Methane production from feather waste pretreated with Ca(OH)₂:Process development and economical analysis

Published: FEB 2014 AbstractThis study investigated the industrial application of feather waste as a substrate for anaerobic digestion. Feather was pretreated with 0-0.2 Ca(OH)(2) g/g TSfeather (total solids of feathers) for 30-120 min at 100-120 degrees C, in order to increase the digestibility, and to enhance the methane yield in a subsequent digestion at 55 degrees C. Based on the results of the batch digestion, an industrial process was developed, which can achieve 0.40 Nm(3)/kgVS(feather) (volatile solids of feathers) methane yield from the pretreated feathers, while it fulfills the animal by-product hygenization requirements as well. This base case of the industrial pretreatment process was designed using SuperPro Designer (R) for utilizing 2,500 tons of feathers per year, which is the waste stream from an average slaughterhouse with a capacity of 60,000 broilers per day. The production cost of the methane is estimated to be 0.475 EUR/Nm(3), while the investments on the pretreatment unit requires 0.97 million EUR as total capital investment, and 0.25 million EUR/year for operating cost. However, the process is sensitive to the plant capacity. Changing the plant capacity from 625 to 10,000 tons of feather per year, results in reducing the biogas production cost from 1.177 to 0.203 EUR/Nm(3). In addition, sensitivity analysis was performed on the base case to investigate the effect of the value of the incoming feather on the overall process profitability. The results showed that the proposed investment could be considered as being financially viable in the case of production of upgraded biomethane even without the current gate fee system

The newborn brain is sensitive to the communicative function of language

Recent studies demonstrated neural systems in bilateral fronto-temporal brain areas in newborns specialized to extract linguistic structure from speech. We hypothesized that these mechanisms show additional sensitivity when identically structured different pseudowords are used communicatively in a turn-taking exchange by two speakers. In an fNIRS experiment newborns heard pseudowords sharing ABB repetition structure in three conditions: two voices turn-takingly exchanged different pseudowords (Communicative); the different pseudowords were produced by a (Single Speaker); two voices turn-takingly repeated identical pseudowords (Echoing). Here we show that left fronto-temporal regions (including Broca’s area) responded more to the Communicative than the other conditions. The results demonstrate that newborns’ left hemisphere brain areas show additional activation when various pseudowords sharing identical structure are exchanged in turn-taking alternation by two speakers. This indicates that language processing brain areas at birth are not only sensitive to the structure but to the functional use of language: communicative information transmission. Newborns appear to be equipped not only with innate systems to identify the structural properties of language but to identify its use, communication itself, that is, information exchange between third party social agents—even outside of the mother–infant dyad

Semantic systems are mentalistically activated for and by social partners

A recently discovered electrophysiological response, the social N400, suggests that we use our language system to track how social partners comprehend language. Listeners show an increased N400 response, when themselves not, only a communicative partner experiences a semantic incongruity. Does the N400 reflect purely semantic or mentalistic computations as well? Do we attribute language comprehension to communicative partners using our semantic systems? In five electrophysiological experiments we identified two subcomponents of the social N400. First, we manipulated the presence-absence of an Observer during object naming: the semantic memory system was activated by the presence of a social partner in addition to semantic predictions for the self. Next, we induced a false belief—and a consequent miscomprehension—in the Observer. Participants showed the social N400, over and above the social presence effect, to labels that were incongruent for the Observer, even though they were congruent for them. This effect appeared only if participants received explicit instructions to track the comprehension of the Observer. These findings suggest that the semantic systems of the brain are not merely sensitive to social information and contribute to the attribution of comprehension, but they appear to be mentalistic in nature