Miracle-dz/UniFAR-FTUs huggingface dataset:
Extended state observer‐based finite time control of electro‐hydraulic system via sliding mode technique

The position tracking control of electro‐hydraulic system (EHS) is disposed in this paper via sliding mode control (SMC) with nonlinear sliding surface. The main feature of the proposed controller is the combination of a totally singular‐free recursive terminal sliding mode controller (RTSMC) with an extended state observer (ESO). The uncertainties (including the unknown external disturbance) together with its derivatives and the unmeasured states of EHS are estimated simultaneously by the ESO while the controller is designed by employing the recursive nonsingular TSMC (RNTSMC), and a nonlinear sliding surface is employed to totally avoid the singularity in the traditional RNTSMC. Moreover, the observer dynamics are considered during the controller design. The position tracking error is proven to be bounded in finite time via Lyapunov theory, and the bound can be effectively reduced by tuning the parameters of the controller and observer. Simulation results show that the proposed controller is not sensitive to model uncertainties and external disturbances.
Design and analysis of high isolated super compact 2 × 2 MIMO antenna for WLAN application

In this article, a DGS structure is applied to enhance the inter‐port isolation of super compact 2 × 2 MIMO antenna. Each element of MIMO antenna configuration is designed using a planar inverted‐F antenna (PIFA) having dimensions 7 × 7 × 0.8 mm3 and elevated at 2.8 mm from the ground plane of dimensions 100 × 50 × 0.8 mm3 (comparable to the size of mobile handsets). The proposed antenna operates from 5.2 to 6 GHz resonating at 5.65 GHz which is suitable for WLAN applications. The proposed design with and without the isolation enhancement technique is resonating at 5.65 GHz. Therefore, the proposed DGS structure is acting as a perfect isolator without affecting the reflection coefficient of the MIMO antenna configuration. It provides high isolation enhancement from 12 to 25 dB at the resonance frequency. All the diversity parameters of the MIMO configuration are calculated and found within the desirable limits. Thus, it is found that the proposed antenna is well suited for modern wireless applications (WLAN). The radiation performances such as 2D and 3D patterns, total antenna efficiency, and peak realized gain are calculated and analyzed. Finally, a prototype is fabricated and validated experimentally.
A parametric cut size prediction model for a turbo air classifier

A new parametric cut size prediction model is put forward based on the simplified single particle motion rule. According to analysis of the inner flow field of a turbo air classifier and Lagrangian equation of particle motion, the particle's trajectory in the annular region is calculated and simulated using MATLAB. Since particles with different sizes have different trajectories in the same flow field, the cut size of a turbo air classifier can also be obtained. The simulated results show the cut size increases by widening the annular region and it decreases by narrowing the annular region. Talc powder classification experiments are carried out to verify this cut size prediction model. The calculated cut sizes using the proposed prediction model are in agreement with the experimental results. A new way to predict cut size is put forward, which provides a theoretical guidance to optimize operational parameters and the structure of the turbo air classifier.
Effect of Adding Emulsifier to Fuel on Work Efficiency and Gas Turbine Emissions

In an effort to reduce the emissivity of transport and energy, numerous studies are being carried out on the impact of the combustion of alternative fuels on the emission and operating parameters of propulsion and energy units. One of the observed trends is the use of emulsion fuels. The addition of an emulsifier to an emulsion fuel reduces the interfacial tension between two liquids, which allows obtaining an emulsion fuel with the expected stability. The research conducted on self-ignition engines and gas turbines (TG) does not give an unambiguous answer as to the influence of the use of fuel-water emulsion on CO emissions. One of the reasons for the discrepancy in the obtained results may be the type and amount of the emulsifier used in the emulsion fuel. Tests were carried out on the GTM-120 gas turbine to compare the operating parameters and emissions between the cases in which TG was supplied with three fuel mixtures—the standard fuel for TG (DF) and DF with 2% and 5% emulsifier addition. It was shown that the addition of 2% of the emulsifier to DF causes an increase in CO emission, with the remaining measured parameters unchanged. On the other hand, increasing the amount of emulsifier in DF to 5% reduces CO emissions to the level observed in the case in which DF was burned reduces NOx emissions and reduces the thermal efficiency of TG.
Student Retention and Degree Completion: The Moderating Effects of Institutional Factors

ABSTRACT This study investigates the impact of institutional factors and student characteristics on student retention and degree completion, with particular attention to how institutional factors moderate the impact of student characteristics. It makes use of a five-year panel data from the College Scorecard database maintained by the US Department of Education. It uses the Feasible Generalized Least Squares model for the estimation to control for panel level heteroscedasticity and panel-specific autocorrelation. The results reveal the importance of student characteristics in affecting retention rate and completion rate. Moreover, their effects are strongly moderated by institutional factors. These findings generate insight on how to increase student retention and degree completion rates and bear implications for university administrators and public policy makers.
Changes in vitro rumen fermentation, methane production and microbial populations in response to green tea extract

Abstract This research was conducted to evaluate the influence of adding increasing levels (0, 250, 500,750, and 1000 μg/mL buffered rumen fluid) of green tea ethanol extract (GTEE) to a basal substrate (50% roughage: 50% concentrate formulated with 50% barley and 50% corn grain) on rumen fermentation, methane emissions, and population of microorganism under in vitro experiment. The potential of gas production (A), methane emission, and methane ratio (mL/mL total gas 24 h) were linearly decreased by increasing the dose of GTEE (p<.001). The control group has the highest methane emission (p<.05), while it was the lowest (p<.05) at a dose of 1000 GTEE (47.74 versus 24.23 mL/g DM). In vitro digestibility of dry and organic matter were negatively affected by GTEE (L and Q; p<.001). The addition of GTEE significantly decreased total volatile fatty acids (TVFA) and N-NH3 concentration (L, p<.001), and also changed the VFA profile compared to the control group by decreasing and increasing the acetate and the propionate proportions (p<.001). The highest decrease in total protozoa population (93%), total fungi (38%), and methanogenic archaea (95%) compared to the control group was observed at the highest dose (1000) of GTEE. The addition of GTEE stimulates the population of Prevotella ruminicola and Selenomonas ruminantium, but Butyrivibrio fibrisolvent population was inhibited, in different supplementation doses. The lowest supplementation level (250 μg/mL) seems to have the most benefits on the in vitro fermentation parameters with minimum negative effects on nutrient digestibility. It can be concluded that GTEE can potentially be used to manipulate ruminal fermentation patterns. Highlights Reducing the methane concentration through the anti-protozoal activity of green tea extract improve rumen fermentation patterns by decreasing acetate and N-NH3 concentration and increasing the propionate proportions. Although the in vitro anti-acidosis potential of GTEE is not as much as monensin, the anti-acidosis potential is significantly increased by increasing GTEE dose compared to the control. The decrease in in vitro total gas, CH4 production, and dry- and organic-matter digestibility on the addition of GTEE could be attributed to the antimicrobial action of GTEE.
Does Online Ratings Matter? An Integrated Framework to Explain Gratifications Needed for Continuance Shopping Intention in Pakistan

Due to the phenomenal growth of e-commerce, online shopping has recently become a worldwide trend. This fosters many online shopping platforms to enter into Asian emerging markets, which evolves a need to understand online decision-making processes in this particular context. Addressing this gap, our study initialized an integrated framework based on Uses and Gratification theory and the Cognitive–Affect–Behavior paradigm to examine the impact of gratification elements on customer satisfaction and convenience enforcing continuance shopping intention. Moreover, we also conceptualize the moderating role of online ratings in our study. In total, 317 valid questionnaires from Pakistani online shoppers were incorporated to statistically test our model using the Structural Equation Modeling (SEM) approach in Amos. Besides, the results confirm the positive impact of layout and functionality on customer satisfaction and convenience, while the impact of PEEIM has been found insignificant. Furthermore, customer satisfaction and convenience are found to be the imperative predictors of continuance shopping intention. Our findings exhibit that a high level of online rating strengthens the direct effect of satisfaction and convenience on continuance intention. Theoretical and practical implications for future scholars and e-commerce shopping platforms are discussed.
Numerical investigation of liquid water dynamics in wave‐like gas channels of PEMFCs

For the air feed in proton exchange membrane fuel cells (PEMFCs), the wave‐like gas channel (GC) shows obvious advantages over the straight GC because the former enhances collision of secondary flow and diffusion in the gas diffusion layer (GDL). However, it is prone to water flooding, which brings greater pressure drop, larger pressure oscillation, and blocking of reaction area. In the present study, numerical models of the water dynamic processes, including water droplets emerging from micropores on the GDL surface and removing through the GC, are established based on the volume of fluid (VOF) method. Water coverage ratio and pressure drop are calculated to evaluate the water flooding. The effects of the dimensional parameters of wave‐like GC and contact angle of channel walls on the water accumulation are studied. The emergence and removal of liquid water is a quasiperiodic and oscillating process. Multicycle simulations show that channel pressure drop increases linearly with greater growth rate than channel length. The equilibrium position of water droplet is strongly dependent on the relative wettability of the GDL and bipolar plate (BPP) surfaces. And the geometric parameters of GC have a significant impact on the pressure, water removal behavior and detachment time. Smaller bent angle brings bigger pressure drop, and larger cycle length is helpful for relieving the oscillation of pressure.
Active-Damping Speed Tracking Technique for Permanent Magnet Synchronous Motors With Transient Performance Boosting Mechanism

This article exhibits a novel solution to the speed tracking problem of permanent magnet synchronous motors (PMSMs) subject to parameter and load uncertainties. The resultant cascade structured solution is designed to give the speed tracking capability to the closed-loop system, which depends on only the nominal PMSM parameter information. This article provides two novel contributions: 1) a variable performance target system describing the desired perfect tracking nature with boosting feedback gains and 2) a robust control law forcing the target tracking system to be invariant through the utilization of active-damping pole-zero cancellation and disturbance observer techniques. The prototype 1-kW PMSM experimental set confirms the practical advantages of the proposed system compared to the recent autotuning controller.
Coronavirus: The Not‐So‐Trivial Loss of Well‐Being

The COVID‐19 outbreak has been one of the world's most severe challenges since World War II, which not only reflected in the observable economic depression, but also in emotional damage that is scarcely underscored. This paper estimates the effect of the epidemic on happiness of Chinese residents by capturing the emotions conveyed through massive social media, combined with city‐level epidemic data. We confirm the significant negative impact of the outbreak on life satisfaction, with an extra 1% of cumulative death cases associated with a 0.54% decrease in expressed happiness. Meanwhile, we find that well‐being drops the most in regions with high‐level risk of COVID‐19, and happiness in regions with higher or lower income levels are more vulnerable to the effects of the epidemic, in comparison to the intermediate‐level income regions. Female sentiment exhibits more sensitivity to the epidemic situation than does male sentiment. Furthermore, the timing of major public events also plays a sizable role in determining self‐reported happiness, and our results suggest that pandemic alerts announced by the World Health Organization significantly increased the loss of well‐being, while announcements of city‐unlocking had the opposite impact. The interaction between the outbreak and real‐time expressed happiness provides an important opportunity for reflection on the future governance policies of epidemic containment.
The Relationship between Transformational Leadership and Innovation and Creativity in Management to Improve Employees’ Academic Performance at Sohar University

This study investigated the relationship between transformational leadership practices and norms and employees' performance at Sohar University in the Sultanate of Oman. This research is based on the fact that traditional methods of leadership handicap the development of modern leadership practices in Sohar University in particular and in Oman in general. This study may contribute to some significant solutions to the extant literature especially in that transformational leadership practices could be of great value if they are supported by modern techniques and high training skills for employees. The present paper adopts qualitative research method. Questionnaire was used as a research instrument of collecting data. The 5-Point Likert Scale was adopted to help researchers analyze the data. The study concludes that Transformational leadership skills are very essential for high-ranking leaders to acquire in Sohar University in the Sultanate of Oman. The study also finds that transformational leadership skills are very essential for high-ranking leaders to acquire in Sohar University in the Sultanate of Oman. Having conducted statistical analysis, this study draws some conclusions and suggests some recommendations for transformational leadership and its use in developing administrative creativity and improving job performance among Sohar University employees. This can be summarized as follows. First, transformational leadership skills are very essential for high-ranking leaders to acquire in Sohar University in the Sultanate of Oman. second, transformational leaders with outstanding leadership skills are found astonishingly effective in managing and leading those working under them. Third, employees are found to be greatly affected by their leaders in respect with academic and managerial activities and finally the study found that Universities in the Sultanate of Oman do not pay special attention to transformational leadership skills, which this negatively affects the quality and credibility of teaching.
Transitioning to Homeownership: Asset Building for Low- and Moderate-Income Households

ABSTRACT This article assesses the asset building of households that take part in shared-equity homeownership (SEH) models. The contribution of this article is a comparison of outcomes for households participating in shared-equity programs with other low- and moderate-income households who rent or own properties without restrictions on appreciation. We matched participants in SEH programs to households with similar characteristics from the Panel Study of Income Dynamics (PSID) over the 1997–2017 period. The findings indicate that in real terms, median SEH homeowners accumulated about $1,700 in housing wealth annually or around $10,000 during their holding period. This amount is lower than the $2,100 median annual gain in home equity experienced by similar PSID owners but statistically and economically significantly larger than the $16 in annual gain experienced by similar PSID renters. The findings provide evidence that households participating in SEH programs experienced positive, but modest, wealth gains that were slightly lower than those of homeowners in unrestricted units but substantially higher than those of renters.
Relationships between heart rate variability and indirect indicators of hydration status in elite male field hockey players

The aim of this study was to examine the relationship between resting morning heart rate variability (HRV) metrics and indirect markers of hydration status in elite male athletes. Twenty-two field hockey players (age 26.8 ± 3.4 yr; height 178.4 ± 6.3 cm; body mass 76.2 ± 7.4 kg) were monitored over 10-d during a pre-Olympic training camp. Measurement of heart rate variability (HRV) during an orthostatic challenge, urine specific gravity (Usg, first morning void) and body mass were captured on seven of the mornings. Individual generalized linear mixed models evaluated the relationships between supine and standing HRV metrics with Usg and day-to-day change in body mass. No meaningful relationships were identified between supine (estimates −0.002 to 0.001) or standing (−0.002 to 0.003) HRV metrics and Usg as well as between supine (−0.003 to 0.016) or standing (−0.004 to 0.006) HRV metrics and changes in body mass. These outcomes indicate that supine and standing HRV metrics are not influenced by indirect indices of hydration status in elite male field hockey players.
Continuous Synthesis of Structurally Uniform Graphene Oxide Materials in a Model Taylor–Couette Flow Reactor

Graphene oxide (GO) has proven to be an invaluable material for a wide range of applications. The development of a bulk-scale continuous process to synthesize GO materials has become crucial. In this study, we used a model Taylor–Couette reactor with axial flow to transform the oxidation of graphite flakes into a continuous process. Efficient mixing of graphite and oxidizing agents was achieved via Taylor vortices, which remarkably shortened the duration of graphite oxide (GtO) synthesis from hours to minutes. Our results reveal that the level of oxidation increased at the Taylor vortex flow (TVF) regime and significantly decreased at other hydrodynamic flow regimes. More importantly, TVF regime resulted in structurally uniform GtO products. This confirms that the developed apparatus offers a robust method to synthesize high-quality, structurally uniform GtO in a continuous manner that can be used in numerous applications.
Molecular systematics of Thouarella (Octocorallia : Primnoidae) with the description of three new species from the Southern Ocean based on combined molecular and morphological evidence

Abstract. Thouarella Gray, 1870, is one of the most speciose genera among gorgonians of the family Primnoidae (Cnidaria : Octocorallia : Anthozoa), being remarkably diverse in the Antarctic and sub-Antarctic seafloor. However, their diversity in the Southern Ocean is likely underestimated. Phylogenetic analyses of mitochondrial and nuclear DNA markers were integrated with species delimitation approaches as well as morphological colonial and polyps features and skeletal SEM examinations to describe and illustrate three new species within Thouarella, from the Weddell Sea, Southern Ocean: T. amundseni sp. nov., T. dolichoespinosa sp. nov. and T. pseudoislai sp. nov. Our species delimitation results suggest, for the first time, the potential presence of Antarctic and sub-Antarctic cryptic species of primnoids, based on the likely presence of sibling species within T. undulata and T. crenelata. With the three new species here described, the global diversity of Thouarella has increased to 41 species, 15 of which are endemic to the Antarctic and sub-Antarctic waters. Consequently, our results provide new steps for uncovering the shelf benthonic macrofauna’s hidden diversity in the Southern Ocean. Finally, we recommend using an integrative taxonomic framework in this group of organisms and species delimitation approaches because the distinctions between some Thouarella species based only on a superficial examination of their macro- and micromorphological features is, in many cases, limited.
Victoire de la vie and L’Espagne vivra by Henri Cartier-Bresson: Two Different Musical Strategies at the Service of Republican Propaganda

From 1936 to 1939, the Spanish Civil War gave several film directors the opportunity to stand side by side with Republican soldiers by filming them in combat. Henri Cartier-Bresson first movie Victoire de la vie (Victory of Life, 1937), then, one year later, as the nationalist side was gaining ground, L’Espagne vivra (Spain shall live, 1938). The music for Cartier Bressons’s two films follows two contrasting strategies: for Victoire de la vie, French composer Charles Kœchlin composed an original soundtrack in a relatively homogeneous style, whereas in L’Espagne vivra, Louis Saguer made use of a compilation of pre-existing symphonic pieces. This article intends to analyse how these two musical approaches align themselves with the contrasting but complementary analyses of the Spanish Civil War provided by Cartier-Bresson's two films.
Critical review of encapsulation methods for stabilization and delivery of astaxanthin

Astaxanthin is an important carotenoid pigment and potent antioxidant with proven health benefits. It is primarily obtained from algae or bacteria and is the natural colorant in crustaceans and salmonids. However, this pigment readily degrades in the presence of light and oxygen and has low absorption rates in the human digestive system. Different encapsulation strategies have been adopted to improve astaxanthin physical stability and bioavailability for nutritional use. This review summarizes and compares different encapsulation techniques and matrices applied to astaxanthin. Typical methods for encapsulation include high pressure homogenization, nano dispersions, liposomes and nanoparticles. More recently low energy methods like membrane and microchannel emulsification have been used to improve astaxanthin stability and delivery. Despites the use of numerous delivery methods, improved delivery systems for concentrated astaxanthin formulations are still required. In addition, not all methods have undergone comprehensive in vivo studies that are required to assure the bioavailability of encapsulated astaxanthin.