Small Solar Panels Can Drastically Reduce the Carbon Footprint of Radio Access Networks

The limited power requirements of new generations of base stations (BSs) make the use of renewable energy sources, solar in particular, extremely attractive for mobile network operators. Exploiting solar energy implies a reduction of the network operation cost as well as of the carbon footprint of radio access networks, but previous research works indicate that the area of the solar panels that are necessary to power a standard macro BS is large, so large to make the solar panel deployment problematic, especially within urban areas. In this paper we use a modeling approach based on Markov reward processes to investigate the possibility of combining small area solar panels with a connection to the power grid to run a macro BS. By so doing, it is possible to increase the amount of renewable energy used to run a radio access network, while also reducing the cost incurred by the network operator to power its base stations. We assume that energy is drawn from the power grid only when needed to keep the BS operational, or during the night, that corresponds to the period with lowest electricity price. This has advantages in terms of both cost and carbon footprint. We show that solar panels of the order of 1-2 kW peak, i.e., with a surface of about 5-10 m2, combined with limited capacity energy storage (of the order of 10-15 kWh, corresponding to about 3-5 car batteries), and a smart energy management policy, can lead to an effective exploitation of renewable energy

On the Use of Small Solar Panels and Small Batteries to Reduce the RAN Carbon Footprint

The limited power requirements of new generations of base stations make the use of renewable energy sources, solar in particular, extremely attractive for mobile network operators. Exploiting solar energy implies a reduction of the network operation cost as well as of the carbon footprint of radio access networks. However, previous research works indicate that the area of the solar panels that are necessary to power a standard macro base station (BS) is large, making the solar panel deployment problematic, especially within urban areas.In this paper we use a modeling approach based on Markov reward processes to investigate the possibility of combining a connection to the power grid with small area solar panels and small batteries to run a macro base station. By so doing, it is possible to exploit a significant fraction of renewable energy to run a radio access network, while also reducing the cost incurred by the network operator to power its base stations. We assume that energy is drawn from the power grid only when needed to keep the BS operational, or during the night, which corresponds to the period with lowest electricity price. The proposed energy management policies have advantages in terms of both cost and carbon footprint. Our results show that solar panels of the order of 1-2 kW peak, i.e., with a surface of about 5-10 m2, combined with limited capacity energy storage (of the order of 1-5 kWh, corresponding to about 1-2 car batteries) and a smart energy management policy, can lead to an effective exploitation of renewable energy

CODAP: um Consenso Multidisciplinar sobre a Definição, Diagnóstico e Tratamento da Dislipidemia Aterogénica em Portugal

Introduction and aims: Atherogenic dyslipidemia is an important contributor to residual cardiovascular (CV) risk, but it is underdiagnosed and undertreated. This study aimed to assess the opinion of Portuguese experts to generate a consensus concerning the diagnosis and treatment of atherogenic dyslipidemia, as well as to contribute toward standardization of clinical practice in this disorder. Methods: The study consisted in the application of a questionnaire to an expert panel, following a modified Delphi methodology. Results: The majority (88.4%) of the proposed items were found to be consensual. The expert panel recognized the importance of the atherogenic dyslipidemia phenotype, the role played by low-density lipoprotein cholesterol and non-high-density lipoprotein cholesterol as risk markers and therapeutic targets, the choice of statins as first-line lipid-lowering drugs, and the value of associating statins with fenofibrate as a means to reduce residual CV risk. However, the role played by triglycerides in CV risk and the therapeutic value of fibrates lacked consensus. Taking into consideration the state of the art and the opinions expressed in this study, the scientific committee developed a treatment algorithm aimed to improve the perception and treatment of atherogenic dyslipidemia. Conclusions: The experts involved in this study were shown to be familiar with the concept and the importance of atherogenic dyslipidemia. The few situations in which a consensus could not be found were mainly related to the interpretation and/or relevance of the available evidence.info:eu-repo/semantics/publishedVersio

Controle biológico aplicado e natural da lagarta-do-cartucho do milho.

bitstream/item/44201/1/controle-biologico-lagarta.pd

Grape yield and must composition of "Cabernet Sauvignon" grapevines with organic compost and urea fertilization.

Urea and organic compost are applied as a nitrogen (N) source in vineyards. The aim of this study was to evaluate the yield, total N content in the leaves and the must composition in grapevines with the application of organic compost and urea. ?Cabernet Sauvignon? grapevines, in the 2008/2009 and 2009/2010 crop seasons were subjected to the application of 40 kg N ha-1 in the form of organic compost and urea; but there were also unfertilized grapevines. In both crop seasons, leaves were collected at the stages of full flowering and at the change in color of the berries, and the total N content were analyzed; grape yield was evaluated and enological attributes were determined in the must. The application of organic compost and urea did not affect the N content in the leaf nor the grape yield in the second crop season evaluated. However, in the first crop season, grape yield was greater in the grapevines with application of organic compost to the soil. The addition of N sources did not affect the total nutrient content in the must but, in the second crop season, the grape must from the grapevines with the addition of organic compost had a lower soluble solids concentration and a higher total acidity value, as well as tartaric and malic acid values. KEYWORDS: nitrogen, leaf analysis, Vitis vinifera L

Estimativa do Índice de Área Foliar (IAF) em diferentes variedades de mandioca a partir de modelos matemáticos, ceptômetro (ACU-PAR LP-80) e software de tratamento de imagens (Image J).

A área foliar se destaca como uma variável de extrema importância na estimativa de produtividade das culturas. Essa relação de extrema importância ocorre devido à íntima relação da quantidade foliar com a capacidade de interceptação da energia luminosa pelas folhas e consequentemente aumento na fotossíntese liquida que é sinônimo de produtividade das culturas. Objetivo ? Nesse contexto esse trabalho teve como objetivo estimar o índice de área foliar (IAF) de plantas de mandioca (Manihot esculenta Crantz) por métodos diretos e indiretos em nível de campo, nas condições do Recôncavo da Bahia

Aplicação de sistemas de avaliação da aptidão agrícola das terras em solos do Estado do Acre, Amazônia.

Os métodos de avaliação da aptidão agrícola tem como objetivo orientar o uso adequado das terras, porém seus resultados apresentam elevado grau de subjetividade devido a serem dependentes da experiência do usuário. Neste trabalho objetivou-se avaliar o uso de um algoritmo para interpretação de propriedades do solo e características da paisagem e compará-lo com a interpretação obtida por um grupo controle, constituído por seis especialistas. Foram utilizadas amostras de solo coletadas por tradagem ao lado dos perfis pedológicos da IX Reunião Brasileira de Correlação e Classificação de Solos, de modo a obter os dados de entrada do algoritmo, enquanto os avaliadores utilizaram os dados físicos, químicos e morfológicos dos perfis pedológicos. A avaliação do grupo controle não identificou as potencialidades para o uso dos solos na Amazônia de forma consistente, enquanto, o algoritmo mostrou-se promissor na avaliação da aptidão para Latossolo, Argissolos, Vertissolos e Luvissolo, no entanto, ainda requer revisões em algumas regras de interpretação para uma avaliação mais coerente da aptidão, principalmente, para o Espodossolo