1,434 research outputs found
Electric-field-induced alignment of electrically neutral disk-like particles: modelling and calculation
This work reveals a torque from electric field to electrically neutral flakes that are suspended in a higher electrical conductive matrix. The torque tends to rotate the particles toward an orientation with its long axis parallel to the electric current flow. The alignment enables the anisotropic properties of tiny particles to integrate together and generate desirable macroscale anisotropic properties. The torque was obtained from thermodynamic calculation of electric current free energy at various microstructure configurations. It is significant even when the electrical potential gradient becomes as low as 100 v/m. The changes of electrical, electroplastic and thermal properties during particles alignment were discussed
Film blowing of PHBV blends and PHBV-based multilayers for the production of biodegradable packages
Poly(hydroxy butyrate-co-valerate) (PHBV) is a biodegradable polymer that is difficult to melt process into films. Such difficulty is mirrored in the lack of literature on film blowing of PHBV- or PHBV-based materials. To circumvent this problem, 70/30 wt % blends of PHBV with a biodegradable compound (PBSebT), or with poly(butylene adipate-co-terephtalate) (PBAT), were prepared and tested for extrusion film blowing. Both blends showed a similar rheological pattern at 175°C, which is the maximum processing temperature with tolerable thermal degradation. Blending stabilized the film bubbles, thus widening the processing window. However, film properties such as tensile modulus, strain at break and tear resistance remained isotropic and crystallinity characteristics in the machine and transverse directions were generally similar. To bypass the thermal degradation associated with polymer blending, PHBV/PBAT films were coextruded. These showed enhanced functional properties when compared with films blown from blends. The mechanical properties of bilayered films matched those of films blown from commercial PBAT designed for food packaging.The authors acknowledge the European Commission for the financial support of the ECOefficient BIOdegradable Composite Advanced Packaging project (EcoBioCAP) within the Seventh Framework Programme (Contract-No. FP7-265669). This work was also supported by FEDER funds through the program COMPETE (project PTDC/AGR-ALI/122741/2010), by the Portuguese Foundation for Science and Technology (PEst-C/CTM/LA0025/2013 - Projecto Estrategico - LA 25 - 2013-2014 - Strategic Project - LA 25 - 2013-2014) and by Programa Operacional Regional do Norte (ON.2) through project "Matepro - Optimizing Materials and Processes", with reference NORTE-07-0124-FEDER-000037 FEDER COMPETE
Population Genetics of Franciscana Dolphins (Pontoporia blainvillei): Introducing a New Population from the Southern Edge of Their Distribution
Due to anthropogenic factors, the franciscana dolphin, Pontoporia blainvillei, is the most threatened small cetacean on the Atlantic coast of South America. Four Franciscana Management Areas have been proposed: Espiritu Santo to Rio de Janeiro (FMA I), São Paulo to Santa Catarina (FMA II), Rio Grande do Sul to Uruguay (FMA III), and Argentina (FMA IV). Further genetic studies distinguished additional populations within these FMAs. We analyzed the population structure, phylogeography, and demographic history in the southernmost portion of the species range. From the analysis of mitochondrial DNA control region sequences, 5 novel haplotypes were found, totalizing 60 haplotypes for the entire distribution range. The haplotype network did not show an apparent phylogeographical signal for the southern FMAs. Two populations were identified: Monte Hermoso (MH) and Necochea (NC)+Claromecó (CL)+Río Negro (RN). The low levels of genetic variability, the relative constant size over time, and the low levels of gene flow may indicate that MH has been colonized by a few maternal lineages and became isolated from geographically close populations. The apparent increase in NC+CL+RN size would be consistent with the higher genetic variability found, since genetic diversity is generally higher in older and expanding populations. Additionally, RN may have experienced a recent split from CL and NC; current high levels of gene flow may be occurring between the latter ones. FMA IV would comprise four franciscana dolphin populations: Samborombón West+Samborombón South, Cabo San Antonio+Buenos Aires East, NC+CL+Buenos Aires Southwest+RN and MH. Results achieved in this study need to be taken into account in order to ensure the long-term survival of the species.Fil: Gariboldi, María Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Tunez, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján; ArgentinaFil: Dejean, Cristina Beatriz. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Ciencias Antropológicas. Sección Antropología Biológica; ArgentinaFil: Failla, Mauricio. Fundación Cethus; ArgentinaFil: Vitullo, Alfredo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Negri, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Cappozzo, Humberto Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentin
Morphological and molecular characterization of Curvularia and related species associated with leaf spot disease of rice in Peninsular Malaysia
Curvularia species are important phytopathogens reported worldwide. They are closely related; consist of major destructive pathogens mainly for grasses and cereal plants including rice (Oryza sativa). A leaf spot symptom of rice is one of the common symptoms found in the rice field and caused reduction of rice yield. However, there are no reports on Curvularia species associated with rice leaves showing spot symptoms. The objectives are to isolate and characterize Curvularia and related species from leaf spot of rice by using morphological and molecular characterization and to determine the phylogenetic relationship between the isolated fungi. Fungal isolation was done from diseased rice leaves showing leaf spot symptoms collected throughout Peninsular Malaysia. Thirty-three isolates were recovered and identified based on their morphological characteristics such as conidia morphology, colony appearance, pigmentation and growth rate for species delimitation. Internal transcribed spacer (ITS) region was amplified to confirm the species identification. The 33 isolates were identified as Bipolaris sorokiniana (10 isolates), Curvularia hawaiiensis (8 isolates), C. geniculata (6 isolates), C. eragrostidis (6 isolates), C. aeria (2 isolates) and C. lunata (1 isolate). A phylogenetic tree was constructed based on ITS sequences using neighbour-joining method. The tree grouped members of Curvularia and Bipolaris into different clades. The phylogenetic tree indicated that the presence of two groups of fungi species; highly virulent and mild pathogens. In conclusion, Curvularia species and Bipolaris sorokiniana were present in rice field in Malaysia and associated with leaf spot of rice
Intimate partner violence against women in an economically vulnerable urban area, Central-West Brazil
OBJETIVO: Estimar a prevalência de tipos de violência e de comportamentos de controle praticados por parceiros íntimos contra mulheres residentes em área economicamente vulnerável. MÉTODOS: Conduziu-se estudo transversal com 278 mulheres de 15 a 49 anos que tiveram parceiros íntimos alguma vez na vida, residentes em uma área metropolitana de Brasília, DF, em 2007. Utilizou-se processo de amostragem aleatória sistemática. O instrumento de pesquisa constou de um questionário com 58 perguntas desenvolvido pela Organização Mundial de Saúde. Foram analisadas as prevalências de violência física, psicológica e sexual. As variáveis independentes consideradas foram características sociodemográficas da mulher, de contexto familiar e comunitário bem como as sociodemográfi cas do parceiro, de comportamento (freqüência do uso de bebidas ou drogas ilícitas e relacionamento extraconjugal). RESULTADOS: A prevalência de violência psicológica foi a mais alta: 80,2% (n=223) das mulheres entrevistadas relataram pelo menos um ato no decorrer da vida e 50% (n=139) nos últimos 12 meses. A prevalência de violência física ao longo da vida foi (58,6%) e nos últimos 12 meses (32%), enquanto a prevalência de mulheres que sofreram violência sexual foi de 28,8% e 15,5%, respectivamente. CONCLUSÕES: As altas prevalências das violências mostram a magnitude da vulnerabilidade e das agressões praticadas contra mulheres nas relações com parceiros íntimos.OBJECTIVE: To estimate the prevalence of gender-based controlling behavior and types of violence committed by intimate partners against women living in an economically vulnerable area. METHODS: A cross-sectional study was performed with 278 women aged between 15 and 49 years, who had had at least one male intimate partner in their lives and lived in a metropolitan area of the city of Brasília, Central-West Brazil, in 2007. Systematic random sampling process was used. The research instrument consisted of a questionnaire with 58 questions, developed by the World Health Organization. Prevalences of physical, psychological and sexual violence were analyzed. Independent variables considered were women’s sociodemographic, family and community context characteristics, in addition to their partners’ sociodemographic and behavior characteristics (frequency of alcohol or illicit drug use and extra-marital relationship). RESULTS: The highest prevalence was that of psychological violence: 80.2% (n=223) of the women interviewed reported at least one act throughout their lives and 50% (n=139) in the last 12 months. Prevalence of physical violence was 58.6% throughout life and 32% in the last 12 months, whereas those of sexual violence were 28.8% and 15.5%, respectively. CONCLUSIONS: High prevalences of violence show the magnitude of vulnerability and aggressions committed against women in relationships with intimate partners
Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector
The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV
Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δϕ modulation for all ΣETPb ranges and particle pT
Determinants on an efficient cellulase recycling process for the production of bioethanol from recycled paper sludge under high solid loadings
Background: In spite of the continuous efforts and investments in the last decades, lignocellulosic ethanol is still not economically competitive with fossil fuels. Optimization is still required in different parts of the process. Namely, the cost effective usage of enzymes has been pursued by different strategies, one of them being recycling.
Results: Cellulase recycling was analyzed on Recycled Paper Sludge (RPS) conversion into bioethanol under intensified conditions. Different cocktails were studied regarding thermostability, hydrolysis efficiency, distribution in the multiphasic system and recovery from solid. Celluclast showed inferior stability at higher temperatures (45-55 ºC), nevertheless its performance at moderate temperatures (40ºC) was slightly superior to other cocktails (ACCELLERASE®1500 and Cellic®CTec2). Celluclast distribution in the solid-liquid medium was also more favorable, enabling to recover 88 % of final activity at the end of the process.
A Central Composite Design studied the influence of solids concentration and enzyme dosage on RPS conversion by Celluclast. Solids concentration showed a significant positive effect on glucose production, no major limitations being found from utilizing high amounts of solids under the studied conditions. Increasing enzyme loading from 20 to 30 FPU/ gcellulose had no significant effect on sugars production, suggesting that 22 % solids and 20 FPU/gcellulose are the best operational conditions towards an intensified process. Applying these, a system of multiple rounds of hydrolysis with enzyme recycling was implemented, allowing to maintain steady levels of enzyme activity with only 50 % of enzyme on each recycling stage. Additionally, interesting levels of solid conversion (70-81 %) were also achieved, leading to considerable improvements on glucose and ethanol production comparatively with the reports available so far (3.4 and 3.8 fold, respectively).
Conclusions: Enzyme recycling viability depends on enzyme distribution between the solid and liquid phases at the end of hydrolysis, as well as enzymes thermostability. Both are critical features to be observed for a judicious choice of enzyme cocktail. This work demonstrates that enzyme recycling in intensified biomass degradation can be achieved through simple means. The process is possibly much more effective at larger scale, hence novel enzyme formulations favoring this possibility should be developed for industrial usage.This work had the fnancial support of the Portuguese Foundation for Science
and Technology (FCT) under the scope of the strategic funding of UID/
BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and the
MultiBiorefnery project (POCI-01-0145-FEDER-016403). Furthermore, FCT
equally supported the Ph.D. grant to DG (SFRH/BD/88623/2012).info:eu-repo/semantics/publishedVersio
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