A physical model for seismic noise generation from sediment transport in rivers

Measuring sediment flux in rivers remains a significant problem in studies of landscape evolution. Recent studies suggest that observations of seismic noise near rivers can help provide such measurements, but the lack of models linking observed seismic quantities to sediment flux has prevented the method from being used. Here, we develop a forward model to describe the seismic noise induced by the transport of sediment in rivers. The model provides an expression for the power spectral density (PSD) of the Rayleigh waves generated by impulsive impacts from saltating particles which scales linearly with the number of particles of a given size and the square of the linear momentum. After incorporating expressions for the impact velocity and rate of impacts for fluvially transported sediment, we observe that the seismic noise PSD is strongly dependent on the sediment size, such that good constraints on grain size distribution are needed for reliable estimates of sediment flux based on seismic noise observations. The model predictions for the PSD are consistent with recent measurements and, based on these data, a first attempt at inverting seismic noise for the sediment flux is provided

Co-creative media: theorising digital storytelling as a platform for researching and developing participatory culture

This paper considers the question, 'what is co-creative media, and why is it a useful idea in social media research'? The term 'co-creative media' is now used by Creative Industries researchers at QUT to theoretically frame their use of digital storytelling as an action research platform for investigating participatory new media culture. Digital storytelling is a set of collaborative digital media production techniques that have been used to facilitate social participation in numerous Australian and international contexts. Digital storytelling has been adapted by Creative Industries researchers at QUT as a platform for researching the potential of vernacular creativity in a variety of contexts, including social inclusion of marginalized and disadvantaged groups; inclusion in public histories of narratives that might be overlooked; and articulation of voices that otherwise remain silent in the formulation of social and economic development strategies. The adaption of digital storytelling to different contexts has been shaped by the reflexive, recursive, and pragmatic requirements of action research. Amongst other things, this activity draws attention to the agency of researchers in facilitating these kinds of participatory media processes and outcomes. This discussion serves to problematise concepts of participatory media by introducing the term 'co-creative media' and differentiating these from other social media production practices

Amino acid substitutions within the heptad repeat domain 1 of murine coronavirus spike protein restrict viral antigen spread in the central nervous system.

Targeted recombination was carried out to select mouse hepatitis viruses (MHVs) in a defined genetic background, containing an MHV-JHM spike gene encoding either three heptad repeat 1 (HR1) substitutions (Q1067H, Q1094H, and L1114R) or L1114R alone. The recombinant virus, which expresses spike with the three substitutions, was nonfusogenic at neutral pH. Its replication was significantly inhibited by lysosomotropic agents, and it was highly neuroattenuated in vivo. In contrast, the recombinant expressing spike with L1114R alone mediated cell-to-cell fusion at neutral pH and replicated efficiently despite the presence of lysosomotropic agents; however, it still caused only subclinical morbidity and no mortality in animals. Thus, both recombinant viruses were highly attenuated and expressed viral antigen which was restricted to the olfactory bulbs and was markedly absent from other regions of the brains at 5 days postinfection. These data demonstrate that amino acid substitutions, in particular L1114R, within HR1 of the JHM spike reduced the ability of MHV to spread in the central nervous system. Furthermore, the requirements for low pH for fusion and viral entry are not prerequisites for the highly attenuated phenotype

Design And Fabrication of Condenser Microphone Using Wafer Transfer And Micro-electroplating Technique

A novel fabrication process, which uses wafer transfer and micro-electroplating technique, has been proposed and tested. In this paper, the effects of the diaphragm thickness and stress, the air-gap thickness, and the area ratio of acoustic holes to backplate on the sensitivity of the condenser microphone have been demonstrated since the performance of the microphone depends on these parameters. The microphone diaphragm has been designed with a diameter and thickness of 1.9 mm and 0.6 $\mu$m, respectively, an air-gap thickness of 10 $\mu$m, and a 24% area ratio of acoustic holes to backplate. To obtain a lower initial stress, the material used for the diaphragm is polyimide. The measured sensitivities of the microphone at the bias voltages of 24 V and 12 V are -45.3 and -50.2 dB/Pa (at 1 kHz), respectively. The fabricated microphone shows a flat frequency response extending to 20 kHz.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Estimating the effect of Earth elasticity and variable water density on tsunami speeds

The speed of tsunami waves is typically calculated using the shallow-water approximation over a rigid-body Earth. Recent comparisons of tsunami arrival times from the 11 March 2011 tsunami suggest, however, that the standard formulation has errors around the 1% level, and it has been suggested that the elasticity of the Earth can explain the discrepancy. While previous work has indeed shown that such elastic deformation can modify tsunami speeds, the effect has been neglected partly due to the difficulty in understanding how large this elastic effect is. Here, we remedy this by providing a new derivation and expression for how to incorporate the first-order effect that solid Earth elasticity and ocean water compressibility have on tsunami speeds. This result is shown to agree approximately with previous theory and helps to explain observed timing discrepancies from the 11 March 2011 tsunami. The dispersive elastic correction and the non-dispersive compressibility correction together may account for the majority of the observed discrepancy

Alternative Pathways To Engineering Success –Using Academic And Social Integration To Understand Two-Year Engineering Student Success

The need for educating engineers in the United States continues as the projected demand is still rising as the number of high school seniors planning to enter engineering careers has remained relatively stable (Sargent, 2014). Additionally, figures show that attrition rates in undergraduate engineering continue to be an area of concern, (Sargent, 2014; Gibbons, 2005; NSF, 2004). Given the projected increased demand for engineers, the engineering education community must explore a variety of pathways for engineering students to be successful. Organizations such as National Science Foundation (Laanan, Jackson, Darrow, 2010) have noted that beginning engineering study at a two-year campus and then transferring to an engineering bachelor’s degree-granting institution is an important path and source for additional engineering students. Although some have explored the logistical issues and curricular design components of two-year campuses that enables engineering students to complete their bachelor degrees elsewhere, there is very little that explores the non-curricular factors on these campuses that help such students successfully progress (Laanan, et al., 2010). Using Tinto’s theory of integration (1975, 1993), this study examines the relationship between student entry characteristics and measures of social and academic integration to engineering learning outcomes. Understanding how integration factors on two-year campuses impact engineering student success can be used to inform the design of curricular and campus-based experiences that support the success of engineering students on two-year campuses.  Results indicate the social and academic integration factors significantly predict engineering students’ learning outcomes, especially their commitment to engineering studies

Трупоспалення чернелів-руського черняхівського могильника

Розглянуто матеріали комплексів із кремаціями чернелів-руського могильника черняхівської культури.В статье рассмотрены материалы комплексов с кремациями чернелив-русского могильника черняховской культуры (Западное Подолье), который относится к категории могильников с доминированием ингумаций, что выделяет его среди биритуальных могильников черняховской культуры. Из 288 исследованных погребений черняховской культуры — только две кремации (погребения 44 и 240), что составляет менее 1 % погребений могильника. Кроме того, в могильнике выявлены ритуально нарушенные ингумации, в заполнении могильных ям которых зафиксированы остатки кремаций, что, возможно, связано с сожжением эксгумированных частей этих ингумаций.The article views the materials from the assemblages with cremations in the burial ground Cherneliv-Rus of Chernyakhivska culture (Western Podillya). Cherneliv-Rus burial ground belongs to the category of burial grounds with inhumation prevailed and stands out against the biritual burial grounds of Chernyakhivska culture. There are only two cremations among 288 excavated burials of Chernyakhivska culture (burials 44 and 240). It comprises less than 1% of burials on the burial ground. The latter includes also ritually disturbed inhumations with the remains of cremations in the fi ll of burial pits, which could be related with the burning of exhumated parts of these inhumations