Willow tree productivity on fertilizer solutions containing various Ca/Al ratios

This research examined the remedial effect of Ca on H- and Al- depression of willow (Salix viminalis L. 78183) growth. A greenhouse experiment was conducted with willow cuttings for 3 and 30 days in two ammonium nutrient solutions, one at pH value of 5.0 and another at 3.8. Nutrient solutions at pH 5.0 were: no Ca additive (NS); 2.75 mol m-3 Ca(H2PO4)2 (NSCaP); 2.75 mol m- 3 CaCl2 (NSCaCl2). Nutrient solutions at pH 3.8 (NSA) were: no Ca additive (NSA), 2.75 mol m-3 CaCl2 (NSACaCl2), 2.75 mol m-3 Ca(H2PO4)2 (NSACaP); 0, 0.26, 0.78, and 1.56 mol m-3 of Al (Al0, Al1, Al2, Al3) were added to each NSA treatment. Tree growth was best with NSCaCl2 over 3 days, but equal the other treatments at 30 days. Over 3 days, the NSACaCl2 treatment (pH 3.8; Al0) resulted in greater growth than occurred in NSA and NSACaP, but the responses of plant parts were different. Root growth (weight and length) in the presence of increasing Al was reduced in the NSA treatments but improved with the addition of CaCl2 and Ca(H2PO4). Total tree growth for 30 days was lowest in NSA, but highest in NSACaCl2Al0 and NSACaPAl0. Calcium in either Cl or PO4 form increased willow growth by partially reducing the depressive effects of H and Al, and increasing plant nutrient concentrations. Leaf weight, root length, and tissue dry weight, hydration, and several other parameters measured were significantly associated with solution calcium-aluminum balance (CAB) (CAB = Log Ca/Al, molar concentrations). The use of the term calcium-aluminum balance might be useful in predicting tree performance under acid conditions.     

Mineralisation of the antibiotic amoxicillin in pure and surface waters by artificial UVA‐ and sunlight‐induced Fenton oxidation

BACKGROUND: The degradation and mineralisation of the antibiotic amoxicillin by photo‐Fenton reactions, mediated by artificial UVA or solar irradiation, were investigated. Experiments were conducted with 30 mg L^?1 amoxicillin solutions prepared with deionised or surface water at Fe²⁺ and H₂O₂ concentrations in the range 0.0179–0.0895 and 1–10 mmol L^?1, respectively. Black‐light irradiation at 365 nm was provided by a 13 W m^?2 lamp, while samples were exposed to sunlight at 20 W m^?2 for solar experiments. RESULTS: In all cases, quantitative amoxicillin degradation occurred within 5 min and this was accompanied by lower mineralisation rates. Mineralisation followed first‐order kinetics with respect to organic carbon content and it was not affected by the water matrix with either type of illumination. Solar‐induced reactions were only marginally faster than artificial irradiation. Increasing the H₂O₂ to Fe²⁺ concentration ratio increases the extent of mineralisation up to a point beyond which degradation is impeded due to radical scavenging associated with the high concentrations of the Fenton reagents. CONCLUSION: Amoxicillin is readily degradable by homogeneous photocatalysis, being converted to more stable intermediates as indicated by lower mineralisation rates. The process can be driven by solar irradiation, thus providing a sustainable treatment technology. Copyright © 2009 Society of Chemical Industry     

A multi-device version of the HYFMGPU algorithm for hyperspectral scenes registration

The Journal of Supercomputing - Hyperspectral image registration is a relevant task for real-time applications like environmental disasters management or search and rescue scenarios. Traditional...     

On the ability of adaptation of speech signals and data hiding

The efficient wavelet masking is a scheme of speech-in-speech hiding based on the ability of adaptation of speech signals under the hypothesis “any (speech) secret signal may seem similar to a (speech) host signal if its wavelet coefficients are sorted” (Ballesteros L & Moreno A, 2012). In this paper, we delimitate the conditions under which the above hypothesis is true, as follows: (i) the secret and host signals must belong to legible voice signals, (ii) both signals must have the same sampling frequency, (iii) both signals must have the same time-frame, and finally (iv) the ratio between the non-zero coefficients of them should be in the interval [0.8 1.2]. Experimental tests were conducted to demonstrate the hypothesis on different cases: vowel to vowel, message to message and vowel & message, in three languages: English, French, and German. The parameter used to measure the similarity between the adapted secret message and the host signal is the squared Pearson correlation coefficient, r². The results demonstrate that the hypothesis is true under the theoretical conditions because in all the test cases r² was closed to 1 and the p-value was lower than 0.05.     

Textural,structural and electrical properties of TiO2 nanoparticles using Brij 35 and P123 as surfactants

The effect of the use of the triblock copolymer Pluronic P123[(PEO)₂₀(PPO)₇₀(PEO)₂₀, Aldrich] and the non-ionic polyoxyethylene-lauryl ether Brij 35 as surfactants on the textural, structural and electrical properties of nanosized TiO₂ is analyzed in this work. The as-obtained samples were thermally treated at 400 °C to eliminate the surfactant, promote dehydroxylation and crystallize the sample. The TiO₂ samples were characterized by thermal analysis, N₂ physisorption, x-ray diffraction analysis, micro-Raman spectroscopy and scanning electron microscopy. To evaluate the TiO₂ electrical features, I–V data were obtained. The x-ray diffraction results show that in the chemical synthesis using surfactants, the crystallite size is smaller than that of the commercial sample. The Raman spectroscopy results clearly indicate that, when P123 is used, the anatase phase of TiO₂ is obtained, whereas when Brij 35 is used a mixture of the anatase and brookite phases is obtained. The specific surface area and crystallite size of the TiO₂ prepared as indicated above are higher and smaller, respectively, than the corresponding properties found in commercial TiO₂. The I–V plot showed a nonlinear behavior of the nanosized TiO₂. The samples obtained with P123 showed the best electrical conductivity.     

The Effect of Contamination on Adhesive Strength: Wettability Characterization by the CSC Method

The correlation between the adhesive strength of joints of aluminum alloys and the wettability of their surfaces was studied. Two alloys, Al-1100 and Al-2024, were used, with two commercial epoxy adhesives, FM-73 and FM-300K, and the BR-127 primer. The wettability of the surfaces was modified by applying coatings of silicone oil and stearic acid at various concentrations. Wettability was characterized by the “complete spreading concentration” (CSC) method and by advancing contact angles. The CSC method was proven to be more reliable than contact angle measurements in detecting variations in the surface energy of the aluminum alloys studied. The adhesive strength was measured by the lap shear strength (LSS) and by the T-peel strength. The adhesive strength is only mildly sensitive to the concentration of silicone oil for the two adhesive systems. For FM-300K, the LSS decreases when the concentration of stearic acid in the coating increases. For FM-73, the LSS is only mildly sensitive to the concentration of stearic acid, but the T-peel strength shows appreciable sensitivity. The failure mode becomes more adhesive as the concentration of stearic acid and thereby the CSC increase. It is only mildly dependent on the concentration of silicone oil. The results indicate that silicone oil probably interacts with either the primer or an adhesive component in a way which counteracts the expected decrease in adhesive strength due to the reduction in surface energy and wettability of the adherends. However, the effect of stearic acid on the adhesive strength is associated with decreased wettability. All cases for which a pronounced decrease in the adhesive strength was measured are associated with contact angles larger than 90° and with either high CSC values or nonspreading situations.     

Mechanical properties of adobe bricks in ancient constructions

A study of the mechanical properties of adobe bricks collected from houses and land dividing walls in Aveiro district, Portugal, representative of existing traditional constructions, was conducted. Cylindrical adobe specimens were subjected to simple compression and splitting tests. From these tests it was possible to evaluate the strength capacity, stiffness and deformation evolution for increasing loading. Correlations between the evaluated properties were determined, and the results obtained for houses and land dividing walls were compared. This study contributes for the characterization of adobes traditionally used in Aveiro district, and provides reference values that can be considered in rehabilitation processes.     

Sardinian goat’s milk as source of bacteriocinogenic potential protective cultures

Goat breeding in Sardinia constitutes an important source of income for farming and shepherding activities. In this study 170 LAB strains were isolated from Sardinian goat’s milk and tested for bacteriocins production against several food-borne pathogenic microorganisms. Four isolates (SD1, SD2, SD3 and SD4) were selected for their effective inhibition on Listeria monocytogenes. The strains were classified as members of Enterococcus genus, according to their biochemical and physiological characteristics, and then genetically identified as Enterococcus faecium. In MRS broth at 37 °C, bacteriocins SD1 and SD2 were produced at much higher levels (51200 AU/ml) compared to bacteriocin SD3 (3200 AU/ml) and bacteriocin SD4 (800 AU/ml). Their peptides were inactivated by proteolytic enzymes, but not when treated with α-amylase, catalase and lipase. The four bacteriocins remained stable at pH from 2.0 to 12.0, after exposure to 100 °C for 120 min and were not affected by the presence of surfactants and salts (N-Laourylsarcosine, NaCl, SDS, Triton X-100, Tween 20, Tween 80 and urea). Their molecular size was determined to be approximately 5 kDa by tricine-SDS-PAGE.Since the strains exhibited a strong antimicrobial activity against 21 L. monocytogenes strains and 6 Salmonella spp. isolates, they should be considered as potential bio-preservatives cultures for fermented food productions. Moreover, due to their technological features, the four strains could be taken in account for using as adjunct NSLAB (non-starter lactic acid bacteria) rather than as starter culture.     

Use of epifluorescence microscopy to assess the effectiveness of phage P100 in controlling Listeria monocytogenes biofilms on stainless steel surfaces

One source of foodborne listeriosis is related to a virulent strain established in the food-processing environment. We used direct epifluorescence microscopy (DEM) to evaluate the effectiveness of phage P100 in controlling Listeria monocytogenes biofilms on stainless steel surfaces, in wet conditions at room temperature. Biofilms that were allowed to develop for 72 h were subsequently treated with different concentrations of phage (5, 6, 7, and 8 log PFU/ml). L. monocytogenes was monitored up to 48 h, using both DEM and cultivation method. When L. monocytogenes was monitored using a cultivation method, the first significant reduction was observed after phage treatment with 7 and 8 log PFU/ml at 8 h. Subsequently, these treatments achieved undetectable levels of pathogen at 48 h, with a mean reduction of 5.29 log CFU/cm². Conversely, when samples were evaluated using DEM in treatments with 6, 7, and 8 log PFU/ml, although disaggregation of biofilms could be observed after 8 h, viable cells were still present up to 48 h (maximal reduction 1.5 log units). The phage titer remained stable or increased up to 2.59 log units during the study period. In conclusion, phage P100 may provide an adjuvant measure to control L. monocytogenes biofilm on stainless steel surfaces. However, phage treatment must be used in combination with other hygienization measures to increase efficacy. In this study, DEM was a good tool to quickly and accurately assess the real effect of phage P100 on L. monocytogenes biofilms.