Review of the untapped potentials of antimicrobial materials in the construction sector

Damage caused by microbes results in compromised structural integrity. One key example is that of microbiologically induced concrete corrosion (MICC) due to the bacteria in concrete sewerage pipes which leads to reduced lifespan of sewer pipes. Antimicrobial materials provide a biocidal approach for eradicating the microbes either by inhibiting their growth, or by actively killing them. An ideal antimicrobial material should possess qualities such as sustainability, durability, eco-friendliness, economic viability to avoid the growing issue of antimicrobial resistance (AMR). The literature covering these topics vital to the construction sector is rather scarce. Therefore, this review paper summarises various types of antimicrobial materials currently used in the construction sector detailing their mode of biocidal activity, and their application in structures. This paper also addresses recent developments, and future scope that may aid in employing antimicrobial material in the construction sector, particularly to benefit plumbing and sanitation used in hospitals and high traffic areas and public places including airports, schools, and other educational establishments. Overall, the study draws attention to newer antimicrobial mechanisms and provides recommendations for developing new, efficient antimicrobial materials that can provide sustainability and a safe environment to the construction sector

Development of Symmetrical Fault Detection During Power Swing Based on Entropy

This paper proposes the new technique for detecting symmetrical faults occurred during power swing. The proposed technique is simulated for the protection of two machine system, distribution system with distributed generation and WSCC 9-bus system in Matlab. Symmetrical fault detection during power swing is a critical issue. Hence, in this paper, modified weighted wavelet packet entropy technique is proposed to detect symmetrical fault during power swing. This entropy criterion is applied to wavelet packet coefficients to enhance the energy of fault signals and to reduce the vector size of the wavelet packet transform coefficients. This technique provides better results irrespective of various fault locations, fault inception angle and power swing frequencies. This technique is compared with conventional scheme and the results are tabulated. Moreover, this technique is also able to detect asymmetrical faults with high impedance during power swing. Mathematical derivation support system performance through simulation

Extração semiautomática de rodovias no espaço-objeto: uso integrado de um estereopar de imagens aéreas e um MDT

Neste artigo é proposto um método semiautomático para extração de rodovias combinando um estereopar de imagens aéreas de baixa resolução com um poliedro gerado a partir de um modelo digital do terreno (MDT). O problema é formulado no espaço-objeto através de uma função objetivo que modela o objeto 'rodovia' como uma curva suave e pertencente a uma superfície poliédrica. A função objetivo proposta depende também de informações radiométricas, que são acessadas no espaço-imagem via relação de colinearidade entre pontos da rodovia no espaço-objeto e os correspondentes nos espaços imagem do estereopar. A linha poligonal que melhor modela a rodovia selecionada é obtida por otimização no espaço-objeto da função objetivo, tendo por base o algoritmo de programação dinâmica. O processo de otimização é iterativo e dependente do fornecimento por um operador de uma aproximação inicial para a rodovia selecionada. Os resultados obtidos mostraram que o método é robusto frente a anomalias existentes ao longo das rodovias, tais como obstruções causadas por sombras e árvores