André Bellin Mariano

Life cycle assessment of biomass production in microalgae compact photobioreactors

This paper presents a life cycle assessment (LCA) of industrial scale microalgae biomass production in compact photobioreactor (PBR) systems (2 × 5 × 8 m) for supplying biofuel/electricity generation processes and synthesis of new materials. Other objectives are as follows: (i) to compare the impact of various raw materials, substances, and services; and (ii) to evaluate environment‐relevant aspects of the proposed system as compared to microalgae raceway ponds. The life cycle inventory assessment shows that (i) only atmospheric CO2 is used for PBR microalgae cultivation, whereas in raceway ponds, injection of CO2 from fossil origin is largely required to allow for microalgae growth; and (ii) the PBR daily production rate of dry biomass is currently at 1.5 kg m−3 day−1 for each PBR, which is 12.82 times larger than the reported average 0.117 kg m−3 day−1 raceway ponds production. It is found that in general the association of the effects of the production of steel, PVC, and the packaging contribute to more than 85% of the total impact in each analyzed category. Therefore, to achieve PBR biomass production impact reduction and sustainability, PVC and steel utilization need to be minimized, as well as packaging materials. Based on the PBR LCA results, that is, due to no CO2 injection from fossil origin and low area occupation, it is expected that high density production of truly renewable microalgae biomass could be obtained from PBR systems.

Millimeter-wave chip set for 77–81 GHz automotive radar application

A millimeter-wave (mmW) chipset for 77–81 GHz automotive radar has been developed in 0.13μm SiGe HBT technology. This work presents the performances of an integrated Low Noise Amplifier (LNA), a Power Amplifier (PA), a down-converting Mixer, and also a Voltage Controlled Oscillator (VCO). For successful implementation of the circuit, considerations on the reliability of the design have been taken into account. Measurements on all circuits confirm the feasibility of mmW front-end using silicon based technologies for W-band application.

A comparison of high-efficiency UHF RFID rectifiers using internal voltage compensation and zero-threshold-voltage MOSFETs

This paper discusses and compares the design of two high-efficiency 4-stage voltage-doubler UHF RFID rectifier operating at 915 MHz. The first rectifier uses conventional 180-nm CMOS transistors applying a technique of internal cancellation in order to compensate the high value of their threshold voltages (Vth). The second proposed rectifier uses zero-Vth transistors, which are available in a 130 nm CMOS process, eliminating the need for compensation circuitry. The circuit implementing Vth compensation occupies a 0.025 mm2 area, achieving a -12 dBm input sensitivity and a 18% power conversion efficiency (PCE) when supplying a 1.2 V output voltage and a 10 μA load current. For the same load conditions, the circuit including zero-Vth transistors presents a reduced area occupation (0.013 mm2), while providing both improved sensitivity (-14.3 dBm) and a 33% PCE at this sensitivity.

Improved method for isolation of coupled mitochondria of Araucaria angustifolia (Bert.) O. Kuntze

A method for the isolation of coupled mitochondria from the callus of Araucaria angustifolia is described for the first time. Mitochondria were isolated from embryogenic callus of A. angustifolia. They were metabolically active, able to sustain oxidative phosphorylation as shown by respiratory control ratio values, which were about 2.4 when respiring on succinate as substrate. Oxygen uptake experiments, using freeze-thawed disrupted mitochondria, showed the presence of alternative rotenone-insensitive NAD(P)H dehydrogenases, which were stimulated by Ca2+. The procedure now described for the isolation of A. angustifolia mitochondria is an important new tool, allowing the investigation of mitochondrial bioenergetics and metabolism and physiology of plants.

Optimization of flocculation with tannin-based flocculant in the water reuse and lipidic production for the cultivation of Acutodesmus obliquus

ABSTRACT This paper evaluated the optimization of natural flocculant in different conditions in a tubular photobioreactor using swine wastewater effluent as culture media in a pilot-scale microalgae production plant. This study aimed to assess the flocculation efficiency of Tanfloc SG via a central composite design (CCD), with varying Tanfloc SG concentration, biomass concentration and pH. Subsequently, the microalga Acutodesmus obliquus was cultivated in medium obtained from the recycled recovery of microalgae cells via flocculation with Tanfloc SG. Results showed that the recycled medium after flocculation with Tanfloc SG had a positive effect on the biomass and lipid production of A. obliquus.

Production and characterization of an extracellular lipase from Candida guilliermondii.

Extracellular lipases from the endophytic yeast Candida guilliermondii isolated from castor leaves (Ricinus communis L.) were produced using low-cost raw materials such as agro-industrial residues and applying them in the esterification of oleic acid for evaluating their potential use in biodiesel production. After partial purification using ammonium sulfate, the enzyme was characterized and presented higher activity (26.8 ± 1.5 U mL−1) in the presence of 5 mmol L−1 NaCl at 30 °C and pH 6.5. The production through submerged fermentation was formerly performed in 150 mL erlenmeyer flasks and, once the enzyme production was verified, assays in a 14 L bioreactor were conducted, obtaining 18 ± 1.4 U mL−1. The produced enzyme was applied in the oleic acid esterification under different solvents: hexane, cyclohexane or cyclohexanone) and different acid:alcohol molar ratios. Higher ester conversion rate (81%) was obtained using hexane and the molar ratio of 1:9 was the best conditions using methanol. The results suggest the potential for development of endophytic yeast in the production of biocatalyst through submerged fermentation using agroindustrial residues as culture medium.

COMPARAÇÃO ENTRE TRÊS BIOPROCESSOS PARA A PRODUÇÃO DE ENZIMAS PROTEOLÍTICAS UTILIZANDO RESÍDUOS AGROINDUSTRIAIS

As proteases sao enzimas capazes de clivar as ligacoes peptidicas de proteinas e dentro das enzimas sao as que mais possuem emprego industrial. O objetivo deste trabalho foi comparar tres diferentes bioprocessos para a producao de proteases. Foram testados uma fermentacao submersa (FSm) e dois tipos de fermentacao no estado solido, uma com suporte natural (FES) e outra com suporte sintetico (PUF). A FES utilizando o suporte natural bagaco de cana de acucar apresentou maior produtividade da enzima e em menor tempo. Este fato pode ser explicado pela grande adaptacao da cepa fungica utilizada ao ambiente fornecido por este processo. Nos ensaios de caracterizacao, a enzima apresentou pH e temperatura otimos em 6,5 e 30oC, respectivamente. A protease tambem apresentou boa resistencia aos ions, apresentando ativacao na presenca de litio e EDTA. E possivel concluir que o processo de FES e uma otima opcao para a producao de metabolitos fungicos de interesse industrial.

Single-chip receiver front-end for 79GHz automotive radar

A 79GHz receiver front-end for automotive applications has been implemented in a 130nm SiGe technology supporting millimeter wave design. The receiver consists of a two-stage LNA, a double-balanced down-conversion Mixer and a synchronized VCO. Design and test results for each RF circuit block are presented, followed by a characterization of the integrated receiver.

Environmental evaluation of flocculation efficiency in the separation of the microalgal biomass of Scenedesmus sp. cultivated in full-scale photobioreactors

ABSTRACT In this paper the environmental evaluation of the separation process of the microalgal biomass Scenedesmus sp. from full-scale photobioreactors was carried out at the Research and Development Nucleus for Sustainable Energy (NPDEAS), with different flocculants (iron sulfate – FeCl3, sodium hydroxide – NaOH, calcium hydroxide – Ca(OH)2 and aluminum sulphate Al2(SO4)3, by means of the life cycle assessment (LCA) methodology, using the SimaPro 7.3 software. Furthermore, the flocculation efficiency by means of optical density (OD) was also evaluated. The results indicated that FeCl3 and Al2(SO4)3 were highly effective for the recovery of microalgal biomass, greater than 95%. Though, when FeCl3 was used, there was an immediate change in color to the biomass after the orange colored salt was added, typical with the presence of iron, which may compromise the biomass use according to its purpose and Al2(SO4)3 is associated with the occurrence of Alzheimers disease, restricting the application of biomass recovered through this process for nutritional purposes, for example. Therefore, it was observed that sodium hydroxide is an efficient flocculant, promoting recovery around 93.5% for the ideal concentration of 144 mg per liter. It had the best environmental profile among the compared flocculant agents, since it did not cause visible changes in the biomass or compromise its use and had less impact in relation to acidification, eutrophication, global warming and human toxicity, among others. Thus, the results indicate that it is important to consider both flocculation efficiency aspects and environmental impacts to identify the best flocculants on an industrial scale, to optimize the process, with lower amount of flocculant and obtain the maximum biomass recovery and decrease the impact on the extraction, production, treatment and reuse of these chemical compounds to the environment. However, more studies are needed in order to evaluate energy efficiency of the process coupled with other microalgal biomass recovery technologies. In addition, studies with natural flocculants, other polymers and changes in pH are also needed, as these are produced in a more sustainable way than synthetic organic polymers and have the potential to generate a biomass free of undesirable contaminants.

65 GHz CMOS-SOI low power consumption voltage controlled oscillator

This paper presents a 65 GHz LC-VCO dedicated to wireless high data rate applications. It is designed in a 65nm CMOS SOI process. The proposed VCO achieves a frequency tuning range (FTR) of some 9.7% and a phase noise of -111 dBc/Hz at 10 MHz of the carrier. The power consumption is 1.1 mW when biased with a 0.8 V power supply. The silicon footprint of the VCO core is only 0.047 mm2.