Orientation State Research Articles

Photo-excitation of long-lived transient intermediates in ultracold reactions

Controlling the pathways and outcomes of reactions is a broadly pursued goal in chemistry. In gas phase reactions, this is typically achieved by manipulating the properties of the reactants, including their translational energy, orientation, and internal quantum state. In contrast, here we influence the pathway of a reaction via its intermediate complex, which is generally too short-lived to be affected by external processes. In particular, the ultracold preparation of potassium-rubidium (KRb) reactants leads to a long-lived intermediate complex (K$_2$Rb$_2^*$), which allows us to steer the reaction away from its nominal ground-state pathway onto a newly identified excited-state pathway using a laser source at 1064 nm, a wavelength commonly used to confine ultracold molecules. Furthermore, by monitoring the change in the complex population after the sudden removal of the excitation light, we directly measure the lifetime of the complex to be $360 \pm 30$ ns, in agreement with our calculations based on the Rice-Ramsperger-Kassel-Marcus (RRKM) statistical theory. Our results shed light on the origin of the two-body loss widely observed in ultracold molecule experiments. Additionally, the long complex lifetime, coupled with the observed photo-excitation pathway, opens up the possibility to spectroscopically probe the structure of the complex with high resolution, thus elucidating the reaction dynamics.

Fiber Orientation Distribution Predictions for an Injection Molded Venturi-Shaped Part Validated Against Experimental Micro-Computed Tomography Characterization

Fil: Quintana, Maria Camila. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnologia de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingenieria. Instituto de Investigaciones en Ciencia y Tecnologia de Materiales; Argentina

Metacognitive Beliefs, Positive States of Mind, and Emotional Approach Coping as the Predictors of Medical Compliance in Patients with Cancer

Background: Medical compliance plays an essential role in the control of cancer and psychological factors such as metacognitive beliefs, positive psychology, and coping styles which are among the predictors of medical compliance. Objectives: The aim of this study was to determine how much metacognitive beliefs, positive states of mind, and emotional approach coping can predict medical compliance in patients with breast cancer. Methods: This was a descriptive correlational study. By available sampling method, 154 women with breast cancer who were medically treated and had inclusion criteria, responded to the Morisky Medication Adherence scale (MMAS), Metacognitive Beliefs questionnaire (MCBQ), Positive states of mind (PSOM) scale, and emotional approach coping (EAC) scale. Stepwise multiple regression analysis by SPSS statistics version 24 was applied for data analysis. Results: There was a significant correlation between positive states of mind and metacognitive beliefs and between emotional approach coping with medical compliance (P < 0.05). Positive states of mind and metacognitive beliefs were the best predictors of medical compliance (P < 0.001), while the emotional approach coping could not predict medical compliance. Results also showed that positive states of mind (β = 0. 51) have the greatest predictive power to medical compliance, and the variable of emotional approach coping is not effective in predicting. Conclusions: Research findings suggest that positive states of mind and orientation toward metacognitive beliefs can control anxiety among patients and predict medical compliance in patients with breast cancer but research about emotional approach coping needs to more investigation.

Temporal social network reconstruction using wireless proximity sensors: model selection and consequences

The emerging technologies of wearable wireless devices open entirely new ways to record various aspects of human social interactions in a broad range of settings. Such technologies allow to log the temporal dynamics of face-to-face interactions by detecting the physical proximity of participants. However, despite the wide usage of this technology and the collected datasets, precise reconstruction methods transforming the raw recorded communication data packets to social interactions are still missing.In this study we analyse a proximity dataset collected during a longitudinal social experiment aiming to understand the co-evolution of children’s language development and social network. Physical proximity and verbal communication of hundreds of pre-school children and their teachers are recorded over three years using autonomous wearable low power wireless devices. The dataset is accompanied with three annotated ground truth datasets, which record the time, distance, relative orientation, and interaction state of interacting children for validation purposes.We use this dataset to explore several pipelines of dynamical event reconstruction including earlier applied naïve approaches, methods based on Hidden Markov Model, or on Long Short-Term Memory models, some of them combined with supervised pre-classification of interaction packets. We find that while naïve models propose the worst reconstruction, Long Short-Term Memory models provide the most precise way to reconstruct real interactions up to {sim} 90% accuracy. Finally, we simulate information spreading on the reconstructed networks obtained by the different methods. Results indicate that small improvement of network reconstruction accuracy may lead to significantly different spreading dynamics, while sometimes large differences in accuracy have no obvious effects on the dynamics. This not only demonstrates the importance of precise network reconstruction but also the careful choice of the reconstruction method in relation with the data collected. Missing this initial step in any study may seriously mislead conclusions made about the emerging properties of the observed network or any dynamical process simulated on it.

Setting benchmarks for modelling gas\u2013surface interactions using coherent control of rotational orientation states

The coherent evolution of a molecular quantum state during a molecule-surface collision is a detailed descriptor of the interaction potential which was so far inaccessible to measurements. Here we use a magnetically controlled molecular beam technique to study the collision of rotationally oriented ground state hydrogen molecules with a lithium fluoride surface. The coherent control nature of the technique allows us to measure the changes in the complex amplitudes of the rotational projection quantum states, and express them using a scattering matrix formalism. The quantum state-to-state transition probabilities we extract reveal a strong dependency of the molecule-surface interaction on the rotational orientation of the molecules, and a remarkably high probability of the collision flipping the rotational orientation. The scattering matrix we obtain from the experimental data delivers an ultra-sensitive benchmark for theory to reproduce, guiding the development of accurate theoretical models for the interaction of H2 with a solid surface.

ОСОБЛИВОСТІ ПЕРЕЖИВАННЯ ПОЧУТТЯ ЩАСТЯ МОЛОДДЮ І ДОРОСЛИМИ В УМОВАХ ЗАХОДІВ ПРОТИДІЇ COVID-19

У статті розглянуто актуальність проблеми особливостей переживання почуття щастя в умовах самоізоляції, соціального дистанціювання, обмеження активності й карантинних заходів, пов’язаних із COVID-19. Розкрито особливості переживання почуттів різної модальності, зокрема, почуття щастя. Проаналізовано чинники та детермінанти впливу на емоційну сферу особистості. Визначено, що соціальні зв’язки є першочерговими для переживання почуття щастя. Такі соціальні контакти мають характеризуватись глибиною, якістю та частотою. Описано особливості почуття щастя залежно від його спрямованості: на стан «тут-і-тепер» і на спрямованість у майбутнє, а також наголошено на афективному, когнітивному та евдемоністичному компонентах щастя. Розроблено широку авторську форму-опитувальник, яка містить пакет різноспрямованих методів: опитувальник, елементи проективних методів (незакінчені речення), асоціативний метод, самоаналіз і самоспостереження, психодіагностична рефлексія. За допомогою зазначених вище методів емпірично встановлено, що почуття щастя молоді й дорослих характеризується ієрархією станів від більш до менш значущого: стан фізичного, психологічного, духовного благополуччя близьких, комфорту, безпеки і спокою, стан щастя як трансцендентне переживання, стан почуттєвої орієнтації на майбутнє. Існують відмінності в об’єктивному сприйнятті щастя та його суб’єктивному переживанні: здоров’я рідних і близьких поєднується з прагненням знаходитись у колі родини та найближчого оточення. Почуття щастя у респондентів загалом спродуковане здоров’ям, присутністю близьких, самоздійсненням, самоствердженням і досягненням цілей. Встановлено статистично значущий зв’язок між усвідомленням почуття власного щастя і наявністю стійких стосунків (родинних, сімейних, подружніх, романтичних, дружніх) (0,323); між усвідомленням щастя та частотою й рівнем соціальної активності, у які були включені досліджувані в докарантинний період (0,221). Визначено, що щастя є чинником подолання негативних переживань в умовах сучасних кризових трансформаційних суспільних процесів.

Phase separation behavior of binary mixture of photopolymerizable diacetylene and unsaturated phospholipids in liposomes

Photopolymerizable lipids, such as diacetylene lipids have attracted much attention for their ability to stabilize lipid bilayer structure. In this study, we investigated the phase separation behavior of a lipid bilayer containing 1,2‑bis(10,12‑tricosadiynoyl)‑sn‑glycero‑3‑phosphocholine (DiynePC). The phase separation behavior of liposomes composed of DiynePC and the non-polymerizable lipid, 1,2‑dioleoyl‑sn‑glycero‑3‑phosphocholine (DOPC) was evaluated using a fluorescence resonance energy transfer (FRET) assay during both the cooling and heating processes. The polymerization behavior and orientation of DiynePC was evaluated by measuring the absorbance contributed by polymerized diacetylene groups. The main phase transition temperature (Tm) and orientation temperature (To) of DiynePC were determined from differential scanning calorimetry (DSC) and absorbance measurements. As a comparison, liposomes composed of 1,2‑dipalmitoyl‑sn‑glycero‑3‑phosphocholine (DPPC), which has a similar Tm as DiynePC, but a dissimilar To, were evaluated as well as, DiynePC-containing liposomes. The DPPC/DOPC liposomes showed phase separation at the Tm of DPPC during both the cooling and heating processes. On the other hand, the phase separation of the DiynePC/DOPC liposomes occurred near To of DiynePC but slightly increased during the cooling process. Interestingly, once the liposomes were cooled to a much lower temperature than the To, the phase separation was promoted by the subsequent heating process, and reached a maximum state of the phase separation near the To. These results indicated that the phase separation of DiynePC is affected by both the orientation state and thermal molecular motion.

How Anionic Lipids Affect Spatiotemporal Properties of KRAS4B on Model Membranes.

RAS proteins are small membrane-anchored GTPases that regulate key cellular signaling networks. It has been recently shown that different anionic lipid types can affect the spatiotemporal properties of RAS through dimerization/clustering and signaling fidelity. To understand the effects of anionic lipids on key spatiotemporal properties of RAS, we dissected 1 ms of data from all-atom molecular dynamics simulations for KRAS4B on two model anionic lipid membranes that have 30% of POPS mixed with neutral POPC and 8% of PIP2 mixed with POPC. We unveiled the orientation space of KRAS4B, whose kinetics were slower and more distinguishable on the membrane containing PIP2 than the membrane containing POPS. Particularly, the PIP2-mixed membrane can differentiate a third kinetic orientation state from the other two known orientation states. We observed that each orientation state may yield different binding modes with an RAF kinase, which is required for activating the MAPK/ERK signaling pathway. However, an overall occluded probability, for which RAF kinases cannot bind KRAS4B, remains unchanged on the two different membranes. We identified rare fast diffusion modes of KRAS4B that appear coupled with orientations exposed to cytosolic RAF. Particularly, on the membrane having PIP2, we found nonlinear correlations between the orientation states and the conformations of the cationic farnesylated hypervariable region, which acts as an anchor in the membrane. Using diffusion coefficients estimated from the all-atom simulations, we quantified the effect of PIP2 and POPS on the KRAS4B dimerization via Green's function reaction dynamics simulations, in which the averaged dimerization rate is 12.5% slower on PIP2-mixed membranes.

On the use of orientation tensors to represent prepreg platelet orientation state and variability

Prepreg platelet molding compounds (PPMCs) have mesoscale (platelet scale) features that are not found in injection molding materials. Beyond the fiber orientation state, the platelet normal orientation state and the expected orientation state variabilities are desirable outputs from flow simulations of PPMC systems. However, theoretical understanding and efficient numerical molding simulation capabilities have primarily been developed for injection molding. Using exact solutions of Jeffery’s equation, two methods are developed: approximation of the second-order normal orientation tensor as a function of the second-order fiber orientation tensor and estimation of the variability in predicted orientation tensors due to scale similarity of the platelets and typical molded geometry thicknesses. These methods are validated using orientation state data obtained from computed tomography for five replicates of a PPMC bracket structure. Finally, the methods are applied as postprocessing of a fiber orientation simulation results, showing good comparison with the experimental data. The developed methods allow existing simulation capabilities to be applied to PPMCs as a reduced order model to enable efficient design iterations for PPMC manufacturing.

Barite Growth Rates as a Function of Crystallographic Orientation, Temperature, And Solution Saturation State

Barite growth kinetics was investigated as a function of crystallographic orientation for temperatures between 10 and 70 °C, and initial saturation indices (SI) of 1.1 and 2.1. The growth rates wer...

Freedericksz transition in a dual-frequency nematic liquid crystal

The Freedericksz transition was investigated in a dual-frequency liquid crystal consisting of a mixture of 2-chloro-4-(4-pentylbenzoyloxy)benzoate and N-(4-methoxybenzylidene)-4-butylaniline, in which dielectric anisotropy strongly depends on the frequency of the applied ac electric field. Because the threshold voltage for the transition from an undistorted state of orientation to a distorted one is a function of the dielectric anisotropy and of the Frank elastic constants, the threshold voltage was expected to depend on the frequency. The threshold voltage increased steeply as the frequency approached the crossover frequency at which the dielectric anisotropy vanished and the threshold voltage eventually diverged. Furthermore, we examined the Freedericksz transition under ac voltages of two different frequencies.

Macroscopic fiber orientation model evaluation for concentrated short fiber reinforced polymers in comparison to experimental data

AbstractAdvanced macroscopic fiber orientation models depend on a variety of phenomenological parameters. The aim of this work is to identify a fiber orientation model for concentrated short fiber reinforced polymers, which depends on a minimum number of parameters. A sliding plate experiment with repeatable initial conditions and a couette experiment, to cover high strains, are used to define an experimental validation curve. The major fiber orientation models (Folgar and Tucker, nematic, reduced strain closure [RSC], anisotropic rotary diffusion, ARD‐RSC) are fitted to the validation curve. Since a slow evolution can be observed, the RSC model is necessary to fit the measured fiber orientation evolution. The dependency of the RSC model on the initial fiber orientation state and the influence of closure approximations are evaluated. Two validation cases show that the obtained parameters give good results in shear dominant parts, but are not able to predict fiber orientation in other flow regimes accurately.

Effect of nanoparticles orientation on morphology of polymeric nanocomposite foams: preparation of foamed nanocomposite fibers by supercritical carbon dioxide

ABSTRACT Polymeric foams have received increasing attention in both academic and industrial communities. Using of nanoparticles as heterogeneous nucleation agent has been verified as one of the most valid means to enhance cell nucleation and improve cell morphology. However, few researches have been conducted to investigate the effect of the nanoparticles’ spatial orientation on their nucleation efficiency. In this work, to study the influence of the orientation of nanoparticles on their performance in improving morphology of polymeric foam, thermoplastic polyurethane (TPU) composite fibers with different nanoparticles (carbon nanotubes, graphene and SiO2) were prepared by using different traction speeds. The different traction speeds lead to different orientation state of the nanoparticles which then resulted different nucleation effect. It was found that carbon nanotubes (CNTs) were easily oriented and aligned along the fiber length direction under the high traction speed, while graphene and SiO2 nanoparticles did not show orientation under the traction speed in this study. As a result, the foam of TPU/CNTs composite fibers from high traction speed exhibited a much smaller cell size and higher cell density compared to the foams of the fibers from low traction speeds, while TPU/graphene, and TPU/SiO2 composite fibers with different traction speeds showed almost similar cell size and size density after foaming, indicating that the orientated nanoparticles possessed higher heterogeneous nucleation efficiency. To our best knowledge, this work, for the first time, demonstrated the high nucleation effect of the aligned nanoparticles, which hopefully open a new path for improving the cell morphology of polymeric foam materials.

Charge transport by global protonic conductivity and relaxational dynamics over hydrogen bonds in Fe2+Fe3+3.2(Mn2+,Zn)0.8(PO4)3(OH)4.2(HOH)0.8

This study deals with the charge transport by protons over hydrogen bonds (HBs) in a rockbridgeite-type compound, Fe2+Fe3+3.2(Mn2+,Zn)0.8(PO4)3(OH)4.2(HOH)0.8. Its dielectric response in a wide frequency range of 1 Hz – 3 GHz from 30 K to 500 K can be traced back to structural properties of this phosphatic oxyhydroxide, revealed by Rietveld refinements using neutron powder diffraction data. The probable charge transport paths for protons are proposed, based on the honeycomb-like distribution of their neutron scattering length densities reconstructed by the Maximum-Entropy Method. Two distinctly decoupled proton dynamic processes occur in this system: at high temperatures, global protonic transport is thermally activated over an energy barrier (EB) of 0.49 eV, showing a dc conductivity (σdc) value of about 10-4 Ω-1 cm-1 at 500 K. The temperature-dependency of σdc becomes weaker at decreased temperatures, indicating the possible onset of proton tunneling-dominated charge transport. At low temperatures, relaxational proton hopping within double-well potentials in HBs is thermally activated with EB = 0.62 eV. An extremely fast relaxation time of ~50 ps at 250 K continuously slows down to ~1 ms at 150 K, pointing to the approach of an orientational proton-glass state at about 125 K. Isosurfaces of bond valence energy landscape maps of H+ at 0.49 eV clearly evidence the honeycomb-shaped route for the protonic conductivity at 393 K.

Computational homogenization of sheet molding compound composites based on high fidelity representative volume elements

Sheet molding compound (SMC) composites combine high lightweight potential with excellent formability and are frequently used in industrial applications. To reduce safety factors in dimensioning SMC parts, the influence of processing parameters and stochastic variation of microstructural and physical properties needs to be quantified accurately.Taking into account the inherent three-scale structure of SMC, we improve the microstructure generator of Chen et al. [Compos. Struct. 188, pp. 25–38, 2018] in various respects. Firstly, we consistently rely upon state-of-the-art closure approximations for the fourth order fiber orientation tensor. More precisely, we show that for a planar fiber orientation state, there is an explicit formula for the fast exact closure approximation of Montgomery-Smith et al. [J. Fluid Mech. 680, pp. 321–335, 2011]. Secondly, we exploit the use of quasi-random numbers in sampling the fiber orientation distribution, leading to dramatic improvements in accuracy compared to pseudo-random Monte Carlo sampling. Last but not least, we rely upon fast Fourier transform based methods for rapid computational homogenization.With these methodological improvements at hand, we thoroughly investigate the influence of the mechanical and microstructural parameters on the effective elastic properties of SMC composites, and compare the results to direct numerical simulations on large scale digital volume images and mean-field estimates.

Tailoring the magnetic field induced by the first higher order mode of an optical fiber.

In this paper, according to the inverse Faraday effect (IFE), the amplitude, phase, polarization and field distribution of the first higher order mode of an optical fiber are tailored carefully, and a magnetic field with arbitrary orientation is generated in the focal region. Compared with traditional strategies to generate a magnetic field with arbitrary orientation, where the configurations are complicated and the components employed for the system are costly, the first higher order mode of a fiber, which has two lobes with opposite instantaneous electric fields, draws more attention for generating a magnetic field with arbitrary orientation. We believe that such an arbitrary orientation state of magnetic field can be applied in the field of confocal and magnetic resonance microscopy and spin dynamics, especially for the use of optical magnetic recording, where laser pulses are used to trigger the magnetization switching.

The theoretical model of a democratic state of social orientation

The theoretical model of a democratic state of social orientation

PE-MIU: A Training-Free Privacy-Enhancing Face Recognition Approach Based on Minimum Information Units

Research on soft-biometrics showed that privacy-sensitive information can be deduced from biometric data. Utilizing biometric templates only, information about a persons gender, age, ethnicity, sexual orientation, and health state can be deduced. For many applications, these templates are expected to be used for recognition purposes only. Thus, extracting this information raises major privacy issues. Previous work proposed two kinds of learning-based solutions for this problem. The first ones provide strong privacy-enhancements, but limited to pre-defined attributes. The second ones achieve more comprehensive but weaker privacy-improvements. In this work, we propose a Privacy-Enhancing face recognition approach based on Minimum Information Units (PE-MIU). PE-MIU, as we demonstrate in this work, is a privacy-enhancement approach for face recognition templates that achieves strong privacy-improvements and is not limited to pre-defined attributes. We exploit the structural differences between face recognition and facial attribute estimation by creating templates in a mixed representation of minimal information units. These representations contain pattern of privacy-sensitive attributes in a highly randomized form. Therefore, the estimation of these attributes becomes hard for function creep attacks. During verification, these units of a probe template are assigned to the units of a reference template by solving an optimal best-matching problem. This allows our approach to maintain a high recognition ability. The experiments are conducted on three publicly available datasets and with five state-of-the-art approaches. Moreover, we conduct the experiments simulating an attacker that knows and adapts to the systems privacy mechanism. The experiments demonstrate that PE-MIU is able to suppress privacy-sensitive information to a significantly higher degree than previous work in all investigated scenarios. At the same time, our solution is able to achieve a verification performance close to that of the unmodified recognition system. Unlike previous works, our approach offers a strong and comprehensive privacy-enhancement without the need of training.

Integrative analysis for prediction of process-induced, orientation-dependent tensile properties in a stochastic prepreg platelet molded composite

Prepreg platelet molded composite (PPMC) is derived from compression molded pieces of chopped unidirectional prepreg tape. The properties of a stochastic PPMC arise from the meso-structure that develops during processing. This paper describes an integrated methodology for analysis of stochastic PPMC to develop process-structure-property relationships. Flow-induced fiber orientation distributions were predicted using an anisotropic viscous constitutive model implemented in a nonlinear, explicit finite element (FE) solver. The predicted orientation state was validated by CT-based orientation measurements and optical microscopy. A computational framework for simulation of tensile property distributions of a stochastic PPMC by progressive failure analysis is presented. The probabilistic simulation results were statistically validated against experimental data. A FE analysis was developed with an explicitly modeled platelet meso-structure wherein the platelets are treated as a homogeneous orthotropic medium using continuum damage mechanics to model the intraplatelet failure and a cohesive zone model for interlaminar disbonding. Panels were molded using partial charge coverage to induce flow alignment of the fibers. Tensile coupons were excised from the molded panels both along (parallel) and transverse (perpendicular) to the preferential fiber direction to compare the composite effective properties with those reported in the literature for planar random orientation states. The composite tensile properties were found to be strongly dependent on the global orientation state.

Peran Pernyataan Orientasi Tujuan Kinerja dan Pernyataan Orientasi Tujuan Pembelajaran terhadap Kemampuan Mahasiswa

Objective orientation is a mental framework as individuals give an impression and respond to situations or events that they face. Typically there are two kinds of goal orientation, namely orientation of performance goals (performance orientation) and orientation of learning goals (learning goal orientation). The phenomenon that there are still students who are extension or extension of time in doing the Final Project are all caused by the ability possessed by the individual. There are three factors that underlie the ability; self-efficacy, goals and performance. The researcher followed up the existence problems in the 2015 Accounting Study Program with four samples of Higher Education in Jember Regency, there were 82 respondents to answer the questionnaire given. Therefore an analytical tool is needed to determine the abilities possessed by students of the Accounting Study Program in Jember Regency. In this study researchers will test performance goal orientation statements (state performance goal orientation) and statement of learning goal orientation (state learning goal orientation) on self-efficacy (self-efficacy), goals (goals) and performance (performance) that each individual has.
 Keywords: Goal Orientation, State Goal Orientation Learning, State Performance Goal Orientation, Self-Efficacy, Goals and Performance.