Eddy current analysis of thin metal container in induction heating by line integral equations

In recent years, induction‐heating cookers have spread rapidly. It is desirable to commercialize flexible and disposable food containers that are suitable for induction heating. In order to develop a good‐quality food container for moderate heating, the eddy currents induced in a thin metal plate must be accurately analyzed. The integral equation method is widely used for solving induction‐heating problems. If the plate thickness approaches zero, the surface integral equations on the upper and lower plate surfaces tend to become the same and the equations become ill‐conditioned. In this paper, we first derive line integral equations from the boundary integral equations under the assumption that the electromagnetic fields in the metal are attenuated more rapidly than those along the metal surface. Next, to test the validity of the line integral equations, we solve for the eddy current induced in a thin metal container in induction heating and obtain the power density imparted to the container and the impedance characteristics of the heating coil. We then compare the computed results with those obtained by the FEM. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(2): 20–27, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20813     

Ultrafast Phase-Coherence in Normal State of Underdoped Bi2Sr2CaCu2O8 + δ Thin Film

A phase-sensitive time-domain terahertz-transmission spectroscopy was carried out on a c-axis oriented underdoped Bi₂Sr₂CaCu₂O_{8 +} thin film. We directly extracted the complex refractive index and conductivity at frequencies from 0.3 to 1.5 THz by numerically solving the observed complex transmittance without Kramers–Kronig analysis. The frequency-resolved real and imaginary part of the conductivity (1.0 THz < f) showed a measurable increase below the characteristic temperature of T* 210 K because of the appearance of partial phase-coherence with an ultrashort lifetime less than about 1 ps.     

Three-layer flow membrane system on a microchip for investigation of molecular transport

A stable three-layer flow system, water/organic solvent/water, has been successfully applied for the first time in a microchannel to get rapid transport through an organic liquid membrane. In the continuous laminar flow region, the analyte (methyl red) was rapidly extracted across the microchannel from the donor to the acceptor phase through the organic solvent phase (cyclohexane). Thermal lens microscopy was used to monitor the process. The thickness of the organic phase, sandwiched by the two aqueous phases, was approximately 64 microm, and it was considered as a thin liquid organic membrane. Permeability studies showed the effects of molecular diffusion, layer thickness, and organic solvent-water partition coefficient on the molecular transport. In the microchip, complete equilibration was achieved in several seconds, in contrast to a conventionally used apparatus, where it takes tens of minutes. The thickness of the organic and aqueous boundary layers was defined as equal to the microchannel dimensions, and the organic solvent-water partition coefficient was determined on a microchip using the liquid/liquid extraction system. Experimental data on molecular transport across the organic membrane were in agreement with the calculated permeability based on the three-compartment water/organic solvent/water model. This kind of experiment can be performed only in a microspace, and the system can be considered as a potential biological membrane for future in vitro study of drug transport.     

TEM Observations of the Initial Oxidation Stages of Nb-Ion-Implanted TiAl

Coupon specimens of TiAl were implanted with Nb ions at an acceleration voltage of 50 kV with a dose of 10²¹ ions m.^–2 They were then slightly oxidized during heating to 900 or 1200 K, or at 1200 K for 3.6 ksec (1 hr) in a flow of purified oxygen under atmospheric pressure. The implanted specimens and oxidized specimens were characterized and observed by AES, X-ray diffractometry, SEM, TEM, EDS, and EPMA. Implantation improves the oxidation resistance significantly by forming virtually -Al₂O₃ scales. The implanted layer is about 75 nm thick; the outer part of 30-nm thickness is -Ti phase and the rest of 45-nm thickness is amorphous. Heating to 900 K in O₂ results in partial crystallization of the amorphous layer to Ti₅Al₃O₂ (Z-phase) and to 1200 K results in oxide scales of 270 to 400 nm thickness consisting mainly of Al₂O₃. The fraction of Al₂O₃ in the scale increases toward the substrate. Oxidation at 1200 K for 3.6 ksec results in Al₂O₃-rich scales of about 400-nm thickness. The oxide grain size is very fine, about 80 nm in size, and becomes smaller toward the outer scale surface. This implies that implantation enhanced the nucleation of Al₂O₃ grains relative to the growth of TiO₂ grains. This finding and the formation of -Ti phase are thought to be responsible for the excellent oxidation resistance obtained.     

Analog Circuit Design Methodology in a Low Power RISC Microprocessor

There are various kinds of analog CMOS circuits in microprocessors. IOs, clock distribution circuits including PLL, memories are the main analog circuits. The circuit techniques to achieve low power dissipation combined with high performance in newest prototype chip in the Super H RISC engines are described. A TLB delay can be decreased by using a CAM with a differential amplifier to generate the match signal. The accelerator circuit also helps to speed up the TLB circuit, enabling single-cycle operation. A fabricated 96-mm² test chip with the super H architecture using 0.35-m four metal CMOS technology is capable of 167-MHz operation at 300 Dhrystone MIPS with 2.0-W power dissipation.     

Antimetastatic efficacy of orally administered ginsenoside Rb1 in dependence on intestinal bacterial hydrolyzing potential and significance of treatment with an active bacterial metabolite

BACKGROUND: Single small enhancing computerized tomographic (CT) lesions (SSECTLs) are common in children with focal seizures. These are considered to represent solitary cysticercus granulomas. Controversy exists regarding their treatment. OBJECTIVE: To evaluate the efficacy of albendazole in cases of focal seizures with SSECTLs. DESIGN: Randomized, placebo-controlled, double blind trial. SETTING: Pediatric service of Nehru Hospital, PGIMER, an urban tertiary care teaching hospital. SUBJECTS: 63 children between 2 and 12 years of age with focal seizures for <3 months and SSECTLs. INTERVENTION: All children were randomly assigned to receive either albendazole (15 mg/kg/ day) or placebo for 28 days. CT scan was done at 1 and 3 months after beginning treatment. Codes opened after 6 months of inclusion in the study showed that 31 had received albendazole and 32 had received placebo. All children were followed up for at least 15 months. RESULTS: Disappearance of lesions on CT scan was noted in 41% of albendazole vs. 16.2% of placebo patients after 1 month of follow-up (P < 0.05) and 64.5% of albendazole- vs. 37.5% of placebo-treated patients after 3 months of follow-up (P < 0.05). During the first 4 weeks of therapy seizure recurrence was seen in 9.7% of albendazole vs. 3.2% of placebo-treated children (odds ratio, 3.32; 95% confidence interval, 0.33 to 33.8). After 4 weeks seizure recurrence was seen in 31.3% of placebo-treated children vs. 12.9% of albendazole-treated children (odds ratio, 3.07; 95% confidence interval, 1.18 to 11.15). CONCLUSIONS: Albendazole therapy results in significantly faster and increased resolution of solitary cysticercus lesions (SSECTLs) and appears to reduce the risk of late seizure recurrences.     

A highly repetitive sequence isolated from genomic DNA of the medaka (Oryzias latipes)

In order to investigate the relationship between various temporomandibular joint (TMJ) pain levels and the detection of high signal intensity (joint effusion) on T2 weighted magnetic resonance imaging (MRI), 19 consecutive patients who complained of unilateral painful TMJ hypomobility (closed locking) were involved in this study. All patients were clinically examined in a routine manner, and all patients rated their pain levels by a visual analogue scale and eight pain questionnaire prior MRI study. T1 and T2 weighted MRI was taken in sagittal section at unilateral affected joint side. The presence or absence of a high signal intensity spot within the TMJ compartment were judged by three examiners. The high signal intensity was detected in 10 joints, but not in 9 joints. In between these two groups, the pain ratio was calculated and compared. The data showed that there was no significant statistical correlation between pain levels and the presence of high signals. This study disclosed that the MRI detection of high signal intensity in the closed locking TMJ did not directly relate to the presence of TMJ pain nor the increased pain level. These indicate the need of further larger studies.     

Three patients with insulin-treated diabetes and senile dementia of Alzheimer''s type

Caught between the successes of modern psychopharmacology, the requests of suffering patients for quick relief, and the shortsightedness of many third-party payers, psychodynamic psychotherapy might seem to be on the ropes. It is, however, thriving and providing crucial help to many individuals for whom medication and brief counseling are insufficient. Meanwhile, many more who could benefit from psychotherapy do not have an opportunity to do so. Although psychodynamic psychotherapy originated and developed within a medical framework, it has minimal visibility on the current medical scene, and many physicians have been provided with little meaningful information about it. This article is intended to give physicians a general idea of what psychodynamic psychotherapy is and how it works.     

Development of new dosimetry using extended DNA fibers

We applied fluorescent microscopy to monitor the damage of DNA upon exposure to gamma radiation. Our developed dosimetry demonstrated that the number of breaks in DNA is proportional to the dose of the irradiation but is not dependent on dose rate of the irradiation and the GC content of DNA.