Detection of low dose radiation induced DNA damage using temperature differential fluorescence assay.

A rapid and sensitive fluorescence assay for radiation-induced DNA damage is reported. Changes in temperature-induced strand separation in both calf thymus DNA and plasmid DNA (puc 19 plasmid from Escherichia coli) were measured after exposure to low doses of radiation. Exposures of between 0.004 and 1 Gy were measured with doses as low as 0.008 Gy yielding significant responses. The double-strand, sensitive dye PicoGreen was used as an indicator of DNA denaturation. Calibration plots indicate that fluorescence changes corresponding to amounts as low as 1 ng of double stranded DNA (10(6) copies for plasmid puc 19) are detected by this method.     

Minimum required angular resolution of smartphone displays for the human visual system

There has been a rapid increase in the resolution of small‐sized and medium‐sized displays. This study determines an upper discernible limit for display resolution. A range of resolutions varying from 254–1016 PPI were evaluated using simulated display by 49 subjects at 300 mm viewing distance. The results of the study conclusively show that users can discriminate between 339 and 508 PPI and in many cases between 508 and 1016 PPI.     

Examination of space-based bulk atmospheric temperatures used in climate research

The Intergovernmental Panel on Climate Change Assessment Report 5 (IPCC AR5, 2013) discussed bulk atmospheric temperatures as indicators of climate variability and change. We examine four satellite datasets producing bulk tropospheric temperatures, based on microwave sounding units (MSUs), all updated since IPCC AR5. All datasets produce high correlations of anomalies versus independent observations from radiosondes (balloons), but differ somewhat in the metric of most interest, the linear trend beginning in 1979. The trend is an indicator of the response of the climate system to rising greenhouse gas concentrations and other forcings, and so is critical to understanding the climate. The satellite results indicate a range of near-global (+0.07 to +0.13°C decade^?1) and tropical (+0.08 to +0.17°C decade^?1) trends (1979–2016), and suggestions are presented to account for these differences. We show evidence that MSUs on National Oceanic and Atmospheric Administration’s satellites (NOAA-12 and ?14, 1990–2001+) contain spurious warming, especially noticeable in three of the four satellite datasets.

Comparisons with radiosonde datasets independently adjusted for inhomogeneities and Reanalyses suggest the actual tropical (20°S-20°N) trend is +0.10 ± 0.03°C decade^?1. This tropical result is over a factor of two less than the trend projected from the average of the IPCC climate model simulations for this same period (+0.27°C decade^?1).     

Bench-Scale Experiment for Structural Control

Experimental verification of structural control strategies is essential for eventual full-scale implementations. However, few researchers have facilities readily available to them that are capable of even small-scale structural control experiments. This paper demonstrates that appropriately constructed bench-scale models can be used to study important aspects of full-scale structural control implementations, including control-structure interaction, actuator and sensor dynamics, actuator saturation effects, limited availability of sensors, output feedback design, digital control implementation, and control spillover. The active control experiment considered herein is shown to be an effective tool for familiarizing students, researchers, and practitioners with control system design and the associated challenges. Moreover, this experiment provides an excellent platform for conducting proof-of-concept tests of control strategies, providing impetus for the most promising approaches to be verified at larger-scale facilities.     

Factors affecting the resistance of moisture transfer during drying of cut grass

Measurements have been made of the drying rate of thin layers of cut grass, with forced convection of air at 250c and 50% relative humidity. From measurements of the exposed surface areas of the grass and the evaporation rates measured during drying, estimates have been made of the grasses' resistance to moisture transfer.

Some of the grasses had been mechanically treated, by conventional agricultural mower conditioners, to improve the drying rates. An expression has been derived relating resistance to moisture transfer to the conditioning treatment and physical characteristics of the grass.     

A new 4H-SiC normally off lateral channel vertical JFET with extremely low power losses: source inserted double-gate structure with a supplementary highly doped region

A novel silicon carbide (SiC) normally off lateral channel vertical junction field-effect transistor (LC-VJFET), namely a source-inserted double-gate structure with a supplementary highly doped region (SHDR), was proposed for achieving extremely low power losses in high-power switching applications. The proposed architecture was based on the combination of an additional source electrode inserted between two adjacent surface gate electrodes and a unique SHDR in the vertical channel region. Two-dimensional numerical simulations for the static and resistive switching characteristics were performed to analyze and optimize the SiC LC-VJFET structures for this purpose. Based on the simulation results, the excellent performance of the proposed structure was compared with optimized conventional structures with regard to total power losses. Finally, the proposed structure showed about a 20% reduction in on-state loss (P/sub on/) compared to the conventional structures, due to the effective suppression of the JFET effect. Furthermore, the switching loss (P/sub sw/) of the proposed structure was found to be much lower than the results of the conventional structures, about a 75% /spl sim/ 95% reduction, by significantly reducing both input capacitance (C/sub iss/) and reverse transfer capacitance (C/sub rss/) of the device.     

DESIGN AND CONSTRUCTION OF POLARISCOPES FOR USE IN GLASS FACTORIES1

This paper presents the most important considerations in the design and construction of polariscopes for routine factory use as found in the author's experience. A short summary of the various methods of obtaining plane-polarized light is given in which preference is given to the reflection method for this type of instrument. The use of binocular analyzers, together with the importance of the matching of the field colors due to the tint-plates, is pointed out.