Understanding Mechanical Response of Elastomeric Graphene Networks

Ultra-light porous networks based on nano-carbon materials (such as graphene or carbon nanotubes) have attracted increasing interest owing to their applications in wide fields from bioengineering to electrochemical devices. However, it is often difficult to translate the properties of nanomaterials to bulk three-dimensional networks with a control of their mechanical properties. In this work, we constructed elastomeric graphene porous networks with well-defined structures by freeze casting and thermal reduction, and investigated systematically the effect of key microstructural features. The porous networks made of large reduced graphene oxide flakes (>20 μm) are superelastic and exhibit high energy absorption, showing much enhanced mechanical properties than those with small flakes (<2 μm). A better restoration of the graphitic nature also has a considerable effect. In comparison, microstructural differences, such as the foam architecture or the cell size have smaller or negligible effect on the mechanical response. The recoverability and energy adsorption depend on density with the latter exhibiting a minimum due to the interplay between wall fracture and friction during deformation. These findings suggest that an improvement in the mechanical properties of porous graphene networks significantly depend on the engineering of the graphene flake that controls the property of the cell walls

Adequação ambiental em áreas de produção de borracha natural do Noroeste do Estado de São Paulo.

The work looks forward to show the study on the situation of a rubber production region in face of the environmental law. The rubber represents a crucial raw material for different industries, such as transportation and military. Despite the fact that the rubber tree is naturally form the Amazon region, it is the northwest of the state of São Paulo where the main production of rubber is concentrated. Therefore, the study area is located in that expressive rubber production place and it was chosen by the project GeoHevea of the Embrapa Satellite Monitoring to study the sustainability in the rubber production. This paper is part of the GeoHevea project, which aims to use geoprocessing tools to verify the Permanent Preservation Areas (APP) situation, according to the law. It was used as reference the Law 12.651/2012 and the CONAMA resolution number 302. It was found that 70% of the APPs are appropriate with the environmental law and the main inappropriate use was due to crops (11,08%) and pasture (13,80%). The rubber trees represent only 2,54% of inappropriate land cover in APPs. As land management guidance, it is recommended to focus on changing those inappropriate land uses inside APPs to improve the environmental adequacy. Finally, the methodology seems to be applicable to the present objectives

Efeito do Deltamethrin e Mancozeb sobre Anthistarcha binocularis (LEP., Gelechiidae), Selenothrips rubrocinctus (THYS., Thripidae) e Aphis gossypii (HOM., Aphididae) em cajueiro.

Foi estudado no municipio de Aracati, Ceara, Brasil, o efeito do Deltamethrin CE e SC (a 14,36 g e 14,39 g do i. a./ha, respectivamente e do fungicida mancozeb ( a 800 g do i. a./ha) nas populacoes da broca - das - pontas. (Anthistarcba binocularis), tripes (Selenotbrips rubrocinctus) e pulgao (Aphis gossypii), em cajueiro (Anacardium occidentale L.). O inseticida piretroide deltamethrin foi eficiente no controle da broca-das-pontas e do tripes, tendo, no entanto, induzido o aumento da populacao de pulgoesbitstream/CNPAT-2010/1892/1/Bp-006.pd

Obsessive-compulsive symptoms, polygenic risk score, and thalamic development in children from the Brazilian High-Risk Cohort for Mental Conditions (BHRCS)

Background: Thalamic volume measures have been linked to obsessive-compulsive disorder (OCD) in children and adolescents. However, it is unclear if alterations in thalamic volumes occur before or after symptom onset and if there is a relation to the presence of sub-clinical obsessive-compulsive symptoms (OCS). Here, we explore the relationship between OCS and the rate of thalamic volume change in a cohort of children and youth at high risk to develop a mental disorder. A secondary aim was to determine if there is a relationship between OCS and the individual’s OCD polygenic risk score (OCD-PRS) and between the rate of thalamic volume change and the OCD-PRS. Methods: The sample included 378 children enrolled in the longitudinal Brazilian High-Risk Cohort for Mental Conditions. Participants were assessed for OCS and the symmetrized percent change (SPC) of thalamic volume across two time-points separated by 3 years, along with the OCD-PRS. Zero-altered negative binomial models were used to analyze the relationship between OCS and thalamic SPC. Multiple linear regressions were used to examine the relationship between thalamic SPC and OCD-PRS. Results: A significant relationship between OCS and the right thalamus SPC (p = 0.042) was found. There was no significant relationship between changes in thalamic volume SPC and OCD-PRS. Conclusions: The findings suggest that changes in the right thalamic volume over the course of 3 years in children may be associated to OCS. Future studies are needed to confirm these results and further characterize the specific nature of OCS symptoms associated with thalamic volumes