865 resultados para Elasticity of output with respect to factors
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The existence and attributes of God -- The Bible -- Christian miracles -- Objections to the miracles of the New Testament answered -- Thoughts on the subject of sin -- The teachings of Scripture concerning punishment -- An examination of some of the erroneous interpretations of Scripture with respect to future retribution -- Exposition of Matthew 25:41 -- Parable of Dives and Lazarus -- The teachings of Jesus and his Apostles concerning the Resurrection and a future state -- On grace.
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The prevalence of dementia is growing in developed countries where elderly patients are increasing in numbers. Neurotransmission modulation is one approach to the treatment of dementia. Cholinergic precursors, anticholinesterases, nicotine receptor agonists and muscarinic M-2 receptor antagonists are agents that enhance cholinergic neurotransmission and that depend on having some intact cholinergic innervation to be effective in the treatment of dementia. The cholinergic precursor choline alfoscerate may be emerging as a potential useful drug in the treatment of dementia, with few adverse effects. Of the anticholinesterases, donepezil, in addition to having a similar efficacy to tacrine in mild-to-moderate Alzheimer's disease (AD), appears to have major advantages; its use is associated with lower drop-out rates in clinical trials, a lower incidence of cholinergic-like side effects and no liver toxicity. Rivastigmine is efficacious in the treatment in dementia with Lewy bodies, a condition in which the other anticholinesterases have not been tested extensively to date. Galantamine is an anticholinesterase and also acts as an allosteric potentiating modulator at nicotinic receptors to increase the release of acetylcholine. Pooled data from clinical trials of patients with mild-to-moderate AD suggest that the benefits and safety profile of galantamine are similar to those of the anticholinesterases. Selective nicotine receptor agonists are being developed that enhance cognitive performance without influencing autonomic and skeletal muscle function, but these have not yet entered clinical trial for dementia. Unlike the cholinergic enhancers, the M, receptor agonists do not depend upon intact cholinergic nerves but on intact M, receptors for their action, which are mainly preserved in AD and dementia with Lewy bodies. The M, receptor-selective agonists developed to date have shown limited efficacy in clinical trials and have a high incidence of side effects. A major recent advancement in the treatment of dementia is memantine, a non-competitive antagonist at NMDA receptors. Memantine is beneficial in the treatment of severe and moderate to-severe AD and may also be of some benefit in the treatment of mild-to-moderate vascular dementia. Drugs that modulate 5-HT, somatostatin and noradrenergic neurotransmission are also being considered for the treatment of dementia.
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The rate of generation of fluctuations with respect to the scalar values conditioned on the mixture fraction, which significantly affects turbulent nonpremixed combustion processes, is examined. Simulation of the rate in a major mixing model is investigated and the derived equations can assist in selecting the model parameters so that the level of conditional fluctuations is better reproduced by the models. A more general formulation of the multiple mapping conditioning (MMC) model that distinguishes the reference and conditioning variables is suggested. This formulation can be viewed as a methodology of enforcing certain desired conditional properties onto conventional mixing models. Examples of constructing consistent MMC models with dissipation and velocity conditioning as well as of combining MMC with large eddy simulations (LES) are also provided. (c) 2005 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
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The growth, maintenance and lysis processes of Nitrobacter were characterised. A Nitrobacter culture was enriched in a sequencing batch reactor (SBR). Fluorescent in situ hybridisation showed that Nitrobacter constituted 73% of the bacterial population. Batch tests were carried out to measure the oxygen uptake rate and/or nitrite consumption rate when both nitrite and CO2 were in excess, and in the absence of either of these two substrates. The results obtained, along with the SBR performance data, allowed the determination of the maintenance coefficient and in situ cell lysis rate of Nitrobacter. Nitrobacter spends a significant amount of energy for maintenance, which varies considerably with the specific growth rate. At maximum growth, Nitrobacter consume nitrite at a rate of 0.042 mgN/mgCOD(biomass)center dot h for maintenance purposes, which increases more than threefold to 0.143 mgN/mgCOD(biomass)center dot h in the absence of growth. In the SBR, where Nitrobacter grew at 40% of its maximum growth rate, a maintenance coefficient of 0.113 mgN/mgCOD center dot h was found, resulting in 42% of the total amount of nitrite being consumed for maintenance. The above three maintenance coefficient values obtained at different growth rates appear to support the maintenance model proposed in Pirt (1982). The in situ lysis rate of Nitrobacter was determined to be 0.07/day under aerobic conditions at 22 C and pH 7.3. Further, the maximum specific growth rate of Nitrobacter was estimated to be 0.02/h (0.48/day). The affinity constant of Nitrobacter with respect to nitrite was determined to be 1.50 mgNO(2)(-)-N/L, independent of the presence or absence of CO2. (c) 2006 Wiley Periodicals, Inc.
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Posttransplantation diabetes (PTD) contributes to cardiovascular disease and graft loss in renal transplant recipients (RTR). Current recommendations advise fasting blood glucose (FBG) as the screening and diagnostic test of choice for PTD. This study sought to determine (1) the predictive power of FBG with respect to 2-h blood glucose (2HBG) and (2) the prevalence of PTD using FBG and 2HBG compared with that using FBG alone, in prevalent RTR. A total of 200 RTR (mean age 52 yr; 59% male; median transplant duration 6.6 yr) who were >6 mo posttransplantation and had no known history of diabetes were studied. Patients with FBG
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This thesis presents an analysis of the stability of complex distribution networks. We present a stability analysis against cascading failures. We propose a spin [binary] model, based on concepts of statistical mechanics. We test macroscopic properties of distribution networks with respect to various topological structures and distributions of microparameters. The equilibrium properties of the systems are obtained in a statistical mechanics framework by application of the replica method. We demonstrate the validity of our approach by comparing it with Monte Carlo simulations. We analyse the network properties in terms of phase diagrams and found both qualitative and quantitative dependence of the network properties on the network structure and macroparameters. The structure of the phase diagrams points at the existence of phase transition and the presence of stable and metastable states in the system. We also present an analysis of robustness against overloading in the distribution networks. We propose a model that describes a distribution process in a network. The model incorporates the currents between any connected hubs in the network, local constraints in the form of Kirchoff's law and a global optimizational criterion. The flow of currents in the system is driven by the consumption. We study two principal types of model: infinite and finite link capacity. The key properties are the distributions of currents in the system. We again use a statistical mechanics framework to describe the currents in the system in terms of macroscopic parameters. In order to obtain observable properties we apply the replica method. We are able to assess the criticality of the level of demand with respect to the available resources and the architecture of the network. Furthermore, the parts of the system, where critical currents may emerge, can be identified. This, in turn, provides us with the characteristic description of the spread of the overloading in the systems.
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A passively switched Ho3+, Pr3+ codoped fluoride fiber laser using a semiconductor saturable absorber mirror (SESAM) is demonstrated. Q-switching and partial mode-locking were observed with the output power produced at a slope efficiency of 24% with respect to the absorbed pump power. The partially mode-locked 2.87 µm pulses operated at a repetition rate of 27.1 MHz with an average power of 132 mW, pulse energy of 4.9 nJ, and pulse width of 24 ps.
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SO2 oxidation has been followed by Fast XPS over Pt{111}. Preadsorbed oxygen reduces the low temperature saturation coverage of SO2 with respect to the clean surface. Heating a mixed O2/SO2 adlayer results in efficient oxidation of both upright and flat-lying SO2 molecules to surface-bound SO4. Sulphate decomposes above room temperature liberating gas-phase SO2 and SO3. Propene adsorbs molecularly at 100 K over clean Pt{111} and dehydrogenates above 250 K to form a stable propylidyne adlayer, which in turn decomposes above 400 K to form graphitic carbon. Preadsorbed surface sulphate enhances the sticking probability of propene via formation of an alkyl-sulphate complex. Thermal decomposition of this complex accounts for low temperature propene combustion and is accompanied by atomic sulpur deposition. Propylidyne forms as on clean Pt but is less reactive undergoing partial oxidation above 450 K with residual surface oxygen.
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Reliability modelling and verification is indispensable in modern manufacturing, especially for product development risk reduction. Based on the discussion of the deficiencies of traditional reliability modelling methods for process reliability, a novel modelling method is presented herein that draws upon a knowledge network of process scenarios based on the analytic network process (ANP). An integration framework of manufacturing process reliability and product quality is presented together with a product development and reliability verification process. According to the roles of key characteristics (KCs) in manufacturing processes, KCs are organised into four clusters, that is, product KCs, material KCs, operation KCs and equipment KCs, which represent the process knowledge network of manufacturing processes. A mathematical model and algorithm is developed for calculating the reliability requirements of KCs with respect to different manufacturing process scenarios. A case study on valve-sleeve component manufacturing is provided as an application example of the new reliability modelling and verification procedure. This methodology is applied in the valve-sleeve component manufacturing processes to manage and deploy production resources.
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The purpose of this research was to explore perceptions among 9 th through 12th grade students from Brazil, Haiti and Jamaica, with respect to their heritage languages: Portuguese, Haitian Creole, and Jamaican Patois. An additional purpose was to understand in greater detail possible variations of perception with respect to heritage language maintenance (or loss) in relation to one’s gender, first language, and place of birth. The research implemented semi-structured interviews with male and female adolescents with these heritage language backgrounds. Participants’ responses were recorded and transcribed. The transcriptions were analyzed via a categorizing of themes emerging from the data. Data were analyzed using inductive analysis. Three categories emerged from the inductive analysis of the data: (a) heritage language, (b) bilingualism, and (c) English as a second language. The analysis reveals that as participants learn English, they continue to value their heritage language and feel positively toward bilingualism, but differ in their preference regarding use of native language and English in a variety of contexts. There seems to be a mismatch between a positive attitude and an interest in learning their heritage language. Families and teachers, as agents, may not be helping students fully understand the advantages of bilingualism. Students seem to have a lack of understanding of bilingualism’s cognitive and bi-literacy benefits. Instead, employment seems to be perceived as the number one reason for becoming bilingual. Also, the students have a desire to add culture to the heritage language curriculum. The study was conducted at one of the most diverse and largest high schools in Palm Beach, in Palm Beach County, Florida. The results of this study imply that given the positive attitude toward heritage language and bilingualism, students need to be guided in exploring their understanding of heritage language and bilingualism. Implications for teaching and learning, as well as recommendations for further research, are included.
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Tree islands in the Shark River Slough of the Everglades National Park (ENP), in the southern state of Florida in the United States, are part of a wetland system of densely vegetated ridges interspersed within relatively open sloughs. Human alteration of this system has had dramatic negative effects on the landscape of the region and restoration efforts will require adjusting the hydrology of the region to assure the preservation of these important ecologic features. The primary objectives of this study were to document the hydrology in the vicinity of tree islands in ENP by measuring velocities in time and space and by characterizing suspended sediments. The results of such measurements were interpreted with respect to factors that may limit tree island growth. The measurements were conducted in the vicinity of three tree islands known as Black Hammock (BH), Gumbo Limbo (GL), and an unnamed island that was named for this study as Satin Leaf (SL). Acoustical Doppler Velocity (ADV) meters were used for measuring the low velocities of the Everglades water flow. Properties of suspended sediments were characterized through measurements of particle size distribution, turbidity, concentration and particle density. Mean velocities observed at each of the tree islands varied from 0.9 to 1.4 cm/s. Slightly higher mean velocities were observed during the wet season (1.2–1.6 cm/s) versus the dry season (0.8–1.3 cm/s). Maximum velocities of more than 4 cm/s were measured in areas of Cladium jamaicense die-off and at the hardwood hammock (head) of the islands. At the island’s head, water is channelized around obstructions such as tree trunks in relatively rapid flow, which may limit the lateral extent of tree island growth. Channelization is facilitated by shade from the tree canopy, which limits the growth of underwater vegetation thereby minimizing the resistance to flow and limiting sediment deposition. Suspended sediment concentrations were low (0.5–1.5 mg/L) at all study sites and were primarily of organic origin. The mean particle size of the suspended sediments was 3 μm with a distribution that was exponential. Critical velocities needed to cause re-suspension of these particles were estimated to be above the actual velocities observed. Sediment transport within the water column appears to be at a near steady state during the conditions evaluated with low rates of sediment loss balanced by presumably the release of equivalent quantities of particles of organic origin. Existing hydrologic conditions do not appear to transport sufficient suspended sediments to result in the formation of tree islands. Of interest would be to collect hydrologic and sediment transport data during extreme hydrologic events to determine if enough sediment is transported under these conditions to promote sufficient sediment accumulations.
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Trenchless methods have been considered to be a viable solution for pipeline projects in urban areas. Their applicability in pipeline projects is expected to increase with the rapid advancements in technology and emerging concerns regarding social costs related to trenching methods. Selecting appropriate project delivery system (PDS) is a key to the success of trenchless projects. To ensure success of the project, the selected project delivery should be tailored to trenchless project specific characteristics and owner needs, since the effectiveness of project delivery systems differs based on different project characteristics and owners requirements. Since different trenchless methods have specific characteristics such rate of installation, lengths of installation, and accuracy, the same project delivery systems may not be equally effective for different methods. The intent of this paper is to evaluate the appropriateness of different PDS for different trenchless methods. PDS are examined through a structured decision-making process called Fuzzy Delivery System Selection Model (FDSSM). The process of incorporating the impacts of: (a) the characteristics of trenchless projects and (b) owners’ needs in the FDSSM is performed by collecting data using questionnaires deployed to professionals involved in the trenchless industry in order to determine the importance of delivery systems selection attributes for different trenchless methods, and then analyzing this data. The sensitivity of PDS rankings with respect to trenchless methods is considered in order to evaluate whether similar project delivery systems are equally effective in different trenchless methods. The effectiveness of PDS with respect to attributes is defined as follows: a project delivery system is most effective with respect to an attribute (e.g., ability to control growth in costs ) if there is no project delivery system that is more effective than that PDS. The results of this study may assist trenchless project owners to select the appropriate PDS for the trenchless method selected.
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Rising concentrations of atmospheric CO2 are changing the carbonate chemistry of the oceans, a process known as ocean acidification (OA). Absorption of this CO2 by the surface oceans is increasing the amount of total dissolved inorganic carbon (DIC) and bicarbonate ion (HCO3) available for marine calcification yet is simultaneously lowering the seawater pH and carbonate ion concentration ([CO3]), and thus the saturation state of seawater with respect to aragonite. We investigated the relative importance of [HCO3] versus [CO3] for early calcification by new recruits (primary polyps settled from zooxanthellate larvae) of two tropical coral species, Favia fragum and Porites astreoides. The polyps were reared over a range of ?ar values, which were manipulated by both acid-addition at constant pCO2 (decreased total [HCO3] and [CO3]) and by pCO2 elevation at constant alkalinity (increased [HCO3], decreased [CO3]). Calcification after 2 weeks was quantified by weighing the complete skeleton (corallite) accreted by each polyp over the course of the experiment. Both species exhibited the same negative response to decreasing [CO3] whether ?ar was lowered by acid-addition or by pCO2 elevation-calcification did not follow total DIC or [HCO3]. Nevertheless, the calcification response to decreasing [CO3] was nonlinear. A statistically significant decrease in calcification was only detected between Omega aragonite = <2.5 and Omega aragonite = 1.1-1.5, where calcification of new recruits was reduced by 22-37% per 1.0 decrease in Omega aragonite. Our results differ from many previous studies that report a linear coral calcification response to OA, and from those showing that calcification increases with increasing [HCO3]. Clearly, the coral calcification response to OA is variable and complex. A deeper understanding of the biomineralization mechanisms and environmental conditions underlying these variable responses is needed to support informed predictions about future OA impacts on corals and coral reefs.
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This study was undertaken to examine how instructor use of emerging technologies can contribute to better quality pre-service teacher education. A group of nine Memorial University Faculty of Education instructors attempted to systematically incorporate mobile tablet (iPad) technologies into their on-campus instruction over the period of one academic year (2013-2014). Participants familiarized themselves with their device; evaluated a range of instructional applications (apps) specific to their discipline and/or teaching focus areas; and attempted to intentionally integrate the device into the classroom-learning environment. The research team utilized several focus groups and semi-structured interviews to elicit the representations of participants with respect to their impressions of the value of tablet technologies and their experiences in implementing tablet technology in their instructional practice.
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Increasing atmospheric pCO2 reduces the saturation state of seawater with respect to the aragonite, high-Mg calcite (Mg/Ca > 0.04), and low-Mg calcite (Mg/Ca < 0.04) minerals from which marine calcifiers build their shells and skeletons. Notably, these polymorphs of CaCO3 have different solubilities in seawater: aragonite is more soluble than pure calcite, and the solubility of calcite increases with its Mg-content. Although much recent progress has been made investigating the effects of CO2-induced ocean acidification on rates of biological calcification, considerable uncertainties remain regarding impacts on shell/skeletal polymorph mineralogy. To investigate this subject, eighteen species of marine calcifiers were reared for 60-days in seawater bubbled with air-CO2 mixtures of 409 ± 6, 606 ± 7, 903 ± 12, and 2856 ± 54 ppm pCO2, yielding aragonite saturation states of 2.5 ± 0.4, 2.0 ± 0.4, 1.5 ± 0.3, and 0.7 ± 0.2. Calcite/aragonite ratios within bimineralic calcifiers increased with increasing pCO2, but were invariant within monomineralic calcifiers. Calcite Mg/Ca ratios (Mg/CaC) also varied with atmospheric pCO2 for two of the five high-Mg-calcite-producing organisms, but not for the low-Mg-calcite-producing organisms. These results suggest that shell/skeletal mineralogy within some-but not all-marine calcifiers will change as atmospheric pCO2 continues rising as a result of fossil fuel combustion and deforestation. Paleoceanographic reconstructions of seawater Mg/Ca, temperature, and salinity from the Mg/CaC of well-preserved calcitic marine fossils may also be improved by accounting for the effects of paleo-atmospheric pCO2 on skeletal Mg-fractionation.