Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950–2019: a comprehensive demographic analysis for the Global Burden of Disease Study 2019

Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2•72 (95% uncertainty interval [UI] 2•66–2•79) in 2000 to 2•31 (2•17–2•46) in 2019. Global annual livebirths increased from 134•5 million (131•5–137•8) in 2000 to a peak of 139•6 million (133•0–146•9) in 2016. Global livebirths then declined to 135•3 million (127•2–144•1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2•1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27•1% (95% UI 26•4–27•8) of global livebirths. Global life expectancy at birth increased from 67•2 years (95% UI 66•8–67•6) in 2000 to 73•5 years (72•8–74•3) in 2019. The total number of deaths increased from 50•7 million (49•5–51•9) in 2000 to 56•5 million (53•7–59•2) in 2019. Under-5 deaths declined from 9•6 million (9•1–10•3) in 2000 to 5•0 million (4•3–6•0) in 2019. Global population increased by 25•7%, from 6•2 billion (6•0–6•3) in 2000 to 7•7 billion (7•5–8•0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58•6 years (56•1–60•8) in 2000 to 63•5 years (60•8–66•1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019. Interpretation: Over the past 20 years, fertility rates have been dropping steadily and life expectancy has been increasing, with few exceptions. Much of this change follows historical patterns linking social and economic determinants, such as those captured by the GBD Socio-demographic Index, with demographic outcomes. More recently, several countries have experienced a combination of low fertility and stagnating improvement in mortality rates, pushing more populations into the late stages of the demographic transition. Tracking demographic change and the emergence of new patterns will be essential for global health monitoring. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

Dynamics of surface melting

The objectives of this program is to study the phenomenon of surface melting of single crystals of metals, to test for its existence, and to investigate its dynamics. Both conventional static electron diffraction and dynamic ultrafast electron diffraction are used in our study. This year, the ultrahigh vacuum facility containing the picosecond electron reflection high-energy electron diffraction system was equipped with a cylindrical mirror analyzer and a static electron gum for Auger spectroscopy. An image analysis system capable of acquiring the pulsed diffraction patterns was assembled and used in analysis of picosecond laser heated surfaces. A large set of time-resolved experiments were conducted to study the thermal response of Pb(110) to picosecond laser heating. The surface Debye-Waller effect was used to time-resolve the evolution of surface temperature. This provided us with a picosecond time-resolved surface lattice temperature probe. Results for laser fluences below surface melting show agreement with a heat-diffusion model. The temperature dependence of the Pb(100) along the (110) and the (001) azimuths using x-ray photoelectron forward scattering of the 4f{sub 7/2} core-level photoelectrons confirmed, for the first time, surface melting of Pb(100) at temperatures as low as 560 K

Investigation of electron-beam charging for inertial-confinement-fusion targets. Charged Particle Research Laboratory report No. 3-82

Techniques for charging inertial confinement fusion targets using electron beam are investigated. A brief review of the various possible charging techniques is presented, along with a discussion of the advantages and disadvantages of each. The reasons for selecting the electron beam charging and a physical picture of the charging mechanism are described. Experimental results are presented and compared with the theoretical predictions

Laser-fluence effects on NbNx thin films fabricated by pulsed laser deposition

Niobium nitride films were deposited on Nb substrate using pulsed laser deposition (PLD) with a Qswitched Nd:YAG laser at different laser fluences. The film crystal structure and surface morphology were studied. The microstructure, texture and surface morphologies of the films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscope (AFM). Highly textured NbNx films were produced by PLD on niobium substrates at different laser fluences for constant background nitrogen pressure and substrate deposition temperature. When the fabrication parameters are fixed except the laser fluence, surface roughness, deposition rate, nitrogen content, and grain size increase together with increasing laser fluence. The nitrogen content in NbNx films increases with the laser fluence up to 15 J cm -2 and decreases thereafter. The films exhibit highly textured structure with a preferential orientation of (1 1 0) parallel to the substrate. The NbNx layers are formed in mixed phase (cubic and hexagonal) with the ratio of hexagonal phase to cubic phase dependent on the laser fluence. These observations can be used to establish guidelines for optimizing the laser fluence to achieve the desired morphology and phase of the grown NbNx thin film. © 2011 Elsevier B.V. All rights reserved.DE-AC05-06OR23177, DE-FG02-97ER45625 National Science FoundationWe would like to thank Drs. G. Rao, G. Ciovati and P. Dhakal for providing the niobium samples and useful discussions, and Dr. Robert Pike for giving us access to XRD. This work was partially supported by U.S. DOE Contract Nos. DE-AC05-06OR23177 and DE-FG02-97ER45625 and by the National Science Foundation Grant Nos. DMR-9988669 and MRI-0821180

Morphological and structural properties of NbN thin films deposited by pulsed laser deposition

Turkish Airlines;TTNET;Gedik Holding;Istanbul Development Agency14th International Conference on Advances in Materials and Processing Technologies, AMPT 2011 --13 July 2011 through 16 July 2011 -- Istanbul --Niobium nitride (NbN) films were deposited on Nb using pulsed laser deposition (PLD), and the effect of substrate deposition temperature on the preferred orientation, phase, and surface properties of NbN films were explored by x-ray diffraction (XRD) and atomic force microscopy (AFM). It was found that the substrate deposition temperature has a significant influence on properties of the NbN films, leading to a pronounced change in the preferred orientation of the crystal structure and the phase. We find that substrate temperature is a critical factor in determining the phase of the NbN films. For a substrate temperature of 650°C - 850°C, the NbN film formed in the cubic ?-NbN phase mixed with the ß-Nb 2N hexagonal phase. With an increase in substrate temperature, NbN layers became ß-Nb 2N single phase. Essentially, films with a mainly ß-Nb 2N hexagonal phase were obtained at deposition temperatures above 850°C. Surface roughness and crystallite sizes of the ß-Nb 2N hexagonal phase increased as the deposition temperatures increased. © (2012) Trans Tech Publications

Pulsed laser deposition of niobium nitride thin films

Ingot Niobium Summary Workshop --42342 -- --Niobium nitride (NbNx) films were grown on Nb and Si(100) substrates using pulsed laser deposition. NbNx films were deposited on Nb substrates using PLD with a Q-switched Nd:YAG laser (? = 1064 nm, ~40 ns pulse width, and 10 Hz repetition rate) at different laser fluences, nitrogen background pressures and deposition substrate temperatures. When all the fabrication parameters are fixed, except for the laser fluence, the surface roughness, nitrogen content, and grain size increase with increasing laser fluence. Increasing nitrogen background pressure leads to a change in the phase structure of the NbNx films from mixed ß-Nb2N and cubic ?-NbN phases to single hexagonal ß-Nb2N. The substrate temperature affects the preferred orientation of the crystal structure. The structural and electronic, properties of NbNx deposited on Si(100) were also investigated. The NbNx films exhibited a cubic ?-NbN with a strong (111) orientation. A correlation between surface morphology, electronic, and superconducting properties was found. The observations establish guidelines for adjusting the deposition parameters to achieve the desired NbNx film morphology and phase. © 2015 AIP Publishing LLC

The effect of heat treatment on structural and electronic properties of niobium nitride prepared by a thermal diffusion method

Niobium nitride (NbNx) coatings were prepared onto Nb substrate by thermal diffusion at high temperatures. The formation of NbNx coating by thermal diffusion was studied in the range of 1250–1500 °C at constant nitrogen background gas pressure (1.3 × 10- 3 Pa) and processing time (180 min). The electronic and crystal structures of the NbNx coatings were investigated. It was found that nitrogen diffuses into Nb forming the Nb-N solid solution (bcc) ?-NbN phase that starts to appear above 1250 °C. Increasing the processing temperature gives richer ?-phase concentration. Besides, X-ray absorption spectroscopy (XAS) was performed to study the electronic structure of the NbNx layer. The results of the electronic structural study corroborate the crystal structural analysis. The Nb M3,2 edge X-ray absorption spectroscopy (XAS) spectrum shows strong temperature dependence. At the highest processing temperature (1500 °C), the number of d holes increased. Electrostatic interaction between d electron and core hole was increased due to nitrogen diffusion into the niobium. For the studied conditions, only the ?-NbN was observed in the X-ray diffraction patterns. © 2016 Elsevier B.V.Ministry of Higher Education, Egypt U.S. Department of Energy Basic Energy SciencesA. H. F. was supported by a scholarship from the Egyptian Ministry of Higher Education and a Jefferson Lab scholarship funded by the Department of Energy Office of Nuclear Physics ARRA-NPQ project at Jefferson Lab under the U.S. DOE Contract No. DE-AC05-06OR23177. The authors are grateful to the Stanford Synchrotron Radiation Light source (SSRL), California, USA, for providing synchrotron-based XAS facility. Use of SSRL source is supported by the US Department of Energy, Office of Basic Energy Sciences, under Contract No. DEAC02-76SF00515. Support of DOE Cooperative Research Program for SESAME project is acknowledged by A.H.F., O.M.O. and Y.U

Studies of nanomechanical properties of pulsed laser deposited NbN films on Si using nanoindentation

2011 MRS Fall Meeting --28 November 2011 through 2 December 2011 -- Boston, MA --Nanomechanical and structural properties of pulsed laser deposited niobium nitride thin films were investigated using X-ray diffraction, atomic force microscopy, and nanoindentation. NbN film reveals cubic ?-NbN structure with the corresponding diffraction peaks from the (111), (200), and (220) planes. The NbN thin films depict highly granular structure, with a wide range of grain sizes that range from 15-40 nm with an average surface roughness of 6 nm. The average modulus of the film is 420±60 GPa, whereas for the substrate the average modulus is 180 GPa, which is considered higher than the average modulus for Si reported in the literature due to pile-up. The hardness of the film increases from an average of 12 GPa for deep indents (Si substrate) measured using XP CSM and load control (LC) modes to an average of 25 GPa measured using the DCM II head in CSM and LC modules. The average hardness of the Si substrate is 12 GPa. © 2012 Materials Research Society.DOE DE-FG02-97ER45625 National Science FoundationThis work was partially supported by U.S. DOE DE-FG02-97ER45625 and by the National Science Foundation Grant Nos. DMR-9988669 and MRI-0821180. The authors would like to thank Dr. D. Gu for preparing the TEM samples

Influence of nitrogen background pressure on structure of niobium nitride films grown by pulsed laser deposition

Depositions of niobium nitride thin films on Nb using pulsed laser deposition (PLD) with different nitrogen background pressures (10.7 to 66.7Pa) have been performed. The effect of nitrogen pressure on NbN formation in this process was examined. The deposited films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), and energy dispersive X-ray (EDX) analysis. Hexagonal ß-Nb2N and cubic ?-NbN phases resulted when growth was performed in low nitrogen background pressures. With an increase in nitrogen pressure, NbN films grew in single hexagonal ß-Nb2N phase. The formation of the hexagonal texture during the film growth was studied. The c/a ratio of the hexagonal ß-Nb2N unit cell parameter increases with increasing nitrogen pressure. Furthermore, the N:Nb ratio has a strong influence on the lattice parameter of the ?-NbN, where the highest value was achieved for this ratio was 1.19. It was found that increasing nitrogen background pressure leads to change in the phase structure of the NbN film. With increasing nitrogen pressure, the film structure changes from hexagonal to a mixed phase and then back to a hexagonal phase. © 2011 Elsevier B.V.National Science Foundation DE-FG02-97ER45625We would like to thank Dr. G. Ciovati for providing the niobium samples and Dr. R. Pike for giving us access to XRD. This work was partially supported by the Jefferson Lab (Dr. G. Rao) and the US Department of Energy Grant number DE-FG02-97ER45625 and by the National Science Foundation Grant Nos. DMR-9988669 and MRI-0821180