다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Vegetation Indices (VIs) obtained from remote sensing based canopies are quite simple and effective algorithms for quantitative and qualitative evaluations of vegetation cover, vigor, and growth dynamics, among other applications These indices have been widely implemented within RS applications using different airborne and satellite platforms with recent advances using Unmanned Aerial Vehicles (UAV) Up to date, there is no unified mathematical expression that defines all VIs due to the complexity of different light spectra combinations, instrumentation, platforms, and resolutions used Therefore, customized algorithms have been developed and tested against a variety of applications according to specific mathematical expressions that combine visible light radiation, mainly green spectra region, from vegetation, and nonvisible spectra to obtain proxy quantifications of the vegetation surface In the real-world applications, optimization VIs are usually tailored to the specific application requirements coupled with appropriate validation tools and methodologies in the ground The present study introduces the spectral characteristics of vegetation and summarizes the development of VIs and the advantages and disadvantages from different indices developed This paper reviews more than 100 VIs, discussing their specific applicability and representativeness according to the vegetation of interest, environment, and implementation precision Predictably, research, and development of VIs, which are based on hyperspectral and UAV platforms, would have a wide applicability in different areas

/pdf/significant-remote-sensing-vegetation-indices-a-review-of-4szax6zlwz.pdf

Significant remote sensing vegetation indices: A review of developments and applications

13. 벼잎선충의 약제처리 방법별 방제 효과

This paper demonstrates a few-picosecond and high-peak-power mode-locked fiber laser, using an erbium-doped fiber as a gain medium and zinc oxide (ZnO) element as a new passively saturable absorber (SA). The ZnO element was synthesized using a seeding solution and amended with a polyvinyl alcohol to form a film. The ZnO has been identified as an ideal SA due to its high nonlinear optical response, high sustainability to damage threshold, and fast recovery time. Self-started mode-locked laser pulses have been generated at a relatively low pump power of 42 mW with a fundamental repetition rate and pulse duration of 3.26 MHz and 2.60 ps, respectively. The proposed laser operates at 1599.5 nm with a 3 dB spectral bandwidth of 1.12 nm. A maximum output power, pulse energy, and peak power of about 6.91 mW, 2.12 nJ, and 0.82 kW, respectively, are obtained at a maximum pump power of 159 mW. From these findings, we confirm that the proposed laser can be viewed as a promising light source in the emerging optical communication system.

A few-picosecond and high-peak-power passively mode-locked erbium-doped fibre laser based on zinc oxide polyvinyl alcohol film saturable absorber

We experimentally demonstrate a passive, stable and low cost Q-switched erbium-doped fiber laser based on molybdenum disulfide (MoS2) and black phosphorus (BP) saturable absorber (SA). Both MoS2 and BP SAs are prepared by mechanically exfoliating the crystal and fixing the acquired flakes onto the end surface of a standard FC/PC fiber connector. By integrating either MoS2 or BP SA into the laser cavity, a stable Q-switched operation is achieved at wavelengths of 1551.4 or 1552.9 nm respectively. Using the MoS2 SA, the repetition rate of the output laser increases from 14.25 to 38.43 kHz as the 980 nm pump power rises from 57 to 170 mW while its pulse width reduces from 10.7 to 5.02 μs. The maximum pulse energy was 141.3 nJ. On the other hand, with the BP SA, the repetition rate and pulse width fall in the ranges of 9.1–44.33 kHz and 20.75–7.04 μs respectively, as the pump power grows from 50 to 170 mW. The laser with the BP SA, produces the maximum pulse energy of 134 nJ. The experimental results indicate that MoS2 and BP SAs can be used to generate stable Q-switching pulses at 1.5 μm region successfully.

Mechanically exfoliated 2D nanomaterials as saturable absorber for Q-switched erbium doped fiber laser

Brillouin fiber laser (BFL) has been demonstrated using a 49 cm long bismuth-based erbium-doped fiber (Bi-EDF) in conjunction with a 20 m long photonic crystal fiber as gain media with a simple ring resonator. The BFL operates at 1559.09 nm, which is 0.09 nm shifted from the Brillouin pump wavelength. The BFL also has a stable output with a side mode suppression ratio of 12 dB.

Brillouin fiber laser with a 49 cm long Bismuth-based erbium-doped fiber

We demonstrate a Q-switched thulium-doped fibre laser operating at approximately 1935 nm wavelength using anatase titanium(IV) oxide (TiO2) embedded in polyvinyl alcohol as the passive newly saturable absorber (SA). The film has absorption loss of 3.5 dB and modulation depth of 33%. It is sandwiched between two fibre ferrules in a ring laser cavity to produce self-started pulse train with a repetition rate that is tuned from 30.12 to 36.96 kHz as the 1552-nm pump power is increased from 289 to 485 mW. At maximum pump power, the laser produced a Q-switching pulse train with pulse duration, output power, pulse energy and peak power of 1.91 μs, 11 mW, 0.3 μJ and 146 mW, respectively. These results show that the TiO2 is a new potential SA material for pulsed laser applications.

Sulaiman Wadi Harun

Papers

A few-picosecond and high-peak-power passively mode-locked erbium-doped fibre laser based on zinc oxide polyvinyl alcohol film saturable absorber

Mechanically exfoliated 2D nanomaterials as saturable absorber for Q-switched erbium doped fiber laser

Brillouin fiber laser with a 49 cm long Bismuth-based erbium-doped fiber

A generation of 2 μm Q-switched thulium-doped fibre laser based on anatase titanium(IV) oxide film saturable absorber

Current Developments In Optical Fiber Technology