The Indian Ocean is the second-largest tuna fishing ground in the world, accounting for approximately 1.2 million tonnes (23%) of the estimated 5.2 million tonnes of global commercial tuna catch in 2023. This study examined the relationship between tuna catches, specifically skipjack, bigeye, and yellowfin tunas, and prey biomass (Nautical Area Scattering Coefficient, NASC) estimated from acoustic surveys conducted in the southwestern Indian Ocean from 20 April to 15 May 2019. Environmental variables were derived from the Copernicus Ocean Model, and tuna length data from the IOTC. The estimated total tuna catch in the study area was approximately 166,400 tonnes, with the northwestern region showing the highest catches and NASC values. Tuna catches increased with NASC; however, the relationship was non-linear. While skipjack showed no significant correlation with NASC, bigeye and yellowfin tunas exhibited weak but significant positive correlations. Environmental analysis revealed that the northern waters had high surface temperatures, low salinity, and low oxygen levels, with mid and deep layers characterized by low temperature, salinity, oxygen, and chlorophyll. These findings offer a foundation for understanding tuna distribution in relation to prey and environmental conditions, highlighting the need for future species- and fishery-specific studies to support sustainable tuna resource management.
Maize (Zea mays. L) is one of the major sources of green fodder for livestock in Pakistan. Crop management plays a key role in obtaining high yields for green fodder. Fertilizer application, seed rate, and row spacing are critical components of crop management, which can significantly affect crop biomass. To determine the best production technology, a two-year (2021-2023) study was conducted at the research area of National Agricultural Research Center, Islamabad. Plant height, number of leaves, leaf area, green fodder yield per acre, and green fodder yield per hectare were recorded. Various row spacing (15 cm, 30 cm, 45 cm, and 60 cm), fertilizer ratio (N: P = 55:30, 65:40, 75:50, and 85:60), and seed rates (30 kg/ac, 35 kg/ac, 40 kg/ac, and 45 kg/ac) were applied. Results obtained experiments revealed that in both growing seasons, the maximum green fodder yield was obtained when fertilizer N: P ratio was 75:50 (green fodder biomass: 74.61 t/ha and 72.56 t/ha). Similarly, the optimal seed rate was found to be 40 kg/ac, which resulted in the highest green fodder yield (73.41 t/ha and 72.88 t/ha in two seasons). Furthermore, the plant of maize at row spacing of 30 cm was found to generate the maximum green fodder yield (72.39 t/ha and 72.40 t/ha, respectively). Green fodder yield per hectare was found to be positively correlated with plant height, number of leaves, and leaf area. These findings underscore the significance of applying a fertilizer ratio of N: P = 75:50, a seed rate 40 kg/ac, and a row spacing of 45 cm for higher yields of green fodder in maize crop.
Production technology trials for PARC’s new fodder oat cultivar (PARC-Oat) were conducted at the National Agricultural Research Center (NARC) under rain-fed conditions in Islamabad from 2021 to 2023. The effects of different fertilizer doses, planting densities (seed rates), and inter-row spacing on green fodder yield were studied. The experiment comprised four fertilizer doses of nitrogen and phosphorus (N:P) (55:30, 65:40, 75:50, and 85:60 kg/ha), four seed rate densities (30 kg/ac, 35 kg/ac, 40 kg/ac, and 45 kg/ac), and four inter-row spacings (15 cm, 30 cm, 45 cm, and 60 cm). Results based o n k ey p arameters a ffecting t he y ield of PARC-O at—namely plant height (cm), leaf area (cm²), leaves per tiller, number of tillers per plant, and green fodder yield (t/ha)—indicated that the maximum yield of 72.74 t/ha was observed with the fertilizer dose of 75:50 kg/ha (N:P). Similarly, a seed rate of 40 kg/ha produced optimal planting densities, resulting in the highest green fodder yield of 72.85 t/ha, while an inter-row spacing of 30 cm yielded the maximum green fodder yield of 74.30 t/ha. These results suggest that to achieve maximum green fodder biomass of oats, best management practices should include the application of a fertilizer dose of 75:50 (N:P), a seed rate of 40 kg/ha, and an inter-row spacing of 30 cm.
Microalgae are efficient fatty acid producers owing to their high photosynthetic activities. They can act as sources of biofuel, feed, and various bioactive compounds. This study aimed to determine optimal culture conditions, including culture medium, temperature, and light intensity, to enhance the biomass and fatty acid content of the indigenous freshwater microalga, Tetradesmus obliquus. Evaluation using a high-throughput photobioreactor revealed that the optimal culture temperature and light intensity were 25°C and 300 μmol m-2 s-1, respectively. Additionally, we optimized components (N, P, and Mg) of the BG-11 medium to enhance the microalgal biomass. Modified BG-11 medium increased the T. obliquus biomass by 37% compared to the standard BG-11 medium. Subsequently, the culture medium was replaced with N- and P-depleted media to determine the abiotic stress factor that could increase the cellular fatty acid content. Notably, fatty acid content was significantly increased from 8.5% up to 14.6% on day 7 of culture in N-deficient (N-P+ and N-P-) media. Sequential optimization effectively increased the biomass by 83% and fatty acid content by >76% in T. obliquus. Our optimization method can be used to enhance the biomass and fatty acid contents of various other microalgae.
Korea is a major chestnut producer, and about half of its production is discarded as chestnut shells. This study aimed to manufacture an environmentally friendly adsorbent using these wastes. For this purpose, the optimum carbonization temperature of chestnut shells was derived through thermogravimetric analysis, with structural change confirmed through SEM analysis. The results showed that the sample that carbonized at 350oC for 60 min after phosphorylation had both the highest initial acetaldehyde removal rate and the longest duration compared to other samples. As a result, an eco-friendly adsorbent for acetaldehyde was produced from chestnut shell biomass. Through this research, it was confirmed that the adsorbent can be effectively used for acetaldehyde control while addressing the issue of recycling chestnut shell wastes.
본 연구는 맹종죽(Phyllostachys edulis) 부산물의 고부가가치 활용을 위한 기초연구로, 맹종죽림 조사 및 소각처리를 통한 죽회 생산 기술을 개발하고자 하였다. 맹종죽림 현장에서의 죽간 벌채 후 남은 상층 부산물(잎, 잔가지, 끝대)과 수년간 방치된 하층 부산물의 바이오매스 총량을 파악한 결과, 입죽 상태의 맹종죽을 벌채할 경우, 활용될 죽간의 중량비는 56.6%, 죽림 내에 방치되는 상층 부산물의 중량비는 43.3%로 나타났다. 방치됐던 하층 부산물은 ha당 약 26톤이 잔존해 있었다. 한편, 부산물을 죽회로 활용하기 위해 소형 소각로 및 대형 무연소각로를 이용한 소각처리를 수행하였다. 현장에 설치된 소각로에서의 조사 결과, 소형소각로(화실, 57.2 ㎥)는 1시간에 10 kg, 1일 최대 80 kg을 소각하는 반면, 대형 무연소각로 (화실, 791.4 ㎥)는 1시간에 70 kg, 1일 최대 560 kg을 소각하여 약 7배의 효율을 보였다. 2차 회화 과정을 통해 얻은 순수 죽회의 수율은 약 84%였으며, 칼륨(80,000 ppm↑), 칼슘(50,000 ppm↑), 인(20,000 ppm↑), 마그네슘(20,000 ppm↑), 망간(10,000 ppm↑), 철(10,000 ppm↑) 등 다양한 무기원소가 함유되어 있었다. 본 연구는 대나무 벌채 현장에서 수행된 실험을 바탕으로, 맹종죽림의 지속 가능한 경영과 새로운 부산물 활용 방안에 대한 제시로 큰 의의가 있을 것으로 판단된다.
This study evaluated the applicability of existing overseas-developed allometric equations for estimating the biomass of domestic apple trees (Malus domestica) in South Korea. To assess their suitability, predicted biomass values derived from these equations were compared with actual measurements obtained through destructive sampling. The results indicate that some overseas equations showed no significant difference when applied to domestic apple trees, suggesting their potential applicability to local conditions. However, it was also noted that certain equations may not fully capture the unique characteristics of domestic apple trees, such as the slender spindle form associated with modern high-density planting practices. Given these findings, the study highlights the need to develop new allometric equations that are specifically optimized for the growth characteristics and cultivation environments of domestic apple orchards. Such equations would enable more accurate biomass estimation, support agricultural sustainability, and provide reliable data for the national greenhouse gas inventory. This research is expected to serve as a foundation for future Tier 2-level studies on biomass and carbon sequestration in apple orchards while also underscoring the importance of expanding research to include various fruit tree species to develop customized biomass estimation models for enhanced agricultural management and environmental conservation.
Super P (SP) is a conductive carbon black that significantly enhances the electrical conductivity of various types of electrodes, making it a widely preferred conductive agent in lithium-ion batteries. By contrast, activated carbon (AC), originally used in capacitors due to its porous structure, is expected to contribute to electrochemical performance through its enhanced interaction with lithium ions. First, the physical properties of both materials were analyzed through various characterization techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM) to confirm the increase in electrochemical properties through the combination of SP and AC. Furthermore, the microstructure and electrical properties of the LiFePO4 (LFP) electrode were analyzed, to determine the impact on battery performance. With a 1.15 M LiPF6 in an ethylene carbonate/diethyl carbonate (EC/DEC) electrolyte, the results indicated that SP-only electrodes exhibited the highest conductivity and lowest surface resistance, making them the most effective at maintaining stable electrochemical performance. In contrast, electrodes with only AC showed higher resistance, demonstrating that SP remains superior in improving LFP electrode conductivity, ultimately optimizing lithium-ion battery performance.
Volatile organic compounds (VOCs) are commonly produced in the combustion of fossil fuels and in chemical industries such as detergents and paints. VOCs in atmosphere cause different degrees of harm to human bodies and environments. Adsorption has become one of the most concerned methods to remove VOCs in atmosphere due to its high efficiency, simple operation and low energy consumption. Biomass-based porous carbon (BPC) has been considered as the most promising adsorption material because of the low cost and high absorption rate. In this paper, the key characteristic (e.g., specific surface area, pore structure, surface functional groups and basic composition) of BPC affecting the adsorption of VOCs in atmosphere were analyzed. The improvement of adsorption capacity of BPC by common modification methods, such as surface oxidation, surface reduction, surface loading and other modification methods, were discussed. Examples of BPC adsorption on different types of VOCs including aldehydes, ketones, aromatic VOCs, and halogenated hydrocarbons, were also reviewed. The specific adsorption mechanism was discussed. Finally, some unsolved problems and future research directions about BPC for adsorbing VOCs were propounded. This review can serve as a valuable reference for future developing effective biomass-based porous carbon VOCs adsorption technology.
The raw material selected for this research was Brazil chestnut shells (BCs), which were utilized to gain porous carbon as a positive electrode for lithium–sulfur batteries (LSBs). The effects of N/S co-doped on the electrochemical properties of porous carbon materials were studied using thiourea as nitrogen and sulfur sources. The experimental results indicate that the N/S co-doped carbon materials have a higher mesopore ratio than the undoped porous carbon materials. The porous carbon material NSPC-2 has a lotus-like structure with uniform pore distribution. The N and S doping contents are 2.5% and 5.4%. The prepared N/S co-doped porous carbon materials were combined with S, respectively, and three kinds of sulfur carbon composites were obtained. Among them, the composite NSPC-2/S can achieve the initial specific discharge capacity of 1018.6 mAh g− 1 at 0.2 C rate. At 1 C rate, the initial discharge capacity of the material is 730.6 mAh g− 1, and the coulomb efficiency is 98.6% and the capacity retention rate is 71.5% after 400 charge–discharge cycles.
Zooplankton biomass is essential for understanding the quantitative structure of lake food webs and for the functional assessment of biotic interactions. In this study, we aimed to propose a biomass (dry weight) estimation method using the body length of cyclopoid copepods. These copepods play an important role as omnivores in lake zooplankton communities and contribute significantly to biomass. We validated several previously proposed estimation equations against direct measurements and compared the suitability of prosomal length versus total length of copepods to suggest a more appropriate estimation equation. After comparing the regression analysis results of various candidate equations with the actual values measured on a microbalance-using the coefficient of variation, mean absolute error, and coefficient of determination-it was determined that the Total Length-DW exponential regression equation [W=0.7775×e2.0183L; W (μg), L (mm)] could be used to calculate biomass with higher accuracy. However, considering practical issues such as the morphological similarity between species and genera of copepods and the limitations of classifying copepodid stages, we derived a general regression equation for the pooled copepod community rather than a species-specific regression equation.
대표적인 초식곤충인 나방은 기주식물 특이성을 갖고 있어 기주식물 분포에 따른 식생구조나 서식지 유형을 이해하는데 사용이 가능한 분류군이다. 나방은 종 다양성이 높고 분류학적으로 잘 알려져 있어 조사가 많이 이루 어져 풍부한 데이터가 존재하여 이들의 공간적, 시간적 규모의 생물량 변화 추세를 확인할 수 있다. 본 연구에서는 공간적인 유형에 따라 나방의 생물량을 비교하고자 하였다. 생물량을 추정하기 위해 이용된 분류군은 자나방과, 밤나방과, 태극나방과로 이들 분류군의 앞날개 길이를 기준으로 종별로 계산을 하였다. 공간적인 유형은 숲의 위치(연속된 숲, 파편화된 숲)와 숲의 구성(침엽수림, 활엽수림, 혼효림)을 사용하였다. 그 결과 숲의 위치에 따라 생물량은 차이가 존재했지만(F = 16.76, P < 0.001), 숲의 구성(F = 1.54, P = 0.22)과 숲 위치와 구성의 상호작용은(F = 0.34, P = 0.71) 생물량의 차이를 확인하지 못하였다. 숲 구성에 따라 차이가 나타날 것으로 예상하였지만 나타나 지 않은 데에는 추후 분류군을 더 늘려 확인하는 것이 필요하다. 또한 식물 생물량 추정을 통한 곤충과 먹이자원의 가용 관계를 파악하는 연구도 필요할 것으로 예상한다.
A thermochemical conversion method known as hydrothermal carbonization (HTC) is appealing, because it may convert wet biomass directly into energy and chemicals without the need for pre-drying. The hydrochar solid product’s capacity to prepare precursors of activated carbon has attracted attention. HTC has been utilized to solve practical issues and produce desired carbonaceous products on a variety of generated wastes, including municipal solid waste, algae, and sludge in addition to the typically lignocellulose biomass used as sustainable feedstock. This study aims to assess the in-depth description of hydrothermal carbonization, highlighting the most recent findings with regard to the technological mechanisms and practical advantages. The process parameters, which include temperature, water content, pH, and retention time, determine the characteristics of the final products. The right setting of parameters is crucial, since it significantly affects the characteristics of hydrothermal products and opens up a range of opportunities for their use in multiple sectors. Findings reveal that the type of precursor, retention time, and temperature at which the reaction is processed were discovered to be the main determinants of the HTC process. Lower solid products are produced at higher temperatures; the carbon concentration rises, while the hydrogen and oxygen content declines. Current knowledge gaps, fresh views, and associated recommendations were offered to fully use the HTC technique's enormous potential and to provide hydrochar with additional useful applications in the future.
The grassland section of the greenhouse gas inventory has limitations due to a lack of review and verification of biomass compared to organic carbon in soil while grassland is considered one of the carbon storages in terrestrial ecosystems. Considering the situation at internal and external where the calculation of greenhouse gas inventory is being upgraded to a method with higher scientific accuracy, research on standards and methods for calculating carbon accumulation of grassland biomass is required. The purpose of this study was to identify international trends in the calculation method of the grassland biomass sector that meets the Tier 2 method and to conduct a review of variables applicable to the Republic of Korea. Identify the estimation methods and access levels for grassland biomass through the National Inventory Report in the United Nations Framework Convention on Climate Change and type the main implications derived from overseas cases. And, a field survey was conducted on 28 grasslands in the Republic of Korea to analyse the applicability of major issues. Four major international issues regarding grassland biomass were identified. 1) country-specific coefficients by land use; 2) calculations on woody plants; 3) loss and recovery due to wildfire; 4) amount of change by human activities. As a result of field surveys and analysis of activity data available domestically, it was found that there was a significant difference in the amount of carbon in biomass according to use type classification and climate zone-soil type classification. Therefore, in order to create an inventory of grassland biomass at the Tier 2 level, a policy and institutional system for making activity data should develop country-specific coefficients for climate zones and soil types.