Algae as a part of microorganisms involved in biocorrosion of cement composites with total replacement of natural aggregates by photovoltaic glass

Algae of the Pleurococcus, Trentepohlia and Stichococcus genera were selected for the experiment on the cement composites with total replacement of natural aggregates by recycled photovoltaic glass. The growth of the algae was monitored on cement beams with dimension 40 x 40 x 8 mm (length x width x height) and on the cement crumbling in various proportion. In the case of cement composites with recycled glass from photovoltaic panels, intensive growth was observed in the Trentepohlia genus from the Chlorophyceae class, while in the case of cement crumbling with recycled photovoltaic glass, the most obvious growth in biomass was recorded in the Pleurococcus genus; the Stichococcus and Trentepohlia genera showed minimal or zero growth. This minimal growth is mainly influenced by the pH value and the fact that biocorrosion is accompanied by the effect of symbiotizing microbiota, which mutually support each other, not just one species.

Effect of Partial and Total Replacement of Broken Rice Instead Wheat on Some Economic Traits of Laying Hen

A total of 105 laying hens (ISA Brown), 60 weeks age, were used in the experiment. They were divided into five treatments with three replicates, were as the following T1: without replacement of the rice broken. T2: replaced 25% of the broken rice instead by 75% of the wheat. T3: replaced 50% of the broken rice instead by 75% of the wheat. T4: replaced 75% of the broken rice instead by 25% of the wheat. T5: replaced 100% of the broken rice instead by 0% of the wheat. The best measure of economic profit, the highest net cash income, and the shortest period of capital recovery was in T3 compare with other treatments. All replacement treatments of rice broken instead of wheat in the diet achieved the best economic profit, net cash income, and the shortest period of capital recovery compared to the control treatment.

Toward a uniform earthquake loss model across Central America

This study presents a probabilistic earthquake loss model for Central America, which is used to evaluate the indicators of the Sendai Framework for Disaster Risk Reduction (SFDRR). The exposure, vulnerability, and hazard components of the model were established using a uniform methodology for all the countries. Earthquake risk is expressed according to three indicators: mortality (A-1), population affected (B-1), and economic losses (C-1). Exposure results indicate that over 9.1 million structures (with an economic value of US$635 billion) are exposed to seismic hazard in the region. The risk results indicate an average annual human loss of 0.7 fatalities per 100,000 inhabitants, an average number of 35 people affected per 100,000 inhabitants, and an average annual economic loss of US$990 million. This represents 0.43% and 0.16% of the regional gross domestic product (GDP) and total replacement value, respectively. Guatemala, Nicaragua, and El Salvador present the highest risk, contributing with 75% of the absolute economic losses and 84% of the average annual fatalities in the region.

Development of a Dynamic Hands-Free Door Opener to Prevent COVID-19 Pandemic Spreading

The situation caused by COVID-19 has shown several vulnerabilities in the attitudes and habits of modern society, inducing the need to adopt new behaviors that will directly impact daily activities. The quickly spreading virus contaminates the surfaces of handles and objects, and subsequent contact with the eyes, nose, or mouth is one of the main contagion factors. There is an urgent need to rethink how we interact with the most-touched surfaces, such as door handles in public places with a high flux of people. A revision was performed of the most-used door handles to develop a proposal that could be applied to already existing models, thus avoiding the need for their total replacement. Through interaction between engineering, design, and ergonomics, an auxiliary hands-free door opener device was developed, following iteration improvement from an initial static geometry and culminating in a dynamic system aiming to provide greater ergonomic comfort in its use. The development followed a methodology using 3D modelling supported by 3D printing of the various components to accurately understand their functioning. In addition, the finite element method supported the prediction of the structural behavior of the developed systems. The final models were produced through CNC machining and submitted to functional validation tests with volunteers. The developed HFDO demonstrated relevant differentiation from the existing models on the market: for its geometry and material, but mainly for its strong emphasis on the interaction between the object and the user, resulting from the dynamic component in its use/manipulation.

Immunity status in patients with periprosthetic knee joint infection

Implant-associated infection is one of the most severe complications after total replacement of larger joints. The diagnosis of periprosthetic infection are often impeded as 5-34% of bacteriological tests are false-negative. Now the investigations of the immune status of patients suspected of periprosthetic infection are considered perspective as these are aimed at finding the most significant indicators for underlying the diagnosis of this pathology. In this research, we assessed immunology indicators in peripheral blood of patients with periprosthetic infection in their knee joints. We determined immunology characteristics associated with the clinical aspects of the progressing pathology. Our findings can be used as the basis for further search of pathophysiological mechanisms of periprosthetic infection progress in the knee joint as well as defining new diagnostic approaches.Reviewers:Ivanov A.N., MD, DSc;Prof. Puchinyan D.M., MD, DSc

A Review on the Philosophies for the Advancement of Polymer-based Composites: Past, Present and Future Perspective

Research has been the tool for recycling existing scientific ideas to promote improved concepts for the development of new materials. All technological innovations have links with the ancient philosophies that are being adapted progressively. Given this, composite material development remains one of the most excellent methods to influence the environment to meet human needs. Various studies have shown that polymer-based composites have emerged as the leading group of composites that are fast displacing all other materials in several applications due to their inherent properties. Polymer-based composites can be entirely synthetic, completely natural, or a mixture of synthetic and natural-based. However, a recent desire for eco-friendly materials has shifted attention from complete synthetic-based materials to natural fibers, whether in a partial or total replacement. Thus, this review provides an overview of research trends from synthetic to natural based polymer composites. The article also highlights the different intrinsic classifications of composites, their development, areas of applications, and their projection into the future in line with considerations for environment and applications.

Retrofitting of Column by Concrete Jacketing

This study has been conducted through basic experimental research in order to analyze retrofitting of the structure is better alternative instead of total replacement of structure. It may even be economical to use Concrete Jacketing for damaged column While Replacing Coarse Aggregate With Broken Glass in Concrete Jacketing. It improves axial and shear strength of column and major strengthening of foundation may avoided. So to study Retrofitting Of RC Square Column By Concrete Jacket Made By Replacing Aggregate With Broken Glass which helps to increase the seismic resistance of a building in both orthogonal directions of a structure and advantages ventilation and natural light.

Condition-Based Maintenance Strategies to Enhance the Durability of ETICS

The increase of awareness with sustainability and the desire of reducing the energy consumption in the construction sector haved increased the application of External Thermal Insulation Composite Systems (ETICS) across Europe in the last decades. Nevertheless, the implementation of appropriate maintenance strategies is still neglected. The aim of this study is to analyse the impact of different maintenance strategies. For that purpose, a condition-based maintenance model, based on Petri nets, is used to evaluate three maintenance strategies: MS1—total replacement only; MS2—combination of minor intervention and total replacement; and MS3—combination of cleaning operations, minor intervention, and total replacement. In the end, a multi-criteria analysis is used to discuss the impact of the three maintenance strategies proposed, evaluating the remaining service life, the global costs over time, the ETICS’ degradation condition, and the number of replacements (end of service life) over the time horizon. For this purpose, a sample of 378 ETICS was analysed, based on in situ visual inspections, carried out in Portugal. The results from this study reveal that maintenance plays an important role to increase the durability of ETICS, and therefore their sustainability. Regular maintenance can promote the extension of the ETICS’s service life between 88% and 159% (between 15 to 27 years), improve the global degradation condition of the ETICS, and reduce the impact on users by reducing the number of deeper interventions. Further research is essential to optimise the maintenance strategies (time interval between inspections, stakeholders’ performance criteria, and environmental exposure).