122,606 research outputs found
Tanaka spaces and products of sequential spaces
No full textsummary:We consider properties of Tanaka spaces (introduced in Mynard F., {\it More on strongly sequential spaces\/}, Comment. Math. Univ. Carolin. {\bf 43} (2002), 525--530), strongly sequential spaces, and weakly sequential spaces. Applications include product theorems for these types of spaces
Space charge and charge trapping characteristics of cross-linked polyethylene subjected to ac electric stresses
No full textThis paper reports on the result of space charge evolution in cross-linked polyethylene (XLPE) planar samples of approximately 220 ?m thick. The space charge measurement technique used in this study is the PEA method. There are two phases to this experiment. In the first phase, the samples were subjected to dc 30 kVdc/mm and ac (sinusoidal) electric stress level of 30 kVpk/mm at frequencies of 1 Hz, 10 Hz and 50 Hz ac. In addition, ac space charge under 30 kVrms/mm and 60 kVpk/mm electric stress at 50 Hz was also investigated. The volts off results showed that the amount of charge trapped in XLPE sample under dc electric stress is significantly bigger than samples under ac stress even when the applied ac stresses are substantially higher. The second phase of the experiment involves studying the dc space charge evolution in samples that were tested under ac stress during the first phase of the experiment. Ac ageing causes positive charge to become more dominant over negative charge. It was also discovered that ac ageing creates deeper traps, particularly for negative charge. This paper also gave a brief overview of the data processing methods used to analyse space charge under ac electric stress
Tanaka formula for the fractional Brownian motion
No full textIn this paper we find the Wiener chaos expansion for the local time of the fractional Brownian motion with Hurst parameter H and we derive a Tanaka formula in the case . As an application we deduce an Itô's formula for convex functions.Fractional Brownian motion Local time Tanaka formula
Nonequilibrium Critical Casimir Effect in Binary Fluids
No full textColloids immersed in a critical binary liquid mixture are subject to critical Casimir forces (CCFs) because they confine its concentration fluctuations and influence the latter via effective surface fields. To date, CCFs have been primarily studied in thermodynamic equilibrium. However, due to the critical slowing down, the order parameter around a particle can easily be perturbed by any motion of the colloid or by solvent flow. This leads to significant but largely unexplored changes in the CCF. Here we study the drag force on a single colloidal particle moving in a near-critical fluid mixture and the relative motion of two colloids due to the CCF acting on them. In order to account for the kinetic couplings among the order parameter field, the solvent velocity field, and the particle motion, we use a fluid particle dynamics method. These studies extend the understanding of CCFs from thermal equilibrium to nonequilibrium processes, which are relevant to current experiments, and show the emergence of significant effects near the critical point
Tanaka formula for the fractional Brownian motion
No full textAbstractIn this paper we find the Wiener chaos expansion for the local time of the fractional Brownian motion with Hurst parameter H and we derive a Tanaka formula in the case H>13. As an application we deduce an Itô's formula for convex functions
Introduction
No full textGiven the consolidated position of English as the international language for communication in business and management, this book depicts a wide scenario in which to analyse and compare interactions between eastern/western European users of English, as well as Asian/European/North American speakers. From each chapter, different sociolinguistic realities emerge. They affect English, as used largely by non-native speakers, but also the relationship between local or national cultures and the global professional discourse community.
In this context not only the specialized lexis is analysed, but rather the ways in which different geo-political cultures construe, manifest and establish their identities. Although it is difficult to classify pragmatic usages of language, the six chapters in the first section deal with language and culture following a genre-based approach, whereas the six chapters of the second section specifically consider corporate identity in intercultural interactions.
This volume is the offspring of a two-day seminar as part of the 10th ESSE (European Society for the Study of English) Conference which was held in Turin, August 2010. The objective and spirit of the seminar, as well as of the book, is not to emphasize contrasts, rather to avoid stereotypes and misunderstandings and promote mutual understanding, arising from awareness about different norms of communication
Severe drought resulting from seasonal and inter-annual variability of rainfall and its impact on transpiration in a hill evergreen forest, northern Thailand
No full textA 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
On the structural heterogeneity of supercooled liquids and glasses
No full textThe status of our basic understanding of the physics and structure of glasses is presented in the light of recent developments in the experimental, phenomenological, and numerical approach to the description of real systems. Spontaneous and induced dynamic heterogeneities appear in the supercooled state of liquids and become frozen intact below the glass transition point. In most cases, mesoscopic heterogeneities due to partial microphase separation are frozen in glasses. Thus, glasses can be described as dynamically arrested heterogeneous supercooled liquids with more solid-like and liquid-like nanoscale regions. The critical issue is that, depending on material type and temperature, the heterogeneities exhibit different size distributions with the solid-like regions probably displaying a degree of hidden quasi-order. This scenario naturally explains some of the important physical properties of real glasses
Trionymus okiensis Tanaka 2018, sp. nov.
No full textTrionymus okiensis sp. nov. (Fig. 1) Type material. HOLOTYPE: adult ♀, JAPAN: SHIMANE / PREFECTURE: Oki Islands, / Dougo Island, / Okinoshima-cho, / Kaminagu. 24.X.2014 // Host plant: Miscanthus / sinensis ANDERSSON / H. TANAKA coll. // Trionymus okiensis / Tanaka, 2018 / HOLOTYPE [red label]’ (mounted on a slide by itself, NSMT-I-Ho 00083. PARATYPES: 3 adult ♀♀, JAPAN: SHIMANE / PREFECTURE: Oki Islands, / Dougo Island, / Okinoshima-cho, / Kaminagu. 24.X.2014 // Host plant: Miscanthus / sinensis ANDERSSON / H. TANAKA coll. // Trionymus okiensis / Tanaka, 2018 / PARATYPE [blue label] (on three slides, 1 slide NSMT-I-Ho 00084, 2 slides in EUMJ). Description. Adult female. Body elongate oval, 2.6 (2.5–3.0) mm long and 1.0 (1.0–1.1) mm wide, derm membranous; segmentation relatively well-developed. Anal lobes distinct but not prominent, dorsum of each lobe with a weakly sclerotized area and ventral surface with a long apical seta, 144–147 (133–166) μm long. Antenna 358–370 (326–370) μm long, with 7 or 8 segments and many flagellate setae; subapical segment with 1 fleshy seta and apical segment with 3 or 4 fleshy setae. Legs well-developed, with many flagellate setae; hind trochanter + femur 320–330 (300–330) μm long, hind tibia + tarsus 334 (313–340) μm long; claw 30 (30–33) μm long. Ratio of lengths of hind tibia + tarsus: trochanter + femur 1.0 (1.0–1.1); ratio of lengths of hind tibia to tarsus 2.1 (1.9–2.2). Paired tarsal digitules present, subequal in length and both minutely knobbed. Translucent pores few, present on hind coxa only. Labium about 77 (75–81) μm long, shorter than clypeus. Circulus present between 3 rd and 4 th ventral abdominal segments, 55 (50–55) μm long and 70 (62–74) μm wide, divided by intersegmental line. Ostioles present, each with inner edges of lips not sclerotized; anterior ostioles each with a total for both lips of 21–30 trilocular pores and 2–4 (0–4) setae; each posterior ostiole with a total of 10–11 (7–11) trilocular pores and 0 (0–1) setae for both lips. Anal ring 92 (80–92) μm wide, with 2–3 rows of cells, bearing 6 setae, each seta 145–155 (138–162) μm long. Cerarii numbering 5 (4–6) pairs, with 1 pair of frontal cerarii on head, other cerarii situated on posterior abdominal segments, but occasionally some cerarii lacking. Anal lobe cerarii situated on sclerotized cuticle, each containing 2 conical setae, each seta 26–29 (27–33) μm long and about 8–10 (8–14) μm wide at base; plus 18–19 (13–19) auxiliary setae and concentration of trilocular pores. Penultimate cerarii each containing 2 conical setae and a few auxiliary setae, situated on membranous cuticle. Cerarii situated further forward generally each with a pair of conical setae and a few auxiliary setae, or with 1 conical seta and with or without a few auxiliary setae. Dorsum. Setae slender and flagellate, each 15–60 (13–60) μm long, longest setae present on posterior part of abdomen. Trilocular pores evenly distributed. Oral-collar tubular ducts of two sizes present: (i) large-type ducts, each about 3–4 μm in diameter, obviously wider than a trilocular pore, present in band across most abdominal segments, marginal area of head and thoracic segments, and medial area of thoracic segments; (ii) small-type ducts, each about 1.5–2 μm in diameter, relatively sparse on abdominal segments, intermixed with the larger type. Discoidal pores sparse, mostly situated on posterior segments. Multilocular disc pores each 7–9 μm wide, present on abdominal segments as follows: I 0 (0), II 1 (0–1), III 1 (0–1), IV 2 (1 or 2), V 6 (1–6), VI 10 (2–10), VII 2 (1–5), VIII 0 (0). Venter. Ventral surface bearing slender flagellate setae, each 20–78 (20–86) μm long, longest on posterior part of abdomen and head. Multilocular disc pores, each 7–9 μm wide, mostly present on posterior abdominal segments, occasionally a few present on some segments of head, thorax and anterior abdomen. Trilocular pores evenly distributed. Oral-collar tubular ducts present in two sizes, same as on dorsum: large type ducts with diameter 3–4 μm (diameter slightly larger than that of a trilocular pore) present in irregular band on head, in transverse bands on all thoracic and abdominal segments, but mostly concentrated on abdominal segments; small-type ducts more sparsely distributed on most abdominal segments, intermixed with the larger type. Discoidal pores rarely present, mostly situated on posterior segments. Differential diagnosis. The only other species of Trionymus so far known from Japan, T. kobotokensis Kanda, 1959, can be relatively easily distinguished from T. okiensis sp. nov. using the identification key below. Outside Japan, T. okiensis sp. nov. is quite similar to T. frontalis McKenzie, 1967 so far only known from California, USA (GARCIA MORALES et al. 2017) in having a pair of frontal cerarii, oral-collar tubular ducts of two different sizes on the dorsal surface, and a circulus divided by an intersegmental line. However, the new species is distinguishable from T. frontalis by the following characters (characters of T. frontalis are given in parentheses): cerarii numbering 4–6 pairs (3 pairs); relatively deep oral-collar tubular ducts on dorsum present in two distinctly different sizes (different types of dorsal ducts are difficult to distinguish from each other, and the ducts are so shallow that outer ductules can be hardly seen in slide-mounted specimens); legs short, with hind trochanter + femur 300–330 μm long (legs relatively long, with hind trochanter + femur 420–458 μm long). Trionymus okiensis sp. nov. is also similar to Dysmicoccus boninsis (Kuwana, 1909), the pantropical pest of sugarcane (Saccharum officinarum L.), in having a pair of frontal cerarii and oral-collar tubular ducts of two different sizes on the dorsal surface. However, it differs from D. boninsis in the following characters (characters of D. boninsis are given in parentheses): more than 10 auxiliary setae on each anal lobe cerarius (fewer than 10); multilocular pores on the dorsum (without dorsal multilocular pores); circulus divided by an intersegmental line (circulus not divided); and narrow and parallel-sided body with the ratio of its maximum length to maximum width 2.5–2.7 (body usually relatively broad, with ratio of maximum body length to maximum body width 1.7–2.0). Etymology. The new species is named after the archipelago where it was first collected (Dougo Island is one of the Oki Islands), combined with the Latin suffix“ -ensis ” indicating the place of origin, in order to form an adjective. Comments on the classification. Some species of the genus Trionymus are very close to several species belonging to Dysmicoccus Ferris, 1950 and the current definitions of these genera are probably arbitrary (WILLIAMS 2004). Most researchers follow MCKENZIE (1967), who placed species with 6 or more pairs of cerarii in Dysmicoccus, and species with 5 or fewer pairs of cerarii in Trionymus. However, on this basis it is difficult to determine the generic position of Dysmicoccus angustifrons (Hall, 1926), which possesses 2–6 (sometimes up to 10) pairs of cerarii (DANZIG & GAVRILOV- ZI- MIN 2015), resulting in some controversy about its placement (e.g., DANZIG & GAVRILOV- ZIMIN 2015, MATILE- FERRERO et al. 2015). A similar taxonomic problem probably occurs also in T. okiensis sp. nov. because it has 4–6 cerarii. In this study, T. okiensis is placed tentatively in Trionymus based on its morphological similarity to T. frontalis (i.e., having two types of oral-collar ducts on dorsum, a small number of multilocular pores on dorsum, a circulus divided by an intersegmental line, and cerarii fewer than 6 pairs).Published as part of Tanaka, Hirotaka, 2018, Trionymus okiensis sp. nov., a new species of mealybug from Japan (Hemiptera: Coccomorpha: Pseudococcidae), pp. 31-34 in Acta Entomologica Musei Nationalis Pragae 58 (1) on pages 33-34, DOI: 10.2478/aemnp-2018-0006, http://zenodo.org/record/367524
- …
