Dynamical evolution of V-type photometric candidates in the outer Main-belt

V-type asteroids, characterized by two absorption bands at 1.0 and 2.0 $\mu m$, are usually thought to be portions of the crust of differentiated or partially differentiated bodies. Most V-type asteroids are found in the inner main belt and are thought to be current or past members of the Vesta dynamical family. Recently, several V-type photometric candidates have been identified in the central and outer main belt. While the dynamical evolution of V-type photometric candidates in the central main belt has been recently investigated, less attention has been given to the orbital evolution of basaltic material in the outer main belt as a whole. Here we identify known and new V-type photometric candidates in this region, and study their orbital evolution under the effect of gravitational and non-gravitational forces. A scenario in which a minimum of three local sources, possibly associated with the parent bodies of (349) Dembowska, (221) Eos, and (1459) Magnya, could in principle explain the current orbital distribution of V-type photometric candidates in the region.Comment: This paper has 6 figures and 1 table. Accepted for publication in MNRAS. arXiv admin note: text overlap with arXiv:1401.633

A multi-domain approach to asteroid families identification

Previous works have identified families halos by an analysis in proper elements domains, or by using Sloan Digital Sky Survey-Moving Object Catalog data, fourth release (SDSS-MOC4) multi-band photometry to infer the asteroid taxonomy, or by a combination of the two methods. The limited number of asteroids for which geometric albedo was known until recently discouraged in the past the extensive use of this additional parameter, which is however of great importance in identifying an asteroid taxonomy. The new availability of geometric albedo data from the Wide-field Infrared Survey Explorer (WISE) mission for about 100,000 asteroids significantly increased the sample of objects for which such information, with some errors, is now known. In this work we proposed a new method to identify families halos in a multi-domain space composed by proper elements, SDSS-MOC4 (a*,i-z) colors, and WISE geometric albedo for the whole main belt (and the Hungaria and Cybele orbital regions). Assuming that most families were created by the breakup of an undifferentiated parent body, they are expected to be homogeneous in colors and albedo. The new method is quite effective in determining objects belonging to a family halo, with low percentages of likely interlopers, and results that are quite consistent in term of taxonomy and geometric albedo of the halo members.Comment: 23 pages, 18 figures, 6 tables. Accepted for publication in MNRA

Dynamical evolution and chronology of the Hygiea asteroid family

The asteroid (10) Hygiea is the fourth largest asteroid of the Main Belt, by volume and mass, and it is the largest member of its own family. Previous works investigated the long-term effects of close encounters with (10) Hygiea of asteroids in the orbital region of the family, and analyzed the taxonomical and dynamical properties of members of this family. In this paper we apply the high-quality SDSS-MOC4 taxonomic scheme of DeMeo and Carry (2013) to members of the Hygiea family core and halo, we obtain an estimate of the minimum time and number of encounter necessary to obtain a $3\sigma$ (or 99.7%) compatible frequency distribution function of changes in proper $a$ caused by close encounters with (10) Hygiea, we study the behavior of asteroids near secular resonance configurations, in the presence and absence of the Yarkovsky force, and obtain a first estimate of the age of the family based on orbital diffusion by the Yarkovsky and YORP effects with two methods. The Hygiea family is at least 2 Byr old, with an estimated age of $T = 3200^{+380}_{-120}$ Myr and a relatively large initial ejection velocity field, according to the approach of Vokrouhlick\'{y} et al. (2006a, b). Surprisingly, we found that the family age can be shortened by $\simeq$ 25% if the dynamical mobility caused by close encounters with (10) Hygiea is also accounted for, which opens interesting new research lines for the dynamical evolution of families associated with massive bodies. In our taxonomical analysis of the Hygiea asteroid family, we also identified a new V-type candidate: the asteroid (177904) (2005 SV5). If confirmed, this could be the fourth V-type object ever to be identified in the outer main belt.Comment: 13 page, 15 figures, and 4 table

Dynamical evolution of V-type asteroids in the central main belt

V-type asteroids are associated with basaltic composition, and are supposed to be fragments of crust of differentiated objects. Most V-type asteroids in the main belt are found in the inner main belt, and are either current members of the Vesta dynamical family (Vestoids), or past members that drifted away. However, several V-type photometric candidates have been recently identified in the central and outer main belt. The origin of this large population of V-type objects is not well understood. Since it seems unlikely that Vestoids crossing the 3J:-1A mean-motion resonance with Jupiter could account for the whole population of V-type asteroids in the central and outer main belt, origin from local sources, such as the parent bodies of the Eunomia, and of the Merxia and Agnia asteroid families, has been proposed as an alternative mechanism. In this work we investigated the dynamical evolution of the V-type photometric candidates in the central main belt, under the effect of gravitational and non-gravitational forces. Our results show that dynamical evolution from the parent bodies of the Eunomia and Merxia/Agnia families on timescales of 2 Byr or more could be responsible for the current orbital location of most of the low-inclined V-type asteroids.Comment: 16 pages, 10 figures, 3 tables. Accepted for publication in MNRA

Energy and seismic retrofit of historic timber-framed houses in Portugal: Building predictive models in future scenarios

This research addresses the comparison of building performance before and after implementing energy and seismic retrofitting techniques within simulation models, under the current climate condition vs. predicted environment conditions (2030-2100). It aims to identify a set of feasible interventions within distinct indoor building conditions (number of inhabitants and occupancy schedule) in three design scenarios. To this end, we adopt parametric modelling tools (Rhinoceros, Grasshopper, EnergyPlus) combined with a multicriteria decision analysis (M-MACBETH, Measuring Attractiveness through a Categorical-Based Evaluation Technique). This model is tested in an historic house, a multi-storey overhanging timber-framed house in Lisbon parish, which is representative of valuable traditional construction systems in high seismic hazard zone in the Mediterranean basin. Future studies can address other building simulations evaluated against architectural, structural, environmental, and economic-related parameters. The influence of weighting on the interventions against different criteria can be addressed also considering the uncertainty about the impact of each group of intervention in sensitivity and robustness analyses.info:eu-repo/semantics/publishedVersio

Desenvolvimento de Novos Métodos Analíticos em Química Forense e Petroleômica por Espectrometria de Massas Ambiente (Paper Spray) e Espectroscopia Portátil na Região do Infravermelho Próximo (MICRONIR)

Com o advento de uma nova família de técnicas de ionização, a espectrometria de massas (MS) ambiente foi introduzida como uma maneira simples de gerar íons na MS. Entre elas, a técnica de ionização por paper spray (PS) demonstrou-se versátil para resolver inúmeros problemas. Neste trabalho, a técnica de PS-MS no modo de ionização positiva (PS(+)-MS) foi aplicada em três subáreas da química forense: drogas de abuso e documentoscopia e ervas fitoterápicas. Na primeira, a técnica PS-(+)-MS determinou o perfil químico de drogas sintéticas tais como selos contendo 25I-NBOMe (2-(4-iodo-2,5-dimetoxifenil)-n-[(2-Metoxifenil) metil] etamina), extratos e folhas de canabinóides naturais (Δ9-THC) e canabinóides sintéticos (JWH-073; 5F-AKB48; JWH-122; JWH-250; e JWH-210). Em todos os casos, as moléculas foram facilmente detectadas na sua forma protonada ([M+H]+) com resolução, m/Δm50% = 67,000 e uma precisão de massa menor que 0,99). Em documentoscopia, a técnica PS(+)-MS foi capaz de obter com sucesso o perfil químico de diferentes canetas vendidas no comercio. A intensidade relativa (RII372) do corante azul de metileno foi monitorada para discriminar os cruzamentos de traços de canetas e, até a data, os documentos questionados. O perfil químico das notas brasileiras de segunda geração de R$ 100,00 (reais) também foi explorado. A técnica PS(+)-MS foi capaz de classificar as notas em autêntico ou falsificadas. Constatando que amostras falsas possuem um perfil químico similar às notas caseiras da impressora Deskjet®. Finalmente, aplicamos PS(+)-MS para verificar a autenticidade de ervas usadas para perda de peso. Quinze diferentes medicamentos à base destas ervas foram analisados por PS(+)-MS. Encontrando diferentes tipos de compostos: sibutramina (m/z 280), cafeína (m/z 195), glicose (m/z 203 [M+Na], m/z 219 [M+K] e sacarose (m/z 381 [M+K]). Todas essas substâncias não estavam listadas em seus rótulos. Em geral, a técnica PS(+)-MS mostrou ser uma excelente ferramenta analítica em química forense. O segundo estudo abordado foi o controle de qualidade de combustíveis com aplicação do micro-espectrômetro portátil na região do infravermelho próximo (MICRONIR). Neste trabalho, verificou-se a potencialidade do MICRONIR no controle da qualidade do combustível. Assim, modelos quimiométricos (usando o PLS - regressão por mínimos quadrados parciais) foram desenvolvidos para quantificar biodiesel em Diesel (LD=0,5 wt%; LQ=1,8 wt%, e RMSEP=1.8 wt%); enxofre em Diesel (LD=2,4 mg L-1; LQ=8,0 mg L-1, e RMSEP=13,2 mg L-1); gasolina, etanol e metanol em gasolina tipo C (LDgas=0,55 wt%; LQgas=1,84 wt%, e RMSEPgas=0,81 wt%; LDet=0,75 wt%; LQgas=2,50 wt%, e RMSEPeth=3,81 wt%; LDmet = 0,85 wt%; LQmet = 2,84 wt%, e RMSEPmet = 1,80 wt%); e água, metanol e etanol em etanol combustível hidratado (LDH2O = 0,04 wt%; LQH2O=1,29 wt%, e RMSEPH2O=1,05 wt%; LDmet= 0,52 wt%; LQmet = 1,73 wt%, e RMSEPmet =2,78wt %; LDet=1,22 wt%; LQet=4,07 wt%, e RMSEPet= 4,41 wt%). O método proposto apresentou alta precisão e exatidão em todos os casos, e os resultados mostraram que a técnica MICRONIR teve excelente desempenho no controle da qualidade do combustível

UTILIZAÇÃO DE TÉCNICAS ESPECTROSCÓPICAS E ANÁLISE TÉRMICA NO MONITORAMENTO DA DEGRADAÇÃO DA POLIAMIDA 11 UTILIZADA EM DUTOS FLEXÍVEIS

Neste trabalho, o potencial das técnicas de fluorescência de raios X (XRF), espectroscopia de infravermelho com transformada de Fourier com o acessório de reflexão total atenuada (FTIR-ATR) e analises térmicas (DSC e DMA) foram avaliados para o monitoramento a degradação do poliamida 11 (PA-11) usada em dutos flexíveis. As amostras foram submetidas a envelhecimento em reatores com pressão controlada e atmosfera inerte. Os corpos de prova foram imersos em água deionizada (pH 7), nas temperaturas de 110, 120 e 140 °C por um período de até 50. A técnica recomendada para monitoramento da degradação da PA-11 é a viscosimetria, através de medidas da viscosidade inerente corrigida (VIC) e a análise termogravimétrica (TGA). O comportamento observado para a VIC e TGA durante o envelhecimento possibilitou a construção de modelos que relacionam as técnicas XRF, FTIR-ATR, DSC e DMA com a degradação sofrida pelo polímero. Os resultados de TGA mostraram uma diminuição na concentração do plastificante (n-butil-benzenosulfonamide) em função do tempo, que foi monitorada através da intensidade do pico atribuído ao enxofre no espectro de XRF. As mudanças correlacionadas com a diminuição da fase amorfa e aumento da fase cristalina na matriz polimérica estão diretamente correlacionados com as mudanças nas propriedades mecânicas da PA-11. A partir dos resultados de FTIR-ATR, a variação na intensidade das bandas atribuídas às fases amorfa e cristalina do polímero, 937 e 1161 Cm-1 respectivamente, possibilitou o monitoramento do envelhecimento. Os dados térmicos foram tratados juntos, e apresentaram resultados que não foram detectados pelas outras técnicas, como: oligômeros formados dentro da matriz da PA-11 e variações na temperatura de transição vítrea do polímero. A classificação por PCA, e os modelos gerados pelos métodos de PLS e LDA foram satisfatórios na previsão do envelhecimento da PA-11, onde os coeficientes de correlações para as técnicas XRF, FTIR-ATR e térmicas foram 0,9035, 0,8185 e 0,7640 respectivamente, já os resultados de LDA tiveram as proporções de acertos de 0,808, 0,944 e 0,971 respectivamente. As técnicas exploradas se mostraram eficientes para monitorar as propriedades do polímero, que estão diretamente relacionadas com o processo de degradação da PA11. Tais técnicas eliminam o uso de solventes orgânicos tóxicos e possibilitam um menor tempo de análise, como é o caso da XRF e da FTIR-ATR

The Rubiaceae family in the Carrancas Mountain Complex, state of Minas Gerais, southeastern Brazil

Rubiaceae is the fourth largest family of the angiosperms in terms of species diversity worldwide. It is present in all plant physiognomies and occupies various vegetation strata, being one of the most important components of tropical vegetation. It is easily recognized by the opposite leaves, interpetiolar stipules, gamopetalous corolla, and inferior ovary. The main objective of this study was to investigate the diversity of the Rubiaceae in the Carrancas Mountain Complex, Minas Gerais, Brazil. This region encompasses approximately 17,609 km2, extending from the southern border of the state of Minas Gerais, approaching the Itatiaia Plateau, to the Sao Joao del-Rei and Barbacena region, where the Sao Francisco River basin begins. It includes the municipalities of Lavras, Itumirim, Ingaí, Itutinga, Carrancas, and Minduri. Situated in an ecotone between the Atlantic Forest and Cerrado domains, it presents a surface covered by various vegetation types, such as campo rupestre, savannas, open fields, scrublands, seasonal semideciduous forests, riparian or gallery forests, and cloud forests at the higher elevations. A total of 681 herbarium specimens were analysed, most of them deposited at the ESAL herbarium, which holds most of the collections made in the region. In this study, 26 genera and 51 species were recorded. These represent noteworthy 37.7% of the genera and 13.5% of the species of Rubiaceae recorded in Minas Gerais, including 14 endemic species to Brazil. Borreria and Palicourea were the most diverse genera (five species each), followed by Cordiera, Galianthe, and Psychotria (four species each). Therefore, this work enriches the taxonomic knowledge of the Rubiaceae family in the state of Minas Gerais, particularly for the flora of the Carrancas Mountain Complex

The effect of soil microtopographic gradients on dry matter yields and species richness in two Mediterranean pastures

The Sown Biodiverse Permanent Pastures Rich in Legumes (SBPPRL) mix a large number of species and cultivars of improved annual pasture species adapted to Mediterranean climate. with a predominance of Trifolium subterraneum. On a commercial mixed farm were explored the effects of soil microtopographic gradients on dry matter (OM) yields and species richness in two intensively grazed nearby pastures - a stabilized SBPPRL and an old seminatural annual pasture (SNP) - established in the same soil calena, with a high PZ05 and KzO availability. As expected the SBPPRL had higher DM yields than the SNP, more stable along the slope system, and with a larger legume fraction. The indigenous genotypes of the SNP seemed unable to translate into biomass soil fertility improvement. SBPPRL improved pasture species depressed significantly pasture species diversity and species spatial turnover. In the SBPPRL legumes mainly substituted many short living low productivity autochthonous species common in the SNP. The buffering of soil ecological gradients is probably important in the explanation of the superior agronomic performance of SBPPRL. SOM accumulation is certainly involved in this process