Assessment on Energy Self-Sufficiency Rate for Building Integrated Photovoltaics and Fuel Cell System in Japan

A building integrated photovoltaic (PV) and fuel cell (FC) system is proposed for assessment of the energy self-sufficiency rate in a city in Japan. The electricity consumed in the building is mainly supplied by solar panels, while the gap between the energy demand and supply is solved by the FC that is powered by the H2 produced by water electrolysis with surplus power of PV. A desktop case study of using the proposed system in Tsu city which is located in central part of Japan, has been conducted. The results found that the self-sufficiency rates of PV system to electricity demand of households (RPV) during the daytime in April and July are higher than those in January and October. The results also reveal that the self-sufficiency rate of FC system to the electricity demand (RFC) is 15% - 38% for the day when the mean amount of horizontal solar radiation is obtained in January, April, July and October. In addition, it is found the optimum tilt angle of solar panel installed on the roof of the buildings should be 0 degree, i.e., placed horizontally.

Carbon Dioxide Emissions and Energy Self-Sufficiency of Woody Biomass Utilization for Residential Heating: A Case Study of Nishiwaga, Japan

Renewable energy sources, including bioenergy, are presently attracting considerable attention as possible substitutes for fossil fuels. Among the various sources of bioenergy, biomass can arguably play a significant role in the reduction of greenhouse gases and the provision of a stable energy supply. However, the use of fossil fuels continues in the production of bioenergy. Consequently, the overall extent to which biomass utilization for energy can reduce carbon dioxide emissions as a substitute for fossil fuels and whether this can improve the energy self-sufficiency rate remains largely unknown. This study responds to these questions using a case of a Japanese rural community using firewood for residential heating. The results showed that woody biomass utilization for energy is able to both reduce the dependence on fossil fuels and mitigate climate change. These findings offer new insights into the development of sustainability in rural communities.

A Quantitative Factorial Component Analysis to Investigate the Recent Changes of Japan’s Weight-Based Food Self-Sufficiency Ratio

We investigate the weight-based food self-sufficiency ratio (WSSR) for Japan over a 50-year period (1961-2011) by applying factorial component analysis technique in order to measure the changes of the WSSR quantitatively. Quantitative data analysis is employed to determine the drivers of those changes. Numerical results show that Japan experienced a drastic decline in its food self-sufficiency ratio (FSSR) during the above period. The factorial component analysis shows that such a decline was caused by the changes in the FSSR of the food groups/items, not in the quantity of the food supply. A number of characteristics of those changes are presented and a list of major food groups that have major impacts on the changes is constructed. The findings in this paper reiterate the alarming food security problem in Japan and provide clear insight into the causes of this problem. The findings in this study pick up where previous studies have left off, aid the food-related policy-making process and identify new ideas for future food research.

Strategies for Promoting Rice Self-sufficiency in Sierra Leone

Rice is the main food of Sierra Leoneans and an important source of employment and income for rural communities. According to the West African Rice Development Association report, annual consumption of rice is amongst the highest in SubSaharan Africa（SSA）, 104 kg. Mainly, small scale farmers who are resource poor on both the upland and various lowlands grow rice. Sierra Leone has not been able to produce enough rice to meet its local consumption demand for a very long time now. 530 000 MT of milled rice is the required consumption need of the Sierra Leonean population per annum. In 2007, national paddy rice production was projected at 638 000 MT. The level of rice self-sufficiency rose from 50.57% in 2002 to 62.15% in 2006 and then to 63.49% in 2007. The remainder must be imported at increasingly expensive prices in the current situation of high food prices, which includes rice. The price of rice has seen a steady increase in the entire country. What most affected by this, is the low-income urban and peri-urban households. The promotion of domestic rice production is therefore a key element in the strategies for improving rice self-sufficiency, stimulating economic growth and increasing rural income. Therefore, supporting rice production programme is the only solution to pull the country out of the worsening rice situation and maintain the present trend in rice self-sufficiency. Therefore, having an understanding of the strategic interventions in rice production in Sierra Leone is an important ingredient in the promotion and attainment of rice self-sufficiency.

CHINA'S INDISPENSABLE WAY TO GRAIN SELF-SUFFICIENCY

In China’s countryside today, so far the foodstuffs for daily-life subsistence are still taken from the traditional farming production in addition to the yield of animal husbandry, while crop plantation takes the lion’s share in our rural economy. During the Medieval Age of the Western countries, however, special stress was placed on raising livestock on pastureland until the Industrial Revolution occurred in the 18th century when grain-oriented agriculture came into being. As a result of the unprecedented boom of modern science and technology now sweeping the whole world, farming productivity has sky-

On-site solar PV generation and use: Self-consumption andself-sufficiency

As energy storage systems are typically not installed with residential solar photovoltaic (PV) systems,any “excess” solar energy exceeding the house load remains unharvested or is exported to the grid.This paper introduces an approach towards a system design for improved PV self-consumptionand self-sufficiency. As a result, a polyvalent heat pump, offering heating, cooling and domestic hotwater, is considered alongside water storage tanks and batteries. Our method of system analysisbegins with annual hourly thermal loads for heating and cooling a typical Australian house inGeelong, Victoria. These hourly heating and cooling loads are determined using Transient SystemSimulation (TRNSYS) software. The house’s annual hourly electricity consumption is analysed usingsmart meter data downloaded from the power supplier and PV generation data measured with aPV system controller. The results reveal that the proposed system could increase PV self-consumptionand self-sufficiency to 41.96% and 86.34%, respectively, resulting in the annual imported energybeing reduced by about 74%. The paper also provides sensitivity analyses for the hot and coldstorage tank sizes, the coefficient of performance of the heat pump, solar PV and battery sizes.After establishing the limits of thermal storage size, a significant impact on self-efficiency can berealised through battery storage. This study demonstrates the feasibility of using a polyvalent heatpump together with water storage tanks and, ultimately, batteries to increase PV self-consumptionand self-sufficiency. Future work will concentrate on determining a best-fit approach to systemsizing embedded within the TRNSYS simulation tool.

What Determines China's Grain Imports and Self-sufficiency? The Role of Rising Domestic Costs and Varying World Market Prices

China s grain sectors have faced unprecedented challenges in recent years as the ever-increasing and historically high level of grain output has failed to reduce grain imports. On the contrary, high grain imports and high domestic stock have accompanied historically high domestic output, a situation dubbed the "triple high" phenomenon in current policy discussion. This paper explores the role of widening domestic-world market price gaps in determining the triple high phenomenon.Unlike earlier studies that relied on production capacities, this paper argues that domestic production and demand (hence imports) are functions of domestic and world market prices and proposes an analytical framework to explicitly capture such price gaps under restricted trade linkages in general equilibrium. Following this approach, a set of price scenarios for the 2011-2020 period are constructed and simulated in a computable general equilibrium model. Results from the core scenarios, in which recent domestic and world market price trends are assumed to continue, suggest that further widening price gaps would substantially increase grain imports and reduce domestic output (by 60 million tons) and self-sufficiency ratios from base levels. In the alternative scenarios with larger (smaller) price gaps, we find higher (lower) imports and larger (smaller) decreases in domestic output and self-sufficiency ratios. Such results provide important policy implications as China's agricultural policy undergoes significant adjustment.

Impacts of Cultivated Land Conversion on Environmental Sustainability and Grain Self-sufficiency in China

Using provincial data, the present paper examines the impact of cultivated land conversion on agriculture and the environment. It is found that the grain production center is gradually moving towards more fragile and water scarce areas, putting more pressure on the environment. Land conversion caused large losses in ecosystem service values in the 1990s, but large scale ecological restoration programs have been implemented since 2000 to compensate for such losses. The ecological restoration programs are concentrated in regions with relatively low land productivity, whereas cultivated land conversion usually takes place in areas with relatively high land productivity. Newly-cultivated land, especially that in areas marginally suit for agricultural production, is likely to have much lower productivity levels than the original cultivated land. Because the stock of potentially cultivable land is almost exhausted, China＇s grain self-suffiency policy can only be maintained by preserving the available stock of arable land and increasing its productivity in a sustainable way.

Irrigated agriculture for food self-sufficiency in the sub-Saharan African region

Increasing agricultural productivity in Africa will have important impacts not only on the agricultural sector but also can be a catalyst for industrialization through agro-processing.Irrigation,therefore,has a crucial role in enhancing food security and reducing hunger in the region.Numerous countries in Africa consider water and irrigation management as a key factor in improving their food security and ensuring access to drinking-water for their populations.Fortunately,there is evidence from a number of places on the continent where the adoption of efficient irrigation systems has led to higher productivity among smallholder farmers.While the appropriate interventions for the diverse agro-ecological zones of sub-Saharan Africa are known,adoption among smallholder farmers still remains a challenge.Digital technology opens the vast untapped potential for farmers,investors,and entrepreneurs to improve the efficiency of food production and consumption in Africa.From precision farming to an efficient food supply chain,technology could bring major economic,social,and environmental benefits.Increasing investment and involvement of the private sector is crucial for the up-scaling of irrigation technologies.Indeed,the sheer optimism across the startup ecosystem is that extreme hunger can be cured in Africa,in this generation,by significantly transforming the industry that employs most of its citizens.This paper draws on lessons from past trends in the irrigation industry and emphasizes on novel directions to ensure that farmers,as well as other stakeholders reap the benefits associated with improved technologies.

Self-sufficient Cytochrome P450s and their potential applications in biotechnology

Cytochrome P450s(CYPs)are ubiquitously found in all kingdoms of life,playing important role in various biosynthetic pathways as well as degradative pathways;accordingly find applications in a vast variety of areas from organic synthesis and drug metabolite production to modification of biomaterials and bioremediation.Significantly,CYPs catalyze chemically challenging CAH and CAC activation reactions using a reactive high-valent iron-oxo intermediate generated upon dioxygen activation at their heme center,while the other oxygen atom is reduced to the level of water by electrons provided through a reductase partner protein.Self-sufficient CYPs,encoding their heme domain and reductase protein in a single polypeptide,facilitate increased catalytic efficiency and render a less complicated system to work with.The self-sufficient CYP enzyme from CYP102A family(CYP102A1,BM3)is among the earliest and most-investigated model enzymes for mechanistic and structural studies as well as for biotechnological applications.An increasing number of self-sufficient CYPs from the same CYP102 family and from other families have also been reported in last decade.In this review,we introduce chemistry and biology of CYPs,followed by an overview of the characteristics of self-sufficient CYPs and representative reactions.Enzyme engineering efforts leading to novel self-sufficient CYP variants that can catalyze synthetically useful natural and non-natural(nature-mimicking)reactions are highlighted.Lastly,the strategy and efforts that aim to circumvent the challenges for improved thermostability,regio-and enantioselectivity,and total turnover number;associated with practical use of self-sufficient CYPs are reviewed.

Modeling the effects of urbanization on grain production and consumption in China

The impact of rapid urbanization on food security of China has received considerable attention.It is not clear whether China can strike a balance between urbanization and food security,especially grain security.There have been numerous studies examining the effects of urbanization on grain production or consumption,but few studies have yet analyzed grain balances.Based on the Chinese World Agricultural Regional Market Equilibrium Model（CWARMEM）,this paper explores the impacts of urbanization on national and regional grain balances through different scenarios.The CWARMEM is a global partial equilibrium multimarket model which captures the differences between urban and rural residents as well as the effects of globalization.The results show that urbanization has a small negative effect on maintaining grain self-sufficiency.Despite of that,China is able to achieve the objective of grain security set by its policymakers.Moreover,urbanization changes regional grain balances across China：The position of Northeast China and North China,as two dominant grain suppliers of China,will be weaken;Central China and East China will increase dependence on other grain suppliers;the grain surplus of Northwest China will increase slightly.Besides,in terms of grain category,urbanization helps China achieve self-sufficiency in food grain（rice and wheat）,while expands deficit of feed grain（maize）.

Energy Assessment of Building Integrated Photovoltaics and Fuel Cell Systems: Design Study for Building(s) of Mie, Japan

A building integrated energy system (photovoltaic (PV) and fuel cell (FC)) is proposed for assessment of the energy self-sufficiency rate in five cities of Mie prefecture in Japan. In this work, it is considered that the electricity requirement of the building is provided by the building integrated photovoltaic (BIPV) system and the gap between the energy demand and BIPV supply is fulfilled by the FC. The FC is powered by the electrolytic H2 produced from the surplus power of PV. A design study of using the proposed system in five cities in Mie prefecture, which are in center part of Japan, has been performed. It has been observed that the monthly power production from BIPV is higher in spring and summer, while it is lower in autumn and winter at all considered locations. The self-sufficiency rate of the FC system is higher with decreasing households’ number and it has been observed that the 12 households are more suitable for full cover of the electricity demand by the combined system of PV and FC. The relationship between the households’ number and self-sufficiency rate of the FC system per solar PV installation area can be expressed by exponential curve. The coefficient of the exponential curve can predict the suitable city for the BIPV system with FC system utilizing electrolytic H2 generated by using excess energy from the PV system.

Energy Characteristics of an Integrated Power Generation System with Photovoltaic and Fuel Cell

An integrated energy system (with photovoltaic (PV) and fuel cell (FC) for building) is proposed and assessed in term of its energy self-sufficiency rate in seven cities (Nagoya, Toyota, Tajimi, Takayama, Ogaki, Hamamatsu, Shizuoka) in Tokai region in Japan in this paper. In this work, it is considered that the electricity requirement of the building for household users is provided by a building integrated photovoltaic (BIPV) system and the gap between the energy demand and BIPV supply is fulfilled by the FC. The FC is powered by the electrolytic H2 produced when PV power was in surplus. Based on the study of applying the proposed system in seven cities, which clarifies the effectiveness of the integrated BIPV, electrolytic H2 and FC power generation system, a universal system model has been developed in this paper. It has been observed that the monthly power production from BIPV as well as FC system are higher in spring and summer, while they are both lower in autumn and winter at all considered locations. The self-sufficiency rate of the FC system is higher with decreasing households’ number and it has been observed that 16 is the most appropriate number of households in a building, whose electricity demand could be fully covered by the integrated PV and FC system. Due to its climate condition, Hamamatsu is the best city in the region for installing the proposed system. The correlation between the households’ number and self-sufficiency rate of the FC system per solar PV installation area can be expressed by the regression curve in the form of y = ax-b well.

Innovative One Water Solutions for a Sustainable Water Supply

Climate change impacts,such as higher average temperatures and prolonged drought conditions,have affected regional and local water supply reliability.The City of Santa Monica has long been a leader in promoting sustainability and is implementing several innovative water supply projects to develop alternative water supplies-including stormwater,dry weather urban runoff,and municipal wastewater-to provide a diverse,sustainable,and drought-resilient local water supply.The City is developing the first MBR(Membrane Bioreactor)system and cartridge filtration system to receive log removal credits for potable reuse in the State of California,the first stormwater treatment project in the State of California that will augment groundwater supplies via direct injection,and the first municipal flow reversal RO(Reverse Osmosis)system in the United States.Collectively,these alternative water supplies sources will reduce the City’s reliance on imported water supplies and meet as much as 99%of its water demands through local water resources.

Tumor microenvironment-activated theranostic nanoreactor for NIR-II Photoacoustic imaging-guided tumor-specific photothermal therapy

Theranostic agents that can be sensitively and specifically activated by the tumor microenvironment(TME)have recently attracted considerable attention.In this study,TME-activatable 3,3′,5,5′-tetramethylbenzidine(TMB)-copper peroxide(CuO_(2))@poly(lactic-co-glycolic acid)(PLGA)@red blood cell membrane(RBCM)(TCPR)nanoparticles(NPs)for second near-infrared photoacoustic imaging-guided tumor-specific photothermal therapy were developed by co-loading CuO_(2)NPs and TMB into PLGA camouflaged by RBCMs.As an efficient H_(2)O_(2)supplier,once exposed to a proton-rich TME,CuO_(2)NPs can generate H_(2)O_(2)and Cu^(2+),which are further reduced to Cu^(+) by endogenous glutathione.Subsequently,the Cu^(+)-mediated Fenton-like reaction produces cytotoxic·OH to kill the cancer cells and induce TMB-mediated photoacoustic and photothermal effects.Combined with the RBCM modification-prolonged blood circulation,TCPR NPs display excellent specificity and efficiency in suppressing tumor growth,paving the way for more accurate,safe,and efficient cancer theranostics.

Improved L -phenylglycine synthesis by introducing an engineered cofactor self-sufficient system

L-phenylglycine(L-phg)is a valuable non-proteinogenic amino acid used as a precursor to β-lactam antibiotics,antitumor agent taxol and many other pharmaceuticals.L-phg synthesis through microbial bioconversion allows for high enantioselectivity and sustainable production,which will be of great commercial and environmental value compared with organic synthesis methods.In this work,an L-phg synthesis pathway was built in Escher-ichia coli resulting in 0.23 mM L-phg production from 10 mM L-phenylalanine.Then,new hydroxymandelate synthases and hydroxymandelate oxidases were applied in the L-phg synthesis leading to a 5-fold increase in L-phg production.To address 2-oxoglutarate,NH_(4)^(+),and NADH shortage,a cofactor self-sufficient system was introduced,which converted by-product L-glutamate and NAD^(+)to these three cofactors simultaneously.In this way,L-phg increased 2.5-fold to 2.82 mM.Additionally,in order to reduce the loss of these three cofactors,a protein scaffold between synthesis pathway and cofactor regeneration modular was built,which further improved the L-phg production to 3.72 mM with a yield of 0.34 g/g L-phe.This work illustrated a strategy applying for whole-cell biocatalyst converting amino acid to its value-added chiral amine in a cofactor self-sufficient manner.

1985-2016年青藏高原不同尺度粮食自给能力时空差异

Capacity for grain self-sufficiency on the Tibetan Plateau(TP)is an important basis for ensuring social stability and regional sustainability.Thus,based on county-level statistical data for population,grain production and consumption,we analyzed patterns and trends in grain supply and demand at regional,provincial,and county levels on the TP between 1985 and 2016.We applied two indices to evaluate capacity for grain self-sufficiency and found that the regional average self-sufficiency rate increased quickly by 1.97%/a since 1989,reaching 173.03%on the plateau over the period between 2010 and 2016.This indicates that grain supply in this region is able to fully meet demand.In addition,all provinces apart from Xinjiang exhibited similar increasing trends,attaining grain self-sufficiency during 2010–2016.Furthermore,59%of counties attained grain self-sufficiency over this period,mainly distributed in southern Tibet,in the Sichuan-Tibet junction area,and in eastern Qinghai Province.A number of gaps in grain supply and demand occurred within the headwater regions of the Yangtze and Yellow rivers as well as on the Qiangtang Plateau.Grain self-sufficiency significantly increased over the study period in 36%of counties,mainly distributed in the agricultural areas of southeastern Tibet and in eastern Qinghai.Across the whole plateau,capacity for grain self-sufficiency substantially increased between 1985 and 2016,although serious spatial imbalances remain.

EXPLORING THE RECYCLING OF MANURE FROM URBAN LIVESTOCK FARMS:A CASE STUDY IN ETHIOPIA

Urban population growth is driving the expansion of urban and peri-urban agriculture(UPA)in developing countries.UPA is providing nutritious food to residents but the manures produced by UPA livestock farms and other wastes are not properly recycled.This paper explores the effects of four scenarios:(1)a reference scenario(business as usual),(2)increased urbanization,(3)UPA intensification,and(4)improved technology,on food-protein self-sufficiency,manure nitrogen(N)recycling and balances for four different zones in a small city(Jimma)in Ethiopia during the period 2015-2050.An N mass flow model with data from farm surveys,field experiments and literature was used.A field experiment was conducted and N use efficiency and N fertilizer replacement values differed among the five types of composts derived from urban livestock manures and kitchen wastes.The N use efficiency and N fertilizer replacement values were used in the N mass flow model.Livestock manures were the main organic wastes in urban areas,although only 20 to 40%of animal-sourced food consumed was produced in UPA,and only 14 to 19%of protein intake by residents was animal-based.Scenarios indicate that manure production in UPA will increase 3 to 10 times between 2015 and 2050,depending on urbanization and UPA intensification.Only 13 to 38%of manure N will be recycled in croplands.Farm-gate N balances of UPA livestock farms will increase to>1 t·ha−1 in 2050.Doubling livestock productivity and feed protein conversion to animal-sourced food will roughly halve manure N production.Costs of waste recycling were high and indicate the need for government incentives.Results of these senarios are wake-up calls for all stakeholders and indicate alternative pathways.

Development of Kabila rocket: A radioisotope heated thermionic plasma rocket engine

A new type of plasma rocket engine, the Kabila rocket, using a radioisotope heated thermionic heating chamber instead of a conventional combustion chamber or catalyst bed is intro- duced and it achieves specific impulses similar to the ones of conventional solid and bipropellant rockets. Curium-244 is chosen as a radioisotope heat source and a thermal reductive layer is also used to obtain precise thermionic emissions. The self-sufficiency principle is applied by simultane- ously heating up the emitting material with the radioisotope decay heat and by powering the differ- ent valves of the plasma rocket engine with the same radioisotope decay heat using a radioisotope thermoelectric generator. This rocket engine is then benchmarked against a 1 N hydrazine thruster configuration operated on one of the Pleiades-HR-1 constellation spacecraft. A maximal specific impulse and power saving of respectively 529 s and 32% are achieved with helium as propellant. Its advantages are its power saving capability, high specific impulses and simultaneous ease of storage and restart. It can however be extremely voluminous and potentially hazardous. The Kabila rocket is found to bring great benefits to the existing spacecraft and further research should optimize its geometric characteristics and investigate the physical principals of its operation.