Nonlinear influence on PM-AM conversion measurement of groupvelocity dispersion in optical fibres

The authors propose a method for measuring the group velocity dispersion, including the polarity, of optical fibre by using a single wavelength light source. The method is based on the interplay between phase modulation-amplitude modulation (PM-AM) conversion and self-phase modulation (SPM)     

Self-healing algorithm for logical mesh connection on ring networks

A self-healing algorithm is proposed for a ring network connected as a logical mesh. It offers good performance in terms of protection line capacity, restoration time, and survivability against multiple failures     

Postoperative complications after coronary bypass operations in patients with pulmonary impairment]

Two women with atrial escape-capture bigeminy were reported in whom sinus P waves and escape P waves alternated with each other. Their electrocardiographic findings showed that, during the bigeminal rhythm, 2:1 exit block of sinus impulses associated with entrance block of escape impulses occurred in the sinoatrial junction. Three phenomena are suggested to explain the observations. (1) Seeming bradycardia-dependent sinoatrial exit block may have occurred, probably as a result of phasic changes in vagal tone due to respiration, with decreased vagal tone depressing conductivity in the sinoatrial junction to a greater degree than automaticity in the sinus node. (2) In case 1, type II second-degree entrance block in the sinoatrial junction may have occurred, reflecting the presence of sinus parasystole with incomplete entrance block. (3) Sinus escape also may have occurred, especially in case 2. These phenomena have never been reported before.     

Determination of captafol,cyhexatin, 1-naphthylacetic acid and quintozene in apple,Japanese pear and melon by simultaneous extraction

A simple and rapid method is described for the determination of the non-registered pesticides, captafol, quintozene (PCNB), cyhexatin and 1-naphthylacetic acid (NAA), in fruits. These pesticides were extracted with acidified acetone, then captafol and PCNB were purified with a Florisil mini column and analyzed by GC-ECD. Cyhexatin was ethylated with ethylmagnesium bromide, and the ethyl derivative was analyzed by GC-FPD (Sn filter). NAA was purified with liquid-liquid extraction and determined by HPLC equipped with a fluorescence detector. These analytes were identified with GC/MS or LC/MS. The minimum identified concentration of the pesticides was below 0.2 ng per injection, which corresponds to a detection limit of below 0.02 microgram/g in the original samples. Recoveries of the pesticides spiked at 0.1 microgram/g into apple, Japanese pear and melon were greater than 61%.     

Transient Monte Carlo analysis and application to heterojunctionbipolar transistor switching

A self-consistent simulation using the Monte Carlo ensemble particle technique for analysis of heterojunction bipolar transistor (HBT) transient behavior, such as switching performance, is presented. The transient Monte Carlo method has been applied to a self-consistent simulation of two HBT designs with improved collector structures for high-speed and high-frequency applications, and the results are compared with the characteristics of conventional HBTs. The simulation results indicate that the two new collector structures, the inverted field collector and the undoped collector, have better switching performance than the conventional HBT. The study of the switching characteristics' dependence on collector-base bias voltage and collector current suggests that the inverted field HBT is the best approach in terms of switching properties. The results are supported and explained by examining electron transport properties such as overshoot velocity and energy valley occupation, as well as band bending in the collector space-charge region at different current levels     

A case of coronary artery bypass grafting for effort angina in a patient with post skin grafting for an extramammary Paget's disease

The extramammary Paget's disease of anogenital area is rare, and is seen as a precancerous lesion or carcinoma in situ. In most cases, surgical treatment including dissection of regional lymph nodes, skin resection and grafting should be considered first. A 74-year-old male suffered from effort angina and underwent triple coronary artery bypass grafting (CABG) including saphenous vein graft (SVG) harvested from right lower leg. Five years previously he underwent skin grafting for extramammary Paget's disease of both inguinal areas and the perineal area. The postoperative course was uneventful and he was discharged 23 days after the CABG operation. Extramammary Paget's disease is localized in epidermis for years and there has been no report of direct invasion into vessels. Therefore, there appears to be no reason not to use an SVG if there is no luminal thrombus or occlusion.     

Monte Carlo analysis of the space-charge effect in AlGaAs/GaAsballistic collection transistors (BCTs) under high currentinjection

AlGaAs/GaAs ballistic collection transistors (BCTs) are investigated by self-consistent Monte Carlo simulation, focusing on the space-charge effect in the collector region. In addition to the conventional BCT collector structure (i-p⁺-n⁺), modified collector structures which have n^--p⁺-n ⁺ and p^--p⁺-n⁺ doping profiles are examined. By taking account of the fact that the collector delay time is composed of transit time and capacitance charging time, it is shown that the n^--p⁺-n⁺ collector structure is effective for the suppression of the base-widening effect (Kirk effect) compared to the i-p⁺-n⁺ or p^- -p⁺-n⁺ structure. Donors in the n^- layer compensate for the negative space charges produced by near-ballistic electrons. For a simulated BCT with an n^--p ⁺-n⁺ collector, the smaller collector capacitance charging time leads to improvement in current-gain cutoff frequency under high current injection     

WDM field trials of 43-Gb/s/channel transport system for optical transport network

This paper describes recent technical challenges and the progress toward the realization of the optical transport network (OTN) based on 43 Gb/s channel. We describe the new digital frame format "OTU3: Optical Channel Transport Unit 3," which is standardized in ITU-T for OTN, for the enhancement of the network management capability in the OTN based on 43-Gb/s channels. We first proposed 43-Gb/s/ch dense wavelength-division multiplexing (DWDM) dispersion-managed transmission system using carrier-suppressed return-to-zero (CS-RZ) format that has several attractive features; it advances the evolution of OTN into 100 GHz-spaced long-haul DWDM transport networks. The first wavelength-division multiplexing (WDM) field trials confirmed the superiority of CS-RZ format in the DWDM transmission performance for the first time. The first 1 Tb/s (25 /spl times/ 43 Gb/s) WDM field trial confirmed the excellent network management capability of OTU3 in future data-centric OTN using the newly developed 43-Gb/s OTN line-terminal prototype.     

Survey of pesticide residues in imported frozen vegetables and fruits (1989.4~2008.3)

A survey of pesticide residues in 595 imported frozen products on the Tokyo market from April 1989 to March 2008 was carried out. Forty three kinds of pesticides, including organophosphorus, organochlorine, carbamate, pyrethroid and others, were detected between levels of trace (below 0.01 ppm) and 4.6 ppm from 162 samples. Chlorpyrifos, cypermethrin and omethoate were frequently detected in green vegetables (komatsuna leaf and spinach), cypermethrin and methamidophos were detected in pods and seeds (green soybean and string pea), chlorpropham (CIPC) was detected in potato, and captan and carbaryl were detected in berries (blueberry, raspberry and strawberry). The hydrophilic pesticide methamidophos was detected in flesh of lychee. Residue levels of these pesticides were calculated as between less than 0.5% and 30% of their ADI values according to the daily intake of frozen products. Therefore, these frozen products should be safe when they were eaten in customary amounts.