1,367 research outputs found
Pollution dispersion from highways: Enhancing particulate matter capture using aerodynamics
No full textPeople living or working close to the highways are at risk to higher exposure levels of different air pollutants, one of which is particulate matter. The Antea group has recently proposed the addition of Electrostatic Precipitators (or ESPs) on the top of sound barriers adjacent to highways, in order to capture the particulate matter and safely discard them. This is an attractive, but expensive, supplement. While estimates of the collection efficiency (i.e. what percentage of particulate matter mass entering the ESP is collected by the device) are known, the aerodynamic efficiency of the ESP (i.e. what percentage of pollutants reach the ESP entrance as compared to the mass emitted) is yet to be determined. The net efficiency of the ESP will be the product of the above two efficiencies, making it necessary to study the latter, prior to large-scale installation.Scaled down experiments were performed in a water channel, housed in the Laboratory for Aero and Hydrodynamics at the Delft University of technology. Simultaneous measurements of the flow velocities and dye intensities in the symmetry-plane of the channel were made through planar Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF). A few flow configurations were studied by varying certain parameters. It was found that: (a) ESP installation is more beneficial on top of shorter sound barriers. (b) Slightly raising the ESP from the top of the sound barrier is advantageous. (c) Installation of ESPs in isolated highway canyons should be done with care, as several flow regimes are observed.First order estimates on the aerodynamic efficiencies of the ESP were determined. This was accompanied by the identification of ESP performance trends that should serve as a guideline for the initial testing of the ESPs at full scale. The guidelines include the physical location and entrance orientation of the ESP. It is known that the collection efficiency of the ESP is a function of the incoming flow velocity. It is recommended that the entrance flow velocities reported here be used as an input for calculating the associated particle collection efficiency. Together, the collection and aerodynamic efficiencies can be used to estimate the overall efficiency of the ESP. If the overall efficiency satisfies a minimum desirable threshold, the field experiments yield promising results, the device clears safety requirements, and the benefits outweigh the costs, the ‘Open Air Line ESP’ can be installed along the highways en masse in the future
Suspension Taylor-Couette flow: Investigation of particle loading effects on transitions between flow regimes
No full textTaylor-Couette (TC) flow refers to the flow in the annulus between two coaxial, independently rotating cylinders. The TC system has been subject to multiple experiments spanning over decades due to the instability phenomena that occur in the flow. When the rotation rates of the cylinders are increased beyond a critical value, instabilities appear in the system that result in the formation of different flow regimes. Single-phase flow in the TC system has been studied extensively and the various flow transitions have been catalogued for different geometrical parameters and rotational conditions. In the current experiments (Radius ratio= 0.917, Aspect ratio= 22), flow visualisation with anisotropic reflective particles has been used to obtain qualitative and quantitative information about the different flow regimes using Space-Time (S-T) plots and their spectral analyses. An aqueous glycerine solution was used as the working fluid for single-phase flows. The critical Reynolds number (calculated based on inner cylinder shear rate) for the transition from laminar Couette flow was found to be slightly higher for the current setup in comparison to other experiments found in literature, but the order of flow transitions and their spectral characterisation for all the flow regimes showed good agreement, serving as a validation for the setup. With the established single-phase flow as a base, the effect of particle loading on the flow transitions was studied. A neutrally buoyant particle-laden suspension was prepared using an aqueous glycerine solution with Poly(methyl methacrylate) (PMMA) particles of 619-micrometer diameter. The volume fraction of the particles was varied from 0.05 till 0.40 and the flow map was constructed for multi-phase flow. The primary effect of particle addition is an earlier onset of the first transition from laminar Couette flow, thus indicating a destabilisation of the flow by particles. In addition to this, several non-axisymmetric flow structures appeared in the suspension experiments which were absent in the single-phase flow experiments. The particles caused the appearance of flow regimes such as spirals (Taylor vortices that move up the cylinder axis in a helical motion) and ribbons (block-like structures that have alternating light and dark squares), which normally occur in the case of counter-rotating cylinders for single-phase flow. The transitions across all volume fractions were characterised based on the S-T plots and/or spectra to obtain a consolidated flow map for particle-laden suspensions. The results presented point towards intriguing flow behaviour that provides a large parameter space for further research in the years to come
Air pollutant sinks on noise barriers: Where do they perform the best?
No full textWhile laboratory experiments, numerical simulations as well as field tests have underlined the influence of noise barriers in dispersing vehicular emissions and reducing downwind peak concentrations, these pollutants still remain in the atmosphere. Artificial pollutant sinks (for example, particle capturing or toxic gas treating devices) installed on top of noise barriers can further alleviate this problem by eliminating the pollutants passing through it. However, it is not known how the installation of a semi-permeable pollutant sink affects the aerodynamics of the pollutants’ flow. By finding an optimal position and orientation for these sinks, the mass of the pollutants reaching the sink inlet can be maximized. Scaled down water tunnel experiments have been used to investigate the effectiveness of installing such a pollutant sink, of fixed dimensions, on top of a noise barrier adjacent to a highway. It is found that installing a sink is more beneficial on top of shorter barriers and that vertically elevating the sink, only slightly, can enhance its pollutant capturing performance. Using a sink in a ‘highway canyon’ (two noise barriers placed symmetrically with respect to the highway) must be done cautiously as there are several flow regimes observed, which are sensitive not only to the canyon aspect ratio (ratio between canyon width and height), but also to the presence/absence of the sink. The results here not only demonstrate the effectiveness of installing pollutant sinks on noise barriers, but also provide ballpark estimates on the optimal placement, orientation and performance of these devices, prior to field tests or even large-scale installation.Accepted Author ManuscriptMulti Phase SystemsFluid Mechanic
Dingo Dash
No full textThe author gives an overview of Dingo Dash videogame made for iOS and how the study the target audience, understanding today’s market and some processes post-launch have a huge impact on the app success. I will use my game as a good example on how to not make and publish a game
AN ADAPTATIVE BITRATE ALGORITHM FOR DASH
No full textDynamic adaptive streaming over HTTP (DASH) has been widely used on the Internet. However, DASH does not impose any algorithm to choose video quality. In this paper, an adaptive bitrate switch algorithm for DASH player is proposed. Firstly, the proposed algorithm takes video playback quality, video rate switching frequency and buffer status into account in order to meet the available bandwidth. Secondly, several measures are designed specially to improve user visual quality. Besides, the proposed player takes a sub-optimal algorithm to avoid video playback interruptions. Experimental results demonstrate that the proposed player can provide better performance compared with Bitdash player in several aspects, such as video quality switch frequency, bandwidth utilization and subjective visual experience.CPCI-S(ISTP)[email protected]; [email protected]; [email protected]; [email protected]
An Interdisciplinary Study of Narrative Structure in Dash Akol as a Short Story and Dash Akol as a Movie
No full textThis paper undertakes an interdisciplinary study of the short story “Dash Akol” and the movie adapted from it. “Dash Akol” is a short story written by a famous Iranian author Sadeq Hedayat in 1932. Hedayat’s “Dash Akol” was made into a movie in 1971 by Masoud Kimiai. There are some discrepancies between the short story “Dash Akol” and the movie, triggering a number of significant implications. This article discusses these discrepancies along with Hedayat’s and Kimiai’s narrative techniques. To this end, it applies Genett’s (1988) Narrative Discourse and his three main narrative methods: narrating, characterization, and focalization. Meanwhile, it brings in Rimmon-Kenen’s (2002) strategy to study characters, and Stam and Burgoyne and Flitterman-lewis (2005) to show the ways in which the movie has deviated from the story. In terms of characterization, it studies traits such as, action, speech, naming and setting
Harvard's Disappointing DASH: Short Update on the Knoll Case
No full text?p=20051 There are now 123 articles by Professor Knoll. None of the 23 newest articles (at the time of my test there were 100 Knoll articles in DASH) is Open Access in DASH - all are only providing links to the published version: "At the direction of the depositing author this work is not currently accessible through DASH." There is now an field "Other sources" with links to eventually free online versions. But these links are not complete, see e.g. http://dash.harvard.edu/handle/1/3190372 W..
Analisis Penerapan Dietary Approaches to Stop Hypertension (DASH) pada Penderita Hipertensi
No full textHypertension is an increase in systolic blood pressure of more than 140 mmHg and a diastolic blood pressure of more than 90 mmHg on two measurements with an interval of five minutes in a state of adequate rest. Of the two nutritionists that have been interviewed by author, both of them gave the same opinion about the DASH daily diet, which is that it is a diet that focuses on reducing salt and saturated fat consumption, and also increases consumption of foods with high potassium, calcium, magnesium, and fiber level, where this diet can reduce high blood pressure. Proof that the DASH daily diet can reduce and maintain blood pressure stability for hypertensive patients can be seen in the two hypertensive patients that have been interviewed by author. Both of them claimed that they have received education about the DASH from doctors who handled them and they have applied the concept of the DASH in their daily lives. And it can be seen that their blood pressure slowly dropped and rarely relapsed after applying this diet. Both of them even admitted that in the last three months, their hypertention had never relapsed again. This can be evidence that the DASH daily diet can be effective in reducing and maintaining blood pressure stability for people with hypertension. For this reason, the author suggest the importance of educating hypertensive patients on the DASH, as well as direct supervision from the family regarding the discipline of sufferers in implementing the DASH daily diet
On the polyfunctionality of punctuation marks in modern German (on the example of the dash)
No full textThe article analyzes the functions of the dash in literary German-language texts. The purpose of the study is to clarify and describe the various functions of the dash, to determine its role in the transmission of the communicative intention of the author of the written text. It is established that the dash is a multifunctional punctuation mark which complicates and specifies its functions depending on the contextual conditions of its use and the communicative situation. Two main groups of functions were identified and described: structural-semantic and expressive. Within the framework of structural and semantic functions, the dash is an indicator of logical relations in an utterance – causal and contrast ones. Being a means of a written text division, the dash performs compositional functions: it signals the transition from one type of speech transmission to another, to a new microtheme, a change of the addressee-addresser of speech. The dash is a graphic means of creating expressiveness, marking expressive syntactic constructions (inserts, separations, introductory structures, attachments, parentheses), pauses in a character’s speech, contributing to the compression of the utterance, the effect of emotional tension, the incompleteness of the utterance. The dash is one of those punctuation marks that have a vivid stylistic potential and are widely used by the authors in order to create a special artistic effect. This applies both to cases where the current punctuation rules allow one to choose between a dash and another character, and when the rules do not require any character at all. The choice of the dash depends on the author’s communicative intention and can be explained based on the context, or by the predominant use of the dash, which is one of the elements of the author’s style.  
Understanding how food labels impact the dash diet and blood pressure
No full textAbstract
Purpose of Project
This study aims to answer the clinical question of What is the impact of understanding food labels and Dietary Approaches to Stop Hypertension (DASH) diet in relationship with blood pressure?
Methodology
This Quasi-Experimental study will take place in northern New Jersey with male and female patients who are eighteen and older and have a blood pressure that is over 130/80. The method of this study will have the participant take a survey at the first appointment and then watch a YouTube video made by the study team on DASH diet and food label education. The patient will then make a follow up appointment in 2 weeks to take the post-intervention survey. Qualtrics and SPSS program will interpret data on whether the food label and DASH diet education was successful and had a relationship with blood pressure.
Results
There were significant statistics p-value = <0.001 which showed improved patient BP to 129/80 or less (70%) when they understood and used food labels regularly & the DASH diet as well as improved patient weight- by at least 1 lb. (96%) when they understood and used food labels & the DASH diet.
Implications for practice
Patients with hypertension had about two thousand dollars higher annual adjusted expenditure than those without hypertension (Benjamin et al.,2017). Hypertensive patients also had “2.5 times the inpatient cost, almost double the outpatient cost, and nearly triple the prescription medication expenditure” (Benjamin et al., 2017). There are countless complications that come from hypertension like renal disease, cardiac disease, stroke, and or death which can lead to life-threatening situations. Recommendation on Food label and DASH diet education which has a powerful impact on blood pressure and weight should be considered during office visits with patients Keywords: Food labels, DASH diet, Blood Pressure, Hypertension, and Pre-HypertensionD.N.P.Includes bibliographical reference
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