495 research outputs found

    ENV-647: REPURPOSING EXISTING INFRASTRUCTURE FOR ENHANCED WET WEATHER FLOW TREATMENT FOR VAUXHALL PCP, CITY OF LONDON

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    The Vauxhall Pollution Control Plant (PCP) is one of the first Ontario municipal wastewater treatment plants to have implemented a wet weather strategy that involves chemically enhanced primary treatment (CEPT) and chemically enhanced secondary clarification processes and repurposes existing infrastructure. Wet weather events were a major concern for the City of London (City). Prior to plant upgrade, when major wet weather flows occurred plant overflow would discharge directly into the Thames River. The solution designed by Dillon Consulting Limited treats wet weather flows of nearly ten times the rated average day plant capacity. The average and peak flow treatment capacity of the treatment plant is 20,900 m3/d and 34,640 m3/d, respectively. The wet weather operating strategy accommodates peak plant flows of about 200, 000 m3/d and includes: New Headworks incorporating grit removal and fine screens sized to handle maximum wet weather flows Chemically enhanced primary clarification to increase wet weather treatment capacity of existing primary clarifiers to 150, 000 m3/d Increased biological treatment capacity of the existing system using chemically enhanced secondary clarification. The treatment capacity of the biological treatment process is increased to 50,000 m3/

    Self-organized Critical Model Of Biological Evolution

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    A punctuated equilibrium model of biological evolution with relative fitness between different species being the fundamental driving force of evolution is introduced. Mutation is modeled as a fitness updating cellular automaton process where the change in fitness after mutation follows a Gaussian distribution with mean x>0x>0 and standard deviation σ\sigma. Scaling behaviors are observed in our numerical simulation, indicating that the model is self-organized critical. Besides, the numerical experiment suggests that models with different xx and σ\sigma belong to the same universality class. PACS numbers: 87.10.+e, 05.40.+jComment: 8 pages in REVTEX 3.0 with 4 figures (Figures available on request by sending e-mail to [email protected]

    Overcoming the critical slowing down of flat-histogram Monte Carlo simulations: Cluster updates and optimized broad-histogram ensembles

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    We study the performance of Monte Carlo simulations that sample a broad histogram in energy by determining the mean first-passage time to span the entire energy space of d-dimensional ferromagnetic Ising/Potts models. We first show that flat-histogram Monte Carlo methods with single-spin flip updates such as the Wang-Landau algorithm or the multicanonical method perform sub-optimally in comparison to an unbiased Markovian random walk in energy space. For the d=1,2,3 Ising model, the mean first-passage time \tau scales with the number of spins N=L^d as \tau \propto N^2L^z. The critical exponent z is found to decrease as the dimensionality d is increased. In the mean-field limit of infinite dimensions we find that z vanishes up to logarithmic corrections. We then demonstrate how the slowdown characterized by z>0 for finite d can be overcome by two complementary approaches - cluster dynamics in connection with Wang-Landau sampling and the recently developed ensemble optimization technique. Both approaches are found to improve the random walk in energy space so that \tau \propto N^2 up to logarithmic corrections for the d=1 and d=2 Ising model

    Proper Motion of Milky Way Dwarf Spheroidals from Line-of-Sight Velocities

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    Proper motions for several Milky Way dwarf spheroidal (dSph) galaxies have been determined using both ground and space-based imaging. These measurements require long baselines and repeat observations and typical errors are of order ten milli-arcseconds per century. In this paper, we utilize the effect of "perspective rotation" to show that systematic proper motion of some dSphs can be determined to a similar precision using only stellar line-of-sight velocities. We show that including the effects of small intrinsic rotation in dSphs increases the proper motion errors by about a factor of two. We provide error projections for future data sets, and show that proposed thirty meter class telescopes will measure the proper motion of a few dSphs with milli-arcsecond per century precision.Comment: 4 pages, 1 figure. Minor changes to match published versio

    tert-Butyl 2-methyl-2-(4-nitro­benzo­yl)propanoate

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    The title compound, C15H19NO5, is bent with a dihedral angle of 61.8 (2)° between the mean planes of the benzene ring and a group encompassing the ester functionality (O=C—O—C). The dihedral angle of 0.8 (2)° between the mean planes of the nitro group and the benzene ring indicates near coplanarity. In the crystal, each mol­ecule is linked to four adjacent mol­ecules by weak C—H⋯O hydrogen-bonding inter­actions. Both benzene H atoms ortho to the ketone O atom form C—H⋯O hydrogen bonds with the keto O atoms of two neighboring mol­ecules (of the keto and ester groups, respectively), and the two other inter­actions involve the H atoms from a methyl group of the dimethyl residue, displaying C—H⋯O inter­actions with the O atoms of the nitro groups. These four inter­actions for each mol­ecule lead to the formation of two-dimensional sheets with a hydro­philic inter­ior, held together by weak hydrogen-bonded inter­actions, and a hydro­phobic exterior composed of protruding methyl groups which interst­ack with the methyl groups in adjacent sheets

    tert-Butyl 2-benzoyl-2-methyl­propanoate

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    The title compound, C15H20O3, is bent with a dihedral angle of 67.28 (9)° between the mean planes of the phenyl ring and a group encompassing the ester functionality (O=C—O—C). In the crystal, mol­ecules related by inversion symmetry are connected by weak C—H⋯O inter­actions into infinite chains. On one side of the mol­ecule there are two adjacent inter­actions between neighbouring mol­ecules involving the H atoms of methyl groups from the dimethyl groups and the O atoms of the ketone; on the other side, there are also two inter­actions to another adjacent mol­ecule involving the H atoms on the phenyl rings and the carbonyl O atoms of the ester functionality

    tert-Butyl 2-methyl-2-(4-methyl­benzo­yl)propanoate

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    The title compound, C16H22O3, is bent with a dihedral angle of 75.3 (1)° between the mean planes of the benzene ring and a group encompassing the ester functionality (O=C—O—C). In the crystal, the mol­ecules are linked into infinite chains held together by weak C—H⋯O hydrogen-bonded inter­actions between an H atom on the benzene ring of one mol­ecule and an O atom on the ketone functionality of an adjacent mol­ecule. The chains are arranged with neighbouring tert-butyl and dimethyl groups on adjacent chains exhibiting hydro­phobic stacking, with short C—H⋯H—C contacts (2.37 Å) between adjacent chain

    Perfectionism and achievement goals revisited: The 3 × 2 achievement goal framework

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    Objectives: Perfectionistic strivings (PS) and perfectionistic concerns (PC) have shown different profiles with the 2 × 2 achievement goals in sport. Whether PS and PC also show comparable profiles with the achievement goals of the expanded 3 × 2 framework, however, is unclear. Design: Cross-sectional. Method: We examined self-reported perfectionistic strivings, perfectionistic concerns, and the 3 × 2 achievement goals in 136 junior athletes (mean age 17.0 years). Results: The results of structural equation modeling showed that PS were positively associated with task-, self-, and other-approach goals and negatively with task- and self-avoidance goals. In contrast, PC were positively associated with task-, self-, and other-avoidance goals and negatively with task- and self-approach goals. Conclusions: The findings suggest that PS and PC show different profiles also with the 3 × 2 achievement goals which may help explain why the two perfectionism dimensions show differential relations with achievement-related outcomes in sport

    Levothyrox® new and old formulations: are they switchable for millions of patients?

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    International audienceIn France, more than 2.5 million patients are currently treated with levothyroxine, mainly as the marketed product Levothyrox ®. In March 2017, at the request of French authorities, a new formulation of Levothyrox ® was licensed, with the objective of avoiding stability deficiencies of the old formulation. Before launching this new formulation, an average bioequivalence trial, based on European Union recommended guidelines, was performed. The implicit rationale was the assumption that the two products, being bioequivalent, would also be switchable, allowing substitution of the new for the old formulation, thus avoiding the need for individual calibration of the dosage regimen of thyroxine, using the thyroid-stimulating hormone level as the endpoint, as required for a new patient on initiating treatment. Despite the fact that both formulations were shown to be bioequivalent, adverse drug reactions were reported in several thousands of patients after taking the new formulation. In this opinion paper, we report that more than 50% of healthy volunteers enrolled in a successful regulatory average bioequivalence trial were actually outside the a priori bioequivalence range. Therefore, we question the ability of an average bioequivalence trial to guarantee the switchability within patients of the new and old levothyroxine formulations. We further propose an analysis of this problem using the conceptual framework of individual bioequivalence. This involves investigating the bioavailability of the two formulations within a subject, by comparing not only the population means (as established by average bioequivalence) but also by assessing two variance terms, namely the within-subject variance and the variance estimating subject-by-formulation interaction. A higher within individual variability for the new formulation would lead to reconsideration of the appropriateness of the new formulation. Alternatively, a possible subject-by-formulation interaction would allow a judgement on the ability, or not, of doctors to manage patients effectively during transition from the old to the new formulation
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