On the waiting time distribution for continuous stochastic systems

The waiting time distribution (WTD) is a common tool for analysing discrete stochastic processes in classical and quantum systems. However, there are many physical examples where the dynamics is continuous and only approximately discrete, or where it is favourable to discuss the dynamics on a discretized and a continuous level in parallel. An example is the hindered motion of particles through potential landscapes with barriers. In the present paper we propose a consistent generalisation of the WTD from the discrete case to situations where the particles perform continuous barrier-crossing characterised by a finite duration. To this end, we introduce a recipe to calculate the WTD from the Fokker-Planck/Smoluchowski equation. In contrast to the closely related first passage time distribution (FPTD), which is frequently used to describe continuous processes, the WTD contains information about the direction of motion. As an application, we consider the paradigmatic example of an overdamped particle diffusing through a washboard potential. To verify the approach and to elucidate its numerical implications, we compare the WTD defined via the Smoluchowski equation with data from direct simulation of the underlying Langevin equation and find full consistency provided that the jumps in the Langevin approach are defined properly. Moreover, for sufficiently large energy barriers, the WTD defined via the Smoluchowski equation becomes consistent with that resulting from the analytical solution of a (two-state) master equation model for the short-time dynamics developed previous by us [PRE 86, 061135 (2012)]. Thus, our approach "interpolates" between these two types of stochastic motion. We illustrate our approach for both symmetric systems and systems under constant force.Comment: 12 pages, 10 figure

Increasing the wheat yield of Kansas

Citation: Adams, Ernest L. and Williams, Robert E. Fertilizer requirements of unproductive soils. Senior thesis, Kansas State Agricultural College, 1907.Morse Department of Special CollectionsIntroduction: The history of winter wheat in Kansas is one of the most interesting chapters in agricultural progress. Every Kansan refers with pride to the developement of the industry from the time farming was commenced a half century ago in the small river valleys of the eastern part of the state, when the state was considered to be more or less a desert, to the present time when Kansas has become one of the greatest wheat producing sections of the world. At the time when wheat was first grown in this State, very little was known about the hard winter wheat for which Kansas has since become famous. Soft wheats were the only varieties grown and when the hard wheats were first introduced it was not thought that they would prove successful. It has scarce been forty years since the introduction of hard winter wheat by the Mennonite immigrants from the Russian Crimea. These hardy newcomers with remarkable foresight settled in the central part of the state and sowed small quantities of the seed-wheat which they had brought with them. This central group of counties has since developed into the principal wheat producing section of the state, and Kansas has come to occupy the foremost rank in the production of hard winter wheat. Kansas raises more wheat than any other state in the Union, yet we must confess that this is due to the number of acres sown rather than to the large yield per acre. The average yield of wheat per acre in Kansas is nearly one-third bushels less than the average for all the states, many of which are less adapted to wheat growing than our own state. The average yield for the state for the last ten years has been 13.1 bushels per acre. Under more favorable cropping conditions, many of which..

Fictionalizing heterodoxy: Various uses of knowledge in the Spanish world from the Archpriest of Hita to Mateo Alemán

The information overload produced by the printing press and the new forms of the structuring of knowledge are echoed in fictional works. The essays assembled in this book study the textualization of problematic forms of knowledge in medieval and early modern Spanish literature. Literary Works like the Libro buen amor, La Lozana Andaluza, or the Guzmán de Alfarache are read against the backdrop of scientific developments of their times

Cooled artery extension

An artery vapor trap. A heat pipe artery is constructed with an extension protruding from the evaporator end of the heat pipe beyond the active area of the evaporator. The vapor migrates into the artery extension because of gravity or liquid displacement, and cooling the extension condenses the vapor to liquid, thus preventing vapor lock in the working portion of the artery by removing vapor from within the active artery. The condensed liquid is then transported back to the evaporator by the capillary action of the artery extension itself or by wick located within the extension

Active Military Student Persistence in Online Courses at California Community Colleges

The diversity of higher education institutions is changing, and more post-traditional students, including those associated with the military, are engaging in higher education. Almost every post-secondary institution in the United States has military students. In 2020, $11.5 billion was spent on over 875,000 eligible military students. Military students often prefer online courses at community colleges due to flexibility around their military career, open-access, and affordability. Yet, few studies examine active military servicemembers alone and, when research is performed, a lack of thorough data collection exists. Therefore, this study focused on active military students in online education in California Community Colleges. It has a significant military presence, offers more online courses, and issues more certificates than any other higher education system, making an ideal place to conduct this initial research. This study examined student course success between online courses and traditional courses, compared course success of active military to non-military, and compared active military, veteran, and non-military students’ credential earning rates. This quantitative, nonexperimental study used ex post facto from the California Community College Chancellor’s Office’s Management Information Systems DataMart. Data from 2012-2013 until 2018-2019 were collected and analyzed using t-tests and trend analysis implemented as multiple regression

Impact of the Study Island Program on Students\u27 Reading Comprehension

School administrators at the research site, which is a public school district, had been under pressure to improve low reading state scores of Grade 11 students as measured by Pennsylvania System of School Assessment (PSSA) tests. A web-based reading software called Study Island was integrated into the literacy curriculum for students to increase their reading proficiency and pass PSSA state tests. The research problem was that the integration of Study Island had not been evaluated and students were not meeting adequate yearly progress (AYP). The purpose of this study was to provide research-based evidence on whether Study Island helped students to improve their reading proficiency. This nonequivalent, quasi-experimental study was based on Tomlinson\u27s differentiated instruction theory and Marzano\u27s intelligence theory. Archived PSSA scores were collected for 2 cohorts of Grade 11 students (N = 800), before and after the curricular integration of Study Island between the academic years 2009--2011 and 2011--2013. An independent samples t test showed that students\u27 reading proficiency scores were significantly higher after receiving the Stony Island software than they were before the software. These findings can be used by school and district administrators regarding the integration of Study Island into other academic subjects. Implications for positive social change may include professional development (PD) for high school teachers to use Study Island in the academic subjects they teach. PD on Study Island for high school teachers may help students pass PSSA testing, meet AYP, and graduate from high school

Divination on stage

Magicians, necromancers and astrologers are assiduous characters in the European golden age theatre. This book deals with dramatic characters who act as physiognomists or palm readers in the fictional world and analyses the fictionalisation of physiognomic lore as a practice of divination in early modern Romance theatre from Pietro Aretino and Giordano Bruno to Lope de Vega, Calderón de la Barca and Thomas Corneille