On the formulation of green open space planning parameters: A parametric tool

[EN] Greenery can affect spatial characteristics such as relationship between hard and soft surfaces and activities inside open spaces. Among different types of greenery, trees have influences on summer shading and winter solar access, and hence usage patterns in open spaces. However, the relationship between tree planting and open space characteristics such as typology, proportion and height-to-width ratio in terms of shading and solar access was rarely investigated. On the other hand, there has been an increasing number of studies on using parametric tools to design urban environment recently. Despite the success in urban fabric planning by parametric tools, the utilization of these tools to design open spaces with a relatively smaller scale has not been revealed. Even worse, parameters that should be included in a parametric design tool for open space planning are still unknown. Accordingly, the primary objective of this study is to, by investigating the design characteristics and concepts of different open spaces, identify parameters for a parametric tool to design green open spaces. Specifically, the possibility of using shaded areas projected by trees and surrounding buildings as one of the parameters will be revealed. The study also aims at examining how the height-to-width ratios, proportions and typologies of open spaces will affect tree planting positions when optimizing shading or solar access of the spaces in different climate zones. Results from this study will provide designers with an additional layer of information when designing open spaces.Leung, T.; Kukina, I.; Yuryevna-Lipovka, A. (2018). On the formulation of green open space planning parameters: A parametric tool. En 24th ISUF International Conference. Book of Papers. Editorial Universitat Politècnica de València. 1685-1682. https://doi.org/10.4995/ISUF2017.2017.60561685168

Beyond graphene oxide: Laser engineering functionalized graphene for flexible electronics

Carbon nanomaterials, especially graphene, are promising due to their abundance and the possibility to exploit them in lightweight, flexible, and wearable electronics enabling paradigms such as the Internet of Things. However, conventional methods to synthesize and integrate graphene into functional materials and flexible devices are either hazardous, time demanding, or excessively energy-consuming. To overcome these issues, here we propose a new concept based on the laser processing of single-layer diazonium-functionalized graphene. This is a safe, inexpensive, and environmentally-friendly method making it a competitive alternative for graphene-device fabrication. Flexible chemiresistors exhibit sensitivity for breath (water vapor and CO2) and ethanol detection up to 1500% higher than laser-reduced graphene oxide devices. We attribute this enhanced sensitivity to an optimal balance between structural defects and electrical conductivity. Flexible electronic circuits demonstrate a superb resilience against scratching and high current stability up to 98% with durability against 180° bending cycles for continuous operation of several weeks. This work can impact biomedical technology and electronics where tunable electrical conductivity, sensitivity, and mechanical stability are of uttermost importance. © 2020 The Royal Society of Chemistry

Different stages of the evolution of cerebral aneurysms: joint analysis of mechanical test data and histological analysis of aneurysm tissue

In practical neurosurgery, an important issue is determining the status of the aneurysm and predicting its further growth, rupture or stabilization. The main approaches for the study of risk analysis asessment are computational hydrodynamics and analysis of the mechanics of the wall of cerebral aneurysm. In this paper, an analysis of various sections of the wall of cerebral aneurysm is given, combining mechanical test data and histological examination data. It was shown that, along with significant differences in mechanics, a different degree of calcification is observed in the tissue, which indicates a different level of impaired transport of substances inside the tissue

The Relationship between the Strength Characteristics of Cerebral Aneurysm Walls with Their Status and Laser-Induced Fluorescence Data

Background: Cerebral aneurysms (CA) are a widespread vascular disease affecting 50 per 1000 population. The study of the influence of histological, morphological and hemodynamic factors on the status of the aneurysm has been the subject of many works. However, an accurate and generally accepted relationship has not yet been identified. Methods: In our work, the results of mechanical and spectroscopic measurements are considered. Total investigated 14 patients and 36 their samples of CA tissue. Results: The excitation–emission matrix of each specimen was evaluated, after which the strength characteristics of the samples were investigated. Conclusions: It has been shown that there is a statistically significant difference in the size of the peaks of two components, which characterizes the status of the aneurysms. In addition, a linear regression model has been built that describes the correlation of the magnitude of the ultimate strain and stress with the magnitude of the peaks of one of the components. The results of this study will serve as a basis for the non-invasive determination of the strength characteristics of the cerebral tissue aneurysms and determination of their status

The Effect of Adding Modified Chitosan on the Strength Properties of Bacterial Cellulose for Clinical Applications

Currently, several materials for the closure of the dura mater (DM) defects are known. However, the long-term results of their usage reveal a number of disadvantages. The use of antibiotics and chitosan is one of the major trends in solving the problems associated with infectious after-operational complications. This work compares the mechanical properties of samples of bacterial nanocellulose (BNC) impregnated with Novochizol™ and vancomycin with native BNC and preserved and native human DM. An assessment of the possibility of controling the mechanical properties of these materials by changing their thickness has been performed by statistical analysis methods. A total of 80 specimens of comparable samples were investigated. During the analysis, the results obtained, the factor of Novochizol™ addition has provided a statistically significant impact on the strength properties (Fisher Criteria p-value 0.00509 for stress and 0.00112 for deformation). Moreover, a stronger relationship between the thickness of the samples and their ultimate load was shown: R2=0.236 for BNC + Novochizol™ + vancomycin, compared to R2=0.0405 for native BNC. Using factor analysis, it was possible to show a significant effect of modified chitosan (Novochizol™) on the ultimate stress (p-value = 0.005)