Valorisation to biogas of macroalgal waste streams: a circular approach to bioproducts and bioenergy in Ireland

© 2016 The Author(s) Seaweeds (macroalgae) have been recently attracting more and more interest as a third generation feedstock for bioenergy and biofuels. However, several barriers impede the deployment of competitive seaweed-based energy. The high cost associated to seaweed farming and harvesting, as well as their seasonal availability and biochemical composition currently make macroalgae exploitation too expensive for energy production only. Recent studies have indicated a possible solution to aforementioned challenges may lay in seaweed integrated biorefinery, in which a bioenergy and/or biofuel production step ends an extractions cascade of high-value bioproducts. This results in the double benefit of producing renewable energy while adopting a zero waste approach, as fostered by recent EU societal challenges within the context of the Circular Economy development. This study investigates the biogas potential of residues from six indigenous Irish seaweed species while discussing related issues experienced during fermentation. It was found that Laminaria and Fucus spp. are the most promising seaweed species for biogas production following biorefinery extractions producing 187–195 mL CH4 gVS−1 and about 100 mL CH4 gVS−1 , respectively, exhibiting overall actual yields close to raw un-extracted seaweed

Geographical variation in the reproduction and sexual dimorphism of the Boddaert's tropical racer, Mastigodryas boddaerti (Serpentes: Colubridae)

We obtained data on time of sexual maturity, dimorphism, fecundity and on the reproductive cycle of Mastigodryas boddaerti (Sentzen, 1796) through the examination of 321 preserved specimens, of which 221 were collected in the Brazilian Amazon region and 100 in the Cerrado savannas of Central Brazil. The degree of sexual size dimorphism (snout-vent length, SVL) was significantly greater in the specimens from the Cerrado in comparison with those from the Amazon. Females had a significantly larger number of ventral scales, on average, whereas males had more sub-caudal scales. However, there was no intersexual difference in tail length or head width, although the heads of the males were significantly longer, which may reflect dietary differences. Breeding females from the Amazon region contained between one and six eggs (N = 12, mean = 3.0), whereas two females from the Cerrado had four to six eggs (N = 10, mean = 5.0). No relationship was found between the SVL of the Amazonian females and the number of eggs or vitellogenic follicles they contained (Cerrado females were not analyzed here due to small sample size). Males are smaller than their female counterpart when they reach sexual maturity. Even though females from the Amazon reproduce throughout the year, females from the Cerrado breed seasonality

Chapter 8 - Resource Management and Network Layer

The Internet protocols have become the worldwide standard for network and transport protocols and are increasingly used in satellite communication networks. Also traditional telecommunication and broadcast applications like VoIP and video streaming are transported over the Internet, although it does not support natively applications with tight QoS requirements. In satellite communication networks, further challenges arise, as bandwidth resources are limited and physical transmission time adds some more pressure on delay constraints. Since resources are limited, the efficient assignment of bandwidth to different data streams has always been an issue for satellite communications. However, supporting QoS for IP-based applications results in additional requirements for resource allocation. In order to provide QoS for applications, several layers of the protocol stack of a satellite communication system will need to be adapted or have to interact with each other in some way. This Chapter will concentrate on different resource management schemes at the MAC layer (layer 2) for supporting IP QoS (layer 3). This Chapter begins with an overview of the current IP QoS frameworks in Section 8.2. In Section 8.3, the discussion is focused on the interaction of layer 2 and layer 3 in satellite environments for the support of IP QoS. This Section ends with an example of implementation for a variant of one of the most popular IP QoS frameworks. The following Section 8.4 provides an in-depth work on achieving QoS requirements by a cross-layer approach over SI-SAP. Section 8.5 looks into another aspect of resource management: the QoS provisioning for terminals supporting dual network access (WiFi and satellite). Implicit cross-layer design methodology is used in Section 8.6 for switched Ethernet over LEO satellite networks. Finally, this Chapter is concluded in Section 8.7. In the studies carried out in this Chapter, Scenario 2 (i.e., GEO-based DVB-S/-RCS systems; see Chapter 1, Section 1.4) has been adopted, except for the considerations made in Section 8.6, where Scenario 3 (i.e., LEO satellite) has been considered. © 2007 Springer Science+Business Media, LLC