Computed tomography reconstruction from two transmission measurements for iodine-marked cancer detection

The authors invented the transXend detector, which measures X-rays as electric currents, and then gives the energy distribution of the X-rays after an unfolding process. In a previous paper, it was shown that the material thickness distributions can be estimated with the transXend detector by using reference points plotted from the electric current ratios, such as the I ₂/I ₁ ? I ₃/I ₁ graph, where I_i denotes the electric current measured by the i-th segment of the transXend detector. In this paper, the tomographic images of iodine, aluminum, and the acrylic those surround the other two materials are reconstructed from their material thickness distributions, which are estimated from two X-ray incidence directions. The X-ray event ratios are also used to estimate the material thickness distributions.     

Multistage Stack with Multiple Pore Radii Applying the Temperature Gradient to a Thermoacoustic Engine

Conventional thermoacoustic engines have a stack pore radius that is almost constant in the axial direction. Hence, a thermoacoustic engine is expected to improve the energy conversion efficiency using a multistage stack with multiple pore radii. The stack comprises several bundles of numerous narrow tubes with specified pore radii. The optimum pore radius of the stack is determined by the oscillation frequency and the temperature in the stack. Consequently, the suitable pore radius changes in the axial direction, because the temperature gradient exists along the stack axis. Therefore, a multistage stack with multiple pore radii is introduced, which achieves a desired optimum pore radius everywhere in the stack. The energy conversion efficiency of the multistage stack, which was studied experimentally for a straight-tube type thermoacoustic engine, was compared with that of a conventional single-stage stack. In these experiments, the improvement of the energy conversion efficiency was confirmed. A numerical method with the transmittance matrix to include the effect of a multistage stack was used, and good agreement between experimental and numerical results was obtained. The results make a future possibilities for stack design intended to higher thermoacoustic engine efficiency expect.     

Thermally induced conformational and structural disordering in polyethylene crystal studied by near-infrared spectroscopy

Thermally induced structural and conformational changes in polyethylene (PE) samples were explored by using near-infrared (NIR) spectroscopy. The differences in the temperature-dependent structural disordering process among six PE samples were depicted by monitoring the intensities of NIR bands characteristic of orthorhombic crystalline phase. The temperature dependency of bands in the NIR region that have been considered to be due to orthorhombic crystalline lattice was compared to that of a band at 1378 cm⁻¹ due to the methyl symmetric bending mode. The intensity decrease of the band in the mid-infrared (MIR) region seems to sensitively reflect the overall disordering of orthorhombic crystalline structure. As a result of this study, the intensity decrease of the bands in the NIR spectral region was found to proceed at lower temperature than that of the band at 1378 cm⁻¹. This finding suggests the status of orthorhombic crystalline structure probed by the intensity of the band at 1378 cm⁻¹ and that by the “crystalline” bands in the NIR spectral region may not be identical. The NIR spectra were further analyzed by two-dimensional (2D) correlation spectroscopy to provide the in-depth analysis of NIR bands. The 2D correlation spectroscopy has detected the presence of two NIR bands at 4342 and 4290 cm⁻¹ due to orthorhombic crystalline phase and those at 5840 and 5640 cm⁻¹ due to amorphous phase. The hetero-spectral 2D correlation analysis was carried out between the NIR spectral region of 4365-4240 cm⁻¹ and the well-established MIR spectral region for CH₂ wagging deformation region of 1390-1240 cm⁻¹, where bands due to nonplanar conformer are detected. This approach allowed us to determine NIR bands, which behave in a way similar to MIR bands originating from conformational defect sequences that exist in the orthorhombic crystalline lattice, the amorphous domain and the chain fold regions. As a result of the hetero-spectral 2D NIR-MIR correlation spectroscopic studies on the development of conformational defect sequence in three types of PE samples, it was concluded that the intensity of a band at 4265 cm⁻¹ changes in the same manner as the MIR bands at 1368, 1353 and 1308 cm⁻¹ assignable to gtg, gg and gtg′ (kink) conformations. This finding means that the state of conformational disorder in PE crystal can be studied by monitoring the intensity of the NIR band at 4265 cm⁻¹. The use of NIR spectroscopy makes it possible to directly probe the degree in the formation of conformational defect sequences in thick PE products typically produced in industry, which cannot be studied by MIR spectroscopy. This paper thus provides in-depth fundamental understandings on NIR spectra of PE as well as the results of our study regarding structural and conformational changes in PE crystals probed by NIR spectroscopy.     

Metabolism of odd-numbered fatty acids and even-numbered fatty acids in mouse

Fatty acids are converted into energy via beta-oxidation. Although almost all natural occurring fatty acids are even-numbered, there are some odd-numbered fatty acids too. The details of the metabolism rate of odd-numbered fatty acids, however, are not clear. In the present study, we simultaneously administered a triacylglycerol containing four types of labeled even-numbered (palmitic acid and stearic acid) and odd-numbered (pentadecanoic acid and heptadecanoic acid) fatty acids to mice to compare the rates of their metabolism. The rates of metabolism were evaluated based on the accumulation of the labeled fatty acids in the small intestine epithelium, liver, and epididymal fat. Odd-numbered fatty acids accumulated mainly in the epididymal fat. In contrast, there was no accumulation of even-numbered fatty acids observed in the small intestine epithelium, liver, or epididymal fat. These results suggest that odd-numbered fatty acids might not be favorable substrates for beta-oxidation-related enzymes.     

Development of HVAC system simulation tool for life cycle energy management Part 1: Concept of life cycle energy management and outline of the developed simulation tool

The importance of LCEM (life cycle energy management) has been recognized from the view of life cycle energy savings for sustainable buildings. The purposes of this research are the proposal of an LCEM framework and development of prototype HVAC system simulation tools for LCEM. In this paper, the necessity of energy simulation tools for LCEM is discussed, and the outline and solution method of the simulation tool are shown.     

Layer-by-layer self-assembled mutilayer films of gold nanoparticles for surface-assisted laser desorption/ionization mass spectrometry

Layer-by-layer (LBL) self-assembled multilayer films of gold nanoparticles (AuNPs) on a silicon wafer were demonstrated to be promising substrates for surface-assisted laser desorption/ionization (SALDI) mass spectrometry (MS) of peptides and environmental pollutants for the first time. LBL multilayer films, (AuNPs/PAHC)n, consisting of alternating layers of ammonium citrate capped AuNPs and poly(allylamine hydrochloride) (PAHC) were prepared on a silicon surface. Silicon plates with aggregated AuNPs were more suitable than those with dispersed AuNPs for the SALDI-MS of peptides. The number of particle layers had a significant effect on the laser desorption/ionization of angiotensin I; the peak intensity of the peptide (molecular ion amount) increased with an increase in the number of layers of AuNPs. As a result, the (AuNPs/PAHC)5 multilayer films increased the sensitivity of the angiotensin I to subfemtomoles and raised the useful analyte mass range, thus making it possible to detect small proteins (a 12 kDa cytochrome c). The signal enhancement when using (AuNPs/PAHC)5 may be due to (i) the high absorption of the UV laser light at 337 nm by the AuNP layers, (ii) the low thermal conductivity due to the AuNPs being covered with a thin monolayer of PAHC, and (iii) the increase in the surface roughness (approximately 100 nm) with the number of AuNP layers. Thus, laser-induced rapid high heating of AuNPs for effective desorption/ionization of peptides is possible. In addition, it was found that (AuNPs/PAHC)5 could be used to extract environmental pollutants (pyrene and dimethyldistearylammonium chloride) from very dilute aqueous solutions with concentrations less than 10(-10) mg/mL, and the analytes trapped in the LBL film could be identified by introducing the film directly into the SALDI mass spectrometer without needing to elute the analytes out of the film.     

Elastodynamic Doppler effects

Summary The Doppler effect is discussed for flexure waves in beam and plate, three body waves (P, SV, SH) in an infinite solid, modal SH waves in a thick plate and a Rayleigh wave on the surface of a semi-infinite solid. The exact closed form solution for each elasto-dynamic problem is obtained and the simple equation for the Doppler frequency shift is derived for all waves. It is shown that the Doppler frequency shift takes place continuously in the 2D plane problems, and that the most sensible wave for the Doppler frequency shift is the non-dispersion wave, such as the body wave and Rayleigh wave. The flexural and modal waves, which have the dispersion nature, are less sensible. Dedicated to Professor Franz Ziegler on the occasion of his 70th birthday     

Analytical solution to compensate for thermal expansion change in photopolymer volume holograms using a tunable laser

For holographic data storage, it is necessary to adjust the wavelength and direction of the reading beam if the reading and recording temperature do not match. An analytical solution for this adjustment is derived using first-order approximations in a two-dimensional model. The optimum wavelength is a linear function of the temperature difference between recording and reading, and is independent of the direction of the reference beam. However, the optimum direction of incidence is not only a linear function of the temperature difference, but also depends on the direction of the reference beam. The retrieved image, which is produced by a diffracted beam, shrinks or expands slightly according to the temperature difference.     

Room temperature crystallization by RF plasma

The crystallization of amorphous thin films was achieved by radiofrequency (RF) plasma treatment. Although various amorphous films are crystallized after 2 min or so, the sample temperature is lower than 150 °C without compulsory cooling even when the films are treated for 1 h. This treatment works on amorphous films of various materials, independently of the film preparation method and substrate materials. Sol-gel-derived TiO₂ films were densified and simultaneously crystallized to anatase structure by the plasma treatment and the obtained films indicate almost the same photocatalytic activities as that of thermally crystallized TiO₂ films. Plasma-crystallized sputtered indium tin oxide (ITO) films have a bixbite structure and the resistivity reached to 1.6 × 10^− 4 Ω cm while the crystallization condition was not optimized. Amorphous silicon films with a small mount of crystallites were deposited by sputtering method and were crystallized by the plasma treatment.