Tunable Double Negative Band Structure from Non-Magnetic Coated Rods

A system of periodic poly-disperse coated nano-rods is considered. Both the coated nano-rods and host material are non-magnetic. The exterior nano-coating has a frequency dependent dielectric constant and the rod has a high dielectric constant. A negative effective magnetic permeability is generated near the Mie resonances of the rods while the coating generates a negative permittivity through a field resonance controlled by the plasma frequency of the coating and the geometry of the crystal. The explicit band structure for the system is calculated in the sub-wavelength limit. Tunable pass bands exhibiting negative group velocity are generated and correspond to simultaneously negative effective dielectric permittivity and magnetic permeability. These can be explicitly controlled by adjusting the distance between rods, the coating thickness, and rod diameters

Ovary Development and Maturation in Nezara viridula (L.) (Hemiptera: Pentatomidae)

Ovary development and maturation of Nezara viridula (L.) were evaluated by examining ovariole morphology and the alterations in the biochemical (protein synthesis related to reproduction) composition of the hemolymph. Quantitative and qualitative protein analyses were performed and ovary structural alterations for the pre-reproductive and reproductive stages were recorded. Total concentration of proteins in female hemolymph gradually increased until the end of the pre-mating stage, remaining unaltered thereafter. Proteins linked to reproduction (vitellogenins) appeared in the hemolymph 10 days after adult emergence and indicated the end of the pre-mating stage. After mating, total protein concentration in the hemolymph was lower compared to virgin females; vitellogenin levels were similar during most of the observation period. Oocyte development and maturation were gradual and age dependent. Ten-day-old females had chorionated oocytes ready for fertilization. Mating did not stimulate oocyte development in N. viridula, but the lack of mating activity appeared to have stimulated oocyte resorption in 17-day-old females.Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq

Convergent power series for fields in positive or negative high-contrast periodic media

We obtain convergent power series representations for Bloch waves in periodic highcontrast media. The material coefficient in the inclusions can be positive or negative. The small expansion parameter is the ratio of period cell width to wavelength, and the coefficient functions are solutions of the cell problems arising from formal asymptotic expansion. In the case of positive coefficient, the dispersion relation has an infinite sequence of branches, each represented by a convergent even power series whose leading term is a branch of the dispersion relation for the homogenized medium. In the negative case, there is a single branch. © Taylor & Francis Group, LLC

Effect of sewage sludge on the incidence of corn stalk rot caused by Fusarium.

During the last decades, sewage started to be treated in order to reduce the pollution of rivers, resulting in the production of a sludge rich in organic matter and nutrients, called sewage sludge. Among the alternatives for final discarding, the agricultural use is one of the most convenient, because it combines disposal and recycling. However, using sewage sludge as a fertilizer causes alterations in the physical, chemical and biological properties of the soils. The soilborne plant pathogens are highly influenced by the way the soil is managed; thus, sewage sludge may interfere with the occurrence of diseases caused by these microorganisms. The objective of this study was to evaluate the effect of sewage sludge on corn stalk rot, caused by Fusarium spp

Targeting energy savings? Better on primary than final energy and less on intensity metrics

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGA eficiencia enerxética é un tema crítico nas políticas públicas, xa que é a clave para desvincular o crecemento económico e o uso da enerxía. Estes obxectivos están a ser aínda máis relevantes para abordar a crise enerxética e os novos escenarios xeopolíticos da guerra de Ucraína. Aínda que varios traballos analizaron os obxectivos de eficiencia enerxética, este traballo céntrase nos obxectivos de aforro enerxético, que representan a principal métrica de eficiencia para a Unión Europea. Este traballo enche un baleiro na literatura ao analizar os impactos económicos e ambientais da consecución de obxectivos de eficiencia enerxética mediante unha política fiscal enerxética, simulada por un modelo de equilibrio xeral computable híbrido con gran detalle tecnolóxico. Defínense seis escenarios para o aforro enerxético no consumo dos produtos enerxéticos, utilizando Portugal como caso de estudo. Os resultados relevantes para os responsables políticos dos escenarios simulados inclúen: (i) acadar obxectivos de aforro enerxético por medios alternativos, é dicir, dirixidos ao consumo de enerxía primaria ou final, proporcionar impactos heteroxéneos na eficiencia do sistema enerxético e no PIB, e algúns inesperados e indesexables nos impactos ambientais; (ii) unha fiscalidade relativamente máis baixa de todos os produtos enerxéticos produce impactos máis grandes e máis distorsionadores na xeración de electricidade que impostos máis elevados só sobre os combustibles fósiles (un resultado contraintuitivo), (iii) as políticas destinadas a reducir a enerxía primaria en lugar da enerxía final proporcionan os mellores resultados (maiores aumentos da eficiencia do sistema enerxético con impactos económicos máis suaves), o que vai en contra do principio da directiva europea sobre impostos enerxéticos pola que deben gravarse os produtos finais, independentemente dos insumos utilizados na súa produción e (iv) e os obxectivos non deben elaborarse en base a indicadores de intensidade enerxética. Polo tanto, móstrase que o tamaño dos impactos no balance entre as preocupacións económicas e ambientais depende do foco no aforro enerxético: de onde (consumo de enerxía primaria ou final) e a que (fósiles ou todos os produtos enerxéticos) sexa aplicado.Energy efficiency is a critical issue in public policies, as it is the key to decoupling economic growth and energy use. These objectives are becoming even more relevant to addressing the energy crisis and the new geopolitical scenarios delivered by the Ukraine war. Although several papers have analyzed energy efficiency goals, this paper focuses on energy savings targets, which represent the main efficiency metric for the European Union. This paper fills a gap in literature by analyzing the economic and environmental impacts of attaining energy efficiency targets through an energy fiscal policy, simulated by a hybrid computable general equilibrium model with technological detail. Six scenarios are defined for energy savings in primary/final energy consumption of fossil-fueled/all energy products, using Portugal as a case study. Relevant insights for policy makers from the simulated scenarios include: (i) achieving energy saving targets by alternative means, i.e., directed at primary or final energy consumption, provide heterogeneous impacts on the efficiency of the energy system and GDP, and some unexpected and undesirable outcomes concerning environmental impacts; (ii) a relatively lower taxation of all energy products deliver larger and more distorting impacts on electricity generation than higher taxes on fossil fuels only (a counterintuitive result), (iii) policies aiming to reduce primary energy instead of final energy provide the best outcomes (further increases in the efficiency of the energy system with smoother economic impacts), thereby pointing against the European Energy Taxation directive principle that taxation should be levied on final products, regardless of inputs used in their production and (iv) and targets should not be set up based on energy intensity indicators. Hence, it is shown that the size of the trade-off between economic and environmental concerns depends on where (primary or final energy consumption) and what (fossil or all energy products) energy savings are targeted.Fundação para a Ciência e a Tecnologia | Ref. UIDB/05037/2020Fundação para a Ciência e a Tecnologia | Ref. UIDP/05037/2020Fundação para a Ciência e a Tecnologia | Ref. UID/04085/2020Ministerio de Ciencia y Educación | Ref. PID2019-106677GB-I00Xunta de Galicia | Ref. GRC2017/063Universidade de Vigo/CISU