| 1. |
- Murray, Christopher J. L., et al.
(author)
-
Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017
- 2018
-
In: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1995-2051
-
Journal article (peer-reviewed)abstract
- Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49·4% (95% uncertainty interval [UI] 46·4–52·0). The TFR decreased from 4·7 livebirths (4·5–4·9) to 2·4 livebirths (2·2–2·5), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83·8 million people per year since 1985. The global population increased by 197·2% (193·3–200·8) since 1950, from 2·6 billion (2·5–2·6) to 7·6 billion (7·4–7·9) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2·0%; this rate then remained nearly constant until 1970 and then decreased to 1·1% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2·5% in 1963 to 0·7% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2·7%. The global average age increased from 26·6 years in 1950 to 32·1 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59·9% to 65·3%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1·0 livebirths (95% UI 0·9–1·2) in Cyprus to a high of 7·1 livebirths (6·8–7·4) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0·08 livebirths (0·07–0·09) in South Korea to 2·4 livebirths (2·2–2·6) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0·3 livebirths (0·3–0·4) in Puerto Rico to a high of 3·1 livebirths (3·0–3·2) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2·0% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress. Funding: Bill & Melinda Gates Foundation.
|
|
| 2. |
- Gonzalez, Monica, et al.
(author)
-
Quasi-static loaded circular testing of serial articulated industrial manipulators
- 2020
-
In: 52nd International Symposium on Robotics, ISR 2020. - : VDE Verlag GmbH. ; , s. 1-6
-
Conference paper (peer-reviewed)abstract
- This research outlines the methodology and application of quasi-static loaded circular testing on serial articulated industrial robots using the Loaded Double Ball Bar (LDBB). The article focuses on measuring the quasi-static path accuracy and repeatability of industrial manipulators to evaluate their performance in industrial contact applications such as trimming, grinding, or deburring. The manipulator is measured under quasi-static loads of 100, 350, 500, and 600N using circular testing following the guidelines of ISO 230-4. The data can be used to discuss core aspects of process planning with industrial manipulators such as workpiece placement, optimal robot pose selection for dexterity as well as stiffness optimization. The article contains a case study of quasi-static loaded circular testing of a mid-size articulated industrial robot from ABB using the LDBB and a Leica AT960 laser tracker for validation. At a load of 600N the path accuracy for both Clock-Wise (CW) and Counter Clock-Wise (CCW) were 2:4 mm, measured with the LDBB, compared to 2.9 mm, measured with the AT960. Finally, the paper ends with a discussion about the opportunities and challenges for the implementation of loaded circular testing for elasto-geometrical calibration of industrial manipulators.
|
|
| 3. |
- Griswold, Max G., et al.
(author)
-
Alcohol use and burden for 195 countries and territories, 1990-2016 : a systematic analysis for the Global Burden of Disease Study 2016
- 2018
-
In: The Lancet. - : Elsevier. - 0140-6736 .- 1474-547X. ; 392:10152, s. 1015-1035
-
Journal article (peer-reviewed)abstract
- Background: Alcohol use is a leading risk factor for death and disability, but its overall association with health remains complex given the possible protective effects of moderate alcohol consumption on some conditions. With our comprehensive approach to health accounting within the Global Burden of Diseases, Injuries, and Risk Factors Study 2016, we generated improved estimates of alcohol use and alcohol-attributable deaths and disability-adjusted life-years (DALYs) for 195 locations from 1990 to 2016, for both sexes and for 5-year age groups between the ages of 15 years and 95 years and older.Methods: Using 694 data sources of individual and population-level alcohol consumption, along with 592 prospective and retrospective studies on the risk of alcohol use, we produced estimates of the prevalence of current drinking, abstention, the distribution of alcohol consumption among current drinkers in standard drinks daily (defined as 10 g of pure ethyl alcohol), and alcohol-attributable deaths and DALYs. We made several methodological improvements compared with previous estimates: first, we adjusted alcohol sales estimates to take into account tourist and unrecorded consumption; second, we did a new meta-analysis of relative risks for 23 health outcomes associated with alcohol use; and third, we developed a new method to quantify the level of alcohol consumption that minimises the overall risk to individual health.Findings: Globally, alcohol use was the seventh leading risk factor for both deaths and DALYs in 2016, accounting for 2.2% (95% uncertainty interval [UI] 1.5-3.0) of age-standardised female deaths and 6.8% (5.8-8.0) of age-standardised male deaths. Among the population aged 15-49 years, alcohol use was the leading risk factor globally in 2016, with 3.8% (95% UI 3.2-4-3) of female deaths and 12.2% (10.8-13-6) of male deaths attributable to alcohol use. For the population aged 15-49 years, female attributable DALYs were 2.3% (95% UI 2.0-2.6) and male attributable DALYs were 8.9% (7.8-9.9). The three leading causes of attributable deaths in this age group were tuberculosis (1.4% [95% UI 1. 0-1. 7] of total deaths), road injuries (1.2% [0.7-1.9]), and self-harm (1.1% [0.6-1.5]). For populations aged 50 years and older, cancers accounted for a large proportion of total alcohol-attributable deaths in 2016, constituting 27.1% (95% UI 21.2-33.3) of total alcohol-attributable female deaths and 18.9% (15.3-22.6) of male deaths. The level of alcohol consumption that minimised harm across health outcomes was zero (95% UI 0.0-0.8) standard drinks per week.Interpretation: Alcohol use is a leading risk factor for global disease burden and causes substantial health loss. We found that the risk of all-cause mortality, and of cancers specifically, rises with increasing levels of consumption, and the level of consumption that minimises health loss is zero. These results suggest that alcohol control policies might need to be revised worldwide, refocusing on efforts to lower overall population-level consumption.
|
|
| 4. |
- Hosseini, Arian, et al.
(author)
-
CFD analysis of a cross-flow turbine for wind and hydrokinetic applications
- 2018
-
In: ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE). - : American Society of Mechanical Engineers (ASME). - 9780791852088
-
Conference paper (peer-reviewed)abstract
- Tidal current and wind energies have become dominant sources of renewable energies in the modern culture. In this work, the aerodynamic characteristics of a novel hybrid vertical axis turbine (VAT) have been studied in flow fields of water and air using CFD analyses. A parametric study was conducted on the hybrid rotor design with the goal of optimizing the solidity ratio to cover a wide operation range, increase initial torque and maintain high coefficient of power values. The hybrid turbine design with a solidity ratio of 0.5 demonstrated improvements to the self-startup feature and achieved the highest coefficient of power (C p ) values of 44.5% and 50% in air and water flows, respectively. The results were in favor of utilizing this design in flow fields of water and air as an enhancement to previous literature. Further studies are required to assess the aerodynamic properties of the model in 3D CFD analyses.
|
|
| 5. |
- Hosseini, Arian, et al.
(author)
-
CFD AND CONTROL ANALYSIS OF A SMART HYBRID VERTICAL AXIS WIND TURBINE
- 2018
-
In: PROCEEDINGS OF THE ASME POWER CONFERENCE, 2018, VOL 1. - : AMER SOC MECHANICAL ENGINEERS. - 9780791851395 ; , s. 1-8
-
Conference paper (peer-reviewed)abstract
- Wind energy has become a dominant source of renewable energy during the past decade. Current hybrid wind turbines are primarily designed and manufactured based on a combination of aerodynamic properties for both Darrieus and Savonius turbines. In this work, the aerodynamic performance characteristics of a smart vertical axis wind turbine (VAWT) with an electro-magnetic switch mechanism for dis-/engagement mechanism is studied analytically and numerically. The proposed novel VAWT offers a high start-up torque by a Savonius turbine and high power coefficient values by a Darrieus turbine. The switch mechanism can further improve the system efficiency by running the turbines together or independently. The proposed hybrid VAWT was modeled as a combined Savonius-type Bach turbine and a 3-bladed H-Darrieus turbine. The hybrid turbine has a self-startup feature and reaches a coefficient of power (C-p) of over 40%. The turbine is also estimated to cover a wide operational range up to TSR 6. The follow on research phases of the project include studying the proposed smart VAWT experimentally and validating the results with those obtained through computational analysis.
|
|
| 6. |
- Hosseini, Arian, et al.
(author)
-
Design and CFD study of a hybrid vertical-axis wind turbine by employing a combined Bach-type and H-Darrieus rotor systems
- 2019
-
In: Energy Conversion and Management. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0196-8904 .- 1879-2227. ; 189, s. 49-59
-
Journal article (peer-reviewed)abstract
- The objective of this work was to design, simulate and evaluate the performance of an innovative hybrid vertical axis wind turbine (VAWT) for obtaining an extended operational range and enhancing self-starting capabilities. An extensive research was conducted to explore the design parameters for obtaining an optimum novel hybrid VAWT configuration. The hybrid VAWT consisting of a 2-bladed modified Savonius Bach-type rotor and a 3-bladed Darrieus turbine was modeled and analyzed in computational fluid dynamics (CFD) to calculate the characteristic parameters of the rotor system. The geometry was then used to generate the grid in ANSYS Meshing for computational fluid dynamics (CFD) analyses to evaluate the performance of the designed hybrid VAWT. Results indicated that while the Darrieus turbine had the highest coefficient of power (C-p) of 48.4% at a TSR of 2.50, it suffered from high start-up torque requirements. The hybrid turbine demonstrated self-starting capabilities while reaching a maximum C-p of 41.4% at a TSR of 2.5 and operation up to a TSR value of 4.5. When compared to previous hybrid VAWT designs, the proposed configuration demonstrated improvements to the efficiency and operational range which support the energy sustainability prospects.
|
|
| 7. |
- Moshfegh, H., et al.
(author)
-
Thermoelectric cooling of a photovoltaic panel
- 2018
-
In: Thermoelectric cooling of a photovoltaic panelThermoelectric cooling of a photovoltaic panel. - Cham : Springer. ; , s. 625-634
-
Book chapter (peer-reviewed)abstract
- The performance of photovoltaic (PV) systems depends on many factors such as PV module temperature, solar radiation availability and the accumulation of dirt on solar panels. The temperature increment is one of the most challenging factors that affects the performance of photovoltaic systems which causes significant degradation in the cell efficiency and the amount of generated power specially in the high concentrator photovoltaics (HCPV); to overcome this issue, a cooling method by using thermoelectric cooling module is proposed and investigated. In this work, a thermoelectric module with a heat sink at the back is considered to be attached to the back side of photovoltaic panel. It is assumed that the required power to run the thermoelectric cooling module is provided by the photovoltaic panel itself. Solar irradiance, ambient temperature, wind velocity and the fin area of the heat sink are the most important parameters that affect the cell temperature and, consequently, the amount of generated power. An analytical model is developed and simulated by MATLAB to determine the cell temperature and calculates the optimized extra power generated by the photovoltaic cells due to cooling effect by the variation of the mentioned parameters. The results demonstrate a potential for improvement; however, the amount of extra generated power relates to the environmental circumstances and concentration ratio
|
|
