Ab-Initio Computational Study on Fe2NiP schreibersite: Bulk and Surface Characterization

<p>Phosphorous is ubiquitous in planet Earth and plays a fundamental role in all living systems. Finding a reasonable prebiotic source of phosphorous is not trivial, as common sources where it is present nowadays are in the form of phosphate minerals, which are rather insoluble and non-reactive materials, and, accordingly, unavailable for being readily incorporated in living organisms. A possible source of phosphorous is from the exogenous meteoritic bombardment and, in particular, in iron/nickel phosphites. These materials, by simple interaction with water, produce oxygenated phosphorous compounds, which can easily react with organic molecules, thus forming C-O-P bonds. In the present work, periodic ab-initio simulations at PBE level (inclusive of dispersive interactions) have been carried out on metallic Fe₂NiP-schreibersite, as a relative abundant component of metallic meteorites, in order to characterize structural, energetics and vibrational properties of both bulk and surfaces of this material. The aim is to study the relative stability among different surfaces, to characterize both the nanocrystal morphology and the reactivity towards water molecules. </p>

The Plausibility Paradox for Resized Users in Virtual Environments

This paper identifies and confirms a perceptual phenomenon: when users interact with simulated objects in a virtual environment where the users’ scale deviates greatly from normal, there is a mismatch between the object physics they consider realistic and the object physics that would be correct at that scale. We report the findings of two studies investigating the relationship between perceived realism and a physically accurate approximation of reality in a virtual reality experience in which the user has been scaled by a factor of ten. Study 1 investigated perception of physics when scaled-down by a factor of ten, whereas Study 2 focused on enlargement by a similar amount. Studies were carried out as within-subjects experiments in which a total of 84 subjects performed simple interaction tasks with objects under two different physics simulation conditions. In the true physics condition, the objects, when dropped and thrown, behaved accurately according to the physics that would be correct at that either reduced or enlarged scale in the real world. In the movie physics condition, the objects behaved in a similar manner as they would if no scaling of the user had occurred. We found that a significant majority of the users considered the movie physics condition to be the more realistic one. However, at enlarged scale, many users considered true physics to match their expectations even if they ultimately believed movie physics to be the realistic condition. We argue that our findings have implications for many virtual reality and telepresence applications involving operation with simulated or physical objects in abnormal and especially small scales.

Ab-Initio Computational Study on Fe2NiP Schreibersite: Bulk and Surface Characterization

<p>Phosphorous is ubiquitous in planet Earth and plays a fundamental role in all living systems. Finding a reasonable prebiotic source of phosphorous is not trivial, as common sources where it is present nowadays are in the form of phosphate minerals, which are rather insoluble and non-reactive materials, and, accordingly, unavailable for being readily incorporated in living organisms. A possible source of phosphorous is from the exogenous meteoritic bombardment and, in particular, in iron/nickel phosphites. These materials, by simple interaction with water, produce oxygenated phosphorous compounds, which can easily react with organic molecules, thus forming C-O-P bonds. In the present work, periodic ab-initio simulations at PBE level (inclusive of dispersive interactions) have been carried out on metallic Fe₂NiP-schreibersite, as a relative abundant component of metallic meteorites, in order to characterize structural, energetics and vibrational properties of both bulk and surfaces of this material. The aim is to study the relative stability among different surfaces, to characterize both the nanocrystal morphology and the reactivity towards water molecules. </p>

Ab-Initio Computational Study on Fe2NiP Schreibersite: Bulk and Surface Characterization

<p>Phosphorous is ubiquitous in planet Earth and plays a fundamental role in all living systems. Finding a reasonable prebiotic source of phosphorous is not trivial, as common sources where it is present nowadays are in the form of phosphate minerals, which are rather insoluble and non-reactive materials, and, accordingly, unavailable for being readily incorporated in living organisms. A possible source of phosphorous is from the exogenous meteoritic bombardment and, in particular, in iron/nickel phosphites. These materials, by simple interaction with water, produce oxygenated phosphorous compounds, which can easily react with organic molecules, thus forming C-O-P bonds. In the present work, periodic ab-initio simulations at PBE level (inclusive of dispersive interactions) have been carried out on metallic Fe₂NiP-schreibersite, as a relative abundant component of metallic meteorites, in order to characterize structural, energetics and vibrational properties of both bulk and surfaces of this material. The aim is to study the relative stability among different surfaces, to characterize both the nanocrystal morphology and the reactivity towards water molecules. </p>

Interactive Digital Experience as an Alternative Laboratory (IDEAL): Creative Investigation of Forensic Biomechanics

An Interactive Digital Experience as an Alternative Laboratory (IDEAL) was developed and implemented in a flipped biomechanics classroom. The IDEAL challenge problem was created to more closely simulate a real-world scenario than typical homework or challenge problems. It added a more involved story, specific characters, simple interaction, and student-led inquiry into a challenge problem. Students analyzed musculoskeletal biomechanics data to conduct a forensic biomechanics investigation of an individual who suffered a fracture. Students ultimately approached the IDEAL problem with a greater appreciation and enjoyment than previous open-ended challenge problems—those that were assigned in a traditional problem-statement manner—throughout the semester. Students who were more fully engaged in the IDEAL challenge problem, as evidenced by the fact that they requested all of the evidence on their own, also performed better on the final report grade. This signals improved learning with respect to biomechanical analysis when the students were creatively participating in the storyline surrounding the forensic investigation.

Framework for Prioritizing Contact Tracing and Mass Testing of COVID-19 Using Graph Theory

Contact tracing has become one of the most useful tools for fighting the novel Corona Virus (COVID-19) pandemic worldwide. The underlining philosophy of contact tracing is determining people who have been in contact with infected persons and thus isolate them from becoming agents of onward transmission of the virus. Slow tracing of contacts and inconsistent or inaccurate information provided by patients usually leads to the spread of the virus along a trajectory at the healthcare systems' blindside. This has led to the proposal of app-based contact tracing solutions. This paper proposes an SQL-based framework that transforms simple interaction data entries into interaction graphs and applies graph theory to prioritize the contact tracing process. The framework returns nodes or individual IDs together with values called Risk_Points to enable individuals' selection for isolation and treatment. Results on simulated data show that the proposed framework can help slow the virus's rate of transmission.

Nature

This chapter discusses the historical origins of the concept of borrowing from nature and coining the science of bio-mimetics. The material also surveys examples of tribological systems in nature. Generation of design in natural systems (geometry, pattern, form, and texture) is shown to be holistic in essence. It synchronizes simple interaction of design constituents and efficient performance. Such an approach yields deterministic design outputs that while conceptually simple are of minimized energy footprint. Natural engineering, it is shown, seeks trans-disciplinary technically viable alternatives to our technological practices. These alternatives, given functional constraints, require minimum effort to construct and economize effort while functioning.

Understanding the mesoscopic scaling patterns within cities

Understanding quantitative relationships between urban elements is crucial for a wide range of applications. The observation at the macroscopic level demonstrates that the aggregated urban quantities (e.g., gross domestic product) scale systematically with population sizes across cities, also known as urban scaling laws. However, at the mesoscopic level, we lack an understanding of whether the simple scaling relationship holds within cities, which is a fundamental question regarding the spatial origin of scaling in urban systems. Here, by analyzing four extensive datasets covering millions of mobile phone users and urban facilities, we investigate the scaling phenomena within cities. We find that the mesoscopic infrastructure volume and socioeconomic activity scale sub- and super-linearly with the active population, respectively. For a same scaling phenomenon, however, the exponents vary in cities of similar population sizes. To explain these empirical observations, we propose a conceptual framework by considering the heterogeneous distributions of population and facilities, and the spatial interactions between them. Analytical and numerical results suggest that, despite the large number of complexities that influence urban activities, the simple interaction rules can effectively explain the observed regularity and heterogeneity in scaling behaviors within cities.

Interaction Patterns for Staggered Assembly of Fibrils from Semiflexible Chains

The design of colloidal interactions to achieve target self-assembled structures has especially been done for compact objects such as spheres with isotropic interaction potentials, patchy spheres and other compact objects with patchy interactions. Inspired by the self-assembly of collagen-I fibrils and intermediate filaments, we here consider the design of interaction patterns on semiflexible chains that could drive their staggered assembly into regular (para)crystalline fibrils. We consider semiflexible chains composed of a finite number of types of interaction beads (uncharged hydrophilic, hydrophobic, positively charged and negatively charged) and optimize the sequence of these interaction beads with respect to the interaction energy of the semiflexible chains in a number of target-staggered crystalline packings. We find that structures with the lowest interaction energies, that form simple lattices, also have low values of L/D (where L is chain length and D is stagger). In the low interaction energy sequences, similar types of interaction beads cluster together to form stretches. Langevin Dynamics simulations confirm that semiflexible chains with optimal sequences self-assemble into the designed staggered (para)crystalline fibrils. We conclude that very simple interaction patterns should suffice to drive the assembly of long semiflexible chains into staggered (para)crystalline fibrils.

HAI: An Instructional Motion Graphic of How to Interact with People with Autism for Grade Schoolers

Autism Spectrum Disorder (ASD) is known as ‘triad impairment’ which consists of communication, interaction, and behaviour problem. They also exhibit hypersensitivities or hyposensitivities to physical sensory stimuli which affect the processing system to be overloaded and cause an uncomfortable feeling or pain. Their reactions then trigger some particular behaviors, which are considered aggressive, harmful, repetitive, and odd. The main problem is most people judge and avoid them solely based on their actions without any effort to find out the reason and learn how to interact with them properly. This one-sided stereotype most probably leads them and their family to emotional insecurities, lack of self-esteem, and rebellious tendency. While this kind of situation is mostly centralized, institutionalized, and deep rooted in society, it can be reconditioned through a small step by teaching people since their early age the appropriate way to interact with people with autism. It is essential to realize that each individual with autism is first and foremost an individual who should not be treated as invisible in society. In order to facilitate this idea, I offer HAI: An Instructional Motion Graphic of How to Interact with People with Autism for Grade Schoolers which consists of several illustrated empirical steps which can be applied in school. The instructions are suitable to interact with several specific types of ASD, such as Classic Autism and Asperger syndrome, by reason of the severity of the symptoms which enables them to live relatively normal lives in society. In other words, the main objective of this project is to encourage and assist people, especially grade schoolers to have short conversation or simple interaction with their autistic friends through practical and proper set of actions. Throughout this project, sequential exploratory design method was implemented by combining qualitative and quantitative method in the process.