545 research outputs found
Traffic management and control in intelligent vehicle highway systems
No full textTraffic congestion is a problem experienced daily by most of us. Among various traffic management schemes, efficient utilisation of the existing roadside infrastructure combined with in-vehicle technologies offers a promising solution to address traffic congestion and related problems. This approach has resulted in the development of Intelligent Vehicle Highway Systems (IVHSs). An IVHS basically consists of roadside infrastructures interacting with automated intelligent vehicles (IVs) that are organised in a closely spaced groups called platoons. With platooning, more vehicles can be accommodated on the highway, thus increasing the traffic flow. In the present situation, most of the existing traffic management and control centers use conventional roadside-based control measures to improve the traffic performance. The objective of the thesis is to provide a framework and a systematic approach for integrating traffic control and management methods into the IVHS. The focus of the thesis is on combining the control capabilities offered by automated platoons with those of the roadside infrastructure. We aim at developing traffic management and control methods to be implemented at various control levels, by incorporating intelligence from and within vehicles. Thus the roadside controllers use both IV-based and conventional traffic control measures for controlling and managing platoons, such that the performance of the traffic is improved.Delft Center for Systems and ControlMechanical, Maritime and Materials Engineerin
L.D. Trotsky and Activity of Research and Technology Division of USSR Supreme Council of National Economy in mid-1920s
No full textThe article considers the activities of L.D. Trotsky as the head of the Research and Technology Division of the Supreme Council of National Economy of the USSR in 1925–1926. The author uses archival documents from the Fund of the Russian State Archive of Economy, documents from the Russian State Archive of Social and Political History and other sources. There is analyzed L.D. Trotsky’s contribution to the development of applied science in the USSR
Manifesto on Neighbourliness
No full textThe manifesto and toolkit offers a starting place for ethical creative inquiry when making work with other people or community from an institutional position, such as student, artist-in-resident, or faculty. It is in response to the author’s experience as a community practice artist who spent their undergraduate degree at Emily Carr University frustrated with the overwhelming pressure to create fast-paced, ethically questionable projects using community as subject. Manifesto on Neighbourliness: Ethics Toolkit for Creative Community Inspiration collates knowledge shared via conversation, reading assignments, making mistakes, and other forms of interdependent inquiry. Mickey L.D. Morgan explores ethics through themes such as care, mitigating violence, responsibility, while at the same time an attempt at practicing these through situating themself within the text
Theoretical studies of the historical development of the accounting discipline: a review and evidence
No full textMany existing studies of the development of accounting thought have either been atheoretical or have adopted Kuhn's model of scientific growth. The limitations of this 35-year-old model are discussed. Four different general neo-Kuhnian models of scholarly knowledge development are reviewed and compared with reference to an analytical matrix. The models are found to be mutually consistent, with each focusing on a different aspect of development. A composite model is proposed. Based on a hand-crafted database, author co-citation analysis is used to map empirically the entire literature structure of the accounting discipline during two consecutive time periods, 1972–81 and 1982–90. The changing structure of the accounting literature is interpreted using the proposed composite model of scholarly knowledge development
Biohydrogen production under hyper salinity stress by an anaerobic sequencing batch reactor with mixed culture
No full textBackground: This study investigated the effect of organic loading rate (OLR) and NaCl concentration on biohydrogen production by preheated anaerobic sludge in a lab scale anaerobic sequencing batch reactor (ASBR) fed with glucose during long time operation. Methods: During ASBR operation, the OLR was increased in steps from 0.5 to 5 g glucose/L.d and NaCl addition started at an OLR of 5 g glucose/L.d, to obtain NaCl concentrations in the reactor in the range of 0.5-30 g/L. Results: With an increasing OLR from 0.5 to 5 g glucose/L.d, the biohydrogen yield increased and reached 0.8 ± 0.4 mol H2/mol glucose at an OLR of 5 g glucose/L.d. A NaCl concentration of 0.5 g/L resulted in a higher yield of biohydrogen (1.1 ± 0.2 mol H2/mol glucose). Concentrations above 0.5 g/L NaCl led to decreasing biohydrogen yield and the lowest yield (0.3 ± 0.1 mol H2/mol glucose) was obtained at 30 g/L of NaCl. The mass balance errors for C, H, and O in all constructed stoichiometric reactions were below 5%. Conclusions: The modified Monod model indicated that r (H2)max and Ccrit values were 23.3 mL H2/g VSS/h and 119.9 g/L, respectively. Additionally, ASBR operation at high concentrations of NaCl shifted the metabolic pathway from acidogenic toward solventogenic.Sanitary Engineerin
Becoming a good host: A beginner’s guide to learning deliberative civic engagement
No full textThis article examines how Deliberative Civic Engagement (DCE) is used as a public engagement process to invite disjointed cultural communities into a shared space to engage in democratically inspired dialogue. Dialogue is sought in DCE events because it encourages reflexivity and allows for collaborative ideation processes. Collaboration among differing groups demands that DCE events are open enough to be influenced by the immediate concerns of the participants involved. In addition, openness and vulnerability are required to support deep level thinking and connection between heterogeneous identities represented.
Kevin L.D. Leaven is a recent graduate of the James Madison University’s graduate program in Communication and Advocacy.
Author\u27s note
As the COVID-19 crisis continues, social distancing is being encouraged to minimize the spread of the coronavirus. Consequently, many conversations between colleagues, friends, and family have moved online using platforms like Zoom and Google Hangouts. Digital technologies have enabled people to overcome some of the obstacles posed by this unprecedented viral event. However, merely having the technology to talk to our peers does not automatically make conversations easier. Nor does COVID-19 erase the social barriers that previously complicated our relationships. However, I believe that people are resilient and that there are ample tools available to spark meaningful discussions amongst our associates. Thus, this article serves as a primer for deliberative civic engagement, which provides one approach to facilitating constructive, informed, and decisive dialogue with others. I argue that cultivating constructive dialogue is a skill with multiple avenues for improvement. So I hope that this article will provide helpful ideas to strengthen your communication skills while encouraging you to engage in fruitful dialogue with others in your life
In-situ product removal by membrane extraction
No full textIn bioproduction processes of chemicals and pharmaceuticals, downstream processing usually is a significant cost factor. The products require a high purity (especially biopharmaceutical products), therefore, the process usually contains a large number of separation steps. Moreover, the high costs in downstream processing are caused by the fact that the products are often produced in a dilute environment. Since high product concentrations can cause inhibition of biological growth and production, the product should be removed from the production medium at relatively low concentrations. The use of in-situ product removal (ISPR) is a useful strategy to overcome this problem. Integration of the first downstream process step with the bioreactor leads to direct removal of product during growth and production reactions, potentially increasing the productivity of the biocatalyst and thus the total yield of product. ISPR potentially decreases waste streams, fermentor volume and the stress on micro-organisms resulting from oxygen limitation and shear stress caused by the cycling of the fermentation broth. In addition, decreasing the number of steps in the downstream processing of the product potentially leads to a decrease in the total process costs and processing time. The aim of this thesis is to study the potential of integrated membrane extraction as a tool for ISPR for the removal of products from a fermentation broth. Membrane extraction (pertraction) enables a large contacting surface area between fermentation broth (aqueous phase) and solvent without the formation of an emulsion and is therefore a useful technique for ISPR. The production of phenol by Pseudomonas putida S12 was chosen as a model process to illustrate product inhibition and to demonstrate the effects of ISPR by extraction with 1-octanol. Phenol was chosen as a model component and is a typical example of a fine chemical. It serves as a good model for aromatics containing a hydroxyl group. Additionally, due to its toxicity, phenol can well illustrate the effects of product inhibition. An experimental study to illustrate product inhibition of phenol on the recombinant organism Pseudomonas putida S12 is described in chapter 2. It was demonstrated that the implementation of membrane extraction does not influence growth and phenol production. When phenol is removed from the fermentation broth by pertraction, a lower maximum aqueous phenol concentration is achieved, while the total phenol production increases to 132% as compared to the fermentation without pertraction. There are indications that the volumetric productivity increases slightly in the fermentations with in-situ pertraction as compared to the reference experiments. In chapter 3, detailed calculations on the production of phenol in a conceptual process design illustrate the benefits and disadvantages of ISPR with an implemented membrane extraction unit in a bioreactor as compared to ISPR with a membrane extraction unit outside the reactor. Results show that running the fermentation process at a lower product concentration results in a more efficient substrate utilization into biomass and phenol. The disadvantage of the integrated process is the need for large distillation columns and a high energy input for solvent regeneration due to the low product concentration in the solvent and the high solvent fluxes. Economic evaluations of the two processes show that to obtain a return of investment of 15%, the product cost price of the integrated process is a factor of three lower as compared to the non-integrated process. In chapter 4 mass transfer is studied for phenol in fermentation systems and single fiber modules. Additionally, an approach is given for a novel membrane extraction module design for implementation in a large scale bioreactor by combining experimental and theoretical results. Factors that were found to influence the overall mass transfer coefficient are the membrane wall thickness, solvent (partition coefficient), sterilization and fouling (negative effect). Furthermore, bottlenecks and strategies for improvement are discussed. The integration of an extra obstacle into the reactor can give rise to several bottlenecks for both the separation process and the biological growth and production processes, mainly caused by the altered mixing pattern. In chapters 5 and 6, the use of alternative solvents consisting of polymeric micelles solubilized in water are discussed and an alternative membrane extraction process evaluation is made. The micelles are formed of poly(ethylene oxide)–poly(propylene oxide) (PEO–PPO–PEO) block copolymers, commercially known as Pluronics. Pluronics are water-soluble, nonionic macromolecular surface active agents which are environmentally mild and hardly toxic to micro-organisms. The applicability of aqueous solutions of Pluronics for the removal of phenol in a separation and regeneration process is evaluated. Experimental results show that Pluronic micelles allow extraction of phenol from aqueous solutions at 30 °C (fermentation temperature). The phenol can be released due to the transition of the Pluronic micelles into unimers with a mild temperature switch from 30 to 8 °C. Ultrafiltration membranes provide a barrier between the aqueous Pluronic stripping solution and the aqueous solution in a (bio)reactor containing the desired product. Steady state model analysis and cost estimation show that the process costs are mainly determined by the required membrane area. In chapter 7 the potential of integrated membrane extraction as an in-situ product recovery tool for the removal of products from a fermentation broth is discussed. Furthermore, improvement of the mass transfer limitation at the reactor side by a discontinuous moving membrane module is discussed. Fouling of micro-organisms and medium components at the aqueous (shell) side of the membrane has a negative effect on the overall mass transfer coefficient by increasing the boundary layer thickness at reactor side at the membrane surface. To improve the shell-side mass transfer, the turbulence at the membrane surface can be increased by the use of alternative membrane modules which cause high surface shear rates along the membrane. The novel membrane module described in this chapter shows interesting possibilities in microfiltration to improve the flux by reducing the fouling at the membrane surface. Finally, it can be concluded that integrated membrane extraction shows potential as a tool for the removal of products from a fermentation broth. The benefits of an integrated process will pay off even more for very toxic and inhibiting products that do not allow for high concentrations in the (bio)reactor. The alternative process based on Pluronic micelles can be suited for products that allow for a higher critical concentration in the (bio)reactor as compared to phenol. The resulting higher driving force for membrane extraction will result in a decrease of the overall process costs. For products with a lower solubility in water, recovery is easy after regeneration of the micellar solvent.BiotechnologyApplied Science
A theory of routing in parallel computers from concept to analysis
No full textElectrical Engineering, Mathematics and Computer Scienc
Idaho Spring Barley Production Guide
No full textBulletin no. 742 Moscow, Idaho :University of Idaho, College of Agriculture, Cooperative Extension System, 1992-01-01. Author(s): Robertson, L.D.; Stark, J.C
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