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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Patterns and variation of seawater characteristics over Cambodian territorial Water) ผู้เขียน: Sukchai Arnupapboon,  ดร.จิตราภรณ์ ฟักโสภา, ผู้ช่วยศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractHorizontal and vertical distributions of salinity, temperature, and density (sigma-t) over Cambodian water at 11 stations in Cambodian water, were investigated during 18 - 26 November, 2005. The data were collected from 11 stations, covering the area from 09?15? to 10?45? N and 102?27? to 103?30? E. All the parameters were measured on board of the ship M.V. SEAFDEC2 using conductivitytemperature- depth sensor (CTD; SBE19). The results show that temperature was stable from surface to 15 - 20 m depth and rapidly increased by 0.5?C between the depth at 20 and 30 m. Temperature decreased again below this depth at all sampling stations, except at station 11 in the offshore area. The salinity and density profiles exhibit a similar pattern with stable values from surface to 15-20 m depth. The surface salinity was around 30.1 psu and surface density was 18.3 kg/m3. However, sudden changes in those parameters were observed in subsurface layer at 20 – 30 m water depth, below which they became stable again with salinity 33.7 - 33.8 psu and density 20.5 - 21.0 kg/m3. At nearshore station, due to river discharge, the salinity (29.8 psu) and density (18.3 kg/m3) were less than those of offshore station with salinity 30.5 psu and density 18.75 kg/m3. The results indicate that main factors influencing water characteristics during the survey period were river runoff, water intrusion and weak upwelling. In this period, Cambodian water can be separated into 2 layers. First layer is diluted water which covered from the surface down to the depth at 20-25 m with strong dilution near the Samit point. Subsurface layer approximately below 25 m is considered non-diluted water, affecting by the intrusion of water mass from South China Sea. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Comparison of Different Light Spectra in Fishing Lamps) ผู้เขียน:ดร.มณฑล อนงค์พรยศกุล, ผู้ช่วยศาสตราจารย์ , Kamonpan Awaiwanont, ศุภชัย อนันต์พงษ์สุข, Sukchai Arnupapboon สื่อสิ่งพิมพ์:pdf AbstractIt is widely recognized that some fish species are attracted to light. Thus, the use of artificial light in some fisheries has been one of the most advanced and successful methods to control fish behavior for capture purposes. In Thailand, fishing with lights utilizes metal halide, incandescent or fluorescent bulbs with various colors. The type of lamp depends on the engine due to the light output requirement for the underwater light intensity. The color of light used differs for different fishing grounds, with the main colors being white, red, green and blue. This research investigated the light spectrum of three types of fishing lamps using a profiling reflectance radiometer system (PRR2006). The lamps tested were: 1) a metal halide light with a spectrum and radiation of about 0.1–0.8 W.cm-2 and the main direction of the light was 90?–120? and 240?–270?, 2) an incandescent lamp with the spectrum and main direction of the radiation about 0.2–2.0 W.cm-2 and 120?–240?, respectively, and 3) A fluorescent bulb with a spectrum that ranged from 0.8 to 2.0 W.cm-2 depending on the color and the radiation surrounding the cylindrical bulb. The main light color radiated by the metal halide lamp was red and by the incandescent lamp was yellow and orange. The results determined that with metal halide and incandescent, lights, the long wavelength had a high intensity although it was diminished to nearly 0 W.cm-2 at 10 m below the sea surface. Only the 500–600 nm range of the spectrum could radiate into deeper waters. |
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