Effects of Measurement Configurations on the Sensitivity of Morpho Butterfly Scales Based Chemical Biosensor

The Morpho butterfly wing with tree-shaped alternating multilayer is an effective chemical biosensor to distinguish between ambient medium, and its detection sensitivity is inextricably linked to the measurement configuration including incident angle, azimuthal angle, and so on. In order to reveal the effects and the selection of measurement configuration. In this work, the model of the Morpho butterfly wing is built using the rigorous coupled-wave analysis method by considering its profile is a rectangular-groove grating. On basis of the above model, the reflectivity of different diffraction orders at a different incident angle and azimuthal angle is calculated, and the influence of incident angle and azimuthal angle on performance of Morpho butterfly scales-based biosensor is analyzed. The optimal incident angle at each azimuthal angle is given according to the proposed choice rule, then the azimuthal angle and the corresponding incident angle can be selected further.

Elementy obrządku pogrzebowego

A total of 65 Przeworsk culture features were discovered in the Żelazna Nowa cemetery. This number included a rectangular groove feature, urned cremations (6), alleged/damaged urned cremations (14), unurned cremations (14), alleged/fully or partly damaged unurned cremations (27), pits containing no bone material (4), undtermined cremations (2), pits containing no archeological material (1). All of the explored burials are cremations. However, a more detailed analysis encounters problems due to the state of preservation of the graves. Features 3, 19A and 19B, 30, 33, 37, 39 have been confidently identified as urned cremations. In many other features fragments of ceramic vessels were found, which may be remains of damaged urns: 18, 21, 23, 25, 31, 35, 44, 46, 47, 48, 49, 56, 57, and 58. Certain unurned cremations are 4, 6, 7, 8, 11–13, 15–17, 22, 24, 32, and 34. The interpretation of the remaining features is uncertain. Among the features uncovered in the cemetery were pits containing no bones: 5, 60, 61, 62, as well as pits containing no archaeological material at all: 55. The majority of unurned cremations contained pyre debris, while no such remains were observed in the following damaged unurned cremations: 15, 40–42, 45, 61, 62. There were a few cases of double burials identified. Three unurned cremations (6, 13, 15) and one urned cremation (39) contained bones of Infans I and an undetermined individual, while feature 19 contained two urns with individual burials: Infans II and an undetermined individual. Urned cremations, and one alleged unurned cremation (56), are distinguished by a higher standard of furnishing and a considerably larger amount of bone remains. This can be given two interpretations: a higher status of those buried there, or different rituals used for urned and unurned cremations. In two graves the urn was covered with an upturned vessel (features 33 and 37). In one case, an apotropaic behaviour characteristic of the Przeworsk culture was recorded, involving driving sharp objects into the pit’s bottom: in grave 41 these were two spearheads.

Woodworking in the Bronze Age Southern Trans-Urals (the case study of the fortified settlement of Kamenny Ambar)

The paper presents the description and analysis of the collection of wood (formwork elements and objects) from wells of the Bronze Age fortified settlement of Kamenny Ambar (Chelyabinsk Oblast). Within the settlement, presented are the layers of the Sintashta, Petrovka and Srubnaya-Alakul traditions, covering the period of the 21st–17th c. BC. We give a short description of the forest resources of the study area. In Southern Urals, wood can be found in the form of charred remains, sometimes in post holes, in burial structures of various state of preserva-tion, as well as in the Bronze Age wells. The latter has been the source of fragments of formwork and some household items for this study. According to palaeobotanical data, the local landscape represented forests mixed with steppe and forb meadows. The total area of forestlands around the settlement in the Bronze Age was roughly similar to the modern one. The analysis of charcoal and wood from wells indicates that pine (51 %) and birch (47 %) were the most common, and to a lesser extent — willow and alder (2 %). Prevailing were the pine trunks with 5 to 30, less often 50, rings. The types of formwork and tools used in their construction have been determined. The importance of woodworking among the household industries of the settlement has been assessed. Remains of wooden structures have been found on the bottom of 16 examined wells, although there may have been more, judging by discrete fragments of wood decay. The wood is represented by stakes, half-logs, chopping blocks, planks, branches, charcoal and fragments of bark. Restored specimens have been examined visually and using a microscope in order to determine the wood species and process tools, and the results have been put down into the database. In the process of excavation, two types of formwork were identified: 1) a wattle cylinder made of twigs intertwined through vertical stakes, and 2) sheeting of the shaft with vertically placed and tightly fitted boards and/or half-logs of small diameter. In a number of wells, the type of construction could not be accurately determined. In addition to wooden structures, wooden objects were also found at the bottom of several wells. It is possible to state that the inhabitants of the Kamenny Ambar settlement were skilled in wood processing. Available data indicate that carpentry craft was highly developed throughout the entire Bronze Age period. Admittedly, peo-ple knew how to joint wooden parts of structures. Since there are no finds of metal nails, we are confident that they used alternative means, such as ropes and other carpentry techniques, in particular, groove joining. An ob-ject with a precise rectangular groove was found in one of the wells. These materials demonstrate the presence of good engineering knowledge, manifested not only in the search for new technologies for the well construction, but also in the overall architecture of the settlement.

Numerical analysis and optimization of rectangular texture for gas foil thrust bearing

Accurate surface texture design is of great significance to improve the performances of gas bearings. In this article, the finite difference method and Newton’s method were combined to obtain the oil film pressure distribution, and the effect of rectangular groove on the lubrication performance was analyzed by changing representative texture parameters. The results show that the performances were more affected by the rectangular texture size compared with the distribution and the bottom shape of texture. The increasing of the surface texture number can only enhance the stability of the bearing. The bearing can provide 30% more bearing capacity by choosing larger size, radial arrangement and plane bottom. These results and analysis can provide technical reference for the bearing texture design.

Effects of Filling Material Roughness on Scattering from a Rectangular Groove

This study investigated the effects of filling material roughness on the H-polarized scattering signatures of a two-dimensional (2D) rectangular groove embedded on an infinite ground plane. Under the assumption of a weakly rough surface on the groove, simplifying suppositions can be used to estimate Green’s functions inside and outside the groove. Enforcing continuity in the tangential magnetic field on the rough surface enables the construction and resolution of a Fredholm’s integral equation with logarithmic singularity. The results were verified via two full-wave electromagnetic field simulations carried out using the finite element method and the method of moments. The findings showed that even a weakly rough surface, such as a polished exterior with weak residual roughness, can considerably affect and change 2D scattering patterns.

A Mode-Matching Solution for TE-Backscattering from an Arbitrary 2D Rectangular Groove in a PEC

In this paper, the simple yet effective mode-matching technique is utilized to compute TE-backscattering from a 2D filled rectangular groove in an infinite perfect electric conductor (PEC). The tangential magnetic fields inside and outside of the groove are represented as the sums of infinite series of cosine harmonics (half-range Fourier cosine series). By applying the continuity of the tangential magnetic field, these modes are matched on the groove to obtain the series coefficients by solving a system of linear equations. For this purpose, some oscillatory logarithmic singular integrals involving Hankel and trigonometric functions are solved numerically, starting by removing the logarithmic singularity via integration by parts. In the following, the new well-behaved highly oscillatory integrals are computed using efficient methods, and several comparisons are made to demonstrate the validity and ability of the presented procedure.

Enhanced Performance of Fabry–Perot Tunable Filter by Groove Geometry Design of Double Folded Cantilever

Different grooves (v-shaped groove, trapezoidal groove and rectangular groove) are introduced into the traditional double-folded cantilever of Fabry–Perot Tunable Filter (FPTF) for the optical sensor. Using finite element simulation, the influence of groove geometry on the voltage–displacement relationship, stress distribution and reflector flatness of the FPTF are studied. The results show that the reflector supported by double folded cantilever with rectangular groove has a maximal displacement of 0.88 μm under 8 V driving voltage, which is 95% higher than double folded cantilever without groove. At 0.5 μm, the best flatness (warping angle of reflector) is only 0.0032° for reflector supported by double folded cantilever with rectangular groove, where the generated maximal stress in the double folded cantilever is 8.49 MPa. Compared with other double folded cantilevers with v-shaped groove, trapezoidal groove and without groove, the unique properties of double folded cantilever with rectangular groove are attributed to lower elastic modulus. The double folded cantilever with rectangular groove enlarges displacement results in wide range of bandpass wavelength of FPTF, and a best flatness to enhance the monochrome of bandpass wavelength.