Rice husk is a by-product of rice milling process that usually finds inadequate final disposal (burning, land filling). Thermoplastics composites filled with rice husk flour are materials that offer ...an alternative for using this agricultural resource viewing the production of low dense materials with some specific properties. In this work composites of polypropylene (PP) and rice husk flour (RHF) were prepared by melt extrusion. Maleic anhydride-modified PP (MAPP) was added as a coupling agent. It was verified that tensile strength decreased with filler loading. The presence of MAPP improved this property showing a strong dependence on the MAPP/RHF ratio (MAPP/RHF = 0.03 produced the best results). The density of the composites slightly increased with filler and coupling agent in comparison to pure PP. The presence of MAPP diminished more than 20% water uptake in highly-loaded composites.
Starch is the most abundant carbohydrate found in grains, roots and tubers. Modified starches are employed to overcome most of native starch limitations in industrial applications. Pinhão is the seed ...of
Araucaria angustifolia
and starch is approximately 36% of its composition. Acid hydrolysis changes the starch physicochemical properties without impairing the granular structure. The native and hydrochloric acid- modified (0.1 and 0.5 mol L
−1
) pinhão starches were investigated using thermal (TG-DTA and DSC), rheological (RVA), structural (XRD and SEM) and statistical analysis (ANOVA and Tukey). The aim of this study was to evaluate the effects of acid modification of pinhão starches in aqueous solutions. The starches were chosen because of their low gelatinization temperature (below 60 °C). TG-DTA results in air atmosphere showed that treated samples presented higher thermal stability. The same analysis using nitrogen atmosphere showed similarities between the samples. DSC results indicate that highest acid concentrations promoted crystallinity reduction and losses in the internal structure of the granule. The genetic sources demonstrated different behaviors. The viscosity parameters decreased with the intensity of acid treatment. The XRD identified the type C pattern for the starches and the relative crystallinity increased according to the intensity of the acid hydrolysis. Superficial changes in the granules were observed by SEM. Therefore, modified pinhão starch has potential use for industrial applications. Further studies are necessary to extend these applications.
Jurasaidae are a family of neotenic elateroid beetles which was described recently from the Brazilian Atlantic Forest biodiversity hotspot based on three species in two genera. All life stages live ...in the soil, including the larviform females, and only adult males are able to fly. Here, we report the discovery of two new species, Jurasai miraculum sp. nov. and J. vanini sp. nov., and a new, morphologically remarkable population of J. digitusdei Rosa et al., 2020. Our discovery sheds further light on the diversity and biogeography of the group. Most species of Jurasaidae are known from the rainforest remnants of the Atlantic Forest, but here for the first time we report a jurasaid species from the relatively drier Atlantic Forest/Caatinga transitional zone. Considering our recent findings, minute body size and cryptic lifestyle of all jurasaids, together with potentially high numbers of yet undescribed species of this family from the Atlantic Forest and possibly also other surrounding ecoregions, we call for both field research in potentially suitable localities as well as for a detailed investigation of a massive amount of already collected but still unprocessed materials deposited in a number of Brazilian institutes, laboratories and collections.
A dynamic light scattering (DLS) study was performed to investigate the interactions of maize straw cellulose nanocrystals (CNC) with the cationic surfactant hexadecyltrimethylammonium bromide ...(CTAB). Phase analysis light scattering (which gives access to zeta potential (
ζ
) and electrical conductance) technique was used with the aim to obtain additional information. Zeta potential behavior demonstrated the colloidal systems are stable. By electrical conductance data, it was verified that the process of formation of micelles is thermodynamically spontaneous. Dynamic light scattering was shown to be very useful to find the optimum hydrolysis time so as to obtain well dispersed and more isolated nanocrystals. In the presence of the cationic surfactant CTAB, the formation of micelles and aggregates CNC/CTAB were well identified by DLS showing that the dynamics of cellulose nanocrystals in aqueous suspensions is strongly affected by the surfactant.
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•Evolved gas analysis of aceclofenac were performad by Pyrolysis-GC–MS and TG-DSC-FTIR.•The used techniques were important in determination of main reactions mechanism in pyrolytic ...atmosphere.•After pyrolysis main compounds were 1-(2,6-dichlorophenyl)-2-indolinone (94.91%) and 2,6-dichloro-N-(2-methylphenyl)–benzenamine (1.21%).
During the twentieth century the growth of industrialisation, urbanisation and populations culminated in huge areas of waste disposal worldwide. Consequently, the management of the disposal of medicines (expired or not) is important in order to minimise the possibility of environmental pollution. A sample of aceclofenac (purity=99.77% and m.p.=151.63°C) was analysed by TG-DSC-FTIR in nitrogen atmosphere. The TG-DSC curves showed two main stages of decomposition, with loss of organic matter generating carbonaceous derivatives as final residue. The use of coupled FTIR suggested the loss of CO, CO2 and/or 2-chloro-propanoic acid/2-chloro-butanoic acid. The use of fast pyrolysis (Pyr) coupled with GC–MS suggested that the main compounds that were released were 1-(2,6-dichlorophenyl)-2-indolinone and 2,6-dichloro-N-(2-methylphenyl)–benzenamine. The differences in the results between the techniques were due to the experimental conditions used for each instrument.
ABSTRACT Water governance systems must be effective in establishing policies capable of guiding decision making. Their framework needs to weigh the intrinsic complexity of inter-scale and multi-level ...interactions. Aspects such as decentralization and stakeholder engagement are pillars to be considered. In shared river basins (international or national), there are challenges to overcome since there is a need for managing water at different scales and multiple levels. This study aims to analyse the degree of implementation of the National Water Resources Policy in a shared federal basin in Brazil (the São Francisco River Basin) considering the basin as a whole (macro level) and its micro level (the 34 sub-basins that compose it). Multi-level interrelationships in the implementation of water policy are analysed. To this end, OECD Water Governance Principle 2 (“Manage water at the appropriate scales”) is considered as the basis for this analysis. An adaptation of the OECD Water Governance Indicator Framework methodology is used to classify the 34 sub-basins at different stages of water policy implementation. The outcomes indicate deficiencies in the process of water policy implementation in sub-basins. There is a need for better interactions at the federal, state and river basin levels to strengthen the governance system.
RESUMO Sistemas de governança de água devem ser eficientes em estabelecer políticas capazes de nortear a tomada de decisão. Os arcabouços precisam ponderar a complexidade intrínseca das interações interescala e multinível. Aspectos como descentralização e comprometimento entre as partes interessadas são pilares a serem considerados. Existem desafios a serem vencidos em bacias compartilhadas (nacionais ou internacionais) uma vez que há a necessidade de gerenciar a água em diferentes escalas e múltiplos níveis. Este estudo tem como objetivo analisar o grau de implementação da Política Nacional de Recursos Hídricos em uma bacia federal compartilhada (a Bacia Hidrográfica do Rio São Francisco) no seu nível macro e no nível micro (as 34 sub-bacias que a compõe). São analisadas as interrelações multiníveis na implementação da política hídrica como balizador da governança da água. Para tal, considera-se o Princípio 2 da Governança da Água da OECD (Gerenciar a água em escalas apropriadas) como fundamento para essa análise. Uma adaptação da metodologia do Quadro de Indicadores da Governança da Água é usada para classificar as 34 sub-bacias em distintos estágios de implementação da política hídrica. Os resultados apontam para deficiências no processo de implementação da política em sub-bacias. Há necessidade de melhores interações nos níveis federal, estadual e das bacias hidrográficas a fim de fortalecer o sistema de governança.
The family Cerophytidae is revised to include Afrocerophytum vix gen. nov. and sp. nov., from the tropical rainforest of western Africa. Afrocerophytum and A. vix (type locality: Ivory Coast, Tai ...Region, neighborhood of Gouleako village) are described and illustrated. A key to the Cerophytidae genera is provided. The new genus is distinguished by four autapomorphies: anterior edge of phallobase rounded and not emarginate, base of tergite IX not fused at middle with the base of sternite IX, basal region of penis weakly constricted, and coxites divided into proximal and distal lobes. A cladistic analysis was conducted including all 22 species of known Cerophytidae and using representatives of the families Eucnemidae, Throscidae, Brachypsectridae and Elateridae as outgroups. The strict consensus cladogram produced from the resulting eighteen most parsimonious trees is (Cerophytum (Afrocerophytum (Brachycerophytum, Phytocerum))). Cerophytum, the Holarctic clade, is the sister group of the Gondwanian clade (Afrocerophytum (Brachycerophytum, Phytocerum)); the Ethiopian clade Afrocerophytum is the sister group of the Neotropical clade (Brachycerophytum, Phytocerum).
Brazilian Dioscoreaceas starches Hornung, Polyanna Silveira; do Prado Cordoba, Layse; da Silveira Lazzarotto, Simone Rosa ...
Journal of thermal analysis and calorimetry,
03/2017, Letnik:
127, Številka:
3
Journal Article
Recenzirano
Determination of the characteristics of native starches is crucial in order to select their best application in various industrial fields. Thus, two different types of non-traditional native starches ...from the Dioscoreaceas species (Dioscorea sp. and Dioscorea piperifolia Humb. var. Wild) were studied regarding their thermal, structural and rheological properties. The results were contrasted with traditional commercial starch sources (potato, cassava and corn). From the thermogravimetric results (TG/DTG), D. piperifolia starch obtained the highest thermal stability of the samples, except for potato starch. Furthermore, using differential scanning calorimetry and viscoamylograph profiles (RVA), it was found that the Dioscoreaceas starches presented a higher onset (T.sub.o) temperature and susceptibility to retrogradation. They also showed lower values in relation to relative crystallinity, which was calculated from their X-ray patterns and tendency to white (L*) colour. The shapes of the Discoreaceas starch granules were determined using electron microscopy; it was found that as the potato starch the Dioscoreaceas starches showed a wide range of particle size.
Solid samples obtained from 4-nitrophenol and aliphatic amines, in excess of amine, were submitted to thermal analysis. The TGA/DTA showed two endothermic events, with exception of
tert
-butylamine, ...which showed three endothermic peaks. The first event was the melting of the ionic salt, which temperature does not follow a pattern, and is maxim for ethylammonium minimal for butylammonium salt. For methylammonium and ethylammonium, the fusion is followed by mass loss corresponding to one amine by 4-nitrophenol, while for the others ammonium salts, this event marks the beginning of the mass variation, that is maintained until the decomposition of the 4-nitrophenol at 485 K. The temperature of the event depends of the length of the chain of the amine, while the second occurs at the same temperature for all amines.
Fireflies (Coleoptera: Lampyridae) are commonly recognized by adult traits, such as a soft exoskeleton, lanterns and associated glow and flash patterns, but their larval stage is far less ...appreciated. However, fireflies spend most of their lives as larvae, and adults of most species rely solely on resources previously obtained. Therefore, studying the immature stages is imperative towards a comprehensive understanding of fireflies. This paper reviews and indicates key gaps in the biology of firefly larvae based on available literature.
We reviewed the literature on firefly larvae to identify key issues and important taxonomic, geographic, and subject biases and gaps.
We found 376 papers that included information on firefly larvae. Only 139 species in 47 genera across eight of eleven lampyrid subfamilies have been studied during larval stages. These numbers reveal a staggering gap, since 94% of species and over half of the genera of fireflies were never studied in a crucial stage of their life cycle. Most studies on firefly larvae focus on two subfamilies (Luciolinae and Lampyrinae) in four zoogeographic regions (Sino-Japanese, Oriental, Nearctic, and Palearctic), whereas the other subfamilies and regions remain largely unstudied. These studies mainly dealt with morphology and behavior, other subjects remaining greatly understudied by comparison, including habitats, life cycle, physiology and interactions.
Together, these literature biases and gaps highlight how little is known about firefly larvae, and warmly invite basic and applied research, in the field and in the lab, to overcome these limitations and improve our understanding of firefly biology to better preserve them.
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