Miracle-dz/UniFAR-FTUs huggingface dataset:
Thermal rectification on asymmetric suspended graphene nanomesh devices

Graphene-based thermal rectification was investigated by measuring the thermal transport properties of asymmetric suspended graphene nanomesh devices. A sub-10 nm periodic nanopore phononic crystal structure was successfully patterned on the half area of the suspended graphene ribbon by helium ion beam milling technology. The ‘differential thermal leakage’ method was developed for thermal transport measurement without disturbance from the leakage of electron current through the suspended graphene bridge. A thermal rectification ratio of up to 60% was observed in a typical device with a nanopore pitch of 20 nm. By increasing the nanopore pitch in a particular range, the thermal rectification ratio showed an increment. However, this ratio was degraded by increasing the environmental temperature. This experiment suggests a promising way to develop a high-performance thermal rectifier by using a phononic crystal to introduce asymmetry on homogeneous material.
Clustering Application for Condition-based Maintenance in Time-varying Processes: A Review

In the field of industrial process monitoring, more and more interest is being shown in specific process categories. These include time-varying processes, that is, those processes whereby the response one receives as output from the system depends on when the input signal is sent into it. There are many reasons for this process variability and such contexts are not always analyzed with this operational characteristic at their core. At the same time, interest in certain categories of techniques is also becoming more prominent, to meet certain application needs. Among these, clustering and unsupervised techniques in general are gaining ground. This is largely due to the difficulty of finding fault data with which to train, for example, supervised models. On the other hand, the clustering technique, on which this contribution focuses, also makes it possible to compensate for the lack of complete knowledge of the structure of the process itself. With these two considerations in mind, this contribution proposes a literature review on the topic of clustering applied in time-varying contexts, in the maintenance field. The aim is to present an overview of the main fields of study, the role of clustering in this context and the main clustering techniques used.
Material invariant properties and reconstruction of microstructure of sandstones by nanoindentation and microporoelastic analysis

The diversity of sandstones and sandstone properties that exist in nature pose a significant problem for engineers who deal with these materials, whether in oil well exploration and exploitation or art and architectural conservation. The solution proposed in this thesis takes a highly reductionist approach to the problem. Properties of the sandstone material are first reduced to material invariant properties of the material phases present in sandstone. These are universal constants which do not vary from one sample to the other. Prom these material invariants, it is then possible to 'nanoengineer' the properties of a specific sandstone sample based only on a few easily measured properties the volume fractions of the material phases. To help identify material invariant phases and reconstruct microstructure, a multi-scale think model for sandstone is developed from ESEM images as well as from the results of mineralogy, grain size, and porosimetry experiments. A nanoindentation campaign is performed to characterize sandstones at multiple scales and an innovative technique is used to separate the various indentation responses that can occur on a heterogeneous composite. Material invariant phase properties are obtained for both the sand grains and the clay minerals. A new technique for estimating volume fractions of composite materials using nanoindentation is developed and verified. Clay stiffnesses are found to be highly dependent on microstructure rather than on mineralogy, and material invariant properties are proposed. A comparison of models to estimate elastic and poro-elastic properties reveal shortcomings that motivate the development of a new predictive model. A multi-scale model employing a self consistent scheme and a double-porosity model is suggested and applied with excellent results predicting poroelastic properties. This model permits the 'nanoengineering' of a specific sandstone sample based only on the volume fractions of the material phases. Thesis Supervisor: Franz-Josef Ulm Title: Associate Professor of Civil and Environmental Engineering
Synthetic Protein Circuits and Devices Based on Reversible Protein-Protein Interactions: An Overview

Protein-protein interactions (PPIs) contribute to regulate many aspects of cell physiology and metabolism. Protein domains involved in PPIs are important building blocks for engineering genetic circuits through synthetic biology. These domains can be obtained from known proteins and rationally engineered to produce orthogonal scaffolds, or computationally designed de novo thanks to recent advances in structural biology and molecular dynamics prediction. Such circuits based on PPIs (or protein circuits) appear of particular interest, as they can directly affect transcriptional outputs, as well as induce behavioral/adaptational changes in cell metabolism, without the need for further protein synthesis. This last example was highlighted in recent works to enable the production of fast-responding circuits which can be exploited for biosensing and diagnostics. Notably, PPIs can also be engineered to develop new drugs able to bind specific intra- and extra-cellular targets. In this review, we summarize recent findings in the field of protein circuit design, with particular focus on the use of peptides as scaffolds to engineer these circuits.
Against the Odds: A Structural Equation Analysis of Family Resilience Processes during Paternal Incarceration

On any given day, approximately 2.1 million children in Europe have an incarcerated parent. Although research indicates that material hardship is associated with parental incarceration, and particularly paternal incarceration, little is known about family processes that may mitigate the harmful effects of such hardship on children with an incarcerated parent. Guided by a resilience framework, this study examined how family processes mediate the effects of material hardship on youth academic adjustment within the context of paternal incarceration. Using Danish data that assessed key family constructs, structural equation modeling was used to perform a mediational within-group analysis of primary caregivers (n = 727) to children with an incarcerated father. Results indicate that although social support and parenting skills did not yield mediating effects, caregiver mental health strongly mediated the effects of material hardship on youth academic adjustment during paternal incarceration. Findings suggest that economic conditions, as well as caregiver mental health symptoms, are important areas of intervention that may promote family-level resilience for youth of an imprisoned father. We conclude with research and practice recommendations to advance our understanding of resilience among families with an incarcerated parent.
Microcystis species and their toxigenic strains in phytoplankton of ten Bulgarian waterbodies

The summer phytoplankton structure of ten Bulgarian waterbodies was studied by HPLC analysis of marker pigments, light microscopy (LM) and PCR amplification of mcyB and mcyE gene sequences. The aim was to detect biodiversity and spread of toxigenic strains of potential microcystin producers and the important bloom-forming genus Microcystis in particular. The screening was done in three waterbodies, where Microcystis had already been found (Lakes Ezerets and Durankulak and Reservoir Koprinka), three waterbodies from which it had not been reported (Reservoirs Shilkovtsi, Zhrebchevo, Suedinenie) and four reservoirs that were sampled for the first time (Malka Smolnitsa, Plachidol 2, Preselka, Duvanli). LM and HPLC data similarly showed that cyanoprokaryotes contributed significantly to the total phytoplankton composition (29%) and biomass (15–87%) in nine sampled waterbodies. Microcystis aeruginosa, M. natans, M. smithii, M. wesenbergii, Microcystis spp. , M. cf. comperei and M. pseudofilamentosa, were identified using LM (the last two tropical species were found for the first time in the country). Despite the low contribution of Microcystis to the phytoplankton diversity (1–4 taxa per sample) and to the total phytoplankton biomass (< 0.01–0.5%), 57 toxigenic strains of this genus were revealed by PCR, most of which demonstrated high similarity with NCBI M. aeruginosa and M. wesenbergii strains.
Study on improving the resolution of an H-shaped piezoelectric ultrasonic actuator by stick-slip principle

Improving the performance of the motion stages driven by piezoelectric actuators is an enduring topic for expanding their applications. For the motion stage with a travel range of tens of millimeters, trade-offs are inevitable between getting high speed (hundreds of millimeters per second) and high resolution (tens of nanometers), due to the inherent limitations of the operating principles of the piezoelectric actuators. In order to improve the output resolution of an H-shaped piezoelectric ultrasonic actuator, sawtooth excitation voltages are used in this work rather than the conventional sinusoidal voltages in previous works. The configuration and operating principle of the actuator are discussed in detail. The actuator consists of two vertical and two horizontal longitudinal transducers. The ends of the vertical transducers act as the driving tips and drive the stage forward with the alternating slow extensions and rapid contraction, during which stick motions and slip motions of the stage are acquired. An analytic model is developed to estimate the horizontal and vertical output displacement of the driving tip. The maximum error between the predicted value of the analytical model and the experimental value is about 14%. A prototype of the motion stage is fabricated and experiments are carried out to evaluate its output characteristics. The experiment results confirm the operating principle and show that the resolution is upgraded to tens of nanometers. The prototype obtains a resolution of 19 nm, a maximum speed of 2.22 μm s−1, and a maximum carrying load of 16.94 kg.
Energy Pattern Generator Understanding the effect of user behaviour on energy systems

To understand and research the effect of user behaviour on energy performance, an Energy Pattern Generator (EPG) is being developed. This software tool produces high resolution electricity and heat demand patterns for five different household types. In addition, energy consumption is related to five common types of dwellings in the Netherlands. Input for the EPG is provided by measured energy demand profiles of common household appliances and statistical data from time-of-use surveys. Internal heat gains due to appliances play an important role in the energy balance of energy efficient buildings. These gains are however often simplified in today’s tools into (at best) fixed weekly schedules. The EPG provides a more realistic representation of (the variation in) occupant behaviour. Varying internal gains are calculated for several user profiles, based on variations in the use of domestic appliances and the household occupancy by the residents. Using the EPG as a “plug-in”, building simulation can determine whether new building concepts are ‘user proof’. The EPG is also of importance in the design of (intelligent) electricity grids as it provides dynamics in the grid’s loads. The EPG provides insight in actual loads which can be scaled up to i.e. district level. Key words: Building Future, Innovative Building Concepts; Energy Pattern Generator (EPG); User Behaviour; Household Profiles; Energy Consumption.
Partial discharge theory and technologies related to traditional testing methods of large rotating apparatus

Partial discharge monitoring is an effective online predictive maintenance test for motors and generators at 4160 volt and above, as well as other electrical distribution equipment. The benefits of online testing allow for equipment analysis and diagnostics during normal production. Corrective actions can be planned and implemented, resulting in reduced unscheduled downtime. An understanding of the theory related to partial discharge, and the relationship to early detection of insulation deterioration is required to properly evaluate this predictive maintenance tool. This paper presents a theory to promote the understanding of partial discharge technology, as well as various implementation and measurement techniques that have evolved in the industry. Data interpretation, corrective actions and application to electrical distribution equipment are also reviewed.
An assessment of environmental impacts of a nextGen implementation scenario and its implications on policy-making

With demand for aviation projected to grow by 5% per year over the next 20 to 25 years, policy makers must not only consider ways to ensure that the air transportation system can accomodate significant growth, but also how their policy decisions will affect the environment. Because environmental issues are becoming increasingly apparent, the sustainability of policy measures will likely constrain responses to this potential increase in aviation demand. Policy makers will need to consider various trade-offs that come with policy decisions, and find ways to balance the demands of the air transport system with the need to reduce the environmental impact of aviation. This thesis assesses the environmental impacts of implementing a policy scenario, which employs both operational and technological improvments to the air transport system. The impacts are presented in both physical and monetary metrics using the Aviation environmental Portfolio Management Tool, to allow for a comparison of trade-offs among different environmental effects. This thesis discusses the limitations of this particular scenario, while also providing an overview of policy-making models, and the observed weaknesses in current policy-making processed involving technical data. In particular, it identifies the mismatch between needs of those involved in the policy-making process, and the information provided by analysts, which can be an obstacle to developing credible and objective support for a policy proposal. It finally provides suggested methods for improving the relationship between different groups involved in developing policy to allow for better informed decision-making, and a more fluid policy-making process.
Equilateral triangular patch antenna for UHF RFID applications

This article proposes an equilateral triangule‐shaped patch antenna for radio frequency identification (RFID) applications in the 900 MHz (902–928 MHz) ultra high frequency (UHF) band. To achieve optimal impedance matching and 10‐dB operating bandwidth at the desired band, the L‐shaped probe‐feed technique was used as the feeding structure of the proposed antenna. Furthermore, a near semicircular notch was also loaded into the patch so that good circularly polarized (CP) radiation can be generated from the proposed patch antenna. By simply shifting the position or radius of this notch, the CP frequency can be varied with ease. Here, 10‐dB impedance bandwidth and 3‐dB axial ratio bandwidth of 25 and 3% were achieved. Furthermore, stable gain variation of approximately 6 dBi was also exhibited across the RFID UHF band. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:580–586, 2014.
The New Superleadership: Leading Others to Lead Themselves

"SuperLeadership" was coined by authors Charles Manz and Henry Sims to describe a management style that focuses on "leading others to lead themselves". In their earlier book of that title, they established a philosophy that moves away from the typical hierarchical models (the traditional autocratic, heroic, or directive approach to leadership) to show how to utilize the richest resource a company can have: employees who are empowered and transformed from followers into "follower self-leaders", or superleaders. In The New SuperLeadership, the authors bring this philosophy into the real world with contemporary examples and profiles from the high-tech and knowledge-based business sectors. Special emphasis is given to how organizations and managers can undertake the transition to this new management style.
Probability of Non-Exceedance of Arsenic Concentration in Groundwater Estimated Using Stochastic Multicomponent Reactive Transport Modeling

Stochastic multicomponent reactive transport modeling is a powerful approach to quantify the probability of non-exceedance (PNE) of arsenic (As) critical concentration thresholds in groundwater. The approach is applied to a well-characterized shallow alluvial aquifer near Venice, Italy. Here, As mobility depends primarily on rainfall-controlled redox-dependent precipitation-dissolution of iron hydroxides. A Monte-Carlo analysis based on a calibrated three-dimensional flow and transport model targeted the geochemical initial conditions as the main source of uncertainty of As concentrations in the studied aquifer. It was found that, during 115 simulated days, the fraction of the entire aquifer volume with As > 10 μgL−1 decreased on average from ~43% to ~39% and the average As concentration from ~32 μgL−1 to ~27 μgL−1. Meanwhile, PNE increased from 55% to 60% when 10 μgL−1 was set as target threshold, and from 71% to 78% for 50 μgL−1. The time dependence of As attenuation can be ascribed to the increase of oxidizing conditions during rainfall-dependent aquifer recharge, which causes As sorption on precipitating iron hydroxides. When computing the same statistics for the shallowest 6 m, As attenuation was even more evident. The volume fraction of aquifer with As > 10μgL−1 dropped from 40% to 28% and the average As concentration from 31 μgL−1 to 20 μgL−1, whereas PNE increased from 58% to 70% for As < 10 μgL−1 and from 71% to 86% for As < 50 μgL−1. Thus, the wells screen depth in the aquifer can be a critical aspect when estimating As risk, owing to the depth-dependent relative change in redox conditions during rainfall events.
Solar cell capacitance measurement

For the new generation of solar cells, like multi-junction GaAs and Si for Low Intensity Low Temperature (LILT) applications, a different solar cell capacitance behaviour is recognised. For large sections, i.e. strings connected in parallel, of these cell types, the time in which the illumination pulse is stable may be too short to measure the large capacitance accurately. It is therefore necessary to increase the pulse duration. Monitoring the step response with a storage oscilloscope requires extra attention as the incorrect time base setting and insufficient sampling rate could result in an overestimation of the capacitance due to aliasing. To cope with these points, an adequate capacitance test set-up and measurement method has been developed. The core of this test set-up is the Vortek Large Area Sun Simulator (VLASS). This solar simulator has the ability to illuminate a solar panel/string continuously, typically 3 to 4 seconds at 1 Solar Constant, and more than 1 minute at low intensities, applicable to deep space missions. Comprehensive knowledge of section capacitance gains importance for many power management systems like Maximum Power Point Trackers (MPPT) and shunt switching regulators.
A mixed-methods study of novice teachers’ technology integration: Do they leverage their TPACK knowledge once entering the profession?

Abstract Research indicates educators benefit from developing Technological Pedagogical Content Knowledge (TPACK), a combination of constructs that inform the design of pedagogically-sound technology-integrated instruction. Applying a mixed-methods explanatory sequential study design, we examined if and how novice K-12 teachers, who developed TPACK during the same teacher education program, transferred that knowledge to their full-time teaching upon graduation. A total of 50 participants completed a survey that explored their perspectives of technology integration. Interviews were conducted with 20 participants to further examine the survey results. Three significant findings were identified: (1) participants perceived technology integration as important to their teaching, (2) a disconnect existed between teachers’ perceived importance of technology-integrated activities and actual integration, and (3) persistent barriers continued to challenge teachers’ integration of technology.
Mental health status and risk factors during Covid-19 pandemic in the Croatia’s adult population

ABSTRACT Background: The Covid-19 pandemic is associated with adverse mental health outcomes for people worldwide. Objective: The study aimed to assess mental health during the Covid-19 pandemic and the key risk factors from the human ecology perspective in Croatia’s adult population. Method: An online panel survey with 1,201 adult participants (50.1% women) was done with a nationally representative sample in terms of gender, age, and country region four months after the nation lockdown began and two months after most of the restrictions were lifted. Indicators of mental health included symptoms of adjustment disorder (ADNM-8); depression, anxiety, and stress (DASS-21); symptoms of post-traumatic stress disorder (PC-PTSD-5); and well-being (WHO-5). Results: In the entire sample, 9.8% (95% confidence interval [CI]: 7.9%, 14.0%) of the participants were at risk of adjustment disorder, 7.7% (95% CI: 6.7%, 11.9%) were at risk of depression disorder, and 7.8% (95% CI: 5.3%, 10.3%) were at risk of anxiety disorder. In addition, 7.2% (95% CI: 5.3%, 10.2%) were experiencing high levels of stress. The average well-being score was 56.5 (SD = 21.91) on a scale from 0 to 100. Among the participants who have lifetime traumatic experience (n = 429), 14% (95% CI: 10.6%, 17.2%) were at risk for PTSD. Key risk factors for specific mental health outcomes differed, but the common ones included: current health status, previous mental health diagnosis, and psychological resilience. Being younger, having a below-average income, and excessively following news about Covid-19 were predictive for some of the mental health problems. Conclusions: Together, the key risk factors identified in this study indicate the need for public health interventions addressing the general population’s mental health, but also for specific risk groups. Lower rates of mental health symptoms assessed soon after lifting quarantine measures that have been found in other studies may indicate human resilience capacity. HIGHLIGHTS Key risk factors for mental health disorders during the Covid-19 pandemic in Croatia were: current health status, previous mental health diagnosis, psychological resilience, younger age, below-average income, and excessively following news about the pandemic.
INSTRUMENTS AND TECHNIQUES USED IN THE DESIGN AND IMPLEMENTATION OF CHANGE MANAGEMENT

Organizations are facing more frequent and larger changes in our current economic climate. A changing marketplace, empowered workforce and technological advancements have all created an environment where change is becoming the only constant or 'business as usual'. In this environment, all the organizations are beginning to recognize the importance of building the competency to rapidly and successfully change. The purpose of this article is to summarize several adjustment instruments and techniques about the nature of change. As change is a coordinate of the present moment, we shall show how successful change can be encouraged and facilitated for a long-term success, through instruments and techniques. The variety and continuity of changes in modern organizations gave rise to multiple approaches to organizational change management. In what follows, we propose the presentation of the instruments of change management and of the techniques that may be useful in managing change within the organizations.