Local Hardening Evaluation of Carbon Steels by Using Frequency Sweeping Excitation and Spectrogram Method

We use steel materials for a car, an industrial machine, a building and so on. The steel materials are used for the main parts of the machine. The steel materials have good mechanical characteristics, however, higher mechanical characteristics by special treatment are often demanded. In this case, some evaluation methods are also required to monitor and control the mechanical characteristics of steel materials. Normally, mechanical destructive testing is used for the evaluation of them, however, all products on line cannot be evaluated because destructing samples are needed by mechanical testing. Therefore, non-destructive evaluation by electromagnetic method is focused on in this paper. We have developed a non-destructive evaluation for hardening steel named as a frequency sweep excitation and spectrogram (FSES) method [1]. This proposed method can evaluate mechanical characteristics non-destructively by using several frequency components of magnetic flux depending on hardening conditions [1]. Figure 1 shows the measured magnetic coercive force Hc and maximum magnetic field strength Hmax. The sample were hardened by induction heating with the current of 80[A]. As shown in Figure 1, in the 8 - 12 [mm] and 16 - 22 [mm] sections, the spectrogram of the maximum magnetic field strength Hmax was changed locally in comparison of the one of the magnetic coercive force Hc. It has been made clear that the magnetic coercive force Hc could evaluate the hardening strength qualitatively and quantitatively [1]. Moreover, it is obvious that the local material changes can be evaluated by the maximum magnetic field strength Hmax as shown in Figure 1

Electron emission from conduction band of diamond with negative electron affinity

Experimental evidence explaining the extremely low-threshold electron emission from diamond reported in 1996 has been obtained for the first time. Direct observation using combined ultraviolet photoelectron spectroscopy/field emission spectroscopy (UPS/FES) proved that the origin of field-induced electron emission from heavily nitrogen (N)-doped chemical vapour deposited (CVD) diamond was at conduction band minimum (CBM) utilising negative electron affinity (NEA). The significance of the result is that not only does it prove the utilisation of NEA as the dominant factor for the extremely low-threshold electron emission from heavily N-doped CVD diamond, but also strongly implies that such low-threshold emission is possible from other types of diamond, and even other materials having NEA surface. The low-threshold voltage, along with the stable intensity and remarkably narrow energy width, suggests that this type of electron emission can be applied to develop a next generation vacuum nano-electronic devices with long lifetime and high energy resolution.Comment: 17 pages, 4 figures, Phys. Rev. B in pres

Variations of multifractal structure in the fetal heartbeats.

Several procedures for evaluating fetal well-being are in clinical use. The cardiotocograph is mostly used as a non-invasive procedure to measure fetal well-being in clinical settings. The cardiotocograph displays the fetal heartbeat counts that vibrate. This variation has been classified into 2 categories. We investigated this variation by a novel method, in which we analyzed the change of structure of the attractors in the phase spaces according to the time course. We adopted the global spectrum, which means the distribution of fractal dimensions, for that structure. In this procedure, we discovered a new variation in which the cycle is much longer than the 2 types of known variabilities. Although loud noises such as white noises with a magnitude 1/4 times as large as the standard deviation of the original data were added to the original data, the variations were still detected. The variation is very difficult to detect by Fourier or wavelet transformation, however, because it changes very slowly. Through this new way of analyzing the vibration phenomena, we obtained a new perspective on the biological information available.</p

DIFFERENCES IN STROKE TECHNIQUE TO EXERT HAND PROPULSION BEWEEN ADVANCED AND INTERMEDIATE SWIMMERS

The aim of this study was to investigate differences in hand propulsion exerted by advanced and intermediate swimmers during insweep and upsweep phases in the front crawl stroke. Swimmers wore pressure sensors on their hands while performing the front crawl stroke in the swimming pool where a motion capture system was set up. The hand propulsive drag (PD) and lift (PL) were estimated during the two phases. The advanced swimmers exerted more PD than PL (70% vs 30%) during the insweep phase and used a similar amount of PD to PL in the upsweep phase. The intermediate swimmers used a similar amount of PD to PL in the insweep phase and exerted more PD than PL in the upsweep phase (65% vs 35%). The advanced swimmers used the different technique to exert hand propulsion in the two phases as compared to the intermediate ones

HOW ELITE SWIMMERS CONTROL THEIR HAND PROPULSIVE FORCE AND ARM COORDINATION WITH INCREASING VELOCITY DURING FRONT CRAWL

The purpose of this study was to investigate the change in the intensity and timing of the hand propulsive force by using pressure sensor and motion capture systems as increasing velocity during front crawl swimming. Twelve elite swimmers participated in this study. The swimmers swam three different velocity; i.e. 70%, 80% and 900h of maximal velocity. The propulsive force of both hands were recorded by multiple pressure sensors, and whole body kinematics was measured by using motion capture system. The average propulsive force during the pull and push phase, and thus, total stroke cycle increased as increasing swimming velocity. The non-propulsive phase decreased as increasing swimming velocity. Swimmers increase their swimming velocity with both increasing their hand propulsive force and decreasing their arm non-propulsive duration during a stroke cycle of front crawl swimming

Prediction markers for respiratory distress syndrome: evaluation of the stable microbubble test, surfactant protein-A and hepatocyte growth factor levels in amniotic fluid.

Surfactant treatment in infants with respiratory distress syndrome (RDS) has decreased neonatal mortality. With the advent of this therapy, it has become important to predict accurately the fetal lung maturity of a fetus before delivery. We evaluated the stable microbubble test (SMT), surfactant protein-A (SP-A) and hepatocyte growth factor (HGF) in amniotic fluid as predicting markers for RDS. Of 55 amniotic fluid samples obtained by amniocentesis from women less than 37 weeks pregnant, the SMT values were as follows: sensitivity 76.5%, specificity 84.2%, positive predictive value 68.4%, negative predictive value 88.9% and overall accuracy 81.8%. For SP-A, the values were 88.2%, 65.8%, 53.6%, 92.6% and 72.7%, respectively. If we used both SMT and SP-A, we could diagnose with 100% accuracy that a case with measurements of SMT &#62; or = 2 and SP-A &#62; or = 420 ng/ml would not complicate with RDS (24/24). However, the RDS diagnostic accuracy of HGF does not equal to those of SMT and SP-A levels. We concluded that the rapidity, simplicity and reliability of SMT was very useful during 24-36 weeks of gestation as a bedside procedure to predict fetuses likely to develop RDS. We also noted the additive effect of SP-A in improving the accuracy of lung maturity diagnosis.</p

Effects of Epidermal Growth Factor on Neonatal Growth of Rat Intestines

The effects of epidermal growth factor (EGF) on neonatal intestines were examined in the rat. In 5-day-old rats, sucrase, trehalase, alkaline phosphatase (ALP) and gamma-glutamyl transpeptidase (gamma-GTP) activities in the small intestines were significantly increased after subcutaneous injection of EGF for 3 days (1 microgram/rat/day). gamma-GTP activity was also accelerated after oral EGF administration (2 micrograms/rat/day). Small intestines of 12-day-old rats injected with EGF for 10 days (1 microgram/rat/day) were significantly heavier than those of controls. These results suggest that EGF influences neonatal growth improving enlargement and functional development of their intestines.</p

Neurological Analysis Based on the Terminal End of the Spinal Cord and the Narrowest Level of Injured Spine in Thoracolumbar Spinal Injuries

This study aimed to clarify neurological differences among the epiconus, conus medullaris, and cauda equina syndromes. Eighty-seven patients who underwent surgery for acute thoracolumbar spinal injuries were assessed. We defined the epiconus as the region from the terminal end of the spinal cord to the proximal 1.0 to 2.25 vertebral bodies, the conus medullaris as the region proximal to < 1.0 vertebral bodies, and the cauda equina as the distal part of the nerve roots originating from the spinal cord. On the basis of the distance from the terminal end of the spinal cord to the narrowest level of the spinal canal, the narrowest levels were ordered as follows: the epiconus followed by the conus medullaris and cauda equina. The narrowest levels were the epiconus in 22 patients, conus medullaris in 37 patients, and cauda equina in 25 patients. On admission, significantly more patients had a narrowed epiconus of Frankel grades A-C than a narrowed cauda equina. At the final follow-up, there were no significant differences in neurological recovery among those with epiconus, conus medullaris, or cauda equina syndrome. Anatomically classifying the narrowest lesion is useful for clarifying the differences and similarities among these three syndromes