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The mortality of seabirds in fisheries has had a serious negative impact on many seabird populations, yet the extent of fishery-derived seabird mortality in pelagic longline fisheries, remains poorly understood. In this study, we analyze fishing effort and catch data of the Taiwanese distant-water longline tuna fleet - the largest fleet in the Atlantic Ocean. These data collected by fishery observers over a 5-year span include 61 trips involving 6181 observed sets of over 20 million hooks, where 198 seabirds were caught (23 of which were released alive). Most birds were caught in the South Atlantic, with estimated seabird bycatch rates ranging from 0.026 birds per thousand hooks in the southwest Atlantic to 0.063 birds per thousand hooks in the southeast Atlantic. Black-browed, Atlantic yellow-nosed, and wandering albatrosses, as well as spectacled and southern giant petrels, were the most frequently caught species. Seabird bycatch hotspots were identified at 20°-40° S/10° W-15° E and 35°-45° S/45°-55° W. In the South Atlantic Ocean, generalized additive models indicated that fishing location and the number of birds sighted significantly influenced seabird bycatch rates. Extrapolating these spatially and temporally explicit seabird bycatch rates to the fishing effort data of other distant-water longline fleets and extrapolating the bycatch rates reported in the literature to the reported fishing effort of coastal nation fleets, we estimate the total seabird incidental mortality from pelagic longline fishing in the southern Atlantic Ocean to be between 3446 and 6083 birds per year from 2004 to 2008. These findings support proposals calling for the required use of best-practice mitigation measures by all pelagic longline vessels operating in seabird bycatch hotspots in the South Atlantic Ocean. International cooperation on research and data sharing is critical to ensure the sustainability of seabird populations and fisheries. [ABSTRACT FROM AUTHOR]

Background Smoking tobacco is a global health problem, and this study highlights adolescent smoking in Taiwan. Smoking was completely banned on campuses under the Tobacco Hazards Prevention Act and School Health Regulations. Few have investigated the association between personnel smoking/school smoking policies and adolescent smoking in Taiwan. The smoking rate has gradually increased for senior high school students in Taiwan from 10.7% in 1994 to 14.7% in 2011. Aim This study examined the influence of family and friends' smoking on the association between the presence of teachers smoking and each stage of adolescents' smoking behaviour. Methods A cross-sectional survey was conducted in nine high schools ( n = 921). Logistic regression analysis was used to examine the association between smoking stage, father smoking, mother smoking, sibling smoking, friends smoking and the presence of smoking teachers. Results After adjusting for gender, school type and grade, fathers', siblings' and friends' smoking were significantly associated with adolescents' ever and current smoking behaviours, but mothers' smoking was only associated with adolescents' current smoking behaviours. Friends' smoking was strongly associated with being a smoker. While there was an interaction between friends' smoking and the presence of smoking teachers on current smoking behaviours indicating the effect of the presence of smoking teachers was increased when friends did not smoke. Discussion The results suggest that teachers smoking on school may increase the likelihood of being a current smoker as their friends do not smoke. Family and friends smoking are associated with adolescent smoking. Conclusion The Taiwanese government has regulated a comprehensive smoking ban in schools to prohibit both student and staff smoking on all school premises. To achieve this, schools should make tobacco control communication efforts. Nurses could address the combined influence of family and friends as well as the effect of school smoking restrictions to help prevent adolescents from smoking. [ABSTRACT FROM AUTHOR]

A maskless technique for the fabrication of U-shaped microstructure arrays on the surface of photosensitive glass by femtosecond laser-induced modification is developed. This technique is followed by heat treatment to crystallize the modified area, and the specimen is then placed in acid solution for chemical etching. The surface roughness of the microstructures is further improved by a secondary annealing process. The fabricated photosensitive glass is used as a mold template, and replicated plano-convex cylindrical arrays by UV-replica are also presented. The focusing ability of the microlens arrays on the glass mold and replicate is demonstrated. [ABSTRACT FROM AUTHOR]

CoPt and CoPt/Au films prepared by magnetron sputtering were studied in this paper. The films were deposited at room temperature followed by a post annealing at temperatures (Ta) from 400°C to 800°C. Ordering of the CoPt and CoPt/Au films occurred at Ta = 600°C and 500° C, respectively, which results in magnetic hardening. With the increase of Ta up to 700° C, coercivity of the both films increased to a maximum value of about 12 kOe. As Ta reached 800°C, a drastic magnetic softening occurs in both samples; meanwhile, the diffraction data indicate a corresponding phase change from tetragonal to cubic. Scanning electron microscopy results revealed an intensive grain growth from 70 nm at 700°C to 160 nm at 800°C for CoPt/glass film and from 110 nm at 700°C to 250 nm at 800°C for CoPt/Au/glass sample. The relation between the abnormal phase change and intensive grain growth indicates that the formation of the cubic phase is driven by large biaxial tensile stress. Further investigations support this explanation and reveal that the cubic phase may be chemically ordered. [ABSTRACT FROM AUTHOR]

Fe53Pt47 and Fe58Pt42 thin films with 300 am in thickness prepared using magnetron sputtering were investigated. The films were deposited on heated glass substrates and annealed at 400°C and 800°C for different time. Single phase FePt films with similar chemical ordering but different substructure size were produced in the two series of samples. The effect of microstructure refinement results in significant enhancement in remanence (Mr) of about 38.1% and 30.8% in the Fe53Pt47 and Fe58Pt42 films, respectively. The energy product, (BH)max, also showed a large increase of 25% and 72%; the maximum value of the two series of films are 16.2 MGOe and 19.6 MGOe, respectively. The large (BH)max was found to originate from the enhancement of Mr and steep slope of demagnetization curve at coercive point (α). As the theoretical predictions, in an isotropic magnet, the magnetic moments in the transition region of magnetization near grain boundary are easy to be aligned by applied field. In this study, it is found that by increasing the magnetic transition region through microstructure refining, the remanence can be effectively enhanced meanwhile facilitate the collective magnetic reversal. Domain structure confirms that the refinement of microstructure effectively reduces the domain size. [ABSTRACT FROM AUTHOR]

Fe100-xPtx (x = 20, 25, and 30) thin films with nominal thickness 50 nm were prepared by radio-frequency (RF) magnetron sputtering onto glass substrates. Crystallographic structure and magnetic properties of such films were investigated by varying Fe content, annealing temperature (400-700 °C), and heating process. Crystallographic structure obtained by X-ray diffraction (XRD) indicated that ordering of L12Fe3Pt phase takes place for Fe75Pt25 postannealed above 400 °C. Ordering parameter of the Fe75Pt25 sample increases from 0.29 to 0.94 as annealing temperature rises from 400 °C to 700 °C. Saturation magnetization 1270 emu/cm³ was obtained in Fe75Pt25 films annealed at 700 °C. Fe70Pt30 films annealed at 700 °C show similar characteristics with those of Fe75Pt25, while Fe80Pt20 films exhibit paramagnetism due to disordered Fe-rich face-centered cubic (fcc) structure. Postannealing seems necessary for formation of pure L12Fe3 Pt phase while in situ annealing leads to formation of a metastable tetragonal Fe3 Pt phase, as confirmed by XRD. [ABSTRACT FROM AUTHOR]

The light extraction enhancement of GaN-based flip-chip indium-tin oxide light-emitting diodes (FC ITO LEDs) with an inclined sidewall coated with TiO2/SiO2 omnidirectional reflectors (ODRs) is presented. At a driving current of 350 mA and a chip size of 1 × 1 mm, the light output power and the light extraction enhancement of the FC ITO LEDs coated TiO2/SiO2 ODRs with inclined sidewall reached 183 mW and 15% when compared with the results from the same device, FC ITO LEDs coated TiO2/SiO2 ODRs with vertical sidewall. Furthermore, by examining the radiation patterns of the FC ITO LEDs, the increased optical power within 1500 cone contributed to the stronger enhancement around the vertical direction of an inclined sidewall ODR within blue regime. Our work offers promising potential for enhancing output powers of commercial light-emitting devices. [ABSTRACT FROM AUTHOR]

InGaN-based nanorods with a rod density of ∼3.0×1010 cm-2 were fabricated from a light-emitting diode structure by an inductively coupled plasma dry-etching with nanoscale nickel metal islands. The nanoscale nickel metal islands were formed from a Ni film by a rapid thermal annealing at 850 °C for 1 min. The influence of thicknesses of Ni metal film on the diameter and density of nanorods was also investigated. Structural and optical properties of the InGaN-based nanorods were studied with field-emission scanning electron microscopy, transmission electron microscopy, and photoluminescence. The diameters and heights of nanorods were estimated to be 60–100 nm and more than 0.28 μm, respectively. The emission-peak wavelength of nanorods showed a blueshift of 5.1 nm from that of the bulk structure. An enhancement by a factor of five times in photoluminescence intensity of nanorods compared to that of the bulk structure was also observed in this work. The blueshift is attributed to the strain relaxation in the well, quantum-confinement effect, or a combination of the two, which result in the enhancement in emission intensity. [ABSTRACT FROM AUTHOR]

High density magnesium (Mg)-doped gallium nitride (GaN) nanorods were fabricated by inductively coupled plasma reactive ion etching technique from the epitaxial film. Under the fixed Cl2/Ar flow rate of 10/25 SCCM (SCCM denotes cubic centimeter per minute at STP) and inductively coupled plasma/bias power of 200/200 W, the nanorods were fabricated with a density of 108–1010 cm2 and dimension of 20–100 nm by varying the chamber pressure from 10 to 30 mTorr. A large blueshift was observed in the photoluminescence (PL) peak energy of Mg-doped GaN nanorods under HeCd laser (325 nm) excitation. The PL spectra of nanorods show a typical donor-acceptor-pair emission around 3.0 eV with a large blueshift compared to the Mg-doped GaN film. The blueshift energy increases from 8 to 67 meV as the excitation intensity varies from 12 to 56 kW/cm2. Possible reasons causing the power dependence of spectral shift in the PL emission energy are discussed. [ABSTRACT FROM AUTHOR]

In this letter, the mechanism for improvement of the dynamic performance of GaN-based light-emitting diodes with an InGaN insertion layer is investigated using the very fast electrical–optical pump-probe technique. Our measurements indicate that, when the bias current is relatively low (100 \A/cm^2), the device with the InGaN insertion layer (device A) exhibits a shorter response time than does the control (device B) without such a layer. However, when the bias current density reaches 0.5 \kA/cm^2, devices A and B exhibit exactly the same response time during operation from room temperature to 200 ^\circ\C. These results indicate that, under low current density (100 \A/cm^2), the piezoelectric (PZ) field inside device A will be stronger, which should result in a lower effective barrier height with a shorter carrier escape time than is the case for device B. On the other hand, under high bias current density, both devices have the same internal response time, which indicates the screening of the PZ field inside due to injected carriers. These dynamic measurement results suggest that the origin of the efficiency droop in our device under low and high bias current densities is carrier leakage and the Auger effect, respectively. [ABSTRACT FROM AUTHOR]

The enhancement of light extraction from GaN-based light-emitting diodes (LEDs) with a patterned sapphire substrate (PSS) and a SiO2 12-fold photonic quasi-crystal (PQC) structure using nanoimprint lithography is presented. At a driving current of 20 mA on transistor-outline-can package, the light output powers of LED with a PSS and LED with a PSS and a SiO2 PQC structure are enhanced by 35% and 48%, compared with the conventional LED. In addition, the higher output power of the LED with a PSS and a SiO2 PQC structure is due to better reflectance on PSS and higher epitaxial quality on an n-GaN using a SiO2 12-fold PQC structure pattern. These results provide promising potential to increase output powers of commercial light-emitting devices. [ABSTRACT FROM AUTHOR]

GaN-based LEDs with a SiO2 oxide PQC pattern on an n-GaN layer by nanoimprint lithography are fabricated and investigated. At a driving current of 20 mA on a Transistor-Outline-can package, the light output power of LED III (d = 1.2 µm) was enhanced by a factor of 1.20. The internal-quantum-efficiency result offers promising potential to enhance the light output power of commercial light-emitting devices with a SiO2 oxide PQC structure on an n-GaN layer. [ABSTRACT FROM AUTHOR]

A high-performance GaN hydrogen sensor fabricated by a Pd-SiO2 mixture to form a rough sensing surface with pores and nanoparticles is investigated. Hydrogen atoms trapped on the GaN surface and within the mixture form two-dimensional and three-dimensional dipoles, respectively, depending on biased voltages. Thus three sensing regions are found in current-voltage characteristics. The sensing response and barrier-height variation are over 107 and 410 mV, which are the highest values ever reported. The response time is as short as 40 s, indicating the proposed hydrogen sensor is very promising for hydrogen detection. [ABSTRACT FROM AUTHOR]

Effect of Ag segregation on magnetic and structural properties of (FePt)77 Ag23 single-layer films were studied. Thin films were first sputtered on the heated glass substrates and cooled to room temperature, a post annealing at temperatures (Tp) from 200 C to 4000 C for 60 mm was then applied. Ll0 structure formed as substrate temperature (Tp) equals to 600 °C and 700 °C. For those ordered films, Ag was observed to precipitate as particles on the film surface and grow with the increasing Ts. After post annealing at 400 °C for 60 mm, those silver particles dissolved into the film, leading to changes in reversal behavior. The optimum condition is obtained in the = 600 °C, Ts = 400 °C sample. Drastic reduction in coercive squareness ratio (from >0.8 to 0.41) and enhanced coercivity (from 4.7 to 6.4 kOe) indicate the reversal behavior alters from cooperative to independent. Negative δM curve suggests that this independent rotation results from the reduction of exchange interactions. [ABSTRACT FROM AUTHOR]

GaN-based vertical-cavity surface emitting laser with 3 λ cavity and hybrid mirrors, consisting of the 25 pairs AlN/GaN dielectric Bragg reflector and the 8 pairs Ta2O5/SiO2, was fabricated. The laser action was achieved under the optical pumping at room temperature with a threshold pumping energy density of about 53 mJ/cm2. The laser emits 448 nm blue wavelength with a linewidth of 0.25 nm and the laser beam has a degree of polarization of about 84%. [ABSTRACT FROM AUTHOR]

Discusses a study which examined magnetic domain structure evolution in the presence of an external magnetic field induced from a live current strip produced underneath patterned permalloy thin films. Review of related literature; Materials and methodology used; Results and conclusions.