The grafting of recycled polyol from waste polyurethane foam onto new polyurethane and its impact on shape recovery and water vapor permeation

Recycled polyols from waste polyurethane (PU) foams were grafted onto PU to improve the properties such as tensile strength, shape recovery, low-temperature flexibility, and water compatibility. The recycled polyol was either purified by column chromatography before grafting or was used directly for grafting. The soft segment melting temperature of PU did not notably increase with the addition of polyol, whereas the glass transition temperature increased with increased polyol content. The tensile strength sharply increased at low polyol content and decreased at high polyol content, while the strain at break did not significantly change with an increase in polyol content. The shape recovery at 10 oC notably improved compared with unmodified PU and remained high after four cyclic tests. Polyol-grafted PU demonstrated better lowtemperature flexibility and reduced the water vapor permeability of PU membranes. Overall, grafting recycled polyol onto PU significantly improved the tensile stress, shape recovery, and low-temperature flexibility of PU.     

Hybridizing <Emphasis Type="Italic">Brassica rapa</Emphasis> with wild crucifers <Emphasis Type="Italic">Diplotaxis erucoides</Emphasis> and <Emphasis Type="Italic">Brassica maurorum</Emphasis>

Two wide hybrids, Diplotaxis erucoides (2n = 14) × Brassica rapa (2n = 20) and B. maurorum (2n = 20) × B. rapa, were developed using the sequential ovary–ovule culture. Reciprocal crosses failed, possibly as a consequence of strong unilateral incompatibility. The F ₁ hybrids in each combination were completely male sterile and morphologically intermediate to the respective parents. DNA marker polymorphism and chromosome counts confirmed their hybrid nature. High frequency of bivalents in the F ₁ and the presence of trivalents/quadrivalents in the derived amphiploids suggested genomic duplications and homoeology of the parental genomes. Up to three homoeologous pairs between the D. erucoides (D^eD^e) and B. rapa (AA) genomes, and one between B. maurorum (B^mB^m) and B. rapa genomes were observed. Successful synthesis of the F ₁ hybrids and amphiploids of B. rapa with D. erucoides and B. maurorum, and allosyndetic chromosome pairing are expected to permit introgressions of desirable loci into the cultivated Brassica germplasm, especially for resistance to Alternaria brassicae and Albugo candida.     

Consumer perception versus scientific evidence of farmed and wild fish: exploratory insights from Belgium

The increasing number of marketable fish being supplied from aquaculture is a response to the increasing demand for healthy food and is filling the gap left by depleting natural fish stocks. Little is known about the awareness and perception of the consumer in terms of farmed fish versus fish from capture fisheries. The consumer's subjective point of view is of overriding importance for the production system and product acceptance as well as for future market success. In this paper consumer perception in Belgium is explored and compared against scientific evidence of farmed versus wild fish. Primary data were collected through a consumer survey (April 2003) and focus group discussions (May 2004) with Belgian consumers. The majority of the consumer sample reported no perceived differences between farmed versus wild fish. However, mean perception scores were slightly in favour of wild fish on the attributes taste, health and nutritious value, in particular among consumers aged 55 years and older. The availability of farmed fish was perceived to be better than that of wild fish, while the consumer's perception of safety did not differ between farmed and wild fish. The focus group discussions indicated that consumers’ opinions and beliefs about farmed fish are mainly based on emotion and image transfer from intensive terrestrial livestock production rather than on awareness and factual knowledge of aquaculture.

Ontogeny of schooling behavior in the oval squid <Emphasis Type="Italic">Sepioteuthis lessoniana</Emphasis>

In contrast to schooling behavior in fish, which is well documented, the schooling behavior of an evolutionary counterpart, squid, has not been adequately described in the literature. In the current study, we investigated the ontogeny of schooling behavior in the oval squid Sepioteuthis lessoniana reared from hatching to about two months of age. During the two months of development, the distance and angle between nearest-neighbor individuals decreased from 5.3 mantle lengths (ML) to 1.8 ML and from 42.7° to 24.2°, respectively. In addition, the swimming distance of individuals in experimental duration decreased from 530.4 to 79.9 ML, and the relative swimming speed also decreased from 17.1 to 4.6 ML/s during the same period, with increasing synchronized hovering of individuals. These observations clearly suggest that oval squid swim randomly until 20 days after hatching, then form a school 30–60 days after hatching with an inter-individual distance of 2.0 ML. At two months after hatching, oval squid individuals swam in a parallel orientation and formed a belt-shaped arrangement, similar to the adult schooling behavior observed in natural populations.     

Evaluating the durability of wood-based panels using internal bond strength results from accelerated aging treatments

In this study, the durability of wood-based panels was evaluated by comparing the internal bond (IB) strength retention after five different laboratory-based accelerated aging tests with the IB retention after 5 years of outdoor exposure in Shizuoka City. In each accelerated aging test, the IB retention of MDI-bonded panels showed high retention compared to other panels. Outdoor exposure in Shizuoka City resulted in an IB retention value for particleboard (PF) and oriented strandboard (aspen) of less than 10% after the 5-year exposure period. Medium-density fiberboards maintained their initial IB strength over the same period. Calculation of the mean IB retention for all board types allowed comparison of the severity of aging between the accelerated test methods and outdoor exposure. The ASTM six-cycle test method was the most severe among the standard treatment cycles applied.     

Laboratory characterization of firebrands involved in spot fires

• Introduction  

Wildfires are considered the most important disturbance in the Mediterranean Basin, and some are propagated over long distances due to lift-off and ignition of firebrands.     

Hyper-spectral remote sensing to monitor vegetation stress

Background, aim, and scope  Vegetation stress diagnoses based on plant sampling and physiochemical analysis using traditional methods are commonly time-consuming, destructive and expensive. The measurement of field spectral reflectance is one basis of airborne or spaceborne remote sensing monitoring. Materials and methods  In this study, paddy plants were grown in the barrels evenly filled with 10.0 kg soil that was mixed respectively with 0, 2.5 × 207.2 and 5.0 × 207.2 mg Pb per 1,000 g soil. Rice canopy spectra were gathered by mobile hyper-spectral radiometer (ASD FieldSpec Pro FR, USA). Meanwhile, canopy leaves in the field-of-view (FOV) of spectroradiometer were collected and then prepared in the laboratory, (1) for chlorophyll measurement by Model 721 spectrophotometer, and (2) for Pb determination by atomic absorption spectrophotometer (SpectraAA-220FS). Results and discussion  Canopy spectral reflectance in the region of visible-to-near-infrared light (VNIR) increased, because ascended Pb concentration caused the decrease of canopy chlorophyll content. In the agro-ecosystem, however, heavy metal contamination is presented typically as mixture and their interactions strongly affect actually occurring effects. Normalized spectral absorption depth (D _n), and shifting distance (DS) of red edge position (REPs) revealed the differences in Pb concentration for canopy leaves, especially at the early tillering stage. Due to insufficient biomass of rice plants, the 30th day was not reliable enough for the selection of crucial growth stages. Some special sensitive bands might be omitted at the same time because of limited sample sets. Conclusions  Our initial experiments are still too few in the amounts of both metals and plants neither to build accurate prediction models nor to discuss the transformation from ground to air/spaceborne remote sensing. However, we are pleased to communicate that ground remote sensing measurements would provide reliable information for the estimation of Pb concentration in rice plants at the early tillering stage when proper features (such as DS and D _n) of reflectance spectra are applied. Recommendations and perspectives  Hyper-spectral remote sensing is a potential and promising technology for monitoring environmental stresses on agricultural vegetation. Further ground remote sensing experiments are necessary to evaluate the possibility of hyper-spectral reflectance spectroscopy in monitoring different kinds of metals’ stress on various plants.     

Interpreting the temperature-induced response of ammonia oxidizing microorganisms in soil using nitrogen isotope fractionation

Purpose  

Although nitrification plays a key role in the fate of soil nitrogen (N) under global warming, little information is available for the nitrifiers’ response to changing temperatures. Nitrogen isotope fractionation associated with nitrification can be a proxy of nitrifiers’ sensitivity to changing temperature. We hypothesized that the temperature-induced balance between the transport of substrate NH₄⁺ into the microbial cell (supply) and the intracellular NH₄⁺ oxidation (consumption) governs the intracellular NH₄⁺ concentration and then affects nitrification rates and associated isotope fractionations. This study was conducted to understand the microbial response of NH₄⁺ oxidation to changing temperatures by examining the effect of changing temperature on nitrification rate and apparent isotope fractionation.     

Confronting collinearity: comparing methods for disentangling the effects of habitat loss and fragmentation

Estimating the relative importance of habitat loss and fragmentation is necessary to estimate the potential benefits of specific management actions and to ensure that limited conservation resources are used efficiently. However, estimating relative effects is complicated because the two processes are highly correlated. Previous studies have used a wide variety of statistical methods to separate their effects and we speculated that the published results may have been influenced by the methods used. We used simulations to determine whether, under identical conditions, the following 7 methods generate different estimates of relative importance for realistically correlated landscape predictors: residual regression, model or variable selection, averaged coefficients from all supported models, summed Akaike weights, classical variance partitioning, hierarchical variance partitioning, and a multiple regression model with no adjustments for collinearity. We found that different methods generated different rankings of the predictors and that some metrics were strongly biased. Residual regression and variance partitioning were highly biased by correlations among predictors and the bias depended on the direction of a predictor’s effect (positive vs. negative). Our results suggest that many efforts to deal with the correlation between amount and fragmentation may have done more harm than good. If confounding effects are controlled and adequate thought is given to the ecological mechanisms behind modeled predictors, then standardized partial regression coefficients are unbiased estimates of the relative importance of amount and fragmentation, even when predictors are highly correlated.