Manufacture of dense sintered bodies containing silicon nitride

Sintered bodies containing 1-32.5 Si oxide and 1.5 wt.% SiC (Si oxide/SiC wt. ratio 3/2) are prepared and kept in a 10-3000 kg/2 sq. cm. N (g) atmosphere at 1500-2300 degrees, while simultaneously maintaining the CO (g) partial pressure around the body lower than the nitrogenation equil. pressure to give a dense sintered body. The prepared dense sintered body has high strength at high temperatures. Thus, SiC 40, oxide 30 and Si3N4 30 wt% were fired to a body which was kept in 1500 kg/sq. cm. N (g) for 20 h at 2000 degrees to give a dense sintered body having high bending strength at high temperatures

An improved method for determining the DC magnetization curve using a ring specimen

When the DC magnetization curve (B-H) of nonoriented material is measured in a ring specimen, there is an intrinsic error due to the assumption that the mean magnetic path length is equal to the mean geometric path length. A novel method for determining the B-H curve accurately is proposed. The validity of the method is verified by experiments</p

Developing Cloud Chambers with High School Students

The result and outcome of the \textit{cloud chamber project}, which aims to develop a cloud chamber useful for science education is reported in detail. A project includes both three high school students and a teacher as a part of Super Science High School (SSH) program in our school. We develop a dry-ice-free cloud chamber using salt and ice (or snow). Technical details of the chamber are described. We also argue how the project have affected student's cognition, motivation, academic skills and behavior. The research project has taken steps of professional researchers, i.e., in planning research, applying fund, writing a paper and giving a talk in conferences. From interviews with students, we have learnt that such style of scientific activity is very effective in promoting student's motivation for learning science.Comment: 9 pages, accepted to the proceedings of APPC12 - the 12th Asia Pacific Physics Conferenc

Ambiguity and language evolution: Evolution of homophones and syllable number of words

We investigate the evolution of homophones and its relation to the evolution of syllable number of words, based on the quantitative analysis on the historical data and simulation. We suggest that homophones are the outcome of arranging form-meaning associations according to Zipf’s law to maximize the referential power under effort for the speaker constraints. We also discuss the neural bases of ambiguity and the relation between ambiguity and robustness in language evolution. Furthermore, we show that homophones are stable and cumulate with the times. To avoid creating homophones, syllable number of words increases, with more recent entry dates of words associated with more syllables. We also explore stability of homophones and instability of synonyms in children’s acquisition process. The mechanism of the evolution of homophones and syllable length of words works cross-linguistically from the emergence of language and goes on at present

Development of High-Precision Three-Dimensional Images for Colonoscopy

Background: For three-dimensional image analysis, SYNAPSE VINCENT (Fujifilm, Japan) has been applied. Authors have continued various clinical practice and research with image study by computer analysis. Patient and Method: The patient is a 65-year-old female with further evaluation of colon. Method included abdominal computed tomography (CT) scan associated with injecting necessary amount of air from the anus. With maintaining this condition, CT scan was conducted two times of supine position and prone position. Results: The case had sigmoid cancer, which was presented irregular surface texture. Further, she had colon polyp in the sigmoid colon and diverticula in the descending colon. These images were presented in the display associated with i) the position and direction for observation, ii) CT image of the corresponding point, iii) endoscopic image for the corresponding region. Discussion: This image analysis system would be useful for clinical diagnosis, because the images have multiple angles and related situations of colon mucosa, folds, and stiffness and so on. The combined data can provide significant information including coronal, horizontal and sagittal planes. When the surgeon operates colon cancer, he can make the correct imagination of the lesion in advance. It seems to be beneficial for smooth treatment of surgical operation

Reconstruction Image of Small Bowel Obstruction (SBO) Due To Japanese Rice Cake (Mochi)

Background: Authors have continued clinical practice with reconstruction method of computed tomography (CT). Case presentation: We have experienced 78-year-old male of acute abdomen complaining strong abdominal pain. Result: Laboratory test showed WBC 14800 /μL, and CT showed two high-density lesions in right middle and left upper abdomen, which has 143/214 Hounsfield unit, respectively. They suggest small bowel obstruction (SBO) by traditional Japanese rice cake (mochi). He was treated conservatively with infusion and relieved. Discussion: Rice cake may cause various problems, such as ileus, gastric ulcer, perforation and suffocation. This report becomes hopefully a reference for future practice and research

EFFECTS OF APPROACH VELOCITY TO THE CONTRIBUTION OF EACH BODY SEGMENTS TO THE TAKE-OFF MOVEMENT IN THE LONG JUMP

INTRODUCTION Much study suggested that approach velocity gave significant effects to the long jump performance However, there are very few studies effects of approach velocity to the role or the contribution of each body segments to the take-off movement in the long Jump, which is the purpose of this study Nine male long jumpers performed the long jump of the three types, Slow jump (S 10----15m-approachrun), Medium jump (M 25----30m-approachrun), Fast jump (F full approach of their own). Their take-off motions were filmed at 200Hz with Nac high speed camera. Two dimensional coordinates were obtained by digitizing the motions with a sampling frequency of 200Hz. The data was filtered with a Butterworth digital filter(Winter 1979) at 10Hz BSP of Chandler et al. (1975) were used to estimate the segmental centers of gravity and mass center of the whole body This data used to calculate the generated momenta and impulses (horizontal, vertical) of the arms (A), trunk (T: head and trunk), free leg (F) and take-off leg (TL), using the method of Ae and Shibukawa (1980). The mean percent contribution of the segments were obtained by dividing total impulse of each segment over the take-off phase by the whole body impulse RESULTS With the regard to the horizontal direction, the body segments contribution suggested the same proportion pattern all of the three types jumps. The highest (positive) contribution was made by the trunk (S: 4155±22.5%, M36.42± 18.23%, F54.85 ± 3024%) The contribution of the arms (S -5.97±281%, M:-6.34±5.21%, F:-9.54± 6.20%), The free leg (S: -5.85±481%, M: -1603±1120%, F: -722±3.10%) and take-off leg (S:-129.73±35.59%, M -11405±48.47%, F:-138.10±6550%) were negative. Most negative contribution was made by the take-off leg As for the vertical direction, the all body segments contribution of the three types jumps showed positive contribution (S; A 4.29±262%, T 4.06±423%, FL 0.69± 2.44%, TL 90 96±7.82%, M; A 600± 1.60%, T 9.54±9.37%, FL 010±210%, TL 84.36±11.14%, F; A 10.5±3.12%, T 8.02±604%, FL: 2.88±1.01%, TL 78.60 ± 14.56%). The take-off leg showed the highest percentage contribution As the approach velocity increased, so did the contribution of the arms, while the contribution of the take-off leg decreased. CONCLUSION With regard to the horizontal direction, the body segments contribution showed the same proportion pattern in all of the three types jumps The trunk made positive contribution to horizontal velocity, the trunk made positive contribution to horizontal velocity, the other body segments made negative contribution to horizontal velocity in horizontal direction. On the other hand, as the approach velocity increased, so did the contribution of the arms, while the contribution of the take-off leg decreased. The arms and take-off leg have a mutually supportive relationship in vertical direction