10 research outputs found
Preparação e caracterização do complexo de inclusão do óleo essencial de Croton zehntneri com β-ciclodextrina
Croton zehntneri, a plant native to northeastern Brazil, is widely used in folk medicine to treat gastrointestinal problems and has rich essential oil content. The essential oil of C. Zehntneri was analyzed by GC-MS, and its inclusion complex with β-cyclodextrin (β-CD) was characterized by both vibrational spectroscopy and differential scanning calorimetry (DSC). Estragol was the major component identified in the essential oil by the study. IR spectra indicated an interaction of β-CD with essential oil from C. zehntneri, a finding corroborated by the stability constant and scanning calorimetry. Microencapsulation within β-CD has the potential to mask sensory attributes and increase aqueous solubility of oils, thereby improving their applicability as drugs
Soil quality indicators for different restoration stages on Amazon rainforest
Despite the global importance of Amazon rainforest, few studies have evaluated soil quality indicators (SQI) in this region. This study evaluated 13 SQIs according to their correlation and sensibility to differentiate four areas under different restoration stages in the Brazilian Amazon rainforest: degraded area (DEGR), two restoration areas (REST1 and REST2) and an undisturbed forest (FORE). The different restoration stages had influence on SQIs. Soil bulk density (ρs), total nitrogen (total N) and exchangeable potassium (K+) on soil showed higher number of correlation (P<0.001; rs>|0.70|) with other SQIs and were sensitive (P<0.05) to distinguish the different areas. Soil bulk density decreased in the following order: DEGR>REST1>REST2>FORE. Otherwise, soil total N decreased on a reverse order: FORE>REST2>REST1>DEGR. Increasing restoration status of Amazon rainforest is associated with lower ρs and higher N and K+ concentration on soil. © 2014 Elsevier B.V
Nanoparticles of Mixed-Valence Oxides MnXCO3-XO4 (0 ≤ X ≤ 1) Obtained with Agar-Agar from Red Algae (Rhodophyta) for Oxygen Evolution Reaction
The development of efficient electrocatalysts for the oxygen evolution reaction (OER) is of paramount importance in sustainable water-splitting technology for hydrogen production. In this context, this work reports mixed-valence oxide samples of the MnXCo3-XO4 type (0 ≤ X ≤ 1) synthesized for the first time by the proteic sol-gel method using Agar-Agar as a polymerizing agent. The powders were calcined at 1173 K, characterized by FESEM, XRD, RAMAN, UV–Vis, FT-IR, VSM, and XPS analyses, and were investigated as electrocatalysts for the oxygen evolution reaction (OER). Through XRD analysis, it was observed that the pure cubic phase was obtained for all samples. The presence of Co3+, Co2+, Mn2+, Mn3+, and Mn4+ was confirmed by X-ray spectroscopy (XPS). Regarding the magnetic measurements, a paramagnetic behavior at 300 K was observed for all samples. As far as OER is concerned, it was investigated in an alkaline medium, where the best overpotential of 299 mV vs. RHE was observed for the sample (MnCo2O4), which is a lower value than those of noble metal electrocatalysts in the literature, together with a Tafel slope of 52 mV dec−1, and excellent electrochemical stability for 15 h. Therefore, the green synthesis method presented in this work showed great potential for obtaining electrocatalysts used in the oxygen evolution reaction for water splitting
Avaliação do desempenho logístico do transporte rodoviário de madeira de áreas de fomento florestal com o uso de rede de Petri Evaluation of the wood hauling logistic performance in farm forest areas using Petri net
Neste estudo, buscou-se aplicar o modelo de avaliação do desempenho logístico de cadeias produtivas (ADELCAP), baseado nos tempos dos elementos do ciclo operacional do transporte de madeira de áreas de fomento de uma empresa produtora de celulose do Estado do Espírito Santo, objetivando apontar meios de otimizar os recursos físicos para garantir um fluxo de abastecimento ininterrupto e apropriado volume de entrada de madeira nos depósitos regionais. O ciclo operacional de transporte de madeira é ordenado pelas atividades de carregamento de madeira no campo, viagem carregada, descarregamento no depósito e viagem vazia. Utilizou-se a Rede de Petri Temporal, por trabalhar com dois tempos duração de sensibilização. Realizaram-se simulações com os softwares JARP e ARP, a fim de simular, analisar e avaliar o desempenho operacional. As variações empregadas em cada cenário se devem à qualidade da estrada, sob as condições atuais quanto à geometria vertical e horizontal e ao quociente de irregularidade, em cada depósito para os diferentes tipos de veículo e forma de carregamento da madeira adotado. Nas regiões de topografia acidentada, a melhoria das estradas alterando seu nível de qualidade tem maior influência para o aumento do desempenho dos veículos, e os veículos 4x2 e 6x2 apresentaram os melhores resultados. Nas regiões de planícies, a escolha do veículo tem maior influência no aumento do desempenho do transporte, já que a topografia e qualidade das estradas atuais já contribuem para isso. Nesses casos, a relação tonelada transportada por distância e tempo será maior para os veículos com capacidade de carga líquida maior.<br>This study aimed at applying the model of logistic performance evaluation of productive chains (ADELCAP), based on the times of the elements of the operational cycle of wood transport from areas of fomentation of a cellulose producing company in the State of Espírito Santo, to indicate means of optimizing physical resources, guaranteeing a flow of uninterrupted provisioning and appropriate volume of wood entrance in the regional deposits. The operational cycle of wood transport is organized by the activities of wood loading in the field, wood hauling, wood unloading in the deposit and unhauling. The Temporal Petri Net was used, because it works with two times - sensitization duration. Simulations were carried out with the ARP and ARP software systems, in order to simulate, analyze and evaluate the operational performance. The variations employed in each scenery are due to the quality of the highway, under the current conditions, as for the vertical and horizontal geometry and the irregularity quotient, in each deposit, for the different types of vehicle and form of the adopted wood loading. In the areas of uneven topography, the improvement of the highways altering their quality level has a higher influence for the increase in the performance of the vehicles, and Toco and Truck presented better results. In the areas of plains, the choice of the vehicle has a higher influence in the increase of the performance of the transport, since the topography and the quality of the current highways already contribute to the performance. In these cases, the relation between transported ton and distance and time will be higher for the vehicles with higher capacity of liquid load
Estudo comparativo envolvendo três métodos de cálculo de custo operacional do caminhão bitrem
Use of Ni-Zn ferrites doped with Cu as catalyst in the transesterification of soybean oil to methyl esters
Molecular characteristics of methicillin-resistant Staphylococcus aureus isolates from hospital and community environments in northeastern Brazil
Saccharomyces cerevisiae strains as bioindicators for titanium dioxide sunscreen photoprotective and photomutagenic assessment
O Protagonismo Infantojuvenil nos Processos Educomunicativos
Neste volume “O protagonismo infantojuvenil nos processos educomunicativos”, reunimos 53 artigos que transitam sobre a temática do protagonismo infantojuvenil em diversas experiências e processos educomunicativos e para facilitar sua leitura e busca por temas de seu interesse, eles estão organizados em 8 capítulos que abordam a educomunicação a partir do fazer das crianças e da apropriação da produção midiática. Expressão artística, rádio, vídeo, jornalismo, cultura digital, redes sociais entre outros são os temas abordados pelos autores destes trabalhos. convidamos o leitor a mergulhar nesta jornada educomunicativa, vivendo e revivendo junto conosco essas experiências vividas por outros, refletindo em cada texto sobre como estamos, como evoluímos e como seguimos os passos daqueles que com sua ousadia, amor e luta elaboraram os fundamentos da educomunicação