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Decay resistance and dimensional stability improvement of wood by low melting point alloy heat treatment

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Journal of Forestry Research 2018年第6期29卷 1797-1805页

作者： Kufre Edet Okon Fengcai Lin Yandan Chen Biao Huang College of Material engineering Fujian Agriculture and Forestry University department of Forestry and Natural environmental Management Faculty of AgricultureUniversity of Uyo

Wood has no inherent natural resistance against agents of biodegradation. We evaluated the effects of metal bath heat treatment(MBHT) on decay resistance and dimensional stability of Chinese parasol(Firmiana simplex) and Chinese fir(Cunninghamia lanceolata) wood. A low melting point alloy was used as heating medium in the treatment of the wood samples at 150, 180, and 210 °C for2, 4, and 8 h. Heat-treated and control samples were exposed to brown rot fungus(Poria placenta) and white rot fungus(Coriolus versicolor) for decay resistance testing and anti-swelling efficiency(ASE). The improved decay resistance with increase temperatures with low mass losses of 7.3 and 7.3% for F. simplex, and 3.9 and 3.6% for *** at 210 °C for 8 h against Coriolus versicolor and Poria placenta, respectively. ASE indicated that MBHT contributed to improved dimensional stability of both wood species after treatment. Scanning electron micrograph results indicate that metal bath-treated samples showed strong decay resistance. Therefore, our approach to thermally modify wood should be explored to overcome the energy utilization by using low melting point alloy for the heat treatment of wood.

关键词： Heat treatment Decay resistance Dimensional stability Chinese fir Chinese parasol Rot fungi

Tin-based metal bath heat treatment: an efficient and recyclable green approach for Pinus massoniana wood modification

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Journal of Forestry Research 2018年第6期29卷 1807-1814页

Pinus massoniana L. was thermally treated with low melting point alloy as heating medium to investigate the strength properties changes. Contact angle, color and scanning electron microscopy were recorded to assess the effectiveness of the treatment. Samples were pre-treated in a micro-wave for 5 min followed by metal bath heat treatment at 150, 180, and 210 °C for 2, 4, and 8 h,respectively. Strength properties of metal bath treated wood were decreased with increase temperature and ***, modulus of rupture, impact bending, modulus of elasticity were reduced for all treatments. Maximum compressive strength slightly increased at 150 °C for 4 h followed by gradual reduction. The Janka hardness was reduced in the tangential and radial directions. Treatment of the wood at 210 °C for 8 h caused the wood to become brittle and rupture. The contact angle was considerably higher after thermal treatment. The color of the wood became darker with increasing temperature of thermal treatment. Micrographs of the heat-treated samples showed damage to the cell wall with increase in temperature. Metal bath heat treatment of wood was carried out successfully and some strength properties were reduced.

关键词： Metal bath heat treatment Strength properties Pinus massoniana Color Contact angle

In-situ stabilisation followed by ex-situ composting for treatment and disposal of heavy metals polluted sediments

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Journal of environmental Sciences 2009年第7期21卷 877-883页

作者： YU Guangwei LEI Hengyi BAI Tao LI Zhong YU Qiang SONG Xianqiang School of environmental Science and engineering Sun Yat-sen University Guangzhou 510275 China department of environmental Science and engineering South China Agriculture University Guangzhou 510642 China

An innovative in-situ stabilisation treatment followed by ex-situ sediment composting was tested for its ability to treat and dispose of heavy-metal-polluted sediments in a river near the Chinese Pearl Delta. First, polluted sediments were treated in-situ to stabilise the heavy metals. Then the treated sediments were dredged, dewatered and sent for high temperature aerobic composting （HTAC） treatment. Finally, the compost products were used as a fertiliser for fiver bank plants. The stabilisation efficiency of heavy metals during the process was investigated and the results are as follows：（1） using in-situ stabilisation, the extraction concentrations of Cu, Zn and Pb were reduced by 65.0%, 82.2% and 90.0%, respectively, which are much lower than the national standard given in the Identification Standard for Hazardous Waste （GB5085.3-1996）; （2） chemical fraction analysis showed that heavy metals were further stabilized during the HTAC treatment; （3） the concentrations of Cu, Zn and Pb in rainwater leachate through the river bank met the level of class V in the environmental Quality Standards for Surface Water in China （GB3838-2002）. Therefore, using this new process, the toxicities of heavy metals in sediments were reduced markedly.

关键词： contaminated sediments treatment and disposal heavy metal in-situ stabilisation resource utilisation

Microwave assisted digestion followed by ICP-MS for determination of trace metals in atmospheric and lake ecosystem

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Journal of environmental Sciences 2017年第5期29卷 1-10页

作者： Manan Ahmed Ying Hui Chin Xinxin Guo Xing-Min Zhao department of environmental engineering Faculty of Engineering and Green TechnologyUniversiti Tunku Abdul Rahman College of Resource and Environment Jilin Agriculture University

The study of trace metals in the atmosphere and lake water is important due to their critical effects on humans, aquatic animals and the geochemical balance of ecosystems. The objective of this study was to investigate the concentration of trace metals in atmospheric and lake water samples during the rainy season （before and after precipitation） between November and December 2015. Typical methods of sample preparation for trace metal determination such as cloud point extraction, solid phase extraction and dispersive liquid- liquid micro-extraction are time-consuming and difficult to perform; therefore, there is a crucial need for development of more effective sample preparation procedure. A convection microwave assisted digestion procedure for extraction of trace metals was developed for use prior to inductively couple plasma-mass spectrometric determination. The result showed that metals like zinc （133.50-419.30 μg/m3） and aluminum （53.58-378.93 μg/m3） had higher concentrations in atmospheric samples as compared to lake samples before precipitation. On the other hand, the concentrations of zinc, aluminum, chromium and arsenic were significantly higher in lake samples after precipitation and lower in atmospheric samples. The relationship between physicochemical parameters （pH and turbidity） and heavy metal concentrations was investigated as well. Furthermore, enrichment factor analysis indicated that anthropogenic sources such as soil dust, biomass burning and fuel combustion influenced the metal concentrations in the atmosphere.

关键词： Trace metals Microwave digestion ICP-MS Atmospheric environment Lake ecosystem

Quality and Crop Yield Potential of Moderately Degraded Alfisols Under Different Nutrient Inputs and Cropping Patterns

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Pedosphere 2019年第2期29卷 235-247页

作者： Wiqar AHMAD Farmanullah KHAN Zahir SHAH Muhammad Jamal KHAN department of Soil and environmental Sciences The University of Agriculture PeshawarAMK Campus department of Soil and environmental Sciences The University of AgriculturePeshawar

Crop performance on degraded soil needs special management practices to overcome soil quality limitations. In a 2-year(from summer 2006 to winter 2007–2008) field trial on a moderately degraded Alfisol in Swabi District(34°7′12′′N, 72°28′20′′E), Pakistan,the effects of three cropping patterns, cereal-cereal(CC), cereal-legume(CL), and cereal-cereal and legume intercrop(CLI), were tested in main plots under four fertilization treatments in sub-plots, including no fertilization(control), farmers' practice(FP, 60:45 kg ha^(-1) N:P_2O_5), recommended dose(RD, 120:90:60 kg ha^(-1) N:P_2O_5:K_2O), and integrated nutrient management(INM, 20 t ha^(-1) farmyard manure integrated with 50% N, 100% P, and K of recommended dose), using a split-plot randomized complete block design. The performance of CL was superior than CC in plant height, leaf area index(LAI), cob length, grain yield, biological yield, and grain protein(8%, 26%, 8%, 5%, 10%, and 8% increases, respectively), while CLI confirmed significant improvement only in LAI(25%) over CC. Response to nutrient inputs from all sources was in the order of INM > RD > FP > control, and the maximum net economic return by INM(23% and 2.5 times higher than RD and FP, respectively) indicated severe deficiency of both macro-and micro-nutrients in the soil as well as degraded physical properties. Increases in soil organic matter, total N, total mineral N, available P and K, total porosity, and available water-holding capacity by 6%, 34%, 24%, 50%, 13%, 5%, and 7%, respectively, and decrease in soil bulk density by 4% after four crop seasons indicated optimistic changes in soil quality as a result of the combined effects of fertilization from organic and inorganic sources and legumes within crop rotation. This study suggests that keeping the soil covered under cereal-legume rotation crops all year round and treatment with INM(50% N from organic source and 50% from inorganic source) are the best management practice for sustained produc

关键词： crop rotation crop performance degraded soil farmyard manure integrated nutrient management legume intercrop sustained production

Electrochemical conversion of methane to bridge the gap in the artificial carbon cycle

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Journal of Energy Chemistry 2025年第1期100卷 286-308页

作者： Yuhao Peng Yuefeng Song Ihar Razanau Juanxiu Xiao Wei Xiao Di Hu Guoxiong Wang College of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University State Key Laboratory of Catalysis Dalian National Laboratory for Clean Energy iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) Dalian Institute of Chemical Physics Chinese Academy of Sciences Laboratory of Physical-Chemical Technologies SSPA Scientific and Practical Materials Research Centre of NAS of Belarus State Key Laboratory of Marine Resources Utilization in South China Sea Collaborative Innovation Center of Marine Science and Technology School of Marine Science and Engineering Hainan University department of Chemical and environmental engineering University of Nottingham Ningbo China

Methane, an abundant one-carbon（C1） resource, is extensively used in the industrial production of vital fuels and value-added chemicals. However, current industrial methane conversion technologies are energy-and carbon-intensive, mainly due to the high activation energy required to break the inert C–H bond, low selectivity, and problematic side reactions, including CO2emissions and coke deposition. Electrochemical conversion of methane（ECM） using intermittent renewable energy offers an attractive solution, due to its modular reactor design and operational flexibility across a broad spectrum of temperatures and pressures. This review emphasizes conversion pathways of methane in various reaction systems, highlighting the significance and advantages of ECM in facilitating a sustainable artificial carbon cycle. This work provides a comprehensive overview of conventional methane activation mechanisms and delineates the complete pathways of methane conversion in electrolysis contexts. Based on surface/interface chemistry, this work systematically analyzes proposed reaction pathways and corresponding strategies to enhance ECM efficiency towards various target products, including syngas, hydrocarbons, oxygenates, and advanced carbon materials. The discussion also encompasses opportunities and challenges for the ECM process, including insights into ECM pathways, rational electrocatalyst design, establishment of benchmarking protocols, electrolyte engineering, enhancement of CH4conversion rates, and minimization of CO2emission.

关键词： Methane Electrochemical conversion Reaction mechanism Catalyst design Electrode Electrocatalysis

Vocal behavior of Crested Guineafowl(Guttera edouardi) based on visual and sound playback surveys in the Umhlanga Lagoon Nature Reserve,Kwa Zulu-Natal province,South Africa

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Chinese Birds 2015年第3期6卷 132-139页

作者： Johann H.van Niekerk department of environmental Sciences College of Agriculture and Environmental SciencesUniversity of South Africa

Background:Generally speaking,playbacks were often ineffective to determine the group sizes of birds since mainly males from leks *** limitation has not been tested properly for flocking birds such as Crested Guineafowl(Guttera edouardi) with the view to use it as a counting *** aims of the study reported in this paper were(1) to describe the cal s of Crested Guineafowl in a social context;(2) to interpret cal s in an evolutionary context;and(3) to demonstrate that playbacks can be used to locate and count Crested Guineafowl in smal isolated ***:The vocal behavior of Crested Guineafowl was observed during a survey conducted in the Umhlanga Lagoon Nature Reserve(Kwa Zulu-Natal,South Africa) from November 2010 to June *** line observations and sound playback methods were ***:The behavioral context and structure of cal s were *** eight cal s described for Crested Guineafowl were produced mainly to unite flock members in the dense understory,where visibility was poor,and to repel *** not disturbed,Crested Guineafowl were quiet and only made soft contact ***:The high rate of call back and the fact that flocks invariably approach the source of the call en masse,shows that field researchers are able to assess the population size of Crested Guineafowl with sound playbacks along a *** value of playbacks as a conservation tool is assessed.

关键词： Guttera edouardi Playback Calls Social behavior Flocking Transect surveys

Intraspecific Variations of Phosphorus Absorption and Remobilization, P Forms, and Their Internal Buffering in Brassica Cultivars Exposed to a P-Stressed Environment

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Journal of Integrative Plant Biology 2008年第6期50卷 703-716页

作者： M. Shahbaz Akhtar Yoko Oki Tadashi Adachi department of environmental Management engineering Faculty of Environmental Science and Technology Graduate School of Environmental Science Okayama University CADGK and Institute of Soil and environmental Sciences University of Agriculture Faisalabad Pakistan

Translocation of absorbed phosphorus （P） from metabolically inactive sites to active sites in plants growing under P deprivation may increase its P utilization efficiency （PUE）. Acclimation to phosphate （Pi） starvation may be caused by a differential storage pool of vacuolar P, its release, and the intensity of re-translocation of absorbed P as P starvation inducible environmental cues （PSlEC） from ambient environment. Biomass assay and three P forms, namely inorganic （Pi）, organic （Po）, and acid-soluble total （Ptas） were estimated in Brassica cultivars exposed to 10 d P deprivation in the culture media. Considering that -aPi/at denotes the rate of Pi release, Pi release velocity （RSPi） was determined as the tangent to the equations obtained for Pi f（t） at the mean point in the period of greatest Pi decrease, whereas the inverse of the RSPi was an estimate of the internal Pi buffering capacity （IBCPi）. Inter cultivar variations in size of the non-metabolic Pi pool, RSPi, re-translocation of Pi from less to more active metabolic sites, and preferential Pi source and sink compartments were evaluated under P starvation. The cultivar ＇Brown Raya＇ showed the highest Pi storage ability under adequate external P supply, and a more intensive release than ＇Rain Bow＇ and ＇Dunkled＇ under P stress. Cultivar ＇B.S.A＇ was inferior to ＇Con-l＇ in its ability to store and use Pi. Roots and upper leaves were the main sink of Pi stored in the lower and middle leaves of all cultivars and showed lower IBCPi and larger RSPi values than lower and middle leaves. In another trial, six cultivars were exposed to P-free nutrition for 29 d after initial feeding on optimum nutrition for 15 d. With variable magnitude, all of the cultivars re-translocatad P from the above ground parts to their roots under P starvation, and [P] at 44 d after transplanting was higher in developing leaves compared with developed leaves. Under P deprivation, translocation of absorbed P from metabolically inactive to ac

关键词： Brassica internal Pi buffering capacity P absorption and remobilization Pi homeostasis Pi release velocity vacuolar P

Strength and compressibility behaviors of expansive soil treated with coffee husk ash

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Journal of Rock Mechanics and Geotechnical engineering 2019年第2期11卷 337-348页

作者： M.K.Atahu F.Saathoff A.Gebissa Geotechnical engineering and Coastal engineering Faculty of Agriculture and Environmental SciencesUniversity of Rostock，Germany

Various factors can affect the durability of roads, such as the strength of sub-grade, the quality of the subbase and base course, the environments and properties of the soil used. Particularly, roads built on expansive soil are susceptible to early damage due to the swelling and shrinkage characteristics of this kind of soil under changing moisture conditions. The most common technique used to improve the properties of problematic soil is stabilization with additives. Using waste materials to improve the properties of expansive soil is a recent trend in soil stabilization. This study deals with the treatment of expansive soil with coffee husk ash(CHA). Coffee husk is a by-product of coffee production, and CHA is the resulting ash after burning it. In this study, the bearing capacity and compressibility characteristics of expansive soil(specifically black cotton(BC) soil) stabilized with varying percentages of CHA(5%, 10%,15%, and 20%) are investigated. Then, scanning electron microscopy(SEM) and energy dispersive X-ray(EDX) were used to analyze the influence of CHA on surface morphology and chemical composition of the studied soil. The results showed that the soil treated with CHA is generally improved in terms of *** of 20% CHA increases the bearing capacity of the soil by three-fold. In addition, the morphological studies of the soil samples treated with 10% and 15% CHA indicated the formation of hydrated particles and cementitious compounds as a result of the reaction between the soil and CHA. This indicates the potential usage of CHA as a stabilization agent and subsequently, it can address the disposal and environmental concerns related to coffee husk.

关键词： Black cotton (BC) soil Coffee husk Stabilization California bearing ratio (CBR) Consolidation Scanning electron microscopy (SEM)