Abstract: In recent years, the construction of buildings with thin reinforced concrete (RC) walls has increased significantly in Colombia and other Latin American countries, mainly due to their speed of construction and economy. The reinforcing steel of most of these walls is commonly arranged in a single layer, without any effective confinement. In cases where boundary elements are included, adequate confinement is not guaranteed due to their reduced thickness. Software tools allow verifying the behavior of these buildings under representative seismic events. This article studies the behavior of thin RC walls using the Non-linear Beam-Truss Model (NL-BTM). The commercial software Perform-3D, widely used in professional practice, has been selected for this research. The calibration of the modeling parameters is carried out using different types of walls tested experimentally. The results are then extrapolated for modeling representative buildings in Bogot ' a. The geometric and mechanical characteristics of the walls correspond to those reported in actual tests, and those of the building are the characteristics indicated in representative building plans. Numerical modeling is performed through non-linear static pushover analysis and non-linear dynamic time-history analysis. The study proposes recommendations and limitations in using the NL-BTM model for modeling thin RC walls in actual buildings.

Abstract: The bewildering morphological diversity found in cells is one of the starkest illustrations of lifes ability to self-organize. Yet the morphogenetic mechanisms that produce the multifarious shapes of cells are still poorly understood. The shared similarities between the walled cells of prokaryotes, many protists, fungi, and plants make these groups particularly appealing to begin investigating how morphological diversity is generated at the cell level. In this review, I attempt a first classification of the different modes of surface deformation used by walled cells. Five modes of deformation were identified: inextensional bending, equi-area shear, elastic stretching, processive intussusception, and chemorheological growth. The two most restrictive modesuinextensional and equi-area deformationsuare embodied in the exine of pollen grains and the wall-like pellicle of euglenoids, respectively. For these modes, it is possible to express the deformed geometry of the cell explicitly in terms of the undeformed geometry and other easily observable geometrical parameters. The greatest morphogenetic power is reached with the processive intussusception and chemorheological growth mechanisms that underlie the expansive growth of walled cells. A comparison of these two growth mechanisms suggests a possible way to tackle the complexity behind wall growth.

Abstract: Extreme learning machine (ELM) is a machine learning technique based on competitive single-hidden layer feedforward neural network (SLFN). However, traclitional ELM and its variants are only based on random assignment of hidden weights using a uniform distribution, and then the calculation of the weights output using the least-squares method. This paper proposes a new architecture based on a non-linear layer in parallel by another non-linear layer and with entries of independent weights. We explore the use of a deterministic assignment of the hidden weight values using low-discrepancy sequences (LDSs). The simulations are performed with Halton and Sobol sequences. The results for regression and classification problems confirm the advantages of using the proposed method called PL-ELM algorithm with the deterministic assignment of hidden weights. Moreover, the PL-ELM algorithm with the deterministic generation using LDSs can be extended to other modified ELM algorithms.

Abstract: Modern society's biggest challenges are affordable, clean energy production and storage. Thus, recent research aims at the discovery of novel electrode materials for enhanced energy production and storage. Herein, nitrogen-implanted carbon particles were synthesized for the first time from the Acorus Calamus for the symmetric supercapacitor application. The KOH-activated carbon particles at 750 degrees C (C-750) under a nitrogen atmosphere revealed the better structural, textural, morphological, and electrochemical performance. The BET analysis confirmed that the C-750 carbon nanoparticles tremendously enhanced the surface area of about 3551.07 m(2)/g. Further, the pore size and pore volume were obtained from BJH analysis that showed 3.70 nm and 0.51 cc/g, respectively. The high surface area along with the mesoporous nature of the C-750 sample effectively enhanced the specific capacitance to 354.44 Fg(-1) at 1 Ag-1 using a 6 M KOH electrolytic solution. Further, the enhancement of energy and power density of the C-750 was observed at about 47.2 Whkg(-1) and 16,000 Wkg(-1), respectively.

Abstract: The commercial viability of organic photovoltaics (OPVs) can be improved by simplifying their device geometry and easing fabrication complexity. Here, we demonstrate that solution-based p-type electrical doping of ternary bulk heterojunction (BHJ) films, which comprise 2 donor polymers and 1 fullerene acceptor (2D:1A), enables the realization of efficient single-layer OPVs. Systematic and detailed investigations of the optoelectronic charac-teristics of films with varying donor ratios, and their photovoltaic performance, demonstrate p-type electrical doping via post-process immersion into a 12-molybdophosphoric acid hydrate (PMA) solution, resulting in a reduced trap density and charge recombination without significantly changing the BHJ morphology. Further-more, PMA doping of films comprising optimized ternary blend compositions and polyethylenimine enables the demonstration of single-layer OPVs with economic top electrode metals and a high level of performance under outdoor and indoor illumination conditions. These PMA-doped 2D:1A BHJ films are an attractive platform to reduce the efficiency-cost gap and accelerate the commercialization of OPVs for emerging applications.

Abstract: Transparent conducting materials (TCMs) are the heart of modern optoelectronic industries and the properties of TCMs could be improved by the introduction of 2D carbon materials. In this report, the influence of order layering on microstructural, transparency and emission characteristics of ZnO:rGO:ZnO:rGO:ZnO and rGO:ZnO: rGO:ZnO:rGO sandwich structures has been investigated. The layer-by-layer approach has been adopted for the fabrication of sandwich structured materials ZnO:rGO:ZnO:rGO:ZnO and rGO:ZnO:rGO:ZnO:rGO through the spin coating technique. The sandwich structures of ZnO and rGO exhibited hexagonal wurtzite structure of ZnO without any impurities were identified through XRD. The ordering of layer's influenced the microstructural parameters and were significantly altered. The spherical nature of the particles and the formation of the sand-wich structures were confirmed by using SEM micrograph. The reduction in an optical transparency and nar-rowing bandgap of the ZnO upon the order of layering were identified through transmission spectra. The lower energy shift of near band edge (NBE) emission and reduction in the emission intensity with respect to pure ZnO nanostructures was observed. The present work provides a simple layer-by-layer approach to fabricating sand-wich structures and improving the optical properties which have potential applications in various optoelectronic devices.

Abstract: Fire spread inside a spacecraft is a constant concern in space travel. Understanding how the fire grows and spreads, and how it can potentially be extinguished is critical for planning future missions. The conditions in-side a spacecraft can greatly vary from those encountered on earth, including microgravity, low velocity flows, reduced ambient pressure and high oxygen, and thus affecting the combustion processes. In microgravity, the contributions of thermal radiation from gaseous species and soot can play a critical role in the spread of a flame and the problem has not been fully understood yet. The overall objective of this work is to address this by studying the soot temperature of microgravity flames spreading over a thin solid in microgravity. The ex-periments presented here were performed as part of the NASA project Saffire IV, conducted in orbit on board the Cygnus resupply vehicle before it re-entered the Earth's atmosphere. The fuel considered is a thin fabric made of cotton and fiberglass (Sibal) exposed to a forced flow of 20 cm/s in a concurrent flow configuration. Reconstruction of the flame temperature fields is extracted from two color broadband emission pyrometry (B2CP) as the flame propagates over the solid fuel. A methodology, relevant assumptions and its applicability to other microgravity experiments are discussed here. The data obtained shows that the technique provides an acceptable average temperature around similar to 1300 K, which remains relatively constant during the spread with an error value smaller than 117 K. The data presented in this work provides a methodology that could be applied to other microgravity experiments to be performed by NASA. It is expected that the results will provide insight for what is to be expected in different conditions relevant for fire safety in future space facilities. (c) 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.