Integration of technical equipment in a project driven learning environment

Purpose: This paper describes the integration of technical equipment in a project driven learning environment in the School of Engineering in the Faculty of Science, Engineering and Built Environment at Deakin University, Geelong, Australia. Technical or laboratory equipment is a critical factor when designing learning environments and more so in a project driven learning environment. Important Findings: Deakin University has strong partnerships with industry and the community and with its cloud and located based learning policy has extremely flexible learning environments tailored to the needs of the students, with all the programs being offered in on-campus mode as well as off-campus mode. The off-campus study mode has made it even more important to have flexibility in the usage and access of the technical equipment in the laboratories. Conclusion: The School of Engineering at Deakin University Australia has developed a project-oriented design based learning environment which allows students to learn through design activities while being driven by the deliverables and outputs of a project. The technical equipment is required to be able to be used for traditional laboratory experiments in order to achieve fundamental knowledge requirements as well as project oriented knowledge and practice

Optimal multi-period consumption and investment with short-sale constraints

Cataloged from PDF version of article.This article examines agents’ consumption-investment problem in a multi-period pure exchange economy where agents are constrained with the short-sale of state-dependent risky contingent claims. In equilibrum, agents hold options written on aggregate consumption in their optimal portfolios. Furthermore, under the specific case of quadratic utility, the optimal risk-sharing rule derived for the pricing agent leads to a multifactor conditional consumption-based capital asset pricing model (CCAPM), where excess option returns appear as factors. 2013 Elsevier Inc. All rights reserved

Behaviour of alloyed cast iron mould materials in the production of glass container

Cam ambalaj üretiminde kullanılan kalıplar, havada yüksek sıcaklıktaki ergimiş camla temas ederek ürüne şekil verirler. Ergimiş cam ile temas eden kalıpların çalışma yüzeyleri, mekanik gerilmelere ve ısıl çevrimlere maruz kalırlar. Bu etkilerle kalıp yüzeylerinde meydana gelen hasarlar, kalıpların kullanım ömürlerini sınırlar ve mamul kalitesini bozar. Cam ambalaj üretimi kalıbı malzemelerinden beklenen özellikleri sağlayan kalıp metalleri arasında en ucuz ve kolay şekil verilebilen malzemeler gri dökme demirlerdir. Bu çalışmada, alaşımlı gri dökme demir kalıp malzemesi örneklerinin, üretim koşullarına benzer koşullar altındaki davranışı laboratuvar ortamında incelenmiştir. Metal-sıvı cam etkileşmesini sağlamak amacıyla, hazırlanan deney düzeneğinde taşıyıcı kola bağlı olan dökme demir örnekler, fırın içerisine aşağıya doğru hareket ettirilerek ergimiş cam banyosuna temas ettirilmiş ve bir süre bekletildikten sonra fırın dışına çıkarılarak üflenen basınçlı hava ile soğutulmuştur. Çevrimsel olarak tekrarlanan bu hareketle oluşturulan performans deneyleri süresince oluşan hasarlar; oksidasyon ve ısıl yorulmanın bir arada olduğu hasarlardır. Yüzeyde, ilerleyen oksitlenme ile poroz yapıda yoğun oksit fazları oluşmaktadır. Isıl gerilmeler ve cama temasla oluşan gerilmeler, hasar oluşumunda ikincil etki olarak, mikro çatlaklar oluşturmakta ve adhesif aşınmada yüzeyden malzeme kaybını hızlandıran kırılma ve ayrılmalara neden olmaktadır. Cam örneklerin yüzeyine kalıp metalinden, adhesif aşınma ile metaloksit kalıntıları geçmekte ve cam yüzeyini kirletmektedir. Hava atmosferi koşullarında yapılan deneylerde camın köpürmeye başladığı sıcaklıklar inert gaz atmosferindeki sıcaklıklardan daha düşüktür Yüksek sıcaklıklarda argon gaz atmosferinde alaşımlı dökme demir ile temas halindeki cama zamana bağlı olarak metal-cam arayüzeyinden demir geçişleri olmaktadır.   Anahtar Kelimeler: Alaşımlı dökme demir, cam ambalaj üretimi, kalıp.  The mould materials used in the glass container production form the glass product by contacting with molten glass in air at elevated temperatures. The performing surfaces, which contact with molten glass, are subjected to the mechanical stresses and the thermal cyclic operations. These failures at the mould surfaces limit the service life of the moulds and affect the quality of glass products. Production of high-quality glass with smooth surface is related with the contact behaviour of the hot glass towards the mould. Therefore, beside cost and rate of production, the selection of a mould material has significant importance in the glass industry. Cast irons are commonly used as a mould material in the production of glass materials. One of the most inexpensive and easily machinable materials is grey cast iron for the mould materials, which meet the desirable properties in the glass container production. However, these materials require further surface treatment applications to improve the surface properties. In this study, behaviour of alloyed grey cast iron mould material under the production conditions simulated in the laboratory and the effects of the hot glass contact and failure formation mechanisms on the glass forming mould surfaces were investigated. The tests were carried out using a combined furnace with a pneumatic movable plunger set-up. The vertically movable holder was mounted on a plunger, to provide the interactions between hot glass and metal. The cast iron samples were attached at the tip of the holder of the experimental set-up. The plunger was moved up and down periodically. At the lower end position, the sample surface and hot glass contact in an exact immersion depth at certain time. Then the plunger lifted out of the furnace immediately, and compressed air was blown against the specimen surface through a nozzle. After the cooling with blown air, the same movement periods were cyclically repeated. This movement carried on until desired cycle number was reached. Then samples were pulled up from the plunger. After the cyclic experimental studies, the surface of the samples was investigated and characterised. The surface hardness of alloyed cast iron decreases during the experimental processes. Thermal and contact stresses create micro cracks and cause the acceleration of material losses from the surface of the material by adhesion, as a secondary factor. The wear tracks, especially through the graphite flakes obtained on the surface of alloyed cast iron. The formation of decarburised pitting at the surface that growth through the graphite flakes, due to the oxidation and the adhesion, propagates material losses causing intensive adhesive wear at the surface. Failures in alloyed cast iron were oxidation and thermal fatigue failures. Adhesive wear occurred on the surfaces because of the formation of micro holes, tracks that molten glass penetrates. The dense oxide phases occurred with the oxidation progressing on the surface. Metal oxides transferred into the glass from mould surface and contaminated the glass surface. The surface of alloyed cast iron was rapidly oxidised at elevated temperatures and thicker oxide layer occurred at the surfaces. The oxide layer pulled out from the surface by molten glass and the surface smoothness decreased. The oxide phases, which occurred at the sample surfaces during the performance experiments, were characterised by x-ray analyses. After 5000 cycle both Fe3O4 and Fe2O3 phases occurred at the alloyed cast iron surface. TG-DTA analyses were carried out in air atmosphere. At about 400 °C oxidation began and the maximum oxidation peak in the DTA curve was recorded at about 750 °C. Decarburisation reaction, which started with mass loss, occurred after 765 °C. The rate of decarburisation increased with rise in temperature from 920 to 973°C. The wetting tests were carried out for determination of the contact angles and the wetting behaviour of alloyed cast iron and glass ball at elevated temperature. The oxygen at the glass-metal interface caused gasification and foaming during the wetting experiments. The glass foaming temperature for the experiments done in air atmosphere was lower then the experiments done in Ar atmosphere for alloyed cast iron. Iron diffusion occurred on the glass-metal interfaces depending on the time in Ar atmosphere. The iron diffusion from alloyed cast iron to the glass increased with time. The contamination occurred at the glass surface by iron diffusion.   Keywords: Alloyed cast iron, glass container production, mould

Investigation on N-gram Approximated RNNLMs for Recognition of Morphologically Rich Speech

Recognition of Hungarian conversational telephone speech is challenging due to the informal style and morphological richness of the language. Recurrent Neural Network Language Model (RNNLM) can provide remedy for the high perplexity of the task; however, two-pass decoding introduces a considerable processing delay. In order to eliminate this delay we investigate approaches aiming at the complexity reduction of RNNLM, while preserving its accuracy. We compare the performance of conventional back-off n-gram language models (BNLM), BNLM approximation of RNNLMs (RNN-BNLM) and RNN n-grams in terms of perplexity and word error rate (WER). Morphological richness is often addressed by using statistically derived subwords - morphs - in the language models, hence our investigations are extended to morph-based models, as well. We found that using RNN-BNLMs 40% of the RNNLM perplexity reduction can be recovered, which is roughly equal to the performance of a RNN 4-gram model. Combining morph-based modeling and approximation of RNNLM, we were able to achieve 8% relative WER reduction and preserve real-time operation of our conversational telephone speech recognition system.Comment: 12 pages, 2 figures, accepted for publication at SLSP 201

Option-Implied Volatility Measures and Stock Return Predictability

Do changes in implied volatilities (IVs) or differences among options at different spots on the volatility surface contain predictive information for future returns? The question has been asked repeatedly—and often answered in the affirmative for specific measures—but questions remain. In this article, the authors perform a comparison test on six return predictors that are all computed as differences among implied and realized volatilities and that have been proposed in the literature. The authors consider more measures, more maturities, and longer samples than earlier articles, and they include a variety of appropriate control variables. They find that the difference between at-the-money (ATM) call and put IV (CPIV) and out-of-the-money (OTM) put IV minus ATM call IV are both highly significant at the individual stock level, while a long–short portfolio strategy based on realized minus implied volatility does very well. The alternative volatility combinations are substantially less effective as return predictors

Adult systemic cat scratch disease associated with therapy for hepatitis C

BACKGROUND: We describe the first case of systemic cat scratch disease in a patient receiving peginterferon α-2a and ribavirin for treatment of hepatitis C. Cases of adult systemic CSD are extremely infrequent and immunomodulatory treatment for hepatitis C has been associated with aberrant host responses to common pathogens. CASE PRESENTATION: A 52 year old man being treated for hepatitis C presented with diffuse lymphadenopathy, weight loss, fevers and splenic lesions. Symptoms were initially confused with adverse effects of his regimen, delaying recognition of his infection. Diagnostic investigation, including histopathology, microbiology and serologic parameters, confirmed that his illness was due to disseminated cat scratch disease with Bartonella henselae. CONCLUSION: Disseminated CSD is exceptionally rare in adults. We describe the first case of disseminated cat scratch disease associated with peginterferon α and ribavirin to alert clinicians of the need to be aware of unusual manifestations of common infections in this population

Analysis of MEFV exon methylation and expression patterns in familial Mediterranean fever

<p>Abstract</p> <p>Background</p> <p>MEFV mutations and decreased expression level of the gene are related to FMF pathology. DNA methylation at CpG islands is a well-known mechanism for transcriptional silencing. MEFV has a CpG island, spanning a part of the first intron and the whole of the second exon of the gene covering 998 bp region. Here, we tested the hypothesis that the MEFV transcript level in FMF patients correlates with its methylation level, and methylation, by allowing transcription silencing, has a role in FMF ethiopathogenesis.</p> <p>Methods</p> <p>The study group was composed of pediatric FMF patients (N = 51) and age-gender matched healthy controls (N = 21). The relative expression level of MEFV was assessed via quantitative real-time PCR (qRT-PCR) and bisulfite sequencing (BS) was performed to analyse the methylation level quantitatively.</p> <p>Results</p> <p>MEFV expression in FMF patients were decreased compared to healthy controls (<it>P </it>= 0.031). Methylation level of exon 2 of MEFV was found to be slightly higher in FMF patients compared to healthy controls (76% versus 74%) (<it>P </it>= 0.049). The expression level of the MEFV was negatively correlated with the methylation level of the CpG island in both FMF and healthy controls groups (cor = -0.29, <it>P </it>= 0.041) but more so in the FMF only group (cor = -0.36, <it>P </it>= 0.035).</p> <p>Conclusions</p> <p>In this study, the relation between reduced MEFV expression level and FMF was confirmed. Observed slight increase in methylation in FMF patients, and correlation of methylation with expression might be indicative of its role in FMF, however a larger dataset is needed to confirm our preliminary findings.</p

Granulomatous hepatitis due to Bartonella henselae infection in an immunocompetent patient

<p>Abstract</p> <p>Background</p> <p><it>Bartonella henselae </it>(<it>B. henselae</it>) is considered a rare cause of granulomatous hepatitis. Due to the fastidious growth characteristics of the bacteria, the limited sensitivity of histopathological stains, and the non-specific histological findings on liver biopsy, the diagnosis of hepatic bartonellosis can be difficult to establish. Furthermore, the optimal treatment of established hepatic bartonellosis remains controversial.</p> <p>Case presentation</p> <p>We present a case of hepatic bartonellosis in an immunocompetent woman who presented with right upper quadrant pain and a five cm right hepatic lobe mass on CT scan. The patient underwent a right hepatic lobectomy. Surgical pathology revealed florid necrotizing granulomatous hepatitis, favoring an infectious etiology. Despite extensive histological and serological evaluation a definitive diagnosis was not established initially. Thirteen months after initial presentation, hepatic bartonellosis was diagnosed by PCR studies from surgically excised liver tissue. Interestingly, the hepatic granulomas persisted and <it>Bartonella henselae </it>was isolated from the patient's enriched blood culture after several courses of antibiotic therapy.</p> <p>Conclusion</p> <p>The diagnosis of hepatic bartonellosis is exceedingly difficult to establish and requires a high degree of clinical suspicion. Recently developed, PCR-based approaches may be required in select patients to make the diagnosis. The optimal antimicrobial therapy for hepatic bartonellosis has not been established, and close follow-up is needed to ensure successful eradication of the infection.</p