230 research outputs found
Economic Feasibility of Ethanol Production from Sweet Sorghum Juice in Texas
The economic feasibility of producing ethanol from sweet sorghum juice is projected using Monte Carlo simulation models to estimate the price ethanol plants will likely have to pay for sweet sorghum and the uncertain returns for ethanol plants. Ethanol plants in high yielding regions will likely generate returns on assets of 11%-12% and in low yield areas the returns on assets will be less than 10%.Sweet Sorghum, Ethanol, Monte Carlo Simulation, Agribusiness, Agricultural Finance, Crop Production/Industries, Farm Management, Risk and Uncertainty, D20 G10 D81 C15,
Economic Analysis of Cellulosic Feedstock for Bioenergy in the Texas Rio Grande Valley
Farm Management,
Impact of stalling events on microcirculatory hemodynamics in the aged brain
ABSTRACT: Objective The role of cerebral microvasculature in cognitive dysfunction can be investigated by identifying the impact of blood flow on cortical tissue oxygenation. In this paper, the impact of capillary stalls on microcirculatory characteristics such as flow and hematocrit (Ht) in the cortical angioarchitecture is studied. Methods Using a deterministic mathematical model to simulate blood flow in a realistic mouse cortex, hemodynamics parameters, including pressure, flow, vessel diameter-adjustable hematocrit, and transit time are calculated as a function of stalling events. Results Using a non-linear plasma skimming model, it is observed that Ht increases in the penetrating arteries from the pial vessels as a function of cortical depth. The incidence of stalling on Ht distribution along the blood network vessels shows reduction of RBCs around the tissue near occlusion sites and decreased Ht concentration downstream from the blockage points. Moreover, upstream of the occlusion, there is a noticeable increase of the Ht, leading to larger flow resistance due to higher blood viscosity. We predicted marked changes in transit time behavior due to stalls which match trends observed in mice in vivo. Conclusions These changes to blood cell quantity and quality may be implicated in the development of Alzheimer's disease and contribute to the course of the illness
Flying Squirrel–associated Typhus, United States
In March 2002, typhus fever was diagnosed in two patients residing in West Virginia and Georgia. Both patients were hospitalized with severe febrile illnesses, and both had been recently exposed to or had physical contact with flying squirrels or flying squirrel nests. Laboratory results indicated Rickettsia prowazekii infection
Printing, characterizing, and assessing transparent 3D printed lenses for optical imaging
High-quality lens production has involved subtractive manufacturing methods for centuries. These methods demand specialist equipment and expertise that often render custom high-grade glass optics inaccessible. A low-cost, accessible, and reproducible method is developed to manufacture high-quality three dimensional (3D) printed lenses using consumer-grade technology. Various planoconvex lenses are produced using a consumer-grade 3D printer and low-cost spin coating setup, and printed lenses are compared to commercial glass counterparts. A range of mechanical and optical methods are introduced to determine the surface quality and curvature of 3D printed lenses. Amongst others, high-resolution interference reflection microscopy methods are used to reconstruct the convex surface of printed lenses and quantify their radius of curvature. The optical throughput and performance of 3D printed lenses are assessed using optical transmissivity measurements and classical beam characterization methods. It is determined that 3D printed lenses have comparable curvature and performance to commercial glass lenses. Finally, the application of 3D printed lenses is demonstrated for brightfield transmission microscopy, resolving sub-cellular structures over a 2.3 mm field-of-view. The high reproducibility and comparable performance of 3D printed lenses present great opportunities for additive manufacturing of bespoke optics for low-cost rapid prototyping and improved accessibility to high-quality optics in low-resource settings
Printing, characterising, and assessing transparent 3D printed lenses for optical imaging
The production of high-quality lenses for optical instrumentation has involved subtractive manufacturing methods for centuries. These methods have demanded specialist equipment and expertise that often render custom high-grade bulk glass optics inaccessible. We aimed to develop a low-cost, accessible, and reproducible method using consumer-grade technology to manufacture high-quality three-dimensional (3D) printed lenses with comparable performance to glass lenses. Various 3D printed planoconvex lenses were produced using a consumer grade 3D printer and low-cost spin coating setup, and printed lenses were compared to their commercial glass counterparts. A range of mechanical and optical methods are introduced to determine the surface curvature of 3D printed lenses, providing a wide range of quality control methods. Amongst others, high-resolution interference reflection microscopy methods were used to reconstruct the convex surface of printed lenses and quantify their radius of curvature. Moreover, the optical throughput and focusing performance of 3D printed lenses were assessed using optical transmissivity measurements and classical beam characterisation methods. We determined that all 3D printed lens prescriptions tested had comparable surface curvature and optical performance to commercial glass lenses. Finally, we demonstrated the application of 3D printed lenses for brightfield transmission microscopy, resolving sub-cellular structures over a 2.3 mm field of view. The high reproducibility and comparable performance of 3D printed lenses present a great opportunity for additive manufacturing in the production of bespoke optical elements for low-cost rapid prototyping and improved accessibility to high-quality optics in low-resource settings
Flying Squirrel–associated Typhus, United States
In March 2002, typhus fever was diagnosed in two patients residing in West Virginia and Georgia. Both patients were hospitalized with severe febrile illnesses, and both had been recently exposed to or had physical contact with flying squirrels or flying squirrel nests. Laboratory results indicated Rickettsia prowazekii infection
Dose escalation using contact X-ray brachytherapy (Papillon) for rectal cancer: does it improve the chance of organ preservation?
Objective: A watch and wait policy for patients with a clinical complete response (cCR) after external beam chemoradiotherapy (EBCRT) for rectal cancer is an attractive option. However, approximately one-third of tumours will regrow, which requires surgical salvage for cure. We assessed whether contact X-ray brachytherapy (CXB) can improve organ preservation by avoiding surgery for local regrowth. Methods: From our institutional database, we identified 200 of 573 patients treated by CXB from 2003 to 2012. Median age was 74 years (range 32–94), and 134 (67%) patients were males. Histology was confirmed in all patients and was staged using CT scan, MRI or endorectal ultrasound. All patients received combined CXB and EBCRT, except 17 (8.5%) who had CXB alone. Results: Initial cCR was achieved in 144/200 (72%) patients. 38/56 (68%) patients who had residual tumour received immediate salvage surgery. 16/144 (11%) patients developed local relapse after cCR, and 124/144 (86%) maintained cCR. At median follow up of 2.7 years, 161 (80.5%) patients were free of cancer. The main late toxicity was bleeding (28%). Organ preservation was achieved in 124/200 (62%) patients. Conclusion: Our data suggest that CXB can reduce local regrowth to 11% compared with around 30% after EBCRT alone. Organ preservation of 62% achieved was higher than reported in most published watch and wait studies. Advances in knowledge: CXB is a promising treatment option to avoid salvage surgery for local regrowth, which can improve the chance of organ preservation in patients who are not suitable for or refuse surgery
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