293 research outputs found
A case study undertaken recycling & reuse of glass fiber reinforced thermoset polumer wastes of composite materials industry
Glass fibre-reinforced plastics (GFRP) have been considered inherently difficult to recycle due to both: crosslinked nature of thermoset resins, which cannot be remoulded, and complex composition of the composite itself.
Presently, most of the GFRP waste is landfilled leading to negative environmental impacts and supplementary added costs. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, efforts were made in order to recycle grinded GFRP waste, proceeding from pultrusion production scrap, into new and sustainable composite materials. For this purpose, GFRP waste recyclates, were incorporated into polyester based mortars as fine aggregate and filler replacements at different load contents and particle size distributions. Potential recycling solution was assessed by mechanical behaviour of resultant GFRP waste modified polymer mortars. Results revealed that GFRP waste filled polymer mortars present improved flexural and compressive behaviour over unmodified polyester based mortars, thus indicating the feasibility of the GFRP industrial waste reuse into concrete-polymer composite materials
Respostas fenolĂłgicas de cultivares brasileiras de trigo Ă vernalização e ao fotoperĂodo
O objetivo deste trabalho foi avaliar o efeito de diferentes combinaçÔes de vernalização e fotoperĂodo no desenvolvimento de cinco cultivares brasileiras de trigo. O experimento foi realizado em Passo Fundo, RS, em trĂȘs Ă©pocas de semeadura: 23/6, 25/7 e 27/8 de 2003. O delineamento experimental foi o de blocos ao acaso com parcelas subsubdivididas e quatro repetiçÔes. Os tratamentos consistiram de: trĂȘs regimes fotoperiĂłdicos - fotoperĂodo natural (FN), fotoperĂodo estendido em quatro horas (FE 4) e fotoperĂodo estendido atĂ© completar vinte horas de luz (FE 20) - locados na parcela principal; dois regimes de vernalização - nĂŁo vernalizado (NV) e vernalizado com 30 dias (V) -, na subparcela; e cinco cultivares de trigo - BRS 179, BRS 194, BRS 207, BRS Figueira e BRS Umbu, avaliadas nas subsubparcelas. Houve interação entre fotoperĂodo e cultivar (semeadura em 23/6), e todas as cultivares tiveram o ciclo reduzido com o aumento do fotoperĂodo, enquanto nas plantas com Ă©pocas de semeadura 25/7 e 27/8, houve interação entre fotoperĂodo e cultivar e entre vernalização e cultivar. Essas variĂĄveis aceleraram o ciclo de desenvolvimento da cultura e interferiram na duração dos subperĂodos importantes para a formação dos componentes do rendimento de grĂŁos
Pre-B Cell Receptor Signaling Induces Immunoglobulin Îș Locus Accessibility by Functional Redistribution of Enhancer-Mediated Chromatin Interactions
During B cell development, the precursor B cell receptor (pre-BCR) checkpoint is thought to increase immunoglobulin Îș light chain (IgÎș) locus accessibility to the V(D)J recombinase. Accordingly, pre-B cells lacking the pre-BCR signaling molecules Btk or Slp65 showed reduced germline VÎș transcription. To investigate whether pre-BCR signaling modulates VÎș accessibility through enhancer-mediated IgÎș locus topology, we performed chromosome conformation capture and sequencing analyses. These revealed that already in pro-B cells the Îș enhancers robustly interact with the âŒ3.2 Mb VÎș region and its flanking sequences. Analyses in wild-type, Btk, and Slp65 single- and double-deficient pre-B cells demonstrated that pre-BCR signaling reduces interactions of both enhancers with IgÎș locus flanking sequences and increases interactions of the 3âČÎș enhancer with VÎș genes. Remarkably, pre-BCR signaling does not significantly affect interactions between the intronic enhancer and VÎș genes, which are already robust in pro-B cells. Both enhancers interact most frequently with highly used VÎș genes, which are often marked by transcription factor E2a. We conclude that the Îș enhancers interact with the VÎș region already in pro-B cells and that pre-BCR signaling induces accessibility through a functional redistribution of long-range chromatin interactions within the VÎș region, whereby the two enhancers play distinct roles
Effect of hofmeister ions on transport properties of aqueous solutions of sodium hyaluronate
Tracer diffusion coefficients obtained from the Taylor dispersion technique at 25.0âŠC were measured to study the influence of sodium, ammonium and magnesium salts at 0.01 and 0.1 mol dmâ3 on the transport behavior of sodium hyaluronate (NaHy, 0.1%). The selection of these salts was based on their position in Hofmeister series, which describe the specific influence of different ions (cations and anions) on some physicochemical properties of a system that can be interpreted as a salting-in or salting-out effect. In our case, in general, an increase in the ionic strength (i.e., concentrations at 0.01 mol dmâ3 ) led to a significant decrease in the limiting diffusion coefficient of the NaHy 0.1%, indicating, in those circumstances, the presence of salting-in effects. However, the opposite effect (salting-out) was verified with the increase in concentration of some salts, mainly for NH4SCN at 0.1 mol dmâ3 . In this particular salt, the cation is weakly hydrated and, consequently, its presence does not favor interactions between NaHy and water molecules, promoting, in those circumstances, less resistance to the movement of NaHy and thus to the increase of its diffusion (19%). These data, complemented by viscosity measurements, permit us to have a better understanding about the effect of these salts on the transport behaviour of NaHy. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Fundacao para a Ciencia e a Tecnologia (FCT) through COMPETE Programme (Operational Programme for Competitiveness) [UIDB/QUI/00313/2020]; Ministry of Education, Youth and Sports of the Czech Republic DKRVO [RP/CPS/2020/003]Ministerstvo Ć kolstvĂ, MlĂĄdeĆŸe a TÄlovĂœchovy, MĆ MT: RP/CPS/2020/003; Fundação para a CiĂȘncia e a Tecnologia, FCT: UIDB/QUI/00313/202
High throughput toxicity screening and intracellular detection of nanomaterials
EC FP7 NANoREG (Grant Agreement NMP4-LA-2013-310584)Free PMC Article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5215403/With the growing numbers of nanomaterials (NMs), there is a great demand for
rapid and reliable ways of testing NM safetyâpreferably using in vitro
approaches, to avoid the ethical dilemmas associated with animal research. Data
are needed for developing intelligent testing strategies for risk assessment of
NMs, based on grouping and read-across approaches. The adoption of high
throughput screening (HTS) and high content analysis (HCA) for NM toxicity
testing allows the testing of numerous materials at different concentrations and
on different types of cells, reduces the effect of inter-experimental variation, and
makes substantial savings in time and cost.info:eu-repo/semantics/publishedVersio
Magnetocaloric effect in spin-1/2 chains with three-spin interactions
We consider the exactly solvable spin-1/2 chain with the three-spin
interactions of the and types in an external (transverse)
magnetic field. We calculate the entropy and examine the magnetocaloric effect
for the quantum spin system. We discuss a relation between the cooling/heating
efficiency and the ground-state phase diagram of the quantum spin model. We
also compare ability to cool/heat in the vicinity of the quantum critical and
triple points. Moreover, we examine the magnetocaloric effect for the spin-1/2
chain with three-spin interactions in a random (Lorentzian) transverse
magnetic field.Comment: 10 pages, 8 figure
- âŠ