Solar energy conversion through the interaction of plasmons with tunnel junctions. Part A: Solar cell analysis. Part B: Photoconductor analysis

A solar cell utilizing guided optical waves and tunnel junctions was analyzed to determine its feasibility. From this analysis, it appears that the limits imposed upon conventional multiple cell systems also limit this solar cell. Due to this limitation, it appears that the relative simplicity of the conventional multiple cell systems over the solar cell make the conventional multiple cell systems the more promising candidate for improvement. It was discovered that some superlattice structures studied could be incorporated into an infrared photodetector. This photoconductor appears to be promising as a high speed, sensitive (high D sup star sub BLIP) detector in the wavelength range from 15 to over 100 micrometers

Final Report on NASA Grant NAG 3-433. Solar Energy Conversion Through the Interaction of Plasmons with Tunnel Junctions. Part A Solar Cell Analysis. Part B Photoconductor Analysis

A novel solar cell utilizing guided optical waves and tunnel junctions has been analyzed to determine its feasibility. From this analysis, it appears that the limits imposed upon conventional multiple cell systems also limit this novel solar cell. Due to this limitation, it appears that the relative simplicity of the conventional multiple cell systems over the novel solar cell make the conventional multiple cell systems the more promising candidate for improvement. In the course of this investigation, it was discovered that some superlattice structures studied could be incorporated into an infrared photodetector. This photoconductor appears to be promising as a high speed, sensitive (high DBLip) detector in the wavelength range from 15 μm to over 100 μm

Energy and width measurements of low-Z pionic X-ray transitions

High resolution spectrometric measurement of energy and natural line widths of 2p-1s pionic X ray transitions, as well as muonic transition energies in Li, Be, B, and C isotope

A new measurement of the lifetime of the positive pion

Digital timing method for measuring positive pion lifetim

Particles in RSOS paths

We introduce a new representation of the paths of the Forrester-Baxter RSOS models which represents the states of the irreducible modules of the minimal models M(p',p). This representation is obtained by transforming the RSOS paths, for the cases p> 2p'-2, to new paths for which horizontal edges are allowed at certain heights. These new paths are much simpler in that their weight is nothing but the sum of the position of the peaks. This description paves the way for the interpretation of the RSOS paths in terms of fermi-type charged particles out of which the fermionic characters could be obtained constructively. The derivation of the fermionic character for p'=2 and p=kp'+/- 1 is outlined. Finally, the particles of the RSOS paths are put in relation with the kinks and the breathers of the restricted sine-Gordon model.Comment: 15 pages, few typos corrected, version publishe

Report on a Periodic Extrinsic Infrared (PEIR) Photoconductor

An infrared photoconductor, designated as the Periodic Extrinsic InfraRed (PEIR) photoconductor, is proposed. A PEIR photoconductor will be useful for detecting wavelengths from 7 μm (1400 cm-1) to longer than 100 μm (100 cm-1). Through epitaxial growth, a PEIR photoconductor is made up of heavily doped layers separated by lightly doped layers. The heavily doped layers are doped such that an impurity band forms but are not doped high enough to cause the impurity band to merge with the conduction or valence band. The lightly doped layers are used to confine the carriers in the impurity bands and consequently, conduction can only occur due to carriers excited to the conduction (n-type device) or valence (p-type device) band. Radiation excites the carriers from the impurity band to the conduction or valence band. The impurity band layers are thin enough that even if the electric field in the impurity band layers is small, there is a high probability the excited carrier will scatter into the lightly doped layer and be swept away by the electric field in the lightly doped layer, A PEIR photoconductor will have two major advantages. First, the absorption coefficient will be high because of the high impurity concentration in the impurity band layers. The absorption coefficient will be from 103cm-1 to as high as 104cm-1. Additionally, a method has been found to approximately determine the highest absorption coefficient attainable in specific host semiconductor:impurity dopant materials systems. Consequently, one can determine the optimum host semiconductor:impurity dopant system to be used in a PEIR photoconductor designed to detect a certain wavelength. Second, some host semiconductors that are being considered are Si and GaAs, which are much easier to work with than HgCdTe (the material of choice for intrinsic photoconductors at wavelengths longer than 7 μm)

An Economic analysis of the potential for precision farming in UK cereal production

The results from alternative spatial nitrogen application studies are analysed in economic terms and compared to the costs of precision farming hardware, software and other services for cereal crops in the UK. At current prices, the benefits of variable rate application of nitrogen exceed the returns from a uniform application by an average of £22 ha−1 The cost of the precision farming systems range from £5 to £18 ha−1 depending upon the system chosen for an area of 250 ha. The benefits outweigh the associated costs for cereal farms in excess of 80 ha for the lowest price system to 200–300 ha for the more sophisticated systems. The scale of benefits obtained depends upon the magnitude of the response to the treatment and the proportion of the field that will respond. To be cost effective, a farmed area of 250 ha of cereals, where 30% of the area will respond to variable treatment, requires an increase in crop yield in the responsive areas of between 0·25 and 1.00 t ha−1 (at £65 t−1) for the basic and most expensive precision farming systems, respectively

Static Socio-Ecological COVID-19 Vulnerability Index and Vaccine Hesitancy Index for England

Background: Population characteristics can be used to infer vulnerability of communities to COVID-19, or to the likelihood of high levels of vaccine hesitancy. Communities harder hit by the virus, or at risk of being so, stand to benefit from greater resource allocation than their population size alone would suggest. This study reports a simple but efficacious method of ranking small areas of England by relative characteristics that are linked with COVID-19 vulnerability and vaccine hesitancy. Methods: Publicly available data on a range of characteristics previously linked with either poor COVID-19 outcomes or vaccine hesitancy were collated for all Middle Super Output Areas of England (MSOA, n=6790, excluding Isles of Scilly), scaled and combined into two numeric indices. Multivariable linear regression was used to build a parsimonious model of vulnerability (static socio-ecological vulnerability index, SEVI) in 60% of MSOAs, and retained variables were used to construct two simple indices. Assuming a monotonic relationship between indices and outcomes, Spearman correlation coefficients were calculated between the SEVI and cumulative COVID-19 case rates at MSOA level in the remaining 40% of MSOAs over periods both during and out with national lockdowns. Similarly, a novel vaccine hesitancy index (VHI) was constructed using population characteristics aligned with factors identified by an Office for National Statistics (ONS) survey analysis. The relationship between the VHI and vaccine coverage in people aged 12+years (as of 2021-06-24) was determined using Spearman correlation. The indices were split into quintiles, and MSOAs within the highest vulnerability and vaccine hesitancy quintiles were mapped. Findings: The SEVI showed a moderate to strong relationship with case rates in the validation dataset across the whole study period, and for every intervening period studied except early in the pandemic when testing was highly selective. The SEVI was more strongly correlated with case rates than any of its domains (rs 0·59 95% CI 0.57-0.62) and outperformed an existing MSOA-level vulnerability index. The VHI was significantly negatively correlated with COVID-19 vaccine coverage in the validation data at the time of writing (rs -0·43 95% CI -0·46 to -0·41). London had the largest number and proportion of MSOAs in quintile 5 (most vulnerable/hesitant) of SEVI and VHI concurrently. Interpretation: The indices presented offer an efficacious way of identifying geographical disparities in COVID-19 risk, thus helping focus resources according to need. Funding: Funder: Integrated Covid Hub North East Award number: n/a Grant recipient: Fiona Matthew

Report on Solar Energy Conversion Through the Interaction of Plasmons with Tunnel Junctions

This report covers the work performed under grant NAG 3-433, “Solar Energy Conversion Through the Interaction of Plasmons with Tunnel Junctions,” during the period from June 1,1983 to December 31, 1984. Personnel performing the work were Prof. R J. Schwartz, Prof. S. Datta and Graduate Research Assistant P. E. Welsh. Much of the detail of the work described in this report is covered in a Master’s Thesis submitted by P. E. Welsh to the School of Electrical Engineering, Purdue University, December 1984

Manipulation of the duration of the initial self-control task within the sequential-task paradigm: effect on exercise performance

Self-control exertion on an initial task has been associated with impaired performance on subsequent physical tasks also requiring self-control; an effect suggested to be mediated by changes in perceptions of pain and motivation. However, the effects of spending longer on the initial self-control task are unknown. This study, therefore, explored the potential for the duration of the initial self-control task to influence subsequent physical performance, perceptions of pain, and perceived motivation; particularly during the early stages of the physical task. In a within-subject design, 29 participants (11 male, 18 female) completed a wall-sit task until volitional exhaustion, on four separate occasions. Prior to each wall-sit, participants completed either a non-self-control task (congruent Stroop task) for 4 min, or a self-control task (incongruent Stroop task) for 4 (short duration), 8 (medium duration), or 16 (long duration) min. Participant’s perceptions of pain and motivation were recorded every 30 s during the wall-sit. Wall-sit performance time was analyzed using one-way ANOVA and perceptions of pain and motivation analyzed using multi-level modeling. Wall-sit performance time was significantly longer on the non-self-control exertion trial compared to all other trials (all p < 0.01), as well as longer on both the short duration and medium duration self-control exertion trials compared to the long duration self-control exertion trial (both p < 0.001). Perceptions of initial (at 30 s) pain and motivation were different between the trials (main effect of trial: pain, p = 0.001; motivation, p < 0.001); whereby longer durations of self-control exertion increased perceptions of pain and decreased motivation. The decrease in motivation during the wall-sit task was greater on the long duration self-control exertion trial compared to all other trials (trial∗ time interactions, all p < 0.05). The present study provides novel evidence that spending longer on the initial self-control task led to greater detrimental effects on subsequent wall-sit performance time. Furthermore, longer duration self-control exertion tasks led to increased perceptions of pain and decreased motivation within the first 30 s of the wall-sit task, as well as a greater decrease in motivation across the wall-sit task. These attentional and motivational shifts may explain performance decrements following the exertion of self-control