely punctate/setose, with granulose microsculpture. Elytra moderately long, hardly dilated posteriad, at suture shorter than pronotum at midline (ratio 0.78), at sides vaguely longer than pronotum at midline (ratio 1.08); punctation very fine and very dense, interspaces between punctures with fine microscopic irregularities, elytra therefore appearing slightly dull. Wings folded under the elytra, but probably non-functional. Abdomen with fifth visible tergite with pale apical seam of palisade setae; tergite 2 (in front of first fully visible tergite) with a row of punctures along apical margin, surface with extremely fine, superficial microsculpture of oblique striae; punctation of all tergites markedly finer and denser than that on elytra, punctation becoming gradually somewhat sparser toward apex of abdomen, interspaces with extremely fine, granulose microsculpture. Male. Sternite 8 with very shallow, inconspicuous, obtuse medioapical emargination. Genital segment with tergite 10 narrow, markedly, evenly narrowed toward subacute apex, apical portion with numerous long, densely set setae, rest of tergite rather densely setose, as in Fig. 1; sternite 9 with narrow basal portion, apical portion with deep and wide medioapical emargination, setose as in Fig. 2. Aedoeagus (Figs 3,4) rather small, median lobe short, parallel-sided, with widely, asymmetrically, arcuate apex; paramere narrow, situated on median lobe quite asymmetrically toward left margin of median lobe, with subacute apex not quite reaching apex of median lobe; with several, minute apical setae on medial margin; underside without sensory peg setae (Fig.4). Female. Tergite 10 of genital segment wide, markedly narrowed toward slightly differentiated, narrow apical portion with narrowly arcuate apex, with numerous, moderately long to very long and strong setae on differentiated portion, rest of tergite setose as in Fig. 5. Length 18.0–23.0 mm. Geographical distribution. The species is at present known from several locations within Taipei City and from Yilan county, both in northern Taiwan. Bionomics. Little is known about the habitat requirement of this species. It seems to occur at lower elevations (one specimen was taken at an elevation of 510 m). The specimen from Ilan, collected by the second author, was taken from under a stone in a valley in a mixed wood forest (Fig. 26). Etymology. The specific epithet is a composition of the Latin adverb aureus, -a, - um (golden) and the noun coma, - ae, f (the hair). It refers to the golden-yellow tomentose spots on the body of the species. Comments. The aedoeagus of the holotype lacks the apical portion. Agelosus auricomus sp. nov., A. weisei (Harold, 1877) and A. nigricollis Smetana, 2018, the latter two from Japan, mainland China, and North and South Korea, share the character state of the paramere of the aedoeagus lacking any sensory peg setae. They apparently form a clade within the genus.Published as part of Smetana, Aleš & Hu, Fang-Shuo, 2019, The genera Agelosus Sharp, 1889 and Apecholinus Bernhauer, 1933 in Taiwan (Coleoptera: Staphylinidae: Staphylinini: Staphylinina), pp. 379-388 in Zootaxa 4638 (3) on pages 380-381, DOI: 10.11646/zootaxa.4638.3.4, http://zenodo.org/record/333877
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