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The use of lignocellulosic fibers as fillers in polymer matrices has aroused the interest of the scientific community and industrial sectors. In Brazil, the high macadamia consumption has generated a significant amount of residues that are incorrectly discharged. Thus, the revalorization of macadamia residues (MR) as filler in castor oil-based polyurethane (PU) foams with different particle sizes (28 and 35 mesh) and filler contents (5–20%wt) was evaluated. The MR, neat PU, and their biocomposites were characterized by Spectroscopy Fourier-transform infrared spectroscopy (FTIR), Optical microscopy (OM), Scanning electron microscopy (SEM), apparent density, contact angle, water adsorption experiments, X-Ray diffraction analysis (XRD), Thermogravimetry (TGA), and mechanical tests. The insertion of MR in the PU matrix provided a nucleating effect producing greater density foams and smaller pore sizes compared to neat PU. Specimens of higher MR contents were highlighted. These biocomposites presented a good hydrophobic character, a low water permeation, and a strong interaction between MR/PU, resulting in biocomposites of good thermal stability and compressive strength. Regarding the statistical study, it was observed that the different MR sizes induced the formation of small pores statistically distinct. Besides, the largest particle (28 mesh) provided better mechanical performance. Therefore, MR as filler in PU foams is a sustainable alternative for the development of materials with several applications. [ABSTRACT FROM AUTHOR]

The search for environmental sustainability has stimulated the construction sector to look for natural materials with an ecological footprint, high strength/weight ratio, and better thermal and mechanical properties. Besides those properties, water absorption studies are necessary to reach these requirements. This research proposes to evaluate changes in the visual appearance, density, chemical structure, morphology, water absorption, porosity, and thermal and mechanical properties in castor oil-based polyurethane reinforced with açaí waste (5–20 wt%). Results exposed that the addition of fiber to the PU reduced the pore size due to the increased cross-link density of PU foams caused by incorporating additional fiber groups, reacting with isocyanate groups. Also, the fibers were hydrogen bonded to the PU molecular chains via the interaction between the O–H of the fibers and the N–H of the PU foam. The water absorption of the biocomposites increased with time and with fiber loading; however, it did not surpass pure PU. The fiber addition improved crystallinity and hydrophobicity. The compressive strength presented a decreasing trend, while, for the impact test, an increase was observed proportionally to the açaí residue content. Thus, the developed biocomposites can be a possibility for alternative eco-efficient building insulators. [ABSTRACT FROM AUTHOR]

The effects of concurrent ocean warming and acidification on Antarctic marine benthos warrant investigation as little is known about potential synergies between these climate change stressors. We examined the interactive effects of warming and acidification on fertilization and embryonic development of the ecologically important sea urchin Sterechinus neumayeri reared from fertilization in elevated temperature (+1.5°C and 3°C) and decreased pH (−0.3 and −0.5 pH units) treatments. Fertilization using gametes from multiple males and females, to represent populations of spawners, was resilient to acidification at ambient temperature (0°C). At elevated temperatures, there was a negative interactive effect of temperature and pH on percentage of fertilization (11% reduction at 3°C). For cleavage stage embryos, there was a significant, but small reduction (6%) in the percentage of normal embryos at pH 7.5. For blastulae, a 10-11% decrease in normal development occurred in the +3°C treatments across all pH levels. Our results highlight the importance of considering the impacts of both temperature and pH in assessing the life history response of S. neumayeri in a changing polar ocean. While fertilization and development to the blastula stage were robust to levels of temperature and pH change predicted over coming decades, deleterious interactive effects were evident between these stressors at levels projected to occur by 2100 and beyond. [ABSTRACT FROM AUTHOR]

This article presents a study on radon levels in combustion stream of a natural gas incinerator power plant. For the study gas samples collected on different sampling days were collected from the combustion stream of a local natural gas recovery power plant using Tedlar bags. The samples were shipped immediately on July 12 and August 5, 1994 to TCS Industries, Inc., Harrisburg, Pennsylvania to analyze the radon concentration in the combusted effluent. The samples were split into two sub samples and aspirated into evacuated Model 300A Lucas cells manufactured by Pylon Electronics Inc. of Canada. The oil lubricated pump was rated for 10-micron vacuum.

Presents research which showed that the homeodomain protein Nkx2.2 has a primary role in ventral neuronal patterning in vertebrate development. Role of the signalling protein Sonic hedgehog (Shh) in neural generation; Traits of mice lacking the homeodomain protein Pax6; Relation between Pax6 and Nkx2.2 in gene expression; Role of Nkx2.2 in interpreting Shh signals and selecting neuronal identity.

Diffusion of water into quartz was studied by measuring H and 18O concentration profiles in surface layers of quartz samples treated hydrothermally in the range of 125° C to 200° C. Sample surfaces were orientated normal to the c-axis. The measurements were performed using the nuclear reactions 1H(15N,αγ)12C and 18O(p,α)15N. The diffusion profiles have widths of up to 500 nm. Diffusion rate constants derived from the profiles are in the range of 10–15 cm2/s to 10–18 cm2/s and show a distinct temperature dependence, yielding a rough estimate of about 60 kJ/mole for the activation energy. [ABSTRACT FROM AUTHOR]

In the absence of gravity, surface tension dominates over the behavior of liquids. While this often poses a challenge in adapting Earth-based technologies to space, it can also provide an opportunity for novel technologies that utilize its advantages. In particular, surface tension drives a liquid body to a constant-mean-curvature shape with extremely smooth surfaces, properties which are highly beneficial for optical components. We here present the design, implementation and analysis of parabolic flight experiments demonstrating the creation and in-situ measurement of optical lenses made entirely by shaping liquids in microgravity. We provide details of the two experimental systems designed to inject the precise amount of liquid within the short microgravity timeframe provided in a parabolic flight, while also measuring the resulting lens' characteristics in real-time using both resolution target-imaging and Shack-Hartmann wavefront sensing. We successfully created more than 20 liquid lenses during the flights. We also present video recordings of the process, from the lenses' creation during microgravity and up until their collapse upon return to gravity. The work thus demonstrates the feasibility of creating and utilizing liquid-based optics in space., (© 2023. Springer Nature Limited.)