16,657 research outputs found
Influence of doping elements on the formation rate of silicon nanowires by silver-assisted chemical etching
No full textMetal-assisted chemical etching (MACE) has gained great interest for the preparation of vertically aligned silicon nanowires (SiNWs); however, the process mechanism has not yet been identified. In this study, the influence of doping elements on the formation rate of SiNWs prepared by silver-assisted chemical etching was investigated. Two n-type silicon substrates, bulk silicon and silicon-on-insulator (SOI) samples, containing different dopant concentrations (from 1011 to 1019 atoms cm− 3) and species (phosphorous and arsenic), were considered. The SiNW formation rates increase with dopant concentration and are influenced by the dopant species. The use of SOI samples allowed highlighting the remarkable loss of the starting device layer in conventional process conditions, never previously observed; such occurrence limits the most achievable SiNW length. The study of the gas evolution both from bulk and SOI samples allowed for the first time the in situ H2 detection as well as to identify one definite overall process reaction
On the properties of the Lambda value at risk: robustness, elicitability and consistency
No full textRecently, the financial industry and regulators have enhanced the debate on the good properties of a risk measure. A fundamental issue is the evaluation of the quality of a risk estimation. On the one hand, a backtesting procedure is desirable for assessing the accuracy of such an estimation and this can be naturally achieved by elicitable risk measures. For the same objective, an alternative approach has been introduced by Davis [Stat. Risk Model. Appl. Finance Insurance, 2016, 33, 67–93] through the so-called consistency property. On the other hand, a risk estimation should be less sensitive with respect to small changes in the available data-set and exhibit qualitative robustness. A new risk measure, the Lambda value at risk (), has been recently proposed by Frittelli et al. [Math. Finance, 2014, 24, 442–463], as a generalization of VaR with the ability to discriminate the risk among P&L distributions with different tail behaviour. In this article, we show that also satisfies the properties of robustness, elicitability and consistency under some conditions
The politics and economics of regulatory impact assessment
No full textThis is the author accepted manuscript. The final version is available from the publisher via the link in this record
Omangidiella parvidactyla Iannilli, Holsinger, Ruffo & Ronald, 2006, new species
No full textOmangidiella parvidactyla new species Figs. 4, 5 Material examined (expedition station number in parentheses is from Stock et al. 1997) Sultanate of Oman. (96 – 67) border of wadi Taww at Halban (23 ° 34 ’N; 58 °01’ E), 3 paratype specimens, 1 April 1996, with thermosbaenaceans, cyclopid copepods, oligochaetes, diverse insect larvae; (96 – 75) Wadi Bani Henay (26 ° 30 ’ 35 "N; 57 ° 19 ’ 34 "E), pump in gravel at 50 cm below sediment surface, 10 paratype specimens, 1 April 1996, with thermosbaenaceans, stenasellid isopods, oligochaetes, chironomids; (96 – 76) same place and date as (96 – 75), probe; at 1.20 cm, 10 paratype specimens (very damaged), with thermosbaenaceans, stenasellid isopods, cyclopid copepods; (96 – 77) Wadi Bani Henay (26 ° 30 ’ 35 "N; 57 ° 19 ’ 34 "E) pump in gravel probe at 90 cm, 1 female paratype, 1 April 1996, with thermosbeanaceans, stenasellids, chironomids. Wadi Nakhl (ca. 23 ° 26 ’ N 57 ° 52 ’ E), Oesterreich Expedition, female holotype (collection date unknown) dissected and mounted in Faure’s medium on slides 4577 –4581, 2 paratypes (slides 4582–4591) deposited in Museo Civico di Storia Naturale Verona (MVRCr 444), and 5 paratypes in ethanol deposited in Zoological Museum Amsterdam. Description The description is based on the holotype female from Wadi Nakhl, with exception of the mouthparts, which are based on a paratype female from Wadi Bani Henay (see above). Female (3.0 mm) with oostegites.— Antenna 1: (Fig. 4 a) ratio of articles 1–3 of peduncle = 1: 0.8: 0.5, articles without spines, with only few short setae; flagellum little longer than peduncle, with 13 articles increasing in length distally, bearing only fine setae, and without aesthetascs; accessory flagellum uniarticulate, shorter than article 1 of flagellum. Antenna 2 (Fig. 4 b) shorter than antenna 1, with few short setae; glandcone not elongate; articles 4 and 5 of peduncle subequal in length; flagellum less than half length of peduncle, with 5 articles, the distal one very short. Mouthparts: labrum (upper lip) rounded distally (Fig. 4 c). Left mandible (Fig. 4 d): incisor 5 dentate; lacinia mobilis also 5 dentate and followed by 4 setulose rakers; molar triturative and articulated on short conical base, bearing 1 long plumose seta; mandibular palp reduced in length, article 2 longer than article 3; article 3 bearing only single apical seta; right mandible (Fig. 4 e) similar to left but lacinia mobilis pluridenticulate; labium (lower lip) (Fig. 4 f) with well developed inner lobes and rather short, blunt lateral processes. Maxilla 1 (Fig. 4 g); palp reduced in length and bearing only 2 apical setae; outer plate with 7 serrate spines (3 external ones 4 toothed and 4 internal ones pectinate); inner plate with 3 naked apical setae. Maxilla 2 (Fig. 4 h): inner plate little shorter than outer, with many fine setae along inner margin distally, apically with 6 distal spines, the 2 inner ones plumose. Maxilliped (Fig. 4 i): coxal endite partially fused with inner lobe and similar to those of Nubigidiella, bearing fine setae distally and 1 spine apically; inner lobe bearing 2 short, stout bifid spines apically; outer lobe scarcely expanded, bearing 3 blade spines subapically on inner margin; palp article 2 expanded; dactylus as long as preceding article, with fine pubescence on inner face. Gnathopod 1 (Fig. 4 l): coxa subrectangular, ratio length:height = 1: 0.7, with 2 setules on anterodistally rounded corner; basis relatively broad, with 3 long setae on posterior margin; merus with pubescent posterior margin; carpus produced into narrowly rounded ventral lobe, partly pubescent and bearing 2 long distal and 2 long subdistal setae; propodus (Fig. 4 l’) subtrapezoidal, palm rather short, only about 40 percent as long as the posterior margin, margin uneven and bearing only few setae and 1 or 2 spines near defining angle; posterior margin nearly straight, without spines or setae; dactylus falcate and closing on defining angle. Gnathopod 2 (Fig. 4 m, n) strikingly different from gnathopod 1: coxa similar to coxa 1 but ventral margin weakly rounded; basis with 2 long setae on posterior margin; carpus elongate, as long as basis and longer than propodus, posterior margin pubescent and bearing 2–4 groups of 2 long setae each; propodus (Fig. 4 n’) elongate and weakly suboval but little shorter than carpus, medial and lateral faces with inferior and superior rows of numerous short, fine setae; palmar margin very short, without defining spines; posterior margin with approximately 9 long setae; dactylus reduced to small, curved, toothlike process. Pereopods 3 and 4 similar (Fig. 5 a): ratio coxa length:height = 1: 0.6, ventral margin with 2 anterodistal setules each; basis broad, anterior margin convex and bearing large lenticular organ; merus, carpus and propodus subequal in length, with few short marginal setae; dactylus rather short, ratio propodus:dactylus = 1: 0.4. Posterior and inferior margins of coxal plates 1–4 thinly sclerotized. Pereopod 5 (Fig. 5 b): coxa anteriorly lobed, with posterodistal spine; basis suboval, anterior and posterior margins with 4 or 5 short spines, distal half with a large lenticular organ; merus, carpus, and propodus subequal in length, with few short marginal spines; ratio propodus:dactylus = 1: 0.4. Pereopod 6 (Fig. 5 c) similar to pereopod 5 but distinctly longer; coxa with anterior lobe of coxa reduced; basis with a large lenticular organ on distal half of posterior margin; ratio propodus:dactylus = 1: 0.4. Pereopod 7 the longest (Fig. 5 d); basis little wider than those of pereopods 5 and 6, without lenticular organ, anterior margin with 4 short spines, posterior margin with 6 short spines; merus, carpus and propodus subequal in length but much stronger than those of pereopods 5 and 6; propodus little longer and more robust than two preceding articles, anterior margin with row of 5 or 6 short spines accompanied by long setae; dactylus comparatively long, ratio propodus:dactylus = 1: 0.37. Anterior and inferior margins of coxal plates 5–7 thinly sclerotized. Oostegites on pereopods 2–5, elongate, with long marginal and distal setae. Pleonal plates: posteroventral corners rounded and not produced (Fig. 5 e). Pleopods (Fig. 5 e) greatly reduced; inner rami absent; outer rami reduced to 3 articles, the terminal one very short; peduncles nearly twice length of rami, each with 2 coupling spines (Fig. 5 e’). Uropod 1 (Fig. 5 f): inner and outer rami subequal in length, armed with only 3 apical spines on outer and 4 on inner; peduncle longer than either rami, armed with 9 or 10 spines on upper margin and 3 basofacial spines. Uropod 2 shorter than uropod 1 (Fig. 5 g): outer ramus shorter than inner ramus, armed with 4 apical spines; inner ramus as long as peduncle, armed with 4 apical spines; peduncle with 5 spines. Uropod 3 (Fig. 5 h): rami approximately equal in length (aequiramus), each bearing several sets of lateral spines in groups of 1, 2, or 3; apex with 3 or 4 spines. Telson (Fig. 5 i) about as broad as long at base but slightly tapered distally; each side with 1 mediolateral spine and 1 penicillate seta; apical margin convex and armed with 2 + 2 distolateral spines. Male unknown. Typelocality Wadi Nakhl, located at approximately 23 ° 26 ’ N; 57 ° 52 ’ E (Fig. 6). There are no other details available on the date of collection or the physical/chemical characteristics of this locality. Derivatio nominis The epithet parvidactyla is derived from the latin parvus (small) and dactylus (finger), denoting the very small dactylus of gnathopod 2.Published as part of Iannilli, Valentina, Holsinger, John R., Ruffo, Sandro & Ronald, 2006, Two new genera and two new species of the subterranean family Bogidiellidae (Crustacea, Amphipoda) from groundwaters in northern Oman, with notes on the geographic distribution of the family, pp. 37-56 in Zootaxa 1208 on pages 46-50, DOI: 10.5281/zenodo.17239
Phase Distribution Efficiency of cm-Scale Ultrasonically Powered Receivers
No full textIn the domain of ultrasonically powered biomedical implants, there is an increasing interest in cm-scale ultrasonic receivers (RX). However, when a single-element transducer is used as the RX transducer, an uneven phase distribution across the RX area can significantly reduce the harvestable power. In this paper, we investigate the impact of lateral and angular misalignment on the acoustic field phase distribution across the RX surface. We show that, for a single-element RX transducer, lateral misalignment has minimal effect on the harvestable power, whereas even small angular misalignments can cause a considerable reduction, especially for larger RX sizes. We present a potential solution that consists of subdividing a large RX transducer (e.g. 20 × 20mm2) into smaller elements, which significantly improves power transfer efficiency by taking advantage of the smaller phase variation across the surface of each element. The trade-offs between achieving a minimum acceptable power transfer efficiency and managing the increased complexity in packaging and matching circuitry are also discussed.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and MaterialsBio-Electronic
Highly efficient laser-driven Compton gamma-ray source
No full textThe recent advancement of high-intensity lasers has made all-optical Compton scattering become a promising way to produce ultrashort brilliant gamma-rays in an ultra-compact system. However, so far achieved Compton gamma-ray sources are limited by low conversion efficiency and spectral intensity. Here we present a highly efficient gamma photon emitter obtained by irradiating a high-intensity laser pulse on a miniature plasma device consisting of a plasma lens and a plasma mirror. This concept exploits strong spatiotemporal laser-shaping process and high-charge electron acceleration process in the plasma lens, as well as an efficient nonlinear Compton scattering process enabled by the plasma mirror. Our full three-dimensional particle-in-cell simulations demonstrate that in this novel scheme, brilliant gamma-rays with very high conversion efficiency (higher than 10(-2)) and spectral intensity (similar to 10(9) photons/0.1%BW) can be achieved by employing currently available petawatt-class lasers with intensity of 10(21) W cm(-2). Such efficient and intense gamma-ray sources would find applications in wide-ranging areas. ©2019 The Author(s)
Nanocrystalline SnO2-based thin films obtained by sol-gel route: A morphological and structural investigation
No full textIndolic squaraines as two-photon absorbing dyes in the visible region: X-ray structure, electrochemical, and nonlinear optical characterization
No full textIn this article, we have shown that it is possible to design
large optical gap squaraines displaying a sizable fs regime
TPA activity in the technologically relevant 700-800 nm
region. Also, we unequivocally assigned, through single
crystal X-ray analysis, the regiochemistry of the squaric acid
condensation reaction at the 3-position of unsubstituted indole derivatives. Finally, we demonstrated that derivative 1 TPA activity in the optical limiting relevant ns regime exceeds
that of one of the most promising quadrupolar derivative so
far employed
CM Periods, CM Regulators, and Hypergeometric Functions, I
No full textWe prove the Gross-Deligne conjecture on CM periods for motives associated with H-2 of certain surfaces fibered over the projective line. Then we prove for the same motives a formula which expresses the K-1-regulators in terms of hypergeometric functions F-3(2), and obtain a new example of non-trivial regulators
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