Line-scan CCD camera calibration in 2D coordinate measurement

We present a line-scan camera calibration method in a plane not perpendicular to but parallel to the optical axis, without requiring the camera motion or a complex calibration pattern. A random 2D reference coordinate system in the calibration plane can be used, images of a rod perpendicular to the calibration plane at known coordinates are captured by the camera, the relation between the given coordinates and the rod image centroid position are analyzed based on a reduced pinhole model and image processing, and then the camera parameters and distortion factors are all estimated. These distortion factors build a sample relation only between the image position in theory and in practice, and they do not change with object position. Two wide-angle line-scan cameras that are used in a 2D-coordinate measurement system are calibrated by this method; the application results illustrate the effectiveness and convenience of this method.     

Molecular characterization of O-methyltransferases involved in isoquinoline alkaloid biosynthesis in Coptis japonica

O-Methyltransferases, which catalyze the production of small molecules in plants, play a crucial role in determining biosynthetic pathways in secondary metabolism because of their strict substrate specificity. Using three O-methyltransferase (OMT) cDNAs that are involved in berberine biosynthesis, we investigated the structure that was essential for this substrate specificity and the possibility of creating a chimeric enzyme with novel substrate specificity. Since each OMT has a relatively well-conserved C-terminal putative S-adenosyl-L-methionine-binding domain, we first exchanged the N-terminal halves of different OMTs. Among the 6 combinations that we tested for creating chimeric OMTs, 5 constructs produced detectable amounts of recombinant proteins, and only one of these with an N-terminal half of 6-OMT and a C-terminal half of 4′-OMT (64′-OMT) showed methylation activity with isoquinoline alkaloids as a substrate. Further enzymological analysis of 64′-OMT reaction product indicated that 64′-OMT retained the regio-specificity of 6-OMT. Further examination of the N-terminal region of 64′-OMT showed that about 90 amino acid residues in the N-terminal half were critical for reaction specificity. The creation of OMTs with novel reactivity is discussed.     

Measuring the fundamental frequency and the harmonic properties of the wingbeat of a large number of mosquitoes in flight using 2D optoacoustic sensors

Mosquito flight tones occur during locomotion and courtship and are mostly analyzed using microphones. The use of microphones is impractical for analyzing the wingbeat of non-tethered insects especially if one is interested in studying the frequency content of wingbeats of a large number of insects. In this study we present a practical setting based on a novel 2D optical sensor that we embed inside insectary cages to record the wingbeats of three mosquito species belonging to three different genera, namely Culex pipiens molestus, Anopheles gambiae and Aedes albopictus. We show that this setting allows to automatically create distributions of parameters related to wingbeat frequency and harmonic properties derived from many non-tethered wingbeats and therefore characterize the wingbeat properties of a whole species with increased confidence. Implications for potential applications are discussed.     

Influence of the substrate position angle on the adhesion of ZnO thin films deposited on polyimide foil substrates

ZnO thin films, as polymer protection layers against ultraviolet radiation, were deposited on polyimide foil substrates using cathodic vacuum arc deposition technique. X-ray diffraction results showed that all the samples had (0 0 2) preferred orientation and the FWHM decreased as the position angle decreased. A fragmentation test was employed to investigate the influence of substrate position angle on the adhesion of ZnO thin films. It was found that the intrinsic adhesion between the ZnO film and the polyimide substrate is about 60 MPa at the substrate position angle of 0°. When the position angle increases to ±60°, the value of intrinsic adhesion decreases to about 30 MPa.     

Intensity and phase distribution in deep Fresnel diffraction region generated by multi-pinhole aperture

The Kirchhoff diffraction theory is applied to the multi-pinhole aperture diffraction screens, and the intensity, the zero-contour of the real and imaginary parts of complex amplitude and the phase distribution in deep Fresnel diffraction region are simulated. It is found that the number of bright spots, the zero-contours of the real and imaginary parts of complex amplitude and the phase singularities are all related to number of pinholes in diffraction screens. The brightness of bright spots in center of each pattern would become larger with increasing number of pinholes. In addition, there are many lines, on which the intensity value is close to 0.     

Investigation of diode parameters using I-V and C-V characteristics of In/SiO2/p-Si (MIS) Schottky diodes

A study on interface states density distribution and characteristic parameters of the In/SiO₂/p-Si (MIS) capacitor has been made. The thickness of the SiO₂ film obtained from the measurement of the corrected capacitance in the strong accumulation region for MIS Schottky diodes was 220 Å. The diode parameters from the forward bias I-V characteristics such as ideality factor, series resistance and barrier heights were found to be 1.75, 106-112 Ω and 0.592 eV, respectively. The energy distribution of the interface state density D_it was determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height. The interface state density obtained using the I-V characteristics had an exponential growth, with bias towards the top of the valance band, from 9.44×10¹³ eV⁻¹ cm⁻² in 0.329-E_v eV to 1.11×10¹³ eV⁻¹ cm⁻² in 0.527-E_v eV at room temperature. Furthermore, the values of interface state density D_it obtained by the Hill-Coleman method from the C-V characteristics range from 52.9×10¹³ to 1.11×10¹³ eV⁻¹ cm⁻² at a frequency range of 30kHz-1 MHz. These values of D_it and R_s were responsible for the non-ideal behaviour of I-V and C-V characteristics.     

Structural and Torsional Properties of o-Cresol and o-Cresol-OD as Obtained from Microwave Spectroscopy and ab Initio Calculations

The microwave spectra of o-cresol and of o-cresol-OD were assigned using molecular beam Fourier transform microwave (MB-FTMW) spectrometers in the frequency range of 3-40 GHz. Two conformers of o-cresol were measured where the hydroxy group is syn with respect to the methyl group in one case and anti in the other. The transitions of both conformers were split due to internal rotation of the methyl group. For syn-o-cresol we found the rotational constants A=3249.45242(18) MHz, B=2202.02546(18) MHz, C=1323.66277(16) MHz, and the barrier to internal rotation of the methyl group V₃=7.912(46) kJ mol⁻¹. In the case of anti-o-cresol A=3273.80084(18) MHz, B=2196.26747(18) MHz, C=1325.36424(22) MHz, and V₃=4.4256(14) kJ mol⁻¹ was obtained. Moreover we were able to determine the quartic centrifugal distortion constants, the angle between the internal rotor axes, and the inertial a axes, and, for the deuterated species, additionally the deuterium nuclear quadrupole coupling constants.     

Phase-oriented surface segregation in an aluminium casting alloy

There have been many reports of the surface segregation of minor elements, especially Mg, into surface layers and oxide films on the surface of Al alloys. LM6 casting alloy (Al-12%Si) represents a challenging system to examine such segregation as the alloy features a particularly inhomogeneous phase structure. The very low but mobile Mg content (approximately 0.001 wt.%), and the surface segregation of modifiers such as Na, mean the surface composition responds in a complex manner to thermal treatment conditions. X-ray photoelectron spectroscopy (XPS) has been used to determine the distribution of these elements within the oxide film. Further investigation by dynamic secondary ion mass spectrometry (DSIMS) confirmed a strong alignment of segregated Na and Mg into distinct phases of the structure.     

Physiological characteristics of tropical rain forest tree species: a basis for the development of silvicultural technology

The physiological characteristics of the dominant tree species in the tropical rain forest mainly belonging to dipterocarps as well as the environmental conditions especially for the light in the forest were studied to establish the silvicultural system for the forest regeneration in the tropical South Asia. The flowering patterns of the dipterocarp trees are usually irregular and unpredictable, which make difficult to collect sufficient seeds for raising the seedlings. The field survey revealed the diverged features of the so-called gregarious or simultaneous flowering of various species of this group. Appropriate conditions and methods for the storage of the seeds were established according to the detailed analyses of the morphological and physiological characteristics of the seeds such as the low temperature tolerance and the moisture contents. The intensity and spectra of the light in the forest primarily determine the growth and the morphological development of the seedlings under the canopy. Based on the measurements of the diffused light at the sites in the tropical forest in the varying sunlight, the parameters such as "the steady state of the diffuse light" and "the turning point" were defined, which were useful to evaluate the light conditions in the forest. To improve the survival of the transplanted seedlings, a planting method of "the bare-root seedlings", the seedlings easy to be handled by removal of all leaves, soil and pots, was developed. Its marked efficiency was proved with various dipterocarps and other tropical trees by the field trial in the practical scale. Tolerance of the various species to the extreme environmental conditions such as fires, acid soils and drought were examined by the experiments and the field survey, which revealed marked adaptability of Shorea roxburghii as a potential species for regeneration of the tropical forests.     

Vibrio parahaemolyticus, enterotoxigenic Escherichia coli, enterohemorrhagic Escherichia coli and Vibrio cholerae

This review highlighted the following: (i) pathogenic mechanism of the thermostable direct hemolysin produced by Vibrio parahaemolyticus, especially on its cardiotoxicity, (ii) heat-labile and heat-stable enterotoxins produced by enterotoxigenic Escherichia coli, especially structure-activity relationship of heat-stable enterotoxin, (iii) RNA N-glycosidase activity of Vero toxins (VT1 and VT2) produced by enterohemorrhagic Escherichia coli O157:H7, (iv) discovery of Vibrio cholerae O139, (v) isolation of new variant of Vibrio cholerae O1 El Tor that carries classical ctxB, and production of high concentration of cholera toxin by these strains, and (vi) conversion of viable but nonculturable (VBNC) Vibrio cholerae to culturable state by co-culture with eukaryotic cells.     

Exchange versus intercalation of n-dodecanethiol monolayers on copper in the presence of n-dodecaneselenol and vice versa

n-Dodecanethiol (RSH) and n-dodecaneselenol (RSeH) molecules have been self-assembled on electrochemically reduced copper sheets. To assess the stability of the resulting monolayers, immersion, during different times varying from minutes to hours, of the modified copper in a solution which contains the competitor molecule has been performed. PM-IRRAS shows a good organisation for all monolayers without any divergence. Based on XPS analysis, we have proved an intercalation process of RSeH molecules followed by adsorption on the free sites of copper modified with the RSH and in similar way the insertion and adsorption of RSH molecules in the RSeH modified copper. The only difference between the two directions is in the kinetics which seems to be faster for thiol compared to selenol.     

Cavity ring down absorption spectroscopy of the BΣ-XΣ transition of YO

The absorption spectrum of the (2, 0) and (2, 1) bands of the B²Σ⁺-X²Σ⁺ transition of YO between 442 and 478 nm were recorded using laser vaporization/reaction with free-jet expansion and cavity ring down laser absorption spectroscopy. Local rotational perturbations have been found for both spin components of the v = 2 level of the B²Σ⁺ state. The observed perturbations could be ascribed to a degenerate perturbing state interacting with the B²Σ⁺ state. Least-squares fit of the observed upper state term values yielded molecular constants for the v = 2 level of the B²Σ⁺ state and the perturbing ²Π state. Earlier ab initio calculations [J. Chem. Phys. 89 (1988) 2160] indicated that the C²Π state is nearby, it is plausible that the C²Π state is the perturbing state.     

Monitoring of pathogen carrying air-borne tea dust particles by light scattering

In order to investigate whether tea (Camellia sinensis (L.) Kuntze) dust particles could be a possible carrier of the pathogen contaminated Mycobacterium a biotechnical procedure was used, and to verify the possibility of monitoring this dust, a laser based light scattering setup was designed and fabricated. Experiments were carried out using the strain Mycobacterium smegmatis mc² 155 as a model organism to study the effect on tea dust particles. Light scattering investigations on both M. smegmatis contaminated and uncontaminated tea dust particle samples were carried out as a function of scattering angle at 543.5, 594.5 and 632.5 nm wavelengths. The results have shown that the behavior of tea dust samples both with and without Mycobacterium varies significantly for all the three different incident laser wavelengths.     

Electric dipole moments as probes of new physics

We review several aspects of flavour-diagonal CP-violation, focussing on the role played by the electric dipole moments (EDMs) of leptons, nucleons, atoms, and molecules, which constitute the source of several stringent constraints on new CP-violating physics. We dwell specifically on the calculational aspects of applying the hadronic EDM constraints, reviewing in detail the application of QCD sum-rules to the calculation of nucleon EDMs and CP-odd pion-nucleon couplings. We also consider the current status of EDMs in the Standard Model, and on the ensuing constraints on the underlying sources of CP-violation in physics beyond the Standard Model, focussing on weak-scale supersymmetry.     

Searching for new conditions for fermion N-representability

New elements of the dual cone of the set of fermion N-representable 2-density operators are proposed. So far, the explicit form of the corresponding necessary conditions for N-representability is obtained for N = 3. In this case the new condition is stronger than the known B- and C-conditions for 3-representability. The results provide evidence that in the spectral decomposition of the N-representable 2-density operator there exists an intrinsic relation between the eigenvalue and the corresponding eigenfunction.     

Luminescence studies of o-hydroxy p-amino and p-dimethylamino methyl benzoate

Steady-state and time-resolved spectroscopic studies of two bisubstituted derivatives of methyl benzoate dissolved in methylcyclohexane (McH), tetrahydrofuran (THF), and ethanol (EtOH) have been performed at 293 and 77 K. The compounds under study are capable of showing multimode fluorescence emission at room temperature. The kind of emission, i.e., locally excited state emission Fl(LE), proton-transfer emission Fl(PT) and twisted intramolecular charge-transfer emission Fl(CT) dependent on the solvent. Low temperature measurements show that for those molecules a phosphorescence enhancement via a proton-transfer tunneling is observed. For the molecules under study compositeness of the emission process is explained on an energy scheme, which is based on experimentally determined and theoretically calculated data. Stated dynamic Stokes shift and phosphorescence red-edge effect indicates that both molecules form an inhomogeneous emitting system in solvents used. The experiments are supported with quantum chemical semiempirical calculations.     

Microbial inactivation in cloudy apple juice by multi-frequency Dynashock power ultrasound

The study determined the efficacy of Dynashock wave power ultrasound as an alternative processing technique for apple juice against a number of pathogenic and spoilage microorganisms. The effects of several implicit, intrinsic and extrinsic properties on the Dynashock wave inactivation of the microorganisms were also investigated. Results showed that acid adaptation increased the resistance of Escherichia coli O157:H7 and Salmonella spp. but decreased that of Listeria monocytogenes. Spoilage yeast mixed inoculum composed of Debaryomyces hansenii, Torulaspora delbrueckii, Clavispora lusitaniae, Pichia fermentans and Saccharomyces cerevisiae was found to be more resistant than any of the adapted or non-adapted pathogens. Among the individual, acid-adapted E. coli O157:H7, the MN-28 isolate was found most resistant; while three other individual isolates had greater resistance than the composited E. coli inoculum. Increased in pulp content decreased the efficacy of Dynashock waves, but co-treatment with ultraviolet-C rays significantly enhanced inactivation in the cloudy apple juice. The results demonstrated the potential of Dynashock wave technology, together with other antimicrobial hurdles as alternative juice processing technique/s.