Intercomparison of scanning probe microscopes

Comparison measurements on reference standards are reported in which 13 partners with different instruments took part. A set of prototype standards which had been produced and calibrated within a European project were used for the measurements. Here, results of measurements on a 240 nm step height standard and a two-dimensional lateral standard with a nominal pitch of 1 μm are reported.     

The effect of aluminium coating on elemental standards in X-ray microanalysis

The standardisation of frozen hydrated bulk biological specimens using gelatin standards is described. The relationship between corrected elemental X-ray counts and ionic concentration was found to be linear, and minimum detectable limits for each element are stated. Variations in uncorrected standard curves were found to be due to changes in aluminium coating thickness. There was an inverse relationship between coating thickness and elemental X-ray counts. The factors causing this are discussed. To avoid errors arising from inconsistent aluminium thickness, experimental material should only be compared with standards of similar aluminium net counts. This can be achieved most easily by mounting and analysing specimen and standard together.     

熔窑玻璃液流数值模拟的新发展

熔窑玻璃液流数值模拟的新发展赵国昌（清华大学核能技术设计研究院，１０００８４）ＮｅｗＤｅｖｅｌｏｐｍｅｎｔｏｆｔｈｅＮｕｍｅｒｉｃａｌＳｉｍｕｌａｔｉｏｎｆｏｒＦｌｏｗａｎｄＨｅａｔＴｒａｎｓｆｅｒｏｆＧｌａｓｓＭｅｌｔｉｎＴａｎｋＦｕｒｎａｃｅ￥Ｚ...     

材料研究中系列试样的单标样法 X 射线定量分析

本文提出了用一个标样进行系列试样 X 射线定量相分析的方法.它克服了一般 X 射线定量方法需要混合研磨和手续烦复的缺点以及无标样 X 射线定量方法存在病态方程不易解决的问题.该方法对常规 X 射线定量分析具有普遍的实用性.     

Quantitative description of the microstructure–porosity of sialons and iron silicide inclusions

Sialon ceramics are a modern type of engineering ceramics with excellent mechanical, thermal and corrosion resistant properties. This paper describes the structure characterisation of porous sialon ceramics. It is possible to significantly improve the strength and crack resistance of sialon ceramics as a result of a reduction of the volume fraction of porosity.     

Systematic analyses and comparison of development performance and product quality of Incremental Process and Agile Process

ContextAlthough Agile software development models have been widely used as a base for the software project life-cycle since 1990s, the number of studies that follow a sound empirical method and quantitatively reveal the effect of using these models over Traditional models is scarce.ObjectiveThis article explains the empirical method of and the results from systematic analyses and comparison of development performance and product quality of Incremental Process and Agile Process adapted in two projects of a middle-size, telecommunication software development company. The Incremental Process is an adaption of the Waterfall Model whereas the newly introduced Agile Process is a combination of the Unified Software Development Process, Extreme Programming, and Scrum.MethodThe method followed to perform the analyses and comparison is benefited from the combined use of qualitative and quantitative methods. It utilizes; GQM Approach to set measurement objectives, CMMI as the reference model to map the activities of the software development processes, and a pre-defined assessment approach to verify consistency of process executions and evaluate measure characteristics prior to quantitative analysis.ResultsThe results of the comparison showed that the Agile Process had performed better than the Incremental Process in terms of productivity (79%), defect density (57%), defect resolution effort ratio (26%), Test Execution V&V Effectiveness (21%), and effort prediction capability (4%). These results indicate that development performance and product quality achieved by following the Agile Process was superior to those achieved by following the Incremental Process in the projects compared.ConclusionThe acts of measurement, analysis, and comparison enabled comprehensive review of the two development processes, and resulted in understanding their strengths and weaknesses. The comparison results constituted objective evidence for organization-wide deployment of the Agile Process in the company.     

Employing early model-based safety evaluation to iteratively derive E/E architecture design

ISO 26262 addresses development of safe in-vehicle functions by specifying methods potentially used in the design and development lifecycle. It does not indicate what is sufficient and leaves room for interpretation. Yet the architects of electric/electronic systems need design boundaries to make decisions during architecture evolutionary design without adding a risk of late changes. Correct selection of safety mechanisms from alternatives at early design stages is vital for time-to-market of critical systems. In this paper we present and discuss an iterative architecture design and refinement process that is centered around ISO 26262 requirements and model-based analysis of safety-related metrics. This process simplifies identification of the most sensitive parts of the architecture, selection of the best suitable safety mechanisms to reduce thereby failure rate on the system level and improve the metrics defined by the standard. To support the defined process we present the metamodels that can be integrated with existing DSL (domain-specific language) frameworks to extend them with information supporting further extraction of fault propagation behavior. We provide a framework for architecture model analysis and selection of safety mechanisms. We provide details on the model-based toolset that has been developed to support the proposed analysis and synthesis methods, and demonstrate its application to analysis of a steer-by-wire system model and selection of safety mechanisms for it.     

Relationship Between Interfacial Water Layer Adhesion Loss of Silicon/Glass Fiber-Epoxy Systems: A Quantitative Study

Water at the polymer/substrate interface is often the major cause of adhesion loss in coatings, adhesives, and fiber-reinforced polymer composites. This study critically assesses the relationship between the interfacial water layer and the adhesion loss in epoxy/siliceous substrate systems. Both untreated and silane-treated Si substrates and untreated and silane-treated E-glass fibers were used. Thickness of the interfacial water layer was measured on epoxy/Si systems by Fourier transform infrared-multiple total internal reflection (FTIR-MTIR) spectroscopy. Adhesion loss of epoxy/Si systems and epoxy/E-glass fiber composites was measured by peel adhesion and short-beam shear tests, respectively. Little water accumulation at the epoxy/Si substrate interface was observed for silane-treated Si substrates, but about 10 monolayers of water accumulated at the interface between the epoxy and the untreated Si substrate following 100 h of exposure at 24 °C. More than 70% of the initial epoxy/untreated Si system peel strength was lost within 75 h of exposure, compared with 20% loss after 600 h for the silane-treated Si samples. Shear strength loss in composites made with untreated E-glass fiber was nearly twice that of composites fabricated with silane-treated fiber after 6 months of immersion in 60 °C water. Further, the silane-treated composites remained transparent, but the untreated fiber composites became opaque after water exposure. Evidence from FTIR-MTIR spectroscopy, adhesion loss, and visual observation strongly indicated that a water layer at the polymer/substrate interface is mostly responsible for the adhesion loss of epoxy/untreated siliceous substrate systems and epoxy/untreated glass fiber composites and that FTIR-MTIR is a viable technique to reliably and conveniently assess the adhesion loss attributable to water sorption at the interface.     

Public Displays of Play: Studying Online Games in Physical Settings

As research on virtual worlds gains increasing attention in educational, commercial, and military domains, a consideration of how player populations are ‘reassembled’ through social scientific data is a timely matter for communication scholars. This paper describes a large‐scale study of virtual worlds in which participants were recruited at public gaming events, as opposed to through online means, and explores the dynamic relationships between players and contexts of play that this approach makes visible. Challenging conventional approaches to quantitatively driven virtual worlds research, which categorizes players based on their involvement in an online game at a particular point in time, this account demonstrates how players' networked gaming activities are contingent on who they are playing with, where, and when.     

Gasoline composition determined by H NMR spectroscopy

A fast and simple ¹H NMR spectroscopic method was developed for the concentration measurement of aromatic, olefinic and aliphatic fractions in gasoline samples. Simultaneously, individual components such as benzene, methyl tert-butyl ether and several dienes could be determined. The method relies on only a few, well-established assumptions about the molecular compositions and is therefore applicable to a broad range of gasolines. It is well suited for laboratories with high sample throughput since measurement time is short and all concentrations are determined within one NMR experiment. The method was applied to commercial gasolines and samples used in European round robin tests. Comparisons of NMR and round robin test results showed excellent agreement.