Effects of NaCl,SO2, NH3, O3, and ultraviolet light on atmospheric corrosion of Zn

The atmospheric corrosion behavior of Zn was studied in laboratory environments containing constituents that have not previously received much attention, in particular, humidity, SO₂, NH ₃, and O ₃, along with ultraviolet (UV) light irradiation and a preloading of NaCl. After exposure, corrosion rates were measured using mass loss, and corrosion products were identified by X-ray diffraction, Fourier transform-infrared spectroscopy, and energy dispersive spectroscopy. In this study, UV light and O ₃ did not significantly affect the Zn corrosion rate in the absence of Cl ⁻. However, when NaCl was present, UV light inhibited the Zn corrosion rate below 90% relative humidity (RH) and accelerated the Zn corrosion rate at 99% RH. The presence of UV light also increased the formation of zinc hydroxyl sulfate and gordaite when exposed to 120 parts per billion (ppb) SO ₂ and NaCl. The combination of SO ₂ and O ₃ with the preloading of NaCl increased the corrosion rate of Zn compared with NaCl alone. NH ₃ at a concentration of 550 ppb did not have a significant effect on the Zn corrosion rate.     

Compositional effects on the Type I hot corrosion of β-NiAl alloys

Cast alloys of nominal compositions Ni-36Al, Ni-36Al-5Co, Ni-36Al-5Pt, Ni-36Al-5Co-5Pt, and Ni-36Al-5Cr (at.%) were tested under Type I (900 °C) hot corrosion conditions in order to determine the influence of various elements commonly found in diffusion aluminide coatings on the resistance to this mode of attack. Chromium was found to be the most effective element in conferring hot corrosion resistance, but improvements in performance were also found with the addition of Co and/or Pt. Experimental evidence is presented which suggests that each of these elements increase the hot corrosion resistance of β-NiAl alloys primarily by increasing their ability to rapidly form a thermally grown Al₂O₃ scale and to heal this scale in the event of damage. Potential explanations for this enhanced scale formation and healing capability are discussed.     

Advanced ePrometheus™ GNF fuel cycle optimization tool

This paper presents the advanced version of ePrometheus™ GNF Fuel Cycle Optimization Tool. ePrometheus is Global Nuclear Fuel-Americas LLC (“GNF”) patented computer system used to optimize Boiling Water Reactor (BWR) fuel management and operations. The advanced version of ePrometheus utilizes a new database structure (Oracle 11 g) and a new C#, WPF based graphical user interface (GUI), and employs a capability of performing refueling calculation. It also displays additional 2-D and 3-D core simulation data that are necessary to improve the fuel cycle design process, and utilizes many more advanced features based on user experience feedback. The objective of this paper is to present new advanced infrastructure of the system, and to provide overall information on the advanced features of the newly released version 3.0.     

Correlation study of damp heat and pressure cooker testing on backsheets

For photovoltaic (PV) modules, high‐quality backsheets are essential. To verify these qualities, hot and humid tests of up to 1000 h are standard in the PV industry. Damp heat (DH) tests are useful for evaluating material quality and infant failures, especially for materials that are sensitive to hydrolysis. However, shorter test periods are needed. Hence, the objective of this study was to investigate and correlate the aging behavior of hydrolysis‐sensitive polyester [poly(ethylene terephthalate) (PET)] based backsheets after exposure to DH and pressure cooker conditions. The material properties, such as thermal and mechanical parameters, correlated well between the pressure cooker at 120 °C and the DH test, with the qualification that differences in the failure mechanism were seen after 96 and 2000 h, respectively. Nevertheless, it should be acceptable to use pressure cooker tests (PCTs) for fast material testing. The PCT is proposed to significantly reduce the testing time for infant failures and material quality to around 4 days for PET‐based backsheets. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44230.     

Economic benefits of improved water quality in the Delaware River (USA)

Water quality in the Delaware River, USA, has improved significantly since the Federal Water Pollution Control Act (1948), Clean Water Act of 1972, and authorization of the Delaware River Basin Commission Compact in 1961. Initial economic analysis by the Federal Water Pollution Administration in 1966 concluded the multimillion dollar pollution abatement programme would generate $350 million in annual benefits by improving dissolved oxygen levels to fishable standards in the Delaware River. Although water quality in the Delaware has improved substantially, scientists have called for raising the 1960s dissolved oxygen criteria from 3.5 mg/L to 5.0 mg/L to ensure year‐round propagation of anadromous American shad and Atlantic sturgeon. This higher level would also mitigate atmospheric warming resulting in increased water temperatures and sea water incursion, both of which would lead to reductions in dissolved oxygen saturation in the river. Additional economic valuation of this water quality improvement shows direct use benefits in the Delaware River to range from $371 million to $1.1 billion per year. Other economic sectors benefiting from improved water quality include recreational boating ($46–$334 million), recreational fishing ($129–$202 million), agriculture ($8–$188 million), nonuse value ($76–$115 million), viewing/boating/fishing ($55–$68 million), bird watching ($15–$33 million), property value ($13–27 million), water supply ($12–$24 million), commercial fishing (up to $17 million), and navigation ($7–$16 million). Future economic research is needed in the Delaware River watershed to more precisely measure nonuse benefits by public willingness to pay for improved water quality.     

Analysis of the Deformation Behavior of Magnesium-Rare Earth Alloys Mg-2 pct Mn-1 pct Rare Earth and Mg-5 pct Y-4 pct Rare Earth by In Situ Energy-Dispersive X-ray Synchrotron Diffraction and Elasto-Plastic Self-Consistent Modeling

The deformation behavior of the Mg-RE alloys ME21 and WE54 was investigated. Although both alloys contain rare earth elements, which alter and weaken the texture, the flow curves of the alloys deviate significantly, especially in uniaxial compression test. Apart from the higher strength of the WE54 alloy, the compression flow curve does not exhibit the typical sigmoidal shape, which is associated with tension twinning. However, optical microscopy, X-ray texture measurements, and EBSD analysis reveal the activity of tension twinning. The combination of in situ energy-dispersive X-ray synchrotron diffraction and EPSC modeling was used to analyze these differences. The investigation reveals that twin propagation is decelerated in the WE54 alloy, which requires a change of the twinning scheme from the ‘finite initial fraction’ to the ‘continuity’ assumption. Furthermore, an enhanced activity of the 〈c+a〉 pyramidal slip system was observed in case of the WE54 alloy.     

Software diversity: state of the art and perspectives

Diversity is prevalent in modern software systems to facilitate adapting the software to customer requirements or the execution environment. Diversity has an impact on all phases of the software development process. Appropriate means and organizational structures are required to deal with the additional complexity introduced by software variability. This introductory article to the special section “Software Diversity—Modeling, Analysis and Evolution” provides an overview of the current state of the art in diverse systems development and discusses challenges and potential solutions. The article covers requirements analysis, design, implementation, verification and validation, maintenance and evolution as well as organizational aspects. It also provides an overview of the articles which are part of this special section and addresses particular issues of diverse systems development.