Liquid supercoolings and droplet cooling rates of remelted argon-atomized Fe–30Ni powder particles

1988 ◽  
Vol 3 (3) ◽  
pp. 441-452 ◽  
Author(s):  
Matthew R. Libera ◽  
Pedro P. Bolsaitis ◽  
R. Erik Spjut ◽  
John B. VanderSande
Keyword(s):  
Standard Deviation ◽  
Cooling Rate ◽  
Metal Droplet ◽  
Liquid Droplets ◽  
Interfacial Velocity ◽  
Gas Atmosphere ◽  
History Of ◽  
Powder Particles ◽  
The Difference ◽  
Individual Particles

Individual particles of argon-atomized Fe-30Ni powder are electrodynamically levitated and remelted by a CO2 laser pulse. The thermal history of each droplet during remelting and solidification is monitored by single-color radiation pyrometry at each of three wavelengths (850, 750, and 550 nm). Experiments are done in an atmosphere of either air or nitrogen. The average supercooling of six experiments performed in nitrogen is 298 K with a standard deviation of 14 K. This value is of the same order as several others reported in the literature using bulk levitation and emulsification techniques. The average supercooling of seven experiments performed in air is 163 K with a standard deviation of 20 K. The difference suggests that oxides are forming in the air-remelting experiments and catalyzing nucleation at relatively low supercoolings. The average cooling rate of the liquid droplets prior to solidification in nitrogen is 1.5 × 105 K/s. This measured cooling rate is somewhat higher than that predicted by Newtonian heat flow modeling, and the difference is attributed to radiative losses not considered in the Newtonian model. The measured cooling rate is used to estimate the total heat transfer coefficient characterizing cooling of a small metal droplet in a quiescent gas atmosphere. A lower bound of 1.5 × 106 K/s on the droplet heating rate during recalescence and a minimum average liquid/solid interfacial velocity during recalescence of 0.1 m/s are estimated.

Isotopic constraints on the thermal history of the Wind River Range, Wyoming: implications for Archean metamorphism

2006 ◽  
Vol 43 (10) ◽  
pp. 1511-1532 ◽  
Author(s):  
Stephen D Keane ◽  
Chris M Hall ◽  
Eric J Essene ◽  
Michael A Cosca ◽  
Charles P DeWolf ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Large Scale ◽  
Time Interval ◽  
High Grade ◽  
Wind River Range ◽  
Metamorphic History ◽  
History Of ◽  
High Grade Metamorphism ◽  
The Difference ◽  
Differential Uplift

Precise U–Pb monazite and 40Ar/39Ar hornblende ages have been obtained from three locations in the high-grade Archean core of the Wind River Range, Wyoming. Monazites from metapelites in the Paradise Basin, Medina Mountain, and Crescent Lake have U–Pb ages of 2718 ± 1, 2633 ± 5, and 2657 ± 2 Ma, respectively. Hornblendes from amphibolites and granulites from the same locations yield plateau 40Ar/39Ar isotope ages of 2652 ± 11, 2572 ± 9, and 2527 ± 8 Ma, respectively, and are interpreted as cooling ages from the last thermal event. The three localities experienced similar peak pressure–temperature conditions. The timing of high-grade metamorphism in the Paradise Basin is older than the emplacement of large subjacent batholiths at 2.63–2.67 Ga. Calculated cooling rates based on monazite–hornblende pairs of 3.4 ± 1.0 °C/Ma for Paradise Basin, 3.8 ± 1.2 °C/Ma for Medina Mountain, and 1.7 ± 0.4 °C/Ma for Crescent Lake cannot be used to rule out reheating during subsequent pluton emplacement. The markedly slower cooling rate inferred for Crescent Lake may indicate early differential uplift or may demark another regional metamorphic event. The difference in 40Ar/39Ar ages between hornblende (2652 ± 11 Ma) and biotite (2637 ± 11 Ma) suggests a more rapid cooling rate, 11 °C/Ma, for Paradise Basin between 2.65 and 2.63 Ga, which may be related to the time of large-scale batholith emplacement elsewhere in the terrane. Combining new data with other ages in the Wind River Range reveals an extended metamorphic history, punctuated by thermal events over a time interval of at least 700 Ma.

Harsdörffers Geschirr

2019 ◽  
Vol 10 (1) ◽  
pp. 23-37
Author(s):  
Natalie Binczek
Keyword(s):  
Design History ◽  
History Of ◽  
The Difference

Der deutsche Barockdichter Georg Philipp Harsdörffer skizziert eine Theorie der Emblematik, die vor allem dessen Anwendungsvielfalt hervorhebt. Er hebt dabei besonders den Unterschied zwischen buchinterner und buchexterner Verwendung auf, indem er sich nicht nur für die Aufnahme der Embleme in Büchern, sondern auch auf Geschirr und Tapeten ausspricht. Der Beitrag liest Harsdörffers extensive Überlegungen nicht nur als Beiträge zur Theorie und Geschichte der Embleme als ›Sinn-Bilder‹, sondern auch als Beitrag zur Designgeschichte. German Baroque poet Georg Philipp Harsdörffer delineates a theory of emblematics that clearly sets itself apart from other contemporary theories, especially by its versatility. In particular, the author negates the difference between internal and external usage of emblems in books not only by promoting the incorporation of emblems into printed works but also by supporting their depiction on dishes and tapestries. This article strives to read Harsdörffer’s extensive thoughts on the matter of emblems not simply as another work on the theory and history of emblematics but rather as a contribution to design history as well

Introduction

2017 ◽  
Author(s):  
Simon Kirchin
Keyword(s):  
Hilary Putnam ◽  
Bernard Williams ◽  
General Methodology ◽  
Thick Concepts ◽  
History Of ◽  
Philippa Foot ◽  
The Difference

This chapter introduces the distinction between thin and thick concepts and then performs a number of functions. First, two major accounts of thick concepts—separationism and nonseparationism—are introduced and, in doing so, a novel account of evaluation is indicated. Second, each chapter is outlined as is the general methodology, followed, third, by a brief history of the discussion of thick concepts, referencing Philippa Foot, Hilary Putnam, Gilbert Ryle, and Bernard Williams among others. Fourth, a number of relevant contrasts are introduced, such as the fact–value distinction and the difference between concepts, properties, and terms. Lastly, some interesting and relevant questions are raised that, unfortunately, have to be left aside.

The Early History of Financial Economics, 1478–1776. By Geoffrey Poitras. Cheltenham and Northampton: Edward Elgar, 2000. Pp. x, 522.

2002 ◽  
Vol 62 (1) ◽  
pp. 268-269
Author(s):  
Larry Neal
Keyword(s):  
Economic History ◽  
Financial Analysis ◽  
Adam Smith ◽  
Economic Thought ◽  
Financial History ◽  
X 522 ◽  
History Of ◽  
The Difference ◽  
Wealth Of Nations ◽  
Simon Fraser University

Economic historians usually have to explain to their economist colleagues the difference between economic history, which focuses on facts, and history of economic thought, which focuses on ideas. Our colleagues in finance departments, typically fascinated by episodes in financial history treated by economic historians, are bound to be disappointed in the lack of attention given to the development of ideas in finance by historians of economic thought. Geoffrey Poitras, a professor of finance at Simon Fraser University, makes a valiant effort to remedy these oversights in his collection of vignettes that highlight the sophistication of financial instruments and analysts of financial markets well before the time of Adam Smith. Starting in 1478 with the publication of the Treviso Arithmetic, a typical textbook of commercial arithmetic for Italian merchants, and ending with brief snippets from the Wealth of Nations, Poitras treats the reader to a fascinating potpourri of excerpts from various manuals, brief biographies of pioneers in financial analysis, and historical discursions on foreign-exchange and stock markets.

scholarly journals Reproducibility and Instruction Following in the Shop Floor Laboratory Work: The Case of a TMS Experiment

2021 ◽  
pp. 016224392110323
Author(s):  
Kristina Popova
Keyword(s):  
Measurement Procedure ◽  
Shop Floor ◽  
Experimental Uncertainty ◽  
Local Measurement ◽  
Replication Crisis ◽  
History Of ◽  
Per Se ◽  
The Difference ◽  
Methodological Guidelines ◽  
Local Procedure

The article addresses the production of reproducibility as a topic that has become acutely relevant in the recent discussions on the replication crisis in science. It brings the ethnomethodological stance on reproducibility into the discussions, claiming that reproducibility is necessarily produced locally, on the shop floor, with methodological guidelines serving as references to already established practices rather than their origins. The article refers to this argument empirically, analyzing how a group of novice neuroscientists performs a series of measurements in a transcranial magnetic stimulation experiment. Based on ethnography and video analysis, the article traces a history of the local measurement procedure invented by the researchers in order to overcome the experimental uncertainty. The article aims to demonstrate (1) how reproducibility of the local procedure is achieved in the shop floor work of the practitioners and (2) how the procedure becomes normalized and questioned as incorrect in the course of experimental practice. It concludes that the difference between guidelines and practical actions is not problematic per se; what may be problematic is that researchers can be engaged in different working projects described by the same instruction.

Incidence of postural headache after lumbar puncture requiring epidural blood patch: Effects of needle caliber; 2-year experience

2021 ◽  
pp. 197140092110006
Author(s):  
Warren Chang ◽  
Ajla Kadribegic ◽  
Kate Denham ◽  
Matthew Kulzer ◽  
Tyson Tragon ◽  
...  
Keyword(s):  
Risk Factors ◽  
Lumbar Puncture ◽  
Conservative Management ◽  
Epidural Blood Patch ◽  
Female Gender ◽  
Regional Hospital ◽  
Younger Age ◽  
Blood Patch ◽  
History Of ◽  
The Difference

Purpose A common complication of lumbar puncture (LP) is postural headaches. Epidural blood patches are recommended if patients fail conservative management. Owing to a perceived increase in the number of post-lumbar puncture headaches (PLPHs) requiring epidural blood patches at a regional hospital in our network, the decision was made to switch from 20 to 22 gauge needles for routine diagnostic LPs. Materials and methods Patients presenting for LP and myelography at one network regional hospital were included in the study. The patients were contacted by nursing staff 3 days post-procedure; those patients who still had postural headaches after conservative management and received epidural blood patches were considered positive cases. In total, 292 patients were included; 134 underwent LP with 20-gauge needles (53 male, 81 female, average age 57.7) and 158 underwent LP with 22-gauge needles (79 male, 79 female, average age 54.6). Results Of 134 patients undergoing LP with 20-gauge needles, 15 (11%) had PLPH requiring epidural blood patch (11 female, 3 male, average age 38). Of 158 patients undergoing LP with 22-gauge needles, only 5 (3%) required epidural blood patches (all female, average age 43). The difference was statistically significant ( p < 0.01). Risk factors for PLPH included female gender, younger age, lower body mass index, history of prior PLPH and history of headaches. Conclusion Switching from 20-gauge to 22-gauge needles significantly decreased the incidence of PLPH requiring epidural blood patch. Narrower gauge or non-cutting needles should be considered in patients with risk factors for PLPH, allowing for CSF requirements.

P007 CROHN’S DISEASE: PREDICTORS OF HOSPITAL DISPOSITION AND COSTS USING DEMOGRAPHIC, CLINICAL, AND TREATMENT DATA

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S48-S48
Author(s):  
Hartman Brunt ◽  
Mason Adams ◽  
Michael Barker ◽  
Diana Hamer ◽  
J C Chapman
Keyword(s):  
Logistic Regression ◽  
Crohn’S Disease ◽  
Abdominal Pain ◽  
Crohn's Disease ◽  
Hospital Admission ◽  
Categorical Variables ◽  
History Of ◽  
The Difference ◽  
The Impact ◽  
Total Charges

Abstract Purpose Crohn’s disease (CD) is an inflammatory bowel disease (IBD) caused by an abnormal immune response to intestinal microbes in a genetically susceptible host. The objective of this cohort analysis is to compare demographic characteristics, cost difference, and treatment modalities between patients who were discharged from the Emergency Department (ED) and those who were admitted to the hospital. Methods This study is a retrospective chart review of adult patients diagnosed with CD who were discharged from the ED and those who were admitted to the hospital between January 1, 2014 and January 1, 2017. We compared demographic and clinical characteristics as well as total charges incurred by these patients. A chi square test of independence and a Mann Whitney U-Test were used to compare categorical variables. Linear and logistic regression analyses were utilized to identify predictors of hospitalization and total charges. Results Of a total 195 patients, 97 were discharged from the ED and 98 were admitted to the hospital (Table 1). Patients who presented with fever, nausea/vomiting, or abdominal pain or who had a history of a fistula or stenosis were more likely to be hospitalized, as were patients who presented on steroids, 5-ASA compounds, or narcotics (Table 2). A logistic regression adjusted for these factors showed patients presenting with abdominal pain (OR=0.239, 95% CI 0.07 – 0.77) are less likely, while patients presenting with fever (OR=7.0, 95% CI 1.9 – 24.5) and history of stenosis (OR=17.8, 95% CI 5.7 – 55.9) are more likely to have a hospital admission. An increase in age and white blood cell count was associated with an increase in likelihood of admission (OR=1.04, 95% CI 1.01 – 1.07 and OR=1.2, 95% CI 1.1 – 1.4), while an increase in HGB was associated with a decrease in likelihood of admission (OR=0.682, 95% CI 0.55 – 0.83). Patients on 5-ASA compounds had the strongest association with hospital admission (OR=4.5, 95% CI 1.03 – 20.4). A linear regression analysis predicting total charges of hospitalization identified an increase of $37,500 (95% CI 6,600 – 68,489) for obese patients and of $29,000 (95% CI 20 – 57,000) for patients on narcotics prior to hospitalization. Notably, blacks were on average 6 years younger than whites (μ=36.2, st.d.=13.2 v μ=42.7, st.d.=18.2, p=0.031, respectively). No other differences in presentation or outcomes of CD were identified between these races. Conclusion This study describes the difference between CD patients who were admitted to the hospital compared to those who were discharged from the ED. The impact that 5-ASA compound, steroid, and narcotic use prior to presentation has on hospital admission and charges highlights the need for consistent outpatient care to manage the symptoms and disease progression in patients with CD in Baton Rouge. The difference in age at presentation between blacks and whites should also be considered in future research.

scholarly journals H. L. Wagner's Unbiased Hit Rate and the Assessment of Categorical Forecasting Accuracy

2013 ◽  
Vol 28 (3) ◽  
pp. 802-814 ◽  
Author(s):  
Timothy W. Armistead
Keyword(s):  
Weather Forecasting ◽  
Skill Score ◽  
Conditional Probabilities ◽  
Paper Briefly ◽  
Forecasting Accuracy ◽  
Hit Rate ◽  
History Of ◽  
The Difference ◽  
Measure Of Association ◽  
Accuracy Rates

Abstract The paper briefly reviews measures that have been proposed since the 1880s to assess accuracy and skill in categorical weather forecasting. The majority of the measures consist of a single expression, for example, a proportion, the difference between two proportions, a ratio, or a coefficient. Two exemplar single-expression measures for 2 × 2 categorical arrays that chronologically bracket the 130-yr history of this effort—Doolittle's inference ratio i and Stephenson's odds ratio skill score (ORSS)—are reviewed in detail. Doolittle's i is appropriately calculated using conditional probabilities, and the ORSS is a valid measure of association, but both measures are limited in ways that variously mirror all single-expression measures for categorical forecasting. The limitations that variously affect such measures include their inability to assess the separate accuracy rates of different forecast–event categories in a matrix, their sensitivity to the interdependence of forecasts in a 2 × 2 matrix, and the inapplicability of many of them to the general k × k (k ≥ 2) problem. The paper demonstrates that Wagner's unbiased hit rate, developed for use in categorical judgment studies with any k × k (k ≥ 2) array, avoids these limitations while extending the dual-measure Bayesian approach proposed by Murphy and Winkler in 1987.

Exercise-induced VA/Q inequality in subjects with prior high-altitude pulmonary edema

1996 ◽  
Vol 81 (2) ◽  
pp. 922-932 ◽  
Author(s):  
A. Podolsky ◽  
M. W. Eldridge ◽  
R. S. Richardson ◽  
D. R. Knight ◽  
E. C. Johnson ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Pulmonary Edema ◽  
High Altitude ◽  
Sea Level ◽  
Control Group ◽  
Pulmonary Capillary ◽  
High Altitude Pulmonary Edema ◽  
History Of ◽  
Capillary Pressures ◽  
Exercise Induced

Ventilation-perfusion (VA/Q) mismatch has been shown to increase during exercise, especially in hypoxia. A possible explanation is subclinical interstitial edema due to high pulmonary capillary pressures. We hypothesized that this may be pathogenetically similar to high-altitude pulmonary edema (HAPE) so that HAPE-susceptible people with higher vascular pressures would develop more exercise-induced VA/Q mismatch. To examine this, seven healthy people with a history of HAPE and nine with similar altitude exposure but no HAPE history (control) were studied at rest and during exercise at 35, 65, and 85% of maximum 1) at sea level and then 2) after 2 days at altitude (3,810 m) breathing both normoxic (inspired Po2 = 148 Torr) and hypoxic (inspired Po2 = 91 Torr) gas at both locations. We measured cardiac output and respiratory and inert gas exchange. In both groups, VA/Q mismatch (assessed by log standard deviation of the perfusion distribution) increased with exercise. At sea level, log standard deviation of the perfusion distribution was slightly higher in the HAPE-susceptible group than in the control group during heavy exercise. At altitude, these differences disappeared. Because a history of HAPE was associated with greater exercise-induced VA/Q mismatch and higher pulmonary capillary pressures, our findings are consistent with the hypothesis that exercise-induced mismatch is due to a temporary extravascular fluid accumulation.

scholarly journals Effect of pterygium excision on mean corneal curvature.

2021 ◽  
Vol 28 (04) ◽  
pp. 568-571
Author(s):  
Saira Bano ◽  
Sumaya Khan ◽  
Mahnoor Waqar ◽  
Moniba Iqbal ◽  
Hamza Waqar Bhatti ◽  
...  
Keyword(s):  
P Value ◽  
Corneal Curvature ◽  
Ocular Surgery ◽  
Department Of Ophthalmology ◽  
Before And After ◽  
Quasi Experimental ◽  
History Of ◽  
Induced Astigmatism ◽  
Pterygium Excision ◽  
The Difference

Objective: To determine the difference in mean corneal curvatures before and after pterygium excision. Study Design: Quasi-experimental study. Setting: Department of Ophthalmology, Holy Family Hospital, Rawalpindi. Period: 1st January 2015 to 1st July 2015. Material & Methods: 68 patients aged between 18 to 65 years were included in the study. Patients with history of ocular trauma, ocular surgery, glaucoma, anti-glaucoma treatment, allergy to steroids, pseudo pterygium, recurrent pterygium and presence of corneal abnormalities such as, scarring that might affect the astigmatic value were excluded. All patients underwent comprehensive ophthalmic examination by slit lamp and best corrected visual acuity and keratometric values were noted. Pterygium excision was done by a single surgeon. BCVA and keratometric readings were taken again after 2 weeks of pterygium excision. Results: Mean age was 37.60 ± 11.11 years. Out of these 68 patients, 44 (64.71%) were male and 24 (35.29%) were females. Mean pre-operative corneal curvature was 2.99 ± 0.69D and post-operative corneal curvature was 1.70 ± 0.40D with P-value of <0.0001 which is statistically significant. Conclusion: This study concluded that pterygium excision brings significant change in corneal curvature in patients of pterygium induced astigmatism.

Sign in / Sign up

Export Citation Format

Share Document