Research on mitigation of the interaction of sea turtle with pelagic longline fishery in the western North Pacific

December 13-14, 2006, Siam City Hotel, Bangkok, ThailandWe conducted shallow-set longline fishing operations on a research vessel in the western North Pacific, May-July, 2002-2004. We investigated sea turtle interaction with a pelagic longline fishery and preliminarily examined the potential gear modifications (bait and hook types) for reducing sea turtle bycatch or mortality. A total of 54 loggerhead sea turtle Caretta caretta were caught in 76 operations (about 74, 000 hooks), which were all alive. The mean straight carapace length was 67 cm (range: 52 - 82 cm); this suggested most of loggerhead sea turtles caught in this area were sub-adult. Loggerhead sea turtle catches ranged from 19.1 to 24.5 °C in sea surface temperature, which were concentrated in warm water masses in the Kuroshio extension. The Loggerhead sea turtle catch was more frequently observed on hooks hauled after sunrise. For bait type, the catches by mackerel bait were fewer than those by squid bait. In the circle hook trial in 2003, the deep-hooking rates (proportion of deep-hooking (at esophagus or pharynx) to total in numbers) on squid bait were 0.41 and 0.23 in 3.8 sun conventional tuna hook (n = 22) and 3.8 sun Tankichi type circle hook (which had similar size to 3.8 sun conventional tuna hook) (n = 13), respectively, but the difference was not significant (P > 0.05, extended Fisher’s exact test). In 2004 the large 18/0 circle hooks (which had a larger size, compared to 3.8 sun tuna hook) were tested, but its effect was not clarified due to very small catch numbers. Following these researches, we have been conducting sea turtle mitigation studies, with evaluation of their impacts on target and other non-target species catches

Sublattice reversal in GaAs/Ge/GaAs and AlAs/Ge/AlAs heterostructures grown on (1 1 3)A and (1 1 3)B GaAs substrates

GaAs/Ge/GaAs and AlAs/Ge/AlAs heterostructures were grown both on (113)B and (113)A GaAs substrates by molecular beam epitaxy. Sublattice reversal in these heterostructures were identified by comparing the anisotropic etching profile of the epitaxy sample with that for reference (113)B and (113)A GaAs substrates. Sublattice reversal in GaAs/Ge/GaAs heterostructures was achieved on (113)B GaAs substrate. On the other hand, sublattice reversal on (113)A GaAs substrate was obtained by using AlAs/Ge/AlAs heterostructures

Nesting and post-nesting studies of loggerhead turtles (Caretta caretta) at Omaezaki, Japan

Organized by Graduate School of Informatics, Kyoto University ; JSPS Bangkok Liaison Office ; Japanese Society of Bio-logging Science ; Informatics Research Center for Development of Knowledge Society InfrastructureDecember 13-15, 2004, Imperial Tara Hotel, Bangkok, ThailandNesting biology, measurement of body size and mitochondrial (mt) DNA haplotypes of loggerhead turtle, Caretta caretta at Omaezaki Beach, Japan were investigated by collecting data and samples during night observations from 6 July to 6 August 2004. In addition, seven post-nesting females, which nested during this observation period, were tracked by satellite telemetry. A total of 33 females were identified in this observation period. Seven females nested twice, with a mean inter-nesting interval of 18.0 days. Even though our observations did not cover the entire nesting beach and period, the frequency of nesting was estimated at three, using a calculation based on the total number of nests at this beach in this nesting season. The range of straight carapace length (SCL) was from 65.8 to 91.6 cm, and the mean (±SD) size was 81.5±5.83 cm. The SCL of females at Omaezaki Beach is significantly lower than at other nesting sites in Japan based on calculation of 90% confidence intervals for mean SCLs. Two haplotypes were detected among 33 females using mitochondrial (mt) DNA analysis. Composition of these two haplotypes of nesting females at Omaezaki Beach was similar to nesting females at other nesting beaches in Japan. Post-nesting feeding grounds of seven loggerhead turtles released from Omaezaki consist of two areas, the northwestern North Pacific and the East China Sea. It is confirmed that nesting females at Omaezaki Beach were from the two groups using the different post-nesting feeding grounds and these two groups can be distinguished by their body size criterion of 85 cm. If different factors impact females in each feeding ground, monitoring the number of females and the composition of body size can be useful in assessing the impact to females

Feasibility of Controlling Gas Concentration and Temperature Distributions in a Semiconductor Chamber with CT-TDLAS

The feasibility to control the gas concentration and temperature distributions in a semiconductor process chamber by measuring them was investigated. Gas concentration and temperature distributions for various flow rates were measured with the computed tomography-tunable diode laser absorption spectroscopy (CT-TDLAS). The infrared absorption spectra of multiple laser paths passing through the measured area were collected and the distributions of methane concentration and temperature in the chamber were reconstructed with the computed tomography (CT) calculations. The measured results indicated that the distributions can be independently controlled by measuring with the CT-TDLAS and adjusting the flow rates and the susceptor temperature

Time-resolved measurements of two-color laser light emitted from GaAs/AlGaAs-coupled multilayer cavity

We measured the two-color laser oscillation from a GaAs/AlGaAs-coupled multilayer cavity at 18–42 °C using current injection. We confirmed simultaneous lasing by detecting the sum frequency generation signal generated by the two-color laser light, and performed time-resolved measurement using a streak camera with a spectrometer. From the observed time transient of the spectra at various temperatures, it it is clarified that the temperature change of the device, induced by current injection, modulates the effective cavity length. Therefore, the temperature control of the device is a key factor in stable two-color lasing and THz wave generation

2-mm-Thick Large-Area CdTe Double-sided Strip Detectors for High-Resolution Spectroscopic Imaging of X-ray and Gamma-ray with Depth-Of-Interaction Sensing

We developed a 2-mm-thick CdTe double-sided strip detector (CdTe-DSD) with a 250 um strip pitch, which has high spatial resolution with a uniform large imaging area of 10 cm$^2$ and high energy resolution with high detection efficiency in tens to hundreds keV. The detector can be employed in a wide variety of fields for quantitative observations of hard X-ray and soft gamma-ray with spectroscopic imaging, for example, space observation, nuclear medicine, and non-destructive elemental analysis. This detector is thicker than the 0.75-mm-thick one previously developed by a factor of $\sim$2.7, thus providing better detection efficiency for hard X-rays and soft gamma rays. The increased thickness could potentially enhance bias-induced polarization if we do not apply sufficient bias and if we do not operate at a low temperature, but the polarization is not evident in our detector when a high voltage of 500 V is applied to the CdTe diode and the temperature is maintained at -20 $^\circ$C during one-day experiments. The ''Depth Of Interaction'' (DOI) dependence due to the CdTe diode's poor carrier-transport property is also more significant, resulting in much DOI information while complicated detector responses such as charge sharings or low-energy tails that exacerbate the loss in the energy resolution. In this paper, we developed 2-mm-thick CdTe-DSDs, studied their response, and evaluated their energy resolution, spatial resolution, and uniformity. We also constructed a theoretical model to understand the detector response theoretically, resulting in reconstructing the DOI with an accuracy of 100 um while estimating the carrier-transport property. We realized the detector that has high energy resolution and high 3D spatial resolution with a uniform large imaging area.Comment: 13 pages, 11 figures, 1 table, Accepted for publication in NIM

Sublattice reversal in GaAs/Ge/GaAs heterostructures grown on (113)B GaAs substrates

GaAs/Ge/GaAs heterostructures were grown on high-index (113)B GaAs substrates by molecular beam epitaxy. Sublattice reversal in GaAs/Ge/GaAs was identified by comparing the anisotropic etching profile of the epitaxial sample with that for reference (113)A and (113)B GaAs substrates. The shape of the resulting mesa for the lower GaAs layer was similar to that for the reference (113)B GaAs substrate, whereas that for the upper GaAs layer was similar to that for the reference (113)A GaAs substrate. An atomic-resolution analysis was also conducted by mapping using energy-dispersive X-ray spectroscopy, whereby the sublattice reversal was directly observed through the atomic arrangements