Nanocomposites of biobased thermoplastic polyurethane (TPU) from dimer fatty acids and halloysite nanotubes (HNT) were elaborated by different melt processing routes such as direct mixing (1 step process) and masterbatch/dilution (2 steps process), at different temperatures (150 and 180 °C). Rheological and transmission electron microscopy (TEM) analyses indicated that the HNT distribution and dispersion were dependent on the processing conditions: the 2 steps process produced well dispersed nanocomposites and the masterbatch dilution at 180 °C improved the HNT distribution through the TPU. Consequently, a high reinforcement was achieved, with a 40% increase in the elastic modulus and 8 °C increase in the relaxation temperature related to the glass transition of the TPU soft segments. Furthermore, a percolated network was attained, even if a large extent of HNT breaking was observed during processing, suggesting that a synergistic effect between the HNT particles and the TPU's hard segments in the molten state occurred. Thus, HNT nanotubes can be seen as highly reinforcing nanofillers when good dispersion and distribution are achieved through the polymeric matrix. 相似文献
This study aimed to assess the influence of two label conditions on the acceptance of boar meat. A central location test was conducted with 145 consumers each assessing 4 pieces of pork loin. 相似文献
Thermal loading induces modifications of the precipitation microstructure of Al–Si–Cu–Mg alloys. This study focuses on the effect of deformation on precipitation microstructure during thermomechanical loadings. Several specimens were thermomechanically cycled while others were exposed to the same thermal cycles without any mechanical loading. The nature and morphological characteristics of the precipitation microstructure of the thermomechanically cycled specimens are compared to those of the thermally aged ones, using transmission electron microscopy (TEM), in order to assess the effect of deformation on the precipitation microstructure and especially on the kinetics of precipitate growth. The absence of any significant effect of superimposed straining during thermal cycling is discussed. Implications for the prevision of yield strength degradation during service operation are briefly presented.
Three new regulated deficit irrigation (RDI) treatments were applied to “Arbequina” olive orchards during pit hardening. Oil quality was determined by measuring analytical parameters for olive oil grading, antioxidant activity, total phenol content, fatty acid profile, volatile compounds profile, and sensory analysis. Oils from RDI were classified as “extra virgin olive oil” and their quality was improved due to their higher antioxidant potential (ABTS+ [increased ~75%] and DPPH˙ [increased ~25%] assays) and phenols (increased ~53%) than control. Concentration of total volatile compounds decreased (~27%) but RDI olive oils showed a more balanced profile (alcohols, aldehydes, and esters). Monounsaturated fatty acid content increased (~5%) and atherogenic and thrombogenic indexes decreased (~8.5%) in RDI olive oil. Regarding sensory analysis, RDI provided more balanced oils with higher fruit aroma than control. Other benefits of RDI olive oil, when compared with oil from full irrigated orchards are reduced use of water and improved functional and sensory quality. 相似文献
In this note, we investigate the finite‐sample properties of Moran's I test statistic for spatial autocorrelation in tobit models suggested by Kelejian and Prucha. We fill a void in the theoretical literature by investigating the finite sample properties of this test statistic in a series of Monte Carlo simulations, using data sets ranging from 49 to 15,625 observations. We find that the test is unbiased, has considerable power and approximates the asymptotic normal distribution even for medium‐sized sample sizes, empirically confirming the theoretical results of Kelejian and Prucha. However, some caution is needed, since the statistic turns out to be sensitive to misspecification in the form of heteroscedasticity. In such instances the test over‐rejects the null hypothesis, mistaking heteroscedasticity for spatial autocorrelation. 相似文献
Herein we describe the design, multicomponent synthesis, and biological, molecular modeling and ADMET studies, as well as in vitro PAMPA‐blood–brain barrier (BBB) analysis of new tacrine–ferulic acid hybrids (TFAHs). We identified (E)‐3‐(hydroxy‐3‐methoxyphenyl)‐N‐{8[(7‐methoxy‐1,2,3,4‐tetrahydroacridin‐9‐yl)amino]octyl}‐N‐[2‐(naphthalen‐2‐ylamino)2‐oxoethyl]acrylamide (TFAH 10 n ) as a particularly interesting multipotent compound that shows moderate and completely selective inhibition of human butyrylcholinesterase (IC50=68.2 nM ), strong antioxidant activity (4.29 equiv trolox in an oxygen radical absorbance capacity (ORAC) assay), and good β‐amyloid (Aβ) anti‐aggregation properties (65.6 % at 1:1 ratio); moreover, it is able to permeate central nervous system (CNS) tissues, as determined by PAMPA‐BBB assay. Notably, even when tested at very high concentrations, TFAH 10 n easily surpasses the other TFAHs in hepatotoxicity profiling (59.4 % cell viability at 1000 μM ), affording good neuroprotection against toxic insults such as Aβ1–40, Aβ1–42, H2O2, and oligomycin A/rotenone on SH‐SY5Y cells, at 1 μM . The results reported herein support the development of new multipotent TFAH derivatives as potential drugs for the treatment of Alzheimer′s disease. 相似文献