Behaviour of Cyclopoid, Harpacticoid, and Calanoid Copepods from Coastal Waters of Taiwan   总被引：1，自引：0，他引：1  

Jiang-Shiou  Hwang Jefferson T.  Turner 《Marine Ecology》1995,16(3):207-216

Abstract. Cinematographic techniques were used to compare behaviour patterns of three cyclopoid, one harpacticoid, and two calanoid species of copepods from coastal waters of Taiwan. Behaviour was quantified in terms of allocation of time to swimming versus non-swimming behaviour, and behavioural transitions/minute. The different species of copepods exhibited different patterns of behaviour. Oithona nana and O. similis had long periods of inactivity punctuated by comparatively few transitions to intermittent leaps of motion. Oncaea venusta had a more jerky pattern of numerous small hops with frequent transitions between motion and rest. Macrosetella gracilis spent more time swimming than did the cyclopoids, but with fewer behavioural transitions than O. venusta , more like the Oithona species. Temora turbinala swam virtually continuously and transitions to non-swimming were rare. Undinula vulgaris var. taiwanicus frequently alternated between upward motion and sinking at rest, making a feeding current about a fourth of the time. There was considerable intraspecific variability between individual animals, but for reasons of experimental design, it was impossible to statistically test the significance of this variation. Differences in behaviour patterns between the different species are discussed within the context of what is known about the feeding ecology of these species from previous investigations.  相似文献   

Recognition of design symbols from midship drawings     

Ho-Jin Hwang  Soonhung Han  Yong-Dae Kim 《Ocean Engineering》2005,32(16):1968-1981

Despite the availability of 3D CAD systems, the designers in shipyards still use 2D CAD systems because of the need to produce drawings rapidly and a shortage of labor. The shipyard spends much time and labor analyzing the design information contained in 2D drawings and creating 3D model for the downstream processes. The design information is represented by symbols that are well known among designers in shipyard. Symbols are expressed by meaningless geometric shapes. These shapes are recognized to have meanings by analysis of experienced and knowledgeable designers.We propose a method for automatic recognition of 2D symbols and the extraction of design information from the midship drawings. The shape and rationale of 2D symbols used in ship design have been analyzed, and symbols have been classified according to the analysis. Based on the classified symbols, the developed system recognizes the symbols expressed in 2D drawings. The extracted design information is assorted by design rationales. The meaningless geometric shape is translated into the design information including designer's intents. The extracted design data can be applied to the design process in shipyards, and the 3D ship model can be automatically created.  相似文献   

In situ high-pressure synchrotron X-ray powder diffraction study of tunnel manganese oxide minerals: hollandite,romanechite, and todorokite     

Gil Chan Hwang  Jeffrey E. Post  Yongjae Lee 《Physics and Chemistry of Minerals》2015,42(5):405-411

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Measurement of solid suspension concentration and flow velocity with temperature compensation using a portable ultrasonic device     

Y. J. Huang  C. C. Sung  J. S. Lai  F. Z. Lee  G. W. Hwang  Y. C. Tan 《水文科学杂志》2013,58(3):615-626

Abstract

Ultrasonic spectroscopy is highly suitable for real-time measurement, in particular for dense particle systems. In the present study, a novel measurement device, namely a portable ultrasonic device (PUD), is designed and manufactured for measuring solid suspension concentration and flow velocity simultaneously with respect to the propagation of ultrasound waves in a solid–liquid mixture at different temperatures. A series of experiments were conducted in the laboratory to obtain the ultrasonic attenuation of kaolin and reservoir sediment solutions within a wide range of concentrations (1000–300 000 mg/L) at various temperatures (15–27°C). The resulting data were regressed to establish linear functions of attenuation and temperature for concentration. The experimental data were compared with theoretical simulated results to show the effect of particle size distribution on concentration measurement. The flow meter part of the PUD was verified by a standard-speed carriage in the towing tank. According to experimental tests by PUD, it was demonstrated that the accuracy for concentration in full scale is ±5%, and the accuracy for flow velocity is ±2%. Compared with sampled data, good agreements were also found by employing the PUD for sediment concentration and flow velocity measurements in turbidity currents during typhoon floods in a reservoir, which demonstrates that the PUD is operable and reliable on site.

Editor D. Koutsoyiannis; Associate editor K. Heal

Citation Huang, Y.J., Sung, C.C., Lai, J.S., Lee, F.Z., Hwang, G.W., and Tan, Y.C., 2013. Measurement of solid suspension concentration and flow velocity with temperature compensation using a portable ultrasonic device. Hydrological Sciences Journal, 58 (3), 615–626.  相似文献   

Origin of rutile needles in star garnet and implications for interpretation of inclusion textures in ultrahigh‐pressure metamorphic rocks          下载免费PDF全文

S.‐L. Hwang  P. Shen  H.‐T. Chu  T.‐F. Yui  Y. Iizuka 《Journal of Metamorphic Geology》2015,33(3):249-272

The asterism effect of star garnet has been attributed to the oriented distribution of needle‐like rutile inclusions. Rutile needles occur in garnet from a wide range of metamorphic settings and rock bulk compositions, and their origin has been ascribed to different mechanisms, such as exsolution, and used to interpret petrological and tectonic processes. Results from an optical and transmission electron microscopy of Idaho star garnet indicate a co‐precipitation origin. It was found that rutile needles are predominantly oriented along the <103>_rt//<111>_grt and <001>_rt//<001>_grt directions following multiple crystallographic orientation relationships (CORs); i.e. COR‐1, 2, 2′, 3, 4 and 5 in 6‐ray star garnet, and are oriented solely along the <103>_rt//<111>_grt directions following exclusively COR‐2 in 4‐ray star garnet. The sole presence of COR‐2 <111>_grt needles in the common 4‐ray star garnet, in contrast to the presence of both <111>_grt and <001>_grt needles with multiple CORs in the rare 6‐ray star garnet, suggests that the COR‐2 <111>_grt needle probably is the energetically most favoured variant, as is also supported by the coincidence site lattice considerations. The unique crystallography‐controlled microstructures of 4‐ray star garnet, including the cloudy domains behind the {111}_grt or {100}_grt fronts with abundant inclusions of rutile needle, rutile compound needle and multiple‐phase‐inclusion, as well as the clear domains behind the {110}_grt fronts with only a few above inclusions concentrated exclusively within the linear, <110>_grt‐oriented, continuous tube‐like domains, further suggest that the COR‐2 <111>_grt needles in 4‐ray star garnet most likely have a growth‐in origin, co‐precipitating with garnet at its growth fronts close to thermodynamic equilibrium conditions. The 6‐ray star garnet, on the other hand, most likely formed under far‐from equilibrium conditions, thereby yielding a maximum of 99 crystallographic variants of rutile needles with multiple CORs in a single crystal. In the light of these findings, along with the common occurrences of the sole COR in many inclusion‐host systems owing to the requirement to minimize the energy barrier in an exsolution process, the presence of both <103>_rt//<111>_grt and <001>_rt//<001>_grt needles with multiple CORs in garnet of Sulu eclogite and Erzegebirge quartzofeldspathic rock would therefore cast doubt on the assertion of an exsolution origin of rutile needles in garnet from these ultrahigh‐pressure rocks.  相似文献   

Molecular and isotopic constraints on the sources of suspended particulate organic carbon on the northwestern Atlantic margin     

Jeomshik Hwang  Daniel Montluçon  Timothy I. Eglinton 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(8):1284-1297

The abundance, carbon isotopic composition (Δ¹⁴C and δ¹³C), and lipid biomarker (alkenones and saturated fatty acids) distributions of suspended particulate organic matter were investigated at three stations centered on the 2000, 3000, and 3500 m isobaths over the New England slope in order to assess particulate carbon sources and dynamics in this highly productive and energetic region. Transmissometry profiles reveal that particle abundances exhibit considerable fine structure, with several distinct layers of elevated suspended particulate matter concentration at intermediate water depths in addition to the presence of a thick bottom nepheloid layer at each station. Excluding surface water samples, the Δ¹⁴C values of particulate organic carbon (POC) indicated the presence of a pre-aged component in the suspended POC pool (Δ¹⁴C<+38‰). The Δ¹⁴C values at the 3000 m station exhibited greater variability and generally were lower than those at the other two stations where the values decreased in a more systematic matter with increasing sampling depth. These lower Δ¹⁴C values were consistent with higher relative abundances of terrigenous long-chain fatty acids at this station than at the other two stations. Two scenarios were considered regarding the potential provenances of laterally transported POC: cross-shelf transport of shelf sediment (Δ¹⁴C=?140‰) and along-slope transport of the slope sediment proximal to the sampling locations (Δ¹⁴C=?260‰). Depending on the scenario, isotopic mass balance calculations indicate allochthonous POC contributions ranging between 15% and 54% in the meso- and bathy-pelagic zone, with the highest proportions at the 3000 m station. Alkenone-derived temperatures recorded on suspended particles from surface waters closely matched in-situ temperatures at each station. However, alkenone-derived temperatures recorded on particles from the subsurface layer down to 250 m were lower than those of overlying surface waters, especially at the 3000 m station, implying supply of phytoplankton organic matter originally produced in cooler surface waters. AVHRR images and temperature profiles indicate that the stations were under the influence of a warm-core ring during the sampling period. The low alkenone-derived temperatures in the subsurface layer coupled with the lower Δ¹⁴C values for the corresponding POC suggests supply of OC on resuspended sediments underlying cooler surface waters distal to the study area, possibly further north or west. Taken together, variations in Δ¹⁴C values, terrigenous fatty acid abundances, and alkenone-derived temperatures among the stations suggest that input of laterally advected OC is a prominent feature of POC dynamics on the NW Atlantic margin, and is spatially heterogeneous on a scale smaller than the distance between the stations (<150 km).  相似文献   

Effects of BPA and DES on longchin goby (Chasmichthys dolichognathus) in vitro during the oocyte maturation     

Baek HJ  Hwang IJ  Kim KS  Lee YD  Kim HB  Yoo MS 《Marine environmental research》2007,64(1):79-86

This study was performed in order to assess whether bisphenol (BPA) and diethylstilbestrol (DES) had agonistic or antagonistic effects on oocyte maturation using marine fish. We tested the effects of these chemicals on in vitro maturation, germinal vesicle breakdown (GVBD), assay using oocytes from the longchin goby, Chasmichthys dolichognathus. During the maturation process, low concentrations of BPA and DES triggered GVBD depending on the stage of oocyte development; BPA at 0.044 nM and DES at 0.037, 0.37, and 3.73 nM induced GVBD in 0.82-0.88 mm diameter oocytes (germinal vesicle located near the center of oocytes). In 0.76-0.80 mm diameter oocytes (fully vitellogenic oocytes), BPA induced GVBD at relatively higher concentrations (4.38, 43.8, and 438 nM). In 0.86-0.90 mm diameter oocytes, BPA and DES had no observable effect on GVBD at the concentrations tested. Oocytes with diameters between 0.82 and 0.88 mm appeared to be more sensitive to these chemicals. Moreover, our results showed that BPA and DES did not inhibit GVBD.  相似文献   

Rapid and Accurate Method for Determining 234Th in Seawater: Fe Co-precipitation,UTEVA Extraction,and Micro-precipitation     

Seo  Junhyeong  Seo  Hojong  Hwang  Jeomshik  Kim  Guebuem 《Ocean Science Journal》2021,56(4):378-384

Ocean Science Journal - Thorium-234 (234Th; t1/2 = 24.1&nbsp;days) has been widely used as a tracer of particle settling and organic carbon export in the ocean. However, the use of...  相似文献   

Experiences with Constructed Wetland Systems in Korea     

Kim Youngchul Hwang Gilson Lee Jin-Woo Park Je-Chul Kim Dong-Sup Kang Min-Gi Chang In-Soung 《中国海洋大学学报(英文版)》2006,5(4):345-350

In spite of the low temperature during the winter season and the high land environment, the wetland treatment system is gaining popularity in Korea because of its lower construction cost and simplicity in operation and maintenance. Many different types of wetland treatment systems have been built during the last 10 years, among which the free water surface wetland has been predominant. Most of the large-scale systems are government projects for improving the water quality of the streams flowing into the estuary dikes and reservoirs. The covering plants used in this system are different in different areas but cattails and reeds or their combinations are common. Constructed wetlands in Korea can be characterized by their shallow depths and short hydraulic residence times. There is no established flow pattern and configuration rules for constructing wetlands, but many efforts have been made with a view to improving their ecological function. Flow control is the most difficult problem in designing a riverbed or riparian wetland. There have been scores of flow rate control devices developed for wetlands, but none of them guarantee wetlands＇ safety against flooding. In earlier wetland construction, the building materials were mainly soil. Recently, strong and durable building materials such as rocks, gravel beds, concrete and steel are used at vulnerable places to protect them from erosion. Our investigation indicated that the wetland system would be an appropriate technology because it is not only cheaper to construct, but also requires less maintenance work. However, we suffer from the reduced effectiveness in performance during the winter. We need to evaluate the partial treatment accomplished during 6 to 7 months per year.  相似文献   

The Global/Regional Integrated Model system (GRIMs)   总被引：5，自引：0，他引：5  

Song-You Hong  Hoon Park  Hyeong-Bin Cheong  Jung-Eun Esther Kim  Myung-Seo Koo  Jihyeon Jang  Suryun Ham  Seung-On Hwang  Byoung-Kwon Park  Eun-Chul Chang  Haiqin Li 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(2):219-243

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