Drying quality of rubberwood: an industrial perspective

In this study, the kiln drying yield of 30 mm Rubberwood (Hevea brasiliensis) used for the furniture manufacturing industry in South East Asia was evaluated. The results showed that the average yield loss was 10%, and end-checks, splits and warping were the most common drying defects. It was found that sawn timber from older trees (> 21 years) were less prone to drying defects, and the use of stress relieving treatments significantly reduced the incidence of drying defects.     

Reforming of olive mill wastewater through a Pd-membrane reactor

This work investigates the exploitation of olive mill wastewater (OMW) for producing hydrogen in a membrane reformer.     

Microstructural study of aged ferrite powders for sensing layers

Nanosized powders of La_0.80Sr_0.20Fe_0.95Cu_0.05O_3?w were investigated in terms of structural, morphological, chemical and surface properties by using several characterization techniques. The XPS and IR measurements showed the presence of surface hydroxide and carbonates species. After calcination of the powders at 900 °C the amount of carbonates decreased but was still significant. The sensing activity of thick film based on La_0.80Sr_0.20Fe_0.95Cu_0.05O_3?w was tested as a function of relative humidity and the results indicate that (i) after one year of ambient storage the sensing material lost quite completely its sensitivity to humidity, (ii) the sensing activity of the film was mostly re-activated after a thermal treatment at 900 °C for 2 h, and (iii) the huge shift of the detection limit to low RH caused by the presence of 5 mol% Cu is also restored.     

Effects of nutrient supplementation on fermentation kinetics, H2S evolution, and aroma profile in Verdicchio DOC wine production

Different yeast nutrient additions were studied for the 2008 and 2009 vintages of Verdicchio grape juice fermentation. Addition of yeast derivatives at the beginning of fermentation and/or different amounts of diammonium phosphate at various times within the first half of fermentation were examined, with initial yeast assimilable nitrogen concentrations set at 200 and 250 mg l^?1. Supplementation with glutathione in combination with this nitrogen addition was also evaluated. Fermentation rates were monitored throughout these fermentations carried out under different nutrient conditions. H₂S production during fermentation and synthesis of volatile compounds in the finished wines were quantified; the wines also underwent sensory evaluation. The fermentation kinetics were almost exclusively influenced by the inorganic nitrogen supplementation with diammonium phosphate. H₂S evolution was more affected by assimilable nitrogen than glutathione. Diammonium phosphate significantly reduced H₂S production, with a further reduction in the presence of yeast derivative. This nitrogen supplementation yielded higher concentrations of acetate esters, and in particular of isoamyl acetate (fruity aromas), which positively influences the analytical and aroma profile of wines and results in a general reduction in 2-phenylethanol production (floral aromas). Overall results (two harvesting times and vintages) indicate that the management with diammonium phosphate and yeast derivative supplementation improves the kinetics of fermentation and provides a good tool to reduce H₂S formation and increase the analytical and sensory quality of Verdicchio wine.     

Particle Size Distribution of Wood Dust in Rubberwood (Hevea Brasiliensis) Furniture Manufacturing

The study evaluated the concentration and particle size distribution of air-borne wood dust in the Rubberwood furniture manufacturing industry. Air quality samples were measured at routing and hand-sanding work stations in furniture factories using the micro-orifice uniform deposit impactor (MOUDI) air-quality measuring instrument. It was found that less than 25% of the air-borne wood dust particles at the two work stations were less than 10 μm in size, which in turn did not pose major respiratory health hazards. However, the high wood dust concentrations at the two work stations is a matter of concern, and efforts must be taken to minimize the air-borne wood dust exposure levels workers are subjected to in the Rubberwood furniture manufacturing industry.     

Verklebung von wachsimprägnierter Buche unter Variation der Klebesysteme und Durchführung einer Plasmabehandlung

Beech wood was impregnated with two hot melting waxes. Contact angle measurement followed to determine hydrophobizing of such treated wood. Tensile shear tests were carried out to test the adhesion properties with three different glues under varying environmental conditions. Furthermore, wax impregnated beech was subjected to plasma treatment prior to glueing. The results demonstrate that wood treated with polar paraffin shows lower adhesion properties compared to montan wax. Therefore, montan wax was investigated more intensely. Beech impregnated with such wax can be used for constructive building elements in the interior sector. D3 Glues for non-constructive applications were realized by using PVAc and phenol-resorcinol resin under permanent influence of humidity. Plasma treatment improves this quality to obtain D4 glue. Back-drying of the water stored specimens proves the suitability of isocyanate glue and also that of PVAc after plasma treatment for 120 s.     

Reliable indirect competitive ELISA used for a survey of ochratoxin A in green coffee from the North of Paraná State, Brazil.

The performance of an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on a monoclonal antibody (mAb) for ochratoxin A (OTA) detection was evaluated in a comparative study with high-performance liquid chromatography (HPLC) analysis using 68 freshly harvested coffee samples from the North of Paraná State, Brazil. The anti-OTA mAb showed high specificity and low cross-reactivity with OTA analogues (OTB and OTalpha), but cross-reacted with OTC. This ic-ELISA showed a detection limit of 3.75 ngg-1 sample, when compared to 0.80 ngg-1 by HPLC, with an ic-ELISA/HPLC correlation coefficient of 0.90. As regards OTA analysis of these coffee samples, natural contamination was detected in 10 samples (14.7%) by both methods, where the ic-ELISA values (range 3.9-7.3 ngg-1) were 1.1 to 1.6-fold higher than HPLC data (2.7-4.7 ngg-1). Five samples (7.4%) were OTA positive (range 0.84-1.30 ngg-1) only by HPLC assay, probably due to the higher detection limit reached by ic-ELISA. OTA was undetectable in 53 samples (77.9%) by both methods, while all positive samples (range 0.84-7.30 ngg-1) showed OTA levels lower than 8 ngg-1 (maximum limit recommended by the European Union). The matrix interference of green coffee was minimized by dilution of sample extracts before carrying out the ELISA assay. This mAb-based ic-ELISA can be effectively applied for OTA screening in coffee, because it is simple, sensitive and sample preparation is easy.     

Thermal etching of GaAs (1 1 3) surfaces

We discuss scanning electron micrographs and atomic force microscope images of thermally etched GaAs(1 1 3) surfaces. The GaAs(1 1 3)A and GaAs(1 1 3)B surfaces are compared. The polarity of the surface leads to a different morphology for the two surfaces after thermal etching. It is found that the Ga-enriched droplets, which form under As-deficient conditions at higher temperatures, are sitting on characteristic pedestals, which are different for the two faces. The facets occurring after this thermal etching process are identified. They represent thermally favourable surfaces under the arsenic-deficient conditions of the thermal etching process. © 1998 Chapman & Hall     

Effects of the 5-HT2 receptor antagonist ritanserin on halothane-induced increase of inositol phosphates in porcine malignant hyperthermia

Recent studies have shown a significant increase of inositol phosphates (IPs) in skeletal muscle during episodes of halothane-induced malignant hyperthermia (MH) in pigs. After treatment with dantrolene and disappearance of MH crisis the IP concentrations returned to basal levels. In order to examine if the increase of IPs during halothane-induced MH may be related to an enhanced IP synthesis in response to activation of 5-HT2 (5-hydroxytryptamine) receptors, the effects of ritanserin, a selective 5-HT2 receptor antagonist, on IP levels were investigated. Biopsies of skeletal muscle of the hindlimbs were obtained in random order and IPs were determined in homozygous MH-susceptible (MHS) and MH-non-susceptible (MHN) swine in the following order: (1) basal, (2) after treatment with ritanserin (2.0 mg/kg), (3) after halothane challenge (3 vol% for 20 min). Basal concentrations of all IPs were higher in MHS than in MHN swine. Ritanserin did not cause any significant changes of IP levels compared to the basal concentrations in MHS and MHN pigs. In MHS pigs, ritanserin did not prevent a halothane-induced MH-crisis. After halothane challenge, 1,3,4-IP3, 1,3,4,6-IP4 and 1,3,4,5-IP4 levels were increased in MHS (during MH crisis) vs. basal concentrations, whereas no changes were found in MHN pigs. Since the increases of IP levels in MHS pigs during MH crisis found in the present study were comparable to those without pretreatment with ritanserin, shown by recent studies, it may be concluded that ritanserin does not prevent the increase of IPs during a halothane-induced MH. Thus, the present data indicate that increases of IP levels during halothane-induced MH in swine are due to other mechanisms than 5-HT mediated enhancement of IP synthesis.