Continuous Slug Flow in Vertical Tubes

1974 ◽  
Vol 96 (3) ◽  
pp. 371-376 ◽  
Author(s):  
R. Clift ◽  
J. R. Grace ◽  
V. Sollazzo
Keyword(s):  
Slug Flow ◽  
Reasonable Agreement ◽  
Reference Level ◽  
Time Intervals ◽  
Numerical Predictions ◽  
Regular Time ◽  
Subsequent Motion ◽  
Vertical Tubes ◽  
The Relationship ◽  
Supply Information

A method of simulating the behavior of continuously slugging vertical columns is presented. Slugs are introduced at regular time intervals at some reference level near the bottom of a column and their subsequent motion and coalescence is simulated numerically. Experiments on coalescing slug pairs are used to supply information on slug interactions, while the relationship between slug length and volume is obtained from experiments on single slugs. The numerical predictions are in reasonable agreement with experimental results for continuously slugging liquids.

scholarly journals Speech rhythm: a metaphor?

2014 ◽  
Vol 369 (1658) ◽  
pp. 20130396 ◽  
Author(s):  
Francis Nolan ◽  
Hae-Sung Jeon
Keyword(s):  
Traditional View ◽  
Time Intervals ◽  
Speech Rhythm ◽  
Linguistic Structure ◽  
Regular Time ◽  
Linguistic Functions ◽  
Absence Of Evidence ◽  
Metaphorical Extension ◽  
Analogical Process

Is speech rhythmic? In the absence of evidence for a traditional view that languages strive to coordinate either syllables or stress-feet with regular time intervals, we consider the alternative that languages exhibit contrastive rhythm subsisting merely in the alternation of stronger and weaker elements. This is initially plausible, particularly for languages with a steep ‘prominence gradient’, i.e. a large disparity between stronger and weaker elements; but we point out that alternation is poorly achieved even by a ‘stress-timed’ language such as English, and, historically, languages have conspicuously failed to adopt simple phonological remedies that would ensure alternation. Languages seem more concerned to allow ‘syntagmatic contrast’ between successive units and to use durational effects to support linguistic functions than to facilitate rhythm. Furthermore, some languages (e.g. Tamil, Korean) lack the lexical prominence which would most straightforwardly underpin prominence of alternation. We conclude that speech is not incontestibly rhythmic, and may even be antirhythmic. However, its linguistic structure and patterning allow the metaphorical extension of rhythm in varying degrees and in different ways depending on the language, and it is this analogical process which allows speech to be matched to external rhythms.

scholarly journals Tornado Warnings, Lead Times, and Tornado Casualties: An Empirical Investigation

2008 ◽  
Vol 23 (2) ◽  
pp. 246-258 ◽  
Author(s):  
Kevin M. Simmons ◽  
Daniel Sutter
Keyword(s):  
United States ◽  
Lead Time ◽  
Empirical Investigation ◽  
Conventional Wisdom ◽  
Lead Times ◽  
Time Intervals ◽  
Consistent Effect ◽  
Tornado Warnings ◽  
The Relationship

Abstract Conventional wisdom holds that improved tornado warnings will reduce tornado casualties, because longer lead times on warnings provide extra opportunities to alert residents who can then take precautions. The relationship between warnings and casualties is examined using a dataset of tornadoes in the contiguous United States between 1986 and 2002. Two questions are examined: Does a warning issued on a tornado reduce the resulting number of fatalities and injuries? Do longer lead times reduce casualties? It is found that warnings have had a significant and consistent effect on tornado injuries, with a reduction of over 40% at some lead time intervals. The results for fatalities are mixed. An increase in lead time up to about 15 min reduces fatalities, while lead times longer than 15 min increase fatalities compared with no warning. The fatality results beyond 15 min, however, depend on five killer tornadoes and consequently are not robust.

Processing and Excellent Oxidation Resistance of Nanocrystalline Fe-Cr Alloys

2010 ◽  
Vol 654-656 ◽  
pp. 1122-1125
Author(s):  
Rajeev K. Gupta ◽  
B.V. Mahesh ◽  
R.K. Singh Raman ◽  
Carl C. Koch
Keyword(s):  
Oxidation Resistance ◽  
Secondary Ion Mass Spectrometry ◽  
Nanocrystalline Alloy ◽  
High Energy ◽  
Processing Route ◽  
Protective Oxide ◽  
Time Intervals ◽  
Regular Time ◽  
Order Of Magnitude ◽  
Energy Ball

Nanocrystalline and microcrystalline Fe-10Cr alloys were prepared by high energy ball milling followed by compaction and sintering, and then oxidized in air for 52 hours at 400°C. The oxidation resistance of nanocrystalline Fe-10Cr alloy as determined by measuring the weight gain after regular time intervals was compared with that of the microcrystalline alloy of same chemical composition (also prepared by the same processing route and oxidized under identical conditions). Oxidation resistance of nanocrystalline Fe10Cr alloy was found to be in excess of an order of magnitude superior than that of microcrystalline Fe10Cr alloy. The paper also presents results of secondary ion mass spectrometry of oxidized samples of nanocrystalline and microcrystalline Fe-Cr alloys, evidencing the formation of a more protective oxide scale in the nanocrystalline alloy.

Modeling the Growth of Salmonella in Cut Red Round Tomatoes as a Function of Temperature

2010 ◽  
Vol 73 (8) ◽  
pp. 1502-1505 ◽  
Author(s):  
WENJING PAN ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Mathematical Model ◽  
Growth Rates ◽  
Low Temperatures ◽  
Safety Concern ◽  
Time Intervals ◽  
Salmonella Serotypes ◽  
Increasing Temperature ◽  
Incubation Temperatures ◽  
Raw Poultry ◽  
The Relationship

Tomato-associated Salmonella outbreaks have recently become a significant food safety concern. Temperature abuse of cut tomatoes may have played a role in some of these outbreaks. The purpose of this study was to develop a mathematical model to describe the growth of Salmonella on cut tomatoes at various temperatures. Four Salmonella serotypes (Typhimurium, Newport, Javiana, and Braenderup) obtained from previous tomato-linked cases of salmonellosis were used in this study. These four serotypes were cultured separately, combined into a cocktail, and inoculated onto whole red round tomatoes and allowed to dry overnight. The tomatoes were then cut into pieces and incubated at a predetermined range of temperatures (10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, and 35°C). Salmonella concentration was measured at specified time intervals to determine the growth curve for Salmonella on cut tomatoes at each temperature. The growth rates were calculated using DMFit and used to build a mathematical model to illustrate the relationship between the growth rates of Salmonella on tomatoes and incubation temperatures from 10 to 35°C. The resulting model compared favorably with a Salmonella growth model for raw poultry developed by our laboratory. The Pathogen Modeling Program underpredicted growth at low temperatures and overpredicted growth at high temperatures. ComBase predicted consistently slower growth rates than were observed in tomatoes but showed parallel increases in growth rate with increasing temperature.

A Method for Quantitative Analysis of the Kinematics of Fibroblast Migration in a Monolayer Wound Model

2011 ◽  
Author(s):  
Gil Topman ◽  
Orna Sharabani-Yosef ◽  
Amit Gefen
Keyword(s):  
Wound Healing ◽  
Cell Migration ◽  
Wound Healing Assay ◽  
Complete Coverage ◽  
Time Intervals ◽  
Fibroblast Migration ◽  
Wound Model ◽  
Regular Time

A wound healing assay is simple but effective method to study cell migration in vitro. Cell migration in vitro was found to mimic migration in vivo to some extent [1,2]. In wound healing assays, a “wound” is created by either scraping or mechanically crushing cells in a monolayer, thereby forming a denuded area. Cells migrate into the denuded area to complete coverage, and thereby “heal” the wound. Micrographs at regular time intervals are captured during such experiments for analysis of the process of migration.

scholarly journals Hubungan Perilaku Perdagangan Investor Dengan Volume Perdagangan Di Bursa Efek Indonesia

2009 ◽  
Vol 2 (1) ◽  
Author(s):  
Ghazali Syamni
Keyword(s):  
Trading Volume ◽  
Stock Exchange ◽  
Time Interval ◽  
Time Intervals ◽  
Using Data ◽  
Changes Over Time ◽  
Relationship Of ◽  
The Relationship ◽  
Order Pattern ◽  
Over Time

This paper examines the relationship of behavior trading investor using data detailed transaction history-corporate edition demand and order history in Indonesia Stock Exchange during period of March, April and May 2005. Peculiarly, behavior placing of investor order at trading volume. The result of this paper indicates that trading volume order pattern to have pattern U shape. The pattern happened that investors have strong desires to places order at the opening and close of compared to in trading periods. While the largest orders are of market at the opening indicates that investor is more conservatively when opening, where many orders when opening has not happened transaction to match. In placing order both of investor does similar strategy. By definition, informed investors’ orders more large than uninformed investors. If comparison of order examined hence both investors behavior relatively changes over time. But, statistically shows there is not ratio significant. This implies behavior trading of informed investors and uninformed investors stable relative over time. The result from regression analysis indicates that informed investors to correlate at trading volume in all time intervals, but not all uninformed investors correlates in every time interval. This imply investor order inform is more can explain trading volume pattern compared to uninformed investor order in Indonesia Stock Exchange. Finally, result of regression also finds that order status match has greater role determines trading volume pattern intraday especially informed buy match and informed sale match. While amend, open and withdraw unable to have role to determine intraday trading volume pattern.

scholarly journals Using approximate Bayesian inference for a “steps and turns” continuous-time random walk observed at regular time intervals

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8452
Author(s):  
Sofia Ruiz-Suarez ◽  
Vianey Leos-Barajas ◽  
Ignacio Alvarez-Castro ◽  
Juan Manuel Morales
Keyword(s):  
State Space ◽  
Continuous Time ◽  
Time Scale ◽  
Animal Movement ◽  
State Space Model ◽  
Movement Direction ◽  
Time Intervals ◽  
Space Model ◽  
Regular Time ◽  
Approximate Bayesian

The study of animal movement is challenging because movement is a process modulated by many factors acting at different spatial and temporal scales. In order to describe and analyse animal movement, several models have been proposed which differ primarily in the temporal conceptualization, namely continuous and discrete time formulations. Naturally, animal movement occurs in continuous time but we tend to observe it at fixed time intervals. To account for the temporal mismatch between observations and movement decisions, we used a state-space model where movement decisions (steps and turns) are made in continuous time. That is, at any time there is a non-zero probability of making a change in movement direction. The movement process is then observed at regular time intervals. As the likelihood function of this state-space model turned out to be intractable yet simulating data is straightforward, we conduct inference using different variations of Approximate Bayesian Computation (ABC). We explore the applicability of this approach as a function of the discrepancy between the temporal scale of the observations and that of the movement process in a simulation study. Simulation results suggest that the model parameters can be recovered if the observation time scale is moderately close to the average time between changes in movement direction. Good estimates were obtained when the scale of observation was up to five times that of the scale of changes in direction. We demonstrate the application of this model to a trajectory of a sheep that was reconstructed in high resolution using information from magnetometer and GPS devices. The state-space model used here allowed us to connect the scales of the observations and movement decisions in an intuitive and easy to interpret way. Our findings underscore the idea that the time scale at which animal movement decisions are made needs to be considered when designing data collection protocols. In principle, ABC methods allow to make inferences about movement processes defined in continuous time but in terms of easily interpreted steps and turns.

scholarly journals Late Permian to Holocene Paleofacies Evolution of the Arabian Plate and its Hydrocarbon Occurrences

GeoArabia ◽  
2001 ◽  
Vol 6 (3) ◽  
pp. 445-504 ◽  
Author(s):  
A.Ziegler Martin
Keyword(s):  
Sediment Supply ◽  
Arabian Plate ◽  
Late Permian ◽  
Time Intervals ◽  
Structural Pattern ◽  
Depositional History ◽  
Petroleum Systems ◽  
Structural Deformations ◽  
History Of ◽  
The Relationship

ABSTRACT A series of 19 paleofacies maps have been generated for given time intervals between the Late Permian and Holocene to reconstruct the depositional history of the Arabian Plate. The succession of changing lithological sequences is controlled by the interplay of eustacy and sediment supply with regional and local tectonic influences. The Mesozoic paleofacies history of the Plate is, in its central and eastern portion east of Riyadh, strongly influenced by an older N-trending, horst and graben system that reflects the grain of the Precambrian Amar Collision and successively younger structural deformations. The late Paleozoic Hercynian orogenic event caused block faulting and relative uplift and resulted in a marked paleorelief. This jointed structural pattern dominated the entire Mesozoic and, to some extent, the Cenozoic facies distribution. The relationship between producing fields and the paleofacies maps illustrates the various petroleum systems of particular times and regions.

scholarly journals METHOD FOR DETECTING SHILLING ATTACKS BASED ON IMPLICIT FEEDBACK IN RECOMMENDER SYSTEMS

2020 ◽  
Vol 5 ◽  
pp. 21-30
Author(s):  
Oksana Chala ◽  
Lyudmyla Novikova ◽  
Larysa Chernyshova ◽  
Angelika Kalnitskaya
Keyword(s):  
Recommender System ◽  
Input Data ◽  
Implicit Feedback ◽  
User Selection ◽  
Time Intervals ◽  
User Interests ◽  
Selection Processes ◽  
Key Characteristics ◽  
The Relationship ◽  
Explicit Feedback

The problem of identifying shilling attacks, which are aimed at forming false ratings of objects in the recommender system, is considered. The purpose of such attacks is to include in the recommended list of items the goods specified by the attacking user. The recommendations obtained as a result of the attack will not correspond to customers' real preferences, which can lead to distrust of the recommender system and a drop in sales. The existing methods for detecting shilling attacks use explicit feedback from the user and are focused primarily on building patterns that describe the key characteristics of the attack. However, such patterns only partially take into account the dynamics of user interests. A method for detecting shilling attacks using implicit feedback is proposed by comparing the temporal description of user selection processes and ratings. Models of such processes are formed using a set of weighted temporal rules that define the relationship in time between the moments when users select a given object. The method uses time-ordered input data. The method includes the stages of forming sets of weighted temporal rules for describing sales processes and creating ratings, calculating a set of ratings for these processes, and forming attack indicators based on a comparison of the ratings obtained. The resulting signs make it possible to distinguish between nuke and push attacks. The method is designed to identify discrepancies in the dynamics of purchases and ratings, even in the absence of rating values at certain time intervals. The technique makes it possible to identify an approach to masking an attack based on a comparison of the rating values and the received attack indicators. When applied iteratively, the method allows to refine the list of profiles of potential attackers. The technique can be used in conjunction with pattern-oriented approaches to identifying shilling attacks

scholarly journals Automatic Target Acquisition and Bull Tracker using Gps and Gsm Technology

2020 ◽  
Vol 9 (3) ◽  
pp. 2776-2779
Keyword(s):  
Real Time ◽  
Mobile Application ◽  
Tracking System ◽  
Target Acquisition ◽  
Time Intervals ◽  
Regular Time ◽  
Arduino Microcontroller

An efficient bull tracking system is designed and implemented for tracking the movement of any bull from any location at any time. The designed device works using GPS and GSM technology for bull tracking. Arduino microcontroller is used to control the GPS and GSM module. The device is embedded on a bull whose position is to be determined and tracked in real time. The microcontroller is used to control the GPS module to get the coordinates at regular time intervals. The GSM module is used to transmit the updated coordinates of bull location to the client via SMS and mobile application. When the SMS is received, the app will automatically read the SMS and update the location of the bull to the user. This device will help the user to always keep an eye on their bull.

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