Spin-orbit induced mixed-spin ground state in RRNiO3_3 perovskites probed by XAS: new insight into the metal to insulator transition

We report on a Ni L$_{2,3}$ edges x-ray absorption spectroscopy (XAS) study in $R$NiO$_3$ perovskites. These compounds exhibit a metal to insulator ($MI$) transition as temperature decreases. The L$_{3}$ edge presents a clear splitting in the insulating state, associated to a less hybridized ground state. Using charge transfer multiplet calculations, we establish the importance of the crystal field and 3d spin-orbit coupling to create a mixed-spin ground state. We explain the $MI$ transition in $R$NiO$_3$ perovskites in terms of modifications in the Ni$^{3+}$ crystal field splitting that induces a spin transition from an essentially low-spin (LS) to a mixed-spin state.Comment: 4 pages, 4 figures, accepted as PRB - Rapid Comm. Dez. 200

Portability vs. Precedent: IMUs vs. 3D Motion Capture for Collecting Kinematic Data in Dancers

The emergence of portable kinematic data collection systems (Inertial Measurement Units - IMUs) have become a potential alternative to 3D video motion capture systems for real-world application. However, there remains little research on the application of IMU technology for the evaluation of dancers’ biomechanical movement. PURPOSE: To assess the validity of the Noraxon IMU system compared with the Cortex 3D video motion capture system for kinematic data collection during a sauté. METHODS: 10 healthy, advanced female dancers were equipped with both a Noraxon IMU (200Hz) system and reflective markers used with a 12-camera Motion Analysis system (Cortex, 250 Hz) for simultaneous data collection. Participants completed an independent After a 10-minute warmup, each participant performed one trial of 10 stationary sautés while barefoot, with feet in second position and arms in fifth position in time with music at 95 bpm. The middle 5 jumps of each participant’s trial were processed and analyzed with Visual3D and MATLAB for the Cortex data, and through Noraxon’s reporting system for the Noraxon data. All results were compared through SPSS with repeated-measures ANOVAs. RESULTS: A main effect of measurement system was found for peak joint angles in the sagittal ((6,4)=0.009, p \u3c 0.001), frontal ((9,1)=0.12, p \u3c 0.001), and transverse ((9,1)=0.009, p \u3c 0.001) planes. Pairwise comparisons revealed significant differences in peak hip flexion, hip extension, knee flexion, knee extension, ankle plantar flexion, ankle dorsiflexion, hip adduction, knee adduction, ankle inversion, hip internal rotation, hip external rotation, knee internal rotation, knee external rotation, and ankle internal rotation. No significant main effect was found between measurement systems for sagittal, frontal, and transverse plane joint excursions ((9,1)=0.12, p=0.253). CONCLUSION: Significant differences in most peak joint angles indicate that Noraxon IMUs do not have strong validity for capturing absolute joint angles compared to 3D video motion capture. However, joint excursion measurements were similar, indicating that Noraxon IMUs may be valid for measuring the total amount of motion during a particular movement. Additional analysis is warranted for further understanding of this technology

Gender differences in V˙O2 and HR kinetics at the onset of moderate and heavy exercise intensity in adolescents

The majority of the studies on (V)over dotO(2) kinetics in pediatric populations investigated gender differences in prepubertal children during submaximal intensity exercise, but studies are lacking in adolescents. The purpose of this study was to test the hypothesis that gender differences exist in the (V)over dotO(2) and heart rate (HR) kinetic responses to moderate (M) and heavy (H) intensity exercise in adolescents. Twenty-one healthy African-American adolescents (9 males, 15.8 +/- 1.1 year; 12 females, 15.7 +/- 1 year) performed constant work load exercise on a cycle ergometer at M and H. The (V)over dotO(2) kinetics of the male group was previously analyzed (Lai et al., Appl. Physiol. Nutr. Metab. 33:107-117, 2008b). For both genders, (V)over dotO(2) and HR kinetics were described with a single exponential at M and a double exponential at H. The fundamental time constant (tau(1)) of (V)over dotO(2) was significantly higher in female than male at M (45 +/- 7 vs. 36 +/- 11 sec, P < 0.01) and H (41 +/- 8 vs. 29 +/- 9 sec, P < 0.01), respectively. The functional gain (G(1)) was not statistically different between gender at M and statistically higher in females than males at H: 9.7 +/- 1.2 versus 10.9 +/- 1.3 mL min(-1) W-1, respectively. The amplitude of the slow component was not significantly different between genders. The HR kinetics were significantly (tau(1), P < 0.01) slower in females than males at M (61 +/- 16 sec vs. 45 +/- 20 sec, P < 0.01) and H (42 +/- 10 sec vs. 30 +/- 8 sec, P = 0.03). The G(1) of HR was higher in females than males at M: 0.53 +/- 0.11 versus 0.98 +/- 0.2 bpm W-1 and H: 0.40 +/- 0.11 versus 0.73 +/- 0.23 bpm W-1, respectively. Gender differences in the (V)over dotO(2) and HR kinetics suggest that oxygen delivery and utilization kinetics of female adolescents differ from those in male adolescents

Performance of soil-matrix composite reinforced with recycled shredded fibers from waste tires

Abstract Some experimental results concerning the performance of fiber-reinforced soil composites made of soil and shredded fibers from waste tires are presented. The composite mixtures were prepared with fiber addition of 0, 15, 30, and 45 wt%. After molding, the specimens were oven-dried and tested for unconfined compressive strength and water immersion durability. The results showed an improvement in durability with the addition of fiber. The results also indicated good compressive strength performance for the composites with a fiber content of 15 and 30 wt%. The 30 wt% fiber addiction was the best choice because of the environmental sustainability appeal to solid waste reduction

Risk-cost optimization of buried pipelines using subset simulation

On the basis of time-dependent reliability analysis, a computational framework called subset simulation (SS) has been applied for risk-cost optimization of flexible underground pipeline networks. SS can provide better resolution for rare failure events that are commonly encountered in pipeline engineering applications. Attention in this work is devoted to scrutinize the robustness of SS in risk-cost optimization of pipelines. SS is first employed to estimate the reliability of flexible underground pipes subjected to externally applied loading and material corrosion. Then SS is extended to determine the intervention year for maintenance and to identify the most appropriate renewal solution and renewal priority by minimizing the risk of failure and whole life-cycle cost. The efficiency of SS compared to genetic algorithm has been demonstrated by numerical studies with a view to prevent unexpected failure of flexible pipes at minimal cost by prioritizing maintenance based on failure severity and system reliability. This paper shows that SS is a more robust method in the decision-making process of reliability-based management for underground pipeline networks

Development of a mobile ten frames app for Philippine K-12 schools

This paper reports on the Quick Images app, whose design framework is informed by research on ten-structured thinking and gamification principles. Inclusivity was also a major consideration, especially in the context of a developing country. Thus, the app was made freely available and required only moderate system requirements. Pilot studies revealed that the app has the potential to promote children’s ability to see two-digit numbers in relation to tens and ones, which is a major goal of elementary school mathematics. Collaborations with the Philippine Department of Education to ensure the app’s sustained use are also discussed

Designing Mobile Apps to Promote Numeracy and Statistical Reasoning

Developing countries typically do not perform well in international benchmarks of mathematics achievement. This may be partially explained by students’ immersion in classrooms characterized by superficial strategies or rote-learning methods. This paper reports on the design of mobile applications (apps) developed by the authors as part of an ongoing project funded by a national government agency and intended to promote structural thinking and statistical reasoning. It describes the general features of the apps, as well as the pedagogical principles upon which the apps’ designs were anchored on. These principles are grounded on research and established practices on number sense and statistical learning. Collaborations with the Philippine Department of Education for widespread implementation and sustainability are also discussed

i-WARM: Development of a Board Examination Reviewer Web Application for Filipino Pre-Service Physical Educators Utilizing the Unified Spaced Repetition and Hypercorrection Techniques

[EN] One of the major parameters by which college graduates' productivity is gauged is their board examination performance. Relevantly, the development and utilization of sophisticated tools and technology to facilitate reviews are encouraged and worthy of such exploration. The study aimed to develop an integrated web application reviewer for MAPEH (music, arts, physical education, and health) (i-WARM) with the use of unified spaced repetition and hypercorrection techniques. This descriptive research and development (R & D) design was used and employed a nine-step process in which functions were built for effective learning and retention of concepts. The evaluation was conducted by 106 graduating Bachelor of Physical Education students from a teacher education institution in Central Luzon, Philippines. Results revealed that the i-WARM is easy to use and easy to learn as it was viewed as clear and understandable, accessible, and has a flexible feature and interface. Pre-service physical educators perceived that the services provided by the web application are useful for their review as it was rated functional and informative. Frequent problems such as crashes and downtimes were not observed by the user during their exposure to the web application. The i-WARM could be explored as a potential aid in assisting learners to acquire concepts easily through an interactive interface. This may likewise assist teachers and students in establishing retention of significant concepts for future licensure examinations.Almario, JIF.; Quiambao, AS.; Sangalang, AM.; Manlutac, AM.; Tolentino, JCG.; Miranda, JPP. (2024). i-WARM: Development of a Board Examination Reviewer Web Application for Filipino Pre-Service Physical Educators Utilizing the Unified Spaced Repetition and Hypercorrection Techniques. Multidisciplinary Journal for Education, Social and Technological Sciences. 11(1):41-71. https://doi.org/10.4995/muse.2024.19347417111

Estrutura do dossel de capim-mombaça sob pastejo intermitente.

Comissão organizadora: Grácia Maria Soares Rosinha, Alexandra Rocha de Oliveir, Rodrigo Carvalho Alva