Fuel Dependent Heat Release Differences between Euro Diesel Fuel and RME in a HSDI Diesel Engine

In the degree that costs and demand of crude oil rise, diminish the economical disadvantages for alternative Diesel fuels, resulting in a variety of feasible substitutes. Diesel fuel substitutes have deviating exhaust emissions from conventional fuel. The methyl ester of rapeseed oil (known as RME/Biodiesel) is receiving increasing attention as an alternative fuel for Diesel engines. RME is a non-toxic, biodegradable, and renewable fuel with the potential to reduce engine exhaust emissions [1]. The main disadvantage for RME is its vaporisation and self ignition characteristics at low load conditions. Engine experiments were carried out at 4 bar IMEP with Euro Diesel fuel (EDF) as reference and RME. During these engine experiments EGR and injection pressure were varied. As a result, differences in exhaust emissions due to EGR, injection pressure and fuel type were observed. The objective of this work was to find answers for fuel dependent differences in indicated load and exhaust gas emissions. As combustion and emission formation of RME has not been fundamentally explained yet [2], a detailed analysis approach based on explanation models for fuel characteristics was chosen to explain the observed differences

Detailed Heat Release Analyses With Regard To Combustion of RME and Oxygenated Fuels in an HSDI Diesel Engine

Experiments on a modern DI Diesel engine were carried out: The engine was fuelled with standard Diesel fuel, RME and a mixture of 85% standard Diesel fuel, 5% RME and 10% higher alcohols under low load conditions (4 bar IMEP). During these experiments, different external EGR levels were applied while the injection timing was chosen in a way to keep the location of 50% heat release constant. Emission analysis results were in accordance with widely known correlations: Increasing EGR rates lowered NOx emissions. This is explained by a decrease of global air-fuel ratio entailing longer ignition delay. Local gas-fuel ratio increases during ignition delay and local combustion temperature is lowered. Exhaust gas analysis indicated further a strong increase of CO, PM and unburned HC emissions at high EGR levels. This resulted in lower combustion efficiency. PM emissions however, decreased above 50% EGR which was also in accordance with previously reported results. Besides those similar trends, fuel dependent differences in indicated thermal efficiency as well as CO, HC, NOx and especially PM emissions were observed. These differences were evaluated by detailed heat release analysis and explanation models based upon fuel characteristics as fuel viscosity and fuel distillation curve. Fuel spray evaporation and heat release were influenced by these fuel characteristics. Due to these characteristics it was concluded that RME has a higher tendency to form fuel rich zones at low load conditions than the other tested fuel types. Moreover it was found that improved fuel spray vaporisation is an option to improve exhaust emissions at low load conditions

African farm trajectories and the sub-continental food crisis

This is a study of farm dynamics in eight African countries, drawing on a sample of more than 3000 farm households. It deals mainly with food crops and in detail with maize and makes a longitudinal analysis by systematically comparing current conditions with those obtaining when the farm was set up under its present management. From the study emerges an overall picture of inadequately exploited production potentials where farmers’ commercial energies are driven towards other food crops than grains, especially vegetables for urban markets. Commercial incentives in food grain production favour small groups of well-placed and usually male farmers, while, the lack of seed-fertiliser technology and commercial incentives means that smallholders devote their energies to other crops or to non-farm sources of income

Temperature Stabilization of the Phase-Reference Line at the European Spallation Source

We consider temperature stabilization of the phase-reference line at the European Spallation Source, a facility for neutron spallation currently under construction. Based on extensive modeling of the heat dynamics, a prototype model-based control system with associated hardware architecture is developed and experimentally evaluated on a small-scale setup. The results indicate that temperature stability within ±0.1°C is possible to achieve, also with significant disturbances in the ambient temperature expected during operation

Global analysis of mRNA stability in the archaeon Sulfolobus

BACKGROUND: Transcript half-lives differ between organisms, and between groups of genes within the same organism. The mechanisms underlying these differences are not clear, nor are the biochemical properties that determine the stability of a transcript. To address these issues, genome-wide mRNA decay studies have been conducted in eukaryotes and bacteria. In contrast, relatively little is known about RNA stability in the third domain of life, Archaea. Here, we present a microarray-based analysis of mRNA half-lives in the hyperthermophilic crenarchaea Sulfolobus solfataricus and Sulfolobus acidocaldarius, constituting the first genome-wide study of RNA decay in archaea. RESULTS: The two transcriptomes displayed similar half-life distributions, with medians of about five minutes. Growth-related genes, such as those involved in transcription, translation and energy production, were over-represented among unstable transcripts, whereas uncharacterized genes were over-represented among the most stable. Half-life was negatively correlated with transcript abundance and, unlike the situation in other organisms, also negatively correlated with transcript length. CONCLUSION: The mRNA half-life distribution of Sulfolobus species is similar to those of much faster growing bacteria, contrasting with the earlier observation that median mRNA half-life is proportional to the minimal length of the cell cycle. Instead, short half-lives may be a general feature of prokaryotic transcriptomes, possibly related to the absence of a nucleus and/or more limited post-transcriptional regulatory mechanisms. The pattern of growth-related transcripts being among the least stable in Sulfolobus may also indicate that the short half-lives reflect a necessity to rapidly reprogram gene expression upon sudden changes in environmental conditions

Affect Consciousness and Adult Attachment

The concept of affect consciousness refers to the ability to perceive, reflect upon, express and respond to one's own or other individuals' affective experiences. The aim of this study was to investigate how affect consciousness and adult attachment are related. Three clinical groups (eating disorders, relational problems, and stress-related problems), and one non-clinical group (total N = 82) completed the Attachment Style Questionnaire and were interviewed using the Affect Consciousness Interview-Self/Other. Results showed associations between high affect consciousness and secure attachment, and between low affect consciousness and insecure attachment. Moreover, attachment style was predicted by consciousness about others' and own affects in general, and specifically by consciousness about others' anger and guilt, and by own joy. Affect consciousness as a potential dimension or moderator of attachment merits further investigation

Simultaneous paralogue knockout using a CRISPR-concatemer in mouse small intestinal organoids

Approaches based on genetic modification have been invaluable for investigating a wide array of biological processes, with gain- and loss-of-function approaches frequently used to investigate gene function. However, the presence of paralogues, and hence possible genetic compensation, for many genes necessitates the knockout (KO) of all paralogous genes in order to observe clear phenotypic change. CRISPR technology, the most recently described tool for gene editing, can generate KOs with unprecedented ease and speed and has been used in adult stem cell-derived organoids for single gene knockout, gene knock-in and gene correction. However, the simultaneous targeting of multiple genes in organoids by CRISPR technology has not previously been described. Here we describe a rapid, scalable and cost effective method for generating double knockouts in organoids. By concatemerizing multiple gRNA expression cassettes, we generated a ‘gRNA concatemer vector’. Our method allows the rapid assembly of annealed synthetic DNA oligos into the final vector in a single step. This approach facilitates simultaneous delivery of multiple gRNAs to allow up to 4 gene KO in one step, or potentially to increase the efficiency of gene knockout by providing multiple gRNAs targeting one gene. As a proof of concept, we knocked out negative regulators of the Wnt pathway in small intestinal organoids, thereby removing their growth dependence on the exogenous Wnt enhancer, R-spondin1.A.A-R. is supported by the Medical Research Council (MRC), A.M.is supported by Wntsapp (Marie Curie ITN) and B-K.K. and R.M. are supported by a Sir Henry Dale Fellowship from the Wellcome Trust and the Royal Society [101241/Z/13/Z] and receive support through a core grant from the Wellcome Trust and MRC to the WT-MRC Cambridge Stem Cell Institute

Replication-biased genome organisation in the crenarchaeon Sulfolobus

<p>Abstract</p> <p>Background</p> <p>Species of the crenarchaeon <it>Sulfolobus </it>harbour three replication origins in their single circular chromosome that are synchronously initiated during replication.</p> <p>Results</p> <p>We demonstrate that global gene expression in two <it>Sulfolobus </it>species is highly biased, such that early replicating genome regions are more highly expressed at all three origins. The bias by far exceeds what would be anticipated by gene dosage effects alone. In addition, early replicating regions are denser in archaeal core genes (enriched in essential functions), display lower intergenic distances, and are devoid of mobile genetic elements.</p> <p>Conclusion</p> <p>The strong replication-biased structuring of the <it>Sulfolobus </it>chromosome implies that the multiple replication origins serve purposes other than simply shortening the time required for replication. The higher-level chromosomal organisation could be of importance for minimizing the impact of DNA damage, and may also be linked to transcriptional regulation.</p

No Strings Attached: Force and Vibrotactile Feedback in a Guitar Simulation

In this paper we propose a multisensory simulation of plucking guitar strings in virtual reality. The auditory feedback is generated by a physics-based simulation of guitar strings, and haptic feedback is provided by a combination of high fidelity vibrotactile actuators and a Phantom Omni haptic device. Moreover, we present a user study (n=29) exploring the perceived realism of the simulation and the relative importance of force and vibrotactile feedback for creating a realistic experience of plucking virtual strings. The study compares four conditions: no haptic feedback, vibrotactile feedback, force feedback, and a combination of force and vibrotactile feedback. The results indicate that the combination of vibrotactile and force feedback eliits the most realistic experience, and during this condition, the participants were less likely to inadvertently hit strings after the intended string had been plucked. Notably, no statistically significant differences were found between the conditions involving either vibrotactile or force feedback, which points towards an indication that haptic feedback is important but does not need to be high fidelity in order to enhance the quality of the experience