The behaviour of particle board and hardboard beams during moisture cycling     

L. D. Armstrong  P. U. A. Grossman 《Wood Science and Technology》1972,6(2):128-137

Summary The effects of creep at constant conditions of moisture content and the effects of deformations occurring during cycling of moisture content have been studied in loaded beams of particleboard and hardboard. The variations in stiffness in loaded and unloaded beams of particleboard during moisture cycling were also determined. Contrary to the findings of some workers but in agreement with the findings of another, the increases in the deflections of loaded beams of particleboard during cycling of moisture content were due mainly to desorption of moisture. Qualitatively similar behaviour was found for particleboard, hardboard and wood but quantitatively the effects were greatest in particleboard and hardboard. It appears that the basic mechanism of the transient effects in bending, arising with the simultaneous action of load and change in moisture content, may be similar in wood, particleboard and hardboard.  相似文献   

Umweltorientierter Pflanzenschutz     

RD Dr. Edmund Leib 《Journal of pest science》1970,43(8):113-117

Ohne Zusammenfassung  相似文献   

Application of real options theory to forestry investment analysis     

Armstrong Duku-Kaakyire  David M. Nanang   《Forest Policy and Economics》2004,6(6):1

This paper demonstrates the utility of the real options approach to forestry investment analysis. The main objectives are to discuss the real option theory and show how it can be adopted to model uncertainty and managerial flexibility in forest management and investment. Secondly, we show how to calculate the option values of selected options that may be available to managers of forest industry firms. The paper provides an empirical application, which compares a forestry investment using the static Faustmann model and the real options approach. Four management options are used for the real options approach: an option to delay reforestation, an option to expand the size of the wood processing plant, an option to abandon the processing plant if timber prices fall below a certain level or due to corporate take-over, and multiple options that evaluated all three options together. All options were evaluated using the binomial option-pricing model, where timber values are assumed to follow a multiplicative binomial process. The results show that the Faustmann analysis rejected the investments as unprofitable, while the option analysis showed that all three options were highly valuable if exercised. When real options are considered, the traditional Faustmann model for assessing the profitability of a forestry investment may fail to provide an adequate decision-making framework because it does not properly value management's ability to adjust to shocks in the economy, as well as risks and uncertainty.  相似文献   

Effects of ration level in rainbow trout, Oncorhynchus mykiss (Walbaum), on sensory characteristics, lipid content and fatty acid composition     

L. JOHANSSON  A. KIESSLING  T. ÅSGÅRD  L. BERGLUND 《Aquaculture Nutrition》1995,1(1):59-66

Effects of feed ration levels (RLs) and age on sensory characteristics, fillet lipid content (LC) and fatty acid composition (FA) of rainbow trout, Oncorhynchus mykiss (Walbaum), fillet were investigated in a longitudinal feeding experiment. Daily RLs were administered as a percentage of the ration size necessary for expected maximum growth (RL100). Fish on RL50, RL75, RL100 and RL200 were sampled at 1.4, 2.0 and 2.4 years of age. Analyses of LC and FA were carried out on a fillet cross-section. Sensory analyses were performed by an expert panel using ranking and conventional profiling. RL had no effect on the intensity of fresh smell or any sensory characteristic of taste or consistency of fish on RLs over 75%, irrespective of age; fish on RL50, however, scored significantly lower for fresh taste and firmness. Age had no effect on the intensity of total taste, whereas fresh taste increased and rancidity decreased with increasing age irrespective of RL. LC related strongly to RL and age, and increased up to 2.0 years of age. An increase in LC resulted in a higher level of monounsaturated FA and a lower level of polyunsaturated FA. A restriction to RL75 had no negative effects on sensory characteristics, LC or FA of the fillet.  相似文献   

Movements of Atlantic salmon migrating upstream through a fish-pass complex in Scotland   总被引：1，自引：0，他引：1  

A. R. D. Gowans  J. D. Armstrong  I. G. Priede  S. Mckelvey 《Ecology of Freshwater Fish》2003,12(3):177-189

Abstract  – Movements of adult Atlantic salmon were tracked through a series of four fish passes and an impoundment on the River Conon system, Northern Scotland. Proportions of fish passing individual obstructions ranged from 63 to 100%. The cumulative effect was that only 4 of the 54 tagged fish reached the spawning areas. The fish were delayed for 1–41 days at a pool-and-overfall ladder and 1–52 days at a Borland fish lift. The fish swam through a 10 km long reservoir at 0.21–1.16 km·h⁻¹. A total of 13 fish negotiated a 2.5 km long, 3 m diameter diversion tunnel through a mountain to their home river. High levels of electromyogram (EMG) activity were recorded during ascent of a pool-and-overfall fish ladder, indicating that high energy demanding burst swimming was required.  相似文献   

Recovery from neuromuscular block in dogs: restoration of spontaneous ventilation does not exclude residual blockade     

Manuel Martin‐Flores  Daniel M Sakai  Luis Campoy  RD Gleed 《Veterinary anaesthesia and analgesia》2014,41(3):269-277

ObjectiveTo evaluate if return of spontaneous ventilation to pre-relaxation values indicates complete recovery from neuromuscular blockade.Study designProspective, with each individual acting as its own control.AnimalsTen healthy adult female Beagle dogs weighing 6.2–9.4 kg.MethodsDogs were anesthetized with propofol, dexemedetomidine and isoflurane. Spontaneous ventilation was assessed by measuring end-tidal CO₂, expired tidal volume, peak inspiratory flow, respiratory rate and minute ventilation. Vecuronium 25 μg kg^?1 IV was administered and neuromuscular block was evaluated by measuring the train-of-four (TOF) ratio with acceleromyography in the hind limb. During spontaneous recovery from neuromuscular block, the TOF ratio when each ventilatory variable returned to baseline was recorded.ResultsThis dose of vecuronium produced moderate neuromuscular block in all dogs, with TOF ratio values of 0–18% at maximal block. Expired tidal volume, peak inspiratory flow and minute ventilation returned to pre-relaxation values when the median TOF ratio was ≤ 20%. The median TOF ratio was 42% when the end-tidal CO₂ returned to pre-relaxation values.Conclusions and clinical relevanceSignificant residual neuromuscular block could be measured at the hind limb with acceleromyography when ventilation had spontaneously returned to pre-vecuronium values. Monitoring spontaneous ventilation, including end-tidal CO₂, expired tidal volume, peak inspiratory flow or minute ventilation cannot be used as a surrogate for objective neuromuscular monitoring, and this practice may increase the risk of postoperative residual paralysis.  相似文献   

Egtved virus: temperature-dependent immune response of trout to infection with low-virulence virus   总被引：1，自引：0，他引：1  

P. E. VESTERGÅRD JØRGENSEN 《Journal of fish diseases》1982,5(1):47-55

Abstract. The present report deals with experiments concerning the theoretical basis for development of a live, attenuated vaccine against viral haemorrhagic septicaemia (VHS) of rainbow trout, Salmo gairdneri Richardson, on the basis of a virus strain derived from the Egtved virus reference strain F, the pathogenicity of which has been strongly reduced by in vitro passage. It is shown that the low pathogenicity of the virus (designated the Reva strain) is a genetically stable feature and that the protection against VHS induced by infection with the virus is due to an immune response. Following immunological priming at 10°C partial protection developed at 5° 10° and 15° but not at 20°C, whereas neutralizing antibody was produced at all four temperatures by some of the fish. The duration of virus persistence in trout was found to be inversely proportional to the water temperature.  相似文献   

An investigation of avoidance by Antarctic krill of RRS James Clark Ross using the Autosub-2 autonomous underwater vehicle     

Andrew S. Brierley  Paul G. Fernandes  Mark A. Brandon  Frederick Armstrong  Nicholas W. Millard  Steven D. McPhail  Peter Stevenson  Miles Pebody  James Perrett  Mark Squires  Douglas G. Bone  Gwyn Griffiths 《Fisheries Research》2003,60(2-3):569-576

The autonomous underwater vehicle (AUV) Autosub-2 was deployed on eight missions ahead of RRS James Clark Ross in the northern Weddell Sea and in the Bransfield Strait, Southern Ocean, to assess avoidance of the research vessel by Antarctic krill Euphausia superba. The AUV was equipped with the same type of scientific echosounder as the research vessel (Simrad EK500 operating at 38 and 120 kHz) and measured the density of krill along transect acoustically (g m⁻² wet mass) prior to the ship’s arrival. We hypothesised that if krill avoided the ship, perhaps in response to radiated noise, then the ship should detect less krill than the AUV which is known to have much lower noise levels than the ship. We were unable to detect any significant difference between the density of krill detected by the ship or the AUV, either at the transect level or at finer scales within transects. We conclude, therefore, that avoidance by krill of RRS James Clark Ross will not significantly bias acoustic estimates of krill abundance by this vessel.  相似文献   

Enteral nutrition by tube     

P J Armstrong  M S Hand  G S Frederick 《Veterinary Clinics of North America: Small Animal Practice》1990,20(1):237-275

When oral intake is unsatisfactory or contraindicated, maintenance of nutrition by tube feeding is an alternative to the parenteral route. A large volume of research data supports the decision to use the enteral route whenever possible. Entry of food into the alimentary tract is a stimulus to structural and functional maintenance of that tract. Enteral nutrition can be given via indwelling nasoesophageal, pharyngostomy, esophagostomy, percutaneous or surgical gastrostomy, or enterostomy tube. Use of an appropriate catheter, familiarity with the technique used, and careful patient selection and monitoring are important factors in successful tube feeding. Blenderized pet food diets should be fed whenever possible; commercially available liquid diets provide an alternative when tube caliber or patient factors preclude the use of blenderized foods.  相似文献   

Positive immunostaining of ovine congenital progressive muscular dystrophy with antibody against N- and C-terminal dystrophin     

H NAKADA  PF JACOBSEN  RD JOHNSEN  BA KAKULAS 《Australian veterinary journal》1990,67(7):271-272

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