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In the marine environment, the symbiotic relationship between Symbiodinium and corals plays a pivotal role in coral growth and development. Against the backdrop of widespread coral bleaching due to the global climate change, the facile and efficient separation and enrichment of different strains of Symbiodinium hold significant importance for studying coral bleaching. This paper aims to report a platform that integrates dielectrophoretic and inertial forces for the separation and enrichment of Symbiodinium, comprising two modular components: a separation module and an enrichment module. Within the separation module, distinct strains of Symbiodinium undergo preliminary stratification in a contraction–expansion microchannel under the influence of inertial forces. Dielectrophoretic forces generated by the indium tin oxide electrodes divert them toward different outlets, achieving separation. In the enrichment module, the Symbiodinium collected from outlets is rapidly focused through a contraction–expansion microchannel and high-purity samples are concentrated through a single outlet. Evaluating separation efficiency is based on the purity of collected Symbiodinium at the outlet under three different flow rates: 13, 16, and 19 μl/min, while the concentration of enriched Symbiodinium at 100, 200, 300, and 400 μl/min flow rates evaluates the effectiveness of the enrichment process. The experimental results demonstrate a separation purity of approximately 90% and an enrichment factor of around 5.5. The platform holds promise for further applications in the selection and targeted enrichment of high-quality coral symbiotic algae, providing essential research foundations for the conservation of coral ecosystems. [ABSTRACT FROM AUTHOR]

To better address climate change and environmental pollution, it is of great practical significance to comprehensively evaluate the impact of low-carbon energy transition policies on carbon emission reduction. This paper conducts a policy quantitative evaluation of low-carbon energy transition policies from three dimensions: policy intensity, policy objective, and policy instrument. On this basis, the ridge regression model is used to analyze the carbon emission reduction effect of policies. The results show that (1) changes in policy quantities mainly cause the evolution of total policy effectiveness. The government's emphasis on low-carbon energy transition has fluctuated. (2) The two policy objectives of optimizing the use of fossil energy and developing a low-carbon concept are less synergistic with other policy objectives and neither has a significant impact on carbon reduction. (3) The government prefers to adopt command control policy instruments, but their actual carbon emission reduction effects are inferior to that of economic incentive policy instruments. These findings can provide a decision-making basis for the government to further formulate and optimize policies. [ABSTRACT FROM AUTHOR]

This paper reveals a large and all-season ozone hole in the lower stratosphere over the tropics (30°N–30°S) existing since the 1980s, where an O3 hole is defined as an area of O3 loss larger than 25% compared with the undisturbed atmosphere. The depth of this tropical O3 hole is comparable to that of the well-known springtime Antarctic O3 hole, whereas its area is about seven times that of the latter. Similar to the Antarctic O3 hole, approximately 80% of the normal O3 value is depleted at the center of the tropical O3 hole. The results strongly indicate that both Antarctic and tropical O3 holes must arise from an identical physical mechanism, for which the cosmic-ray-driven electron reaction model shows good agreement with observations. The whole-year large tropical O3 hole could cause a great global concern as it can lead to increases in ground-level ultraviolet radiation and affect 50% of the Earth's surface area, which is home to approximately 50% of the world's population. Moreover, the presence of the tropical and polar O3 holes is equivalent to the formation of three "temperature holes" observed in the stratosphere. These findings will have significances in understanding planetary physics, ozone depletion, climate change, and human health. [ABSTRACT FROM AUTHOR]

We develop and test machine learning techniques for successfully using past state time series data and knowledge of a time-dependent system parameter to predict the evolution of the "climate" associated with the long-term behavior of a non-stationary dynamical system, where the non-stationary dynamical system is itself unknown. By the term climate, we mean the statistical properties of orbits rather than their precise trajectories in time. By the term non-stationary, we refer to systems that are, themselves, varying with time. We show that our methods perform well on test systems predicting both continuous gradual climate evolution as well as relatively sudden climate changes (which we refer to as "regime transitions"). We consider not only noiseless (i.e., deterministic) non-stationary dynamical systems, but also climate prediction for non-stationary dynamical systems subject to stochastic forcing (i.e., dynamical noise), and we develop a method for handling this latter case. The main conclusion of this paper is that machine learning has great promise as a new and highly effective approach to accomplishing data driven prediction of non-stationary systems. [ABSTRACT FROM AUTHOR]

Under the global climate change and energy crisis, solar energy has become the focus of research, development, and utilization throughout the world. Therefore, an empirical study on the awareness of residents for solar photovoltaic power generation is of great significance. Based on the 330 questionnaire data, by adopting the single factor variance analysis (S-N-K test) methodology, this paper first analyzed the differences between various groups of residents from varied perspectives of Chinese residents, i.e., different ages, different education attainments, different income levels, different genders, and different industries. Then, it conducted a regression analysis of the demographic variables by using linear regression models. The results indicate that: (1) the awareness of different types of Chinese residents is significantly different; (2) education and income levels have significant impacts on their awareness. Finally, this paper proposed corresponding policy recommendations based on these findings. [ABSTRACT FROM AUTHOR]

In this paper, we report the comparison of the experimental results with numerical simulation. The numerical simulation was performed using TRNSYS. Fourteen weeks of data (January 28 to May 7) were collected and compared against numerical simulation results obtained using TRNSYS. For the 14-week period, the results showed that there was close agreement between the experimental measurement and the numerical simulation. The measured average temperature was 8.1 °C compared to the simulated average temperature of 8.6 °C. The measured maximum and minimum temperatures were 21 °C and -7.8 °C, respectively, while the numerical simulation maximum and minimum temperatures were 17.8 °C and -7.5 °C, respectively. For the five-year seasonal simulation, the system became fully charged by June 14. The maximum temperature the sand-bed achieved annually was 24.83 °C, occurring approximately on July 10, with a minimum of 11.1 °C occurring on January 24. The results demonstrate that sand-bed solar thermal storage systems are suitable for climates in regions with long periods of freezing temperatures which can contribute towards the net-zero energy status of a residential home. We reported the first experimental study, to the authors' knowledge, of sand-bed solar thermal storage conducted in a region with an extended freezing period carried out on a home situated in Palmer, Alaska, 61.6°N, 149.1°W [see G. Hailu et al., Energies 10, 1873 (2017)]. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical study of the effects of subsidizing energy contracts. The major findings are as follows. First, under the pressure of competition, technology promotion of energy service companies (ESCOs) reduces the price of energy contracts, while improving both demand and energy conservation. Second, subsidies for energy contracts improve market demand, ESCO's profits, and energy conservation. Finally, subsidies stimulate ESCO's ability to innovate, whereas competition deters innovation. [ABSTRACT FROM AUTHOR]

A new model has been developed in this paper to evaluate the impact of different photovoltaic modules on room, floor, and solar cell temperature, along with daylight savings and solar cell electrical efficiency. Computations have been carried out on a building-integrated semitransparent photovoltaic thermal system integrated with the roof of a room for Varanasi climatic conditions in winter months. The electrical efficiency of the module and temperature coefficient impact the system's performance significantly. Mono-Si, poly-Si, amorphous Si, and Photovoltaic Thermal (PVT) systems are discussed. Compared with the previous model, the results of the study indicate that there is a 4.39% decrease in the overall exergy efficiency; hence, the PVT system is recommended for energy efficiency, and m-Si is suitable for electrical exergy. [ABSTRACT FROM AUTHOR]

It is clear that much more drastic and early actions than those that are presently being undertaken are needed to limit the average global temperature increase to 1.5 °C above pre-industrial levels. The Asian region, accounting for a significant portion of global greenhouse gas emissions and growing at a rapid economic pace, has a major role to play in the world's transition to a low carbon society (LCS). To design leapfrog pathways to low carbon and sustainable development, it is important to have a scientific tool that can develop LCS pathways and analyze the effectiveness of policies to achieve them under different scenarios. The Asia-Pacific Integrated Assessment Model (AIM) is an effective tool to support these analyses. It has been developed by researchers in Asia and used in policymaking processes in Asia. It can provide comprehensive and consistent assessment of various policies, including macro-economic policies and technological measures. It can analyze trade-offs between rapid economic growth in Asia and its environmental impact and assess sustainable development policies. This paper presents the processes of designing LCS policies and how modeling tools can support the analyses of the leapfrog pathways to a LCS. As a modeling tool, the family of AIM models is explained and their applications in Asia are presented. Procedures to design and implement low carbon policies together with the Plan-Do-Check-Act cycle are also presented. [ABSTRACT FROM AUTHOR]

The very mounting demand for the electricity supply and the raising concern about global warming and climate change have motivated the electricity sector to adopt renewable and local sources of energy. The incorporation of such sources into the distribution network poses a variety of benefits as well as challenges to the Distribution System Operators. The paper analyses a real life 4.3 MVA unbalanced distribution feeder in Kerala, India for its voltage profile improvement and power loss reduction with the addition of Photovoltaic (PV) units at the specified locations with optimal sizing. A methodology based on the Learning Automata (LA) algorithm is developed in order to find out the suitable size of the PV units to be installed at suitable locations in an unbalanced distribution feeder. The LA algorithm is efficient in handling the uncertainty associated with the PV power generation which is modelled using Beta Probability Density Function. The proposed algorithm is validated using the balanced feeder in the literature and extended for several unbalanced test feeders and the selected practical distribution feeder. [ABSTRACT FROM AUTHOR]

Energy is essential for the development of a city. The energy structure of China, dominated by coal, has caused serious problems, such as resource depletion, environmental pollution, and climate change. These problems have posed severe challenges to the sustainable development of mega--cities such as Shanghai. In order to ensure security of energy supply and alleviate the corresponding environmental pollution, these cities should effectively restructure their energy supply. This paper quantitatively analyzed the future energy consumption demand in Shanghai and its effects on environmental quality based on the MARKAL model with the aim of providing theoretical support for the government decision regarding energy policy, energy technology, adjustment of energy supply structure, etc. Different scenarios have been set up in light of the natural gas distributed supply system, clean and efficient coal-fired power technologies, energy-saving of industrial boilers technologies, Integrated Gasification Combined Cycle (advanced power generation technology), and wind power technologies. The results obtained by the MARKAL model show that total consumption of the whole society energy in Shanghai will reach 143 572 700 tons of standard coal in 2015, and 199 645 800 tons of standard coal in 2020. Thus, the future demand for energy consumption is huge astronomical, with about an average annual growth rate of 4%. The consumption of coal and other primary energy could decline by improving the energy efficiency and increasing renewable energy use, which would reduce pollutants emissions. At the same time, Shanghai should continue research on carbon dioxide emissions technology and its application in response to climate change. [ABSTRACT FROM AUTHOR]

The deleterious consequences of climate change are well documented. Future climate treaties might mandate greenhouse gas (GHG) emissions measurement from signatories in order to verify compliance. The acquisition of atmospheric chemistry would benefit from low cost, small size/weight/power of microsystems. In this paper, we investigated several key materials science aspects of a phase-change microvalve (PCμV) technology with low power/size/weight/cost for ubiquitous GHG sampling. The novel design, based on phase-change material low-melting-point eutectic metal alloys (indium-bismuth, InBi and tin-lead, SnPb), could be actuated at temperatures as low as 72 °C. Valve manufacturing was based on standard thick and thin-film processes and solder technologies that are commonly used in industry, enabling low-cost, high-volume fabrication. Aging studies showed that it was feasible to batch fabricate the PCμVs and store them for future use, especially in the case of SnPb alloys. Hermetic sealing of the valve prototypes was demonstrated through helium leak testing, and Mil spec leak rates less than 1 × 10-9 atm cm3/s were achieved. This confirms that the sample capture and analysis interval can be greatly expanded, easing the logistical burdens of ubiquitous GHG monitoring. Highly conservative and hypothetical CO2 bias due to valve actuation at altitude in 1 cm3 microsamplers would be significantly below 1.0 and 2.2 ppmv for heat-treated InBi and SnPb solders, respectively. The CO2 bias from the PCμV scales well, as a doubling of sampler volume halved the bias. We estimated the shelf life of the SnPb PCμVs to be at least 2.8 years. These efforts will enable the development of low cost, low dead volume, small size/weight microsystems for monitoring GHGs and volatile organic compounds. [ABSTRACT FROM AUTHOR]

This paper aims at determining the optimum tilt angle for south facing flat-plate solar collectors in Iran. Solar radiation on a horizontal surface was estimated by applying an empirical method and employing meteorological data from 80 selected cities. A mathematical model was used for estimating the solar radiation at different tilt angles. Daily, monthly, seasonally, bi-annually, and yearly optimum tilt angles and solar radiations were determined for 80 selected cities. Recommendations were made on the optimum tilt angle adjustment for different places in the country in order to benefit the best solar radiation available. The averaged benefits of annual solar radiation for 80 cities were 21.3% for daily, 21% for monthly, 19.6% for seasonal, 19.3% for bi-annual, and 13.3% for yearly adjustments compared with the radiation on the horizontal collector. Based on these results, adjusting tilt angles, at least twice a year, is recommended. Optimum tilt angles for cloudy sky cities with a low clearness index are lower than those for cities at the same latitude angle having a higher clearness index. In addition to latitude angle, the climate conditions are also important for determining the optimum tilt angle. [ABSTRACT FROM AUTHOR]

Solar energy, which is inexhaustible and abundant, has become an economically viable and environmentally preferable alternative to fossil fuels. There is the inherent advantage of solar energy in mitigation of climate change, generation of employment, and reduction of poverty, as well as increased energy security and supply. It is therefore important to continue to evaluate the global solar radiation levels in countries such as Nigeria with considerably high solar energy potential. In this paper, we report such evaluation for southern Nigeria; in particular, the correlations of meteorological estimates from National Aeronautics and Space Administration (NASA) and calculated Hargreaves estimates for this region of Nigeria (latitude of 4.75°-7.77°N and longitude of 3.33°-8.32°E) are carried out and the results show a good agreement in all the sites, thereby strengthening the case we make for decentralized renewable energy investments in the region. [ABSTRACT FROM AUTHOR]

The impact of escalating human activities on greenhouse gas emission, global warming, and changes in global climate patterns is almost certainly the most discussed issue in the first decade of the 21st century. Two-thirds of Africa’s energy consumption consists of various forms of highly inefficient traditional biomass. In rural areas, low energy consumption is both a cause and consequence of poor development and also of the degradation of the natural environment. The burning of biomass or vegetation as a conventional land preparation method has a net negative impact on the soil organic carbon as well as on the environment through the oxidation of carbon into carbon dioxide, an anthropogenic greenhouse gas. This paper reports the findings of an experiment to investigate the impact of the heat due to burning on soil organic carbon at soil depths of 0–5 and 5–10 cm. It was observed that 21% decline in soil organic carbon resulted in the release of 1446 CO2 kg ha-1 into the atmosphere. This underscores the fact that burning of biomass as a land preparation method may not be sustainable when viewed against the backdrop that the African continent encompasses the most vulnerable regions and populations for current climate variability. This study is significant in that it is the first to shed light on the effects of burning on soil carbon in the coastal savanna ecosystem of Ghana and would potentially provide the impetus for further research. [ABSTRACT FROM AUTHOR]

Cities are responsible for nearly 75% of the world’s energy consumption; expectedly, about 90% of future growth will occur in urban areas. However, we consider that cities will be at the forefront of implementing groundbreaking technologies and policies, as evidenced in the initiatives taken by many cities here and worldwide to resolve issues in energy and climate change. In addition to affording energy and environmental benefits, investments in energy efficient and renewable technologies have huge potential to boost local economies, as demonstrated by the recent federal allocation of stimulus funding. Inclined to give priority to stopgap measures, many cities tend to regard comprehensive long-term planning as secondary. However, such solutions would bring multiple benefits to the community. The paper showcases an energy and environment systems model to provide a quantitative vision of technology and management strategy options for effectively deploying energy efficiency and renewable energy for reducing the carbon footprint, while sustainably maintaining the energy demands of the community and the servicing environmental infrastructure. We provide results of a case study completed for New York City, to showcase usefulness of long-term planning for achieving low carbon cities. Combined with appropriate stakeholder participation, such a technology explicit bottom-up approach holds the promise of influencing the current energy planning, environmental regulatory regime, including multimedia aspects of carbon control for cities locally and internationally. [ABSTRACT FROM AUTHOR]

Mid- and long-term energy requirements and greenhouse gas emission scenarios for China were presented by using the Integrated Policy Assessment Model of China. Technologies are the key component to reach a low carbon future. Technologies are identified with the scenario analysis. In order to realize the low carbon future, a technology roadmap was presented to reach the emission reduction up to 2050 in China. Twenty-eight key technologies are given in the paper for the technology roadmap, presenting learning curves. With full adoption of these key technologies, we do see ample opportunities for China to make the emission stable after 2020, without a large increase, and even start to have a deep reduction after 2030. [ABSTRACT FROM AUTHOR]

The aim of this paper is to define low carbon society (LCS) based on the phase diagram with the variables from the IPAT [Human Impact (I) on the environment equals the product of population (P) affluence (A) and technology (T)], starting from the problem definitions: (1) Economy is not everything for LCS and (2) it is not clear if speed on the constraint is more important than liberation from it. To tackle these problems, two research questions are set: (1) What are the basic indicators, objects, and constraints to shape the argument of LCSs and (2) what are the historical paths of several countries and what can be said for their future paths toward carbon societies? Time series data from 1900 or before are used, while the phase diagram with the variables from the IPAT equation is used as the core methodology. In addition to the IPAT variables, the importance of land per capita shall be considered as another basic indicator for LCS related to the carrying capacity. The three different kinds of objects [i.e., total gross domestic product (GDP), GDP per capita, and social indicator] and the two constraints (i.e., total emission and emission per capita) are considered, and it is shown that the combination of these objects and constraints strongly affects the argument of the carrying capacity of climate and land, development of economic system and economic man, and other human developments. Among the four cases analyzed in the phase diagram, the case where GDP per capita is object and total emission is constraint is given the most attention and requires the further research in the future since it does not contradict with a definition of LCS. It is also suggested that if changing the direction of the path with low carbon technology development takes time and cost, institutional arrangement would be additionally necessary in addition to market mechanism where optimal solutions are found on constraint. [ABSTRACT FROM AUTHOR]

In this paper, we study a model of many species that compete, directly or indirectly, for a pool of common resources under the influence of periodic, stochastic, and/or chaotic environmental forcing. Using numerical simulations, we find the number and sequence of species going extinct when the community is initially packed with a large number of species of random initial densities. Thereby, any species with a density below a given threshold is regarded to be extinct. [ABSTRACT FROM AUTHOR]