Simple method for improving the sampling in profile measurements by use of the Ronchi test

We present a simple method for increasing the number of data points obtained during performance of profilometric measurements with the Ronchi test. The method is based on multiple ronchigram acquisitions that are superimposed after a few very simple data-processing operations. The measurement method, experimental setup, and data processing are described in detail from the ronchigram to the measured profile, and experimental results for a concave surface of an spherical ophthalmic lens are provided. The radius of curvature values measured for that surface are compared with the ones obtained with a high-precision radioscope, showing very good agreement and demonstrating the capability of the technique to measure topographic profiles of reflective samples.     

Multifrequency Doppler: improving the quality of spectralestimation by making full use of the information present in thebackscattered RF echoes

This paper investigates the application of the two-dimensional Fourier transform in the context of pulsed wave Doppler. It is shown that two-dimensional spectral analysis of the backscattered RF echoes provides individual Doppler spectra corresponding to the whole range of transmitted frequencies which can be combined, after proper scaling, to form a “multifrequency” spectral estimate. Theoretical expressions are derived for the signal-to-noise ratio of the multifrequency sonogram which predict substantial gains over the conventional (one-dimensional) approach for Doppler processing. These predictions are verified by means of extensive simulations, which also provide an insight into the effect of electronic noise     

On the method of finite spheres in applications: towards the use with ADINA and in a surgical simulator

 In this paper we report some recent advances regarding applications using the method of finite spheres; a truly meshfree numerical technique developed for the solution of boundary value problems on geometrically complex domains. First, we present the development of a preprocessor for the generation of nodal points on two-dimensional computational domains. Then, the development of a specialized version of the method of finite spheres using point collocation and moving least squares approximation functions and singular weight functions is reported for rapid computations in virtual environments involving multi-sensory (visual and touch) interactions. Dedicated to the memory of Prof. Mike Crisfield, for his cheerfulness and cooperation as a colleague and friend over many years.     

An approach to the design of production systems giving a high quality of working life and production efficiency

People's social and economic desires are gradually becoming more versatile and fragmented. Industries should be developed in such a way that these versatile human desires are brought into harmony with the organizational needs of production engineering.

In this paper we report on the state of the desires and motivations of Japanese workers in 1974 and 1977 resulting from investigation and analysis using application methods of multivariate analysis and give an example of new production systems in which workers are in harmony with organizational needs.     

Determination of quality and adulteration of tequila through the use of surface plasmon resonance

In this work, the surface plasmon resonance (SPR) technique is used to determine the quality or adulteration of tequila beverages. Graphic analyses of the position and width of the SPR curve are related to the complex refractive index of the sample, showing differentiated regions where one can easily and unambiguously identify white, aged, or extra-aged tequilas, and even adulterated or low quality tequilas. The curves generated by aged and extra-aged tequilas, with respect to those obtained from white tequilas, are wider, while the resonant peak shifts towards larger angles. This behavior should be attributed to the aging process. The resonance curve is generated in 20?s, minimizing the variations of the SPR curve parameters due to temperature fluctuations.     

Reducing the use of nullable types through non-null by default and monotonic non-null

With Java 5 annotations, the authors note a marked increase in tools that can statically detect potential null dereferences. To be effective, such tools require that developers annotate declarations with nullity modifiers and have annotated API libraries. Unfortunately, in the experience of the authors, specifying moderately large code bases, the use of non-null annotations is more labour intensive than it should be. Motivated by this experience, the authors conducted an empirical study of five open source projects totalling 700K lines-of-code, which confirms that, on average, 75% of reference declarations are meant to be non-null, by design. Guided by these results, the authors propose the adoption of non-null-by-default semantics. This new default has advantages of better matching general practice, lightening developer annotation burden and being safer. The authors also describe the Eclipse Java Modelling Language (JML) Java Development Tooling (JDT), a tool supporting the new semantics, including the ability to read the extensive API library specifications written in the JML. Issues of backwards compatibility are addressed. In a second phase of the empirical study, the authors analysed the uses of null and noted that over half of the nullable field references are only assigned non-null values. For this category of reference, the authors introduce the concept of monotonic non-null type and illustrate the benefits of its use.     

Determination of compressibility and virial co-efficients by the burnett method

An analytical method of determining the compressibility and virial coefficients from the experimental results by the Burnett method is described.     

A step forward towards the development of stable freeze-dried liposomes: a quality by design approach (QbD)

This study highlights the advantages of using a Quality by Design (QbD) approach in order to gain a more comprehensive understanding of the freeze-drying process of pravastatin-loaded long-circulating liposomes (LCL-PRAV). Within the QbD paradigm, the present study aimed to establish the design space for the optimization of freeze-dried LCL-PRAV by means of Design of Experiment (DOE). The encapsulated solute retention (ESR), the average particle size, and zeta potential after freeze-drying, the residual moisture content, the macroscopic cake appearance, the glass transition temperature (T_g) of the freeze-dried cake, and the primary drying time were defined as critical quality attributes (CQAs) for the freeze-dried final product. Further on, the influence of lyoprotectant type, freezing rate, shelf temperature during primary drying, and the presence of an annealing step on the CQAs was investigated through a 21-run D-optimal experimental design. Three-dimensional response surfaces were generated to complete the statistical analysis and for a better understanding of the influence of variables and their interactions on the responses. The developed model was then used to build the design space for the freeze-dried liposomes, within which the product quality was assured and the process variability was minimized.     

Volume holographic grating couplers: rigorous analysis by use of the finite-difference frequency-domain method

Two configurations of volume holographic grating couplers are rigorously analyzed by means of the finite-difference frequency-domain method (FDFD) for both TE and TM polarizations and for 0- and 45-deg output coupling. The two configurations depend on the position of the grating coupler, which can be placed either in the film or in the cover waveguide region. The FDFD results are compared with those obtained by the rigorous coupled-wave analysis in conjunction with the leaky-mode approach (RCWA-LM). Because the FDFD method is a rigorous solution of the Maxwell equations, it simulates the VHGC configuration and takes into account the waveguide-coupler discontinuity effects as well as the multimode excitation and interference effects, all of which are neglected by the traditional RCWA-LM.     

Fringe-pattern analysis with high accuracy by use of the fourier-transform method: theory and experimental tests

The Fourier-transform method is often used to evaluate fringe patterns. The fundamental limitations of its accuracy are examined. Special filter functions leading to an improved spatial definition and a fringe-extrapolation algorithm that reduces the errors at the border of the pattern are presented. Numerical simulations predict an accuracy of the phase evaluation of less than 6 mrad under certain conditions. We investigated the reproducibility by experiments with a Michelson interferometer. Deviations of approximately 10 mrad were found. In a second test a Ronchi ruling was imaged, and a well-defined phase change was introduced. We deduce an accuracy of less than 5 mrad rms.     

Characterization of vegetable oils by electrospray ionization mass spectrometry fingerprinting: classification, quality, adulteration, and aging

An improved approach for the direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis of vegetable oils is described. The more polar components of the oils, including the fatty acids, are simply extracted with methanol/water (1:1) solution and analyzed by direct infusion ESI-MS in both the negative and positive ion modes. This fingerprinting analysis was applied to genuine samples of olive, soybean, corn, canola, sunflower, and cottonseed oil, to admixtures of these oils, and samples of aged soybean oil. ESI-MS fingerprints in the positive ion mode of the extracts divide the oils into well-defined groups, as confirmed by principal component analysis, whereas ESI-MS fingerprints in the negative ion mode clearly differentiate olive oil from the five other refined oils. The method is also shown to detect aging and adulteration of vegetable oils.     

Determination of the thermal conductivity and diffusivity of thin fibres by the composite method

It is suggested that the thermal conductivity of very fine fibres can be evaluated indirectly with the aid of composite theory using the experimental data for the heat transport properties of an appropriate composite which contains the fibres. The feasibility of this approach was investigated by determining the thermal conductivity and diffusivity of fibres of amorphous silicon carbide from 25° C to 1000° C contained within a lithium aluminosilicate glass-ceramic using the laser-flash technique for measurement of the thermal diffusivity of the composite. Due to the amorphous nature of the fibres, values for their thermal conductivity and diffusivity were found to be far less than the corresponding data for crystalline silicon carbide. The positive temperature dependence of the thermal conductivity, coupled with the independent observation of an increase in thermal conductivity with specimen thickness, suggests that radiative heat transfer makes a significant contribution to the total heat transferred. A number of advantages and limitations of the composite method for the evaluation of thermal transport properties of fibres are discussed.     

A new approach towards the growth of cadmium sulphide thin film by CBD method and its characterization

Cadmium sulphide thin films were deposited by the chemical bath deposition method using tartaric acid as a complexing agent and annealed at different temperature in nitrogen atmosphere and characterized. The crystallographic structure and the crystallite size were studied by the X-ray diffraction (XRD) pattern. Transmittance of the deposited film is significantly higher in the visible region. The optical band-gap of deposited film is 2.4 eV and it decreases with increase in annealing temperature. Temperature dependence of resistivity confirmed the semiconducting behaviour of the film. Scanning electron micrographs (SEM) showed the presence of grain particles of size < 1 μm. X-ray photoelectron spectroscopy (XPS) studies supported the composition of cadmium sulphide thin film determined by EMPA and also indicated the presence of carbon and oxygen as impurity in the film.     

Fibromyalgia: its prevalence and impact on the quality of life on a hemodialyzed population

Fibromyalgia syndrome (FMS) is characterized by widespread musculoskeletal pain. It has negative effects on quality of life and has been poorly investigated in specific populations. Our aim was to determine the prevalence of FMS in Brazilian hemodialysis (HD) patients and to investigate its effects on the quality of life. We investigated 311 patients on HD who were submitted to physical examination towards the classification of FMS. All subjects from FMS and control groups were submitted to laboratorial investigation and completed questionnaires of quality of life. The prevalence of FMS was 3.9%, which was close to that of the general population. Most patients were females and from non-Caucasian races. No difference between FMS and control groups was observed regarding race, dialysis adequacy, nutritional status and level of schooling. Ionized calcium was higher in the FMS group than in the control group. There was no association between FMS and secondary hyperparathyroidism. On the other hand, FMS was associated with worse quality of life, depression and anxiety. In conclusion, the prevalence of FMS in HD patients was similar to that of the general population. It was associated with decreasing quality of life in HD patients, in addition to higher degrees of depression and anxiety. No laboratory tests could identify FMS patients on HD. Fibromyalgia syndrome subsequently follows without a well-established mechanism of pathogenesis, and seems to be due to multifactorial causes. Its true impact on the quality of life of HD patients deserves more attention by nephrologists.     

On the use of journal classification in social sciences and humanities: evidence from an Italian database

Scientometrics - In social sciences and humanities, a two-tier journal classification is currently used in Italy in the context of the National Habilitation programme; peer review is also available...     

Determination of the refractive index and thickness of transparent pellicles by use of the polarization-independent absentee-layer condition

The refractive index and the thickness of a transparent pellicle are determined when the pellicle is placed between two vertical crossed polarizers and rotated in the horizontal plane. The transmission axes of the polarizers are neither parallel nor perpendicular to the plane of incidence. The light transmitted through the crossed polarizers reaches a minimum when the pellicle satisfies the absentee-layer condition. The refractive index and the film thickness are obtained from the pellicle orientation angles under such a condition.     

Spaceborne estimate of atmospheric CO2 column by use of the differential absorption method: error analysis

For better knowledge of the carbon cycle, there is a need for spaceborne measurements of atmospheric CO2 concentration. Because the gradients are relatively small, the accuracy requirements are better than 1%. We analyze the feasibility of a CO2-weighted-column estimate, using the differential absorption technique, from high-resolution spectroscopic measurements in the 1.6- and 2-microm CO2 absorption bands. Several sources of uncertainty that can be neglected for other gases with less stringent accuracy requirements need to be assessed. We attempt a quantification of errors due to the radiometric noise, uncertainties in the temperature, humidity and surface pressure uncertainty, spectroscopic coefficients, and atmospheric scattering. Atmospheric scattering is the major source of error [5 parts per 10 (ppm) for a subvisual cirrus cloud with an assumed optical thickness of 0.03], and additional research is needed to properly assess the accuracy of correction methods. Spectroscopic data are currently a major source of uncertainty but can be improved with specific ground-based sunphotometry measurements. The other sources of error amount to several ppm, which is less than, but close to, the accuracy requirements. Fortunately, these errors are mostly random and will therefore be reduced by proper averaging.