An Economic Analysis of Small-Scale Biodiesel Production: Implementation of Ethyl Ester Production in a Job Shop Setting

Biodiesel is becoming a demanded consumer automotive alternative fuel used in diesel vehicles today. An emerging trend is toward small-scale biodiesel production performed by the final consumer. A limited source of commercially available production systems exists and has resulted in many systems being designed and built by the user. Preliminary research conducted by the authors has shown biodiesel to be the least-cost alternative to petroleum diesel after as few as 8 months of system use. This study examines the economic viability of building and producing biodiesel using a small-scale production system versus buying consumer petroleum diesel. During production, measurements were taken to determine labor hours, energy consumed and total cost of system construction. These results generate an economic view of biodiesel production

Mapping Low-Density Intergalactic Gas: a Third Helium Lyman-alpha Forest

We present a new HST/STIS spectrum of the z=3.18 quasar PKS 1935-692 and summarize the spectral features shortwards of 304A in the rest frame likely to be caused by foreground HeII Lyman-alpha absorption. In accord with previous results on two other quasars at similar redshifts, we demonstrate a correlation with the HI Lyman-alpha forest absorption, and show that much of the helium absorption is caused by a comparable quantity of more diffuse gas with Omega~0.01, that is not detected in HI. The helium ionization zone around the quasar is detected as well as a void seen in both HI and HeII. The properties of the absorption are in broad agreement with those of the other quasars and with models of the protogalactic gas distribution and ionization at this redshift.Comment: 17 pages including 5 figures. As accepted for publication in The Astronomical Journal (minor revisions

Finite element modelling of the uplift behaviour of screw piles in sand

In this paper a simplified procedure to incorporate some installations effects into the numerical finite element modelling of screw pile uplift is presented. The procedure consists of the approximation of the installation phase through 1) the application of a compression loading corresponding to successive embedment depths, 2) the use of modified soil properties over a disturbed zone. Pre-defined failure mechanisms are added to introduce some weakened zones due to either soil disturbance or strain-localisation. The results of numerical simulations are compared to a centrifuge test undertaken at the University of Dundee. The simulation considering an inclined failure mechanism and the simulated installation better captures the uplift capacity and initial stiffness

Vertical integration and firm boundaries : the evidence

Since Ronald H. Coase's (1937) seminal paper, a rich set of theories has been developed that deal with firm boundaries in vertical or input–output structures. In the last twenty-five years, empirical evidence that can shed light on those theories also has been accumulating. We review the findings of empirical studies that have addressed two main interrelated questions: First, what types of transactions are best brought within the firm and, second, what are the consequences of vertical integration decisions for economic outcomes such as prices, quantities, investment, and profits. Throughout, we highlight areas of potential cross-fertilization and promising areas for future work

Efficiency improvement of vertical axis wind turbines with an upstream deflector.

The suitability of using an upstream deflector to improve the efficiency of a vertical axis wind turbine is presented in this study. A two-dimensional vertical axis wind turbine (VAWT) was modelled and simulated using ANSYS Fluent 14.0 computational fluid dynamics (CFD) software to solve the k-epsilon (RNG) turbulence model. Firstly, the open rotor design was optimised by varying orientation and pitch angle, prior to analysing the effect increasing wind speed had on the turbine performance. A maximum efficiency of 19.101% was achieved and was used as the open rotor design. A series of curved upstream deflectors were then evaluated in terms of efficiency improvements against the original open rotor design. Installation of the deflector resulted in a redirection of the fluid flow from the returning turbine blade, therefore reducing the negative torque induced on the system. Additionally, deflector width angles of 45o and 36o were found to improve the turbine performance by 1.266%. Finally, a scale model of the wind turbine was constructed and experimentally tested using a wind tunnel. No correlation between the CFD and experimental results was found due to variations in the wind speed tested by both methods. However, the VAWT design operated at a reasonably efficient level during the experimental testing, even under suboptimal conditions

Coronaridine congeners attenuate fentanyl seeking during prolonged abstinence

Background: The prevalence of opioid use disorder (OUD) has reached epidemic proportions with a record-breaking number of overdose deaths. Over 70% of the record-breaking number of overdose deaths are caused by synthetic opioids, including fentanyl. Fentanyl is commonly administered intravenously or by inhalation (smoking/vaping), which results in rapid drug bioavailability in the brain. There is a current need to identify a novel pharmacologic therapy to treat OUD, and there is increasing evidence to support the use of novel compounds referred to as coronaridine congeners to treat OUD and other psychiatric illnesses. In preclinical models, coronaridine congeners have been shown to decrease self-administration of drugs of abuse and induce antidepressant and anxiolytic effects. Here we used a preclinical fentanyl vapor self-administration model and fast-scan cyclic voltammetry (FSCV) to study the anti-addictive effects of two coronaridine congeners, 18-methoxycoronaridine (18-MC) and catharanthine (Cath).Methods: C57BL/6J mice were trained to self-administer vaporized fentanyl (5 mg/mL) or vehicle in airtight operant chambers. Mice self-administered vapor for 1 hour per day for 10 days (sessions were conducted for 5 consecutive days, followed by 2 days off). Chambers were equipped with two nosepokes, one active and one inactive. A successful response in the active nosepoke resulted in a vapor delivery that coincided with the presentation of a cue light, followed by a 1-minute timeout period. Mice learned to self-administer vapor with 3-second vapor deliveries for the first 3 days of training, which was then reduced to 1.5-second vapor deliveries the remaining 7 days. After training, mice were returned to their home cages for a forced abstinence period. Cue-induced drug seeking tests were conducted on abstinence days (AD) 20 and 25. During cue-induced seeking tests, successful responses in the active nosepoke resulted in presentation of the drug-associated cue, but no vapor was delivered (i.e. extinction conditions). Cue-induced drug seeking tests were conducted using a crossover design where half of subjects received coronaridine treatment (18-MC or Cath), while the other half received vehicle (ddH2O), on AD20. On AD25, subjects received the opposite treatment compared to AD20. Mice were injected (i.p.) with either vehicle or coronaridine treatment 1 hour before seeking tests. To examine the molecular mechanism of coronaridine congeners, FSCV was conducted on dopaminergic pre-synaptic terminals in the nucleus accumbens (NAc) neurons to measure dopamine (DA) release in the presence of 18-MC and Cath with or without nicotinic acetylcholine receptor antagonists.Results: We found that both 18-MC and Cath significantly reduced fentanylseeking during prolonged abstinence with no effect on mice that had previously self-administered vehicle. Furthermore, FSCV revealed that 18-MC and Cath significantly reduced DA release onto NAc neurons.Conclusion: In this study, we report that both 18-MC and Cath decrease fentanyl seeking during prolonged abstinence. DA release is important for opioid-related behaviors, and we found that 18-MC and Cath reduce DA release in the NAc, a mechanism that may underlie the effect of coronaridine congeners on fentanyl seeking. Together, these results provide evidence that coronaridine congeners may be promising novel compounds for the pharmacotherapeutic treatment of OUD

Comparative study of imaging at 3.0 T versus 1.5 T of the knee

The objectives of the study were to compare MR imaging at 1.5 and 3.0 T in the same patients concerning image quality and visualization of cartilage pathology and to assess diagnostic performance using arthroscopy as a standard of reference. Twenty-six patients were identified retrospectively as having comparative 1.5 and 3.0 T MR studies of the knee within an average of 102 days. Standard protocols included T1-weighted and fat-saturated intermediate-weighted fast spin-echo sequences in three planes; sequence parameters had been adjusted to account for differences in relaxation at 3.0 T. Arthroscopy was performed in 19 patients. Four radiologists reviewed each study independently, scored image quality, and analyzed pathological findings. Sensitivities, specificities, and accuracies in diagnosing cartilage lesions were calculated in the 19 patients with arthroscopy, and differences between 1.5 and 3.0 T exams were compared using paired Student’s t tests with a significance threshold of p < 0.05. Each radiologist scored the 3.0 T studies higher than those obtained at 1.5 T in visualizing anatomical structures and abnormalities (p < 0.05). Using arthroscopy as a standard of reference, diagnosis of cartilage abnormalities was improved at 3.0 T with higher sensitivity (75.7% versus 70.6%), accuracy (88.2% versus 86.4%), and correct grading of cartilage lesions (51.3% versus 42.9%). Diagnostic confidence scores were higher at 3.0 than 1.5 T (p < 0.05) and signal-to-noise ratio at 3.0 T was approximately twofold higher than at 1.5 T. MRI at 3.0 T improved visualization of anatomical structures and improved diagnostic confidence compared to 1.5 T. This resulted in significantly better sensitivity and grading of cartilage lesions at the knee

LSST: from Science Drivers to Reference Design and Anticipated Data Products

(Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5$\sigma$ point-source depth in a single visit in $r$ will be $\sim 24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta<+34.5^\circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg$^2$ region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to $r\sim27.5$. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at http://www.sdss3.org/dr

The Eighth Data Release of the Sloan Digital Sky Survey: First Data from SDSS-III

The Sloan Digital Sky Survey (SDSS) started a new phase in August 2008, with new instrumentation and new surveys focused on Galactic structure and chemical evolution, measurements of the baryon oscillation feature in the clustering of galaxies and the quasar Ly alpha forest, and a radial velocity search for planets around ~8000 stars. This paper describes the first data release of SDSS-III (and the eighth counting from the beginning of the SDSS). The release includes five-band imaging of roughly 5200 deg^2 in the Southern Galactic Cap, bringing the total footprint of the SDSS imaging to 14,555 deg^2, or over a third of the Celestial Sphere. All the imaging data have been reprocessed with an improved sky-subtraction algorithm and a final, self-consistent photometric recalibration and flat-field determination. This release also includes all data from the second phase of the Sloan Extension for Galactic Understanding and Evolution (SEGUE-2), consisting of spectroscopy of approximately 118,000 stars at both high and low Galactic latitudes. All the more than half a million stellar spectra obtained with the SDSS spectrograph have been reprocessed through an improved stellar parameters pipeline, which has better determination of metallicity for high metallicity stars.Comment: Astrophysical Journal Supplements, in press (minor updates from submitted version