520 research outputs found
Optical Rotation by a Free Electron on an Oriented Helix
Article信州大学工学部紀要 63: 1-8 (1988)departmental bulletin pape
Exciton-Phonon Interaction in Optical Rotation
Article信州大学工学部紀要 57: 1-10 (1985)departmental bulletin pape
Crack Detection Using Low-frequency Ultrasonic Waves Caused by Low Directivity and Scattering
In recent years, nondestructive testing techniques for maintenance and checking of materials and structures have been more required with social infrastructure’s aging. Although ultrasonic waves are valid in internal inspection, conventional ultrasonic detection techniques are inadequate for detecting fatigues or closed cracks, because ultrasound waves hardly reflect at them[1]. However, it has been reported that the transmitted wave through a closed crack contains nonlinear ultrasonic waves[2] such as super- and sub- harmonics, and they have been expected to be used for an alternative detecting method.
In our previous research, we experimentally examined transmission of ultrasonic waves through contact surfaces of two metal blocks stacked and compressed in order to simulate a closed crack as in ref[3]. The experiments showed that an ultrasonic wave transmitted over a contact solid interface consists of not only the transmitted fundamental frequency component but also much lower frequency spectra[4]. The magnitude of the low-frequency component is a function of the incident angle and expected to use for developing a comprehensive method which allows unskilled engineers to detect cracks. In this paper, we focused on angles for developing a new method by low-frequency components. The objective of this paper is investigating characteristics of low frequency spectra for the relative angle between the transmitting and receiving transducer.
We conducted two experiments. The first experiments showed that the ratio of low frequency components changed significantly when the incident angle was near the directivity angle. If there is a crack in a specimen, ultrasonic waves, after scattered at the crack tip, are received from oblique direction. This can cause change in the ratio of low frequency components. In the second experiments, in order to identify the position of the crack tip, we used the dependence of ratio of low frequency components on the incident angle. From the above results, we proposed a new method to identify cracks by using low frequency components and the directivity angle
Proposal and Performance Analysis of Hybrid NDN Based Ad Hoc Routing Combining Proactive and Reactive Mechanisms
This paper is an extension of our previous conference paper. In this paper, we propose a new routing protocol for named data networking (NDN) based ad hoc networks. One feature of our protocol is that it adopts a hybrid approach where a proactive routing is used in the producer side network and a reactive routing is used in the consumer side network. Another feature is that we focus only on the name prefix advertisement in the proactive routing. The result of performance evaluation focusing on the communication overhead shows that our proposal has a moderate overhead both for routing control messages and Interest packets compared with some of conventional NDN based ad hoc routing mechanisms proposed so far. The performance evaluation for a network configuration with a moving consumer node also shows the proposal realizes an effective content retrieval
Two sisters reveal autosomal recessive inheritance of epidermodysplasia verruciformis: a case report
BACKGROUND: Epidermodysplasia verruciformis is a rare genodermatosis characterized by a unique susceptibility to cutaneous human papillomaviruses infection. Most patients show autosomal recessive patterns of inheritance. CASE PRESENTATION: We report a case of two sisters with clinically epidermodysplasia verruciformis specific lesions on the face, neck, trunk, and extremities. PCR analysis indicated the presence of human papillomavirus type 5 in the lesions. Electron microscopic examination showed viral-like particles in keratinocyte nuclei and the stratum corneum of the epidermodysplasia verruciformis lesions. In addition, we examined the EVER1 and EVER2 genes using eight different primer pairs without finding any nonsense or frameshift mutations in the gDNA from lymphocytes of the elder sister. CONCLUSIONS: In this report, the patient’s parents did not have epidermodysplasia verruciformis lesions or a consanguineous marriage. EV did not develop in the elder sister until five years of age, so the parents did not perceive EV as an inherited disease. The probability that EV developed in both sisters was only 6.25%. Thus, it is rare for both sisters to develop epidermodysplasia verruciformis lesions considering that the parents were presumed to be carriers and the disease reveal an autosomal recessive pattern of inheritance
Two sisters reveal autosomal recessive inheritance of epidermodysplasia verruciformis: a case report
Isolation of Acanthamoeba with Sabouroud's glucose agar plate
Isolation of Acanthamoeba or finding out the cysts from corneal leasions is necessary to confirm the diagnosis of Acanthamoeba keratitis. However, we cannot always find out the cyst from corneal scrapings of the lesions. In these cases the isolation of Acanthamoeba is very important to confirm the diagnosis.
Non-nutrient agar plates are generally used to isolate Acanthamoeba, but it is difficult to get them easily at many hospitals.
To find out another agar that can be used to isolate Acanthamoeba and got easily, Sabouroud's glucose agar plates were compared with non-nutrient agar plates for the isolation of Acanthamoeba.
Both agar plates seeded with Escherichia coli showed a nice growth of trophozoites first and cysts later. A clinical material, stock solution of contact lens used by a suspected patient of Acanthamoeba keratitis, was put on Sabouroud's glucose agar plate seeded with Escherichia coli. After three days of incubation at 25°C Acanthamoeba was found on the plate.
Sabouroud's glucose agar plate was a very useful agar plate for the isolation of Acanthamoeba
Variable Stars in the Magellanic Clouds: Results from OGLE and SIRIUS
We have performed a cross-identification between OGLE-II data and
single-epoch SIRIUS JHK survey data in the LMC and SMC. After eliminating
obvious spurious variables, we determined the pulsation periods for 9,681 and
2,927 variables in the LMC and SMC, respectively. Based on these homogeneous
data, we studied the pulsation properties and metallicity effects on period-K
magnitude (PK) relations by comparing the variable stars in the LMC and SMC.
The sample analyzed here is much larger, and we found the following new
features: (1) variable red giants in the SMC form parallel sequences on the PK
plane, just like those found by Wood (2000) in the LMC; (2) both of the
sequences A and B of Wood (2000) have discontinuities, and they occur at the
K-band luminosity of the TRGB; (3) the sequence B of Wood (2000) separates into
three independent sequences B+- and C'; (4) comparison between the theoretical
pulsation models (Wood et al. 1996) and observational data suggests that the
variable red giants on sequences C and newly discovered C' are pulsating in the
fundamental and first overtone mode, respectively; (5) the theory can not
explain the pulsation mode of sequences A+- and B+-, and they are unlikely to
be the sequences for the first and second overtone pulsators, as was previously
suggested; (6) the zero points of PK relations of Cepheids in the metal
deficient SMC are fainter than those of LMC ones by ~0.1 mag but those of SMC
Miras are brighter than those of LMC ones by ~0.13 mag, which are probably due
to metallicity effects.Comment: 9 pages, 10 figures, accepted for publication in MNRAS. High
resolution version is available at:
http://www.ioa.s.u-tokyo.ac.jp/~yita/scr/astro/papers/RefereedPaper/yitaMD250
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