cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Experimental position-time entanglement with degenerate single photons
Creators: name: Bennett, A. J.
name: Gevaux, D. G.
name: Yuan, Z. L.
name: Shields, A. J.
name: Atkinson, P.
name: Ritchie, D. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We report an experiment in which two-photon interference occurs between degenerate single photons that never meet. The two photons travel in opposite directions through our fibre-optic interferometer and interference occurs when the photons reach two different, spatially separated, 2-by-2 couplers at the same time. We show that this experiment is analogous to the conventional Franson-type entanglement experiment where the photons are entangled in position and time. We measure wavefunction overlaps for the two photons as high as 94 $\pm$ 3%.
description: Updated to published version, new fig. 4., corrected typos
Multi-scale Deterministic Optimisation of Blended Composite Structures: Case Study of a Box-Wing
Creators: name: Scardaoni, M. Picchi
name: Izzi, M. I.
name: Montemurro, M.
name: Panettieri, E.
name: Cipolla, V.
name: Binante, V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This work presents a multi-scale design methodology for the deterministic optimisation of thin-walled composite structures integrating a global-local approach for the assessment of the buckling strength and a dedicated strategy to recover blended stacking sequences. The methodology is based on the multi-scale two-level optimisation strategy for anisotropic materials and structures. In the first step, focused on the macroscopic scale, several design requirements are included in the problem formulation: lightness, feasibility, manufacturing, blending, buckling failure, static failure and stiffness. The second step, which focuses on the laminate mesoscopic scale, deals with the recovery of blended stacking sequences, for the structure at hand, matching the optimal geometric and elastic properties determined in the first step. As a case study, the unconventional PrandtlPlane box-wing system is used to show the effectiveness of the proposed design methodology.
Quantum Interest in (3+1) dimensional Minkowski space
Creators: name: Abreu, Gabriel
name: Visser, Matt
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The so-called "Quantum Inequalities", and the "Quantum Interest Conjecture", use quantum field theory to impose significant restrictions on the temporal distribution of the energy density measured by a time-like observer, potentially preventing the existence of exotic phenomena such as "Alcubierre warp-drives" or "traversable wormholes". Both the quantum inequalities and the quantum interest conjecture can be reduced to statements concerning the existence or non-existence of bound states for a certain one-dimensional quantum mechanical pseudo-Hamiltonian. Using this approach, we shall provide a simple proof of one version of the Quantum Interest Conjecture in (3+1) dimensional Minkowski space.
description: V1: 8 pages, revtex4; V2: 10 pages, some technical changes in details of the argument, no change in physics conclusions, this version essentially identical to published version
title: ÐÐ¼Ð¸ÑÐ°ÑÐ¸Ð¾Ð½Ð½Ð¾Ðµ Ð¼Ð¾Ð´ÐµÐ»Ð¸ÑÐ¾Ð²Ð°Ð½Ð¸Ðµ ÑÐ¸ÑÑÐ¾Ð²Ð¾Ð¹ Ð¿Ð¾Ð´ÑÑÐ°Ð½ÑÐ¸Ð¸
title: Ð²ÑÐ¿ÑÑÐºÐ½Ð°Ñ ÐºÐ²Ð°Ð»Ð¸ÑÐ¸ÐºÐ°ÑÐ¸Ð¾Ð½Ð½Ð°Ñ ÑÐ°Ð±Ð¾ÑÐ° Ð¼Ð°Ð³Ð¸ÑÑÑÐ°
titleType: Subtitle
title: Simulation of a digital substation
Creators: name: ÐÑÐ¸Ð¼Ð°Ðº, ÐÑÐ±Ð¾Ð²Ñ
Publisher: name: Ð¡Ð°Ð½ÐºÑ-ÐÐµÑÐµÑÐ±ÑÑÐ³ÑÐºÐ¸Ð¹ Ð¿Ð¾Ð»Ð¸ÑÐµÑÐ½Ð¸ÑÐµÑÐºÐ¸Ð¹ ÑÐ½Ð¸Ð²ÐµÑÑÐ¸ÑÐµÑ ÐÐµÑÑÐ° ÐÐµÐ»Ð¸ÐºÐ¾Ð³Ð¾
Year: 2023
Subjects: Ð ÐµÐ»ÐµÐ¹Ð½Ð°Ñ Ð·Ð°ÑÐ¸ÑÐ°
ÐÐ°ÑÐµÐ¼Ð°ÑÐ¸ÑÐµÑÐºÐ¾Ðµ Ð¼Ð¾Ð´ÐµÐ»Ð¸ÑÐ¾Ð²Ð°Ð½Ð¸Ðµ
ÑÐ¸ÑÑÐ¾Ð²Ð°Ñ Ð¿Ð¾Ð´ÑÑÐ°Ð½ÑÐ¸Ñ
ÑÐ¾Ð¾Ð±ÑÐµÐ½Ð¸Ñ GOOSE
ÑÐ¾Ð¾Ð±ÑÐµÐ½Ð¸Ñ MMS
ÑÐ¾Ð¾Ð±ÑÐµÐ½Ð¸Ñ SV
digital substation
GOOSE messages
MMS messages
SV messages

description: Ð Ð°Ð±Ð¾ÑÐ° Ð¿Ð¾ÑÐ²ÑÑÐµÐ½Ð° ÑÐ¾Ð·Ð´Ð°Ð½Ð¸Ñ Ð¼Ð¾Ð´ÐµÐ»Ð¸ ÑÐ¸ÑÑÐ¾Ð²Ð¾Ð¹ Ð¿Ð¾Ð´ÑÑÐ°Ð½ÑÐ¸Ð¸, Ð² ÐºÐ¾ÑÐ¾ÑÐ¾Ð¹ Ð¾ÑÑÐ°Ð¶ÐµÐ½ Ð¿ÑÐ¾ÑÐµÑÑ Ð¾Ð±Ð¼ÐµÐ½Ð° Ð¸Ð½ÑÐ¾ÑÐ¼Ð°ÑÐ¸Ð¸ Ð¼ÐµÐ¶Ð´Ñ ÑÐ°Ð·Ð»Ð¸ÑÐ½ÑÐ¼Ð¸ ÑÑÐ¾Ð²Ð½ÑÐ¼Ð¸ ÑÐ¸ÑÑÐµÐ¼Ñ Ð½Ð° Ð¾ÑÐ½Ð¾Ð²Ðµ Ð¿ÑÐ¾ÑÐ¾ÐºÐ¾Ð»Ð¾Ð² ÑÑÐ°Ð½Ð´Ð°ÑÑÐ° ÐÐ­Ð 61850, Ð¸ Ð¿ÑÐ¾Ð²ÐµÐ´ÐµÐ½Ð¸Ñ Ñ Ð½ÐµÐ¹ ÑÐ°Ð·Ð»Ð¸ÑÐ½ÑÑ ÑÐºÑÐ¿ÐµÑÐ¸Ð¼ÐµÐ½ÑÐ¾Ð². ÐÐ»Ñ ÑÐµÑÐµÐ½Ð¸Ñ Ð¿Ð¾ÑÑÐ°Ð²Ð»ÐµÐ½Ð½ÑÑ Ð·Ð°Ð´Ð°Ñ ÑÐ°ÑÑÐ¼Ð¾ÑÑÐµÐ½Ñ ÑÑÑÑÐºÑÑÑÐ° ÑÐ¸ÑÑÐ¾Ð²Ð¾Ð¹ Ð¿Ð¾Ð´ÑÑÐ°Ð½ÑÐ¸Ð¸, ÑÑÐ°Ð½Ð´Ð°ÑÑ ÐÐ­Ð 61580 Ð¸ Ð¿ÑÐ¾ÑÐ¾ÐºÐ¾Ð»Ñ Ð¿ÐµÑÐµÐ´Ð°ÑÐ¸ Ð´Ð°Ð½Ð½ÑÑ: SV, GOOSE, MMS; Ð¿ÑÐ¾Ð²ÐµÐ´ÑÐ½ Ð°Ð½Ð°Ð»Ð¸Ð· Ð¾ÑÐ½Ð¾Ð² ÑÐµÐ»ÐµÐ¹Ð½Ð¾Ð¹ Ð·Ð°ÑÐ¸ÑÑ Ð¸ ÑÑÑÑÐ¾Ð¹ÑÑÐ² Ð ÐÐ Ñ ÑÐ¾ÑÐºÐ¸ Ð·ÑÐµÐ½Ð¸Ñ Ð¾ÑÐ½Ð¾Ð²Ð½ÑÑ ÑÐ³ÑÐ¾Ð· Ð´Ð»Ñ ÐºÐ¸Ð±ÐµÑÐ±ÐµÐ·Ð¾Ð¿Ð°ÑÐ½Ð¾ÑÑÐ¸ Ð¿ÑÐµÐ´Ð¿ÑÐ¸ÑÑÐ¸Ñ Ð¸ ÑÐ¸ÑÑÐ¾Ð²Ð¾Ð¹ Ð¿Ð¾Ð´ÑÑÐ°Ð½ÑÐ¸Ð¸ Ð¸ Ð¾Ð¿ÑÐµÐ´ÐµÐ»ÐµÐ½Ñ Ð¼ÐµÑÐ¾Ð´Ñ Ð·Ð°ÑÐ¸ÑÑ Ð¿ÑÐ¾ÑÐ¸Ð² Ð½Ð¸Ñ. Ð ÑÐ¸ÑÑÐµÐ¼Ðµ Ð¸Ð¼Ð¸ÑÐ°ÑÐ¸Ð¾Ð½Ð½Ð¾Ð³Ð¾ Ð¼Ð¾Ð´ÐµÐ»Ð¸ÑÐ¾Ð²Ð°Ð½Ð¸Ñ AnyLogic Ð¿Ð¾ÑÑÑÐ¾ÐµÐ½Ð° Ð¼Ð¾Ð´ÐµÐ»Ñ, Ð² ÐºÐ¾ÑÐ¾ÑÐ¾Ð¹ Ð¿ÑÐ¾Ð¸ÑÑÐ¾Ð´Ð¸Ñ Ð¾Ð±Ð¼ÐµÐ½ Ð¸Ð½ÑÐ¾ÑÐ¼Ð°ÑÐ¸Ð¸ Ð¼ÐµÐ¶Ð´Ñ Ð¾Ð±ÑÐµÐºÑÐ°Ð¼Ð¸ Ð² ÑÐ¾Ð¾ÑÐ²ÐµÑÑÑÐ²Ð¸Ð¸ ÑÐ¾ ÑÑÐ°Ð½Ð´Ð°ÑÑÐ¾Ð¼. ÐÑÐ¾Ð²ÐµÐ´ÐµÐ½Ñ ÑÐºÑÐ¿ÐµÑÐ¸Ð¼ÐµÐ½ÑÑ Ñ Ð¼Ð¾Ð´ÐµÐ»ÑÑ, ÑÐµÐ»ÑÑ ÐºÐ¾ÑÐ¾ÑÑÑ Ð±ÑÐ» Ð°Ð½Ð°Ð»Ð¸Ð· ÑÐµÑÐµÐ²Ð¾Ð³Ð¾ ÑÑÐ°ÑÐ¸ÐºÐ° Ð² ÑÐ¸ÑÑÐ¾Ð²Ð¾Ð¹ Ð¿Ð¾Ð´ÑÑÐ°Ð½ÑÐ¸Ð¸ Ð¿ÑÐ¸ ÑÐ°Ð·Ð»Ð¸ÑÐ½ÑÑ Ð¿Ð¾ÐºÐ°Ð·Ð°ÑÐµÐ»ÑÑ.
description: This work is devoted to the creation of a digital model of a substation reflecting the process of information exchange between different levels of the system based on protocols of the IEC 61850 standard, and conducting various experiments with it. Tasks that were solved during the work: analysis of the structure of the digital substation and the IEC 61580 standard; viewing data on transmission protocols: SV, GOOSE, MMS; analysis of information about the basics of relay protection and RPA devices from the viewpoint of the main threats to the cybersecurity of the enterprise and the digital substation and methods of protection against them. A model was built in the AnyLogic modeling system in which information exchange between objects is carried out in accordance with the standard. Experiments were conducted with the model, the purpose of which was to analyze network traffic at a digital substation according to various indicators.
Corona splashing triggered by a loose monolayer of particles
Creators: name: Esmaili, Ehsan
name: Chen, Zih-Yin
name: Pandey, Anupam
name: Kim, Seungho
name: Lee, Sungyon
name: Jung, Sunghwan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In nature, high-speed raindrops often impact and spread on particulate surfaces (e.g., soil, plant leaves with spores or pollen). We study the dynamics of droplet impact on a loosely packed monolayer of particles by combining experimental and mathematical approaches. We find that the presence of mobile particles lowers the critical impact velocity at which the droplet exhibits corona splashing, as the particle area fraction is systematically increased. We rationalize this experimental observation by considering the jamming of frictional particles at the spreading rim. Elucidating the splashing transition of the drop on a particulate bed can lead to a better understanding of soil loss and erosion from falling raindrops.
Scaling and Memory Effect in Volatility Return Interval of the Chinese Stock Market
Creators: name: Qiu, Tian
name: Guo, Liang
name: Chen, Guang
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Finance (q-fin.ST)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Economics and business
subject: FOS: Physical sciences

description: We investigate the probability distribution of the volatility return intervals $τ$ for the Chinese stock market. We rescale both the probability distribution $P_{q}(τ)$ and the volatility return intervals $τ$ as $P_{q}(τ)=1/\barτ f(τ/\barτ)$ to obtain a uniform scaling curve for different threshold value $q$. The scaling curve can be well fitted by the stretched exponential function $f(x) \sim e^{-αx^γ}$, which suggests memory exists in $τ$. To demonstrate the memory effect, we investigate the conditional probability distribution $P_{q} (τ|τ_{0})$, the mean conditional interval $$ and the cumulative probability distribution of the cluster size of $τ$. The results show clear clustering effect. We further investigate the persistence probability distribution $P_{\pm}(t)$ and find that $P_{-}(t)$ decays by a power law with the exponent far different from the value 0.5 for the random walk, which further confirms long memory exists in $τ$. The scaling and long memory effect of $τ$ for the Chinese stock market are similar to those obtained from the United States and the Japanese financial markets.
description: 10 elsart pages including 7 eps figures
Infrared phonon dynamics of multiferroic BiFeO3 single crystal
Creators: name: Lobo, R. P. S. M.
name: Moreira, R. L.
name: Lebeugle, D.
name: Colson, D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We discuss the first infrared reflectivity measurement on a BiFeO3 single crystal between 5 K and room temperature. The 9 predicted ab-plane E phonon modes are fully and unambiguously determined. The frequencies of the 4 A1 c-axis phonons are found. These results settle issues between theory and data on ceramics. Our findings show that the softening of the lowest frequency E mode is responsible for the temperature dependence of the dielectric constant, indicating that the ferroelectric transition in BiFeO3 is soft-mode driven.
description: 5 pages (figures included)
Adapting drinking-water systems to coastal climate change: evidence from Viet Nam and the Philippines
Creators: name: Ojomo, Edema
name: Bartram, Jamie
Publisher: name: Springer Nature
Year: 2016

description:
Coastal areas will increasingly experience adverse climate hazards such as coastal flooding and severe storms as a result of climate change. These hazards adversely affect drinking-water systems and thereby reduce access to safe drinking-water. Effective adaptation implementation minimizes the damaging impacts of these hazards. However, research on the enablers of and barriers to effective adaptation in low-income countries is lacking. This study maps enablers and barriers to climate change adaptation of water systems in coastal low-income countries using evidence from Viet Nam and the Philippines, countries which experience frequent extreme climate events. Interviews were carried out with staff from 29 water utilities and government agencies. A systematic framework for diagnosing barriers to climate change adaptation was used to analyze the responses. Five factors were identified as relevant to effective adaptation: partnerships; financial resources; human and technical resources; leadership and political will; and awareness of climate change. The factors identified were related to all the elements of the framework—actors, system of concern, and context—and were relevant to the three phases of the adaptation process (understanding the problem, planning the adaptation, and managing the implementation). Our findings can assist water system managers in diagnosing barriers to effective adaptation that may exist and identifying relevant partnerships and resources that will aid in overcoming these barriers.
Structural and electrical characterization of the monolayer Kondo-lattice compound CePt$_6$/Pt(111)
Creators: name: Ienaga, Koichiro
name: Kim, Sunghun
name: Miyamachi, Toshio
name: Komori, Fumio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report the growth process, structure, and electronic states of 1 unit layer (u.l.) of a Ce-Pt intermetallic compound on Pt(111) using scanning tunneling microscopy/spectroscopy (STM/STS) and low-energy electron diffraction. An ordered $(2 \times 2)$ structure was observed in the form of films or nanoislands depending on Ce dose by annealing at around 700 K. A structural model constructed from atomically resolved STM images and quasiparticle interference (QPI) patterns indicates the formation of a new surface compound 1 u.l. CePt$_6$ on Pt(111) terminated by a Pt layer. A lateral lattice constant of the 1 u.l. CePt$_6$ on Pt(111) is expanded from the value of a bulk CePt$_5$ crystal to match the Pt(111) substrate. By measuring d$I$/d$V$ spectra and QPI, we observed an onset energy of the surface state found on Pt(111) above Fermi energy ($E_F$) shifts below $E_F$ on the Pt layer of the 1 u.l. CePt$_6$ due to charge transfer from the underneath CePt$_2$ layer. We discuss a possible two-dimensional coherent Kondo effect with the observed spectra on the 1 u.l. CePt$_6$.
description: 10 pages, 7 figures
Search for TeV Scale Physics in Heavy Flavour Decays
Creators: name: Hou, George W. S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The subject of heavy flavour decays as probes for physics at and beyond the TeV scale is covered from the experimental perspective. Emphasis is placed on the more traditional Beyond the Standard Model topics that have potential for impact in the early LHC era, and in anticipation of the B factory upgrade(s). The aim is to explain the physics, without getting too involved in the details, whether experimental or theoretical, to give the interested nonexpert a perspective on the Flavour/TeV link. We cover the forefront topics of $CP$ violation in $b\to s$ transitions involving penguin and box diagrams, and probes of charged Higgs, right-handed and scalar interactions. We touch briefly on $Υ$ decay, $D^0$ mixing, rare $K$ decays, and lepton flavor violating probes in $τ$ decay. Our own phemonenology work is often used for illustration.
description: 19 pages, 20 figures, to be published in the special volume "Supersymmetry on the Eve of the LHC", dedicated to Julius Wess, in European Physical Journal C
Evolution of Elemental Abundances During B-Class Solar Flares: Soft X-ray Spectral Measurements with Chandrayaan-2 XSM
Creators: name: Mondal, Biswajit
name: Sarkar, Aveek
name: Vadawale, Santosh V.
name: Mithun, N. P. S.
name: Janardhan, P.
name: Del Zanna, Giulio
name: Mason, Helen E.
name: Mitra-Kraev, Urmila
name: Narendranath, S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The Solar X-ray Spectrometer (XSM) payload onboard Chandrayaan-2 provides disk-integrated solar spectra in the 1-15 keV energy range with an energy resolution of 180 eV (at 5.9 keV) and a cadence of 1~second. During the period from September 2019 to May 2020, covering the minimum of Solar Cycle 24, it observed nine B-class flares ranging from B1.3 to B4.5. Using time-resolved spectroscopic analysis during these flares, we examined the evolution of temperature, emission measure, and absolute elemental abundances of four elements -- Mg, Al, Si, and S. These are the first measurements of absolute abundances during such small flares and this study offers a unique insight into the evolution of absolute abundances as the flares evolve. Our results demonstrate that the abundances of these four elements decrease towards their photospheric values during the peak phase of the flares. During the decay phase, the abundances are observed to quickly return to their pre-flare coronal values. The depletion of elemental abundances during the flares is consistent with the standard flare model, suggesting the injection of fresh material into coronal loops as a result of chromospheric evaporation. To explain the quick recovery of the so-called coronal "First Ionization Potential (FIP) bias" we propose two scenarios based on the Ponderomotive force model.
description: Accepted for publication in the Astrophysical Journal, 19 pages, 12 figures
Cosmological Radar Ranging in an Expanding Universe
Creators: name: Lewis, Geraint F.
name: Francis, Matthew J.
name: Barnes, Luke A.
name: Kwan, Juliana
name: James, J. Berian
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: While modern cosmology, founded in the language of general relativity, is almost a century old, the meaning of the expansion of space is still being debated. In this paper, the question of radar ranging in an expanding universe is examined, focusing upon light travel times during the ranging; it has recently been claimed that this proves that space physically expands. We generalize the problem into considering the return journey of an accelerating rocketeer, showing that while this agrees with expectations of special relativity for an empty universe, distinct differences occur when the universe contains matter. We conclude that this does not require the expansion of space to be a physical phenomenon, rather that we cannot neglect the influence of matter, seen through the laws of general relativity, when considering motions on cosmic scales.
description: 6 Pages. To appear in MNRAS
Long GRBs from binary stars: runaway, Wolf-Rayet progenitors
Creators: name: Cantiello, M.
name: Yoon, S. -C.
name: Langer, N.
name: Livio, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The collapsar model for long gamma-ray bursts requires a rapidly rotating Wolf-Rayet star as progenitor. We test the idea of producing rapidly rotating Wolf-Rayet stars in massive close binaries through mass accretion and consecutive quasi-chemically homogeneous evolution; the latter had previously been shown to provide collapsars below a certain metallicity threshold for single stars. The binary channel presented here may provide a means for massive stars to obtain the high rotation rates required to evolve quasi-chemically homogeneous and fulfill the collapsar scenario. Moreover, it suggests that a possibly large fraction of long gamma-ray bursts occurs in runaway stars.
description: To appear in the proceedings of the conference "Unsolved problems in stellar physics" - Cambridge, July 2007
Nonlocal Phenomenology for anisotropic MHD turbulence
Creators: name: Alexakis, Alexandros
Publisher: name: arXiv
Year: 2007
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: A non-local cascade model for anisotropic MHD turbulence in the presence of a guiding magnetic field is proposed. The model takes into account that (a) energy cascades in an anisotropic manner and as a result a different estimate for the cascade rate in the direction parallel and perpendicular to the guiding field is made. (b) the interactions that result in the cascade are between different scales. Eddies with wave numbers $k_\|$ and $k_\perp$ interact with eddies with wave numbers $q_\|,q_\perp$ such that a resonance condition between the wave numbers $q_\|,q_\perp$ and $k_\|,k_\perp$ holds. As a consequence energy from the eddy with wave numbers $k_\|$ and $k_\perp$ cascades due to interactions with eddies located in the resonant manifold whose wavenumbers are determined by: $q_\|\simeq ε^{{1}/{3}}k_\perp^{2/3}/B$, $q_\perp=k_\perp$ and energy will cascade along the lines $k_\|\sim C+k_\perp^{2/3} ε^{1/3}/B_0$. For a uniform energy injection rate in the parallel direction the resulting energy spectrum is $E(k_\|,k_\perp)\simeq ε^{2/3}k_\|^{-1}k_\perp^{-5/3}$. For a general forcing however the model suggests a non-universal behavior. The connections with previous models, numerical simulations and weak turbulence theory are discussed.
description: Submited to Astophys. Lett
Efficient automated U-Net based tree crown delineation using UAV multi-spectral imagery on embedded devices
Creators: name: Blekos, Kostas
name: Nousias, Stavros
name: Lalos, Aris S
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Image and Video Processing (eess.IV)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Delineation approaches provide significant benefits to various domains, including agriculture, environmental and natural disasters monitoring. Most of the work in the literature utilize traditional segmentation methods that require a large amount of computational and storage resources. Deep learning has transformed computer vision and dramatically improved machine translation, though it requires massive dataset for training and significant resources for inference. More importantly, energy-efficient embedded vision hardware delivering real-time and robust performance is crucial in the aforementioned application. In this work, we propose a U-Net based tree delineation method, which is effectively trained using multi-spectral imagery but can then delineate single-spectrum images. The deep architecture that also performs localization, i.e., a class label corresponds to each pixel, has been successfully used to allow training with a small set of segmented images. The ground truth data were generated using traditional image denoising and segmentation approaches. To be able to execute the proposed DNN efficiently in embedded platforms designed for deep learning approaches, we employ traditional model compression and acceleration methods. Extensive evaluation studies using data collected from UAVs equipped with multi-spectral cameras demonstrate the effectiveness of the proposed methods in terms of delineation accuracy and execution efficiency.
description: 6 pages, 7 figures, 2 tables
Emission line profiles as a probe of physical conditions in planetary nebulae
Creators: name: Zhang, Yong
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present an analysis of physical conditions in planetary nebulae (PNe) in terms of collisionally-excited line (CEL) and optical-recombination line (ORL) profiles. We aim to investigate whether line profiles could be used to study the long-standing CEL/ORL abundance-discrepancy problem in nebular astrophysics. Using 1D photoionization models and their assumed velocity fields, we simulate the line profiles of various ionic species. We attempt to use our model to account for the observed CEL and ORL profiles. As a case study we present a detailed study of line profiles of the low-excitation planetary nebula (PN) IC 418. Our results show that the profiles of classical temperature and density diagnostic lines, such as [O III] 4363,5007, [S II] 6716,6731, and [Ar IV] 4711,4740, provide a powerful tool to study nebular temperature and density variations. The method enables the CEL/ORL abundance-discrepancy problem to be studied more rigorously than before. A pure photoionization model of a chemically-homogeneous nebula seems to explain the observed disagreements in the profiles for the [O III] 4363 and the 5007 lines, but cannot account for the differences between the [O III] CELs and the O II ORLs. We also investigate the temperature and density variations in the velocity space of a sample of PNe, which are found to be insignificant.
description: 9 pages, 10 figures, Accepted for publication in A&A
Laser Cooling of a Yb Doped Silica Fiber by 18 Kelvin From Room Temperature
Creators: name: Topper, Brian
name: Peysokhan, Mostafa
name: Albrecht, Alexander R.
name: Flores, Angel S.
name: Kuhn, Stefan
name: Haessner, Denny
name: Hein, Sigrun
name: Hupel, Christian
name: Nold, Johannes
name: Haarlammert, Nicoletta
name: Schreiber, Thomas
name: Sheik-Bahae, Mansoor
name: Mafi, Arash
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: A ytterbium doped silica optical fiber has been cooled by 18.4K below ambient temperature by pumping with 20W of 1035nm light in vacuum. In air, cooling by 3.6K below ambient was observed with the same 20W pump. The temperatures were measured with a thermal imaging camera and differential luminescence thermometry. The cooling efficiency is calculated to be 1.2+-0.1%. The core of the fiber was codoped with Al3+ for an Al to Yb ratio of 6:1, to allow for a larger Yb concentration and enhanced laser cooling.
Supplementary Online Appendix_EJPG_DAgostino.pdf
Creators: name: D'Agostino, Serena
Publisher: name: figshare
Year: 2021
Subjects: subject: 160699 Political Science not elsewhere classified
subject: FOS: Political science

description: Additional Data Sources(excluding own interviews, policy documents and websites/social media accounts):speeches; public statements; declarations; strategies; position papers; on-line interviews
Using data to support law enforcement decision making around illegal drug parcels
Creators: name: Morales, Ana
Publisher: name: Scottish Centre for Administrative Data Research
Year: 2021
Subjects: Drugs; post; data; harm

description: Using data from the National Crime Agency on drug parcels intercepted en route to Scotland between 2011 and 2016, this project aimed to identify what factors were most important in determining which parcels were used to conduct a controlled delivery. Specifically, we examined factors relating to the level of harm posed by the parcel itself (in terms of the type and amount of drugs it contained) and factors relating to the level of drug-related harm in the communities to which the parcels were destined. We found that decisions taken by law enforcement agencies were related to the amount and type of drug contained in parcels, but not to wider community factors.
Using data to classify the likely ‘motivation’ of online drug purchasers
Creators: name: Pantoja, Fernando
Publisher: name: Scottish Centre for Administrative Data Research
Year: 2021
Subjects: Drugs; post; data; law enforcement; drug use

description: We used data provided by the National Crime Agency about illegal consignments intercepted through the postal service by the UK Border Force and destined for Scotland to establish a new approach for the classification of drug purchases with a view to helping law enforcement to judge the likely usage and harm of such packages.
Division of the two-qubit Hilbert space according to the entanglement sudden death under composite noise environment
Creators: name: Li, Peng
name: Zhang, Qun
name: You, J. Q.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show theoretically that according to the disentanglement behavior under composite noise environment, the Hilbert space of a two-qubit system can be divided into two separate parts: a 3-dimensional subspace in which all states disentangle asymptotically, and the rest in which all states disentangle abruptly. The violation of additivity for entanglement decay rates under weak noises [see, PRL 97, 140403 (2006)] therefore can be explained in terms of such division of the Hilbert space.
description: 4 reference added
Establishment and placement of a Multi-purpose Phasor measurement unit to improve parallel state estimation in distribution Networks
Creators: name: Khashroum, Zeyad
name: Chaharabi, Ali Dehghan
name: Palmero, Lorena
name: Yasukawa, Keiichiro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Today, microgrids in distribution networks are in dire need of improvement to cope with economic challenges, human losses, and equipment placement issues. Today, there is the issue of scattered resources in distribution systems, which has created many problems in the areas of environment, economy, and human and animal losses. The most important challenge in this section is the existence of voltage and frequency fluctuations during the occurrence of possible events such as severe load changes or errors in distribution networks. Having such a big problem can call a distribution network into question and destroy it. Therefore, it is necessary to provide an optimal method that can meet and cover these challenges. For this purpose, the present research deals with the problem of establishing and placing a multifunctional phasor measurement unit to improve the parallel state estimation in distribution networks, which offers a control approach. This approach determines the time of occurrence of internal and external disturbances after using the phasor unit. The approach of this research is to use a neural-fuzzy method because there is uncertainty in the distribution network due to the mentioned challenges, and training in the system is needed to accurately deploy and place possible errors. Do not occur. When setting up and placing the phasor measuring unit, the most important issue is the proper distribution of the load in the distribution network. The simulation results in the MATLAB / Simulink environment show the improvement of the results according to the proposed approach. Keywords: Distribution Network, Neural-Fuzzy Network, Optimal Load Distribution, Parallel State Estimation, Phasor Measurement Unit.
description: 17 pages, 19 figures
Enveloping algebras of Hom-Lie algebras
Creators: name: Yau, Donald
Publisher: name: arXiv
Year: 2007
Subjects: subject: Rings and Algebras (math.RA)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 05C05, 17A30, 17A32, 17A50, 17B01, 17B35, 17D25

description: Enveloping algebras of Hom-Lie and Hom-Leibniz algebras are constructed.
description: 16 pages. To appear in Journal of Generalized Lie Theory and Applications
Internationalization of Metadata Guidelines in Repositories
Creators: name: Holt, Ilkay
Publisher: name: Zenodo
Year: 2019
Subjects: Metadata schemas
International metadata framework
Metadata requirements
OpenAIRE
LA Referencia
JPCOAR
RIOXX
BASE
CORE

description: This presentation was made at the COAR 2019 Annual Meeting & General Assembly, Lyon (France)
การศึกษาระดับโมเลกุลของผู้ป่วยคนไทยโรค Mucopolysaccharidosis ชนิดที่ 1 (Molecular Analysis of Thai Patients with Mucopolysaccharidosis Type I)
Creators: name: ลักขณา งิ้วสระ
Publisher: name: Genetics Society of Thailand
Year: 2013
Subjects: mucopolysaccharidosis, alpha-L-iduronidase, glycosaminoglycans

description: S1 (Special Issue 1), S.1, Thai Journal of Genetics
Spitzer Quasar and ULIRG Evolution Study (QUEST): II. The Spectral Energy Distributions of Palomar-Green Quasars
Creators: name: Netzer, Hagai
name: Lutz, Dieter
name: Schweitzer, Mario
name: Contursi, Alessandra
name: Sturm, Eckhard
name: Tacconi, Linda J.
name: Veilleux, Sylvain
name: Kim, D. -C.
name: Rupke, David
name: Baker, Andrew J.
name: Dasyra, Kalliopi
name: Mazzarella, Joseph
name: Lord, Steven
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: This is the second paper studying the QSOs in the spitzer QUEST sample. Previously we presented new PAH measurements and argued that most of the observed far infrared (FIR) radiation is due to star-forming activity. Here we present spectral energy distributions (SEDs) by supplementing our data with optical, NIR and FIR observations. We define two sub-groups of ``weak FIR'' and ``strong FIR'' QSOs, and a third group of FIR non-detections. Assuming a starburst origin for the FIR, we obtain ``intrinsic'' AGN SEDs by subtracting a starburst template from the mean SEDs. The resulting SEDs are remarkably similar for all groups. They show three distinct peaks corresponding to two silicate emission features and a 3mic bump that we interpret as the signature of the hottest AGN dust. They also display drops beyond 20mic that we interpret as the signature of the minimum temperature (about 200K) dust. This component must be optically thin to explain the silicate emission and the slope of the long wavelength continuum. We discuss the merits of an alternative model where most of the FIR emission is due to AGN heating. Such models are unlikely to explain the properties of our QSOs but they cannot be ruled out for more luminous objects. We also find correlations between the luminosity at 5100A and two infrared starburst indicators: L(60mic) and L(PAH 7.7mic). The correlation of L(5100A) with L(60mic) can be used to measure the relative growth rates and lifetimes of the black hole and the new stars.
description: 12 pages, 6 figures, accepted by ApJ
三生万物:以科学精度解释世界的形成
Creators: name: Chen, Shu Jian
Publisher: name: Zenodo
Year: 2025

description: **请在右侧确认选择最新版本我们生活的世界充满了规律与结构——从原子的运动到银河的旋转,从时间的节奏到意识的流动。然而,这一切秩序的源头究竟从何而来?为什么这个宇宙有这些常数、这些法则,以及我们这样的观察者?

 

本篇文章以通俗易懂的语言,介绍一个名为“三生万物”(Triogenesis)的理论框架,它揭示了世界可能是由一条简单、递归、充满创造力的数学法则逐层生成出来的。这一法则不仅能解释空间、时间、质量与能量的来源,还自然地将“意识”纳入其中,为我们提供一个融合物理、哲学与生命经验的整体视角。

 

本文章并非专业科研论文,而是写给普通读者、年轻读者与所有对世界充满好奇的人。你无需掌握高等数学,也不必具备物理背景,只需要一颗愿意思考与感受的心,就能从中发现共鸣。

 

如果你想更深入地了解三生万物的数学原理与科学推导,欢迎阅读以下两篇英文原始研究论文:

• 📘 Triogenesis: A Closed-Form Framework for the Emergence of Physical Order and Consciousness

展示如何用三生万物框架精确推导出氢原子的能级结构,与薛定谔方程的实验值达到 99.95% 的一致性。

• 📘Emergence of Schrödinger's Equation Solution for the Hydrogen Atom from Triogenesis

英文原版:• 📘Triogenesis: Explaining the Formation of the World with Scientific Precision
A Quantum Adiabatic Algorithm for Factorization and Its Experimental Implementation
Creators: name: Peng, Xinhua
name: Liao, Zeyang
name: Xu, Nanyang
name: Qin, Gan
name: Zhou, Xianyi
name: Suter, Dieter
name: Du, Jiangfeng
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose an adiabatic quantum algorithm capable of factorizing numbers, using fewer qubits than Shor's algorithm. We implement the algorithm in an NMR quantum information processor and experimentally factorize the number 21. Numerical simulations indicate that the running time grows only quadratically with the number of qubits.
description: 5 pages, 3 figures
Variability of sperm histones in Anura contrasts with relative constancy in Urodela, Squamata and Aves
Creators: name: Mann, Mairi Elizabeth
Publisher: name: University of British Columbia
Year: 2010

description: Sperm histone diversity in the vertebrates has been examined in order to delineate possible macroevolutionary trends. Sperm basic proteins have been characterized cytochemically in testis sections and by electrophoresis in polyacrylamide and starch gels. Representative species of Anura (frogs and toads), Urodela (newts and salamanders), Squamata (lizards and snakes) and Aves (birds) have been compared. The testis-specific basic proteins of Anura demonstrated a high degree of diversity. Cytochemically, sperm histones of the genus Rana resembled those of somatic cells while those of the genera Hyla, Bufo and Scaphiopus appeared to be of the more basic "intermediate type". Electrophoresis revealed differences between the testis-specific basic proteins of these genera, and in the genus Xenopus, sperm nuclear proteins varied at the species and even sub-species levels. X. tropicalis and X. so. n. Ill (Zaire), distantly related to the rest of the genus, were found to have somatic-like sperm histones as opposed to the intermediate type proteins displayed by other Xenopus species. The array of basic proteins found in the sperm of urodeles, reptiles and birds appeared more conservative than in anurans. All the urodeles studied showed a cytochemically detectable transistion from somatic histones to stable protamines to protamines during the course of spermiogenesis. The protamine-like protein appeared to be electrophoretically similar in all urodele species. Lizards and snakes also demonstrated testis- and sperm-specific basic proteins with similar electrophoretic mobilities, although cytochemistry suggested that the lizard sperm histones had a higher content of arginine than the proteins found in snake sperm. Cytochemically, the sperm nuclear proteins of seven species of birds, representing four avian orders, were found to be of the protamine type. Intact protamines were difficult to isolate from avian testes but similarities were noted between the major testis-specific electrophoretic bands of all the birds studied. Overall, there appeared to be a trend in vertebrate phylogeny from sperm histone diversity in teleost fish and anuran amphibians to relative constancy in Urodela, Reptilia, Aves and Mammalia. This evolutionary trend was discussed in terms of the possible, functions of the basic nuclear proteins of sperm and the appearance of internal fertilization and chromosomally-based sex-determination in the vertebrates.
Constraint Complexity of Realizations of Linear Codes on Arbitrary Graphs
Creators: name: Kashyap, Navin
Publisher: name: arXiv
Year: 2008
Subjects: subject: Discrete Mathematics (cs.DM)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: A graphical realization of a linear code C consists of an assignment of the coordinates of C to the vertices of a graph, along with a specification of linear state spaces and linear ``local constraint'' codes to be associated with the edges and vertices, respectively, of the graph. The $\k$-complexity of a graphical realization is defined to be the largest dimension of any of its local constraint codes. $\k$-complexity is a reasonable measure of the computational complexity of a sum-product decoding algorithm specified by a graphical realization. The main focus of this paper is on the following problem: given a linear code C and a graph G, how small can the $\k$-complexity of a realization of C on G be? As useful tools for attacking this problem, we introduce the Vertex-Cut Bound, and the notion of ``vc-treewidth'' for a graph, which is closely related to the well-known graph-theoretic notion of treewidth. Using these tools, we derive tight lower bounds on the $\k$-complexity of any realization of C on G. Our bounds enable us to conclude that good error-correcting codes can have low-complexity realizations only on graphs with large vc-treewidth. Along the way, we also prove the interesting result that the ratio of the $\k$-complexity of the best conventional trellis realization of a length-n code C to the $\k$-complexity of the best cycle-free realization of C grows at most logarithmically with codelength n. Such a logarithmic growth rate is, in fact, achievable.
description: Submitted to IEEE Transactions on Information Theory
A New Sedimentation Model for Greater Cloud Diversity in Giant Exoplanets and Brown Dwarfs
Creators: name: Rooney, Caoimhe M.
name: Batalha, Natasha E.
name: Gao, Peter
name: Marley, Mark S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The observed atmospheric spectrum of exoplanets and brown dwarfs depends critically on the presence and distribution of atmospheric condensates. The Ackerman & Marley (2001) methodology for predicting the vertical distribution of condensate particles is widely used to study cloudy atmospheres and has recently been implemented in an open-source python package virga. The model relies upon input parameter $f_{\text{sed}}$, the sedimentation efficiency, which until now has been held constant. The relative simplicity of this model renders it useful for retrieval studies due to its rapidly attainable solutions. However, comparisons with more complex microphysical models such as CARMA have highlighted inconsistencies between the two approaches, namely that the cloud parameters needed for radiative transfer produced by virga are dissimilar to those produced by CARMA. To address these discrepancies, we have extended the original Ackerman and Marley methodology in virga to allow for non-constant $f_{\text{sed}}$ values, in particular those that vary with altitude. We discuss one such parameterization and compare the cloud mass mixing ratio produced by virga with constant and variable $f_{\text{sed}}$ profiles to that produced by CARMA. We find that the variable $f_{\text{sed}}$ formulation better captures the profile produced by CARMA with heterogeneous nucleation, yet performs comparatively to constant $f_{\text{sed}}$ for homogeneous nucleation. In general, virga has the capacity to handle any $f_{\text{sed}}$ with an explicit anti-derivative, permitting a plethora of alternative cloud profiles that are otherwise unattainable by constant $f_{\text{sed}}$ values. The ensuing flexibility has the potential to better agree with increasingly complex models and observed data.
description: Accepted ApJ; GitHub: http://github.com/natashabatalha/virga Docs: http://natashabatalha.github.io/virga/# Virga Tutorials: http://natashabatalha.github.io/virga/tutorials.html
Yukawa Textures From Singular Spectral Data
Creators: name: Karkheiran, Mohsen
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The Yukawa textures of effective heterotic models are studied by using singular spectral data. One advantage of this approach is that it is possible to dissect the cohomologies of the bundles into smaller parts and identify the pieces that contain the zero modes, which can potentially have non-zero Yukawa couplings. Another advantage is the manifest relationship between the Yukawa textures in heterotic models and local F-theory models in terms of fields living in bulk or localized inside the 7-branes. We only work with Weierstrass elliptically fibered Calabi-Yau manifolds here. The idea for generalizing this approach to every elliptically fibered Calabi-Yau with rational sections is given at the end of this paper.
description: 61 pages, 12 figures, 3 tables
On the Dirac delta as initial condition for nonlinear Schrödinger equations
Creators: name: Banica, Valeria
name: Vega, Luis
Publisher: name: arXiv
Year: 2007
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this article we will study the initial value problem for some Schrödinger equations with Diraclike initial data and therefore with infinite L2 mass, obtaining positive results for subcritical nonlinearities. In the critical case and in one dimension we prove that after some renormalization the corresponding solution has finite energy. This allows us to conclude a stability result in the defocusing setting. These problems are related to the existence of a singular dynamics for Schrödinger maps through the so called Hasimoto transformation.
description: 17 pages, to appear in in AnIHP Ann Non Lin
Infall of planetesimals onto growing giant planets: onset of runaway gas accretion and metallicity of their gas envelopes
Creators: name: Shiraishi, Masakazu
name: Ida, Shigeru
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have investigated the planetesimal accretion rate onto giant planets that are growing through gas accretion, using numerical simulations and analytical arguments. We derived the condition for gap opening in the planetesimal disk, which is determined by a competition between the expansion of the planet's Hill radius due to the planet growth and the damping of planetesimal eccentricity due to gas drag. We also derived the semi-analytical formula for the planetesimal accretion rate as a function of ratios of the rates of the Hill radius expansion, the damping, and planetesimal scattering by the planet. The predicted low planetesimal accretion rate due to gap opening in early gas accretion stages quantitatively shows that "phase 2," which is a long slow gas accretion phase before onset of runaway gas accretion, is not likely to occur. In late stages, rapid Hill radius expansion fills the gap, resulting in significant planetesimal accretion, which is as large as several $M_{\oplus}$ for Jupiter and Saturn. The efficient onset of runaway gas accretion and the late pollution may reconcile the ubiquity of extrasolar giant planets with metal-rich envelopes of Jupiter and Saturn inferred from interior structure models. These formulae will give deep insights into formation of extrasolar gas giants and the diversity in metallicity of transiting gas giants.
description: 19 pages, 9 figures, accepted for publication in ApJ
Kaon and antikaon optical potentials in isospin asymmetric hyperonic matter
Creators: name: Mishra, Amruta
name: Kumar, Arvind
name: Sanyal, Sambuddha
name: Schramm, Stefan
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The medium modifications of the energies of kaons and antikaons in isospin asymmetric hyperonic matter are investigated using a chiral SU(3) model. The isospin dependent medium effects, are important for asymmetric heavy ion collision experiments, as well as relevant for the neutron star phenomenology as the bulk matter in the interior of the neutron star is highly isospin asymmetric. The effects of hyperons on the medium modifications of the kaons and antikaons in the strange hadronic matter are investigated in the present work and are seen to be appreciable for hadronic matter with large strangeness fractions. The study of the K-mesons in the asymmetric strange hadronic matter can be especially relevant for the compressed strange baryonic matter which can result from asymmetric heavy ion collision experiments in the future accelerator facility FAIR at GSI.
description: 18 pages, 12 figures
On the Poisson-Lie T-plurality of boundary conditions
Creators: name: Albertsson, Cecilia
name: Hlavaty, Ladislav
name: Snobl, Libor
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Conditions for the gluing matrix defining consistent boundary conditions of two-dimensional nonlinear sigma-models are analyzed and reformulated. Transformation properties of the right-invariant fields under Poisson-Lie T-plurality are used to derive a formula for the transformation of the boundary conditions. Examples of transformation of D-branes in two and three dimensions are presented. We investigate obstacles arising in this procedure and propose possible solutions.
description: 25 pages, LaTeX; major revision, discussion of boundary fields added; author's version of the published paper
Trends in reproductive health indicators in Nigeria using demographic and health surveys (1990–2013)
Creators: name: Okigbo, Chinelo C.
name: Adegoke, Korede K.
name: Olorunsaiye, Comfort Z.
Publisher: name: Taylor & Francis
Year: 2016

description:
There is an urgent need to improve reproductive health (RH) in Nigeria - the most populous country in Africa. In 2015, Nigeria had the highest number of maternal deaths in the world. This study assessed the trends in select RH indicators in Nigeria over two decades. Data used were from Nigeria Demographic and Health Surveys (NDHS) conducted between 1990 and 2013. The NDHS uses a two-stage cluster sampling design to select nationally representative samples of reproductive-age women. The study sample ranged from 7620 to 38,948 women aged 15-49 across the five surveys. Trends in modern contraceptive prevalence rate, skilled antenatal care, skilled birth attendance, and adolescent birth were assessed. The results show increasing trends in modern contraceptive prevalence rate from 4% in 1990 to 11% in 2013 (p < .001); in skilled antenatal care from 57% in 1990 to 61% in 2013 (p < .001); and in skilled birth attendance from 31% in 1990 to 40% in 2013 (p < .001). The trend in adolescent birth decreased from 24% in 1990 to 17% in 2013 (p < .001). Marked disparities exist as rural, poor, and less educated women bear the greatest burden. Interventions should target the at-risk populations to improve their access and use of RH services.