Anaerobic digestion at mesophilic and thermophilic temperature

During anaerobic digestion of organic wastes, nutrient-rich digestate is produced. This digestate has great potential as a fertiliser on farmland. However, one concern is the content of organic pollutants in the digestate, as these may influence the soil fertility in the long-term perspective. Different organic pollutants have been found in various organic wastes and types of digestate. This thesis describes the effect of temperature on the anaerobic degradation of different organic pollutant i.e. aromatic compounds and on the structure of microbial communities. To isolate the impact of temperature on the degradation, investigations were carried out in two laboratory-scale bioreactors that were stable and equivalent in performance apart from process temperature and hydraulic retention time. These reactors have treated the same type of organic municipal household waste for many years. The aromatic compounds were chosen to represent important anaerobic reaction steps and key intermediates. Several of the selected compounds were efficiently degraded at the mesophilic temperature (37 ºC). In contrast, phenols and phthalic acid were not degraded at the thermophilic temperature (55 ºC). This limited degradation at the higher temperature is contrary to the general degradation rate of organic matter, which increase with elevated temperatures. Chemical analysis of the digestate from the laboratory-scale reactor operating at thermophilic temperature detected a comparably higher content of phenols, verifying the degradation results. The effect of temperature on phenol degradation was further confirmed in a study including several large-scale bioreactors. To investigate the impact of temperature on microbial community structure, phylogenetic analysis was performed with 16S rRNA genes from the archaeal and bacterial communities in the same two laboratory-scale bioreactors as used for the degradation study. This analysis revealed a lower microbial diversity at the higher temperature. This difference in diversity can possibly explain the observed difference in degradation capacity. The microorganisms responsible for the degradation of phenol were studied in enrichment cultures originating from the two laboratory-scale bioreactors. Two different bacteria were suggested to perform the phenol degradation in these cultures, a finding that highlights the influence of temperature on community structure

Traveling of the Electrons Belonging to the Elements of d-Orbits (Transition Elements) (Third Report) : 5d-Orbits Elements

第二報に続いて5d軌道元素に就いても電子の動きを検討したが此系列の元素は所謂貴金属に所属するものが多く化合物としてよりも金属単体として利用価値の高いものが多く化合物の電子は極めて動き易く従って化合物による触媒作用も3d, 4d系列の元素とはその触媒機構の異なった形式を取るものが多い様に見受けられ特に錯体の形及びその触媒作用に就いても可成り異なった形式を取る様であ尚比系列中で原子番号(58)Ce→(71)Luまでは4f軌道元素(稀土類元素)として除外する事にした

Forecasting Intermittent Demand by Hyperbolic-Exponential Smoothing

Croston's method is generally viewed as superior to exponential smoothing when demand is intermittent, but it has the drawbacks of bias and an inability to deal with obsolescence, in which an item's demand ceases altogether. Several variants have been reported, some of which are unbiased on certain types of demand, but only one recent variant addresses the problem of obsolescence. We describe a new hybrid of Croston's method and Bayesian inference called Hyperbolic-Exponential Smoothing, which is unbiased on non-intermittent and stochastic intermittent demand, decays hyperbolically when obsolescence occurs and performs well in experiments.Comment: Earlier versions of this work were presented at the 25th European Conference on Operations Research, 2012; and at the 54th Annual Conference of the UK Operational Research Society, 2012. A journal version is in preparatio

Strengths and weaknesses in executive functioning in children with intellectual disability

Children with intellectual disability (ID) were given a comprehensive range of executive functioning measures, which systematically varied in terms of verbal and non-verbal demands. Their performance was compared to the performance of groups matched on mental age (MA) and chronological age (CA), respectively. Twenty-two children were included in each group. Children with ID performed on par with the MA group on switching, verbal executive-loaded working memory and most fluency tasks, but below the MA group on inhibition, planning, and non-verbal executive-loaded working memory. Children with ID performed below CA comparisons on all the executive tasks. We suggest that children with ID have a specific profile of executive functioning, with MA appropriate abilities to generate new exemplars (fluency) and to switch attention between tasks, but difficulties with respect to inhibiting pre-potent responses, planning, and non-verbal executive-loaded working memory The development of different types of executive functioning skills may, to different degrees, be related to mental age and experience

Potential of pineapple waste extract (PWE) as co-substrate in anaerobic digestion of rice straw washwater (RSWW): enhancement of biogas production

This study aims to investigate the potential methane yield by mono-anaerobic digestion of rice straw washwater (RSWW) and pineapple waste extract (PWE) as well as the co-digestion of both RSWW and PWE at a ratio of 50:50 (v/v). The experiment was conducted at a controlled mesophilic temperature of 37 °C in Upflow Anaerobic Sludge Blanket (UASB) reactor for a period of approximately 55 days. The process performances were evaluated based on the efficiency of COD removal and methane production in relation to other parameters such as pH, organic loading rate (OLR) and alkalinity ratio. This study confirmed that the rate of COD removal for RSWW, PWE, and RSWW:PWE (50:50) were achieved the stable condition at 81, 89, and 86% respectively. The alkalinity ratio value and pH throughout the experimental period remained below 0.30 and kept in the range of 6.5–7.0 indicated the stable and good environment existed for anaerobic digestion within the UASB reactor. This study implies that the co-digestion of RSWW:PWE found to improve the efficiency of COD removal and production of methane during the mono-digestion of RSWW from 81 to 86% and 0.093 to 0.13 LCH4/g CODrem by the increment of 6.2 and 40%, respectively

Open-system orchestration as a relational source of sensing capabilities: Evidence from a venture association

Research on innovation networks has highlighted the pivotal role that actors with more prominence and power, such as hub firms, may play in orchestrating the activities of other network members along a collective innovation effort. Our study examined the undertheorized, but no less important, type of orchestration that characterizes other organizations, such as business incubators and venture associations, who seek to support the dispersed entrepreneurial efforts of network members. We refer to this type as ‘open-system’ orchestration, as opposed to the commonly studied ‘closed-system’ type performed by hub firms. Our findings reveal how the processes of open-system orchestration differ markedly from those of closed-system orchestration, and detail how these processes influence the micro-foundations of network members’ sensing capabilities. By doing so, we also offer empirical substantiation and theoretical elaboration to the idea that dynamic capabilities might not reside exclusively inside firms, but could be co-created relationally with other parties in the business ecosystem