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In 2021, according to the statistical research presented, 2 billion videos would be seen on YouTube every day, and more than a billion individuals will subscribe to channels and use the site on a regular basis. Because of its widespread usage and ease of accessibility, YouTube video technology has been shown in several studies to have advantages for classroom instruction and lifetime learning. The persistent reason for this research was to investigate the perspective of teacher-trainees' interest in using video in teaching Microteaching skills, by applying YouTube video technology as an educational instrument in the instructional process. The research survey design was applied with 300 teacher-trainees in all NCE and B. Ed. programmes as the respondents to the research from all various departments. The questionnaires were distributed to them after watching the video clips on YouTube. The collected data was analysed using simple frequencies used for the test of the research question and analysis of Person correlation coefficient to retain or discard the hypothesis. The result revealed that teacher trainees have an interest in the usage of YouTube video technology, and it can be used to attain the educational ends achieved through the usage of YouTube video technology in teaching micro-teaching skills. The exciting findings of the result show that teachers and trainees from all departments agree and are satisfied that YouTube technology is an educational resource for modern instruction. The research recommends that YouTube should be used as a digital alternative to traditional microteaching (face-to-face), and it will address students' congestion due to the lack of appropriate lab equipment and qualified technicians in traditional microteaching laboratories. [ABSTRACT FROM AUTHOR]

Micro-teaching, the contemporary innovation in teaching and learning, is a teacher training strategy that is presently being used all over the globe, and is an opportunity for teacher-trainees to improve their instructional skills. Microteaching encourages in-themoment classroom instruction, improving fundamental abilities and allowing new and experienced teachers to master numerous teaching skills. This research was conducted to investigate the impact of MCT on teachertrainees' academic performance. Applying Kcieje and Morgan's technique, the respondents of the research were 133 respondents from various departments, both males and females. The null hypotheses of the study were rejected, and the result revealed that MCT has a significant impact on prospective teachers. The most attractive finding of the results showed that MCT plays a vital role in producing professional teachers, and teachers would not qualify without knowledge of MCT skills. [ABSTRACT FROM AUTHOR]

A parallel mechanism was designed and developed to perform tasks with micro meter accuracy within millimeter-range workspace. The system employs two Stewart platforms while squiggle motors were used in one of the platforms to provide larger workspace, the second platform which uses piezoelectric actuators accurately positions the tool tip in the desired point. Error model for tool tip was developed for the first platform. Considering worst case scenario and using Particle Swarm Optimization algorithm, positioning error of the first platform was evaluated numerically throughout the respective workspace, upon which the design of the fine tuning piezo driven second stage was carried out. Positioning error and workspace of the whole system was evaluated using a single-deck platform with squiggle motors caused 40 micrometers positioning error while application of the fine-tuning piezo-driven Stewart platform reduced the total positioning error to 10 micrometers. [ABSTRACT FROM AUTHOR]

The coupled transport of charge and heat provide fundamental insights into the microscopic thermodynamics and kinetics of materials. We describe a sensitive ac differential resistance bridge that enables measurements of the temperature difference on two sides of a coin cell with a resolution of better than 10 μK. We use this temperature difference metrology to determine the ionic Peltier coefficients of symmetric Li-ion electrochemical cells as a function of Li salt concentration, solvent composition, electrode material, and temperature. The Peltier coefficients Π are negative, i.e. , heat flows in the direction opposite to the drift of Li ions in the applied electric field, large, -Π > 30 kJ mol -1 , and increase with increasing temperature at T > 300 K. The Peltier coefficient is approximately constant on time scales that span the characteristic time for mass diffusion across the thickness of the electrolyte, suggesting that heat of transport plays a minor role in comparison to the changes in partial molar entropy of Li at the interface between the electrode and electrolyte. Our work demonstrates a new platform for studying the non-equilibrium thermodynamics of electrochemical cells and provides a window into the transport properties of electrochemical materials through measurements of temperature differences and heat currents that complement traditional measurements of voltages and charge currents.

Interfaces have crucial, but still poorly understood, roles in the performance of secondary solid-state batteries. Here, using crystallographically oriented and highly faceted thick cathodes, we directly assess the impact of cathode crystallography and morphology on the long-term performance of solid-state batteries. The controlled interface crystallography, area and microstructure of these cathodes enables an understanding of interface instabilities unknown (hidden) in conventional thin-film and composite solid-state electrodes. A generic and direct correlation between cell performance and interface stability is revealed for a variety of both lithium- and sodium-based cathodes and solid electrolytes. Our findings highlight that minimizing interfacial area, rather than its expansion as is the case in conventional composite cathodes, is key to both understanding the nature of interface instabilities and improving cell performance. Our findings also point to the use of dense and thick cathodes as a way of increasing the energy density and stability of solid-state batteries., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

Thermal management in Li-ion batteries is critical for their safety, reliability, and performance. Understanding the thermal conductivity of the battery materials is crucial for controlling the temperature and temperature distribution in batteries. This work provides systemic quantitative measurements of the thermal conductivity of three important classes of solid electrolytes (SEs) over the temperature range 150 < T < 350 K. Studies include the oxides Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 and Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 , sulfides Li 2 S-P 2 S 5 , Li 6 PS 5 Cl, and Na 3 PS 4 , and halides Li 3 InCl 6 and Li 3 YCl 6 . Thermal conductivities of sulfide and halide SEs are in the range 0.45-0.70 W m -1  K -1 ; thermal conductivities of Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 and Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 are 1.4 and 2.2 W m -1  K -1 , respectively. For most of the SEs studied in this work, the thermal conductivity increases with increasing temperature, that is, the thermal conductivity has a glass-like temperature dependence. The measured room-temperature thermal conductivities agree well with the calculated minimum thermal conductivities indicating that the phonon mean-free-paths in these SEs are close to an atomic spacing. The low, glass-like thermal conductivity of the SEs investigated is attributed to the combination of their complex crystal structures and the atomic-scale disorder induced by the materials processing methods that are typically needed to produce high ionic conductivities., (© 2021 Wiley-VCH GmbH.)

We introduce an intermediate-temperature (350 °C) dry molten sodium hydroxide-mediated binder-free electrodeposition process to grow the previously electrochemically inaccessible air- and moisture-sensitive layered sodium transition metal oxides, Na x MO 2 (M = Co, Mn, Ni, Fe), in both thin and thick film form, compounds which are conventionally synthesized in powder form by solid-state reactions at temperatures ≥700 °C. As a key motivation for this work, several of these oxides are of interest as cathode materials for emerging sodium-ion-based electrochemical energy storage systems. Despite the low synthesis temperature and short reaction times, our electrodeposited oxides retain the key structural and electrochemical performance observed in high-temperature bulk synthesized materials. We demonstrate that tens of micrometers thick >75% dense Na x CoO 2 and Na x MnO 2 can be deposited in under 1 h. When used as cathodes for sodium-ion batteries, these materials exhibit near theoretical gravimetric capacities, chemical diffusion coefficients of Na + ions (∼10 -12 cm 2 ⋅s -1 ), and high reversible areal capacities in the range ∼0.25 to 0.76 mA⋅h⋅cm -2 , values significantly higher than those reported for binder-free sodium cathodes deposited by other techniques. The method described here resolves longstanding intrinsic challenges associated with traditional aqueous solution-based electrodeposition of ceramic oxides and opens a general solution chemistry approach for electrochemical processing of hitherto unexplored air- and moisture-sensitive high valent multinary structures with extended frameworks., Competing Interests: The authors declare no competing interest.

The interaction of a droplet with a solid surface is characterized by two parameters, the contact angle and the wetted area under the droplet. The Cassie-Baxter and the Wenzel modes make predictions on the interfacial area by comparing the contact angles on smooth surfaces (the intrinsic wettability) with those on rough surfaces (the apparent wettability). In these models, the actual wetted area is used as a fitting parameter. In this work, we highlight the significance of determining the actual wetted area under the droplet and the limitation of using only the contact angle to represent the wetting behavior of a surface. Our experimental studies were performed on hydrophilic carbon surfaces where a combination of optical measurements (contact angle and hysteresis) along with an electrochemical approach was employed. An electrochemical method was used to determine the true wetted area using a droplet of aqueous electrolyte on the surface. The interfacial area was then used to correlate wetting behavior to that of the model predictions. We examined the impact of electrolyte concentration and potential sweep rate in our evaluation of the wetted area. Our results show that, for a rough hydrophilic surface, the decrease in contact angles with increasing solid-liquid interfacial areas is not always valid, as generally predicted by the Wenzel and the Cassie-Baxter models., (Copyright © 2017 Elsevier Inc. All rights reserved.)

A key advancement target for oxygen reduction reaction catalysts is to simultaneously improve both the electrochemical activity and durability. To this end, the efficacy of a new highly conductive support that comprises of a 0.5 nm titanium oxynitride film coated by atomic layer deposition onto an array of carbon nanotubes has been investigated. Support effects for pure platinum and for a platinum (50 at %)/nickel alloy have been considered. Oxynitride induces a downshift in the d-band center for pure platinum and fundamentally changes the platinum particle size and spatial distribution. This results in major enhancements in activity and corrosion stability relative to an identically synthesized catalyst without the interlayer. Conversely, oxynitride has a minimal effect on the electronic structure and microstructure, and therefore, on the catalytic performance of platinum-nickel. Calculations based on density functional theory add insight with regard to compositional segregation that occurs at the alloy catalyst-support interface., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Here we provide the first report on several compositions of ternary Sn-Ge-Sb thin film alloys for application as sodium ion battery (aka NIB, NaB or SIB) anodes, employing Sn50Ge50, Sb50Ge50, and pure Sn, Ge, Sb as baselines. Sn33Ge33Sb33, Sn50Ge25Sb25, Sn60Ge20Sb20, and Sn50Ge50 all demonstrate promising electrochemical behavior, with Sn50Ge25Sb25 being the best overall. This alloy has an initial reversible specific capacity of 833 mAhg(-1) (at 85 mAg(-1)) and 662 mAhg(-1) after 50 charge-discharge cycles. Sn50Ge25Sb25 also shows excellent rate capability, displaying a stable capacity of 381 mAhg(-1) at a current density of 8500 mAg(-1) (∼10C). A survey of published literature indicates that 833 mAhg(-1) is among the highest reversible capacities reported for a Sn-based NIB anode, while 381 mAhg(-1) represents the optimum fast charge value. HRTEM shows that Sn50Ge25Sb25 is a composite of 10-15 nm Sn and Sn-alloyed Ge nanocrystallites that are densely dispersed within an amorphous matrix. Comparing the microstructures of alloys where the capacity significantly exceeds the rule of mixtures prediction to those where it does not leads us to hypothesize that this new phenomenon originates from the Ge(Sn) that is able to sodiate beyond the 1:1 Na:Ge ratio reported for the pure element. Combined TOF-SIMS, EELS TEM, and FIB analysis demonstrates substantial Na segregation within the film near the current collector interface that is present as early as the second discharge, followed by cycling-induced delamination from the current collector.

It is a challenge to meld the energy of secondary batteries with the power of supercapacitors. Herein, we created electrodes finely tuned for this purpose, consisting of a monolayer of MnO nanocrystallites mechanically anchored by pore-surface terminations of 3D arrays of graphene-like carbon nanosheets ("3D-MnO/CNS"). The biomass-derived carbon nanosheets should offer a synthesis cost advantage over comparably performing designer nanocarbons, such as graphene or carbon nanotubes. High Li storage capacity is achieved by bulk conversion and intercalation reactions, while high rates are maintained through stable ∼20 nm scale diffusion distances. For example, 1332 mAh g(-1) is reached at 0.1 A g(-1), 567 mAh g(-1) at 5 A g(-1), and 285 mAh g(-1) at 20 A g(-1) with negligible degradation at 500 cycles. We employed 3D-MnO/CNS (anode) and carbon nanosheets (cathode) to create a hybrid capacitor displaying among the most promising performances reported: based on the active materials, it delivers 184 Wh kg(-1) at 83 W kg(-1) and 90 Wh kg(-1) at 15 000 W kg(-1) with 76% capacity retention after 5000 cycles.

We demonstrate that peat moss, a wild plant that covers 3% of the earth's surface, serves as an ideal precursor to create sodium ion battery (NIB) anodes with some of the most attractive electrochemical properties ever reported for carbonaceous materials. By inheriting the unique cellular structure of peat moss leaves, the resultant materials are composed of three-dimensional macroporous interconnected networks of carbon nanosheets (as thin as 60 nm). The peat moss tissue is highly cross-linked, being rich in lignin and hemicellulose, suppressing the nucleation of equilibrium graphite even at 1100 °C. Rather, the carbons form highly ordered pseudographitic arrays with substantially larger intergraphene spacing (0.388 nm) than graphite (c/2 = 0.3354 nm). XRD analysis demonstrates that this allows for significant Na intercalation to occur even below 0.2 V vs Na/Na(+). By also incorporating a mild (300 °C) air activation step, we introduce hierarchical micro- and mesoporosity that tremendously improves the high rate performance through facile electrolyte access and further reduced Na ion diffusion distances. The optimized structures (carbonization at 1100 °C + activation) result in a stable cycling capacity of 298 mAh g(-1) (after 10 cycles, 50 mA g(-1)), with ∼150 mAh g(-1) of charge accumulating between 0.1 and 0.001 V with negligible voltage hysteresis in that region, nearly 100% cycling Coulombic efficiency, and superb cycling retention and high rate capacity (255 mAh g(-1) at the 210th cycle, stable capacity of 203 mAh g(-1) at 500 mA g(-1)).

Thermodynamic destabilization of MgH2 formation through interfacial interactions in free-standing Mg-AlTi multilayers of overall "bulk" (0.5 μm) dimensions with a hydrogen capacity of up to 5.5 wt% is demonstrated. The interfacial energies of Mg-AlTi and Mg-Ti (examined as a baseline) are calculated to be 0.81 and 0.44 J m(-2). The enhanced interfacial energy of AlTi opens the possibility of creating ultrathin alloy interlayers that provide further thermodynamic improvements in metal hydrides.

We have synthesized a new metastable metal hydride with promising hydrogen storage properties. Body centered cubic (bcc) magnesium niobium hydride (Mg(0.75)Nb(0.25))H(2) possesses 4.5 wt% hydrogen gravimetric density, with 4 wt% being reversible. Volumetric hydrogen absorption measurements yield an enthalpy of hydride formation of -53 kJ mol(-1) H(2), which indicates a significant thermodynamic destabilization relative to the baseline -77 kJ mol(-1) H(2) for rutile MgH(2). The hydrogenation cycling kinetics are remarkable. At room temperature and 1 bar hydrogen it takes 30 minutes to absorb a 1.5 μm thick film at sorption cycle 1, and 1 minute at cycle 5. Reversible desorption is achieved in about 60 minutes at 175 °C. Using ab initio calculations we have examined the thermodynamic stability of metallic alloys with hexagonal close packed (hcp) versus bcc crystal structure. Moreover we have analyzed the formation energies of the alloy hydrides that are bcc, rutile or fluorite.

Alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), is among the most destructive pests of alfalfa, Medicago sativa L., in the world. Survivorship and fecundity schedules of H. postica were investigated to characterize the population growth potential of the weevil at six constant temperatures: 11.5, 14.0, 19.0, 24.0, 29.0, and 31.5 degrees C. Preoviposition period, oviposition period and female longevity significantly decreased with rising temperature within the temperature range tested. At the respective temperatures adult female lived an average of 294.2, 230.2, 163.6, 141.0, 84.10, and 32.9 d, with average lifetime progeny production of 470, 814, 2209, 3619, 2656, and 338 eggs per female. The net reproductive rates (R0) were 86.9, 288.0, 869.7, 1,479.7, 989.8, and 107.8 females per female, respectively. Mean daily fecundity (Mx) was modeled as a function of time by using both Enkegaard and Analytis models. Survivorship data (l(x)) of adult females were summarized and compared using the shape and scale parameters of the Weibull frequency distribution model across the temperature range tested. Life table entropy values within the range 14.0-31.5 degrees C (H < 0.5) indicates Slobodkin's type I survivorship curve; however, the value of 0.806 at 11.5 degrees C (H > 0.5) corresponds to type III. As temperature increased, the r(m) exhibited an asymmetrical dome-shaped pattern, with a maximum value of 0.114 females per female per d at 29.0 degrees C. The r(m)-temperature relation of weevils was modeled and critical temperatures (T(Min), T(Opt), and T(Max)) for intrinsic rate of increase of the weevil were computed as 8.83, 30.61, and 32.14 degrees C and 5.72, 29.94, and 32.12 degrees C by using Analytis/Allahyari and Analytis/Briere-2 models, respectively.

Immature survival and development of alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), were examined at 15 constant temperatures ranging from 9 to 37 degrees C. At 9 and 37 degrees C, eggs did not develop. Embryos developed to adulthood between 11.5 and 36 degrees C, although survival was low at both ends of the temperature range. Distribution of development times for all stages of alfalfa weevil were skewed toward longer times mainly at moderate temperatures. Constant proportion of time spent in egg, larva, and pupa indicated rate isomorphy within the range 14-31.5 degrees C. No significant difference was shown between development time of males and females at any of the temperatures tested. Two linear and 23 nonlinear models were fitted to describe development rate of immature stages of H. postica as a function of temperature, as well as estimating the thermal constant and critical temperatures (i.e., T(min), T(opt), and T(max)). There was no statistical difference between the estimated parameters, using Ikemoto and ordinary linear methods. Of the nonlinear models fitted, the Logan-6/Lactin-2, Analytis-3/Briere-2, and Analytis-3/Briere-2 models were found to be the best for modeling development rate of egg, larva, and entire immature stages of H. postica, respectively. Our findings will be incorporated in more efficient phenological models of this pest and its population dynamics.