Realization of a temperature sensor using both two- and three-dimensional photonic structures through a machine learning technique

A temperature sensor based on photonic crystal structures with two- and three-dimensional geometries is proposed, and its measurement performance is estimated using a machine learning technique. The temperature characteristics of the photonic crystal structures are studied by mathematical modeling. The physics of the structure is investigated based on the effective electrical permittivity of the substrate (silicon) and column (air) materials for a signal at 1200 nm, whereas the mathematical principle of its operation is studied using the plane-wave expansion method. Moreover, the intrinsic characteristics are investigated based on the absorption and reflection losses as frequently considered for such photonic structures. The output signal (transmitted energy) passing through the structures determines the magnitude of the corresponding temperature variation. Furthermore, the numerical interpretation indicates that the output signal varies nonlinearly with temperature for both the two- and three-dimensional photonic structures. The relation between the transmitted energy and the temperature is found through polynomial-regression-based machine learning techniques. Moreover, rigorous mathematical computations indicate that a second-order polynomial regression could be an appropriate candidate to establish this relation. Polynomial regression is implemented using the Numpy and Scikit-learn library on the Google Colab platform.

     

3D geometry reconstruction from orthographic views: A method based on 3D image processing and data fitting

Industrial esthetic designers typically produce hand-drawn sketches in the form of orthographic projections. A subsequent translation from 2D-drawings to 3D-models is usually necessary. This involves a considerably time consuming process, so that some automation is advisable.     

Extragenital donovanosis of the foot

Kartagener's syndrome (KS) usually includes mirror-image dextrocardia. The incidence of congenital heart disease in KS is comparable with that in the general population. This paper reports on a case of Kartagener's syndrome associated with dextrocardia, corrected transposition of the great arteries (I,D,D), ventricular septal defect, and valvar pulmonary stenosis in an 8-year-old girl.     

Synthesis and characterization of soluble narrow band gap conducting polymers based on diketopyrrolopyrrole and propylenedioxythiophenes

A series of novel electro-active conjugated polymers containing 2,5-dialkyl-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-diones (DPPs) and 3,4-dihydro-3,3-dialkyl-2H-thieno[3,4-b][1,4]dioxepines (dialkyl-ProDOTs) were synthesized using Stille coupling reaction in presence of CuO. The molecular weights of the synthesized polymers were found to be in the range of 18,000–45,000. Incorporation of the electron deficient DPP units and the electron rich dialkyl-ProDOT units in the conjugated backbone leads to low band gap polymers. All the polymers were found to be highly soluble in most chlorinated organic solvents as well THF and toluene with excellent film forming properties. From the UV–vis spectra, the band gap of the polymers was determined as 1.40–1.42 eV which is lower than the poly(dialkylProDOT)s. From the electrochemical study, highest occupied molecular orbital (HOMO) energy levels of the synthesized polymers were found to be in the range of 5.54–5.51 eV. Because of such high HOMO level, the resulting polymers were found to be more oxidatively stable. Polymers are thermally stable till 325–346 °C with only 5% weight loss which was confirmed from thermogravimetric analysis (TGA). The polymers were found to be moderately conducting with maximum conductivity up to 0.2–6.0 S/cm.     

Ferroelectric Properties of Tungsten Bronze Morphotropic Phase Bounary Systems

Tungsten bronze ferroelectrics which have a morphotropic phase boundary (MPB) can have a number of enhanced dielectric, piezoelectric, and electrooptic properties compared to more conventional ferroelectric materials. The structural and ferroelectric properties of several MPB bronze systems are presented, including data from sintered and hot-pressed ceramics, epitaxial thin films, and bulk single crystals. Included among these are three systems which had not been previously identified as morphotropic. The potential advantages and limitations of these MPB systems are discussed, along with considerations of the appropriate growth methods for their possible utilization in optical, piezoelectric, or pyroelectric device applications.     

Investigations on Buckling Behaviour of Laminated Curved Composite Stiffened Panels

In Industrial applications structural efficiency is primary concern, this brings about the need of strong and lightweight materials. Due to their high specific strength, fibre reinforced polymers find wide application in these areas. Panels made of composite materials are widely used in aerospace structures, automobile, civil, marine and biomedical industries because of their good mechanical properties, impact resistance, excellent damage tolerance and also low fabrication cost. In this Paper, buckling and post-buckling analysis was performed on composite stiffened panel to obtain the critical load and modes of failures, with different parameters like ply-orientation, different composite materials, and stiffeners and by changing the number of stiffeners was derived. To analyze the post buckling behaviour of composite stiffened panels the nonlinear finite element analysis is employed and substantial investigations are undertaken using finite element (FE) model. Effect of critical parameters on buckling behaviour is studied and parametric studies were conducted with analytical tool to understand the structural behaviour in the post buckling range.     

Case report: calcification within aneurysmal bone cyst

Aneurysmal bone cyst (ABC) usually affects older children or young adults. The radiological appearance is of a purely osteolytic expansile metaphyseal lesion with thinned out cortex and internal septations. We present a case of ABC in a 5-year-old girl which showed internal calcification and was initially diagnosed as enchondroma. However, pathological examination revealed typical appearance of ABC with large area of dystrophic calcification.     

The multicast capacity of deterministic relay networks with no interference

The multicast capacity is determined for networks that have deterministic channels with broadcasting at the transmitters and no interference at the receivers. The multicast capacity is shown to have a cut-set interpretation. It is further shown that one cannot always layer channel and network coding in such networks. The proof of the latter result partially generalizes to discrete memoryless broadcast channels and is used to bound the common rate for problems where one achieves a cut bound on throughput.