Photon echo without a free induction decay in a double-Lambda system

We have characterized a novel photon-echo pulse sequence for a double-$\Lambda$ type energy level system where the input and rephasing transitions are different to the applied $\pi$-pulses. We show that despite having imperfect $\pi$-pulses (associated with large coherent emission due to free induction decay), the noise added is only 0.019$\pm$0.001 relative to the shot noise in the spectral mode of the echo. Using this echo pulse sequence in the `rephased amplified spontaneous emission' (RASE) scheme \cite{Ledingham2010} will allow for generation of entangled photon pairs that are in different frequency, temporal, and potentially spatial modes to any bright driving fields. The coherence and efficiency properties of this sequence were characterized in a Pr:YSO crystal

Non-classical photon streams using rephased amplified spontaneous emission

We present a fully quantum mechanical treatment of optically rephased photon echoes. These echoes exhibit noise due to amplified spontaneous emission, however this noise can be seen as a consequence of the entanglement between the atoms and the output light. With a rephasing pulse one can get an "echo" of the amplified spontaneous emission, leading to light with nonclassical correlations at points separated in time, which is of interest in the context of building wide bandwidth quantum repeaters. We also suggest a wideband version of DLCZ protocol based on the same ideas.Comment: 5 pages, 4 figures. Added section

Improved Lubrication Performance of Chainsaw Cutting Systems

Chainsaws serve as one of the primary tools used by logging corporations, ranches, and farms for forestry management. Lubricating oil remains one of the heaviest operational expenditures for chainsaws. This largely in part due to chainsaw lubrication being a total loss system in which nearly all lubricating oil applied is expelled during operation. The majority of lubrication research is focused on mitigating component breakdown due to wear or the inclusion of more environmentally friendly lubricating oils. Little research is available to the public on the improvement of chainsaw lubrication so that less lubricant can be used during operation. Patents and products exist that aid in lubricating chainsaw cutting systems but few are capable of reducing the lubricant required. An investigation into the current lubrication method of a chainsaw cutting system was conducted using a standard sprocket nose guide bar and accompanying saw chain. Testing utilized a lab-based test apparatus for controlling and operating the chainsaw cutting system along with an infrared camera for collecting steady-state guide bar temperature measurements. Observation of the guide bar’s thermal profile during operation in a controlled environment aided in the design of a concept prototype. Preliminary free-running tests with varied oil-input flow rates indicated a 75% reduction in oil flow rate while achieving the same steady-state maximum guide bar temperature was possible using the concept prototype. Developing this concept further into a prototype guide bar, a free-running test was conducted to compare the prototype to the standard guide bar. This tested both standard and prototype guide bars at 16lb and 22lb chain tension along with oil flow rates of 0.8mL/min and 3.3mL/min. The prototype guide bar operated at lower maximum guide bar temperatures at the 0.8mL/min flow rate at both 16lb and 22lb chain tension settings. Lastly, three replicates of the prototype and standard guide bar conducted 1,400 bucking cuts from which the wear on the guide bar rails and the stretch of the chain were measured. The prototype guide bar rails measured less average wear than the standard bar at 0.8mL/min flow rate. The saw chains used on the prototype guide bar also measured less stretch than those used on the standard guide bars at the same flow rate. The testing conducted indicated the prototype guide bars potential for reducing the amount of lubricant required while maintaining a similar amount of component wear

Can the strong get stronger? A laboratory investigation of natural selection for antimicrobial resistance

The students, Sarah Grace Keaveany and Elizabeth Ramsey, completed original research with to investigate 1) standing variation among common bacterial species (Escherichia coli and Stapholococcus epidermidis) in the amount of resistance to triclosan, a common anti-microbial used in hand washes; and 2) the capacity for these bacteria to develop increased resistance to triclosan through selection. The students have developed lab modules based on this research. One module includes a wet lab, where students will culture their own bacteria. The other module allows students to obtain data from photographs of bacterial plates in lieu of a wet lab component

Qualitative Analysis of Reflective Narratives of Physical Therapy Students Attempting to Implement Biopsychosocial Approaches to Care

Purpose: To examine the learning process of physical therapy students attempting to apply BPS principles to clinical treatment during both an initial training period under mentorship, and during clinical rotations

Very Shallow Water Bathymetry Retrieval from Hyperspectral Imagery at the Virginia Coast Reserve (VCR\u2707) Multi-Sensor Campaign

A number of institutions, including the Naval Research Laboratory (NRL), have developed look up tables for remote retrieval of bathymetry and in-water optical properties from hyperspectral imagery (HSI) [6]. For bathymetry retrieval, the lower limit is the very shallow water case (here defined as \u3c 2m), a depth zone which is not well resolved by many existing bathymetric LIDAR sensors, such as SHOALS [4]. The ability to rapidly model these shallow water depths from HSI directly has potential benefits for combined HSI/LIDAR systems such as the Compact Hydrographic Airborne Rapid Total Survey (CHARTS) [10]. In this study, we focused on the validation of a near infra-red feature, corresponding to a local minimum in absorption (and therefore a local peak in reflectance), which can be correlated directly to bathymetry with a high degree of confidence. Compared to other VNIR wavelengths, this particular near-IR feature corresponds to a peak in the correlation with depth in this very shallow water regime, and this is a spectral range where reflectance depends primarily on water depth (water absorption) and bottom type, with suspended constituents playing a secondary role

Diamond nano-pillar arrays for quantum microscopy of neuronal signals

Modern neuroscience is currently limited in its capacity to perform long term, wide-field measurements of neuron electromagnetics with nanoscale resolution. Quantum microscopy using the nitrogen vacancy centre (NV) can provide a potential solution to this problem with electric and magnetic field sensing at nano-scale resolution and good biocompatibility. However, the performance of existing NV sensing technology does not allow for studies of small mammalian neurons yet. In this paper, we propose a solution to this problem by engineering NV quantum sensors in diamond nanopillar arrays. The pillars improve light collection efficiency by guiding excitation/emission light, which improves sensitivity. More importantly, they also improve the size of the signal at the NV by removing screening charges as well as coordinating the neuron growth to the tips of the pillars where the NV is located. Here, we provide a growth study to demonstrate coordinated neuron growth as well as the first simulation of nano-scopic neuron electric and magnetic fields to assess the enhancement provided by the nanopillar geometry.Comment: 18 pages including supplementary and references, 12 figure

Farm to School Program Evaluation

A large school district in the southeastern United States has embraced the national Farm to School (F2S) movement. The school district grows organic produce at its farm as well as two greenhouses. The goal of the program is to improve the eating habits of students while giving them insight into the importance of agriculture through educational opportunities. The study of the school district’s F2S program was conducted to determine the effectiveness of the program. The effectiveness was determined utilizing two metrics: the cost of production and the qualitative educational dynamic. The study found that the production aspect is sustainable. The F2S program is saving money on the produce utilized in the cafeterias of the school district. The educational dynamic is progressing but lacks clarity and advertisement. The study found that the F2S program is viable from a production standpoint and is worthwhile from a qualitative educational aspect