Optical demultiplexer device operating in the visible spectrum

In this paper, we present results on the use of multilayered a-SiC:H heterostructures as a device for wavelength-division demultiplexing of optical signals. These devices are useful in optical communications applications that use the wavelength division multiplexing technique to encode multiple signals into the same transmission medium. The device is composed of two stacked p-i-n photodiodes, both optimized for the selective collection of photo generated carriers. Band gap engineering was used to adjust the photogeneration and recombination rate profiles of the intrinsic absorber regions of each photodiode to short and long wavelength absorption in the visible spectrum. The photocurrent signal using different input optical channels was analyzed at reverse and forward bias and under steady state illumination. A demux algorithm based on the voltage controlled sensitivity of the device was proposed and tested. An electrical model of the WDM device is presented and supported by the solution of the respective circuit equations

Climate Modelling of a Greenhouse with Proportional Environmental Control

Performance of greenhouse environmental control systems can be evaluated by predictive climate models. In this work, a model for the prediction of environmental parameters such as temperature and humidity based on energy and mass balances, was developed and validated for a greenhouse controlled with a proportional environmental control system. The greenhouse is in Viveiros do Furadouro, a forestry nursery from the Altri Group, located near Óbidos, Portugal. The greenhouse under study is a Venlo greenhouse covered with glass with an area of 1632 m2 and is used for Eucalyptus globulus Labbill. vegetative propagation through minicuttings. Eucalyptus globulus is characterized by having low rooting ability and environmental control has to be very accurate and requires the use of multiple control equipments, such as heating, cooling (pad or fog), thermal/shade screens, natural and dynamic ventilation. The proportional control of each equipment, such as the fan and wet pad for cooling, is difficult and requires good knowledge of the dynamics of greenhouse environmental parameters, as well as the influence of individual equipment. However, it allows different alternatives to achieve the set points. The climate data were recorded every 8 min and were used to develop a climatic model based on energy and mass balances, to use for prediction of internal environmental parameters. Information about the activation percentage of the environmental control systems was also included. The extraction of the coefficients for the balances combines direct calculation and interaction using Microsoft Excel® SOLVER®, until reaching the minimum absolute difference between simulated and measured inside temperature and humidity. The climate model was validated by comparison between measured and simulated values for temperature and humidity. This model can be used to optimize the greenhouse environment in order to achieve the production objectives

Modelação do clima em estufa climatizada com sistema de controlo proporcional – Modelo de aquecimento

O controlo ambiental em culturas protegidas assume uma grande importância e, a par da rega e da nutrição, é um dos factores limitantes do crescimento e desenvolvimento das plantas. A eficácia deste controlo pode ser avaliada pela utilização de modelos matemáticos para a previsão das condições climáticas interiores, que após a sua validação, permite a simulação para diferentes condições climáticas exteriores e/ou diferentes estratégias de funcionamento dos equipamentos de condicionamento ambiental. Neste trabalho é apresentado um modelo de simulação de temperatura e de humidade, baseado em balanços de energia e de massa para uma situação de Inverno – modelo de aquecimento. O modelo foi desenvolvido para uma estufa do tipo “Venlo” em vidro, equipada para a propagação clonal de Eucalyptus globulus Labill. pela técnica de miniestacaria. O modelo proposto foi validado estatisticamente comparando os valores medidos e simulados. As diferenças absolutas entre os valores de temperatura e humidade relativa medidos e simulados foram, respectivamente, de 1,31ºC e 7,46% e o erro padrão da estimativa de 0,91ºC e 7,65%

A haplotype-resolved draft genome of the European sardine (Sardina pilchardus)

The European sardine (Sardina pilchardus Walbaum, 1792) is culturally and economically important throughout its distribution. Monitoring studies of sardine populations report an alarming decrease in stocks due to overfishing and environmental change, which has resulted in historically low captures along the Iberian Atlantic coast. Important biological and ecological features such as population diversity, structure, and migratory patterns can be addressed with the development and use of genomics resources.Agência financiadora Portuguese national funds from FCT-Foundation for Science and Technology: UID/Multi/04326/2016; European Regional Development Fund (FEDER): 22153-01/SAICT/2016; ALG-01-0145-FEDER-022121; ALG-01-0145-FEDER-022231; MAR2020 operational programme of the European Maritime and Fisheries Fund (project SARDI-NOMICS): MAR-01.04.02-FEAMP-0024; European Union's Horizon 2020 research and innovation programme: 654008info:eu-repo/semantics/publishedVersio

Entire hemithorax irradiation for Masaoka stage IVa thymomas

Thymomas are rare neoplasms that have an indolent growth with a preferentially intra-thoracic dissemination pattern. Surgery is currently the standard treatment of thymomas; however radiotherapy is often used in an adjuvant setting due to a high sensitivity of these tumors to such treatment. Postoperative entire hemithoracic irradiation has been used in selected Masaoka stage IVa cases after complete surgical excision of metastatic lesions. In the present article, the authors report three cases of Masaoka stage IVa thymoma that underwent entire hemithorax irradiation after surgical excision of metastatic lesions. The first two patients presented as stage IVa thymomas. The third case consisted of a pleural recurrence of a thymoma. Hemithoracic irradiation with low doses has been used by different authors; the available data shows that it is a well-tolerated treatment that could potentially lead to better loco-regional control and increased overall survival

Preparation and Characterization of a-SiC:H Absorber Layer for Semi-transparent Solar Cells

AbstractThis paper reports on device-quality silicon-carbon alloy (a-SiC:H) application as an absorber material in semi-transparent solar cells. Films with an optical bandgap ranging from 2 to 2.3 eV were prepared by plasma enhanced chemical vapour deposition (PECVD). The n-i-p structures with undoped SiC:H layers deposited under the same experimental conditions were also fabricated and characterized. The optimized devices showed forward current-voltage characteristics with a diode ideality factor in the range from 1.4 to 1.8, and an open circuit voltage up to 0.92 V. The density of deep defect states in a SiC:H was estimated from the transient current measurements and correlated with the optical bandgap