The flexural properties of young Pinus elliottii x Pinus caribaea var. hondurensis timber from the Southern Cape and their prediction from acoustic measurements

The objectives of this study were to determine the bending strength and stiffness properties of young Pinus elliottii x P. caribaea var. hondurensis timber from the Southern Cape, South Africa, and to evaluate the predictability of these properties from acoustic measurements on standing trees, logs and their sawn boards. The timber has good bending strength (MOR) properties but the mean stiffness (MOE_stat) was significantly lower than that required for structural-grade timber. The mean MOE_stat was also about 30% lower than a P. radiata control sample. The MOE_stat of sawn boards could be predicted from acoustic stress wave measurements on standing trees with a correlation (r) of 0.48 and from acoustic resonance frequency measurements on sawn boards with a correlation of 0.85. The MOR of sawn boards was not significantly correlated with acoustic stress wave measurements on standing trees and only moderately correlated with acoustic resonance frequency measurements on sawn boards (r = 0.45).     

Impact of alum on crust prevention and aggregation of calcareous soil: laboratory studies

Alum was applied at rates of 0.01, 0.02, 0.05, 0.1 and 0.2% by weight to a calcareous silty clay soil in an attempt to reduce soil crusting and improve soil aggregation. Results indicated that the modulus of rupture (MR) was reduced from 176 to 60 kPa with the addition of 0.2% alum. The mean weight diameter (MWD) was doubled when the application rate of alum increased from 0 to 0.2%. Alum apparently modified the soil physical environment by making the soil fluffy which in turn reduces its MR. Gypsum was formed by the reaction of alum with calcium carbonate in proportion to the amount of alum applied, increasing from 0.2% in the control soil to 1.1% with the highest rate of alum applied. This increase may have lead to the reduction in the MR and an increase in the MWD. This research showed that alum was effective in improving soil aggregate stability and decreasing aggregate rupture stress.     

Inguinal rupture with herniation of the urinary bladder through the scrotal fascia in a Shetland pony foal

Herniation of the urinary bladder in the inguinal region has not previously been described in the horse. A case of inguinal rupture with herniation of the bladder through the scrotal fascia in a 3‐month‐old Shetland pony, diagnosed by external palpation, urinary catheterisation and external ultrasonographic examination is reported. Surgical management of the case was by dissection of the scrotal fascia, partial cystectomy and unilateral castration. During the period of hospitalisation the only complication was a slight seroma, which resolved spontaneously. Follow‐up after 6 months did not reveal any abnormality.     

Characterization of major,unused, and unvalued Indonesian wood species I. Dependencies of mechanical properties in transverse direction on the changes of moisture content and/or temperature

Mechanical property changes due to the moisture content (MC) and/or temperature changes were examined for 15 Indonesian wood species. A static bending test was carried out at 20°C, 65% relative humidity (air-dry), and water-saturated at 20°C (wet-20) and 80°C (wet-80). For individual test conditions, modulus of elasticity (MOE) and modulus of rupture (MOR) increased linearly with specific gravity regardless of wood species; however, maximum deflection did not correlate with specific gravity for any MC or temperature conditions. The relative values of MOE and MOR measured in wet-20 to air-dry conditions were variously affected from slightly to strongly depending on the wood species. However, the relative values always decreased markedly when saturated in water at 80°C, regardless of wood species. The relative MOE, MOR, and maximum deflection values due to the change in MC or MC and temperature combined were independent of specific gravity but may be dependent on wood type: softwood or hardwood.     

Physical and mechanical properties of wood after moisture conditioning

Some properties of wood (hinoki:Chamaecyparis obtusa) moisture-conditioned by an adsorption process from a dry state and by two desorption processes (from a water-saturated state and from a state with a moisture content slightly below the fiber saturation point) were investigated. The moisture contents of wood conditioned by the adsorption process and by the desorption process continued to approach to one another for the moisture-conditioning period of over 50 weeks. Accordingly, sorption hysteresis should be regarded as a transitional phenomenon that occurs during the process of approaching the true equilibrium, which requires a long time. The wood conditioned by the desorption process beginning from a water-saturated state showed slightly smaller dimensions than those conditioned by the adsorption process with the same moisture content; however, the wood conditioned by the desorption process from a moisture content below the fiber saturation point showed slightly larger dimensions than those conditioned by the adsorption process. The wood conditioned by the adsorption process from a dry state showed a higher modulus of elasticity and modulus of rupture than did the wood conditioned from a water-saturated state with the same moisture content. The mechanical properties of the wood also varied based on the states at which the desorption process was started. This is a notable characteristic of the relation between the drying condition and the mechanical properties of wood.     

Effective sampling method for estimating bending strength distribution of Japanese larch square-sawn timber

Information on the strength distribution of timbers and other wood products seems to have become more important for users and producers after revision of the Japan architectural standard in 1998, which emphasizes the performance requirements of structures. Because there is no way other than expensive destructive tests to collect strength data, many researchers have proposed many inspecting methods for predicting strength by nondestructive evaluation. The most popular method for structural timber is the mechanical grading method based on the relation between Young's modulus (E) and strength () with some linear regression models. On the other hand, it is well known that the proof loading test is superior for obtaining information on the lower tail of distribution. If the E distribution of the objective timbers is known approximately, selecting timbers nearest to the projected E values saves timbers for destructive tests. We examined the alternative sampling method using the reported e- data sets of Japanese larch square-sawn timber. The simulated results showed that the estimated lower tail of the bending strength distribution by the alternative method was a better approximation of the experimental distribution than that derived from the conventional linear regression model.Part of this paper was presented at the 47th Annual Meeting of the Japan Wood Research Society, Kochi, April 1997     

STUDY ON DEVELOPMENTAL BEHAVIOUR AND DEFORMATIONAL FRACTURE MECHANISM OF SHIJIANG SLIDE IN CHONGQING

In this paper,the geological background as well as thedevelopment characteristics,deformation rupture behavior,and slideformation mechanics of the old and new slide area and the creeping rupturezone of Chongqing Shijialiang Landslide are analyzed in full detail.Onthe basis of this,the forecasting comment on the stability of the slide ismade and the protection measures are suggested.     

Results and complications of a novel technique for primary castration with an inguinal approach in horses

Reasons for performing study: Complications associated with equine castration can have medical and financial consequences. This retrospective study investigated a novel method of castration via an inguinal approach in mature stallions and compared the incidence of complications with other methods. Hypothesis: Castration via an inguinal approach has a low complication rate at the site of surgery compared with other castration techniques. Methods: Mature stallions (n = 238) were castrated under general anaesthesia in dorsal recumbency using an inguinal approach. The vaginal process was incised, the spermatic cord ligated twice and the testis removed. After suturing, the vaginal process and one or 2 layers of fascia, the subcutis and cutis were closed in a simple continuous pattern. Results: Five of 238 (2.1%) horses had post operative haemorrhage and a haematoma in the scrotal region, which required additional treatment. All horses made a full recovery. Five of 238 (2.1%) of the horses had a post operative respiratory infection, which resolved with antibiotic therapy. Sixteen of 238 (8.8%) had transient signs of colic shortly after surgery. Conclusion: This technique of castration with an inguinal approach had a low incidence of complications at the site of surgery compared with other methods. An inguinal approach and leaving the vaginal tunic in situ may cause less soft tissue trauma than a scrotal approach.