PHYSICAL PROPERTIES AND PRESERVATIVE TREATMENT OF EUCALYPTUS AND CORYMBIA WOOD

The properties of wood influence its use as a final product, so it is essential to know their relation and influence on the quality of preservation. In this sense, for the present study we aim at the determination of the physical properties of Corymbia citriodora [Eucalyptus citriodora Hook]; Eucalyptus camaldulensis Dehnh. and Eucalyptus camaldulensis Dehn. x Eucalyptus grandis, and the quality of the preservative treatment with CCA-C in an autoclave. We determined diameter, heartwood and sapwood percentages, and their relationship, as well as the basic density for the three genetic materials. The quality of the preservation was evaluated through the area treated and not treated by CCA, besides its penetration and retention. The highest proportion of sapwood, treated area, and highest density value was found in C. citriodora, whereas the hybrid E. camaldulensis x E. grandis presented the highest level of CCA retention. The diameter and density showed the highest correlation with CCA retention in wood, the length and moisture of the small logs also shown to be influential. All clones presented satisfactory chemical treatment quality for use as fence posts.

Influence of the treatment phase on the gluing performance of glued laminated timber

Glued laminated timber (glulam) is a wood-based product with frequent use in timber construction. Maritime pine (Pinus pinaster Ait.) is a species suitable for glulam production and is available with abundance in Portuguese forests. This study assessed the influence of the phase in which the preservative treatment is applied in the surface bonding performance. Several elements were produced considering different treatment scenarios: timber without treatment, timber treated before gluing, and timber treated after gluing. The bonding quality was tested by both shear strength and delamination tests, following the indications given in EN 14080 (2013). Glulam elements treated after gluing (TAG) presented less delamination when compared with the ones treated before gluing (TBG). However, TBG elements presented higher shear strength values than TAG elements. Despite the recorded differences, all the considered sets performed adequately both for delamination and shear strength tests.

CCB RETENTION AND PENETRATION IN EUCALYPTUS FENCE POSTS IN FUNCTION OF CONDITION OF PRESERVATIVE TREATMENT

The objective of this work was to evaluate the efficiency of the industrial preservative treatment with Chromated Copper Borate (CCB) in different concentrations and pressure time in the autoclave through retention and penetration in Eucalyptus wood. Nine Eucalyptus trees were felled, debarking and cut into fence posts with a length of 2.20 meters and diameters ranging from 9.2 to 15.4 cm. The Eucalyptus fence posts were submitted to the industrial autoclave (Bethel method) in nine conditions, according to the CCB concentration and the pressure times: 1.5%, 2.0%, and 2.5% and 30, 60 and 90 minutes. The retention and penetration tests were performed. The application of 1.5% CCB concentration and 30 minutes of pressure in the autoclave provided penetration and retention according to the levels required for the application of the wood as fence posts in contact with the soil, and is the conditions indicated for the treatment E. urograndis wood preservative with CCB.

Physical and mechanical behavior of glulam beams produced with rubberwood treated with preservatives

ABSTRACT This work aimed to evaluate the physical and mechanical behavior of glued laminated timber (GLT) - glulam pieces of Hevea brasiliensis treated with chromed copper arsenate (CCA), chromed copper borate (CCB) and pyrethroid in the production of GLT. The pieces were produced using three wooden laminae with dimensions of 60 x 20 x 1200 mm, (width x thickness x length), joined with epoxy adhesive under 1.0 MPa pressure for 24h at room temperature. The rubberwood had an apparent density of 0.624 g cm-3, a value close to that of Eucalyptus grandis wood, a species traditionally used in the manufacture of GLT. Regarding the GLT parts, it was observed that the preservative treatment with CCA and CCB influenced negatively the values of the mechanical properties. For resistance modulus (MOR), a reduction of 75.44 MPa to 62.36 and 58.57 MPa was found for the parts untreated and treated with CCA and CCB, respectively. There was no statistical difference for surface treatment with pyrethroid. The photomicrographs of the glue line showed that the reduction in these values was mainly due to the penetration of preservative solutions into the wood structure (cell lumens and vessels or pores), impairing the anchoring of the adhesive.

Pudendal neuralgia: diagnostics and treatment

The article considers the main causes of the occurrence of pudendal neuralgia. The criteria for diagnosing this state are described in detail. We present basic methods of treatment of pudendal neuralgia starting with comprehensive preservative treatment (physical therapy, medication, blockade), which in most cases are effective. And in case of its ineffectiveness or relapse of the pain syndrome, issues of conduction of pulsed RF-frequency therapy of the nerve are examined. Currently, the possibility of using hyaluronic acid preparations, botulinum toxin for the treatment of sexual neuropathy, as well as cryoanalgesia is being studying. The surgical decompression of the sexual nerve is possible in case of inefficient conservative treatment.