Exergoeconomic optimization of surface heat exchangers

A method for exergoeconomic optimization of the surface heat exchangers and basic considerations on optimizing them are outlined.     

Multiband current transformers

The design and principle of action of the new multiband transformer of a current is considered in which the expansion of the top range of measurements is carried out by creation against a magnet driving force in the closed core.     

Computational method for investigation of solid fuel combustion in combustion chambers of a heat power plant

Solid fuel combustion in an actual combustion chamber using coal with an ash content of more than 40% for minimization of the deleterious effects (environmental pollution) of heat power plants on environment. The FLOREAN application package was used for simulation and determination of various parameters of combustion.     

Point Dynamic Loads on a Sandwich Structure

Russian Engineering Research - The action of dynamic point loads on a three-layer structure with fiberglass filler is studied experimentally. The experimental data are compared with theoretical...     

A high-sensitivity Hall magnetometer

Based on two Hall transducers, a low-frequency magnetometer with a sensitivity of 2.5 × 10^–3 G/Hz^1/2 is designed. The dynamic range of the magnetometer at a frequency of 19 Hz varies from 2.5 × 10^–3 to ±8 × 10⁴ G.     

Some Studies on Starch Carbamate

Starch carbamate was prepared by reacting maize starch with urea using solid state technique. The different factors affecting this reaction were studied. These factors include urea concentration, type of starch, reaction and duration. The carbamate extent and carbamation reaction efficiency (%) were traced by estimating the nitrogen content of the reaction product. Solubility, viscosity and total ester content of starch carbamate samples were estimated. The carbamate extent increases by increasing urea concentration as well as reaction temperature and duration. Increasing the reaction temperature and duration has the same effect on carbamation reaction efficiency (%), while increasing urea concentration do the reverse. The solubility (%) of starch carbamate samples depends on urea concentration, reaction temperature and duration as well as the type of starch used. The maximum solubility obtained was 63% and 43% for starch carbamate derived from pregelled and native starch, respectively. Tentative mechanism for the reaction between starch and urea has been proposed.     

Photo-Thermal-Elastic Interaction in a Functionally Graded Material (FGM) and Magnetic Field

Silicon - In this work, we aim to investigate the photo-thermal-elastic waves interaction in a nano-composite semiconductor, elastic and functionally graded material (FGM). The governing equations...     

Investigating Biomarkers for USH2A Retinopathy Using Multimodal Retinal Imaging

Pathogenic mutations in USH2A are a leading cause of visual loss secondary to non-syndromic or Usher syndrome-associated retinitis pigmentosa (RP). With an increasing number of RP-targeted clinical trials in progress, we sought to evaluate the photoreceptor topography underlying patterns of loss observed on clinical retinal imaging to guide surrogate endpoint selection in USH2A retinopathy. In this prospective cross-sectional study, twenty-five patients with molecularly confirmed USH2A-RP underwent fundus autofluorescence (FAF), spectral-domain optical coherence tomography (SD-OCT) and adaptive optics scanning laser ophthalmoscopy (AOSLO) retinal imaging. Analysis comprised measurement of FAF horizontal inner (IR) and outer (OR) hyperautofluorescent ring diameter; SD-OCT ellipsoid zone (EZ) and external limiting membrane (ELM) width, normalised EZ reflectance; AOSLO foveal cone density and intact macular photoreceptor mosaic (IMPM) diameter. Thirty-two eyes from 16 patients (mean age ± SD, 36.0 ± 14.2 years) with USH2A-associated Usher syndrome type 2 (n = 14) or non-syndromic RP (n = 2) met the inclusion criteria. Spatial alignment was observed between IR-EZ and OR-ELM diameters/widths (p < 0.001). The IMPM border occurred just lateral to EZ loss (p < 0.001), although sparser intact photoreceptor inner segments were detected until ELM disruption. EZ width and IR diameter displayed a biphasic relationship with cone density whereby slow cone loss occurred until retinal degeneration reached ~1350 μm from the fovea, beyond which greater reduction in cone density followed. Normalised EZ reflectance and cone density were significantly associated (p < 0.001). As the strongest correlate of cone density (p < 0.001) and best-corrected visual acuity (p < 0.001), EZ width is the most sensitive biomarker of structural and functional decline in USH2A retinopathy, rendering it a promising trial endpoint.