Miracle-dz/UniFAR-FTUs huggingface dataset:
Development of amphibious biomimetic robots

Amphibious robots are becoming increasingly important for civilian, scientific, and environmental missions. They are widely used in disaster rescue, ecosystem monitoring, and entertainment. However, some have two different locomotion systems that need to be changed manually to fulfill both swimming in the water and moving on land, which may reduce their efficiency and reliability. Applying bioinspiration and biomimetics, many recently developed amphibious robots can undertake various tasks in complex amphibious environments with high mobility, flexibility, and energy efficiency. This review overviews the latest developments in amphibious robots, emphasizing biomimetic design concepts, backbone driving mechanisms, and typical applications. The performance indices of amphibious robots mimicking 13 different natural sources are compared, based on 10 different propulsion principles/modes, travel speed, working efficiency, maneuverability, and stability. Finally, the current challenges and perspectives of amphibious bio-inspired robots are discussed. This article summarizes the current types of amphibious robots and their movement and behavior solutions. The design concepts and operating mechanisms of amphibious robots reviewed here can be readily applied to other robotic studies.
The critical thinking skill of mathematics education students during pandemic: A Review

Learning in higher education is expected to be able to optimize students' critical thinking skills. However, learning mathematics during the pandemic encountered many obstacles affecting students' critical thinking skills. Furthermore, even before the pandemic occurs, mathematics education students still face difficulties optimizing their critical thinking skills. This study aims to analyze the level of critical thinking skills of mathematics education students during the pandemic and the learning models that can be applied to improve these abilities through online learning. The method used is a systematic literature review (SLR) on Google Scholar, ERIC, Science Direct, and DOAJ databases restricted for publish year in 2019-2022. The findings are the level of critical thinking ability of mathematics education students varies depending on the course used in the research. Secondly, several models or learning media can be applied in online classes during the pandemic to improve the critical thinking skills of mathematics education students. Some of them are a combination of Google meet with scaffolding-based online Geogebra, E-Academic based on collaborative learning, PDEODE strategy. The use of Geogebra Javascript, Realistic Mathematics Education approach, Problem Based Learning, using e-books instead conventional books and articles in newspapers as learning media.
RESEARCH NOTES AND COMMUNICATIONS THE DEVELOPMENT OF STRATEGIC MANAGEMENT: JOURNAL QUALITY AND ARTICLE IMPACT

Quality ratings of strategic management journals by experts correlate closely with objective quality measures of current article impact and cumulative journal influence. In part, journal quality seems determined by editors' research stature. Over 12 years, scholarly influence of strategic management periodicals has grown nearly three-fold, as two new journals directed to conceptual development of management as a whole have risen to prominence. Expansion of strategic management research and growth of its influence may be in response to challenges posed by the continuing crisis of managerial and business performance.
Adolescents’ Understanding of the Model of Sponsored Content of Social Media Influencer Instagram Stories

Our study stresses the importance of developing understandable and easily recognizable ad disclosures for adolescents as a specific target group of social media influencer (SMI) advertising. A comprehensive advertising literacy concept that includes a cognitive, performative, and attitudinal component builds the theoretical background of the present research. We examine the effectiveness of ad disclosure in the native language of adolescent Instagram users, explore their understanding of the economic mechanism behind SMIs’ advertising activities, and their skepticism toward sponsored content. Furthermore, we analyze the role that sponsorship transparency on Instagram stories plays in adolescents’ responses to advertising. A three-level between-subjects survey-based experimental design (manipulating the absence of ad disclosure versus ad disclosure in the participants’ native language versus standardized paid partnership ad disclosure in English) was conducted online with female adolescent participants (N = 241) in a European country. Findings showed that adolescents who understand the economic model behind SMI advertising have positive intentions toward the SMI and intend to spread online information about the promoted brand. However, even if ad disclosure made in the adolescents’ native language improved ad recognition, such knowledge did not result in more sophisticated defense mechanisms in the form of critical evaluations of the ads.
Novel compact model for multi-level spin torque magnetic tunnel junctions

Spin-transfer torque (STT) and spin-orbit torque (SOT) based magnetic tunnel junction (MTJ) devices are emerging as strong contenders for the next generation memories. Conventional STT magneto-resistive random access memory (MRAM) offers lower power, non-volatility and CMOS process compatibility. However, higher current requirement during the write operation leads to tunnel barrier reliability issues and larger access devices. SOT-MRAM eliminates the reliability issues with strong spin polarized current (100%) and separate read/write current paths; however, the additional two access transistors in SOT-MRAM results into increased cell area. Multilevel cell (MLC) structure paves a way to circumvent the problems related to the conventional STT/SOT based MTJ devices and provides enhanced integration density at reduced cost per bit. Conventional STT/SOT-MRAM requires a unit cell area of ~10-60 F2 and reported simulations have been based on available single-level MTJ compact models. However, till date no compact model exists that can capture the device physics of MLC-MTJ accurately. Hence, a novel compact model is proposed in this paper to capture the accurate device physics and behaviour of the MLC-MTJs. It is designed for MLCs with different MTJ configurations demonstrated so far, such as series and parallel free layer based MLC-MTJs. The proposed model is coded in Verilog-A, which is compatible with SPICE for circuit level simulations. The model is in close agreement with the experimental results exhibiting an average error of less than 15%.
Can Green Credit Policy Promote Firms’ Green Innovation? Evidence from China

To achieve the twin goals of “stable growth” and “environmental protection”, it is necessary to promote green innovation in firms and green transformation of the economy. This paper regards China’s Green Credit Guidelines policy in 2012 as a quasi-natural experiment to explore the impact of the policy on the green innovation of heavy-polluting firms. This analysis uses Chinese A-share listed industrial enterprises from 2008–2019 as the research sample and difference-in-difference (DID) as the empirical method. The results show that implementing the green credit policy has significantly contributed to firms’ green technology innovation enhancement. Moreover, the mechanism suggests that the green credit policy can promote firms’ green innovation through channels, such as inhibiting the compression of heavy-polluting firms’ financing space, increasing their debt financing costs, and promoting firm transformation and upgrading. Further study finds that the green credit policy promotes green innovation significantly for state-owned and large firms but not for non-state-owned and small-scale firms. Based on our empirical results, we can conclude that the green credit policy is an efficient way to realize the goal of “environmental excellence” and guide firms to effectively carry out green innovation.
Unified theory of torque production in switched and synchronous reluctance motors

One of the difficulties in comparing the capabilities of the switched reluctance motor with those of AC motors is the lack of a unified theory of torque production, in which the same equation can be used for both motors so that the comparison can be reduced to the comparison of coefficients. The main impediment to the development of such a theory has been the fact that the switched reluctance motor does not satisfy the necessary conditions for the dq-axis transformation, because of its double saliency. Essentially it produces torque in impulses and it is analysed by calculating the energy converted from electrical to mechanical during one stroke. This is equal to the area enclosed by the trajectory of the operating point in the phase flux-linkage versus phase-current diagram. In this paper the torque production in the synchronous reluctance motor is analysed by the same energy conversion loop method. The new concept of the ellipse diagram not only allows a direct comparison with the switched reluctance motor, but also enables the calculation of torque ripple, this not being possible using conventional dq-axis theory. < >
Scale dependence of drilling predation in the Holocene of the northern Adriatic Sea across benthic habitats and nutrient regimes

Abstract. Predation has strongly shaped past and modern marine ecosystems, but the scale dependency of patterns in drilling predation, the most widely used proxy for predator–prey interactions in the fossil record, is a matter of debate. To assess the effects of spatial and taxonomic scale on temporal trends in the drilling frequencies (DFs), we analyzed Holocene molluscan assemblages of different benthic habitats and nutrient regimes from the northern Adriatic shelf in a sequence-stratigraphic context. Although it has been postulated that low predation pressures facilitated the development of high-biomass epifaunal communities in the eastern, relatively oligotrophic portion of the northern Adriatic shelf, DFs reaching up to 30%–40% in the studied assemblage show that drilling predation levels are comparable to those typical of late Cenozoic ecosystems. DFs tend to increase from the transgressive systems tract (TST) into the highstand systems tract (HST) at the local scale, reflecting an increase in water depth by 20–40 m and a shift from infralittoral to circalittoral habitats over the past 10,000 years. As transgressive deposits are thicker at shallower locations and highstand deposits are thicker at deeper locations, a regional increase in DFs from TST to HST is evident only when these differences are accounted for. The increase in DF toward the HST can be recognized at the level of total assemblages, classes, and few abundant and widespread families, but it disappears at the level of genera and species because of their specific environmental requirements, leading to uneven or patchy distribution in space and time.
Enhanced NAPL Removal and Mixing With Engineered Injection and Extraction

Aquifer remediation with in‐situ soil washing techniques and enhanced oil removal typically involves the injection of liquid solutions into the geological formation to displace and mobilize non‐aqueous phase liquids (NAPLs). The efficiency of these systems is oftentimes low because the displacing fluid bypasses large quantities of NAPL due to the inherent complexity of a heterogeneous natural system. Here, engineered injection and extraction (EIE) generated by rotating periodic injection is proposed as a method to enhance NAPL removal and mixing. To evaluate the method, we perform two‐phase flow simulations in multiple realizations of random permeability fields with different correlation structures and connectivity between injection and extraction wells embedded in a five‐spot pattern. Results show that EIE can significantly improve removal efficiency and mixing depending on several controlling factors. The effects of EIE are more significant under unfavorable conditions, that is, when injection and extraction wells are well‐connected through preferential channels, permeabilities are highly heterogeneous, and/or the mobility ratio between the wetting and the non‐wetting fluids is larger than one. Removal efficiency reaches its maximum value when the Kubo number is close to one, that is, when the saturation front travels one range of the permeability field in an injection pulse. These effects can develop in just a few cycles. However, removal efficiency should undergo first an early stage with detrimental effects in order to maximize removal in the long term. EIE not only enhances NAPL removal and mixing but also reduces the uncertainty, making the system more reliable and less dependent on heterogeneity.
Análise de viabilidade econômica de um confinamento de bovinos de corte

A adocao do sistema de confinamento de bovinos permite maior controle dos custos, porem o levantamento dos gastos deve ser bem planejado. O presente estudo objetivou analisar e avaliar a viabilidade economica da producao de um confinamento de bovinos de corte, em Auriflama, SP. Os custos com insumos integraram 85,14%, porem obteve indice de lucratividade 68,55% e valor presente liquido positivo a partir do 4o ano. Considerando as analises estudadas, a pecuaria apresenta ser uma atividade rentavel e viavel.
Exploiting modal interaction during run-up of a magnetically supported Jeffcott rotor

Introducing a parametric anti-resonance in a vibrating system couples two of the many vibration modes and enables an energy exchange between those two. This feature is employed during the run-up of a JEFFCOTT rotor supported by two active magnetic bearings. The vibration performance at bearing stiffness modulation is compared to the well-known performance at nominal bearing characteristics for a simple run-up at a constant acceleration. It is shown that by introducing a specific periodic change of the bearing stiffness coefficients, a mode coupling between two selected modes is activated. This coupling impacts the maximum amplitude developed during passage through resonance. At each critical speed transient vibrations of the corresponding mode are excited. Due to the modal coupling, if one mode is excited at a critical speed then energy is exchanged with the coupled mode. On one hand, the maximum amplitude at the first critical speed is decreased by modulation since some vibration energy is transferred to the highly damped second mode where it is partly dissipated. On the other hand, the maximum amplitude at the second critical speed is increased by modulation since some vibration energy is transferred to the lightly damped first mode. The concept is outlined in detail based on numerical studies.
Marine Collagen Isolation and Processing Envisaging Biomedical Applications

The authors would like to acknowledge the funding from ERDF through POCTEP Project 0687_NOVOMAR_1_P, from ERDF through Atlantic Area Transnational Cooperation Programme Project MARMED (2011-1/164) and from European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement nr. REGPOT-CT2012-316331-POLARIS. Joana Moreira-Silva thank the Portuguese Foundation for Science and Technology (FCT) for the Post-Doctoral fellowship financed by POPH/FSE (SFRH/BPD/70230/2010). Dario Fassini is gratefully acknowledged for the assistance with the SDS-Page analysis.
Design and analysis of a fault-tolerant fractional slot PMSM for a vehicle application

The permanent magnet synchronous motor (PMSM) is an interesting alternative for an electric motor drive system in automotive applications, due to to the high efficiency requirement; as only a limited amount of energy can be stored in the relatively expensive battery. Another advantage is the high torque and power density a PMSM can achieve since it is very important to save especially space but also weight in vehicle applications. As the battery technology develops, pure electric cars are expected to become a more and more interesting alternative. It is then natural that the requirement of reliability on the electric drive system becomes an aspect of utmost importance as the electric drive is the only driving force. In this thesis, a fault-tolerant fractional slot PMSM is designed and its capability to operate even after a fault occurs is investigated. The faults investigated are phase open circuit and phase short circuit, and it is shown that the thesis machine design can be operated during both circumstances. The fault-tolerant thesis machine design is compared with two reference machines; one existing PMSM design of the same size and a smaller prototyped PMSM, also including measurements for the later. All three machines are evaluated both during normal and during phase open circuit operation, using amethod where the remaining two phase currents are rearranged in order to get constant currents in the rotating dq reference frame. It is found that themaximum torque is reduced to approximately 58% and the maximum speed to roughly 1/2, in relation to what is achievable for each machine during normal operation. The thermal limits are investigated and shown to follow the electrical limits for the thesis design and for the prototyped IPM machine. However, when this method is used, it is noticed that the torque quality might be reduced significantly. A semi-analytical machine modeling approach is introduced and used to model the individual saturation levels of the phases. The same model is used to calculate new current wave forms in order to reduce the torque ripple during the unbalanced conditions associated with the operation during fault. Consequently, for the thesis design with reduced torque ripple, the maximum torque is reduced to approximately 50% and the maximum speed is reduced to roughly 1/3 or 1/4 of the maximum speed in case of a phase open circuit fault or a phase short circuit fault respectively.
Thermal imaging outshines spotlighting for detecting cryptic, nocturnal mammals in tropical rainforests

Abstract Context. Thermal imaging has been shown to be a valuable technique for detecting a range of terrestrial mammals across different environments. The limited studies looking at its effectiveness in detecting arboreal mammals in rainforest ecosystems have had mixed success due to the complexity of the environment and limitations of the technology itself. Aims. We investigated whether using a hand-held thermal imaging device would detect more individuals of six species of nocturnal arboreal mammal in tropical rainforests than the most-used detection method of spotlighting. We determined whether environmental variables effecting either equipment operation or mammal behaviour would influence these results. Methods. We surveyed eight transects across the Wet Tropics of northern Queensland for six species of arboreal mammals using both a hand-held thermal imager and a spotlight. We used a measure of underestimation to compare counts of individual species, and then modelled total mammal counts with detection method and environmental variables to find the best approximating model. Key results. Spotlighting underestimated the total number of each species by between 33 and 100% when compared with thermal imaging. Detection method alone without any environmental interaction term provided the best approximating model (AICc = 275.58, marginal pseudo R2 = 0.286), with thermal imaging technology detecting almost double the number of our target individuals (12.3 ± 1.76) compared with spotlighting (6.7 ± 1.02). Conclusions. Despite recorded operational limitations, thermal imaging technology greatly improved our ability to locate both small and large nocturnal, arboreal mammals, including a species that is rarely observed in the wild. Implications. The potential to not only improve detection of nocturnal, arboreal mammals but also improve cryptic species distribution and abundance measures suggests thermal imaging technology is an important tool for use globally across rainforests environments.
Advancing Autonomous Structural Health Monitoring

The focus of this dissertation is aimed at advancing autonomous structural health monitoring. All the research is based on developing the impedance method for monitoring structural health. The impedance technique utilizes piezoelectric patches to interrogate structures of interested with high frequency excitations. These patches are bonded directly to the structure, so information about the health of the structure can be seen in the electrical impedance of the piezoelectric patch. However, traditional impedance techniques require the use of a bulky and expensive impedance analyzer. Research presented here describes efforts to miniaturize the hardware necessary for damage detection. A prototype impedance-based structural health monitoring system, incorporating wireless based communications, is fabricated and validated with experimental testing. The first steps towards a completely autonomous structural health monitoring sensor are also presented. Power harvesting from ambient energy allows a prototype to be operable from a rechargeable power source. Aerospace vehicles are equipped with thermal protection systems to isolate internal components from harsh reentry conditions. While the thermal protection systems are critical to the safety of the vehicle, finding damage in these structures presents a unique challenge. Impedance techniques will be used to detect the standard damage mechanism for one type of thermal protection system. The sensitivity of the impedance method at elevated temperatures is also investigated. Sensors are often affixed to structures as a means of identifying structural defects. However, these sensors are susceptible to damage themselves. Sensor diagnostics is a field of study directed at identifying faulty sensors. The influence of temperature on these techniques is largely unstudied. In this dissertation, a model is generated to identify damaged sensors at any temperature. A sensor diagnostics method is also adapted for use in developed hardware. The prototype used is completely digital, so standard sensor diagnostics techniques are inapplicable. A new method is developed to work with the digital hardware.