Evaluation of surface smoothness by a laser displacement sensor II: comparison of lateral effect photodiode and multielement array

Development of accurate surface assessment technology is of vital interest to modern wood industries. In this experiment we investigated new and fast noncontacting sensors to determine their usefulness for wood surface evaluation and to verify their accuracy. Two types of laser displacement sensors [equipped with a position sensitive detector (PSD) and a charge coupled device (CCD) detector] are compared with a conventional stylus and with theoretical profiles. Hornbeam workpieces with triangular profiles of differing slope and height were used for the evaluation. The results show that resolution of both sensors decreases as the height of the profile decreases. The error ratio of the laser-scanned profiles changes as a function of profile height, in the range 5%–33%. The CCD method is superior for accurate surface roughness evaluation, although the PSD approach can still be used for monitoring the error of form in most applications.Parts of this work were presented at the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April 2000 and at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001     

Locating and identifying splits and holes on sugi by the laser displacement sensor

The split and the hole are two common defects on sugi (Cryptomeria japonica D.Don). They have a common feature in that they are associated with surface irregularities. We have developed a laser scanning system to detect the splits and the holes based on their thickness, which correlates spatially with the profile information. The displacements measured by the laser sensor were converted to pixel values to generate the displacement profile image. Both the splits and the holes manifested well in the image. A dedicated image-processing program written in Visual Basic has been developed. The defects regions were accurately located by the image processing. To identify the defects, eight recognition rules based on four features have been utilized. Furthermore, a method based on the pixel model was proposed to compute the area of the defect. The results indicated that the defects could be identified correctly, and the areas could be computed accurately using the pixels model.     

On-line determination of the grain angle using ellipse analysis of the laser light scattering pattern image

Under fixed cutting conditions, the surface finish roughness is correlated to the grain angle. However, the means of determining the grain angle automatically and accurately is still a challenge for on-line control of the router. It is therefore necessary to develop a new technology to determine the grain angle accurately and automatically. In this research, a laser light scattering pattern was used to accurately determine the grain angle. The light scattering pattern image was a quasi-ellipse caused by the grain direction and tracheid effect. A new modified Hough transform ellipse analysis technology was adopted to determine the ellipse parameters that could be used to determine the grain angle. The results indicated that the measured grain angle using the method proposed here was accurate and effective. The measured grain angle coincided with the real grain angle. There was an insignificant difference between the measured grain angle of Japanese beech (Fagus crenata blume) and that of sugi (Cryptomeria japonica D.Don) under two machining conditions that gave planed or sawn finishes. However, the accuracy of the measured grain angle of sugi was better than that of Japanese beech for the planed finish, the accuracy of the measured grain angle of Japanese beech was better than that of sugi for the sawn finish, and the accuracy of the measured grain angle for planed samples was better than that for sawn samples of both sugi and Japanese beech.     

Antioxidative and antiradical activities of <Emphasis Type="Italic">Eucalyptus camaldulensis</Emphasis> leaf oils from Thailand

The leaf essential oils (six samples) from three clones of Eucalyptus camaldulensis Dehnh. were characterized by gas chromatography-mass spectrometry. Radical scavenging and antioxidant properties were investigated by the 1,1-diphenyl-2-picylhydrazyl (DPPH) assay and the β-carotene bleaching test. It was found that the whole essential oil and its fractions had significant antioxidant effects when they were tested by each method. In the DPPH assay, the E. camaldulensis leaf oils showed IC₅₀ inhibitory concentrations in the range of 1.75–12.62 mg/ml. In the β-carotene bleaching test, the IC₅₀ valued were in the range of 14.30–118.55 μg/ml. Part of this report was presented at the 18th meeting of the Chugoku-Shikoku Branch of the Japan Wood Research Society, November 2006     

间歇光照对雄性肉仔鸡代谢能摄入量和产热量的影响

肉仔鸡通常在近乎连续的光照条件下饲养以维持最大的采食量和生长速率。但有报道 ,间歇光照 ( IL)条件下饲养的肉仔鸡比连续光照 ( CL)条件下饲养的生产性能更高 ( Savory,1 976;Dorminey 等 ,1 977;Cave,1 981 ;Deaton 等 ,1 981 )。从 CL到 IL的早期转换会导致短期的生长延缓 ,但后期生长却很快 ( Mc Daniel等 ,1 977;Cave,1 985;Renden,1 991 ;Buyse,1 996;Ohtani等 ,1 997)。IL条件下这种生长曲线的变化原因尚不清楚。育成期仔鸡用于物理性活动消耗的能量相当大 ,大约占到代谢能摄入的 7%～ 1 5%( Wenk等 ,1 976)。既然 IL条…     

Grain Growth Rates of MgSiO3 Perovskite and Periclase Under Lower Mantle Conditions

The grain growth rates of MgSiO3 perovskite and periclase in aggregates have been determined at 25 gigapascals and 1573 to 2173 kelvin. The average grain size (G) was fitted to the rate equation, and the grain growth rates of perovskite and periclase were G10.6 = 1 x 10(-57.4) t exp(-320.8/RT) and G10.8 = 1 x 10(-62.3) t exp(-247.0/RT), respectively, where t is the time, R is the gas constant, and T is the absolute temperature. These growth rates provide insight into the mechanism for grain growth in minerals relevant to the Earth's lower mantle that will ultimately help define the rheology of the lower mantle.     

Actions of intravenous injections of AVP and oxytocin on plasma ACTH,GH, insulin and glucagon concentrations in goats

This study was conducted to investigate the arginine‐vasopressin (AVP)‐ and oxytocin‐induced changes in plasma adrenocorticotropic hormone (ACTH), growth hormone (GH), insulin and glucagon levels and their metabolite concentrations in goats. In this study, five goats were intravenously injected with either AVP (0.3 nmol/kg body weight (BW)) or oxytocin (0.7 IU/kg BW). AVP injection significantly increased ACTH and GH secretions compared to controls, although insulin and glucagon concentrations were not altered. The incremental areas (ICAs) of the ACTH and GH concentrations were higher in the AVP group than in the saline group. Oxytocin injections increased insulin and glucagon secretions, while ACTH level was not altered. GH levels became elevated 30 min after the oxytocin injection. The ICAs of insulin and glucagon after oxytocin was injected were higher than those of the control. Results indicate that AVP is a potent stimulant of ACTH and GH secretions, while oxytocin uses different pathways to regulate insulin and glucagon secretions in goats.     

Annual reproductive cycle of the greasyback shrimp Metapenaeus ensis in Ise Bay,Japan

The greasyback shrimp Metapenaeus ensis is widely distributed along the coast of India and the West Pacific where it is an important fisheries species. We have examined seasonal changes in ovarian development, spermatogenesis, and mating of Me. ensis in histological studies and by external observations on specimens collected in Ise Bay, its northernmost habitat. Ovaries were found to be previtellogenic from February to May, with the first signs of development being the accumulation of yolk in oocytes in late May. Ovarian shadow ratios were high during the period late July to mid-September. The formation of cortical rods in the peripheries of oocytes and germinal vesicle breakdown were observed in ovaries from late June to September. Male shrimps had sperm in the testes during the period early June to early October, and female shrimps had spermatophores in spermatheca after early July. In late July, some post-spawn female shrimps had exogenous vitellogenic oocytes in their ovaries, indicating that ovarian development had been repeated in preparation for the next spawning. Ovarian shadow ratios, which were positively correlated with gonadosomatic indices and ovarian development, seem to be a useful marker to determine ovarian development. Our results indicate that mating in Me. ensis started in early July and that the spawning season ranged from July to September with more than two cycles of spawning in Ise Bay.

     

An Isolate of Alternaria alternata That Is Pathogenic to Both Tangerines and Rough Lemon and Produces Two Host-Selective Toxins, ACT- and ACR-Toxins

ABSTRACT Two different pathotypes of Alternaria alternata cause Alternaria brown spot of tangerines and Alternaria leaf spot of rough lemon. The former produces the host-selective ACT-toxin and the latter produces ACR-toxin. Both pathogens induce similar symptoms on leaves or young fruits of their respective hosts, but the host ranges of these pathogens are distinct and one pathogen can be easily distinguished from another by comparing host ranges. We isolated strain BC3-5-1-OS2A from a leaf spot on rough lemon in Florida, and this isolate is pathogenic on both cv. Iyokan tangor and rough lemon and also produces both ACT-toxin and ACR-toxin. Isolate BC3-5-1-OS2A carries both genomic regions, one of which was known only to be present in ACT-toxin producers and the other was known to exist only in ACR-toxin producers. Each of the genomic regions is present on distinct small chromosomes, one of 1.05 Mb and the other of 2.0 Mb. Alternaria species have no known sexual or parasexual cycle in nature and populations of A. alternata on citrus are clonal. Therefore, the ability to produce both toxins was not likely acquired through meiotic or mitotic recombination. We hypothesize that a dispensable chromosome carrying the gene cluster controlling biosynthesis of one of the host-selective toxins was transferred horizontally and rearranged by duplication or translocation in another isolate of the fungus carrying genes for biosynthesis of the other host-selective toxin.