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Live above-and belowground biomass of a Mozambican evergreen forest:a comparison of estimates based on regression equations and biomass expansion factors

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Forest Ecosystems 2016年第1期3卷 1-12页

作者： Tarquinio Mateus Magalhāes departamento de engenharia Florestal Universidade Eduardo MondlaneCampus Universitario

Background： Biomass regression equations are claimed to yield the most accurate biomass estimates than biomass expansion factors （BEFs）. Yet, national and regional biomass estimates are generally calculated based on BEFs, especially when using national forest inventory data. Comparison of regression equations based and BEF-based biomass estimates are scarce. Thus, this study was intended to compare these two commonly used methods for estimating tree and forest biomass with regard to errors and biases. Methods： The data were collected in 2012 and 2014. In 2012, a two-phase sampling design was used to fit tree component biomass regression models and determine tree BEFs. In 2014, additional trees were felled outside sampling plots to estimate the biases associated with regression equation based and BEF-based biomass estimates; those estimates were then compared in terms of the following sources of error： plot selection and variability, biomass model, model parameter estimates, and residual variability around model prediction. Results： The regression equation based below-, aboveground and whole tree biomass stocks were, approximately, 7.7, 8.5 and 8.3 % larger than the BEF-based ones. For the whole tree biomass stock, the percentage of the total error attributed to first phase （random plot selection and variability） was 90 and 88 % for regression- and BEF-based estimates, respectively, being the remaining attributed to biomass models （regression and BEF models, respectively）. The percent bias of regression equation based and BEF-based biomass estimates for the whole tree biomass stock were -2.7 and 5.4 %, respectively. The errors due to model parameter estimates, those due to residual variability around model prediction, and the percentage of the total error attributed to biomass model were larger for BEF models （than for regression models）, except for stem and stem wood components. Conclusions＂ The regression equation based biomass stocks were found to be slightly larg

关键词： Androstachysjohnsonii Prain Mecrusse Root growth Biomass additivity Double sampling Forest biomassinventory Carbon allocation

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Performance of aerogel as a thermal insulation material towards a sustainable design of residential buildings for tropical climates in Nigeria

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Energy and Built Environment 2022年第3期3卷 291-315页

作者： Aminu Wali Bashir Brenda Chaves Coelho Leite departamento de engenharia de Construção civil Escola Politécnica da Universidade de São PauloSão Paulo 05508-010Brasil

The building sector accounts for nearly 40%of global energy *** Nigeria,more than two-thirds of the consumption comes from residential *** efficiency measures through the adoption of insulation materials are tools that could crash the peak demand of energy in buildings while improving its thermal comfort and aerogel is considered as the most effective material for insulation,owing to its unique thermal *** this paper,we present the performance of aerogel as a thermal insulation material towards a sustainable design of residential buildings for tropical climates in ***,a typical residential building in the tropical region was modeled with conventional materials utilized in the region and was later modified through the application of aerogel material on various surfaces of the model.A whole building energy simulation was then carried out in each variation and the outcome was compared to effectively conclude on the significance of aerogel in terms of thermal comfort improvement and energy consumption *** show that aerogel had the highest influence when inserted in the attic and floor slabs of the designed model.A reduction of more than 6%was attained in the recorded indoor mean air and operative temperatures while still maintaining an acceptable humidity *** energy consumption,a reduction of more than 15%was ***,the high price of aerogel may hinder its application on the studied building but could be a good investment where climate change and sustainability are of high importance and less concern is given to *** demonstrated significant potential with respect to both thermal comfort improvement and energy consumption reduction on the designed *** outcome of the study is hoped to serve as a base reference for the insulation of residential buildings with similar climate and characteristics to the adopted case building.

关键词： Aerogels Building energy consumption Energy efficiency Thermal insulation materials Thermal comfort Building energy simulation

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Growth of Variable Aspect Ratio ZnO Nanorods by Solochemical Processing

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Journal of Materials Science & Technology 2015年第1期31卷 10-15页

作者： Marivone Gusatti Daniel A.R.Souza Nivaldo C.Kuhnen Humberto G.Riella departamento de engenharia Química e engenharia de Alimentos Programa de Pós-Graduacao em Engenharia Química LABMAC Universidade Federal de Santa Catarina (UFSC) Campus UniversitárioCP 476 Florianópolis Santa Catarina 88040-900 Brazil

In this work,variable aspect ratio（length divided by diameter） zinc oxide nanorods were synthesized through a simple solochemical method by reacting a Zn2+precursor with sodium hydroxide at low reaction *** analysis of the X-ray diffraction data indicated that the samples had hexagonal wurtzite structure and nanometric size *** transmission electron microscopy（TEM） images of the products prepared at60 and 80 ℃ exhibited rod-like architecture,showing that the reaction temperature did not affect the ZnO *** average aspect ratio of the ZnO nanorods decreased from 3.4 to 2.4 when the reaction temperature was raised from 60 to 80 ℃.The samples presented a blue shift in the excitonic absorption compared to ZnO bulk that increased alongside with reaction *** addition,this research investigated the results obtained by varying the concentration of zinc chloride *** the same temperature,it could be verified that when the zinc concentration was increased,the diameter of the ZnO nanorods also slightly increased,and much shorter nanorods were achieved,especially in the reactions performed at 50 and 70 ℃.Finally,the growth mechanism of the ZnO nanostructures was proposed based on the results obtained by changing the zinc precursor concentration and reaction temperature.

关键词： Chemical synthesis ZnO nanorods Growth mechanism

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TRANSIENT ANALYSIS OF COMPOSITE PLATES BY A LOCAL RADIAL BASIS FUNCTIONS-FINITE DIFFERENCE TECHIQUE

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Acta Mechanica Solida Sinica 2012年第1期25卷 22-36页

作者： C.M.C.Roque D.Cunha A.J.M.Ferreira INEGI Faculdade de Engenharia da Universidade do PortoRua Dr.Roberto Frias departamento de engenharia Mecnica Faculdade de Engenharia da Universidade do PortoRua Dr.Roberto Frias

The use of local numerical schemes,such as finite differences produces much better conditioned matrices than global collocation radial basis functions ***,finite differ-ence schemes are limited to special *** scattered points,a combination of finite differences and radial basis functions would be a possible *** this paper,we use a higher-order shear deformation plate theory and a radial basis function-finite difference technique for predicting the transient behavior of thin and thick composite *** numerical experiments on beams and composite plates,the accuracy and efficiency of this collocation technique is demonstrated.

关键词： meshless beam composite plate

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Highly electroactive N–Fe hydrothermal carbons and carbon nanotubes for the oxygen reduction reaction

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Journal of Energy Chemistry 2020年第11期29卷 260-270页

作者： R.G.Morais N.Rey-Raap J.L.Figueiredo M.F.R.Pereira Associate Laboratory LSRE-LCM Departamento de Engenharia QuimicaFaculdade de EngenhariaUniversidade do PortoR.Dr.Roberto Frias s/n4200-465PortoPortugal

Glucose-derived carbons were prepared by hydrothermal carbonization of glucose followed by carbonization or activation to obtain carbon materials with different microporosities. These microporous carbons and carbon nanotubes(CNTs) were functionalized with melamine and/or iron(Ⅱ) phthalocyanine(FePc)following three different methodologies:(i) Functionalization with melamine via thermal treatment,(ii)incorporation of the lowest amount of FePc reported in the literature via incipient wetness impregnation followed by thermal treatment and(iii) functionalization with melamine followed by Fe Pc *** chemical and textural characterization of the prepared materials and their electrochemical assessment allowed to understand the role of microporosity in the incorporation of FePc and its effect on the oxygen reduction reaction(ORR). It was observed that FePc was preferentially incorporated inside the porous structure, especially in samples with more developed microporosity. However, functionalization with melamine modified the textural properties and the surface chemistry, favoring the incorporation of FePc on the surface. Regarding the electrochemical performance, the presence of FePc greatly enhanced the electroactivity of the microporous catalysts. An onset potential of 0.88 V and a four-electron pathway were obtained for glucose-derived carbons, whereas the limiting current densities and kinetic current densities rose by 126% and 222%, respectively, in comparison to the base sample. Notwithstanding, the highest electrochemical activity was observed for the sample prepared with CNTs, due to the synergy between the active metal centers and their highly graphitic carbon structure. The electrochemical parameters of CNTFeP csurpass the commercial Pt/C. The half-wave potential is 40 mV higher, the limiting current density increases by 17%, and a negligible production of by-products(< 1%) was observed.

关键词： Iron(Ⅱ)phthalocyanine Hydrothermal carbons Carbon nanotubes Oxygen reduction reaction Electrocatalysis

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Environmental parameters and tree physiology in two semiarid land use systems in Brazil

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Journal of Forestry Research 2019年第2期30卷 397-407页

作者： Marlete Moreira Mendes Ivanov Claudivan Feitosa de Lacerda Francisco Eden Fernandes Paiva Ana Clara Rodrigues Cavalcante Teogenes Senna de Oliveira departamento de Biologia Universidade Federal do Piaui departamento de engenharia Agricola Campus do PiciUniversidade Federal do Ceara Embrapa Caprinos e Ovinos departamento de Solos Universidade Federal de Vicosa

To determine if reduced tree densities(number of trees per unit area) lead to changes in micro-meteorological and tree physiological characteristics, two areas with different tree densities were assessed. One was an agrosilvopastoral system(AGP) with low tree density, and the other, a secondary forest(SF) with greater tree numbers, both located in a semiarid region of Brazil. Data were collected simultaneously by two automated weather stations: rainfall, air(T_a) and soil temperatures(T_(s5 cm)), relative humidity(RHair), photosynthetically active radiation(PAR), soil moisture at two depths(M_(s30 cm)and M_(s50 cm)),and wind velocity(Vw). Net photosynthesis in Cordia oncocalyx Allema?o trees was measured with an infrared gas analyzer in February, March, May, July, August and September 2011, which encompasses a rainy period followed by a dry period. Average values of Ta, T_(s5 cm), Vwand PAR were greater and average values of RHairand M_(s50 cm) were lesser in the AGP. Photosynthetic rates were greater in plants growing under the AGP at the onset of the dry season when Vw, PAR and T_(s5 cm)were greater and M_(s50 cm) was lesser. Photosynthetic rates correlated strongly with physical parameters during the dry season, especially under SF. Differences in tree numbers between AGP and SF led to differences in physical environmental parameters;however, the latter had less influence on photosynthetic rates in C. oncocalyx during the rainy season. During the dry season, all physical parameters had an impact on net photosynthesis under SF but not under AGP. This indicates a certain independence of plants in AGP.

关键词： Agrosilvopastoral system Net photosynthesis Secondary forest Tree density

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Poly(Butylene Adipate-Co-Terephthalate)and Poly(ε-Caprolactone)and Their Bionanocomposites with Cellulose Nanocrystals:Thermo-Mechanical Properties and Cell Viability Study

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Journal of Renewable Materials 2019年第3期7卷 269-277页

作者： Marcia Cristina Branciforti Caroline Faria Bellani Carolina Lipparelli Morelli Alice Ferrand Nadia Benkirane-Jessel Rosario Elida Suman Bretas departamento de engenharia de Materiais Universidade de Sao PauloSao CarlosSPBrasil departamento de engenharia de Materiais Universidade Federal de Sao CarlosSao CarlosSPBrasil Institut National de la Santéet de la Recherche Médicale Universitéde StrasbourgStrasbourgFrance

Although nanocomposites have recently attracted special interest in the tissue engineering area,due to their potential to reinforce scaffolds for hard tissues applications,a number of variables must be set prior to any clinical *** manuscript addresses the evaluation of thermo-mechanical properties and of cell proliferation of cellulose nanocrystals(CNC),poly(butylene adipate-co-terephthalate)(PBAT),poly(ε-caprolactone)(PCL)films and their bionanocomposites with 2 wt% of CNC obtained by casting *** nanocrystals extracted from Balsa wood by acid hydrolysis were used as a reinforcing phase in PBAT and PCL matrix *** films and pure CNC at different concentrations were cultured with osteoblasts MG-63 and the cell proliferation was assessed by AlamarBlue?*** thermal-mechanical properties of the films were evaluated by dynamic-mechanical thermal analysis(DMTA).It was found by DMTA that the CNC acted as reinforcing *** addition of CNCs in the PBAT and PCL matrices induced higher storage moduli due to the reinforcement effects of *** cell viability results showed that neat CNC favored osteoblast proliferation and both PBAT and PCL films incorporated with CNC were biocompatible and supported cell proliferation along *** nature of the polymeric matrix or the presence of CNC practically did not affect the cell proliferation,confirming they have no in vitro *** features make cellulose nanocrystals a suitable candidate for the reinforcement of biodegradable scaffolds for tissue engineering and biomedical applications.

关键词： Cell viability thermo-mechanical properties cellulose nanocrystals(CNC) biocompatible polymers tissue engineering bionanocomposites

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An advanced anaerobic biofilter with effluent recirculation for phenol removal and methane production in treatment of coal gasification wastewater

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Journal of Environmental Sciences 2016年第9期28卷 23-33页

作者： Yajie Li Salma Tabassum Zhenjia Zhang School of Environmental Science and Engineering Shanghai Jiao Tong University LCM-Laboratory of Catalysis and Materials Associate Laboratory LSRE-LCMDepartamento de Engenharia QuímicaFaculdade de EngenhariaUniversidade do Porto

An advanced anaerobic biofilter（AF） was introduced for the treatment of coal gasification wastewater（CGW）,and effluent recirculation was adopted to enhance phenol removal and methane *** results indicated that AF was reliable in treating diluted CGW,while its efficiency and stability were seriously reduced when directly treating raw ***,its performance could be greatly enhanced by effluent *** optimal effluent recirculation of 0.5 to the influent,concentrations of chemical oxygen demand（COD） and total phenol in the effluent could reach as low as 234.0 and 14.2 mg/L,***,the rate of methane production reached 169.0 m L CH_4/L/*** CGW seemed to restrain the growth of anaerobic microorganisms,especially methanogens,the inhibition was temporary and reversible,and anaerobic bacteria presented strong *** activities of methanogens cultivated in CGW could quickly recover on feeding with glucose wastewater（GW）.However,the adaptability of anaerobic bacteria to the CGW was very poor and the activity of methanogens could not be improved by long-term *** analysis using the Haldane model,it was further confirmed that high effluent recirculation could result in high activity for hydrolytic bacteria and substrate affinity for toxic matters,but only suitable effluent recirculation could result in high methanogenic activity.

关键词： Coal gasification wastewater Effluent recirculation Methane production Anaerobic biofilters

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Numerical modeling of local scour of non-uniform graded sediment for two arrangements of pile groups

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International Journal of Sediment Research 2023年第4期38卷 597-614页

作者： Saeid Okhravi Saeed Gohari Mahdi Alemi Rodrigo Maia Institute of Hydrology Slovak Academy of Sciences department of Water Engineering College of Agriculture Bu-Ali Sina University departamento de engenharia civil Faculdadede Engenharia Universidade do Porto CIIMAR-Interdisciplinary Centre of Marine and Environmental Research University of Porto

A three-dimensional(3D) non-hydrostatic numerical model is established to investigate local scour around four aligned circular piles in uniform and non-uniform sediment mixtures and to provide information for improving scour countermeasures design. In the current study, unsteady Reynolds averaged Navier-Stokes(URANS) equations along with a Re-normalization Group(RNG) k-ε model were applied to simulate the flow field. A non-uniform sediment transport model was applied to estimate the bedload transport. The simulations lasted up to 8 h. The laboratory results of a reference single pile case in uniform and non-uniform sediment were utilized to validate the simulation results of bed elevation changes and time evolution of scour depth and reflected a good agreement. The influence of pile spacing for two arrangements of pile groups, one column(tandem) and two columns(nontandem) of four aligned piles, on spatial/temporal variations of the bed surface in both sediment bed configurations are discussed in detail. The results reveal the significant effects of the pile spacing on the flow field and patterns of scour hole formation and sediment deposition. In general, lower pile spacing results in more scour upstream of the front pile(s) and shifts deposition more downstream due to the existence of higher energy in the wake region of the piles for both sediment types. Side scouring dominates for non-uniform sediment around each pile due to flow deviating because of the presence of relatively larger particles in front of the pile(s). For non-uniform sediment, deposition begins to develop at the exit area of the scour hole and enhances boundary resistance to scour. The knowledge gained from this study is suitable for the accurate determination of riprap dimensions around the front pile(s)and rear piles in a pile group.

关键词： Local bridge pier scour Non-uniform sediment Numerical modeling Pile groups Pile spacing Sediment transport

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Species-specific biomass allometric models and expansion factors for indigenous and planted forests of the Mozambique highlands

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Journal of Forestry Research 2021年第3期32卷 1047-1065页

作者： Tarquinio Mateus Magalhaes Victoria Norberto Cossa Benard Soares Guedes Amélia Saraiva Monguela Fanheiro departamento de engenharia Florestal Faculdade de Agronomia e Engenharia FlorestalUniversidade Eduardo MondlaneCampus UniversitárioEdifício no.1257MaputoRepública de Mocambique departamento de Sociologia Rural Escola Superior de Desenvolvimento RuralUniversidade Eduardo MondlaneVilankuloRepública de Mocambique

Secondary Miombo woodlands and forest plantations occupy increasing areas in Mozambique,the former due to anthropogenic ***,mainly species of Eucalyptus and Pinus,are being established on sites previously covered by secondary Miombo *** affects the evolution,cycle and spatiotemporal patterns of carbon(C)storage and stocks in forest *** estimation of C storage,which is indispensable for formulating climate change policies on sequestrating CO_(2),requires tools such as biomass models and biomass conversion and expansion factors(BCEF).In Mozambique,these tools are needed for both indigenous forests and *** objective of this study is to fit species-specific allometric biomass models and BCEF for exotic and indigenous tree *** incorporate efficient inter-species variability,biomass equations were fitted using nonlinear mixed-effects *** tree component biomass models had good predictability;however,better predictive accuracy and ability was observed for the 2-predictors biomass model with tree height as a second *** majority of the variability in BCEF was explained by the variation in tree *** species had larger crown biomass per unit of stem diameter and stored larger amounts of biomass per stem ***,due to relatively rapid growth,larger stem diameters,heights,and stand density,the plantations stored more biomass per tree and per unit area.

关键词： Biomass allometry Biomass partitioning Miombo Exotic forest plantations Brachystegia spiciformis Julbernardia globifl ora Eucalyptus Pinus

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