26 research outputs found
Lateral Loading Response of CFS Framed Shear Wall with Cement Board Panels
Shear wall panels are commonly used as lateral load resisting elements to provide stability of the cold-formed steel-framed houses in Australia against wind and earthquake actions. The effectiveness of their lateral resistance behavior is obtained usually by experimental testing although it can also be done by analytical modeling. This paper presents racking test results of steel-framed wall panels with different aspect ratios sheathed with fibre cement board subjected to monotonic and cyclic loading protocol. Performance parameters of the wall panels are obtained from the experimentally observed load-deflection curves using various existing methods and evaluation method is proposed. The evaluation method considers various performance characteristics including ductility modification factor, residual displacement recovery and load levels satisfying ultimate and serviceability limit state conditions
Characterization of Italian honeys (Marche Region) on the basis of their mineral content and some typical quality parameters
<p>Abstract</p> <p>Background</p> <p>The characterization of three types of Marche (Italy) honeys (Acacia, Multifloral, Honeydew) was carried out on the basis of the their quality parameters (pH, sugar content, humidity) and mineral content (Na, K, Ca, Mg, Cu, Fe, and Mn). Pattern recognition methods such as principal components analysis (PCA) and linear discriminant analysis (LDA) were performed in order to classify honey samples whose botanical origins were different, and identify the most discriminant parameters. Lastly, using ANOVA and correlations for all parameters, significant differences between diverse types of honey were examined.</p> <p>Results</p> <p>Most of the samples' water content showed good maturity (98%) whilst pH values were in the range 3.50 – 4.21 confirming the good quality of the honeys analysed. Potassium was quantitatively the most relevant mineral (mean = 643 ppm), accounting for 79% of the total mineral content. The Ca, Na and Mg contents account for 14, 3 and 3% of the total mineral content respectively, while other minerals (Cu, Mn, Fe) were present at very low levels. PCA explained 75% or more of the variance with the first two PC variables. The variables with higher discrimination power according to the multivariate statistical procedure were Mg and pH. On the other hand, all samples of acacia and honeydew, and more than 90% of samples of multifloral type have been correctly classified using the LDA. ANOVA shows significant differences between diverse floral origins for all variables except sugar, moisture and Fe.</p> <p>Conclusion</p> <p>In general, the analytical results obtained for the Marche honeys indicate the products' high quality. The determination of physicochemical parameters and mineral content in combination with modern statistical techniques can be a useful tool for honey classification.</p
Diastatic activity in some unifloral honeys
Determinations of diastatic activity in 12 groups of unifloral honey were made to study variability according to the botanical origin of the honey. Robinia, Citrus, Erica, Taraxacum and Arbutus honeys were found to have a very low enzyme content. On the contrary Hedysarum, Castanea, Honeydew, Eucalyptus and Thymus honeys showed high diastase activity. The relationship between the absorbance at 5 min and the diastatic index was quantified
Characterization of unifloral honeys
The characterization of 14 types of Italian unifloral honeys was carried out on the basis of the organoleptic, microscopic (qualitative and quantitative melissopalynological analysis) and physicochemical properties (colour, moisture, ash, HMF, diastase, pH, total acidity, electrical conductivity, specific rotation and sugars). The botanical origins of the examined honeys were Arbutus unedo L, Castanea sativa Mill, Citrus spp, Erica arborea L, Eucalyptus camaldulensis Dehnh, Hedysarum coronarium L, Helianthus annuus L, Rhododendron spp, Robinia pseudoacacia L, Taraxacum officinale Web, Thymus capitatus Hofmgg et LK, Tila spp, honeydew honey from Abies and honey from Metcalfa pruinosa honeydew. The synoptic picture emerging from the results can be used as a reference framework for the diagnosis of unifloral honeys
Transvenous internal cardioversion for atrial fibrillation: A randomized comparison between catheters with different coil length
Objectives The aim of this study was to evaluate the effects of 2 different right atrial electrode coil lengths on energy and voltage requirements for transvenous atrial cardioversion. Methods Twenty-six patients (mean age 61+/-11 years) with chronic persistent atrial fibrillation (AF) (mean duration 11+/-10 months) underwent transvenous cardioversion. A 6F catheter with a 5.5-cm coil was positioned in the coronary sinus. Another catheter with either a 5.5-cm or an 8-cm coil was positioned along the lateral wall of the right atrium, according to a randomized allocation. R wave-synchronized biphasic shocks were delivered according to a step-up protocol. After cardioversion of baseline AF, AF was reinduced, the right atrial catheter was substituted, and cardioversion was repeated with the alternative right atrial coil. Results successful cardioversion was obtained in all of the patients. Leading edge voltage of effective shocks was significantly lower when catheters with an 8-cm coil in right atrium were used compared with the alternative 5-cm coil catheters (301+/-80 volts vs 340+/-78 volts, P<.001); and delivered energy (6.75&PLUSMN;4.25 joules vs 7.86&PLUSMN;4.29 joules, P=.043) and shock impedance (60&PLUSMN;9 ohm vs 66&PLUSMN;10 ohm, P<.001) were lower. Moreover, shock-induced discomfort, evaluated by assessment of pain score, was reduced (3.69+/-1.09 vs 4.12+/-0.99, P=.035). Conclusions The use of a longer right atrial coil results in lower shock impedance, lower energy and voltage requirements, and lower discomfort during transvenous atrial cardioversion. The results of the current study are of value either for transvenous internal cardioversion of chronic persistent AF or for implantable atrial defibrillators
Flavor and free amino acid composition of lavender and eucalyptus honeys
Unifloral honeys have highly characteristic flavors due to various volatiles probably derived from the original plant sources. The volatile compounds of honeys from two unifloral sources, lavender and eucalyptus, were investigated. Volatile compounds were extracted with dichloromethane, followed by Likens-Nickerson's simultaneous steam distillation/solvent extraction. The extracts had an intense honey aroma that varied with the type of honey. Compounds (400) were separated by gas chromatography and detected by mass spectrometry. Major flavor compounds were very characteristic of each floral source (linear aldehydes, n-hexanol, coumarin, and phenylacetaldehyde in lavender honeys; diketones, hydroxyketones, 3-hexanol, sulfur compounds, and alkanes in eucalyptus samples)