495 research outputs found
ENV-647: REPURPOSING EXISTING INFRASTRUCTURE FOR ENHANCED WET WEATHER FLOW TREATMENT FOR VAUXHALL PCP, CITY OF LONDON
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
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 and standard deviation . 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 and 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
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
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
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
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
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
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?
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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