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Has global deforestation accelerated due to the cOVID-19 pandemic?

Journal of Forestry Research 2023年第4期34卷 1153-1165页

作者： jonnathan céspedes Janelle M.Sylvester Lisset Pérez-Marulanda Paula Paz-Garcia Louis Reymondin Mehran Khodadadi Jhon J.Tello Augusto castro-Nunez The Alliance of Bioversity International and International center for Tropical Agriculture(cIAT) Km 17 Recta Cali-PalmiraCaliColombia Department of Geosciences and Natural Resource Management University of CopenhagenCopenhagenDenmark Leibniz centre for Agricultural Landscape Research(ZALF) MünchebergGermany

As the cOVID-19 pandemic unfolded,questions arose as to whether the pandemic would amplify or pacify tropical *** reports warned of increased deforestation rates;however,these studies were limited to a few months in 2020 or to selected *** better understand how the pandemic infl uenced tropical deforestation globally,this study used historical deforestation data(2004–2019)from the Terra-i pantropical land cover change monitoring system to project expected deforestation trends for 2020,which were used to determine whether observed deforestation deviated from expected trajectories after the fi rst cOVID-19 cases were *** series analyses were conducted at the regional level for the Americas,Africa and Asia and at the country level for Brazil,colombia,Peru,the Democratic Republic of congo and *** results suggest that the pandemic did not alter the course of deforestation trends in some countries(e.g.,Brazil,Indonesia),while it did in others(e.g.,Peru).We posit the importance of monitoring the long-term eff ects of the pandemic on deforestation trends as countries prioritize economic recovery in the aftermath of the pandemic.

关键词： Deforestation cOVID-19 Time series Terra-i Drivers of deforestation monitoring

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Experimental evaluation and simulation of volumetric shrinkage and warpage on polymeric composite reinforced with short natural fibers

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Frontiers of Mechanical Engineering 2015年第3期10卷 287-293页

作者： jonnathan D. SANTOS Jorge I. FAJARDO Alvaro R. cUJI Jaime A. GARcIA Luis E. GARZON Luis M. LOPEZ Department of Mechanical Engineering Universidad Polit6cnicaSalesiana Elia Liut Ecuador Department of Mechanical Engineering Universidad PontificiaBolivariana Medellin Columbia

A polymeric natural fiber-reinforced composite is developed by extrusion and injection molding process. The shrinkage and warpage of high-density polyethylene reinforced with short natural fibers of Guadua angustifolia Kunth are analyzed by experimental measure- ments and computer simulations. Autodesk Moldflow and Solid Works are employed to simulate both volumetric shrinkage and warpage of injected parts at different configurations： 0wt.%, 20wt.%, 30wt.% and 40 wt.% reinforcing on shrinkage and warpage behavior of polymer composite. Become evident the restrictive effect of reinforcing on the volumetric shrinkage and warpage of injected parts. The results indicate that volumetric shrinkage of natural composite is reduced up to 58% with fiber increasing, whereas the warpage shows a reduction form 79% to 86% with major fiber content. These results suggest that it is a highly beneficial use of natural fibers to improve the assembly properties of polymeric natural fiber-reinforced composites.

关键词： biocomposite natural fiber shrinkage,simulation warpage

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Natural hazards in Santo Domingo de Heredia, costa Rica, central America

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Natural Science 2014年第3期6卷 121-129页

作者： jonnathan Reyes Mario Fernández Sara Grineski Timothy collins Department of Sociology and Anthropology University of Texas El Paso USA School of Geography University of Costa Rica (UCR) San José Costa Rica University of costa Rica San José Costa Rica School of Geology University of Costa Rica San José Costa Rica center for Research in Geological Sciences University of Costa Rica San José Costa Rica Red Sismológica Nacional (RSN: IcE-UcR) San José Costa Rica

Santo Domingo de Heredia, costa Rica is a county facing serious risks from natural hazards, specifically flooding, earthquakes, volcanic activity and landslides. In order to inform disaster risk reduction efforts and improve the safety and well-being of local residents, this article assessed these natural hazards using a geographical approach. First, we described the four hazards based on a review of reports from previous emergencies, scientific papers and newspaper articles. Second, we integrated spatial data on each hazard to create a hazard density index for the county at the level of the census unit (n = 140). Results demonstrate that river flooding has caused the most damage of the four hazards in recent times. Both seismic and volcanic risks (specifically ash fall from volcanic eruptions) affect the entire area of Santo Domingo. Landslides have affected localized, settled areas of steep river canyons in the southern part of the county. In general, the highest density of hazards is located in the southern reaches of Santo Domingo. As such, we recommend that local authorities concentrate their management efforts in that area.

关键词： Hazards Earthquakes Floods Eruptions Landslides Faults Index

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Assessment of Physical Vulnerability in Santo Domingo De Heredia, costa Rica, central America

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World Journal of Engineering and Technology 2014年第3期2卷 78-84页

作者： jonnathan Reyes chaves Mario Fernandez Arce Daniel Solis Rafael Bolanos Villalobos Escuela de Geografia Universidad de Costa Rica(UCR Preventec-Universidad de costa Rica(UcR) Escuela de Geografia-UCR and Centro de Investigaciones en Ciencias Geologicas-UCR Preventec-UcR casa de la cultura de Santo Domingo de Heredia

This work assesses the physical vulnerability of the Santo Domingo canton in the province of Heredia in costa Rica. We evaluate the vulnerability of areas located in high risk zones as well as the structural resistance of structures of the canton and then combine them to obtain an index of Physical Vulnerability. Most of the communities in high risk areas in this canton have not been properly identified and mapped. This identification and mapping will enhance the management of disaster risks, reduce the infrastructure vulnerability and protect vulnerable families in there. We created an index ranging between 0 and 1 for each indicator of physical vulnerability (human settlements in areas of high risk and structural resistance) and another similar index resulting from the combination of vulnerability information from both indicators. The greater part of the territory of Santo Domingo has low physical vulnerability but there are critical sites in the West and the East of the canton.

关键词： Vulnerability Santo Domingo Heredia Disasters Prevention costa Rica

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通勤时间影响你的身心健康

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英语沙龙（初级版） 2010年第12期 41-41页

作者： jonnathan coleman 陈烨

三分之一通勤时间超过90分钟的雇员称，在过去一年里，他们经常脖子痛或背痛。差不多也是三分之一的雇员被诊断为患有高胆固醇。而在通勤时间少于20分钟的雇员中，只有20％的雇员有高胆固醇、背痛或脖子痛。

关键词：身心健康时间胆固醇雇员

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