Korea Rural Economic Institute

The Food and Agricultural Organization (FAO) reported that approximately one-third of all produced foods (1.3 billion tons of edible food) for human consumption is lost and wasted every year across the entire supply chain. Significant impacts of food loss and waste (FLW) have increased interest in establishing prevention programs around the world. This paper aims to provide an overview of FLW occurrence and prevention. Economic, political, cultural, and socio-demographic drivers of FLW are described, highlighting the global variation. This approach might be particularly helpful for scientists, governors, and policy makers to identify the global variation and to focus on future implications. The main focus here was to identify the cause of the FLW occurrence throughout the food supply chain. We have created a framework for FLW occurrence at each stage of the food supply chain. Several feasible solutions are provided based on the framework.

We investigated the feeding by 18 red-tide dinoflagellate species on the cyanobacterium Synechococcus sp. We also calculated grazing coefficients by combining the field data on abundances of the dinoflagellates Prorocentrum donghaiense and P. micans and co-occurring Synechococcus spp. with laboratory data on ingestion rates obtained in the present study. All 17 cultured red-tide dinoflagellates tested (Akashiwo sanguinea, Alexandrium catenella, A. minutum, A. tamarense, Cochlodinium polykrikoides, Gonyaulax polygramma, G. spinifera, Gymnodinium catenatum, G, impudicum, Heterocapsa rotundata, H. triquetra, Karenia brevis, Lingulodinium polyedrum, Prorocentrum donghaiense, P. minimum, P. micans, and Scrippsiella trochoidea) were able to ingest Synechococcus. Also, Synechococcus cells were observed inside the protoplasms of P, triestinum cells collected from the coastal waters off Shiwha, western Korea, during red tides dominated by the dinoflagellate in July 2005. When prey concentrations were 1.1 to 2.3 x 10(6) cells ml(-1), the ingestion rates of these cultured red-tide dinoflagellates on Synechococcus sp. (1.0 to 64.2 cells dinoflagellate(-1) h(-1)) generally increased with increasing size of the dinoflagellate predators (equivalent spherical diameters = 5.2 to 38.2 mu m). The ingestion rates of P. donghaiense and P. micans on Synechococcus sp. increased with increasing mean prey concentration, with saturation occurring at a mean prey concentration of approximately 1.1 to 1.4 x 10(6) cells ml(-1). The maximum ingestion and clearance rates of P. micans on Synechococcus sp. (38.2 cells dinoflagellate(-1) h(-1) and 4.3 mu l dinoflagellate(-1) h(-1)) were much higher than those of P. donghaiense on the same prey species (7.7 cells dinoflagellate(-1) h(-1) and 2.6 mu l dinoflagellate(-1) h(-1)). The ingestion rates of red-tide dinoflagellates on Synechococcus sp. were comparable to those of the heterotrophic nanoflagellates and ciliates on Synechococcus spp., so far reported in the literature. The calculated grazing coefficients attributable to small Prorocentrum spp. (R donghaiense + P. minimum) and P. micans on co-occurring Synechococcus spp. were up to 3.6 and 0.15 h(-1), respectively. The results of the present study suggest that red-tide dinoflagellates potentially have a considerable grazing impact on populations of Synechococcus.

Food labels provide measurable benefits by improving diet quality of Americans by as much as four to six points on a 100‐point Healthy Eating Index scale. Among nutritional panels, serving sizes, nutrient content claims, list of ingredients, and health claims, the use of health claims on food labels provides the highest level of improvement in diet quality. The data source for this analysis is the 1994 to 1996 Continuing Survey of Food Intakes for Individuals (CSFII) and the accompanying Diet and Health Knowledge Survey (DHKS).

Two standard test problems that are nonconvex with multiple local minima are considered. An outer flow search–inner optimization procedure is proposed for choosing better local minima. Each pipe network is judiciously subjected to the outer-search scheme that chooses alternative flow configurations to find an optimal flow division among pipes. An inner linear program is used for the design of least-cost diameters. The algorithm can also be used for the optimal design of parallel expansion of existing networks. Because the problem is nonconvex, two global-search schemes, MULTISTART and ANNEALING, are used to permit a local-optimum-seeking method to migrate among various local minima. MULTISTART selectively saturates portions of the feasible region to identify the local minima. ANNEALING iteratively improves the objective function by finding successive better points, and, to escape out of a local minimum, it exercises the metropolis step, which requires an occasional acceptance of a worse point. The optimal solutions thus found have significantly smaller costs than the ones reported previously by other researchers.

Here, a hierarchical nanostructure composed of Ni-doped α-FeOOH (Ni:FeOOH) nanosheets coupled with N-doped graphite foam (NGF) is demonstrated as a three-dimensional (3D) self-supported electrocatalyst for highly efficient and durable water oxidation. A facile, one-step directional growth of catalytically active Ni:FeOOH nanosheets on highly conducting 3D NGF results in a fully integrated, hierarchical, nanostructured electrocatalyst with (i) the high intrinsic activity of Ni:FeOOH, (ii) the outstanding electrical conductivity of NGF, and (iii) a well-defined porous structure with an enhanced active surface area. As a result, the self-supported 3D Ni:FeOOH/NGF electrocatalyst exhibits remarkable electrocatalytic activity for the oxygen evolution reaction (OER) in an alkaline solution with an overpotential of 214 mV at 10 mA/cm2, a high stability for over 60 h, a low Tafel slope of 36.2 mV dec–1, and a capability of delivering a high current density of 300 mA/cm2 at an overpotential of 368 mV. In contrast to photodeposition, electrodeposition, and hydrothermal methods for the formation/integration of (oxy)hydroxides, this facile solution strategy for designing an attractive and efficient structure with a highly active metal (oxy)hydroxide and highly conducting NGF provides a pathway to develop other earth-abundant electrocatalysts for a multitude of energy-conversion-device applications.

is efficient and economical biostimulant in improving plant growth and quality of Chinese chives and spinach in organic farm.

Transition-metal phosphide (TMP) nanostructures have been extensively studied for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). However, phase-controlled synthesis of colloidal Ni2P nanocrystals (NCs) or related heterostructures remains challenging and their use as bifunctional electrocatalysts in overall water splitting (OWS) is not systematically studied. Herein, zero-dimensional (0D) colloidal Ni2P NCs are synthesized using a robust solution-phase method and encapsulated in two-dimensional (2D) N- and S-doped graphene (NSG) nanosheets via facile ex situ sonication to form a 0D@2D Ni2P@NSG heterostructure. The interaction between surface functionalities of Ni2P NCs and defective NSG via strong van der Waals force provides a robust sheath to Ni2P NCs when encapsulated in NSG nanosheets, further enhancing the specific surface area and active site exposure. Density functional theory calculations indicate that the dual interaction of N and S dopants with Ni2P benefits the synergistic effect of optimized water and hydrogen free energy adsorption. As a result, Ni2P@NSG electrocatalysts manifest high catalytic activity toward HER and OER, and a two-electrode alkaline electrolyzer assembled by Ni2P@NSG as both an anode and a cathode requires only 1.572 V to reach a current density of 10 mA/cm2.

We examine the impact of current and future climate on crop mixes over space in the US. We find using historical data that temperature and precipitation are among the causal factors for shits in crop production location and mixes, with some crops being more sensitive than others. In particular, we find that when temperature rises, cotton, rice, sorghum and winter wheat are more likely to be chosen. We also find that barley, sorghum, winter wheat, spring wheat and hay are more likely to be chosen as regions become drier, and corn, cotton, rice and soybeans are more likely to be selected in wetter regions. Additionally, we assess how much of the observed crop mix shifts between 1970 and 2010 were contributed to by climate change. There we find climate explains about 7-50% of the shift in latitude, 20-36% in longitude and 4-28% of that in elevation. Finally, we estimate climate change impacts on future crop mix under CMIP5 scenarios. There we find shifts in US production regions for almost all major crops with the movement north and east. The estimates describe how the farmers respond to altering climate and can be used for planning future crop allocations.

Abstract Electrochemical water splitting plays a vital role in facilitating the transition towards a sustainable energy future by enabling renewable hydrogen (H 2 ) production, energy storage, and emission‐free transportation. Developing earth‐abundant electrocatalysts with outstanding overall water‐splitting performance, excellent catalytic activity, and robust long‐term stability is highly important in the practical application of water electrolysis. Self‐supported electrocatalysts have emerged as the most appealing candidate for practical H 2 production due to their increased active site loading, rapid mass and charge transfer, and strong interaction with the underneath conducting support. Additionally, these electrocatalysts also provide enhanced reaction kinetics and stability. Here, a comprehensive review of recent progress in developing self‐supported Fe‐based electrocatalysts for water splitting and selective oxidation reactions is presented with examples of oxyhydroxides, layered double hydroxides, oxides, chalcogenides, phosphides, nitrides, and other Fe‐containing electrocatalysts. A comprehensive historical development in the synthesis of self‐supported Fe‐based electrocatalysts is provided, with an emphasis on the various deposition methods and the choice of self‐supported conducting substrates considering large‐scale commercial applications. An overview of mechanistic understanding and approaches for enhanced H 2 production are also presented. Finally, the challenges and opportunities associated with developing Fe‐based electrocatalysts for practical applications in water splitting and alternative oxidation reactions are discussed.

A cation substitution in Cu2ZnSn(S,Se)4 (CZTSSe) offers a viable strategy to reduce the open-circuit voltage (Voc)-deficit by altering the characteristics of band-tail states, antisite defects, and related defect clusters. Herein, we report a facile single process, i.e., simply introducing a thin Ag layer on a metallic precursor, to effectively improve the device characteristics and performances in kesterite (Agx,Cu1–x)2ZnSn(Sy,Se1–y)4 (ACZTSSe) solar cells. Probing into the relationship between the external quantum efficiency derivative (dEQE/dλ) and device performances revealed the Voc-deficit characteristics in the ACZTSSe solar cells as a function of Cu and Ag contents. The fabricated champion ACZTSSe solar cell device showed an efficiency of 12.07% and a record low Voc-deficit of 561 mV. Thorough investigations into the mechanism underpinning the improved performance in the ACZTSSe device further revealed the improved band-tailing characteristic, effective minority carrier lifetime, and diode factors as well as reduced antisite defects and related defect clusters as compared to the CZTSSe device. This study demonstrates the feasibility of effectively suppressing antisite defects, related defect clusters, and band-tailing characteristics by simply introducing a thin Ag layer on a metallic precursor in the kesterite solar cells, which in turn effectively reduces the Voc-deficit.

The major objective of this study is to estimate Korean food shoppers’ willingness to pay (WTP) for imported beef with traceability. We use an experimental elicitation method, the random nth price auction, to identify consumers’ valuation for traceable imported beef. We also analyse the effect of different types of information on these valuations. Results indicate that consumers are generally willing to pay a 39 per cent premium for the traceable imported beef over similar beef without traceability. Results also suggest that in contrast to the insignificant effect of positive information, negative and two-sided information about traceability significantly reduces WTP.

Natural windbreaks such as trees are very efficient barriers to high velocity winds. The windbreaks exert drag force causing a net loss of momentum and thus disturb the characteristics of flow. The main factors which can affect the efficiency of the windbreaks are tree height, width, tree arrangement, porosity, etc. However, tree porosity which is strongly related to the windbreak drag is very difficult to establish. In this study, the results of a wind tunnel test were introduced to find the aerodynamic porosity and resistance factor of a tree windbreak. Black pine tree (Pinus thunbergii), a typical tree windbreak in Korea was chosen as the experimental tree. With the main factors of wind velocity, static pressure and density of the tree, the aerodynamic porosity as well as the resistance factor of the tree was found. The average porosity at varied tree density were found to be 0.91, 0.69 and 0.42 for one, two and three trees, respectively. The resistance factors which can be equaled to the drag coefficient were 0.55, 0.82 and 1.08 for one, two and three trees, respectively. The determined aerodynamic porosity and windbreak drag will be used later as input data in computer simulation studies such as computational fluid dynamics (CFD). Moreover, the experimental procedure as well as the use of real trees in the wind tunnel experiment of finding the aerodynamic porosity and windbreak drag of various tree windbreaks was established through this study.

A bloom-forming dinoflagellate was isolated from coastal waters in western Korea during a red tide event in March 2008 and clonal cultures were established. The dinoflagellate was identified as Gymnodinium aureolum based on morphological and genetic analyses (GenBank accession no. FN392226). We report here for the first time that the red-tide dinoflagellate G. aureolum, which has previously been thought to be exclusively autotrophic, is a mixotrophic species. G. aureolum fed on algal prey using a peduncle. Among the algal prey provided, G. aureolum ingested heterotrophic bacteria, the cyanobacterium Synechococcus sp., and small algal species that had equivalent spherical diameters (ESDs) of 11.5 m. However, it did not feed on larger algal species (ESD 12 m) or the small diatom Skeletonema costatum. The specific growth rates for G. aureolum on the cryptophyte Teleaulax sp. increased continuously with increasing mean prey concentration before saturating at prey concentrations of ca. 190 ng C ml -1 (11 050 cells ml -1 ). The maximum specific growth rate (mixotrophic growth) of G. aureolum on Teleaulax sp. was 0.169 d -1 , at 20C under a 14:10 h light:dark cycle of 20 E m -2 s -1 , while its growth rate (phototrophic growth) under the same light conditions without added prey was 0.120 d -1 . The maximum ingestion and clearance rates of G. aureolum on Teleaulax sp. were 0.058 ng C grazer -1 d -1 (3.4 cells grazer -1 d -1 ) and 0.003 l grazer -1 h -1 , respectively. The calculated in situ grazing coefficient for G. aureolum on co-occurring cryptophytes ranged up to 0.498 d -1

Despite the implementation of intensive phosphorus reduction measures, periodic outbreaks of cyanobacterial blooms in large rivers remain a problem in Korea, raising the need for more effective solutions to reduce their occurrence. This study sought to evaluate whether phosphorus or nitrogen limitation is an effective approach to control cyanobacterial (Microcystis) blooms in river conditions that favor this non-nitrogen-fixing genus. These conditions include nutrient enrichment, high water temperature, and thermal stratification during summer. Mesocosm bioassays were conducted to investigate the limiting factors for cyanobacterial blooms in a river reach where severe Microcystis blooms occur annually. We evaluated the effect of five different nitrogen (3, 6, 9, 12, and 15 mg/L) and phosphorus (0.01, 0.02, 0.05, 0.1, and 0.2 mg/L) concentrations on algae growth. The results indicate that nitrogen treatments stimulated cyanobacteria (mostly Microcystis aeruginosa) more than phosphorus. Interestingly, phosphorus additions did not stimulate cyanobacteria, although it did stimulate Chlorophyceae and Bacillariophyceae. We conclude that phosphorus reduction might have suppressed the growth of Chlorophyceae and Bacillariophyceae more than that of cyanobacteria; therefore, nitrogen or at least both nitrogen and phosphorus control appears more effective than phosphorus reductions alone for reducing cyanobacteria in river conditions that are favorable for non-nitrogen-fixing genera.

Abstract A two-stage approach is used to estimate sensitivity of corn, wheat, and soybean yields to changes in prices and land idled. Estimated elasticity of demand for fertilizer per acre with respect to expected output price equals 0.47, 0.10, and 0.82 for corn, wheat, and soybeans. Upper estimates of the elasticity of yield with respect to fertilizer equals +0.58, +0.29, and +0.16 for corn, wheat, and soybeans. Yields are found to be quite insensitive to price changes. Fertilizer demands and yields are insensitive to land idled under farm programs.

Rotifer community is often used as a taxon-based bioindicator for water quality. However, studies of the planktonic community from the viewpoint of functional groups in freshwater ecosystems have been limited, particularly for rotifers. Because rotifers have various trophi types determining their feeding strategies, thereby representing an ecological niche, their functional feeding groups can act as biological and ecological indicators in lakes and reservoirs where planktonic communities are dominant. We analyzed the patterns of spatial distribution of the rotifer community in various reservoirs and then its relationship with water quality through redundancy and regression analyses. Compared with taxon-based composition, the response of trophi-based composition appears simplistic and showed clearer tendency in relation with water-quality variables. Each trophi responded differently by the degree of eutrophication indicating that each trophi group is possibly affected by environments such as the combinations of water-quality variables in different ways.

This paper examines the effects of aging and income subsidies on farm efficiency in Korea by utilizing the Korean Farm Household Economic Survey from 2008 to 2015. A stochastic frontier model with a non-monotonic assumption on the effect of efficiency factors is implemented to reflect a super aging and less developed production structure in Korean agriculture. This study finds continuously decreasing farm efficiency with age, which contradicts the commonly assumed inverted-U relationship between age and productivity. Especially, we find that labor is the most important factor to explain recent farm efficiency losses in Korea. Furthermore, this paper finds that the Korean income subsidy has a negative effect on farm efficiency. Our results provide two policy implications for the government of Korea. First, even though the “Returns to the Farm and Rural program” is appropriate, Korea should modify the program to encourage more young people to participate this program rather than old people, in order to attain the sustainable development of the agricultural sector. Second, a policy maker in Korea should consider a coupled subsidy that is directly related to farm production rather than a decoupled subsidy, regardless of the lower efficiency of the coupled subsidy in achieving agricultural development.

Comprehensive field surveys, including various hydrogeological and geophysical methods, were carried out to appraise the applicability of those methods to a leakage problem at the Sandong earth fill dam in southwestern Korea. The methods applied in the field site were tracer tests, monitoring of drawdown and leakage with discharge of reservoir water, electrical resistivity surveys using the dipole-dipole array, self-potential (SP), and temperature logging methods. The leakage pattern in the reservoir wall was demonstrated by hydrogeological methods and was further clarified by the geophysical surveys. Leakage turned out to be through the right abutment of the reservoir wall. In this study, we confirmed that the electrical resistivity method is effective in detecting the zones favorable to leakage, and SP methods are useful for delineating the leakage pathways themselves, because leaks generate strong streaming-potential anomalies.

Drought is the meteorological phenomenon with the greatest impact on agriculture. Accordingly, drought forecasting is vital in lessening its associated negative impacts. Utilizing remote exploration in the agricultural sector allows for the collection of large amounts of quantitative data across a wide range of areas. In this study, we confirmed the applicability of drought assessment using the evaporative stress index (ESI) in major East Asian countries. The ESI is an indicator of agricultural drought that describes anomalies in actual/reference evapotranspiration (ET) ratios that are retrieved using remotely sensed inputs of land surface temperature (LST) and leaf area index (LAI). The ESI is available through SERVIR Global, a joint venture between the National Aeronautics and Space Administration (NASA) and the United States Agency for International Development (USAID). This study evaluated the performance of ESI in assessing drought events in South Korea. The evaluation of ESI is possible because of the availability of good statistical data. Comparing drought trends identified by ESI data from this study to actual drought conditions showed similar trends. Additionally, ESI reacted to the drought more quickly and with greater sensitivity than other drought indices. Our results confirmed that the ESI is advantageous for short and medium-term drought assessment compared to vegetation indices alone.

The Raman analysis of Cu 2 ZnSn(S,Se) 4 thin films revealed a change in the relative defect concentration and device performance with composition.