Evaluating pedagogical practices supporting collaborative learning for model-based system development courses

Model-based software development (MBSD) has been widely used in industry for its effectiveness of code generation, code reuse and system evolution. At different stages of the software lifecycle, models -- as opposed to actual code -- are used as abstractions to present software development artifacts. In a university software engineering curriculum, compared to other concrete and tangible courses, e.g., game and app development, these levels of abstraction are often difficult for students to understand, and further, to see models' usefulness in practice. This paper presents an evaluation of pedagogical practices supporting collaborative learning for MBSD courses from experiences of teaching them at University of Oslo. The focus is to answer two research questions: 1) What are the challenges and possibilities when using a collaborative learning approach for teaching modelling and architecture? 2) What are the challenges and benefits of having a holistic approach to MBSD courses in light of the requirements of academia and the needs of industry? The term “holistic” is understood 1) as an approach that involves human factors (users), technology and processes, 2) as an approach to teaching MBSD courses where modelling for Enterprise Architecture is taught together with System Architecture and Model-Driven Language Engineering. Empirical data was collected through interviews, questionnaires, and document analysis. The paper’s research results show that three different course perspectives (Modeling for Enterprise Architecture with Business Architecture, System Architecture and Model Driven Language Engineering) are essential parts of teaching modeling courses, and an industry field study shows that industry sees the potential of having junior architects to provide support to a team and solving basic architectural problems

Investigations of ash pipes displacement in BP-1150 boiler

Artykuł prezentuje metody pomiarów zmieniającej się topologii podczas procesu uruchamiania i odstawiania bloku energetycznego. Autorzy sku-piają swoją uwagę na przemieszczeniach układów kompensacyjnych pyłoprzewodów wraz z ich opisem.The article presents methods of surveying changing topology during the process of boiler startup and shutdown. Possibility of abnormal movement occurred which led to extensive research of ash pipes. Methodology of those research based on using complex equipment able to measure from a distance up to 200 m with uncertainty of 2 to 5 mm and direct laser measurements was introduced. The main focus of the publication is fixed on describing complicated ash pipe displacements and it's compensation systems as well as exhibition of preliminary results

Laboratory stand for flowmeters tests

W artykule omówiono budowę i zasadę działania zautomatyzowanego stanowiska do badania i wzorcowania przepływomierzy spiętrzających przepływ. Przedstawiono podstawowe elementy wchodzące w skład stanowiska: tunel aerodynamiczny typu otwartego oraz zespół rurociągów o średnicach od 104 do 381 mm wraz z instrumentami pomiarowymi. Stanowisko zarządzane było autorskimi programami pracującymi w środowisku LabView, dzięki którym możliwe było m.in. wyznaczanie charakterystyk współczynnika przepływu K rurek uśredniających ciśnienie dynamiczne w czasie rzeczywistym oraz ich archiwizacja w celu przygotowania charakterystyk metrologicznych. Zamieszczono w pracy analizę niepewności pomiaru rurkami uśredniającymi ciśnienie dynamiczne oraz wykresy współczynnika przepływu dla wybranych średnic rurociągu i porównano je ze sobą. Sformułowano wnioski natury metrologicznej.In this article it was discussed construction and principle of operation of automated measurement stand for testing differential pressure flowmeters. It was shown basic elements of measurement stand: open type wind tunnel and system of pipelines (D=104-381 mm) with measurement instrumentation. This stand was controlled by means of author’s computer programs working in LabView environment. The programs served to observe flow coefficient K in real time and to archive them in order to prepare metrological characteristics. Additionally it was placed metrological uncertainty analysis using two-profile Flow Averaging Tube and its flow coefficient K characteristics for selected diameters of pipeline. Results of measurements was compared to each other for different pipeline diameters. Metrological summary was formulated

l-DNA-Based Catalytic Hairpin Assembly Circuit

Isothermal, enzyme-free amplification methods based on DNA strand-displacement reactions show great promise for applications in biosensing and disease diagnostics but operating such systems within biological environments remains extremely challenging due to the susceptibility of DNA to nuclease degradation. Here, we report a catalytic hairpin assembly (CHA) circuit constructed from nuclease-resistant l-DNA that is capable of unimpeded signal amplification in the presence of 10% fetal bovine serum (FBS). The superior biostability of the l-DNA CHA circuit relative to its native d-DNA counterpart was clearly demonstrated through a direct comparison of the two systems (d versus l) under various conditions. Importantly, we show that the l-CHA circuit can be sequence-specifically interfaced with an endogenous d-nucleic acid biomarker via an achiral peptide nucleic acid (PNA) intermediary, enabling catalytic detection of the target in FBS. Overall, this work establishes a blueprint for the detection of low-abundance nucleic acids in harsh biological environments and provides further impetus for the construction of DNA nanotechnology using l-oligonucleotides

Heterochiral DNA Strand-Displacement Circuits

The absence of a straightforward strategy to interface native d-DNA with its enantiomer l-DNAoligonucleotides of opposite chirality are incapable of forming contiguous Watson–Crick base pairs with each otherhas enforced a “homochiral” paradigm over the field of dynamic DNA nanotechnology. As a result, chirality, a key intrinsic property of nucleic acids, is often overlooked as a design element for engineering of DNA-based devices, potentially limiting the types of behaviors that can be achieved using these systems. Here we introduce a toehold-mediated strand-displacement methodology for transferring information between orthogonal DNA enantiomers via an achiral intermediary, opening the door for “heterochiral” DNA nanotechnology having fully interfaced d-DNA and l-DNA components. Using this approach, we demonstrate several heterochiral DNA circuits having novel capabilities, including autonomous chiral inversion of DNA sequence information and chirality-based computing. In addition, we show that heterochiral circuits can directly interface endogenous RNAs (e.g., microRNAs) with bioorthogonal l-DNA, suggesting applications in bioengineering and nanomedicine. Overall, this work establishes chirality as a design parameter for engineering of dynamic DNA nanotechnology, thereby expanding the types of architectures and behaviors that can be realized using DNA

SHALLOW DOPING PROFILES FOR HIGH-SPEED BIPOLAR TRANSISTORS

Within the framework of a double polysilicon self-aligned bipolar technology shallow base widths WB for npn transistors were obtained by low-energy implantation of boron into either crystalline Si (WB = 150 nm), preamorphized Si (WB = 125 nm) or by diffusing boron out of polysilicon (WB= 85 nm). Rapid thermal processing was used for the emitter drive-in. A transit frequency of 22 GHz was achieved for WB = 85 nm. Comparison with one-dimensional calculations indicates the potential of further enhancement of intrinsic device speed by optimization of the proposed technological approaches

Analogues of the Allosteric Heat Shock Protein 70 (Hsp70) Inhibitor, MKT-077, As Anti-Cancer Agents

The rhodacyanine, MKT-077, has anti-proliferative activity against cancer cell lines through its ability to inhibit members of the heat shock protein 70 (Hsp70) family of molecular chaperones. However, MKT-077 is rapidly metabolized, which limits its use as either a chemical probe or potential therapeutic. We report the synthesis and characterization of MKT-077 analogs designed for greater stability. The most potent molecules, such as 30 (JG-98), were at least 3-fold more active than MKT-077 against the breast cancer cell lines MDA-MB-231 and MCF-7 (EC50 values of 0.4 ± 0.03 μM and 0.7 ± 0.2 μM, respectively). The analogs modestly destabilized the chaperone "clients", Akt1 and Raf1, and induced apoptosis in these cells. Further, the microsomal half-life of JG-98 was improved at least 7-fold (t1/2 = 37 min) compared to MKT-077 (t1/2 < 5 min). Finally, NMR titration experiments suggested that these analogs bind an allosteric site that is known to accommodate MKT-077. These studies advance MKT-077 analogs as chemical probes for studying Hsp70's roles in cancer