Graduate School of Science

Increasing prices and demand for biofuel and cooking oil from importer countries have caused a remarkable expansion of oil palm plantations in Indonesia. In this paper, we attempt to monitor the expansion of oil palm plantations on peat land and in tropical forests. We measure the GHG emissions from the land conversion activities at provincial scale. Using Landsat images from three different periods (1990s, 2000s and 2012), we classified LULC of the Riau Province, which is the largest oil palm producing region in Indonesia. A hybrid method of integration, generated by combining automatic processing and manual analysis, yields the best results. We found that the tropical rainforest cover decreased from ,63% in the 1990s to ,37% in the 2000s. By 2012, the remaining tropical rainforest cover was only ,22%. From the 1990s to the 2000s, conversion of forests and peat lands was the primary source of emissions, total CO 2 emitted to the atmosphere was estimated at ,26.6 million tCO 2 .y -1 , with 40.62% and 59.38% of the emissions from conversion of peat lands and forests, respectively. Between 2000 and 2012, the total CO 2 emitted to the atmosphere was estimated at ,5.2 million tCO 2 . y -1 , with 69.94% and 27.62% of the emissions from converted peat lands and converted forests, respectively. The results show that in the Riau Province, the oil palm industry boomed in the period from 1990 to 2000, with transformation of tropical forest and peat land as the primary source of emissions. The decrease of CO 2 emissions in the period from 2000 to 2012 is possibly due to the enforcement of a moratorium on deforestation.

by the high-intensity 800 nm laser field Svetlana Vui -Topical Review A M Popov, O V Tikhonova and E A Volkova -Complex rotation in 2D mesh calculations Mikhail V Ivanov -Recent citations Nonlinear optical polarization response and plasma generation in noble gases: Comparison of metastable-electronicstate-approach models to experiments Anand Bahl et al -This content was downloaded from IP address 3.95.17.81 on 16/10

R-Pyridinylpyrroles 1 and their reduced derivatives, pyrrolidines 2, have attracted considerable interest from pharmaceutical and medicinal chemists due to their biological activities. 1 The synthetic methodologies for these pyrroles are divided into two major categories: (1) pyridine derivatives, having an alkyl chain with a 1,4-diketone functional group at the ortho, meta, or para position, are synthesized first, and then they are converted to the corresponding pyrroles through the standard procedures; 2 (2) the coupling reaction between R-metallopyrroles and halopyridines (or vice versa) under the Kumada, Negishi, and other conditions gives the desired products 1. 3 Catalytic hydrogenation of 1 gives pyrrolidine derivatives 2. 4 We report herein an entirely new approach for the synthesis of 1 (eq 1). The palladium-catalyzed reaction of the methyleneaziridines 3 with o-acetylpyridine 4a gave the o-pyridinylpyrroles 1 in good to high yields. Not only o-but also m-and p-acetylpyridines and related substrates can be used as the starting acetyl derivatives. The results of the reaction of 4a with 3, having various R substituents, are summarized in .

The copper-catalyzed reaction of arylidenecyclopropanes (1) with 2oxazolidinone (2) gave the corresponding homoallylic oxazolidinones (3) in good to high yields. For example, the reaction of diphenylmethylenecyclopropane (1a), {bis(p-tolyl)methylenecyclopropane (1b), and {bis(p-anisyl)methylene}cyclopropane (1d) in the presence of 10 mol% of Cu(OTf) 2 without solvent proceeded at 120 °C, giving the corresponding homoallylic oxazolidinones (3a, 3b, and 3d) in 89, 80, and 58% yields, respectively.

The effect of systemically administered phencyclidine (PCP) on the extracellular concentration of aspartate (Asp) and glutamate (Glu) in the rat anterior cingulate cortex was investigated using in vivo microdialysis. PCP significantly reduced the K+-evoked release of Asp and Glu, while it had no effect on the basal efflux of Asp and Glu. These results suggest that PCP might inhibit excitatory amino acid (EAA) release through an N-methyl-D-aspartate (NMDA) receptor-mediated mechanism.

Complete studies of the radiative processes of thermal emission from the amorphous dust from microwave through far-infrared wavebands are presented by taking into account, self-consistently for the first time, the standard two-level systems (TLS) model of amorphous materials. The observed spectral energy distributions (SEDs) for the Perseus molecular cloud (MC) and W 43 from microwave through far-infrared are fitted with the SEDs calculated with the TLS model of amorphous silicate. We have found that the model SEDs reproduce the observed properties of the anomalous microwave emission (AME) well. The present result suggests an alternative interpretation for the AME being carried by the resonance emission of the TLS of amorphous materials without introducing new species. Simultaneous fitting of the intensity and polarization SEDs for the Perseus MC and W 43 are also performed. The amorphous model reproduces the overall observed feature of the intensity and polarization SEDs of the Per...

The temporal profile measurement for ultra-short electron bunches is one of the key issues for accelerator-based coherent light sources. A bunch length measurement system using Cherenkov radiation (CR) is under development at the Research Center for Electron Photon Science, Tohoku University. This system allows for the real-time diagnostics of electron bunches. The system comprises a thin silica aerogel as the Cherenkov radiator, a specially designed optical transport line, and a high-speed streak camera. The electron bunch length can be obtained by measuring the time spread of the CR from the electrons passing through the radiator medium using the streak camera. In this paper, we describe the novel bunch length measurement system using CR, discuss the expected time resolution of the system, and finally present the measurement results.

The generation of coherent THz radiation from femtosecond electron bunches passing through an undulator was demonstrated with a test accelerator as a coherent terahertz source (t-ACTS) at Tohoku University. The velocity bunching scheme in the traveling wave accelerating structure was employed to generate electron bunches much shorter than the THz wavelength. The electron bunch length was measured with the spectrum analysis method for coherent transition radiation. A 2.5-m long undulator with 25 periods and peak magnetic field of 0.41 T was utilized to generate the tunable coherent undulator radiation ranging from 2.6 to 3.6 THz at the t-ACTS. The measured frequency spectrum and spatial distribution of the coherent undulator radiation are presented.

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Linear focal Cherenkov ring camera (LFC-Camera) has been developed for single shot measurement of longitudinal phase space distribution of quasi-relativistic electron beam, where the electron’s velocity still depends on its energy. The LFC-camera employs velocity dependence of opening angle of Cherenkov light produced by electron beam to observe its energy (momentum) distribution. Since the Cherenkov light contains the time information if the radiator medium is thin enough, we can get the longitudinal phase space distribution measuring both time and energy spectra simultaneously using a streak camera. We employ a thin silica aerogel with water-free hydrophobic treatment as Cherenkov radiator. We have evaluated characteristics of the silica aerogel radiator, and demonstration of the LFC-camera at a beam diagnosis section of t-ATCS is being proceeded. LINEAR FOCAL CHERENKOV-RING CAMERA Concept and Principle A test accelerator for an intense coherent THz light source project (test Acce...

A test accelerator as a coherent terahertz source (t-ACTS) has been under development at Tohoku University, in which an intense coherent terahertz (THz) radiation generated by an extremely short electron bunch [1]. Velocity bunching scheme in a traveling accelerating structure is employed to generate femtosecond electron bunches [2]. Spatial and temporal coherent radiation in THz region can be produced by the electron bunches with small transverse emittance. A long-period undulator, which has 25 periods with a period length of 10 cm and a peak magnetic field of 0.41 T, has been also developed and installed to provide intense coherent THz undulator radiation. By optimizing the bunch length, we found that it is possible to generate a coherent undulator radiation that contains only the fundamental wave from numerical studies. Beam experiment was performed to generate and observe the coherent undulator radiation from extremely short electron bunches. Coherent undulator radiation from 2....

In case of that bunch length is shorter than the radiation wavelength and ݂ሺߣሻ is not zero, the radiated power ଶܰ has a coherent term that is proportional to ሻ ߣ ሺ ଴ܲ A test-Accelerator as Coherent Terahertz Source (tACTS) project has been under development at Research Center for Electron Photon Science, Tohoku University. In order to generate a coherent radiation in terahertz (THz) region, it is necessary to produce sub-picosecond . Transition radiation is produced by the passage of charged particles through the boundary between media with different dielectric constant. In the case of that elec­ tron bunch passes through a perfect conductor tilted 45o, electron pulses. Velocity bunching scheme is employed for the short electron pulse production in t-ACTS. We experimentally confirmed the production of short electron pulse under 500 fs by measuring the bunch length using a streak camera. Coherent transition radiation in THz region was produced by which the short electron pulses pass ...

We have developed crossed-undulator configuration to control the polarization of coherent THz radiation at the femto-second electron beam facility, t-ACTS [1], that has been established at Research Center for Electron Photon Science, Tohoku University. The t-ACTS linac equips a thermionic RF gun, a 3 m accelerating structure and a 50 MW klystron modulator. Ultra-short electron bunch (~80 fs) train can be supplied via velocity bunching scheme. The crossed-undulator system is consisted with two identical transverse undulators intersected by a chicane type phase shifter. Deflecting planes of two undulators are at right angles each other, and the phase shifter makes path length difference between the electrons and the radiation. Target radiation frequency is around 2 THz employing a beam energy of 22 MeV. Since electron bunch trails behind the radiation by the slippage-effect and the nonrelativistic-effect that the electron speed is a bit slower than the speed of light, the radiation fr...

Cherenkov radiation (CR) emitted from low-refractive index material such as silica-aerogel is a useful tool for electron beam diagnostics because the opening angle (Cherenkov angle) is small and the CR can be transported onto a detector located far from the radiator. We have prepared a thin (1-mm thick) hydrophobic silica-aerogel with a refractive index of 1.05 that has been developed at Chiba University.* Since the intensity of CR is much stronger than that of optical transition radiation, the CR is a better light source for low-intensity beam diagnostics. In order to apply the CR to measurements of a bunch length of electron beams, we have investigated sources of finite time resolution by a numerical simulation study using the Liénard-Wiechert potentials. We will report results of simulations such as pulse duration of CR and discuss what deteriorates the time resolution.