Während eines Betriebsrundgangs mit dem Werkleiter zur Beurteilung der Ergonomie an Arbeitsplätzen verweilte dieser on einer lärmintensiven Anlage, zog sein Smartphone aus der Jackettasche und hielt es in Richtung der Maschine, um deren Schallpegel zu messen. Augenblicke später recherchierte er über die Suchfunktion des Gerätes nach zulässigen Grenzwerten. Am Ende des Rundgangs entspann sich eine Diskussion über die Aussagefähigkeit und Zuverlässigkeit Smartphone-gestützter Messungen von Arbeitsumweltfaktoren. Eine Studie am Institut für Produktionstechnik der Westsächsischen Hochschule Zwickau sollte klaren, ob es überhaupt noch des Einsatzes spezifischer Messtechnik bedarf. Das Ergebnis der Studie zeigt deutlich, dass sowohl die eingesetzte Hardware aktueller Smartphones und Tablets als auch die zur Verfügung stehen Programme bislang nicht den Ansprüchen einer Messung aus arbeitswissenschaftlicher Sicht entsprechen. Angesichts der Begeisterung vieler Gerätebesitzer in Kombination mit der Unkenntnis tatsächlicher Fähigkeiten solcher Apps ist es dringend notwendig, Aufklärungsarbeit zu leisten. Unabhängig von diesen Analyseergebnissen sollte die Chance betrachtet werden, dass durch zertifizierte messtechnische Erweiterungen von Smartphones eine engmaschigere und einfachere Überprüfung ergonomischer Arbeitsbedingungen möglich ist. Da es sich bei Smartphones vordergründig um Geräte zur Aufbereitung von Informationen handelt, verweist die Studie auf die Kopplung geeigneter Messsonden mit einem Smartphone. In dieser Kombination könnten Messsysteme zur Arbeitssystembeurteilung mit integrierter Anleitung entstehen, welche es vor allem ermöglichen, nicht nur korrekt zu messen, sondern die Ergebnisse auch richtig zu interpretieren und einzuordnen.
The science of ergonomics studies the conditions and effects of human labour in order to obtain rules for assessment and design. As working life changes, the general working conditions also change dynamically. The causes of such change processes are changes in working and lifestyle, human-technology-interaction, working time, as well as the demands on flexibility, mobility, decision-making skills and self-organization. The consequences of this development are a constant increase in the complexity of work-related requirements. The burdens associated with work can no longer be considered in a situational and detached way, as in many classical methods of work analysis, but should be taken into account in their holistic effect of mutual relations.
This article theoretically and empirically deals first with the question of whether the use of wearables provides support and assistance for the analysis of working conditions. Second it asks whether the application of wearables is a way to investigate complex stress conditions more effectively and whether it might supplement, substitute or further develop established and esteemed methods of work system analysis.
Die Arbeitswissenschaft untersucht die Bedingungen und Auswirkungen menschlicher Arbeit, um daraus Beurteilungs- und Gestaltungsregeln zu gewinnen. Mit dem Wandel des Arbeitslebens verändern sich auch die Rahmenbedingungen der Arbeit selbst dynamisch. Auslöser solcher Prozesse sind Veränderungen von Arbeits- und Lebensstil, der Mensch-Technik-Interaktion, der Arbeitszeit sowie den damit verbundenen Anforderungen an Flexibilität, Mobilität, Entscheidungsfähigkeit und Selbstorganisation. Als Folge dieser Entwicklung lässt sich ein Anstieg der Komplexität arbeitsbezogener Anforderungen feststellen. Eine korrekte Einordnung entsprechender Arbeitsbelastungen bedarf einer ganzheitlichen Betrachtung der Wirkung gegenseitiger Beziehungen. Damit schließen sich eine Vielzahl klassischer Verfahren der Arbeitsanalyse, die die einzelnen Sachverhalte situativ und losgelöst voneinander betrachten, aus.
Da eine Beurteilung komplexer Anforderungssituationen für den einzelnen Arbeitsanalytiker nur bedingt beherrschbar sein kann, setzt sich der Beitrag theoretisch und empirisch mit der Frage auseinander, ob durch den Einsatz von Wearables eine analytische Begleitung und Assistenz menschlicher Arbeit möglich ist. Es wird der Frage nachgegangen, ob mittels Wearables objektive und belastbare Aussagen zur Wirkung dynamischer Bündel unterschiedlicher Belastungen möglich sind, um anerkannte Verfahren der Arbeitssystemanalyse zu ergänzen, zu substituieren bzw. weiterzuentwickeln.
The purpose of this study is to examine the relationship between contextual work-related factors in terms of job demands (workload-WL) and job resources (work flexibility-WF), work-life conflict (WLC) and the burnout dimension emotional exhaustion (EE) in a large population-based sample. Building on the job demands resources model (JDRM), we have developed the hypothesis that WL has an indirect effect on EE that is mediated by WLC. We conducted a secondary analysis using data from the Dresden Burnout Study (DBS, N = 4246, mean age (SD) = 42.7 years (10.5); 36.4% male). Results from structural equation modelling revealed that EE is positively associated with WL (β = 0.15, p = 0.001) and negatively associated with WF (β = -0.13, p = 0.001), also after accounting for potential confounding variables (demography, depressive symptoms, and lifetime diagnosis of burnout). Both effects are mediated by WLC (β = 0.18; p = 0.001 and β = 0.08; p = 0.001, respectively) highlighting the important role of WLC in employee health. In summary, WF may help to reduce burnout symptoms in employees, whereas WL may increase them. Study results suggest that both associations depend on WLC levels.
Hybrid manufacturing of titanium Ti-6Al-4V combining laser metal deposition and cryogenic milling
(2020)
Hybrid manufacturing, which, e.g., combines additive manufacturing with conventional machining processes, can be a way of overcoming limitations currently encountered in additive manufacturing. Cryogenic milling might be a viable option for hard-to-cut materials, as it leaves a contamination-free surface and can increase surface quality and tool life compared to conventional cooling concepts. In this study, the influence of cryogenic milling with carbon dioxide on titanium Ti-6Al-4V specimens manufactured with laser metal deposition (LMD) was investigated regarding tool wear and surface integrity in comparison to dry machining and machining with cooling lubricants. Moreover, additional layers of material were deposited on top of conventionally and cryogenically machined surfaces by means of LMD. The interface zone was then examined for defects. The milling process was closely monitored by means of thermal and high-speed imaging. Optical and tactile surface analysis provided evidence that lower roughness values and improved surface qualities could be obtained with cryogenic machining in comparison to dry machining. Moreover, significantly less tool wear was observed when a cryogenic cooling medium was applied. Although the utilization of conventional cooling lubricants resulted in satisfying surface qualities, substantial residual contamination on the milled surface was detected by means of fluorescence analysis. These contaminants are suspected to cause defects when the next layer of material is deposited. This is supported by the fact that pores were found in the weld bead applied on top of the milled specimens by means of LMD. Conversely, cryogenic machining resulted in very clean surfaces due to the residue-free evaporation of the coolant. Hence, a good metallurgical bonding between the weld bead and the milled substrate could be achieved. The results indicate the great potential of cryogenic milling in hybrid manufacturing, especially in terms of intermediate machining, as it provides residue-free surfaces for subsequent material deposition without an additional cleaning step and can significantly prolongate tool life.
Prussian blue (PB) layers were electrodeposited for the fabrication of Au/PB/Ag stacks to study the resistive switching effect. The PB layers were characterized by different techniques to prove the homogeneity, composition, and structure. Electrical measurements confirmed the bipolar switching behavior with at least 3 orders of magnitude in current and the effect persisting for the 200 cycles tested. The low resistance state follows the ohmic conduction with an activation energy of 0.2 eV.
This paper provides a critical reading of Janek Wasserman’s The Marginal Revolutionaries: How Austrian Economists Fought the War of Ideas. Wasserman depicts the evolution of the Austrian School from the 1860s until today, a particularly illuminating narrative for the readers of this journal. The breadth of portrayed economists, their cultural embeddedness in Austrian and US contexts, and the complexity of configurations across the school’s generations create a rich and readable story. The last third of the book suffers from allegations about the ideological agenda and institutional power of the Austrian economists which sometimes lack sufficient substantiation. The paper indicates how both in their theorizing and in their political activities, the Austrian economists can be seen as reformers instead of revolutionaries, and as constitutionalists instead of anti-democrats. Despite these disagreements, Wasserman’s portrayals evoke largely fair and challenging impulses both to scholars working in the Austrian research program and to those interested in the Austrian School’s long history, regardless of one’s ideological positions.
Hintergrund/Zielstellung: Aufgrund des gestiegenen Informationsbedürfnisses von Patienten wird für Ärzte ein eigener Webauftritt als Informationsmittler mit dem Ziel der Patientengewinnung und -bindung zunehmend bedeutsam. In der vorliegenden Studie wurde daher die Patientenorientierung der Internetauftritte niedergelassener Fachärzte für Orthopädie und/oder Unfallchirurgie in Sachsen untersucht.
Methode/Stichprobe: Alle Websites der im Arztregister der Kassenärztlichen Vereinigung Sachsen gelisteten Fachärzte für Orthopädie und/oder Unfallchirurgie wurden mithilfe einer standardisierten Checkliste analysiert.
Ergebnisse: Von allen untersuchten Fachärzten (n = 349) besaßen 140 (40,1 %) einen eigenen Internetauftritt. In der Arztpraxis durchgeführte diagnostische Methoden und Therapiemaßnahmen wurden auf je ca. 90,0 % der Websites genannt und auf ca. der Hälfte hiervon erklärt. Der Kontrast konnte auf 10 Websites angepasst werden. Eine Meinungsäußerung wurde den Patienten auf 28 Websites ermöglicht. Rechtlich verpflichtende Impressuminhalte wurden auf 45,0 % der Internetauftritte nicht hinreichend beachtet.
Diskussion/Schlussfolgerung: Die Ergebnisse weisen darauf hin, dass die Gestaltung der Internetauftritte sowie deren Informationsgehalt differieren und Verbesserungspotenziale existieren. Ein standardisierter Kriterienkatalog könnte ein einheitliches Qualitätsniveau gewährleisten und von den Ärzten als Handlungsempfehlung genutzt werden.
Dissipation energy based parameter identification of anisotropic linear viscoelastic composites
(2020)
The current work presents a relaxation analysis based procedure to identify effective material parameters of the multiaxial generalized Maxwell model (GMM) by a numerical homogenization of the microscopic dissipation energy density for anisotropic linear viscoelastic composites. The employed GMM enables the derivation of a thermodynamically consistent constitutive law and a function of the dissipation energy density for direction‐dependent viscoelastic materials. The identity of this energy function to the microstructure's homogenized dissipation energy density is utilized for the identification of effective relaxation times. Furthermore, the identified relaxation times enable a simple determination of the remaining stiffness parameters. Finally, the presented procedure is demonstrated and evaluated for a randomly endless fibre‐reinforced plastic with a polymer matrix exhibiting a significant viscoelastic behaviour.
Lewis–Mogridge Points: A Nonarbitrary Method to Include Induced Traffic in Cost-Benefit Analyses
(2020)
We propose a new method to estimate benefits of road network improvements, which allows to include the induced demand without arbitrary assumptions. Instead of estimating induced demand (which is nontrivial and hardly possible in practice), we search for demand induction where initial benefits are mitigated to zero. Such approach allows to formulate a dual measure of benefit, covering both the potential benefits and the likelihood of consuming them by the induced traffic. We first estimate benefits of road network improvement assuming that traffic demand is fixed. Consequently, we find demand model configurations at which the benefits of the new investment become null, i.e., all the initial benefits are consumed by the traffic demand growth. We call such states of induced demand the Lewis–Mogridge points of the analysed improvement. We select the most probable of such points and use it to calculate the proposed novel indicator μ, for which the initial benefits (obtained under a fixed-demand assumption) are multiplied with a demand increase rate needed to consume them. We believe that such measure allows to include the critical phenomena of induced traffic and, at the same time, to overcome problems associated with reliable estimation of induced demand. As we illustrate with the case of two alternative road improvement schemes in Kraków, Poland, the proposed method allows to estimate maximal threshold of induced traffic and to select scenario more resilient to induced traffic.
Recent surveys and political research have shown that the acceptance of the political programmes of populist parties, such as the “Alternative für Deutschland (AfD)”, is relatively high amongst the population of the three eastern German federal states, especially in Saxony, where the AfD won nine of the 13 rural districts during the local elections in May 2019. Thus, it seems relevant to take a closer look at the persuasive discourse of a so-called populist party. In its public discourse, the AfD responds to the fears and concerns of those people who tend to use social media platforms to gain information when making political decisions. The aim of the article is to show which verbal and visual resources characterize the persuasive discourse of the AFD Saxony on their Facebook account. For this purpose, we propose a qualitative, multimodal analysis of selected entries which the party uploaded on its Facebook account between November 2018 and March 2019.
Hintergrund: Der überwiegende Teil der Patienten in Deutschland verstirbt entgegen ihres Wunsches nicht zu Hause. Eine Entscheidungshilfe für das notfallmedizinische Team kann nachfolgende Klinikeinweisungen von Patienten am Lebensende vermeiden.
Material und Methoden: Die Entscheidungshilfe Notarzt wurde im Rahmen des G-BA-Projektes AVENUE-Pal basierend auf einem Expertenkonsens mittels qualitativer und quantitativer Befragungen entwickelt. Sie stellt einen Teilaspekt des Gesamtprojektes dar.
Ergebnisse: Die EH Notarzt definiert 7 Ziele, die durch die Dimensionen „Information“, „Beratung“, „Unterstützung“, „Schulung“, „Anleitung“, „Übung“, „Kooperation“ und „Dokumentation“ erreicht werden sollen. Die EH Notarzt stellt eine Möglichkeit der Optimierung der notfallmedizinischen Behandlung von Patienten am Lebensende dar.
Diskussion: Die EH Notarzt ist eine Entwicklung zur Verbesserung der präklinischen Versorgung von Patienten am Lebensende und zur Vermeidung von Klinikeinweisungen am Lebensende. Derzeit ist die EH Notarzt ein theoretisches Hilfsmittel, welches in die praktische Anwendung überführt werden und weiterhin an die Notwendigkeiten der täglichen Patientenversorgung angepasst werden muss.
Emotionale Kompetenzen und psychische Gesundheit: Eine Querschnittstudie in Gesundheitsberufen
(2021)
Hintergrund
Im Jahr 2020 waren 5,7 Mio. Menschen in Gesundheits- und Pflegeberufen tätig. Der Kontakt mit anderen Menschen ist in diesen Berufen Teil des Arbeitsauftrags und der Mensch ist der Arbeitsgegenstand.
Ziel der Arbeit
Das Ziel der Arbeit ist die Untersuchung der Auswirkung von psychischer Belastung (Arbeitsintensität, Spielräume), emotionaler Erschöpfung und emotionalen Kompetenzen (Regulation) auf das psychische Wohlbefinden bei Beschäftigten in Gesundheitsberufen.
Material und Methoden
Die Erhebung der Querschnittstudie von 624 Beschäftigten aus der Altenpflege und dem Rettungsdienst (72,5 % weiblich) erfolgte im Rahmen zweier Projekte zur betrieblichen Gesundheitsförderung. Zum Einsatz kamen standardisierte validierte Verfahren, welche mittels Korrelationsanalysen sowie einer hierarchischen Regressionsanalyse zur Vorhersage des psychischen Wohlbefindens ausgewertet wurden.
Ergebnisse
Hohe Arbeitsintensität, hohe Spielräume, hohe emotionale Erschöpfung und eine hohe emotionale Kompetenz (Regulation) tragen zur Aufklärung des psychischen Wohlbefindens bei (R2 = 33 %).
Schlussfolgerung
Anhand der Ergebnisse wird deutlich, dass neben dem Erleben von Arbeit und Gesundheit auch emotionale Kompetenzen einen Einfluss auf die psychische Gesundheit bei Beschäftigten in Gesundheitsberufen haben. Damit leistet die Studie einen wichtigen Beitrag für die Entwicklung von Maßnahmen des betrieblichen Gesundheitsmanagements in diesen Berufsgruppen.
Introduction: In the spring of 2020, coronavirus disease 2019 posed a substantial challenge for countries and their healthcare systems. In Germany, over 70% of all cancer patients are treated in an outpatient setting, so gynecologic oncology practices are the guarantors of optimal patient care. We developed a survey to evaluate the management of gynecologic oncology patients.
Methods: The survey consisted of 38 questions and was sent to the members of the Berufsverband Niedergelassener Gynäkologischer Onkologen in Deutschland e.V. (BNGO), a professional association of gynecologic oncologists in the outpatient sector in Germany.
Results: The survey was completed by 54 out of 133 (41%) gynecologic oncologists from 14 out of 15 (93%) federal states where the BNGO is represented. Facing the pandemic, popular measures were mask requirements (100%), restriction of access to practices (94%), increased number of disinfectant dispensers (85%), installment of panes of acrylic glass (76%), or spatial alterations (67%). For most patients the pandemic had no influence on prioritization of therapies (82%) or prescribed systemic treatments (87%). Despite an increase in perceived psychological burden among the staff (72%), 85% (45/54) of the practices were not offered any additional psychological support.
Discussion and Conclusion: As most cancer patients in Germany are treated in an outpatient setting, a suitable reaction of oncology centers to the new circumstances was crucial to secure optimal treatment and patient care. Nevertheless, the low prioritization of mental health or distress of healthcare workers poses a serious threat to the maintenance of optimal medical care in further waves of the pandemic.
Effect of acoustic excitation on fiber-reinforced polypropylene and the influence on melt viscosity
(2021)
The paper describes a novel technological approach to influencing the rheological properties of thermoplastic materials exposed to acoustic energy. The flow behavior of polypropylene with different mass percentages of glass fibers is investigated in a parallel plate rheometer under high-frequency longitudinal excitation. The influence of oscillation frequency on the melt viscosity is explained by means of shear thinning criteria. The dependence of the oscillation shape using sinusoidal excitation on shear thinning as a function of different fiber reinforcement percentages is also investigated. A phenomenological view describes the mutually influencing parameters with regard to different material compositions and different excitation frequencies over the time course of the rheometric measurement. Interacting relationships are analyzed and discussed and the potential of the actuator system to influence the plastic melt is worked out. Based on this, a technological approach follows which describes the transfer of an oscillating mold surface to plastics processing methods, which, especially in the case of energy-intensive injection molding technology, leads to the expectation of possible resource efficiency in energy and material.
This paper presents numerical analysis of the discrete fundamental solution of the discrete Laplace operator on a rectangular lattice. Additionally, to provide estimates in interior and exterior domains, two different regularisations of the discrete fundamental solution are considered. Estimates for the absolute difference and lp‐estimates are constructed for both regularisations. Thus, this work extends the classical results in the discrete potential theory to the case of a rectangular lattice and serves as a basis for future convergence analysis of the method of discrete potentials on rectangular lattices.
The intention of the paper is to consider the role of technologies used to overcome the COVID-19’s challenges in higher education. On investigating, it has been found that the digital strategies utilizing innovation technologies help students to adapt to pandemic consequences. This study enlightens the various technologies that assist systems of healthcare and education in diverse aspects to outlive against COVID-19. Furthermore, the technological shift of world economy that happened during the pandemic and its influence in the society is discussed. Besides the considered innovation technologies, this paper also deals with changes that have taken place in education system of Kazakhstan in pandemic circumstances. Alongside our suggested solution for further educational process issues is also presented.
A detailed review of the literature is done on COVID-19, digital technologies in education, blended learning using appropriate keywords on SCOPUS, Springer, Science Direct, and Google Scholar. To get insights some relevant sites and blogs are also taken into account. We have identified technologies used in Kazakhstan that play an important role now.
There have been chosen exploratory and conclusive research design. Fifty-nine students provided qualitative responses; ninety-eight students and graduates participated in quantitative survey. The results of study has shown students’ increased awareness concerning blended learning.
The scientific novelty lies in the description of the experience gained by higher schools during the quarantine. We believe that in the future, blended learning should be used largely. The innovations in the learning process cover two areas. The first is related to software used. It is like creation of a virtual university that facilitates communication between students and teachers. The second area correlates with content, without which any innovation will fail.
Objectives: Evidence-based clinical guidelines play an important role in healthcare and can be a valuable source for quality indicators (QIs). However, the link between guidelines and QI is often neglected and methodological standards for the development of guideline-based QI are still lacking. The aim of this qualitative study was to get insights into experiences of international authors with developing and implementing guideline-based QI.
Setting: We conducted semistructured interviews via phone or skype (September 2017–February 2018) with guideline authors developing guideline-based QI.
Participants: 15 interview participants from eight organisations in six European and North American countries.
Methods: Organisations were selected using purposive sampling with a maximum variation of healthcare settings. From each organisation a clinician and a methodologist were asked to participate. An interview guide was developed based on the QI development steps according to the ‘Reporting standards for guideline-based performance measures’ by the Guidelines International Network. Interviews were analysed using qualitative content analysis with deductive and inductive categories.
Results: Interviewees deemed a programmatic approach, involvement of representative stakeholders with clinical and methodological knowledge and the connection to existing quality improvement strategies important factors for developing QI parallel to or after guideline development. Methodological training of the developing team and a shared understanding of the QI purpose were further seen conducive. Patient participation and direct patient relevance were inconsistently considered important, whereas a strong evidence base was seen essential. To assess measurement characteristics interviewees favoured piloting, but often missed implementation. Lack of measurability is still experienced a serious limitation, especially for qualitative aspects and individualised care.
Conclusion: Our results suggest that developing guideline-based QI can succeed either parallel to or following the guideline process with careful planning and instruction. Strategic partnerships seem key for implementation. Patient participation and relevance, measurement of qualitative aspects and piloting are areas for further development.
Trial registration number: German Clinical Trials Registry (DRKS00013006).
Analgesic drug use of recreational and competitive badminton players: Starting points for prevention
(2021)
Traffic calming is introduced to minimise the negative results of motor vehicle use, for example, low safety level or quality of life, high noise and pollution. It can be implemented through the introduction of road infrastructure reducing the velocity and the traffic volume. In this paper, we studied how traffic-calming influences the traffic assignment. For the research, a traffic-calming measure of speed cushions on the Stachiewicza street in Krakow was taken. A method of extracting trajectories from aerial footage was shown, and it was used to build a model. For a given example, through driving characteristics research and microscopic modelling, volume–delay BPR functions were estimated—for a street with and without traffic calming. Later, a toy network of two roads of the same length, connecting the same origin and destination, was simulated using an equilibrium traffic assignment method. Simulations were conducted both with the use of PTV Vissim and Visum software and through individual calculations. According to the results of this paper, there was a difference in traffic volume according to the equilibrium traffic assignment in the aforementioned toy network as a function of total network traffic volume.
This paper presents an analytical method for determining the bending stresses and deformations in prismatic, noncircular profile shafts with trochoidal cross sections. The so-called higher trochoids can be used as form-fit shaft-hub connections. Hybrid (mixed) higher trochoids (M-profiles) were developed for the special application as a profile contour for the form-fit shaft and hub connections in an earlier work by the author. M-profiles combine the advantages of the two standardised polygonal and spline contours, which are used as shaft-hub connections for the transmission of high torques. In this study, the geometric and mechanical properties of the higher hybrid trochoids were investigated using complex functions to simplify the calculations. The pure bending stress and shaft deflection were determined for M-profiles using bending theory based on the theory of mathematical elasticity. The loading cases consisted of static and rotating bends. Analytical, numerical, and experimental results agreed well. The calculation formulas developed in this work enable reliable and low-cost dimensioning with regard to the stresses and elastic deformations of profile shafts subjected to bending loads.
Introduction
(2022)
Context
VR as an application to enhance well-being is sparsely researched in the elderly population. The aim of the pilot study was to analyze the effect of 360° videos of different categories on the state of mind of seniors in nursing facilities. Furthermore, for the implementation in everyday life, the usability of the system and the experience for seniors should be evaluated.
Methods
The VR experience was used as a supplement to existing care services in three facilities on eight subjects. Mood state was assessed using the Questionnaire for the Assessment of Happiness before and after the intervention. Demographic data and technology acceptance were collected beforehand. After the intervention, subjects were interviewed about confounding factors and side effects, and nursing home staff were interviewed about the usability of the system and the organizational concept of implementation.
Results
There was a positive effect on state of mind. Gender and spatial mobility turned out to be influencing factors. Categories containing people, animals and action achieved the highest increases in the state of mind. Interest in using technical devices correlated negatively with the change in mood state. None of the subjects found the VR goggles distracting or reported motion sickness. Very good usability was indicated by the employees.
Conclusion
A very high willingness to use this technology was found among nursing staff and residents. The tendencies of the positive effect of 360° videos on the state of mind, as well as differentiation based on the mentioned characteristics gender and spatial mobility, should be verified by a larger sample to empirically validate the use of this technology to increase the quality of life.
Hintergrund: Wenn professionelle Unterstützung fehlt, erkennen pflegende Angehörige selten eigene Überlastungssituationen und nehmen Unterstützungsleistungen bei Pflegebedürftigkeit daher unzureichend in Anspruch.
Ziel: Die Studie untersucht die Versorgung von Menschen mit Pflegebedarf, den Kenntnisstand zu Entlastungsleistungen sowie Belastungsfaktoren bei der Übernahme pflegerischer Leistungen aus Sicht informell Pflegender und Nicht-Pflegender.
Methode: Es wurde eine Querschnittstudie mittels standardisierter Computer Assisted Telephone Interviews (CATI) mit Personen ab dem 18. Lebensjahr in Sachsen durchgeführt. Deskriptive und bivariate Statistiken wurden berechnet.
Ergebnisse: Die Versorgung durch einen ambulanten Pflegedienst oder durch pflegende Angehörige bewerteten von 601 Teilnehmenden 259 informell Pflegende gegenüber 342 Nicht-Pflegenden signifikant besser ( N = 601). Weiterhin hatten die informell Pflegenden und die Nicht-Pflegenden unterschiedliche Kenntnisse über den nächstgelegenen Ort der Pflegeberatung und über Ausgleichzahlungen der Rentenversicherung. Schlussfolgerungen: In einzelnen Bereichen der abgefragten Beratungsleistungen und Entlastungsmöglichkeiten hat sich das Antwortverhalten von pflegenden Angehörigen gegenüber den anderen Teilnehmenden signifikant unterschieden. Es kann von einem geringen Informationsvorsprung der pflegenden Angehörigen bei der Inanspruchnahme von Unterstützungsleistungen ausgegangen werden.
Routing games over time are widely studied due to various applications, e.g., transportation, road and air traffic control, logistic in production systems, communication networks like the internet, and financial flows. In this article, we present a new competitive packet routing game with edge priorities motivated by traffic and transportation. In this model a set of selfishly acting players travels through the network over time. If the number of players who want to enter an edge at the same time exceeds the inflow capacity of this edge, then edge priorities with respect to the preceding edge are used to resolve these conflicts, which is similar to right-of-way rules in traffic. We analyze the efficiency of pure Nash equilibria, present an efficient algorithm for computing equilibria in symmetric games, and show that it is NP-hard to decide whether a Nash equilibrium exists in an asymmetric game. Furthermore, we address the problem of constructing optimal priorities.
Analysis of a Film Forming Process through Coupled Image Correlation and Infrared Thermography
(2022)
The aim of the present investigation was to determine the dependence of the material and process parameters of the bending process of thermoplastic films. In this context, parameter combinations leading to high resulting forming ratios were identified. To measure the relevant parameters within the hot bending process, a coupled evaluation of infrared thermography (IRT) and deformation measurement using digital image correlation (DIC) was performed. The coupled measurement enables the identification of the actual mechanically stressed bending area of the film as a result of the bending process. This allows for the specification of the local forming temperatures required for the desired forming ratios. Furthermore, the mechanical and thermal strain along the defined measuring sections and their deviation in individual tests as well as the effect of thermal strain on process control on a larger scale were determined. Based on the results, a process window was defined for the film materials investigated, which will serve as a starting point for future efforts to develop a continuous manufacturing process.
In this work, a new method for selecting suitable materials is presented. This method has a high potential for a variety of engineering applications, such as the design of sound-absorbing and vibration-loaded structures, where a large number of different requirements have to be met. The method is based on the derivation of functional dependencies of selected material parameters. These dependencies can be used in parameter studies to consider parameter combinations that lie in the range of real existing and targeted material groups. This allows the parameter space to be reduced, the calculation to be accelerated, and suitable materials to be (pre-)selected for the respective application, which contributes to a more target-oriented design. The method is applied to the example of a plate resonator. For this purpose, a semi-analytical model is implemented to calculate the transmission loss as well as the reflected and dissipated sound power of plate silencers, taking into account the influence of flow velocity and fluid temperature on the performance of plate silencers.
A novel approach to consider triaxial tensile stresses within the framework of a failure criterion
(2022)
For use in micromechanical simulations of continuous fiber reinforced polymers, a more general form of the paraboloid failure criterion by Stassi‐D'Alia for matrix failure was developed with explicit consideration of the hydrostatic tension strength. Regarding polymers, limits for hydrostatic tensile strength based on isotropic linear elasticity could be derived. The comparison of the newly developed extended paraboloid criterion with experimental data for yielding as well as for material separation (fracture) shows good agreement.
Background
Stroke is one of the most frequent causes of death in Germany and the developed countries. After a stroke, those affected often suffer particularly from functional motor restrictions of the upper extremities. Newer techniques such as the BCI-FES systems aim to establish a communication channel between the brain and external devices with a neuromuscular intervention. The electrical activity of the brain is measured, processed, translated into control signals and can then be used to control an application.
Methods
As a mixed-methods design (exploratory design), eight guideline-based expert interviews were conducted first. For the quantitative expert survey, 95 chief physicians from the field of neuromedicine in rehabilitation facilities nationwide were subsequently invited to participate in an online survey.
Results
In our data analysis, we found that doctors are largely open-minded towards new technical rehabilitation systems. In addition to the proper functioning of the system, they consider the understanding of the functionality and the meaningfulness of the system to be particularly important. In addition, the system should be motivating for individuals, generate meaningful movements, be easy to use, evidence-based and quick to set up. Concerns were expressed regarding the understanding of the system’s processes, especially in the acute phase after a stroke, as well as the excessive expectation of results from the system on the part of the persons. The experts named stroke patients in rehabilitation phase C, which is about mobilization and recovery, as well as all persons who can understand the language requirements as benefiting groups of people.
Conclusion
The present study shows that more research should and must be done in the field of BCI-FES interfaces, and various development trends have been identified. The system has the potential to play a leading role in the rehabilitation of stroke patients in the future. Nevertheless, more work should be done on the improvement and implementation as well as the system’s susceptibility to interference in everyday patient life.
Zusammenfassung
Hintergrund
Die COVID-19(„coronavirus disease 2019“)-Pandemie hat die Ad-hoc-Digitalisierung an Hochschulen vorangetrieben. Zugleich stand die digitale Hochschullehre vor der Herausforderung der Ausgestaltung der Lehre im Zusammenhang mit den vorbestehenden Ressourcen, der digitalen und didaktischen Kompetenzen sowie der zur Verfügung stehenden technischen Infrastruktur.
Ziel der Arbeit/Fragestellung
Das Ziel der Umfrage war die Einschätzung der digitalen Lehre, die die Präsenzlehre infolge der COVID-19-Pandemie zum großen Teil bzw. gänzlich ersetzt hat, aus der Perspektive der Lehrenden in Public Health, Medizin und Pflege.
Material und Methode
Die Querschnitterhebung fand online von Juni bis August 2020 statt und die Daten wurden über www.soscisurvey.de erhoben. Die schriftliche Befragung wurde unter Mitgliedern der Deutschen Gesellschaft für Public Health (DGPH) und des Ausschusses Digitalisierung der Gesellschaft für medizinische Ausbildung (GMA) und der Sektionen Bildung und Beratung der Deutschen Gesellschaft für Pflegewissenschaft (DGP) sowie der Arbeitsgruppe Lehre der Deutschen Gesellschaft für Medizinische Soziologie (DGMS) durchgeführt (n = 100).
Ergebnisse
Bei der Nutzung der digitalen Technologien in den Veranstaltungen rangieren auf der obersten Stelle Präsentationstools, gefolgt von Lernmanagementsystemen, Videoangeboten sowie digitalen Texten. Die Teilnehmenden geben hinsichtlich der Nutzung unterschiedliche (Konferenz‑)Tools an. Das Erstellen von Lehrvideos bejahen 53 % der Befragten, Abstimmungstools) werden bis 50 % als unbekannt genannt. Als Herausforderungen werden digitale Infrastruktur der Hochschulen, fehlende didaktische Beratung/Unterstützung sowie rechtliche Fragen (Nutzungsrechte, Datenschutz) angegeben.
Schlussfolgerung
Neue Technologie werden vorwiegend für Wissenserwerb, Wissensvermittlung genutzt, selten zur Aktivierung von Studierenden und zur Gestaltung kollaborativer Lehr- und Lernarrangements sowie Neugestaltung von Lernaufgaben und Lernprozessen (individualisiertes Lernen). Welche der aktuell erprobten digitalen Lehr- und Lernformate zukünftig in der Hochschullehre zunehmend eingesetzt werden, hängt von vielen Faktoren ab, u. a. von digitaler Kompetenz sowie der Bereitschaft der Lehrenden und Lernenden die digitale Lernkultur mitzugestalten.
Sieg/Maschmann, Unternehmensumstrukturierung – Arbeitsrecht, Datenschutz, Due Diligence, 3. Aufl.
(2022)
Abstract
This article presents a cost-effective ultraviolet-ozone cleaner (UV/O3 Cleaner) for surface pre-treatment of substrates in the field of semiconductor technology. The cleaner consists of two chambers, the upper one contains the electronics, including the time counter. The lower chamber contains the two UV sterilisation lamps and a UV reflector of anodized aluminium, which confines the area of high Ozone concentration in the area of interest. The device is successfully used for surface cleaning and modification of different materials. To this end, the two important wavelengths 253.7 nm (excitation of organic residues) and 184.9 nm (production of ozone from the atmospheric environment as a strong oxidant) were first detected. The effectiveness of UV/O3 cleaning is demonstrated by improving the properties of indium tin oxide (ITO) for OLED fabrication. The contact angle of water to ITO could be reduced from 90° to 3° and for diiodomethane, it was reduced from 55° to 31° within the 10 min of irradiation. This greatly improved wettability for polar and non-polar liquids can increase the flexibility in further process control. In addition, an improvement in wettability is characterized by measuring the contact angles for titanium dioxide (TiO2) and polydimethylsiloxane (PDMS). The contact angle of water to TiO2 decreased from 70° to 10°, and that of diiodomethane to TiO2 from 54° to 31°. The wettability of PDMS was also greatly increased. Here, the contact angle of water was reduced from 109° to 24° and the contact angle to diiodomethane from 89° to 49°.
Article Highlights
We report a cost-effective dry-cleaning device for surface cleaning and modification based on ultraviolet-ozone irradiation.
Contact angle measurements show an increase of wettability for different materials due to surface modification.
The UVO3 pre-treatment improves layer formation and optoelectrical properties of OLEDs.
Hintergrund
Die Studienzeit ist eine Phase, in der die jungen Erwachsenen mit spezifischen Anforderungen konfrontiert werden. Studierende der Medizin gelten als besonders psychisch belastet. Untersuchungen, in denen sie diesbezüglich mit Studienfächern der gleichen Branche verglichen werden, sind jedoch rar.
Fragestellung
Ziel der Untersuchung war es, die psychische Gesundheit von Medizinstudierenden sowie von Gesundheits- und Pflegemanagementstudierenden zu untersuchen und zu vergleichen.
Material und Methoden
Untersucht wurden Studierende der Studiengänge Gesundheits- sowie Pflegemanagement (WHZ) und Medizinstudierende der (TU Dresden). Verschiedene Aspekte psychischer Gesundheit wurden mithilfe eines Online-Fragebogens erhoben. Dieser beinhaltete die Instrumente zur Erfassung der Prüfungsängstlichkeit (TAI-G-Kurzskala) und psychischen Belastung (BSI-18), sowie ein Item zur Ermittlung der subjektiv wahrgenommenen Studienbelastung. 258 Studierende nahmen an der Befragung teil.
Ergebnisse
Es konnten keine signifikanten Unterschiede hinsichtlich des Gesamtscores der Prüfungsängstlichkeit und der psychischen Belastung zwischen den Studierenden beider Studienfächer festgestellt werden. Dahingegen gaben Medizinstudierende an, dass sie im Vergleich zu Studierenden der anderen beiden Studienfächer eine signifikant höhere Studienbelastung wahrnehmen.
Schlussfolgerung
Die ermittelten Gesamtscores lagen teilweise über den Werten in vergleichbaren Studien. Die Studierenden sollten bereits präventiv unterstützt werden, um eigene Bewältigungsstrategien zu entwickeln. Nicht nur die Bereitstellung von Hilfen ist notwendig, sondern vielmehr das aktive Eingreifen mithilfe von gesundheitsfördernden Maßnahmen durch die Institution Hochschule, in die die Studierenden frühzeitig integriert werden sollten.
The removal of bacterial infections within the root canal system is still a challenge. Therefore, the cleansing effect of established and new irrigation-protocols (IP) containing silver diamine fluoride (SDF) 3.8% on the whole root canal system was analyzed using quantitative PCR (qPCR) and 4′,6-diamidino-phenylindole-(DAPI)-staining. Extracted human premolars were instrumented up to F2 (ProTaper Gold) under NaCl 0.9% irrigation and incubated with Enterococcus faecalis for 42 days. Subsequently, different ultrasonically agitated IP were applied to the roots: control (no irrigation), 1. NaOCl 3%, EDTA 20%, CHX 2%, 2. NaOCl 3%, EDTA 20%, 3. NaOCl 3%, EDTA 20%, SDF 3.8%, 4. SDF 3.8%, and 5. NaCl 0.9%. One half of the root was investigated fluorescent-microscopically with DAPI. The other half was grinded in a cryogenic mill and the bacterial DNA was quantified with qPCR. The qPCR results showed a statistically significant reduction of bacteria after the application of IP 1, 2, and 3 compared to the control group. While IP 4 lead to a bacterial reduction which was not significant, IP 5 showed no reduction. These data corresponded with DAPI staining. With qPCR a new molecular-biological method for the investigation of the complete root canal system was implemented. The novel IP 3 had an equally good cleansing effect as the already established IP.
Structures made of the thermoplastic polymer polyether ether ketone (PEEK) are widely used in dynamically-loaded applications due to their high-temperature resistance and high mechanical properties. To design these dynamic applications, in addition to the well-known stiffness and strength properties the vibration-damping properties at the given frequencies are required. Depending on the application, frequencies from a few hertz to the ultrasonic range are of interest here. To characterize the frequency-dependent behavior, an experimental approach was chosen and applied to a sample polymer PEEK. The test setup consists of a piezoelectrically driven base excitation of the polymeric specimen and the non-contact measurement of the velocity as well as the surface temperature. The beam’s bending vibrations were analyzed by means of the Timoshenko theory to determine the polymer’s storage modulus. The mechanical loss factor was calculated using the half-power bandwidth method. For PEEK and a considered frequency range of 1 kHz to 16 kHz, a storage modulus between 3.9 GPa and 4.2 GPa and a loss factor between 9 × 10−3 and 17 × 10−3 were determined. For the used experimental parameters, the resulting mechanical properties were not essentially influenced by the amplitude of excitation, the duration of excitation, or thermal degrad.ation due to self-heating, but rather slightly by the clamping force within the fixation area.
Based on a real-world application in the semiconductor industry, this article models and discusses a hybrid flow shop problem with time dependencies and priority constraints. The analyzed problem considers a production where a large number of heterogeneous jobs are processed by a number of machines. The route that each job has to follow depends upon its type, and, in addition, some machines require that a number of jobs are combined in batches before starting their processing. The hybrid flow model is also subject to a global priority rule and a “same setup” rule. The primary goal of this study was to find a solution set (permutation of jobs) that minimizes the production makespan. While simulation models are frequently employed to model these time-dependent flow shop systems, an optimization component is needed in order to generate high-quality solution sets. In this study, a novel algorithm is proposed to deal with the complexity of the underlying system. Our algorithm combines biased-randomization techniques with a discrete-event heuristic, which allows us to model dependencies caused by batching and different paths of jobs efficiently in a near-natural way. As shown in a series of numerical experiments, the proposed simulation-optimization algorithm can find solutions that significantly outperform those provided by employing state-of-the-art simulation software.
The atomizing gas dynamics and the applied process energy have a significant influence on the produced particles. The melting process of the two wires can be influenced by current modulation. As for arc welding processes, more and more electronic and software-controlled machines are being used for arc spraying and will have replaced conventional power sources in the future. Due to the highly dynamic, fast regulating computing technology in the latest energy source, technology arcs can be operated with different current forms and types. The modern machines allow process-stable, reproducible variation of the particles and heat input into the substrate. Constant and pulsed current can be used as current forms. Usable current types are direct current (DC) and alternating current (AC). The electrical parameters must be analyzed to evaluate the process behavior. The consumable used is a wire-shaped iron-based alloy with a diameter of 1.6 mm. Relevant process parameters such as basic current Iground, pulse current Ipulse, pulse duration tpulse, impulse frequency fpulse, and alternating current frequency, fAC, are varied and recorded using appropriate measurement technology. The aim is to change the process performance and thereby the particle formation in a broad band. High-speed images are used to observe the arc and the deposition process. In addition, particle sizes are determined.
The electrical conduction mechanism of resistive switching Prussian white (PW) thin films obtained by the electrodeposition method was examined by AC impedance spectroscopy and DC current–voltage measurements. Using an electrode tip to contact PW grown over Au, robust unipolar resistive switching was observed with a current change of up to three orders of magnitude, high repeatability, and reproducibility. Moreover, electrical impedance spectroscopy showed that the resistive switching comes from small conductive filaments formed by potassium ions before the establishment of larger conductive channels. Both voltammetry and EIS measurements suggest that the electrical properties and conductive filament formation are influenced by defects and ions present in the grain boundaries. Thus, PW is a potential material for the next generation of ReRAM devices.
Abstract:
Background: Proctoring represents a cornerstone in the acquisition of state‐of‐the‐art cardiovascular interventions. Yet, travel restrictions and containment measures during the COVID‐19 pandemic limited on‐site proctoring for training and expert support in interventional cardiology.
Methods and Results: We established a teleproctoring setup for training in a novel patent foramen ovale closure device system (NobleStitch EL, HeartStitch Inc, Fountain Valley, CA) at our institution using web‐based real‐time bidirectional audiovisual communication. A total of 6 patients with prior paradoxical embolic stroke and a right‐to‐left shunt of grade 2 or 3 were treated under remote proctorship after 3 cases were performed successfully under on‐site proctorship. No major device/procedure‐related adverse events occurred, and none of the patients had a residual right‐to‐left shunt of grade 1 or higher after the procedure. Additionally, we sought to provide an overview of current evidence available for teleproctoring in interventional cardiology. Literature review was performed identifying 6 previous reports on teleproctoring for cardiovascular interventions, most of which were related to the current COVID‐19 pandemic. In all reports, teleproctoring was carried out in similar settings with comparable setups; no major adverse events were reported.
Conclusions: Teleproctoring may represent a feasible and safe tool for location‐independent and cost‐effective training in a novel patent foramen ovale closure device system. Future prospective trials comparing teleproctoring with traditional on‐site proctoring are warranted.
Zusammenfassung: Auf digitalen Märkten besteht, wer die zugrundeliegenden digitalen, unternehmensbezogenen oder akteursübergreifenden institutionellen Arrangements versteht und aktiv gestaltet. Dazu werden ausgereifte, von Forschung und Praxis diskutierte und gemeinsam weiter entwickelte Methoden zum Design digitaler Plattformen, Geschäftsmodelle und Service-Ökosysteme benötigt. Einen gemeinschaftlichen Aufschlag hierzu macht der folgende Artikel. Er entstand aus einem offenen Aufruf in der Wirtschaftsinformatik-Community – über Mailing-Listen und soziale Medien. Im Ergebnis führen sieben Forschergruppen (oder einzelne Forscher und Forscherinnen) ihre aktuellen Erkenntnisse zu diesem Thema zusammen.
Abstract: Die Automobilproduktion steht aktuell vor der Herausforderung, einen sich weiter diversifizierenden Antriebsmix effizient zu produzieren. Der vorliegende Beitrag erläutert die grundsätzlichen Einflüsse alternativer Antriebsarten auf die Fahrzeugproduktion, welche mithilfe umfangreicher Experteninterviews ermittelt wurden. Diese Erkenntnisse können genutzt werden, um langfristig die richtigen Produktionsstrategien für die Gestaltung effizienter Produktionsnetzwerke abzuleiten.
Alternative Leistungskennzahlen (APM) in der Finanzberichterstattung österreichischer Emittenten
(2022)
Der General
(2022)
Sodium iron hexacyanoferrate (NaFeHCF) films were electrodeposited on Au/Cr/Si for the study of growth behavior and physical properties. The NaFeHCF films were studied by different analytical methods to prove the chemical composition, morphology and crystal structure. The grains of the film grow with a cubic structure with an average lattice parameter of 10.10 Å and the preferential growth direction along the [111] direction of the cubic cell. The films show a repeatable bipolar resistive switching behavior accompanied by high current changes (up to a factor of ~105). The different resistive states in the materials are dominated by ohmic conduction.
En 1985 inició el Ministerio de Educación en Venezuela el Modelo de Atención Integral al Niño Sordo, un cambio de la práctica oralista a un modelo bilingüe en las escuelas de sordos. Eso implicaba eliminar la enseñanza del español hablado como objetivo principal e introducir la Lengua de Señas Venezolana (LSV) a las escuelas. Se desencadenó así un intenso período de cambios que marcó indeleblemente a la comunidad sorda. Aquí se aborda el Modelo desde la perspectiva de la planeación lingüística, describiendo sus objetivos y sus efectos sobre la adquisición, la estructura (el corpus) y el estatus de la LSV: La LSV y el español señado fueron reubicados en la diglosia existente hasta entonces; surgió una variante académica de la LSV y aumentó el número de usuarios de la LSV. El estudio se basó en el análisis cualitativo de entrevistas realizadas a cinco testigos de aquel proceso.
Die Autoren bringen langjährige Erfahrung in verschiedenen Industriebranchen und der akademischen Ausbildung im Lean- und Project and Process Management mit sich. Im Rahmen der beruflichen Tätigkeit und der akademischen Arbeit hat sich immer wieder die Frage gestellt, wie die Philosophie des Lean Management mit den Aufgaben des Projekt Management Office interagieren können. Viele Ansätze des Lean Management, vor allem organisatorische Methoden zeigen eine breite Anwendungsmöglichkeit und sollten somit auch dem Projekt Management Office (PMO) hilfreich sein. Vor einiger Zeit hat sich schon der Begriff des Lean Office [YDF01] etabliert, der aber sowohl in der Büroorganisation als auch der Dokumentenpflege Ansatz findet. Im Rahmen des PMO soll dieser Lean Office auf die bereitzustellenden Prozesse und deren Integration ins Enterprise Ressource Planning Anwendung finden. Je schlanker und effizienter die Projekt- und Programmprozesse einer Organisation aufgestellt werden, desto leichter können diese abgebildet und in die Enterprise Ressource Planning (ERP)-Datenlandschaft übertragen werden. Somit wird ein solider Grundstein über den gesamten Produktprozess gelegt - von der Entwicklung, über die Herstellung bis hin zur schlussendlichen Verwertung schlank, effizient, automatisiert und digitalisiert abgebildet zu sein.
The research was carried out for the selection of optimal options for the heat supply of multi-apartment buildings, taking as an example several new buildings in Yerevan. The purpose of the study is to confirm the choice of the best method of providing heat in apartment complexes. It was used to calculate and analyze the energy-economic and operational-technical indicators of individual heating boilers, small centralized systems, and hybrid systems to solve this problem. The calculations considered both natural gas tariffs and fluctuations in the value of the Armenian dram against the US dollar. The value of 1 kWh of thermal energy or specific heat capacity has been determined as an important criterion for choosing the most efficient method of heat supply, considering the careful analysis of almost all variable factors.
Conceptual Approach to an AI-Based Adaptive Study Support System for Individualized Higher Education
(2023)
In the context of the digital transformation, the targeted implementation of AI-based or AI-supported technologies in "teaching & learning" as well as "administration & service" holds considerable potential for organizational change and quality enhancement for higher education institutions. The use of AI in higher education teaching and services lags behind the level in research. Therefore, holistic solutions must be planned and implemented in unity of teaching and research for the AI-based support of the stakeholders’ inclusive administration, the further development or the establishment of new digital study programs and offers as well as the prospective qualification of university staff in the field of AI. The solutions must be analyzed, systematized, and structured to generate a conceptual approach via an integrated architecture with adaptive services.
This paper is an evolution of the concept presented at the Learning Ideas Conference 2022 and includes, in addition to explanations of the current state of the arts, the presentation of a systems-oriented approach for AI in higher education as well as the conception of the student lifecycle management at the author’s university. The paper ends with the presentation of a concept regarding a decision support system for individualized studying.
Abstract: Die Automobilindustrie befindet sich seit Jahren im Ausnahmezustand, da der Wechsel von einer Einheitsantriebsart hin zu einem Mix an Antriebsarten parallel zu globalen Krisen bewältigt werden muss. Der vorliegende Beitrag liefert dazu beispielhafte Betrachtungen zur indikativen Bewertung der gegensätzlichen Produktionsstrategien Mix- oder sortenreiner Produktion von Fahrzeugen mit alternativen und konventionellen Antrieben. Die Erkenntnisse können genutzt werden, um Modelle zur Wahl der richtigen Produktionsstrategien abzuleiten.
Zusammenfassung: Die für die Planung des Materialflusses relevanten Fertigungsprozesse lassen sich sehr genau planen, beispielsweise über die Leistung der Maschine (Durchsatz je Zeiteinheit). Bei der Planung eines Projektes spielen logistische Prozesse, die zu den Kernprozessen eines Unternehmens gehören, eine wichtige Rolle. Jedoch werden sie meist nur grob terminiert und mit großen Puffern kalkuliert. Dies kann zu einer Verlängerung der Projektdauer führen. Für eine genauere Terminierung eines Projektes ist es daher entscheidend, die Dauer der logistischen Prozesse mindestens in dem Maße wie die Fertigungsprozesse zu ermitteln, um das Risiko einer Projektverzögerung zu minimieren.In diesem Beitrag wird deshalb eine Methode zur datenbasierten Schätzung von Prozessdauern mit dem Ziel der Wiederverwendung von Projektwissen vorgestellt, die es dem Projektmanagement ermöglichen soll, Dauern von logistischen Prozessen präziser zu schätzen als das aktuell basierend auf Erfahrungswissen erfolgt. Besonderes Augenmerk liegt dabei auf der Herleitung der Entwurfsaktivitäten. Durch die Anwendung der Methode soll das Projektmanagement von einer genaueren, datenbasierten Schätzung von (Logistik‑)Prozessdauern profitieren und so entstandenes Wissen über einen Ontologieansatz wiederverwenden können.
Abstract: The demand for thorough disinfection within ambulances is essential, given the in-vehicle medical procedures and the potential high risk of infections due to patients' open wounds. One solution that can address this hygiene challenge involves the application of reactive products generated from atmospheric (air) oxygen and water vapor, activated through the use of cold plasma. Cold plasma's charged particles perforate the cell membranes of microorganisms. This process does not work in human cells, as proteins in the form of enzymes within the body break down the cold plasma and protect the cells. The study was done on an ambulance that was contaminated in eight places. Samples were taken from each site, and two surfaces measuring approximately 8 × 8 cm were carefully sealed and marked. These surfaces were deliberately contaminated by applying an Enterococcus faecium suspension of 8.5 × 107 CFU/mL using a sterile cotton swab. It was followed by the disinfection procedure, that was initiated with the PLASMOCAR device. It was positioned on the front workspace and operated for a duration of 30 min, utilizing the vehicle's onboard voltage. Throughout the operation, all doors and windows were closed and the vehicle's air conditioning system remained active. After the completion of the disinfection process, samples were collected from the surfaces for bacterial counts. A reduction of 3.73 log levels in initial bacteria was accomplished within the rescue vehicle for Enterococcus faecium, equivalent to a 10–fourfold reduction in bacteria, eliminating up to 99.99% of the initial microorganisms. This success makes the process well-suited and convenient as an ongoing "background" procedure to enhance the established disinfection procedures. The established disinfection procedures outlined in the hygiene plan must be promptly implemented whenever mechanical surface cleaning is required. The use of PLASMOCAR offers an extra layer of protection and security, significantly decreasing the risk of microorganism transmission through cross-contamination and aerosols. This is a significant benefit for the well-being of both staff and patients.
This paper deals with systematic approaches for the analysis of stability properties and controller design for nonlinear dynamical systems. Numerical methods based on sum-of-squares decomposition or algebraic methods based on quantifier elimination are used. Starting from Lyapunov’s direct method, these methods can be used to derive conditions for the automatic verification of Lyapunov functions as well as for the structural determination of control laws. This contribution describes methods for the automatic verification of (control) Lyapunov functions as well as for the constructive determination of control laws.
Liquid deposition modeling is an energy-efficient, additive manufacturing process for pasty materials. Physical material properties were determined for a water-based paste consisting of the binder carboxymethyl cellulose and wood flour. A continuously operating dual screw extruder was developed, which was used to manufacture a table frame with a height of 18 cm.
Electrical and thermal measurements were conducted during the plasma electrolytic polishing (PEP) of cemented tungsten carbide (WC-Co) materials to characterize energetic aspects of the process in relation to the temporal development of the gaseous layer near the workpiece. The power transferred to the workpiece is determined using a calorimetric probe and employing the time derivative of the temperature curve. It shows distinct heating phases due to the generation of the gaseous layer. At the beginning of the process, a typical power of 367 ± 17 W is transferred to the workpiece of a surface area of 14 cm2. At longer process times, a stabilized gaseous layer limits the power transferred to the workpiece to 183 ± 3 W. In an attempt to describe the heat transferred to the electrolyte, the electrolyte temperature was measured using a thermocouple situated 15 mm away from the workpiece. The local electrolyte temperature increases from 70 to 81 °C for an immersion depth of 20 mm. Moreover, the spatiotemporal development of the electrolyte temperature was obtained by 2D-hydrodynamic modeling using COMSOL Multiphysics®. The modeling results for the local temporal temperature development are in excellent agreement with the experimental values when the turbulent model is applied up to t = 65 s. Afterward, the laminar model leads to a better agreement. Furthermore, line scan x-ray photoelectron spectroscopy revealed that aliphatic carbon was preferentially removed. Only a slight compositional gradient in the vertical direction after the PEP process was observed.
Models of artificial root canals are used in several fields of endodontic investigations and pre-clinical endodontic training. They allow the physical testing of dental treatments, the operating of instruments used and the interaction between these instruments and the tissues. Currently, a large number of different artificial root canal models exist whose geometry is created either on the basis of selected natural root canal systems or to represent individual geometrical properties. Currently, only a few geometric properties such as the root canal curvature or the endodontic working width are taken into consideration when generating these models. To improve the representational capability of the artificial root canal models, the aim of the current study is therefore to generate an artificial root canal based on the statistical evaluation of selected natural root canals. Here, the approach introduced by Kucher for determining the geometry of a root canal model is used, which is based on the measurement and statistical evaluation of the root canal center line’s curvatures and their cross-sectional dimensions. Using the example of unbranched distal root canals of mandibular molars (n = 29), an artificial root canal model representing the mean length, curvature, torsion and cross-sectional dimensions of these teeth could be derived.
The aim of this study was to investigate the antimicrobial efficacy of different disinfection protocols in a novel Enterococcus faecalis biofilm model based on a visualization method and to evaluate the potential alteration of dentinal surface. A total of 120 extracted human premolars were allocated to 6 groups with different irrigation protocols. The assessment of the effectiveness of each protocol and the alteration of dentinal surface were visualized by using SEM and fluorescence microscopy (DAPI). A dense E. faecalis biofilm with a penetration depth of 289 μm (medial part of the root canal) and 93 μm (apical part) validated that the biofilm model had been successfully implemented. A significant difference between the 3% NaOCl groups and all the other groups in both observed parts of the root canal (p < 0.05) was detected. However, the SEM analysis revealed that the dentinal surface in the 3% NaOCl groups was severely altered. The established biofilm model and the visualization method based on DAPI are appropriate for bacterial quantification and evaluation of the depth effect of different disinfection protocols in the root canal system. The combination of 3% NaOCl with 20% EDTA or MTAD with PUI allows the decontamination of deeper dentine zones within the root canal but simultaneously alters the dentinal surface.
Certifying Fully Dynamic Algorithms for Recognition and Hamiltonicity of Threshold and Chain Graphs
(2023)
Solving problems on graphs dynamically calls for algorithms to function under repeated modifications to the graph and to be more efficient than solving the problem for the whole graph from scratch after each modification. Dynamic algorithms have been considered for several graph properties, for example connectivity, shortest paths and graph recognition. In this paper we present fully dynamic algorithms for the recognition of threshold graphs and chain graphs, which are optimal in the sense that the costs per modification are linear in the number of modified edges. Furthermore, our algorithms also consider the addition and deletion of sets of vertices as well as edges. In the negative case, i.e., where the graph is not a threshold graph or chain graph anymore, our algorithms return a certificate of constant size. Additionally, we present optimal fully dynamic algorithms for the Hamiltonian cycle problem and the Hamiltonian path problem on threshold and chain graphs which return a vertex cutset as certificate for the non-existence of such a path or cycle in the negative case.
Sometimes cranioplasty is necessary to reconstruct skull bone defects after a neurosurgical operation. If an autologous bone is unavailable, alloplastic materials are used. The standard technical approach for the fabrication of cranial implants is based on 3D imaging by computed tomography using the defect and the contralateral site. A new approach uses 3D surface scans, which accurately replicate the curvature of the removed bone flap. For this purpose, the removed bone flap is scanned intraoperatively and digitized accordingly. When using a design procedure developed for this purpose creating a patient-specific implant for each bone flap shape in short time is possible. The designed skull implants have complex free-form surfaces analogous to the curvature of the skull, which is why additive manufacturing is the ideal manufacturing technology here. In this study, we will describe the intraoperative procedure for the acquisition of scanned data and its further processing up to the creation of the implant.