Maintaining the postharvest freshness of Allium microdictyon Prokh, a highly perishable wild vegetable rich in bioactive compounds, remains a major challenge due to its susceptibility to ethylene-induced deterioration. This study aimed to develop an eco-friendly and efficient active packaging system using torrefied wood–based ethylene scavengers to extend the shelf life of A. microdictyon. Oak (Quercus variabilis) biomass was torrefied at 255 ℃ to produce porous, carbon-rich scavenger chips, which were integrated into polymer films composed of LDPE, HDPE, PP, and PVC. The ethylene absorption capacity and preservation performance of these composite packaging materials were evaluated over 30 days of storage at 27 ± 2 ℃ and 65 ± 5% relative humidity. The results demonstrated that torrefied wood effectively reduced internal ethylene concentration by over 70% in most polymer matrices, with HDPE + scavenger and LDPE + scavenger films showing the highest adsorption efficiencies. The treated samples exhibited significantly lower weight loss, higher moisture retention, and reduced chlorophyll degradation compared with the control (p < 0.05). Sensory and color analyses confirmed that ethylene scavenger–integrated packaging preserved the freshness and green coloration of A. microdictyon for up to 30 days, whereas control samples deteriorated rapidly. These findings highlight that torrefied wood is a safe and sustainable alternative to chemical absorbers, offering a promising bio-based solution for active packaging applications to enhance postharvest quality and reduce food waste in ethylene-sensitive crops.

This work introduces a high-performance absorber based on a lightweight composite material of corn straw biochar and magnetic cobalt nickel zinc ferrite. A composite absorber of corn straw biochar with hierarchical pore structure and magnetic zinc cobalt nickel ferrite particles (Ni–Co–Zn ferrite/C) was prepared by a simple two-step approach of carbonization followed by in-situ growth method. The morphology, structure, function, and absorbing properties of the prepared samples were characterized, and RCS simulation was performed. The results show that the optimal reflection loss value of Ni–Co–Zn ferrite/C-2 reaches −38.04 dB when the layer thickness is 3.5 mm, and the effective absorption bandwidth is 4.32 GHz. The potential of Ni–Co–Zn ferrite/C-2 composite material in stealth applications is verified. It is mainly attributed to the excellent impedance matching performance caused by the multi-level pore structure and the strong polarization loss caused by the rich heterogeneous interface and active sites, which plays a key role in the attenuation of electromagnetic waves. This study provides a useful reference for the design of magnetic ferrite particles/metal oxides/biomass-derived carbon microwave absorbing materials with hierarchical porous structure characteristics.

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.

Structural design and element doping are the research hotspots in the preparation of lightweight absorbers with high absorption performance and low filling rate. This study employs different temperature carbonization and etching techniques to prepare the structure of hollow nitrogen-doped carbon flowers (HNC) and evaluate their microwave absorption performance. At an ultra-low filler loading of 5 wt.%, the microwave absorption intensity of HNC-800 remains stable at -50 dB with a thickness of 3.2 mm. It is noteworthy that the HNC-800 achieved the broadest effective absorption frequency band at a matching thickness of 2 mm, with a bandwidth of 5.36 GHz (ranging from 12.4 to 17.76 GHz). Such remarkable broadband and reflection loss performance can be attributed to the synergistic effects of the hollow porous network structure, interface polarization, and dipole relaxation mechanisms. More significantly, the reduction of the radar cross-section (RCS) amounts to as much as 31.67 dB m2, and it has been attested to possess excellent adsorption efficacy in practical application scenarios. HNC-800, as an absorbing material, holds potential for broad application prospects.

본 연구는 광도와 습도 조건에 따라 다양한 이끼 종의 CO2 흡수 능력을 평가하여 실내 공기질 개선을 위한 적합 식생 자 원을 탐색하고자 수행되었다. 6종의 이끼를 밀폐형 아크릴 챔 버에서 재배하며 광도(50, 200μmol·m-2·s-1)와 상대습도(75, 85, 100%)에 따른 CO2 흡수량을 정량적으로 분석하였다. 그 결과, Hypnum plumaeforme와 Racomitrium yakushimense 는 두 광조건에서 가장 높은 CO2 흡수 능력을 나타냈으며, 고 광도에서 흡수량이 평균 2.6배 증가하였다. 또한 상대습도 100%에서 최대 CO2 흡수 능력이 확인되었고, 광합성 속도는 호흡 속도보다 약 2.9배 빠른 것으로 나타났다. 본 연구의 결과 는 이끼가 광·습도 조건에 따라 CO2 흡수량이 변화하는 것을 보여주며, 실내 공기질 개선, 탄소 저감형 도시 녹화, 밀폐 환 경 내 생태 기반 공기정화 기술 개발의 기초 자료로 활용될 수 있다.

본 연구는 국가산림조사 자료를 활용하여 주요 조림수종(잣나무, 일본잎갈나무, 상수리나무 및 굴참나무)의 지위지수를 우세목 수고 및 입지환경인 자로서 추정하고, 수종별 탄소저장량 및 흡수량을 산정하였다. 지위지수는 Schumacher 모델로 추정식을 도출하고, 지위지수분류곡선을 도식화하였 다. 여기에서 도출된 지위지수는 각 표본점에 연계시켜 입지환경인자와의 관계를 구명하였다. 입지환경인자는 해발고, 경사도, 지형, 사면방위 등 6개 인자를 활용하였으며, 관계분석은 수량화이론을 적용시켰다. 수량화분석 결과, 4개 수종 모두에 관계하는 인자는 해발고, 경사도, 사면방위 였으며, 그외 지형, 암석노출도, 토양침식 등은 일부 수종에서 지위에 영향을 미치는 것으로 나타났다. 적용시킨 수량화 모델은 수종에 따라 17~49% 의 설명력을 가졌으며, 모델은 유의수준 1%에서 유의성이 인정되었다. 그리고 4개 수종별 연평균재적생장량(MAI)을 도출하고, 여기에 각 수종별 탄소배출계수를 적용시켜 탄소량을 산정하였다. 4개 수종별로 60년에 이를 때 산림 내 누적 탄소저장량은 잣나무, 일본잎갈나무 임분은 448~468 CO2 ton/ha, 상수리나무와 굴참나무 임분은 545~574 CO2 ton/ha으로 산출되었다. 연간탄소흡수량은 잣나무와 일본잎갈나무임분은 20년생일 때 각각 연간 최고인 10.94 CO2 ton/ha/yr와 10.15 CO2 ton/ha/yr을 흡수할 것으로 예측되며, 활엽수인 상수리나무와 굴참나무 임분은 침엽수와는 다르게 30년생일 때 각각 11.84 CO2 ton/ha/yr와 12.49 CO2 ton/ha/yr로 최고 탄소흡수량을 나타내었다.

This study examined the simultaneous application of absorption and adsorption by adding granular activated carbon to tap water (Absorbent-A) and sodium hypochlorite (Absorbent-B), with the aim of improving the removal performance of gaseous acetaldehyde applying hybrid process. Prior to the main experiment, preliminary tests were conducted to assess the effects of HOCl concentration (50~150 ppm) and reactor temperature (25~35oC). In the main experiment, the removal performance under activated carbon-added conditions was compared using the concentration ratio (Co/ Ci) and its rate of change over time. As a result, the addition of activated carbon led to a more gradual saturation and concentration change compared to the non-addition condition, with the addition showing the most stable trend. This study suggests a basic reference for improving the performance of conventional absorbents enhancing the durability and efficiency with the activated carbon as an auxiliary material for future field applications.

Porous carbon has been intensively used for microwave absorption in merits of its outstanding specific surface area and dielectric properties. This study investigates the microwave absorption capacity of saturated wood-based activated carbon (SWAC) which was used for methylene blue treatment. The results demonstrate that SWAC, subjected to high temperature calcination, exhibits excellent microwave absorption properties. The structure, composition, micro-morphology, and electromagnetic parameters of SWAC were comprehensively analyzed using various techniques. The findings reveal that after calcination, SWAC possesses a rich pore structure, optimized material impedance matching, and the introduction of N atoms from the organic substance methylene blue into the carbon lattice of SWAC, thereby providing dipole polarization loss. These properties significantly contribute to its microwave absorption performance. The optimal reflection loss of SWAC at 6 GHz reaches −50.29 dB with an effective absorption bandwidth of 2.01 GHz, achieved at a calcination temperature of 700 °C and a paraffin matrix additive amount of 25%. The one-step treatment of SWAC proves to be a competitive and cost-effective method for producing microwave absorbers, which holds significant importance for the recovery of SWAC.

Biomass-derived carbon materials have attracted considerable attention in electromagnetic wave (EMW) absorption applications due to their advantages of low cost, light weight, and sustainability. Herein, bagasse-based porous carbon (BPC) was prepared by canonization and activation process from natural waste bagasse. The porous flower-like MoS2/ BPC composites were successfully prepared for efficient microwave absorption via hydrothermal process by in-situ formation of flower-like MoS2 into the porous structure of BPC. The effect of hydrothermal time and hydrothermal temperature on surface morphology, degree of graphitization, surface chemical composition and impedance matching of the prepared samples was investigated. Results demonstrated that when the hydrothermal temperature was 220 °C, and the hydrothermal time was 24 h, the obtained MoS2/ BPC sample (named as MoS2/ BPC-220 ℃) showed the minimum reflection loss value (RL) of − 41.6 dB at 8.96 GHz and exhibited effective microwave absorption bandwidth (EAB) of 4.32 GHz at a relatively thin thickness of 1.5 mm. This work provides a promising way to prepare novel biomass-derived porous carbon for strong broadband electromagnetic absorption.

본 연구에서는 전하 이동 특성을 가지는 분자[쿠마린(C)-DNP]의 흡수 스펙트럼을 정확하게 예측하기 위해 장거 리 보정 밀도 범함수 이론 (long-range corrected density functional theory, LC-DFT)인 LC-BLYP의 범위 분리 매개변수 (μ)를 여러 가지 피팅 방법을 이용하여 최적화하였다. 기체 상태의 Koopmans 이론을 기반으로 최적화된 μ값은 실험적 흡수 피크에 비해 청색 이동(blue-shift)되는 경향성을, 반대로 용매 환경에서 최적화된 μ값은 과도하게 적색 이동 (red-shift)이 되는 경향성을 보였다. 반면, 실험적 데이터에 맞춰 조정된 μ값은 흡수 스펙트럼의 피크 위치와 세기를 가 장 고정확도로 재현하였으며, 특히 C-DNP와 C-OH 분자에서 나타나는 최대 흡수 피크 에너지의 차이를 잘 예측하였 다. C-DNP의 HOMO와 LUMO 전자 분포는 모든 μ값에서 일정한 모양(shape)을 가지고 있었으며, HOMO에서 LUMO 의 전이는 C에서 DNP로의 분자 내 전하 이동(Intramolecular Charge Transfer, ICT)임을 보였다.

기후변화로 인해 대기 중 온실가스가 빠르게 증가하면서 전 세계적으로 극한 기상 현상이 급증하고 있다. 해양 기후기술은 기 후변화 관찰, 온실가스 감축, 흡수 및 저장, 해양 분야에서의 기후 관련 피해 방지를 목표로 함으로써 환경 문제를 극복하고 기후변화를 해결하는 유망한 대안으로 여겨진다. 본 연구는 해양 기후기술에 대한 분류체계를 수립하고 연구 동향을 파악하며, 한국, 미국, 중국, 일 본, 유럽연합(EU) 등 주요국의 기술 수준을 분석하여 기술 개발 전략을 위한 정보를 제공하는 것을 목표로 하였다. 본 연구에서는 해양 기후기술의 온실가스 감축 및 흡수 분야를 중심으로 주요국의 관련 연구 논문 데이터를 수집하여 2013~2022년의 연구 활동과 영향력을 분석 및 비교하였다. 또한, 본 연구는 델파이 기법을 활용하여 주요국의 현재 기술 현황에 대한 정량적 및 정성적 분석 결과를 제시하였 다. 2단계에 걸쳐 수행된 설문 결과는 기술 수준, 기술격차, 기술 발전단계 등의 중요한 측면을 포함하였다. 결과에 따른 우리나라의 기술 격차 주요 요인은 기초 연구 지원 및 연구 개발 자금 부족, 정부 정책 미비 등인 것으로 조사되었다. 우리나라의 해양 기후기술 발전을 위해서는 기초 연구 지원 확대, 연구개발 자금 증대, 그리고 체계적인 정부 정책 마련이 필요할 것으로 시사된다.

최근 국내외 화장품과 식품산업에서 다양하게 사용되어 지고 있는 콜라겐 단백질 제품은 점차 그 용도와 특성에 따라 보다 고도화, 기능화 되어 가고 있다. 피부 건강의 지표인 콜라겐은 다양한 용도로 개발되어 사용되고 있으 며, 콜라겐의 소비가 증가함에 따라 용도에 적합한 최적 화된 콜라겐 제품의 개발이 중요한 연구 분야이다. 특히 여러 기업과 연구기관들에 의해서 콜라겐의 흡수율을 높 이기 위한 다양한 노력이 이루어지고 있다. 따라서 본 연 구에서는 프란즈(Franz) 세포 시스템을 이용하여 국내에서 판매되는 다양한 분자량별 콜라겐 제품의 경피 및 구강 상피세포 투과성을 비교하였다. 그 결과, 피부 표피/진피 조직과 비교하여 구강점막 조직의 콜라겐 흡수율이 분자 량 500달톤과 1,000달톤의 경우 모두 통계적으로 유의하 게(각각 약 10배, 2배) 높은 것으로 확인되었다. 또한, 분 자량별 구강점막 조직 흡수율을 비교한 결과, 분자량 500 달톤의 콜라겐이 분자량 1,000달톤 제품에 비해 흡수율이 2-3배 증가함을 확인하였다. 분자량 500달톤의 경우 Cmax 와 AUCt 값이 가장 높게 나타났으며, 피부 표피/진피 세 포에 비해 구강점막세포 시험군의 모든 지표가 높은 것으 로 나타났다. 본 연구 결과는 피부 흡수보다는 구강 점막 세포를 통한 콜라겐의 흡수방법이 콜라겐 체내 흡수증가 에 유효한 수단임을 시사하며, 분자량 1,000달톤 이하에서 도 보다 더 작은 500달톤의 저분자 콜라겐의 흡수율이 증 가되는 것으로 보아 콜라겐의 분자량이 흡수율 증가의 주 요한 요소임을 확인할 수 있었다.

In the development of eco-friendly vehicles such as electric vehicles, weight reduction has become a very important design target. Seat weight reduction is very important in vehicle weight reduction. In this study, the energy absorption characteristics of Almag material, an alloy of aluminum and magnesium, and mild steel SAFH440, SAFH590, SAFC780, and SAFH980 were analyzed to obtain a true stress versus true strain curve that was correlated with the test. By performing the seat frame structure analysis using the obtained analysis material property, it was possible to compare the deformation between lightweight material, Almag and mild steel materials. In addition, it was confirmed that the weight reduction effect was 25.8% when applying Almag, an equivalent lightweight material that gives the same maximum deformation as SAFH980, a high-strength mild steel.

This study investigated the noise reduction effect according to the structure of the sound-absorption and insulating materials in order to maximize the noise reduction effect in various noise environments. For this purpose, the transmission loss according to the change in hole size of the performated plate in sound-absorption and insulating board was predicted using an CAE model. The sound-absorption and insulating board was modeled and the computation of the transmission loss was performed after applying the physical properties and boundary conditions. The pure sounds of 32Hz to 4,000Hz were generated, and the analysis was performed by changing the diameter and pitch of the perforated plate. It was confirmed that the influence of the diameter and pitch of the perforated plate is closely related to the structure that make up the sound-absorption and insulating material. In order to effectively reduce the variously changing noises, it is believed that a method of improving transmission loss for each frequency band of interest is needed by changing the structure of the sound-absorption and insulating material so that the diameter and pitch of the perforated plate can be changed.