On the Evaluation of the Shielding Effectiveness of Electrically Large Enclosure

The shielding effectiveness (SE) has become afundamental step in testing active or passive electricdevices. The Reverberating Chamber (RC) is a wellestablishedmethod for determining the SE since has theadvantage to expose the material to a more realisticenvironment. In this paper the SEe of electrically largeenclosure with a metallic mesh grid in a RC is evaluated.Enclosures made with metallic mesh are considered. Inparticular, it is shown that the SE of a material is unable toprovide complete information for the SEe of electricallylarge enclosure made with the same material. Moreover,this latter one is related to the loading conditions within theenclosure itself. Measurements accomplished at RC of theUniversità di Napoli Parthenope (formerly IstitutoUniversitario Navale, IUN) confirm the physical soundnessof the proposed approach

Do regional brain volumes and major depressive disorder share genetic architecture?:A study of Generation Scotland (<i>n</i>=19,762), UK Biobank (<i>n</i>=24,048) and the English Longitudinal Study of Ageing (<i>n</i>=5,766)

Major depressive disorder (MDD) is a heritable and highly debilitating condition. It is commonly associated with subcortical volumetric abnormalities, the most replicated of these being reduced hippocampal volume. Using the most recent published data from Enhancing Neuroimaging Genetics through Meta-analysis (ENIGMA) consortium's genome-wide association study of regional brain volume, we sought to test whether there is shared genetic architecture between seven subcortical brain volumes and intracranial volume (ICV) and MDD. We explored this using linkage disequilibrium score regression, polygenic risk scoring (PRS) techniques, Mendelian randomisation (MR) analysis and BUHMBOX. Utilising summary statistics from ENIGMA and Psychiatric Genomics Consortium, we demonstrated that hippocampal volume was positively genetically correlated with MDD (rG=0.46, P=0.02), although this did not survive multiple comparison testing. None of the other six brain regions studied were genetically correlated and amygdala volume heritability was too low for analysis. Using PRS analysis, no regional volumetric PRS demonstrated a significant association with MDD or recurrent MDD. MR analysis in hippocampal volume and MDD identified no causal association, however, BUHMBOX analysis identified genetic subgrouping in GS:SFHS MDD cases only (P=0.00281). In this study, we provide some evidence that hippocampal volume and MDD may share genetic architecture in a subgroup of individuals, albeit the genetic correlation did not survive multiple testing correction and genetic subgroup heterogeneity was not replicated. In contrast, we found no evidence to support a shared genetic architecture between MDD and other regional subcortical volumes or ICV

Bioreactor for microalgal cultivation systems: strategy and development

Microalgae are important natural resources that can provide food, medicine, energy and various bioproducts for nutraceutical, cosmeceutical and aquaculture industries. Their production rates are superior compared to those of terrestrial crops. However, microalgae biomass production on a large scale is still a challenging problem in terms of economic and ecological viability. Microalgal cultivation system should be designed to maximize production with the least cost. Energy efficient approaches of using light, dynamic mixing to maximize use of carbon dioxide (CO2) and nutrients and selection of highly productive species are the main considerations in designing an efficient photobioreactor. In general, optimized culture conditions and biological responses are the two overarching attributes to be considered for photobioreactor design strategies. Thus, fundamental aspects of microalgae growth, such as availability of suitable light, CO2 and nutrients to each growing cell, suitable environmental parameters (including temperature and pH) and efficient removal of oxygen which otherwise would negatively impact the algal growth, should be integrated into the photobioreactor design and function. Innovations should be strategized to fully exploit the wastewaters, flue-gas, waves or solar energy to drive large outdoor microalgae cultivation systems. Cultured species should be carefully selected to match the most suitable growth parameters in different reactor systems. Factors that would decrease production such as photoinhibition, self-shading and phosphate flocculation should be nullified using appropriate technical approaches such as flashing light innovation, selective light spectrum, light-CO2 synergy and mixing dynamics. Use of predictive mathematical modelling and adoption of new technologies in novel photobioreactor design will not only increase the photosynthetic and growth rates but will also enhance the quality of microalgae composition. Optimizing the use of natural resources and industrial wastes that would otherwise harm the environment should be given emphasis in strategizing the photobioreactor mass production. To date, more research and innovation are needed since scalability and economics of microalgae cultivation using photobioreactors remain the challenges to be overcome for large-scale microalgae production

Estimate of the shielding effectiveness of an electrically large enclosure made with pierced metallic plate in a well-stirred reverberation chamber

In this document, a simple and efficacious method to estimate the shielding effectiveness of an electrically large enclosure (SEe) made with pierced metallic plate is shown under uniform and isotropic field conditions, which are produced in a reverberation chamber (RC) where the field is well stirred. The estimate is made by the calculation of the transmission cross sections (TCSs) of the walls of an enclosure and absorption cross sections (ACSs) of the inner losses. TCSs and ACSs are connected to the shielding effectiveness (SE) of the walls and inner losses, respectively; the latter are also connected to the reflectivity of the enclosure internal walls. The comparison with measurements made in an RC matches enough. It shows that the method shown here is sound. Moreover, the results support a recent model that connects SEe to SE by the reflectivity of the enclosure internal walls, and show still further that unloaded electrically large enclosures with distributed apertures are not very efficacious