supply and demand
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Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 618
Author(s):  
Emanuela Marzi ◽  
Mirko Morini ◽  
Agostino Gambarotta

Europe stated the ambitious target of becoming carbon neutral by 2050 to combat climate change and meet the requirements imposed by the Paris Agreement, and renewable energy has proved to be a promising solution for the decarbonization of many sectors. Nonetheless, their aleatory nature leads to grid unbalances due to the difference between supply and demand. Storage solutions are needed, and electrofuels become a key factor in this context: they are fuels produced from electricity, which leads to carbon-neutral fuels if it originates from renewable sources. These can constitute a key solution to store the surplus energy and to decarbonize the so-called hard-to-abate sectors. Electrofuel production technologies have not yet been fully developed, and, in this context, extensive study of the state-of-the-art of existing projects can be very useful for researchers and developers. This work researches the European projects funded by the Horizon 2020 Programme regarding electrofuel production. The projects were analyzed in-depth using specific features, and the results were presented.


2022 ◽  
Author(s):  
Jiawei Zhou ◽  
Xiaohong Chen ◽  
Chuang Xu ◽  
Pan Wu

Abstract Socioeconomic drought is a phenomenon of water shortage caused by an imbalance between the supply and demand of water resources in natural and human socioeconomic systems. Occurrence of these droughts is closely related to sustainable socioeconomic development. However, compared with meteorological drought, hydrological drought and agricultural drought, socioeconomic drought has received relatively little attention. Therefore, this paper proposes a universal and relatively simple socioeconomic drought assessment index, the Standardized Supply and Demand Water Index (SSDWI). Taking the Jianjiang River Basin (JJRB) in Guangdong Province, China as an example, socioeconomic drought characteristics and trends during 1985-2019 were analyzed. The return period of different levels of drought were calculated using a copula function to estimate the risk of socioeconomic drought in the basin, and the relationship between socioeconomic, meteorological, and hydrological droughts and their potential drivers were discussed. The results showed that: (1) SSDWI was a better index for characterizing socioeconomic drought in the JJRB. 29 socioeconomic droughts occurred in the basin during the past 35 years, with an average duration of 6.16 months and an average severity of 5.82 per events. Socioeconomic droughts mainly occurred in autumn and winter, which also had more severe droughts than other seasons. (2) In the JJRB, the joint return periods of ‘∪’ and ‘∩’ for moderate drought, severe drought and extreme drought were 8.81a and 10.81a, 16.49a and 26.44a, and 41.68a and 91.13a, respectively; (3) Due to the increasing outflow from Gaozhou Reservoir, the risk of socioeconomic drought and hydrological drought in the JJRB has significantly declined since 2008. The reasonable operation of the reservoir has played an important role in alleviating the hydrological and socioeconomic drought in the basin.


Network ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 21-35
Author(s):  
Hai Trieu Le ◽  
Tran Thanh Lam Nguyen ◽  
Tuan Anh Nguyen ◽  
Xuan Son Ha ◽  
Nghia Duong-Trung

Due to the rapid change of population structure, leading to lower birth rates and quick aging rates, the demand for blood supply is increasing significantly. In most countries, blood quality and origin are managed by blood management information systems, such as national authorities. Nevertheless, the traditional system has limitations in this field, such as a lack of detailed blood information, making it challenging to manage blood quality, supply, and demand. Hence, to solve these issues, this paper proposes a blockchain-based system called BloodChain, an improved system to support blood information management, providing more detailed information about blood, such as blood consumption and disposal. BloodChain exploits private blockchain techniques with a limited number of relatively fast and reliable participants, making them suitable for B2B (Business to Business) transactions. In this paper, we also develop a proposed system based on the architecture of Hyperledger Fabric. The evaluation of BloodChain is performed in several scenarios to prove our proposed model’s effectiveness.


2022 ◽  
Author(s):  
Nhuong Tran ◽  
U-Primo Rodriguez ◽  
Chin Yee Chan ◽  
Yee Mon Aung ◽  
Long Chu ◽  
...  

Bangladesh has made significant progress in social and economic development in recent years, but micronutrient deficiencies and poor dietary diversity remain a significant challenge. This paper developed eight scenarios to explore fish supply-demand futures in Bangladesh using the AsiaFish model, with special emphasis on the role of fish in micronutrient supply to address the nation’s malnutrition and nutrition security challenges. A business-as-usual (BAU) scenario followed historical trends for exogenous variables used in the model. The seven alternative scenarios explored were: the implications of increase productivity of farmed tilapia, pangasius and rohu carp (AS1); productivity changes in hilsa production (AS2); improvements in the quality of feeds (AS3); reduction in the price of plant-based feeds (AS4); disease outbreak in farmed shrimps and prawns (AS5); and climate change impact (AS6) and stagnant capture fisheries (AS7). The BAU scenario indicates that aquaculture growth will be a prominent contribution to increasing total fish supply and demand and fish exports to 2040. Apart from the scenarios that are favourable to aquaculture sector development, other alternative scenarios highlighted the lower growth rate of capture fisheries and aquaculture compared to BAU, resulting in declining in per capita fish consumption, fish exports and nutrient supply from fish as a consequence. Increased availability of aquaculture fish can slightly compensate for the lower growth of capture fisheries in term of their nutrition quality and dietary diversity, particularly for poor consumers. Policies towards sustaining fisheries and a nutrition-sensitive approach to aquaculture is recommended as both capture fisheries and aquaculture are essential for sustaining healthy and nutritious diets in Bangladesh.


PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0258334
Author(s):  
Mark S. Reed ◽  
Tom Curtis ◽  
Arjan Gosal ◽  
Helen Kendall ◽  
Sarah Pyndt Andersen ◽  
...  

Ecosystem markets are proliferating around the world in response to increasing demand for climate change mitigation and provision of other public goods. However, this may lead to perverse outcomes, for example where public funding crowds out private investment or different schemes create trade-offs between the ecosystem services they each target. The integration of ecosystem markets could address some of these issues but to date there have been few attempts to do this, and there is limited understanding of either the opportunities or barriers to such integration. This paper reports on a comparative analysis of eleven ecosystem markets in operation or close to market in Europe, based on qualitative analysis of 25 interviews, scheme documentation and two focus groups. Our results indicate three distinct types of markets operating from the regional to national scale, with different modes of operation, funding and outcomes: regional ecosystem markets, national carbon markets and green finance. The typology provides new insights into the operation of ecosystem markets in practice, which may challenge traditionally held notions of Payment for Ecosystem Services. Regional ecosystem markets, in particular, represent a departure from traditional models, by using a risk-based funding model and aggregating both supply and demand to overcome issues of free-riding, ecosystem service trade-offs and land manager engagement. Central to all types of market were trusted intermediaries, brokers and platforms to aggregate supply and demand, build trust and lower transaction costs. The paper outlines six options for blending public and private funding for the provision of ecosystem services and proposes a framework for integrating national carbon markets and green finance with regional ecosystem markets. Such integration may significantly increase funding for regenerative agriculture and conservation across multiple habitats and services, whilst addressing issues of additionality and ecosystem service trade-offs between multiple schemes.


Author(s):  
Xin Xu ◽  
Jing Hu ◽  
Li Lv ◽  
Jiaojiao Yin ◽  
Xiaobo Tian

An urban ecological recreational space (UERS), which connects the natural environment with urban residents, is an important guarantee for developing a livable city and improving the well-being of residents. However, there is a serious imbalance between the supply of UERSs and the demand of residents in many big, rapidly developing cities. Previous studies usually used indicators such as scale or quantity to measure the supply level of UERS enjoyed by residents, ignoring its own quality differences. Therefore, taking the urban development area of Wuhan as the research object, we measured the quality of UERS from four dimensions using the entropy method and designed a method to measure the supply service level under the hierarchical travel threshold to analyze the supply level of UERSs based on a community unit. Finally, combined with the demand characteristics of different groups, the matching relationship between supply and demand of UERSs in each community is quantitatively analyzed. The results show the following: (1) The quality of UERS in urban development area of Wuhan varies greatly and its distribution is extremely uneven. (2) The level of supply services and the demand level vary greatly, and the overall performance has a trend of decreasing from the city center to the periphery. (3) The overall matching relationship between supply and demand of UERS is not ideal, and more than half of the communities are in supply deficit or without services. Our study provides a novel perspective on quantifying the supply–demand relationship of UERS. It can more accurately guide decision-makers and planners in determining areas with mismatches between the supply and demand of UERSs and in making targeted layouts of UERSs and relevant policies.


Author(s):  
Wayde Morse ◽  
Lee Cerveny ◽  
Dale Blahna

Recreation opportunities exist as a system at multiple scales and are offered by a variety of recreation providers sometimes with different goals and objectives. Incremental and disparate planning across providers can lead to mismatched supply and demand and inefficient use of resources. Furthermore, traditional recreation supply and demand studies have not systematically considered compatible benefits from conserving recreation lands including demand for and provision of biodiversity and wildlife conservation, ecosystem services, human health, and environmental justice issues.Historically, the supply of outdoor recreation and conservation lands was assembled by different state and federal agencies, counties and municipalities, Native American tribes, non-governmental organizations, or private organizations for the lands they directly managed with little systematic coordination. A national level Protected Area Databased (PAD-US) developed by the United States Geological Survey (USGS) Gap Analysis Project is changing this. It is the official, publicly available, and comprehensive spatial inventory of every park and protected area in the US. The PAD-US program has developed a standardized data set with consistent protocols and methodologies for data collection for continuous updates.Demand assessments are currently conducted by various federal and state agencies, industry associations, and academics. These studies are independently conducted at various levels form recreation site, across land ownership, by activity, or state and national studies. Initiated in 1960, what became the National Survey of Recreation and the Environment (NSRE) collected recreation demand data for analysis at state and national levels. Many recreation planners used this data until it was discontinued in 2014. While there has been coordination and systemization and standardization of recreation supply data collection, no similar actions have occurred for demand.Following the PAD-US, we identify opportunities to coordinate, standardize, and systematize the collection of demand data across agencies, ownerships, and scales. We propose a parallel publicly available National Recreation Demand Database (NRDD) with consistent protocols and methodologies to be the comprehensive and authoritative inventory of recreation demand. We suggest that a new National Survey on People and the Environment (NSPE) be developed to replace the NSRE to collect improved data on outdoor recreation, other resource uses, and compatible benefit demand information.


Author(s):  
Neeti Dutt ◽  
Sushil Sharma ◽  
Meena Sidhu

Background: The COVID-19 pandemic has major implications for blood transfusion. There are uncertain patterns of demand, and transfusion institutions need to plan for reductions in donations and loss of crucial staff because of sickness and public health restrictions. A range of strategies need to be planned to maintain ongoing equitable access to blood for transfusion during the pandemic, in addition to providing new therapies such as convalescent plasma. The main role of transfusion institutions during this period, is the monitoring of supply and demand so that sufficient blood stocks are maintained to support ongoing critical needs. The main aim of our study was to study the impact of COVID-19 outbreak on blood transfusion services (BTS) and to identify the challenges faced by our blood center and mitigation strategies adopted to combat it.Methods: Total number of donations and total number of blood and its components issued were noted from the donor and issue registers respectively, both during the pre-COVID and COVID-19 pandemic and the results were compared thereafter. Various strategies were adopted during the COVID pandemic in order to maintain balance between demand and supply of blood and its products.Results: There has been sudden decrease in the number of blood donations in the month of April 2020 (35%) in the COVID pandemic as compared to pre-COVID time with percentage difference of 65%. This was followed by gradual decrease in the no. of donations in COVID pandemic when compared with donations in the pre-COVID time. The percentage difference in blood donation gradually improved over a period of time from 65% in April 2020 to 7% in April 2021. Similarly, no. of blood units issued also decreased from 1147 in April 2019 to 553 units in April 2020.Conclusions: The BTS need to provide an uninterrupted blood supply, and this stays true even in the face of a pandemic. The plan of action has to be started early so that the supply can be maintained and monitored effectively. Health-care workers being one of the main pillars in the fight against COVID-19 have to be supported and protected. 


Author(s):  
Jiajie Dai ◽  
Qianyu Zhu ◽  
Nan Jiang ◽  
Wuyang Wang

The shared autonomous mobility-on-demand (AMoD) system is a promising business model in the coming future which provides a more efficient and affordable urban travel mode. However, to maintain the efficient operation of AMoD and address the demand and supply mismatching, a good rebalancing strategy is required. This paper proposes a reinforcement learning-based rebalancing strategy to minimize passengers’ waiting in a shared AMoD system. The state is defined as the nearby supply and demand information of a vehicle. The action is defined as moving to a nearby area with eight different directions or staying idle. A 4.6 4.4 km2 region in Cambridge, Massachusetts, is used as the case study. We trained and tested the rebalancing strategy in two different demand patterns: random and first-mile. Results show the proposed method can reduce passenger’s waiting time by 7% for random demand patterns and 10% for first-mile demand patterns.


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