EFFECTS OF VISCOSITY OF LIQUID FOODS ON PALATAL PRESSURE

The deglutition of non-Newtonian liquids introduced into the mouth was studied dynamically by measuring palatal pressure (P) with pressure transducers set at three locations on the palate. The value of P and the swallowing pressure (S) changed only from 100 to 200 g/cm² over the viscosity range 10⁻² to 10¹ Pa.s. The retaining time (T) and work (W), required for swallowing after the liquid entered the mouth, remained almost constant up to a critical value of 1.0 Pa.s. above which both T and W increased markedly. When the viscosity was low, all of the liquid was swallowed in one deglutition, up to 15 mL volume. Therefore, T was almost constant but S increased with the volume. When the viscosity was high, the liquid was swallowed in several smaller portions. When the volume was high, T increased and S was either constant or it decreased.     

手机短信中的沟通主题

文章通过日志法收集到10840条真实手机短信,并采用编码分析的方法对其进行分类,得到两大类短信:工具类和表达类.短信主题对短信长度有显著的影响.表达类中关心问候的短信较长,工具类中请求要求类的短信最长.在沟通中,男性发送的工具类短信比表达类短信多,而女性发送的工具类短信则比表达类短信少.偏好短信者发送的表达类短信比偏好手机通话沟通的人发送的多.     

EFFECTS OF DIMENSIONS OF AGAR AND GELATIN GELS ON PALATAL PRESSURE PATTERNS

Eating of agar and gelatin gels in the mouth was studied dynamically in detail. The palatal presures on agar and gelatin gels of various concentrations and dimensions were detected by pressure transducers installed at three locations of the palate. For each of the gels, Pm (the maximum palatal pressure at the initial stage of mastication), P (the mean palatal pressure), W (work), and T (retaining time in the mouth) changed significantly when their concentrations increased. Moreover, gel dimensions also affected Pm, P and W. For a bite-size gel, Pm, P and W increased or remained constant, while for a finer sized gel, Pm, P and W were nearly constant regardless of the increase in rupture strength or gel concentration.     

EFFECT OF RELATIVE SLIP AMPLITUDE ON FRETTING FATIGUE OF HIGH STRENGTH STEEL

Abstract— The effect of relative slip amplitude on fretting fatigue in high strength steel was studied at various contact pressures using fretting pads of various lengths. Under a given contact pressure, the fretting fatigue life showed a minimum at a certain relative slip amplitude. Under a fixed pad length, the life also showed a minimum at a certain contact pressure. A map of fretting fatigue life versus contact pressure and relative slip amplitude was obtained using the data of this study. The map indicated that both the phenomena which showed a minimum life in relation to slip dependence and contact pressure dependence were the same, as were the underlying mechanisms. The minimum life was interpreted in terms of local stress concentration at the fretted area.     

RHYTHMIC AND IRREGULAR MOVEMENT OF THE FIRST MOLAR WHILE EATING FOODS WITH DIFFERENT TEXTURES

The three-dimensional movement of a tooth, any tooth, while naturally eating, was measured by an apparatus developed in our laboratory. The movement of the first molar on the usually used side is reported here. The mastication movements are divided into two parts, namely the rhythmical chewing period during which there are mastication pressure loads on the molar and the irregularly pulsated moving period in preparation for the swallowing followed by the rhythmical one during which there is no more pressure on it. The amplitudes of the up and down movements of the molar are 10–22mm for the rhythmical chewing period which are bigger than those for the irregularly moving period. The rhythmical chewing periods are distributed around 10–40 s depending on 14 kinds of food texture, and also on the size of the food, in a fairly similar manner for the participants. The period is longer for tough foods and bigger samples. The irregularly pulsated moving periods are widely distributed, 2–45s, and depend both on the food texture and on the participant. The irregular moving periods are longer for foods which scatter in the mouth or adhere to the teeth when chewing. The ingestion difficulty of the food was divided into two groups. One is where it is difficult to break down the food with the teeth and the other is where it is difficult to prepare for swallowing.     

Oxygen-Sensor-Based Simple Assay of Histamine in Fish Using Purified Amine Oxidase

Oxygen consumption was measured by an oxygen sensor after addition of purified fungal amine oxidase to fish extracts. The oxidation of histamine to imidazoleacetaldehyde proceeded stoichiometrically. Based on the equimolar relationship between histamine and oxygen consumption, histamine was determined selectively by the oxygen sensor. Neither sample pretreatment removing interfering materials nor daily calibration by histamine standard was required. Histamine contents in scombroid fish were determined rapidly with good accuracy. AOAC and oxygen sensor methods showed a very high correlation (r=0.999, n=6).     

Recent progress on ultrafast/ultrashort/frequency-stabilized erbium-doped fiber lasers and their applications

There are many kinds of fiber lasers in the 1.5 μm band using erbium-doped fiber amplifiers. Our group has been studying and developing advanced fiber lasers, such as 1) 10-40 GHz harmonically mode-locked fiber lasers, 2) femtosecond fiber lasers that use single-wall carbon nanotube (CNT)-doped polymers as a saturable absorber, and 3) frequency-stabilized fiber lasers that employ acetylene C2H2. We will describe recent progress on these fiber lasers and their applications in this article.     

Design Method for Improving Motor Efficiency of Switched Reluctance Motor

The motor efficiencies of switched reluctance motors (SRMs) are inferior to those of permanent magnet synchronous motors. This paper describes a design procedure for an SRM to obtain a higher motor efficiency. The first step in the design procedure makes clear the principle for improving the motor efficiency. The cross‐sectional and axial shapes of the rotor and stator cores are designed by magnetic field analysis with the two‐dimensional (2D) and 3D finite element method. A high‐efficiency SRM with 12 stator poles and eight rotor poles is designed. The designed SRM was produced experimentally, and was tested to verify its performance. The motor efficiency was improved in comparison to the standard SRM with six stator poles and four rotor poles.     

The Proposal of Isolated Single‐Stage AC‐DC Converter

An isolated ac‐dc converter has been used in various applications, such as power supply and as a battery charger for electric vehicle. In conventional converters, a loss in each conversion stage can be reduced by applying a soft switching method. However, a conventional converter has many conversion stages including the rectifier stage, power factor correction, and dc/dc converter stages; thus, it is difficult to reduce the total converter loss and size. In this paper, we propose a novel isolated‐type ac‐dc converter with only one conversion stage; it can realize a zero‐voltage switching operation in all switching devices.