Formation of cracks on photodegraded nylon 6 filaments

Cracks were found on the surface of drawn nylon 6 filaments irradiated with ultraviolet (UV) light from a mercury lamp under various humidities at room temperature. The cracks were formed perpendicular to the fiber axis and were of varying sizes. No cracks were observed on undrawn filaments or drawn filaments exposed to UV light in a dry atmosphere. Considerable shrinkage was found in drawn samples by thermomechanical analysis indicating the presence of residual stress in the material. The cracking is explained in terms of the residual stress and plasticization by moisture.     

Women in academe: Is the glass completely full?

Replies to comments published by M. J. Harris (see record 2003-03406-011) and A. Bleske-Rechek and R. M. Webb (see record 2003-03406-012) in reference to the original article by M. E. Kite et al (see record 2001-10045-002), which summarized the findings and recommendations of the Task Force on the Status of Women in Academe. Here Kite et al reply in detail to the published comments. Four primary issues are addressed: equity in compensation, the question of special treatment, the importance of continuing to transform the academy, and the need for continued vigilance and monitoring to ensure that advances in gender equity do not prove to be just a passing phase. Kite et al emphasize both the importance of continuing to transform the academy and the need for continued vigilance on issues of gender equity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Observation of recorded magnetization patterns by electron holography

Magnetization patterns recorded on Co thin films prepared by oblique incidence vacuum deposition were directly observed by electron holography. Complicated ellipse-like interference fringes were observed along the sawtooth-like walls in the transition regions. Stray magnetic flux was observed in empty space beyond the edge of the film. The following results were obtained from analysis of these interference images. The smaller the product of the remanence and the film thickness, and the higher the coercivity, the narrower is the transition length that determines the limit of the recording density of a medium. It was confirmed that longitudinal magnetic recording of a density of up to 170 kBPI is attainable using Co film 30 nm thick and with coercivity of 112 kA/m. It was quantitatively proven that the intensity of the recorded magnetization in a medium is equal to its remanence when the magnetized area is distinguishable from the transition region.     

Use of ESR for deterioration diagnosis of electrolytic capacitor

A new deterioration diagnosis method for the electrolytic capacitor is proposed for a forward-type converter and a buck-boost converter. It was observed that the ESR (equivalent series resistance) of the electrolytic capacitor increases as it deteriorates, and the knowledge that ripple varies proportionally to the ESR increase was used. With this method, the electrolytic capacitor life-cycle aging rate can be projected for the active circuit over the system life. This approach to deterioration is valid for any load condition, no matter whether the circuit has feedback control or not     

Frequency separation locking and synchronization for FDM opticalsources using widely frequency tunable laser diodes

A laser diode (LD) frequency separation locking method (called the reference pulse method) is proposed. This method has advantageous features for frequency division multiplexing (FDM) networks from the viewpoint of frequency separation stability with a strict frequency separation standard, modulation format independence, controllability over a large number of LDs, and frequency synchronization capability. Frequency locking experiments, using four and ten controlled LDs, confirmed that the control system using the method can stabilize frequency spacing for more than 100 LDs. The frequency fluctuation is suppressed to less than 10 MHz. Frequency synchronization, utilizing the reference pulse method, is proposed and demonstrated experimentally for two controlled LD groups, each consisting of three LDs. Frequency discrepancy between two LD groups was only 2.7% of the frequency separation. Required frequency-swept light power and controlled LD power at the detector input for frequency synchronization indicate that more than 50000 LD groups within a 10 km area, each having 100 LDs, can be synchronized simultaneously     

Interfacial reaction in bimetallic Sn/Cu thin films

Interfacial reaction in electroplated bimetallic Sn/Cu (the layer grown last is given first) thin films was studied by Auger depth profiling and X-ray diffraction measurements. Direct experimental evidence was found for the formation of intermetallic compounds in the SnCu interface, i.e. η'-Cu₆Sn₅ at room temperature and both η'-Cu₆Sn₅ and ε-Cu₃Sn at 150°C. The results of a quantitative analysis of the film composition and sputtering-induced effects are also discussed.