Carbon materials doped with nitrogen are active catalysts for the electrochemical two‐electron oxygen reduction reaction (ORR) to hydrogen peroxide. Insights into the individual role of the various ...chemical nitrogen functionalities in the H2O2 production, however, have remained scarce. Here, we explore a catalytically very active family of nitrogen‐doped porous carbon materials, prepared by direct pyrolysis of ordered mesoporous carbon (CMK‐3) with polyethylenimine (PEI). Voltammetric rotating ring‐disk analysis in combination with chronoamperometric bulk electrolysis measurements in electrolysis cells demonstrate a pronounced effect of the applied potentials, current densities, and electrolyte pH on the H2O2 selectivity and absolute production rates. H2O2 selectivity up to 95.3 % was achieved in acidic environment, whereas the largest H2O2 production rate of 570.1 mmol g−1catalyst h−1 was observed in neutral solution. X‐ray photoemission spectroscopy (XPS) analysis suggests a key mechanistic role of pyridinic‐N in the catalytic process in acid, whereas graphitic‐N groups appear to be catalytically active moieties in neutral and alkaline conditions. Our results contribute to the understanding and aid the rational design of efficient carbon‐based H2O2 production catalysts.
Nitrogen‐doped porous carbon catalysts were prepared by using CMK‐3 and polyethylenimine, exhibiting high H2O2 selectivity of 95.3 % in acid, and a large production rate of 570.1 mmol gcat.−1 h−1 in neutral solution. Ex situ X‐ray photoemission spectroscopy analysis suggests a key mechanistic role of pyridinic‐N in acid, whereas graphitic‐N groups appear to be catalytically active moieties in neutral and alkaline conditions.
Social computing technologies typically have multiple features that allow users to reveal their personal information to other users. Such self-disclosure (SD) behavior is generally considered ...positive and beneficial in interpersonal communication and relationships. Using a newly proposed model based on social exchange theory, this paper investigates and empirically validates the relationships between SD technology use and culture. In particular, we explore the effects of culture on information privacy concerns and the desire for online interpersonal awareness, which influence attitudes toward, intention to use, and actual use of SD technologies. Our model was tested using arguably the strongest social computing technology for online SD-instant messaging (IM)-with users from China and the United States. Our findings reveal that cross-cultural dimensions are significant predictors of information privacy concerns and desire for online awareness, which are, in turn, found to be predictors of attitude toward, intention to use, and actual use of IM. Overall, our proposed model is applicable to both cultures. Our findings enhance the theoretical understanding of the effects of culture and privacy concerns on SD technologies and provide practical suggestions for developers of SD technologies, such as adding additional control features to applications.
•Survey design tests effects of collectivism and ownership on security decisions.•Factorial survey method experimentally manipulates variables in scenarios.•Collectivism affects intention and ...psychological ownership.•Psychological ownership affects native PMT variables and intention.•Significant differences shown between U.S. and China sample populations.
Increased deregulation and globalization have encouraged organizations to expand the cultural diversity of their employees. Integrating each employee into an organization's culture, including practices regarding the protection of information, is critical. Because active employee participation is important for security, managers may need to evaluate individual cultural values to motivate employees to perform secure behaviors. This study analyzes these potential differences by examining two individual characteristics – collectivism and psychological ownership of information – within the context of information security-related behaviors. The results of this study indicate that an individual's personal orientation toward collectivism has an impact on psychological ownership and the intention not to perform secure behaviors. Furthermore, psychological ownership was shown to have a significant impact on the protection motivation constructs as well as on intention. The findings of this study contribute to information security research by studying collectivism's effect on psychological ownership and psychological ownership's impact on protection motivation.
Image formation historically - using the example of Giovanni Bellini's wife at the toilet At the beginning of the 16th century, Giovanni Bellini painted a naked woman sitting next to an opening in a ...wall (fig. 1). Lost in her face in the hand mirror, she straightens her hairstyle, which another mirror on the wall shows from behind.' The pictorial space is closed off from the outside world in that the landscape is reduced to a view and moved into the distance, while the viewer is obviously not in the picture. The wall mirror shows the mirror images in Jan van Eyck's so-called Arnolfini Wedding of 1434 or later in Diego Velåzquez' Las Meninas of 1656, in which the viewer appears in the person of the artist alongside the royal couple as a participant in the picture in the mirrors on the back wall Bellini only the back of the woman's head. The impression thus created, of seeing the unprotected, authentic face of the woman as an unrecognized voyeur, thanks to the alleged intimacy, immediately proves to be a deception. Next to the woman lies an open letter on which the Venetian painter signed and dated the picture (Joannes bellinus faciebat M.D.X. By declaring the picture to be a work by Bellini, the signature addresses its status as a medium of representation, as Klaus Krüger has made clear-2 Because the signed letter “fits in homogeneously with the world of objects inside the picture in the sense of a deceptively real illusion and forms a part of it; and yet it is at the same time the testimony of its fictitiousness.
Mixed Ni–Fe oxides are attractive anode catalysts for efficient water splitting in solar fuels reactors. Because of conflicting past reports, the catalytically active metal redox state of the ...catalyst has remained under debate. Here, we report an in operando quantitative deconvolution of the charge injected into the nanostructured Ni–Fe oxyhydroxide OER catalysts or into reaction product molecules. To achieve this, we explore the oxygen evolution reaction dynamics and the individual faradaic charge efficiencies using operando differential electrochemical mass spectrometry (DEMS). We further use X-ray absorption spectroscopy (XAS) under OER conditions at the Ni and Fe K-edges of the electrocatalysts to evaluate oxidation states and local atomic structure motifs. DEMS and XAS data consistently reveal that up to 75% of the Ni centers increase their oxidation state from +2 to +3, while up to 25% arrive in the +4 state for the NiOOH catalyst under OER catalysis. The Fe centers consistently remain in the +3 state, regardless of potential and composition. For mixed Ni100–x Fe x catalysts, where x exceeds 9 atomic %, the faradaic efficiency of O2 sharply increases from ∼30% to 90%, suggesting that Ni atoms largely remain in the oxidation state +2 under catalytic conditions. To reconcile the apparent low level of oxidized Ni in mixed Ni–Fe catalysts, we hypothesize that a kinetic competition between the (i) metal oxidation process and the (ii) metal reduction step during O2 release may account for an insignificant accumulation of detectable high-valent metal states if the reaction rate of process (ii) outweighs that of (i). We conclude that a discussion of the superior catalytic OER activity of Ni–FeOOH electrocatalysts in terms of surface catalysis and redox-inactive metal sites likely represents an oversimplification that fails to capture essential aspects of the synergisms at highly active Ni–Fe sites.
Three-dimensional calculations of the meniscus of a magnetic fluid placed around a current carrying vertical and cylindrical wire are presented. Based on the material properties of experimentally ...used magnetic fluids, the numerically determined menisci are compared with the experimentally measured ones reported by May. The comparison is made for a linear law of magnetisation as well as for the experimentally measured nonlinear magnetisation curve. Up to moderate strengths of the applied current ( I < = 45 A), i.e., up to moderate strengths of the magnetic field close to the wire, the calculated profiles agree satisfyingly with the experimentally measured ones for a linear as well as for a nonlinear law of magnetisation. At a great strength of the applied current ( I = 70 A), i.e., at a large strength of the magnetic field close to the wire, the agreement is less good than in the range up to moderate strengths. Our analysis revealed that the numerically assumed isothermal conditions are not present in the experiment, particularly at the great strength of the applied current. A control of the temperature in the experiment and the implementation of a coupled thermal model in the numerics are considered the most relevant future steps for an improved agreement.
Only a limited number of animal species lend themselves to becoming model organisms in multiple biological disciplines: one of these is the great pond snail,
. Extensively used since the 1970s to ...study fundamental mechanisms in neurobiology, the value of this freshwater snail has been also recognised in fields as diverse as host-parasite interactions, ecotoxicology, evolution, genome editing and 'omics', and human disease modelling. While there is knowledge about the natural history of this species, what is currently lacking is an integration of findings from the laboratory and the field. With this in mind, this article aims to summarise the applicability of
and points out that this multipurpose model organism is an excellent, contemporary choice for addressing a large range of different biological questions, problems and phenomena.
Information Security (InfoSec) research is far reaching and includes many approaches to deal with protecting and mitigating threats to the information assets and technical resources available within ...computer based systems. Although a predominant weakness in properly securing information assets is the individual user within an organization, much of the focus of extant security research is on technical issues. The purpose of this paper is to highlight future directions for Behavioral InfoSec research, which is a newer, growing area of research. The ensuing paper presents information about challenges currently faced and future directions that Behavioral InfoSec researchers should explore. These areas include separating insider deviant behavior from insider misbehavior, approaches to understanding hackers, improving information security compliance, cross-cultural Behavioral InfoSec research, and data collection and measurement issues in Behavioral InfoSec research.
In Detestable and Wicked Arts, Paul B. Moyer places early New England's battle against black magic in a transatlantic perspective. Moyer provides an accessible and comprehensive examination of witch ...prosecutions in the Puritan colonies that discusses how their English inhabitants understood the crime of witchcraft, why some people ran a greater risk of being accused of occult misdeeds, and how gender intersected with witch-hunting. Focusing on witchcraft cases in New England between roughly 1640 and 1670, Detestable and Wicked Arts highlights ties between witch-hunting in the New and Old Worlds. Informed by studies on witchcraft in early modern Europe, Moyer presents a useful synthesis of scholarship on occult crime in New England and makes new and valuable contributions to the field.
The ultimate goal of any prescribed medical therapy is to achieve desired outcomes of patient care. However, patient nonadherence has long been a major problem detrimental to patient health and, ...thus, is a concern for all health care providers. Moreover, nonadherence is extremely costly for global medical systems because of unnecessary complications and expenses. Traditional patient education programs often serve as an intervention tool to increase patients' self-care awareness, disease knowledge, and motivation to change patient behaviors for better adherence. Patient trust in physicians, patient-physician relationships, and quality of communication have also been identified as critical factors influencing patient adherence. However, little is known about how mobile patient education technologies help foster patient adherence.
This study aimed to empirically investigate whether and how a mobile patient education system (MPES) juxtaposed with patient trust can increase patient adherence to prescribed medical therapies.
This study was conducted based on a field survey of 125 patients in multiple states in the United States who have used an innovative mobile health care system for their health care education and information seeking. Partial least squares techniques were used to analyze the collected data.
The results revealed that patient-physician communication and the use of an MPES significantly increase patients' trust in their physicians. Furthermore, patient trust has a prominent effect on patient attitude toward treatment adherence, which in turn influences patients' behavioral intention and actual adherence behavior. Based on the theory of planned behavior, the results also indicated that behavioral intention, response efficacy, and self-efficacy positively influenced patients' actual treatment adherence behavior, whereas descriptive norms and subjective norms do not play a role in this process.
Our study is one of the first that examines the relationship between patients who actively use an MPES and their trust in their physicians. This study contributes to this context by enriching the trust literature, addressing the call to identify key patient-centered technology determinants of trust, advancing the understanding of patient adherence mechanisms, adding a new explanation of the influence of education mechanisms delivered via mobile devices on patient adherence, and confirming that the theory of planned behavior holds in this patient adherence context.
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