LDEF fiber-composite materials characterization

Degradation of a number of fiber/polymer composites located on the leading and trailing surfaces of LDEF where the atomic oxygen (AO) fluences ranged from 10(exp 22) to 10(exp 4) atoms/cm(sup 2), respectively, was observed and compared. While matrices of the composites on the leading edge generally exhibited considerable degradation and erosion-induced fragmentation, this 'asking' process was confined to the near surface regions because these degraded structures acted as a 'protective blanket' for deeper-lying regions. This finding leads to the conclusion that simple surface coatings can significantly retard AO and other combinations of degrading phenomena in low-Earth orbit. Micrometeoroid and debris particle impacts were not a prominent feature on the fiber composites studied and apparently do not contribute in a significant way to their degradation or alteration in low-Earth orbit

Truss is good news for Labour’s electoral prospects

The fact that Liz Truss was not the most popular candidate among Conservative MPs bodes ill for the Conservatives. Andreas Murr and Stephen Fisher write that no party has won a general election with a leader that lost the contest for support from their own MPs. They say the Party Leadership Model forecasts that the Conservatives will lose the next general election

Social networks and citizen election forecasting: the more friends the better

Most citizens correctly forecast which party will win a given election, and such forecasts usually have a higher level of accuracy than voter intention polls. How do citizens do it? We argue that social networks are a big part of the answer: much of what we know as citizens comes from our interactions with others. Previous research has considered only indirect characteristics of social networks when analyzing why citizens are good forecasters. We use a unique German survey and consider direct measures of social networks in order to explore their role in election forecasting. We find that three network characteristics – size, political composition, and frequency of political discussion – are among the most important variables when predicting the accuracy of citizens’ election forecasts

Optimisation of osmotic dehydration of cashew apple (Anacardium occidentale L.) in sugar solutions.

Osmotic dehydration of cashew apple in sucrose and corn syrup solids solution as influenced by temperature (3050oC), sugar syrup concentration (40-60% w/w) and immersion time (90-240min) was studies through response surface methodology. Responses of water loss (%) and solid gain (%) were fitted to polynomials, with multiple correlation coefficients ranging from 0,92 to 0,99. The fitted functions were optimised for maximum water loss and minimised incorporation of solids in order to obtain a product resembling non-processed fruit. Three optimum sets were selected for each solute and the ascorbic acid content was determined. The ascorbic acid losses were similar to those reported for osmpotic dehydration process

Citizen forecasting 2020 : a state-by-state experiment

The leading approaches to scientific election forecasting in the United States consist of structural models, prediction markets and opinion polling. With respect to the last, by far the dominant mode relies on vote intention polling, e.g., “If the election were held tomorrow, who would you vote for?” However, there exists an abiding opinion polling strategy that shows a good deal of promise—citizen forecasting. That is, rather than query on vote intention, query on vote expectation, e.g., “Who do you think will win the upcoming election?” This approach has been pursued most extensively in the United Kingdom (Murr 2016) and the United States (LewisBeck and Tien 1999). Recent performance evaluations have shown that in the United Kingdom vote expectations clearly offer more predictive accuracy than vote intentions (Murr et al. forthcoming) and that in the United States vote expectations appear to be superior to an array of rival forecasting tools (Graefe 2014). However, the timing of the data collection has forced most of the studies using citizen forecasts to forecast elections ex post, i.e., after they occurred. Indeed, to date, there are only two ex ante citizen forecasting papers to have appeared before a national election (Lewis-Beck and Stegmaier 2011; Murr 2016). Both these efforts forecasted British General Elections, with Murr (2016) relatively most accurate among 12 academic forecasts (Fisher and Lewis-Beck 2016). With respect to the United States, the case at hand, none of the work has been ex ante and all studies have focused on the national level, with the exception of a lone study carried out at the state level (Murr, 2015). The latter point seems critical, since the final selection of the president takes place in the Electoral College. The citizen forecasting research here stands unique, being ex ante and focusing on the states. Utilizing survey questions on Amazon.com’s Mechanical Turk (MTurk), administered in July, we render forecasts for the November 2020 presidential contest. This experiment, which has been conducted before-the-fact and looks at the states, provides a strong test of the quality of citizen forecasting in this American election

Mass transfer kinetics of osmotic dehydration of cherry tomato.

Cherry tomato samples were osmotically dehydrated in different hypertonic NaCI solutions (with or without sucrose) at two different concentrations. Mass transfer kinetics were modelled according to Peleg, Fick and Page equations. The Peleg equation presented the best fitting for water loss and Page model showed the best predictive capacity for salt gain data. The effective diffusivity determined using Fick's second law applied to a spherical geometry was found to be in the range of O.43 x 10-9-1.77 x 10-9 m2/s for water loss and 0.04 x 10-9-0.54 x 10-9 m2/s for salt gain. Increased solution concentration resulted in higher water loss and salt gain. An addition of sucrose to osmotic solutions decreased the driving force of the process

Asking people in each state who they think will win suggests that the presidential election may be very close.

In new survey research, Andreas E. Murr and Michael S. Lewis-Beck asked people in each of the 50 states and Washington DC who they thought would win their state in the presidential election. Adding up their raw data, their survey suggests that President Trump will win re-election next week with 320 electoral votes to 218 for former Vice President, Democrat Joe Biden

Nanotailoring Stereolithography Resins for Unique Applications using Carbon Nanotubes

Nanostructured materials and exploiting their properties in stereolithography (SL) may open new markets for unique rapidly manufactured functional devices. Controlled amounts of multiwalled carbon nanotubes (MWCNTs) were successfully dispersed in SL epoxy-based resins and complex three-dimensional (3D) parts were successfully fabricated by means of a multi-material SL setup. The effect of the nanosized filler was evaluated using mechanical testing. Small dispersions of MWCNTs resulted in significant effects on the physical properties of the polymerized resin. A MWCNT concentration of .05 wt% (w/v) in DSM Somos® WaterShed™ 11120 resin increased the ultimate tensile stress and fracture stress an average of 17% and 37%, respectively. Electron microscopy was used to examine the morphology of the nanocomposite and results showed affinity between the MWCNTs and SL resin and identified buckled nanotubes that illustrated strong interfacial bonding. These improved physical properties may provide opportunities for using nanocomposite SL resins in end-use applications. Varying types and concentrations of nanomaterials can be used to tailor existing SL resins for particular applications.Mechanical Engineerin

On the Geometry of Surface Stress

We present a fully general derivation of the Laplace--Young formula and discuss the interplay between the intrinsic surface geometry and the extrinsic one ensuing from the immersion of the surface in the ordinary euclidean three-dimensional space. We prove that the (reversible) work done in a general surface deformation can be expressed in terms of the surface stress tensor and the variation of the intrinsic surface metric