Calculating Valid Domains for BDD-Based Interactive Configuration

In these notes we formally describe the functionality of Calculating Valid Domains from the BDD representing the solution space of valid configurations. The formalization is largely based on the CLab configuration framework

The effect of mixed-enzyme addition in anaerobic digestion on methane yield of dairy cattle manure

This study investigates the effect of applying a mixture of enzymes (ME) to dairy cattle manure (DCM) as substrate in anaerobic digestion (AD). The aims of this study were to evaluate different methods of ME application to DCM at different temperatures and to investigate the effect of adding ME during the pre-treatment of the solid fractions of dairy cattle manure (SFDCM). The results showed that there was no positive effect of direct ME addition to substrate at either mesophilic (35 C) or thermophilic (50 ◦ C) process temperatures, but there was a significant 4.44% increase in methane yield when DCM, which had been incubated with ME addition at 50 ◦ C for three days, was fed to a digester when compared to a control digester operating at the same retention time. Methane production was detected during the pre-treatment incubation, and the total sum methane yield during pre-treatment and digestion was found to be 8.33% higher than in the control. The addition of ME to the SFDCM in a pre-incubation stage of 20 h at 35 ◦ C gave a significant increase in methane yield by 4.15% in a digester treating a mixed substrate (30% liquid fractions DCM and 70% enzyme-treated SFDCM) when compared with the control digester treating a similar mixed substrate with inactivated enzyme addition. The results indicate that direct physical contact of enzyme molecules and organic material in DCM prior to AD, without the intervention of extracellular enzymes from the indigenous microorganism population, was needed in order to increase methane yields. Keywords: biogas; mixed enzymes; pre-treatment; incubation; manur

New Zealand’s Performance Based Research Funding (PBRF) model undermines Maori research

The Performance Based Research Funding (PBRF) model was instigated in 2002 to increase “the quality of research through peer assessment and performance indicators” in New Zealand (Ministry of Education 2002: 17). It is used to allocate funding between universities, departments and researchers according to the putative quality and quantity of their research outputs over the preceding 6 years. PBRF is expected to incentivise improved research excellence and efficiency, and allow government to invest research funds where greatest returns will result. This is potentially a huge gain for Māori. However, “by changing the conditions of knowledge production, research assessment exercises may also alter the shape and direction of disciplines by diverting and channelling researchers’ intellectual attention and political engagement, influencing what they study, how they do it, and how they report and write” (Middleton 2009: 194). Indeed, universities repeatedly encourage researchers to focus on activities that will improve their PBRF rankings. We believe that an unintended consequence of PBRF is the creation of significant barriers to increasing the volume, scope and quality of environmental research for Māori

Perbandingan Kinerja Satu dan Dua Fase Digester Biogas dengan Substrat Campuran Manure Sapi Perah dan Manure Sapi Perah yang Diasamkan.

Dibeberapa negara maju manure ternak merupakan sumber utama emisi amonia. Salah satu strategi untuk menurunkan emisi amonia dari manure ternak adalah dengan menurunkan pH manure dengan penambahan senyawa asam sampai mencapai pH 5,6. Media yang lazim digunakan adalah asam sulfat. Penelitian ini mengkaji penggunaan campuran (1:1) manure sapi perah yang telah diasamkan dengan manure sapi perah normal sebagai substrat pada digester biogas baik pada satu fase (R3) maupun pada dua fase digester (R2). Rerata produksi methan setelah dua kali hydraulic retention time (HRT) sebesar 175,71 ml/g VS pada R2 dan 166,96 ml/g VS pada R3. Namun produksi methan turun drastis setelah tiga kali HRT yaitu 2,45 ml/g VS pada R2 dan 6,85 ml/g VS pada R3. Kecernaan bahan organik juga mengalami penurunan yang sangat drastis dari sekitar 30% pada kedua digester setelah dua kali HRT menjadi hanya 11,64% pada R2 dan 19,03% pada R3. Konsentrasi volatile fatty acid (VFA) yang mengalami peningkatan yang sangat drastis diakhir penelitian yaitu sebesar 7870,41 mg/L pada R2 dan 6719,13 mg/L pada R3 mengindikasikan adanya inhibisi pada bakteri methanogenik. Hasil penelitian ini mengindikasikan bahwa campuran manure yang telah diasamkan dengan manure normal dengan perbandingan 1:1 tidak sesuai untuk digunakan sebagai substrat biogas yang ditandai dengan rendahnya produki methan dan tingginya akumulasi VFA. Kata kunci: biogas, manure yang diasamkan, dua fase digester

5G for LEO – Technical Challenges and Initial Results

In December 2019, 3GPP have for the 5G specification decided to separate the Narrowband IoT Non-Terrestrial Network (NB-IoT NTN) from the New Radio NTN. Due to this change, NB-IoT NTN becomes a very attractive candidate for LEO IoT satellite constellations. The decision emphasises that there is a strong push for cellular standards into the space industry and that commercial utilizations in large scale is getting closer. However, it also entails significant technical challenges in terms of connectivity, backhaul integration and operational features. GateHouse Telecom currently work on an ARTES supported project (Narrowband IoT standard for small satellites). Based on the existing 3GPP terrestrial NB-IoT standard the purpose of this project is to identify areas of adaptations to utilize this from space. Further, the project will provide solutions to overcome the waveform challenges related to doppler, latency, timing, propagation loss etc. This poster provides initial results from the project in terms of architecture, suggested adaptations and technical challenges related to architecture and implementation

Art + Science + Dung Beetles: Collaborating to Sustain People, Land and Water

Report from the Art+Water, art and science project 2019.Dung beetles connect history, myth, science, and economy. They symbolise regeneration and restoration of life. They keep vital ecological cycles churning, build soil, disperse nutrients, and even play a role in protecting our streams. They improve soils to help feed people. That makes dung beetles joiners and menders – what better agents for connecting the minds and hearts of an artist (Jessica Ritchie), an entomologist (Emma Curtin) and an ecologist (Henrik Moller) in an Art+Water project

Opportunities and challenges for multicriteria assessment of food system sustainability

The focus of the Special Feature on “Multicriteria assessment of food system sustainability” is on the complex challenges of making and communicating overall assessments of food systems sustainability based on multiple and varied criteria. Four papers concern the choice and development of appropriate tools for making multicriteria sustainability assessments that handle built-in methodological conflicts and trade-offs between different assessment objectives. They underscore the value of linking diverse methods and tools, or nesting and stepping their deployment, to help build resilience and sustainability. They conclude that there is no one tool, one framework, or one indicator set that is appropriate for the different purposes and contexts of sustainability assessment. The process of creating the assessment framework also emerges as important: if the key stakeholders are not given a responsible and full role in the development of any assessment tool, it is less likely to be fit for their purpose and they are unlikely to take ownership or have confidence in it. Six other papers reflect on more fundamental considerations of how assessments are based in different scientific perspectives and on the role of values, motivation, and trust in relation to assessments in the development of more sustainable food systems. They recommend a radical break with the tradition of conducting multicriteria assessment from one hegemonic perspective to considering multiple perspectives. Collectively the contributions to this Special Feature identify three main challenges for improved multicriteria assessment of food system sustainability: (i) how to balance different types of knowledge to avoid that the most well-known, precise, or easiest to measure dimensions of sustainability gets the most weight; (ii) how to expose the values in assessment tools and choices to allow evaluation of how they relate to the ethical principles of sustainable food systems, to societal goals, and to the interests of different stakeholders; and (iii) how to enable communication in such a way that the assessments can effectively contribute to the development of more sustainable food systems by facilitating a mutual learning process between researchers and stakeholders. The wider question of how to get from assessment to transformation goes across all three challenges. We strongly recommend future research on the strengths, weaknesses, and complementarities of taking a values-based rather than a performance-based approach to promoting the resilience and sustainability of coupled ecological, economic, and social systems for ensuring food security and agroecosystem health in the coming millennium

Effects of stock type, irrigation and effluent dispersal on earthworm species composition, densities and biomasses in New Zealand pastures

We investigated the effects of grazing stock, irrigation and effluent dispersal on earthworm species compositions, densities and biomasses in 615 locations across 41 farms in the Waitaki Basin, New Zealand, between April and September 2012. No native megascolecid earthworms were found, but four introduced European species were encountered. Among earthworms collected, Aporrectodea caliginosa accounted for 70% of the total, 23% were Lumbricus rubellus and 4% Aporrectodea longa. When compared with untreated locations, total earthworm density was higher by 42% in effluent only locations and 72% in irrigated only locations. Maximum densities and biomasses occurred where both effluent and irrigation were applied. L. rubellus density was 32% higher in effluent only locations, 123% higher in irrigated only locations and 180% higher in effluent and irrigated locations than untreated locations. A. longa occurred in 24% of the sampled locations and appeared to be suppressed in irrigated locations. When equivalent treatments were applied, earthworm densities were 15.4% to 36.6% higher on sheep farms than on dairy farms; earthworm biomasses differed by –3.3% to 55.8% between these two kinds of stock animal farms. Treatment effects on earthworms were evident only in the upper 10 cm soil layer. Effluent and water application may have reduced the risk of desiccation and increased the availability of resources for earthworms. However, local absence of the deep burrowing species (e.g. A. longa) raises concerns about ecosystem functioning. This is a topic that should be explored further.Peer Reviewe

Effects of high-temperature isochoric pre-treatment on the methane yields of cattle, pig and chicken manure

Cattle manure, dewatered pig manure and chicken manure were pre-treated in a high-temperature reactor under isochoric conditions for 15 min at temperatures between 100 and 225 ◦ C with 25 ◦ C intervals to study the effect on their methane yield. After 27 days of batch incubation, cattle manure showed a significant improvement in its biochemical methane potential (BMP) of 13% at 175 ◦ C and 21% at 200 ◦ C. Pig manure showed improvements at temperatures of 125 C and above, with a maximum 29% increase in yield at 200 ◦ C. The BMP of chicken manure was reduced by 18% at 225 C, but at lower temperatures there were no significant changes. It was found that this method of pre-treatment could be feasible if sufficient surplus energy was available or if the energy used in the pre-treatment could be recovered. Keywords: BMP; manure; biogas; thermal; pre-treatment; energy requirement