461 research outputs found
Final Project Report: Hydraulic Model Waves and Circulation Within Sister Bay Municipal Harbor Expansion Sister Bay, Wisconsin
https://deepblue.lib.umich.edu/bitstream/2027.42/154187/1/39015101405069.pd
Stepped spillway model pressures characteristics, Susu Dam Malaysia
Susu Dam is an RCC Dam under construction in Peninsula Malaysia. The dam design has been carried out by SMEC International in its offices in Kuala Lumpur. The dam is some 90 m tall. The overfall stepped spillway provides for discharges to enter a hydraulic jump stilling basin for energy dissipation, prior to passing through a culvert under a roadway. The spillway was subject to hydraulic model testing at the Utah Water Research Laboratory of Utah State University (USA), at a length scale of 1:30. The hydraulic performance of the spillway design was evaluated up to the 4,700 m3/s Probable Maximum Flood (PMF) discharge (almost 1,000 L/s model scale). The spillway was tested through a number of configurations, prior to the development of the final arrangement. The purpose of the paper is to describe the modelling detail, and then focus on the flow behaviour at the stair-stepped spillway chute with 2.4 m high steps, in particular the piezometric pressures and transient pressures on the tread and riser of the steps. The spillway chute converged from ~100 m at the crest to 78 m at the bottom at entrance to the stilling basin; the unit discharge entering the stilling basin was ~ 60 m2/s for the PMF. Of particular interest was the occurrence of negative pressures on the steps, and the paper will describe the transients for several discharges from the AEP 1 in 1,000 up to the PMF; the results indicating very low pressures into a cavitation region. The design provides for an aerator across the spillway in order to counter the effects of possible cavitation. Results will be presented with and without the aerator operating. The paper provides useful design information for the hydraulic design of stepped spillways
A Desire for the Dark Side: An Examination of Individual Personality Characteristics and Their Desire for Adverse Characteristics in Leaders
Powerful and charismatic leaders are often highly desired by organizations and the followers that work within them. However, leaders who are highly skilled at developing relationships and accomplishing what they need to are often those individuals who rate very high on personality traits or characteristics that are considered “dark.” Although much attention has been paid to leaders and dark characteristics, we know much less regarding the dark side of leadership and followers’ susceptibility to these leaders. This article investigates the extent to which follower traits (i.e., the dark triad and the Big Five) predict a follower’s propensity to accept leader behaviors indicative of psychopathy (measured via the Hare P-Scan). Results suggest a follower’s psychopathy leads to the desire for dark leaders. Implications and future research suggest a more in-depth examination of followers and why certain individuals desire dark leadership, as well as examining negative environments
Final Project Report: Laboratory Investigation River Rouge Combined Sewer Overflow Control Facility
https://deepblue.lib.umich.edu/bitstream/2027.42/154197/1/39015101405242.pd
The ABCD of usability testing
We introduce a methodology for tracking and auditing feedback, errors and suggestions for software packages. This short paper describes how we innovate on the evaluation mechanism, introducing an (Antecedent, Barrier, Consequence and Development) ABCD form, embedded within an eParticipation platform to enable end users to easily report on any usability issues. This methodology will be utilised to improve the STEP cloud eParticipation platform (part of the current STEP Horizon2020 project http://step4youth.eu. The platform is currently being piloted in real life contexts, with the participation of public authorities that are integrating the eParticipation platform into their regular decision-making practices. The project is involving young people, through engagement and motivation strategies and giving them a voice in Environmental decision making at the local level. The pilot evaluation aims to demonstrate how open engagement needs to be embedded within public sector processes and the usability methodology reported here will help to identify the key barriers for wide scale deployment of the platform
Molecular consequences of cystic fibrosis transmembrane regulator (CFTR) gene mutations in the exocrine pancreas
Background and aims: We tested the hypothesis that the actual or predicted consequences of mutations in the cystic fibrosis transmembrane regulator gene correlate with the pancreatic phenotype and with measures of quantitative exocrine pancreatic function. Methods: We assessed 742 patients with cystic fibrosis for whom genotype and clinical data were available. At diagnosis, 610 were pancreatic insufficient, 110 were pancreatic sufficient, and 22 pancreatic sufficient patients progressed to pancreatic insufficiency after diagnosis. Results: We identified mutations on both alleles in 633 patients (85.3%), on one allele in 95 (12.8%), and on neither allele in 14 (1.9%). Seventy six different mutations were identified. The most common mutation was ΔF508 (71.3%) followed by G551D (2.9%), G542X (2.3%), 621+1G→T (1.2%), and W1282X (1.2%). Patients were categorized into five classes according to the predicted functional consequences of each mutation. Over 95% of patients with severe class I, II, and III mutations were pancreatic insufficient or progressed to pancreatic insufficiency. In contrast, patients with mild class IV and V mutations were consistently pancreatic sufficient. In all but four cases each genotype correlated exclusively with the pancreatic phenotype. Quantitative data of acinar and ductular secretion were available in 93 patients. Patients with mutations belonging to classes I, II, and III had greatly reduced acinar and ductular function compared with those with class IV or V mutations. Conclusion: The predicted or known functional consequences of specific mutant alleles correlate with the severity of pancreatic disease in cystic fibrosis.published_or_final_versio
MRI-guided radiotherapy of the SK-N-SH neuroblastoma xenograft model using a small animal radiation research platform
Objective: Neuroblastoma has one of the lowest survival rates of all childhood cancers, despite the use of intensive treatment regimens. Preclinical models of neuroblastoma are essential for testing new multimodality protocols, including those that involve radiotherapy (RT). The aim of this study was to develop a robust method for RT planning and tumour response monitoring based on combined MRI and cone-beam CT (CBCT) imaging and to apply it to a widely studied mouse xenograft model of neuroblastoma, SK-N-SH. Methods: As part of a tumour growth inhibition study, SK-N-SH xenografts were generated in BALB/c nu/nu mice. Mice (n58) were placed in a printed MR-And CT-compatible plastic cradle, imaged using a 4.7-T MRI scanner and then transferred to a small animal radiation research platform (SARRP) irradiator with on-board CBCT. MRI/CBCT co-registration was performed to enable RT planning using the soft-Tissue contrast afforded by MRI prior to delivery of RT (5Gy). Tumour response was assessed by serial MRI and calliper measurements. Results: SK-N-SH xenografts formed soft, deformable tumours that could not be differentiated from surrounding normal tissues using CBCT. MR images, which allowed clear delineation of tumours, were successfully coregistered with CBCT images, allowing conformal RT to be delivered. MRI measurements of tumour volume 4 days after RT correlated strongly with length of survival time. Conclusion: MRI allowed precision RT of SK-N-SH tumours and provided an accurate means of measuring tumour response. Advances in knowledge: MRI-based RT planning of murine tumours is feasible using an SARRP irradiator
Dioxinlike properties of a trichloroethylene combustion-generated aerosol.
Conventional chemical analyses of incineration by-products identify compounds of known toxicity but often fail to indicate the presence of other chemicals that may pose health risks. In a previous report, extracts from soot aerosols formed during incomplete combustion of trichloroethylene (TCE) and pyrolysis of plastics exhibited a dioxinlike response when subjected to a keratinocyte assay. To verify this dioxinlike effect, the complete extract, its polar and nonpolar fractions, some containing primarily halogenated aromatic hydrocarbons, were evaluated for toxicity using an embryo assay, for antiestrogenicity using primary liver cell cultures, and for the ability to transform the aryl hydrocarbon receptor into its DNA binding form using liver cytosol in a gel retardation assay. Each of these assays detect dioxinlike effects. Medaka (Oryzias latipes) embryos and primary liver cell cultures of rainbow trout (Oncorhynchus mykiss) were exposed to concentrations of extract ranging from 0.05 to 45 micrograms/l. Cardiotoxicity with pericardial, yolk sac, and adjacent peritoneal edema occurred after exposure of embryos to concentrations of 7 micrograms/l or greater. These same exposure levels were associated with abnormal embryo development and, at the higher concentrations, death. Some of the fractions were toxic but none was as toxic as the whole extract. In liver cells, total cellular protein and cellular lactate dehydrogenase activity were not altered by in vitro exposure to whole extract (0.05-25 micrograms/l). However, induction of cytochrome P4501A1 protein and ethoxyresorufin O-deethylase activity occurred. In the presence of whole extract, estradiol-dependent vitellogenin synthesis was reduced. Of the fractions, only fraction 1 (nonpolar) showed a similar trend, although vitellogenin synthesis inhibition was not significant. The soot extract and fractions bound to the Ah receptor and showed a significantly positive result in the gel retardation/DNA binding test. Chemical analyses using GC-MS with detection limits for 2,3,7,8-tetrachlorodibenzo-p-dioxin and dibenzofuran in the picomole range did not show presence of these compounds. Our results indicate that other chemicals associated with TCE combustion and not originally targeted for analysis may also pose health risks through dioxinlike mechanisms
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Investigation of cavitation and vapor shedding mechanisms in a Venturi nozzle
Cavitating flow dynamics are investigated in an axisymmetric converging-diverging Venturi nozzle. Computational Fluid Dynamics (CFD) results are compared with those from previous experiments. New analysis performed on the quantitative results from both data sets reveals a coherent trend and show that the simulations and experiments agree well. The CFD results have confirmed the interpretation of the high-speed images of the Venturi flow, which indicated there are two vapor shedding mechanisms that exist under different running conditions: re-entrant jet and condensation shock. Moreover, they provide further detail of the flow mechanisms that cannot be extracted from the experiments. For the first time with this cavitating Venturi nozzle, the re-entrant jet shedding mechanism is reliably achieved in CFD simulations. The condensation shock shedding mechanism is also confirmed, and details of the process are presented. These CFD results compare well with the experimental shadowgraphs, space-time plots and time-averaged reconstructe computed tomography (CT) slices of vapor fraction
The Role of Physical, Chemical, and Microbial Heterogeneity on the Field-Scale Transport and Attachment of Bacteria
A field-scale bacterial transport experiment was conducted at the Narrow Channel Focus Area of the South Oyster field site located in Oyster, Virginia. The goal of the field experiment was to determine the relative influence of subsurface heterogeneity and microbial population parameters on flow direction, velocity, and attachment of bacteria at the field scale. The field results were compared with results from laboratory-scale column experiments to develop a method for predicting field-scale bacterial transport. The field site is a shallow, sandy, unconfined, aerobic aquifer that has been characterized by geophysical, sedimentological, and hydrogeological methods. Comamonas sp. strain DA001 and a conservative tracer, bromide (Br), were injected into an area of high permeability for 12 hours. The Br and bacterial concentrations in the groundwater were monitored for 1 week at 192 sampling ports spaced over a 2-m vertical zone located from 0.5 to 7 m down-gradient of the injection well. The bacterial and Br plume was observed to move past 95 sampling ports. The densely characterized field site enabled the comparison of variations in DA001 transport to the aquifer properties. The velocity of the injected plume was correlated with geophysical estimates of hydraulic conductivity. The bacterial and Br plume appeared to follow flow paths not coincident with the hydraulic gradient but through a zone of higher permeability located off the flow axis. The amount of breakthrough of the bacteria was similar in both the high and low permeability layers with only a weak correlation between the observed hydraulic conductivity and amount of bacterial breakthrough. The uniformity in the observed attachment rates across varying grain sizes could be explained by heterogeneity of microbial properties within the single strain of injected bacteria. Application of colloid filtration theory to the field data indicated that variations in the microbial population were described by a lognormal distribution of the collision efficiency (a). Core-scale studies were used to predict the a distribution and field-scale transport distances of DA001. In sandy aquifers, physical heterogeneity may play a secondary role in controlling field-scale bacterial transport, and future research should focus on the microbial factors affecting transport
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