429 research outputs found
Mechanical and fatigue properties of long carbon fiber reinforced plastics at low temperature
The mechanical properties of long unidirectional (UD) and crossply (CR) carbon fiber reinforced plastics (CFRPs) were investigated at a low temperature (−196 °C). The CFRPs were fabricated from 60 vol.% carbon fiber and epoxy resin. The bending strength of the UD-CFRP was approximately twice that of the CR-CFRP. The high strength of the UD-CFRP was directly attributed to the amount of carbon fiber oriented along the loading direction: 60% for UD-CFRP compared with 30% for CR-CFRP. The low-temperature (−196 °C) tensile and fatigue strengths of the UD-CFRP were over 1.5 times greater than those at room temperature (20 °C). This was attributed to the increased epoxy strength at low temperatures along with the internal compressive stress arising from the different thermal expansion coefficients of the carbon fiber and epoxy. Both the epoxy strength and internal compressive strength were employed as factors in a compound law to numerically estimate the low-temperature tensile strength. This work presents a systematic analysis for changes in the CFRP material properties at low temperatures
Thermomechanical noise of arrayed capacitive accelerometers with 300-NM-gap sensing electrodes
2017 19th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS), 18-22 June 2017.Thermomechanical noise of arrayed capacitive accelerometers with sub-micrometer sensing electrodes was evaluated. The unit accelerometer of the array was 80-μm square, designed as a proportional scale-down of a conventional single-axis accelerometer. Since the size effect shows the capacitance sensitivity per unit volume increases by proportional downsizing, a 10-by-10 array of the one-tenth sized unit accelerometer would have the same sensitivity of a single accelerometer of same occupied area. However, the thermomechanical noise needs to be controlled and reduced by vacuum encapsulation because size reduction causes noise increase. By measuring the electrical impedance at the resonant frequency, the damping coefficient was estimated using electrical equivalent circuit modeling. The estimated thermomechanical noise was reduced below 3 μg√VHZ by encapsulating at 100 Pa, which is low enough for instrumentation applications
Simplest fidelity-estimation method for graph states with depolarizing noise
Graph states are entangled states useful for several quantum information
processing tasks such as measurement-based quantum computation and quantum
metrology. As the size of graph states realized in experiments increases, it
becomes more essential to devise efficient methods estimating the fidelity
between the ideal graph state and an experimentally-realized actual state. Any
efficient fidelity-estimation method, in general, must use multiple
experimental settings, i.e., needs to switch between at least two measurements.
Recently, it has been shown that a single measurement is sufficient if the
noise can be modeled as the phase-flip error. Since the bit-flip error should
also occur in several experiments, it is desired to extend this simplest method
to noise models that include phase and bit-flip errors. However, it seems to be
nontrivial because their result strongly depends on properties of the
phase-flip error. In this paper, by analyzing effects of the bit-flip error on
stabilizer operators of graph states, we achieve the extension to the
depolarizing noise, which is a major noise model including phase and bit-flip
errors. We also numerically evaluate our simplest method for noise models
interpolating between the phase-flip and depolarizing noises.Comment: 10 pages, 6 figure
ヒトCYP1B1遺伝子の発現調節機構
取得学位:博士(薬学),学位授与番号:博甲第807号,学位授与年月日:平成18年3月22日,学位授与年:200
Preoperative diagnosis of an asymptomatic cancer restricted to the cystic duct
AbstractINTRODUCTIONEven now, cystic duct cancer (CDC) as defined by Farrar is rare and has a better prognosis than gallbladder cancer, although CDC as defined by Ozden et al., the definition of which could apply to early and advanced cases of CDC, is not rare and has a poorer prognosis than the CDC defined by Farrar.PRESENTATION OF CASEA 78-year-old woman with no complaints was found to have a tumor restricted to the cystic duct. Three cytology examinations of the patient's bile could not establish that the tumor was an adenocarcinoma. However, adenocarcinoma was suspected due to the hypervascularity shown on contrast-enhanced computed tomography. Cholecystectomy and extrahepatic bile duct resection with D2 lymph node dissection was performed. The pathological study revealed it to be CDC. Her postoperative course has been uneventful and without recurrence for 21 months.DISCUSSIONAt their first medical examination, many CDC patients are found to have such advanced spread of the cancer to adjacent organs that an extended operation might be necessary. As in our case, better patient outcome results when no lymph node or remote metastasis is present.CONCLUSIONDiagnosing CDC as early as possible contributes to curative resections and favorable patient outcomes and also allows surgeons to recommend a mini-invasive procedure to their patients rather than extended resection including that of adjacent organs
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