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Sample records for buried oxide silicon-on-insulator

  1. Total dose radiation response of modified commercial silicon-on-insulator materials with nitrogen implanted buried oxide

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhong-Shan; Liu Zhong-Li; Yu Fang; Li Ning

    2012-01-01

    Nitrogen ions of various doses are implanted into the buried oxide (BOX) of commercial silicon-on-insulator (SOI)materials,and subsequent annealings are carried out at various temperatures.The total dose radiation responses of the nitrogen-implanted SOI wafers are characterized by the high frequency capacitance-voltage (C-V) technique after irradiation using a Co-60 source.It is found that there exist relatively complex relationships between the radiation hardness of the nitrogen implanted BOX and the nitrogen implantation dose at different irradiation doses.Fhe experimental results also suggest that a lower dose nitrogen implantation and a higher post-implantation annealing temperature are suitable for improving the radiation hardness of SOI wafer.Based on the measured C-V data,secondary ion mass spectrometry (SIMS),and Fourier transform infrared (FTIR) spectroscopy,the total dose responses of the nitrogen-implanted SOI wafers are discussed.

  2. Optimizing Design of Breakdown Voltage to Eliminate Back Gate Bias Effect in Silicon-on-Insulator Diode Using Low Doping Buried Layer

    Institute of Scientific and Technical Information of China (English)

    H0 Chi-Hon; LIAO Chen-Nan; CHIEN Feng-Tso; TSAI Yao-Tsung

    2009-01-01

    This work presents the optimal design of a silicon-on-insulator (SOI) diode structure to eliminate the back gate bias effect and to improve breakdown voltage. The SOI structure is characterized by inserting a silicon low doping buried layer (LDBL) between the silicon layer and the buried oxide layer. The LDBL thickness is a key parameter that affects the strong inversion condition of the back MOS capacitor of the new SOI diode. The optimal LDBL thickness in the SOI diode is 2.65μm. The LDBL shielding layer improved the breakdown voltage.

  3. Synthesis of buried silicon oxynitride layers by ion implantation for silicon-on-insulator (SOI) structures

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, A.D. [Department of Physics, University of Mumbai, Vidyanagari Campus, Santacruz (E), Mumbai 400 098 (India)]. E-mail: adyadav@physics.mu.ac.in; Polji, Rucha H. [Department of Physics, University of Mumbai, Vidyanagari Campus, Santacruz (E), Mumbai 400 098 (India); Singh, Vibha [Department of Physics, University of Mumbai, Vidyanagari Campus, Santacruz (E), Mumbai 400 098 (India); Dubey, S.K. [Department of Physics, University of Mumbai, Vidyanagari Campus, Santacruz (E), Mumbai 400 098 (India); Gundu Rao, T.K. [Regional Sophisticated Instrumentation Center, IIT Bombay, Powai, Mumbai 400 076 (India)

    2006-04-15

    Silicon oxynitride (Si {sub x}O {sub y}N {sub z}) buried insulating layers were synthesized by SIMNOX (separation by implanted nitrogen-oxygen) process by {sup 14}N{sup +} and {sup 16}O{sup +} ion implantation to high fluence levels 1 x 10{sup 17}, 2.5 x 10{sup 17} and 5 x 10{sup 17} ions cm{sup -2} sequentially in the ratio 1:1 at 150 keV into p-type (1 0 0) silicon wafers. The identification of structures and defects in the ion beam synthesized buried layers were carried out by FTIR, XRD and ESR measurements before and after RTA treatments at different temperatures in nitrogen ambient. The FTIR spectra show single broad absorption band in the wavenumber range 1250-600 cm{sup -1} confirming the formation of silicon oxynitride. The integrated absorption band intensity is found to increase with increasing ion fluence and on annealing indicating gradual chemical transformation of the ion implanted layer into silicon oxynitride. The XRD data of the implanted samples show the formation of Si{sub 2}N{sub 2}O (O) phase of silicon oxynitride. On annealing the samples, SiO{sub 2} (H)/Si{sub 3}N{sub 4} (H) phases are also formed in addition to Si{sub 2}N{sub 2}O (O) phase. The concentration of the formed phases is found to increase with increase in the ion fluence as well as the annealing temperature. The ESR studies both at room temperature and at low temperatures reveal the presence of a defect center associated with silicon dangling bonds. The increase in ion fluence gives rise to small variations in g-values and increase in the spin density. The spin density decreases in general with increasing the annealing temperature.

  4. Influence of high-dose nitrogen implantation on the positive charge density of the buried oxide of silicon-on-insulator wafers%高剂量注氮对注氧隔离硅材料埋氧层中正电荷密度的影响

    Institute of Scientific and Technical Information of China (English)

    唐海马; 郑中山; 张恩霞; 于芳; 李宁; 王宁娟; 李国花; 马红芝

    2011-01-01

    The influence of nitrogen implantation on the properties of silicon-on-insulator buried oxide using separation by oxygen implantation was studied. Nitrogen ions were implanted into the buried oxide layer with a high-dose of 1016 cm-2.The experimental results showed that the positive charge density of the nitrogen-implanted buried oxide was obviously increased, compared with the control sampes without nitrogen implantation. It was also found that the post-implantation annealing caused an additional increase of the positive charge density in the nitrogen implanted samples. However,annealing time displayed a small effect on the positive charge density of the nitrogen implanted buried oxide, compared with the significant increase induced by nitrogen implantation. Moreover, the capacitance-voltage results showed that the positive charge density of the unannealed sample with nitrogen implanted is approximately equal to that of the sample annealed at 1100 ℃ for 2. 5 h in N2 ambient, despite an additional increase brought with annealing, and the buried oxide of the sample after 0.5 h annealing has a maximum value of positive charge density. According to the simulating results,the nitrogen implantation resulted in a heavy damage to the buried oxide, a lot of silicon and oxygen vacancies were introduced in the buried oxide during implantation. However, the Fourier transform infrared spectroscopy of the samples indicates that implantation induced defects can be basically eliminated after an annealing at 1100 ℃ for 0. 5 h. The increase of the positive charge density of the nitrogen implanted buried oxide is ascribed to the accumulation of implanted nitrogen near the interface of buried oxide and silicon, which caused the break of weak Si - Si bonds and the production of positive silicon ions in the silicon-rich region of the buried oxide near the interface, and this conclusion is supported by the results of secondary ion mass spectrometry.%为研究注氮改性对注氧

  5. A Novel Fully Depleted Air AlN Silicon-on-Insulator Metal-Oxide-Semiconductor Field Effect Transistor

    Institute of Scientific and Technical Information of China (English)

    YANG Yuan; GAO Yong; GONG Peng-Liang

    2008-01-01

    @@ A novel fully depleted air AlN silicon-on-insulator (SOI) metal-oxide-semiconductor field effect transistor (MOS-FET) is presented, which can eliminate the self-heating effect and solve the problem that the off-state current of SOI MOSFETs increases and the threshold voltage characteristics become worse when employing a high thermal conductivity material as a buried layer. The simulation results reveal that the lattice temperature in normal SOI devices is 75K higher than the atmosphere temperature, while the lattice temperature is just 4K higher than the atmosphere temperature resulting in less severe self-heating effect in air AlN SOI MOSFETs and AlN SOI MOSFETs. The on-state current of air AlN SOI MOSFETs is similar to the AlN SOI structure, and improves 12.3% more than that of normal SOI MOSFETs. The off-state current of AlN SOI is 6.7 times of normal SOI MOSFETs, while the counterpart of air AlN SOI MOSFETs is lower than that of SOI MOSFETs by two orders of magnitude. The threshold voltage change of air AlN SOI MOSFETs with different drain voltage is much less than that of AlN SOI devices, when the drain voltage is biased at 0.8 V, this difference is 28mV, so the threshold voltage change induced by employing high thermal conductivity material is cured.

  6. Process-induced strain in silicon-on-insulator materials

    CERN Document Server

    Tiberj, A; Blanc, C; Contreras, S; Camassel, J

    2002-01-01

    We present a detailed investigation of the influence of oxidation and thinning processes on the in-plane stress in silicon-on-insulator materials. Combining double x-ray diffraction, Fourier transformed infrared and micro-Raman spectroscopy, we show that one can separately evaluate the stress present in the silicon over layer, the buried oxide and the underlying (handle) silicon wafer at any time of a device-forming process.

  7. Numerically controlled atmospheric-pressure plasma sacrificial oxidation using electrode arrays for improving silicon-on-insulator layer uniformity

    Science.gov (United States)

    Takei, Hiroyasu; Yoshinaga, Keinosuke; Matsuyama, Satoshi; Yamauchi, Kazuto; Sano, Yasuhisa

    2015-01-01

    Silicon-on-insulator (SOI) wafers are important semiconductor substrates in high-performance devices. In accordance with device miniaturization requirements, ultrathin and highly uniform top silicon layers (SOI layers) are required. A novel method involving numerically controlled (NC) atmospheric-pressure plasma sacrificial oxidation using an electrode array system was developed for the effective fabrication of an ultrathin SOI layer with extremely high uniformity. Spatial resolution and oxidation properties are the key factors controlling ultraprecision machining. The controllability of plasma oxidation and the oxidation properties of the resulting experimental electrode array system were examined. The results demonstrated that the method improved the thickness uniformity of the SOI layer over one-sixth of the area of an 8-in. wafer area.

  8. A New Structure of Silicon-on-Insulator Metal-Oxide-Semiconductor Field Effect Transistor to Suppress the Floating Body Effect

    Institute of Scientific and Technical Information of China (English)

    朱鸣; 林青; 张正选; 林成鲁

    2003-01-01

    Considering that the silicon-on-insulator (SOI) devices have an inherent floating body effect, which may cause substantial influences in the performance of SOI device and circuit, we propose a novel device structure to suppress the floating body effect. In the new structure there is a buried p+ region under the n+ source and that region is extended to outside of the source, and this additional p+ region provides a path for accumulated holes to flow out of the body. Numerical simulations were carried out with Medici, and the output characteristics and gate characteristics were compared with those of conventional SOI counterparts. The simulated results show the suppression of floating body effect in the novel SOI device as expected.

  9. Analysis of the breakdown mechanism for an ultra high voltage high-side thin layer silicon-on-insulator p-channel low-density metal-oxide semiconductor

    Institute of Scientific and Technical Information of China (English)

    Zhuang Xiang; Qiao Ming; Zhang Bo; Li Zhao-Ji

    2012-01-01

    This paper discusses the breakdown mechanism and proposes a new simulation and test method of breakdown voltage (BV) for an ultra-high-voltage (UHV) high-side thin layer silicon-on-insulator (SOI) p-channel low-density metaloxide semiconductor (LDMOS).Compared with the conventional simulation method,the new one is more accordant with the actual conditions of a device that can be used in the high voltage circuit.The BV of the SOI p-channel LDMOS can be properly represented and the effect of reduced bulk field can be revealed by employing the new simulation method.Simulation results show that the off-state (on-state) BV of the SOI p-channel LDMOS can reach 741 (620) V in the 3-μm-thick buried oxide layer,50-un-length drift region,and at -400 V back-gate voltage,enabling the device to be used in a 400 V UHV integrated circuit.

  10. Ultra-low power high temperature and radiation hard complementary metal-oxide-semiconductor (CMOS) silicon-on-insulator (SOI) voltage reference.

    Science.gov (United States)

    Boufouss, El Hafed; Francis, Laurent A; Kilchytska, Valeriya; Gérard, Pierre; Simon, Pascal; Flandre, Denis

    2013-12-13

    This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID) radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI) industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of -40-200 °C and for different process corners. Robustness to radiation was simulated using custom model parameters including TID effects, such as mobilities and threshold voltages degradation. The proposed circuit has been tested up to high total radiation dose, i.e., 1 Mrad (Si) performed at three different temperatures (room temperature, 100 °C and 200 °C). The maximum drift of the reference voltage V(REF) depends on the considered temperature and on radiation dose; however, it remains lower than 10% of the mean value of 1.5 V. The typical power dissipation at 2.5 V supply voltage is about 20 μW at room temperature and only 75 μW at a high temperature of 200 °C. To understand the effects caused by the combination of high total ionizing dose and temperature on such voltage reference, the threshold voltages of the used SOI MOSFETs were extracted under different conditions. The evolution of V(REF) and power consumption with temperature and radiation dose can then be explained in terms of the different balance between fixed oxide charge and interface states build-up. The total occupied area including pad-ring is less than 0.09 mm2.

  11. Ultra-Low Power High Temperature and Radiation Hard Complementary Metal-Oxide-Semiconductor (CMOS Silicon-on-Insulator (SOI Voltage Reference

    Directory of Open Access Journals (Sweden)

    El Hafed Boufouss

    2013-12-01

    Full Text Available This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of -40–200 °C and for different process corners. Robustness to radiation was simulated using custom model parameters including TID effects, such as mobilities and threshold voltages degradation. The proposed circuit has been tested up to high total radiation dose, i.e., 1 Mrad (Si performed at three different temperatures (room temperature, 100 °C and 200 °C. The maximum drift of the reference voltage VREF depends on the considered temperature and on radiation dose; however, it remains lower than 10% of the mean value of 1.5 V. The typical power dissipation at 2.5 V supply voltage is about 20 μW at room temperature and only 75 μ W at a high temperature of 200 °C. To understand the effects caused by the combination of high total ionizing dose and temperature on such voltage reference, the threshold voltages of the used SOI MOSFETs were extracted under different conditions. The evolution of VREF and power consumption with temperature and radiation dose can then be explained in terms of the different balance between fixed oxide charge and interface states build-up. The total occupied area including pad-ring is less than 0.09 mm2.

  12. Ultra-Low Power High Temperature and Radiation Hard Complementary Metal-Oxide-Semiconductor (CMOS) Silicon-on-Insulator (SOI) Voltage Reference

    OpenAIRE

    El Hafed Boufouss; Francis, Laurent A.; Valeriya Kilchytska; Pierre Gérard; Pascal Simon; Denis Flandre

    2013-01-01

    This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID) radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI) industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of -40–200 °C and for differ...

  13. Ultra-low-loss inverted taper coupler for silicon-on-insulator ridge waveguide

    DEFF Research Database (Denmark)

    Pu, Minhao; Liu, Liu; Ou, Haiyan;

    2010-01-01

    An ultra-low-loss coupler for interfacing a silicon-on-insulator ridge waveguide and a single-mode fiber in both polarizations is presented. The inverted taper coupler, embedded in a polymer waveguide, is optimized for both the transverse-magnetic and transverse-electric modes through tapering...... the width of the silicon-on-insulator waveguide from 450 nm down to less than 15 nm applying a thermal oxidation process. Two inverted taper couplers are integrated with a 3-mm long silicon-on-insulator ridge waveguide in the fabricated sample. The measured coupling losses of the inverted taper coupler...

  14. Charging effects on the carrier mobility in silicon-on-insulator wafers covered with a high-k layer

    Science.gov (United States)

    Halley, D.; Norga, G.; Guiller, A.; Fompeyrine, J.; Locquet, J. P.; Drechsler, U.; Siegwart, H.; Rossel, C.

    2003-11-01

    The carrier mobility μ in low-doped silicon-on-insulator wafers is found to be strongly modified by the deposition of a thin ZrO2 or SrZrO3 top layer grown by molecular-beam epitaxy. Pseudo-metal-oxide-semiconductor field-effect-transistor measurements performed on several samples clearly show a correlation between μ and the density of interface traps (Dit) at the Si/buried-oxide interface. The reduction of Dit by a forming gas anneal leads to a corresponding increase in mobility. Moreover, the high-k/Si interface can contribute to the total drain current via the creation of an inversion channel induced by trapped charges in the high-k layer. Using Hall-effect measurements, we took advantage of this additional current to evaluate the carrier mobility at the high-k/Si interface, without the need of a top gate electrode.

  15. Silicon on insulator (SOI) technology; Technologie silicium sur isolant (SOI)

    Energy Technology Data Exchange (ETDEWEB)

    Cristoloveanu, S.; Balestra, F. [Centre National de la Recherche Scientifique (CNRS), Institut de Microelectronique, Electromagnetisme et Photonique, IMEP, Ecole Nationale Superieure d' Electronique et de Radioelectricite de Grenoble, ENSERG, 38 - Grenoble (France)

    2002-05-01

    The silicon on insulator (SOI) technology was invented in the 1960's and 1970's in order to satisfy the demand of hardened integrated circuits with respect to ionizing radiations. This technology uses an embedded oxide for a perfect dielectric insulation between the active circuit (superficial) layer and the massive silicon substrate (responsible of undesirable parasite effects). The SOI technology is a first-class technology for the fabrication of low consumption and high frequency components. This article describes the state-of-the-art of the SOI technology, starting with the methods of synthesis of the main materials. The essential advantages of SOI circuits with respect to conventional massive silicon devices are presented with some typical examples of components (totally or partially depleted MOS transistors, miniaturization of conventional MOS transistors, innovative architectures). Finally the challenges to be taken up by the SOI technology to spread over the market of microelectronics are discussed. (J.S.)

  16. Space and military radiation effects in silicon-on-insulator devices

    Energy Technology Data Exchange (ETDEWEB)

    Schwank, J.R.

    1996-09-01

    Advantages in transient ionizing and single-event upset (SEU) radiation hardness of silicon-on-insulator (SOI) technology spurred much of its early development. Both of these advantages are a direct result of the reduced charge collection volume inherent to SOI technology. The fact that SOI transistor structures do not include parasitic n-p-n-p paths makes them immune to latchup. Even though considerable improvement in transient and single-event radiation hardness can be obtained by using SOI technology, there are some attributes of SOI devices and circuits that tend to limit their overall hardness. These attributes include the bipolar effect that can ultimately reduce the hardness of SOI ICs to SEU and transient ionizing radiation, and charge buildup in buried and sidewall oxides that can degrade the total-dose hardness of SOI devices. Nevertheless, high-performance SOI circuits can be fabricated that are hardened to both space and nuclear radiation environments, and radiation-hardened systems remain an active market for SOI devices. The effects of radiation on SOI MOS devices are reviewed.

  17. Silicon-on-Insulator-Based Waveguide Switch with Fast Response

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuan-Yuan; LI Yun-Tao; XIA Jin-Song; LIU Jing-Wei; CHEN Shao-Wu; YU Jin-Zhong

    2005-01-01

    @@ Based on thermo-optical effect of silicon, a 2 × 2 switch is fabricated in silicon-on-insulator by chemical etching.The switch presents an extinction ratio of 26dB and a power consumption of 169mW. The response time is ~ 10.5μs.

  18. Integrated programmable photonic filter on the silicon -on- insulator platform

    DEFF Research Database (Denmark)

    Liao, Shasha; Ding, Yunhong; Peucheret, Christophe

    2014-01-01

    We propose and demonstrate a silicon - on - insulator (SOI) on - chip programmable filter based on a four - tap finite impulse response structure. The photonic filter is programmable thanks to amplitude and phase modulation of each tap controlled by thermal heater s. We further demonstrate...

  19. The breakdown mechanism of a high-side pLDMOS based on a thin-layer silicon-on-insulator structure

    Institute of Scientific and Technical Information of China (English)

    Zhao Yuan-Yuan; Qiao Ming; Wang Wei-Bin; Wang Meng; Zhang Bo

    2012-01-01

    A high-side thin-layer silicon-on-insulator (SOI) pLDMOS is proposed,adopting field implant (FI) and multiple field plate (MFP) technologies.The breakdown mechanisms of back gate (BG) turn-on,surface channel punch-through,and vertical and lateral avalanche breakdown are investigated by setting up analytical models,simulating related parameters and verifying experimentally.The device structure is optimized based on the above research.The shallow junction achieved through FI technology attenuates the BG effect,the optimized channel length eliminates the surface channel punch-through,the advised thickness of the buried oxide dispels the vertical avalanche breakdown,and the MFP technology avoids premature lateral avalanche breakdown by modulating the electric field distribution.Finally,for the first time,a 300 V high-side pLDMOS is experimentally realized on a 1.5 μm thick thin-layer SOI.

  20. Temporal ringdown of silicon-on-insulator racetrack resonators.

    Science.gov (United States)

    Karle, T J; Raineri, F; Roppo, V; Bordas, F; Monnier, P; Ali, S; Sivan, I; Raj, R

    2013-07-01

    Ring-down temporal measurements of silicon-on-insulator wire racetrack resonators are performed with 150 fs input pulses using a parametric process in a nonlinear crystal to gate and amplify the weak output pulses. We measure the cavity round trip time and the quality factor of these all-pass filters and find excellent agreement with continuous wave spectroscopic measurements as well as with an analytic model built using numerical solutions for the fully vectorial waveguide modes.

  1. Grating-assisted silicon-on-insulator racetrack resonator reflector.

    Science.gov (United States)

    Boeck, Robert; Caverley, Michael; Chrostowski, Lukas; Jaeger, Nicolas A F

    2015-10-05

    We experimentally demonstrate a grating-assisted silicon-on-insulator (SOI) racetrack resonator reflector with a reflect port suppression of 10.3 dB and no free spectral range. We use contra-directional grating couplers within the coupling regions of the racetrack resonator to enable suppression of all but one of the peaks within the reflect port spectrum as well as all but one of the notches within the through port spectrum.

  2. On the two-dimensional metallic state in silicon-on-insulator structures

    OpenAIRE

    Brunthaler, G.; Prinz, A.; Pillwein, G.; Lindelof, P. E.; Ahopelto, J.

    2002-01-01

    It is shown that the electronic conduction in silicon-on-insulator (SOI) layers exhibits a metallic regime which is very similar to that in high-mobility Si-metal oxide semiconductor structures (MOS). The peak in the electron mobility versus density, the strong drop in resistivity and the critical concentration for the metal-insulator transition are all consistent. On the basis of our SOI data for the temperature and in-plane magnetic field dependence of the resistivity, we discuss several mo...

  3. Pulse quenching induced by multi-collection effects in 45 nm silicon-on-insulator technology

    Science.gov (United States)

    Artola, L.; Hubert, G.

    2016-12-01

    This paper presents the analysis of pulse quenching effects induced in silicon-on-insulator (SOI) technology. Simulation results emphasize the need to consider multi-collection effects in the occurrence mechanisms of single event transients (SET) in very large scaling integration (VLSI) components even with SOI technologies, which is known to be initially less sensitive to soft errors (SE). The impacts of gate-to-gate spacing and voltage scaling on the SET occurrence and characteristics have been highlighted. The simulations have been performed with the soft error prediction tool MUSCA SEP3 developed for digital complementary metal oxide semiconductor (CMOS) technologies (SOI, Bulk).

  4. Model of Vernier devices in silicon-on-insulator technology

    Science.gov (United States)

    Fan, Guofang; Li, Yuan; Hu, Chunguang; Lei, Lihua; Zhao, Dong; Li, Hongyu; Luo, Yunhan; Zhen, Zhen

    2014-07-01

    In order to increase the number of channels that could be multiplexed or demultiplexed in the dense wavelength division multiplexed (DWDM) system based on the resonators on silicon-on-insulator (SOI) technology, the Vernier effect in the series-coupled racetrack resonators is presented to extend the free spectral range (FSR) of the DWDM systems. A method is developed based on a matrix approach to simulate Vernier devices. A three-dimensional full vectorial finite difference (FVFD) model, specifically suited for high index contrast and smaller size waveguides, for example, a waveguide in SOI technology, is developed to obtain the properties of a waveguide. Finally, the Vernier effect in the two series-coupled racetrack resonators is experimentally verified with an improved FSR and interstitial resonance suppression.

  5. A NEW STRUCTURE AND ITS ANALYTICAL BREAKDOWN MODEL OF HIGH VOLTAGE SOI DEVICE WITH STEP UNMOVABLE SURFACE CHARGES OF BURIED OXIDE LAYER

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new SOI (Silicon On Insulator) high voltage device with Step Unmovable Surface Charges(SUSC) of buried oxide layer and its analytical breakdown model are proposed in the paper. The unmovable charges are implemented into the upper surface of buried oxide layer to increase the vertical electric field and uniform the lateral one. The 2-D Poisson's equation is solved to demonstrate the modulation effect of the immobile interface charges and analyze the electric field and breakdown voltage with the various geometric parameters and step numbers. A new RESURF (REduce SURface Field) condition of the SOI device considering the interface charges and buried oxide is derived to maximize breakdown voltage. The analytical results are in good agreement with the numerical analysis obtained by the 2-D semiconductor devices simulator MEDICI. As a result, an 1200V breakdown voltage is firstly obtained in 3μm-thick top Si layer, 2μm-thick buried oxide layer and 70μm-length drift region using a linear doping profile of unmovable buried oxide charges.

  6. Synthesis of wirelike silicon nanostructures by dispersion of silicon on insulator using electroless etching

    Science.gov (United States)

    Mantey, Kevin; Shams, Somayeh; Nayfeh, Munir H.; Nayfeh, Osama; Alhoshan, Mansour; Alrokayan, Salman

    2010-12-01

    We employ electroless etching to disperse silicon on insulator (SOI) wafers in ionic silver HF into wirelike silicon nanostructures. The procedure allows detachment of the nanowires at the oxide interface and enables easy recovery of dispersions for subsequent controlled delivery. Nanowires 10 μm long and 50-100 nm thick are demonstrated using an SOI substrate of 10 μm device thickness. Direct material analysis shows no silver contamination after a wet-etch silver clean. Anodization treatment of the wires was conducted. Our measurements and analysis show that the wires are not amenable to anodization resulting from the fact that the nanowire radius is less than the thickness of depletion layer. The procedure has the potential of providing dispersions of arbitrarily long wirelike nanostructures which are useful for composite and energy applications.

  7. Lithographically defined few-electron silicon quantum dots based on a silicon-on-insulator substrate

    Energy Technology Data Exchange (ETDEWEB)

    Horibe, Kosuke; Oda, Shunri [Department of Physical Electronics and Quantum Nanoelectronics Research Center, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8552 (Japan); Kodera, Tetsuo, E-mail: kodera.t.ac@m.titech.ac.jp [Department of Physical Electronics and Quantum Nanoelectronics Research Center, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8552 (Japan); Institute for Nano Quantum Information Electronics, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan)

    2015-02-23

    Silicon quantum dot (QD) devices with a proximal single-electron transistor (SET) charge sensor have been fabricated in a metal-oxide-semiconductor structure based on a silicon-on-insulator substrate. The charge state of the QDs was clearly read out using the charge sensor via the SET current. The lithographically defined small QDs enabled clear observation of the few-electron regime of a single QD and a double QD by charge sensing. Tunnel coupling on tunnel barriers of the QDs can be controlled by tuning the top-gate voltages, which can be used for manipulation of the spin quantum bit via exchange interaction between tunnel-coupled QDs. The lithographically defined silicon QD device reported here is technologically simple and does not require electrical gates to create QD confinement potentials, which is advantageous for the integration of complicated constructs such as multiple QD structures with SET charge sensors for the purpose of spin-based quantum computing.

  8. Radio-Frequency Silicon-on-Insulator Modeling Considering the Neutral-Body Effect

    Science.gov (United States)

    Wang, Sheng-Chun; Su, Pin; Chen, Kun-Ming; Lin, Chien-Ting; Liang, Victor; Huang, Guo-Wei

    2008-04-01

    This paper presents small-signal modeling for state-of-the-art radio-frequency (RF) silicon-on-insulator (SOI) metal-oxide-semiconductor field effect transistors (MOSFETs). Especially, we have incorporated the neutral-body effect in our RF SOI model. This effect is significant in both RF extrinsic and intrinsic modeling stages. In addition, we have developed a physically-accurate parameter extraction method based on our analytical expressions. Our modeling results agree well with the measured data and can capture the frequency dependences of both output conductance and capacitance in the GHz frequency region. The anomalous S22 and S21 behaviors as well as the output conductance rising effect observed in our measurements can be predicted and described using the proposed model.

  9. Hot-carrier-induced linear drain current and threshold voltage degradation for thin layer silicon-on-insulator field P-channel lateral double-diffused metal-oxide-semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xin; Qiao, Ming; He, Yitao; Li, Zhaoji; Zhang, Bo, E-mail: bozhang@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China)

    2015-11-16

    Hot-carrier-induced linear drain current (I{sub dlin}) and threshold voltage (V{sub th}) degradations for the thin layer SOI field p-channel lateral double-diffused MOS (pLDMOS) are investigated. Two competition degradation mechanisms are revealed and the hot-carrier conductance modulation model is proposed. In the channel, hot-hole injection induced positive oxide trapped charge and interface trap gives rise to the V{sub th} increasing and the channel conductance (G{sub ch}) decreasing, then reduces I{sub dlin}. In the p-drift region, hot-electron injection induced negative oxide trapped charge enhances the conductance of drift doping resistance (G{sub d}), and then increases I{sub dlin}. Consequently, the eventual I{sub dlin} degradation is controlled by the competition of the two mechanisms due to conductance modulation in the both regions. Based on the model, it is explained that the measured I{sub dlin} anomalously increases while the V{sub th} is increasing with power law. The thin layer field pLDMOS exhibits more severe V{sub th} instability compared with thick SOI layer structure; as a result, it should be seriously evaluated in actual application in switching circuit.

  10. Near infrared light amplification in Gold diffused Silicon-on-Insulator waveguides

    CERN Document Server

    Stepanov, S

    2016-01-01

    We report near infrared optical amplification in gold diffused silicon-on-insulator waveguides by visible optical pumping. More then 30dB/cm gain was measured for a light carrier at a wavelength of 1.55 microns

  11. Microwave photonic phase shifter based on tunable silicon-on-insulator microring resonator

    DEFF Research Database (Denmark)

    Pu, Minhao; Liu, Liu; Xue, Weiqi;

    2010-01-01

    We demonstrate a microwave photonic phase shifter based on an electrically tunable silicon-on-insulator microring resonator. A continuously tunable phase shift of up to 315° at a microwave frequency of 15GHz is obtained.......We demonstrate a microwave photonic phase shifter based on an electrically tunable silicon-on-insulator microring resonator. A continuously tunable phase shift of up to 315° at a microwave frequency of 15GHz is obtained....

  12. 总剂量效应致0.13µm部分耗尽绝缘体上硅N型金属氧化物半导体场效应晶体管热载流子增强效应∗%Enhanced channel hot carrier effect of 0.13 µm silicon-on-insulator N metal-oxide-semiconductor field-effect transistor induced by total ionizing dose effect

    Institute of Scientific and Technical Information of China (English)

    周航; 郑齐文; 崔江维; 余学峰; 郭旗; 任迪远; 余德昭; 苏丹丹

    2016-01-01

    In this paper, a series of hot carriers tests of irradiated 130 nm partially depleted silicon-on-insulator NMOSFETs is carried out in order to explore the HCI influence on the ionizing radiation damage. Some devices are irradiated by up to 3000 Gy before testing the hot carriers, while other devices experience hot carriers test only. All the devices we used in the experiments are fabricated by using a 130 nm partially depleted (PD) SOI technology. The devices each have a 6 nm-thick gate oxide, 100 nm-thick silicon film, and 145 nm-thick buried oxide, with using shallow trench isolation (STI) for isolation scheme. The irradiation experiments are carried by 60Co-γ ray at the Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, with a dose rate of 0.8 Gy(Si)/s. During irradiation all the samples are biased at 3.3 V, i.e., VGS =3.3 V and other pins are grounded, and when the devices are irradiated respectively by total doses of 500, 1000, 2000 and 3000 Gy(Si), we test the characteristic curves again. Then 168-hour room temperature anneal experiments are carried out for the irradiated devices, using the same biases under irradiation. The HCI stress condition is chosen by searching for the maximum substrate current. The cumulative stress time is 5000 s, and the time intervals are 10, 100, 500, 1000 and 5000 s respectively. After each stress interval, the device parameters are measured until stress time termination appears. Through the comparison of characteristic between pre-irradiated and unirradiated devices, we find that the total dose damage results in the enhanced effect of hot carriers: the substrate current value which characterizes the hot carrier effect (for SOI device are the body to the ground current) increases with the increase of total dose, as the pre-irradiated and unirradiated device do under the same conditions of hot carrier stress, the degradations of key electrical parameters are more obvious for the pre-irradiated one

  13. First order Bragg grating filters in silicon on insulator waveguides

    Science.gov (United States)

    Waugh, Peter Michael

    2008-08-01

    The subject of this project is the design; analysis, fabrication and characterisation of first order Bragg Grating optical filters in Silicon-on-Insulator (SOI) planar waveguides. It is envisaged that this work will result in the possibility of Bragg Grating filters for use in Silicon Photonics. It is the purpose of the work to create as far as is possible flat surface waveguides so as to facilitate Thermo-Optic tuning and also the incorporation into rib-waveguide Silicon Photonics. The spectral response of the shallow Bragg Gratings was modelled using Coupled Mode Theory (CMT) by way of RSoft Gratingmod TM. Also the effect of having a Bragg Grating with alternate layers of refractive index of 1.5 and 3.5 was simulated in order to verify that Silica and Silicon layered Bragg Gratings could be viable. A series of Bragg Gratings were patterned on 1.5 micron SOI at Philips in Eindhoven, Holland to investigate the variation of grating parameters with a) the period of the gratings b) the mark to space ratio of the gratings and c) the length of the region converted to Bragg Gratings (i.e. the number of grating period repetitions). One set of gratings were thermally oxidised at Philips in Eindhoven and another set were ion implanted with Oxygen ions at the Ion Beam Facility, University of Surrey, England. The gratings were tested and found to give transmission minima at approximately 1540 nanometres and both methods of creating flat surfaces were found to give similar minima. Atomic Force Microscopy was applied to the grating area of the as-implanted samples in the Advanced Technology Institute, University of Surrey, which were found to have surface undulations in the order of 60 nanometres.

  14. Atomically flattening of Si surface of silicon on insulator and isolation-patterned wafers

    Science.gov (United States)

    Goto, Tetsuya; Kuroda, Rihito; Akagawa, Naoya; Suwa, Tomoyuki; Teramoto, Akinobu; Li, Xiang; Obara, Toshiki; Kimoto, Daiki; Sugawa, Shigetoshi; Ohmi, Tadahiro; Kamata, Yutaka; Kumagai, Yuki; Shibusawa, Katsuhiko

    2015-04-01

    By introducing high-purity and low-temperature Ar annealing at 850 °C, atomically flat Si surfaces of silicon-on-insulator (SOI) and shallow-trench-isolation (STI)-patterned wafers were obtained. In the case of the STI-patterned wafer, this low-temperature annealing and subsequent radical oxidation to form a gate oxide film were introduced into the complementary metal oxide semiconductor (CMOS) process with 0.22 µm technology. As a result, a test array circuit for evaluating the electrical characteristics of a very large number (>260,000) of metal oxide semiconductor field effect transistors (MOSFETs) having an atomically flat gate insulator/Si interface was successfully fabricated on a 200-mm-diameter wafer. By evaluating 262,144 nMOSFETs, it was found that not only the gate oxide reliability was improved, but also the noise amplitude of the gate-source voltage related to the random telegraph noise (RTN) was reduced owing to the introduction of the atomically flat gate insulator/Si interface.

  15. 360° tunable microwave phase shifter based on silicon-on-insulator dual-microring resonator

    DEFF Research Database (Denmark)

    Pu, Minhao; Xue, Weiqi; Liu, Liu;

    2010-01-01

    We demonstrate tunable microwave phase shifters based on electrically tunable silicon-on-insulator dual-microring resonators. A quasi-linear phase shift of 360° with ~2dB radio frequency power variation at a microwave frequency of 40GHz is obtained......We demonstrate tunable microwave phase shifters based on electrically tunable silicon-on-insulator dual-microring resonators. A quasi-linear phase shift of 360° with ~2dB radio frequency power variation at a microwave frequency of 40GHz is obtained...

  16. High-Q silicon-on-insulator optical rib waveguide racetrack resonators.

    Science.gov (United States)

    Kiyat, Isa; Aydinli, Atilla; Dagli, Nadir

    2005-03-21

    In this work, detailed design and realization of high quality factor (Q) racetrack resonators based on silicon-on-insulator rib waveguides are presented. Aiming to achieve critical coupling, suitable waveguide geometry is determined after extensive numerical studies of bending loss. The final design is obtained after coupling factor calculations and estimation of propagation loss. Resonators with quality factors (Q) as high as 119000 has been achieved, the highest Q value for resonators based on silicon-on-insulator rib waveguides to date with extinction ratios as large as 12 dB.

  17. High-Q silicon-on-insulator optical rib waveguide racetrack resonators

    Science.gov (United States)

    Kiyat, Isa; Aydinli, Atilla; Dagli, Nadir

    2005-03-01

    In this work, detailed design and realization of high quality factor (Q) racetrack resonators based on silicon-on-insulator rib waveguides are presented. Aiming to achieve critical coupling, suitable waveguide geometry is determined after extensive numerical studies of bending loss. The final design is obtained after coupling factor calculations and estimation of propagation loss. Resonators with quality factors (Q) as high as 119000 has been achieved, the highest Q value for resonators based on silicon-on-insulator rib waveguides to date with extinction ratios as large as 12 dB.

  18. Breakdown voltage model and structure realization of a thin silicon layer with linear variable doping on a silicon on insulator high voltage device with multiple step field plates

    Institute of Scientific and Technical Information of China (English)

    Qiao Ming; Zhuang Xiang; Wu Li-Juan; Zhang Wen-Tong; Wen Heng-Juan; Zhang Bo; Li Zhao-Ji

    2012-01-01

    Based on the theoretical and experimental investigation of a thin silicon layer (TSL) with linear variable doping (LVD) and further research on the TSL LVD with a multiple step field plate (MSFP),a breakdown voltage (BV) model is proposed and experimentally verified in this paper.With the two-dimensional Poisson equation of the silicon on insulator (SOI) device,the lateral electric field in drift region of the thin silicon layer is assumed to be constant.For the SOI device with LVD in the thin silicon layer,the dependence of the BV on impurity concentration under the drain is investigated by an enhanced dielectric layer field (ENDIF),from which the reduced surface field (RESURF) condition is deduced.The drain in the centre of the device has a good self-isolation effect but the problem of the high voltage interconnection (HVI) line will become serious.The two step field plates including the source field plate and gate field plate can be adopted to shield the HVI adverse effect on the device.Based on this model,the TSL LVD SOI n-channel lateral double-diffused MOSFET (nLDMOS) with MSFP is realized.The experimental breakdown voltage (BV) and specific on-resistance (Ron,sp) of the TSL LVD SOI device are 694 V and 21.3 Ω.mm2 with a drift region length of 60 μm,buried oxide layer of 3 μm,and silicon layer of 0.15 μm,respectively.

  19. Sensitivity analysis of silicon-on-insulator quadruple Vernier racetrack resonators

    Science.gov (United States)

    Boeck, Robert; Chrostowski, Lukas; Jaeger, Nicolas A. F.

    2015-11-01

    We present a theoretical sensitivity analysis of silicon-on-insulator quadruple Vernier racetrack resonators based on varying, one at a time, various fabrication-dependent parameters. These parameters include the waveguide widths, heights, and propagation losses. We show that it should be possible to design a device that meets typical commercial specifications while being tolerant to changes in these parameters.

  20. Tunable microwave phase shifter based on silicon-on-insulator microring resonator

    DEFF Research Database (Denmark)

    Pu, Minhao; Liu, Liu; Xue, Weiqi;

    2010-01-01

    We demonstrate microwave phase shifters based on electrically tunable silicon-on-insulator microring resonators (MRRs). MRRs with different quality factors are fabricated and tested. A continuously tunable phase shift of up to 336 at a microwave frequency of 40 GHz is obtained using a high...

  1. Widely tunable microwave phase shifter based on silicon-on-insulator dual-microring resonator

    DEFF Research Database (Denmark)

    Pu, Minhao; Liu, Liu; Xue, Weiqi;

    2010-01-01

    We propose and demonstrate tunable microwave phase shifters based on electrically tunable silicon-on-insulator microring resonators. The phase-shifting range and the RF-power variation are analyzed. A maximum phase-shifting range of 0~600° is achieved by utilizing a dual-microring resonator...

  2. Ultrafast nonlinear all-optical processes in silicon-on-insulator waveguides

    NARCIS (Netherlands)

    Dekker, R.; Usechak, N.; Först, M.; Driessen, A.

    2007-01-01

    In this review we present an overview of the progress made in recent years in the field of integrated silicon-on-insulator (SOI) waveguide photonics with a strong emphasis on third-order nonlinear optical processes. Although the focus is on simple waveguide structures the utilization of complex stru

  3. Focused ion beam milling of photonic crystals in silicon on insulator

    NARCIS (Netherlands)

    Hu, Wenbin; Hopman, Wico; Ridder, de René

    2009-01-01

    A photonic crystal slab, consisting of an array of circular sub-micron diameter holes in Silicon on Insulator (SOI), has been fabricated using focused ion beam (FIB) milling. This application requires the sidewalls of the holes to be very smooth and as nearly perpendicular to the slab as possible. T

  4. Silicon-on-insulator polarization splitting and rotating device for polarization diversity circuits

    DEFF Research Database (Denmark)

    Liu, Liu; Ding, Yunhong; Yvind, Kresten;

    2011-01-01

    A compact and efficient polarization splitting and rotating device built on the silicon-on-insulator platform is introduced, which can be readily used for the interface section of a polarization diversity circuit. The device is compact, with a total length of a few tens of microns. It is also...

  5. Ultra-low loss nano-taper coupler for Silicon-on-Insulator ridge waveguide

    DEFF Research Database (Denmark)

    Pu, Minhao; Liu, Liu; Ou, Haiyan;

    2010-01-01

    A nano-taper coupler is optimized specially for the transverse-magnetic mode for interfacing light between a silicon-on-insulator ridge waveguide and a single-mode fiber. An ultra-low coupling loss of ~0.36dB is achieved for the nano-taper coupler....

  6. Effect of cryogenic temperature characteristics on 0.18-μm silicon-on-insulator devices

    Science.gov (United States)

    Bingqing, Xie; Bo, Li; Jinshun, Bi; Jianhui, Bu; Chi, Wu; Binhong, Li; Zhengsheng, Han; Jiajun, Luo

    2016-07-01

    The experimental results of the cryogenic temperature characteristics on 0.18-μm silicon-on-insulator (SOI) metal-oxide-silicon (MOS) field-effect-transistors (FETs) were presented in detail. The current and capacitance characteristics for different operating conditions ranging from 300 K to 10 K were discussed. SOI MOSFETs at cryogenic temperature exhibit improved performance, as expected. Nevertheless, operation at cryogenic temperature also demonstrates abnormal behaviors, such as the impurity freeze-out and series resistance effects. In this paper, the critical parameters of the devices were extracted with a specific method from 300 K to 10 K. Accordingly, some temperature-dependent-parameter models were created to improve fitting precision at cryogenic temperature. Project supported by the National Natural Science Foundation of China (Grant Nos. 61176095 and 61404169) and the Youth Innovation Promotion Association of Chinese Academy of Sciences.

  7. Carrier-transport mechanism of Er-silicide Schottky contacts to strained-silicon-on-insulator and silicon-on-insulator.

    Science.gov (United States)

    Jyothi, I; Janardhanam, V; Kang, Min-Sung; Yun, Hyung-Joong; Lee, Jouhahn; Choi, Chel-Jong

    2014-11-01

    The current-voltage characteristics and the carrier-transport mechanism of the Er-silicide (ErSi1.7) Schottky contacts to strained-silicon-on-insulator (sSOI) and silicon-on-insulator (SOI) were investigated. Barrier heights of 0.74 eV and 0.82 eV were obtained for the sSOI and SOI structures, respectively. The barrier height of the sSOI structure was observed to be lower than that of the SoI structure despite the formation of a Schottky contact using the same metal silicide. The sSOI structure exhibited better rectification and higher current level than the SOI structure, which could be associated with a reduction in the band gap of Si caused by strain. The generation-recombination mechanism was found to be dominant in the forward bias for both structures. Carrier generation along with the Poole-Frenkel mechanism dominated the reverse-biased current in the SOI structure. The saturation tendency of the reverse leakage current in the sSOI structure could be attributed to strain-induced defects at the interface in non-lattice-matched structures.

  8. Hydrogen interactions with silicon-on-insulator materials

    NARCIS (Netherlands)

    Rivera de Mena, A.J.

    2003-01-01

    The booming of microelectronics in recent decades has been made possible by the excellent properties of the Si/SiO2 interface in oxide on silicon systems.. This semiconductor/insulator combination has proven to be of great value for the semiconductor industry. It has made it possible to continuously

  9. Monolithic integration of erbium-doped amplifiers with silicon-on-insulator waveguides.

    Science.gov (United States)

    Agazzi, Laura; Bradley, Jonathan D B; Dijkstra, Meindert; Ay, Feridun; Roelkens, Gunther; Baets, Roel; Wörhoff, Kerstin; Pollnau, Markus

    2010-12-20

    Monolithic integration of Al2O3:Er3+ amplifier technology with passive silicon-on-insulator waveguides is demonstrated. A signal enhancement of >7 dB at 1533 nm wavelength is obtained. The straightforward wafer-scale fabrication process, which includes reactive co-sputtering and subsequent reactive ion etching, allows for parallel integration of multiple amplifier and laser sections with silicon or other photonic circuits on a chip.

  10. Analysis of Temperature Dependence of Silicon-on-Insulator Thermo-Optic Attenuator

    Institute of Scientific and Technical Information of China (English)

    LI Yun-Tao; YU Jin-Zhong; CHEN Yuan-Yuan; SUN Fei; CHEN Shao-Wu

    2007-01-01

    The temperature dependence of silicon-on-insulator thermo-optic attenuators is analysed, which originates from the temperature dependence of characteristics of multimode interference. The attenuator depth and power consumption are independent of temperature while the insertion loss depends on the temperature heavily. The variation of the insertion loss decreases from 4.3 dB to 1 dB as the temperature increases from 273 K to 343 K.

  11. Microstructural and Electrical Properties of ZrO2 Thin Films Prepared on silicon on Insulator with Thin Top silicon

    Institute of Scientific and Technical Information of China (English)

    章宁琳; 宋志棠; 沈勤我; 林成鲁

    2003-01-01

    Amorphous zirconia thin films were deposited directly on silicon-on-insulator (SOI) substrates with thin top silicon by ultra-high vacuum electron beam evaporation. Spreading resistance profile and scanning transmission-electron microscopy (TEM) were used to detect the interface quality and microstructure, revealing that the interface between the zirconium oxide films and top silicon was abrupt and clear. The films kept to be amorphous up to the rapid thermal temperature of 700°C for 300s, but arriving at 700°C an unknown interfacial product appeared,which was probably ZrSixOy. High frequency capacitance-voltage (C- V) characteristics at 1 MHz performed on metal-oxide-SOI structure revealed that this interfacial product exhibited good electrical properties of zirconia thin films. When the annealing temperature increased from 600°C to 700°C, flat voltage VFB changed from -2.451 to -1.741 eV, showing the improvement in the quality of the films. The cumulative region capacitance decreased from 3.058 × 10-11F to 3.012 × 10-11F, indicating increasing equivalent oxide thickness, which is in agreement with the result of high-resolution cross-sectional TEM.

  12. Threshold voltage analytical model of fully depleted strained Si single Halo silicon-on-insulator metal-oxide semiconductor field effect transistor∗%单Halo全耗尽应变Si绝缘硅金属氧化物半导体场效应管的阈值电压解析模型*

    Institute of Scientific and Technical Information of China (English)

    辛艳辉†; 刘红侠; 范小娇; 卓青青

    2013-01-01

      为了改善金属氧化物半导体场效应管(MOSFET)的短沟道效应(SCE)、漏致势垒降低(DIBL)效应,提高电流的驱动能力,提出了单Halo全耗尽应变硅绝缘体(SOI) MOSFET结构,该结构结合了应变Si,峰值掺杂Halo结构, SOI三者的优点。通过求解二维泊松方程,建立了全耗尽器件表面势和阈值电压的解析模型。模型中分析了弛豫层中的Ge组分对表面势、表面场强和阈值电压的影响,不同漏电压对表面势的影响, Halo掺杂对阈值电压和DIBL的影响。结果表明,该新结构能够抑制SCE和DIBL效应,提高载流子的输运效率。%A single Halo fully depleted strain Si Silicon-On-insulator (SOI) structure, which has the advantages of strained Si, Halo doping, and SOI structure, is proposed to improve driving current, suppress the short channel effect (SCE) and drain induced barrier lowering (DIBL) effect. A two-dimensional analytical model for the surface potential, the surface electric field and the threshold voltage is proposed by solving Poisson’s equation. The effects of Ge fraction in the relaxed layer on surface potential and threshold voltage are investigated. In the paper we analyze the influence of drain voltage on surface potential. Finally the effects of Halo doping on threshold voltage and DIBL are investigated. The results show that the novel device can suppress the short channel effect and DIBL effect, and increase carrier transport speed.

  13. Propagation of Ultra-fast Femtosecond Pulses in Silicon-on-insulator Optical Waveguides

    Institute of Scientific and Technical Information of China (English)

    WU Jian-wei; LUO Feng-guang; Cristiano de Mello Gallep

    2007-01-01

    A complete theoretical modeling, avoiding any priori-assumption, is deduced and demonstrated for ultra-fast femtosecond optical pulses in silicon-on-insulator optical waveguides which includes the group velocity dispersion, third-order dispersion, self-phase and cross-phase modulations, self-steepening and shock formation, Raman depletion, propagation loss, two-photon absorption, free-carrier absorption, and free-carrier dispersion. Finally, the temporal and spectral characteristics of 100 fs optical pulses at 1.55 μm are numerically observed in 5-mm-long waveguides while considering different initial chirps and incident peak intensity levels.

  14. Patterning of graphene on silicon-on-insulator waveguides through laser ablation and plasma etching

    Science.gov (United States)

    Van Erps, Jürgen; Ciuk, Tymoteusz; Pasternak, Iwona; Krajewska, Aleksandra; Strupinski, Wlodek; Van Put, Steven; Van Steenberge, Geert; Baert, Kitty; Terryn, Herman; Thienpont, Hugo; Vermeulen, Nathalie

    2016-05-01

    We present the use of femtosecond laser ablation for the removal of monolayer graphene from silicon-on-insulator (SOI) waveguides, and the use of oxygen plasma etching through a metal mask to peel off graphene from the grating couplers attached to the waveguides. Through Raman spectroscopy and atomic force microscopy, we show that the removal of graphene is successful with minimal damage to the underlying SOI waveguides. Finally, we employ both removal techniques to measure the contribution of graphene to the loss of grating-coupled graphene-covered SOI waveguides using the cut-back method. This loss contribution is measured to be 0.132 dB/μm.

  15. Silicon-on-Insulator Based Electro-optic Variable Optical Attenuator with a Series Structure

    Institute of Scientific and Technical Information of China (English)

    HE Yue-Jiao; LI Fang; LIU Yu-Liang

    2005-01-01

    An electro-optic variable optical attenuator in silicon-on-insulator is designed and fabricated. A series structure is used to improve the device efficiency. Compared to the attenuator in the single p-i-n diode structure in the same modulating length, the attenuation range of the device in the series structure improves 2-3 times in the same injecting current density, while the insertion loss is not affected. The maximum dynamic attenuation of the device is greater than 30dB. The response frequency is obtained to be about 2MHz.

  16. Analysis and Simulation of S-shaped Waveguide in Silicon-on-insulator

    Institute of Scientific and Technical Information of China (English)

    WANG Zhang-tao; FAN Zhong-cao; XIA Jin-song; CHEN Shao-wu; Yu Jinzhong

    2004-01-01

    The simulation and analysis of S-shaped waveguide bend are presented.Bend radius larger than 30 mm assures less than 0.5 dB radiation loss for a 4-μm-wide silicon-on-insulator waveguide bend with 2-μm etch depth.Intersection angle greater than 20° provides negligible crosstalk (<-30 dB) and very low insertion loss.Any reduction in bend radius and intersection angle is at the cost of the degradation of characteristics of bent waveguide and intersecting waveguide, respectively.

  17. A 4 × 4 Strictly Nonblocking Silicon-on-Insulator Thermo-Optic Switch Matrix

    Institute of Scientific and Technical Information of China (English)

    YANG Di; LI Yan-Ping; CHEN Shao-Wu; YU Jin-Zhong

    2005-01-01

    @@ A 4 × 4 strictly nonblocking thermo-optic switch matrix implemented with a 2 × 2 Mach-Zehnder switch unit was fabricated in silicon-on-insulator wafer. Insertion losses of the shortest and the longest path in the device are about 14.8dB and 19.2dB, respectively. The device presents a very low loss dependent on wavelength. For one switch unit, the power consumption needed for operation is measured to be 0.270 W-0.288 W and the switching time is about 13 ± 1μs.

  18. Fabrication of Thermo-Optic Switch in Silicon-on-Insulator

    Institute of Scientific and Technical Information of China (English)

    王章涛; 夏金松; 樊中朝; 陈少武; 余金中

    2003-01-01

    Silicon-on-insulator technology has been used to fabricate 2 × 2 thermo-optic switches. The switch shows crosstalk of-23.4 dB and extinction ratio of 18.1 dB in the bar-state. The switching speed is less than 30 μs and the power consumption is about 420mW. The measured excess loss is 1.8 dB. These merits make the switch more attractive for applications in wavelength division multiplexing.

  19. Guided acoustic and optical waves in silicon-on-insulator for Brillouin scattering and optomechanics

    Science.gov (United States)

    Sarabalis, Christopher J.; Hill, Jeff T.; Safavi-Naeini, Amir H.

    2016-10-01

    We numerically study silicon waveguides on silica showing that it is possible to simultaneously guide optical and acoustic waves in the technologically important silicon on insulator (SOI) material system. Thin waveguides, or fins, exhibit geometrically softened mechanical modes at gigahertz frequencies with phase velocities below the Rayleigh velocity in glass, eliminating acoustic radiation losses. We propose slot waveguides on glass with telecom optical frequencies and strong radiation pressure forces resulting in Brillouin gains on the order of 500 and 50 000 W-1m-1 for backward and forward Brillouin scattering, respectively.

  20. Strain dependence of the direct energy bandgap in thin silicon on insulator layers

    OpenAIRE

    Munguía, J; Bluet, J-M; Chouaib, H.; Bremond, G.; Mermoux, Michel; Bru-Chevallier, C

    2010-01-01

    Abstract Photoreflectance spectroscopy is applied on tensilely-strained silicon on insulator (sSOI) thin layers in order to evaluate the biaxial strain effect on the Si direct bandgap. The measured redshift of the transition (i.e. direct bandgap) with strain (~ -100 meV/%), corresponds to theoretical predictions. The hydrostatic and valence band deformation potential parameters for E 1 (i.e. transition close to L-point along the ?-direction) are also measured: and ' 0 E eV D 5. 0 5 . 7 1 1...

  1. Integrated programmable photonic filter on the silicon-on-insulator platform.

    Science.gov (United States)

    Liao, Shasha; Ding, Yunhong; Peucheret, Christophe; Yang, Ting; Dong, Jianji; Zhang, Xinliang

    2014-12-29

    We propose and demonstrate a silicon-on-insulator (SOI) on-chip programmable filter based on a four-tap finite impulse response structure. The photonic filter is programmable thanks to amplitude and phase modulation of each tap controlled by thermal heaters. We further demonstrate the tunability of the filter central wavelength, bandwidth and variable passband shape. The tuning range of the central wavelength is at least 42% of the free spectral range. The bandwidth tuning range is at least half of the free spectral range. Our scheme has distinct advantages of compactness, capability for integrating with electronics.

  2. High temperature study of flexible silicon-on-insulator fin field-effect transistors

    KAUST Repository

    Diab, Amer El Hajj

    2014-09-29

    We report high temperature electrical transport characteristics of a flexible version of the semiconductor industry\\'s most advanced architecture: fin field-effect transistor on silicon-on-insulator with sub-20 nm fins and high-κ/metal gate stacks. Characterization from room to high temperature (150 °C) was completed to determine temperature dependence of drain current (Ids), gate leakage current (Igs), transconductance (gm), and extracted low-field mobility (μ0). Mobility degradation with temperature is mainly caused by phonon scattering. The other device characteristics show insignificant difference at high temperature which proves the suitability of inorganic flexible electronics with advanced device architecture.

  3. Operation of Silicon-on-Insulator (SOI) Micro-ElectroMechanical Systems (MEMS) Gyroscopic Sensor as a Two-Axis Accelerometer

    Science.gov (United States)

    2012-04-01

    TECHNICAL REPORT RDMR-WS-12-02 OPERATION OF SILICON-ON-INSULATOR (SOI) MICRO-ELECTROMECHANICAL SYSTEMS ( MEMS ) GYROSCOPIC SENSOR...DATES COVERED Final 4. TITLE AND SUBTITLE Operation of Silicon-on-Insulator (SOI) Micro-ElectroMechanical Systems ( MEMS ) Gyroscopic Sensor as a...existing Silicon-on-Insulator (SOI) Micro- ElectroMechanical Systems ( MEMS ) gyroscopic sensor previously developed in the early-2000s under MEMS

  4. Narrow line-width single-longitudinal-mode fiber laser using silicon-on-insulator based micro-ring-resonator

    Science.gov (United States)

    Liu, Yang; Hsu, Yung; Hsu, Chin-Wei; Yang, Ling-Gang; Chow, Chi-Wai; Yeh, Chien-Hung; Lai, Yin-Chieh; Tsang, Hon-Ki

    2016-02-01

    In this work, we propose and demonstrate a stable single-longitudinal-mode (SLM) fiber laser with narrow line-width by using an integrated silicon-on-insulator micro-ring resonator (SOI MRR) and two subsidiary fiber rings for the first time, to the best of our knowledge. The laser is tunable over the wavelength range from 1546 to 1570 nm, with only step tuning of 2 nm steps. A maximum 49 dB side mode suppression ratio (SMSR) can be achieved. The compact SOI MRR provides a large free-spectral-range (FSR), while the subsidiary rings provide Vernier effect producing a single lasing mode. The FSR of the SOI MRR can be very large and controllable (since it is easy to fabricate small SOI MRR when compared with making small fiber-rings) using the complementary-metal-oxide-semiconductor (CMOS) compactable SOI fabrication processes. In our proposed laser, the measured single sideband (SSB) spectrum shows that the densely spaced longitudinal modes can be significantly suppressed to achieve SLM. The laser linewidth is only 3.5 kHz measured by using the self-heterodyne method. 30 min stability evaluation in terms of lasing wavelength and optical power is performed; showing the optical wavelength and power are both very stable, with fluctuations of only 0.02 nm and 0.8 dB, respectively.

  5. Investigation of negative bias temperature instability dependence on fin width of silicon-on-insulator-fin-based field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Young, Chadwin D., E-mail: chadwin.young@utdallas.edu; Wang, Zhe [Materials Science and Engineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, Texas 75080 (United States); Neugroschel, Arnost [Department of Electrical and Computer Enginering, University of Florida, Gainesville, Florida 32611 (United States); Majumdar, Kausik; Matthews, Ken; Hobbs, Chris [SEMATECH, Albany, New York 12203 (United States)

    2015-01-21

    The fin width dependence of negative bias temperature instability (NBTI) of double-gate, fin-based p-type Field Effect Transistors (FinFETs) fabricated on silicon-on-insulator (SOI) wafers was investigated. The NBTI degradation increased as the fin width narrowed. To investigate this phenomenon, simulations of pre-stress conditions were employed to determine any differences in gate oxide field, fin band bending, and electric field profile as a function of the fin width. The simulation results were similar at a given gate stress bias, regardless of the fin width, although the threshold voltage was found to increase with decreasing fin width. Thus, the NBTI fin width dependence could not be explained from the pre-stress conditions. Different physics-based degradation models were evaluated using specific fin-based device structures with different biasing schemes to ascertain an appropriate model that best explains the measured NBTI dependence. A plausible cause is an accumulation of electrons that tunnel from the gate during stress into the floating SOI fin body. As the fin narrows, the sidewall device channel moves in closer proximity to the stored electrons, thereby inducing more band bending at the fin/dielectric interface, resulting in a higher electric field and hole concentration in this region during stress, which leads to more degradation. The data obtained in this work provide direct experimental proof of the effect of electron accumulation on the threshold voltage stability in FinFETs.

  6. Optical refractive index biosensor using evanescently coupled lateral Bragg gratings on silicon-on-insulator

    Science.gov (United States)

    Mendez-Astudillo, Manuel; Takahisa, Hiroki; Okayama, Hideaki; Nakajima, Hirochika

    2016-08-01

    In this paper, we present a compact silicon-on-insulator optical biosensor based on lateral Bragg gratings evanescently coupled to a waveguide. The device is fabricated by electron-beam lithography and dry-etched in a single step with inductive coupled plasma reactive ion etching (ICP-RIE). Fully etched grating couplers are used to couple the light in and out of the chip, while lateral Bragg gratings are used as the sensing element of the device. A sensitivity of 22 nm/RIU is obtained by exposing the device to deionized water with different NaCl concentrations with a footprint area of 15 × 4 µm2 that allows for densely multiplexed solutions.

  7. Impact of Free Carriers on Modulational Instability in Silicon-on-insulator Nanowaveguides

    CERN Document Server

    Chaturvedi, Deepa

    2016-01-01

    We have numerically studied the effect of free-carrier-induced loss and dispersion on the modulational instability (MI) gain at low input powers in silicon-on-insulator (SOI) nanowaveguides with normal and anomalous second-order dispersion. We have shown that the free carriers affect the gain spectra even at low input powers. First time we have reported the gain in normal SOI nanowaveguides even in the absence of higher order dispersion parameters, which is due to the interaction of free-carrier-induced dispersion and nonlinearity. The MI gain in an anomalous SOI nanowaveguide vanishes even at a few milliwatt range of input power due to this interaction. We have shown that the gain could be achieved in an anomalous nanowaveguides by reducing the free carrier lifetime.

  8. Thermo-optic Goos-Hänchen effect in silicon-on-insulator waveguide

    Science.gov (United States)

    Tang, Tingting; Luo, Li; Liu, Wenli; He, Xiujun; Zhang, Yanfen

    2015-09-01

    We study the thermo-optic Goos-Hänchen (TOGH) effect in a prism-waveguide coupling structure with silicon-on-insulator waveguide. Stationary-phase method is utilized to calculate the TOGH shift. When the waveguide is regarded as a two-dimensional planar waveguide, a nonlinear relation between GH shift and temperature is obtained. Based on the noticeable TOGH effect, a sensitive temperature modulator or sensor can be realized. As the waveguide width is limited, the proposed structure can be regarded as a three-dimensional rectangular waveguide. We explore the GH shift and TOGH effect for different modes propagating in rectangular waveguide which show different linear relations between GH shift and temperature, which can be used to design mode-selective device based on TO effect.

  9. Development of the Pixelated Photon Detector Using Silicon on Insulator Technology for TOF-PET

    CERN Document Server

    Koyama, Akihiro; Takahashi, Hiroyuki; Orita, Tadashi; Arai, Yasuo; Kurachi, Ikuo; Miyoshi, Toshinobu; Nio, Daisuke; Hamasaki, Ryutaro

    2015-01-01

    To measure light emission pattern in scintillator, higher sensitivity and faster response are required to photo detector. Such as single photon avalanche diode (SPAD), conventional pixelated photo detector is operated at Geiger avalanche multiplication. However higher gain of SPAD seems very attractive, photon detection efficiency per unit area is low. This weak point is mainly caused by Geiger avalanche mechanism. To overcome these difficulties, we designed Pixelated Linear Avalanche Integration Detector using Silicon on Insulator technology (SOI-Plaid). To avoid dark count noise and dead time comes from quench circuit, we are planning to use APD in linear multiplication mode. SOI technology enables laminating readout circuit and APD layer, and high-speed and low-noise signal reading regardless smaller gain of linear APD. This study shows design of linear APD by using SOI fabrication process. We designed test element group (TEG) of linear APD and inspected optimal structure of linear APD.

  10. Crosstalk analysis of silicon-on-insulator nanowire-arrayed waveguide grating

    Science.gov (United States)

    Li, Kai-Li; An, Jun-Ming; Zhang, Jia-Shun; Wang, Yue; Wang, Liang-Liang; Li, Jian-Guang; Wu, Yuan-Da; Yin, Xiao-Jie; Hu, Xiong-Wei

    2016-12-01

    The factors influencing the crosstalk of silicon-on-insulator (SOI) nanowire arrayed waveguide grating (AWG) are analyzed using the transfer function method. The analysis shows that wider and thicker arrayed waveguides, outsider fracture of arrayed waveguide, and larger channel space, could mitigate the deterioration of crosstalk. The SOI nanowire AWGs with different arrayed waveguide widths are fabricated by using deep ultraviolet lithography (DUV) and inductively coupled plasma etching (ICP) technology. The measurement results show that the crosstalk performance is improved by about 7 dB through adopting 800 nm arrayed waveguide width. Project supported by the National High Technology Research and Development Program of China (Grant No. 2015AA016902), the National Natural Science Foundation of China (Grant Nos. 61274047, 61435013, 61307034, and 61405188), and the National Key Research and Development Program of China (Grant No. 2016YFB0402504).

  11. A comparison of the kink effect in polysilicon thin film transistors and silicon on insulator transistors

    Science.gov (United States)

    Armstrong, G. A.; Brotherton, S. D.; Ayres, J. R.

    1996-09-01

    Polysilicon thin film transistors (TFTs) differ from conventional silicon on insulator (SOI) transistors in that the TFT exhibits a fundamental gate length dependence of the voltage at which a kink occurs in the output characteristics. This difference is shown to be caused by the peak lateral electric field being strongly dependent on the doping density in an SOI transistor, but relatively insensitive to trap distribution in a TFT. Source barrier lowering which occurs in SOI transistors is absent in a TFT, where the increase in current is the result of a field redistribution along the channel. For very short gate lengths, the TFT exhibits a small pseudo-bipolar gain. Estimates of this bipolar gain can be made by simulation of TFT characteristics with and without impact ionisation. The magnitude of the gain is shown to be approximately inversely proportional to gate length.

  12. Vertical optical ring resonators fully integrated with nanophotonic waveguides on silicon-on-insulator substrates

    CERN Document Server

    Madani, Abbas; Stolarek, David; Zimmermann, Lars; Ma, Libo; Schmidt, Oliver G

    2015-01-01

    We demonstrate full integration of vertical optical ring resonators with silicon nanophotonic waveguides on silicon-on-insulator substrates to accomplish a significant step towards 3D photonic integration. The on-chip integration is realized by rolling up 2D differentially strained TiO2 nanomembranes into 3D microtube cavities on a nanophotonic microchip. The integration configuration allows for out of plane optical coupling between the in-plane nanowaveguides and the vertical microtube cavities as a compact and mechanically stable optical unit, which could enable refined vertical light transfer in 3D stacks of multiple photonic layers. In this vertical transmission scheme, resonant filtering of optical signals at telecommunication wavelengths is demonstrated based on subwavelength thick walled microcavities. Moreover, an array of microtube cavities is prepared and each microtube cavity is integrated with multiple waveguides which opens up interesting perspectives towards parallel and multi-routing through a ...

  13. Structure Dependence of Mode Edges in Photonic Crystal Waveguide with Silicon on Insulator

    Institute of Scientific and Technical Information of China (English)

    TANG Hai-Xia; ZUO Yu-Hua; YU Jin-Zhong; WANG Qi-Ming

    2006-01-01

    @@ The mode edges of photonic crystal waveguide with triangular lattice based on a silicon-on-insulator slab are investigated by combination of the effective index method and the two-dimensional plane wave expansion method.The variations of waveguide-mode edges with the structure parameters of photonic crystal are deduced. When the ratio of the radius of air holes to the lattice constant, r/Λ, is fixed and the lattice constant of photonic crystal,Λ, increases, the waveguide-mode edges shift to longer wavelengths. When Λ is fixed and r/Λ increases, the waveguide-mode edges shift to shorter wavelengths. Additionally, when r/Λ and Λ are both fixed, the radius of the two-row air holes adjacent to the waveguide increases, the waveguide-mode edges shift to shorter wavelengths.

  14. Hot-Electron Bolometer Mixers on Silicon-on-Insulator Substrates for Terahertz Frequencies

    Science.gov (United States)

    Skalare, Anders; Stern, Jeffrey; Bumble, Bruce; Maiwald, Frank

    2005-01-01

    A terahertz Hot-Electron Bolometer (HEB) mixer design using device substrates based on Silicon-On-Insulator (SOI) technology is described. This substrate technology allows very thin chips (6 pm) with almost arbitrary shape to be manufactured, so that they can be tightly fitted into a waveguide structure and operated at very high frequencies with only low risk for power leakages and resonance modes. The NbTiN-based bolometers are contacted by gold beam-leads, while other beamleads are used to hold the chip in place in the waveguide test fixture. The initial tests yielded an equivalent receiver noise temperature of 3460 K double-sideband at a local oscillator frequency of 1.462 THz and an intermediate frequency of 1.4 GHz.

  15. Optical functions of silicon from reflectance and ellipsometry on silicon-on-insulator and homoepitaxial samples

    Energy Technology Data Exchange (ETDEWEB)

    Humlíček, J., E-mail: humlicek@physics.muni.cz [CEITEC, Masaryk University, Kamenice 753/5, 62500 Brno (Czech Republic); Šik, J. [ON Semiconductor, 1. máje 2230, 75661 Rožnov p. Radhoštěm (Czech Republic)

    2015-11-21

    The optical properties of silicon have been determined from 0.2 to 6.5 eV at room temperature, using reflectance spectra of silicon-on-insulator (SOI) and ellipsometric spectra of homoepitaxial samples. Optimized Fabry-Perot-type SOI resonators exhibit high finesse even in near ultraviolet. Very high precision values of the real part of the refractive index are obtained in infrared up to a photon energy of 1.3 eV. The spectra of the extinction coefficient, based on observations of light attenuation, extend to 3.2 eV due to measurements on SOI layers as thin as 87 nm. These results allowed us to correct spectroellipsometric data on homoepitaxial samples for the presence of reduced and stabilized surface layers.

  16. A highly pH-sensitive nanowire field-effect transistor based on silicon on insulator

    Directory of Open Access Journals (Sweden)

    Denis E. Presnov

    2013-05-01

    Full Text Available Background: An experimental and theoretical study of a silicon-nanowire field-effect transistor made of silicon on insulator by CMOS-compatible methods is presented.Results: A maximum Nernstian sensitivity to pH change of 59 mV/pH was obtained experimentally. The maximum charge sensitivity of the sensor was estimated to be on the order of a thousandth of the electron charge in subthreshold mode.Conclusion: The sensitivity obtained for our sensor built in the CMOS-compatible top-down approach does not yield to the one of sensors built in bottom-up approaches. This provides a good background for the development of CMOS-compatible probes with primary signal processing on-chip.

  17. Optimization of silicon-on-insulator based optical switch using tapered waveguides

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Optimiz ed 2×2 switches based on silicon-on-insulator (SOI) were demonstrated. In the design, single mode rib waveguides and multimode interferences (MMIs) are connected by tapered waveguides to reduce the mode coupling loss between the two types of waveguides. The average insertion loss of the switches is about -16.9 dB and the excess loss of one is measured of -1.3 dB. The worst crosstalk is larger than 25 dB. Experimental results indicate that some of the main characteristics of optical switches are improved in the modified design, which is according with theoretic analysis. The novel design can be used to improve the characteristics of optical switch matrixes based on 2×2 switch units.

  18. Design and simulation of blue/violet sensitive photodetectors in silicon-on-insulator

    Institute of Scientific and Technical Information of China (English)

    Han Zhitao; Chu Jinkui; Meng Fantao; Jin Rencheng

    2009-01-01

    According to Lambert's law, a novel structure of photodetectors, namely photodetectors in silicon on-insulator, is proposed. By choosing a certain thickness value for the SOI layer, the photodetector can absorb blue/violet light effectively and affect the responsivity of the long wavelength in the visible and near-infrared re gion, making a blue/violet filter unnecessary. The material of the SOI layer is high-resistivity floating-zone silicon which can cause the neutral N type SOI layer to become fully depleted after doping with a P type impurity. This can improve the collection efficiency of short-wavelength photogenerated carriers. The device structure was optimized through numerical simulation, and the results show that the photodiode is a kind of high performance photodetector in the blue/violet region.

  19. Fabrication of Si-based planar type patch clamp biosensor using silicon on insulator substrate

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.L.; Asano, T. [Graduate University for Advanced Studies, Myodaiji, Okazaki, 444-8585 (Japan); Uno, H. [Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan); Tero, R. [Graduate University for Advanced Studies, Myodaiji, Okazaki, 444-8585 (Japan); Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan); Suzui, M.; Nakao, S. [Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan); Kaito, T. [SII NanoTechnology Inc., 36-1, Takenoshita, Oyama-cho, Sunto-gun, Shizuoka, 410-1393 (Japan); Shibasaki, K.; Tominaga, M. [Okazaki Institute for Integrative Bioscience, 5-1, Higashiyama, Myodaiji, Okazaki, 444-8787 (Japan); Utsumi, Y. [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2, Koto, Kamigori, Ako-gun, Hyogo, 678-1205 (Japan); Gao, Y.L. [Department of Physics and Astronomy, Rochester University, Rochester, New York 14627 (United States); Urisu, T. [Graduate University for Advanced Studies, Myodaiji, Okazaki, 444-8585 (Japan); Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan)], E-mail: urisu@ims.ac.jp

    2008-03-03

    The aim of this paper is to fabricate the planar type patch clamp ion-channel biosensor, which is suitable for the high throughput screening, using silicon-on-insulator (SOI) substrate. The micropore with 1.2 {mu}m diameter is formed through the top Si layer and the SiO{sub 2} box layer of the SOI substrate by focused ion beam (FIB). Then the substrate is assembled into the microfluidic circuit. The human embryonic kidney 293 (HEK-293) cell transfected with transient receptor potential vanilloid type 1 (TRPV1) is positioned on the micropore and the whole-cell configuration is formed by the suction. Capsaicin is added to the extracellular solution as a ligand molecule, and the channel current showing the desensitization unique to TRPV1 is measured successfully.

  20. A Two-Dimensional Photonic Crystal Slab Mirror with Silicon on Insulator for Wavelength 1.3μm

    Institute of Scientific and Technical Information of China (English)

    TANG Hai-Xia; ZUO Yu-Hua; YU Jin-Zhong; WANG Qi-Ming

    2006-01-01

    @@ A concrete two-dimensional photonic crystal slab with triangular lattice used as a mirror for the light at wavelength 1.3μm with a silicon-on-insulator (SOI) substrate is designed by the three-dimensional plane wave expansion method.

  1. Characterization of the influence of strain on the optical properties of waveguides and microresonators in silicon-on-insulator technology

    NARCIS (Netherlands)

    Westerveld, W.J.; Harmsma, P.J.; Schmits, R.; Tabak, E.; Pozo Torres, J.M.; Urbach, H.P.; Yousefi, M.

    2011-01-01

    Silicon-on-insulator (SOI) technology has become one of the focus platforms for photonic integrated circuits (PICs). The CMOS technology opens the possibility for reliable mass fabrication of cost-effective photonic circuits. Recently there has been a growing interest in direct optical sensing of, f

  2. Optical microcavities based on surface modes in two-dimensional photonic crystals and silicon-on-insulator photonic crystals

    DEFF Research Database (Denmark)

    Xiao, Sanshui; Qiu, M.

    2007-01-01

    Surface-mode optical microcavities based on two-dimensional photonic crystals and silicon-on-insulator photonic crystals are studied. We demonstrate that a high-quality-factor microcavity can be easily realized in these structures. With an increasing of the cavity length, the quality factor is gr...

  3. Integrated optical phased array based large angle beam steering system fabricated on silicon-on-insulator

    Science.gov (United States)

    Kwong, David N.; Zhang, Yang; Hosseini, Amir; Chen, Ray T.

    2011-01-01

    In this paper, we present a highly compact silicon nano-membrane based optical phased array fabricated using conventional CMOS processing on silicon-on-insulator that provides for over 10 degrees of beam steering in a silicon slab at λ=1.55μm using transverse-electrical polarized light. A low loss 1-to-12 multi-mode interference (MMI) optical beam splitter with high uniformity is used to provide inputs to the optical phased array. Using an unequally spaced waveguide array permits us to relax the half-wavelength spacing requirement for large angle beam steering, thereby avoiding the optical coupling between adjacent waveguides and reducing the side-lobe-level of the array radiation pattern. S-bend waveguides convert the equally spaced MMI output to the unequally spaced wave guide array, while passively equalizing the phases of each array element to compensate for the MMI output phase profile. Independently controllable thin film metal heaters are used to achieve phase shifting using the strong thermo-optic response of silicon. Heat-insulating air grooves minimize thermal crosstalk, while also achieving and low power consumption.

  4. Defect-mediated resonance shift of silicon-on-insulator racetrack resonators.

    Science.gov (United States)

    Ackert, J J; Doylend, J K; Logan, D F; Jessop, P E; Vafaei, R; Chrostowski, L; Knights, A P

    2011-06-20

    We present a study on the effects of inert ion implantation of Silicon-On-Insulator (SOI) racetrack resonators. Selective ion implantation was used to create deep-level defects within a portion of the resonator. The resonant wavelength and round-trip loss were deduced for a range of sequential post-implantation annealing temperatures from 100 to 300 °C. As the devices were annealed there was a concomitant change in the resonance wavelength, consistent with an increase in refractive index following implantation and recovery toward the pre-implanted value. A total shift in resonance wavelength of ~2.9 nm was achieved, equivalent to a 0.02 increase in refractive index. The excess loss upon implantation increased to 301 dB/cm and was reduced to 35 dB/cm following thermal annealing. In addition to providing valuable data for those incorporating defects within resonant structures, we suggest that these results present a method for permanent tuning (or trimming) of ring resonator characteristics.

  5. Mode hybridization and conversion in silicon-on-insulator nanowires with angled sidewalls.

    Science.gov (United States)

    Dai, Daoxin; Zhang, Ming

    2015-12-14

    The mode property and light propagation in a tapered silicon-on-insulator (SOI) nanowire with angled sidewalls is analyzed. Mode hybridization is observed and mode conversion between the TM fundamental mode and higher-order TE modes happens when light propagates in a waveguide taper which is used very often in the design of photonic integrated devices. This mode conversion ratio is possible to be very high (even close to 100%) when the taper is long enough to be adiabatic, which might be useful for some applications of multimode photonics. When the mode conversion is undesired to avoid any excess loss as well as crosstalk for photonic integrated circuits, one can depress the mode conversion by compensating the vertical asymmetry in the way of reducing the sidewall angle or introducing an optimal refractive index for the upper-cladding. It is also possible to eliminate the undesired mode conversion almost and improve the desired mode conversion greatly by introducing an abrupt junction connecting two sections with different widths to jump over the mode hybridization region.

  6. Study and simulation for the sharp-corner of silicon-on-insulator waveguides

    Science.gov (United States)

    Sun, De-Gui; Li, Xiaoqi; Wong, Dongxia; Hall, Trevor

    2008-04-01

    The semiconductor industry appears to be encouraging the photonic industry to make highly integrated low-cost optical systems. Planar lightwave circuit (PLC) technology is widely accepted for manufacturing photonic components and Silicon-on-insulator (SOI) waveguides have attracted much research for implementing the highly integrated PLC-based devices. In this work, starting with the guided-mode conversion process and the principle of transportation waves, we mathematically model the structure of corner mirrors of SOI waveguides with a model of effective reflecting interface (ERI). Then we simulate the transfer efficiencies with FDTD method and testify the simulation results with commercial FDTD software tool. Further, we analyze the simulation results and conclude that the conversion efficiency of a corner mirror is determined by several parameters including the geometrical structure, the index-difference of waveguide-reflector materials and the roughness of waveguide-reflector interface. For the corner structure from 90-120°, the optimal transfer efficiency can be achieved more than 98% and the access loss is less than 0.1 dB if the scattering loss of waveguide is not taken into account, but they become 95% and 0.2 dB if the scattering loss is taken into account. For some important PLC components, the deflection angle of 90-120° is good enough for implementing the compact design of highly integrated PLC-based devices.

  7. Ultrafast, green third-harmonic generation and strong-field phenomena in silicon-on-insulator nanoplasmonic waveguides

    OpenAIRE

    Sederberg, Shawn; Elezzabi, Abdulhakem Y.

    2013-01-01

    The emergence of strong-field nanoplasmonics brings extreme laser field-matter interaction into the realm of nanoscale science, unveiling exciting new physics. Highly nonlinear interaction is enabled by tightly confined electric fields in nanoplasmonic structures, permitting use of optical fields from low-power laser oscillators. Here, we report the first demonstration of visible 517nm third harmonic generation in ultracompact nanoplasmonic waveguides on a silicon-on-insulator platform at an ...

  8. Design and fabrication of sub-μs silicon-on-insulator thermo-optic 4×4 switch matrix

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4×4 switch matrix with spot size converters (SSCs) and a new driving circuit are designed and fabricated. The introduction of a spot size converter (SSC) has decreased the insertion loss to less than 10dB and the new driving circuit has improved the response speed to less than 1μs.

  9. Thin buried oxide in oxygen-implanted silicon

    Energy Technology Data Exchange (ETDEWEB)

    Spaggiari, C.; Bertoni, S.; Cerofolini, G.F.; Fumagalli, P.; Meda, L. (Istituto Guido Donegani, Novara (Italy))

    1993-01-01

    SiO[sub 2] precipitation in oxygen-supersaturated silicon was studied. Oxygen was inserted by ion implantation into single-crystal silicon. Evidence is given for a special phenomenon of oxygen blocking due to hot clouds resulting from collisional cascades. In the region where blocking is active, precipitates are formed in as-implanted conditions. A model is formulated and specialized to predict the dependence on depth of precipitate density and size. The existence of a buried region of precipitates is useful for producing a thin buried oxide. The Low-Dose SIMOX (LODOX) structure obtained provides a solution for many problems that are typical of silicon substrates for complementary metal-oxide silicon (CMOS) applications. (Author).

  10. A new analytical model of high voltage silicon on insulator (SOI) thin film devices

    Institute of Scientific and Technical Information of China (English)

    Hu Sheng-Dong; Zhang Bo; Li Zhao-Ji

    2009-01-01

    A new analytical model of high voltage silicon on insulator (SOI) thin film devices is proposed, and a formula of silicon critical electric field is derived as a function of silicon film thickness by solving a 2D Poisson equation from an effective ionization rate, with a threshold energy taken into account for electron multiplying. Unlike a conventional silicon critical electric field that is constant and independent of silicon film thickness, the proposed silicon critical electric field increases sharply with silicon film thickness decreasing especially in the case of thin films, and can come to 141 V/μm at a film thickness of 0.1 μm which is much larger than the normal value of about 30 V/μm. From the proposed formula of silicon critical electric field, the expressions of dielectric layer electric field and vertical breakdown voltage (VB,V) are obtained. Based on the model, an ultra thin film can be used to enhance dielectric layer electric field and so increase vertical breakdown voltage for SOI devices because of its high silicon critical electric field, and with a dielectric layer thickness of 2 μm the vertical breakdown voltages reach 852 and 300V for the silicon film thicknesses of 0.1 and 5μm, respectively. In addition, a relation between dielectric layer thickness and silicon film thickness is obtained, indicating a minimum vertical breakdown voltage that should be avoided when an SOI device is designed. 2D simulated results and some experimental results are in good agreement with analytical results.

  11. Solar thermoelectric generators fabricated on a silicon-on-insulator substrate

    Science.gov (United States)

    de Leon, Maria Theresa; Chong, Harold; Kraft, Michael

    2014-08-01

    Solar thermal power generation is an attractive electricity generation technology as it is environment-friendly, has the potential for increased efficiency, and has high reliability. The design, modelling, and evaluation of solar thermoelectric generators (STEGs) fabricated on a silicon-on-insulator substrate are presented in this paper. Solar concentration is achieved by using a focusing lens to concentrate solar input onto the membrane of the STEG. A thermal model is developed based on energy balance and heat transfer equations using lumped thermal conductances. This thermal model is shown to be in good agreement with actual measurement results. For a 1 W laser input with a spot size of 1 mm, a maximum open-circuit voltage of 3.06 V is obtained, which translates to a temperature difference of 226 °C across the thermoelements and delivers 25 µW of output power under matched load conditions. Based on solar simulator measurements, a maximum TEG voltage of 803 mV was achieved by using a 50.8 mm diameter plano-convex lens to focus solar input to a TEG with a length of 1000 µm, width of 15 µm, membrane diameter of 3 mm, and 114 thermocouples. This translates to a temperature difference of 18 °C across the thermoelements and an output power under matched load conditions of 431 nW. This paper demonstrates that by utilizing a solar concentrator to focus solar radiation onto the hot junction of a TEG, the temperature difference across the device is increased; subsequently improving the TEG’s efficiency. By using materials that are compatible with standard CMOS and MEMS processes, integration of solar-driven TEGs with on-chip electronics is seen to be a viable way of solar energy harvesting where the resulting microscale system is envisioned to have promising applications in on-board power sources, sensor networks, and autonomous microsystems.

  12. Mach-Zehnder Interferometers with Asymmetric Modulation Arms in Applications of High Speed Silicon-on-Insulator Based Optical Switches

    Institute of Scientific and Technical Information of China (English)

    SUN Fei; YU Jin-Zhong

    2006-01-01

    @@ Modulation arms with different widths are introduced to Mach-Zehnder interferometers (MZIs) to obtain improved performance. Theoretical analysis and numerical simulation have shown that when the widths of the two arms are properly designed to achieve an inherent mπ/2 (m is an odd integer) optical phase difference between the arms, the asymmetric MZI presents higher modulation speed. Furthermore, the carrier-absorption induced divergence of insertion losses in silicon-on-insulator (SOI) based MZI optical switches can be obviously improved.

  13. Stimulated and spontaneous four-wave mixing in silicon-on-insulator coupled photonic wire nano-cavities

    Science.gov (United States)

    Azzini, Stefano; Grassani, Davide; Galli, Matteo; Gerace, Dario; Patrini, Maddalena; Liscidini, Marco; Velha, Philippe; Bajoni, Daniele

    2013-07-01

    We report on four-wave mixing in coupled photonic crystal nano-cavities on a silicon-on-insulator platform. Three photonic wire cavities are side-coupled to obtain three modes equally separated in energy. The structure is designed to be self-filtering, and we show that the pump is rejected by almost two orders of magnitude. We study both the stimulated and the spontaneous four-wave mixing processes: owing to the small modal volume, we find that signal and idler photons are generated with a hundred-fold increase in efficiency as compared to silicon micro-ring resonators.

  14. Compact wavelength router based on a Silicon-on-insulator arrayed waveguide grating pigtailed to a fiber array.

    Science.gov (United States)

    Dumon, P; Bogaerts, W; Van Thourhout, D; Taillaert, D; Baets, R; Wouters, J; Beckx, S; Jaenen, P

    2006-01-23

    We demonstrate a compact, fiber-pigtailed, 4-by-4 wavelength router in Silicon-on-insulator photonic wires, fabricated using CMOS processing methods. The core is an AWG with a 250GHz channel spacing and 1THz free spectral range, on a 425x155 microm(2) footprint. The insertion loss of the AWG was reduced to 3.5dB by applying a two-step processing technique. The crosstalk is -12dB. The device was pigtailed using vertical fiber couplers and an eight-fiber array connector.

  15. A Silicon-on-Insulator-Based Thermo-Optic Waveguide Switch with Low Insertion Loss and Fast Response

    Institute of Scientific and Technical Information of China (English)

    LI Yan-Ping; YU Jin-Zhong; CHEN Shao-Wu

    2005-01-01

    @@ A silicon-on-insulator-based thermo-optic waveguide switch integrated with spot size converters is designed and fabricated by inductively coupled plasma reactive ion etching. The device shows good characteristics, including low insertion loss of 8 ± 1 dB for wavelength 1530-1580nm and fast response times of 4.6 μs for rising edge and 1.9μs for falling edge. The extinction ratios of the two channels are 19.1 and 18 dB, respectively.

  16. Stimulated and spontaneous four-wave mixing in silicon-on-insulator coupled photonic wire nano-cavities

    OpenAIRE

    Azzini, Stefano; Grassani, Davide; Galli, Matteo; Gerace,Dario; Patrini, Maddalena; Liscidini, Marco; Velha, Philippe; Bajoni, Daniele

    2013-01-01

    We report on four-wave mixing in coupled photonic crystal nano-cavities on a silicon-on-insulator platform. Three photonic wire cavities are side-coupled to obtain three modes equally separated in energy. The structure is designed to be self-filtering, and we show that the pump is rejected by almost two orders of magnitudes. We study both the stimulated and the spontaneous four-wave mixing processes: owing to the small modal volume, we find that signal and idler photons are generated with a h...

  17. High Speed Signal Wavelength Conversion Using Stimulated Raman Effect in Ultrasmall Silicon-on-Insulator Optical Waveguides

    Institute of Scientific and Technical Information of China (English)

    WU Jian-Wei; LUO Feng-Guang; GALLEP Cristiano de Mello

    2008-01-01

    We propose the high speed signal wavelength conversion based on stimulated Raman effect on silicon waveguides.Simulation results of non-return-to-zero(NRZ)pseudorandom bit sequence(27-1 code)at 500-Gb/s rate of conversion in an ultrasmall silicon-on-insulator(SOI)optical wavegnide are presented by co-propagating pump optical field.The most attractive issue is that the inverted converted signal can be obtained at the same wavelength as that of primary signal.In addition,the conversion performances,including extinction ratio(ER)and average peak power of conversion signal,depend strongly on the launching pump intensity.

  18. Design and analysis of polarization independent all-optical logic gates in silicon-on-insulator photonic crystal

    Science.gov (United States)

    Rani, Preeti; Kalra, Yogita; Sinha, R. K.

    2016-09-01

    In this paper, we have reported design and analysis of polarization independent all optical logic gates in silicon-on-insulator photonic crystal consisting of two dimensional honeycomb lattices with two different air holes exhibiting photonic band gap for both TE and TM mode in the optical communication window. The proposed structures perform as an AND optical logic gate and all the optical logic gates based on the phenomenon of interference. The response period and bit rate for TE and TM polarizations at a wavelength of 1.55 μm show improved results as reported earlier.

  19. Design and fabrication of a planar patch-clamp substrate using a silicon-on-insulator wafer

    Science.gov (United States)

    Zhenlong, Zhang; Xiangyang, Liu; Yanli, Mao

    2009-09-01

    The planar patch-clamp technique has been applied to high throughput screening in drug discovery. The key feature of this technique is the fabrication of a planar patch-clamp substrate using appropriate materials. In this study, a planar patch-clamp substrate was designed and fabricated using a silicon-on-insulator (SOI) wafer. The access resistance and capacitance of SOI-based planar patch-clamp substrates are smaller than those of bulk silicon-based planar substrates, which will reduce the distributed RC noise.

  20. Substrate bias effects on collector resistance in SiGe heterojunction bipolar transistors on thin film silicon-on-insulator

    Institute of Scientific and Technical Information of China (English)

    Xu Xiao-Bo; Zhang He-Ming; Hu Hui-Yong; Qu Jiang-Tao

    2011-01-01

    An analytical expression for the collector resistance of a novel vertical SiGe heteroj unction bipolar transistor (HBT)on thin film silicon-on-insulator (SOI) is obtained with the substrate bias effects being considered. The resistance is found to decrease slowly and then quickly and to have kinks with the increase of the substrate-collector bias, which is quite different from that of a conventional bulk HBT. The model is consistent with the simulation result and the reported data and is useful to the frequency characteristic design of 0.13 μm millimeter-wave SiGe SOI BiCMOS devices.

  1. Formation of silicon-on-insulator layer with midair cavity for meniscus force-mediated layer transfer and high-performance transistor fabrication on glass

    Science.gov (United States)

    Akazawa, Muneki; Sakaike, Kohei; Higashi, Seiichiro

    2015-08-01

    We attempted to transfer a phosphorus ion (P+)-implanted oxidized silicon-on-insulator (SOI) layer with a midair cavity to a glass substrate using meniscus force at a low temperature. The SiO2 column size was controlled by etching time and the minimum column size was 104 nm. The transfer yield of the implanted sample was significantly improved by decreasing the column size, and the maximum transfer yield was 95% when the implantation dose was 1 × 1015 cm-2. The causes of increasing transfer yield are considered to be the tapered SiO2 column shape and the hydrophilicity of the surface of oxidized samples with implantation. N-channel thin-film transistors (TFTs) fabricated using the films on glass at 300 °C showed a field-effect mobility of 505 cm2 V-1 s-1, a threshold voltage of 2.47 V and a subthreshold swing of 324 mV/dec. on average.

  2. Novel high-voltage power lateral MOSFET with adaptive buried electrodes

    Institute of Scientific and Technical Information of China (English)

    Zhang Wen-Tong; Wu Li-Juan; Qiao Ming; Luo Xiao-Rong; Zhang Bo; Li Zhao-Ji

    2012-01-01

    A new high-voltage and low-specific on-resistance (Ron,sp) adaptive buried electrode (ABE) silicon-on-insulator (SOI) power lateral MOSFET and its analytical model of the electric fields are proposed.The MOSFET features are that the electrodes are in the buried oxide (BOX) layer,the negative drain voltage Vd is divided into many partial voltages and the output to the electrodes is in the buried oxide layer and the potentials on the electrodes change linearly from the drain to the source.Because the interface silicon layer potentials are lower than the neighboring electrode potentials,the electronic potential wells are formed above the electrode regions,and the hole poteutial wells are formed in the spacing of two neighbouring electrode regions.The interface hole concentration is much higher than the electron concentration through designing the buried layer electrode potentials.Based on the interface charge enhanced dielectric layer field theory,the electric field strength in the buried layer is enhanced.The vertical electric field EI and the breakdown voltage (BV) of ABE SOI are 545 V/μm and -587 V in the 50 μm long drift region and the 1 tm thick dielectric layer,and a low Ron,sp is obtained.Furthermore,the structure also alleviates the self-heating effect (SHE).The analytical model matches the simulation results.

  3. Heteroepitaxial growth of Ge on compliant strained nano-structured Si lines and dots on (001) silicon on insulator substrate

    Energy Technology Data Exchange (ETDEWEB)

    Zaumseil, Peter, E-mail: zaumseil@ihp-microelectronics.com [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Yamamoto, Yuji; Schubert, Markus Andreas [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Schroeder, Thomas [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Brandenburgische Technische Universität Cottbus, Konrad-Zuse-Str.1, Cottbus, 03046 (Germany); Tillack, Bernd [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Technische Universität Berlin, HFT4, Einsteinufer 25, 10587 Berlin (Germany)

    2014-04-30

    On the way to integrate lattice mismatched semiconductors on Si(001) we studied the Ge/Si heterosystem with the aim of a misfit dislocation free deposition that offers the vision to integrate defect-free alternative semiconductor structures on Si. Periodic Ge nano-structures (dots and lines) were selectively grown by chemical vapor deposition on Si nano-islands on silicon on insulator substrate with a thin (about 10 nm) SiGe buffer layer between Si and Ge. The strain state of the structures was measured by grazing incidence and specular diffraction using laboratory-based X-ray diffraction technique. The SiGe improves the compliance of the Si compared to direct Ge deposition, prevents plastic relaxation during growth, and allows elastic relaxation before Ge is deposited on top. As a result, an epitaxial growth of Ge on Si fully free of misfit dislocations was achieved. - Highlights: • Realization of nano-structured Si islands (dots and lines) on silicon on insulator substrate • Selective Ge epitaxy on nano-structured periodic Si islands with thin SiGe buffer • Strain characterization of Ge nano-structures by X-ray diffraction • Ge heteroepitaxy on Si without misfit dislocation confirmed by transmission electron microscopy.

  4. Strong room temperature electroluminescence from lateral p-SiGe/i-Ge/n-SiGe heterojunction diodes on silicon-on-insulator substrate

    Science.gov (United States)

    Lin, Guangyang; Yi, Xiaohui; Li, Cheng; Chen, Ningli; Zhang, Lu; Chen, Songyan; Huang, Wei; Wang, Jianyuan; Xiong, Xihuan; Sun, Jiaming

    2016-10-01

    A lateral p-Si0.05Ge0.95/i-Ge/n-Si0.05Ge0.95 heterojunction light emitting diode on a silicon-on-insulator (SOI) substrate was proposed, which is profitable to achieve higher luminous extraction compared to vertical junctions. Due to the high carrier injection ratio of heterostructures and optical reflection at the SiO2/Si interface of the SOI, strong room temperature electroluminescence (EL) at around 1600 nm from the direct bandgap of i-Ge with 0.30% tensile strain was observed. The EL peak intensity of the lateral heterojunction is enhanced by ˜4 folds with a larger peak energy than that of the vertical Ge p-i-n homojunction, suggesting that the light emitting efficiency of the lateral heterojunction is effectively improved. The EL peak intensity of the lateral heterojunction, which increases quadratically with injection current density, becomes stronger for diodes with a wider i-Ge region. The CMOS compatible fabrication process of the lateral heterojunctions paves the way for the integration of the light source with the Ge metal-oxide-semiconductor field-effect-transistor.

  5. Impact of strain on gate-induced floating body effect for partially depleted silicon-on-insulator p-type metal–oxide–semiconductor-field-effect-transistors

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Wen-Hung [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan, ROC (China); Chang, Ting-Chang, E-mail: tcchang@mail.phys.nsysu.edu.tw [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan, ROC (China); Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan, ROC (China); Dai, Chih-Hao [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan, ROC (China); Chung, Wan-Lin [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan, ROC (China); Chen, Ching-En; Ho, Szu-Han [Department of Electronics Engineering, National Chiao Tung University, Hsinchu, Taiwan, ROC (China); Tsai, Jyun-Yu [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan, ROC (China); Chen, Hua-Mao [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan, ROC (China); Liu, Guan-Ru [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan, ROC (China); Cheng, Osbert; Huang, Cheng-Tung [Device Department, United Microelectronics Corporation, Tainan Science Park, Taiwan, ROC (China)

    2013-01-01

    This work investigates impact of mechanical strain on gate-induced-floating-body-effect (GIFBE) for partially depleted silicon-on-insulator p-type metal–oxide–semiconductor field effect transistors (PD SOI p-MOSFETs). First part, the original mechanism of GIFBE on PD SOI p-MOSFETs is studied. The experimental results indicate that GIFBE causes a reduction in oxide electric field (E{sub ox}), resulting in an underestimate of negative-bias temperature instability (NBTI) degradation. This can be attributed to the electrons tunneling from the process-induced partial n{sup +} poly gate and anode electron injection (AEI) model, rather than the electron valence band tunneling (EVB) widely accepted as the mechanism for n-MOSFETs. And then, the second part shows that the strained FB device has less NBTI degradation than the unstrained devices. This behavior can be attributed to the fact that more electron accumulation was induced by strain-induced band gap narrowing, reducing NBTI significantly. - Highlights: ► This work investigates the impact of mechanical strain on GIFBE for PD SOI p-MOSFETs. ► FB device shows an insignificant NBTI due to GIFBE. ► GIFBE results from the partial n{sup +} poly gate and anode electron injection model. ► The strained FB device has less NBTI degradation than unstrained devices. ► We verify the band gap narrowing causes less NBTI on strained FB device.

  6. Silicon-on-insulator-based high-voltage, high-temperature integrated circuit gate driver for silicon carbide-based power field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Tolbert, Leon M [ORNL; Huque, Mohammad A [ORNL; Blalock, Benjamin J [ORNL; Islam, Syed K [ORNL

    2010-01-01

    Silicon carbide (SiC)-based field effect transistors (FETs) are gaining popularity as switching elements in power electronic circuits designed for high-temperature environments like hybrid electric vehicle, aircraft, well logging, geothermal power generation etc. Like any other power switches, SiC-based power devices also need gate driver circuits to interface them with the logic units. The placement of the gate driver circuit next to the power switch is optimal for minimising system complexity. Successful operation of the gate driver circuit in a harsh environment, especially with minimal or no heat sink and without liquid cooling, can increase the power-to-volume ratio as well as the power-to-weight ratio for power conversion modules such as a DC-DC converter, inverter etc. A silicon-on-insulator (SOI)-based high-voltage, high-temperature integrated circuit (IC) gate driver for SiC power FETs has been designed and fabricated using a commercially available 0.8--m, 2-poly and 3-metal bipolar-complementary metal oxide semiconductor (CMOS)-double diffused metal oxide semiconductor (DMOS) process. The prototype circuit-s maximum gate drive supply can be 40-V with peak 2.3-A sourcing/sinking current driving capability. Owing to the wide driving range, this gate driver IC can be used to drive a wide variety of SiC FET switches (both normally OFF metal oxide semiconductor field effect transistor (MOSFET) and normally ON junction field effect transistor (JFET)). The switching frequency is 20-kHz and the duty cycle can be varied from 0 to 100-. The circuit has been successfully tested with SiC power MOSFETs and JFETs without any heat sink and cooling mechanism. During these tests, SiC switches were kept at room temperature and ambient temperature of the driver circuit was increased to 200-C. The circuit underwent numerous temperature cycles with negligible performance degradation.

  7. A novel structure of silicon-on-insulator microring biosensor based on Young's two-slit interference and its simulation

    Institute of Scientific and Technical Information of China (English)

    Su Baoqing; Wang Chunxia; Kan Qiang; Li Junhua; Xie Yiyang; Wang Zhenzhen; Chen Hongda

    2011-01-01

    A novel silicon-on-insulator microring biosensor based on Young's twoslit interference has been demonstrated.The transducer signal from electric field intensity distribution on the interference screen is given by using the transfer matrix method (TMM) and two-slit interference principle.The result shows that the structure we propose is advantageous for sensing as the interference pattern is very sensitive to the ambient refractive index around the microring.A small perturbation in refractive index around the microring △nc will result in a notable shift of destructive interference points (DIPs) on the interference screen.By detecting the shift of the DIPs,the ambient refractive index change can be obtained.

  8. Tailoring the spectral response of add/drop single and multiple resonators in silicon-on-insulator Invited Paper

    Institute of Scientific and Technical Information of China (English)

    B. Timotijevic; G. Mashanovich; A. Michaeli; O. Cohen; V. M. N. Passaro; J. Crnjanski; G. T. Reed

    2009-01-01

    Channel dropping waveguide filters based on single and multiple resonators in silicon-on-insulator (SOI) technology are of great interest due to their compactness and high wavelength selectivity, which is a desir- able feature for photonic modulators, detectors, and other optically integrated components in telecommu- nication systems, in particular for wavelength division multiplexing (WDM) systems. Particular advantage of these filters is that they are capable of producing relatively large free spectral range (FSR) as well as narrow 3-dB bandwidth of the filter resonances. Herein we report experimental results and discuss the pos- sibility of designing mono-mode and (nearly) polarization independent SOI ring and racetrack resonators with the FSR in excess of 30 nm.

  9. Ultrafast, green third-harmonic generation and strong-field phenomena in silicon-on-insulator nanoplasmonic waveguides

    CERN Document Server

    Sederberg, Shawn

    2013-01-01

    The emergence of strong-field nanoplasmonics brings extreme laser field-matter interaction into the realm of nanoscale science, unveiling exciting new physics. Highly nonlinear interaction is enabled by tightly confined electric fields in nanoplasmonic structures, permitting use of optical fields from low-power laser oscillators. Here, we report the first demonstration of visible 517nm third harmonic generation in ultracompact nanoplasmonic waveguides on a silicon-on-insulator platform at an unprecedented conversion efficiency of ~10^{-5}. Exponential growth of broadband white light generation confirms a new strong-field phenomenon of ponderomotive force-driven electron avalanche multiplication. Using time-resolved experiments, we show that the strong nanoplasmonic field confinement allows nonlinear interaction to occur on an ultrafast timescale of 1.98 +/- 0.40 ps, despite the long free-carrier lifetime in silicon. These findings uncover a new strong-field interaction that can be used in sensitive nanoplasmo...

  10. An Analytical Avalanche Multiplication Model for Partially Depleted Silicon-on-Insulator SiGe Heterojunction Bipolar Transistors

    Institute of Scientific and Technical Information of China (English)

    XU Xiao-Bo; ZHANG He-Ming

    2011-01-01

    An analytical expression for avalanche multiplication of a novel vertical SiGe partially depleted heterojunction bipolar transistor (HBT) on a thin silicon-on-insulator (SOI) layer is obtained,considering vertical and horizontal impact ionization effects.The avalanche multiplication is found to be dependent on the collector width and doping concentration,and shows kinks with the increase of reverse base-collector bias,which is quite different from that of a conventional bulk HBT.The model is consistent with the experimental and simulation data and is found to be significant for the design and simulation of 0.13μm millimeter wave SiGe SOI BiCMOS technology.

  11. Thermo-optic Imbert-Fedorov effect in a prism-waveguide coupling system with silicon-on-insulator

    Science.gov (United States)

    Tang, Tingting; Li, Chaoyang; Luo, Li; Zhang, Yanfen; Yuan, Quan

    2016-07-01

    In this paper, a prism-waveguide coupling system based on silicon-on-insulator (SOI) is revisited. We find that thermo-optic Imbert-Fedorov (TOIF) effect displays in this four-layer optical system which has not been proposed before. Furthermore, we discuss the TOIF shifts in prism/SiO2/Si/SiO2 and prism/Au/Si/SiO2 waveguides with different parameters and study the observed phenomena from physical point of view. It is shown that the maximum IF shift can achieve 140 μm in a prism/Au/Si/SiO2 waveguide which is large enough to be directly measured by the calculation results. Accordingly, TOIF shift provides a temperature control method for the enhancement and modulation of IF shift.

  12. Silicon-on-insulator 1×2 Y-junction Optical Switch Based on Waveguide-vanishing Effect①②

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    The silicon-on-insulator(SOI)1×2Y-junction optical waveguide switch has been proposed and fabricated,which is based on the large cross-section single-mode rib waveguide condition,the waveguide-vanishing effect and the free-carrier plasma dispersion effect.In the switch,the SOI technique utilizer silicon and silicon dioxide thermal bonding and back-polishing.The insertion loss and extinction ratio of the device are measured to be less than 4.78dB and 20.8dB respectively at a wavelength of 1.3μm and an injection current of 45mA.Response time is about 160ns.

  13. Design of a vector-sum integrated microwave photonic phase shifter in silicon-on-insulator waveguides.

    Science.gov (United States)

    Qu, Pengfei; Liu, Caixia; Dong, Wei; Chen, Weiyou; Li, Fumin; Li, Haibin; Gong, Zhaoxin; Ruan, Shengping; Zhang, Xindong; Zhou, Jingran

    2011-06-10

    An orthogonal vector-sum integrated microwave photonic phase shifter (IMWPPS), consisting of mode-order converter multiplexers (MOCMs), a variable optical power splitter (VOPS), an optical switch (OS) and fixed time delay lines (FTDLs), was theoretically demonstrated in a silicon-on-insulator wafer. MOCMs, as a key element of our device, were employed to generate orthogonal vector signals and served as lossless optical combiners. Combining with the thermo-optical VOPS, OS and FTDLs, the microwave phase shift of 0∼2π could be achieved by a refractive index variation of 0∼15×10(-3) in the millimeter wave band. The corresponding tuning resolution was about 1.64°/°C. This work, for the first time to our knowledge, provides an attractive solution to transferring a vector-sum method based bulk MWPPS into a integrated one, which is very important for large-scale optically controlled phase array antenna.

  14. Fabrication of open-top microchannel plate using deep X-ray exposure mask made with silicon on insulator substrate

    CERN Document Server

    Fujimura, T; Etoh, S I; Hattori, R; Kuroki, Y; Chang, S S

    2003-01-01

    We propose a high-aspect-ratio open-top microchannel plate structure. This type of microchannel plate has many advantages in electrophoresis. The plate was fabricated by deep X-ray lithography using synchrotron radiation (SR) light and the chemical wet etching process. A deep X-ray exposure mask was fabricated with a silicon on insulator (SOI) substrate. The patterned Si microstructure was micromachined into a thin Si membrane and a thick Au X-ray absorber was embedded in it by electroplating. A plastic material, polymethylmethacrylate (PMMA) was used for the plate substrate. For reduction of the exposure time and high-aspect-ratio fast wet development, the fabrication condition was optimized with respect to not the exposure dose but to the PMMA mean molecular weight (M.W.) changing after deep X-ray exposure as measured by gel permeation chromatography (GPC). Decrement of the PMMA M.W. and increment of the wet developer temperature accelerated the etching rate. Under optimized fabrication conditions, a microc...

  15. Grating couplers in silicon-on-insulator: The role of photonic guided resonances on lineshape and bandwidth

    Science.gov (United States)

    Passoni, M.; Gerace, D.; Carroll, L.; Andreani, L. C.

    2017-01-01

    Most grating couplers for silicon photonics are designed to match the approximately 10 μm mode-field diameter (MFD) of single-mode telecom fibres. In this letter, we analyse grating-coupler designs in the Silicon-on-Insulator (SOI) platform in a wide range of MFDs (4-100 μm) and related footprints, to give a physical understanding of the trends in efficiency and lineshape of the corresponding coupling spectra. We show that large-footprint grating couplers have an intrinsic Lorentzian lineshape that is determined by the quasi-guided photonic modes (or guided resonances) of the corresponding photonic crystal slab, while small-footprint grating couplers have a Gaussian lineshape resulting from the k-space broadening of the incident mode. The crossover between the two regimes is characterized by Voigt lineshapes. Multi-objective particle-swarm optimisation of selected small-footprint apodized grating-couplers is then used to locate the "Pareto fronts;" along which the highest coupling efficiency is achieved for a given bandwidth. This approach identifies several high-efficiency 220 nm SOI grating coupler designs with 1 dB bandwidths exceeding 100 nm. Such grating couplers are ideally suited for broadband photonic applications, such as wavelength-division multiplexing and environmental sensing, and are compatible with commercially available ultra-high numerical aperture fibres.

  16. High-stroke silicon-on-insulator MEMS nanopositioner: control design for non-raster scan atomic force microscopy.

    Science.gov (United States)

    Maroufi, Mohammad; Fowler, Anthony G; Bazaei, Ali; Moheimani, S O Reza

    2015-02-01

    A 2-degree of freedom microelectromechanical systems nanopositioner designed for on-chip atomic force microscopy (AFM) is presented. The device is fabricated using a silicon-on-insulator-based process and is designed as a parallel kinematic mechanism. It contains a central scan table and two sets of electrostatic comb actuators along each orthogonal axis, which provides displacement ranges greater than ±10 μm. The first in-plane resonance modes are located at 1274 Hz and 1286 Hz for the X and Y axes, respectively. To measure lateral displacements of the stage, electrothermal position sensors are incorporated in the design. To facilitate high-speed scans, the highly resonant dynamics of the system are controlled using damping loops in conjunction with internal model controllers that enable accurate tracking of fast sinusoidal set-points. To cancel the effect of sensor drift on controlled displacements, washout controllers are used in the damping loops. The feedback controlled nanopositioner is successfully used to perform several AFM scans in contact mode via a Lissajous scan method with a large scan area of 20 μm × 20 μm. The maximum scan rate demonstrated is 1 kHz.

  17. High-stroke silicon-on-insulator MEMS nanopositioner: Control design for non-raster scan atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Maroufi, Mohammad, E-mail: Mohammad.Maroufi@uon.edu.au; Fowler, Anthony G., E-mail: Anthony.Fowler@uon.edu.au; Bazaei, Ali, E-mail: Ali.Bazaei@newcastle.edu.au; Moheimani, S. O. Reza, E-mail: Reza.Moheimani@newcastle.edu.au [School of Electrical Engineering and Computer Science, University of Newcastle, Callaghan NSW 2308 (Australia)

    2015-02-15

    A 2-degree of freedom microelectromechanical systems nanopositioner designed for on-chip atomic force microscopy (AFM) is presented. The device is fabricated using a silicon-on-insulator-based process and is designed as a parallel kinematic mechanism. It contains a central scan table and two sets of electrostatic comb actuators along each orthogonal axis, which provides displacement ranges greater than ±10 μm. The first in-plane resonance modes are located at 1274 Hz and 1286 Hz for the X and Y axes, respectively. To measure lateral displacements of the stage, electrothermal position sensors are incorporated in the design. To facilitate high-speed scans, the highly resonant dynamics of the system are controlled using damping loops in conjunction with internal model controllers that enable accurate tracking of fast sinusoidal set-points. To cancel the effect of sensor drift on controlled displacements, washout controllers are used in the damping loops. The feedback controlled nanopositioner is successfully used to perform several AFM scans in contact mode via a Lissajous scan method with a large scan area of 20 μm × 20 μm. The maximum scan rate demonstrated is 1 kHz.

  18. Infrared response of the lateral PIN structure of a highly titanium-doped silicon-on-insulator material

    Institute of Scientific and Technical Information of China (English)

    Ma Zhi-Hua; Cao Quan; Zuo Yu-Hua; Zheng Jun; Xue Chun-Lai; Cheng Bu-Wen; Wang Qi-Ming

    2011-01-01

    The intermediate band (IB) solar cell is a promising third-generation solar cell that could possibly achieve very high efficiency above the Shockley-Queisser limit.One of the promising ways to synthesize IB material is to introduce heavily doped deep level impurities in conventional semiconductors.High-doped Ti with a concentration of 1020 cm-3- 1021 cm-3 in the p-type top Si layer of silicon-on-insulator (SOI) substrate is obtained by ion implantation and rapid thermal annealing (RTA).Secondary ion mass spectrometry measurements confirm that the Ti concentration exceeds the theoretical Mott limit,the main requirement for the formation of an impurity intermediate band.Increased absorption is observed in the infrared (IR) region by Fourier transform infrared spectroscopy (FTIR) technology.By using a lateral p-i-n structure,an obvious infrared response in a range of 1100 nm-2000 nm is achieved in a heavily Ti-doped SOl substrate,suggesting that the improvement on IR photoresponse is a result of increased absorption in the IR.The experimental results indicate that heavily Ti-implanted Si can be used as a potential kind of intermediate-band photovoltaic material to utilize the infrared photons of the solar spectrum.

  19. Design and theoretical investigation of a silicon-on-insulator based electro-optical logic gate device

    Science.gov (United States)

    Li, Lei; Qi, Zhipeng; Hu, Guohua; Yun, Binfeng; Zhong, Yuan; Cui, Yiping

    2016-10-01

    A compact electro-optical "NOR" logic gate device based on silicon-on-insulator (SOI) platform is proposed and investigated theoretically. By introducing a hook-type waveguide, the signal could be coupled between the bus and hook-type waveguide to form an optical circuit and realize NOR logic gate. We can easily realize the NOR logical function by the voltage applied on the coupling components. The numerical simulation shows that a high coupling efficiency of more than 99% is obtained at the wavelength of 1550 nm, and the footprint of our device is smaller than 90 μm2. In addition, the response time of the proposed NOR logic gate is 3 ns with a switching voltage of 1.8 V. Moreover, it is demonstrated that such NOR logic gate device could obtain an extinction ratio of 21.8 dB. Thus, it has great potential to achieve high speed response, low power consumption, and small footprint, which fulfill the demands of next-generation on-chip computer multiplex processors.

  20. Super-enhancement of 1.54 μm emission from erbium codoped with oxygen in silicon-on-insulator

    Science.gov (United States)

    Lourenço, M. A.; Milošević, M. M.; Gorin, A.; Gwilliam, R. M.; Homewood, K. P.

    2016-11-01

    We report on the super enhancement of the 1.54 μm Er emission in erbium doped silicon-on-insulator when codoped with oxygen at a ratio of 1:1. This is attributed to a more favourable crystal field splitting in the substitutional tetrahedral site favoured for the singly coordinated case. The results on these carefully matched implant profiles show that optical response is highly determined by the amount and ratio of erbium and oxygen present in the sample and ratios of O:Er greater than unity are severely detrimental to the Er emission. The most efficient luminescence is forty times higher than in silicon-on-insulator implanted with Er only. This super enhancement now offers a realistic route not only for optical communication applications but also for the implementation of silicon photonic integrated circuits for sensing, biomedical instrumentation and quantum communication.

  1. Oxygen in zone-melting-recrystallized silicon-on-insulator films: Its distribution and possible role in sub-boundary formation

    Science.gov (United States)

    Fan, John C. C.; Tsaur, B.-Y.; Chen, C. K.; Dick, J. R.; Kazmerski, L. L.

    1984-06-01

    Using secondary-ion mass spectroscopy, we have found that oxygen is strongly concentrated at the sub-boundaries in zone-melting-recrystallized silicon-on-insulator films prepared by the graphite strip heater technique. This observation suggests that the formation of sub-boundaries during recrystallization may be caused by constitutional supercooling resulting from the presence of oxygen that is dissolved into the molten Si zone from the adjacent SiO2 layers.

  2. Novel Folding Large-Scale Optical Switch Matrix with Total Internal Reflection Mirrors on Silicon-on-Insulator by Anisotropy Chemical Etching

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-Wei; YU Jin-Zhong; CHEN Shao-Wu

    2005-01-01

    A compact optical switch matrix was designed, in which light circuits were folded by total internal reflective (TIR) mirrors. Two key elements, 2 × 2 switch and TIR mirror, have been fabricated on silicon-on-insulator wafer by anisotropy chemical etching. The 2 × 2 switch showed very low power consumption of 140mW and avery high speed of 8 ± 1 μs. An improved design for the TIR mirror was developed, and the fabricated mirror with smooth and vertical reflective facet showed low excess loss of 0.7 ± 0.3 dB at 1.55μm.

  3. Material and device engineering in fully depleted silicon-on-insulator transistors to realize a steep subthreshold swing using negative capacitance

    Science.gov (United States)

    Ota, Hiroyuki; Migita, Shinji; Hattori, Junichi; Fukuda, Koichi; Toriumi, Akira

    2016-08-01

    This paper discusses material and device engineering in field-effect transistors (FETs) with HfO2-based ferroelectric gate insulators to attain a precipitous subthreshold swing (SS) by exploiting negative capacitance. Our physical analysis based on a new concept of a negative dielectric constant reveals that fully depleted silicon-on-insulator (FD-SOI) channels with a modest remnant polarization P r (3 µC/cm2 at most) are more suitable for realizing SS HfO2-based ferroelectric materials. We also confirm SS ferroelectric HfO2 gate insulators by device simulation.

  4. Ultrafast all-optical switching and error-free 10 Gbit/s wavelength conversion in hybrid InP-silicon on insulator nanocavities using surface quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Bazin, Alexandre; Monnier, Paul; Beaudoin, Grégoire; Sagnes, Isabelle; Raj, Rama [Laboratoire de Photonique et de Nanostructures (CNRS UPR20), Route de Nozay, Marcoussis 91460 (France); Lenglé, Kevin; Gay, Mathilde; Bramerie, Laurent [Université Européenne de Bretagne (UEB), 5 Boulevard Laënnec, 35000 Rennes (France); CNRS-Foton Laboratory (UMR 6082), Enssat, BP 80518, 22305 Lannion Cedex (France); Braive, Rémy; Raineri, Fabrice, E-mail: fabrice.raineri@lpn.cnrs.fr [Laboratoire de Photonique et de Nanostructures (CNRS UPR20), Route de Nozay, Marcoussis 91460 (France); Université Paris Diderot, Sorbonne Paris Cité, 75207 Paris Cedex 13 (France)

    2014-01-06

    Ultrafast switching with low energies is demonstrated using InP photonic crystal nanocavities embedding InGaAs surface quantum wells heterogeneously integrated to a silicon on insulator waveguide circuitry. Thanks to the engineered enhancement of surface non radiative recombination of carriers, switching time is obtained to be as fast as 10 ps. These hybrid nanostructures are shown to be capable of achieving systems level performance by demonstrating error free wavelength conversion at 10 Gbit/s with 6 mW switching powers.

  5. FTIR and RBS study of ion-beam synthesized buried silicon oxide layers

    Energy Technology Data Exchange (ETDEWEB)

    Patel, A.P. [Department of Physics, University of Mumbai, Vidyanagari campus, Santacruz (E), Mumbai 400098 (India); Yadav, A.D. [Department of Physics, University of Mumbai, Vidyanagari campus, Santacruz (E), Mumbai 400098 (India)], E-mail: adyadav@physics.mu.ac.in; Dubey, S.K. [Department of Physics, University of Mumbai, Vidyanagari campus, Santacruz (E), Mumbai 400098 (India); Panigrahi, B.K.; Nair, K.G.M. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2008-04-15

    Single crystal silicon samples were implanted at 140 keV by oxygen ({sup 16}O{sup +}) ion beam to fluence levels of 1.0 x 10{sup 17}, 2.5 x 10{sup 17} and 5.0 x 10{sup 17} cm{sup -2} to synthesize buried silicon oxide insulating layers by SIMOX (separation by implanted oxygen) process at room temperature and at high temperature (325 deg. C). The structure and composition of the ion-beam synthesized buried silicon oxide layers were investigated by Fourier transform infrared (FTIR) and Rutherford backscattering spectroscopy (RBS) techniques. The FTIR spectra of implanted samples reveal absorption in the wavenumber range 1250-750 cm{sup -1} corresponding to the stretching vibration of Si-O bonds indicating the formation of silicon oxide. The integrated absorption band intensity is found to increase with increase in the ion fluence. The absorption peak was rather board for 325 deg. C implanted sample. The FTIR studies show that the structures of ion-beam synthesized buried oxide layers are strongly dependent on total ion fluence. The RBS measurements show that the thickness of the buried oxide layer increases with increase in the oxygen fluence. However, the thickness of the top silicon layer was found to decrease with increase in the ion fluence. The total oxygen fluence estimated from the RBS data is found to be in good agreement with the implanted oxygen fluence. The high temperature implantation leads to increase in the concentration of the oxide formation compared to room temperature implantation.

  6. A low on-resistance buried current path SOI p-channel LDMOS compatible with n-channel LDMOS

    Institute of Scientific and Technical Information of China (English)

    Zhou Kun; Luo Xiao-Rong; Fan Yuan-Hang; Luo Yin-Chun; Hu Xia-Rong; Zhang Bo

    2013-01-01

    A novel low specific on-resistance (Ron,sp) silicon-on-insulator (SOI) p-channel lateral double-diffused metal-oxide semiconductor (pLDMOS) compatible with high voltage (HV) n-channel LDMOS (nLDMOS) is proposed.The pLDMOS is built in the N-type SOI layer with a buried P-type layer acting as a current conduction path in the on-state (BP SOI pLDMOS).Its superior compatibility with the HV nLDMOS and low voltage (LV) complementary metal-oxide semiconductor (CMOS) circuitry which are formed on the N-SOI layer can be obtained.In the off-state the P-buried layer built in the N-SOI layer causes multiple depletion and electric field reshaping,leading to an enhanced (reduced) surface field (RESURF)effect.The proposed BP SOI pLDMOS achieves not only an improved breakdown voltage (BV) but also a significantly reduced Ron,sp.The BV of the BP SOI pLDMOS increases to 319 V from 215 V of the conventional SOI pLDMOS at the same half cell pitch of 25 μm,and Ron,sp decreases from 157 mΩ·cm2 to 55 mΩ·cm2.Compared with the PW SOI pLDMOS,the BP SOI pLDMOS also reduces the Ron,sp by 34% with almost the same BV.

  7. Analytical base-collector depletion capacitance in vertical SiGe heterojunction bipolar transistors fabricated on CMOS-compatible silicon on insulator

    Institute of Scientific and Technical Information of China (English)

    Xu Xiao-Bo; Zhang He-Ming; Hu Hui-Yong; Ma Jian-Li; Xu Li-Jun

    2011-01-01

    The base-collector depletion capacitance for vertical SiGe npn heterojunction bipolar transistors (HBTs) on silicon on insulator (SOI) is split into vertical and lateral parts. This paper proposes a novel analytical depletion capacitance model of this structure for the first time. A large discrepancy is predicted when the present model is compared with the conventional depletion model, and it is shown that the capacitance decreases with the increase of the reverse collectorbase bias-and shows a kink as the reverse collector-base bias reaches the effective vertical punch-through voltage while the voltage differs with the collector doping concentrations, which is consistent with measurement results. The model can be employed for a fast evaluation of the depletion capacitance of an SOI SiGe HBT and has useful applications on the design and simulation of high performance SiGe circuits and devices.

  8. Determination of the quasi-TE mode (in-plane) graphene linear absorption coefficient via integration with silicon-on-insulator racetrack cavity resonators.

    Science.gov (United States)

    Crowe, Iain F; Clark, Nicholas; Hussein, Siham; Towlson, Brian; Whittaker, Eric; Milosevic, Milan M; Gardes, Frederic Y; Mashanovich, Goran Z; Halsall, Matthew P; Vijayaraghaven, Aravind

    2014-07-28

    We examine the near-IR light-matter interaction for graphene integrated cavity ring resonators based on silicon-on-insulator (SOI) race-track waveguides. Fitting of the cavity resonances from quasi-TE mode transmission spectra reveal the real part of the effective refractive index for graphene, n(eff) = 2.23 ± 0.02 and linear absorption coefficient, α(gTE) = 0.11 ± 0.01dBμm(-1). The evanescent nature of the guided mode coupling to graphene at resonance depends strongly on the height of the graphene above the cavity, which places limits on the cavity length for optical sensing applications.

  9. A Numerical Study on the Anisotropic Thermal Conduction by Phonon Mean Free Path Spectrum of Silicon in Silicon-on-Insulator Transistor

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyung Sun; Koh, Young Ha; Jin, Jae Sik [Chosun Univ., Kwangju (Korea, Republic of)

    2016-02-15

    The primary concern of this research is to examine the phonon mean free path (MFP) spectrum contribution to heat conduction. The size effect of materials is determined by phonon MFP, and the size effect appears when the phonon MFP is similar to or less than the characteristic length of materials. Therefore, knowledge of the phonon MFP is essential to increase or decrease the heat conduction of a material for engineering applications, such as micro/nanosystems. In this study, frequency dependence of the phonon transport is considered using the Boltzmann transport equation based on a full phonon dispersion model. Additionally, the phonon MFP spectrums of in-plane and out-of plane heat transport are investigated by varying the film thickness of the silicon layer from 41 nm to 177 nm. This will increase the understanding of anisotropic heat conduction in a SOI (Silicon-on-Insulator) transistor.

  10. Low Power-Consumption and High Response Frequency Thermo-Optic Variable Optical Attenuators Based on Silicon-on-Insulator Materials

    Institute of Scientific and Technical Information of China (English)

    FANG Qing; CHEN Peng; XIN Hong-Li; WANG Chun-Xia; LI Fang; LIU Yu-Liang

    2005-01-01

    @@ A novel silicon-on-insulator thermo-optic variable optical attenuator with isolated grooves based on a multimode interference coupler principle is fabricated by the inductive coupled plasma etching technology. The maximum fibre-to-fibre insertion loss is lower than 2.2 dB, the dynamic attenuation range is from 0 to 30 dB in the wavelength range 1500-1600nm, and the maximum power consumption is only 140mW. The response frequency of the fabricated variable optical attenuator is about 30 kHz. Compared to the variable optical attenuator without isolated grooves, the maximum power consumption decreases more than 220mW, and the response frequency rises are more than 20kHz.

  11. Fabrication of core-shell nanostructures via silicon on insulator dewetting and germanium condensation: towards a strain tuning method for SiGe-based heterostructures in a three-dimensional geometry

    Science.gov (United States)

    Naffouti, Meher; David, Thomas; Benkouider, Abdelmalek; Favre, Luc; Cabie, Martiane; Ronda, Antoine; Berbezier, Isabelle; Abbarchi, Marco

    2016-07-01

    We report on a novel method for the implementation of core-shell SiGe-based nanocrystals combining silicon on insulator dewetting in a molecular beam epitaxy reactor with an ex situ Ge condensation process. With an in situ two-step process (annealing and Ge deposition) we produce two families of islands on the same sample: Si-rich, formed during the first step and, all around them, Ge-rich formed after Ge deposition. By increasing the amount of Ge deposited on the annealed samples from 0 to 18 monolayers, the islands’ shape in the Si-rich zones can be tuned from elongated and flat to more symmetric and with a larger vertical aspect ratio. At the same time, the spatial extension of the Ge-rich zones is progressively increased as well as the Ge content in the islands. Further processing by ex situ rapid thermal oxidation results in the formation of a core-shell composition profile in both Si and Ge-rich zones with atomically sharp heterointerfaces. The Ge condensation induces a Ge enrichment of the islands’ shell of up to 50% while keeping a pure Si core in the Si-rich zones and a ˜25% SiGe alloy in the Ge-rich ones. The large lattice mismatch between core and shell, the absence of dislocations and the islands’ monocrystalline nature render this novel class of nanostructures a promising device platform for strain-based band-gap engineering. Finally, this method can be used for the implementation of ultralarge scale meta-surfaces with dielectric Mie resonators for light manipulation at the nanoscale.

  12. The impact of etched trenches geometry and dielectric material on the electrical behaviour of silicon-on-insulator self-switching diodes

    Energy Technology Data Exchange (ETDEWEB)

    Farhi, G; Charlebois, S A [Departement de genie electrique et genie informatique, et Institut interdisciplinaire d' innovation technologique (3IT), Universite de Sherbrooke, 2500, Boulevard de l' Universite, J1K 2R1, Sherbrooke, QC (Canada); Morris, D [Departement de physique et Institut interdisciplinaire d' innovation technologique (3IT), Universite de Sherbrooke, 2500, Boulevard de l' Universite, J1K 2R1, Sherbrooke, QC (Canada); Raskin, J-P, E-mail: ghania.farhi@usherbrooke.ca [Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Universite catholique de Louvain, Place du Levant, 3, B-1348 Louvain-la-Neuve (Belgium)

    2011-10-28

    Hole electrical transport in a p-doped nanochannel defined between two L-shape etched trenches made on a silicon-on-insulator substrate is investigated using a TCAD-Medici simulator. We study the impact of the etched trenches' geometry and dielectric filling materials on the current-voltage characteristics of the device. Carrier accumulation on frontiers defined by the trenches causes a modulation of the hole density inside the conduction channel as the bias voltage varies and this gives rise to a diode-like characteristic. For a 1.2 {mu}m-long channel, plots of the electric field distribution show that a nonlinear transport regime is reached at a moderate reverse and forward bias of {+-} 2 V. Plots of the carrier velocity along the conduction channel show that holes remain hot for a few hundreds of nm outside the nanometre-wide channel, at a bias of {+-} 10 V. Filling the etched trenches with a high-{kappa} dielectric material gives rise to a lower threshold voltage, V{sub th}. A similar decrease of V{sub th} is also achieved by reducing the longitudinal and/or the transverse trench width. Our simulation results provide useful design guidelines for future integrated self-switching-diode-based circuits.

  13. High-responsivity vertical-illumination Si/Ge uni-traveling-carrier photodiodes based on silicon-on-insulator substrate

    CERN Document Server

    Li, Chong; Liu, Zhi; Cong, Hui; Cheng, Buwen; Guo, Xia; Liu, Wuming

    2015-01-01

    Si/Ge uni-traveling carrier photodiodes exhibit higher output current when space-charge effects are overcome and thermal effects are suppressed, which is highly beneficial for increasing the dynamic range of various microwave photonic systems and simplifying high-bit-rate digital receivers in different applications. From the point of view of packaging, detectors with vertical-illumination configuration can be easily handled by pick-and-place tools and are a popular choice for making photo-receiver modules. However, vertical-illumination Si/Ge uni-traveling carrier (UTC) devices suffer from inter-constraint between high speed and high responsivity. Here, we report a high responsivity vertical-illumination Si/Ge UTC photodiode based on a silicon-on-insulator substrate. The maximum absorption efficiency of the devices was 2.4 times greater than the silicon substrate owing to constructive interference. The Si/Ge UTC photodiode was successfully fabricated and had a dominant responsivity at 1550 nm of 0.18 A/W, a 5...

  14. Manipulation of the coherent spatial and angular shifts of Goos-Hänchen effect to realize the digital optical switch in silicon-on-insulator waveguide corner

    Science.gov (United States)

    Sun, DeGui

    2016-11-01

    In this work, based on the quantum process of the Goos-Hänchen (GH) spatial shift, a quantum process of the GH angular shift is also theoretically investigated. Then, the coherence between spatial and angular shifts in the GH effect is discovered and developed to manipulate the final total displacement for a digital optical switch. It is found that a waveguide corner structure always makes the reflected guide-mode have a GH angular shift in the minus direction when the incident beam is in the Brewster angle vicinity, while it always makes the spatial shift in the plus direction. Meanwhile, the coherence of these two GH shifts has an interesting distribution with the incident angle, and only in the common linear response area to the incident angle, the two GH shifts are mutually enhancing, and then a mini refractive index modulation of the guided-mode at the reflecting interface can create a great stable jump of reflected beam displacement at an eigenstate under the GH effect. As a result, on the 220 nm CMOS-compatible silicon-on-insulator waveguide platform, with a tapered multimode interference (MMI) waveguide, a 5 × 1018cm-3 concentration variation of free carriers can create an absolute digital total displacement of 8-25 μm of the reflected beam on the MMI waveguide output end, leading to a 1 × 5 scale digital optical switching function.

  15. Compact silicon-on-insulator-based 2 × 2 Mach-Zehnder interferometer electro-optic switch with low crosstalk

    Institute of Scientific and Technical Information of China (English)

    Jiejiang Xing; Zhiyong Li; Peiji Zhou; Yuanhao Gong; Yude Yu; Manqing Tan; Jinzhong Yu

    2015-01-01

    We report a compact 2 × 2 Mach-Zehnder interferometer (MZI) electro-optic switch fabricated on a siliconon-insulator using standard complementary metal-oxide semiconductor (CMOS) processes.With a short modulation arm length of 200 μm,the crosstalk is reduced to-22 dB by the new modulation scheme of push-pull modulation with a pre-biased π/2 phase shift.The new modulation scheme can also work with a fast switching time of about 5.4 ns.

  16. Determination of thickness and density of a wet multilayer polymer system with sub-nanometer resolution by means of a dual polarization silicon-on-insulator microring

    Science.gov (United States)

    Hoste, J.-W.; De Geest, Bruno G.; Bienstman, Peter

    2015-03-01

    Determination of both thickness and refractive index of a thin biomolecular or polymer layer in wet conditions is a task not easily performed. Available tools such as XPS, AFM, ellipsometry and integrated photonic sensors often have difficulties with the native wet condition of said agents-under-test, perform poorly in the sub-5 nm regime or do not determine both characteristics in an absolute simultaneous way. The thickness of a multilayer system is often determined by averaging over a large amount of layers, obscuring details of the individual layers. Even more, the interesting behavior of the first bound layers can be covered in noise or assumptions might be made on either thickness or refractive index in order to determine the other. To demonstrate a solution to these problems, a silicon-on-insulator (SOI) microring is used to study the adsorption of a bilayer polymer system on the silicon surface of the ring. To achieve this, the microring is simultaneously excited with TE and TM polarized light and by tracking the shifts of both resonant wavelengths, the refractive index and the thickness of the adsorbed layer can be determined with a resolution on thickness smaller than 0.1 nm and a resolution on refractive index smaller than 0.01 RIU. An adhesive polyethyleneimine (PEI) layer is adsorbed to the surface, followed by the adsorption of poly(sodium-4-styrene sulfonate) (PSS) and poly(allylamine) hydrochloride (PAH). This high-resolution performance in wet conditions with the added benefits of the SOI microring platform such as low cost and multiplexibility make for a powerful tool to analyze thin layer systems, which is promising to research binding conformation of proteins as well.

  17. On-chip interrogation of a silicon-on-insulator microring resonator-based ethanol vapor sensor with an arrayed waveguide grating (AWG) spectrometer

    Science.gov (United States)

    Yebo, Nebiyu A.; Bogaerts, Wim; Hens, Zeger; Baets, Roel

    2012-01-01

    Silicon -on -insulator (SOI) optical microring resonators fabricated with the standard CMOS fabrication technology have recently gained considerable attention for energy efficient, compact and low cost biomedical and environmental sensing applications. High sensitivity to the surrounding refractive index variations, high compactness, direct wavelength multiplexing capabilities, simplicity, and the promise for mass fabrication are among the interesting features supported by SOI microring resonators. On the other hand, despite the strong case for microring resonators for sensing, there exist some issues which need to be addressed in order to ensure the feasibility of such sensors. One major limitation currently is the cost of optical sources and /or spectrum analyzers required to drive and interrogate these sensors. Either expensive light sources or spectrum analyzers are usually used with sensors built around microring resonators. An attractive approach to address this problem is the use of on-chip spectrometers along with cheap broadband light sources. We experimentally demonstrate on-chip interrogation of an SOI microring resonator based gas sensor with a compact Arrayed Waveguide Grating (AWG) spectrometer. We have designed and fabricated a 200GHz AWG with strongly overlapping output channels, and used it to interrogate the wavelength shift from a ring resonator based ethanol vapor sensor on the same chip. Ethanol vapor concentrations in 100-1000ppm range are readily detected by monitoring the intensity ratio between two adjacent AWG channels to which the microring resonance overlaps. Such an integrated sensor-interrogator approach is presented as an alternative to the current costly and off-chip read-out systems used for ring resonator based sensors.

  18. A proposal for digital electro-optic switches with free-carrier dispersion effect and Goos-Hanchen shift in silicon-on-insulator waveguide corner mirror

    Science.gov (United States)

    Sun, DeGui

    2013-09-01

    In a silicon-on-insulator (SOI) waveguide corner mirror (WCM) structure, with the quantum process of a frustrated total internal reflection (FTIR) phenomenon and the time delay principle in the two-dimensional potential barrier tunneling process of a mass of particles, we derive an accurate physical model for the Goos-Hanchen (GH) shift of optical guided-mode in the FTIR process, and in principle match the GH shift jumping states with the independent guided-modes. Then, we propose and demonstrate a new regime of 1 × N digital optical switches with a matching state between the free-carrier dispersion (FCD) based refractive index modulation (RIM) of silicon to create a GH shift jumping function of a photonic signal at the reflecting interface and the independent guided-modes in the FTIR process, where a MOS-capacitor type electro-optic modulation regime is proposed and discussed to realize an effective FCD-based RIM. At the critical matching state, i.e., the incident of an optical beam is at the vicinity of Brewster angle in the WCM, a mini-change of refractive index of waveguide material can cause a great jump of GH shift along the FTIR reflecting interface, and further a 1 × N digital optical switching process could be realized. For a 350-500 nm single-mode rib waveguide made on the 220 nm CMOS-compatible SOI substrate and with the FCD effect based RIM of silicon crystal, a concentration variation of 1018-1019 cm-3 has caused a 0.5-2.5 μm GH shift of reflected beam, which is at 2-5 times of a mode-size and hence radically convinces an optical switching function with a 1 × 3-1 × 10 scale.

  19. Electrical performance of silicon-on-insulator field-effect transistors with multiple top-gate organic layers in electrolyte solution.

    Science.gov (United States)

    Khamaisi, Bassam; Vaknin, Oshri; Shaya, Oren; Ashkenasy, Nurit

    2010-08-24

    The utilization of field-effect transistor (FET) devices in biosensing applications have been extensively studied in recent years. Qualitative and quantitative understanding of the contribution of the organic layers constructed on the device gate, and the electrolyte media, on the behavior of the device is thus crucial. In this work we analyze the contribution of different organic layers on the pH sensitivity, threshold voltage, and gain of a silicon-on-insulator based FET device. We further monitor how these properties change as function of the electrolyte screening length. Our results show that in addition to electrostatic effects, changes in the amphoteric nature of the surface also affect the device threshold voltage. These effects were found to be additive for the first (3-aminopropyl)trimethoxysilane linker layer and second biotin receptor layer. For the top streptavidin protein layer, these two effects cancel each other. The number and nature of amphoteric groups on the surface, which changes upon the formation of the layers, was shown also to affect the pH sensitivity of the device. The pH sensitivity reduces with the construction of the first two layers. However, after the formation of the streptavidin protein layer, the protein's multiple charged side chains induce an increase in the sensitivity at low ionic strengths. Furthermore, the organic layers were found to influence the device gain due to their dielectric properties, reducing the gain with the successive construction of each layer. These results demonstrate the multilevel influence of organic layers on the behavior of the FET devices.

  20. 基于绝缘体上硅的一种改进的Mach-Zehnder声光调制器∗%An improved Mach-Zehnder acousto-optic mo dulator on a silicon-on-insulator platform

    Institute of Scientific and Technical Information of China (English)

    秦晨; 余辉; 叶乔波; 卫欢; 江晓清

    2016-01-01

    The interdigital transducer (IDT) of the traditional Mach-Zehnder (MZ) acousto-optic modulator on a silicon-on-insulator (SOI) platform is located outside its two arms. The crest and trough of the surface acoustic wave (SAW) are used to modulate the two arms of the MZ interferometer so as to achieve a high modulation efficiency. Therefore, the distance between the two arms must be odd multiples of half acoustic wavelength. However, since the substrate is usually not uniform, the wavelength of the SAW changes as it transmits through the surface of the device. As a result, the exact distance between the two arms is difficult to choose. On the other hand, the SAW losses a portion of energy after passing through the first arm of the MZ interferometer, so the modulation of the second arm becomes much weaker. To solve these problems, we propose a new structure where its IDT is situated in the middle of the two arms of the MZ interferometer. With this scheme, the two arms of the MZ interferometer are located exactly at the crest and the trough of the SAW, while they are modulated with equal strength. In this paper, we first use the finite element method to simulate the acoustic frequency and the surface displacement of the excited SAW. Then we deduce the refractive index variations of all layers according to their acousto-optic effects. After that, we analyze the influences of different factors on the acousto-optic modulation efficiency, including the type and size of waveguide, the thickness of zinc oxide (ZnO) layer, and the area it covers, the number of electrodes, etc. These parameters are accordingly optimized to enhance the modulation efficiency. Modeling result based on COMSOL Multiphysics indicates that when the width of the strip waveguide is 6 µm, the ZnO layer covers only the area under the IDT and has a thickness of 2.2 µm, and the number of the electrodes is 50, the effective refractive index variation of the waveguide reaches 4.08 × 10−4 provided that

  1. Numerical analysis of the self-heating effect in SGOI with a double step buried oxide

    Energy Technology Data Exchange (ETDEWEB)

    Li Bin; Liu Hongxia; Li Jin; Yuan Bo; Cao Lei, E-mail: 13389232181@189.cn [Key Laboratory for Wide Band Gap Semiconductor Materials and Devices of Education, School of Microelectronics, Xidian University, Xi' an 710071 (China)

    2011-03-15

    To reduce the self-heating effect of strained Si grown on relaxed SiGe-on-insulator (SGOI) n-type metal-oxide-semiconductor field-effect transistors (nMOSFETs), this paper proposes a novel device called double step buried oxide (BOX) SGOI, investigates its electrical and thermal characteristics, and analyzes the effect of self-heating on its electrical parameters. During the simulation of the device, a low field mobility model for strained Si MOSFETs is established and reduced thermal conductivity resulting from phonon boundary scattering is considered. A comparative study of SGOI nMOSFETs with different BOX thicknesses under channel and different channel strains has been performed. By reducing moderately the BOX thickness under the channel, the channel temperature caused by the self-heating effect can be effectively reduced. Moreover, mobility degradation, off state current and a short-channel effect such as drain induced barrier lowering can be well suppressed. Therefore, SGOI MOSFETs with a thinner BOX under the channel can improve the overall performance and long-term reliability efficiently. (semiconductor devices)

  2. Numerical analysis of the self-heating effect in SGOI with a double step buried oxide

    Institute of Scientific and Technical Information of China (English)

    Li Bin; Liu Hongxia; Li Jin; Yuan Bo; Cao Lei

    2011-01-01

    To reduce the self-heating effect of strained Si grown on relaxed SiGe-on-insulator (SGOI) n-type metal-oxide-semiconductor field-effect transistors (nMOSFETs),this paper proposes a novel device called double step buried oxide (BOX) SGOI,investigates its electrical and thermal characteristics,and analyzes the effect of self-heating on its electrical parameters.During the simulation of the device,a low field mobility model for strained Si MOSFETs is established and reduced thermal conductivity resulting from phonon boundary scattering is considered.A comparative study of SGOI nMOSFETs with different BOX thicknesses under channel and different channel strains has been performed.By reducing moderately the BOX thickness under the channel,the channel temperature caused by the self-heating effect can be effectively reduced.Moreover,mobility degradation,off state current and a short-channel effect such as drain induced barrier lowering can be well suppressed.Therefore,SGOI MOSFETs with a thinner BOX under the channel can improve the overall performance and long-term reliability efficiently.

  3. Computer simulation for the formation of the insulator layer of silicon-on-insulator devices by N sup + and O sup + Co-implantation

    CERN Document Server

    Lin Qing; Xie Xin Yun; Lin Chenglu; Liu Xiang Hua

    2002-01-01

    A buried sandwiched layer consisting of silicon dioxide (upper part), silicon oxynitride (medium part) and silicon nitride (lower part) is formed by N sup + and O sup + co-implantation in silicon wafers at a constant temperature of 550 degree C. The microstructure is performed by cross-sectional transmission electron microscopy. To predict the quality of the buried sandwiched layer, the authors study the computer simulation for the formation of the SIMON (separated by implantation of oxygen and nitrogen) structure. The simulation program for SIMOX (separated by implantation of oxygen) is improved in order to be applied in O sup + and N sup + co-implantation on the basis of different formation mechanism between SIMOX and SIMNI (separated by implantation of nitrogen) structures. There is a good agreement between experiment and simulation results verifying the theoretical model and presumption in the program

  4. A 94GHz Temperature Compensated Low Noise Amplifier in 45nm Silicon-on-Insulator Complementary Metal-Oxide Semiconductor (SOI CMOS)

    Science.gov (United States)

    2014-01-01

    discovering techniques to build wide temperature range electronics for millimeter wave imaging applications. Realization of this plan has resulted in a...State Circuits. 41.12 (December 2006): 2992-2997. 8. De Vida , G., and G. Iannaccone. “An Ultra-Low Power, Temperature Compensated Voltage

  5. Analysis of Impact of Thermo Optical Effect on a 2×2 Electro-optical Switch in Silicon-on-insulators%SOI电光开关中热光效应分析

    Institute of Scientific and Technical Information of China (English)

    严清峰; 余金中

    2003-01-01

    分析了SOI (silicon-on-insulator)2×2电光开关工作时热光效应对等离子色散效应的影响.采用二维半导体器件模拟器PISCES-Ⅱ对器件进行了模块.结果表明,热光效应对等离子色散效应的影响与调制区长度密切相关,当调制区长度较短时,热光效应的影响不容忽视;当调制区长度大于500 μm时,这种影响可以忽略不计.

  6. VACUUM ULTRAVIOLET PHOTON-STIMULATED OXIDATION OF BURIED ICE: GRAPHITE GRAIN INTERFACES

    Energy Technology Data Exchange (ETDEWEB)

    Shi, J.; Grieves, G. A.; Orlando, T. M., E-mail: Thomas.Orlando@chemistry.gatech.edu [School of Chemistry and Biochemistry Georgia Institute of Technology, Atlanta, GA 30332-0400 (United States)

    2015-05-01

    The vacuum ultraviolet (VUV) synthesis of CO and CO{sub 2} on ice-coated graphite and isotopic labeled {sup 13}C graphite has been examined for temperatures between 40 and 120 K. The results show that CO and CO{sub 2} can be formed at the buried ice:graphite interface with Lyα photon irradiation via the reaction of radicals (O and OH) produced by direct photodissociation and the dissociative electron attachment of the interfacial water molecules. The synthesized CO and CO{sub 2} molecules can desorb in hot photon-dominated regions and are lost to space when ice coated carbonaceous dust grains cycle within the protoplanetary disks. Thus, the nonthermal formation of CO and CO{sub 2} at the buried ice:grain interface by VUV photons may help regulate the carbon inventory during the early stage of planet formation. This may contribute to the carbon deficits in our solar system and suggests that a universal carbon deficit gradient may be expected within astrophysical bodies surrounding center stars.

  7. Involvement of nitric oxide in anticompulsive-like effect of agmatine on marble-burying behaviour in mice.

    Science.gov (United States)

    Gawali, Nitin B; Chowdhury, Amrita A; Kothavade, Pankaj S; Bulani, Vipin D; Nagmoti, Dnyaneshwar M; Juvekar, Archana R

    2016-01-01

    In view of the reports that nitric oxide modulates the neurotransmitters implicated in obsessive-compulsive disorder (OCD), patients with OCD exhibit higher plasma nitrate levels, and drugs useful in OCD influence nitric oxide. Agmatine is a polyamine and widely distributed in mammalian brain which interacts with nitrergic systems. Hence, the present study was carried out to understand the involvement of nitrergic systems in the anticompulsive-like effect of agmatine. We used marble-burying behaviour (MBB) of mice as the animal model of OCD, and nitric oxide levels in hippocampus (HC) and cortex homogenate were measured. Results revealed that, agmatine (20 and 40mg/kg, i.p) significantly inhibited the MBB. Intraperitoneal administration of nitric oxide enhancers viz. nitric oxide precursor - l-arginine (l-ARG) (400mg/kg and 800mg/kg) increased MBB as well as brain nitrites levels, whereas treatment with N(G)-nitro-l-arginine methyl ester (l-NAME) neuronal nitric oxide synthase inhibitor (30mg/kg and 50mg/kg, i.p.) and 7-nitroindazole (7-NI) (20mg/kg and 40mg/kg) attenuated MBB and nitrites levels in brain. Further, in combination studies, the anticompulsive-like effect of agmatine (20mg/kg, ip) was exacerbated by prior administration of l-ARG (400mg/kg) and conversely l-NAME (15mg/kg) or 7-NI (10.0mg/kg) attenuated OCD-like behaviour with HC and cortex changes in the levels of NO. None of the above treatment had any significant influence on locomotor activity. In conclusion, Agmatine is effective in ameliorating the compulsive-like behaviour in mice which appears to be related to nitric oxide in brain.

  8. Ratiometric, filter-free optical sensor based on a complementary metal oxide semiconductor buried double junction photodiode.

    Science.gov (United States)

    Yung, Ka Yi; Zhan, Zhiyong; Titus, Albert H; Baker, Gary A; Bright, Frank V

    2015-07-16

    We report a complementary metal oxide semiconductor integrated circuit (CMOS IC) with a buried double junction (BDJ) photodiode that (i) provides a real-time output signal that is related to the intensity ratio at two emission wavelengths and (ii) simultaneously eliminates the need for an optical filter to block Rayleigh scatter. We demonstrate the BDJ platform performance for gaseous NH3 and aqueous pH detection. We also compare the BDJ performance to parallel results obtained by using a slew scanned fluorimeter (SSF). The BDJ results are functionally equivalent to the SSF results without the need for any wavelength filtering or monochromators and the BDJ platform is not prone to errors associated with source intensity fluctuations or sensor signal drift.

  9. Improving breakdown voltage and self-heating effect for SiC LDMOS with double L-shaped buried oxide layers

    Science.gov (United States)

    Bao, Meng-tian; Wang, Ying

    2017-02-01

    In this paper, a SiC LDMOS with double L-shaped buried oxide layers (DL-SiC LDMOS) is investigated and simulated. The DL-SiC LDMOS consists of two L-shaped buried oxide layers and two SiC windows. Using 2-D numerical simulation software, Atlas, Silvaco TCAD, the breakdown voltage, and the self-heating effect are discussed. The double-L shaped buried oxide layers and SiC windows in the active area can introduce an additional electric field peak and make the electric field distribution more uniform in the drift region. In addition, the SiC windows, which connect the active area to the substrate, can facilitate heat dissipation and reduce the maximum lattice temperature of the device. Compared with the BODS structure, the DL-SiC LDMOS and BODS structures have the same device parameters, except of the buried oxide layers. The simulation results of DL-SiC LDMOS exhibits outstanding characteristics including an increase of the breakdown voltage by 32.6% to 1220 V, and a low maximum lattice temperature (535 K) at room temperature.

  10. Research on total-dose hardening for H-gate PD NMOSFET/SIMOX by ion implanting into buried oxide

    Institute of Scientific and Technical Information of China (English)

    QIAN Cong; ZHANG Zheng-Xuan; ZHANG Feng; LIN Cheng-Lu

    2008-01-01

    In this work,we investigate the back-gate I-V characteristics for two kinds of NMOSFET/SIMOX transistors with H gate structure fabricated on two different SOI wafers.A transistors are made on the wafer implanted with Si+ and then annealed in N2,and B transistors are made on the wafer without implantation and annealing.It is demonstrated experimentally that A transistors have much less back-gate threshold voltage shift AVth than B transistors under X-ray total dose irradiation.Subthreshold charge separation technique is employed to estimate the build-up of oxide charge and interface traps during irradiation,showing that the reduced △Vth for A transistors is mainly due to its less build-up of oxide charge than B transistors.Photoluminescence (PL) research indicates that Si implantation results in the formation of silicon nanocrystalline (nanocluster) whose size increases with the implant dose.This structure can trap electrons to compensate the positive charge build-up in the buried oxide during irradiation,and thus reduce the threshold voltage negative shift.

  11. Methods for precisely controlling the residual stress and temperature coefficient of the frequency of a MEMS resonator based on an AlN cavity silicon-on-insulator platform

    Science.gov (United States)

    Wang, Nan; Xu, Jinghui; Zhang, Xiaolin; Wu, Guoqiang; Zhu, Yao; Li, Wei; Gu, Yuandong

    2016-07-01

    In this paper, we report an experimentally verified numerical model developed for precisely predicting and controlling the initial bending of a multi-layer-stack composite cantilever structure which is caused by the residual stress of the individual constituting layers, as well as the cantilever’s thermal coefficient of frequency (TCF). The developed model is exemplified using a flexural-mode cantilever resonator according to the process flow of the aluminium nitride (AlN) cavity silicon-on-insulator (SOI) platform. The same AlN cavity SOI platform is also utilized to fabricate the exemplified cantilever, which is then used to experimentally verify the accuracy and consistency of the numerical model. The experimental results show a difference of less than 3.5% is observed in terms of the deflection at the tip of the cantilever as compared with the numerical model, demonstrating the accuracy of the developed numerical model and the feasibility to optimize the cantilever’s initial deflection and TCF simultaneously, achieving minimum values for both parameters at the same time.

  12. Effect of the technology of implanting nitrogen into buried oxide on the radiation hardness of the top gate oxide for partially depleted SOI PMOSFET

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhong-Shan; Liu Zhong-Li; Zhang Guo-Qiang; Li Ning; Fan Kai; Zhang En-Xia; Yi Wan-Bing; Chen Meng; Wang Xi

    2005-01-01

    The effect of implanting nitrogen into buried oxide on the top gate oxide hardness against total irradiation does has been investigated with three nitrogen implantation doses(8×1015,2×1016 and 1×1017cm -2) for partially depleted SOI PMOSFET.The experimental results reveal the trend of negative shift of the thershold voltages of the studied transistors with the incerase of nitrogen implantation dose before irradition. After the irradiation with a total dose of 5×105 rad (Si)under a positive gate voltage of 2V,the threshold voltage shift of the transistors corresponding to the nitrogen implantation dose 8×1015cm -2 is smaller than that of the transistors without implantation.However, when the implantation dose reaches 2×1016 and 1×1017cm-2, for the majority of the tested transistors,their top gate oxide was badly damaged due to irratiation. In addition, the radiation also causes damage to the body -drain junctions of thetransistors with the gate oxide damaged.All the results can be interpreted by tracing back to the nitrogen implantation damage to the crystal lattices in the top silicon.

  13. Chemical interaction at the buried silicon/zinc oxide thin-film solar cell interface as revealed by hard X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wimmer, M., E-mail: mark.wimmer@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Gerlach, D.; Wilks, R.G.; Scherf, S.; Félix, R. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Lupulescu, C. [Institute for Optics and Atomic Physics, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Ruske, F.; Schondelmaier, G.; Lips, K. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Hüpkes, J. [Institute for Energy Research, Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52425 Jülich (Germany); Gorgoi, M. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Eberhardt, W. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Institute for Optics and Atomic Physics, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Rech, B. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Bär, M., E-mail: marcus.baer@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Institut für Physik und Chemie, Brandenburgische Technische Universität Cottbus, Konrad-Wachsmann-Allee 1, 03046 Cottbus (Germany)

    2013-10-15

    Highlights: •We used HAXPES to identify chemical interactions at the buried silicon/aluminum-doped zinc oxide thin-film solar cell interface. •The results indicate a diffusion of zinc and aluminum into the silicon upon annealing procedures which are part of the solar cell processing. •The contamination of the silicon may be detrimental for the solar cell performance. -- Abstract: Hard X-ray photoelectron spectroscopy (HAXPES) is used to identify chemical interactions (such as elemental redistribution) at the buried silicon/aluminum-doped zinc oxide thin-film solar cell interface. Expanding our study of the interfacial oxidation of silicon upon its solid-phase crystallization (SPC), in which we found zinc oxide to be the source of oxygen, in this investigation we address chemical interaction processes involving zinc and aluminum. In particular, we observe an increase of zinc- and aluminum-related HAXPES signals after SPC of the deposited amorphous silicon thin films. Quantitative analysis suggests an elemental redistribution in the proximity of the silicon/aluminum-doped zinc oxide interface – more pronounced for aluminum than for zinc – as explanation. Based on these insights the complex chemical interface structure is discussed.

  14. 一种改进的2×2 SOI Mach-Zehnder热光开关%An Improvement on 2×2 Silicon-on-Insulator Mach-Zehnder Thermo-Optical

    Institute of Scientific and Technical Information of China (English)

    杨笛; 余金中; 陈少武

    2008-01-01

    本文设计并制作了基于强限制多模干涉耦合器的2×2 SOI马赫-曾德热光开关.这种光开关采用了深刻蚀结构的多模干涉耦合器和输入/输出波导,较大地提高了干涉耦合器的性能并减少了连接耦合损耗.同时,在调制臂区域采用浅刻蚀结构,保持其单模调制状态.深刻蚀多模干涉耦合器具有优越的特性,在实验中测得不均衡度只有0.03 dB,插入损耗-0.6 dB.基于这种耦合器的新型热光开关,其插入损耗为-6.8 dB,其中包括光纤-波导耦合损耗-4.3 dB,开关时间为6.8 μs.%An improved 2×2 silicon-on-insulator Mach-Zehnder thermo-optical switch is designed and fabricated, which is based on strongly guided multimode interference couplers and single-mode phase-shifting arms. The multimode interference couplers and input/output waveguides are deeply etched to improve coupler performances and coupler-waveguide coupling efficiencies. However, shallow etching is used in the phase-shifting arms to guarantee single-mode property. The strongly guided coupler presents an attractive uniformity about 0.03 dB and a low propagation loss of -0.6 dB. The 2×2 switch shows an insertion loss as low as -6.8 dB, where the fiber-waveguide coupling loss of -4.3 dB is included, and the response-time is measured as short as 6.8 μs, which are much better than our previous results.

  15. Investigation of AlN Thin Films as Buried Insulator in SOI Structure

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Self-heating effects in silicon-on-insulator (SOI) devices limit the applicability of SOI materials in electronics in cases where high power dissipation is expected. AlN film as a potential candidate for buried insulator material in SOI-structures is investigated. Ion-beam-enhanced deposition (IBED) is used to manufacture large area AlN films. SIMS measurements indicate the formation of AlN films. The characterization of the films reveals that the quality of the films strongly depends on the evaporation rate of Al. For the film with high quality deposited at 0.05nm/s, it has higher component of N, excellent dielectric property and a smoother surface with roughness RMS value of 0.13nm, and can be bonded directly at room temperature by the smart-cut process. SOI structure with the AlN film as buried insulator has formed successfully for the first time, which is confirmed by XTEM micrograph.

  16. Plasmonics in buried structures

    OpenAIRE

    Romero, I. T.; García de Abajo, Francisco Javier

    2009-01-01

    We describe plasmon propagation in silica-filled coupled nanovoids fully buried in gold. Propagation bands and band gaps are shown to be tunable through the degree of overlap and plasmon hybridization between contiguous voids. The effect of disorder and fabrication imperfections is thoroughly investigated. Our work explores a novel paradigm for plasmon photonics relying on plasmon modes in metal-buried structures, which can benefit from long propagation distances, cancelation of radiative los...

  17. Buried Craters of Utopia

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-365, 19 May 2003Beneath the northern plains of Mars are numerous buried meteor impact craters. One of the most heavily-cratered areas, although buried, occurs in Utopia Planitia, as shown in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image. The history of Mars is complex; impact craters provide a tool by which to understand some of that history. In this case, a very ancient, cratered surface was thinly-buried by younger material that is not cratered at all. This area is near 48.1oN, 228.2oW; less than 180 km (112 mi) west of the Viking 2 lander site. Sunlight illuminates the scene from the lower left.

  18. Plasmonics in buried structures.

    Science.gov (United States)

    Romero, I; García de Abajo, F J

    2009-10-12

    We describe plasmon propagation in silica-filled coupled nanovoids fully buried in gold. Propagation bands and band gaps are shown to be tunable through the degree of overlap and plasmon hybridization between contiguous voids. The effect of disorder and fabrication imperfections is thoroughly investigated. Our work explores a novel paradigm for plasmon photonics relying on plasmon modes in metal-buried structures, which can benefit from long propagation distances, cancelation of radiative losses, minimum crosstalk between neighboring waveguides, and maximum optical integration in three-dimensional arrangements.

  19. Integrated MMI Optical Couplers and Optical Switches in Silicon-on-Insulator Technology%采用绝缘体上的半导体技术制备集成的多模干涉型光耦合器和光开关

    Institute of Scientific and Technical Information of China (English)

    余金中; 魏红振; 严清峰; 夏金松; 张小峰

    2003-01-01

    在光学系统中,SOI(绝缘体上的半导体)上制备集成的MMI(多模干涉)型光耦合器已成为一种愈来愈引人注目的无源器件.由于Si和SiO2之间具有大的折射率差,在SOI波导中可以采用SiO2薄膜(<1.0μm)作限制层,这与超大规模集成电路工艺相兼容.描述了采用SOI技术制备集成的MMI型光耦合器和光开关的设计和制造结果.业已证实,2×2 MMI-MZI(多模干涉-麦赫-曾德干涉)型热光开关的开关时间小于20μs.%Integrated multimode interference (MMI) coupler based on silicon-on-insulator(SOI) has been becoming a kind of more and more attractive device in optical systems. SiO2thin cladding layers (<1.0 μm) can be usedin SOI waveguide due to the large index step be-tween Si and SiO2, making them compatible with VLSI technology. The design and fabrica-tion of MMI optical couplers and optical switches in SOI technology are presented in thepa-per. We demonstrated the switching time of 2 × 2 MMI-MZI thermo-optical switch is less than 20 μs:

  20. 异质栅单Halo沟道SOI中隐埋层对器件特性的影响%Impact of Buried Oxide Layer on Characteristics of Dual Material Gate SOI MOSFETs with Single Halo

    Institute of Scientific and Technical Information of China (English)

    黄玮; 钟传杰

    2011-01-01

    研究异质栅单Halo沟道SOI MOS器件的隐埋层中二维效应对器件特性,如电势分布、阈值电压等的影响,仿真结果表明,隐埋层中的二维效应会引起更明显的SCE及DIBL效应.在考虑隐埋层二维效应的基础上,提出了一个新的二维阈值电压模型,能较好地吻合二维器件数值模拟软件Medici的仿真结果.%In this paper, the study of the impact of the two-dimensional effects in a buried oxide layer on device characteristics is presented, such as potential distribution, and threshold voltage. The simulation results indicate that the short-channel effect and drain-induced barrier lowering effect become more serious due to the two-dimensional effect. With taking the two-dimensional effect in a buried oxide layer into account, a novel two-dimensional analytical model is proposed, and the calculated results are in good agreement with those from two-dimensional device simulator of Medici.

  1. Topology optimized design for silicon-on-insulator mode converter

    DEFF Research Database (Denmark)

    Frellsen, Louise Floor; Frandsen, Lars Hagedorn; Ding, Yunhong

    2015-01-01

    The field of photonic integrated circuits (PICs) has attracted interest in recent years as they allow high device density while requiring only low operating power. The possibility of exploiting mode division multiplexing (MDM) in future optical communication networks is being investigated...... as a potential method for supporting the constantly increasing internet traffic demand [1]. Mode converters are important components necessary to support on-chip processing of MDM signals and multiple approaches has been followed in realizing such devices [2], [3]. Topology optimization (TO) [4] is a powerful...

  2. Energetic, spatial, and momentum character of the electronic structure at a buried interface: The two-dimensional electron gas between two metal oxides

    Science.gov (United States)

    Nemšák, S.; Conti, G.; Gray, A. X.; Palsson, G. K.; Conlon, C.; Eiteneer, D.; Keqi, A.; Rattanachata, A.; Saw, A. Y.; Bostwick, A.; Moreschini, L.; Rotenberg, E.; Strocov, V. N.; Kobayashi, M.; Schmitt, T.; Stolte, W.; Ueda, S.; Kobayashi, K.; Gloskovskii, A.; Drube, W.; Jackson, C. A.; Moetakef, P.; Janotti, A.; Bjaalie, L.; Himmetoglu, B.; Van de Walle, C. G.; Borek, S.; Minar, J.; Braun, J.; Ebert, H.; Plucinski, L.; Kortright, J. B.; Schneider, C. M.; Balents, L.; de Groot, F. M. F.; Stemmer, S.; Fadley, C. S.

    2016-06-01

    The interfaces between two condensed phases often exhibit emergent physical properties that can lead to new physics and novel device applications and are the subject of intense study in many disciplines. We here apply experimental and theoretical techniques to the characterization of one such interesting interface system: the two-dimensional electron gas (2DEG) formed in multilayers consisting of SrTi O3 (STO) and GdTi O3 (GTO). This system has been the subject of multiple studies recently and shown to exhibit very high carrier charge densities and ferromagnetic effects, among other intriguing properties. We have studied a 2DEG-forming multilayer of the form [6unit cells (u .c .) STO /3 u .c .of GTO ] 20 using a unique array of photoemission techniques including soft and hard x-ray excitation, soft x-ray angle-resolved photoemission, core-level spectroscopy, resonant excitation, and standing-wave effects, as well as theoretical calculations of the electronic structure at several levels and of the actual photoemission process. Standing-wave measurements below and above a strong resonance have been exploited as a powerful method for studying the 2DEG depth distribution. We have thus characterized the spatial and momentum properties of this 2DEG in detail, determining via depth-distribution measurements that it is spread throughout the 6 u.c. layer of STO and measuring the momentum dispersion of its states. The experimental results are supported in several ways by theory, leading to a much more complete picture of the nature of this 2DEG and suggesting that oxygen vacancies are not the origin of it. Similar multitechnique photoemission studies of such states at buried interfaces, combined with comparable theory, will be a very fruitful future approach for exploring and modifying the fascinating world of buried-interface physics and chemistry.

  3. A Novel Nanoscale FDSOI MOSFET with Block-Oxide

    Directory of Open Access Journals (Sweden)

    Jyi-Tsong Lin

    2013-01-01

    Full Text Available We demonstrate improved device performance by applying oxide sidewall spacer technology to a block-oxide-enclosed Si body to create a fully depleted silicon-on-insulator (FDSOI nMOSFET, which overcomes the need for a uniform ultrathin silicon film. The presence of block-oxide along the sidewalls of the Si body significantly reduces the influence of drain bias over the channel. The proposed FDSOI structure therefore outperforms conventional FDSOI with regard to its drain-induced barrier lowering (DIBL, on/off current ratio, subthreshold swing, and threshold voltage rolloff. The new FDSOI structure is in fact shown to behave similarly to an ultrathin body (UTB SOI but without the associated disadvantages and technological challenges of the ultrathin film, because a thick Si body allows for reduced sensitivity to self-heating, thereby improving thermal stability.

  4. Quantitative Chemically-Specific Coherent Diffractive Imaging of Buried Interfaces using a Tabletop EUV Nanoscope

    CERN Document Server

    Shanblatt, Elisabeth R; Gardner, Dennis F; Mancini, Giulia F; Karl, Robert M; Tanksalvala, Michael D; Bevis, Charles S; Vartanian, Victor H; Kapteyn, Henry C; Adams, Daniel E; Murnane, Margaret M

    2016-01-01

    Characterizing buried layers and interfaces is critical for a host of applications in nanoscience and nano-manufacturing. Here we demonstrate non-invasive, non-destructive imaging of buried interfaces using a tabletop, extreme ultraviolet (EUV), coherent diffractive imaging (CDI) nanoscope. Copper nanostructures inlaid in SiO2 are coated with 100 nm of aluminum, which is opaque to visible light and thick enough that neither optical microscopy nor atomic force microscopy can image the buried interfaces. Short wavelength (29 nm) high harmonic light can penetrate the aluminum layer, yielding high-contrast images of the buried structures. Moreover, differences in the absolute reflectivity of the interfaces before and after coating reveal the formation of interstitial diffusion and oxidation layers at the Al-Cu and Al-SiO2 boundaries. Finally, we show that EUV CDI provides a unique capability for quantitative, chemically-specific imaging of buried structures, and the material evolution that occurs at these buried ...

  5. 47 CFR 32.2423 - Buried cable.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Buried cable. 32.2423 Section 32.2423... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2423 Buried cable. (a) This account shall include the original cost of buried cable as well as the cost of other material...

  6. Theory buried under heavy description

    Directory of Open Access Journals (Sweden)

    Vivian B. Martin Ph.D.

    2010-12-01

    Full Text Available In journalism when a reporter puts the main news or point of the story deep down in the text, we say she’s buried the lead, the lead being the main point of the story and usually the first paragraph. In Children in Genocide: extreme traumatization and affect regulation, psychoanalyst Suzanne Kaplan buries her theory. Her study of the after effects of trauma among Holocaust survivors who were children during their persecution and survivors of atrocities during the Rwandan atrocities of the 1990s, is filled with highly descriptive material from the many interviews that serve as data. An interesting grounded theory is peeking out from under all the disciplinary discourse and historical background one must read through to get to what grounded theory readers will consider the juicy parts: concepts on affect regulation in trauma survivors.

  7. BATATA: a buried muon hodoscope

    Science.gov (United States)

    Sánchez, F.; Supanitsky, A. D.; Medina-Tanco, G.; Paic, G.; Salazar, M. E. Patiño; D'Olivo, J. C.; Molina, R. Alfaro

    2009-04-01

    Muon hodoscopes have several applications, ranging from astrophysics to fundamental particle physics. In this work, we present a detector dedicated to the study, at ground level, of the main signals of cosmic-ray induced showers above 6 PeV. The whole detector is composed by a set of three parallel dual-layer scintillator planes buried at fix depths ranging from 120 g/cm2 to 600 g/cm2 and by a triangular array of water cerenkov detectors located nearby on ground.

  8. Explicit Compact Surface-Potential and Drain-Current Models for Generic Asymmetric Double-Gate Metal-Oxide-Semiconductor Field-Effect Transistors

    Science.gov (United States)

    Zhu, Zhaomin; Zhou, Xing; Chandrasekaran, Karthik; Rustagi, Subhash C.; See, Guan Huei

    2007-04-01

    In this paper, explicit surface potentials for undoped asymmetric-double-gate (a-DG) metal-oxide-semiconductor field-effect transistors (MOSFETs) suitable for compact model development are presented for the first time. The model is physically derived from Poisson’s equation in each region of operation and adopted in a unified regional approach. The proposed model is physically scalable with oxide/channel thicknesses and has been verified with generic implicit solutions for independent gate biases as well as for different gate/oxide materials. The model is extendable to silicon-on-insulator (SOI) and symmetric-DG (s-DG) MOSFETs. Finally, a continuous, explicit drain-current equation has been derived on the basis of the developed explicit surface-potential solutions.

  9. Transparent conducting oxide electro-optic modulators on silicon platforms: A comprehensive study based on the drift-diffusion semiconductor model

    Science.gov (United States)

    Sinatkas, Georgios; Pitilakis, Alexandros; Zografopoulos, Dimitrios C.; Beccherelli, Romeo; Kriezis, Emmanouil E.

    2017-01-01

    Electro-optic waveguide modulators exploiting the carrier-induced epsilon-near-zero effect in transparent conducting oxides are comprehensively studied and evaluated using a rigorous multi-physics modeling framework. The examined amplitude modulators integrate indium tin oxide with two representative examples of the silicon-on-insulator technology, the silicon-rib and silicon-slot platform, with the latter design exhibiting superior performance, featuring μm modulation lengths, switching speeds exceeding 100 GHz, and a sub-pJ per bit of energy consumption. The effect of free carriers is rigorously introduced by combining the drift-diffusion model for the description of the carrier dynamics with near-infrared carrier-dependent permittivity models, leading to a seamless and physically consistent integration of solid-state physics and Maxwell wave theory on a unified finite-element platform.

  10. Locating a buried earth penetrator

    Energy Technology Data Exchange (ETDEWEB)

    Caffey, T.W.H.

    1977-11-01

    The purpose of this work was to assist the recovery of a buried earth penetrator by locating the vertical projection of the penetator upon the surface within a horizontal radius error of one meter. The penetrator will carry a small coil which is driven by an alternating current to form a magnetic dipole. Five measurements of the magnetic field vector upon the surface of the earth are shown to be sufficient for determining not only the xyz-coordinates of the dipole, but also the orientation of the dipole axis. The theory, computation process, and field tests are comprehensively described. Results of 26 field tests with the dipole at 9 different combinations of location and orientation are given. Average radial and vertical location errors are 0.27 m and -0.05 m, respectively, while the mean errors in the tilt and orientation angles of the dipole axis are 3 degrees and 8 degrees, respectively. The results are applied to the design of a locating system for a Pershing II penetrator which contains a recessed, rear-mounted coil.

  11. Approaches of Buried Object Detection Technology

    Directory of Open Access Journals (Sweden)

    Nagashree R N

    2014-03-01

    Full Text Available This paper describes the different art of buried object detection technology and algorithms. This detection of buried object finds application in many areas, importantly in the Landmine detection which is of growing concern due to the danger of buried landmines to people’s lives, economic growth and development. This paper describes and analyzes different technology available. The approaches discussed are Electrical Impedance Tomography, X-ray backscatter, Infrared Systems, Acoustics/seismic systems; Neutron based Method and finally Ground-Penetrating Radar with two commonly available approaches: Least squares and SVD approach. Finally, the paper concludes highlighting the need to improve the way this information is processed and compared.

  12. Tabernaemontana divaricata leaves extract exacerbate burying behavior in mice

    Directory of Open Access Journals (Sweden)

    Raj Chanchal

    2015-06-01

    Full Text Available Objective: Tabernaemontana divaricata (TD from Apocynaceae family offers the traditional folklore medicinal benefits such as an anti-epileptic, anti-mania, brain tonic, and anti-oxidant. The aim of the present study was to evaluate the effect of ethanolic extract of TD leaves on burying behavior in mice. Materials and Methods:Mice were treated with oral administration (p.o. of ethanolic extract of TD (100, 200, and 300 mg/kg. Fluoxetine (FLX, a selective serotonin reuptake inhibitor was used as a reference drug. Obsessive-compulsive behavior was evaluated using marble-burying apparatus. Results:TD at doses of 100, 200, and 300 mg/kg dose-dependently inhibited the obsessive and compulsive behavior. The similar results were obtained from 5, 10, and 20 mg/kg of FLX. TD and FLX did not affect motor activity. Conclusion: The results indicated that TD and FLX produced similar inhibitory effects on marble-burying behavior.

  13. SOI metal-oxide-semiconductor field-effect transistor photon detector based on single-hole counting.

    Science.gov (United States)

    Du, Wei; Inokawa, Hiroshi; Satoh, Hiroaki; Ono, Atsushi

    2011-08-01

    In this Letter, a scaled-down silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET) is characterized as a photon detector, where photogenerated individual holes are trapped below the negatively biased gate and modulate stepwise the electron current flowing in the bottom channel induced by the positive substrate bias. The output waveforms exhibit clear separation of current levels corresponding to different numbers of trapped holes. Considering this capability of single-hole counting, a small dark count of less than 0.02 s(-1) at room temperature, and low operation voltage of 1 V, SOI MOSFET could be a unique photon-number-resolving detector if the small quantum efficiency were improved.

  14. American burying beetle site records : Valentine NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is specific site records of American burying beetle on Valentine Nationl Wildlife Refuge to date. It includes a map of site location. A discussion...

  15. Design of a 1200-V Thin-Silicon-Layer p-Channel SOI LDMOS Device

    Institute of Scientific and Technical Information of China (English)

    胡盛东; 张玲; 罗小蓉; 张波; 李肇基; 吴丽娟

    2011-01-01

    A 1200-V thin-silicon-layer p-channel silicon-on-insulator(SOI)lateral double-diffused metal-oxide-semiconductor (LDMOS)transistor is designed.The device named INI SO1 p-LDMOS is characterized by a series of equidistant high concentration n+ islands inserted at the interface of a top silicon layer and a buried oxide layer.Accumulation-mode holes,caused by the electric potential dispersion between the device surface and the substrate,are located in the spacing between two neighboring n+ islands,and greatly enhance the electric field of the buried oxide layer and therefore,effectively increase the device breakdown voltage.Based on a 2-μm-thick buried oxide layer and a 1.5-μm-thick top silicon layer,a breakdown voltage of 1224 V is obtained,resulting in the high electric field(608 V/μm)of the buried oxide layer.%A 1200-V thin-silicon-layer p-channel silicon-on-insulator (SOI) lateral double-diffused metal-oxide-semiconductor (LDMOS) transistor is designed. The device named INI SOI p-LDMOS is characterized by a series of equidistant high concentration n+ islands inserted at the interface of a top silicon layer and a buried oxide layer. Accumulation-mode holes, caused by the electric potential dispersion between the device surface and the substrate, are located in the spacing between two neighboring n+ islands, and greatly enhance the electric field of the buried oxide layer and therefore, effectively increase the device breakdown voltage. Based on a 2-[im-thick buried oxide layer and a 1.5-um-thick top silicon layer, a breakdown voltage of 1224 V is obtained, resulting in the high electric field (608 V/\\im) of the buried oxide layer.

  16. Effects of buried penis on the structure and function of corpus cavernosum in a rat model

    Institute of Scientific and Technical Information of China (English)

    CHENG Fan; YU Wei-min; XIA Yue; ZHANG Xiao-bin; YANG Si-xing; GE Ming-huan

    2010-01-01

    Background While the abnormal appearance of the concealed penis has been well recognized, the effect of buried penis on the structure and function of corpus cavernosum has not been well studied. To explore this issue, we established a rat model and evaluated the effect of buried penis on cavernosum weight, contents and ultrastructure of tissue, and nitric oxide synthase (NOS) activity.Methods Two hundred and ten rats were randomly divided into 3 equal cohorts for 2, 4 and 6 months study (groups A, B and C). Each group was randomly divided into buried group (n=40), control group (n=15), and normal group (n=15), respectively. Intra-purse-string suture of the root of the penis was used to establish the model. Macroscopic development was judged by measuring the weight of the corpus cavernosum. Masson's trichrome staining was performed for observing microstructure while a transmission electron microscope was used for observing ultrastructure. The NOS activity was detected by a NOS activity assay kit.Results Buried penis had no significant influence on the appearance and weight of the corpus cavemosum. Buried penis resulted in decreased smooth muscle content (P>0.05 in group A, and P0.05 in groups A and B, and P <0.05 in group C) compared with the normal and control groups. Ultrastructural abnormalities of corpus cavernosum were observed in the 6-month buried group. Moreover, there was decrease of NOS activity in groups B and C (P<0.05 in group B and P<0.01 in group C) when compared with the normal and control groups.Conclusion Buried penis affects the structure and function of corpus cavemosum in rats and the effect is positively correlated with the buried time, but there is no significant effect on the macroscopic development.

  17. Influence of a highly doped buried layer for HfInZnO thin-film transistors

    Science.gov (United States)

    Chong, Eugene; Lee, Sang Yeol

    2012-01-01

    Hafnium-indium-zinc oxide (HIZO) channel thin-film transistors (TFTs) have been reported with a 12 nm thick indium-zinc oxide (IZO)-buried layer. IZO-buried HIZO TFTs show excellent electrical characteristics and stabilities such as a high mobility (µFE) of ˜41.4 cm2 V-1 s-1 which is three times higher than that of conventional HIZO TFTs and significantly enhanced bias-temperature-induced stability. High mobility could be obtained since the current path is mainly formed on a highly conductive buried layer with a high carrier concentration over 1018 cm-3. Enhanced stability could be achieved mainly because the generation of the additional trap state was considerably reduced near the drain region due to a relatively short path since the current flows vertically from a highly conductive buried layer to a drain electrode through the HIZO channel via a relatively low carrier density region.

  18. A vertically integrated dynamic RAM-cell: Buried bit line memory cell with floating transfer layer

    NARCIS (Netherlands)

    Mouthaan, Ton; Vertregt, Maarten

    1986-01-01

    A charge injection device has been realized in which charge can be injected on to an MOS-capacitor from a buried layer via an isolated transfer layer. The cell is positioned vertically between word and bit line. LOCOS (local oxidation) is used to isolate the cells and (deep) ion implantation to real

  19. Buried Waste Integrated Demonstration stakeholder involvement model

    Energy Technology Data Exchange (ETDEWEB)

    Kaupanger, R.M.; Kostelnik, K.M.; Milam, L.M.

    1994-04-01

    The Buried Waste Integrated Demonstration (BWID) is a program funded by the US Department of Energy (DOE) Office of Technology Development. BWID supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that together form a comprehensive remediation system for the effective and efficient remediation of buried waste. Stakeholder participation in the DOE Environmental Management decision-making process is critical to remediation efforts. Appropriate mechanisms for communication with the public, private sector, regulators, elected officials, and others are being aggressively pursued by BWID to permit informed participation. This document summarizes public outreach efforts during FY-93 and presents a strategy for expanded stakeholder involvement during FY-94.

  20. Photoconductive multi-layer graphene photodetectors fabricated on etched silicon-on-insulator substratesr

    Science.gov (United States)

    Wang, Yu-Bing; Yin, Wei-Hong; Han, Qin; Yang, Xiao-Hong; Ye, Han; Lv, Qian-Qian; Yin, Dong-Dong

    2017-02-01

    Not Available Project supported by the National Key Research and Development Program of China (Grant No. 2016YFB0402404), the High-Tech Research and Development Program of China (Grant Nos. 2013AA031401, 2015AA016902, and 2015AA016904), and the National Natural Science Foundation of China (Grant Nos. 61674136, 61176053, 61274069, and 61435002).

  1. Performance improvement to silicon-on-insulator waveguide directional-coupler based devices

    Science.gov (United States)

    Sun, DeGui; Hasan, Imad; Abdul-Majid, Sawsan; Vandusen, Rob; Zheng, Qi; Hussien, Ali; Wang, Chunxia; Hu, Zhongming; Tarr, T. Garry; Hall, Trevor J.

    2010-10-01

    For the SOI-waveguide directional coupler (WDC), optical access loss (OAL) and polarization dependence (PD) are two critical performance specifications which seriously affect the adoptability and deployment of a device, including optical on-chip loss (OCL), polarization dependent loss (PDL) and extinction ratio of a 3dB-coupler based device. In this work, using a commercial software tool - FIMMPROP, the performance of an SOI-WDC is simulated. Simulations find that the curved waveguides for the turning sections of a 3dB WDC not only enlarge the footprint size, but also seriously deteriorate the device performance. For instance, the two curved waveguide sections of a WDC induce an unpredictably large change in the 3dB-coupling length, increase an OAL of 0.4-0.9dB, and seriously deteriorate the PD, and these performance changes radically depend on rib size. After a corner-turning mirror (CTM) structure is introduced to a 3dB SOI-WDC, the experiments show both the footprint length and 3dB-coupling length are unchanged, the OAL of the 3dB coupler is only 0.5dB which is close to the simulation value. Therefore, for a 3dB-coupler based Mach-Zehnder interference (MZI) structure, the OCL will be controlled to be <1.0dB in device design and will not depend on rib size.

  2. Structure Tuning of Line-Defect Waveguides Based on Silicon-on-Insulator Photonic Crystal Slabs

    Institute of Scientific and Technical Information of China (English)

    WANG Chun-Xia; XU Xing-Sheng; XIONG Gui-Guang; HU Hai-Yang; SONG Qian; DU Wei; CHEN Hong-Da

    2007-01-01

    We present fabrication and experimental measurement of a series of photonic crystal waveguides. The complete devices consist of an injector taper down from 3 μm into a triangular-lattice air-hole single-line-defect waveguide with lattice constant from 410nm to 470nm and normalized radius 0.31. We fabricate these devices on a siliconon-insulator substrate and characterize them using a tunable laser source over a wavelength range from 1510 nm to 1640nm. A sharp attenuation at photonic crystal waveguide mode edge is observed for most structures. The edge of guided band is shifted about 30nm with the 10nm increase of the lattice constant. We obtain high-efficiency light propagation and broad flat spectrum response of the photonic crystal waveguides.

  3. Mode conversion losses in silicon-on-insulator photonic wire based racetrack resonators.

    Science.gov (United States)

    Xia, Fengnian; Sekaric, Lidija; Vlasov, Yurii A

    2006-05-01

    Two complimentary types of SOI photonic wire based devices, the add/drop (A/D) filter using a racetrack resonator and the Mach-Zehnder interferometer with one arm consisting of an identical resonator in all-pass filter (APF) configuration, were fabricated and characterized in order to extract the optical properties of the resonators and predict the performance of the optical delay lines based on such resonators. We found that instead of well-known waveguide bending and propagation losses, mode conversion loss in the coupling region of such resonators dominates when the air gap between the racetrack resonator and access waveguide is smaller than 120nm. We also show that this additional loss significantly degrades the performance of the optical delay line containing cascaded resonators in APF configuration.

  4. Growth of carbon nanotubes on fully processed silicon-on-insulator CMOS substrates.

    Science.gov (United States)

    Haque, M Samiul; Ali, S Zeeshan; Guha, P K; Oei, S P; Park, J; Maeng, S; Teo, K B K; Udrea, F; Milne, W I

    2008-11-01

    This paper describes the growth of Carbon Nanotubes (CNTs) both aligned and non-aligned on fully processed CMOS substrates containing high temperature tungsten metallization. While the growth method has been demonstrated in fabricating CNT gas sensitive layers for high temperatures SOI CMOS sensors, it can be employed in a variety of applications which require the use of CNTs or other nanomaterials with CMOS electronics. In our experiments we have grown CNTs both on SOI CMOS substrates and SOI CMOS microhotplates (suspended on membranes formed by post-CMOS deep RIE etching). The fully processed SOI substrates contain CMOS devices and circuits and additionally, some wafers contained high current LDMOSFETs and bipolar structures such as Lateral Insulated Gate Bipolar Transistors. All these devices were used as test structures to investigate the effect of additional post-CMOS processing such as CNT growth, membrane formation, high temperature annealing, etc. Electrical characterisation of the devices with CNTs were performed along with SEM and Raman spectroscopy. The CNTs were grown both at low and high temperatures, the former being compatible with Aluminium metallization while the latter being possible through the use of the high temperature CMOS metallization (Tungsten). In both cases we have found that there is no change in the electrical behaviour of the CMOS devices, circuits or the high current devices. A slight degradation of the thermal performance of the CMOS microhotplates was observed due to the extra heat dissipation path created by the CNT layers, but this is expected as CNTs exhibit a high thermal conductance. In addition we also observed that in the case of high temperature CNT growth a slight degradation in the manufacturing yield was observed. This is especially the case where large area membranes with a diameter in excess of 500 microns are used.

  5. High-reflectivity high-contrast grating focusing reflector on silicon-on-insulator wafer

    Science.gov (United States)

    Fang, Wenjing; Huang, Yongqing; Duan, Xiaofeng; Liu, Kai; Fei, Jiarui; Ren, Xiaomin

    2016-11-01

    A high-contrast grating (HCG) focusing reflector providing phase front control of reflected light and high reflectivity is proposed and fabricated. Basic design rules to engineer this category of structures are given in detail. A 1550 nm TM polarized incident light of 11.86 mm in focal length and 0.8320 in reflectivity is obtained in experiment. The wavelength dependence of the fabricated HCGs from 1530 nm to 1580 nm is also tested. The test results show that the focal length is in the range of 11.81-12 mm, which is close to the designed focal length of 15 mm. The reflectivity is almost above 0.56 within a bandwidth of 50 nm. At a distance of 11.86 mm, the light is focused to a round spot with the highest concentration, which is much smaller than the size of the incident beam. The FWHM of the reflected light beam decreases to 120 nm, and the intensity increases to 1.18. Project supported by the National Natural Science Foundation of China (Grant Nos. 61274044, 61574019 and 61020106007), the National Basic Research Program of China (Grant No. 2010CB327600), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130005130001), the Natural Science Foundation of Beijing, China (Grant No. 4132069), the Key International Science and Technology Cooperation Project of China (Grant No. 2011RR000100), the 111 Project of China (Grant No. B07005), and the Program for Changjiang Scholars and Innovative Research Team in Universities of China (Grant No. IRT0609).

  6. Topology optimized mode multiplexing in silicon-on-insulator photonic wire waveguides

    DEFF Research Database (Denmark)

    Frellsen, Louise Floor; Ding, Yunhong; Sigmund, Ole;

    2016-01-01

    We design and experimentally verify a topology optimized low-loss and broadband two-mode (de-)multiplexer, which is (de-)multiplexing the fundamental and the first-order transverse-electric modes in a silicon photonic wire. The device has a footprint of 2.6 μm x 4.22 μm and exhibits a loss 14 dB ...

  7. Optical and thermal properties of periodic photonic structures on a silicon-on-insulator platform

    Science.gov (United States)

    Song, Weiwei

    Silicon photonics is the leading candidate to fulfill the high bandwidth requirement for the future communication networks. Periodic photonic structures, due to their fascinating properties including compact size, high efficiency, and ease of design, play an important role in photonic systems. In this dissertation, SOI-based one-dimensional and two-dimensional periodic photonic structures are studied. Low crosstalk, high density integration of bus waveguides is demonstrated by employing a novel waveguide array structure. Inspired by the low coupling strength shown by initial pair waveguide experiments, novel waveguide array structures are studied by generalizing the nearest-neighbor tight-bonding model. Based on the theory, waveguide arrays have been designed and fabricated. The waveguide arrays have been characterized to demonstrate high density bus waveguides with minimal crosstalk. Two-dimensional photonic crystal waveguide (PCW) structure was then investigated aiming at reducing the propagation loss. A general cross-sectional eigenmode orthogonality relation is first derived for a one dimensional periodic system. Assisted by this orthogonality, analytic formulas are obtained to describe the propagation loss in PCW structures. By introducing the radiation and backscattering loss factors alpha1 and alpha2, the total loss coefficient alpha can be written as alpha = alpha1ng + alpha2ng2 ( ng is the group index). It is analytically shown the backscattering loss generally dominates the radiation loss for ng>10. Combined with systematic simulations of loss dependences on key structure parameters, this analytic study helps identify promising strategies to reduce the slow light loss. The influence of the substrate on the performance of a thermo-optic tuning photonic crystal device was studied in the following section. The substrate-induced thermo-optic tuning is obtained as a function of key physical parameters, based on a semi-analytic theory that agrees well with numeric simulations. It is shown that for some devices, the substrate's contribution to the thermo-optic tuning can exceed 10% for a heater located in the waveguide core and much higher for some other configurations. The slow response of the substrate may also significantly slow down the overall response time of the device. Strategies of minimizing the substrate's influence are discussed.

  8. Raman amplification of Stokes pulse in ultra-small silicon on-insulator optical waveguide

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The stimulated Raman amplification of picosecond Stokes pulse is numerically investigated in ultra-small silicon-oninsulator optical waveguide. Numerical results show that we obtain the gain of up to 30-dB for weak Stokes pulse in the copropagation configuration for 10 mm Jength waveguide using high intensity pump optical pulse. The peak gain, pulse width, rise time, and fall time of Stokes pulse will experience the variation course of decaying then increasing with increasing waveguide length. The time delay of output Stokes pulse is controlled by adjusting the initial time delay of both pump and Stokes pulses.

  9. Novel Applications of a Thermally Tunable Bistable Buckling Silicon-on-Insulator (SOI) Microfabricated Membrane

    Science.gov (United States)

    2015-09-17

    friendship . Without his assistance, none of this would have been possible. Next, thank you to all my fellow MEMS group students, past and present. Having...55 IPA isopropyl alcohol ...reactive ion etching (DRIE). size of these scallops can be controlled by adjusting the process parameters. Scallop depth is most prominently affected

  10. Guided Acoustic and Optical Waves in Silicon-on-Insulator for Brillouin Scattering and Optomechanics

    Science.gov (United States)

    2016-08-01

    environment, they also isolate devices from heat-dissipating thermal linkages and on-chip electronics. The intuition of “index-guided” confinement of...coupling. Consider the optical guided modes for 100 nm wide fins spaced 40 nm apart in 340 nm thick silicon shown in Figure 2(b). For these

  11. Silicon-on-Insulator-Based Compact Optical Demultiplexer Employing Etched Diffraction Grating

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-Hui; TANG Yan-Zhe; WANG Yun-Xiang; QU Hong-Chang; WU Ya-Ming; LI Tie; YANG Jian-Yi; WANG Yue-Lin; LIU Ming

    2004-01-01

    A compact optical demultiplexer with etched diffraction grating (EDG) is designed and fabricated on a siliconon-insulator (SOI) material. Several 90° turning mirrors are used to bend the waveguides, and the size of the EDG-based demultiplexer is minimized to only 16 × 1.7mm2. The crosstalk is about -18 dB. The on-chip loss is about 18.2dB, which is composed of about 16.9dB excess loss and 1.3dB diffraction loss. Measures to improve the performance are discussed.

  12. Detection of Buried Objects : The MUD Project

    NARCIS (Netherlands)

    Quesson, B.A.J.; Vossen, R. van; Zampolli, M.; Beckers, A.L.D.

    2011-01-01

    The aim of the Mine Underwater Detection (MUD) project at TNO is to experimentally investigate the acoustic and magnetic detection of explosives underwater, buried in a soft sediment layer. This problem is relevant for the protection of harbors and littoral assets against terrorist attacks and for t

  13. Detection of buried mines with seismic sonar

    Science.gov (United States)

    Muir, Thomas G.; Baker, Steven R.; Gaghan, Frederick E.; Fitzpatrick, Sean M.; Hall, Patrick W.; Sheetz, Kraig E.; Guy, Jeremie

    2003-10-01

    Prior research on seismo-acoustic sonar for detection of buried targets [J. Acoust. Soc. Am. 103, 2333-2343 (1998)] has continued with examination of the target strengths of buried test targets as well as targets of interest, and has also examined detection and confirmatory classification of these, all using arrays of seismic sources and receivers as well as signal processing techniques to enhance target recognition. The target strengths of two test targets (one a steel gas bottle, the other an aluminum powder keg), buried in a sand beach, were examined as a function of internal mass load, to evaluate theory developed for seismic sonar target strength [J. Acoust. Soc. Am. 103, 2344-2353 (1998)]. The detection of buried naval and military targets of interest was achieved with an array of 7 shaker sources and 5, three-axis seismometers, at a range of 5 m. Vector polarization filtering was the main signal processing technique for detection. It capitalizes on the fact that the vertical and horizontal components in Rayleigh wave echoes are 90 deg out of phase, enabling complex variable processing to obtain the imaginary component of the signal power versus time, which is unique to Rayleigh waves. Gabor matrix processing of this signal component was the main technique used to determine whether the target was man-made or just a natural target in the environment. [Work sponsored by ONR.

  14. 7 CFR 1755.505 - Buried services.

    Science.gov (United States)

    2010-01-01

    ... and Drawings for Service Installations at Customer Access Locations. The wire used for buried services... has been reached by management to provide joint occupancy services, the services may be installed... (11) Experience indicates that there are objections from many owners of buildings covered...

  15. 47 CFR 32.6423 - Buried cable expense.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Buried cable expense. 32.6423 Section 32.6423... FOR TELECOMMUNICATIONS COMPANIES Instructions for Expense Accounts § 32.6423 Buried cable expense. (a) This account shall include expenses associated with buried cable. (b) Subsidiary record...

  16. Revealing the semiconductor–catalyst interface in buried platinum black silicon photocathodes

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Jeffery A.; Anderson, Nicholas C.; Neale, Nathan R.

    2016-01-01

    Nanoporous 'black' silicon semiconductors interfaced with buried platinum nanoparticle catalysts have exhibited stable activity for photoelectrochemical hydrogen evolution even after months of exposure to ambient conditions. The mechanism behind this stability has not been explained in detail, but is thought to involve a Pt/Si interface free from SiOx layer that would adversely affect interfacial charge transfer kinetics. In this paper, we resolve the chemical composition and structure of buried Pt/Si interfaces in black silicon photocathodes from a micron to sub-nanometer level using aberration corrected analytical scanning transmission electron microscopy. Through a controlled electrodeposition of copper on samples aged for one month in ambient conditions, we demonstrate that the main active catalytic sites are the buried Pt nanoparticles located below the 400-800 nm thick nanoporous SiOx layer. Though hydrogen production performance degrades over 100 h under photoelectrochemical operating conditions, this burying strategy preserves an atomically clean catalyst/Si interface free of oxide or other phases under air exposure and provides an example of a potential method for stabilizing silicon photoelectrodes from oxidative degradation in photoelectrochemical applications.

  17. A Monolithic active pixel sensor for ionizing radiation using a 180nm HV-SOI process

    OpenAIRE

    Hemperek, Tomasz; Kishishita, Tetsuichi; Krüger, Hans; Wermes, Norbert

    2014-01-01

    An improved SOI-MAPS (Silicon On Insulator Monolithic Active Pixel Sensor) for ionizing radiation based on thick-film High Voltage SOI technology (HV-SOI) has been developed. Similar to existing Fully Depleted SOI-based (FD-SOI) MAPS, a buried silicon oxide inter-dielectric (BOX) layer is used to separate the CMOS electronics from the handle wafer which is used as a depleted charge collection layer. FD-SOI MAPS suffer from radiation damage such as transistor threshold voltage shifts due to ch...

  18. Buried caldera of mauna kea volcano, hawaii.

    Science.gov (United States)

    Porter, S C

    1972-03-31

    An elliptical caldera (2.1 by 2.8 kilometers) at the summit of Mauna Kea volcano is inferred to lie buried beneath hawaiite lava flows and pyroclastic cones at an altitude of approximately 3850 meters. Stratigraphic relationships indicate that hawaiite eruptions began before a pre-Wisconsin period of ice-cap glaciation and that the crest of the mountain attained its present altitude and gross form during a glaciation of probable Early Wisconsin age.

  19. Multiple instance learning for buried hazard detection

    Science.gov (United States)

    Rice, Joseph; Pinar, Anthony; Havens, Timothy C.; Webb, Adam; Schulz, Timothy J.

    2016-05-01

    Buried explosives hazards are one of the many deadly threats facing our Soldiers, thus the U.S. Army is interested in the detection and neutralization of these hazards. One method of buried target detection uses forward-looking ground-penetrating radar (FLGPR), and it has grown in popularity due to its ability to detect buried targets at a standoff distance. FLGPR approaches often use machine learning techniques to improve the accuracy of detection. We investigate an approach to explosive hazard detection that exploits multi-instance features to discriminate between hazardous and non-hazardous returns in FLGPR data. One challenge this problem presents is a high number of clutter and non-target objects relative to the number of targets present. Our approach learns a bag of words model of the multi-instance signatures of potential targets and confuser objects in order to classify alarms as either targets or false alarms. We demonstrate our method on test data collected at a U.S. Army test site.

  20. Field application of innovative grouting agents for in situ stabilization of buried waste sites

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, G.G.; Farnsworth, R.K. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-12-31

    This paper presents field applications for two innovative grouting agents that were used to in situ stabilize buried waste sites, via jet grouting. The two grouting agents include paraffin and a proprietary iron oxide based cement grout called TECT. These materials were tested in specially designed cold test pits that simulate buried transuranic waste at the Idaho National Engineering Laboratory (INEL). The field demonstrations were performed at the INEL in an area referred to as the Cold Test Pit, which is adjacent to the INEL Radioactive Waste Management Complex (RWMC). At the RWMC, 56,000 m{sup 3} of transuranic (TRU) waste is co-mingled with over 170,000 m{sup 3} of soil in shallow land burial. Improving the confinement of this waste is one of the options for final disposition of this waste. Using jet-grouting technology to inject these materials into the pore spaces of buried waste sites results in the creation of buried monolithic waste forms that simultaneously protect the waste from subsidence, while eliminating the migratory potential of hazardous and radioactive contaminants in the waste.

  1. CMOS-compatible method for doping of buried vertical polysilicon structures by solid phase diffusion

    Science.gov (United States)

    Turkulets, Yury; Silber, Amir; Ripp, Alexander; Sokolovsky, Mark; Shalish, Ilan

    2016-03-01

    Polysilicon receives attention nowadays as a means to incorporate 3D-structured photonic devices into silicon processes. However, doping of buried layers of a typical 3D structure has been a challenge. We present a method for doping of buried polysilicon layers by solid phase diffusion. Using an underlying silicon oxide layer as a dopant source facilitates diffusion of dopants into the bottom side of the polysilicon layer. The polysilicon is grown on top of the oxide layer, after the latter has been doped by ion implantation. Post-growth heat treatment drives in the dopant from the oxide into the polysilicon. To model the process, we studied the diffusion of the two most common silicon dopants, boron (B) and phosphorus (P), using secondary ion mass spectroscopy profiles. Our results show that shallow concentration profiles can be achieved in a buried polysilicon layer using the proposed technique. We present a quantitative 3D model for the diffusion of B and P in polysilicon, which turns the proposed method into an engineerable technique.

  2. Virtual environmental applications for buried waste characterization technology evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    The project, Virtual Environment Applications for Buried Waste Characterization, was initiated in the Buried Waste Integrated Demonstration Program in fiscal year 1994. This project is a research and development effort that supports the remediation of buried waste by identifying and examining the issues, needs, and feasibility of creating virtual environments using available characterization and other data. This document describes the progress and results from this project during the past year.

  3. System and Method for Fabricating Super Conducting Circuitry on Both Sides of an Ultra-Thin Layer

    Science.gov (United States)

    Brown, Ari D. (Inventor); Mikula, Vilem (Inventor)

    2017-01-01

    A method of fabricating circuitry in a wafer includes depositing a superconducting metal on a silicon on insulator wafer having a handle wafer, coating the wafer with a sacrificial layer and bonding the wafer to a thermally oxide silicon wafer with a first epoxy. The method includes flipping the wafer, thinning the flipped wafer by removing a handle wafer, etching a buried oxide layer, depositing a superconducting layer, bonding the wafer to a thermally oxidized silicon wafer having a handle wafer using an epoxy, flipping the wafer again, thinning the flipped wafer, etching a buried oxide layer from the wafer and etching the sacrificial layer from the wafer. The result is a wafer having superconductive circuitry on both sides of an ultra-thin silicon layer.

  4. Landslide Buries Valley of the Geysers

    Science.gov (United States)

    2007-01-01

    Geysers are a rare natural phenomena found only in a few places, such as New Zealand, Iceland, the United States (Yellowstone National Park), and on Russia's far eastern Kamchatka Peninsula. On June 3, 2007, one of these rare geyser fields was severely damaged when a landslide rolled through Russia's Valley of the Geysers. The landslide--a mix of mud, melting snow, trees, and boulders--tore a scar on the land and buried a number of geysers, thermal pools, and waterfalls in the valley. It also blocked the Geyser River, causing a new thermal lake to pool upstream. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this infrared-enhanced image on June 11, 2007, a week after the slide. The image shows the valley, the landslide, and the new thermal lake. Even in mid-June, just days from the start of summer, the landscape is generally covered in snow, though the geologically heated valley is relatively snow free. The tree-covered hills are red (the color of vegetation in this false-color treatment), providing a strong contrast to the aquamarine water and the gray-brown slide. According to the Russian News and Information Agency (RIA) [English language], the slide left a path roughly a kilometer and a half (one mile) long and 200 meters (600 feet) wide. Within hours of the landslide, the water in the new lake inundated a number of additional geysers. The geysers directly buried under the landslide now lie under as much as 60 meters (180 feet) of material, according to RIA reports. It is unlikely that the geysers will be able to force a new opening through this thick layer, adds RIA. Among those directly buried is Pervenets (Firstborn), the first geyser found in the valley, in 1941. Other geysers, such as the Bolshoi (Greater) and Maly (Lesser) Geysers, were silenced when buried by water building up behind the new natural dam. According to Vladimir and Andrei Leonov of the Russian Federation Institute of

  5. A Buried Vertical Filter for Micro and Nanoparticle Filtration

    NARCIS (Netherlands)

    Li, S.J.; Shen, C.; Sarro, P.M.

    2011-01-01

    This paper presents a silicon micromachined filter for micro- and nanoparticles. The filter is vertical and completely buried beneath the surface. The buried aspect allows additional features to be integrated above the filter, while the vertical aspect allows the creation of highly uniform pores and

  6. Buried injector logic, a vertical IIL using deep ion implantation

    NARCIS (Netherlands)

    Mouthaan, A.J.

    1987-01-01

    A vertically integrated alternative for integrated injection logic has been realized, named buried injector logic (BIL). 1 MeV ion implantations are used to create buried layers. The vertical pnp and npn transistors have thin base regions and exhibit a limited charge accumulation if a gate is satura

  7. Including Arbitrary Antenna Patterns in Microwave Imaging of Buried Objects

    DEFF Research Database (Denmark)

    Meincke, Peter; Kim, Oleksiy S.; Lenler-Eriksen, Hans-Rudolph

    2004-01-01

    A linear inversion scheme for microwave imaging of buried objects is presented in which arbitrary antennas are accounted for through their plane-wave transmitting and receiving spectra......A linear inversion scheme for microwave imaging of buried objects is presented in which arbitrary antennas are accounted for through their plane-wave transmitting and receiving spectra...

  8. VIPMOS-A novel buried injector structure for EPROM applications

    NARCIS (Netherlands)

    Wijburg, Rutger C.; Hemink, Gertjan J.; Middelhoek, Jan; Wallinga, Hans; Mouthaan, Ton J.

    1991-01-01

    A buried injector is proposed as a source of electrons for substrate hot electrons injection. To enhance the compatibility with VLSI processing, the buried injector is formed by the local overlap of the n-well and p-well of a retrograde twin-well CMOS process. The injector is activated by means of p

  9. Diagenesis of shallowly buried cratonic sandstones, southwest Sinai, Egypt

    Science.gov (United States)

    Salem, Alaa M. K.; Abdel-Wahab, Antar; McBride, Earle F.

    1998-08-01

    In spite of their age, quartzose and feldspathic Lower Carboniferous sandstones deposited on the Arabian shield in western Sinai remain friable and porous (average of 19%, maximum of 25%) except for strongly cemented ferricretes and silcretes. These fluvial and shallow-marine sandstones were not buried more than 1.5 km until Late Cretaceous and younger time, when the deepest rocks reached 2.5 km. Owing to shallow burial depths and episodic exposure, meteoric water dominated the pore system for most of geologic time: iron oxides had multiple diagenetic stages and yield Carboniferous and Late Cretaceous paleomagnetic signatures, and oxygen isotopic data for authigenic quartz, sparry calcite, and kaolinite yield meteoric signatures. The most significant diagenetic changes were: (1) cementation by iron oxide that locally reaches 40% in groundwater ferricretes; (2) reduction in porosity to 19% from an assumed original porosity 45% (19% porosity was lost by compaction and 7% by cementation); (3) generation of diagenetic quartzarenites by the loss of 7% detrital feldspar by kaolinization and dissolution; and (4) development of three thin mature silcretes apparently by thermal groundwaters. Some outcrop samples have halite and gypsum cements of young but uncertain origin: recycled from topographically higher younger rocks or from aerosols? Mature silcretes are strongly cemented by microcrystalline quartz, multiply zoned syntaxial quartz, and, originally, minor opal. Quartz overgrowths in most sandstones average only 2.2%, but display a variety of textures and in places overprint isopachous opal (now dissolved) grain coats. These features have more in common with incipient silcrete cement than normal burial quartz cement. Most silica was imported in groundwater.

  10. Compact Buried Ducts in a Hot-Humid Climate House

    Energy Technology Data Exchange (ETDEWEB)

    Mallay, Dave [Home Innovation Research Labs, Upper Marlboro, MD (United States)

    2016-01-07

    "9A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval. The primary research question with buried ducts is potential condensation at the outer jacket of the duct insulation in humid climates during the cooling season. Current best practices for buried ducts rely on encapsulating the insulated ducts with closed-cell spray polyurethane foam insulation to control condensation and improve air sealing. The encapsulated buried duct concept has been analyzed and shown to be effective in hot-humid climates. The purpose of this project is to develop an alternative buried duct system that performs effectively as ducts in conditioned space - durable, energy efficient, and cost-effective - in a hot-humid climate (IECC warm-humid climate zone 3A) with three goals that distinguish this project: 1) Evaluation of design criteria for buried ducts that use common materials and do not rely on encapsulation using spray foam or disrupt traditional work sequences; 2) Establishing design criteria for compact ducts and incorporate those with the buried duct criteria to further reduce energy losses and control installed costs; 3) Developing HVAC design guidance for performing accurate heating and cooling load calculations for compact buried ducts.

  11. Buried plastic scintillator muon telescope (BATATA)

    Energy Technology Data Exchange (ETDEWEB)

    Alfaro, R. [Inst. de Fisica, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); De Donato, C.; D' Olivo, J.C.; Guzman, A.; Medina-Tanco, G. [Inst. de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); Moreno Barbosa, E. [Fac. de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico); Paic, G.; Patino Salazar, E. [Inst. de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); Salazar Ibarguen, H. [Fac. de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico); Sanchez, F.A., E-mail: federico.sanchez@nucleares.unam.m [Inst. de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); Supanitsky, A.D. [Inst. de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); Valdes-Galicia, J.F. [Inst. de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico, D.F., C.P. 04510 (Mexico); Vargas Trevino, A.D.; Vergara Limon, S. [Fac. de Ciencias de la Electronica, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico); Villasenor, L.M. [Inst. de Fisica y Matematicas, Universidad Michoacana de San Nicolas Hidalgo Morelia (Mexico); Observatorio Pierre Auger, Av. San Martin Norte 304 (5613) Malarguee, Prov. Mendoza (Argentina)

    2010-05-21

    Muon telescopes have multiple applications in the area of cosmic ray research. We are currently building such a detector with the objective of comparing the ground penetration of muon vs. electron-gamma signals originated in cosmic ray showers. The detector is composed by a set of three parallel dual-layer scintillator planes, buried at fixed depths ranging from 120 to 600g/cm{sup 2}. Each layer is 4m{sup 2} and is composed by 49 rectangular strips of 4cmx2m, oriented at a 90{sup 0} angle with respect to its companion layer, which gives an xy-coincidence pixel of 4x4cm{sup 2}. The scintillators are MINOS extruded polystyrene strips, with an embedded Bicron BC92 wavelength shifting (WLS) fibers, of 1.5 mm in diameter. Light is collected by Hamamatsu H7546B multi-anode PMTs of 64 pixels. The front-end (FE) electronics works in counting mode and signals are transmitted to the surface DAQ stage using low-voltage differential signaling (LVDS). Any strip signal above threshold opens a GPS-tagged 2{mu}s data collection window. Data, including signal and background, are acquired by a system of FPGA (Spartan 2E) boards and a single-board computer (TS7800).

  12. Buried plastic scintillator muon telescope (BATATA)

    Science.gov (United States)

    Alfaro, R.; de Donato, C.; D'Olivo, J. C.; Guzmán, A.; Medina-Tanco, G.; Moreno Barbosa, E.; Paic, G.; Patiño Salazar, E.; Salazar Ibarguen, H.; Sánchez, F. A.; Supanitsky, A. D.; Valdés-Galicia, J. F.; Vargas Treviño, A. D.; Vergara Limón, S.; Villaseñor, L. M.; Auger Collaboration

    2010-05-01

    Muon telescopes have multiple applications in the area of cosmic ray research. We are currently building such a detector with the objective of comparing the ground penetration of muon vs. electron-gamma signals originated in cosmic ray showers. The detector is composed by a set of three parallel dual-layer scintillator planes, buried at fixed depths ranging from 120 to 600g/cm2. Each layer is 4m2 and is composed by 49 rectangular strips of 4cm×2m, oriented at a 90∘ angle with respect to its companion layer, which gives an xy-coincidence pixel of 4×4cm2. The scintillators are MINOS extruded polystyrene strips, with an embedded Bicron BC92 wavelength shifting (WLS) fibers, of 1.5 mm in diameter. Light is collected by Hamamatsu H7546B multi-anode PMTs of 64 pixels. The front-end (FE) electronics works in counting mode and signals are transmitted to the surface DAQ stage using low-voltage differential signaling (LVDS). Any strip signal above threshold opens a GPS-tagged 2μs data collection window. Data, including signal and background, are acquired by a system of FPGA (Spartan 2E) boards and a single-board computer (TS7800).

  13. Buried waste containment system materials. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Weidner, J.R.; Shaw, P.G.

    1997-10-01

    This report describes the results of a test program to validate the application of a latex-modified cement formulation for use with the Buried Waste Containment System (BWCS) process during a proof of principle (POP) demonstration. The test program included three objectives. One objective was to validate the barrier material mix formulation to be used with the BWCS equipment. A basic mix formula for initial trials was supplied by the cement and latex vendors. The suitability of the material for BWCS application was verified by laboratory testing at the Idaho National Engineering and Environmental Laboratory (INEEL). A second objective was to determine if the POP BWCS material emplacement process adversely affected the barrier material properties. This objective was met by measuring and comparing properties of material prepared in the INEEL Materials Testing Laboratory (MTL) with identical properties of material produced by the BWCS field tests. These measurements included hydraulic conductivity to determine if the material met the US Environmental Protection Agency (EPA) requirements for barriers used for hazardous waste sites, petrographic analysis to allow an assessment of barrier material separation and segregation during emplacement, and a set of mechanical property tests typical of concrete characterization. The third objective was to measure the hydraulic properties of barrier material containing a stop-start joint to determine if such a feature would meet the EPA requirements for hazardous waste site barriers.

  14. Buried nanoantenna arrays: versatile antireflection coating.

    Science.gov (United States)

    Kabiri, Ali; Girgis, Emad; Capasso, Federico

    2013-01-01

    Reflection is usually a detrimental phenomenon in many applications such as flat-panel-displays, solar cells, photodetectors, infrared sensors, and lenses. Thus far, to control and suppress the reflection from a substrate, numerous techniques including dielectric interference coatings, surface texturing, adiabatic index matching, and scattering from plasmonic nanoparticles have been investigated. A new technique is demonstrated to manage and suppress reflection from lossless and lossy substrates. It provides a wider flexibility in design versus previous methods. Reflection from a surface can be suppressed over a narrowband, wideband, or multiband frequency range. The antireflection can be dependent or independent of the incident wave polarization. Moreover, antireflection at a very wide incidence angle can be attained. The reflection from a substrate is controlled by a buried nanoantenna array, a structure composed of (1) a subwavelength metallic array and (2) a dielectric cover layer referred to as a superstrate. The material properties and thickness of the superstrate and nanoantennas' geometry and periodicity control the phase and intensity of the wave circulating inside the superstrate cavity. A minimum reflectance of 0.02% is achieved in various experiments in the mid-infrared from a silicon substrate. The design can be integrated in straightforward way in optical devices. The proposed structure is a versatile AR coating to optically impedance matches any substrate to free space in selected any narrow and broadband spectral response across the entire visible and infrared spectrum.

  15. Buried nodules and associated sediments from the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.; Dutta, P.

    Buried nodules from siliceous sediments in the central Indian Basin are morphologically variable and mineralogically consist of d-MnO2 incipient todorokite. Compositionally they are weakly diagenetic. The sediment coarse fractions ( 63 mu m...

  16. A Review of Celestial Burying Ground in Tibet

    Institute of Scientific and Technical Information of China (English)

    YUQIAN

    2005-01-01

    Celestial burying ground ,also called “Mandala”,is where life leaves and comes.A huge piece of stone hidden in high mountains is surrounded by burning plants that give up smoke going up into the air.

  17. Sub-micron imaging of buried integrated circuit structures using scanning confocal electron microscopy.

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, S. P.; Levine, Z.; Zaluzec, N. J.; Materials Science Division; Northern Arizona Univ.; NIST

    2002-09-09

    Two-dimensional images of model integrated circuit components were collected using the technique of scanning confocal electron microscopy. For structures embedded about 5 {mu}m below the surface of a silicon oxide dielectric, a lateral resolution of 76{+-}9 nm was measured. Elemental mapping via x-ray emission spectrometry is demonstrated. A parallax analysis of images taken for various tilt angles to the electron beam allowed determination of the spacing between two wiring planes. The results show that scanning confocal electron microscopy is capable of probing buried structures at resolutions that will be necessary for the inspection of next-generation integrated circuit technology.

  18. Dynamic Pressure of Seabed around Buried Pipelines in Shallow Water

    OpenAIRE

    Changjing Fu; Guoying Li; Tianlong Zhao; Donghai Guan

    2015-01-01

    Due to the obvious nonlinear effect caused by the shallow waves, the nonlinear wave loads have a great influence on the buried pipelines in shallow water. In order to ensure their stability, the forces on the pipelines that resulted from nonlinear waves should be considered thoroughly. Based on the Biot consolidation theory and the first-order approximate cnoidal wave theory, analytical solutions of the pore water pressure around the buried pipelines in shallow water caused by waves are first...

  19. Data fusion for the detection of buried land mines

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.A.; Sengupta, S.K.; Schaich, P.C.; Sherwood, R.J.; Buhl, M.R.; Hernandez, J.E.; Kane, R.J.; Barth, M.J.; Fields, D.J.; Carter, M.R.

    1993-10-01

    The authors conducted experiments to demonstrate the enhanced delectability of buried land mines using sensor fusion techniques. Multiple sensors, including imagery, infrared imagery, and ground penetrating radar, have been used to acquire data on a number of buried mines and mine surrogates. The authors present this data along with a discussion of the application of sensor fusion techniques for this particular detection problem. The authors describe the data fusion architecture and discuss some relevant results of these classification methods.

  20. Classification of Target Buried in the Underground by Radar Polarimetry

    OpenAIRE

    Moriyama, Toshifumi; Nakamura, Masafumi; Yamaguchi, Yoshio; Yamada, Hiroyoshi; Boerner, Wolfgang-M.

    1999-01-01

    This paper discusses the classification of targets buried in the underground by radar polarimetry. The subsurface radar is used for the detection of objects buried beneath the ground surface, such as gas pipes, cables and cavities, or in archeological exploration operation. In addition to target echo, the subsurface radar receives various other echoes, because the underground is inhomogeneous medium. Therefore, the subsurface radar needs to distinguish these echoes. In order to enhance the di...

  1. Compact Buried Ducts in a Hot-Humid Climate House

    Energy Technology Data Exchange (ETDEWEB)

    Mallay, D. [Home Innovation Research Labs, Upper Marlboro, MD (United States)

    2016-01-01

    A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval.

  2. Review of Concrete Biodeterioration in Relation to Buried Nuclear Waste

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C; Berry, C.

    2012-10-15

    Long-term storage of low level radioactive material in below ground concrete disposal units (DUs) (Saltstone Disposal Facility) is a means of depositing wastes generated from nuclear operations of the U.S. Department of Energy. Based on the currently modeled degradation mechanisms, possible microbial induced effects on the structural integrity of buried low level wastes must be addressed. Previous international efforts related to microbial impacts on concrete structures that house low level radioactive waste showed that microbial activity can play a significant role in the process of concrete degradation and ultimately structural deterioration. This literature review examines the recent research in this field and is focused on specific parameters that are applicable to modeling and prediction of the fate of concrete vaults housing stored wastes and the wastes themselves. Rates of concrete biodegradation vary with the environmental conditions, illustrating a need to understand the bioavailability of key compounds involved in microbial activity. Specific parameters require pH and osmotic pressure to be within a certain range to allow for microbial growth as well as the availability and abundance of energy sources like components involved in sulfur, iron and nitrogen oxidation. Carbon flow and availability are also factors to consider in predicting concrete biodegradation. The results of this review suggest that microbial activity in Saltstone, (grouted low level radioactive waste) is unlikely due to very high pH and osmotic pressure. Biodegradation of the concrete vaults housing the radioactive waste however, is a possibility. The rate and degree of concrete biodegradation is dependent on numerous physical, chemical and biological parameters. Results from this review point to parameters to focus on for modeling activities and also, possible options for mitigation that would minimize concrete biodegradation. In addition, key chemical components that drive microbial

  3. Effect of Hydrogen Implantation on SIMOX SOI Materials

    Institute of Scientific and Technical Information of China (English)

    易万兵; 陈静; 陈猛; 王曦; 邹世昌

    2004-01-01

    Hydrogen ions were implanted into separation by implantation of oxygen (SIMOX) silicon-on-insulator (SOI)wafers near the oxygen-implantation-induced damage peak under different conditions of energy and dose. It was found that the implanted hydrogen ions not only accelerate the diffusion of oxygen atoms from the annealing ambience into the wafer but also cause an outward diffusion of oxygen atoms in the buried oxide (BOX) layer.Thus, greatly broadened buried oxygen-rich (BOR) layers were formed in our experiments, which are 18%-79%broader than the BOX layer of standard SIMOX SOI wafers under the same conditions of oxygen implantation.The mechanism was discussed. A potential low cost method to fabricate SIMOX SOI wafers is proposed.

  4. The evolution of the River Nile. The buried saline rift lakes in Sudan—I. Bahr El Arab Rift, the Sudd buried saline lake

    Science.gov (United States)

    Salama, Ramsis B.

    The River Nile in Sudan, was during the Tertiary, a series of closed lake basins. Each basin occupying one of the major Sudanese rift systems (Salama, 1985a). In this paper evidence is presented for the presence of the buried saline Sudd Lake in Bahr El Arab rift. The thick Tertiary sediments filling the deep grabens were eroded from the elevated blocks; Jebel Marra, Darfur Dome, Nuba Mountains and the Nile-Congo Divide. The thick carbonate deposits existing at the faulted boundaries of Bahr El Arab defines the possible boundaries between the fresh and saline water bodies. The widespread presence of kanker nodules in the sediments was a result of continuous efflorescence, leaching and evaporative processes. The highly saline zone in the central part of the Sudd was formed through the same processes with additional sulphate being added by the oxidation of the hydrogen sulphide gases emanating from the oil fields.

  5. End effectors and attachments for buried waste excavation equipment

    Energy Technology Data Exchange (ETDEWEB)

    King, R.H.

    1993-09-01

    The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that form a comprehensive remediation system for the effective and efficient remediation of buried waste. Their efforts are identified and coordinated in support of the U.S. Department of Energy (DOE), Environmental Restoration and Waste Management (ER&WM) Department`s needs and objectives. The present focus of BWID is to support retrieval and ex-situ treatment configuration options. Future activities will explore and support containment, and stabilization efforts in addition to the retrieval/ex situ treatment options. This report presents a literature search on the state-of-the-art in end effectors and attachments in support of excavator of buried transuranic waste. Included in the report are excavator platforms and a discussion of the various attachments. Also included is it list of vendors and specifications.

  6. Heating and cooling potential of buried pipes in southern Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Abadie, Marc O.; Santos, Gerson H. dos; Freire, Roberto Z.; Mendes, Nathan [Pontificia Universidade Catolica do Parana (PUC-PR), Curitiba, PR (Brazil). Lab. de Sistemas Termicos], e-mail: mabadie@univ-lr.fr, e-mail: gerson.santos@pucpr.br, e-mail: rozafre@terra.com.br; Mendes, Nathan [Pontifical Catholic University of Parana (PUCPR/CCET), Curitiba, PR (Brazil). Thermal Systems Laboratory - LST], e-mail: nathan.mendes@pucpr.br

    2006-07-01

    The present numerical study aims to evaluate the heating and cooling potential of buried pipes in three cities of South Brazil i.e. Curitiba, Florianopolis and Porto-Alegre. In a first part, ground temperatures at the buried pipe location (between 1 and 3 m depth) are calculated by both a simplified model and a three-dimensional volume-finite code (SOLUM). Then, a prototypical house and its buried pipe are modeled with a building energy simulation tool (TRNSYS) to evaluate the positive and negative effects of such system on thermal comfort and heating and cooling energy. Results show that this passive system is particularly efficient in Curitiba, can reduce energy consumption in Porto Alegre and is not well-adapted to Florianopolis. (author)

  7. Autonomous robotic platforms for locating radio sources buried under rubble

    Science.gov (United States)

    Tasu, A. S.; Anchidin, L.; Tamas, R.; Paun, M.; Danisor, A.; Petrescu, T.

    2016-12-01

    This paper deals with the use of autonomous robotic platforms able to locate radio signal sources such as mobile phones, buried under collapsed buildings as a result of earthquakes, natural disasters, terrorism, war, etc. This technique relies on averaging position data resulting from a propagation model implemented on the platform and the data acquired by robotic platforms at the disaster site. That allows us to calculate the approximate position of radio sources buried under the rubble. Based on measurements, a radio map of the disaster site is made, very useful for locating victims and for guiding specific rubble lifting machinery, by assuming that there is a victim next to a mobile device detected by the robotic platform; by knowing the approximate position, the lifting machinery does not risk to further hurt the victims. Moreover, by knowing the positions of the victims, the reaction time is decreased, and the chances of survival for the victims buried under the rubble, are obviously increased.

  8. Buried waste integrated demonstration FY 94 deployment plan

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, R.A.; Walker, S.; Garcia, M.M.

    1994-05-01

    The Buried Waste Integrated Demonstration (BWID) is a program funded by the U.S. Department of Energy Office of Technology Development. BWID supports the applied research, development, demonstration, testing, and evaluation of a suite of advanced technologies that together form a comprehensive remediation system for the effective and efficient remediation of buried waste. The fiscal year (FY) 1994 effort will fund thirty-eight technologies in five areas of buried waste site remediation: site characterization, waste characterization, retrieval, treatment, and containment/stabilization. This document is the basic operational planning document for deployment of all BWID projects. Discussed in this document are the BWID preparations for INEL field demonstrations, INEL laboratory demonstrations, non-INEL demonstrations, and paper studies. Each technology performing tests will prepare a test plan to detail the specific procedures, objectives, and tasks of each test. Therefore, information specific to testing each technology is intentionally omitted from this document.

  9. Damage Assessment for Buried Structures Against Internal Blast Load

    Institute of Scientific and Technical Information of China (English)

    MA Guowei; HUANG Xin; LI Jianchun

    2008-01-01

    The soil-structure interaction(SSI)decoupling is applied to simplify buried structure against internal blast lpad as spring effect.Shear failure.bending failure and Combined failure modes are considered based on five transverse velocity profiles for the rigid-plastic structural element.The critical equations for shear and bending failure are derived respectively.Pressure impulse diagrams are accordingly developed to assess damage of the buried structures against internal blast lpad.Cornparison is done to show influences of soil-structure interaction and shear to-bending strength ratio of a structural element.A case study is conducted to show the application of damage assessment to a reinforced concrete beam element of buried structure.

  10. Theoretical sensitivity analysis of quadruple Vernier racetrack resonators designed for fabrication on the silicon-on-insulator platform

    Science.gov (United States)

    Boeck, Robert; Chrostowski, Lukas; Jaeger, Nicolas A. F.

    2014-09-01

    Vernier racetrack resonators offer advantages over single racetrack resonators such as extending the free spectral range (FSR).1-3 Here, we have presented a theoretical sensitivity analysis on quadruple Vernier racetrack resonators based on varying, one at a time, various fabrication dependent parameters. These parameters include the waveguide widths, heights, and propagation losses. We have shown that it should be possible to design a device that meets typical commercial specifications while being tolerant to changes in these parameters.

  11. Note: A silicon-on-insulator microelectromechanical systems probe scanner for on-chip atomic force microscopy.

    Science.gov (United States)

    Fowler, Anthony G; Maroufi, Mohammad; Moheimani, S O Reza

    2015-04-01

    A new microelectromechanical systems-based 2-degree-of-freedom (DoF) scanner with an integrated cantilever for on-chip atomic force microscopy (AFM) is presented. The silicon cantilever features a layer of piezoelectric material to facilitate its use for tapping mode AFM and enable simultaneous deflection sensing. Electrostatic actuators and electrothermal sensors are used to accurately position the cantilever within the x-y plane. Experimental testing shows that the cantilever is able to be scanned over a 10 μm × 10 μm window and that the cantilever achieves a peak-to-peak deflection greater than 400 nm when excited at its resonance frequency of approximately 62 kHz.

  12. Note: A silicon-on-insulator microelectromechanical systems probe scanner for on-chip atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, Anthony G.; Maroufi, Mohammad; Moheimani, S. O. Reza, E-mail: Reza.Moheimani@newcastle.edu.au [School of Electrical Engineering and Computer Science, University of Newcastle, Callaghan, NSW 2308 (Australia)

    2015-04-15

    A new microelectromechanical systems-based 2-degree-of-freedom (DoF) scanner with an integrated cantilever for on-chip atomic force microscopy (AFM) is presented. The silicon cantilever features a layer of piezoelectric material to facilitate its use for tapping mode AFM and enable simultaneous deflection sensing. Electrostatic actuators and electrothermal sensors are used to accurately position the cantilever within the x-y plane. Experimental testing shows that the cantilever is able to be scanned over a 10 μm × 10 μm window and that the cantilever achieves a peak-to-peak deflection greater than 400 nm when excited at its resonance frequency of approximately 62 kHz.

  13. Integration of CMOS-electronics and particle detector diodes in high-resistivity silicon-on-insulator wafers

    Energy Technology Data Exchange (ETDEWEB)

    Dierickx, B.; Wouters, D.; Willems, G.; Alaerts, A.; Debusschere, I.; Simoen, E.; Vlummens, J.; Akimoto, H.; Claeys, C.; Maes, H.; Hermans, L. (IMEC, Leuven (Belgium)); Heijne, E.H.M.; Jarron, P.; Anghinolfi, F.; Campbell, M.; Pengg, F.X.; Aspell, P. (CERM, Geneve (Switzerland)); Bosisio, L.; Focardi, E.; Forti, F.; Kashigin, S. (INFN sezione di Pisa, Pisa (Italy)); Mekkaoui, A.; Habrard, M.C.; Sauvage, D. (CPPM, Marseille (France)); Delpierre, P. (Coll. de France/IN2P3-CNRS, Paris (France)); Detector R and D Collaboration

    1993-08-01

    A new approach to monolithic pixel detectors, based on SOI wafers with high resistivity substrate, is being pursued by the CERN RD19 collaboration. This paper reports on the used fabrication methods, and on the results of the electrical evaluation of the SOI - MOSFET devices and of the detector structures fabricated in the bulk. The leakage current of the high-resistivity PIN-diodes was kept in the order of 5 to 10 aA/cm[sup 2]. The SOI preparation processes considered (SIMOX and ZMR) produced working electronic circuits and appear to be compatible with the fabrication of detectors to suitable quality.

  14. Silicon-on-Insulator-Based Broadband 1×3 Adiabatic Splitter with Simultaneous Tapering of Velocity and Coupling

    Science.gov (United States)

    Gong, Yuan-Hao; Li, Zhi-Yong; Yu, Jin-Zhong; Yu, Yu-De

    2016-09-01

    Not Available Supported by the National High-Technology Research and Development Program of China under Grant Nos 2015AA016904 and 2013AA014402, the National Basic Research Program of China under Grant No 2011CB301701, and the National Natural Science Foundation of China under Grant No 61275065.

  15. Design of photonic phased array switches using nano electromechanical systems on silicon-on-insulator integration platform

    Science.gov (United States)

    Hussein, Ali Abdulsattar

    This thesis presents an introduction to the design and simulation of a novel class of integrated photonic phased array switch elements. The main objective is to use nano-electromechanical (NEMS) based phase shifters of cascaded under-etched slot nanowires that are compact in size and require a small amount of power to operate them. The structure of the switch elements is organized such that it brings the phase shifting elements to the exterior sides of the photonic circuits. The transition slot couplers, used to interconnect the phase shifters, are designed to enable biasing one of the silicon beams of each phase shifter from an electrode located at the side of the phase shifter. The other silicon beam of each phase shifter is biased through the rest of the silicon structure of the switch element, which is taken as a ground. Phased array switch elements ranging from 2x2 up to 8x8 multiple-inputs/multiple-outputs (MIMO) are conveniently designed within reasonable footprints native to the current fabrication technologies. Chapter one presents the general layout of the various designs of the switch elements and demonstrates their novel features. This demonstration will show how waveguide disturbances in the interconnecting network from conventional switch elements can be avoided by adopting an innovative design. Some possible applications for the designed switch elements of different sizes and topologies are indicated throughout the chapter. Chapter two presents the design of the multimode interference (MMI) couplers used in the switch elements as splitters, combiners and waveguide crossovers. Simulation data and design methodologies for the multimode couplers of interest are detailed in this chapter. Chapter three presents the design and analysis of the NEMS-operated phase shifters. Both simulations and numerical analysis are utilized in the design of a 0°-180° capable NEMS-operated phase shifter. Additionally, the response of some of the designed photonic phased array switch elements is demonstrated in this chapter. An executive summary and conclusions sections are also included in the thesis.

  16. High-performance and power-efficient 2${\\times}$2 optical switch on Silicon-on-Insulator

    CERN Document Server

    Han, Zheng; Checoury, Xavier; Bourderionnet, Jérôme; Boucaud, Philippe; De Rossi, Alfredo; Combrié, Sylvain

    2015-01-01

    A compact (15{\\mu}m${\\times}${\\mu}m) and highly-optimized 2${\\times}$2 optical switch is demonstrated on a CMOS-compatible photonic crystal technology. On-chip insertion loss are below 1dB, static and dynamic contrast are 40dB and >20dB respectively. Owing to efficient thermo-optic design, the power consumption is below 3 mW while the switching time is 1 {\\mu}s.

  17. Effect of Doping Position on the Active Silicon-on-Insulator Micro-Ring Resonator Based on Free Carrier Injection

    Directory of Open Access Journals (Sweden)

    B. Mardiana

    2012-01-01

    Full Text Available Problem statement: Metal interconnects have become significant limitation on the scaling of CMOS technologies in electronics integrated circuit. Silicon photonics has offers great potential to overcome this critical bottleneck due to the advantages of optical interconnects. Silicon-based optical micro-ring resonator is promising basic element of future electronic-photonic integrated circuits because of its wide applications on photonic devices such as modulator, switch and sensor. Approach: This study highlights the study of the free carrier injection effect on the active SOI micro-ring resonator. The effect of the free carrier injection on micro-ring resonator is evaluated by varying the p+ and n+ doping position. Device performances are predicted using numerical modeling software 2D SILVACO as well as Finite Difference Time Domain (FDTD simulation software, RSOFT. Results: The results show that the refractive index change increases as the p+ and n+ doping position become closer to the rib waveguide. A shift in resonant wavelength of around 2 and 3 nm was is predicted at 0.9V drive forward voltage for 0.5 and 1.0 μm gap distance between p+ and n+ doping regions and the sidewall of the rib waveguide. It is also shown that 10 and 9.2 dB maximum change of the output response obtained through the output of the transmission spectrum of the device with gap 0.5 and 1.0 μm. Conclusion: The closer distance between p+ and n+ doping regions and the rib waveguide has optimal shift of resonance wavelength and better extinction ratio of transmission spectrum.

  18. Electron–phonon heat transport and electronic thermal conductivity in heavily doped silicon-on-insulator film

    OpenAIRE

    Kivinen, P; Savin, A.; Zgirski, M.; Törmä, P.; Pekola, Jukka P; Prunnila, M.; Ahopelto, J.

    2003-01-01

    Electron–phonon interaction and electronic thermal conductivity have been investigated in heavily doped silicon at subKelvin temperatures. The heat flow between electron and phonon systems is found to be proportional to T6. Utilization of a superconductor–semiconductor–superconductor thermometer enables a precise measurement of electron and substrate temperatures. The electronic thermal conductivity is consistent with the Wiedemann–Franz law. Peer reviewed

  19. Low-energy MOS depletion modulators in silicon-on-insulator micro-donut resonators coupled to bus waveguides.

    Science.gov (United States)

    Soref, Richard; Guo, Junpeng; Sun, Greg

    2011-09-12

    Electrical, optical and electro-optical simulations are presented for a waveguided, resonant, bus-coupled, p-doped Si micro-donut MOS depletion modulator operating at the 1.55 μm wavelength. To minimize the switching voltage and energy, a high-K dielectric film of HfO₂ or ZrO₂ is chosen as the gate dielectric, while a narrow ring-shaped layer of p-doped poly-silicon is selected for the gate electrode, rather than metal, to minimize plasmonic loss loading of the fundamental TE mode. In a 6-μm-diam high-Q resonator, an infrared intensity extinction ratio of 6 dB is predicted for a modulation voltage of 2 V and a switching energy of 4 fJ/bit. A speed-of-response around 1 ps is anticipated. For a modulator scaled to operate at 1.3 μm, the estimated switching energy is 2.5 fJ/bit.

  20. Buried wire gage for wall shear stress measurements

    Science.gov (United States)

    Murthy, V. S.; Rose, W. C.

    1978-01-01

    A buried wire gage for measuring wall shear stress in fluid flow was studied and further developed. Several methods of making this relatively new type of gage were examined to arrive at a successful technique that is well-suited for wind-tunnel testing. A series of measurements was made to demonstrate the adequacy of a two-point calibration procedure for these gages. The buried wire gage is also demonstrated to be ideally suited for quantitative measurement of wall shear stress in wind-tunnel testing.

  1. Silicon buried channels for pixel detector cooling

    Energy Technology Data Exchange (ETDEWEB)

    Boscardin, M., E-mail: boscardi@fbk.eu [Fondazione Bruno Kessler Trento, Via Sommarive 18, I-38123 Trento (Italy); Conci, P.; Crivellari, M.; Ronchin, S. [Fondazione Bruno Kessler Trento, Via Sommarive 18, I-38123 Trento (Italy); Bettarini, S. [Universitá di Pisa, L.go B. Pontecorvo 3, I-56127 Pisa (Italy); Istituto Nazionale di Fisica Nucleare, Sez. di Pisa, L.go B. Pontecorvo 3, I-56127 Pisa (Italy); Bosi, F. [Istituto Nazionale di Fisica Nucleare, Sez. di Pisa, L.go B. Pontecorvo 3, I-56127 Pisa (Italy)

    2013-08-01

    The support and cooling structures add important contributions to the thickness, in radiation length, of vertex detectors. In order to minimize the material budget of pixel sensors, we developed a new approach to integrate the cooling into the silicon devices. The microchannels are formed in silicon using isotropic SF{sub 6} plasma etching in a DRIE (deep reactive ion etcher) equipment. Due to their peculiar profiles, the channels can be sealed by a layer of a PECVD silicon oxide. We have realized on a silicon wafer microchannels with different geometries and hydraulic diameters. We describe the main fabrication steps of microchannels with focus on the channel definition. The experimental results are reported on the thermal characterization of several prototypes, using a mixture of glycol and water as a liquid coolant. The prototypes have shown high cooling efficiency and high-pressure breaking strength.

  2. Buried Waste Integrated Demonstration Technology Preparedness and Status Report Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Blacker, P.B.; Bonnenberg, R.W.; Cannon, P.G.; Hyde, R.A.; Watson, L.R.

    1994-04-01

    A Technology Preparedness and Status Report is required for each Technical Task Plan funded by the Buried Waste Integrated Demonstration. This document provides guidance for the preparation of that report. Major sections of the report will include a subset of the need for the technology, objectives of the demonstration, technology description and readiness evaluation, demonstration requirements, and preparedness checklist and action plan.

  3. Modeling of the Uplift Response of Buried Pipelines

    DEFF Research Database (Denmark)

    Choobbasti, Asskar Janalizadeh; Vahdatirad, Mohammadjavad; Firouzianbandpey, Sarah;

    2009-01-01

    Over the years, researchers have tried to understand the complex behavior of buried pipelines subjected to ground ruptures due to landslides, earthquakes, faults and uplift forces in shallow trenches. In an attempt to understand this complex behavior, an experimental investigation program has been...

  4. Detection of Buried Mines and Unexploded Ordnance (UXO)

    Science.gov (United States)

    2007-04-20

    maintenance and performance of the animals. q. Biological Systems: Plants Using a transgenic plant bioindicator implanted in the annual weed Thale... bioindicator implanted in the annual weed Thale Cress (Arabidopsis thaliana) that detects NO2 from buried land mines by changing color from green to red

  5. 49 CFR 195.248 - Cover over buried pipeline.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION...

  6. Ground Penetrating Radar Imaging of Buried Metallic Objects

    DEFF Research Database (Denmark)

    Polat, A. Burak; Meincke, Peter

    2001-01-01

    During the past decade there has been considerable research on ground penetrating radar (GPR) tomography for detecting objects such as pipes, cables, mines and barrels buried under the surface of the Earth. While the earlier researches were all based on the assumption of a homogeneous background...

  7. Electronic Structure of Buried Interfaces - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Zachary [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-25

    In the electronics behind computer memory storage, the speed and size are dictated by the performance of permanent magnets inside devices called read heads. Complicated magnets made of stacked layers of thin films can be engineered to have properties that yield more energy storage and faster switching times compared to conventional iron or cobalt magnets. The reason is that magnetism is a result of subtle interactions amongst electrons; just how neurons come together on large scales to make cat brains and dog brains, ensembles of electrons interact and become ferromagnets and paramagnets. These interactions make magnets too difficult to study in their entirety, so I focus on the interfaces between layers, which are responsible for the coupling materials physicists hope to exploit to produce next-generation magnets. This project, I study a transition metal oxide material called LSCO, Lanthanum Cobaltite, which can be a paramagnet or a ferromagnet depending on how you tweak the electronic structure. It exhibits an exciting behavior: its sum is greater than the sum of its parts. When another similar material called a LSMO, Lanthanum Manganite, is grown on top of it, their interface has a different type of magnetism from the LSCO or the LSMO! I hope to explain this by demonstrating differently charged ions in the interface. The typical method for quantifying this is x-ray absorption, but all conventional techniques look at every layer simultaneously, averaging the interfaces and the LSCO layers that we want to characterize separately. Instead, I must use a new reflectivity technique, which tracks the intensity of reflected x-rays at different angles, at energies near the absorption peaks of certain elements, to track changes in the electronic structure of the material. The samples were grown by collaborators at the Takamura group at U.C. Davis and probed with this “resonant reflectivity” technique on Beamline 2-1 at the Stanford Synchrotron Radiation Lightsource

  8. Effect of Backpacking and Internal Pressurization on Stresses Transmitted to Buried Cylinders.

    Science.gov (United States)

    Various aspects of the behavior of buried cylinders associated with backpacking , internal pressurization, and slippage at the interface are...considered. Parametric curves are presented for horizontally and vertically buried cylinders with and without backpacking . Four configurations of statically...loaded, horizontally buried cylinders were considered: no backpacking , rectangular backpacking placed above the cylinder, backpacking placed around

  9. Effects of substrate voltage on noise characteristics and hole lifetime in SOI metal-oxide-semiconductor field-effect transistor photon detector.

    Science.gov (United States)

    Putranto, Dedy Septono Catur; Priambodo, Purnomo Sidi; Hartanto, Djoko; Du, Wei; Satoh, Hiroaki; Ono, Atsushi; Inokawa, Hiroshi

    2014-09-08

    Low-frequency noise and hole lifetime in silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistors (MOSFETs) are analyzed, considering their use in photon detection based on single-hole counting. The noise becomes minimum at around the transition point between front- and back-channel operations when the substrate voltage is varied, and increases largely on both negative and positive sides of the substrate voltage showing peculiar Lorentzian (generation-recombination) noise spectra. Hole lifetime is evaluated by the analysis of drain current histogram at different substrate voltages. It is found that the peaks in the histogram corresponding to the larger number of stored holes become higher as the substrate bias becomes larger. This can be attributed to the prolonged lifetime caused by the higher electric field inside the body of SOI MOSFET. It can be concluded that, once the inversion channel is induced for detection of the photo-generated holes, the small absolute substrate bias is favorable for short lifetime and low noise, leading to high-speed operation.

  10. Micromorphological and ultramicroscopic aspects of buried remains: Time-dependent markers of decomposition and permanence in soil in experimental burial.

    Science.gov (United States)

    Zangarini, Sara; Trombino, Luca; Cattaneo, Cristina

    2016-06-01

    A buried body not only determines an environmental response at the deposition site but it is also affected by the soil. The experiment was performed using eleven swine carcasses buried in an open site (Northern Italy). Changes occurring in bone tissue at different post-burial intervals were evaluated observing thin sections of bones through micromorphological and ultramicroscopic (SEM-EDS) techniques. These methods allowed the identification of: (a) magnesium phosphate (Mg3(PO4)2) crystallizations, probably linked to decomposition of bones and soft tissues; (b) significant sulphur levels which seem to be related to hydrogen sulphide (H2S) fixation in bone tissue; (c) metal oxide concentrations in the form of unusual violet-blue colorations, which probably are evidence of the soil's action and penetration in bones, also testified by (d) the presence of mineral grains enclosed in the osseous tissue. The results underline the possibility of identifying both time-dependent markers of decomposition and indicators of permanence in soil in buried bones.

  11. Radar glory from buried craters on icy moons

    Science.gov (United States)

    Eshleman, Von R.

    1986-10-01

    Three ice-covered moons of Jupiter, in comparison with rocky planets and earth's moon, produce radar echoes of astounding strengths and bizarre polarizations. Scattering from buried craters can explain these and other anomalous properties of the echoes. The role of such craters is analogous to that of the water droplets that create the apparition known as 'the glory', the optically bright region surrounding an observer's shadow on a cloud. Both situations involve the electromagnetic phenomenon of total internal reflection at a dielectric interface, operating in a geometry that strongly favors exact backscattering. Dim surface craters are transformed into bright glory holes by being buried under somewhat denser material, thereby increasing the intensity of their echoes by factors of hundreds. The dielectric interface thus formed at the crater walls nicely accounts for the unusual polarizations of the echoes.

  12. Centrifuge modeling of PGD response of buried pipe

    Institute of Scientific and Technical Information of China (English)

    Michael O'Rourke; Vikram Gadicherla; Tarek Abdoun

    2005-01-01

    A new centrifuge based method for determining the response of continuous buried pipe to PGD is presented.The physical characteristics of the RPI's 100 g-ton geotechnical centrifuge and the current lifeline experiment split-box are described: The split-box contains the model pipeline and surrounding soil and is manufactured such that half can be offset, in flight, simulating PGD. In addition, governing similitude relations which allow one to determine the physical characteristics,(diameter, wall thickness and material modulus of elasticity) of the model pipeline are presented. Finally, recorded strains induced in two buried pipes with prototype diameters of 0.63 m and 0.95 m (24 and 36 inch) subject to 0.6 and 2.0 meters (2and 6 feet) of full scale fault offsets and presented and compared to corresponding FE results.

  13. Prediction of the TNT signature from buried UXO/landmines

    Energy Technology Data Exchange (ETDEWEB)

    Webb, S.W.; Phelan, J.M. [Sandia National Labs., Albuquerque, NM (United States); Finsterle, S.A.; Pruess, K. [Lawrence Berkeley National Lab., CA (United States)

    1998-06-01

    The detection and removal of buried unexploded ordnance (UXO) and landmines is one of the most important problems facing the world today. Numerous detection strategies are being developed, including infrared, electrical conductivity, ground-penetrating radar, and chemical sensors. Chemical sensors rely on the detection of TNT molecules, which are transported from buried UXO/landmines by advection and diffusion in the soil. As part of this effort, numerical models are being developed to predict TNT transport in soils including the effect of precipitation and evaporation. Modifications will be made to TOUGH2 for application to the TNT chemical sensing problem. Understanding the fate and transport of TNT in the soil will affect the design, performance and operation of chemical sensors by indicating preferred sensing strategies.

  14. Imaging and controlling plasmonic interference fields at buried interfaces

    Science.gov (United States)

    Lummen, Tom T. A.; Lamb, Raymond J.; Berruto, Gabriele; Lagrange, Thomas; Dal Negro, Luca; García de Abajo, F. Javier; McGrouther, Damien; Barwick, B.; Carbone, F.

    2016-10-01

    Capturing and controlling plasmons at buried interfaces with nanometre and femtosecond resolution has yet to be achieved and is critical for next generation plasmonic devices. Here we use light to excite plasmonic interference patterns at a buried metal-dielectric interface in a nanostructured thin film. Plasmons are launched from a photoexcited array of nanocavities and their propagation is followed via photon-induced near-field electron microscopy (PINEM). The resulting movie directly captures the plasmon dynamics, allowing quantification of their group velocity at ~0.3 times the speed of light, consistent with our theoretical predictions. Furthermore, we show that the light polarization and nanocavity design can be tailored to shape transient plasmonic gratings at the nanoscale. This work, demonstrating dynamical imaging with PINEM, paves the way for the femtosecond and nanometre visualization and control of plasmonic fields in advanced heterostructures based on novel two-dimensional materials such as graphene, MoS2, and ultrathin metal films.

  15. Planar ion-channeling measurements on buried nano-films

    NARCIS (Netherlands)

    Selen, LJM; Janssen, FJJ; van IJzendoorn, LJ; de Voigt, MJA; Smulders, PJM; Theunissen, MJJ

    2001-01-01

    Planar MeV ion-channeling measurements on 2.2 nm thick Si1-xGex nano-films buried in Si are presented. The presence of the nano-film leads to a step in the yield of the host crystal in a {0 1 1} planar channeled RBS spectrum. In previous work we showed that with the help of Monte Carlo (MC) simulati

  16. Global Earthing Systems: Characterization of Buried Metallic Parts

    OpenAIRE

    Tommasini, Riccardo; Colella, Pietro; Pons, Enrico

    2016-01-01

    International Standards IEC 61936-1 and EN 50522 define a Global Earthing System (GES) as the earthing network, created by the interconnection of local earthing systems, that should guarantee the absence of dangerous touch voltages. This is achieved through two effects: the division of the earth fault current between many earthing systems and the creation of a quasi equipotential surface. The second effect can be enhanced by the presence of buried metallic parts, such as light poles and water...

  17. Nonparametric Bayesian Context Learning for Buried Threat Detection

    Science.gov (United States)

    2012-01-01

    route clearance patrols, the vast majority of GPR data collected in the field will be free of buried threats. In current processing strategies , the large...mining competition spearheaded by Netflix , which sought to improve its movie recommen- dation algorithm [146]. As more customer data becomes available...no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control

  18. A method for the detection of shallow buried objects

    Directory of Open Access Journals (Sweden)

    T. M. McGee

    2000-06-01

    Full Text Available Numerous geophysical techniques have successfully contributed to geotechnical engineering and environmental problems of the shallow subsurface. Geophysical surveys are used to: delineate geologic features, measure in-situ engineering properties, and detect hidden cultural features. Most technologies for the detection of shallow buried objects are electromagnetic methods which measure the contrast in ferrous content, electrical conductivity, or dielectric constant between the object and surrounding soil. Seismic technologies measure the contrast in mechanical properties of the subsurface, however, scaled down versions of conventional seismic methods are not suitable for the detection shallow buried objects. In this paper, we discuss the development of a method based on acoustic to seismic coupling for the detection of shallow buried object. Surface vibrations induced by an impinging acoustic wave from a loudspeaker is referred to as acoustic to seismic coupling. These vibrations can be remotely detected using a laser-Doppler vibrometer (LDV. If an object is present below the surface of the insonified patch, the transmitted wave is back scattered by the target towards the surface. For targets very close to the surface, the scattered field produces anomalous ground vibrational velocities that are indicative of the shape and size of the target.

  19. Degradation of carbohydrates and lignins in buried woods

    Science.gov (United States)

    Hedges, John I.; Cowie, Gregory L.; Ertel, John R.; James Barbour, R.; Hatcher, Patrick G.

    1985-03-01

    Spruce, alder, and oak woods deposited in coastal sediments were characterized versus their modern counterparts by quantification of individual neutral sugars and lignin-derived phenols as well as by scanning electron microscopy, 13C NMR, and elemental analysis. The buried spruce wood from a 2500 yr old deposit was unaltered whereas an alder wood from the same horizon and an oak wood from an open ocean sediment were profoundly degraded. Individual sugar and lignin phenol analyses indicate that at least 90 and 98 wt% of the initial total polysaccharides in the buried alder and oak woods, respectively, have been degraded along with 15-25 wt% of the lignin. At least 75% of the degraded biopolymer has been physically lost from these samples. This evidence is supported by the SEM, 13C NMR and elemental analyses, all of which indicate selective loss of the carbohydrate moiety. The following order of stability was observed for the major biochemical constituents of both buried hardwoods: vanillyl and p- hydroxyl lignin structural units > syringyl lignin structural units > pectin > α-cellulose > hemicellulose. This sequence can be explained by selective preservation of the compound middle lamella regions of the wood cell walls. The magnitude and selectivity of the indicated diagenetic reactions are sufficient to cause major changes in the chemical compositions of wood-rich sedimentary organic mixtures and to provide a potentially large in situ nutrient source.

  20. Degradation of carbohydrates and lignins in buried woods

    Science.gov (United States)

    Hedges, J.I.; Cowie, G.L.; Ertel, J.R.; James, Barbour R.; Hatcher, P.G.

    1985-01-01

    Spruce, alder, and oak woods deposited in coastal sediments were characterized versus their modern counterparts by quantification of individual neutral sugars and lignin-derived phenols as well as by scanning electron microscopy, 13C NMR, and elemental analysis. The buried spruce wood from a 2500 yr old deposit was unaltered whereas an alder wood from the same horizon and an oak wood from an open ocean sediment were profoundly degraded. Individual sugar and lignin phenol analyses indicate that at least 90 and 98 wt% of the initial total polysaccharides in the buried alder and oak woods, respectively, have been degraded along with 15-25 wt% of the lignin. At least 75% of the degraded biopolymer has been physically lost from these samples. This evidence is supported by the SEM, 13C NMR and elemental analyses, all of which indicate selective loss of the carbohydrate moiety. The following order of stability was observed for the major biochemical constituents of both buried hardwoods: vanillyl and p-hydroxyl lignin structural units > syringyl lignin structural units > pectin > ??-cellulose > hemicellulose. This sequence can be explained by selective preservation of the compound middle lamella regions of the wood cell walls. The magnitude and selectivity of the indicated diagenetic reactions are sufficient to cause major changes in the chemical compositions of wood-rich sedimentary organic mixtures and to provide a potentially large in situ nutrient source. ?? 1985.

  1. FY-95 technology catalog. Technology development for buried waste remediation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    The US Department of Energy`s (DOE) Buried Waste Integrated Demonstration (BWID) program, which is now part of the Landfill Stabilization Focus Area (LSFA), supports applied research, development, demonstration, and evaluation of a multitude of advanced technologies dealing with underground radioactive and hazardous waste remediation. These innovative technologies are being developed as part of integrated comprehensive remediation systems for the effective and efficient remediation of buried waste sites throughout the DOE complex. These efforts are identified and coordinated in support of Environmental Restoration (EM-40) and Waste Management (EM-30) needs and objectives. Sponsored by the DOE Office of Technology Development (EM-50), BWID and LSFA work with universities and private industry to develop technologies that are being transferred to the private sector for use nationally and internationally. This report contains the details of the purpose, logic, and methodology used to develop and demonstrate DOE buried waste remediation technologies. It also provides a catalog of technologies and capabilities with development status for potential users. Past FY-92 through FY-94 technology testing, field trials, and demonstrations are summarized. Continuing and new FY-95 technology demonstrations also are described.

  2. Structural coupling between FKBP12 and buried water.

    Science.gov (United States)

    Szep, Szilvia; Park, Sheldon; Boder, Eric T; Van Duyne, Gregory D; Saven, Jeffery G

    2009-02-15

    Globular proteins often contain structurally well-resolved internal water molecules. Previously, we reported results from a molecular dynamics study that suggested that buried water (Wat3) may play a role in modulating the structure of the FK506 binding protein-12 (FKBP12) (Park and Saven, Proteins 2005; 60:450-463). In particular, simulations suggested that disrupting a hydrogen bond to Wat3 by mutating E60 to either A or Q would cause a structural perturbation involving the distant W59 side chain, which rotates to a new conformation in response to the mutation. This effectively remodels the ligand-binding pocket, as the side chain in the new conformation is likely to clash with bound FK506. To test whether the protein structure is in effect modulated by the binding of a buried water in the distance, we determined high-resolution (0.92-1.29 A) structures of wild-type FKBP12 and its two mutants (E60A, E60Q) by X-ray crystallography. The structures of mutant FKBP12 show that the ligand-binding pocket is indeed remodeled as predicted by the substitution at position 60, even though the water molecule does not directly interact with any of the amino acids of the binding pocket. Thus, these structures support the view that buried water molecules constitute an integral, noncovalent component of the protein structure. Additionally, this study provides an example in which predictions from molecular dynamics simulations are experimentally validated with atomic precision, thus showing that the structural features of protein-water interactions can be reliably modeled at a molecular level.

  3. The thermal regime around buried submarine high-voltage cables

    Science.gov (United States)

    Emeana, C. J.; Hughes, T. J.; Dix, J. K.; Gernon, T. M.; Henstock, T. J.; Thompson, C. E. L.; Pilgrim, J. A.

    2016-08-01

    The expansion of offshore renewable energy infrastructure and the need for trans-continental shelf power transmission require the use of submarine high-voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70 °C and are typically buried 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the heat flow pattern and potential effects on the sedimentary environments around such anomalously high heat sources in the near-surface sediments are poorly understood. We present temperature measurements from a 2-D laboratory experiment representing a buried submarine HV cable, and identify the thermal regimes generated within typical unconsolidated shelf sediments—coarse silt, fine sand and very coarse sand. We used a large (2 × 2.5 m2) tank filled with water-saturated spherical glass beads (ballotini) and instrumented with a buried heat source and 120 thermocouples to measure the time-dependent 2-D temperature distributions. The observed and corresponding Finite Element Method simulations of the steady state heat flow regimes and normalized radial temperature distributions were assessed. Our results show that the heat transfer and thus temperature fields generated from submarine HV cables buried within a range of sediments are highly variable. Coarse silts are shown to be purely conductive, producing temperature increases of >10 °C up to 40 cm from the source of 60 °C above ambient; fine sands demonstrate a transition from conductive to convective heat transfer between cf. 20 and 36 °C above ambient, with >10 °C heat increases occurring over a metre from the source of 55 °C above ambient; and very coarse sands exhibit dominantly convective heat transfer even at very low (cf. 7 °C) operating temperatures and reaching temperatures of up to 18 °C above ambient at a metre from the source at surface temperatures of only 18 °C. These findings are important for the surrounding near

  4. Remote Excavation System technology evaluation report: Buried Waste Robotics Program

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    This document describes the results from the Remote Excavation System demonstration and testing conducted at the Idaho National Engineering Laboratory during June and July 1993. The purpose of the demonstration was to ascertain the feasibility of the system for skimming soil and removing various types of buried waste in a safe manner and within all regulatory requirements, and to compare the performances of manual and remote operation of a backhoe. The procedures and goals of the demonstration were previously defined in The Remote Excavation System Test Plan, which served as a guideline for evaluating the various components of the system and discussed the procedures used to conduct the tests.

  5. UTBB FDSOI: Evolution and opportunities

    Science.gov (United States)

    Monfray, Stephane; Skotnicki, Thomas

    2016-11-01

    As today's 28 nm FDSOI (Fully Depleted Silicon On Insulator) technology is at the industrialization level, this paper aims to summarize the key advantages allowed by the thin BOX (Buried Oxide) of the FDSOI, through the technology evolution but also new opportunities, among logic applications and extending the possibilities offered by the platform. We will summarize how the advantages provided by the thin BOX have been first explored and developed, and how the back biasing techniques are the key to the outstanding performances provided by the FDSOI at low voltage. Then, as the FDSOI technology is also a solution to develop innovative platforms and applications, we will detail some opportunities. In particular, we will present monolithic 3D integration, ultra-low power devices for IoT (Internet of Things) and ultra-sensitive sensors.

  6. TID Simulation of Advanced CMOS Devices for Space Applications

    Science.gov (United States)

    Sajid, Muhammad

    2016-07-01

    This paper focuses on Total Ionizing Dose (TID) effects caused by accumulation of charges at silicon dioxide, substrate/silicon dioxide interface, Shallow Trench Isolation (STI) for scaled CMOS bulk devices as well as at Buried Oxide (BOX) layer in devices based on Silicon-On-Insulator (SOI) technology to be operated in space radiation environment. The radiation induced leakage current and corresponding density/concentration electrons in leakage current path was presented/depicted for 180nm, 130nm and 65nm NMOS, PMOS transistors based on CMOS bulk as well as SOI process technologies on-board LEO and GEO satellites. On the basis of simulation results, the TID robustness analysis for advanced deep sub-micron technologies was accomplished up to 500 Krad. The correlation between the impact of technology scaling and magnitude of leakage current with corresponding total dose was established utilizing Visual TCAD Genius program.

  7. Increase in the scattering of electric field lines in a new high voltage SOI MESFET

    Science.gov (United States)

    Anvarifard, Mohammad K.

    2016-09-01

    This paper illustrates a new efficient technique to enhance the critical features of a silicon-on-insulator metal-semiconductor field-effect transistor (SOI MESFET) applied in high voltage applications. The structure we proposed utilizes a new method to scatter the electric field lines along the channel region. Realization of two trenches with different materials, which a trench is created in the channel region and the other one is created in the buried oxide, helps the proposed structure to improve the breakdown voltage, driving current, drain-source conductance, minimum noise figure, unilateral power gain and output power density. Exploring the obtained results, the proposed structure has superior electrical performance in comparison to the conventional structure.

  8. Probing Molecular Organization and Electronic Dynamics at Buried Organic Interfaces

    Science.gov (United States)

    Roberts, Sean

    2015-03-01

    Organic semiconductors are a promising class of materials due to their ability to meld the charge transport capabilities of semiconductors with many of the processing advantages of plastics. In thin film organic devices, interfacial charge transfer often comprises a crucial step in device operation. As molecular materials, the density of states within organic semiconductors often reflect their intermolecular organization. Truncation of the bulk structure of an organic semiconductor at an interface with another material can lead to substantial changes in the density of states near the interface that can significantly impact rates for interfacial charge and energy transfer. Here, we will present the results of experiments that utilize electronic sum frequency generation (ESFG) to probe buried interfaces in these materials. Within the electric dipole approximation, ESFG is only sensitive to regions of a sample that experience a breakage of symmetry, which occurs naturally at material interfaces. Through modeling of signals measured for thin organic films using a transfer matrix-based formalism, signals from buried interfaces between two materials can be isolated and used to uncover the interfacial density of states.

  9. Full-scale retrieval of simulated buried transuranic waste

    Energy Technology Data Exchange (ETDEWEB)

    Valentich, D.J. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

    1993-09-01

    This report describes the results of a field test conducted to determine the effectiveness of using conventional type construction equipment for the retrieval of buried transuranic (TRU) waste. A cold (nonhazardous and nonradioactive) test pit (1,100 yd{sup 3} volume) was constructed with boxes and drums filled with simulated waste materials, such as metal, plastic, wood, concrete, and sludge. Large objects, including truck beds, tanks, vaults, pipes, and beams, were also placed in the pit. These materials were intended to simulate the type of wastes found in TRU buried waste pits and trenches. A series of commercially available equipment items, such as excavators and tracked loaders outfitted with different end effectors, were used to remove the simulated waste. Work was performed from both the abovegrade and belowgrade positions. During the demonstration, a number of observations, measurements, and analyses were performed to determine which equipment was the most effective in removing the waste. The retrieval rates for the various excavation techniques were recorded. The inherent dust control capabilities of the excavation methods used were observed. The feasibility of teleoperating reading equipment was also addressed.

  10. Preliminary observations of arthropods associated with buried carrion on Oahu.

    Science.gov (United States)

    Rysavy, Noel M; Goff, M Lee

    2015-03-01

    Several studies in Hawaii have focused on arthropod succession and decomposition patterns of surface remains, but the current research presents the first study to focus on shallow burials in this context. Three domestic pig carcasses (Sus scrofa L.) were buried at the depths of 20-40 cm in silty clay loam soil on an exposed ridge on the leeward side of the volcanically formed Koolau Mountain Range. One carcass was exhumed after 3 weeks, another after 6 weeks, and the last carcass was exhumed after 9 weeks. An inventory of arthropod taxa present on the carrion and in the surrounding soil and observations pertaining to decomposition were recorded at each exhumation. The longer the carrion was buried, the greater the diversity of arthropod species that were recovered from the remains. Biomass loss was calculated to be 49% at the 3-week interval, 56% at the 6-week interval, and 59% at the 9-week interval.

  11. Measure Guideline: Buried and/or Encapsulated Ducts

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Zoeller, W. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Mantha, P. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2013-08-01

    Buried and/or encapsulated ducts (BEDs) are a class of advanced, energy-efficiency strategies intended to address the significant ductwork thermal losses associated with ducts installed in unconditioned attics. BEDs are ducts installed in unconditioned attics that are covered in loose-fill insulation and/or encapsulated in closed cell polyurethane spray foam insulation. This Measure Guideline covers the technical aspects of BEDs as well as the advantages, disadvantages, and risks of BEDs compared to other alternative strategies. This guideline also provides detailed guidance on installation of BEDs strategies in new and existing homes through step-by-step installation procedures. Some of the procedures presented here, however, require specialized equipment or expertise. In addition, some alterations to duct systems may require a specialized license.

  12. A Natural Seismic Isolating System: The Buried Mangrove Effects

    CERN Document Server

    Gueguen, Philippe; Foray, Pierre; Rousseau, Christophe; Maury, Julie; 10.1785/0120100129

    2011-01-01

    The Belleplaine test site, located in the island of Guadeloupe (French Lesser Antilles) includes a three-accelerometer vertical array, designed for liquefac- tion studies. The seismic response of the soil column at the test site is computed using three methods: the spectral ratio method using the vertical array data, a numerical method using the geotechnical properties of the soil column, and an operative fre- quency domain decomposition (FDD) modal analysis method. The Belleplaine test site is characterized by a mangrove layer overlaid by a stiff sandy deposit. This con- figuration is widely found at the border coast of the Caribbean region, which is exposed to high seismic hazard. We show that the buried mangrove layer plays the role of an isolation system equivalent to those usually employed in earthquake engineering aimed at reducing the seismic shear forces by reducing the internal stress within the structure. In our case, the flexibility of the mangrove layer reduces the distortion and the stress in the...

  13. Bryophytes of beach forests in Chon Buri Province, Thailand

    Directory of Open Access Journals (Sweden)

    Phiangphak Sukkharak

    2014-10-01

    Full Text Available An investigation of bryophyte diversity of three beach forests including Had Tung Prong, Had Tein Talay, and the beach forest in Thai Island and Sea Natural History Museum in Chon Buri Province, Thailand, was carried out. From 137 enumerated specimens, 16 species (6 mosses, 10 liverworts in 12 genera (5 mosses, 7 liverworts and eight families (5 mosses, 3 liverworts were found. Among those the most common families of mosses are Fissidentaceae (2 species and the most common families of liverwort are Lejeuneaceae (8 species. A comparison of species richness among the three areas revealed that the highest species richness of bryophytes was found in Had Tung Prong. Moreover, of all bryophyte species found, Weissia edentula Mitt. was the most common one.

  14. Retrieval of Shape Characteristics for Buried Objects with GPR Monitoring

    Science.gov (United States)

    Soldovieri, F.; Comite, D.; Galli, A.; Valerio, G.; Barone, P. M.; Lauro, S. E.; Mattei, E.; Pettinelli, E.

    2012-04-01

    Information retrieval on the location and the geometrical features (dimensions and shape) of buried objects is of fundamental importance in geosciences areas involving environmental protection, mine clearance, archaeological investigations, space and planetary exploration, and so forth. Among the different non-invasive sensing techniques usually employed to achieve this kind of information, those based on ground-penetrating-radar (GPR) instruments are well-established and suitable to the mentioned purposes [1]. In this context, our interest in the present work is specifically focused on testing the potential performance of typical GPR instruments by means of appropriate data processing. It will be shown in particular to what extent the use of a suitable "microwave tomographic approach" [2] is able to furnish a shape estimation of the targets, possibly recognizing different kinds of canonical geometries, even having reduced cross sections and in critical conditions, where the scatterer size is comparable with resolution limits imposed by the usual measurement configurations. Our study starts by obtaining the typical "direct" information from the GPR techniques that is the scattered field in subsurface environments under the form of radargrams. In order to get a wide variety of scenarios for the operating conditions, this goal is achieved by means of two different and independent approaches [3]. One approach is based on direct measurements through an experimental laboratory setup: commercial GPR instruments (typically bistatic configurations operating around 1 GHz frequency range) are used to collect radargram profiles by investigating an artificial basin filled of liquid and/or granular materials (sand, etc.), in which targets (having different constitutive parameters, shape, and dimensions) can be buried. The other approach is based on numerical GPR simulations by means of a commercial CAD electromagnetic tool (CST), whose suitable implementation and data

  15. Self-Consistent C-V Characterization of Depletion Mode Buried Channel InGaAs/InAs Quantum Well FET Incorporating Strain Effects

    CERN Document Server

    Ahmed, Imtiaz; Alam, Md Hasibul; Chowdhury, Nadim; Azim, Zubair Al; Khosru, Quazi Deen Mohd

    2012-01-01

    We investigated Capacitance-Voltage (C-V) characteristics of the Depletion Mode Buried Channel InGaAs/InAs Quantum Well FET by using Self-Consistent method incorporating Quantum Mechanical (QM) effects. Though the experimental results of C-V for enhancement type device is available in recent literature, a complete characterization of electrostatic property of depletion type Buried Channel Quantum Well FET (QWFET) structure is yet to be done. C-V characteristics of the device is studied with the variation of three important process parameters: Indium (In) composition, gate dielectric and oxide thickness. We observed that inversion capacitance and ballistic current tend to increase with the increase in Indium (In) content in InGaAs barrier layer.

  16. SEM based overlay measurement between resist and buried patterns

    Science.gov (United States)

    Inoue, Osamu; Okagawa, Yutaka; Hasumi, Kazuhisa; Shao, Chuanyu; Leray, Philippe; Lorusso, Gian; Baudemprez, Bart

    2016-03-01

    With the continuous shrink in pattern size and increased density, overlay control has become one of the most critical issues in semiconductor manufacturing. Recently, SEM based overlay of AEI (After Etch Inspection) wafer has been used for reference and optimization of optical overlay (both Image Based Overlay (IBO) and Diffraction Based Overlay (DBO)). Overlay measurement at AEI stage contributes monitor and forecast the yield after formation by etch and calibrate optical measurement tools. however those overlay value seems difficult directly for feedback to a scanner. Therefore, there is a clear need to have SEM based overlay measurements of ADI (After Develop Inspection) wafers in order to serve as reference for optical overlay and make necessary corrections before wafers go to etch. Furthermore, to make the corrections as accurate as possible, actual device like feature dimensions need to be measured post ADI. This device size measurement is very unique feature of CDSEM , which can be measured with smaller area. This is currently possible only with the CD-SEM. This device size measurement is very unique feature of CD-SEM , which can be measured with smaller area. In this study, we assess SEM based overlay measurement of ADI and AEI wafer by using a sample from an N10 process flow. First, we demonstrate SEM based overlay performance at AEI by using dual damascene process for Via 0 (V0) and metal 1 (M1) layer. We also discuss the overlay measurements between litho-etch-litho stages of a triple patterned M1 layer and double pattern V0. Second, to illustrate the complexities in image acquisition and measurement we will measure overlay between M1B resist and buried M1A-Hard mask trench. Finally, we will show how high accelerating voltage can detect buried pattern information by BSE (Back Scattering Electron). In this paper we discuss the merits of this method versus standard optical metrology based corrections.

  17. STUDY ON EXTRACTING METHODS OF BURIED GEOLOGICAL INFORMATION IN HUAIBEI COAL FIELD

    Institute of Scientific and Technical Information of China (English)

    王四龙; 赵学军; 凌贻棕; 刘玉荣; 宁书年; 侯德文

    1999-01-01

    It is discussed features and the producing mechanism of buried geological information in geological, geophysical and remote sensing data in Huaibei coal field, and studied the methods extracting buried tectonic and igneous rock information from various geological data using digital image processing techniques.

  18. A breakdown voltage model for implanted resurf p-LDMOS device on n+ buried layer

    NARCIS (Netherlands)

    Zhou, Ming-Jiang; Van Calster, A.

    1994-01-01

    This paper presents an analytical expression of the breakdown voltage of a high voltage implanted RESURF p-LDMOS device which uses the n+ buried layer as an effective device substrate. In this model, the doping profile of the buried layer is considered and discussed. The implant dose for the drift r

  19. Direct Measurement of the Band Structure of a Buried Two-Dimensional Electron Gas

    DEFF Research Database (Denmark)

    Miwa, Jill; Hofmann, Philip; Simmons, Michelle Y.;

    2013-01-01

    We directly measure the band structure of a buried two dimensional electron gas (2DEG) using angle resolved photoemission spectroscopy. The buried 2DEG forms 2 nm beneath the surface of p-type silicon, because of a dense delta-type layer of phosphorus n-type dopants which have been placed there. ...

  20. Efficient calculation of broadband acoustic scattering from a partially, obliquely buried cylinder

    NARCIS (Netherlands)

    Nijhof, M.J.J.; Espana, A.; Williams, K.

    2013-01-01

    An efficient model for the Target In Environment Response (TIER) of buried/half buried, mine-like objects and UXOs is essential for the development and training of automatic target detection and classification methods and for use in sonar performance prediction models. For instance, to investigate t

  1. Isolated Islands by Selective Local Oxidation (islo): a Silicon-On (soi) Technology for Nanoelectronic and Nanoelectromechanical Applications.

    Science.gov (United States)

    Arney, Susanne Christine

    The development of an advanced fully-integrated nanometer-scale isolation technology called the Isolated Islands of Substrate-Silicon by Selective Lateral Oxidation (ISLO) technology is reported. The versatility and applicability of the ISLO technology for diverse nanoelectronic and nanoelectromechanical devices and systems are described relative to the challenging issues of isolation and contacts. The basic ISLO structure is fabricated using electron beam lithography and standard VLSI reactive ion etching and oxidation processes. Single crystal silicon (SCS) islands 100-300-nm-wide, and 500 -2000-nm-tall are electrically and thermally isolated from the underlying substrate by selective lateral thermal oxidation at the base of the islands. Dislocation-free fully-isolated islands are obtained. Full-isolation of the basic ISLO structure depends on island linewidth, oxidation-masking film thicknesses, recess etch profile, and oxidation time and temperature. The extended ISLO technology provides 100-nm-wide, movable, suspended, high stiffness, low mass, SCS or SCS-dielectric-composite beam segments with integrated electrical contacts and metallization for high frequency (5-10 MHz) nanodynamic applications. Fixed or cantilevered beam segments are isolated from the underlying substrate -silicon by thermally grown oxide or an air-bridge. Wedge -pairs or tip-pairs vertically opposed across the isolation oxide or air-bridge have application to electron tunneling or field emission devices. A selectively-sharpened tip -above-a-tip structure is formed at the intersection of cantilevered beam segments. Vertical triple-tip and quadruple -tip structures are demonstrated. A new deep-submicron self-aligned sidewall source/drain, top-surface gate Thin -Film-Silicon-On-Insulator (TFSOI) MOSFET (ISLO FET) based on the inherently three-dimensional, non-planar ISLO structure is presented. Stress-related defect generation and dopant segregation during the oxidation, erosion of the high

  2. Contribution to classification of buried objects based on acoustic impedance matching.

    Science.gov (United States)

    Stepanić, J; Wüstenberg, H; Krstelj, V; Mrasek, H

    2003-03-01

    Determination of material the buried objects are made of could contribute significantly to their recognition, or classification. This is important in detecting buried antipersonnel landmines within the context of humanitarian demining, as well as in a variety of other applications. In this article the concept has been formulated of the approach to buried object's material determination starting with ultrasonic impulse propagation analysis in a particular testing set configuration. The impulse propagates through a characterized transfer material in such a way that a part of it, a reflected wave, carries the information about the buried object's surface material acoustic impedance. The limit of resolution capability is theoretically analyzed and experimentally evaluated and the influencing factors described. Among these, the contact between clean surfaces of the transfer material and buried object is emphasized.

  3. EFFECT OF CORTICOTROPIN-RELEASING FACTOR ANTAGONIST ON BEHAVIORAL AND NEUROENDOCRINE RESPONSES DURING EXPOSURE TO DEFENSIVE BURYING PARADIGM IN RATS

    NARCIS (Netherlands)

    KORTE, SM; KORTEBOUWS, GAH; BOHUS, B; KOOB, GF

    1994-01-01

    Defensive burying behavior is a coping strategy in rodents in response to an aversive stimulus where fear will facilitate burying and treatment with anxiolytics will result in less burying. To test the hypothesis that endogenous corticotropin-releasing factor (CRF) is involved in the defensive buryi

  4. Bedrock mapping of buried valley networks using seismic reflection and airborne electromagnetic data

    Science.gov (United States)

    Oldenborger, G. A.; Logan, C. E.; Hinton, M. J.; Pugin, A. J.-M.; Sapia, V.; Sharpe, D. R.; Russell, H. A. J.

    2016-05-01

    In glaciated terrain, buried valleys often host aquifers that are significant groundwater resources. However, given the range of scales, spatial complexity and depth of burial, buried valleys often remain undetected or insufficiently mapped. Accurate and thorough mapping of bedrock topography is a crucial step in detecting and delineating buried valleys and understanding formative valley processes. We develop a bedrock mapping procedure supported by the combination of seismic reflection data and helicopter time-domain electromagnetic data with water well records for the Spiritwood buried valley aquifer system in Manitoba, Canada. The limited spatial density of water well bedrock observations precludes complete depiction of the buried valley bedrock topography and renders the water well records alone inadequate for accurate hydrogeological model building. Instead, we leverage the complementary strengths of seismic reflection and airborne electromagnetic data for accurate local detection of the sediment-bedrock interface and for spatially extensive coverage, respectively. Seismic reflection data are used to define buried valley morphology in cross-section beneath survey lines distributed over a regional area. A 3D model of electrical conductivity is derived from inversion of the airborne electromagnetic data and used to extrapolate buried valley morphology over the entire survey area. A spatially variable assignment of the electrical conductivity at the bedrock surface is applied to different features of the buried valley morphology identified in the seismic cross-sections. Electrical conductivity is then used to guide construction of buried valley shapes between seismic sections. The 3D locus of points defining each morphological valley feature is constructed using a path optimization routine that utilizes deviation from the assigned electrical conductivities as the cost function. Our resulting map represents a bedrock surface of unprecedented detail with more

  5. Thermal processing system concepts and considerations for RWMC buried waste

    Energy Technology Data Exchange (ETDEWEB)

    Eddy, T.L.; Kong, P.C.; Raivo, B.D.; Anderson, G.L.

    1992-02-01

    This report presents a preliminary determination of ex situ thermal processing system concepts and related processing considerations for application to remediation of transuranic (TRU)-contaminated buried wastes (TRUW) at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Beginning with top-level thermal treatment concepts and requirements identified in a previous Preliminary Systems Design Study (SDS), a more detailed consideration of the waste materials thermal processing problem is provided. Anticipated waste stream elements and problem characteristics are identified and considered. Final waste form performance criteria, requirements, and options are examined within the context of providing a high-integrity, low-leachability glass/ceramic, final waste form material. Thermal processing conditions required and capability of key systems components (equipment) to provide these material process conditions are considered. Information from closely related companion study reports on melter technology development needs assessment and INEL Iron-Enriched Basalt (IEB) research are considered. Five potentially practicable thermal process system design configuration concepts are defined and compared. A scenario for thermal processing of a mixed waste and soils stream with essentially no complex presorting and using a series process of incineration and high temperature melting is recommended. Recommendations for applied research and development necessary to further detail and demonstrate the final waste form, required thermal processes, and melter process equipment are provided.

  6. The Challenging Buried Bumper Syndrome after Percutaneous Endoscopic Gastrostomy

    Directory of Open Access Journals (Sweden)

    Ibrahim Afifi

    2016-05-01

    Full Text Available Buried bumper syndrome (BBS is a rare complication developed after percutaneous endoscopic gastrostomy (PEG. We report a case of a 38-year-old male patient who sustained severe traumatic brain injury that was complicated with early BBS after PEG tube insertion. On admission, bedside PEG was performed, and 7 days later the patient developed signs of sepsis with rapid progression to septic shock and acute kidney injury. Abdominal CT scan revealed no collection or leakage of the contrast, but showed malpositioning of the tube bumper at the edge of the stomach and not inside of it. Diagnostic endoscopy revealed that the bumper was hidden in the posterolateral part of the stomach wall forming a tract inside of it, which confirmed the diagnosis of BBS. The patient underwent laparotomy with a repair of the stomach wall perforation, and the early postoperative course was uneventful. Acute BBS is a rare complication of PEG tube insertion which could be manifested with severe complications such as pressure necrosis, peritonitis and septic shock. Early identification is the mainstay to prevent such complications. Treatment selection is primarily guided by the presenting complications, ranging from simple endoscopic replacement to surgical laparotomy.

  7. The Challenging Buried Bumper Syndrome after Percutaneous Endoscopic Gastrostomy.

    Science.gov (United States)

    Afifi, Ibrahim; Zarour, Ahmad; Al-Hassani, Ammar; Peralta, Ruben; El-Menyar, Ayman; Al-Thani, Hassan

    2016-01-01

    Buried bumper syndrome (BBS) is a rare complication developed after percutaneous endoscopic gastrostomy (PEG). We report a case of a 38-year-old male patient who sustained severe traumatic brain injury that was complicated with early BBS after PEG tube insertion. On admission, bedside PEG was performed, and 7 days later the patient developed signs of sepsis with rapid progression to septic shock and acute kidney injury. Abdominal CT scan revealed no collection or leakage of the contrast, but showed malpositioning of the tube bumper at the edge of the stomach and not inside of it. Diagnostic endoscopy revealed that the bumper was hidden in the posterolateral part of the stomach wall forming a tract inside of it, which confirmed the diagnosis of BBS. The patient underwent laparotomy with a repair of the stomach wall perforation, and the early postoperative course was uneventful. Acute BBS is a rare complication of PEG tube insertion which could be manifested with severe complications such as pressure necrosis, peritonitis and septic shock. Early identification is the mainstay to prevent such complications. Treatment selection is primarily guided by the presenting complications, ranging from simple endoscopic replacement to surgical laparotomy.

  8. Measure Guideline: Buried and/or Encapsulated Ducts

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.; Zoeller, W.; Mantha, P.

    2013-08-01

    Buried and/or encapsulated ducts (BEDs) are a class of advanced, energy-efficiency strategies intended to address the significant ductwork thermal losses associated with ducts installed in unconditioned attics. BEDs are ducts installed in unconditioned attics that are covered in loose-fill insulation and/or encapsulated in closed cell polyurethane spray foam insulation. This Measure Guideline covers the technical aspects of BEDs as well as the advantages, disadvantages, and risks of BEDs compared to other alternative strategies. This guideline also provides detailed guidance on installation of BEDs strategies in new and existing homes through step-by-step installation procedures. This Building America Measure Guideline synthesizes previously published research on BEDs and provides practical information to builders, contractors, homeowners, policy analysts, building professions, and building scientists. Some of the procedures presented here, however, require specialized equipment or expertise. In addition, some alterations to duct systems may require a specialized license. Persons implementing duct system improvements should not go beyond their expertise or qualifications. This guideline provides valuable information for a building industry that has struggled to address ductwork thermal losses in new and existing homes. As building codes strengthen requirements for duct air sealing and insulation, flexibility is needed to address energy efficiency goals. While ductwork in conditioned spaces has been promoted as the panacea for addressing ductwork thermal losses, BEDs installations approach - and sometimes exceed - the performance of ductwork in conditioned spaces.

  9. Detection of Buried Human Remains Using Bioreporter Fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Vass, A. Dr.; Singleton, G. B.

    2001-10-01

    The search for buried human remains is a difficult, laborious and time-consuming task for law enforcement agencies. This study was conducted as a proof of principle demonstration to test the concept of using bioreporter microorganisms as a means to cover large areas in such a search. These bioreporter microorganisms are affected by a particular component of decaying organic matter that is distinct from decaying vegetation. The diamino compounds cadaverine and putrescine were selected as target compounds for the proof-of-principle investigation, and a search for microorganisms and genes that are responsive to either of these compounds was conducted. One recombinant clone was singled out for characterization based on its response to putrescine. The study results show that small concentrations of putrescine increased expression from this bioreporter construct. Although the level of increase was small (making it difficult to distinguish the signal from background), the results demonstrate the principle that bioreporters can be used to detect compounds resulting from decaying human remains and suggest that a wider search for target compounds should be conducted.

  10. Surface wave propagation effects on buried segmented pipelines

    Institute of Scientific and Technical Information of China (English)

    Peixin Shi

    2015-01-01

    This paper deals with surface wave propagation (WP) effects on buried segmented pipelines. Both simplified analytical model and finite element (FE) model are developed for estimating the axial joint pullout movement of jointed concrete cylinder pipelines (JCCPs) of which the joints have a brittle tensile failure mode under the surface WP effects. The models account for the effects of peak ground velocity (PGV), WP velocity, predominant period of seismic excitation, shear transfer between soil and pipelines, axial stiffness of pipelines, joint characteristics, and cracking strain of concrete mortar. FE simulation of the JCCP interaction with surface waves recorded during the 1985 Michoacan earthquake results in joint pullout movement, which is consistent with the field observations. The models are expanded to estimate the joint axial pullout movement of cast iron (CI) pipelines of which the joints have a ductile tensile failure mode. Simplified analytical equation and FE model are developed for estimating the joint pullout movement of CI pipelines. The joint pullout movement of the CI pipelines is mainly affected by the variability of the joint tensile capacity and accumulates at local weak joints in the pipeline.

  11. Detecting buried explosive hazards with handheld GPR and deep learning

    Science.gov (United States)

    Besaw, Lance E.

    2016-05-01

    Buried explosive hazards (BEHs), including traditional landmines and homemade improvised explosives, have proven difficult to detect and defeat during and after conflicts around the world. Despite their various sizes, shapes and construction material, ground penetrating radar (GPR) is an excellent phenomenology for detecting BEHs due to its ability to sense localized differences in electromagnetic properties. Handheld GPR detectors are common equipment for detecting BEHs because of their flexibility (in part due to the human operator) and effectiveness in cluttered environments. With modern digital electronics and positioning systems, handheld GPR sensors can sense and map variation in electromagnetic properties while searching for BEHs. Additionally, large-scale computers have demonstrated an insatiable appetite for ingesting massive datasets and extracting meaningful relationships. This is no more evident than the maturation of deep learning artificial neural networks (ANNs) for image and speech recognition now commonplace in industry and academia. This confluence of sensing, computing and pattern recognition technologies offers great potential to develop automatic target recognition techniques to assist GPR operators searching for BEHs. In this work deep learning ANNs are used to detect BEHs and discriminate them from harmless clutter. We apply these techniques to a multi-antennae, handheld GPR with centimeter-accurate positioning system that was used to collect data over prepared lanes containing a wide range of BEHs. This work demonstrates that deep learning ANNs can automatically extract meaningful information from complex GPR signatures, complementing existing GPR anomaly detection and classification techniques.

  12. An Effective Method for Borehole Imaging of Buried Tunnels

    Directory of Open Access Journals (Sweden)

    Loreto Di Donato

    2012-01-01

    Full Text Available Detection and imaging of buried tunnels is a challenging problem which is relevant to both geophysical surveys and security monitoring. To comply with the need of exploring large portions of the underground, electromagnetic measurements carried out under a borehole configuration are usually exploited. Since this requires to drill holes in the soil wherein the transmitting and receiving antennas have to be positioned, low complexity of the involved apparatus is important. On the other hand, to effectively image the surveyed area, there is the need for adopting efficient and reliable imaging methods. To address these issues, in this paper we investigate the feasibility of the linear sampling method (LSM, as this inverse scattering method is capable to provide almost real-time results even when 3D images of very large domains are built, while not requiring approximations of the underlying physics. In particular, the results of the reported numerical analysis show that the LSM is capable of performing the required imaging task while using a quite simple measurement configuration consisting of two boreholes and a few number of multiview-multistatic acquisitions.

  13. Surface wave propagation effects on buried segmented pipelines

    Directory of Open Access Journals (Sweden)

    Peixin Shi

    2015-08-01

    Full Text Available This paper deals with surface wave propagation (WP effects on buried segmented pipelines. Both simplified analytical model and finite element (FE model are developed for estimating the axial joint pullout movement of jointed concrete cylinder pipelines (JCCPs of which the joints have a brittle tensile failure mode under the surface WP effects. The models account for the effects of peak ground velocity (PGV, WP velocity, predominant period of seismic excitation, shear transfer between soil and pipelines, axial stiffness of pipelines, joint characteristics, and cracking strain of concrete mortar. FE simulation of the JCCP interaction with surface waves recorded during the 1985 Michoacan earthquake results in joint pullout movement, which is consistent with the field observations. The models are expanded to estimate the joint axial pullout movement of cast iron (CI pipelines of which the joints have a ductile tensile failure mode. Simplified analytical equation and FE model are developed for estimating the joint pullout movement of CI pipelines. The joint pullout movement of the CI pipelines is mainly affected by the variability of the joint tensile capacity and accumulates at local weak joints in the pipeline.

  14. Diagenetic Variations between Upper Cretaceous Outcrop and Deeply Buried Reservoir Chalks of the North Sea Area

    DEFF Research Database (Denmark)

    Hjuler, Morten Leth; Fabricius, Ida Lykke

    2007-01-01

    In the central North Sea Basin hydrocarbon-bearing chalks are deeply buried (2-3 km) whereas chalks in the rim areas are cropping out in the surrounding countries. The differing diagenetic histories between buried and outcrop chalk result in different rock properties, which is of great importance...... when simulating reservoir conditions using outcrop chalks as models. In general deeply buried reservoir chalks show significant overgrowth as witnessed by reshaping of particles together with strengthening of particle contacts. Most outcrop chalks are moderately affected with looser inter...

  15. Pannus Is the New Prepuce? Penile Cancer in a Buried Phallus

    Directory of Open Access Journals (Sweden)

    Jared Manwaring

    2015-01-01

    Full Text Available Two males presented to our urology department with complaints of bleeding and malodor from buried phallus within a suprapubic fat pad. Although both men had neonatal circumcisions, advanced penile carcinoma was found in both men. Formal penectomies showed high grade, poorly differentiated squamous cell carcinoma invading the corporal bodies and urethra. Buried penis represents a difficulty in early detection of suspicious lesions but may also provide an environment susceptible to poor hygiene and subsequent chronic inflammation. Patients with buried penis may be at a higher risk for development of invasive penile cancer and may benefit from regular and thorough genital exams.

  16. An integrated systems approach to remote retrieval of buried transuranic waste using a telerobotic transport vehicle, innovative end effector, and remote excavator

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.M.; Rice, P.; Hyde, R. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States); Peterson, R. [RAHCO International, Spokane, WA (United States)

    1995-02-01

    Between 1952 and 1970, over two million cubic feet of transuranic mixed waste was buried in shallow pits and trenches in the Subsurface Disposal Area at the Idaho National Engineering Laboratory Radioactive Waste Management Complex. Commingled with this two million cubic feet of waste is up to 10 million cubic feet of fill soil. The pits and trenches were constructed similarly to municipal landfills with both stacked and random dump waste forms such as barrels and boxes. The main contaminants are micron-sized particles of plutonium and americium oxides, chlorides, and hydroxides. Retrieval, treatment, and disposal is one of the options being considered for the waste. This report describes the results of a field demonstration conducted to evaluate technologies for excavating, and transporting buried transuranic wastes at the INEL, and other hazardous or radioactive waste sites throughout the US Department of Energy complex. The full-scale demonstration, conduced at RAHCO Internationals facilities in Spokane, Washington, in the summer of 1994, evaluated equipment performance and techniques for digging, dumping, and transporting buried waste. Three technologies were evaluated in the demonstration: an Innovative End Effector for dust free dumping, a Telerobotic Transport Vehicle to convey retrieved waste from the digface, and a Remote Operated Excavator to deploy the Innovative End Effector and perform waste retrieval operations. Data were gathered and analyzed to evaluate retrieval performance parameters such as retrieval rates, transportation rates, human factors, and the equipment`s capability to control contamination spread.

  17. The Activity of Liaocheng-Lankao Buried Fault During the Quaternary——An Important Buried Active Fault in the Eastern China Plain

    Institute of Scientific and Technical Information of China (English)

    Xiang Hongfa; Wang Xuechao; Hao Shujian; Zhang Hui; Guo Shunmin; Li Jinzhao; Li Hongwu; Lin Yuanwu; Zhang Wanxia

    2001-01-01

    On the basis of locating by the geochemical prospecting, shallow seismic sounding, drilling,geological profiling, and neogeochronological dating, we first found out the dislocation amount along the Liaocheng-Lankao buried fault since the Quaternary and the age of its latest activity phase and determined that the upper break point by the fault dislocation reaches 20 m below the surface. The latest activity phase was in the early Holocene and the fault is a shallow-buried active fault. An average dislocation rate along the fault is 0.12 mm/a since the Quaternary.Thus, it is a buried active fault with intermediate to strong movement strength in the eastern China.

  18. Buried late Pleistocene fluvial channels on the inner continental shelf off Vengurla, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    SubbaRaju, L.V.; Krishna, K.S.; Chaubey, A.K.

    Analysis of echosounding, side-scan sonar and shallow seismic data collected west of Burnt islands off Vengurla, west coast of India, revealed a featureless seabed, thicknesses of subsurface layers, and presence of buried channels filled...

  19. Potential of bioremediation for buried oil removal in beaches after an oil spill.

    Science.gov (United States)

    Pontes, Joana; Mucha, Ana P; Santos, Hugo; Reis, Izabela; Bordalo, Adriano; Basto, M Clara; Bernabeu, Ana; Almeida, C Marisa R

    2013-11-15

    Bioremediation potential for buried oil removal, an application still lacking thorough research, was assessed in a specifically designed system in which an artificially contaminated oil layer of sand was buried in a sand column subjected to tidal simulation. The efficiency of biostimulation (BS, fertilizer addition) and bioaugmentation (BA, inoculation of pre-stimulated indigenous hydrocarbon-degrading microorganisms plus fertilizer) compared to natural attenuation was tested during a 180-day experimental period. The effect of BA was evident after 60 days (degradation of hydrocarbons reached 80%). BS efficacy was revealed only after 120 days. Microorganisms and nutrients added at the top of the sand column were able to reach the buried oil layer and contributed to faster oil elimination, an important feature for effective bioremediation treatments. Therefore, autochthonous BA with suitable nutritive conditions results in faster oil-biodegradation, appears to be a cost-effective methodology for buried oil remediation and contributes to the recovery of oil-impacted areas.

  20. Status Report for South Dakota Refuges: American Burying Beetle Searches, 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This memo describes the efforts made throughout South Dakota attempting to locate American Burying Beetles. No beetles were found, but plans for a 1996 involve a...

  1. 2004 American Burying Beetle Annual Report - Pond Creek National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Survey efforts for the endangered American Burying Beetle at Pond Creek NWR in 2004 are reported from 14 sampling locations on the refuge. American buring beetle was...

  2. Seismic fragility analysis of buried steel piping at P, L, and K reactors

    Energy Technology Data Exchange (ETDEWEB)

    Wingo, H.E.

    1989-10-01

    Analysis of seismic strength of buried cooling water piping in reactor areas is necessary to evaluate the risk of reactor operation because seismic events could damage these buried pipes and cause loss of coolant accidents. This report documents analysis of the ability of this piping to withstand the combined effects of the propagation of seismic waves, the possibility that the piping may not behave in a completely ductile fashion, and the distortions caused by relative displacements of structures connected to the piping.

  3. Effect of Biostimulation and Bioaugmentation on Degradation of Polyurethane Buried in Soil▿

    OpenAIRE

    Cosgrove, L.; McGeechan, P. L.; Handley, P. S.; Robson, G. D.

    2009-01-01

    This work investigated biostimulation and bioaugmentation as strategies for removing polyurethane (PU) waste in soil. Soil microcosms were biostimulated with the PU dispersion agent “Impranil” and/or yeast extract or were bioaugmented with PU-degrading fungi, and the degradation of subsequently buried PU was determined. Fungal communities in the soil and colonizing buried PU were enumerated on solid media and were analyzed using denaturing gradient gel electrophoresis (DGGE). Biostimulation w...

  4. Study of Controll over Karstification of Buried Carbonate Hill Reservoir in Renqiu Oilfield

    Institute of Scientific and Technical Information of China (English)

    于俊吉; 韩宝平; 罗承建

    2004-01-01

    Based on boreholes and dynamic development data, the control over karstification of buried carbonate hill reservoir in Renqiu oil field was studied. The result shows that 1) Karstific caves, fissures, and pores in dolomite of Wumishan Formation are the most important reservoir voids, 2) the barrier of argillaceous dolomite can result in the existence of residual oil areas under oil-water interface, and 3) the mosores located on the surface of buried hill are also potential areas of residual oil.

  5. Thin films and buried interfaces characterization with X-ray standing waves

    Energy Technology Data Exchange (ETDEWEB)

    Lagomarsino, S. [CNR, Rome (Italy). Istituto Elettronica Stato Solido

    1996-09-01

    The X-ray standing wave techniques is a powerful, non destructive method to study interfaces at the atomic level. Its basic features are described here together with the peculiarities of its applications to epitaxial films and buried interfaces. As examples of applications, experiments carried out on Si/silicide interfaces, on GaAs/InAs/GaAs buried interfaces and on Si/Ge superlattices are shown.

  6. Molecular phylogeny of the burying beetles (Coleoptera: Silphidae: Nicrophorinae).

    Science.gov (United States)

    Sikes, Derek S; Venables, Chandra

    2013-12-01

    Burying beetles (Silphidae: Nicrophorus) are well-known for their monopolization of small vertebrate carcasses in subterranean crypts and complex biparental care behaviors. They have been the focus of intense behavioral, ecological, and conservation research since the 1980s yet no thorough phylogenetic estimate for the group exists. Herein, we infer relationships, test past hypotheses of relationships, and test biogeographic scenarios among 55 of the subfamily Nicrophorinae's currently valid and extant 72 species. Two mitochondrial genes, COI and COII, and two nuclear genes, the D2 region of 28S, and the protein coding gene CAD, provided 3,971 nucleotides for 58 nicrophorine and 5 outgroup specimens. Ten partitions, with each modeled by GTR+I+G, were used for a 100 M generation MrBayes analysis and maximum likelihood bootstrapping with Garli. The inferred Bayesian phylogeny was mostly well-resolved with only three weak branches of biogeographic relevance. The common ancestor of the subfamily and of the genus Nicrophorus was reconstructed as Old World with four separate transitions to the New World and four reverse colonizations of the Old World from the New. Divergence dating from analysis with BEAST indicate the genus Nicrophorus originated in the Cretaceous, 127-99 Ma. Most prior, pre-cladistic hypotheses of relationships were strongly rejected while most modern hypotheses were largely congruent with monophyletic groups in our estimated phylogeny. Our results reject a recent hypothesis that Nicrophorus morio Gebler, 1817 (NEW STATUS as valid species) is a subspecies of N. germanicus (L., 1758). Two subgenera of Nicrophorus are recognized: NecroxenusSemenov-Tian-Shanskij, 1933, and NicrophorusFabricius, 1775.

  7. FOREWORD: Special section on electromagnetic characterization of buried obstacles

    Science.gov (United States)

    Lesselier, Dominique; Chew, Weng Cho

    2004-12-01

    This Inverse Problems special section on electromagnetic characterization of buried obstacles contains a selection of 14 invited papers, involving 41 authors and 19 research groups worldwide. (Though this section consists of invited papers, the standard refereeing procedures of Inverse Problems have been rigorously observed.) We do not claim to have reached all the high-level researchers in the field, but we believe that we have made a fair attempt. As illustrated by the variety of contributions included, the aim of this special section is to address theoretical and practical inversion problems (and the solutions thereof) that arise in the field of electromagnetic characterization of obstacles (artificial or natural) buried on the Earth or in planetary subsoil. Civil and military engineering, archaeological and environmental issues are typically among those within the scope of the investigation. An example is the characterization of a single (or multiple) obstacle(s) located near the interface or at shallow depths via electromagnetic means operating within relevant frequency bands. However, we also welcomed novel and thought-provoking investigations, even though their direct application to the real world, or even to laboratory-controlled settings, may still be far off. Within this general mathematical and applied framework, the submitted papers focused on a combination of theoretical, computational and experimental developments. They either reviewed the most recent advances in a particular area of research or were an original and specialized contribution. Let us now take the opportunity to remind the readers that this special section harks back (in addition to sharing some common contributors) to two special sections already published in the journal which possessed the same flavour of wave-field inversion and its many applications. They were `Electromagnetic imaging and inversion of the Earth's subsurface', which was published in October 2000 (volume 16, issue 5

  8. A process for ensuring regulatory compliance at the INEL`s buried waste integrated demonstrations

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, P.G.; Watson, L.R.; Blacker, P.B. [EG and G Idaho, Inc., Idaho Falls, ID (United States). Idaho National Engineering Lab.

    1993-03-01

    The Buried Waste Integrated Demonstration Program is funded by the Department of Energy Office of Technology Development. The mission of this Integrated Demonstration is to identify, evaluate, and demonstrate a suite of innovative technologies for the remediation of radioactive and hazardous waste buried throughout the DOE complex between 1950 and 1970. The program approach to development of a long-range strategy for improving buried waste remediation capabilities is to combine systems analysis with already identified remediation needs for DOE complex buried waste. The systems analysis effort has produced several configuration options (a top-level block diagram of a cradle-to-grave remediation system) capable of remediating the transuranic-contaminated waste pits and trenches at the Idaho National Engineering Laboratory. Technologies for demonstration are selected using three criteria: (a) the ability to satisfy a specific buried waste need, (b) the ability to satisfy functional and operational requirements defined for functional sub-elements in a configuration option, and (c) performance against Comprehensive Environmental Restoration and Compensation Liability Act selection criteria, such as effectiveness, implementability, and cost. Early demonstrations experienced problems with missed requirements, prompting the Buried Waste Integrated Demonstration Program Office to organize a Corrective Action Team to identify the cause and recommend corrective actions. The result of this team effort is the focus of this paper.

  9. Enforced water drinking induces changes in burying behavior and social interaction test in rats.

    Science.gov (United States)

    Saldívar-González, J A; Hernández-León, M J; Mondragón-Ceballos, R

    1996-09-01

    The effect of water deprivation and water intake on experimental anxiety in rats was tested using burying behavior (BB) and social interaction (SI) anxiety paradigms. Two groups of animals were studied: a control group with free access to water, and a 72-h water-deprived experimental group. Anxiety was studied in a water-deprived group or following a 10-min period of ad lib water drinking. An increase in the mean time of defensive burying in animals deprived for 72 h was observed, whereas an important reduction occurred in the levels of burying behavior immediately after the animals were allowed to drink ad lib for 10 min. These results suggest that the observed increase in defensive burying in the water-deprived animals represents an anxiogenic effect, whereas the decrease in this behavior in water-satiated animals is considered an anxiolytic action. The temporal course of reduction in burying behavior, observed after water drinking, revealed that the anxiolytic action lasts 5 min, whereas 15-30 min after drinking, burying behavior levels were similar to those in the control group. In the social interaction experiment a partial anxiogenic/anxiolytic effect of water deprivation and water intake was observed. The adaptive meaning of anxiogenic and anxiolytic changes linked to consummatory behaviors in rats is discussed on the basis of behavioral and biochemical data.

  10. Differentiating Mild Papilledema and Buried Optic Nerve Head Drusen Using Spectral Domain Optical Coherence Tomography

    Science.gov (United States)

    Kulkarni, Kaushal M.; Pasol, Joshua; Rosa, Potyra R.; Lam, Byron L.

    2013-01-01

    Purpose To evaluate the clinical utility of spectral domain optical coherence tomography (SD-OCT) in differentiating mild papilledema from buried optic nerve head drusen (ONHD). Design Comparative case series. Participants 16 eyes of 9 patients with ultrasound-proven buried ONHD, 12 eyes of 6 patients with less than or equal to Frisén grade 2 papilledema due to idiopathic intracranial hypertension. 2 normal fellow eyes of patients with buried ONHD were included. Methods A raster scan on the optic nerve and retinal nerve fiber layer (RNFL) thickness analysis was performed on each eye using SD-OCT. Eight eyes underwent enhanced depth imaging SD-OCT. Images were assessed qualitatively and quantitatively to identify differentiating features between buried ONHD and papilledema. Five clinicians trained with a tutorial and masked to the underlying diagnosis reviewed the SD-OCT images of each eye independently to determine the diagnosis. Main outcome measures Differences in RNFL thickness in each quadrant between the two groups, and diagnostic accuracy of five independent clinicians based on the SD-OCT images alone. Results We found no statistically significant difference in RNFL thickness between buried ONHD and papilledema in any of the four quadrants. Diagnostic accuracy among the readers was low and ranged from 50–64%. The kappa coefficient of agreement among the readers was 0.35 (95% Confidence interval: 0.19, 0.54). Conclusions SD-OCT is not clinically reliable in differentiating buried ONHD and mild papilledema. PMID:24321144

  11. Cannabidiol reverses the mCPP-induced increase in marble-burying behavior.

    Science.gov (United States)

    Nardo, Mirella; Casarotto, Plinio C; Gomes, Felipe V; Guimarães, Francisco S

    2014-10-01

    Cannabidiol (CBD), one of the main components of Cannabis sp., presents clinical and preclinical anxiolytic properties. Recent results using the marble-burying test (MBT) suggest that CBD can also induce anticompulsive-like effects. Meta-chloro-phenyl-piperazine (mCPP) is a nonspecific serotonergic agonist (acting mainly at 5HT1A, 5HT2C and 5HT1D receptors) reported to increase symptoms in OCD patients and block the anticompulsive-like effect of serotonin reuptake inhibitors (SRIs) in animal models. The aim of this study was to investigate the interference of CBD on mCPP effects in repetitive burying. Administration of mCPP showed dual effects in the MBT, increasing the number of buried marbles at lower (0.1 mg/kg) while decreasing it at higher doses (1 mg/kg), an effect not related to a general increase in anxiety-like behavior. As found previously, CBD (30 mg/kg) and the positive control fluoxetine (FLX; 10 mg/kg) decreased burying behavior without changing general exploratory activity. A similar effect was found when subeffective doses of CBD (15 mg/kg) and FLX (3 mg/kg) were administered together. These subeffective doses alone were also able to block mCPP-induced repetitive burying. The results, in addition to reinforcing a possible anticompulsive effect of CBD, also suggest that mCPP-induced repetitive burying could be a useful test for the screening of compounds with presumed anticompulsive properties.

  12. Wintertime storage of water in buried supraglacial lakes across the Greenland Ice Sheet

    Directory of Open Access Journals (Sweden)

    L. S. Koenig

    2014-07-01

    Full Text Available Surface melt over the Greenland Ice Sheet (GrIS is increasing and estimated to account for half or more of the total mass loss. Little, however, is known about the hydrologic pathways that route surface melt within the ice sheet. In this study, we present over-winter storage of water in buried supraglacial lakes as one hydrologic pathway for surface melt, referred to as buried lakes. Airborne radar echograms are used to detect the buried lakes that are distributed extensively around the margin of the GrIS. The subsurface water can persist through multiple winters and is, on average, ~4.2 + 0.4 m below the surface. The few buried lakes that are visible at the surface of the GrIS have a~unique visible signature associated with a darker blue color where subsurface water is located. The volume of retained water in the buried lakes is likely insignificant compared to the total mass loss from the GrIS but the water will have important implications locally for the development of the englacial hydrologic network, ice temperature profiles and glacial dynamics. The buried lakes represent a small but year-round source of meltwater in the GrIS hydrologic system.

  13. Modelling the buried human body environment in upland climes using three contrasting field sites.

    Science.gov (United States)

    Wilson, Andrew S; Janaway, Robert C; Holland, Andrew D; Dodson, Hilary I; Baran, Eve; Pollard, A Mark; Tobin, Desmond J

    2007-06-14

    Despite an increasing literature on the decomposition of human remains, whether buried or exposed, it is important to recognise the role of specific microenvironments which can either trigger or delay the rate of decomposition. Recent casework in Northern England involving buried and partially buried human remains has demonstrated a need for a more detailed understanding of the effect of contrasting site conditions on cadaver decomposition and on the microenvironment created within the grave itself. Pigs (Sus scrofa) were used as body analogues in three inter-related taphonomy experiments to examine differential decomposition of buried human remains. They were buried at three contrasting field sites (pasture, moorland, and deciduous woodland) within a 15 km radius of the University of Bradford, West Yorkshire, UK. Changes to the buried body and the effect of these changes on hair and associated death-scene textile materials were monitored as was the microenvironment of the grave. At recovery, 6, 12 and 24 months post-burial, the extent of soft tissue decomposition was recorded and samples of fat and soil were collected for gas chromatography mass spectrometry (GCMS) analysis. The results of these studies demonstrated that (1) soil conditions at these three burial sites has a marked effect on the condition of the buried body but even within a single site variation can occur; (2) the process of soft tissue decomposition modifies the localised burial microenvironment in terms of microbiological load, pH, moisture and changes in redox status. These observations have widespread application for the investigation of clandestine burial and time since deposition, and in understanding changes within the burial microenvironment that may impact on biomaterials such as hair and other associated death scene materials.

  14. Development of hard X-ray photoelectron SPLEED-based spectrometer applicable for probing of buried magnetic layer valence states

    Energy Technology Data Exchange (ETDEWEB)

    Kozina, Xeniya, E-mail: kozina@uni-mainz.de [Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo 679-5198 (Japan); Ikenaga, Eiji [Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo 679-5198 (Japan); Viol Barbosa, Carlos Eduardo; Ouardi, Siham; Karel, Julie [Max-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden (Germany); Yamamoto, Masafumi [Division of Electronics for Informatics, Hokkaido University, Sapporo 060-0814 (Japan); Kobayashi, Keisuke [Japan Atomic Energy Agency, SPring-8, Hyogo 679-5148 (Japan); Elmers, Hans Joachim; Schönhense, Gerd [Institut für Physik, Johannes Gutenberg – Universität, 55099 Mainz (Germany); Felser, Claudia [Max-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden (Germany)

    2016-08-15

    Highlights: • A high-voltage compatible spin-HAXPES detector based on SPLEED from W(001) has been developed. • Magnetic properties of a TMR device were studied by core-level photoemission on the Fe 2p{sub 3/2} states. • The developed instrument enabled probing of buried layers in the region of the valence states. - Abstract: A novel design of high-voltage compatible polarimeter for spin-resolved hard X-ray photoelectron spectroscopy (Spin-HAXPES) went into operation at beamline BL09XU of SPring-8 in Hyogo, Japan. The detector is based on the well-established principle of electron diffraction from a W(001) single-crystal at a scattering energy of 103.5 eV. It's special feature is that it can be operated at a high negative bias potential up to 10 kV, necessary to access the HAXPES range. The polarimeter is operated behind a large hemispherical analyzer (Scienta R-4000). It was optimized for high transmission of the transfer optics. A delay-line detector (20 mm dia.) is positioned at the exit plane of the analyzer enabling conventional multichannel intensity spectroscopy simultaneously with single-channel spin analysis. The performance of the combined setup is demonstrated by the spin-resolved data for the valence-region of a FeCo functional layer of a tunneling device, buried beneath 3 nm of oxidic material. The well-structured spin polarization spectrum validates Spin-HAXPES in the valence energy range as powerful method for bulk electronic structure analysis. The spin polarization spectrum exhibits a rich structure, originating from clearly discernible transitions in the majority and minority partial spin spectra.

  15. High-responsivity 40 Gbit/s InGaAs/InP PIN photodetectors integrated on silicon-on-insulator waveguide circuits

    Science.gov (United States)

    Dongdong, Yin; Tingting, He; Qin, Han; Qianqian, Lü; Yejin, Zhang; Xiaohong, Yang

    2016-11-01

    This paper presents a high-responsivity and high-speed InGaAs/InP PIN photodetector integrated onto the silicon waveguide substrate utilizing the divinyltetramethyldisiloxane-benzocyclobutene (DVS-BCB) adhesive bonding method. A grating coupler is adopted to couple light from the fiber to the silicon waveguide. Light in the silicon photonic waveguide is evanescently coupled into the photodetector. The integrated photodetector structure is first simulated using the FDTD (finite difference time domain) solutions software and the simulation results show a detection efficiency of 95%. According to the simulation result, the integrated photodetector is fabricated. The measured responsivity of the fabricated integrated photodetector with a detection length of 30 μm is 0.89 A/W excluding the coupling loss between the fiber and the grating coupler and the silicon propagation loss at the wavelength of 1550 nm with a reverse bias voltage of 3 V. Measured 3-dB bandwidth is 27 GHz using the Lightwave Component Analyzer (LCA). The eye diagram signal test results indicate that the photodetector can operate at a high speed of 40 Gbit/s. The integrated photodetector is of great significance in the silicon-based optoelectronic integrated chip which can be applied to the optical communication and the super node data transmission chip of the high-performance computer. Project supported by the High-Tech Research and Development Program of China (Nos. 2015AA016904, 2015AA012302), the National Basic Research Program of China (Nos. 2012CB933503, 2013CB932904), and the National Natural Foundation of China (Nos. 61274069, 61176053, 61021003, 61435002).

  16. Tunable filter based on silicon-on-insulator microring resonator%SoI基微环谐振可调谐滤波器

    Institute of Scientific and Technical Information of China (English)

    姜宏伟; 吴远大

    2011-01-01

    采用电子束光刻和ICP刻蚀等工艺制作出绝缘体上Si(SoI)基纳米线波导微环谐振(MRR)滤波器,波导截面尺寸为300 nm×320 nm,微环半径为5 μm.测试结果表明,器件的自由频谱宽度(FSR)为16.8nm,1.55μm波长附近的消光比(ER)为18.1 dB.通过对MRR滤波器进行热光调制,在21.4~60.0℃温度范围内实现了4.8 nm波长范围的可调谐滤波特性,热光调谐效率达到0.12nm/℃.%Microring-resonator filters are fabricated by E-beam photolithography and inductive-coupled-plasma(ICP) etching technology. The cross-section size of the strip waveguides is 300 nm×320 ran,and the bending radius of the microring is 5 fun. The measured results show that the free spectral range (FSR) and extinction ratio (ER) at the wavelength of 1550 nm are 16. 8 nm and 18.1 dB,respectively. After thermo-optic modulation, the tunable filter wavelength range reaches 4. 8 nm,and the tuning efficiency is 0.12 nm /℃.

  17. Strain mapping with nm-scale resolution for the silicon-on-insulator generation of semiconductor devices by advanced electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, David; Denneulin, Thibaud; Barnes, Jean-Paul; Hartmann, Jean-Michel; Hutin, Louis; Le Royer, Cyrille [CEA, LETI France MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Beche, Armand [CEA, LETI, and FEI France MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Rouviere, Jean-Luc [CEA, INAC, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

    2012-12-15

    Strain engineering in the conduction channel is a cost effective method of boosting the performance in state-of-the-art semiconductor devices. However, given the small dimensions of these devices, it is difficult to quantitatively measure the strain with the required spatial resolution. Three different transmission electron microscopy techniques, high-angle annular dark field scanning transmission electron microscopy, dark field electron holography, and nanobeam electron diffraction have been applied to measure the strain in simple bulk and SOI calibration specimens. These techniques are then applied to different gate length SiGe SOI pFET devices in order to measure the strain in the conduction channel. For these devices, improved spatial resolution is required, and strain maps with spatial resolutions as good as 1 nm have been achieved. Finally, we discuss the relative advantages and disadvantages of using these three different techniques when used for strain measurement.

  18. Theoretical-Experimental Analysis of the Effects of Grain Boundaries on the Electrical Properties of SOI (Silicon-on-Insulator) MOSFETS.

    Science.gov (United States)

    1983-11-01

    Insulating Substrate", IEEE Electron Device Lett., vol. EDL-l, pp. 206-208, Oct. 1980. 2. B.-Y. Tsaur, M. W. Geis, J. C. C. Fan, D. J. Silversmith , and P...Electron Device Lett., vol. EDL-I, pp. 206-208, Oct. 1980. 3. B.-Y. Tsaur, M. W. Geis, J. C. C. Fan, D. J. Silversmith , and P. W. Mountain, "n-Channel Deep...Lett., vol. EDL-I, pp. 206-208, Oct. 1980. 2. B.-Y. Tsaur, M. W. Geis, J. C. C. Fan, D. J. Silversmith , and R. W. Mountain, "n-Channel Deep-Depletion

  19. A Laboratory Project on the Theory, Fabrication, and Characterization of a Silicon-on-Insulator Micro-Comb Drive Actuator with Fixed-Fixed Beams

    Science.gov (United States)

    Abbas, K.; Leseman, Z. C.

    2012-01-01

    A laboratory course on the theory, fabrication, and characterization of microelectromechanical systems (MEMS) devices for a multidisciplinary audience of graduate students at the University of New Mexico, Albuquerque, has been developed. Hands-on experience in the cleanroom has attracted graduate students from across the university's engineering…

  20. Accelerometer measurements of acoustic-to-seismic coupling above buried objects.

    Science.gov (United States)

    Attenborough, Keith; Qin, Qin; Jefferis, Jonathan; Heald, Gary

    2007-12-01

    The surface velocity of sand inside a large PVC container, induced by the sound pressure from either a large loudspeaker radiating into an inverted cone and pipe or a Bruel and Kjaer point source loudspeaker mounted with its axis vertical, has been measured using accelerometers. Results of white noise and stepped frequency excitation are presented. Without any buried object the mass loading of an accelerometer creates resonances in the spectral ratio of sand surface velocity to incident acoustic pressure, i.e., the acoustic-to-seismic (A/S) admittance spectra. The A/S responses above a buried compliant object are larger and distinctive. The linear A/S admittance spectra in the presence of a buried electronic components box have been studied as a function of burial depth and sand state. The nonlinear responses above the buried box have been studied as a function of depth, sand state, and amplitude. Predictions of a modified one-dimensional lumped parameter model have been found to be consistent with the observed nonlinear responses. Also the modified model has been used to explain features of the A/S responses observed when using an accelerometer without any buried object.

  1. Real-time corrosion control system for cathodic protection of buried pipes for nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Tae; Kim, Hae Woong; Kim, Young Sik [School of Materials Science and Engineering, Andong National University, Andong (Korea, Republic of); Chang, Hyun Young; Lim, Bu Taek; Park, Heung Bae [Power Engineering Research Institute, KEPCO Engineering and Construction Company, Seongnam (Korea, Republic of)

    2015-02-15

    Since the operation period of nuclear power plants has increased, the degradation of buried pipes gradually increases and recently it seems to be one of the emerging issues. Maintenance on buried pipes needs high quality of management system because outer surface of buried pipe contacts the various soils but inner surface reacts with various electrolytes of fluid. In the USA, USNRC and EPRI have tried to manage the degradation of buried pipes. However, there is little knowledge about the inspection procedure, test and manage program in the domestic nuclear power plants. This paper focuses on the development and build-up of real-time monitoring and control system of buried pipes. Pipes to be tested are tape-coated carbon steel pipe for primary component cooling water system, asphalt-coated cast iron pipe for fire protection system, and pre-stressed concrete cylinder pipe for sea water cooling system. A control system for cathodic protection was installed on each test pipe which has been monitored and controlled. For the calculation of protection range and optimization, computer simulation was performed using COMSOL Multiphysics (Altsoft co.)

  2. Buried free flaps in head and neck reconstruction: higher risk of free flap failure?

    Science.gov (United States)

    Reiter, M; Harréus, U; Kisser, U; Betz, C S; Baumeister, Ph

    2017-01-01

    Thrombosis of the pedicle is central to free flap failure, and early revision of a compromised flap is the key to successfully salvage a flap. Therefore, the majority of free flaps in reconstructive head and neck surgery are used with the ability to visually examine the flap. Sometimes, due to intra-operative circumstances, it is necessary to use a flap that cannot be monitored externally. These flaps are called buried flaps and have the reputation of being put at risk. The current literature provides only limited data to support or disprove this position. A single institution retrospective review of patient charts between 2007 and 2015 was performed. Flap monitoring was carried out with hand-held Doppler of the pedicle hourly for the first 72 h in all cases. Additional duplex ultrasound was performed in the majority of buried flaps. A total of 437 flaps were included into the study. 37 flaps (7.8 %) were identified to fulfill the criteria of a buried free flap. In total, four patients had complications, three of which required operative reexploration. All interventions were successful, resulting in no flap loss in our series. An accurate operation technique combined with meticulous monitoring protocols supported by duplex ultrasound can result in satisfactory outcome of buried flaps. No enhanced risk of flap loss of buried flaps was found in our cohort.

  3. Predicting arsenic concentrations in the porewaters of buried uranium mill tailings

    Science.gov (United States)

    Langmuir, Donald; Mahoney, John; MacDonald, Anjali; Rowson, John

    1999-10-01

    The proposed JEB Tailings Management Facility (TMF) to be emplaced below the groundwater table in northern Saskatchewan, Canada, will contain uranium mill tailings from McClean Lake, Midwest and Cigar Lake ore bodies, which are high in arsenic (up to 10%) and nickel (up to 5%). A serious concern is the possibility that high arsenic and nickel concentrations may be released from the buried tailings, contaminating adjacent groundwaters and a nearby lake. Laboratory tests and geochemical modeling were performed to examine ways to reduce the arsenic and nickel concentrations in TMF porewaters so as to minimize such contamination from tailings buried for 50 years and longer. The tests were designed to mimic conditions in the mill neutralization circuit (3 hr tests at 25°C), and in the TMF after burial (5-49 day aging tests). The aging tests were run at, 50, 25 and 4°C (the temperature in the TMF). In order to optimize the removal of arsenic by adsorption and precipitation, ferric sulfate was added to tailings raffinates having Fe/As ratios of less that 3-5. The acid raffinates were then neutralized by addition of slaked lime to nominal pH values of 7, 8, or 9. Analysis and modeling of the test results showed that with slaked lime addition to acid tailings raffinates, relatively amorphous scorodite (ferric arsenate) precipitates near pH 1, and is the dominant form of arsenate in slake limed tailings solids except those high in Ni and As and low in Fe, in which cabrerite-annabergite (Ni, Mg, Fe(II) arsenate) may also precipitate near pH 5-6. In addition to the arsenate precipitates, smaller amounts of arsenate are also adsorbed onto tailings solids. The aging tests showed that after burial of the tailings, arsenic concentrations may increase with time from the breakdown of the arsenate phases (chiefly scorodite). However, the tests indicate that the rate of change decreases and approaches zero after 72 hrs at 25°C, and may equal zero at all times in the TMF at 4

  4. 3D Imaging of Dielectric Objects Buried under a Rough Surface by Using CSI

    Directory of Open Access Journals (Sweden)

    Evrim Tetik

    2015-01-01

    Full Text Available A 3D scalar electromagnetic imaging of dielectric objects buried under a rough surface is presented. The problem has been treated as a 3D scalar problem for computational simplicity as a first step to the 3D vector problem. The complexity of the background in which the object is buried is simplified by obtaining Green’s function of its background, which consists of two homogeneous half-spaces, and a rough interface between them, by using Buried Object Approach (BOA. Green’s function of the two-part space with planar interface is obtained to be used in the process. Reconstruction of the location, shape, and constitutive parameters of the objects is achieved by Contrast Source Inversion (CSI method with conjugate gradient. The scattered field data that is used in the inverse problem is obtained via both Method of Moments (MoM and Comsol Multiphysics pressure acoustics model.

  5. Effect of soil restraint on the buckling response of buried pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Mahdavi Amiri, H.; Kenny, Shawn [Memorial University of Newfoundland (Canada); Phillips, Ryan [C-CORE (Canada); Popescu, Radu [URS Corporation (United States)

    2010-07-01

    In the oil and gas sector, transportation and distribution are mainly done suing onshore buried steel pipelines. These pipelines are subjected to numerous geohazards which can provoke significant deformations and it is thus important to evaluate the pipeline strain capacity. Common practice is to use a model developed using the pipeline mechanical response for in-air conditions; however, this does not account for the soil effect and the authors have developed a criterion for pipelines buried in stiff clay. The aim of this paper is to compare both methods and evaluate the effect of soil restraint on local buckling response. Results of the investigations showed that the in-air based criteria provide lower critical strain values than the developed criterion; they also showed that the soil has a restraining effect, which increases the pipeline bending resistance. This paper demonstrated that the soil effect should be considered when calculating the strain capacity of a buried pipeline.

  6. 3D Characteristic Diagram of Acoustically Induced Surface Vibration with Different Landmines Buried

    Institute of Scientific and Technical Information of China (English)

    吴智强; 张燕丽; 王驰; 朱俊; 徐文文; 袁志文

    2016-01-01

    The 3Dcharacteristic diagram of acoustically induced surface vibration was employed to study the influence of different buried landmines on the acoustic detection signal. By using the vehicular experimental system for acoustic landmine detection and the method of scanning detection, the 3D characteristic diagrams of surface vibration were measured when different objects were buried underground, including big plastic landmine, small plastic landmine, big metal landmine and bricks. The results show that, under the given conditions, the surface vi-bration amplitudes of big plastic landmine, big metal landmine, small plastic landmine and bricks decrease in turn. The 3D characteristic diagrams of surface vibration can be used to further identify the locations of buried land-mines.

  7. Selective emitters in buried contact silicon solar cells. Some low-cost solutions

    Energy Technology Data Exchange (ETDEWEB)

    Pirozzi, L.; Arabito, G.; Artuso, F.; Barbarossa, V.; Besi-Vetrella, U.; Loreti, S.; Mangiapane, P.; Salza, E. [ENEA Casaccia, Via Anguillarese 301, 00060 Roma (Italy)

    2001-01-01

    We present the results of our study on the formation of selective emitter structures in buried contact cells. In particular, our attention has been focused on those processes that seem to be scalable to industry. To this aim, specific dopant sources and fabrication steps have been selected.Two different kinds of dopants have been considered: the P-doped SOD and the screen-printed dopant paste. For both sources we have tested the feasibility of the selective diffusion formation in a single step, together with the application of suitable techniques to get selective doping, such as laser enhanced diffusion into the grooves, or selective deposition of screen printed paste in buried grid pattern. SEM and SEM-EBIC analyses have been used to investigate the occurrence of doping. Several batches of buried contact, mechanically grooved cells have prepared and tested.

  8. Testing MODFLOW-LGR for simulating flow around Buried Quaternary valleys - synthetic test cases

    DEFF Research Database (Denmark)

    Vilhelmsen, Troels Norvin; Christensen, Steen

    In Denmark the water supply is entirely based on ground water. In some parts of the country these resources are found in buried quaternary tunnel valleys. Intensive mapping has shown that the valleys typically have a complex internal hydrogeology with multiple cut and ­fill structures. The admini...... on the results we will evaluate how to use the method to re­fine a regional scale model covering an area north of the town of Aarhus, Denmark. The area, which contains several buried valleys, is marked with a red square on the map.......­finement (LGR) method developed for MODFLOW-2005 for simulation of groundwater flow in areas containing buried valleys. The tests are conducted as comparative analysis between simulations made with a globally refi­ned model, a locally re­fined model, and a globally coarse model, respectively. Based...

  9. Numerical Modeling for Impact-resistant Pipes Buried at Shallow Depth

    Science.gov (United States)

    Wang, Ching-Jong; Hsu, Jung-Fu

    2010-05-01

    The plastic pipes buried at shallow depth are popular for underground telecommunication lines. To assess their impact-worthiness under loads from heavy traffics, the study establishes a numerical model to correlate with field data. Field impact tests were carried out where a 50-kg mass free-falling at 2.2 m height was dropped onto the soil backfill directly above a buried pipe. A contact-impact model incorporating finite elements of disjoined material regions is developed to simulate the phenomena of mass-soil-pipe interaction and soil dent. Plastic soil deformations are accounted for. Also implemented is a new erosion scheme for dealing with numerical instability caused by crumpled elements during heavy impact. Reasonable agreements can be observed between the analyzed and measured soil dent. This model is versatile in making design evaluations for buried pipes to withstand impact loads. It has potential applications to cemented soil fills and blast loads.

  10. Imaging of dielectric objects buried under a rough surface via distorted born iterative method

    Energy Technology Data Exchange (ETDEWEB)

    Altuncu, Y [Nigde University, Electrical and Electronic Engineering Department, Nigde (Turkey); Akleman, F; Semerci, O; Ozlem, C [Istanbul Technical University, Electrical and Electronic Faculty, Maslak-Istanbul (Turkey)], E-mail: altuncuy@itu.edu.tr

    2008-11-01

    A method is given for the shape, permittivity and conductivity reconstruction of lossy dielectric objects buried under rough surfaces using the Distorted Born Iterative Method (DBIM). The method is based on the refreshing of the Green's function of the two-part space media with rough interface by updating the complex permittivity of the reconstruction domain at each iteration step. The scattered field data are measured at multiple locations for multiple transmitters operating at a single frequency where both transmitters and receivers are located above the rough surface interface. The Green's function of the problem is obtained by using the buried object approach (BOA) method where the fluctuations of the rough surface from the flat one are assumed to be buried objects in a two-part space with planar interface. The performance of the method is tested by some numerical applications and satisfactory results are obtained.

  11. A one dimensional numerical approach for computing the eigenmodes of elastic waves in buried pipelines

    Science.gov (United States)

    Duan, Wenbo; Kirby, Ray; Mudge, Peter; Gan, Tat-Hean

    2016-12-01

    Ultrasonic guided waves are often used in the detection of defects in oil and gas pipelines. It is common for these pipelines to be buried underground and this may restrict the length of the pipe that can be successfully tested. This is because acoustic energy travelling along the pipe walls may radiate out into the surrounding medium. Accordingly, it is important to develop a better understanding of the way in which elastic waves propagate along the walls of buried pipes, and so in this article a numerical model is developed that is suitable for computing the eigenmodes for uncoated and coated buried pipes. This is achieved by combining a one dimensional eigensolution based on the semi-analytic finite element (SAFE) method, with a perfectly matched layer (PML) for the infinite medium surrounding the pipe. This article also explores an alternative exponential complex coordinate stretching function for the PML in order to improve solution convergence. It is shown for buried pipelines that accurate solutions may be obtained over the entire frequency range typically used in long range ultrasonic testing (LRUT) using a PML layer with a thickness equal to the pipe wall thickness. This delivers a fast and computationally efficient method and it is shown for pipes buried in sand or soil that relevant eigenmodes can be computed and sorted in less than one second using relatively modest computer hardware. The method is also used to find eigenmodes for a buried pipe coated with the viscoelastic material bitumen. It was recently observed in the literature that a viscoelastic coating may effectively isolate particular eigenmodes so that energy does not radiate from these modes into the surrounding [elastic] medium. A similar effect is also observed in this article and it is shown that this occurs even for a relatively thin layer of bitumen, and when the shear impedance of the coating material is larger than that of the surrounding medium.

  12. Characteristics and genetic mechanism of deep-buried clastic eureservoir in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Systematic researches to the clastic reservoirs in various types and various geological ages basins in China indicate that the present burial depth of deep buried clastic eureservoir ranges from 3000 to 6000 m,and its geological ages from Paleozoic,Mesozoic to Cenozoic. It mainly deposited in delta (including braid delta,fan delta,normal delta),river,also shore,shallow lake,gravity flow channel and turbidity fan facies. The quartzose sandstone is the main reservoir rock of deep-buried clastic eureservoir in the shore facies in Paleozoic,but the arenite and arkose sandstones are the main reservoir rock types in delta,river,shallow lake and gravity flow facies in Mesozoic and Cenozoic. The porosity of most of deep-buried clastic eureservoir is more than 10% and permeability more than 10×10?3 μm2. The forma-tion of the deep-buried eureservoir was related to the paleotectonics,paleotemperature,sedimentary environment,the deep dissolution caused by organic acid or carbonic acid,burial style,the abnormal high pore fluid pressure,early hydrocarbon charging,gyprock sealing,hot convective fluid flow and the mode of sand-mud interbedded,etc. The paleotectonics controls the burial style of sandstones,and the paleotemperature controls the diagenesis process. The sedimentary environment is the precondi-tion and foundation,the dissolution is the direct reason to generate the deep buried clastic eureservoir. The abnormal high pore fluid pressure,gyprock sealing,the mode of sand-mud interbedded,early hy-drocarbon charging and the structure fractures were the assistant factors of generating the deep buried clastic eureservoir.

  13. Real-time buried threat detection and cueing capability in VPEF environment

    Science.gov (United States)

    Ling, Bo; Agarwal, Sanjeev; Olivera, Santiago; Vasilkoski, Zlatko; Phan, Chung; Geyer, Chris

    2015-05-01

    In this paper, we present a vehicular buried threat detection approach developed over the past several years, and its latest implementation and integration in VPEF environment. Buried threats have varying signatures under different operation environment. To reliably detect the true targets and minimizing the number of false alarms, a suite of false alarm mitigators (FAMs) have been developed to process the potential targets identified by the baseline module. A vehicle track can be formed over a number of frames and targets are further analyzed both spatially and temporally. Algorithms have been implemented in C/C++ as GStreamer plugins and are suitable for vehicle mounted, on-the-move realtime exploitation.

  14. Experimental Study of Surface Detection of Gas Pipeline Buried in Soil

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Pipeline is a key segment in the transportation of city gas and its safety affects the safety of industrial and domestic application. The characteristics of Shi Dongkou east gas steel pipeline buried in soil were discussed and its parameters related to safety were measured, including the state of anticorrosive layer, the soil resistivity,the natural potential and the protective potential of gas pipeline. The experimental results were confirmed by excavating, which are of value to the knowledge of the gas pipeline buried in soil in Shanghai. The experimental data were analyzed which provide the scientific basis for the assurance of the gas pipeline safety and the reparation of anticorrosivelayer.

  15. Electron Temperature Measurement of Buried Layer Targets Using Time Resolved K-shell Spectroscopy

    Science.gov (United States)

    Marley, Edward; Foord, M. E.; Shepherd, R.; Beiersdorfer, P.; Brown, G.; Chen, H.; Emig, J.; Schneider, M.; Widmann, K.; Scott, H.; London, R.; Martin, M.; Wilson, B.; Iglesias, C.; Mauche, C.; Whitley, H.; Nilsen, J.; Hoarty, D.; James, S.; Brown, C. R. D.; Hill, M.; Allan, P.; Hobbs, L.

    2016-10-01

    Short pulse laser-heated buried layer experiments have been performed with the goal of creating plasmas with mass densities >= 1 g/cm3 and electron temperatures >= 500 eV. The buried layer geometry has the advantage of rapid energy deposition before significant hydrodynamic expansion occurs. For brief periods (PIC simulation done using LSP, which shows late time heating from the non-thermal electron population. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  16. Micro-buried spiral zone plate in a lithium niobate crystal

    Science.gov (United States)

    Tian, Zhen-Nan; Hua, Jian-Guan; Hao, Juan; Yu, Yan-Hao; Chen, Qi-Dai; Sun, Hong-Bo

    2017-01-01

    We present a micro-buried spiral zone plate (MBSZP) in the lithium niobate crystal fabricated with femtosecond laser direct writing technology. The microstructures of the MBSZP are buried under the surface of the crystal, which ensures the stability of the optical performance in various refractive index environments. The optical performances of imaging and focusing capabilities were demonstrated. In addition, the experiment showed good agreement with simulation results based on the optical wave propagation method. This novel optical element will have important applications in multistate information encoding, optical manipulation, quantum communication, and computation, especially in high integration, contact coupling, and variable refractive index environments.

  17. Centrifuge modelling of lateral displacement of buried pipelines; Modelagem fisica centrifuga de flambagem lateral de dutos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Jose Renato Moreira da Silva de; Almeida, Marcio de Souza Soares de; Marques, Maria Esther Soares; Almeida, Maria Cascao Ferreira de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE); Costa, Alvaro Maia da [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2003-07-01

    This work discusses soil-structure interaction applied to the buckling phenomena of buried pipelines subjected to heated oil flow. A set of physical modelling tests on lateral buckling of pipelines buried on soft clay is presented using COPPE/UFRJ geotechnical centrifuge. A 1:30 pipeline model was moved side ward through a soft clay layer during centrifuge flight, varying the burial depth, in order to simulate the lateral buckling in plane strain condition. The results show different behaviour concerning horizontal and vertical forces measured at pipeline level due to soil reaction. (author)

  18. Burying of channel optical waveguides: relation between near-field measurement and Ag concentration profile

    Science.gov (United States)

    Tsai, Wan-Shao; Liu, Yen-Huang; Barkman, Ondrej; Prajzler, Vaclav; Stanek, Stanislav; Nekvindova, Pavla

    2015-01-01

    Two-step field-assisted ion-exchanged waveguides have been fabricated on a glass substrate. The concentration profiles of the exchanged ions were measured with electron microprobe. The waveguides were characterized under scanning electron microscope and optical microscope for the investigation of burying structures. Guiding mode patterns were characterized with near-field measurement, where symmetric profiles were observed for the burying-type waveguide. The refractive index profiles were also measured with a modified end-fire coupling method. The relation between ion concentration profiles and index profiles were compared for the waveguides with different fabrication process.

  19. Latex-modified grouts for in-situ stabilization of buried transuranic/mixed waste

    Energy Technology Data Exchange (ETDEWEB)

    Allan, M.L.

    1996-06-01

    The Department of Applied Science at Brookhaven national Laboratory was requested to investigate latex-modified grouts for in-situ stabilization of buried TRU/mixed waste for INEL. The waste exists in shallow trenches that were backfilled with soil. The objective was to formulate latex-modified grouts for use with the jet grouting technique to enable in-situ stabilization of buried waste. The stabilized waste was either to be left in place or retrieved for further processing. Grouting prior to retrieval reduces the potential release of contaminants. Rheological properties of latex-modified grouts were investigated and compared with those of conventional neat cement grouts used for jet grouting.

  20. Performance-Based Technology Selection Filter description report. INEL Buried Waste Integrated Demonstration System Analysis project

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, M.C.; Morrison, J.L.; Morneau, R.A.; Rudin, M.J.; Richardson, J.G.

    1992-05-01

    A formal methodology has been developed for identifying technology gaps and assessing innovative or postulated technologies for inclusion in proposed Buried Waste Integrated Demonstration (BWID) remediation systems. Called the Performance-Based Technology Selection Filter, the methodology provides a formalized selection process where technologies and systems are rated and assessments made based on performance measures, and regulatory and technical requirements. The results are auditable, and can be validated with field data. This analysis methodology will be applied to the remedial action of transuranic contaminated waste pits and trenches buried at the Idaho National Engineering Laboratory (INEL).

  1. Buried waste integrated demonstration fiscal year 1992 close-out report

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, P.G.; Kostelnik, K.M.; Owens, K.J.

    1993-02-01

    The mission of the Buried Waste Integrated Demonstration Program (BWID) is to support the development and demonstration of a suite of technologies that when integrated with commercially-available baseline technologies form a comprehensive remediation system for the effective and efficient remediation of buried waste disposed of throughout the US Department of Energy complex. To accomplish this mission of identifying technological solutions for remediation deficiencies, the Office of Technology Development initiated the BWID at the Idaho National Engineering Laboratory in fiscal year (FY)-91. This report summarizes the activities of the BWID Program during FY-92.

  2. Electronic structure of (In,Mn)As quantum dots buried in GaAs investigated by soft-x-ray ARPES

    Science.gov (United States)

    Bouravleuv, A. D.; Lev, L. L.; Piamonteze, C.; Wang, X.; Schmitt, T.; Khrebtov, A. I.; Samsonenko, Yu B.; Kanski, J.; Cirlin, G. E.; Strocov, V. N.

    2016-10-01

    Electronic structure of a molecular beam epitaxy-grown system of (In,Mn)As quantum dots (QDs) buried in GaAs is explored with soft-x-ray angle-resolved photoelectron spectroscopy (ARPES) using photon energies around 1 keV. This technique, ideally suited for buried systems, extends the momentum-resolving capabilities of conventional ARPES with enhanced probing depth as well as elemental and chemical state specificity achieved with resonant photoexcitation. The experimental results resolve the dispersive energy bands of the GaAs substrate buried in ∼2 nm below the surface, and the impurity states (ISs) derived from the substitutional Mn atoms in the (In,Mn)As QDs and oxidized Mn atoms distributed near the surface. An energy shift of the Mn ISs in the QDs compared to (In,Mn)As DMS is attributed to the band offset and proximity effect at the interface with the surrounding GaAs. The absence of any ISs in the vicinity of the VBM relates the electron transport in (In,Mn)As QDs to the prototype (In,Mn)As diluted magnetic semiconductor. The SX-ARPES results are supported by measurements of the shallow core levels under variation of probing depth through photon energy. X-ray absorption measurements identify significant diffusion of interstitial Mn atoms out of the QDs towards the surface, and the role of magnetic circular dichroism is to block the ferromagnetic response of the (In,Mn)As QDs. Possible routes are drawn to tune the growth procedure aiming at practical applications of the (In,Mn)As based systems.

  3. Electronic structure of (In,Mn)As quantum dots buried in GaAs investigated by soft-x-ray ARPES.

    Science.gov (United States)

    Bouravleuv, A D; Lev, L L; Piamonteze, C; Wang, X; Schmitt, T; Khrebtov, A I; Samsonenko, Yu B; Kanski, J; Cirlin, G E; Strocov, V N

    2016-10-21

    Electronic structure of a molecular beam epitaxy-grown system of (In,Mn)As quantum dots (QDs) buried in GaAs is explored with soft-x-ray angle-resolved photoelectron spectroscopy (ARPES) using photon energies around 1 keV. This technique, ideally suited for buried systems, extends the momentum-resolving capabilities of conventional ARPES with enhanced probing depth as well as elemental and chemical state specificity achieved with resonant photoexcitation. The experimental results resolve the dispersive energy bands of the GaAs substrate buried in ∼2 nm below the surface, and the impurity states (ISs) derived from the substitutional Mn atoms in the (In,Mn)As QDs and oxidized Mn atoms distributed near the surface. An energy shift of the Mn ISs in the QDs compared to (In,Mn)As DMS is attributed to the band offset and proximity effect at the interface with the surrounding GaAs. The absence of any ISs in the vicinity of the VBM relates the electron transport in (In,Mn)As QDs to the prototype (In,Mn)As diluted magnetic semiconductor. The SX-ARPES results are supported by measurements of the shallow core levels under variation of probing depth through photon energy. X-ray absorption measurements identify significant diffusion of interstitial Mn atoms out of the QDs towards the surface, and the role of magnetic circular dichroism is to block the ferromagnetic response of the (In,Mn)As QDs. Possible routes are drawn to tune the growth procedure aiming at practical applications of the (In,Mn)As based systems.

  4. Y chromosomal and sex effects on the behavioral stress response in the defensive burying test in wild house mice

    NARCIS (Netherlands)

    Sluyter, F; Korte, SM; Van Baal, GCM; De Ruiter, AJH; Van Oortmerssen, GA

    1999-01-01

    Genetically selected short attack latency (SAL) and long attack latency (LAL) male wild house mice behave differently in the defensive burying test. When challenged, SAL males respond actively with more time spent on defensive burying, whereas LAL males are more passive with more time remaining immo

  5. Influence of Zn Diffusion on Bandwidth and Extinction in MQW Electroabsorption Modulators Buried with Semi-Insulating InP

    Institute of Scientific and Technical Information of China (English)

    Takayuki; Yamanaka; Hideki; Fukano; Ken; Tsuzuki; Munehisa; Tamura; Ryuzo; Iga; Matsuyuki; Ogasawara; Yasuhiro; Kondo; Tadashi; Saitoh

    2003-01-01

    A comprehensive analysis of multi-quantum-well electroabsorption modulators buried with semi-insulating (SI)-InP is presented. We quantitatively demonstrate that suppression of Zn diffusion into the burying and optical core layers plays a key role in high-speed and high-extinction operation.

  6. 49 CFR 192.455 - External corrosion control: Buried or submerged pipelines installed after July 31, 1971.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.455 External corrosion control: Buried or... against external corrosion, including the following: (1) It must have an external protective...

  7. 49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2)...

  8. A dicing-free SOI process for MEMS devices based on the lag effect

    Science.gov (United States)

    Xie, J.; Hao, Y.; Shen, Q.; Chang, H.; Yuan, W.

    2013-12-01

    This paper presents a dicing-free process for silicon-on-insulator (SOI) microelectromechanical systems (MEMS). In the process, the lag effect in deep reactive ion etching (DRIE) is used to form the breaking trenches. In the backside DRIE, the wide backside cavities are etched down to the buried oxide layer. The narrow breaking trenches, in contrast, are not etched to the buried oxide layer. Therefore, the narrow trench can be used to break the wafer after the entire process; in addition, the handle layer can still act as a bracing structure before ‘breaking’. Finally, the device layer is patterned, and a DRIE step is used to form the MEMS devices. In this way, the dicing step can be omitted to prevent further damages from high pressure water jets and silicon dust. Meanwhile, the process can also prevent notching simply because the insulating layer is removed before device etching. To demonstrate the feasibility of the proposed fabrication process, a micromachined gyroscope is designed and fabricated.

  9. Investigation of veritcal graded channel doping in nanoscale fully-depleted SOI-MOSFET

    Science.gov (United States)

    Ramezani, Zeinab; Orouji, Ali A.

    2016-10-01

    For achieving reliable transistor, we investigate an amended channel doping (ACD) engineering which improves the electrical and thermal performances of fully-depleted silicon-on-insulator (SOI) MOSFET. We have called the proposed structure with the amended channel doping engineering as ACD-SOI structure and compared it with a conventional fully-depleted SOI MOSFET (C-SOI) with uniform doping distribution using 2-D ATLAS simulator. The amended channel doping is a vertical graded doping that is distributed from the surface of structure with high doping density to the bottom of channel, near the buried oxide, with low doping density. Short channel effects (SCEs) and leakage current suppress due to high barrier height near the source region and electric field modification in the ACD-SOI in comparison with the C-SOI structure. Furthermore, by lower electric field and electron temperature near the drain region that is the place of hot carrier generation, we except the improvement of reliability and gate induced drain lowering (GIDL) in the proposed structure. Undesirable Self heating effect (SHE) that become a critical challenge for SOI MOSFETs is alleviated in the ACD-SOI structure because of utilizing low doping density near the buried oxide. Thus, refer to accessible results, the ACD-SOI structure with graded distribution in vertical direction is a reliable device especially in low power and high temperature applications.

  10. OMRC Technology Effectively Develops the Massive Thick Metamorphic Buried Hill Reservoir

    Institute of Scientific and Technical Information of China (English)

    Ren Fangxiang; Zhang Fangli; Sun Yan; Gong Yaojin; Xu Ning; Zhao Zhigang

    2010-01-01

    @@ Introduction Optimized maximum reservoir contact technology(OMRC)is developed based on the maximum reservoir contact(MRC)technology,which is a kind of technology to optimize candidate multilaterals with appropriate specification based on the reservoir conditions.By applying the technology in XLT buried hill reservoir in Liaohe Oilfield satisfactory effects are obtained.

  11. Four point probe structures with buried electrodes for the electrical characterization of ultrathin conducting films

    NARCIS (Netherlands)

    Groenland, A.W.; Wolters, R.A.M.; Kovalgin, A.Y.; Schmitz, J.

    2009-01-01

    Test structures for the electrical characterization of ultrathin conductive (ALD) films are presented based on buried electrodes on which the ultrathin film is deposited. This work includes test structure design and fabrication, and the electrical characterization of ALD TiN films down to 4 nm. It i

  12. Scattering from a Buried Circular Cylinder Illuminated by a Three-Dimensional Source

    DEFF Research Database (Denmark)

    Hansen, T.B.; Meincke, Peter

    2002-01-01

    We employ plane and cylindrical wave expansions with the fast Fourier transform to solve scattering problems involving a circular cylinder buried in soil. The illumination is provided by a three-dimensional source located in air above ground. Plane wave expansions describe transmitted and reflected...

  13. Capturing buried defects in metal interconnections with electron beam inspection system

    Science.gov (United States)

    Xiao, Hong; Jiang, Ximan; Trease, David; Van Riet, Mike; Ramprasad, Shishir; Bhatia, Anadi; Lefebvre, Pierre; Bastard, David; Moreau, Olivier; Maher, Chris; MacDonald, Paul; Campochiaro, Cecelia

    2013-04-01

    In this paper we present a novel mode of electron beam inspection (EBI), entitled super wide optics (SWO) mode, which can effectively detect buried defects in tungsten (W) plugs and copper (Cu) wires. These defects are defects of interest (DOI) to integrated circuit (IC) manufacturers because they are not detectable in optical inspection, voltage contrast (VC) mode EBI or physical mode EBI. We used engineering systems to study two samples, a tungsten chemical mechanical polish (CMP) wafer and a copper CMP wafer with a silicon carbon nitride (SiCN) cap layer. EBI with our novel SWO mode was found to capture many dark defects on these two wafers. Furthermore, defect review with all three EBI modes found some of these dark defects were unique to SWO mode. For verification, physical failure analysis was performed on some SWO-unique DOI. The cross-sectional scanning electron microscope (SEM) images and transmission electron microscope (TEM) images confirmed that the unique DOI were buried voids in W-plugs and copper wire thinning caused by either buried particles or buried particle induced metal trench under-etch. These DOI can significantly increase the resistance of metal interconnects of IC chip and affect the chip yield. This new EBI mode can provide an in-line monitoring solution for these DOI, which does not exist before this study.

  14. Advanced modeling of thermal NDT problems: from buried landmines to defects in composites

    Science.gov (United States)

    Vavilov, Vladimir P.; Burleigh, Douglas D.; Klimov, Alexey G.

    2002-03-01

    Advanced thermal models that can be used in the detection of buried landmines and the TNDT (thermographic nondestructive testing) of composites are discussed. The interdependence between surface temperature signals and various complex parameters, such as surface and volumetric moisture, the shape of a heat pulse, material anisotropy, etc., is demonstrated.

  15. Long-term dynamics of buried organic carbon in colluvial soils

    Directory of Open Access Journals (Sweden)

    Z. Wang

    2013-08-01

    Full Text Available Colluvial soils are enriched in soil organic carbon (SOC in comparison to the soils of upslope areas due to the deposition and subsurface burial of SOC. It has been suggested that the burial of SOC has important implications for the global carbon cycle, but the long-term dynamics of buried SOC remains poorly constrained. We address this issue by determining the SOC burial efficiency (i.e., the fraction of originally deposited SOC that is preserved in colluvial deposits of buried SOC as well as the SOC stability in colluvial soils. We quantify the turnover rate of deposited SOC by establishing sediment and SOC burial chronologies. The SOC stability is derived from soil incubation experiments and the δ13C values of SOC. The C burial efficiency was found to decrease exponentially with time reaching a constant ratio of approximately 17%. This exponential decrease is attributed to the increasing recalcitrance of buried SOC with time and a less favourable environment for SOC decomposition with increasing depth. Buried SOC is found to be more stable and degraded in comparison to SOC sampled at the same depth at a stable site. This is due to preferential mineralization of the labile fraction of deposited SOC resulting in enrichment of more degraded and recalcitrant SOC in colluvial soils. In order to better understand the long-term effects of soil erosion for the global C cycle, the temporal variation of deposited SOC and its controlling factors need to be characterized and quantified.

  16. Influence of Population Density on Offspring Number and Size in Burying Beetles

    Science.gov (United States)

    Rauter, Claudia M.

    2010-01-01

    This laboratory exercise investigates the influence of population density on offspring number and size in burying beetles. Students test the theoretical predictions that brood size declines and offspring size increases when competition over resources becomes stronger with increasing population density. Students design the experiment, collect and…

  17. Composition and origin of buried ferromanganese nodules from central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Parthiban, G.

    76°00'E) at a water depth of 5260 m These nodules were analysed for major, trace and rare earth element (REE) concentrations to understand their genesis and compare with the surface and buried nodules in the top 1 m of the sediment column from...

  18. Electrochemical deposition of buried contacts in high-efficiency crystalline silicon photovoltaic cells

    DEFF Research Database (Denmark)

    Jensen, Jens Arne Dahl; Møller, Per; Bruton, Tim

    2003-01-01

    This article reports on a newly developed method for electrochemical deposition of buried Cu contacts in Si-based photovoltaic ~PV! cells. Contact grooves, 20 mm wide by 40 mm deep, were laser-cut into Si PV cells, hereafter applied with a thin electroless NiP base and subsequently filled with Cu...

  19. ANALYSIS OF THE PERFORMANCE OF THE BURIED PIPE GRID OF A HEAT PUMP,

    Science.gov (United States)

    An analysis is presented of experimental records obtained from a buried pipe grid of a heat pump , operated over a full heating season. The purpose of the analysis is to compare actual pipe performance with theory over a long period of time, thereby judging the applicability of the theory for practical use and to indicate the suitability of simplified design methods. (Author)

  20. Identification of immunity-related genes in the burying beetle Nicrophorus vespilloides by suppression subtractive hybridization.

    Science.gov (United States)

    Vogel, H; Badapanda, C; Vilcinskas, A

    2011-12-01

    Burying beetles reproduce on small vertebrate cadavers which they bury in the soil after localization through volatiles emitted from the carcass. They then chemically preserve the carcass and prepare it as a diet for the adults and their offspring. It is predicted that exposure to high loads of soil and/or carrion-associated microbes necessitates an effective immune system. In the present paper, we report experimental screening for immunity-related genes in the burying beetle Nicrophorus vespilloides using the suppression subtractive hybridization approach. A total of 1179 putative gene objects were identified in the Nicrophorus cDNA library, which was enriched for transcripts differentially expressed upon challenge with heat-inactivated bacteria. In addition to genes known to be involved in immunity-related recognition and signalling, we found transcripts encoding for antimicrobial peptides and for an array of enzymes that can be linked to immunity or to stress-induced pathways. We also determined proteins that may contribute to detoxification of toxins produced by microbial competitors. In addition, factors involved in mRNA stability determination and central components of the RNA interference machinery were identified, implying transcriptional reprogramming and potential stress-induced retrotransposon elimination. The identified candidate immune effector and stress-related genes may provide important information about the unusual ecology and evolution of the burying beetles.

  1. Results of a monitoring pilot with a permanent buried multicomponent seismic array at Ketzin

    NARCIS (Netherlands)

    Arts, R.J.; Meekes, J.A.C.; Brouwer, J.H.; Werf, M. van der; Noorlandt, R.P.; Paap, B.; Visser, W.; Vandeweijer, V.; Lüth, S.; Giese, R.; Maas, J.

    2011-01-01

    To monitor the migration of the injected CO2 in the Ketzin project (Germany) a permanently buried multi-component seismic array has been installed in August 2009. Since then the array has been continuously recording passive seismic data. Additionally an active seismic survey resulting in a 230 m lon

  2. Laser-induced acoustic landmine detection with experimental results on buried landmines

    NARCIS (Netherlands)

    Heuvel, J.C. van den; Putten, F.J.M. van; Koersel, A.C. van; Schleijpen, H.M.A.

    2004-01-01

    Acoustic landmine detection (ALD) is a technique for the detection of buried landmines including non-metal mines. Since it gives complementary results with GPR or metal detection, sensor fusion of these techniques with acoustic detection would give promising results. Two methods are used for the aco

  3. Feasibility of fast neutron analysis for the detection of explosives buried in soil

    Energy Technology Data Exchange (ETDEWEB)

    Faust, A.A. [Defence R and D Canada - Suffield, Medicine Hat, Alta. (Canada); McFee, J.E., E-mail: John.McFee@drdc-rddc.gc.ca [Defence R and D Canada - Suffield, Medicine Hat, Alta. (Canada); Bowman, C.L.; Mosquera, C. [Defence R and D Canada - Suffield, Medicine Hat, Alta. (Canada); Andrews, H.R.; Kovaltchouk, V.D.; Ing, H. [Bubble Technology Industries, Chalk River, Ont. (Canada)

    2011-12-11

    A commercialized thermal neutron analysis (TNA) sensor has been developed to confirm the presence of buried bulk explosives as part of a multi-sensor anti-tank landmine detection system. Continuing improvements to the TNA system have included the use of an electronic pulsed neutron generator that offers the possibility of applying fast neutron analysis (FNA) methods to improve the system's detection capability. This paper describes an investigation into the use of FNA as a complementary component in such a TNA system. The results of a modeling study using simple geometries and a full model of the TNA sensor head are presented, as well as preliminary results from an experimental associated particle imaging (API) system that supports the modeling study results. The investigation has concluded that the pulsed beam FNA approach would not improve the detection performance of a TNA system for landmine or buried IED detection in a confirmation role, and could not be made into a practical stand-alone detection system for buried anti-tank landmines. Detection of buried landmines and IEDs by FNA remains a possibility, however, through the use of the API technique.

  4. A shear wave ground surface vibration technique for the detection of buried pipes

    Science.gov (United States)

    Muggleton, J. M.; Papandreou, B.

    2014-07-01

    A major UK initiative, entitled 'Mapping the Underworld' aims to develop and prove the efficacy of a multi-sensor device for accurate remote buried utility service detection, location and, where possible, identification. One of the technologies to be incorporated in the device is low-frequency vibro-acoustics; the application of this technology for detecting buried infrastructure, in particular pipes, is currently being investigated. Here, a shear wave ground vibration technique for detecting buried pipes is described. For this technique, shear waves are generated at the ground surface, and the resulting ground surface vibrations measured. Time-extended signals are employed to generate the illuminating wave. Generalized cross-correlation functions between the measured ground velocities and a reference measurement adjacent to the excitation are calculated and summed using a stacking method to generate a cross-sectional image of the ground. To mitigate the effects of other potential sources of vibration in the vicinity, the excitation signal can be used as an additional reference when calculating the cross-correlation functions. Measurements have been made at two live test sites to detect a range of buried pipes. Successful detection of the pipes was achieved, with the use of the additional reference signal proving beneficial in the noisier of the two environments.

  5. Finite element analysis of fluid-structure interaction in buried liquid-conveying pipeline

    Institute of Scientific and Technical Information of China (English)

    朱庆杰; 陈艳华; 刘廷权; 代兆立

    2008-01-01

    Long distance buried liquid-conveying pipeline is inevitable to cross faults and under earthquake action,it is necessary to calculate fluid-structure interaction(FSI) in finite element analysis under pipe-soil interaction.Under multi-action of site,fault movement and earthquake,finite element model of buried liquid-conveying pipeline for the calculation of fluid structure interaction was constructed through combinative application of ADINA-parasolid and ADINA-native modeling methods,and the direct computing method of two-way fluid-structure coupling was introduced.The methods of solid and fluid modeling were analyzed,pipe-soil friction was defined in solid model,and special flow assumption and fluid structure interface condition were defined in fluid model.Earthquake load,gravity and displacement of fault movement were applied,also model preferences.Finite element research on the damage of buried liquid-conveying pipeline was carried out through computing fluid-structure coupling.The influences of pipe-soil friction coefficient,fault-pipe angle,and liquid density on axial stress of pipeline were analyzed,and optimum parameters were proposed for the protection of buried liquid-conveying pipeline.

  6. Determination of the electronic density of states near buried interfaces: Application to Co/Cu multilayers

    DEFF Research Database (Denmark)

    Nilsson, A.; Sthör, J.; Wiell, T.;

    1996-01-01

    High-resolution L(3) x-ray absorption and emission spectra of Co and Cu in Co/Cu multilayers are shown to provide unique information on the occupied and unoccupied density of d states near buried interfaces. The d bands of both Co and Cu interfacial layers are shown to be considerably narrowed...

  7. Application of forecasting structural cracks technique of 3DMove in Chengdao buried hill

    Institute of Scientific and Technical Information of China (English)

    WU Shiguo; WANG Xiuling; JI Yuxin; LIU Yuzhen; HAN Wengong

    2005-01-01

    3DMove software, based on the three-dimension structural model of geologic interpretation, can forecast reservoir cracks from the point of view of formation of the structural geology, and analyze the characteristics of the cracks. 3DMove software dominates in forecasting cracks. We forecast the developments and directions of the cracks in Chengbei buried hill with the application of forecasting technique in 3DMove software, and obtain the chart about strain distributing on top in buried hill and the chart about relative density and orientation and the chart about the analysis of crack unsealing. In Chengbei 30 buried hill zone, north-west and north-east and approximately east-west cracks in Cenozoic are very rich and the main directions in every fault block are different. Forecasting results that are also verified by those of drilling approximately accord with the data from well logging, the case of which shows that the technique has the better ability in forecasting cracks, and takes more effects on exploration and exploitation of crack reservoir beds in ancient buried hill reservoirs.

  8. Low frequency synthetic aperture sonar for detecting and classifying buried objects

    NARCIS (Netherlands)

    Hunter, A.J.; Vossen, R. van; Quesson, B.A.J.; Colin, M.E.G.D.; Zampolli, M.; Beckers, A.L.D.

    2012-01-01

    Sidescan high-frequency (HF) sonar (i.e., with frequencies higher than 100 kHz) is ideally suited for providing high-resolution images of the seafloor. However, since sound does not penetrate into the sediment at these frequencies, such systems cannot be used for the detection of buried objects, suc

  9. Novel applications of optical techniques to the study of buried semiconductor interfaces

    Science.gov (United States)

    Wilson, Barbara A.

    1989-01-01

    Detailed electronic and structural information about buried semiconductor interfaces obtained through application of optical techniques is discussed. The measurements described include the determination of band discontinuities, strain, and disorder associated with semiconductor heterointerfaces. The contactless and nondestructive nature of these optical techniques is particularly important for the study of heterointerfaces which are inherently inaccessible to direct electrical or physical contact.

  10. Application of EM tomography to detect a buried pipe; EM tomography no maisetsukan tansa eno tekiyorei

    Energy Technology Data Exchange (ETDEWEB)

    Sakashita, S. [OYO Corp., Tokyo (Japan)

    1996-10-01

    EM tomography was applied to detect buried pipes. Underground radar exploration method is limited to 10m in depth. Positive use of bored holes is desirable, and in such case, magnetic logging based on the magnetic susceptibility (MS) contrast between buried body and surrounding ground is effective. The primary magnetic field is generated by coil current, and the secondary one is generated by the primary one responding to foreign bodies in the ground. Since the measured primary magnetic field of low frequency within 10Hz can be treated as static magnetic field responding to MS in the ground, it is useful to determine MS distributions. Since the measured magnetic field of high frequency within 100kHz can be treated as induction field responding to conductivity in the ground, it is useful to determine resistivity distributions. The EM tomography which can image both above distributions by using electromagnetic wave in a wide frequency range, was applied to detect buried pipes. The EM tomography could detect an buried foreign body of 3m in diameter at 10m in distance between bored holes. The theoretical equation for analysis was also derived. 5 refs., 9 figs., 1 tab.

  11. 49 CFR 192.459 - External corrosion control: Examination of buried pipeline when exposed.

    Science.gov (United States)

    2010-10-01

    ... pipeline when exposed. 192.459 Section 192.459 Transportation Other Regulations Relating to Transportation... exposed. Whenever an operator has knowledge that any portion of a buried pipeline is exposed, the exposed... operator shall investigate circumferentially and longitudinally beyond the exposed portion (by...

  12. Early Monitoring of the Viability of the Buried Intrathoracic Omental Flap: A Feasibility Study

    NARCIS (Netherlands)

    J.J. van Wingerden; J.M.P. Collins; E.H. Coret; P.J.J. Schröder

    2010-01-01

    Purpose. The value of mobile, high-resolution gray-scale and color Doppler ultrasonography (US) in the immediate postoperative, intensive care setting for monitoring the buried flap and vascular pedicle of the laparoscopic or transdiaphragmatic harvested omentum for intrathoracic reconstruction was

  13. Gravity field separation and mapping of buried quaternary valleys in Lolland, Denmark using old geophysical data

    DEFF Research Database (Denmark)

    Møller, M.J.; Olsen, Henrik; Ploug, C.;

    2007-01-01

    In this paper we utilise the old industrial data for planning new surveys. The overall purpose is a detailed mapping of possible aquifers for the island of Lolland, Denmark. This is done through detection and modelling of the buried quaternary valleys, which either can serve as potential aquifers...

  14. The development of a ballistic method for simulating fragments from buried explosive devices

    NARCIS (Netherlands)

    Jagt-Deutekom, M.J. van der

    2016-01-01

    No standard scientific methodology currently exists to assess the performance of personal protection equipment (PPE) against secondary debris, such as soil, grit and stones, ejected when a buried improvised explosive device (IED) detonates. Different test methods are used for this evaluation. The PP

  15. Low dose effects of a Withania somnifera extract on altered marble burying behavior in stressed mice

    Science.gov (United States)

    Dey, Amitabha; Chatterjee, Shyam Sunder; Kumar, Vikas

    2016-01-01

    Aim: Withania somnifera root (WSR) extracts are often used in traditionally known Indian systems of medicine for prevention and cure of psychosomatic disorders. The reported experiment was designed to test whether low daily oral doses of such extracts are also effective in suppressing marble burying behavior in stressed mice or not. Materials and Methods: Groups of mice treated with 10, 20, or 40 mg/kg daily oral doses of WSR were subjected to a foot shock stress-induced hyperthermia test on the 1st, 5th, 7th, and 10th day of the experiment. On the 11th and 12th treatment days, they were subjected to marble burying tests. Stress response suppressing effects of low dose WSR were estimated by its effects on body weight and basal core temperature of animals during the course of the experiment. Results: Alterations in bodyweight and basal core temperature triggered by repeated exposures to foot shock stress were absent even in the 10 mg/kg/day WSR treated group, whereas the effectiveness of the extract in foot shock stress-induced hyperthermia and marble burying tests increased with its increasing daily dose. Conclusion: Marble burying test in stressed mice is well suited for identifying bioactive constituents of W. somnifera like medicinal plants with adaptogenic, anxiolytic and antidepressant activities, or for quantifying pharmacological interactions between them. PMID:27366354

  16. Decreases in nestlet shredding of mice by serotonin uptake inhibitors: comparison with marble burying.

    Science.gov (United States)

    Li, Xia; Morrow, Denise; Witkin, Jeffrey M

    2006-03-20

    Methods for detection of anxiolytic-like behavioral effects of serotonin uptake inhibitors are limited. The present study introduces a new quantitative method that permits dose-effect analysis of these compounds. Male NIH Swiss mice were given 60-min access to a piece of cotton gauze and the amount of material not torn into nesting material was weighed. Other groups of mice were individually placed in containers with 20 marbles resting on top of sawdust bedding. The number of marbles buried (2/3) by sawdust after 30 min was counted. Mice were first placed on a 6-rpm rotorod and the number of mice falling off twice in 2 min was measured. Serotonin uptake inhibitors (clomipramine, citalopram, fluoxetine, and venlafaxine) dose-dependently suppressed nestlet shredding and marble burying at doses that were generally without effect on rotorod performance. The amine-based antidepressant agents imipramine and desipramine as well as the selective norepinephrine transport inhibitor nisoxetine produced similar qualitative effects on these behaviors. Anxiolytics (chlordiazepoxide, bretazenil, buspirone, and pentobarbital) produced effects in the nestlet assay that were similar to those reported using another anxiolytic assay in mice (punished responding), whereas these compounds were not active at non-motor-impairing doses in the marble burying assay. The antipsychotic agents chlorpromazine and risperidone generally demonstrated suppression of nestlet shredding and marble burying at doses that impaired rotorod performance. Although d-amphetamine suppressed nestlet shredding and marble burying at doses without effect on the rotorod, d-amphetamine but not fluoxetine stimulated locomotor activity. Both nestlet shredding and marble burying behaviors were generally consistent across five consecutive experimental sessions and fluoxetine did not produce any systematic trends over repeated testing. The methods should have utility in defining pharmacological effects of these compounds

  17. Late diagenetic indicators of buried oil and gas

    Science.gov (United States)

    Donovan, Terrence J.; Dalziel, Mary C.

    1977-01-01

    At least three hydrocarbon seepage mechanisms are interpreted to operate over oil and gas fields. These are: (1) effusion ofh ydrocarbons through inadequate caprocks and along faults and fractures, (2) low-molecular-weight hydrocarbons dissolved in water moving vertically through capping shales as a result of a hydrodynamic or chemical potential drive, and (3) diffusion of gases dissolved in water. Combinations of these mechanisms may also occur. Seeping hydrocarbons are oxidized near the earth's surface, and the resulting carbon dioxide reacts with water producing bicarbonate ions, which combine with calcium and magnesium dissolved in ground waters to yield isotopically distinctive pore-filling carbonate cements and surface rocks. The passage of hydrocarbons and associated compounds such as hydrogen sulfide through surface rocks causes a reducing environment and consequent reduction, mobilization, and loss of iron from iron-bearing minerals commonly resulting in a discoloration. Other metals such as manganese are also mobilized and redistributed. These changes in the physical and chemical properties of surface rocks correlate with the subsurface distribution of petroleum, and potentially can be detected from both airborne and spaceborne platforms.

  18. Detecting buried metallic weapons in a controlled setting using a conductivity meter.

    Science.gov (United States)

    Dionne, Charles A; Schultz, John J; Murdock, Ronald A; Smith, Stephen A

    2011-05-20

    Forensic personnel may face a daunting task when searching for buried weapons at crime scenes or potential disposal sites. In particular, it is common to search for a small firearm that was discarded or buried by a perpetrator. When performing forensic searches, it is recommended to first use non-invasive methods such as geophysical instruments to minimize damage to evidence and to the crime scene. Geophysical tools are used to pinpoint small areas of interest across a scene for invasive testing, rather than digging large areas throughout the site. Prior to this project, there was no published research that tested the utility of the conductivity meter to search for metallic weapons such as firearms and blunt and sharp edged weapons. A sample comprised of 32 metallic weapons including firearms, blunt and sharp edged weapons, and scrap metals was buried in a controlled setting to test the applicability of a conductivity meter for forensic searches. Weapons were tested at multiple depths and after data collection was performed for one depth, the weapons were reburied 5 cm deeper until they were no longer detected. Variables such as weapon size, burial depth, transect interval spacing (25 and 50 cm), and metallic composition were tested. All of the controlled variables influenced maximum depth of detection. For example, size was a factor as larger weapons were detected at deeper depths compared to smaller weapons. Metal composition affected maximum depth of detection as the conductivity meter detected items comprised of ferrous metals at deeper depths than non-ferrous metals. Searches for large buried items may incorporate a transect interval spacing of 50 cm but small weapons may be undetected between transects and therefore a transect interval spacing of 25 cm is recommended. Overall, the conductivity meter is a geophysical tool to consider when searching for larger-sized metallic weapons or to use in conjunction with an all-metal detector, particularly when

  19. Micro-imaging of buried layers and interfaces in ultrathin films by X-ray reflectivity

    Science.gov (United States)

    Jiang, Jinxing; Hirano, Keiichi; Sakurai, Kenji

    2016-09-01

    X-ray reflectivity is a promising technique for characterizing buried layers and interfaces in ultrathin films because of its ability to probe the electron density profile along the depth in a non-destructive manner. While routine X-ray reflectivity assumes the in-plane uniformity of the sample to be measured, it is also quite important to see buried inhomogeneous/patterned layers and interfaces. The present paper describes the addition of spatial resolution and imaging capability to an X-ray reflectivity technique to visualize surfaces and buried interfaces. To visualize quite wide viewing area size quickly, the image reconstruction scheme has been employed instead of the scanning of microbeam. Though the mathematics is quite close to X-ray computer tomography, the technique gives the image contrast caused by the difference in reflectivity at each in-plane point in the thin film sample. By choosing a grazing angle, the image gives inhomogeneity of X-ray reflectivity at the specific wavevector transfer. With a collimated monochromatic synchrotron X-ray beam of 0.05 mm (H) × 8 mm (V), the intensity profiles of X-ray reflection projections have been taken at many different in-plane rotation angles, from 0° to 180°. We have succeeded in visualizing buried layers and interfaces of the 8 mm dia area with the spatial resolution of better than 20 μm. Because of the brilliance of synchrotron radiation, the typical measuring time is shorter than 1 min. Three analytical cases have been discussed: (i) imaging of a buried layer and an interface covered by a protection layer, (ii) distinguishing different local parts of different thicknesses in an ultrathin film, and (iii) selective imaging of a specific metal in the thin film form.

  20. Development of hard x-ray photoelectron SPLEED-based spectrometer applicable for probing of buried magnetic layer valence states

    CERN Document Server

    Kozina, Xeniya; Karel, Julie; Ouardi, Siham; Yamamoto, Masafumi; Kobayashi, Keisuke; Schonhense, Gerd; Fecher, Gerhard H; Felser, Claudia; Ikenaga, Eiji

    2015-01-01

    A novel design of high-voltage compatible polarimeter for spin-resolved hard x-ray photoelectron spectroscopy (Spin-HAXPES) went into operation at beamline BL09XU of SPring-8 in Hyogo, Japan. The detector is based on the well-established principle of electron diffraction from a W(001) single-crystal at a scattering energy of 103.5 eV. Its special feature is that it can be operated at a high negative bias potential up to 10 kV, necessary to access the HAXPES range. The polarimeter is operated behind a large hemispherical analyzer (Scienta R-4000). It was optimized for high transmission of the transfer optics. The exit plane of the analyzer contains a delay-line detector (20 mm dia.) for conventional multichannel intensity spectroscopy simultaneously with single-channel spin analysis. The performance of the combined setup is demonstrated by the first spin-resolved data for the valence-region of a FeCo functional layer of a tunneling device, buried beneath 3 nm of oxidic material. The well-structured spin polari...

  1. Modelling the effect of buried valleys on groundwater flow: case study in Ventspils vicinity, Latvia

    Science.gov (United States)

    Delina, Aija; Popovs, Konrads; Bikse, Janis; Retike, Inga; Babre, Alise; Kalvane, Gunta

    2015-04-01

    Buried subglacial valleys are widely distributed in glaciated regions and they can have great influence on groundwater flow and hence on groundwater resources. The aim of this study is to evaluate the effect of the buried valleys on groundwater flow in a confined aquifer (Middle Devonian Eifelian stage Arukila aquifer, D2ar) applying numerical modelling. The study area is located at vicinity of Ventspils Town, near wellfield Ogsils where number of the buried valleys with different depth and filling material are present. Area is located close to the Baltic Sea at Piejūra lowland Rinda plain and regional groundwater flow is towards sea. Territory is covered by thin layer of Quaternary sediments in thicknesses of 10 to 20 meters although Prequaternary sediments are exposed at some places. Buried valleys are characterized as narrow, elongated and deep formations that is be filled with various, mainly Pleistocene glacigene sediments - either till loam of different ages or sand and gravel or interbedding of both above mentioned. The filling material of the valleys influences groundwater flow in the confined aquifers which is intercepted by the valleys. It is supposed that glacial till loam filled valleys serves as a barrier to groundwater flow and as a recharge conduit when filled with sand and gravel deposits. Numerical model was built within MOSYS modelling system (Virbulis et al. 2012) using finite element method in order to investigate buried valley influence on groundwater flow in the study area. Several conceptual models were tested in numerical model depending on buried valley filling material: sand and gravel, till loam or mixture of them. Groundwater flow paths and travel times were studied. Results suggested that valley filled with glacial till is acting as barrier and it causes sharp drop of piezometric head and downward flow. Valley filled with sand and gravel have almost no effect on piezometric head distribution, however it this case buried valleys

  2. Pharmacological evaluation of the adequacy of marble burying as an animal model of compulsion and/or anxiety.

    Science.gov (United States)

    Jimenez-Gomez, Corina; Osentoski, Andrew; Woods, James H

    2011-10-01

    Marble-burying behavior in rodents has been used commonly as an animal model of compulsive and/or anxiety behavior. The purpose of this study was to further assess the adequacy of marble burying as a preclinical animal model of compulsive behaviors using pharmacological tools. In particular, we were interested in whether dopamine D2/D3 agonists (e.g. pramipexole) known to produce compulsive behaviors in humans would increase marble burying. The effects of pramipexole on marble-burying behavior and locomotor activity were compared with those of the following: diazepam, a drug known to decrease marble burying; D-amphetamine, a stimulant that increases locomotor activity; and methyl β-carboline-3-carboxylate, a β-carboline previously shown to produce anxiogenic effects in rodents. All drugs produced dose-dependent decreases in marble burying, which were not always related to the locomotor effects of these drugs. The inability of pramipexole and methyl β-carboline-3-carboxylate to increase marble burying questions the validity of this assay as an adequate animal model of compulsive and/or anxiety behavior.

  3. Army Science Conference Proceedings Held in Orlando, Florida on June 22 - 25, 1992. Volume 2, Principal Authors H Through M.

    Science.gov (United States)

    1992-06-25

    Edgar C. See Reid, Robert H. III 35 Boesch, H. Edwin,Jr. Trapping Characteristics of I 135 Radiation-Generated Charge in Silicon-on-Insulator Buried...Sergio A. See Bishop, Steven S. I 119 Shafferman, Avigdor See Sadoff, Jerald C. III 79 Shattuck, Edgar See Ross, Edward III 49 Shen, Hongen Non Contact...Filpus, J. Frasch, L., Whitehair,S., Hoekstra, C., Morin , T., and Chapman, R., "A Review of Research and Development on the Microwave-Plasma

  4. Vertical coupling of laser glass microspheres to buried silicon nitride ellipses and waveguides

    CERN Document Server

    Navarro-Urrios, Daniel; Capuj, Nestor E; Berencen, Yonder; Garrido, Blas; Tredicucci, Alessandro

    2015-01-01

    We demonstrate the integration of Nd3+ doped Barium-Titanium-Silicate microsphere lasers with a Silicon Nitride photonic platform. Devices with two different geometrical configurations for extracting the laser light to buried waveguides have been fabricated and characterized. The first configuration relies on a standard coupling scheme, where the microspheres are placed over strip waveguides. The second is based on a buried elliptical geometry whose working principle is that of an elliptical mirror. In the latter case, the input of a strip waveguide is placed on one focus of the ellipse, while a lasing microsphere is placed on top of the other focus. The fabricated elliptical geometry (ellipticity=0.9) presents a light collecting capacity that is 50% greater than that of the standard waveguide coupling configuration and could be further improved by increasing the ellipticity. Moreover, since the dimensions of the spheres are much smaller than those of the ellipses, surface planarization is not required. On th...

  5. Reducing Thermal Losses and Gains With Buried and Encapsulated Ducts in Hot-Humid Climates

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.; Magee, A.; Zoeller, W.

    2013-02-01

    The Consortium for Advanced Residential Buildings (CARB) monitored three houses in Jacksonville, FL, to investigate the effectiveness of encapsulated and encapsulated/buried ducts in reducing thermal losses and gains from ductwork in unconditioned attics. Burying ductwork beneath loose-fill insulation has been identified as an effective method of reducing thermal losses and gains from ductwork in dry climates, but it is not applicable in humid climates where condensation may occur on the outside of the duct jacket. By encapsulating the ductwork in closed cell polyurethane foam (ccSPF) before burial beneath loose-fill mineral fiber insulation, the condensation potential may be reduced while increasing the R-value of the ductwork.

  6. CMOS buried quad p-n junction photodetector for multi-wavelength analysis.

    Science.gov (United States)

    Richard, Charles; Courcier, Thierry; Pittet, Patrick; Martel, Stéphane; Ouellet, Luc; Lu, Guo-Neng; Aimez, Vincent; Charette, Paul G

    2012-01-30

    This paper presents a buried quad p-n junction (BQJ) photodetector fabricated with a HV (high-voltage) CMOS process. Multiple buried junction photodetectors are wavelength-sensitive devices developed for spectral analysis applications where a compact integrated solution is preferred over systems involving bulk optics or a spectrometer due to physical size limitations. The BQJ device presented here is designed for chip-based biochemical analyses using simultaneous fluorescence labeling of multiple analytes such as with advanced labs-on-chip or miniaturized photonics-based biosensors. Modeling and experimental measurements of the spectral response of the device are presented. A matrix-based method for estimating individual spectral components in a compound spectrum is described. The device and analysis method are validated via a test setup using individually modulated LEDs to simulate light from 4-component fluorescence emission.

  7. Non-destructive imaging of buried electronic interfaces using a decelerated scanning electron beam.

    Science.gov (United States)

    Hirohata, Atsufumi; Yamamoto, Yasuaki; Murphy, Benedict A; Vick, Andrew J

    2016-09-02

    Recent progress in nanotechnology enables the production of atomically abrupt interfaces in multilayered junctions, allowing for an increase in the number of transistors in a processor. However, uniform electron transport has not yet been achieved across the entire interfacial area in junctions due to the existence of local defects, causing local heating and reduction in transport efficiency. To date, junction uniformity has been predominantly assessed by cross-sectional transmission electron microscopy, which requires slicing and milling processes that can potentially introduce additional damage and deformation. It is therefore essential to develop an alternative non-destructive method. Here we show a non-destructive technique using scanning electron microscopy to map buried junction properties. By controlling the electron-beam energy, we demonstrate the contrast imaging of local junction resistances at a controlled depth. This technique can be applied to any buried junctions, from conventional semiconductor and metal devices to organic devices.

  8. Prediction Technology of Buried Water-Bearing Structures in Coal Mines Using Transient Electromagnetic Method

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhi-hai; YUE Jian-hua; LIU Shu-cai

    2007-01-01

    Buried water-conducting and water-bearing structures in front of the driving head may easily lead to water bursts in coal mines. Therefore, it is very important for the safety of production to make an accurate and timely forecast about water bursts. Based on the smoke ring effect of transient electromagnetic fields, the principle of transient electromagnetic method used in detecting buried water-bearing structures in coal mines in advance, is discussed. Small multi-turn loop configurations used in coal mines are proposed and a field procedure of semicircular sector scanning is presented. The application of this method in one coal mine indicates that the technology has many advantages compared with others. The method is inexpensive, highly accurate and efficient. Suggestions are presented for future solutions to some remaining problems.

  9. Noise characteristics of resistors buried in low-temperature co-fired ceramics

    CERN Document Server

    Kolek, A; Dziedzic, A

    2003-01-01

    The comparison of noise properties of conventional thick film resistors prepared on alumina substrates and resistors embedded in low-temperature co-fired ceramics (LTCCs) is presented. Both types of resistors were prepared from commercially available resistive inks. Noise measurements of LTCC resistors below 1 kHz show Gaussian 1/f noise. This is concluded from the calculations of the second spectra as well as from studying the volume dependence of noise intensity. It has occurred that noise index of LTCC resistors on average is not worse than that of conventional resistors. A detailed study of co-fired surface resistors and co-fired buried resistors show that burying a resistor within LTCC substrate usually leads to (significant) enhancement of resistance but not of noise intensity. We interpret this behaviour as another argument in favour of tunnelling as the dominant conduction mechanism in LTCC resistors.

  10. Experimental investigation of buried landmine detection using time division multiplexing of multibeam laser Doppler vibrometer channels

    Science.gov (United States)

    Burgett, Richard; Aranchuk, Vyacheslav; Aranchuk, Ina

    2012-06-01

    Producing vibration images of buried landmines using a multi-beam laser Doppler vibrometer (MB-LDV) operating from a stationary platform have been accomplished in the past. Detection from a continuously moving platform can reduce the time of detection compared to stop-and-stare measurement. However, there is a speed limitation, imposed by the required spatial and frequency resolution. NCPA proposed a concept of time division multiplexing (TDM) of laser beams of a MB-LDV to overcome that speed limitation. The system, based on 16-beam MB-LDV, has been built and experimentally tested at an Army test facility. Vibration velocity profiles of buried mines have been obtained at different system speeds. Algorithms for speckle noise reduction in continuously moving MB-LDV signals have been developed and explored. The results of the current data collection, recent past data collection as well as the results of the effectiveness of speckle noise reduction techniques are presented.

  11. Infectivity of Trichinella spiralis larvae in pork buried in the ground

    Directory of Open Access Journals (Sweden)

    Jovic S.

    2001-06-01

    Full Text Available Time of survival and infectivity of Trichinella spiralis larvae in pig muscle tissue, buried at various depths in the ground were assessed. In the pork pieces the number of infective larvae was 250 ML/g. Meat originated from pig halves was divided in 39 equal pieces, 0.7 kg each, disposed in three groups of 1 3, and buried in depths of 30, 50, and 100 centimeters respectively. The pork was dug up at 13 intervals, approximately every week, until 91st day of the experiment. After each time interval, infectivity of larvae was assessed by bioassay on rats. The artificially infected rats were sacrificed on 42nd day after the infection and meat was examined by the following methods - artificial digestion and trichinoscopy. It was found that the larvae during all 90 days preserved infectivity in each depth.

  12. Birefringence measurement of glass ion-exchanged waveguides: burying depth or cover layer influence

    Science.gov (United States)

    Jamon, D.; Garayt, J. P.; Jordan, E.; Parsy, F.; Ghibaudo, E.; Neveu, S.; Broquin, J.-E.; Royer, F.

    2016-02-01

    This paper deals with an experimental non-destructive technique for the measurement of polarization behavior of integrated optical waveguides. It is based on a high resolution polarimeter associated to an ellipsometric-type calibration which allows determining the full state of polarization of the output light. A magneto-optic perturbation is also added to generate TE/TM mode beating, whose spatial period is directly linked to the modal TE/TM birefringence. This equipment is first qualified by the measurement of modal birefringence in totally or partially buried ion exchanged waveguides. The results show that the value of the birefringence varies as a function of the diffusion aperture width or with the burying depth. By adding a magneto-optical cover layer, consisting in magnetic nanoparticles doped silica matrix obtained by a sol gel process 1, we evidence a huge increase of the beating magnitude and a decrease of the modal birefringence.

  13. Comparison of nerve graft integration after segmentar resection versus epineural burying in crushed rat sciatic nerves

    Directory of Open Access Journals (Sweden)

    Cunha Marco Túlio Rodrigues da

    1997-01-01

    Full Text Available The aim of the present paper is to compare and correlate the take of nerve segments in a severely crushed nerve. Forty adult Wistar rats had their right sciatic nerve by a "Péan-Murphy" forceps for 40 minutes. In Group 1 (n=20, a segmentar serection in the crushed sciatic nerve was made. A sural nerve segment from the opposite hindpaw was placed in the gap. In Group 2 (n=20, a lontudinal insision in the epineurium of the lesioned sciatic nerve was made. A sural nerve segment was buried underneath the epineurium. The crushed sciatic nerves undergone Wallerian degeneration and endoneurial fibrosis. Sciatic nerves from Group 2 had significant better histological aspects than those from Group 1. Sural nerve grafts presented better degrees of regeneration than crushed sciatic nerves. Sural nerve grafts from Group 2 (burying method integrated as well as those from Group 1 (segmentar resection.

  14. Detection of buried objects by fusing dual-band infrared images

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.A.; Sengupta, S.K.; Sherwood, R.J.; Buhl, M.R.; Schaich, P.C.; Kane, R.J.; Barth, M.J.; Fields, D.J.; Carter, M.R.

    1993-11-01

    We have conducted experiments to demonstrate the enhanced detectability of buried land mines using sensor fusion techniques. Multiple sensors, including visible imagery, infrared imagery, and ground penetrating radar (GPR), have been used to acquire data on a number of buried mines and mine surrogates. Because the visible wavelength and GPR data are currently incomplete. This paper focuses on the fusion of two-band infrared images. We use feature-level fusion and supervised learning with the probabilistic neural network (PNN) to evaluate detection performance. The novelty of the work lies in the application of advanced target recognition algorithms, the fusion of dual-band infrared images and evaluation of the techniques using two real data sets.

  15. Preceding bronchial cutting for exposure of the pulmonary artery buried in scar tissue after chemoradiotherapy.

    Science.gov (United States)

    Nomori, Hiroaki; Cong, Yue; Sugimura, Hiroshi

    2017-01-01

    It is often difficult to expose the pulmonary artery buried in a scar tissue, especially in lung cancer patients that responded well to neoadjuvant chemoradiotherapy. Difficulty to access pulmonary artery branches may lead to potentially unnecessary pneumonectomy. To complete lobectomy in such cases, a technique with preceding bronchial cutting for exposure of the pulmonary artery is presented. After dissecting the pulmonary vein, the lobar bronchus is cut from the opposite side of the pulmonary artery with scissors. The back wall of the lobar bronchus is cut using a surgical knife from the luminal face, which can expose the pulmonary artery behind the bronchial stump and then complete lobectomy. Fourteen patients have been treated using the present technique, enabling complete resection by lobectomy (including sleeve lobectomy in 3 patients) without major bleeding. The present procedure can expose pulmonary artery buried in scar tissue, resulting in making the lobectomy safer.

  16. Development of buried wire gages for measurement of wall shear stress in Blastane experiments

    Science.gov (United States)

    Murthy, S. V.; Steinle, F. W.

    1986-01-01

    Buried Wire Gages operated from a Constant Temperature Anemometer System are among the special types of instrumentation to be used in the Boundary Layer Apparatus for Subsonic and Transonic flow Affected by Noise Environment (BLASTANE). These Gages are of a new type and need to be adapted for specific applications. Methods were developed to fabricate Gage inserts and mount those in the BLASTANE Instrumentation Plugs. A large number of Gages were prepared and operated from a Constant Temperature Anemometer System to derive some of the calibration constants for application to fluid-flow wall shear-stress measurements. The final stage of the calibration was defined, but could not be accomplished because of non-availability of a suitable flow simulating apparatus. This report provides a description of the Buried Wire Gage technique, an explanation of the method evolved for making proper Gages and the calibration constants, namely Temperature Coefficient of Resistance and Conduction Loss Factor.

  17. Development and calibration of buried wire gages for wall shear stress measurements in fluid flow

    Science.gov (United States)

    Murthy, Sreedhara V.; Steinle, Frank W.

    1988-01-01

    Special methods were developed to arrange 'Buried Wire Gage' inserts flush to the contoured flow surfaces of instrument plugs of a boundary-layer flow apparatus. The fabrication process was aimed at producing proper bonding of the sensor wire to the substrate surface, without causing excessive surface waviness. A large number of gages were built and first calibrated for the resistance-temperature characteristics. The gages were then installed in a flow calibration apparatus and operated from a constant temperature anemometer system for a series of flow settings to derive the calibration constants of each of the gages. The flow settings included a range of subsonic freestream Mach numbers in order to help establish the gage calibration characteristics for compressible flow fields. This paper provides a description of the buried wire gage technique, an explanation of the method evolved for making proper gages, the procedure for calibrating the gages and the results of measurements performed for determining the calibration constants.

  18. Buried waste integrated demonstration Fiscal Year 1993 close-out report

    Energy Technology Data Exchange (ETDEWEB)

    Owens, K.J.; Hyde, R.A.

    1994-04-01

    The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a multitude of advanced technologies. These technologies are being integrated to form a comprehensive remediation system for the effective and efficient remediation of buried waste. These efforts are identified and coordinated in support of the U.S. Department of Energy Environmental Restoration and Waste Management needs and objectives. BWID works with universities and private industry to develop these technologies, which are being transferred to the private sector for use nationally and internationally. A public participation policy has been established to provide stakeholders with timely and accurate information and meaningful opportunities for involvement in the technology development and demonstration process. To accomplish this mission of identifying technological solutions for remediation deficiencies, the Office of Technology Development initiated BWID at the Idaho National Engineering Laboratory. This report summarizes the activities of the BWID program during FY-93.

  19. Scanning near-field infrared micro-spectroscopy on buried InAs quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Fehrenbacher, Markus; Jacob, Rainer; Winnerl, Stephan; Schneider, Harald; Helm, Manfred [Institut fuer Ionenstrahlphysik und Materialforschung, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Wenzel, Marc Tobias; Krysztofinski, Anja; Ribbeck, Hans-Georg von; Eng, Lukas M. [Institut fuer Angewandte Photophysik, TU Dresden (Germany)

    2012-07-01

    Providing an optical resolution on the nanometer length scale, scanning near-field optical microscopy (SNOM) turned out to be a capable technique to investigate the optical properties of perovskites, buried semiconductors and single quantum dots. Thereby, the line-width of the observed resonances (5 - 8 meV) is significantly smaller than the inhomogeneously broadened line-width of other spectroscopic measurements. Using a scattering-type-SNOM (s-SNOM) combined with a tunable free-electron laser (FEL) light source we investigated the electronic structure of single InAs quantum dots, capped under a 70 nm thick GaAs layer. Spectroscopic near-field scans clearly identified two inter-sublevel transitions within the quantum dots at 85 meV and 120 meV, contrasting from the surrounding medium. Moreover, spatially scanning the s-SNOM tip at fixed excitation energies allowed mapping the 3D distribution of such buried quantum dots.

  20. Measurement of buried undercut structures in microfluidic devices by laser fluorescent confocal microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Li Shiguang; Liu Jing; Nguyen, Nam-Trung; Fang Zhongping; Yoon, Soon Fatt

    2009-11-20

    Measuring buried, undercut microstructures is a challenging task in metrology. These structures are usually characterized by measuring their cross sections after physically cutting the samples. This method is destructive and the obtained information is incomplete. The distortion due to cutting also affects the measurement accuracy. In this paper, we first apply the laser fluorescent confocal microscopy and intensity differentiation algorithm to obtain the complete three-dimensional profile of the buried, undercut structures in microfluidic devices, which are made by the soft lithography technique and bonded by the oxygen plasma method. The impact of material wettability and the refractive index (n) mismatch among the liquid, samples, cover layer, and objective on the measurement accuracy are experimentally investigated.

  1. Coherent phonon spectroscopy characterization of electronic bands at buried semiconductor heterointerfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ishioka, Kunie, E-mail: ishioka.kunie@nims.go.jp [Nano Characterization Unit, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Brixius, Kristina; Beyer, Andreas; Stolz, Wolfgang; Volz, Kerstin; Höfer, Ulrich [Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, 35032 Marburg (Germany); Rustagi, Avinash; Stanton, Christopher J. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Petek, Hrvoje [Department of Physics and Astronomy and Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)

    2016-02-01

    We demonstrate an all-optical approach to probe electronic band structure at buried interfaces involving polar semiconductors. Femtosecond optical pulses excite coherent phonons in epitaxial GaP films grown on Si(001) substrate. We find that the coherent phonon amplitude critically depends on the film growth conditions, specifically in the presence of antiphase domains, which are independently characterized by transmission electron microscopy. We determine the Fermi levels at the buried interface of GaP/Si from the coherent phonon amplitudes and demonstrate that the internal electric fields are created in the nominally undoped GaP films as well as the Si substrates, possibly due to the carrier trapping at the antiphase boundaries and/or at the interface.

  2. Sequential feature selection for detecting buried objects using forward looking ground penetrating radar

    Science.gov (United States)

    Shaw, Darren; Stone, Kevin; Ho, K. C.; Keller, James M.; Luke, Robert H.; Burns, Brian P.

    2016-05-01

    Forward looking ground penetrating radar (FLGPR) has the benefit of detecting objects at a significant standoff distance. The FLGPR signal is radiated over a large surface area and the radar signal return is often weak. Improving detection, especially for buried in road targets, while maintaining an acceptable false alarm rate remains to be a challenging task. Various kinds of features have been developed over the years to increase the FLGPR detection performance. This paper focuses on investigating the use of as many features as possible for detecting buried targets and uses the sequential feature selection technique to automatically choose the features that contribute most for improving performance. Experimental results using data collected at a government test site are presented.

  3. Assessment of incineration and melting treatment technologies for RWMC buried waste

    Energy Technology Data Exchange (ETDEWEB)

    Geimer, R.; Hertzler, T.; Gillins, R. (Science Applications International Corp., Idaho Falls, ID (United States)); Anderson, G.L. (EG and G Idaho, Inc., Idaho Falls, ID (United States))

    1992-02-01

    This report provides an identification, description, and ranking evaluation of the available thermal treatment technologies potentially capable of treating the Idaho National Engineering Laboratory Radioactive Waste Management Complex (RWMC) buried mixed waste. The ranking evaluation focused separately upon incinerators for treatment of combustible wastes and melters for noncombustible wastes. The highest rank incinerators are rotary kilns and controlled air furnaces, while the highest rank melters are the hearth configuration plasma torch, graphite electrode arc, and joule-heated melters. 4 refs.

  4. An analytical model of the electric field distributions of buried superjunction devices

    Institute of Scientific and Technical Information of China (English)

    Huang Haimeng; Chen Xingbi

    2013-01-01

    An analytical model of the electric field distributions of buried superjunction structures,based on the charge superposition method and Green's function approach,is derived.An accurate approximation of the exact analytical model of the vertical electric field is also proposed and demonstrated by numerical simulation.The influence of the dimension and doping concentration of each layer on the electric field is discussed in detail,and the breakdown voltage is demonstrated by simulations.

  5. Electromagnetic diffraction by an impedance cylinder buried halfway between two half-spaces

    KAUST Repository

    Salem, Mohamed

    2011-08-01

    We consider the problem of electromagnetic diffraction from a cylinder with impedance surface and half-buried between two dielectric media. An arbitrary located electric dipole provides the excitation. The harmonic solution is presented as a series sum over a spectrum of a discrete-index Hankel transform, and the spectral amplitudes are determined by solving an infinite linear system of equations, which is constructed by applying the orthogonality relation of the 1D Green\\'s function. © 2011 IEEE.

  6. Pristine Early Eocene Wood Buried Deeply in Kimberlite from Northern Canada

    OpenAIRE

    Wolfe, Alexander P.; Csank, Adam Z.; Reyes, Alberto V.; McKellar, Ryan C.; Ralf Tappert; Karlis Muehlenbachs

    2012-01-01

    We report exceptional preservation of fossil wood buried deeply in a kimberlite pipe that intruded northwestern Canada's Slave Province 53.3±0.6 million years ago (Ma), revealed during excavation of diamond source rock. The wood originated from forest surrounding the eruption zone and collapsed into the diatreme before resettling in volcaniclastic kimberlite to depths >300 m, where it was mummified in a sterile environment. Anatomy of the unpermineralized wood permits conclusive identificatio...

  7. Fabrication and Characterization of Multilayer Capacitors Buried in a Low Temperature Co-Fired Ceramic Substrate

    OpenAIRE

    Chan, Y. C.; G. Y. Li

    1998-01-01

    Multilayer ceramic capacitors designed to be embedded in a low temperature co-fired ceramic substrate have been successfully fabricated. Low and high value capacitors were respectively embedded in the low K multilayer substrate and high K dielectric layer. The buried capacitor has a capacitance density range (1 kHz) from about 220 pF/cm2 to 30 nF/cm2. The design took material compatibility and shrinkage characteristics specifically into account. The effects of heating rat...

  8. Seed longevity of Eragrostis plana Nees buried in natural grassland soil

    Directory of Open Access Journals (Sweden)

    Renato Borges de Medeiros

    2014-11-01

    Full Text Available The objective of this research was to evaluate the seed longevity of Eragrostis plana Nees buried at different soil depths, in a natural-grassland area in the Pampa biome (46 m altitude, 30º05´S and 51º40´W of Rio Grande do Sul State, Brazil. The experimental design was a split-plot type in complete blocks with two factors: seeds buried at five different depth levels (soil surface and 2.5, 5, 10 and 20 cm and seven exhumation dates. The blocks were allocated in natural grassland grazed by cattle, allocated in a 12-m-long transection. Fifty-four permeable nylon bags filled with 100 seeds in each division, with five vertical divisions, were buried in each row. Seven exhumation dates were used: the first on October 14, 2003 and the last on January 14, 2006. The percentage of viable seeds of E. plana, collected at seven exhumation times and set at different depths in the soil horizon, were described by simple negative exponential equations. Based on the model, the percentage of viable seeds collected at the five depths, (soil surface and 2.5, 5, 10, and 20 cm, after 2.5 years of burial, were 0.1, 0.5, 1.0, 7.4 and 22.1%, respectively. Increase in depth is directly associated with physical and physiological seed integrity of E. plana. Negative simple exponential equations can be used to predict seed longevity of E. plana buried in nylon bags. This invader species accumulates soil seed-bank of high longevity.

  9. Buried ion-exchanged glass waveguides: burial-depth dependence on waveguide width.

    Science.gov (United States)

    Madasamy, P; West, B R; Morrell, M M; Geraghty, D F; Honkanen, S; Peyghambarian, N

    2003-07-01

    A detailed theoretical and experimental study of the depth dependence of buried ion-exchanged waveguides on waveguide width is reported. Modeling, which includes the effect of nonhomogeneous time-dependent electric field distribution, agrees well with our experiments showing that burial depth increases linearly with waveguide width. These results may be used in the proper design of integrated optical circuits that need waveguides of different widths at different sections, such as arrayed waveguide gratings.

  10. Attribute-driven transfer learning for detecting novel buried threats with ground-penetrating radar

    Science.gov (United States)

    Colwell, Kenneth A.; Collins, Leslie M.

    2016-05-01

    Ground-penetrating radar (GPR) technology is an effective method of detecting buried explosive threats. The system uses a binary classifier to distinguish "targets", or buried threats, from "nontargets" arising from system prescreener false alarms; this classifier is trained on a dataset of previously-observed buried threat types. However, the threat environment is not static, and new threat types that appear must be effectively detected even if they are not highly similar to every previously-observed type. Gathering a new dataset that includes a new threat type is expensive and time-consuming; minimizing the amount of new data required to effectively detect the new type is therefore valuable. This research aims to reduce the number of training examples needed to effectively detect new types using transfer learning, which leverages previous learning tasks to accelerate and improve new ones. Further, new types have attribute data, such as composition, components, construction, and size, which can be observed without GPR and typically are not explicitly included in the learning process. Since attribute tags for buried threats determine many aspects of their GPR representation, a new threat type's attributes can be highly relevant to the transfer-learning process. In this work, attribute data is used to drive transfer learning, both by using attributes to select relevant dataset examples for classifier fusion, and by extending a relevance vector machine (RVM) model to perform intelligent attribute clustering and selection. Classification performance results for both the attribute-only case and the low-data case are presented, using a dataset containing a variety of threat types.

  11. Reference standard of penile size and prevalence of buried penis in Japanese newborn male infants.

    Science.gov (United States)

    Matsuo, Nobutake; Ishii, Tomohiro; Takayama, John I; Miwa, Masayuki; Hasegawa, Tomonobu

    2014-01-01

    The present study set forth the reference values for penile size and determined the prevalence of buried penis in Japanese full-term newborns. The stretched penile length was measured and the presence of buried penis was assessed at 1-7 days of age in 547 Japanese full-term newborn infants born between 2008 and 2012 in Tokyo. The stretched penile lengths were compared at 1-12 hours and 1-7 days of age in 63 infants and by two observers in 73 infants to estimate postnatal changes and interobserver variation, respectively. The mean stretched penile length was 3.06 cm (SD, 0.26; 95% confidence interval [CI], 3.04-3.08) and the mean ratio of penile length to body length was 6.24 × 100(-1) (SD, 0.55 × 100(-1)), both of which were significantly smaller than those in Caucasian newborn infants. Buried penis was identified in 20 of 547 infants (3.7%; 95% CI, 2.1-5.2%). The first measurements of penile length at 1-12 hours were significantly smaller than the next measurements at 1-7 days (95% CI of the difference, 0.22-0.34). The 95% CI for the limits of agreement in the penile lengths measured by the two observers was -0.58 to -0.40 for the lower limit and 0.33 to 0.51 for the upper limit. These findings indicate that the penile length should be assessed after 24 hours of age by the reference standard of the same ethnicity for identifying micropenis and that buried penis is not uncommon in Japanese full-term newborns.

  12. Bistatic, above-critical angle scattering measurements of fully buried unexploded ordnance (UXO) and clutter.

    Science.gov (United States)

    Waters, Z J; Simpson, H J; Sarkissian, A; Dey, S; Houston, B H; Bucaro, J A; Yoder, T J

    2012-11-01

    Laboratory grade bistatic scattering measurements are conducted in order to examine the acoustic response of realistic fully buried unexploded ordnance (UXO) from above-critical angle insonification, between 2 and 40 kHz. A 127 mm diameter rocket UXO, a 155 mm diameter artillery shell, a natural rock of approximately the same size, and a cinder block are fully buried in water-saturated medium grained sand (mean grain diameter, 240 μm) at depths of 10 cm below the water-sediment interface. A two-dimensional array of bistatic scattering measurements is generated synthetically by scanning a single hydrophone in steps of 3 cm over a 1 m × 1 m patch directly above the targets at a height of 20 cm above the water-sediment interface. Three-dimensional volumetric acoustic images generated from the return waveforms reveal scattering components attributed to geometric and elastic scattering, as well as multiple-scattering interactions of returns between the sediment-water interface and the buried objects. The far-field target strength of the objects is estimated through extrapolation of the angular spectrum. Agreement is found between experimental data and simulated data generated from a finite-element-based, three-dimensional time-harmonic model (2-25 kHz). Separation of the measured UXO from the clutter objects is demonstrated through exploitation of structural-acoustics-based features.

  13. Rescue missions for totally buried avalanche victims: conclusions from 12 years of experience.

    Science.gov (United States)

    Hohlrieder, Matthias; Thaler, Stephanie; Wuertl, Walter; Voelckel, Wolfgang; Ulmer, Hanno; Brugger, Hermann; Mair, Peter

    2008-01-01

    The planning and execution of avalanche rescue missions to search for totally buried avalanche victims are mostly based on personal experience and preference, as evidence-based information from literature is almost completely missing. Hence, the aim of this study was to identify major factors determining the survival probability of totally buried victims during avalanche rescue missions carried out by organized rescue teams (Austrian Mountain Rescue Service, Tyrol). During the 12-year period studied, 109 totally buried persons (56 off-piste, 53 backcountry), were rescued or recovered; 18.3% survived to hospital discharge. Median depth of burial was 1.25 m; median duration of burial was 85 min. The majority (61.6%) of the rescue missions were conducted under considerably dangerous avalanche conditions. The probability of survival was highest when located visually and lowest for those located by avalanche transceiver; survival did not significantly differ between those found by rescue dogs and those located with avalanche probes. Multivariate analysis revealed short duration of burial and off-piste terrain to be the two independent predictors of survival. Whenever companion rescue fails, snow burial in an avalanche is associated with extraordinarily high mortality. Searching the avalanche debris with probe lines seems to be equally effective as compared to searching with rescue dogs. The potential hazard for rescuers during avalanche rescue missions comes mainly from self-triggered avalanches, hence thorough mission planning and critical risk-benefit assessment are of utmost importance for risk reduction.

  14. COMBINATION OF VENLAFAXINE AND DIAZEPAM ATTENUATES MARBLE-BURYING BEHAVIOR OF MICE

    Directory of Open Access Journals (Sweden)

    Parle Milind

    2011-03-01

    Full Text Available Obsessive-Compulsive Disorder (OCD is an anxiety disorder featuring intrusive and troubling symptoms, which are perceived as the products of one’s own mind. This disorder is characterized by absurd, recurrent and persistent thoughts (obsessions followed by certain stereotyped actions (compulsions. The OCD patients realize the irrational nature of thoughts and rituals, but feel helpless and hopeless about controlling them. Numerous genes modulating the serotonin and dopaminergic systems are thought to participate in the pathophysiology of OCD. Marble-burying behavior of mice has been employed to study anxiety disorders including obsessive–compulsive disorder (OCD. The aim of this study was to test the efficacy of venlafaxine and diazepam per se and in combination on marble-burying behavior of mice. In the present project a total of 126 male Swiss mice divided in 21 groups were employed. Venlafaxine (1 mg kg-1i.p. per se as well as diazepam (0.25 mg kg-1i.p. per se did not show any anti-compulsive activity. But, the combination comprising of ineffective doses of venlafaxine (1 mg kg-1i.p. and diazepam (0.25 mg kg-1i.p. showed significant anti-compulsive activity as reflected by inhibition of marble-burying behavior.

  15. Site Assessment of Multiple-Sensor Approaches for Buried Utility Detection

    Directory of Open Access Journals (Sweden)

    Alexander C. D. Royal

    2011-01-01

    Full Text Available The successful operation of buried infrastructure within urban environments is fundamental to the conservation of modern living standards. Open-cut methods are predominantly used, in preference to trenchless technology, to effect a repair, replace or install a new section of the network. This is, in part, due to the inability to determine the position of all utilities below the carriageway, making open-cut methods desirable in terms of dealing with uncertainty since the buried infrastructure is progressively exposed during excavation. However, open-cut methods damage the carriageway and disrupt society's functions. This paper describes the progress of a research project that aims to develop a multi-sensor geophysical platform that can improve the probability of complete detection of the infrastructure buried beneath the carriageway. The multi-sensor platform is being developed in conjunction with a knowledge-based system that aims to provide information on how the properties of the ground might affect the sensing technologies being deployed. The fusion of data sources (sensor data and utilities record data is also being researched to maximize the probability of location. This paper describes the outcome of the initial phase of testing along with the development of the knowledge-based system and the fusing of data to produce utility maps.

  16. Diagnosing The English Patient: schizoid fantasies of being skinless and of being buried alive.

    Science.gov (United States)

    Doidge, N

    2001-01-01

    The psychological world of The English Patient is explored to deepen the understanding of schizoid states. The protagonist, Almásy, is a remote desert explorer whose triangular sadomasochistic affair with the married Katharine destroys them all. His damaged skin is understood as a symbolic representation of his psychological condition. For the schizoid, love consumes and leads to obliteration of the self, represented by the loss of identifying features, and to traumatic permeability (i.e., the loss of boundaries between self and other, and between the ego and repressed desires). Other schizoid themes are the animation of the inanimate, as in the depiction of the desert as a woman; hidden or buried identities; the digital and destructive experience of emotion represented by the conundrum of the bomb defuser; the sense that everything good is imaginary and might suddenly explode; and the moral unevenness of the characters. Almásy collaborates with the Nazis so he can retrieve Katharine's three-year-old corpse, with which he has necrophilic contact in a cave. Fantasies of the lost object buried within the self, of being buried alive, and of being skinned alive are related to the schizoid condition. Hyperpermeability is proposed as a core schizoid state, underlying schizoid withdrawal.

  17. Detection of buried targets using a new enhanced very early time electromagnetic (VETEM) prototype system

    Science.gov (United States)

    Cui, T.J.; Chew, W.C.; Aydiner, A.A.; Wright, D.L.; Smith, D.V.

    2001-01-01

    In this paper, numerical simulations of a new enhanced very early time electromagnetic (VETEM) prototype system are presented, where a horizontal transmitting loop and two horizontal receiving loops are used to detect buried targets, in which three loops share the same axis and the transmitter is located at the center of receivers. In the new VETEM system, the difference of signals from two receivers is taken to eliminate strong direct-signals from the transmitter and background clutter and furthermore to obtain a better SNR for buried targets. Because strong coupling exists between the transmitter and receivers, accurate analysis of the three-loop antenna system is required, for which a loop-tree basis function method has been utilized to overcome the low-frequency breakdown problem. In the analysis of scattering problem from buried targets, a conjugate gradient (CG) method with fast Fourier transform (FFT) is applied to solve the electric field integral equation. However, the convergence of such CG-FFT algorithm is extremely slow at very low frequencies. In order to increase the convergence rate, a frequency-hopping approach has been used. Finally, the primary, coupling, reflected, and scattered magnetic fields are evaluated at receiving loops to calculate the output electric current. Numerous simulation results are given to interpret the new VETEM system. Comparing with other single-transmitter-receiver systems, the new VETEM has better SNR and ability to reduce the clutter.

  18. Microbial communities of buried soils of the Tsaritsyn Defense Line (1718-1720)

    Science.gov (United States)

    Demkina, T. S.; Khomutova, T. E.; Kuznetsova, T. V.; Kontoboitseva, A. A.; Borisov, A. V.

    2016-01-01

    Microbial communities of recent surface soils and the soils buried beneath the rampart of the Tsaritsyn Defense Line (1718-1720) in the Little Ice Age were studied. The contribution of the time factor to the variability in the number of microorganisms from different trophic groups was shown to be minor (0.2-0.3%), although significant. In the upper horizon of the paleosols reflecting the environmental conditions intrinsic to the period of the rampart construction, the lower (by two times) content of live microbial biomass, the lower metabolic activity of the microbial community, and the more contrasting changes in the microbiological parameters as compared to these characteristics in the recent soils were found for all the elements of the local topography. The stabilities of the microbial communities in the buried and recent soils were almost the same. The ecological-trophic structure of the microbial communities in the buried soils evidences that, the climate of the 18th century in the southern Privolzhskaya Upland was more humid than now. At the same time, temperature conditions of the Little Ice Age did not prevent the development of steppe vegetation and corresponding soil microbial communities in this area. Our data on the morphology and physicochemical properties of the soils confirm the assumption about more humid climatic conditions at the beginning of the 18th century in the studied area.

  19. Detection of Microbial sulfate-reduction associated with buried stainless steel coupons

    Energy Technology Data Exchange (ETDEWEB)

    Mark E. Delwiche; M. Kay Adler Flitton; Alicia Olson

    2007-03-01

    The objective of this study was to demonstrate applicability of an innovative radioactive isotope method for imaging microbial activity in geological materials to a comprehensive study of metal corrosion. The method was tested on a sample of stainless steel coupons that had been buried as part of a corrosion study initiated by the National Institute of Standards and Testing or NIST (known as National Bureau of Standards prior to 1988) in 1970. The images showed evidence of microbial activity that could be mapped on a millimeter scale to coupon surfaces. A second more conventional isotope tracer method was also used to provide a quantitative measure of the same type of microbial activity in soil proximal to the buried coupons. Together the techniques offer a method for evaluating low metabolic levels of activity that have the potential for significant cumulative corrosion effects. The methods are powerful tools for evaluation of potential for microbial induced corrosion to buried steel components used on pipelines, in the power and communications infrastructure, and in nuclear waste repository containers.

  20. Comparison of broadband and hyperspectral thermal infrared imaging of buried threat objects

    Science.gov (United States)

    McFee, John E.; Achal, Steve B.; Diaz, Alejandra U.; Faust, Anthony A.

    2013-06-01

    Previous research by many groups has shown that broad-band thermal infrared (TIR) imagers can detect buried explosive threat devices, such as unexploded ordnance (UXO), landmines and improvised explosive devices (IEDs). Broad-band detection measures the apparent temperature - an average over the wave band of the product of the true soil surface temperature and the emissivity. Broad-band detection suffers from inconsistent performance (low signal, high clutter rates), due in part to diurnal variations, environmental and meteorological conditions, and soil surface effects. It has been suggested that hyperspectral TIR imaging might have improved performance since it can, in principle, allow extraction of the wavelength-dependent emissivity and the true soil surface temperature. This would allow the surface disturbance effects to be separated from the soil column (bulk) effects. A significant, and as yet unanswered, question is whether hyperspectral TIR images provide better detection capability (higher probability of detection and/or lower false alarm rate) than do broad-band thermal images. TIR hyperspectral image data of threat objects, buried and surface-laid in bare soil, were obtained in arid, desert-like conditions over full diurnal cycles for several days. Regions of interest containing threat objects and backgrounds were extracted throughout the time period. Simulated broad-band images were derived from the hyperspectral images. The diurnal variation of the images was studied. Hyperspectral was found to provide some advantage over broad-band imaging in detection of buried threat objects for the limited data set studied.

  1. Modelling of coupled heat and moisture flows around a buried electrical cable

    Directory of Open Access Journals (Sweden)

    Eslami Hossein

    2016-01-01

    Full Text Available The admissible current within a buried electrical power cable is limited by the maximum allowed temperature of the cable (Joule effect. The thermal properties of the surrounding soil controls heat dissipation around the cable. The main focus of the study was to evaluate the coupled heat and moisture flow around such buried electrical cables. The heat dissipation of a buried power cable was simulated in the surrounding soil at unsteady conditions. The hydro-thermal coupling was modelled by taking into account the moisture flow of liquid water and vapour, and the heat flow in the soil by convection and advection. As the thermal vapour diffusion enhancement factor (η appears to be a key parameter, the sensitivity study of the coupled heat and moisture flow in the ground regarding this parameter was performed. The variations of the degree of saturation and the temperature of the surrounding soil were studied over 180 days of heating. The results showed that the moisture flow was mainly caused by the vapour transport under temperature gradients. These results emphasized the significant effect of the hydrothermal characteristics of surrounding soil. The radius of influence of the power cable was also evaluated.

  2. Investigation solution to improve the irradiation reliability of SOI NMOSFET

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A solution is developed to improve the irradiation reliability of SOI NMOSFET(N-type Metal Oxide Semiconductor Field Effect Transistor).This solution,including SOI(Silicon On Insulator)wafer hardening and transistor structure hardening,protects the SOI circuit from total dose irradiation effect.

  3. Characterization of Single-Photon Avalanche Diodes in Standard 140-nm SOI CMOS Technology

    NARCIS (Netherlands)

    Lee, M.J.; Sun, P.; Charbon, E.

    2015-01-01

    We report on the characterization of single-photon avalanche diodes (SPADs) fabricated in standard 140-nm silicon on insulator (SOI) complementary metal-oxide-semiconductor (CMOS) technology. As a methodology for SPAD optimization, a test structure array, called SPAD farm, was realized with several

  4. Characterization of Semiconductor Materials Using AOTF Instruments

    Science.gov (United States)

    Li, G. P.; Cheng, L. J.

    1997-01-01

    A non-invasive characterization of silicon-on-insulator (SOI) wafers using white light interference measured by an AOTF polarimetric hyperspectral imaging instrument will be presented an an illustration of the technology potential. Experiments provided high resolution thickness maps of both silicon and oxide layers with accuracy and observed optically active imperfections and distributions in the structure.

  5. 3D mapping of buried underworld infrastructure using dynamic Bayesian network based multi-sensory image data fusion

    Science.gov (United States)

    Dutta, Ritaban; Cohn, Anthony G.; Muggleton, Jen M.

    2013-05-01

    The successful operation of buried infrastructure within urban environments is fundamental to the conservation of modern living standards. In this paper a novel multi-sensor image fusion framework has been proposed and investigated using dynamic Bayesian network for automatic detection of buried underworld infrastructure. Experimental multi-sensors images were acquired for a known buried plastic water pipe using Vibro-acoustic sensor based location methods and Ground Penetrating Radar imaging system. Computationally intelligent conventional image processing techniques were used to process three types of sensory images. Independently extracted depth and location information from different images regarding the target pipe were fused together using dynamic Bayesian network to predict the maximum probable location and depth of the pipe. The outcome from this study was very encouraging as it was able to detect the target pipe with high accuracy compared with the currently existing pipe survey map. The approach was also applied successfully to produce a best probable 3D buried asset map.

  6. Structure and evolution of the Afanasy Nikitin seamount, buried hills and 85 degrees E Ridge in the northeastern Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.

    Geophysical data of the Afanasy Nikitin seamount (ANS), partly buried hills and 85 degrees E Ridge in the northeastern Indian Ocean were studied together with published seismic refraction results to understand genesis and evolution of the structures...

  7. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 496: Buried Rocket Site, Antelope Lake, Tonopah Test Range

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office; Bechtel Nevada

    2004-05-01

    This Streamlined Approach for Environmental Restoration (SAFER) plan details the activities necessary to close Corrective Action Unit 496: Buried Rocket Site, Antelope Lake. CAU 496 consists of one site located at the Tonopah Test Range, Nevada.

  8. Buried valleys within the Standing Rock Indian Reservation, Sioux County, North Dakota, and Corson County, South Dakota

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage contains information about the buried valleys within the Standing Rock Indian Reservation, Sioux County, North Dakota, and Corson County, South...

  9. Underground riparian wood: Buried stem and coarse root structures of Black Poplar (Populus nigra L.)

    Science.gov (United States)

    Holloway, James V.; Rillig, Matthias C.; Gurnell, Angela M.

    2017-02-01

    Despite the potential importance of tree species in influencing the processes of wood recruitment, transport, retention, and decay that control river wood budgets, focus has been relatively limited on this theme within fluvial wood research. Furthermore, one of the least investigated topics is the belowground living wood component of riparian trees. This paper presents observations of the morphology and age of buried stem and coarse root structures of eight Populus nigra individuals located in the riparian woodland of two sites on the middle to lower Tagliamento River, Italy. This species was selected because of its wide distribution along European rivers and its frequent dominance of riparian woodland. Each tree was excavated by hand to expose a minimum of half of the root system with complete exposure of the main axis. Smaller roots were then removed and larger protruding roots cut back to permit access to the main axis. The excavated structures were photographed from multiple angles for photogrammetric modelling; the structure and character of the exposed sediments around the tree's main axis were recorded; and wood samples were taken from the main aboveground stem(s), sections of the main buried axis, and major roots for dendrochronological analysis. Results from these field observations and laboratory dating of the wood samples were combined to describe the belowground morphology of each tree and to draw inferences concerning the impact of fluvial disturbances. Common features of these excavated structures included: (i) rooting depths to below the bar surface where the original tree established, with many young roots also existing at depth; (ii) translocation of the main buried axis in a downstream direction; (iii) a main buried axis comprised mainly of stems that have become buried and then generated new shoots, including multistem patches, and adventitious roots; (iv) the presence of steps and bends in the main buried axis associated with the generation of

  10. Detection of buried pipes by polarimetric borehole radar; Polarimetric borehole radar ni yoru maisetsukan no kenshutsu jikken

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M.; Niitsuma, H. [Tohoku University, Sendai (Japan); Nakauchi, T. [Osaka Gas Co. Ltd., Osaka (Japan)

    1997-05-27

    If the borehole radar is utilized for detection of buried pipes, the underground radar measurement becomes possible even in the situation where the mesurement on the earth surface is difficult, for example, such a place as under the road where there is much traffic. However, since buried pipes are horizontally installed and the existing borehole radar can send/receive only vertical polarization, the measurement conducted comes to be poor in efficiency from a viewpoint of the polarization utilization. Therefore, by introducing the polarimetric borehole radar to the detection of buried pipes, a basic experiment was conducted for the effective detection of horizontal buried pipes. Proposing the use of a slot antenna which can send/receive horizontal polarization in borehole in addition to a dipole antenna which sends/receives vertical polarization, developed was a step frequency type continuous wave radar of a network analyzer basis. As a result of the experiment, it was confirmed that reflection from buried pipes is largely dependent on polarization. Especially, it was found that in the slot dipole cross polarization mesurement, reflection from buried pipes can be emphasized. 4 refs., 5 figs.

  11. A Monolithic active pixel sensor for ionizing radiation using a 180nm HV-SOI process

    CERN Document Server

    Hemperek, Tomasz; Krüger, Hans; Wermes, Norbert

    2014-01-01

    An improved SOI-MAPS (Silicon On Insulator Monolithic Active Pixel Sensor) for ionizing radiation based on Partially Depleted High Voltage SOI technology (PD-SOI) has been developed. Similar to existing Fully Depleted SOI-based (FD-SOI) MAPS, a buried silicon oxide inter-dielectric (BOX) layer is used to separate the CMOS electronics from the handle wafer which is used as a depleted charge collection layer while FD-SOI MAPS suffer from radiation damage such as transistor threshold voltage shifts due to charge traps in the oxide layers and charge states created at the silicon oxide boundaries (back gate effect). The XFAB 180-nm HV-SOI technology offers an additional isolation by deep non-depleted implant between the BOX layer and the active circuitry witch mitigates this problem. Therefore we see in this technology a high potential to implement radiation-tolerant MAPS with fast charge collection property. The design and measurement results from a first prototype are presented including charge collection in neu...

  12. A Monolithic Active Pixel Sensor for ionizing radiation using a 180 nm HV-SOI process

    Science.gov (United States)

    Hemperek, Tomasz; Kishishita, Tetsuichi; Krüger, Hans; Wermes, Norbert

    2015-10-01

    An improved SOI-MAPS (Silicon On Insulator Monolithic Active Pixel Sensor) for ionizing radiation based on thick-film High Voltage SOI technology (HV-SOI) has been developed. Similar to existing Fully Depleted SOI-based (FD-SOI) MAPS, a buried silicon oxide inter-dielectric (BOX) layer is used to separate the CMOS electronics from the handle wafer which is used as a depleted charge collection layer. FD-SOI MAPS suffers from radiation damage such as transistor threshold voltage shifts due to charge traps in the oxide layers and charge states created at the silicon oxide boundaries (back gate effect). The X-FAB 180-nm HV-SOI technology offers an additional isolation by deep non-depleted implant between the BOX layer and the active circuitry which mitigates this problem. Therefore we see in this technology a high potential to implement radiation-tolerant MAPS with fast charge collection property. The design and measurement results from a first prototype are presented including charge collection in neutron irradiated samples.

  13. UNCOVERING BURIED VOLCANOES: NEW DATA FOR PROBABILISTIC VOLCANIC HAZARD ASSESSMENT AT YUCCA MOUNTAIN

    Energy Technology Data Exchange (ETDEWEB)

    F.V. Perry

    2005-10-13

    Basaltic volcanism poses a potential hazard to the proposed Yucca Mountain nuclear waste repository because multiple episodes of basaltic volcanism have occurred in the Yucca Mountain region (YMR) in the past 11 Ma. Intervals between eruptive episodes average about 1 Ma. Three episodes have occurred in the Quaternary at approximately 1.1 Ma (5 volcanoes), 350 ka (2 volcanoes), and 80 ka (1 volcano). Because Yucca Mountain lies within the Basin and Range Province, a significant portion of the pre-Quaternary volcanic history of the YMR may be buried in alluvial-filled basins. An exceptionally high-resolution aeromagnetic survey and subsequent drilling program sponsored by the U.S. Department of Energy (DOE) began in 2004 and is gathering data that will enhance understanding of the temporal and spatial patterns of Pliocene and Miocene volcanism in the region (Figure 1). DOE has convened a ten-member expert panel of earth scientists that will use the information gathered to update probabilistic volcanic hazard estimates originally obtained by expert elicitation in 1996. Yucca Mountain is a series of north-trending ridges of eastward-tilted fault blocks that are bounded by north to northeast-trending normal faults. Topographic basins filled with up to 500 m of alluvium surround it to the east, south and west. In the past several decades, nearly 50 holes have been drilled in these basins, mainly for Yucca Mountain Project Site Characterization and the Nye County Early Warning Drilling Program. Several of these drill holes have penetrated relatively deeply buried (300-400 m) Miocene basalt; a Pliocene basalt dated at 3.8 Ma was encountered at a relatively shallow depth (100 m) in the northern Amargosa Desert (Anomaly B in Figure 1). The current drilling program is the first to specifically target and characterize buried basalt. Based on the new aeromagnetic survey and previous air and ground magnetic surveys (Connor et al. 2000; O'Leary et al. 2002), at least eight

  14. Electrophoretic Extraction and Proteomic Characterization of Proteins Buried in Marine Sediments

    Directory of Open Access Journals (Sweden)

    Eli K. Moore

    2014-10-01

    Full Text Available Proteins are the largest defined molecular component of marine organic nitrogen, and hydrolysable amino acids, the building blocks of proteins, are important components of particulate nitrogen in marine sediments. In oceanic systems, the largest contributors are phytoplankton proteins, which have been tracked from newly produced bloom material through the water column to surface sediments in the Bering Sea, but it is not known if proteins buried deeper in sediment systems can be identified with confidence. Electrophoretic gel protein extraction methods followed by proteomic mass spectrometry and database searching were used as the methodology to identify buried phytoplankton proteins in sediments from the 8–10 cm section of a Bering Sea sediment core. More peptides and proteins were identified using an SDS-PAGE tube gel than a standard 1D flat gel or digesting the sediment directly with trypsin. The majority of proteins identified correlated to the marine diatom, Thalassiosira pseudonana, rather than bacterial protein sequences, indicating an algal source not only dominates the input, but also the preserved protein fraction. Abundant RuBisCO and fucoxanthin chlorophyll a/c binding proteins were identified, supporting algal sources of these proteins and reinforcing the proposed mechanisms that might protect proteins for long time periods. Some preserved peptides were identified in unexpected gel molecular weight ranges, indicating that some structural changes or charge alteration influenced the mobility of these products during electrophoresis isolation. Identifying buried photosystem proteins suggests that algal particulate matter is a significant fraction of the preserved organic carbon and nitrogen pools in marine sediments.

  15. A label propagation approach for detecting buried objects in handheld GPR data

    Science.gov (United States)

    Reid, Graham; Frigui, Hichem

    2016-05-01

    Detection of buried landmines and other explosive objects using ground penetrating radar (GPR) has been investigated for almost two decades and several classifiers have been developed. Most of these methods are based on the supervised learning paradigm where labeled target and clutter signatures are needed to train a classifier to discriminate between the two classes. Typically, large and diverse labeled training samples are needed to improve the performance of the classifier by overcoming noise and adding robustness and generalization to unseen examples. Unfortunately, even though unlabeled GPR data may be abundant, labeled data are often available in small quantities as the labeling process is tedious and can be ambiguous for most of the data. In this paper, we propose an algorithm for detecting landmines and buried objects that uses unlabeled data to help labeled data in the classification process. Our algorithm is graph-based and propagates the nodes labels to neighboring nodes according to their proximity in the feature space. For labeled data, we use a set of prototypes that are extracted from a small set of labeled training samples. For unlabeled data, we use a collection of signatures that are extracted from the vicinity of the alarm being tested. This choice is based on the assumption that many spatially close signatures are expected to have similar features and thus, unlabeled samples can create dense regions that link different regions of the labeled samples and propagate their labels to test samples. In other words, unlabeled samples are explored to create a context for each test alarm. To validate the proposed label propagation based classifier, we use it to detect buried explosive objects in GPR data collected by an experimental hand held demonstrator. We show that our approach is robust and computationally efficient to be used for both target discrimination and prescreening.

  16. INL Reactor Technology Complex Out-of-Service Buried Piping Hazards

    Energy Technology Data Exchange (ETDEWEB)

    Douglas M. Gerstner

    2008-05-01

    Idaho National Laboratory (INL) Reactor Technology Complex (RTC) buried piping and components are being characterized to determine if they should be managed as hazardous waste and subject to the Hazardous Waste Management Act /Resource Conservation and Recovery Act (RCRA). RTC buried piping and components involve both active piping and components from currently operating nuclear facilities, such as the Advanced Test Reactor (ATR), and inactive lines from facilities undergoing D&D activities. The issue exists as to the proper methods to analyze and control hazards associated with D&D activities on facilities collocated with existing operating nuclear facilities, or future collocated facilities being considered with the resurgent nuclear industry. During initial characterization activities, it was determined that residual radioactive material in several inactive RTC lines and components could potentially exceed hazard category (HC) 3 thresholds. In addition, concerns were raised as to how to properly isolate active nuclear facility piping and components from those inactive lines undergoing RCRA actions, and whether the operating facility safety basis could be impacted. Work was stopped, and a potential inadequacy in the safety analysis (PISA) was declared, even though no clear safety basis existed for the inactive, abandoned lines and equipment. An unreviewed safety question (USQ) and an occurrence report resulted. A HC 3 or greater Nuclear Facility/Activity for the buried piping and components was also declared in the occurrence report. A qualitative hazard assessment was developed to evaluate the potential hazards associated with characterization activities, and any potential effects on the safety basis of the collocated RTC operating nuclear facilities. The hazard assessment clearly demonstrated the low hazards associated with the activities based on form and dispersiblity of the radioactive material in the piping and components. The hazard assessment developed

  17. Angle-beam shear wave scattering from buried crack-like defects in bonded specimens

    Science.gov (United States)

    Maki, Carson T.; Michaels, Jennifer E.; Weng, Yu; Michaels, Thomas E.

    2017-02-01

    Ultrasonic wavefield imaging, which refers to the measurement of wave motion on a 2-D rectilinear grid resulting from a fixed source, has been previously applied to angle-beam shear wave propagation in simple plates with through-holes and far-surface notches. In this prior work, scattered waves were analyzed using baseline subtraction of wavefields acquired before and after a notch was introduced. In practice, however, defects of interest often occur between bonded layers and it is generally not possible to record data from the same specimen in both the undamaged and damaged states, even in the laboratory. Direct baseline subtraction of wavefields thus becomes impractical as a tool for analyzing scattering. This present work considers measurement and analysis of angle-beam waves in bonded specimens with and without buried defects originating from fastener holes. Data from fastener holes with and without simulated damage in the form of notches are compared, and it is shown that wavefield baseline subtraction, even after correcting for misalignment between scans, is ineffective for isolating scattering from the notch. A combination of frequency-wavenumber filtering and spatial windowing is proposed and implemented as an alternative approach to quantify scattering from damage. Despite unavoidable deviations from specimen-to-specimen caused by factors such as variations in bonding, transducer mounting, and fastener hole machining, it is shown that scattering from buried notches can be clearly visualized in recorded wavefield data of bonded plates containing a buried defect as opposed to "baseline" wavefield data taken from a nominally similar specimen with no defect present. Backscattering is further quantified in the form of scattering patterns at different scattering frames to quantify the effect of the notch on the total backscattered wavefield.

  18. A fisher vector representation of GPR data for detecting buried objects

    Science.gov (United States)

    Karem, Andrew; Khalifa, Amine B.; Frigui, Hichem

    2016-05-01

    We present a new method, based on the Fisher Vector (FV), for detecting buried explosive objects using ground- penetrating radar (GPR) data. First, low-level dense SIFT features are extracted from a grid covering a region of interest (ROIs). ROIs are identified as regions with high-energy along the (down-track, depth) dimensions of the 3-D GPR cube, or with high-energy along the (cross-track, depth) dimensions. Next, we model the training data (in the SIFT feature space) by a mixture of Gaussian components. Then, we construct FV descriptors based on the Fisher Kernel. The Fisher Kernel characterizes low-level features from an ROI by their deviation from a generative model. The deviation is the gradient of the ROI log-likelihood with respect to the generative model parameters. The vectorial representation of all the deviations is called the Fisher Vector. FV is a generalization of the standard Bag of Words (BoW) method, which provides a framework to map a set of local descriptors to a global feature vector. It is more efficient to compute than the BoW since it relies on a significantly smaller codebook. In addition, mapping a GPR signature into one global feature vector using this technique makes it more efficient to classify using simple and fast linear classifiers such as Support Vector Machines. The proposed approach is applied to detect buried explosive objects using GPR data. The selected data were accumulated across multiple dates and multiple test sites by a vehicle mounted mine detector (VMMD) using GPR sensor. This data consist of a diverse set of conventional landmines and other buried explosive objects consisting of varying shapes, metal content, and burial depths. The performance of the proposed approach is analyzed using receiver operating characteristics (ROC) and is compared to other state-of-the-art feature representation methods.

  19. Effect of biostimulation and bioaugmentation on degradation of polyurethane buried in soil.

    Science.gov (United States)

    Cosgrove, L; McGeechan, P L; Handley, P S; Robson, G D

    2010-02-01

    This work investigated biostimulation and bioaugmentation as strategies for removing polyurethane (PU) waste in soil. Soil microcosms were biostimulated with the PU dispersion agent "Impranil" and/or yeast extract or were bioaugmented with PU-degrading fungi, and the degradation of subsequently buried PU was determined. Fungal communities in the soil and colonizing buried PU were enumerated on solid media and were analyzed using denaturing gradient gel electrophoresis (DGGE). Biostimulation with yeast extract alone or in conjunction with Impranil increased PU degradation 62% compared to the degradation in untreated control soil and was associated with a 45% increase in putative PU degraders colonizing PU. Specific fungi were enriched in soil following biostimulation; however, few of these fungi colonized the surface of buried PU. Fungi used for soil bioaugmentation were cultivated on the surface of sterile wheat to form a mycelium-rich inoculum. Wheat, when added alone to soil, increased PU degradation by 28%, suggesting that wheat biomass had a biostimulating effect. Addition of wheat colonized with Nectria haematococca, Penicillium viridicatum, Penicillium ochrochloron, or an unidentified Mucormycotina sp. increased PU degradation a further 30 to 70%, suggesting that biostimulation and bioaugmentation were operating in concert to enhance PU degradation. Interestingly, few of the inoculated fungi could be detected by DGGE in the soil or on the surface of the PU 4 weeks after inoculation. Bioaugmentation did, however, increase the numbers of indigenous PU-degrading fungi and caused an inoculum-dependent change in the composition of the native fungal populations, which may explain the increased degradation observed. These results demonstrate that both biostimulation and bioaugmentation may be viable tools for the remediation of environments contaminated with polyurethane waste.

  20. The effect of soil texture on the degradation of textiles associated with buried bodies.

    Science.gov (United States)

    Lowe, A C; Beresford, D V; Carter, D O; Gaspari, F; O'Brien, R C; Stuart, B H; Forbes, S L

    2013-09-10

    There are many factors which affect the rate of decomposition in a grave site including; the depth of burial, climatic conditions, physical conditions of the soil (e.g. texture, pH, moisture), and method of burial (e.g. clothing, wrappings). Clothing is often studied as a factor that can slow the rate of soft tissue decomposition. In contrast, the effect of soft tissue decomposition on the rate of textile degradation is usually reported as anecdotal evidence rather than being studied under controlled conditions. The majority of studies in this area have focused on the degradation of textiles buried directly in soil. The purpose of this study was to investigate the effect of soil texture on the degradation and/or preservation of textile materials associated with buried bodies. The study involved the burial of clothed domestic pig carcasses and control clothing in contrasting soil textures (silty clay loam, fine sand and fine sandy loam) at three field sites in southern Ontario, Canada. Graves were exhumed after 2, 12 and 14 months burial to observe the degree of degradation for both natural and synthetic textiles. Recovered textile samples were chemically analyzed using infrared (IR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) to investigate the lipid decomposition by-products retained in the textiles. The findings of this study demonstrate that natural textile in contact with a buried decomposing body will be preserved for longer periods of time when compared to the same textile buried directly in soil and not in contact with a body. The soil texture did not visually impact the degree of degradation or preservation. Furthermore, the natural-synthetic textile blend was resistant to degradation, regardless of soil texture, contact with the body or time since deposition. Chemical analysis of the textiles using GC-MS correctly identified a lipid degradation profile consistent with the degree of soft tissue decomposition. Such information may be

  1. Structure of the Buried Metal-Molecule Interface in Organic Thin Film Devices

    DEFF Research Database (Denmark)

    Hansen, Christian Rein; Sørensen, Thomas Just; Glyvradal, Magni

    2009-01-01

    By use of specular X-ray reflectivity (XR) the structure of a metal-covered organic thin film device is measured with angstrom resolution. The model system is a Langmuir-Blodgett (LB) film, sandwiched between a silicon substrate and a top electrode consisting of 25 Å titanium and 100 Å aluminum....... By comparison of XR data for the five-layer Pb2+ arachidate LB film before and after vapor deposition of the Ti/Al top electrode, a detailed account of the structural damage to the organic film at the buried metal-molecule interface is obtained. We find that the organized structure of the two topmost LB layers...

  2. Results of a monitoring pilot with a permanent buried multicomponent seismic array at Ketzin

    OpenAIRE

    2011-01-01

    To monitor the migration of the injected CO2 in the Ketzin project (Germany) a permanently buried multi-component seismic array has been installed in August 2009. Since then the array has been continuously recording passive seismic data. Additionally an active seismic survey resulting in a 230 m long 2D seismic line roughly passing over the monitoring well Ktzi 202/2007 has been acquired in November 2009. This relatively small set-up is meant as a pre-screening study to demonstrate the added ...

  3. Buried paleoindian-age landscapes in stream valleys of the central plains, USA

    Science.gov (United States)

    Mandel, R.D.

    2008-01-01

    A systematic study of late-Quaternary landscape evolution in the Central Plains documented widespread, deeply buried paleosols that represent Paleoindian-age landscapes in terrace fills of large streams (> 5th order), in alluvial fans, and in draws in areas of western Kansas with a thick loess mantle. Alluvial stratigraphic sections were investigated along a steep bio-climatic gradient extending from the moist-subhumid forest-prairie border of the east-central Plains to the dry-subhumid and semi-arid shortgrass prairie of the west-central Plains. Radiocarbon ages indicate that most large streams were characterized by slow aggradation accompanied by cumulic soil development from ca. 11,500 to 10,000??14C yr B.P. In the valleys of some large streams, such as the Ninnescah and Saline rivers, these processes continued into the early Holocene. The soil-stratigraphic record in the draws of western Kansas indicates slow aggradation punctuated by episodes of landscape stability and pedogenesis beginning as early as ca. 13,300??14C yr B.P. and spanning the Pleistocene-Holocene boundary. The development record of alluvial fans in western Kansas is similar to the record in the draws; slow aggradation was punctuated by multiple episodes of soil development between ca. 13,000 and 9000??14C yr B.P. In eastern Kansas and Nebraska, development of alluvial fans was common during the early and middle Holocene, but evidence shows fan development as early as ca. 11,300??14C yr B.P. Buried soils dating between ca. 12,600 and 9000??14C yr B.P. were documented in fans throughout the region. In stream valleys across the Central Plains, rapid alluviation after ca. 9000??14C yr B.P. resulted in deeply buried soils that may harbor Paleoindian cultural deposits. Hence, the paucity of recorded stratified Paleoindian sites in the Central Plains is probably related to poor visibility (i.e., deep burial in alluvial deposits) instead of limited human occupation in the region during the terminal

  4. Best period for high spatial resolution satellite images for the detection of marks of buried structures

    Directory of Open Access Journals (Sweden)

    Dimitrios Kaimaris

    2012-06-01

    Full Text Available Improvements in sensor technology in recent decades led to the creation of ground, air and space imaging systems, whose data can be used in archaeological studies. Greece is one of the lucky areas that are rich in archaeological heritage. The detection of prehistoric/historic undiscovered constructions on satellite images or aerial photos is a complex and complicated matter. These marks are not visible from the ground, they can, however, be traced on satellite or aerial images, because of the differences in tone and texture. These differences appear as crop, soil and shadow marks. Undoubtedly, the detection of buried structures requires a suitable spatial resolution image, taken under appropriate meteorological conditions and during the best period of the vegetation growing cycle. According to the pertinent literature, detecting covered memorials may be achieved either accidentally or, usually, after a systematic investigation based on historical narratives. The purpose of this study is to determine the factors that facilitate or hinder the detection of buried structures through high spatial resolution satellite imagery. In this study, pan sharpened images from the QuickBird-2 satellite were used, of a spatial resolution of 0.60-0.70 m. This study concerns the detection of marks of the ancient Via Egnatia, from the ancient Amphipolis to Philippi (Eastern Macedonia, Greece. We studied different types of vegetation in the region and their phenological cycle. Taking into account the vegetation phenological cycle of the study area as well as the meteorological data, four pan sharpened QuickBird-2 images of a spatial resolution of 0.60–0.70 m. were used, during four different seasons. By processing the four images, we can determine the one acquired during the most appropriate conditions for the detection of buried structures. The application of this methodology in the study area had positive results, and not only was the main purpose of this

  5. Rapid Binary Gage Function to Extract a Pulsed Signal Buried in Noise

    Directory of Open Access Journals (Sweden)

    Bagaria William J

    2004-01-01

    Full Text Available The type of signal studied in this paper is a periodic pulse, with the pulse length short compared to the period, and the signal is buried in noise. If standard techniques such as the fast Fourier transform are used to study the signal, the data record needs to be very long. Additionally, there would be a very large number of calculations. The rapid binary gage function was developed to quickly determine the period of the signal, and the start time of the first pulse in the data. Once these two parameters are determined, the pulsed signal can be recovered using a standard data folding and adding technique.

  6. Buried Object Detection by an Inexact Newton Method Applied to Nonlinear Inverse Scattering

    Directory of Open Access Journals (Sweden)

    Matteo Pastorino

    2012-01-01

    Full Text Available An approach to reconstruct buried objects is proposed. It is based on the integral equations of the electromagnetic inverse scattering problem, written in terms of the Green’s function for half-space geometries. The full nonlinearity of the problem is exploited in order to inspect strong scatterers. After discretization of the continuous model, the resulting equations are solved in a regularization sense by means of a two-step inexact Newton algorithm. The capabilities and limitations of the method are evaluated by means of some numerical simulations.

  7. Ground Clutter Reduction from GPR Data for Identification of Shallowly Buried Landmines

    Science.gov (United States)

    Nishimoto, Masahiko; Jandieri, Vakhtang

    A method for reducing ground clutter contribution from ground penetrating radar (GPR) data is proposed for discrimination of landmines located in shallow depth. The algorithm of this method is based on the Matching Pursuit (MP) that is a technique for non-orthogonal signal decomposition using dictionary of functions. As the dictionary of function, a wave-based dictionary constructed by taking account of scattering mechanisms of electromagnetic (EM) wave by rough surfaces is employed. Through numerical simulations, performance of ground clutter reduction is evaluated. The results show that the proposed method has good performance and is effective for GPR data preprocessing for discrimination of shallowly buried landmines.

  8. Self-organized growth of nanoparticles on a surface patterned by a buried dislocation network.

    Science.gov (United States)

    Leroy, F; Renaud, G; Letoublon, A; Lazzari, R; Mottet, C; Goniakowski, J

    2005-10-28

    The self-organized growth of Co nanoparticles is achieved at room temperature on an inhomogenously strained Ag(001) surface arising from an underlying square misfit dislocation network of 10 nm periodicity buried at the interface between a 5 nm-thick Ag film and a MgO(001) substrate. This is revealed by in situ grazing-incidence small-angle x-ray scattering. Simulations of the data performed in the distorted wave Born approximation framework demonstrate that the Co clusters grow above the dislocation crossing lines. This is confirmed by molecular dynamic simulations indicating preferential Co adsorption on tensile sites.

  9. Evaluation for Adhesion Strength of Coating and Substrate by Burying Beforehand Specimen

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Adhesion strength is an important target in evaluating the quality of coating layers.The traditional way of adhesion strength test is bonding pull-off method for thick layers and scratch test for thin films.The drawbacks of these two methods are discussed in this paper,and an evaluating method for adhesion strength of coating by burying beforehand specimen is proposed.The adhesion strength of samples is measured with two methods.The dispersity of testing data is lower than that in the ASTM-C663-79 Standard.

  10. Not always buried deep a second course in elementary number theory

    CERN Document Server

    Pollack, Paul

    2009-01-01

    Number theory is one of the few areas of mathematics where problems of substantial interest can be fully described to someone with minimal mathematical background. Solving such problems sometimes requires difficult and deep methods. But this is not a universal phenomenon; many engaging problems can be successfully attacked with little more than one's mathematical bare hands. In this case one says that the problem can be solved in an elementary way. Such elementary methods and the problems to which they apply are the subject of this book. Not Always Buried Deep is designed to be read and enjoye

  11. An approximate factorization method for inverse medium scattering with unknown buried objects

    Science.gov (United States)

    Qu, Fenglong; Yang, Jiaqing; Zhang, Bo

    2017-03-01

    This paper is concerned with the inverse problem of scattering of time-harmonic acoustic waves by an inhomogeneous medium with different kinds of unknown buried objects inside. By constructing a sequence of operators which are small perturbations of the far-field operator in a suitable way, we prove that each operator in this sequence has a factorization satisfying the Range Identity. We then develop an approximate factorization method for recovering the support of the inhomogeneous medium from the far-field data. Finally, numerical examples are provided to illustrate the practicability of the inversion algorithm.

  12. Direct measurement of graphene contact resistivity to pre-deposited metal in buried contact test structure

    KAUST Repository

    Qaisi, Ramy M.

    2013-08-01

    We demonstrate a buried contact based novel test structure for direct contact resistivity measurement of graphene-metal interfaces. We also observe excellent contact resistivity 1 μO-cm2 without any additional surface modification suggesting that the intrinsic Au-graphene contact is sufficient for achieving devices with low contact resistance. The chemical mechanical polishing less test structure and data described herein highlights an ideal methodology for systematic screening and engineering of graphene-metal contact resistivity to enable low power high speed carbon electronics. © 2013 IEEE.

  13. Characterization of rocks buried in the subsurface by the GPR WISDOM/ExoMars 2020

    Science.gov (United States)

    Hervé, Yann; Ciarletti, Valérie; Le Gall, Alice; Guiffaut, Christophe

    2016-10-01

    The search for evidence of past life on Mars is the main objective of the ESA-Roscosmos ExoMars Rover mission. Given the hostile environment at the surface, if such evidence is to be found anywhere, it will most likely be in the subsurface. This is why the ExoMars rover mission has been optimized to investigate the subsurface. Among the instruments accommodated onboard the Rover, the polarimetric ground penetrating radar WISDOM (Water Ice Subsurface Deposits Observation On Mars, Ciarletti et al., 2011) has been designed to investigate the shallow subsurface and search for the most favorable locations where to drill and collect samples for analysis. WISDOM is able to probe down to a depth of few meters with a vertical resolution of a few centimeters, and will provide key information on the geological context of the environment.In particular, insights into density, size and shape of the rocks buried beneath the rover would be clues for a better understanding of the geological and hydrological history of the Rover site. In addition, the density and size of the buried rocks will have to be taken into account for the safety of the drilling operations.In this paper, we will focus on the ability of WISDOM to detect, localize and characterize (in terms of size and shape), rocks in the shallow subsurface of Mars. More specifically, we use a 3D numerical code based on the Finite Difference in Time Domain method to model the antenna system of WISDOM and simulate the instrument operations on realistic environments with buried rocks. In this approach, size-frequency distribution of rocks in agreement with observations from orbit and by cameras operated from the Martian surface will be considered. We will present results of simulations for different density and shape of buried rocks, including critical configurations where the density of rocks is too high to allow individual detection of rocks. In addition, we will present experimental data for comparison with the simulated data

  14. In situ chemical state analysis of buried polymer/metal adhesive interface by hard X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa, Kenichi, E-mail: ozawa.k.ab@m.titech.ac.jp [Department of Chemistry and Materials Science, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Kakubo, Takashi; Shimizu, Katsunori; Amino, Naoya [The Yokohama Rubber Co., Ltd., Oiwake, Hiratsuka 254-8601 (Japan); Mase, Kazuhiko [Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan); Ikenaga, Eiji; Nakamura, Tetsuya; Kinoshita, Toyohiko; Oji, Hiroshi [Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, Hyogo 679-5198 (Japan)

    2014-11-30

    Highlights: • Chemical state analysis of the buried rubber/brass interface is conducted by HAXPES. • Ultrathin rubber films are prepared on the brass surface by two methods. • A high density of Cu{sub 2}S is found on the rubber side of the buried adhesive layer. • The chemical states of the buried and exposed interfaces are compared. - Abstract: Chemical state analysis of adhesive interfaces is important to understand an adhesion mechanism between two different materials. Although photoelectron spectroscopy (PES) is an ideal tool for such an analysis, the adhesive interfaces must be exposed to the surface because PES is essentially a surface sensitive technique. However, an in situ observation is possible by hard X-ray PES (HAXPES) owing to its large probing depth. In the present study, HAXPES is applied to investigate the adhesive interface between rubber and brass without exposing the interface. It is demonstrated that copper sulfides formed at the buried rubber/brass interface are distinguished from S-containing species in the rubber overlayer. The chemical state of the buried interface is compared with that of the “exposed” interface prepared by so-called a filter-paper method.

  15. Protein-protein interactions: general trends in the relationship between binding affinity and interfacial buried surface area.

    Science.gov (United States)

    Chen, Jieming; Sawyer, Nicholas; Regan, Lynne

    2013-04-01

    Protein-protein interactions play key roles in many cellular processes and their affinities and specificities are finely tuned to the functions they perform. Here, we present a study on the relationship between binding affinity and the size and chemical nature of protein-protein interfaces. Our analysis focuses on heterodimers and includes curated structural and thermodynamic data for 113 complexes. We observe a direct correlation between binding affinity and the amount of surface area buried at the interface. For a given amount of surface area buried, the binding affinity spans four orders of magnitude in terms of the dissociation constant (Kd ). Across the entire dataset, we observe no obvious relationship between binding affinity and the chemical composition of the interface. We also calculate the free energy per unit surface area buried, or "surface energy density," of each heterodimer. For interfacial surface areas between 500 and 2000 Å(2) , the surface energy density decreases as the buried surface area increases. As the buried surface area increases beyond about 2000 Å(2) , the surface energy density levels off to a constant value. We believe that these analyses and data will be useful for researchers with an interest in understanding, designing or inhibiting protein-protein interfaces.

  16. a Uav Based 3-D Positioning Framework for Detecting Locations of Buried Persons in Collapsed Disaster Area

    Science.gov (United States)

    Moon, H.; Kim, C.; Lee, W.

    2016-06-01

    Regarding spatial location positioning, indoor location positioning theories based on wireless communication techniques such as Wi-Fi, beacon, UWB and Bluetooth has widely been developing across the world. These techniques are mainly focusing on spatial location detection of customers using fixed wireless APs and unique Tags in the indoor environment. Besides, since existing detection equipment and techniques using ultrasound or sound etc. to detect buried persons and identify survival status for them cause 2nd damages on the collapsed debris for rescuers. In addition, it might take time to check the buried persons. However, the collapsed disaster sites should consider both outdoor and indoor environments because empty spaces under collapsed debris exists. In order to detect buried persons from the empty spaces, we should collect wireless signals with Wi-Fi from their mobile phone. Basically, the Wi-Fi signal measure 2-D location. However, since the buried persons have Z value with burial depth, we also should collect barometer sensor data from their mobile phones in order to measure Z values according to weather conditions. Specially, for quick accessibility to the disaster area, a drone (UAV; Unmanned Arial Vehicle) system, which is equipped with a wireless detection module, was introduced. Using these framework, this study aims to provide the rescuers with effective rescue information by calculating 3-D location for buried persons based on the wireless and barometer sensor fusion.

  17. Inferring the location of buried UXO using a support vector machine

    Science.gov (United States)

    Fernández, Juan Pablo; Sun, Keli; Barrowes, Benjamin; O'Neill, Kevin; Shamatava, Irma; Shubitidze, Fridon; Paulsen, Keith D.

    2007-04-01

    The identification of unexploded ordnance (UXO) using electromagnetic-induction (EMI) sensors involves two essentially independent steps: Each anomaly detected by the sensor has to be located fairly accurately, and its orientation determined, before one can try to find size/shape/composition properties that identify the object uniquely. The dependence on the latter parameters is linear, and can be solved for efficiently using for example the Normalized Surface Magnetic Charge model. The location and orientation, on the other hand, have a nonlinear effect on the measurable scattered field, making their determination much more time-consuming and thus hampering the ability to carry out discrimination in real time. In particular, it is difficult to resolve for depth when one has measurements taken at only one instrument elevation. In view of the difficulties posed by direct inversion, we propose using a Support Vector Machine (SVM) to infer the location and orientation of buried UXO. SVMs are a method of supervised machine learning: the user can train a computer program by feeding it features of representative examples, and the machine, in turn, can generalize this information by finding underlying patterns and using them to classify or regress unseen instances. In this work we train an SVM using measured-field information, for both synthetic and experimental data, and evaluate its ability to predict the location of different buried objects to reasonable accuracy. We explore various combinations of input data and learning parameters in search of an optimal predictive configuration.

  18. Vertical coupling of laser glass microspheres to buried silicon nitride ellipses and waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Navarro-Urrios, D., E-mail: daniel.navarrourrios@nano.cnr.it [NEST, Istituto Nanoscienze—CNR and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa I-56127 (Italy); Ramírez, J. M.; Berencén, Y.; Garrido, B. [Departament d' Electrònica, Universitat de Barcelona, Barcelona 08028 (Spain); Capuj, N. E. [Depto. Física, Universidad de la Laguna, 38206, La Laguna (Spain); Tredicucci, A. [NEST, Istituto Nanoscienze and Dipartimento di Fisica, Università di Pisa, Largo Pontecorvo 3, Pisa I-56127 (Italy)

    2015-09-07

    We demonstrate the integration of Nd{sup 3+} doped barium-titanium-silicate microsphere lasers with a silicon nitride photonic platform. Devices with two different geometrical configurations for extracting the laser light to buried waveguides have been fabricated and characterized. The first configuration relies on a standard coupling scheme, where the microspheres are placed over strip waveguides. The second is based on a buried elliptical geometry whose working principle is that of an elliptical mirror. In the latter case, the input of a strip waveguide is placed on one focus of the ellipse, while a lasing microsphere is placed on top of the other focus. The fabricated elliptical geometry (ellipticity = 0.9) presents a light collecting capacity that is 50% greater than that of the standard waveguide coupling configuration and could be further improved by increasing the ellipticity. Moreover, since the dimensions of the spheres are much smaller than those of the ellipses, surface planarization is not required. On the contrary, we show that the absence of a planarization step strongly damages the microsphere lasing performance in the standard configuration.

  19. Exposure to the social interaction test in rats induces changes in defensive burying.

    Science.gov (United States)

    Saldívar-González, A; Hernández-León, M J; Mondragón-Ceballos, R

    1996-08-01

    To detect changes in experimental anxiety, defensive burying (DB) was studied in several groups of rats after being exposed to social interaction (SI). Animals were studied in the DB paradigm after being submitted to the following SI treatments: control (without SI exposure), and SI for 1.5, 5, 10 and 15 min respectively. A bimodal effect was found: facilitated DB response values in the group tested after a 1.5 min exposure to SI and a strong reduction of DB in the 10 and 15 min groups. The inhibition in DB elicited by the 15 min exposure to SI revealed a slow recovery, returning to control levels after 30 min. The actions of novelty on defensive burying were assessed in a third experiment. Animals were tested for DB immediately after being placed for 1.5 or 15 min in the SI arena without a partner. DB levels increased in these animals. Another group was placed in the SI arena for 1.5 min and tested in the DB paradigm 13.5 min after being returned to the home cage. A return to the basal control DB levels was observed in this group. Data are discussed in terms of anxiety-like fluctuations and the adaptive functions underlying these.

  20. In situ experiments on width and evolution characteristics of excavation damaged zone in deeply buried tunnels

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The seven long tunnels of Jinping II hydropower station are deeply buried.The width and evolution characteristics of excavation damaged zone(EDZ) are the key problem to the design of tunnels excavation and supports.In order to study this problem,several specific experimental tunnels with different overburden and geometric sizes were excavated at this site.Digital borehole camera,sliding micrometer,cross-hole acoustic wave equipment and acoustic emission apparatus were adopted.This paper introduced the comprehensive in situ experimental methods through pre-installed facilities and pre-drilled boreholes.Typical properties of the surrounding rock mass,including cracks,deformation,elastic wave and micro fractures,were measured during the whole process of the tunnel excavation.The width and characteristics of formation and evolution of tunnels EDZ were analyzed under different construction methods involving of TBM and drilling and blasting,the test tunnels were excavated by full-face or two benches.The relationships between EDZ and tunnel geometry sizes,overburden and excavation method were described as well.The results will not only contribute a great deal to the analysis of rock mass behavior in deeply buried rock mass,but also provide direct data for support design and rockburst prediction.

  1. Leaching of solutes from ion-exchange resins buried in Bandelier Tuff

    Energy Technology Data Exchange (ETDEWEB)

    Essington, E.H.; Fuentes, H.R.; Polzer, W.L.; Lopez, E.A.; Stallings, E.A.

    1986-10-01

    Prediction of solute transport at shallow land burial facilities requires a knowledge of the rates of release of solutes (source term) from the buried wastes and of those processes affecting transport through the surrounding media. The leaching (removal) of lithium, strontium, and cesium from a resin/tuff mixture (Bandelier Tuff) was conducted under unsaturated steady and unsteady (drainage) flow conditions in both laboratory columns and large-scale field caissons to approximate the conditions of buried contaminated-waste resins. Lithium was leached most rapidly and strontium least rapidly. Stopping the flow for a period of 40 to 60 days to create drainage (unsteady flow) conditions had very little effect on the concentrations of solutes leached from the resin/tuff layer. Leaching of these solutes in laboratory columns simulated the large-scale (caisson) leaching very well. Thus, laboratory studies may be reasonable predictors of leaching under certain large-scale field conditions. Also, leaching appears to be a kinetics-controlled process that, for the experimental conditions of this study, may be represented by simple first-order kinetics. Further work should concentrate on understanding the effect of environmental factors such as solute mixtures, concentrations, and temperature, as well as those mechanisms that control leaching of solutes. Also, the evaluation and development of alternative mathematical models for describing the source term are needed.

  2. An investigation into the persistence of textile fibres on buried carcasses.

    Science.gov (United States)

    DeBattista, Roslyn; Tidy, Helen; Thompson, Tim J U; Robertson, Peter

    2014-07-01

    A significant amount of research has been carried out on fibres to aid the forensic scientist in determining the significance of these when found on a victim or suspect. This work has focused on open-air environments, and as such no research has been undertaken to examine the persistence of fibres on bodies in the burial environment. Wool and cotton fibres, known to fluoresce under ultraviolet (UV) light, were transferred onto the skin of four porcine (Sus scrofa) carcasses (two carcasses per fibre type). The number of fibres transferred was recorded from images taken under UV light. The remains were subsequently placed in four burial sites and left interred for 14 days. After this period the carcasses were excavated and lightly brushed down to remove the soil layer that had adhered to the skin. Once again photography under UV light was used to record the number of fibres which persisted on the skin. Results showed that after 14 days, wool and cotton fibres remain on the surface of the buried carcasses. In no circumstance was there a total loss of fibres suggesting that in such scenarios, the likelihood of finding fibres is high but the initial number of fibres transferred would be strongly diminished. This has important implications for both the excavation protocol for buried remains and the subsequent analysis for physical evidence.

  3. Staying with the young enhances the fathers' attractiveness in burying beetles.

    Science.gov (United States)

    Chemnitz, Johanna; Bagrii, Nadiia; Ayasse, Manfred; Steiger, Sandra

    2017-02-01

    Studying the relationship between parental and mating effort helps us to understand the evolution of parental care and, consequently, has been the subject of many theoretical and empirical investigations. Using burying beetles as a model, we found no correlation between the intensity of a sexual signal (sex pheromone quantity) and the amount of care provided by males. However, males that were given the opportunity to breed and care for young went on to produce a higher amount of their sexual signal and attracted three times more females in the field than control males that were not given the opportunity to breed. The likely explanation for our finding is that specific aspects of care in burying beetles, that is the defense and preservation of a nutrient rich breeding resource, a small vertebrate cadaver, is not only beneficial for the offspring but also for the adults themselves. Obtaining a good carrion meal possibly enables males to store resources that they can subsequently allocate toward sexual signaling. Collectively, our results highlight that conditions can exist where male participation in brood care has a positive effect on its sexual attractiveness. This in turn might have facilitated the evolution of male assistance in parental care.

  4. Petrochemistry and origin of basalt breccia from Ban Sap Sawat area, Wichian Buri, Phetchabun, central Thailand

    Directory of Open Access Journals (Sweden)

    Phisit Limtrakun

    2013-08-01

    Full Text Available Thailand is usually considered to be controlled by escape tectonics associated with India-Asia collision during theLate Cenozoic, and basaltic volcanism took place in this extensional period. This volcanism generated both subaqueous andsubaerial lava flows with tholeiitic to alkalic basaltic magma. The subaqueous eruptions represented by the studied WichianBuri basalts, Ban Sap Sawat in particular, are constituted by two main types of volcanic lithofacies, including lava flows andbasalt breccias. The lava flows are commonly porphyritic with olivine and plagioclase phenocrysts and microphenocrysts,and are uncommonly seriate textured. The basalt breccias are strongly vitrophyric texture with olivine and plagioclasephenocrysts and microphenocrysts. Chemical analyses indicate that both lava flows and basalt breccias have similar geochemical compositions, signifying that they were solidified from the same magma. Their chondrite normalized REE patternsand N-MORB normalized patterns are closely analogous to the Early to Middle Miocene tholeiites from central Sinkhote-Alinand Sakhalin, northeastern margin of the Eurasian continent which were erupted in a continental rift environment. The originfor the Wichian Buri basalts show similarity of lava flows and basalt breccias, in terms of petrography and chemical compositions, signifying that they have been formed from the same continental within-plate, transitional tholeiitic magma.

  5. Telluride buried channel waveguides operating from 6 to 20 μm for photonic applications

    Science.gov (United States)

    Vigreux, C.; Escalier, R.; Pradel, A.; Bastard, L.; Broquin, J.-E.; Zhang, X.; Billeton, T.; Parent, G.; Barillot, M.; Kirschner, V.

    2015-11-01

    One of the technological challenges of direct observation of extra-solar planets by nulling interferometry is the development of a modal filter operating from 6 to 20 μm. In the present paper a candidate technology for the fabrication of such modal filters is presented: Integrated Optics. A solution based on all-telluride buried channel waveguides is considered. In the proposed waveguides, vertical guiding of light is achieved by a 15 μm-thick Te83Ge17 core film deposited onto a lower-index Te75Ge15Ga10 substrate, and covered by a 15 μm-thick Te76Ge24 superstrate. Horizontal guiding of light is obtained by modifying the geometry of the core layer by ion beam etching. As this stage, all-telluride buried channel waveguide prototypes demonstrate light guiding and transmission from 2 to 20 μm. The validity of the technology and the good quality of the fabrication process, in particular the input and output facets surface finish are thus confirmed. These results consolidate the potential of Te-based integrated optics components for nulling interferometry.

  6. Structural characterization of buried nitride layers formed by nitrogen ion implantation in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, A.D. [Department of Physics, University of Mumbai, Vidyanagari Campus, Santacruz (E), Mumbai, Maharashtra 400098 (India)], E-mail: adyadav@physics.mu.ac.in; Patel, A.P.; Dubey, S.K. [Department of Physics, University of Mumbai, Vidyanagari Campus, Santacruz (E), Mumbai, Maharashtra 400098 (India); Panigrahi, B.K.; Kesavamoorthy, R.; Nair, K.G.M. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu 603102 (India)

    2008-04-15

    The synthesis of buried silicon nitride insulating layers was carried out by SIMNI (separation by implanted nitrogen) process using implantation of 140 keV nitrogen ({sup 14}N{sup +}) ions at fluence of 1.0 x 10{sup 17}, 2.5 x 10{sup 17} and 5.0 x 10{sup 17} cm{sup -2} into <1 1 1> single crystal silicon substrates held at elevated temperature (410 deg. C). The structures of ion-beam synthesized buried silicon nitride layers were studied by X-ray diffraction (XRD) technique. The XRD studies reveal the formation of hexagonal silicon nitride (Si{sub 3}N{sub 4}) structure at all fluences. The concentration of the silicon nitride phase was found to be dependent on the ion fluence. The intensity and full width at half maximum (FWHM) of XRD peak were found to increase with increase in ion fluence. The Raman spectra for samples implanted with different ion fluences show crystalline silicon (c-Si) substrate peak at wavenumber 520 cm{sup -1}. The intensity of the silicon peak was found to decrease with increase in ion fluence.

  7. Seismic fragility formulations for segmented buried pipeline systems including the impact of differential ground subsidence

    Energy Technology Data Exchange (ETDEWEB)

    Pineda Porras, Omar Andrey [Los Alamos National Laboratory; Ordaz, Mario [UNAM, MEXICO CITY

    2009-01-01

    Though Differential Ground Subsidence (DGS) impacts the seismic response of segmented buried pipelines augmenting their vulnerability, fragility formulations to estimate repair rates under such condition are not available in the literature. Physical models to estimate pipeline seismic damage considering other cases of permanent ground subsidence (e.g. faulting, tectonic uplift, liquefaction, and landslides) have been extensively reported, not being the case of DGS. The refinement of the study of two important phenomena in Mexico City - the 1985 Michoacan earthquake scenario and the sinking of the city due to ground subsidence - has contributed to the analysis of the interrelation of pipeline damage, ground motion intensity, and DGS; from the analysis of the 48-inch pipeline network of the Mexico City's Water System, fragility formulations for segmented buried pipeline systems for two DGS levels are proposed. The novel parameter PGV{sup 2}/PGA, being PGV peak ground velocity and PGA peak ground acceleration, has been used as seismic parameter in these formulations, since it has shown better correlation to pipeline damage than PGV alone according to previous studies. By comparing the proposed fragilities, it is concluded that a change in the DGS level (from Low-Medium to High) could increase the pipeline repair rates (number of repairs per kilometer) by factors ranging from 1.3 to 2.0; being the higher the seismic intensity the lower the factor.

  8. Determining the location of buried plastic water pipes from measurements of ground surface vibration

    Science.gov (United States)

    Muggleton, J. M.; Brennan, M. J.; Gao, Y.

    2011-09-01

    ‘Mapping the Underworld' is a UK-based project, which aims to create a multi-sensor device that combines complementary technologies for remote buried utility service detection and location. One of the technologies to be incorporated in the device is low-frequency vibro-acoustics, and techniques for detecting buried infrastructure, in particular plastic water pipes, are being investigated. One of the proposed techniques involves excitation of the pipe at some known location with concurrent vibrational mapping of the ground surface in order to infer the location of the remainder of the pipe. In this paper, measurements made on a dedicated pipe rig are reported. Frequency response measurements relating vibrational velocity on the ground to the input excitation were acquired. Contour plots of the unwrapped phase revealed the location of the pipe to within 0.1-0.2 m. Magnitude contour plots revealed the excitation point and also the location of the pipe end. By examining the unwrapped phase gradients along a line above the pipe, it was possible to identify the wave-type within the pipe responsible for the ground surface vibration. Furthermore, changes in the ground surface phase speed computed using this method enabled the location of the end of the pipe to be confirmed.

  9. Imaging of buried and foliage-obscured objects with an ultrawide-bandwidth polarimetric SAR

    Science.gov (United States)

    Sheen, Dan R.; Lewis, Terry B.; Wei, Susan C.; Kletzli, D. W., Jr.

    1993-11-01

    The Environmental Research Institute of Michigan (ERIM) has developed a unique ground- based, portable, synthetic aperture radar (SAR). This SAR images targets in their natural backgrounds without the expense of an airborne sensor and with higher performance (bandwidth, resolution) than existing airborne systems. A horizontal 36-foot long aluminum truss supports a rail and an antenna cartridge, which is moved along the rail to allow synthetic aperture focusing. The system is fully-polarimetric and has collected data over the frequency band of 400 - 1300 MHz resulting in a nominal resolution of 0.17 m in range and 0.5 m in cross-range. The low frequency range of the system allows for penetration of soil (to shallow depths) as well as foliage and the system has been used to collect images of buried and foliage- obscured targets. The ground imagery collected to date includes steel oil drums buried at depths of up to one-meter. Both the drums as well as the disturbances due to digging the holes are visible in the imagery. Foliage imagery includes portions of a Lear jet under a mature hardwood forest. Due to the low frequency and wide bandwidth of the sensor (400 - 1300 MHz), obscured objects are clearly visible in the SAR imagery. Other responses in the foliage imagery are due to the dihedral-like ground-trunk reflections.

  10. Characteristics of hydrocarbon source rocks of No.3 buried-hill region in Nanpu Sag

    Institute of Scientific and Technical Information of China (English)

    Ma Guanghua; Zhang Hongchen; Qian Fengyan; Chen Haixia

    2014-01-01

    Based on the data of 44 samples of hydrocarbon source rocks in Nanpu No.3 buried-hill region,the kerogen type is judged through the pyrolysis and microscopic identification. At the same time,organic matter maturity and hydrocarbon generation threshold are studied by using vitrinite reflectance,pyrolysis yield and hy-drocarbon abundance. Meanwhile the hydrocarbon expulsion threshold is calculated. And the characteristics of organic hydrocarbon generation and expulsion are preliminarily revealed and evaluated. The result shows that the No.3 buried-hill region has abundant hydrocarbon source rocks with high content of organic carbon. And the primary types of kerogen areⅡ1 andⅡ2. The hydrocarbon source rocks which passed biochemistry,thermolysis and thermal cracking have developed into the mature-postmature phase of different extents. And plenty of oil and gas were expelled out. It is believed the depth of oil-generating window is 3 600 m and the depth of hydro-carbon-expulsion threshold is 4 100 m. The comprehensive analysis indicates that Nanpu No.3 burried-hill re-gion has a certain condition to generate hydrocarbon which is very promising in oil exploration and thus can be-come an important exploration and development target next.

  11. Probabilistic Modeling of Landfill Subsidence Introduced by Buried Structure Collapse - 13229

    Energy Technology Data Exchange (ETDEWEB)

    Foye, Kevin; Soong, Te-Yang [CTI and Associates, Inc., 51331 W. Pontiac Trail, Wixom, MI 48393 (United States)

    2013-07-01

    The long-term reliability of land disposal facility final cover systems - and therefore the overall waste containment - depends on the distortions imposed on these systems by differential settlement/subsidence. The evaluation of differential settlement is challenging because of the heterogeneity of the waste mass and buried structure placement. Deterministic approaches to long-term final cover settlement prediction are not able to capture the spatial variability in the waste mass and sub-grade properties, especially discontinuous inclusions, which control differential settlement. An alternative is to use a probabilistic model to capture the non-uniform collapse of cover soils and buried structures and the subsequent effect of that collapse on the final cover system. Both techniques are applied to the problem of two side-by-side waste trenches with collapsible voids. The results show how this analytical technique can be used to connect a metric of final cover performance (inundation area) to the susceptibility of the sub-grade to collapse and the effective thickness of the cover soils. This approach allows designers to specify cover thickness, reinforcement, and slope to meet the demands imposed by the settlement of the underlying waste trenches. (authors)

  12. Near-specular acoustic scattering from a buried submarine mud volcano.

    Science.gov (United States)

    Gerig, Anthony L; Holland, Charles W

    2007-12-01

    Submarine mud volcanoes are objects that form on the seafloor due to the emission of gas and fluidized sediment from the Earth's interior. They vary widely in size, can be exposed or buried, and are of interest to the underwater acoustics community as potential sources of active sonar clutter. Coincident seismic reflection data and low frequency bistatic scattering data were gathered from one such buried mud volcano located in the Straits of Sicily. The bistatic data were generated using a pulsed piston source and a 64-element horizontal array, both towed over the top of the volcano. The purpose of this work was to appropriately model low frequency scattering from the volcano using the bistatic returns, seismic bathymetry, and knowledge of the general geoacoustic properties of the area's seabed to guide understanding and model development. Ray theory, with some approximations, was used to model acoustic propagation through overlying layers. Due to the volcano's size, scattering was modeled using geometric acoustics and a simple representation of volcano shape. Modeled bistatic data compared relatively well with experimental data, although some features remain unexplained. Results of an inversion for the volcano's reflection coefficient indicate that it may be acoustically softer than expected.

  13. Amended Electric Field Distribution: A Reliable Technique for Electrical Performance Improvement in Nano scale SOI MOSFETs

    Science.gov (United States)

    Ramezani, Zeinab; Orouji, Ali A.

    2017-04-01

    To achieve reliable transistors, we propose a new silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET) with an amended electric field in the channel for improved electrical and thermal performance, with an emphasis on current leakage improvement. The amended electric field leads to lower electric field crowding and thereby we assume enhanced reliability, leakage current, gate-induced drain leakage (GIDL), and electron temperature. To modify the electric field distribution, an additional rectangular metal region (RMR) is utilized in the buried oxide of the SOI MOSFET. The location and dimensions of the RMR have been carefully optimized to achieve the best results. The electrical, thermal, and radiofrequency characteristics of the proposed structure were analyzed using two-dimensional (2-D) numerical simulations and compared with the characteristics of the conventional, fully depleted SOI MOSFET (C-SOI). Also, critical short-channel effects (SCEs) such as threshold voltage, drain-induced barrier lowering (DIBL), subthreshold slope degradation, hot-carrier effect, GIDL, and leakage power consumption are improved. According to the results obtained, the proposed nano SOI MOSFET is a reliable device, especially for use in low-power and high-temperature applications.

  14. Non-depletion floating layer in SOI LDMOS for enhancing breakdown voltage and eliminating back-gate bias effect

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhi; Li Wei; Li Ping

    2013-01-01

    A non-depletion floating layer silicon-on-insulator (NFL SOI) lateral double-diffused metal-oxide-semiconductor (LDMOS) is proposed and the NFL-assisted modulated field (NFLAMF) principle is investigated in this paper.Based on this principle,the floating layer can pin the potential for modulating bulk field.In particular,the accumulated high concentration of holes at the bottom of the NFL can efficiently shield the electric field of the SOI layer and enhance the dielectric field in the buried oxide layer (BOX).At variation of back-gate bias,the shielding charges of NFL can alsoeliminate back-gate effects.The simulated results indicate that the breakdown voltage (BV) is increased from 315 V to 558 V compared to the conventional reduced surface field (RESURF) SOI (CSOI) LDMOS,yielding a 77% improvement.Furthermore,due to the field shielding effect of the NFL,the device can maintain the same breakdown voltage of 558 V with a thinner BOX to resolve the thermal problem in an SOI device.

  15. Instability of buried hydration sites increases protein subdomains fluctuations in the human prion protein by the pathogenic mutation T188R

    Science.gov (United States)

    Tomobe, Katsufumi; Yamamoto, Eiji; Akimoto, Takuma; Yasui, Masato; Yasuoka, Kenji

    2016-05-01

    The conformational change from the cellular prion protein (PrPc) to scrapie prion protein (PrPsc) is a key process in prion diseases. The prion protein has buried water molecules which significantly contribute to the stability of the protein; however, there has been no report investigating the influence on the buried hydration sites by a pathogenic mutation not adjacent to the buried hydration sites. Here, we perform molecular dynamics simulations of wild type (WT) PrPc and pathogenic point mutant T188R to investigate conformational changes and the buried hydration sites. In WT-PrPc, four buried hydration sites are identified by residence time and rotational relaxation analysis. However, there are no stable buried hydration sites in one of T188R simulations, which indicates that T188R sometimes makes the buried hydration sites fragile. We also find that fluctuations of subdomains S1-H1-S2 and H1-H2 increase in T188R when the buried hydration sites become unstable. Since the side chain of arginine which is replaced from threonine in T188R is larger than of threonine, the side chain cannot be embedded in the protein, which is one of the causes of the instability of subdomains. These results show correlations between the buried hydration sites and the mutation which is far from them, and provide a possible explanation for the instability by mutation.

  16. Instability of buried hydration sites increases protein subdomains fluctuations in the human prion protein by the pathogenic mutation T188R

    Directory of Open Access Journals (Sweden)

    Katsufumi Tomobe

    2016-05-01

    Full Text Available The conformational change from the cellular prion protein (PrPc to scrapie prion protein (PrPsc is a key process in prion diseases. The prion protein has buried water molecules which significantly contribute to the stability of the protein; however, there has been no report investigating the influence on the buried hydration sites by a pathogenic mutation not adjacent to the buried hydration sites. Here, we perform molecular dynamics simulations of wild type (WT PrPc and pathogenic point mutant T188R to investigate conformational changes and the buried hydration sites. In WT-PrPc, four buried hydration sites are identified by residence time and rotational relaxation analysis. However, there are no stable buried hydration sites in one of T188R simulations, which indicates that T188R sometimes makes the buried hydration sites fragile. We also find that fluctuations of subdomains S1-H1-S2 and H1-H2 increase in T188R when the buried hydration sites become unstable. Since the side chain of arginine which is replaced from threonine in T188R is larger than of threonine, the side chain cannot be embedded in the protein, which is one of the causes of the instability of subdomains. These results show correlations between the buried hydration sites and the mutation which is far from them, and provide a possible explanation for the instability by mutation.

  17. Role of nitric oxide in obsessive-compulsive behavior and its involvement in the anti-compulsive effect of paroxetine in mice.

    Science.gov (United States)

    Umathe, S N; Bhutada, P S; Jain, N S; Mundhada, Y R; Borkar, S S; Dhumal, B

    2009-09-01

    In view of the reports that nitric oxide modulates the neurotransmitters implicated in obsessive-compulsive disorder, patients with obsessive-compulsive disorder exhibit higher plasma nitrate levels, and drugs useful in obsessive-compulsive disorder influence nitric oxide, we hypothesized that nitric oxide may have some role in obsessive-compulsive behavior. We used marble-burying behavior of mice as the animal model of obsessive-compulsive disorder, and nitric oxide levels in brain homogenate were measured using amperometric nitric oxide-selective sensor method. Intraperitoneal administration of nitric oxide enhancers viz. nitric oxide precursor-l-arginine (800 mg/kg), nitric oxide donor-sodium nitroprusside (3 mg/kg) or phosphodiesterase type 5 inhibitor-sildenafil (3 mg/kg) significantly increased marble-burying behavior as well as brain nitrites levels, whereas treatment with 7-nitroindazole-neuronal nitric oxide synthase inhibitor (20-40 mg/kg, i.p.) or paroxetine-selective serotonin reuptake inhibitor (5-10 mg/kg, i.p.) dose dependently attenuated marble-burying behavior and nitrites levels in brain. Further, co-administration of sub-effective doses of 7-nitroindazole (10 mg/kg) and paroxetine (2.5 mg/kg) significantly attenuated marble-burying behavior. Moreover, pretreatment with l-arginine (400 mg/kg, i.p.), sodium nitroprusside (2.0 mg/kg, i.p.) or sildenafil (2.0 mg/kg, i.p.) significantly attenuated the inhibitory influence of 7-nitroindazole (40 mg/kg) or paroxetine (10 mg/kg) on marble-burying behavior as well as on brain nitrites levels. None of the above treatment had any significant influence on locomotor activity. In conclusion, obsessive compulsive behavior in mice appears related to nitric oxide in brain, and anti-compulsive effect of paroxetine appears to be related to decrease central levels of nitric oxide.

  18. PREFACE: Buried Interface Sciences with X-rays and Neutrons 2010

    Science.gov (United States)

    Sakurai, Kenji

    2011-09-01

    The 2010 summer workshop on buried interface science with x-rays and neutrons was held at Nagoya University, Japan, on 25-27 July 2010. The workshop was organized by the Japan Applied Physics Society, which established a group to develop the research field of studying buried function interfaces with x-rays and neutrons. The workshop was the latest in a series held since 2001; Tsukuba (December 2001), Niigata (September 2002), Nagoya (July 2003), Tsukuba (July 2004), Saitama (March 2005), Yokohama (July 2006), Kusatsu (August 2006), Tokyo (December 2006), Sendai (July 2007), Sapporo (September 2007), Tokyo (December 2007), Tokyo-Akihabara (July 2009) and Hiratsuka (March 2010). The 2010 summer workshop had 64 participants and 34 presentations. Interfaces mark the boundaries of different material systems at which many interesting phenomena take place, thus making it extremely important to design, fabricate and analyse the structures of interfaces at both the atomic and macroscopic scale. For many applications, devices are prepared in the form of multi-layered thin films, with the result that interfaces are not exposed but buried under multiple layers. Because of such buried conditions, it is generally not easy to analyse such interfaces. In certain cases, for example, when the thin surface layer is not a solid but a liquid such as water, scientists can observe the atomic arrangement of the liquid-solid interface directly by using a scanning probe microscope, of which the tip is soaked in water. However, it has become clear that the use of a stylus tip positioned extremely close to the interface might change the structure of the water molecules. Therefore it is absolutely crucial to develop non-contact, non-destructive probes for buried interfaces. It is known that analysis using x-rays and neutrons is one of the most powerful tools for exploring near-surface structures including interfaces buried under several layers. In particular, x-ray analysis using 3rd

  19. Numerical study of heat transfer from an offshore buried pipeline under steady-periodic thermal boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Barletta, A.; Zanchini, E.; Lazzari, S. [Universita di Bologna, Dipartimento di Ingegneria Energetica, Nucleare e del Controllo Ambientale (DIENCA), Laboratorio di Montecuccolino, Via dei Colli 16, I-40136 Bologna (Italy); Terenzi, A. [Snamprogetti S.p.A., Via Toniolo 1, I-61032 Fano (PS) (Italy)

    2008-07-15

    The steady-periodic heat transfer between offshore buried pipelines for the transport of hydrocarbons and their environment is investigated. This heat transfer regime occurs for shallow water buried pipelines, as a consequence of the temperature changes of the seabed during the year. First, the unsteady two dimensional conduction problem is written in a dimensionless form; then, it is transformed into a steady two dimensional problem and solved numerically by means of the finite-element software package Comsol Multiphysics (copyright Comsol, Inc.). Several values of the burying depth and of the radius of the pipeline, as well as of the thermal properties of the soil are considered. The numerical results are compared with those obtainable by means of an approximate method employed in industrial design. The comparison reveals that important discrepancies with respect to this approximate method may occur. (author)

  20. An Approach for Predicting the Shape and Size of a Buried Basic Object on Surface Ground Penetrating Radar System

    Directory of Open Access Journals (Sweden)

    Nana Rachmana Syambas

    2012-01-01

    Full Text Available Surface ground-penetrating radar (GPR is one of the radar technology that is widely used in many applications. It is nondestructive remote sensing method to detect underground buried objects. However, the output target is only hyperbolic representation. This research develops a system to identify a buried object on surface GPR based on decision tree method. GPR data of many basic objects (with circular, triangular, and rectangular cross-section are classified and extracted to generate data training model as a unique template for each type of basic object. The pattern of object under test will be known by comparing its data with the training data using a decision tree method. A simple powerful algorithm to extract feature parameters of object which is based on linear extrapolation is proposed. The result showed that tested buried basic objects can be correctly predicted and the developed system works properly.

  1. Generation of High-Frequency P and S Wave Energy by Rock Fracture During a Buried Explosion

    Science.gov (United States)

    2015-07-20

    AFRL-RV -PS- TR-2015-0145 AFRL-RV -PS- TR-2015-0145 GENERATION OF HIGH-FREQUENCY P AND S WAVE ENERGY BY ROCK FRACTURE DURING A BURIED EXPLOSION ...SUBTITLE Generation of High-Frequency P and S Wave Energy by Rock Fracture During a Buried Explosion 5a. CONTRACT NUMBER FA9453-12-C-0210 5b...underground nuclear explosions . This model predicts the generation of strong S wave radiation in the non-linear source region whenever spherical

  2. Pilot study on tracing the rapidly buried rock avalanche deposits within the accumulation zone of glacier

    Science.gov (United States)

    Reznichenko, Natalya; Dunning, Stuart; Rosser, Nick; McColl, Sam

    2015-04-01

    Recent studies shown that large mass failure events significantly contribute to the glacial sediment budget and affect its final deposition. However, in accumulation zone these events are exceptionally fast subsumed by snowfall and become ingested into the glacier with no evident surface expression. This leads to poor understanding of the magnitude-frequency of these events and their contribution to the sediment budget of the glaciers. The buried rock avalanches travel as englacial load within the ice that becomes the unique geomorphic horizon, which may constitute a major fraction of total glacial debris supplied to supraglacial cover of many debris-covered glaciers, but usually re-emerging in ablation zones not in a form usable to reconstruct the magnitude-frequency of these events. Here we present a first attempt to detect the rock avalanche deposit within the ice that becomes the unique geomorphic horizon or isochrones. Ground Penetrating Radar (GPR) was applied over the large deposit of well documented in January 2013 Mt. Haast/Dixon rock avalanche in Southern Alps of New Zealand, one year after emplacement. The large deposit 2 x 106 m3 of rock, snow and ice travelled 2.9 km over the northern margins of the Grand Plateau, just 200 m west of Plateau Hut, stalling close to the top of the Hochstetter Icefall, Aoraki/ Mt. Cook. The large deposit was lost to conventional remote sensing within 3 month after the event. In April 2014, at the time of the survey the deposit was entirely buried beneath the snow/firn cover, leaving no topographic expression of the deposit at the snow surface. The buried deposit was visible in crevasses, in the Hochstetter Ice Fall, in the Grand Plateau, and the icefall beneath Mt Haast, at depths estimated to be in the order of 5-10 m. Our subsurface data shows a good preservation of a rock avalanche deposit under about 3-5 m of snow and firn with the thickness broadly consistent along the length of the transect (1-2 m), with a thicker (5

  3. SOI CMOS Imager with Suppression of Cross-Talk

    Science.gov (United States)

    Pain, Bedabrata; Zheng, Xingyu; Cunningham, Thomas J.; Seshadri, Suresh; Sun, Chao

    2009-01-01

    A monolithic silicon-on-insulator (SOI) complementary metal oxide/semiconductor (CMOS) image-detecting integrated circuit of the active-pixel-sensor type, now undergoing development, is designed to operate at visible and near-infrared wavelengths and to offer a combination of high quantum efficiency and low diffusion and capacitive cross-talk among pixels. The imager is designed to be especially suitable for astronomical and astrophysical applications. The imager design could also readily be adapted to general scientific, biological, medical, and spectroscopic applications. One of the conditions needed to ensure both high quantum efficiency and low diffusion cross-talk is a relatively high reverse bias potential (between about 20 and about 50 V) on the photodiode in each pixel. Heretofore, a major obstacle to realization of this condition in a monolithic integrated circuit has been posed by the fact that the required high reverse bias on the photodiode is incompatible with metal oxide/semiconductor field-effect transistors (MOSFETs) in the CMOS pixel readout circuitry. In the imager now being developed, the SOI structure is utilized to overcome this obstacle: The handle wafer is retained and the photodiode is formed in the handle wafer. The MOSFETs are formed on the SOI layer, which is separated from the handle wafer by a buried oxide layer. The electrical isolation provided by the buried oxide layer makes it possible to bias the MOSFETs at CMOS-compatible potentials (between 0 and 3 V), while biasing the photodiode at the required higher potential, and enables independent optimization of the sensory and readout portions of the imager.

  4. PHOTOINDUCED HOLOGRAPHIC PHASE GRATINGS BURIED IN AZOBENZENE SIDE-CHAIN POLYMER FILMS WITH A CHIRAL GROUP

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    An optically active polymer (PM1) containing azobenzene moieties with a chiral group (s-2-methyl-butyl) was synthesized by homopolymerization of monomer, 4-[2-(methacryloyloxy)ethyloxy]-4'-(s-2-methyl-1-butyloxycarbonyl)azobenzene, using the free radical polymerization method. The polymer dissolved in tetrahydrofuran (THF) could be easily processed into high optical quality films. The optical anisotropy of the polymer films was investigated by polarizing optical microscopy (POM). The experimental results showed that irradiation with a circularly polarized beam could align the orientation of the molecules in the polymer films. Moreover, the holographic phase gratings of photo-induced polymer films were detected by atomic force microscopy (AFM) and POM. In comparison with polymer containing no chiral group, it was found from the preliminary measurement of the photo-induced holographic phase gratings that PM1 containing a chiral group could form holographic phase gratings buried in the films.

  5. Initiation of breakout of half-buried submarine pipe from sea bed due to wave action

    Energy Technology Data Exchange (ETDEWEB)

    Law, A.W.K. [Nanyang Technological Univ. (Singapore). School of Civil and Structural Engineering; Foda, M.A. [California Univ., Berkeley, CA (United States). Dept. of Civil Engineering

    1996-12-31

    A formulation is presented for the analysis of the breakout of a half-buried submarine pipe due to wave action. The formulation accounts for the contact between the pipe and the soil due to the oscillating horizontal hydrodynamic force. Results demonstrate the existence of an initial gap in the breakout experiments. With this initial gap the gap flux dominated the influx of water into the gap throughout the breakout process. The linear pipe rise persisted although the second-order expansion of the gap should have grown to the same order of magnitude as the initial gap with the poro-rigid soil assumption. It is postulated that the persistence of the linear rise was due to the localized passive failure around the ends of the soil trench which inhibited the growth of the opening due to the pipe`s rise. (Author)

  6. Interedge backscattering in buried split-gate-defined graphene quantum point contacts

    Science.gov (United States)

    Xiang, Shaohua; Mreńca-Kolasińska, Alina; Miseikis, Vaidotas; Guiducci, Stefano; Kolasiński, Krzysztof; Coletti, Camilla; Szafran, Bartłomiej; Beltram, Fabio; Roddaro, Stefano; Heun, Stefan

    2016-10-01

    Quantum Hall effects offer a formidable playground for the investigation of quantum transport phenomena. Edge modes can be deflected, branched, and mixed by designing a suitable potential landscape in a two-dimensional conducting system subject to a strong magnetic field. In the present work, we demonstrate a buried split-gate architecture and use it to control electron conduction in large-scale single-crystal monolayer graphene grown by chemical vapor deposition. The control of the edge trajectories is demonstrated by the observation of various fractional quantum resistances, as a result of a controllable interedge scattering. Experimental data are successfully modeled both numerically and analytically within the Landauer-Büttiker formalism. Our architecture is particularly promising and unique in view of the investigation of quantum transport via scanning probe microscopy, since graphene constitutes the topmost layer of the device. For this reason, it can be approached and perturbed by a scanning probe down to the limit of mechanical contact.

  7. Swift Heavy Ion Beam-induced Recrystallisation of Buried Silicon Nitride Layer (Review Paper

    Directory of Open Access Journals (Sweden)

    T. Som

    2009-07-01

    Full Text Available Studies on MeV heavy ion beam-induced epitaxial crystallisation of a buried silicon nitride layer are reported. Transmission electron micrographs and selected area diffraction patterns have been used to study the recrystallisation of an ion beam-synthesised layer. Complete recrystallisation of the silicon nitride layer having good quality interfaces with the top- and the substrate-Si has been obsorved. Recrystallisation is achieved at significantly lower temperatures of 100 and 200OC for oxygen and silver ions, respectively. The fact that recrystallisation is achieved at the lowest temperature for the oxygen ions is discussed on the basis of energy loss processes.Defence Science Journal, 2009, 59(4, pp.351-355, DOI:http://dx.doi.org/10.14429/dsj.59.1533

  8. Experimental study on similarity materials for soft rock of deep-buried tunnels

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yu; PENG Hai-you

    2011-01-01

    When every parameter is properly scaled down in accordance with some similarity coefficients, it is possible to study the physical-mechanical properties of rock mass with a scale model. To identify the key mechanisms of soft rock in deep buried tunnels, the proper sand, binder and ratio were selected. During the process, the model manufacture technology was introduced and typical tests were done and the results were presented. The physical and mechanical properties effects caused by each composition were discussed. It is shown that the physical and mechanical properties of chosen ratio material such as uniaxial compressive strength tests, elasticity modulus, tensile strength, internal frictional angle, and Poisson's ratio meet with similarity relationship well. The physical and mechanical properties of deep soft rock are simulated successfully.

  9. Visualization of Au Nanoparticles Buried in a Polymer Matrix by Scanning Thermal Noise Microscopy

    Science.gov (United States)

    Yao, Atsushi; Kobayashi, Kei; Nosaka, Shunta; Kimura, Kuniko; Yamada, Hirofumi

    2017-02-01

    Several researchers have recently demonstrated visualization of subsurface features with a nanometer-scale resolution using various imaging schemes based on atomic force microscopy. Since all these subsurface imaging techniques require excitation of the oscillation of the cantilever and/or sample surface, it has been difficult to identify a key imaging mechanism. Here we demonstrate visualization of Au nanoparticles buried 300 nm into a polymer matrix by measurement of the thermal noise spectrum of a microcantilever with a tip in contact to the polymer surface. We show that the subsurface Au nanoparticles are detected as the variation in the contact stiffness and damping reflecting the viscoelastic properties of the polymer surface. The variation in the contact stiffness well agrees with the effective stiffness of a simple one-dimensional model, which is consistent with the fact that the maximum depth range of the technique is far beyond the extent of the contact stress field.

  10. Seismic damage estimation for buried pipelines - challenges after three decades of progress

    Energy Technology Data Exchange (ETDEWEB)

    Pineda-porras, Omar Andrey [Los Alamos National Laboratory; Najafi, Mohammand [U. OF TEXAS

    2009-01-01

    This paper analyzes the evolution over the past three decades of seismic damage estimation for buried pipelines and identifies some challenges for future research studies on the subject. The first section of this paper presents a chronological description of the evolution since the mid-1970s of pipeline fragility relations - the most common tool for pipeline damage estimation - and follows with a careful analysis of the use of several ground motion parameters as pipeline damage indicators. In the second section of the paper, four gaps on the subject are identified and proposed as challenges for future research studies. The main conclusion of this work is that enhanced fragility relations must be developed for improving pipeline damage estimation, which must consider relevant parameters that could influence the seismic response of pipelines.

  11. New perspectives on the damage estimation for buried pipeline systems due to seismic wave propagation

    Energy Technology Data Exchange (ETDEWEB)

    Pineda Porras, Omar Andrey [Los Alamos National Laboratory

    2009-01-01

    Over the past three decades, seismic fragility fonnulations for buried pipeline systems have been developed following two tendencies: the use of earthquake damage scenarios from several pipeline systems to create general pipeline fragility functions; and, the use of damage scenarios from one pipeline system to create specific-system fragility functions. In this paper, the advantages and disadvantages of both tendencies are analyzed and discussed; in addition, a summary of what can be considered the new challenges for developing better pipeline seismic fragility formulations is discussed. The most important conclusion of this paper states that more efforts are needed to improve the estimation of transient ground strain -the main cause of pipeline damage due to seismic wave propagation; with relevant advances in that research field, new and better fragility formulations could be developed.

  12. Buried heterostructure vertical-cavity surface-emitting laser with semiconductor mirrors

    CERN Document Server

    Zhao, G; Deppe, D G; Konthasinghe, K; Muller, A

    2012-01-01

    We report a buried heterostructure vertical-cavity surface-emitting laser fabricated by epitaxial regrowth over an InGaAs quantum well gain medium. The regrowth technique enables microscale lateral confinement that preserves a high cavity quality factor (loaded $Q\\approx$ 4000) and eliminates parasitic charging effects found in existing approaches. Under optimal spectral overlap between gain medium and cavity mode (achieved here at $T$ = 40 K) lasing was obtained with an incident optical power as low as $P_{\\rm th}$ = 10 mW ($\\lambda_{\\rm p}$ = 808 nm). The laser linewidth was found to be $\\approx$3 GHz at $P_{\\rm p}\\approx$ 5 $P_{\\rm th}$.

  13. Treatment of simulated INEL buried wastes using a graphite electrode DC arc furnace

    Energy Technology Data Exchange (ETDEWEB)

    Surma, J.E.; Lawrence, W.E. [Pacific Northwest Lab., Richland, WA (United States); Titus, C.H. [T& R Associates, Wayne, PA (United States); Wittle, J.K.; Hamilton, R.A. [Electro-Pyrolysis, Inc., Wayne, PA (United States); Cohn, D.R.; Rhea, D.; Thomas, P.; Woskov, P.P. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1994-08-01

    A program has been established under the auspices of the Department of Energy (DOE), Office of Technology Development (OTD), to develop the graphite electrode DC arc technology for the application of treating buried heterogenous solid wastes. A three way {open_quotes}National Laboratory-University-Industry{close_quotes} partnership was formed to develop this technology in the most timely and cost effective manner. This program is presently testing a newly fabricated pilot-scale DC arc furnace with associated diagnostics at the Plasma Fusion Center at the Massachusetts Institute of Technology. Initial testing in a smaller engineering scale furnace has established the viability of this technology for the treatment of solid heterogeneous wastes. Two diagnostic tools were developed under this program which support the evaluation of the DC arc technology. The diagnostics provide for both spatially resolved temperature measurements within the furnace and real time monitoring of the furnace metal emissions.

  14. 3D reconstruction of the source and scale of buried young flood channels on Mars.

    Science.gov (United States)

    Morgan, Gareth A; Campbell, Bruce A; Carter, Lynn M; Plaut, Jeffrey J; Phillips, Roger J

    2013-05-01

    Outflow channels on Mars are interpreted as the product of gigantic floods due to the catastrophic eruption of groundwater that may also have initiated episodes of climate change. Marte Vallis, the largest of the young martian outflow channels (Mars hydrologic activity during a period otherwise considered to be cold and dry. Using data from the Shallow Radar sounder on the Mars Reconnaissance Orbiter, we present a three-dimensional (3D) reconstruction of buried channels on Mars and provide estimates of paleohydrologic parameters. Our work shows that Cerberus Fossae provided the waters that carved Marte Vallis, and it extended an additional 180 kilometers to the east before the emplacement of the younger lava flows. We identified two stages of channel incision and determined that channel depths were more than twice those of previous estimates.

  15. Buried glacier ice in permafrost, a window to the past: examples from Bylot Island, Canadian Arctic

    Science.gov (United States)

    Fortier, D.; Coulombe, S.; Kanevskiy, M. Z.; Paquette, M.; Shur, Y.; Stephani, E.

    2011-12-01

    Bylot Island is located north of Baffin Island (73°N, 80°W) and is extensively covered by an ice cap and its outlet glaciers flowing towards the arctic lowland of the Lancaster formation. During summers of 2009 and 2011 several active-layer detachment slides exposed large massive ice bodies and other types of debris-rich ice that were interpreted as buried glacier ice. The upper part of the massive ice and debris-rich ice were usually in contact with various types of ice-contact or glacio-fluvial sediments and in some cases they were covered by mass wasting/colluvial deposits. This suggests that their preservation was likely related to burial of the ice and refreezing of the overlying sediments following permafrost aggradation. A preliminary analysis of the ice facies and ice crystals revealed the presence of four distinct types of ice: 1) clear-ice bodies with very few sediment and no organic inclusions. The ice crystals were large (cm), randomly oriented and air bubbles were observed at the junction of crystals. These characteristics could potentially indicate an englacial (snow-neve metamorphism) origin for these clear ice bodies; 2) large, meter thick, clear ice layers with no sediment, nor organics. The ice crystals were large (cm), several cm long, oriented in the same direction, and vertically aligned. These characteristics could potentially point to water that refroze in a tunnel incised in englacial ice; 3) Successive, mm to cm thick, ice layers, separated by undulating sand and gravel bands also containing cobles to boulder size rock fragments. These characteristics could potentially represent regelation ice formed at the base of glaciers and incorporated to the glacier sole; 4) mm to cm suspended aggregate of fine-grained sediments in clear ice. These micro-suspended and suspended cryostructures were sometimes deformed and aligned in the form of thin (mm) undulating layers. These micro-structures were very similar to basal ice facies, presumably

  16. Pristine Early Eocene wood buried deeply in kimberlite from northern Canada.

    Directory of Open Access Journals (Sweden)

    Alexander P Wolfe

    Full Text Available We report exceptional preservation of fossil wood buried deeply in a kimberlite pipe that intruded northwestern Canada's Slave Province 53.3±0.6 million years ago (Ma, revealed during excavation of diamond source rock. The wood originated from forest surrounding the eruption zone and collapsed into the diatreme before resettling in volcaniclastic kimberlite to depths >300 m, where it was mummified in a sterile environment. Anatomy of the unpermineralized wood permits conclusive identification to the genus Metasequoia (Cupressaceae. The wood yields genuine cellulose and occluded amber, both of which have been characterized spectroscopically and isotopically. From cellulose δ(18O and δ(2H measurements, we infer that Early Eocene paleoclimates in the western Canadian subarctic were 12-17°C warmer and four times wetter than present. Canadian kimberlites offer Lagerstätte-quality preservation of wood from a region with limited alternate sources of paleobotanical information.

  17. Pristine Early Eocene wood buried deeply in kimberlite from northern Canada.

    Science.gov (United States)

    Wolfe, Alexander P; Csank, Adam Z; Reyes, Alberto V; McKellar, Ryan C; Tappert, Ralf; Muehlenbachs, Karlis

    2012-01-01

    We report exceptional preservation of fossil wood buried deeply in a kimberlite pipe that intruded northwestern Canada's Slave Province 53.3±0.6 million years ago (Ma), revealed during excavation of diamond source rock. The wood originated from forest surrounding the eruption zone and collapsed into the diatreme before resettling in volcaniclastic kimberlite to depths >300 m, where it was mummified in a sterile environment. Anatomy of the unpermineralized wood permits conclusive identification to the genus Metasequoia (Cupressaceae). The wood yields genuine cellulose and occluded amber, both of which have been characterized spectroscopically and isotopically. From cellulose δ(18)O and δ(2)H measurements, we infer that Early Eocene paleoclimates in the western Canadian subarctic were 12-17°C warmer and four times wetter than present. Canadian kimberlites offer Lagerstätte-quality preservation of wood from a region with limited alternate sources of paleobotanical information.

  18. Uplifting behavior of shallow buried pipe in liquefiable soil by dynamic centrifuge test.

    Science.gov (United States)

    Huang, Bo; Liu, Jingwen; Lin, Peng; Ling, Daosheng

    2014-01-01

    Underground pipelines are widely applied in the so-called lifeline engineerings. It shows according to seismic surveys that the damage from soil liquefaction to underground pipelines was the most serious, whose failures were mainly in the form of pipeline uplifting. In the present study, dynamic centrifuge model tests were conducted to study the uplifting behaviors of shallow-buried pipeline subjected to seismic vibration in liquefied sites. The uplifting mechanism was discussed through the responses of the pore water pressure and earth pressure around the pipeline. Additionally, the analysis of force, which the pipeline was subjected to before and during vibration, was introduced and proved to be reasonable by the comparison of the measured and the calculated results. The uplifting behavior of pipe is the combination effects of multiple forces, and is highly dependent on the excess pore pressure.

  19. Uplifting Behavior of Shallow Buried Pipe in Liquefiable Soil by Dynamic Centrifuge Test

    Directory of Open Access Journals (Sweden)

    Bo Huang

    2014-01-01

    Full Text Available Underground pipelines are widely applied in the so-called lifeline engineerings. It shows according to seismic surveys that the damage from soil liquefaction to underground pipelines was the most serious, whose failures were mainly in the form of pipeline uplifting. In the present study, dynamic centrifuge model tests were conducted to study the uplifting behaviors of shallow-buried pipeline subjected to seismic vibration in liquefied sites. The uplifting mechanism was discussed through the responses of the pore water pressure and earth pressure around the pipeline. Additionally, the analysis of force, which the pipeline was subjected to before and during vibration, was introduced and proved to be reasonable by the comparison of the measured and the calculated results. The uplifting behavior of pipe is the combination effects of multiple forces, and is highly dependent on the excess pore pressure.

  20. Performance of an improved thermal neutron activation detector for buried bulk explosives

    Energy Technology Data Exchange (ETDEWEB)

    McFee, J.E., E-mail: jemcfee@gmail.com [Defence R and D Canada – Suffield, Medicine Hat (Canada); Faust, A.A. [Defence R and D Canada – Suffield, Medicine Hat (Canada); Andrews, H.R.; Clifford, E.T.H. [Bubble Technology Industries Inc., Chalk River (Canada); Mosquera, C.M. [Defence R and D Canada – Suffield, Medicine Hat (Canada)

    2013-06-01

    First generation thermal neutron activation (TNA) sensors, employing an isotopic source and NaI(Tl) gamma ray detectors, were deployed by Canadian Forces in 2002 as confirmation sensors on multi-sensor landmine detection systems. The second generation TNA detector is being developed with a number of improvements aimed at increasing sensitivity and facilitating ease of operation. Among these are an electronic neutron generator to increase sensitivity for deeper and horizontally displaced explosives; LaBr{sub 3}(Ce) scintillators, to improve time response and energy resolution; improved thermal and electronic stability; improved sensor head geometry to minimize spatial response nonuniformity; and more robust data processing. The sensor is described, with emphasis on the improvements. Experiments to characterize the performance of the second generation TNA in detecting buried landmines and improvised explosive devices (IEDs) hidden in culverts are described. Performance results, including comparisons between the performance of the first and second generation systems are presented.