Subcritical switching dynamics and humidity effects in nanoscale studies of domain growth in ferroelectric thin films

Ferroelectric domain switching in c-axis-oriented epitaxial Pb(Zr$_{0.2}$Ti$_{0.8}$)O$_3$ thin films was studied using biased scanning probe microscopy tips. While linear and logarithmic dependence of domain size on tip bias and writing time, respectively, are well known, we report an additional linear dependence on relative humidity in the 28-65% range. We map out the switched domain size as a function of both the tip bias and the applied pulse time and describe a growth-limited regime for very short pulses and a nucleation-limited regime for very low tip bias. Using "interrupted-switching" measurements, we probe the nucleation regime with subcritical pulses and identify a surprisingly long relaxation time on the order of 100 ms, which we relate to ionic redistribution both on the surface and within the thin film itself.Comment: 11 pages, 4 figure

An Overview of Microbial Source Tracking Using Host-Specific Genetic Markers to Identify Origins of Fecal Contamination in Different Water Environments

Fecal contamination of water constitutes a serious health risk to humans and environmental ecosystems. This is mainly due to the fact that fecal material carries a variety of enteropathogens, which can enter and circulate in water bodies through fecal pollution. In this respect, the prompt identification of the polluting source(s) is pivotal to guiding appropriate target-specific remediation actions. Notably, microbial source tracking (MST) is widely applied to determine the host origin(s) contributing to fecal water pollution through the identification of zoogenic and/or anthropogenic sources of fecal environmental DNA (eDNA). A wide array of host-associated molecular markers have been developed and exploited for polluting source attribution in various aquatic ecosystems. This review is intended to provide the most up-to-date overview of genetic marker-based MST studies carried out in different water types, such as freshwaters (including surface and groundwaters) and seawaters (from coasts, beaches, lagoons, and estuaries), as well as drinking water systems. Focusing on the latest scientific progress/achievements, this work aims to gain updated knowledge on the applicability and robustness of using MST for water quality surveillance. Moreover, it also provides a future perspective on advancing MST applications for environmental research.publishedVersio

From Curved Bonding to Configuration Spaces

Bonding curves are continuous liquidity mechanisms which are used in market design for cryptographically-supported token economies. Tokens are atomic units of state information which are cryptographically verifiable in peer-to-peer networks. Bonding curves are an example of an enforceable mechanism through which participating agents influence this state. By designing such mechanisms, an engineer may establish the topological structure of a token economy without presupposing the utilities or associated actions of the agents within that economy. This is accomplished by introducing configuration spaces, which are proper subsets of the global state space representing all achievable states under the designed mechanisms. Any global properties true for all points in the configuration space are true for all possible sequences of actions on the part of agents. This paper generalizes the notion of a bonding curve to formalize the relationship between cryptographically enforced mechanisms and their associated configuration spaces, using invariant properties of conservation functions. We then proceed to apply this framework to analyze the augmented bonding curve design, which is currently under development by a project in the non-profit funding sector.Series: Working Paper Series / Institute for Cryptoeconomics / Interdisciplinary Researc

Nanoscale studies of domain wall motion in epitaxial ferroelectric thin films

Atomic force microscopy was used to investigate ferroelectric switching and nanoscale domain dynamics in epitaxial PbZr0.2Ti0.8O3 thin films. Measurements of the writing time dependence of domain size reveal a two-step process in which nucleation is followed by radial domain growth. During this growth, the domain wall velocity exhibits a v ~ exp[-(1/E)^mu] dependence on the electric field, characteristic of a creep process. The domain wall motion was analyzed both in the context of stochastic nucleation in a periodic potential as well as the canonical creep motion of an elastic manifold in a disorder potential. The dimensionality of the films suggests that disorder is at the origin of the observed domain wall creep. To investigate the effects of changing the disorder in the films, defects were introduced during crystal growth (a-axis inclusions) or by heavy ion irradiation, producing films with planar and columnar defects, respectively. The presence of these defects was found to significantly decrease the creep exponent mu, from 0.62 - 0.69 to 0.38 - 0.5 in the irradiated films and 0.19 - 0.31 in the films containing a-axis inclusions.Comment: 13 pages, 15 figures, to be published in J. App. Phys. special issue on ferroelectric

Economic Games as Estimators

Discrete event games are discrete time dynamical systems whose state transitions are discrete events caused by actions taken by agents within the game. The agents’ objectives and associated decision rules need not be known to the game designer in order to impose struc- ture on a game’s reachable states. Mechanism design for discrete event games is accomplished by declaring desirable invariant properties and restricting the state transition functions to conserve these properties at every point in time for all admissible actions and for all agents, using techniques familiar from state-feedback control theory. Building upon these connections to control theory, a framework is developed to equip these games with estimation properties of signals which are private to the agents playing the game. Token bonding curves are presented as discrete event games and numerical experiments are used to investigate their signal processing properties with a focus on input-output response dynamics.Series: Working Paper Series / Institute for Cryptoeconomics / Interdisciplinary Researc

Understanding polarization vs. charge dynamics effects in ferroelectric-carbon nanotube devices

To optimize the performance of multifunctional carbon nanotube-ferroelectric devices, it is necessary to understand both the polarization and charge dynamics effects on their transconductance. Directly comparing ferroelectric Pb(Zr0.2Ti0.8)O3 and dielectric SrTiO3 field effect transistors, we show that the two effects strongly compete, with transient charge dynamics initially masking up to 40% of the ferroelectric field effect. For applications, it is therefore crucial to maximize the quality of the ferroelectric film and the interface with the carbon nanotube to take full advantage of the switchable polarization.Comment: 5 pages, 4 figure

Conduction at domain walls in insulating Pb(Zr0.2_{0.2}Ti0.8_{0.8})O3_3 thin films

Among the recent discoveries of domain wall functionalities, the observation of electrical conduction at ferroelectric domain walls in the multiferroic insulator BiFeO3 has opened exciting new possibilities. Here, we report evidence of electrical conduction also at 180{\deg} ferroelectric domain walls in the simpler tetragonal ferroelectric PZT thin films. The observed conduction shows nonlinear, asymmetric current-voltage characteristics, thermal activation at high temperatures and high stability. We relate this behavior to the microscopic structure of the domain walls, allowing local defects segregation, and the highly asymmetric nature of the electrodes in our local probe measurements

Między zasadami rynku a bezpieczeństwem państwa: Ład gospodarczy w międzywojennej Polsce w warunkach systemu autorytarnego (1926–1939)

The article performs the analysis of the political views on economy that had an important impact on the concepts of economic policy in the Republic of Poland put forward by Piłsudski and Piłsudski’s camp – the authoritarian camp ruling in the Republic of Poland from 1926 to 1939. The author investigates the traces and the evidence of the political thought (i.e. the source material produced by the politicians of the political party and the description of decisions they made at that time).The scope of the interest included the property regulations that were grounded not only in the economical context, but, in particular – the political one. The political bases for economic decisions made by Józef Piłsudski and his camp and the successors were under research. In the period of the power transfer the followers of Józef Piłsudski did not legitimise the coup using the economic perspective even though the financial situation of the country was to deteriorate. Only after the coup had succeeded was the property order formulated, including the scope and the dimension of the economic order.Artykuł jest analizą poglądów politycznych na gospodarkę decydujących o koncepcjach polityki gospodarczej, realizowanej w Polsce międzywojennej przez obóz piłsudczykowski – obóz autorytarny rządzący w tym państwie w latach 1926–1939. Dokonano analizy śladów i świadectw myśli politycznych, czyli źródeł wytworzonych przez polityków tej formacji politycznej oraz opisów podjętych wówczas decyzji. Przedmiotem zainteresowania były regulacje własnościowe, które miały nie tylko kontekst ekonomiczny, lecz przede wszystkim polityczny. Zbadano polityczne podstawy decyzji ekonomicznych podejmowanych przez dyktatora Józefa Piłsudskiego i jego współpracowników oraz następców, a także recepcję ówczesnych teorii ekonomicznych. W czasie przejęcia władzy zwolennicy nie uzasadniali zamachu stanu za pomocą argumentów ekonomicznych, mimo, iż sytuacja w gospodarce nosiła znamiona kryzysowej. Dopiero po zamachu opracowano postulowany ład własnościowy, w tym zakres i zasięg zmian w porządku gospodarczym

From Trusted Confidant to Witness for the Prosecution: The Case Against the Recognition of a Dangerous-Patient Exception to the Psychotherapist-Patient Privilege

[Excerpt] “In 1996, in Jaffee v. Redmond, the U.S. Supreme Court, pursuant to the authority set forth in Federal Rule of Evidence 501, recognized a psychotherapist-patient privilege in the federal courts. In doing so, the Court acknowledged the essential role that confidentiality plays in a therapist-patient relationship and also recognized the important role that psychotherapy plays in the mental health of the American citizenry. However, in dicta set out in a footnote near the conclusion of the opinion (footnote 19 of the opinion), the Court suggested that the privilege might not be absolute, that it might need to “give way [in situations where] . . . a serious threat of harm to the patient or to others can be averted only by means of a disclosure by the therapist.” In the years since this decision, the lower federal courts have wrestled with how to determine the contours of the psychotherapist-patient privilege, particularly in light of the Supreme Court’s comments contained within footnote 19. Currently, the federal circuit courts are split over whether the Court intended to establish a dangerous-patient exception to the psychotherapist-patient privilege and the situations in which this exception would be appropriate. A year and a half after Jaffee was decided, the Tenth Circuit, in United States v. Glass, crafted a dangerous-patient exception to the privilege, which was fashioned after the criteria set forth by the Jaffee Court in footnote 19. However, the Sixth and Ninth Circuits have refused to recognize the exception on the grounds that the footnote is dicta and that a dangerous-patient exception contravenes the rationale and the holding of the Jaffee opinion. This article addresses the dangerous-patient exception to the psychotherapist-patient privilege and argues against the recognition of this exception. Parts I and II of this article present a discussion of the history of privileges and the development of the psychotherapist patient privilege, culminating with an in-depth discussion of the Supreme Court’s opinion in Jaffee. This section also includes a brief discussion of the two distinct rationales supporting privileges: the deontological rationale and the utilitarian rationale espoused by Dean John Henry Wigmore and adopted by the U.S. Supreme Court. Part III of this article presents the opinions of the federal circuit courts that have grappled with the question of whether to recognize the dangerous-patient exception to the psychotherapist-patient privilege. In Part IV, this article sets forth reasons why the Glass court and the other courts that have adopted the Glass test are wrong. It explains that the comments set forth in the Jaffee footnote are mere obiter dicta and, thus, have negligible value. It also demonstrates that interpreting this footnote as authorizing a dangerous-patient exception is wholly inconsistent with the Jaffee opinion and the Supreme Court’s sanctioning of the legislative history of Federal Rule of Evidence 501, particularly the proposed but rejected rules related to privileges. Part IV also argues that the Part IV also argues that the Glass court erred in crafting the test by failing to conduct the proper legal analysis in light of the privileges that the Supreme Court set forth in Jaffee and, two years later, in Swidler & Berlin v. United States. Part IV also addresses the “reason and experience” requirement of Federal Rule of Evidence 501, which provides that privileges are to be governed by the principles of the common law “as they may be interpreted by the [federal] courts . . . in light of reason and experience.” This section presents the reasons why “reason and experience” do not support the recognition of the dangerous-patient exception to the privilege. It shows not only that there is no clear consensus among the states with respect to a therapist’s duty to protect third parties, but also that there is much confusion among the laws of the states with respect to the dangerous-patient exception. Finally, this section examines the “reason and experience” requirement of Rule 501 in light of the commonly recognized exceptions to the other federal communication privileges. It concludes that because neither the attorney-client privilege, the spousal privilege, nor the clergy-penitent privilege are subject to a “dangerous-person” exception, “reason and experience” do not support the recognition of this type of exception to the psychotherapist-patient privilege. Part V of this article discusses the limited situations in which a therapist might be compelled to testify about a patient’s confidential communications. This article concludes with a discussion of, and recommendation for, procedures that courts should follow when presented with challenges to the psychotherapist-patient privilege. It recommends that courts conduct in camera review of the evidence proffered in support of exceptions to the privilege and require that the proponent of the exception prove the necessary elements by a preponderance of the evidence. These procedures will provide protection against the needless public disclosure of confidential patient information and serve to protect the confidentiality of the therapist-patient relationship, which the Jaffee Court recognized is a “sine qua non for successful psychiatric treatment.”