The Vietnamese government has been fostering an enabling environment for vertical integration within t he rice v alue c hain t hrough c ontract farming (CF) to enhance value chains, improve product quality, and increase farmers’ incomes. While previous studies have explored the impacts of CF participation versus non-participation, there is limited evidence on the differing effects of specific CF types. This study addresses self-selection bias using propensity score matching (PSM) to evaluate and compare the effects of two CF types―indirect contract farming (CF-I) and direct contract farming (CF-D)―on rice farmers’ income and yield in the Mekong Delta region of Vietnam. Data were collected from 437 rice farmers across three provinces: Can Tho, An Giang, and Hau Giang. The findings indicate that participation in contract farming is not scale-neutral; CF-D tends to benefit larger-scale farmers. Additionally, farmers involved in CF-I experienced higher yields and incomes compared to non-CF farmers, with yield increases ranging from 0.44 to 0.76 tons/ha and income increases from 7.48 to 8.99 million VND/ha. Farmers participating in CF-D saw income increases of 5.04 to 5.54 million VND/ha, but the change in yield was not statistically significant. Moreover, those involved in CF-I had both higher yields and incomes than those engaging in CF-D. This study provides comparative evidence on the effects of different CF types in the rice sector and suggests that scaling up CF, particularly CF-I, can effectively enhance farmers’ yields and incomes.

This study compares the microstructure and properties of pure Cu and Cu-5 wt.% Al2O3 composites fabricated by spark plasma sintering under strictly identical processing conditions at 800-1000°C. Pure Cu samples achieved near-full densification and exhibited a bimodal grain structure dominated by coarse grains with increasing sintering temperature. In contrast, the composite samples showed lower density and non-monotonic densification behavior, with a minimum relative density at 900°C and significantly refined equiaxed grains due to strong grain-boundary pinning by nano Al2O3 particles. The higher fractions of high-angle boundaries and pronounced orientation disruption were observed in the composite samples, while high-resolution analysis confirmed the presence of grain-boundary Al2O3-rich regions that restricted Cu grain coalescence and continuity of grain boundary migration. X-ray diffraction results confirmed the absence of reaction phases in both materials. Hardness peaked at 900°C for both samples, and the composite samples showed consistently lower hardness due to retained porosity. The apparent electrical conductivity of the composite displays a non-linear temperature dependence, reflecting the competing influences of densification, microstructural recovery, and the insulating nature of Al2O3.

In this study, a composite material based on agricultural waste coconut shells was successfully developed as an efficient, lightweight, and sustainable electromagnetic wave (EMW) absorber. Specifically, coconut shells were used as the raw material, and a simple one-step activation charring process was employed to obtain coconut shell porous carbon (CSPC). ZnFe2O4 with a hollow spherical structure was then in situ grown on the surface of CSPC, resulting in a special ZnFe2O4/ CSPC composite material. Due to its unique hollow structure, porous characteristics, and heterogeneous interfaces, the composite material achieved optimized impedance matching, leading to excellent EMW absorption performance. The fabricated ZnFe2O4/ CSPC composite demonstrated a minimum reflection loss ( RLmin) of − 37.32 dB at 10.80 GHz and an effective absorption bandwidth of 2.40 GHz at a thickness of only 2.0 mm. SEM and TEM analyses confirmed that the composite possessed a hollow and porous structure, while the BET specific surface area was measured at 133.709 m2 g⁻1. Based on the synergistic effects of ZnFe2O4 and CSPC, dielectric losses, magnetic losses, and impedance matching, the potential EMW absorption mechanisms were proposed. The ZnFe2O4/ CSPC composite material prepared in this study was a novel, green, and sustainable EMW absorber.

This study compares the optical and radiative cooling performance of single-layer films embedded with TiO2 or Al2O3 nanoparticles dispersed in a polymer matrix and backed with an aluminum reflector. Optical constants of both materials were obtained from literature, and wavelength-dependent scattering efficiencies were calculated using Mie theory. A Monte Carlo ray-tracing simulation was performed to evaluate the spectral reflectance, absorptance, and emissivity of each film across the solar and thermal-infrared regions. The TiO2-based film exhibited strong visible-light scattering but suffered significant ultraviolet (UV) absorption, resulting in an average solar reflectance of ~0.90. In contrast, the Al2O3-based film showed negligible UV absorption and maintained high reflectance (> 0.95) throughout the 0.3-2.5 μm solar band, leading to a higher net cooling power of approximately 105 W/m² compared to 85 W/m² for TiO2. These results demonstrate that UV reflectance is a key determinant of effective radiative cooling and indicate that Al2O3-based coatings offer strong potential for passive cooling applications in buildings and agricultural environments.

This study proposes a Dispersion-Induced Decarburization (DID) process using polar solvents to address the degradation of luminescence efficiency in SrAl2O4:Eu phosphors caused by carbon contamination from carbon crucibles during high-temperature synthesis. Conventional high-temperature oxidation treatments are effective for carbon removal but induce the oxidation of Eu2+ ions and structural collapse of the SrAl2O4 host, resulting in severe degradation of luminescence properties. The proposed DID process physically removes carbon impurities by dispersing SrAl2O4:Eu powders in highly polar solvents such as distilled water (DI), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), and N,N-dimethylformamide (DMF). Among them, DI exhibited the highest purification efficiency, completely eliminating carbon-related diffraction peaks. As a result, the photoluminescence quantum yield (PLQY) of SrAl2O4:Eu improved from 32 % to 50 %, and a maximum PLQY of 55.2 % with a luminance of 6,000 cd･m-2 was achieved for the 20 mol% Eu-doped powder. This work presents a novel and effective purification strategy that overcomes carbon contamination in SrAl2O4:Eu phosphors, significantly enhancing their luminescence efficiency without structural damage.

Silicon based anode materials offer high theoretical capacity but suffer from severe volume expansion and unstable interfacial properties during repeated lithiation and delithiation, resulting in rapid performance degradation. In this study, a thin aluminum oxide coating layer was deposited on Si/SiOx Carbon anode materials using a powder atomic layer deposition (PALD) process to address these limitations. EDS mapping and XRD analyses confirmed the uniform formation of an amorphous aluminum oxide coating with increasing thickness as the deposition cycles increased. Electrochemical evaluation showed that the electrode coated with 5 PALD cycles exhibited approximately 78% higher capacity retention after 100 cycles at 1 A g-1 and a higher initial Coulombic efficiency compared to the bare electrode. The coated electrode also delivered approximately 22% higher capacity at a high current density of 5 A g-1, indicating enhanced rate capability. Cyclic voltammetry analysis revealed increased surface controlled reaction contributions and improved reaction kinetics. These results demonstrate that PALD derived aluminum oxide coatings effectively stabilize the electrode electrolyte interface and enhance the electrochemical performance of silicon based anodes, highlighting their potential for next generation high capacity lithium ion batteries. generation high capacity lithium ion battery anode materials.

목적: 본 연구는 주의력결핍 과잉행동장애(Attention-Deficit/Hyperactivity Disorder; ADHD)를 가진 성인을 대상으로 실행기능(executive function) 중재를 시행한 무작위 대조군 연구를 체계적으로 고찰함으로 써, 중재법과 효과 및 평가도구를 분석하고 임상 적용 가능성에 대한 근거를 제시하고자 하였다. 연구방법: 2015년 1월부터 2024년 11월까지 10년간 국외 학술지에 게재된 무작위 대조군 연구를 PubMed, Web of Science, PsycINFO에서 검색하였다. 주요 검색어로는“attention deficit hyperactivity disorder”, “executive function”, “randomized controlled trial”, “intervention”, “program”, “training”과 “therapy”를 사용하였다. 선정 및 배제기준에 따라 최종적으로 13편을 선정하였다. 결과: 선정된 연구의 비뚤림 위험, 중재법 및 기간, 중재의 효과, 평가도구를 분석하였다. 비뚤림 위험 수준은 ‘낮음’ 1편, ‘일부 우려’ 6편, ‘높음’ 6편으로 나타났다. 중재법은 크게 세 가지 접근법으로 구분되었고, 인지적 접근이 가장 많이 활용되었으며 활동 기반 접근과 신체 기반 접근이 그 뒤를 이었다. 모든 중재는 실행기능을 향상시키는 효과를 보였고, 특히 전반적인 실행기능, 억제, 작업기억의 개선이 두드러졌다. 실행기능 외의 효과로 ADHD 및 심리사회적 증상 감소, 삶의 질 및 작업수행능력 향상이 함께 관찰되었다. 총 12가지의 평가도구가 사용되었으며, BRIEF-A (Behavior Rating Inventory of Executive Function-Adult version) 가 가장 높은 빈도를 보였다. 결론: 본 연구는 성인 ADHD를 대상으로 한 실행기능 중재가 다양한 접근법을 통해 실행기능 및 관련 증상 개선에 효과가 있음을 확인하였으며, 실행기능 중재의 임상 적용 및 향후 연구 설계를 위한 기초 자료를 제공하였다는 점에서 의의가 있다.

본 연구는 S–O–R(Stimulus–Organism–Response) 모형을 토대로 라 이브 공연 관객의 체험이 어떠한 과정을 거쳐 행동의도로 이어지는지를 탐색하였다. 이를 위해 최근 1년 이내 뮤지컬, 연극, 오페라, 콘서트 등 라이브 공연을 관람한 성인 관객을 대상으로 편의표집(convenience sampling) 방식의 온라인 설문조사를 실시하였으며, 최종적으로 387부 의 응답을 분석에 활용하였다. 분석 결과, 관객이 경험한 체험 수준이 높 을수록 재관람이나 추천과 같은 향후 행동의도가 강화되는 경향이 나타 났다. 이 과정에서 지각된 가치가 매개 역할을 했는데, 특히 사회적 가치 는 뚜렷한 영향력을 보인 반면, 정서적 가치는 통계적으로 의미 있는 결 과를 보이지 않았다. 다시 말해, 공연 관람을 통해 얻는 순간적 정서적 환기보다는 관객 간 교류와 공동체적 소속감이 행동으로 이어지는 보다 안정적인 경로로 작용한 것이다. 이러한 결과는 공연예술 맥락에서 S–O –R 모형의 Organism 단계를 확장할 수 있는 가능성을 보여주며, 동시 에 라이브 공연의 현장성과 사회적 특성이 관객 경험을 설명하는 본질적 인 토대가 될 수 있음을 의미한다.

Akaganeite (β-FeOOH) and hybrid active materials (akaganeite/maghemite (γ-Fe2O3)) containing carbon nanoparticles have been successfully developed through hydrothermal process using oxidation debris of graphene oxide and iron (II) chloride tetrahydrate. The obtained akaganeite sample and the hybrid material containing 29% akaganeite and 71% maghemite were confirmed using Mӧssbauer analysis. Two types of cathode made of akaganeite (β-FeOOH) and hybrid active materials supported on reduced graphene oxide (RGO) for RGO/AKA-100 and RGO/AKA-29 were taken as the main air electrode. The full-cell zinc–air battery prototypes (with 6 M KOH electrolyte) were tested for 500 cycles at room temperature. The result showed that the discharge capacity was achieved as high as 131.05 mAh/cm2 for RGO/AKA-100 and 137.26 mAh/ cm2 for RGO/AKA-29. These performances are better than that using zinc–air batteries with carbon black/MnO2 (CB/ MnO2) as air cathode, that give a discharge capacity of 115.7 mAh/cm2. The charge–discharge efficiency of RGO/AKA-100 and RGO/AKA-29 was examined in relation to their distinct catalytic activity for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) when incorporated into electrochemically rechargeable zinc–air batteries. In addition, the different morphology of zinc deposit and dendrite was characterized using SEM, TEM, and PXRD analysis. From this study, the high performance of active material was suggested to be due to the hybrid effect among akaganeite, maghemite, and reduced graphene oxide, which can produce a synergetic improvement.

본 논문은 고온 환경에 노출된 TRM 보강 RC 보의 잔존강도를 예측하기 위한 해석적 연구결과를 제시한다. 연구를 위해 상용 유한요소해석 프로그램인 ABAQUS가 사용되었으며, 콘크리트, 철근, CFRP grid, 모르타르에 대한 재료모델이 제안되었다. 본 연구에서 제안된 유한요소해석 모델의 검증을 위해 선행 연구결과에 대한 재현 해석이 수행되었다. 제안된 유한요소해석 모델의 예측 된 결과는 실험결과와 비교하여 잔존 극한하중과 극한하중 시점에서 각각 약 97.6%, 90.58%의 정확도를 보이는 것으로 나타났다. 또한, 유한요소해석을 통한 균열양상은 실험결과와 비교적 정확하게 예측되었다. 따라서 본 연구에서 제안된 해석모델은 고온 환경에 노출된 TRM 보강 RC 보의 잔존강도를 예측하기 위해 효과적으로 사용될 수 있을 것으로 판단된다.