A molecular dynamics simulation of sublimation of silicene and silicon films of different thikness is performed. It is shown that thiner films sublimate at lower temperatures. The sublimation temperature comes to a saturated value of $T=1725$ K at the films thiker than $16$ atomc layers. These results are consistent with the surface mediated collaps of the crystal structure. At the same time this mechanism is different from the crystal structure collapse of graphite and graphene.
An interactive learning strategy was a method or technique the teacher used when presenting learning materials where the teacher became the main actor in creating an educative interactive situation. The objective of this study was to create interactive media for theme learning that focuses on the development of soft skills and to evaluate its quality and usefulness. This study used Borg and Gall's Research and Development (R&D) approach, with four parsimonious stages of development: analysis, design, development, and implementation. This research used observation and interview sheets as data collection methods. The assessment of the interactive media's validity, quality, and efficacy based on soft skills was conducted through instrument and product validation methods involving media specialists and reviews from instructors and students. The study showed that students and teachers rated interactive learning media based on soft skills in the high-quality category. In addition, soft skill-based learning media was considered effective in fulfilling the criteria for assessing teacher activity in learning media, namely in the very effective category. It was concluded that the soft skill-based interactive learning media developed in this study were valid, high quality, and effective, so they were suitable for use in Penggalang 4 public elementary schools. We recommend that schools implement interactive media based on soft skills so that students become active and critical learners. Future research can adapt our model to other educational levels or domains, such as employee business development.
We present a multi-edge-length aperiodic tiling which exhibits 6--fold rotational symmetry. The edge lengths of the tiling are proportional to 1:$τ$, where $τ$ is the golden mean $\frac{1+\sqrt{5}}{2}$. We show how the tiling can be generated using simple substitution rules for its three constituent tiles, which we then use to demonstrate the bipartite nature of the tiling vertices. As such, we show that there is a relatively large sublattice imbalance of $1/[2τ^2]$. Similarly, we define allowed vertex configurations before analysing the tiling structure in 4-dimensional hyperspace.
An active bath, made of self-propelling units, is a nonequilibrium medium in which the Einstein relation $D=μk_B T$ between the mobility $μ$ and the diffusivity $D$ of a tracer particle cannot be expected to hold a priori. We consider here heavy tracers for which these coefficients can be related to correlation functions which we estimate. We show that, to a good approximation, an Einstein relation does hold in an active bath upon using a different temperature which is defined mechanically, through the pressure exerted on the tracer.
Mengembangkan wilayah untuk mengurangi kesenjangan dan menjamin pemerataan merupakan salah satu dari tujuh agenda Pembangunana RPJMN IV Tahun 2020-2024. Setiap wilayah tentunya memiliki potensi yang berbeda, baik potensi fisik maupun non-fisik. Perbedaan inilah yang menjadi dasar dalam pengelompokan desa sehingga pembangunan desa menjadi lebih terarah. Secara umum metode klaster dapat dibedakan menjadi dua kelompok yaitu hard clustering dan soft clustering. Pada hard clustering setiap objek dipetakan terhadap setiap kelompok. Metode yang populer pada kelompok hard clustering adalah Cluster K-Means. Sedangkan pada soft clustering objek tidak hanya dipetakan kedalam satu kelompok. Fuzzy K Means (FCM) merupakan salah satu metode dalam soft clustering, dimana Fuzzy K Means merupakan pengembangan dari Cluster K-Means. Cara kerja FCM adalah objek diberi probabilitas yang pada dasarnya menggambarkan kepemilikan objek ke dalam Cluster.
We perform a numerical study of a new microcanonical polymer model on the three dimensional cubic lattice, consisting of ideal chains whose range and number of nearest-neighbor contacts are fixed to given values. Our simulations suggest an interesting exact relation concerning the internal energy per monomer of the Interacting Self-Avoiding Walk at the $θ-$point.
We provide a detailed derivation of the mode-coupling equations for a colloidal liquid confined by two parallel smooth walls. We introduce irreducible memory kernels for the different relaxation channels thereby extending the projection operator technique to colloidal liquids in slit geometry. Investigating both the collective dynamics as well as the tagged-particle motion, we prove that the mode-coupling functional assumes the same form as in the Newtonian case corroborating the universality of the glass-transition singularity with respect to the microscopic dynamics.
Ventricular Arrhythmia during Electronic Gaming Three children had four episodes of syncope or presyncope while playing electronic war games. In all three, a potentially arrhythmogenic cardiac cond...
We present the compact group approach to analysis of the long-wavelength dielectric and optical characteristics of substances which can be modeled as macroscopically homogeneous and isotropic systems of hard dielectric particles embedded into a dielectric matrix. After the basics of the method are outlined, we discuss the results obtained with it for the effective permittivity of such systems and the single-scattering intensity of light scattered by them.
Patrick Delisle-Houde, Ryan E. R. Reid, Jessica A. Insogna
et al.
Abstract Delisle-Houde, P, Reid, RER, Insogna, JA, Prokop, NW, Buchan, TA, Fontaine, SL, and Andersen, RE. Comparing DXA and air-displacement-plethysmography to assess body composition of male collegiate hockey players. J Strength Cond Res 33(2): 474–478, 2019—Accurate assessment of body composition is an important consideration for athletes because it is a health/performance variable. However, little is known about the variability in values obtained across different assessment methods for specific athlete populations. The purpose of this study was to compare 2 common laboratory methods that assess body composition: air displacement plethysmography (BOD POD) and dual energy x-ray absorptiometry (DXA). Twenty-nine male collegiate hockey players, (Age = 24.07 ± 1.49, BMI = 26.5 ± 2.74) participated in this study. All participants underwent back-to-back BOD POD and DXA evaluations. Paired t-tests and Bland–Altman analyses were performed to compare differences in fat mass, fat percentage, and fat-free mass between methods. Average fat percentage reported by the DXA and BOD POD was 15.34 ± 3.53 and 11.66 ± 4.82 respectively, resulting in a bias score of 3.78 ± 2.33 kg (t(28) = 8.71, p ⩽ 0.001). Average fat mass reported by the DXA and BOD POD was 13.42 ± 3.59 and 10.15 ± 4.54 kg respectively, resulting in a bias score of 3.27 ± 1.92 kg (t(28) = 9.18, p ⩽ 0.001). Average fat-free mass reported by the DXA and BOD POD was 73.31 ± 5.30 and 76.25 ± 5.74 kg respectively, resulting in a bias score of −2.93 ± 2.06 kg (t(28) = −7.66, p ⩽ 0.001). Our findings can help make more insightful comparisons between studies that use different body composition methodologies among athletic populations.
Abstract Ruan, M, Zhang, Q, and Wu, X. Acute effects of static stretching of hamstring on performance and anterior cruciate ligament injury risk during stop-jump and cutting tasks in female athletes. J Strength Cond Res 31(5): 1241–1250, 2017—There is limited research investigating antagonist stretch. The purpose of this study was to evaluate the influence of static stretching of hamstrings (SSH) on performance and anterior cruciate ligament (ACL) injury risk during stop-jump and 180° cutting tasks. Twelve female college athletes (age 20.8 ± 0.7 years; height 1.61 ± 0.05 m; mass 54.25 ± 4.22 kg) participated in this study. Subjects performed stop-jump and 180° cutting tasks under 2 conditions: after warm-up with 4 × 30 seconds SSH or after warm-up without SSH. Three-dimensional kinematic and kinetic data as well as electromyography of biceps femoris, rectus femoris, vastus medialis, and gastrocnemius medialis were collected during testing. Static stretching of hamstrings significantly enhanced jump height by 5.1% (p = 0.009) but did not change the takeoff speed of cutting. No significant changes in peak knee adduction moment or peak anterior tibia shear force were observed with SSH regardless of the task. The peak lateral tibia shear force during cutting was significantly (p = 0.036) reduced with SSH. The co-contraction of hamstring and quadriceps during the preactivation (stop-jump: p = 0.04; cutting: p = 0.05) and downward phases (stop-jump: p = 0.04; cutting: p = 0.05) was significantly reduced after SSH regardless of the task. The results suggest that SSH enhanced the performance of stop-jump because of decreased co-contraction of hamstring and quadriceps but did not change the performance of cutting. In addition, SSH did not increase ACL injury risk during stop-jump and cutting tasks and even reduced medial-lateral knee loading during cutting.