Cement dust as an absorbent for so2 removal from stack gases

“The limestone-wet scrubbing process for SO2 removal from stack gases has undergone much study which has resulted in construction of at least three full scale operating plants. The process used in these plants is based on calcining the limestone, by injection into the boiler, which is subsequently absorbed from the flue gases in a wet scrubber where reaction with the SO2 takes place (injection­ scrubbing process). A variation of this process, whereby 11mAstone is added directly to the scrubber slurry has also been investigated (scrubber addition process). However, this process has not been utilized because it requires more limestone than the injection process to achieve the same SO2 removal. It therefore has higher operating cost. Lime is known to be a more effective absorbent in this process, but it is much too costly. It was postulated that waste cement dust, having a calcium content comparable to limestone, might be a lower cost absorbent; but, it was not known how cement dust compares with limestone or lime for removal of SO2 in the scrubber addition process. Therefore, a bench scale scrubber system was built and this experimental investigation was conducted in an effort to obtain a preliminary comparison of cement dust with lime and limestone as a scrubber addition absorbent for re­moval of SO2. The results of these experiments indicate that the cement dust is a better absorbent than limestone and its effectiveness ap­proaches that of lime. It has been recommended that further testing be conducted in a pilot scale system.”--Summary

The reluctant customer:case study research exploring the impact of marketisation on pedagogy and practice at three universities in england

The marketisation of English Higher Education (HE) has become an important issue in recent years, yet little empirical research exists that explores the impact of marketisation on pedagogy and practice. This research aims to explore the relationship between marketisation and a customer culture in HE, whether the idea of a student-customer is internalised by staff and students, and if these factors shape student-centred learning (SCL). Through the lens of critical pedagogy, this study uses mixed methods to investigate macro, meso, and micro level processes. The analysis of 113 published university mission statements identified marketing-focussed statements as making up almost half of the content, showing that competition to bolster reputations and attract students is increasingly important as a result of marketisation. Case study research at three different English universities was the context for gathering quantitative and qualitative data. Questionnaire data obtained from 145 students, and interviews with 24 participants, which included senior university managers, lecturers and students, provided meso and micro level data. The findings show that the consequences of marketisation influences the opinions and behaviours of participants, leading to customer-focussed relationships between staff and students; an increased focus on instrumental learning; teaching being primarily focussed on imparting knowledge; and SCL principles being employed less than many students would like. Student opinions regarding the purpose and goals of HE were influenced by tuition fees, which created a focus on the financial elements of HE, and an acceptance that students are customers of HE. Despite this, both staff and students revealed a reluctance to fully internalise a student-customer concept, and were against the idea that knowledge should be imparted as part of a transactional experience. The study concludes that marketisation contributes to creating a customer culture and impedes SCL, but that there is growing resistance from staff and students against these consequences

Detection of bearing failure in mechanical devices using neural networks

We present a novel time-domain method for the detection of faulty bearings that has direct applicability to monitoring the health of the turbo pumps on the Space Shuttle Main Engine. A feed-forward neural network was trained to detect modelled roller bearing faults on the basis of the periodicity of impact pulse trains. The network's performance was dependent upon the number of pulses in the network's input window and the signal-to-noise ratio of the input signal. To test the model's validity, we fit the model's parameters to an actual vibration signal generated by a faulty roller element bearing and applied the network trained on this model to detect faults in actual vibration data. When this network was tested on the actual vibration data, it correctly identified the vibration signal as a fault condition 76 percent of the time

User-initialized active contour segmentation and golden-angle real-time cardiovascular magnetic resonance enable accurate assessment of LV function in patients with sinus rhythm and arrhythmias.

BackgroundData obtained during arrhythmia is retained in real-time cardiovascular magnetic resonance (rt-CMR), but there is limited and inconsistent evidence to show that rt-CMR can accurately assess beat-to-beat variation in left ventricular (LV) function or during an arrhythmia.MethodsMulti-slice, short axis cine and real-time golden-angle radial CMR data was collected in 22 clinical patients (18 in sinus rhythm and 4 patients with arrhythmia). A user-initialized active contour segmentation (ACS) software was validated via comparison to manual segmentation on clinically accepted software. For each image in the 2D acquisitions, slice volume was calculated and global LV volumes were estimated via summation across the LV using multiple slices. Real-time imaging data was reconstructed using different image exposure times and frame rates to evaluate the effect of temporal resolution on measured function in each slice via ACS. Finally, global volumetric function of ectopic and non-ectopic beats was measured using ACS in patients with arrhythmias.ResultsACS provides global LV volume measurements that are not significantly different from manual quantification of retrospectively gated cine images in sinus rhythm patients. With an exposure time of 95.2 ms and a frame rate of > 89 frames per second, golden-angle real-time imaging accurately captures hemodynamic function over a range of patient heart rates. In four patients with frequent ectopic contractions, initial quantification of the impact of ectopic beats on hemodynamic function was demonstrated.ConclusionUser-initialized active contours and golden-angle real-time radial CMR can be used to determine time-varying LV function in patients. These methods will be very useful for the assessment of LV function in patients with frequent arrhythmias

Good infinity : Hegel, Levinas and the accomplishment of ethical life

This study presents a critique of the social and political thought of Emmanuel Levinas. We aim to demonstrate that Levinas' hostile characterisation of Hegel's System serves to disguise a latent 'Hegelian' dimension in his own thought. Levinas' covert Hegelianism has essentially three aspects: first, Levinas, like Hegel, advances a post-critical concept of the infinite; second, his philosophical discourse bears a strong family resemblance to Hegel's speculative logic: and, third, notwithstanding his protests to the contrary, his philosophy exhibits a systematic structure (in the speculative sense of the term). By identifying these speculative motifs in Levinas' work we show, first, that it is possible to subject Levinas to an immanent Hegelian critique and we then proceed to execute it. The dominant trend in Levinasian interpretation, follows Derrida, and tends to overlook the significance of Levinas' concept of society. We aim to show, however, that the notion of a visible ethical community is at the centre of Levinas' philosophy. Moreover, we attempt to demonstrate that Levinas’ concept of an ethical community is ultimately incompatible with the subjective principle underlying modem social and political life. This in turn leads Levinas to violate his own emphasis on respecting the absolute alterity of the Other. Finally, we attempt to show that Hegel's System provides a way of redeeming the ambition of Levinas' philosophy, while avoiding its negative implications

Collaborative design of assessment criteria to improve undergraduate student engagement and performance

Student engagement is vital in enhancing the student experience and encouraging deeper learning. Involving students in the design of assessment criteria is one way in which to increase student engagement. In 2011, a marking matrix was used at Aston University (UK) for logbook assessment (Group One) in a project-based learning module. The next cohort of students in 2012 (Group Two) were asked to collaboratively redesign the matrix and were given a questionnaire about the exercise. Group Two initially scored a lower average logbook mark than Group One. However, Group Two showed the greatest improvement between assessments, and the quality of, and commitment to, logbooks was noticeably improved. Student input resulted in a more defined, tougher mark scheme. However, this provided an improved feedback system that gave more scope for self-improvement. The majority of students found the exercise incorporated their ideas, enhanced their understanding, and was useful in itself