[en] An analytical solution of flexural vibration responses on taped atomic force microscope (AFM) cantilevers has been derived and a closed-form expression obtained. The results coincide with previously published analytical solutions for two special cases that are used with the rectangular AFM cantilever. The analytical solution derived in this Letter, can easily assist in obtaining the resonance frequency at arbitrary dimensions and tip radii. It is useful for the design of the AFM cantilever, including the solid or hollow circular and rectangular cross-section, and can serve to evaluate the accuracy of the approximate or numerical solutions for the AFM cantilever with a complicated cross-section. Furthermore, the solution was confirmed and can also be applied to obtain the resonant frequency of a conical cantilever with an elongated tip which is used for imaging the deep trenches and complex structures

[en] High quality fluorine-doped tin oxide (SnO₂:F) films on glass substrates were been prepared using chemical vapor deposition (CVD) method. The electrical properties, surface morphologies, structural properties and optical properties of the films were studied by varying the freon flow rates. The structure was analyzed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to study the morphology. Energy-dispersive spectroscopy (EDS) was conducted to understand the surface fluorine composition of the film. The results showed that crystalline structure of the film had a have cassiterite-like diffraction patterns with a preferred orientation of (1 1 0). Surface roughness was evaluated by atomic force microscopy, characterized by root mean square (RMS) and average value (Ra). The SnO₂:F resistivity decreased as the freon flow rate increased. The films had a uniform thickness and a transmittance of 80-90% within the visible region of the spectrum

[en] We study the generation of neutrino masses in the SU(3)_W electroweak unified theory in M₄xS₁/(Z₂xZ'₂) spacetime. By appropriate orbifolding, the bulk symmetry SU(3)_W is broken into SU(2)_LxU(1)_Y at one of the fixed points, where the quarks reside. The leptons form SU(3)_W triplets, localized at the other symmetric fixed point. The fermion masses arise from the bulk Higgs sector containing a triplet and an anti-sextet. We construct neutrino Majorana masses via 1-loop quantum corrections by adding a parity odd bulk triplet scalar. No right-handed neutrino is needed. The neutrino mass matrix is of the inverted hierarchy type. We show that the model can easily accommodate the bi-large mixing angle solution favored by the recent neutrino experiments without much fine tuning of parameters. The constraints from μ→3e transition and neutrinoless double β decays are discussed

[en] Purpose/Objective: The purpose of this study was to elucidate the changes in tumor blood flow, tumor pO₂ and the radiation response of the tumors caused by mild temperature hyperthermia (MTH). Materials And Methods: Experiments were carried out using the R3230 Adenocarcinoma (R3230 AC tumor), grown subcutaneously in the right hind limbs of male Fischer rats. Tumors were heated once at 40.5 deg.to 43.5 deg.C for 30 or 60 min, or twice at a 24 hr interval. Tumor blood flow and tumor pO₂ were measured immediately after the hyperthermic treatments or after 24 hr using a radioactive microsphere method and by an Eppendorf pO₂ Histograph, respectively. The influence of MTH on the effect of X-irradiation (250 kVp) on this tumor was investigated with tumor growth delay and the in vivo/in vitro excision assay for surviving tumor cell fraction. Results: Tumor blood flow and pO₂ increased upon heating for 30 min at 40.5 deg.C to 43.5 deg.C, but following 60 min heating, the pO₂ was similar to that in control tumors. The tumor blood flow increased about 1.4-fold and the tumor pO₂ increased more than 3 times after 30 min heating at 42.5 deg.C. Therefore, the in vivo/in vitro assay and the growth delay were carried out following treatment with 42.5 deg.C for 30 min. As shown in Table 1, the reduction in surviving fraction by MTH before radiation was markedly greater than that by MTH after radiation. Table 1 also shows that MTH alone caused no growth delay compared to control and while heat after radiation increased the growth delay by 2 days, MTH before radiation increased the growth delay by 5 days compared to radiation alone. Conclusion: The results indicate that MTH is effective in increasing tumor blood flow and oxygenation and that MTH for 30 min at 42.5 deg.C, applied before radiation, significantly improves the radiation response of R3230 AC tumors

[en] A cylindrical gamma camera is designed for brain SPECT imaging based on multiple one-dimensional position-sensitive bar detectors. The current design involves 84 bar detectors, with the bar detectors oriented in the longitudinal direction of the cylinder. An array of photomultiplier tubes (PMTs) is coupled directly to the outside of the detector cylinder for two-dimensional position sensing. In the transverse direction, each PMT is shared by three adjacent bar detectors. Since the bar detector in which a scintillation occurred can be identified by the unique combination of PMTs, only a one-dimensional position sensing scheme along the bar detector is needed

[en] Purpose: To determine the most effective combination of carbogen breathing with mild temperature hyperthermia (MTH) to increase the oxygenation and radiation response in murine tumors. Methods and Materials: MTH at 41.5 deg. C for 60 min was applied by immersion of the tumor in a precisely controlled water bath. The tumor pO₂ was measured with a polarographic microelectrode. The radiation response of the tumor was determined using the in vivo/in vitro assay for surviving tumor cells. Results: In the FSaII fibrosarcoma the median pO₂increased from a control value of 6.5 ± 0.5 mm Hg to 16.6 ± 1.1 mm Hg immediately after MTH and was 10.9 ± 1.3 mm Hg 24 h later. Carbogen breathing for 5 min increased the FSaII pO₂ to 19.9 ± 2.1 mm Hg. Carbogen breathing for 5 min beginning immediately after MTH increased the median pO₂ more than 5 times to 35.4 ± 3.8 mm Hg. This combined treatment also substantially increased the response of the tumors to a radiation exposure of 20 Gy. In another tumor model, the SCK mammary carcinoma, MTH treatment increased the median pO₂ from the control level of 4.4 ± 0.2 mm Hg to 12.6 ± 1.2 mm Hg, and it returned to 4.3 ± 0.3 mm Hg 24 h later. Carbogen breathing for 5 min increased the SCK tumor pO₂ to 17.1 ± 1.4 mm Hg. The median SCK pO₂ was increased about 7 times to 31.2 ± 4.2 mm Hg when MTH was followed immediately with carbogen breathing for 5 min. The radiation response was also markedly increased by this combination. When the animals breathed carbogen for 15 or 30 min, the pO₂ and radiosensitivity in both tumor types either remained the same or was lower than that after 5 min of breathing. In addition, both FSaII and SCK tumors were radiosensitized 24 h after MTH treatment alone or with 5 min of carbogen breathing. Conclusions: A shorter carbogen breathing time immediately after MTH causes the most tumor radiosensitization. The results of this study also demonstrate that MTH increases radiosensitivity with and without carbogen breathing up to 24 h after the mild hyperthermia treatment

[en] The effect of interactive damping on the sensitivity of flexural and torsional vibration modes of an atomic force microscope (AFM) rectangular cantilever has been analyzed and a closed-form expression is derived. When the normal contact stiffness (β_n) is low, the following effects were observed: firstly the flexural sensitivities of the first three modes apparently fall when the normal damping effect is taken into account. The smaller the value of β_n, the more the damping effect is. Secondly, the sensitivity of flexural mode 1 clearly decreases with increasing normal interactive damping coefficient. The higher damping coefficient can influence the larger range of β_n value. When the lateral contact stiffness (β_t) is low, the effects of the lateral damping on the torsional modal sensitivity are similar. The smaller the value of β_t, the more the lateral damping effect is

[en] The application of seven-pinhole tomography has been adopted predominantly to thallium-201 myocardial imaging. In view of the stationary nature of the collimator, with all views accumulating simultaneously, seven-pinhole tomography can be adapted to dynamic cardiac imaging, namely, multigated blood-pool imaging. Existing reconstruction software was modified to process the gated blood-pool data. The performance parameters of the seven-pinhole system were investigated at Tc-99m energy. This work provides an additional understanding of the seven-pinhole system as well as its potential application to abnormalities of ventricular wall motion or the quantitation of other cardiac parameters from reconstructed data

[en] A quadrant slant-hole (QSH) collimator was constructed for myocardial perfusion tomography on a 15-inch large-field gamma camera. This system optimizes the crystal area for multiple-view photon detection while at the same time offering excellent tomographic performance. In addition to the advantages associated with parallel slant-hole collimation, this system's four orthogonal views provide a solution to the problem of patient positioning, namely, proper alignment of the long axis of the left ventricle to the camera. Rapid data acquisition, together with fast reconstruction, make the QSH system a practical approach to tomographic imaging of the myocardium

[en] The Supper System Code of KAERI (SSC-K) is a best-estimate system code for analyzing a variety of off-normal or accidents in the heat transport system of a pool type LMR design. It is being developed at Korea Atomic Energy Research Inititution (KAERI) on the basis of SSC-L, originally developed at BNL to analyze loop-type LMR transients. SSC-K can handle both designs of loop and pool type LMRs. SSC-K contains detailed mechanistic models of transient thermal, hydraulic, neutronic, and mechanical phenomena to describe the response of the reactor core, coolant, fuel elements, and structures to accident conditions. This report provides an overview of recent model developmentsvfor the SSC-K computer code, focusing on phenomenological model descriptions for new thermal, hydraulic, neutronic, and mechnaical modules. A comprehensive description of the models for pool-type reactor is given in Chapters 2 and 3; the steady-state plant characterization, prior to the initiation of transient is described in Chapter 2 and their transient counterparts are discussed in Chapter 3. In Chapter 4, a discussion on the intermediate heat exchanger (IHX) is presented. The IHX model of SSC-K is similar to that used in the SSC-L, except for some changes required for the pool-type configuration of reactor vessel. In Chapter 5, an electromagnetic (EM) pump is modeled as a component. There are two pump choices available in SSC-K; a centrifugal pump which was originally imbedded into the SSC-L, and an EM pump which was introduced for the KALIMER design. In Chapter 6, a model of passive safety decay heat removal system(PSDRS) is discussed, which removes decay heat through the reactor and containment vessel walls to the ambient air heat sink. In Chapter 7, models for various reactivity feedback effects are discussed. Reactivity effects of importance in fast reactor include the Doppler effect, effects of sodium density changes, effects of dimensional changes in core geometry. Finally in Chapter 8, constitutive laws and correlations required to execute the SSC-K are described. It is noted that the user's manual will be revised later with the further development of SSC-K