Portable Sawmilling Costs for Landholders in Western Queensland

Portable sawmilling trials with Acacia aneura (mulga) and A. cambagei (gidgee) have been undertaken to estimate the private landholder costs associated with small-scale timber production from woodlands in western Queensland, Australia. A time study of harvesting and milling operations facilitated estimation of landholder labour input requirements. The scarcity and small size of millable logs, coupled with the prevalence of timber defects, make harvesting and portable sawmilling of western Queensland acacias an expensive undertaking for landholders. The cost of producing sawn timber that meets the High Feature (HF) grade of Australian Standard AS2796 is estimated at between A$3,000-m3 and A$3,400/m3 of HF timber.

Impact of Facility Location on the Financial Performance of Integrated and Distributed LVL Production in Subtropical Eastern Australia

In subtropical eastern Australia, the declining availability of traditional, large hardwood native forest logs has motivated hardwood sawmills to explore potentially utilising small logs in the manufacture of veneer-based engineered wood products (EWPs), such as laminated veneer lumber (LVL). An aspatial mathematical model that maximises net present value (NPV) over a 30-year project life has been applied to estimate the financial performance of LVL manufacture in this region. Of particular interest was how facility location affected financial performance, and whether distributed production of veneer (close to the log resource) and LVL (distant from the log resource) may be more profitable than integrated production under some circumstances. While integrated production of veneer and LVL near the resource maximised NPV, distributed production was found to be more profitable than integrated production in situations where the LVL manufacturing facility had to be located relatively far from the resource. Nevertheless, the level of value-adding and processing scale had a greater impact on financial performance than facility location. The analysis also highlighted that log procurement strategy substantially affected financial performance. Encouragingly for forest growers and wood processors, utilising large volumes of small diameter logs, was important for maximisation of NPV of larger-scale LVL facilities

FRW Quantum Cosmology with a Generalized Chaplygin Gas

Cosmologies with a Chaplygin gas have recently been explored with the objective of explaining the transition from a dust dominated epoch towards an accelerating expansion stage. We consider the hypothesis that the transition to the accelerated period involves a quantum mechanical process. Three physically admissible cases are possible. In particular, we identify a minisuperspace configuration with two Lorentzian sectors, separated by a classically forbidden region. The Hartle-Hawking and Vilenkin wave functions are computed, together with the transition amplitudes towards the accelerating epoch. Furthermore, it is found that for specific initial conditions, the parameters characterizing the generalized Chaplygin gas become related through an expression involving an integer $n$. We also introduce a phenomenological association between some brane-world scenarios and a FRW minisuperspace cosmology with a generalized Chaplygin gas. The aim is to promote a discussion and subsequent research on the quantum creation of brane cosmologies from such a perspective. Results suggest that the brane tension would become related with generalized Chaplygin gas parameters through another expression involving an integer.Comment: 13 pages, 3 figures, RevTeX

Clinical assessment of the physical activity pattern of chronic fatigue syndrome patients: a validation of three methods

Contains fulltext : 79568.pdf (publisher's version ) (Open Access)BACKGROUND: Effective treatment of chronic fatigue syndrome (CFS) with cognitive behavioural therapy (CBT) relies on a correct classification of so called 'fluctuating active' versus 'passive' patients. For successful treatment with CBT is it especially important to recognise the passive patients and give them a tailored treatment protocol. In the present study it was evaluated whether CFS patient's physical activity pattern can be assessed most accurately with the 'Activity Pattern Interview' (API), the International Physical Activity Questionnaire (IPAQ) or the CFS-Activity Questionnaire (CFS-AQ). METHODS: The three instruments were validated compared to actometers. Actometers are until now the best and most objective instrument to measure physical activity, but they are too expensive and time consuming for most clinical practice settings. In total 226 CFS patients enrolled for CBT therapy answered the API at intake and filled in the two questionnaires. Directly after intake they wore the actometer for two weeks. Based on receiver operating characteristic (ROC) curves the validity of the three methods were assessed and compared. RESULTS: Both the API and the two questionnaires had an acceptable validity (0.64 to 0.71). None of the three instruments was significantly better than the others. The proportion of false predictions was rather high for all three instrument. The IPAQ had the highest proportion of correct passive predictions (sensitivity 70.1%). CONCLUSION: The validity of all three instruments appeared to be fair, and all showed rather high proportions of false classifications. Hence in fact none of the tested instruments could really be called satisfactory. Because the IPAQ showed to be the best in correctly predicting 'passive' CFS patients, which is most essentially related to treatment results, it was concluded that the IPAQ is the preferable alternative for an actometer when treating CFS patients in clinical practice

Tortricid Moths Reared from the Invasive Weed Mexican Palo Verde, Parkinsonia aculeata, with Comments on their Host Specificity, Biology, Geographic Distribution, and Systematics

As part of efforts to identify native herbivores of Mexican palo verde, Parkinsonia aculeata L. (Leguminosae: Caesalpinioideae), as potential biological control agents against this invasive weed in Australia, ten species of Tortricidae (Lepidoptera) were reared from Guatemala, Mexico, Nicaragua, and Venezuela: Amorbia concavana (Zeller), Platynota rostrana (Walker), Platynota helianthes (Meyrick), Platynota stultana Walsingham (all Tortricinae: Sparganothini), Rudenia leguminana (Busck), Cochylis sp. (both Tortricinae: Cochylini), Ofatulena duodecemstriata (Walsingham), O. luminosa Heinrich, Ofatulena sp. (all Olethreutinae: Grapholitini), and Crocidosema lantana Busck (Olethreutinae: Eucosmini). Significant geographic range extensions are provided for O. duodecemstriata and R. leguminana. These are the first documented records of P. aculeata as a host plant for all but O. luminosa. The four species of Sparganothini are polyphagous; in contrast, the two Cochylini and three Grapholitini likely are specialists on Leguminosae. Ofatulena luminosa is possibly host specific on P. aculeata. Host trials with Rudenia leguminana also provide some evidence of specificity, in contrast to historical rearing records. To examine the possibility that R. leguminana is a complex of species, two data sets of molecular markers were examined: (1) a combined data set of two mitochondrial markers (a 781-basepair region of cytochrome c oxidase I (COI) and a 685-basepair region of cytochrome c oxidase II) and one nuclear marker (a 531-basepair region of the 28S domain 2); and (2) the 650-basepair “barcode” region of COI. Analyses of both data sets strongly suggest that individuals examined in this study belong to more than one species

Portable Sawmilling Costs for Landholders in Western Queensland

Portable sawmilling trials with Acacia aneura (mulga) and A. cambagei (gidgee) have been undertaken to estimate the private landholder costs associated with small-scale timber production from woodlands in western Queensland, Australia. A time study of harvesting and milling operations facilitated estimation of landholder labour input requirements. The scarcity and small size of millable logs, coupled with the prevalence of timber defects, make harvesting and portable sawmilling of western Queensland acacias an expensive undertaking for landholders. The cost of producing sawn timber that meets the High Feature (HF) grade of Australian Standard AS2796 is estimated at between A$3,000-m3 and A$3,400/m3 of HF timber

A mathematical model to support investment in veneer and LVL manufacturing in subtropical eastern Australia

In subtropical eastern Australia, hardwood sawmills are exploring opportunities to adapt to declining availability of traditional, large hardwood native forest logs through the manufacture of veneer and laminated veneer lumber (LVL) from comparatively abundant small, native forest logs. This paper introduces an operations research model that evaluates the financial performance of veneer and LVL investment opportunities. Application of the model to subtropical eastern Australia revealed that production and sale of green and dry veneer was not financially viable. One-stage LVL manufacture was profitable at larger scales of production; however, the superior investment alternative was the manufacture of two-stage LVL. Strong economies of scale were revealed in the production of LVL. The mix of logs procured for veneering had a large impact on financial performance due to the combined effects of mill-delivered log cost, the rate at which logs can be processed and veneer recovery from log volume. Encouragingly for forest growers and wood processors, it was optimal for 42.6% of log volume to be small logs at the 30,000 m3 y−1 of log processing scale. The major policy implication arising from this study is that opportunities for processors to profitably manufacture LVL will be enhanced by government forest policy and codes of practice for private land that permit utilisation of small logs, particularly from suppressed trees that will never attain the specifications of traditional log types. The model framework and several parameter estimates adopted for analysis are likely to be useful for forestry decision-making environments outside Australia