665 research outputs found
Investor preferences for oil spot and futures based on mean-variance and stochastic dominance
This paper examines investor preferences for oil spot and futures based on mean-variance (MV) and stochastic dominance (SD). The mean-variance criterion cannot distinct the preferences of spot and market whereas SD tests leads to the conclusion that spot dominates futures in the downside risk while futures dominate spot in the upside profit. It is also found that risk-averse investors prefer investing in the spot index, whereas risk seekers are attracted to the futures index to maximize their expected utilities. In addition, the SD results suggest that there is no arbitrage opportunity between these two markets. Market efficiency and market rationality are likely to hold in the oil spot and futures markets.stochastic dominance;futures market;risk averter;risk seeker;spot market;G15;C14;G12
Market Efficiency of Oil Spot and Futures: A Stochastic Dominance Approach
This paper examines the market efficiency of oil spot and futures prices by using a stochastic dominance (SD) approach. As there is no evidence of an SD relationship between oil spot and futures, we conclude that there is no arbitrage opportunity between these two markets, and that both market efficiency and market rationality are not rejected in the oil spot and futures markets.stochastic dominance;futures market;risk averter;risk seeker;spot market
Laboratory Evaluation of Soft Rot Resistance of Non-Durable Lesser-Known Malaysian Hardwoods
Resistance of six non-durable lesser-known Malaysian hardwoods, Pulai (Alstonia spp.), Rubberwood (Hevea brasiliensis), Ludai (Sapium spp.), Jelutong (Dyera costulata), Gaham Badak (Blumeodendron tokbrai) and Kayu arang (Diospyros spp.) compared with temperate Scots pine sapwood (Pinus sylvestris), were evaluated using the unsterile soil burial (mixed with Chaetomium globosum) versus vermiculite-burial (of C. globosum only) laboratory techniques and decay rates expressed as either percent mass/mass or percent mass/volume basis. Scots pine was expectedly soft rot resistant but Pulai wood was almost immune to decay. Other wood species varied from being moderately to highly susceptible to soft rot decay. The vermiculite-burial technique favoured greater soft rot degradation activity than unsterile soil-burial. Results also suggest that soft rot decay rates of susceptible woods could also be accelerated with higher surface area/volume ratios of test blocks. The use of mass/volume basis indicated similar reduced degrees of soft rot resistance among most test wood species whereas apparent differences among woods were found using mass/mass comparisons probably due to variable basic densities among these timbers
Resistance of two commercial cement-bonded rubberwood particle composites to decay and termites
Two types of cement-bonded rubberwood (Hevea brasiliensis) particle composites
(tradenames: CemboardTM” and PrimaflexTM in Malaysia), were evaluated for termite
resistance (prevalent termite: Coptotermes curvignathus) in the field, and decay
resistance (test white rot fungi: Schizophyllum commune and Pycnoporus sanguineus; test
brown rot fungus: Gloeophyllum trabeum; test soft rot fungi: Phialophora fastigiata and
compost-Chaetomium globosum mixed inocula) in the laboratory. Three termite- or
decay- susceptible wood materials [rubberwood, kempas (Koompasia malaccensis) and
radiata pine (Pinus radiata) pressed pulp] were also included for comparison. Both types
of wood-cement composites were consistently shown to be immune to decay fungi and
subterranean termites, recording also much lower final moisture contents of the
composites compared with rubberwood, kempas and radiata pine pressed pulp. These
wood-cement composites are therefore suitable for use in a severe decay and termite
hazard
Performance of Two Imidacloprid-Treated Malaysian Hardwoods in an Accelerated Aboveground Termite Test
The performance of the chloronicotinyl insecticide imidacloprid as a wood protecting
termiticide, under a simulated Malaysian biological hazard class H2 (exposure
aboveground indoors against termites and wood borers), was evaluated by a novel termite
field test protocol. Replicate end-grain sealed air dried test blocks (20 x 20 x 20 mm) of
two Malaysian hardwoods, Kembang Semangkok (Scaphium spp.) and Rubberwood
(Hevea brasiliensis) were vacuum-atmospheric pressure-impregnated in the laboratory in
butanolic solution of imidacloprid to target retention of 0 (control), 1 and 3 g/m3. Halve
the replicated blocks were then subjected to a prescribed water-leaching cycle, and
conditioned blocks then installed in a novel aboveground H2 hazard class-type termite
field test where Coptotermes curvignathus are prevalent. After 8 weeks exposure,
untreated hardwoods were severely (termite ratings 1-2) or moderately attacked (ratings:
6.3-7.5), while, with the exception of occasional light grazing, none of the leached nor
non-leached test blocks treated with imidacloprid to both target termiticide retention were
regarded to be attacked (ratings: 9.8-10)
Investor preferences for oil spot and futures based on mean-variance and stochastic dominance
This paper examines investor preferences for oil spot and futures based on mean-variance (MV) and stochastic dominance (SD). The mean-variance criterion cannot distinct the preferences of spot and market whereas SD tests leads to the conclusion that spot dominates futures in the downside risk while futures dominate spot in the upside profit. It is also found that risk-averse investors prefer investing in the spot index, whereas risk seekers are attracted to the futures index to maximize their expected utilities. In addition, the SD results suggest that there is no arbitrage opportunity between these two markets. Market efficiency and market rationality are likely to hold in the oil spot and futures markets
Market Efficiency of Oil Spot and Futures: A Stochastic Dominance Approach
This paper examines the market efficiency of oil spot and futures prices by using a stochastic dominance (SD) approach. As there is no evidence of an SD relationship between oil spot and futures, we conclude that there is no arbitrage opportunity between these two markets, and that both market efficiency and market rationality are not rejected in the oil spot and futures markets
Comparative Laboratory Leaching Test Methods to Study Post-Treatment Storage Period Impacts on CCA Leachability and Fixation in Treated Kempas (Koompassia malaccensis) Heartwood
Three laboratory leaching test methods were compared to determine the effects of different
post-treatment storage fixation periods on leachability/fixation of CCA components from
treated kempas (Koompassia malaccensis) permeable heartwood. End-sealed test wood
blocks of permeable were treated with CCA to target retention of 5.6 kg/m3, immediately
stored to fix at ambient conditions for 0 and 48 hours, 1, 2 and 4 weeks, followed by a 2
weeks leaching test comparing 3 leaching tests: the methods of EN84 (consisting of initial
vacuum impregnation of wood in water), EN84-1 (replacing initial vacuum impregnation
with initial immersion of wood in water) and a new, and least severe, test EN84-2 (daily
routine of soaking wood for 5 hours in water followed by drip drying for 19 hours).
Leachates harvested from these leaching tests were analysed for cumulative leaching losses
of copper (Cu), chromium (Cr) and arsenic (As) that occurred over the 2 weeks leaching
period. Overall, leached CCA elements ranged from 0.48 – 4.02μg/ml Cu, 0.61 – 5.76 μg/ml
Cr and 0.46 – 4.02 μg/ml As. There were significant variations in leaching losses (P<0.05)
between unfixed and stored fixed blocks among the 3 laboratory leaching test methods.
Significant variations of Cu, Cr and As levels existed between the least severe method and
the other two methods that used prolonged immersion of wood in water. However, there were
no significant differences in CCA leaching losses between EN84 method and the EN84-1
method, while the merits of the least severe leaching regime as indicators of realistic CCA
leaching of “fixed” treated wood aboveground outdoors are discussed
The High Decay Resistance in the Sapwood of the Naturally Durable Malaysian Hardwood Belian (Eusideroxylon zwageri)
It has long been assumed that the observed natural durability of the heartwood in certain
timbers is perhaps associated with a relatively lower decay susceptibility also of the
sapwood of these species. While the heartwood of Belian is reputedly highly decay
resistant among the tropical hardwoods of Southeast Asia, laboratory decay tests reported
in this paper have also confirmed the high decay resistance of the sapwood of this timber
species. The sapwood of Belian is found to be resistant to decay by soft rot (Chaetomium
globosum), white rot (Pycnoporus sanguineus & Coriolus versicolor) and brown rot
(Poria sp. & Gloeophyllum trabeum) fungi after 12 weeks of decay testing, sustaining
<2% mass loss, equivalent to that in its heartwood. The reference sapwood species
Rubberwood (Hevea brasiliensis) and the heartwood of Kempas (Koompassia
malaccensis) sustained significant mass losses from decay of up to 59% and 17%,
respectively. Microscopic observations of Belian sapwood revealed extensive
proliferation of extractives in the lumina of various cell types showing a pattern of
extractive distribution similar extent to that in the heartwood tissues, although the extent
of cell filling by extractives was not quite as high as for the heartwood. It is plausible that
the inherent wood extractives deposited in the cells confer the same degree of anti-fungal
properties to both the heartwood and sapwood of Belian
Variation in infection rates of blue-stain, mould and white rot tropical fungi on mixed light Malaysian woods
The modified 3-week FRIM laboratory method for screening of anti-sapstain
formulations against three representative tropical fungi causing blue-stain
(Botryodiplodia theobromae), mould (Paecilomyces variotii) and white rot
(Schizophyllum commune) infection of sapwood species was used to examine the relative
resistance of the sapwood of eight mixed light Malaysian woods, Scots pine (Pinus
sylvestris), medium density fibreboard produced from Rubberwood (Hevea brasiliensis)
and the heartwood of Sentang (Azadirachta excelsa), to infection by these organisms.
After 21 days it was found that Ramin (Gonystylus spp.), Rubberwood, Mersawa
(Anisoptera sp.), Ludai (Sapium spp.), Yellow meranti (Shorea spp.), Scots pine and
Jelutong (Dyera costulata) were highly susceptible to the pooled combinations of bluestain,
mould or white rot infection often sustaining >50% overall mean fungal coverage
or when at least one of the infection types has reached maximum mean coverage (75.5%)
of the wood samples. However, the Rubberwood-based fibreboard, and particularly
Sentang, and the softwood Agathis spp. from Kelantan (trade name: Damar minyak) and
Sarawak (trade name: Bindang), were relatively moderately susceptible to infection,
sustaining between 9 and 47% overall mean fungal coverage after 21 days, or even
considerably less susceptible (5 – 20% overall coverage) after 14 days. There was
absence of both blue-stain and white rot fungal growth on all samples dipped in a low
(0.03%/0.03%) fungicide concentration of a MBT/TCMTB anti-sapstain formulation.
Such laboratory test results could have significant implications to field or industrial
sapstain control of sapwood timbers concerning the lag time between tree felling and
anti-sapstain treatment and seasoning
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