The characteristics of the energy structure of rich coal,less oil and less gas,coupling with a high external dependence on oil and natural gas and the emphasis on the efficient and clean utilisation of coal,have broug...The characteristics of the energy structure of rich coal,less oil and less gas,coupling with a high external dependence on oil and natural gas and the emphasis on the efficient and clean utilisation of coal,have brought opportunities for coal chemical industry.However,with the large-scale popularisation of coal gasification technology,the production and resulting storage of coal gasification slag continue to increase,which not only result in serious environmental pollution and a waste of terrestrial resources,but also seriously affect the sustainable development of coal chemical enterprises.Hence,the treatment of coal gasification slag is extremely important.In this paper,the production,composition,morphology,particle size structure and water holding characteristics of coal gasification slag are introduced,and the methods of carbon ash separation of gasification slag,both domestically and abroad,are summarised.In addition,the paper also summarises the research progress on gasification slag in building materials,ecological restoration,residual carbon utilisation and other high-value utilisation,and ultimately puts forward the idea of the comprehensive utilisation of gasification slag.For large-scale consumption to solve the environmental problems of enterprises and achieve high-value utilisation to increase the economic benefits of enterprises,it is urgent to zealously design a reasonable and comprehensive utilisation technologies with simple operational processes,strong adaptability and economic benefits.展开更多
Using political ecology as its conceptual framework,this paper focuses on the changes in forest utilisation and management of South Kyrgyzstan’s walnut-fruit forests over the last century. The aim of this study on hu...Using political ecology as its conceptual framework,this paper focuses on the changes in forest utilisation and management of South Kyrgyzstan’s walnut-fruit forests over the last century. The aim of this study on human-environment interactions is to investigate the relationship between actors on the one side,their interests and demands,and the forests and forested lands on the other. Forest resource utilisation and management — and even the recognition of different forest products as resources — are connected with political and socio-economic conditions that change with time. The walnut-fruit forests of South Kyrgyzstan are unique,characterised by high biodiversity and a multiplicity of usable products;and they have been utilised for a long time. Centralised and formal management of the forests started with the Russian occupation and was strengthened under Soviet rule,when the region became a part of the USSR. During this era,a state forest administration that was structured from Moscow all the way down to the local level drew up detailed plans and developed procedures for utilising the different forest products. Since the collapse of the Soviet Union,the socio-political and economic frame conditions have changed significantly,which has brought not only the sweeping changes in the managing institutions,but also the access rights and interests in the forest resources. At present,the region is suffering from a high unemployment rate,which has resulted in the forests’ gaining considerable importance in the livelihood strategies of the local population. Political and economic liberalization,increased communication and trans-regional exchange relations have opened the door for international companies and agents interested in the valuable forest products. Today,walnut wood and burls,walnuts,wild apples and mushrooms are all exported to various countries in the world. Scientists and members of various international organisations stress the ecological value of the forests and are trying to establish nature conservation areas. Nevertheless,it is to fear that a multiplicity of interrelated factors — the present transformation and globalization processes,the appearance of new actors,the local population’s insecure economic situation and the erosion of managing institutions — are all leading to an intensified and unregulated exploitation of the forests,resulting in their degradation.展开更多
This study presents research results which comprise the following selected communities： Phalaridetum arundinaceae, Alopecuretum pratensis, community with Deschampsia caespitosa, Holcetum lanati, Lolio-Cynosuretum, co...This study presents research results which comprise the following selected communities： Phalaridetum arundinaceae, Alopecuretum pratensis, community with Deschampsia caespitosa, Holcetum lanati, Lolio-Cynosuretum, community Poa pratensis-Festuca rubra. The investigated phytocenoses developed in conditions of lack of utilisation, occasional cutting, occasional alternating meadow-pasture utilisation, pastures with uncut left-overs, 2 cuts and light grazing of the sward by cattle and 2-3 cuts. For the above-mentioned communities the following parameters were assessed： total species number and mean number of species in a phytosociological rel6ves besides Shannon-Wiener diversity index （H＇）, proportion of synanthropic species, natural valorisation number according to Ogwit and fodder value score （FVS）. Regular sward utilisation of plant communities exerts a positive impact not only on the natural values as evidenced by the total and mean number of species in a phytosociological survey and higher biodiversity index （H＇） but it also impacts the sward fodder value scores of meadows and pastures. The strongest negative influence on the floristic composition of meadow communities and their stability is exerted by sporadic, incorrect utilization as it favours taking over of green areas by grass expansive species and development of communities of low natural and use values （community with Deschampsia caespitosa, Ass. Holcetum lanati and community with Agropyron repens）. The strongest impact on the maintenance of meadow and pasture biological stability in the examined region is exerted by their regular, moderate cutting or grazing.展开更多
Western China includes 12 provincial divisions (the 7 provinces of Sichuan, Guizhou, Yunnan, Shaanxi, Gansu, Qinghai and; 5 autonomous regions of Tibet, Ningxia, Xinjiang, Inner Mongolia and Guangxi; and one city of C...Western China includes 12 provincial divisions (the 7 provinces of Sichuan, Guizhou, Yunnan, Shaanxi, Gansu, Qinghai and; 5 autonomous regions of Tibet, Ningxia, Xinjiang, Inner Mongolia and Guangxi; and one city of Chongqing), which comprise 71.4% of the national land area, 28.5% of the national population and produce 17.5% of the national GDP in China. There are 17 countries that have riparian relationships with western China, most of which are water-short countries. All are listed by UN ESCAP as countries with potential water crisis. The co-operative development and coordinated management of international rivers in western China is an important step toward the implementation of the national Great Western Development program. Taking into account of the national strategy and object hierarchy, as well as the development demand of the western region, it is necessary to pursue the multi-disciplinary study of the equitable allocation, utilisation, and eco-environment protection of transboundary water resources in the region. Such efforts will undoubtedly provide scientific evidence and support for the decision-making of the environmental protection and ecological construction and management in the western regions, the enforcement of the sub-regional economic co-operation, mitigation of trans-boundary conflicts, and enhancing bio-diversity conservation.展开更多
Land-use efficiency is essential in ports, in particular those that are constrained for space and experiencing congestion. In such situations, ports have been noted to invest in off-dock container yards. This study an...Land-use efficiency is essential in ports, in particular those that are constrained for space and experiencing congestion. In such situations, ports have been noted to invest in off-dock container yards. This study analysed land use efficiency of four off-dock yards located near the Port of Tema, Ghana’s largest seaport responsible for 85 percent of its trade. The study found that the terminals utilised 0.13 to 0.52 hectares of land, largely influenced by the dwell time and stacking height of containers. It was recommended that regulatory agencies need to coordinate better to reduce the time spent on cargo inspection and validation. In addition, terminals may need to incentivise customers to clear their import containers within shorter periods.展开更多
Background and purpose:Despite HIV testing and counselling(HTC)being recognized as important elements of any effective prevention,detection,care,and management programmes across many societies as part of their primary...Background and purpose:Despite HIV testing and counselling(HTC)being recognized as important elements of any effective prevention,detection,care,and management programmes across many societies as part of their primary health care package,it is surprising that research evidence on related issues,especially in developing countries like Ghana is sparse.This study examined the extent of knowledge,attitudes and utilisation of HIV testing,and counselling services among trainee nurses of the public nursing and midwifery training colleges in the Central Region of Ghana.Methods and results:A descriptive cross-sectional design was employed to collect data from 375 nursing and midwifery students using multistage sampling procedures.Findings showed that students’HTC knowledge was high(85%)whereas attitudes toward HTC were rated positive(95%).However,HTC utilisation was low(47%).Further results revealed a statistically significant difference between class level and HTC utilisation(χ2[1,N=375]=14.263,p=0.000).In contrast,no statistically significant differences in student nurses’class level and HTC knowledge(χ2[1,N=375]=0.624,p=0.475)as well as class level and attitudes toward HTC services(χ2[1,N=375]=2.334,p=0.158)were realized.Conclusion:The low HTC utilisation among the student nurses may potentially lead to missing opportunities for early diagnoses,care,treatment,and support services for primary,secondary or tertiary prevention modes.Organisation of programmes by college authorities on the importance of HTC and the need for student nurses to utilise these services is crucial.展开更多
This Article discusses a comprehensive review of biomass energy sources, environment and sustainable development. This includes all the biomass energy technologies, energy efficiency systems, energy conservation scena...This Article discusses a comprehensive review of biomass energy sources, environment and sustainable development. This includes all the biomass energy technologies, energy efficiency systems, energy conservation scenarios, energy savings and other mitigation measures necessary to reduce emissions. The current literature is reviewed regarding the ecological, social, cultural and economic impacts of biomass technology. This article gives an overview of present and future use of biomass as an industrial feed-stock for production of fuels, chemicals and other materials. However, to be truly competitive in an open market situation, higher value products are required. Results suggest that biomass technology must be encouraged, promoted, invested, implemented, and demonstrated, but especially in remote rural areas.展开更多
In this study, a five-year (2010-2014) production and energy utilisation data in a sausage producing company in Nigeria was analysed for energy consumption, energy intensity, energy productivity, cost of energy per un...In this study, a five-year (2010-2014) production and energy utilisation data in a sausage producing company in Nigeria was analysed for energy consumption, energy intensity, energy productivity, cost of energy per unit product and Normalized Performance Indicator (NPI). The average annual energy consumption was 15,853.22 GJ. The energy consumption mix was 27.66% PHCN main, 32.06% diesel generators and 40.28% oven gas. Main electricity supply from utility company contributed to 25.04% of the total energy cost while diesel was 44.24% and oven gas was 30.71% of the total cost. The average production output from the factory was 595,700 tonnes and the average cost of energy input was 6.71 kobo/kg for the five-year period. The values of cost of energy input per unit product showed a decreasing trend for the five years. The energy intensity also increased through the study years with an average of 1.67 GJ/m2 while the energy productivity decreased throughout the years with an average of 28.3 kJ/kg. The Normalized Performance Indicator (NPI) values calculated for the five years showed steady increment with an average of 1.61 GJ/m2. This indicated a “very poor” range which implies an excessive energy usage, immediate action should be taken to investigate and remedy this.展开更多
Background: Emergency Contraception (EC) is used after unprotected sexual intercourse, following sexual abuse, misuse of regular contraception or non-use of contraception. Seventeen percent of pregnancies in Kenya are...Background: Emergency Contraception (EC) is used after unprotected sexual intercourse, following sexual abuse, misuse of regular contraception or non-use of contraception. Seventeen percent of pregnancies in Kenya are unintended, potentially leading to unsafe abortion that contributes to the high maternal mortality rate in Country. According to 2016 Kenya Demographic and Health Survey (KDHS), the maternal mortality ratio was 362 maternal deaths per 100,000 live births. Female students in University or College are vulnerable to unplanned pregnancies and illegal abortions resulting in mortality, morbidity and psychosocial problems. Knowledge on EC is very important for students as they are not in stable relationships and not using regular contraception. Therefore, the aim of this study was to determine the knowledge and use of Emergency Contraception among female undergraduate students in the University of Nairobi. Materials and Methods: We used an institution-based cross sectional, quantitative study to sample was employed among 383 female undergraduate students at the University of Nairobi. The University of Nairobi has six colleges and systematic random sampling was used to select study participants from each college. Data were collected using self-administered questionnaires and analysed using SPSS Version 16. Bivariate analysis and logistic regression were used to determine sample characteristics significantly associated with knowledge and utilisation of Emergency Contraception. Results: Most (53%) of the respondents were sexually active, and only 20% of the sexually active female students had ever used Emergency Contraception. Emergency Contraception awareness was high at 86.4%. However, based on a predefined criterion, accurate knowledge of Emergency Contraception was low at 42.6%.The majority (82.5%) of the respondents depended on mass media as a source of information on Emergency Contraception. Factors associated with Emergency Contraception knowledge on bivariate analysis were: age 20 years and above (p = 0.001), enrolment in college of health science (p = 0.001), being in year three of study and above (p = 0.0001) and having an insurance cover (p = 0.021). Ever use of Emergency Contraception was associated with enrolment in the College of health science (p = 0.025) and age 20 years and above (p = 0.050). In multivariate analysis, older age (Aor 1.885 p = 0.003) as well as being in the College of health science (Aor 0.001) were significantly associated with increased probability of being knowledgeable about Emergency Contraception. Conclusion: Although University of Nairobi female undergraduate students are aware of the existence of Emergency Contraception, their specific knowledge on correct timing of taking EC after unprotected sex and on effectiveness is poor. EC use is also low, compounded by underutilisation of public facilities as a source of the EC and underutilisation of health workers as a source of EC information. Therefore, an educative forum may be needed to improve the knowledge of EC among University of Nairobi female students. Health education on the availability of EC in public facilities needs to be addressed. Possible use of informal sources of information such as peer education could be an area to explore in client education on EC knowledge and use. Further research is recommended to establish factors that influence utilisation of public health workers as a source of EC information.展开更多
Although refugee adolescents and children are recognised as a health risk population, few studies have explored their Health-related Quality of Life (HRQOL). The present study investigated 1) the sociodemographic pred...Although refugee adolescents and children are recognised as a health risk population, few studies have explored their Health-related Quality of Life (HRQOL). The present study investigated 1) the sociodemographic predictors of HRQOL such as ethnicity, trauma exposure, and length of residency in Australia in a multiethnic paediatric population with refugee experiences and 2) the relationship between mental healthcare utilisation and HRQOL. Method: Participants were 458 adolescents and children, aged 4 - 17 years, living in South Australia. Parents provided data across the sample and adolescents also completed questionnaires. Overall HRQOL and its composite functional dimensions were assessed using the Paediatric Quality of Life (PedsQL) instrument. Questions from the Child and Adolescent Component of the Australian National Survey of Mental Health and Wellbeing were used to assess service utilisation. Results: Migration region/ethnicity predicted better HRQOL as well as physical, emotional and psychosocial functioning for both children and adolescents. African youths indicated higher HRQOL than those from the former Yugoslavia and the Middle East/South Asia respectively. Pre-migration trauma exposure was associated with lower HRQOL;and longer stay in Australia was related to lower emotional functioning in children. There was a negative association between healthcare service utilisation and PedsQL scores, with participants accessing services demonstrating lower HRQOL. Conclusion: Using more rigorous methods, future research is needed to investigate additional sociodemographic predictors of HRQOL, and protective/risk factors that impact on HRQOL of young refugees.展开更多
The study sought to assess the level of knowledge on the utilization of termites,harvesting methods and characterise local edible termite species.Focus group discussion with key informants was used to collect data tha...The study sought to assess the level of knowledge on the utilization of termites,harvesting methods and characterise local edible termite species.Focus group discussion with key informants was used to collect data that was analysed using SPSS Version 21.0 to generate descriptive statistics.Results indicated different levels of termites’utilisation where 45%of farmers use alates as food,35%as feed for chicks and quails,while 20%use the queen to fatten young bulls.Majority of farmers(40%)prefer the use of termites as feed because it is readily available,followed with 20%that use it because of nutritive value,10%relate its use with better taste of poultry products,5%associate termite use in enhancing early maturity weight while 5%said it improves growth and strength of bulls.On harvesting,three methods are commonly used with most farmers(45%)using underground trapping method,(35%)use above ground trapping method but 20%use mound excavation.Varied plant materials are used as attractants and the effect is more when combined with dry cow dung.Farmers further characterised species based on time of emergence of alates and habitat’s physical features.Most respondents(45%)associated:big mounds with Macrotermes bellicosus(Mafendete);small mount to Macrotermes subhyalinus(Kitunda);presence of open big tunnels with Coptotermes millitaris(Riamke)while seasonal gallaries and small tunnels was a confirmatory feature of either Pseudocanthotermes militaris(Chiisiisi)and Pseudocanthotermes spiniger(Maburi).The study demonstrates the richness in indigenous knowledge on techniques of termite production and utilization.展开更多
With the intensification of the energy crisis and the worsening greenhouse effect,the development of sustainable integrated energy systems(IES)has become a crucial direction for energy transition.In this context,this ...With the intensification of the energy crisis and the worsening greenhouse effect,the development of sustainable integrated energy systems(IES)has become a crucial direction for energy transition.In this context,this paper proposes a low-carbon economic dispatch strategy under the green hydrogen certificate trading(GHCT)and the ladder-type carbon emission trading(CET)mechanism,enabling the coordinated utilization of green and blue hydrogen.Specifically,a proton exchange membrane electrolyzer(PEME)model that accounts for dynamic efficiency characteristics,and a steam methane reforming(SMR)model incorporating waste heat recovery,are developed.Based on these models,a hydrogen production–storage–utilization framework is established to enable the coordinated deployment of green and blue hydrogen.Furthermore,the gas turbine(GT)unit are retrofitted using oxygenenriched combustion carbon capture(OCC)technology,wherein the oxygen produced by PEME is employed to create an oxygen-enriched combustion environment.This approach reduces energy waste and facilitates low-carbon power generation.In addition,the GHCT mechanism is integrated into the system alongside the ladder-type CET mechanism,and their complementary effects are investigated.A comprehensive optimization model is then formulated to simultaneously achieve carbon reduction and economic efficiency across the system.Case study results show that the proposed strategy reduces wind curtailment by 7.77%,carbon emissions by 65.98%,and total cost by 12.57%.This study offers theoretical reference for the low-carbon,economic,and efficient operation of future energy systems.展开更多
Tree allometry plays a crucial role in tree survival,stability,and timber quantity and quality of mixed-species plantations.However,the responses of tree allometry to resource utilisation within the framework of inter...Tree allometry plays a crucial role in tree survival,stability,and timber quantity and quality of mixed-species plantations.However,the responses of tree allometry to resource utilisation within the framework of interspecific competition and complementarity remain poorly understood.Taking into consideration strong-and weakspace competition(SC and WC),as well as N_(2)-fixing and non-N_(2)-fixing tree species(FN and nFN),a mixedspecies planting trial was conducted for Betula alnoides,a pioneer tree species,which was separately mixed with Acacia melanoxylon(SC+FN),Erythrophleum fordii(WC+FN),Eucalyptus cloeziana(SC+nFN)and Pinus kesiya var.langbianensis(WC+nFN)in southern China.Six years after planting,tree growth,total nitrogen(N)and carbon(C)contents,and the natural abundances of^(15)N and^(13)C in the leaves were measured for each species,and the mycorrhizal colonisation rates of B.alnoides were investigated under each treatment.Allometric variations and their relationships with space competition and nutrient-related factors were analyzed.The results showed a consistent effect of space competition on the height-diameter relationship of B.alnoides in mixtures with FN or nFN.The tree height growth of B.alnoides was significantly promoted under high space competition,and growth in diameter at breast height(DBH),tree height and crown size were all expedited in mixtures with FN.The symbiotic relationship between ectomycorrhizal fungi and B.alnoides was significantly influenced by both space competition and N_(2) fixation by the accompanying tree species,whereas such significant effects were absent for arbuscular mycorrhizal fungi.Furthermore,high space competition significantly decreased the water use efficiency(WUE)of B.alnoides,and its N use efficiency(NUE)was much lower in the FN mixtures.Structural equation modeling further demonstrated that the stem allometry of B.alnoides was affected by its NUE and WUE via changes in its height growth,and crown allometry was influenced by the mycorrhizal symbiotic relationship.Our findings provide new insights into the mechanisms driving tree allometric responses to above-and belowground resource competition and complementarity in mixed-species plantations,which are instructive for the establishment of mixed-species plantations.展开更多
Carbon dioxide capture and reduction(CCR)process emerges as an efficient catalytic strategy for CO_(2)capture and conversion to valuable chemicals.K-promoted Cu/Al_(2)O_(3)catalysts exhibited promising CO_(2)capture e...Carbon dioxide capture and reduction(CCR)process emerges as an efficient catalytic strategy for CO_(2)capture and conversion to valuable chemicals.K-promoted Cu/Al_(2)O_(3)catalysts exhibited promising CO_(2)capture efficiency and highly selective conversion to syngas(CO+H_(2)).The dynamic nature of the Cu-K system at reaction conditions complicates the identification of the catalytically active phase and surface sites.The present work aims at more precise understanding of the roles of the potassium and copper and the contribution of the metal oxide support.Whileγ-Al_(2)O_(3)guarantees high dispersion and destabilisation of the potassium phase,potassium and copper act synergistically to remove CO_(2)from diluted streams and promote fast regeneration of the active phase for CO_(2)capture releasing CO while passing H_(2).A temperature of 350℃is found necessary to activate H_(2)dissociation and generate the active sites for CO_(2)capture.The effects of synthesis parameters on the CCR activity are also described by combination of ex-situ characterisation of the materials and catalytic testing.展开更多
Due to the expected rise in the world population,an increase in the requirements for quality and safety of food and feed is expected,which leads to the growing demand for new sources of sustainable and renewable prote...Due to the expected rise in the world population,an increase in the requirements for quality and safety of food and feed is expected,which leads to the growing demand for new sources of sustainable and renewable protein.Insect protein is gaining importance as a renewable material for several reasons,reflecting its potential contribu-tions to sustainability,resource efficiency,and environmental conservation.Some insect species are known to be able to efficiently convert organic waste into high-value products such as protein,requiring less land and water compared to traditional livestock.In addition,insect farming produces fewer greenhouse gas emissions,contri-buting to mitigating climate change.Insects are considered as a major potential alternative to animal or plant protein due to their many nutritional benefits,including high protein,mineral,and vitamin contents.On average,the protein content of insects ranges between 35%and 60%dry weight,which exceeds plant protein sources,such as cereal,soybeans,and lentils.As the acceptance of insect protein grows and technologies advance,the food and feed industries continue to explore and expand their applications,offering consumers diverse and sustainable pro-tein choices.In this review,we discuss the recentfindings relating to insect protein focusing on its characteristics,extraction methods,applications,and opportunities along with some trade-offs and uncertainties.展开更多
An innovative in-situ stabilisation treatment followed by ex-situ sediment composting was tested for its ability to treat and dispose of heavy-metal-polluted sediments in a river near the Chinese Pearl Delta. First, p...An innovative in-situ stabilisation treatment followed by ex-situ sediment composting was tested for its ability to treat and dispose of heavy-metal-polluted sediments in a river near the Chinese Pearl Delta. First, polluted sediments were treated in-situ to stabilise the heavy metals. Then the treated sediments were dredged, dewatered and sent for high temperature aerobic composting （HTAC） treatment. Finally, the compost products were used as a fertiliser for fiver bank plants. The stabilisation efficiency of heavy metals during the process was investigated and the results are as follows： （1） using in-situ stabilisation, the extraction concentrations of Cu, Zn and Pb were reduced by 65.0%, 82.2% and 90.0%, respectively, which are much lower than the national standard given in the Identification Standard for Hazardous Waste （GB5085.3-1996）; （2） chemical fraction analysis showed that heavy metals were further stabilized during the HTAC treatment; （3） the concentrations of Cu, Zn and Pb in rainwater leachate through the river bank met the level of class V in the Environmental Quality Standards for Surface Water in China （GB3838-2002）. Therefore, using this new process, the toxicities of heavy metals in sediments were reduced markedly.展开更多
基金financially supported by the National Key Research and Development Program of China(2019YFC1904302)Foundation of State Key Laboratory of High-efficiency Utilisation of Coal and Green Chemical Engineering(2021-K81)the Technology of Coal-to-liquids Research Institute of National Energy Group([2020]010)。
文摘The characteristics of the energy structure of rich coal,less oil and less gas,coupling with a high external dependence on oil and natural gas and the emphasis on the efficient and clean utilisation of coal,have brought opportunities for coal chemical industry.However,with the large-scale popularisation of coal gasification technology,the production and resulting storage of coal gasification slag continue to increase,which not only result in serious environmental pollution and a waste of terrestrial resources,but also seriously affect the sustainable development of coal chemical enterprises.Hence,the treatment of coal gasification slag is extremely important.In this paper,the production,composition,morphology,particle size structure and water holding characteristics of coal gasification slag are introduced,and the methods of carbon ash separation of gasification slag,both domestically and abroad,are summarised.In addition,the paper also summarises the research progress on gasification slag in building materials,ecological restoration,residual carbon utilisation and other high-value utilisation,and ultimately puts forward the idea of the comprehensive utilisation of gasification slag.For large-scale consumption to solve the environmental problems of enterprises and achieve high-value utilisation to increase the economic benefits of enterprises,it is urgent to zealously design a reasonable and comprehensive utilisation technologies with simple operational processes,strong adaptability and economic benefits.
文摘Using political ecology as its conceptual framework,this paper focuses on the changes in forest utilisation and management of South Kyrgyzstan’s walnut-fruit forests over the last century. The aim of this study on human-environment interactions is to investigate the relationship between actors on the one side,their interests and demands,and the forests and forested lands on the other. Forest resource utilisation and management — and even the recognition of different forest products as resources — are connected with political and socio-economic conditions that change with time. The walnut-fruit forests of South Kyrgyzstan are unique,characterised by high biodiversity and a multiplicity of usable products;and they have been utilised for a long time. Centralised and formal management of the forests started with the Russian occupation and was strengthened under Soviet rule,when the region became a part of the USSR. During this era,a state forest administration that was structured from Moscow all the way down to the local level drew up detailed plans and developed procedures for utilising the different forest products. Since the collapse of the Soviet Union,the socio-political and economic frame conditions have changed significantly,which has brought not only the sweeping changes in the managing institutions,but also the access rights and interests in the forest resources. At present,the region is suffering from a high unemployment rate,which has resulted in the forests’ gaining considerable importance in the livelihood strategies of the local population. Political and economic liberalization,increased communication and trans-regional exchange relations have opened the door for international companies and agents interested in the valuable forest products. Today,walnut wood and burls,walnuts,wild apples and mushrooms are all exported to various countries in the world. Scientists and members of various international organisations stress the ecological value of the forests and are trying to establish nature conservation areas. Nevertheless,it is to fear that a multiplicity of interrelated factors — the present transformation and globalization processes,the appearance of new actors,the local population’s insecure economic situation and the erosion of managing institutions — are all leading to an intensified and unregulated exploitation of the forests,resulting in their degradation.
文摘This study presents research results which comprise the following selected communities： Phalaridetum arundinaceae, Alopecuretum pratensis, community with Deschampsia caespitosa, Holcetum lanati, Lolio-Cynosuretum, community Poa pratensis-Festuca rubra. The investigated phytocenoses developed in conditions of lack of utilisation, occasional cutting, occasional alternating meadow-pasture utilisation, pastures with uncut left-overs, 2 cuts and light grazing of the sward by cattle and 2-3 cuts. For the above-mentioned communities the following parameters were assessed： total species number and mean number of species in a phytosociological rel6ves besides Shannon-Wiener diversity index （H＇）, proportion of synanthropic species, natural valorisation number according to Ogwit and fodder value score （FVS）. Regular sward utilisation of plant communities exerts a positive impact not only on the natural values as evidenced by the total and mean number of species in a phytosociological survey and higher biodiversity index （H＇） but it also impacts the sward fodder value scores of meadows and pastures. The strongest negative influence on the floristic composition of meadow communities and their stability is exerted by sporadic, incorrect utilization as it favours taking over of green areas by grass expansive species and development of communities of low natural and use values （community with Deschampsia caespitosa, Ass. Holcetum lanati and community with Agropyron repens）. The strongest impact on the maintenance of meadow and pasture biological stability in the examined region is exerted by their regular, moderate cutting or grazing.
基金National Natural Science Foundation of ChinaNo.49631020+1 种基金The Key Project of "inth Five-Year Plan" of the National Program for Science and TechnologyNo.2000-K01-02-01
文摘Western China includes 12 provincial divisions (the 7 provinces of Sichuan, Guizhou, Yunnan, Shaanxi, Gansu, Qinghai and; 5 autonomous regions of Tibet, Ningxia, Xinjiang, Inner Mongolia and Guangxi; and one city of Chongqing), which comprise 71.4% of the national land area, 28.5% of the national population and produce 17.5% of the national GDP in China. There are 17 countries that have riparian relationships with western China, most of which are water-short countries. All are listed by UN ESCAP as countries with potential water crisis. The co-operative development and coordinated management of international rivers in western China is an important step toward the implementation of the national Great Western Development program. Taking into account of the national strategy and object hierarchy, as well as the development demand of the western region, it is necessary to pursue the multi-disciplinary study of the equitable allocation, utilisation, and eco-environment protection of transboundary water resources in the region. Such efforts will undoubtedly provide scientific evidence and support for the decision-making of the environmental protection and ecological construction and management in the western regions, the enforcement of the sub-regional economic co-operation, mitigation of trans-boundary conflicts, and enhancing bio-diversity conservation.
文摘Land-use efficiency is essential in ports, in particular those that are constrained for space and experiencing congestion. In such situations, ports have been noted to invest in off-dock container yards. This study analysed land use efficiency of four off-dock yards located near the Port of Tema, Ghana’s largest seaport responsible for 85 percent of its trade. The study found that the terminals utilised 0.13 to 0.52 hectares of land, largely influenced by the dwell time and stacking height of containers. It was recommended that regulatory agencies need to coordinate better to reduce the time spent on cargo inspection and validation. In addition, terminals may need to incentivise customers to clear their import containers within shorter periods.
文摘Background and purpose:Despite HIV testing and counselling(HTC)being recognized as important elements of any effective prevention,detection,care,and management programmes across many societies as part of their primary health care package,it is surprising that research evidence on related issues,especially in developing countries like Ghana is sparse.This study examined the extent of knowledge,attitudes and utilisation of HIV testing,and counselling services among trainee nurses of the public nursing and midwifery training colleges in the Central Region of Ghana.Methods and results:A descriptive cross-sectional design was employed to collect data from 375 nursing and midwifery students using multistage sampling procedures.Findings showed that students’HTC knowledge was high(85%)whereas attitudes toward HTC were rated positive(95%).However,HTC utilisation was low(47%).Further results revealed a statistically significant difference between class level and HTC utilisation(χ2[1,N=375]=14.263,p=0.000).In contrast,no statistically significant differences in student nurses’class level and HTC knowledge(χ2[1,N=375]=0.624,p=0.475)as well as class level and attitudes toward HTC services(χ2[1,N=375]=2.334,p=0.158)were realized.Conclusion:The low HTC utilisation among the student nurses may potentially lead to missing opportunities for early diagnoses,care,treatment,and support services for primary,secondary or tertiary prevention modes.Organisation of programmes by college authorities on the importance of HTC and the need for student nurses to utilise these services is crucial.
文摘This Article discusses a comprehensive review of biomass energy sources, environment and sustainable development. This includes all the biomass energy technologies, energy efficiency systems, energy conservation scenarios, energy savings and other mitigation measures necessary to reduce emissions. The current literature is reviewed regarding the ecological, social, cultural and economic impacts of biomass technology. This article gives an overview of present and future use of biomass as an industrial feed-stock for production of fuels, chemicals and other materials. However, to be truly competitive in an open market situation, higher value products are required. Results suggest that biomass technology must be encouraged, promoted, invested, implemented, and demonstrated, but especially in remote rural areas.
文摘In this study, a five-year (2010-2014) production and energy utilisation data in a sausage producing company in Nigeria was analysed for energy consumption, energy intensity, energy productivity, cost of energy per unit product and Normalized Performance Indicator (NPI). The average annual energy consumption was 15,853.22 GJ. The energy consumption mix was 27.66% PHCN main, 32.06% diesel generators and 40.28% oven gas. Main electricity supply from utility company contributed to 25.04% of the total energy cost while diesel was 44.24% and oven gas was 30.71% of the total cost. The average production output from the factory was 595,700 tonnes and the average cost of energy input was 6.71 kobo/kg for the five-year period. The values of cost of energy input per unit product showed a decreasing trend for the five years. The energy intensity also increased through the study years with an average of 1.67 GJ/m2 while the energy productivity decreased throughout the years with an average of 28.3 kJ/kg. The Normalized Performance Indicator (NPI) values calculated for the five years showed steady increment with an average of 1.61 GJ/m2. This indicated a “very poor” range which implies an excessive energy usage, immediate action should be taken to investigate and remedy this.
文摘Background: Emergency Contraception (EC) is used after unprotected sexual intercourse, following sexual abuse, misuse of regular contraception or non-use of contraception. Seventeen percent of pregnancies in Kenya are unintended, potentially leading to unsafe abortion that contributes to the high maternal mortality rate in Country. According to 2016 Kenya Demographic and Health Survey (KDHS), the maternal mortality ratio was 362 maternal deaths per 100,000 live births. Female students in University or College are vulnerable to unplanned pregnancies and illegal abortions resulting in mortality, morbidity and psychosocial problems. Knowledge on EC is very important for students as they are not in stable relationships and not using regular contraception. Therefore, the aim of this study was to determine the knowledge and use of Emergency Contraception among female undergraduate students in the University of Nairobi. Materials and Methods: We used an institution-based cross sectional, quantitative study to sample was employed among 383 female undergraduate students at the University of Nairobi. The University of Nairobi has six colleges and systematic random sampling was used to select study participants from each college. Data were collected using self-administered questionnaires and analysed using SPSS Version 16. Bivariate analysis and logistic regression were used to determine sample characteristics significantly associated with knowledge and utilisation of Emergency Contraception. Results: Most (53%) of the respondents were sexually active, and only 20% of the sexually active female students had ever used Emergency Contraception. Emergency Contraception awareness was high at 86.4%. However, based on a predefined criterion, accurate knowledge of Emergency Contraception was low at 42.6%.The majority (82.5%) of the respondents depended on mass media as a source of information on Emergency Contraception. Factors associated with Emergency Contraception knowledge on bivariate analysis were: age 20 years and above (p = 0.001), enrolment in college of health science (p = 0.001), being in year three of study and above (p = 0.0001) and having an insurance cover (p = 0.021). Ever use of Emergency Contraception was associated with enrolment in the College of health science (p = 0.025) and age 20 years and above (p = 0.050). In multivariate analysis, older age (Aor 1.885 p = 0.003) as well as being in the College of health science (Aor 0.001) were significantly associated with increased probability of being knowledgeable about Emergency Contraception. Conclusion: Although University of Nairobi female undergraduate students are aware of the existence of Emergency Contraception, their specific knowledge on correct timing of taking EC after unprotected sex and on effectiveness is poor. EC use is also low, compounded by underutilisation of public facilities as a source of the EC and underutilisation of health workers as a source of EC information. Therefore, an educative forum may be needed to improve the knowledge of EC among University of Nairobi female students. Health education on the availability of EC in public facilities needs to be addressed. Possible use of informal sources of information such as peer education could be an area to explore in client education on EC knowledge and use. Further research is recommended to establish factors that influence utilisation of public health workers as a source of EC information.
文摘Although refugee adolescents and children are recognised as a health risk population, few studies have explored their Health-related Quality of Life (HRQOL). The present study investigated 1) the sociodemographic predictors of HRQOL such as ethnicity, trauma exposure, and length of residency in Australia in a multiethnic paediatric population with refugee experiences and 2) the relationship between mental healthcare utilisation and HRQOL. Method: Participants were 458 adolescents and children, aged 4 - 17 years, living in South Australia. Parents provided data across the sample and adolescents also completed questionnaires. Overall HRQOL and its composite functional dimensions were assessed using the Paediatric Quality of Life (PedsQL) instrument. Questions from the Child and Adolescent Component of the Australian National Survey of Mental Health and Wellbeing were used to assess service utilisation. Results: Migration region/ethnicity predicted better HRQOL as well as physical, emotional and psychosocial functioning for both children and adolescents. African youths indicated higher HRQOL than those from the former Yugoslavia and the Middle East/South Asia respectively. Pre-migration trauma exposure was associated with lower HRQOL;and longer stay in Australia was related to lower emotional functioning in children. There was a negative association between healthcare service utilisation and PedsQL scores, with participants accessing services demonstrating lower HRQOL. Conclusion: Using more rigorous methods, future research is needed to investigate additional sociodemographic predictors of HRQOL, and protective/risk factors that impact on HRQOL of young refugees.
基金World Bank funded under The Africa Center of Excellence in Sustainable Use of Insects as Food and Feeds(INSEFOODS)at Jaramogi Oginga Odinga University of Science and Technology(JOOUST),Kenya.
文摘The study sought to assess the level of knowledge on the utilization of termites,harvesting methods and characterise local edible termite species.Focus group discussion with key informants was used to collect data that was analysed using SPSS Version 21.0 to generate descriptive statistics.Results indicated different levels of termites’utilisation where 45%of farmers use alates as food,35%as feed for chicks and quails,while 20%use the queen to fatten young bulls.Majority of farmers(40%)prefer the use of termites as feed because it is readily available,followed with 20%that use it because of nutritive value,10%relate its use with better taste of poultry products,5%associate termite use in enhancing early maturity weight while 5%said it improves growth and strength of bulls.On harvesting,three methods are commonly used with most farmers(45%)using underground trapping method,(35%)use above ground trapping method but 20%use mound excavation.Varied plant materials are used as attractants and the effect is more when combined with dry cow dung.Farmers further characterised species based on time of emergence of alates and habitat’s physical features.Most respondents(45%)associated:big mounds with Macrotermes bellicosus(Mafendete);small mount to Macrotermes subhyalinus(Kitunda);presence of open big tunnels with Coptotermes millitaris(Riamke)while seasonal gallaries and small tunnels was a confirmatory feature of either Pseudocanthotermes militaris(Chiisiisi)and Pseudocanthotermes spiniger(Maburi).The study demonstrates the richness in indigenous knowledge on techniques of termite production and utilization.
基金supported by National Natural Science Foundation of China(52477101)Natural Science Foundation of Jiangsu Province(BK20210932).
文摘With the intensification of the energy crisis and the worsening greenhouse effect,the development of sustainable integrated energy systems(IES)has become a crucial direction for energy transition.In this context,this paper proposes a low-carbon economic dispatch strategy under the green hydrogen certificate trading(GHCT)and the ladder-type carbon emission trading(CET)mechanism,enabling the coordinated utilization of green and blue hydrogen.Specifically,a proton exchange membrane electrolyzer(PEME)model that accounts for dynamic efficiency characteristics,and a steam methane reforming(SMR)model incorporating waste heat recovery,are developed.Based on these models,a hydrogen production–storage–utilization framework is established to enable the coordinated deployment of green and blue hydrogen.Furthermore,the gas turbine(GT)unit are retrofitted using oxygenenriched combustion carbon capture(OCC)technology,wherein the oxygen produced by PEME is employed to create an oxygen-enriched combustion environment.This approach reduces energy waste and facilitates low-carbon power generation.In addition,the GHCT mechanism is integrated into the system alongside the ladder-type CET mechanism,and their complementary effects are investigated.A comprehensive optimization model is then formulated to simultaneously achieve carbon reduction and economic efficiency across the system.Case study results show that the proposed strategy reduces wind curtailment by 7.77%,carbon emissions by 65.98%,and total cost by 12.57%.This study offers theoretical reference for the low-carbon,economic,and efficient operation of future energy systems.
基金supported by National Natural Science Foundation of China (31972949)National Nonprofit Institute Research Grant of Chinese Academy of Forestry,China (CAFYBB2023MB006)。
文摘Tree allometry plays a crucial role in tree survival,stability,and timber quantity and quality of mixed-species plantations.However,the responses of tree allometry to resource utilisation within the framework of interspecific competition and complementarity remain poorly understood.Taking into consideration strong-and weakspace competition(SC and WC),as well as N_(2)-fixing and non-N_(2)-fixing tree species(FN and nFN),a mixedspecies planting trial was conducted for Betula alnoides,a pioneer tree species,which was separately mixed with Acacia melanoxylon(SC+FN),Erythrophleum fordii(WC+FN),Eucalyptus cloeziana(SC+nFN)and Pinus kesiya var.langbianensis(WC+nFN)in southern China.Six years after planting,tree growth,total nitrogen(N)and carbon(C)contents,and the natural abundances of^(15)N and^(13)C in the leaves were measured for each species,and the mycorrhizal colonisation rates of B.alnoides were investigated under each treatment.Allometric variations and their relationships with space competition and nutrient-related factors were analyzed.The results showed a consistent effect of space competition on the height-diameter relationship of B.alnoides in mixtures with FN or nFN.The tree height growth of B.alnoides was significantly promoted under high space competition,and growth in diameter at breast height(DBH),tree height and crown size were all expedited in mixtures with FN.The symbiotic relationship between ectomycorrhizal fungi and B.alnoides was significantly influenced by both space competition and N_(2) fixation by the accompanying tree species,whereas such significant effects were absent for arbuscular mycorrhizal fungi.Furthermore,high space competition significantly decreased the water use efficiency(WUE)of B.alnoides,and its N use efficiency(NUE)was much lower in the FN mixtures.Structural equation modeling further demonstrated that the stem allometry of B.alnoides was affected by its NUE and WUE via changes in its height growth,and crown allometry was influenced by the mycorrhizal symbiotic relationship.Our findings provide new insights into the mechanisms driving tree allometric responses to above-and belowground resource competition and complementarity in mixed-species plantations,which are instructive for the establishment of mixed-species plantations.
文摘Carbon dioxide capture and reduction(CCR)process emerges as an efficient catalytic strategy for CO_(2)capture and conversion to valuable chemicals.K-promoted Cu/Al_(2)O_(3)catalysts exhibited promising CO_(2)capture efficiency and highly selective conversion to syngas(CO+H_(2)).The dynamic nature of the Cu-K system at reaction conditions complicates the identification of the catalytically active phase and surface sites.The present work aims at more precise understanding of the roles of the potassium and copper and the contribution of the metal oxide support.Whileγ-Al_(2)O_(3)guarantees high dispersion and destabilisation of the potassium phase,potassium and copper act synergistically to remove CO_(2)from diluted streams and promote fast regeneration of the active phase for CO_(2)capture releasing CO while passing H_(2).A temperature of 350℃is found necessary to activate H_(2)dissociation and generate the active sites for CO_(2)capture.The effects of synthesis parameters on the CCR activity are also described by combination of ex-situ characterisation of the materials and catalytic testing.
文摘Due to the expected rise in the world population,an increase in the requirements for quality and safety of food and feed is expected,which leads to the growing demand for new sources of sustainable and renewable protein.Insect protein is gaining importance as a renewable material for several reasons,reflecting its potential contribu-tions to sustainability,resource efficiency,and environmental conservation.Some insect species are known to be able to efficiently convert organic waste into high-value products such as protein,requiring less land and water compared to traditional livestock.In addition,insect farming produces fewer greenhouse gas emissions,contri-buting to mitigating climate change.Insects are considered as a major potential alternative to animal or plant protein due to their many nutritional benefits,including high protein,mineral,and vitamin contents.On average,the protein content of insects ranges between 35%and 60%dry weight,which exceeds plant protein sources,such as cereal,soybeans,and lentils.As the acceptance of insect protein grows and technologies advance,the food and feed industries continue to explore and expand their applications,offering consumers diverse and sustainable pro-tein choices.In this review,we discuss the recentfindings relating to insect protein focusing on its characteristics,extraction methods,applications,and opportunities along with some trade-offs and uncertainties.
基金supported by the Scientific and Tech- nological Planning Project of Guangdong Province (No. 2003A3040404)the Guangdong & Hong Kong Tech- nology Cooperation Funding (No. 2006A36702001)
文摘An innovative in-situ stabilisation treatment followed by ex-situ sediment composting was tested for its ability to treat and dispose of heavy-metal-polluted sediments in a river near the Chinese Pearl Delta. First, polluted sediments were treated in-situ to stabilise the heavy metals. Then the treated sediments were dredged, dewatered and sent for high temperature aerobic composting （HTAC） treatment. Finally, the compost products were used as a fertiliser for fiver bank plants. The stabilisation efficiency of heavy metals during the process was investigated and the results are as follows： （1） using in-situ stabilisation, the extraction concentrations of Cu, Zn and Pb were reduced by 65.0%, 82.2% and 90.0%, respectively, which are much lower than the national standard given in the Identification Standard for Hazardous Waste （GB5085.3-1996）; （2） chemical fraction analysis showed that heavy metals were further stabilized during the HTAC treatment; （3） the concentrations of Cu, Zn and Pb in rainwater leachate through the river bank met the level of class V in the Environmental Quality Standards for Surface Water in China （GB3838-2002）. Therefore, using this new process, the toxicities of heavy metals in sediments were reduced markedly.
