Soil radon depth dependence

The knowledge of the soil radon levels is important for the planning and construction of new buildings in order to estimate the radon risk and to classify the ground for construction purposes.

The purpose of this investigation was to study in situ the radon levels at various depths 0–2 m in terrain where the geology is comparatively uniform. The data from the measurements was fitted to simple functions in order to facilitate future extrapolations of radon levels from various depths to 1 m at measurements anywhere.

The plastic film Kodak LR 115 was used as the detector of the radon levels at four different depths in the interval 0–2 m. The measurements were made along a 2200 m long profile at 16 different points.     

Investigation of resolution of the stereoscopic 3D images

Evaluation of 3D images is an important part of 3D display developments. In this paper, we propose an evaluation method which can reflect the characteristics of the stereoscopic 3D images in the depth direction. Perception of the depth planes is verified using a subjective evaluation method. Resolution of the stereoscopic 3D images which represents the distribution of the 3D images in the depth direction quantitatively is calculated and analyzed.     

Orthoscopic integral imaging display by use of the computational method based on lenslet model

In this paper, we propose a computational depth conversion method based on the lenslet model to display the orthoscopic 3D images in 3D integral imaging display. The proposed method permits the synthesis of elemental images for the orthoscopic 3D images at any arbitrary position without any restrictions and requires no additional procedure during the depth conversion process. Due to the lenslet model involved in the depth conversion procedure, the proposed method can broaden the flexibility of 3D image reconstruction in the integral imaging display system. We carry out the preliminary experiments to prove the feasibility of the proposed method. The experimental results reveal that the proposed method is an effective depth conversion method that allows the reconstruction of the orthoscopic 3D images at any arbitrary position.     

A new procedure using membrane chromatography for the valorization of fraction IV from Kistler and Nitschmann's fractionation of blood plasma

Summary The aim of this work was to recover albumin from Kistler and Nitschmann's fraction IV using membrane chromatography. The best solubilization results were obtained at pH 6.5 using a phosphate buffer containing 150 mM NaCl. More than 90% of the initial albumin content was recovered.The purification procedure included 2 main steps: the first one was a depth filtration in order to remove fine particles and a selective depth filter treatment for lipid removal. The second step was ion exchange chromatography. We used membrane chromatography systems where the fluid flows radially allowing fast flow purification under low operating pressures. The eluted albumin was free from IgG. Because of the absence of contaminating IgG and its high microbiological quality compared to standard animal sera, this albumin preparation can be used as a culture medium additive. It can also be further purified by ultrafiltration. The equipment used here is easy to handle and to sterilize, and meets the FDA Code of Federal Regulations. Additionally, this procedure is flexible enough to allow the co-purification of other fraction IV proteins such as transferrin or alpha-1-anti-trypsin.     

Fiber Grating Based Optical Recirculating Filter with an Optimized Response

A novel optical recirculating filter for RF applications is described, which exploits a specially designed fiber grating with a ramped spectral profile to enable optimization of the filter response. The design overcomes the limitations imposed by loss in conventional fiber recirculating filters. Additionally, a tunable free spectral range is demonstrated by using the device in a grating array. Both theoretical and experimental results are presented and discussed.     

瑞利判断与斯托列尔准则(兼论光学系统景深与清晰度法定焦精度)

本文根据圆孔菲涅耳衍射象点附近的振幅和光强空间分布,论证了瑞利判断与斯托列尔准则是统一的.指出应用光学中景深的概念存在问题,传统的用物理景深和几何景深相加来计算清晰度法定焦精度是不妥的.     

Integral trimmed regions

We define a new family of central regions with respect to a probability measure. They are induced by a set or a family of sets of functions and we name them integral trimmed regions. The halfspace trimming and the zonoid trimming are particular cases of integral trimmed regions. We focus our work on the derivation of properties of such integral trimmed regions from conditions satisfied by the generating classes of functions. Further we show that, under mild conditions, the population integral trimmed region of a given depth can be characterized in terms of certain regions based on empirical distributions.     

A comparative study of secondary ion yield from model biological membranes using Aun and C60 primary ion sources

Au_n⁺ and C₆₀⁺ primary ion sources have been used to acquire spectra from phospholipids, symmetric liposomes and asymmetric liposomes. We demonstrate that when using different ion beams different chemical information can be obtained. Symmetric and asymmetric liposomes, with 95% asymmetry, were produced and analysed with Au⁺, Au₃⁺ and C₆₀⁺ primary ion beams. C₆₀⁺ gave the greatest yield from the symmetric liposome but after correcting for the yield effects on the data obtained from the asymmetric liposome it has been shown that C₆₀⁺ is the most surface sensitive, providing the least information from the inner leaflet of the liposome. Au_n⁺ provides the greatest amount of information from the inner leaflet. The results present the possibility of designing ToF-SIMS experiments that selectively probe specific regions of a (bio)molecular surface.     

Temperature-controlled depth profiling in polymeric materials using cluster secondary ion mass spectrometry (SIMS)

Secondary ion mass spectrometry (SIMS) employing an SF₅⁺ polyatomic primary ion source was used to depth profile through poly(methylmethacrylate) (PMMA), poly(lactic acid) (PLA) and polystyrene (PS) thin films at a series of temperatures from −125 °C to 150 °C. It was found that for PMMA, reduced temperature analysis produced depth profiles with increased secondary ion stability and reduced interfacial widths as compared to analysis at ambient temperature. Atomic force microscopy (AFM) images indicated that this improvement in interfacial width may be related to a decrease in sputter-induced topography. Depth profiling at higher temperatures was typically correlated with increased sputter rates. However, the improvements in interfacial widths and overall secondary ion stability were not as prevalent as was observed at low temperature. For PLA, improvements in signal intensities were observed at low temperatures, yet there was no significant change in secondary ion stability, interface widths or sputter rates. High temperatures yielded a significant decrease in secondary ion stability of the resulting profiles. PS films showed rapid degradation of characteristic secondary ion signals under all temperatures examined.     

The impact of molecular emission in compositional depth profiling using Glow Discharge-Optical Emission Spectroscopy

The scope of this paper is to investigate and discuss how molecular emission can affect elemental analysis in glow discharge optical emission (GD-OES), particularly in compositional depth profiling (CDP) applications. Older work on molecular emission in glow discharges is briefly reviewed, and the nature of molecular emission spectra described. Work on the influence of hydrogen in the plasma, in particular elevated background due to a continuum spectrum, is discussed. More recent work from sputtering of polymers and other materials with a large content of light elements in a Grimm type source is reviewed, where substantial emission has been observed from several light diatomic molecules (CO, CH, OH, NH, C₂). It is discussed how the elevated backgrounds from such molecular emission can lead to significant analytical errors in the form of “false” depth profile signals of several atomic analytical lines. Results from a recent investigation of molecular emission spectra from mixed gases in a Grimm type glow discharge are presented. An important observation is that dissociation and subsequent recombination processes occur, leading to formation of molecular species not present in the original plasma gas. Experimental work on depth profiling of a polymer coating and a thin silicate film, using a spectrometer equipped with channels for molecular emission lines, is presented. The results confirm that molecular emission gives rise to apparent depth profiles of elements not present in the sample. The possibilities to make adequate corrections for such molecular emission in CDP of organic coatings and very thin films are discussed.