Scalable method for bio-based solid foams that mimic wood

Mimicking natural structures allows the exploitation of proven design concepts for advanced material solutions. Here, our inspiration comes from the anisotropic closed cell structure of wood. The bubbles in our fiber reinforced foam are elongated using temperature dependent viscosity of methylcellulose and constricted drying. The oriented structures lead to high yield stress in the primary direction; 64 times larger than compared to the cross direction. The closed cells of the foam also result in excellent thermal insulation. The proposed novel foam manufacturing process is trivial to up-scale from the laboratory trial scale towards production volumes on industrial scales.

Flow of Non-Newtonian Fluids in a Single-Cavity Microchannel

Having a basic understanding of non-Newtonian fluid flow through porous media, which usually consist of series of expansions and contractions, is of importance for enhanced oil recovery, groundwater remediation, microfluidic particle manipulation, etc. The flow in contraction and/or expansion microchannel is unbounded in the primary direction and has been widely studied before. In contrast, there has been very little work on the understanding of such flow in an expansion–contraction microchannel with a confined cavity. We investigate the flow of five types of non-Newtonian fluids with distinct rheological properties and water through a planar single-cavity microchannel. All fluids are tested in a similarly wide range of flow rates, from which the observed flow regimes and vortex development are summarized in the same dimensionless parameter spaces for a unified understanding of the effects of fluid inertia, shear thinning, and elasticity as well as confinement. Our results indicate that fluid inertia is responsible for developing vortices in the expansion flow, which is trivially affected by the confinement. Fluid shear thinning causes flow separations on the contraction walls, and the interplay between the effects of shear thinning and inertia is dictated by the confinement. Fluid elasticity introduces instability and asymmetry to the contraction flow of polymers with long chains while suppressing the fluid inertia-induced expansion flow vortices. However, the formation and fluctuation of such elasto-inertial fluid vortices exhibit strong digressions from the unconfined flow pattern in a contraction–expansion microchannel of similar dimensions.

Numerical Investigation of an Induced Draft Air-Cooled Condenser Under Crosswind Conditions

This study numerically investigated the performance of a 64-fan induced draft Air-Cooled Condenser (ACC) subjected to crosswind conditions. An Actuator Disk Model (ADM) was used to model the axial flow fans and a combination of the Darcy-Forchheimer porosity model and the Effectiveness Number of Transfer Units (ε-NTU) heat transfer model were used to model the heat exchangers. Crosswind conditions were applied to the ACC model in multiple directions and multiple reference velocities, with the results compared to a reference case where no wind was present. The induced draft ACC attained a mean fan volumetric effectiveness of 1.065, a mean heat transfer effectiveness of 1.039 and a mean heat-to-power ratio of 120.6 when no crosswinds were present. At relatively high crosswind velocities of 9 m/s the mean volumetric effectiveness decreased by 10.1% from wind coming from the primary direction, and by 10.3% from wind coming from the secondary direction. Similarly, the mean heat transfer effectiveness decreased by 21.7% under primary cross-winds, and by 31.3% under secondary crosswinds. Finally, the heat-to-power ratio of the ACC decreased to 92.5 under primary crosswinds, and by 77.6 under secondary crosswinds.

Native Extracellular Matrix Orientation Determines Multipotent Vascular Stem Cell Proliferation in Response to Cyclic Uniaxial Tensile Strain and Simulated Stent Indentation

Cardiovascular disease is the leading cause of death worldwide, with multipotent vascular stem cells (MVSC) implicated in contributing to diseased vessels. MVSC are mechanosensitive cells which align perpendicular to cyclic uniaxial tensile strain. Within the blood vessel wall, collagen fibers constrain cells so that they are forced to align circumferentially, in the primary direction of tensile strain. In these experiments, MVSC were seeded onto the medial layer of decellularized porcine carotid arteries, then exposed to 10%, 1 Hz cyclic tensile strain for 10 days with the collagen fiber direction either parallel or perpendicular to the direction of strain. Cells aligned with the direction of the collagen fibers regardless of the orientation to strain. Cells aligned with the direction of strain showed an increased number of proliferative Ki67 positive cells, while those strained perpendicular to the direction of cell alignment showed no change in cell proliferation. A bioreactor system was designed to simulate the indentation of a single, wire stent strut. After 10 days of cyclic loading to 10% strain, MVSC showed regions of densely packed, highly proliferative cells. Therefore, MVSC may play a significant role in in-stent restenosis, and this proliferative response could potentially be controlled by controlling MVSC orientation relative to applied strain.

A Logic of Directions

We propose a logic of directions for points (LD) over 2D Euclidean space, which formalises primary direction relations east (E), west (W), and indeterminate east/west (Iew), north (N), south (S) and indeterminate north/south (Ins). We provide a sound and complete axiomatisation of it, and prove that its satisfiability problem is NP-complete.

Anti-terrorist Function of the State: Search for New Forms of Implementation

The paper considers the importance of the anti-terrorist function of the state, which consists in the possibility of neutralizing the main threat-forming factors of illegal encroachments on the constitutional system: 1) radicalism; 2) enmity and hatred; 3) extremism; 4) terrorism. The purpose of the paper is to search for effective support of all areas of the state’s antiterrorist function: 1) prevention; 2) struggle; 3) elimination of harmful consequences; 4) self-sufficiency. The analysis of the category "anti-terrorist function of the state" is carried out in the combination of dialectical and systemic research methods, as well as by a conceptual approach to identifying new forms of implementation. In the course of the analysis, the author formulates and scientifically substantiates his position: the support of the anti-terrorist function of the state determines the social purpose and social significance of the prevention of terrorism as the primary direction of anti-terrorist activities. The paper reflects the currently important feature of the considered function — the socio-political component of countering terrorism as a point of contact between the opposing entities. The transformation of manifestations of terrorism, which creates threats to individual, public, state, collective, regional, and international security, requires anti-terrorist actors to act ahead of the curve. A citizen protected from terrorist influence will expect the state to maintain such a safe state. At the same time, the average citizen is far from being able to participate in strengthening the anti-terrorist function of the state. A separate set of state measures is of interest in the course of systematizing the functions of the modern Russian state. Modern terrorists, using the achievements of humanity, are embedded in an invulnerable actor of the planetary level. Attempts to reduce these manifestations to an acceptable level only by anti-criminal methods of law enforcement agencies are comparable to the failure and beginning of the reproduction of terrorism. Without a comprehensive approach in the anti-terrorist sphere, it is impossible to create sustainable development and conditions for the implementation of national interests. This system is formed, implemented, optimized, improved and harmonized under the influence of many socio-political factors. The stability of the system under study is conditional due to the variability of various external and internal sources of government that affect its processes.

Changes in Gender Roles within Intangible Cultural Heritage: A Survey of Gender Roles and Gender Restrictions within the Yama Hoko Yatai Float Festivals in Japan

This paper presents the results of a study on gender roles and gender restrictions within a certain type of festival in Japan—the Yama Hoko Yatai float festivals—taking place in various regions throughout the country. In addition to mapping gender roles, the study was also focused on mapping changes that have occurred in these gender roles and identifying the reasons for the changes. A survey was conducted among the preservation associations connected to the 36 concerned festivals in the form of a questionnaire sent by post. The results of the survey show the differences between the festivals in terms of gender roles and gender restrictions. While some festivals display a more gender-inclusive approach, others are reportedly performed exclusively by men, and some display gender-based role divisions. Approximately half of the replies reported that some changes in the gender roles had occurred, and the primary direction of change was towards increased inclusion (increased female participation). Concerning the reasons behind the increased female participation, the replies suggest that a primary trigger of change was a shortage of people to participate, caused by declining birth rates. A change in attitude/consciousness towards female participation was mentioned in a few cases.

Removing Stripes, Scratches, and Curtaining with Nonrecoverable Compressed Sensing

Highly-directional image artifacts such as ion mill curtaining, mechanical scratches, or image striping from beam instability degrade the interpretability of micrographs. These unwanted, aperiodic features extend the image along a primary direction and occupy a small wedge of information in Fourier space. Deleting this wedge of data replaces stripes, scratches, or curtaining, with more complex streaking and blurring artifacts—known within the tomography community as “missing wedge” artifacts. Here, we overcome this problem by recovering the missing region using total variation minimization, which leverages image sparsity-based reconstruction techniques—colloquially referred to as compressed sensing (CS)—to reliably restore images corrupted by stripe-like features. Our approach removes beam instability, ion mill curtaining, mechanical scratches, or any stripe features and remains robust at low signal-to-noise. The success of this approach is achieved by exploiting CS's inability to recover directional structures that are highly localized and missing in Fourier Space.

A toolbox for volumetric visualization of light properties

In this paper, we introduce a toolbox for the perceptually based visualization of light in a volume, focusing on the visual effects of illumination. First, our visualizations extend the conventional methods from a two-dimensional representation on surfaces to the whole volume of a scene. Second, we extend the conventional methods from showing only light intensity to visualizing three light properties (mean illuminance, primary direction and diffuseness). To make our methods generally available and easily accessible, we provide a web-based tool, to which everybody can upload data, measured by a cubic or simple illuminance meter or even a smartphone-app, and generate a variety of three-dimensional visualizations of the light field. The importance of considering the light field in its full complexity (and thus as a three-dimensional vector field instead of its two-dimensional sections) is widely acknowledged. Our toolbox allows easy access to sophisticated methods for analysing the spatial distribution of light and its primary qualities as well as how they vary throughout space. It is our hope that our results raise interest in ‘third stage’ approaches to lighting research and design, and the toolbox offers a practical solution to this complex problem.