ABSTRACT
Artificially prepared microbial spores have excellent electromagnetic attenuation properties due to their special composition and structure. At present, studies on the optical properties of microbial spores have mainly focused on those with a single band or a single germplasm, which has limitations and cannot reveal the optical properties comprehensively. In this paper, 3 kinds of laboratory-prepared microbial spores were selected for compounding, and the spectral reflectivities of single-germplasm biospores and compound biospores were measured in the wavebands of 0.25–2.4 and 3–15 μm. The complex refractive indices (CRIs) were calculated in combination with the Kramers–Kronig (K-K) algorithm. Relying on the smoke box broadband test system, the transmittance of single-germplasm bioaerosols and compound bioaerosols from the ultraviolet (UV) band to the far-infrared (FIR) band was measured, and the mass extinction coefficients were calculated. The results indicate that the trend of the complex refractive indices of the compound spores is consistent with that of the single-germplasm spores with a larger particle size. For the single-germplasm bioaerosols, the lowest transmittance values were 2.21, 5.70 and 6.27% in the visible (VIS), near-infrared (NIR) and middle-infrared (FIR) bands, and the mass extinction coefficients reached 1.15, 0.87 and 0.84 m2/g, respectively. When AO and BB spores were compounded at 4:1, the extinction performance of the bioaerosols somewhat improved in all wavebands. These results can help to comprehensively analyze the optical properties of bioaerosols and provide ideas for the development of new extinction materials.
ABSTRACT
This review highlights origin, symptoms, diagnosis, causative agents, mode of transmission and persistence of coronavirus disease (COVID-19) through human activities. In the current scenario researchers, doctors and scientists are striving to combat the transmission of COVID-19 among society. Origin and growth of pandemic has raised the serious concern to address the causative agents, mode of transmission, persistence, preventive measures, diagnosis and possibilities of treatment. The broad-spectrum antiviral antiphrastic, complementary and alternative medicines are currently proposed for possible eradication of the pandemic. The current world is relying on, prevention and control of infection through sanitization and quarantine and onwards waiting for appropriate virucidal agents, sanitizers and strategic vaccination and immunization to combat the pandemic of SARS-CoV-2. Eradication of COVID-19 under stringent guidelines of WHO regarding social practices, intensive care, administration of complementary medicines and innovation of vaccines are under active considerations across the world to combat the pandemic.
ABSTRACT
In Europe, the recent application of regulations oriented to zero-energy buildings and climate neutrality in 2050 has led to a reduction in energy consumption for heating and cooling in the construction sector. The thermal insulation of the building envelope plays a key role in this process and the requirements about the maximum allowable thermal transmittance are defined by country-specific guidelines. Typically, high insulation values provide low energy consumption for heating;however, they may also entail a risk of overheating in summer period and thus negatively affect the overall performance of the building. In addition, the embodied energy and related emissions caused by the manufacturing and transportation processes of thermal insulation cannot be further neglected in the evaluation of the best optimal solution. Therefore, this paper aims to evaluate the influence in terms of embodied and operational energy of various walls’ thermal insulation thicknesses on residential buildings in Europe. To this end, the EnergyPlus engine was used for the energy simulation within the Ladybug and Honeybee tools, by parametrically conducting multiple iterations;53 variations of external wall U-value, considering high- and low-thermal-mass scenarios, were simulated for 100 representative cities of the European context, using a typical multifamily building as a reference. The results demonstrate that massive walls generally perform better than lightweight structures and the best solution in terms of energy varies according to each climate. Accordingly, the wall’s thermal transmittance for the samples of Oslo, Bordeaux, Rome and Almeria representative of the Continental, oceanic temperate, Mediterranean, and hot, semi-arid climates were, respectively: 0.12, 0.26, 0.42, and 0.64 W/m2K. The optimal solutions are graphically reported on the map of Europe according to specific climatic features, providing a guidance for new constructions and building retrofit.
ABSTRACT
The building sector continues to play an essential role in reducing worldwide energy consumption. The reduced consumption is accompanied by stricter regulation for the thermotechnical design of the building envelope. The redefined nearly Zero Energy Building levels that will come into force for each member state will pressure designers to rethink the constructive details so that mandatory levels can be reached, without increasing the construction costs over an optimum level but at the same time reducing greenhouse gas emissions. The paper aims to illustrate the main conclusions obtained in assessing the thermo-energy performance of a steel-framed building representing a holistically designed modular laboratory located in a moderate continental temperate climate, characteristic of the south-eastern part of the Pannonian Depression with some sub-Mediterranean influences. An extensive numerical simulation of the main junctions was performed. The thermal performance was established in terms of the main parameters, the adjusted thermal resistances and global thermal insulation coefficient. Further on, the energy consumption for heating was established, and the associated energy rating was in compliance with the Romanian regulations. A parametric study was done to illustrate the energy performance of the investigated case in the five representative climatic zones from Romania. An important conclusion of the research indicates that an emphasis must be placed on the thermotechnical design of Light Steel Framed solutions against increased thermal bridge areas caused by the steel’s high thermal conductivity for all building components to reach nZEB levels. Nevertheless, the results indicate an exemplary behaviour compared to classical solutions, but at the same time, the need for an iterative redesign so that all thermo-energy performance indicators are achieved.
ABSTRACT
COVID 19, a furious virus, exploded across the globe in 2020. Treatment, tracing and testing are the only way to retain a normal life. But the biggest obstacle is the shortage of proper testing kits which makes life horrendous. As a consequence it demands time to ramp up the development of a suitable test kit. In this scenario we propose a kit that is made up of a two-dimensional (2-D) Si-based photonic crystal structure (PCS) that could distinguish the novel coronaviruses (n-CoV) from ordinary coronaviruses. The principle of identification relies on the reflectance, absorbance and transmittance characteristics at the signal of 412 nm wavelength obtained from a laser diode (LD);moreover, the operational mechanism deals with the manipulation of the signal with the proposed PCS structure which contains the virus solution. Finally, the output transmitted energy differentiates the viruses pertaining to their nature;for example, an output with visible light energy gives an indication of normal flu;on the other hand, output energy within the infrared (IR) range confirms the case of novel coronavirus infection.
ABSTRACT
We are living in uncertain times and facing a paradigm shift in human health and sustainability. The number of SARS-CoV-2 victims is rising daily and all nations are going through dramatic effects and exploring various solutions to this imminent calamity facing the humanity. The world is confronting a public health issue that has forced it to come to a halt and evaluate the future of our modern society and our way of living. It can be stated that the sustainability of our societies inextricably depends on the performance of our global trade and supply chains. This review article is the first published assessment on the global trade and especially packaging's role in the transmittance of SARS-CoV-2 virus. Surprisingly, based on our findings, the lack of knowledge on transmittance and survival of SARS-CoV-2 in supply chain and packaging is substantial. Although there are several existing and available technologies that can be used for the risk mitigation, our assessment shows a major and timely need for broad conceptual advancements and necessary understanding of the supply chain risks associated with the viral surface transmittances. The specificity to the current and possibly future pandemics demands an increasing amount of multidisciplinary research and involvement of public and private sectors. This proposed erudition is imminent and may be highly critical in safeguarding and the sustainability of the critical supply chains in our society now and in the future.