1,494 research outputs found
Effects Of Line Inclination On The Hydrodynamics Of Riser Transport In The Non-slugging Dense Phase Flow Regime
The present work was undertaken to evaluate the effects of slight line inclinations ({dollar}\theta\ \le\ 18\sp\circ{dollar} from the vertical) on the hydrodynamics of non-slugging dense phase upwards cocurrent gas-solids flows. Previous research and operating experience has focused on the dilute phase flow regime where ({dollar}\rm\partial(\partial P/\partial z)\rbrack/\partial U\sb{lcub}g{rcub}\ \u3e\ 0{dollar}. This thesis is restricted to the regime where ({dollar}\partial(\partial P/\partial z)\rbrack/\partial U\sb{lcub}g{rcub}\ \u3c\ 0{dollar} and for which refluxing of particles, without slug flow, dominates in the flow patterns.;Experiments were conducted with 197 {dollar}\mu{dollar}m sand particles and 441 {dollar}\mu{dollar}m glass beads in a 3.2 cm diameter Plexiglas tube. Use of the two particle sizes (Geldart Group B powders) enabled the characterization of different systems: the first with sand, showed a slow transition from the non-slugging dense (reflux flows) to the dense slugging regime; the other using glass beads, collapsed abruptly into a slugging flow with a slight decrease of gas velocity near the choking point.;The pressure gradient and solids holdup ({dollar}\alpha{dollar}) in the fully developed riser test section increased linearly with both the solids flux (50-300 kg/m{dollar}\sp2{dollar}s) and solids mass loading ratio (5-40), but decreased with the gas velocity for both sand (4.5-12 m/s) and glass beads (6-16 m/s). The solids-wall frictional pressure gradient contributed between {dollar}-{dollar}25% and 25% of the total gradient, and was negative whenever there was solids refluxing at the wall. A 2-parameter semi-empirical model was developed which was successfully employed for the correlation of negative solids-wall friction factors.;A lifting efficiency of 2-phase transport in oblique risers ({dollar}\eta{dollar}) was defined, which decreased with {dollar}\theta{dollar}, from 75% (of the theoretical single particle lifting efficiency in dilute phase transport), to 35-45% for {dollar}\theta\ \ge\ 11\sp\circ{dollar}. The decrease of {dollar}\eta{dollar} was attributed to extensive refluxing near choking. A previous study has shown that {dollar}\eta \u3c 10\%{dollar} for dilute phase transport.;The dominant frequency from the power spectrum of the pressure gradient time series was 5 Hz for sand and 3 Hz for glass beads. The pressure gradient time series could be stochastically modelled with a linear stationary ARIMA model of the form AR(2) or AR(3)
STWalk: Learning Trajectory Representations in Temporal Graphs
Analyzing the temporal behavior of nodes in time-varying graphs is useful for
many applications such as targeted advertising, community evolution and outlier
detection. In this paper, we present a novel approach, STWalk, for learning
trajectory representations of nodes in temporal graphs. The proposed framework
makes use of structural properties of graphs at current and previous time-steps
to learn effective node trajectory representations. STWalk performs random
walks on a graph at a given time step (called space-walk) as well as on graphs
from past time-steps (called time-walk) to capture the spatio-temporal behavior
of nodes. We propose two variants of STWalk to learn trajectory
representations. In one algorithm, we perform space-walk and time-walk as part
of a single step. In the other variant, we perform space-walk and time-walk
separately and combine the learned representations to get the final trajectory
embedding. Extensive experiments on three real-world temporal graph datasets
validate the effectiveness of the learned representations when compared to
three baseline methods. We also show the goodness of the learned trajectory
embeddings for change point detection, as well as demonstrate that arithmetic
operations on these trajectory representations yield interesting and
interpretable results.Comment: 10 pages, 5 figures, 2 table
Isolated laryngeal amyloidosis mimicking laryngeal cancer
Amyloidosis is the deposition of an extracellular fibrillar protein in the tissues leading to organ dysfunction. Laryngeal amyloidosis is a rare phenomenon. We report a case of isolated laryngeal amyloidosis which was initially suspicious for laryngeal cancer on magnetic resonance imaging (MRI) but histopathology showed the presence of amyloid. Systemic workup was negative. The patient is being managed conservatively
A Cyber -Physical System for Industrial Air Pollution Monitoring using Raspberry Pi
In this paper the proposed system will focus on the monitoring of air pollutants concentration with the help of combination of Internet of things with wireless sensor networks. The analysis of air quality can be done by calculating air quality index. This information will be displayed on the webpage via internet in real time. By the combination of internet of things and wireless sensor networks for purpose of air pollution monitoring it becomes easy to keep the air quality data updated in real time. Also the system is cost effective which make its installation possible in various areas. The system existing before was based on microcontroller based toxic gas detecting and alerting system and the developing system will have a complete monitoring system which is IOT based. Also the information will be directly sent to the internet from system; no need of computer for transmission purpose which reduces the cost further. The main objective of this system is to monitor air pollution by using internet of things application. Also to obtain cost effective system that will help to keep track of concentration of pollutants in air and find effect of concentration of pollutants on air in terms of air quality index to achieve real time monitoring by continuously updating the data on webpage via internet
PREVENTIVE MEASURES IN THE DEPARTMENT OF SHALYATANTRA (GENERAL SURGERY) DURING CORONAVIRUS DISEASE 2019 PANDEMIC
The challenges of COVID-19 pandemic not only calls for rapidly changing responses with time, but also requires clarity among healthcare professionals about setting protocols at all levels and locations. Moreover these guidelines must be clear enough to be clearly understood by all stakeholders and should include all the modifications required to count for local needs and availability (or still better- paucity) of resources. On one hand all platforms of knowledge circulation are flooded with information, it is difficult to pick the time and place appropriate set of guidelines which are not only endorsed by appropriate authorities but also practically possible with current ground realities in terms of supplies and local needs. This work essentially dwells on an endeavour to go through all recent works on the topic and compile the best possible set of guidelines require for the department of Shalyatantra (Surgery) with corona relate concerns. After an extensive online search for the above mentioned requirements the relevant excerpts are compiled. Although all efforts are made to search for most recent twists till date it is almost sure that these will lose relevance with time and will need continuous update
Life threatening acute kidney injury in a patient of rheumatoid arthritis, is it drug or disease related?
Even low-dose MTX therapy for treatment of rheumatic diseases is claimed to cause impairment in renal function. We report an insidious and progressive deterioration of renal function of patient with RA on low-dose MTX in a 41-year-old woman. We suggest that patients on low-dose MTX therapy should be periodically monitored for creatinine levels
India's Firewood Crisis Re-examined
Households in rural India are highly dependent on firewood as their main source of energy, partly because non-biofuels tend to be expensive. The prevailing view is therefore that, when faced with shortages of firewood in the village commons, such households, and especially the women in them, have to spend more and more time searching for firewood and eventually settle for poorer-quality biomass such as twigs, branches and dry leaves. Using data from a random sample of rural households in the Indian state of Madhya Pradesh, we come to very different conclusions, however. We find that households in villages with degraded forests do not spend longer hours searching for firewood, but instead switch to either using firewood from private trees or to using agricultural waste for fuel. In the long run, moreover, households respond to the firewood shortage by altering the mix of private trees on their land in favor of firewood, as opposed to fruit, trees. We find also that, Joint Forest Management, a government program initiated in the 1990s, is having a positive impact on the firewood economy.firewood crisis, time allocation, fuel switching, JFM, India
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