| 1. |
- Naghavi, Mohsen, et al.
(författare)
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Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013
- 2015
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Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 385:9963, s. 117-171
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Tidskriftsartikel (refereegranskat)abstract
- Background Up-to-date evidence on levels and trends for age-sex-specifi c all-cause and cause-specifi c mortality is essential for the formation of global, regional, and national health policies. In the Global Burden of Disease Study 2013 (GBD 2013) we estimated yearly deaths for 188 countries between 1990, and 2013. We used the results to assess whether there is epidemiological convergence across countries. Methods We estimated age-sex-specifi c all-cause mortality using the GBD 2010 methods with some refinements to improve accuracy applied to an updated database of vital registration, survey, and census data. We generally estimated cause of death as in the GBD 2010. Key improvements included the addition of more recent vital registration data for 72 countries, an updated verbal autopsy literature review, two new and detailed data systems for China, and more detail for Mexico, UK, Turkey, and Russia. We improved statistical models for garbage code redistribution. We used six different modelling strategies across the 240 causes; cause of death ensemble modelling (CODEm) was the dominant strategy for causes with sufficient information. Trends for Alzheimer's disease and other dementias were informed by meta-regression of prevalence studies. For pathogen-specifi c causes of diarrhoea and lower respiratory infections we used a counterfactual approach. We computed two measures of convergence (inequality) across countries: the average relative difference across all pairs of countries (Gini coefficient) and the average absolute difference across countries. To summarise broad findings, we used multiple decrement life-tables to decompose probabilities of death from birth to exact age 15 years, from exact age 15 years to exact age 50 years, and from exact age 50 years to exact age 75 years, and life expectancy at birth into major causes. For all quantities reported, we computed 95% uncertainty intervals (UIs). We constrained cause-specific fractions within each age-sex-country-year group to sum to all-cause mortality based on draws from the uncertainty distributions. Findings Global life expectancy for both sexes increased from 65.3 years (UI 65.0-65.6) in 1990, to 71.5 years (UI 71.0-71.9) in 2013, while the number of deaths increased from 47.5 million (UI 46.8-48.2) to 54.9 million (UI 53.6-56.3) over the same interval. Global progress masked variation by age and sex: for children, average absolute diff erences between countries decreased but relative diff erences increased. For women aged 25-39 years and older than 75 years and for men aged 20-49 years and 65 years and older, both absolute and relative diff erences increased. Decomposition of global and regional life expectancy showed the prominent role of reductions in age-standardised death rates for cardiovascular diseases and cancers in high-income regions, and reductions in child deaths from diarrhoea, lower respiratory infections, and neonatal causes in low-income regions. HIV/AIDS reduced life expectancy in southern sub-Saharan Africa. For most communicable causes of death both numbers of deaths and age-standardised death rates fell whereas for most non-communicable causes, demographic shifts have increased numbers of deaths but decreased age-standardised death rates. Global deaths from injury increased by 10.7%, from 4.3 million deaths in 1990 to 4.8 million in 2013; but age-standardised rates declined over the same period by 21%. For some causes of more than 100 000 deaths per year in 2013, age-standardised death rates increased between 1990 and 2013, including HIV/AIDS, pancreatic cancer, atrial fibrillation and flutter, drug use disorders, diabetes, chronic kidney disease, and sickle-cell anaemias. Diarrhoeal diseases, lower respiratory infections, neonatal causes, and malaria are still in the top five causes of death in children younger than 5 years. The most important pathogens are rotavirus for diarrhoea and pneumococcus for lower respiratory infections. Country-specific probabilities of death over three phases of life were substantially varied between and within regions. Interpretation For most countries, the general pattern of reductions in age-sex specifi c mortality has been associated with a progressive shift towards a larger share of the remaining deaths caused by non-communicable disease and injuries. Assessing epidemiological convergence across countries depends on whether an absolute or relative measure of inequality is used. Nevertheless, age-standardised death rates for seven substantial causes are increasing, suggesting the potential for reversals in some countries. Important gaps exist in the empirical data for cause of death estimates for some countries; for example, no national data for India are available for the past decade.
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| 2. |
- Forouzanfar, Mohammad H, et al.
(författare)
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Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013 : a systematic analysis for the Global Burden of Disease Study 2013.
- 2015
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Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 386:10010, s. 2287-2323
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for prevention. The GBD 2013 provides a timely opportunity to update the comparative risk assessment with new data for exposure, relative risks, and evidence on the appropriate counterfactual risk distribution.METHODS: Attributable deaths, years of life lost, years lived with disability, and disability-adjusted life-years (DALYs) have been estimated for 79 risks or clusters of risks using the GBD 2010 methods. Risk-outcome pairs meeting explicit evidence criteria were assessed for 188 countries for the period 1990-2013 by age and sex using three inputs: risk exposure, relative risks, and the theoretical minimum risk exposure level (TMREL). Risks are organised into a hierarchy with blocks of behavioural, environmental and occupational, and metabolic risks at the first level of the hierarchy. The next level in the hierarchy includes nine clusters of related risks and two individual risks, with more detail provided at levels 3 and 4 of the hierarchy. Compared with GBD 2010, six new risk factors have been added: handwashing practices, occupational exposure to trichloroethylene, childhood wasting, childhood stunting, unsafe sex, and low glomerular filtration rate. For most risks, data for exposure were synthesised with a Bayesian meta-regression method, DisMod-MR 2.0, or spatial-temporal Gaussian process regression. Relative risks were based on meta-regressions of published cohort and intervention studies. Attributable burden for clusters of risks and all risks combined took into account evidence on the mediation of some risks such as high body-mass index (BMI) through other risks such as high systolic blood pressure and high cholesterol.FINDINGS: All risks combined account for 57·2% (95% uncertainty interval [UI] 55·8-58·5) of deaths and 41·6% (40·1-43·0) of DALYs. Risks quantified account for 87·9% (86·5-89·3) of cardiovascular disease DALYs, ranging to a low of 0% for neonatal disorders and neglected tropical diseases and malaria. In terms of global DALYs in 2013, six risks or clusters of risks each caused more than 5% of DALYs: dietary risks accounting for 11·3 million deaths and 241·4 million DALYs, high systolic blood pressure for 10·4 million deaths and 208·1 million DALYs, child and maternal malnutrition for 1·7 million deaths and 176·9 million DALYs, tobacco smoke for 6·1 million deaths and 143·5 million DALYs, air pollution for 5·5 million deaths and 141·5 million DALYs, and high BMI for 4·4 million deaths and 134·0 million DALYs. Risk factor patterns vary across regions and countries and with time. In sub-Saharan Africa, the leading risk factors are child and maternal malnutrition, unsafe sex, and unsafe water, sanitation, and handwashing. In women, in nearly all countries in the Americas, north Africa, and the Middle East, and in many other high-income countries, high BMI is the leading risk factor, with high systolic blood pressure as the leading risk in most of Central and Eastern Europe and south and east Asia. For men, high systolic blood pressure or tobacco use are the leading risks in nearly all high-income countries, in north Africa and the Middle East, Europe, and Asia. For men and women, unsafe sex is the leading risk in a corridor from Kenya to South Africa.INTERPRETATION: Behavioural, environmental and occupational, and metabolic risks can explain half of global mortality and more than one-third of global DALYs providing many opportunities for prevention. Of the larger risks, the attributable burden of high BMI has increased in the past 23 years. In view of the prominence of behavioural risk factors, behavioural and social science research on interventions for these risks should be strengthened. Many prevention and primary care policy options are available now to act on key risks.FUNDING: Bill & Melinda Gates Foundation.
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| 3. |
- Zhu, Y., et al.
(författare)
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Volatile-char interactions during co-pyrolysis of sewage sludge and poplar wood
- 2024
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Ingår i: Journal of the Energy Institute. - : Elsevier. - 1743-9671 .- 1746-0220. ; 117
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Tidskriftsartikel (refereegranskat)abstract
- Pyrolysis is a thermo-chemical conversion method for harmless and resource utilization of sewage sludge, which gives carbon-containing products with high added value and benefits for GHG reduction towards “carbon peaking and carbon neutrality” goals. In this work, co-pyrolysis of sewage sludge and poplar wood was studied to investigate the effects of the wood blend ratio and the volatile-char interactions on the pyrolysis product characteristics. It was found that the synergistic effect during co-pyrolysis could enhance the production of aromatic hydrocarbons but inhibit the formation of nitrogen-containing and phenolic compounds. Meanwhile, the aromaticity of the char increased with increasing the wood blend ratio, resulting in an enhanced quality of the char. The volatile-char interactions could facilitate the cracking of large molecules in volatiles into small-molecule gases, leading to an increase in the gas yield of 0.6–14.6 %, and especially the H2 yield of 16.2–53.8 %, as compared to the case without interaction in the experiment. The char yields hold fairly constant but the physicochemical structure of the char changed significantly with the interactions. Specifically, the O-containing functional groups on the char surface decreased significantly with increasing aromaticity and stability. More importantly, the total phosphorus content of char was increased by 11.3–33.6 %, as compared to the case without interaction, with the enhanced conversion of non-hydroxyapatite phosphorus to hydroxyapatite phosphorus. The interaction can increase bio-availability of the phosphorus and make biochar to be a better organic fertilizer in application.
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| 4. |
- Yang, W., et al.
(författare)
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Effect of Densification on Biomass Combustion and Particulate Matter Emission Characteristics
- 2022
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Ingår i: Atmosphere. - : MDPI AG. - 2073-4433. ; 13:10
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Tidskriftsartikel (refereegranskat)abstract
- The effect of biomass densification on combustion characteristics and particulate matter (PM) emission was studied in this work by means of thermogravimetric, combustion kinetic, and PM analyses with respect to the size distribution and elementary composition. Cornstalk as a typical agricultural biomass residue and camphorwood as a woody biomass were used in the experiment for comparison. It can be concluded that the biomass densification increases the ignition, burnout, and composite combustion indexes, leading to a better performance of biomass combustion. The main reaction mechanism of cornstalk pellets can be well-expressed with the chemical reaction series model, whereas the diffusion mechanism and chemical reaction series models can be applied to the combustion of camphorwood pellets. The biomass densification has little effect on the composition of PM but significantly changes the yield of PM. The influence of biomass densification on PM emission is related to the biomass properties. The densification significantly reduces the PM emission for cornstalk but significantly increases the yield of particles of aerodynamic cutoff diameters less than 1μm (PM1) for camphorwood.
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| 5. |
- Zhu, Y., et al.
(författare)
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Catalytic pyrolysis of duckweed with phosphoric acid : Pyrolysis behavior and kinetics analysis
- 2024
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 177
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Tidskriftsartikel (refereegranskat)abstract
- Duckweed (DW) has a promising potential for wastewater treatment due to its outstanding performance in the fixation of nutrient elements and heavy metals. The conversion of harvested duckweed into value-added products through pyrolysis is an attractive method for duckweed utilization as fuels or chemicals. In this work, the duckweed was prepared by deashing treatment and subsequent impregnation with different phosphoric acid concentrations (ADW-P). The pyrolysis behavior and kinetics of raw and impregnated duckweeds were studied with respect to the ash contained in the duckweed and the phosphoric acid catalytic effect by thermogravimetric analysis-fourier transform infrared spectrometer (TG-FTIR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results show that the pyrolysis reaction zone is extended for the impregnated duckweed by reducing the initial pyrolysis temperature and increasing the final temperature. Specifically, a shoulder peak situated at the right side of the main peak is present in the DTG curves of ADW-P, suggesting the formation of relatively stable substance after phosphoric acid impregnation. Phosphoric acid promotes the release of H2O, CH4, CO2 and NH3 as well as light volatiles with C[dbnd]C and C[dbnd]O groups during pyrolysis. Meanwhile, decarboxylation and aromatization as well as deamination of organic compounds are strengthened, resulting in an increase of aromatic hydrocarbons and furans and a decrease of N-heterocyclic compounds. The activation energy of ADW-P is lower than that of DW and ADW at conversion rate less than 75% but increases remarkably at high conversion rate. This implies that phosphoric acid facilitates the thermal decomposition of DW at low temperatures but hinders its decomposition at high temperatures probably due to the formation of stable cross-linked structures such as phosphate and polyphosphate esters.
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| 6. |
- Zhu, Youjian, et al.
(författare)
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Effect of sodium carboxymethyl cellulose addition on particulate matter emissions during biomass pellet combustion
- 2018
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 230, s. 925-934
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Tidskriftsartikel (refereegranskat)abstract
- Sodium carboxymethyl cellulose (CMC) can be used as a cost-effective and environmentally friendly binder in the pelletizing process for production of biomass pellets with good quality. However, the effect of its addition on the emission of particulate matters (PM) during the combustion process, are still not clear. In this study, four typical biomass fuels, cotton stalk, cornstalk, camphorwood and rice husk, were used to investigate the effect of the addition of 5 wt% CMC in the biomass pellets on PM emissions during the combustion process. In the case of pure CMC combustion, a large amount of PM mainly with PM2.5 were generated, which was associated to the evaporation and condensation of NaOH and Na2CO3. The PM10 emission from the combustion of the four biomass fuels varied from 9.72 mg/Nm3 to 23.12 mg/Nm3 with mainly PM1. The addition of 5 wt% CMC in cotton stalk, corn stalk and camphorwood significantly increased the PM emissions due to the evaporation and subsequent condensation of Na-containing species, e.g. NaCl, Na2SO4, NaOH and Na2CO3. For rice husk, the addition of CMC hardly affected PM1 emission due to the dominated SiO2 component in rice husk ash, which reacted with the Na-containing species from the combustion of CMC and facilitated the formation of coarse ash particles and the reduction of PM1 emission. Although the addition of CMC in biomass fuels can greatly enhance the pellets qualities, its addition increases the PM emissions to varying degree. Therefore, in the industrial application of CMC to biomass densification, countermeasures such as mixing of high Si-containing rice husk or SiO2-rich minerals with biomass fuels should be taken to alleviate the PM issues resulting from the introduction of CMC.
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| 7. |
- Zhu, Y., et al.
(författare)
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Effects of volatile-char interaction on the product properties from municipal sludge pyrolysis
- 2023
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 335
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Tidskriftsartikel (refereegranskat)abstract
- In order to realize the harmless treatment and resource utilization of municipal sludge, the effect of volatile-char interaction on the properties of sludge pyrolysis products was investigated using a two-stage pyrolysis reactor. The experimental results show that volatile-char interaction promotes the decomposition of organic compounds into small molecular gases, which increases the gas yield and reduces the liquid and oil yields. Under the experimental conditions, the volatile-char interaction increases the mass yields of H2, CO and CO2 to varying degrees, and the yield of H2 increases maximum by 55.7–114.5% compared to that without interaction. The effect of interaction on the composition of bio-oil occurs mainly at low temperature range of 400–600 ℃ by reducing the content of oxygen-containing compounds except for aldehydes/ketones. The physical and chemical structure of solid char changes dramatically with the interaction. The enhanced removal of O-containing groups occurs and the degree of aromaticity of the char is increased due to the strengthened dehydrogenation and polycondensation of hydrocarbons. Meanwhile, the transformation of non-hydroxyapatite phosphorus to hydroxyapatite phosphorus in solid phase products is greatly promoted at high temperature of 700–800 ℃, increasing the potential utilization of char as carbon-based phosphate fertilizer in agriculture.
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| 8. |
- Liu, Huihui, et al.
(författare)
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Conversion of high-ash microalgae through hydrothermal liquefaction
- 2020
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Ingår i: Sustainable Energy & Fuels. - : Royal Society of Chemistry (RSC). - 2398-4902. ; 4:6, s. 2782-2791
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Tidskriftsartikel (refereegranskat)abstract
- Natural microalgae (NM,Scenedesmus) cultivated by utilization of exhaust gas from a municipal solid waste combustion power plant were used for the biofuel production through hydrothermal liquefaction (HTL). The high-ash NM underwent acid-washing to obtain deashing microalgae (DA). HTL experiments were carried out at different temperatures from 260 °C to 340 °C with NM and DA. Products derived from NM and DA were examined by various techniques in order to identify the influence of the ash on the hydrothermal decomposition behavior. The results show that the ash inhibits the transformation of microalgae. The bio-oil yield including heavy oil and light oil is in the range of 17.59-22.09% for NM and 24.30-31.14% for DA, respectively. Calcium carbonate in the ash promotes deamination, resulting in an increase in the relative content of ketones in the NM-derived light oil. The concentration of NH4+in the aqueous phase derived from NM is in the range of 1373-1860 mg L−1, and PO43−is undetected due to the precipitation reaction between phosphorus and calcium ions. The HHV values of NM-derived hydrochars are low, ranging from 8.83 MJ kg−1to 9.88 MJ kg−1, compared with those of DA-derived hydrochars,. For natural microalgae, the deashing pretreatment before HTL is of great significance for improving the biocrude yield and quality, as well as the biomass conversion efficiency, nitrogen utilization and the hydrochar quality.
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| 9. |
- Liu, Huihui, et al.
(författare)
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Hydrothermal carbonization of natural microalgae containing a high ash content
- 2019
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 249, s. 441-448
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Tidskriftsartikel (refereegranskat)abstract
- The potential to convert natural microalgae (Scenedesmus) into solid fuels by hydrothermal carbonization (HTC) was evaluated. The deashing microalgae (DA) were obtained by acid-washing natural microalgae (NM) with HCl. The deashing efficiency was high from 44.66% for NM to 14.45% for DA. HTC carried out at temperature in the range from 180 to 260 degrees C with this two types feedstock (i.e. NM and DA). The results showed that DA-derived hydrochars had good physicochemical and fuel properties compared with that of NM-derived hydrochars. HTC process of DA was mainly based on polymerization, and the hydrolysis process was short. The hydrochars obtained from DA at 220 degrees C (HC-D220) had the highest value of 51.86% with a carbon content and fixed carbon content 1.15 and 1.33 times, respectively, greater than that of DA. The high heating value (HHV) of HC-D220 reached 26.64 MJ/kg which is equivalent to medium-high calorific coal. The thermogravimetric analysis (TG) demonstrated that the hydrochars derived from DA have good combustion properties with stable at high temperature zones. They can easily mix with coal or replace coal in combustion application. The results of this study revealed that natural microalgae can be utilized by hydrothermal carbonization to generate renewable fuel resources.
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| 10. |
- Liu, Huihui, et al.
(författare)
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Hydrothermal Treatment of High Ash Microalgae : Focusing on the Physicochemical and Combustion Properties of Hydrochars
- 2020
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 34:2, s. 1929-1939
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Tidskriftsartikel (refereegranskat)abstract
- Natural microalgae with high ash content are common in water environment. Converting them into biofuels not only meets the energy demands but also improves the aquatic environment. This study aims to explore the physicochemical properties and molecular structural features of hydrochars derived from hydrothermal treatment of natural microalgae. Meanwhile, the combustion behavior and kinetics analysis of hydrochars were also evaluated. The hydrothermal treatment was performed with natural microalgae and its acid-washing microalgae under different temperatures from 260 to 340 °C to reveal the effect of ash on hydrochars properties. The results indicate that the ash significantly influences the functional groups composition and physicochemical property of hydrochars. The yields of hydrochars derived from deashing microalgae are lower than those of hydrochars derived from natural microalgae. However, the relative content of the C-C/C-H/C=C groups representing hydrocarbon carbon in hydrochars derived from deashing microalgae is higher than that of hydrochars derived from natural microalgae. Both natural microalgae and deashing microalgae contain the protein-N and pyrrole-N, and natural microalgae also contain a small amount of inorganic-N. The Brunauer-Emmett-Teller (BET) surface areas of hydrochars derived from natural microalgae and deashing microalgae are in the range of 5.97-10.29 and 21.34-34.74 m2 g-1, respectively. The thermogravimetric analysis results show that hydrochars derived from deashing microalgae have better fuel quality in view of the comprehensive combustibility indexes compared with hydrochars derived from natural microalgae, which is conducive to their application to solid fuels. The acid-washing pretreatment can effectively improve the utilization of natural microalgae.
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