Quiescent cosmology and the final state of the universe

It has long been a primary objective of cosmology to understand the apparent isotropy in our universe and to provide a mathematical formulation for its evolution. A school of thought for its explanation is quiescent cosmology, which already possesses a mathematical framework, namely the definition of an Isotropic Singularity, but only for the initial state of the universe. A complementary framework is necessary in order to also describe possible final states of the universe. Our new definitions of an Anisotropic Future Endless Universe and an Anisotropic Future Singularity, whose structure and properties differ significantly from those of the Isotropic Singularity, offer a promising realisation for this framework. The combination of the three definitions together may then provide the first complete formalisation of the quiescent cosmology concept.Comment: 7 pages, 3 figures, essay receiving honorable mention in the 2007 Gravity Research Foundation Essay award

Price Determinants in Top Quality E-Auctioned Specialty Coffees

The US specialty coffee industry has grown from $1 billion in 1990 to$11 billion in 2006 and is expected to continue to grow into the foreseeable future. This growth particularly depends on prices coordinating the specialty coffee supply chain through two-way information exchange between roasters and producers. We analyze the determinants of specialty coffee prices by estimating a hedonic price function for specialty Central and South American coffees traded at e-auctions. We hypothesize that since specialty coffee is a differentiated product, prices will be determined by both sensory and reputation attributes. The results show that prices are influenced by the quality rating, which is a sensory variable, and by the quality rankings established in the cupping competition previous to the auction, the country of origin and the coffee variety, which are reputation variables. In addition, the macro variables, harvest year and commodity price were found to be significant.Specialty coffee, hedonic price analysis, differentiated food pricing, sensory attributes, reputation attributes, Demand and Price Analysis,

What Adds Value in Specialty Coffee? Managerial Implications from Hedonic Price Analysis of Central and South American E-Auctions

We analyze price and quality information at the procurement level in the specialty coffee supply chain using data from small and large volume e-auctions. Hedonic price equations reveal that the Cup of Excellence auction is a more differentiated market disclosing more information about coffee values associated with ratings, rankings, quantities available, and country reputations whereas information in the Q auction is more limited and tends to be remunerated to a lesser extent. These results indicate that there are different business models and valuation of product characteristics within the specialty coffee industry. Management implications are drawn for specialty coffee producers and roasters.specialty coffee, e-auctions, hedonic analysis, business models, Demand and Price Analysis,

The solar dynamic radiator with a historical perspective

A historical perspective on pumped-fluid loop space radiators provides a basis for the design of the Space Station Solar Dynamic (SD) power module radiator. SD power modules, capable of generating 25 kW (electrical) each, are planned for growth in Station power requirements. The Brayton cycle SD module configuration incorporates a pumped-fluid loop radiator that must reject up to 99 kW (thermal). The thermal/hydraulic design conditions in combination with required radiator orientation and packaging envelope form a unique set of constraints as compared to previous pumped-fluid loop radiator systems. Nevertheless, past program successes have demonstrated a technology base that can be applied to the SD radiator development program to ensure a low risk, low cost system

Modelling a New Product Model on the Basis of an Existing STEP Application Protocol

During the last years a great range of computer aided tools has been generated to support the development process of various products. The goal of a continuous data flow, needed for high efficiency, requires powerful standards for the data exchange. At the FZG (Gear Research Centre) of the Technical University of Munich there was a need for a common gear data format for data exchange between gear calculation programs. The STEP standard ISO 10303 was developed for this type of purpose, but a suitable definition of gear data was still missing, even in the Application Protocol AP 214, developed for the design process in the automotive industry. The creation of a new STEP Application Protocol or the extension of existing protocol would be a very time consumpting normative process. So a new method was introduced by FZG. Some very general definitions of an Application Protocol (here AP 214) were used to determine rules for an exact specification of the required kind of data. In this case a product model for gear units was defined based on elements of the AP 214. Therefore no change of the Application Protocol is necessary. Meanwhile the product model for gear units has been published as a VDMA paper and successfully introduced for data exchange within the German gear industry associated with FVA (German Research Organisation for Gears and Transmissions). This method can also be adopted for other applications not yet sufficiently defined by STEP.

Quantum Frame Relativity of Subsystems, Correlations and Thermodynamics

It was recently noted that different internal quantum reference frames (QRFs) partition a system in different ways into subsystems, much like different inertial observers in special relativity decompose spacetime in different ways into space and time. Here we expand on this QRF relativity of subsystems and elucidate that it is the source of all novel QRF dependent effects, just like the relativity of simultaneity is the origin of all characteristic special relativistic phenomena. We show that subsystem relativity, in fact, also arises in special relativity with internal frames and, by implying the relativity of simultaneity, constitutes a generalisation of it. Physical consequences of the QRF relativity of subsystems, which we explore here systematically, and the relativity of simultaneity may thus be seen in similar light. We focus on investigating when and how subsystem correlations and entropies, interactions and types of dynamics (open vs. closed), as well as quantum thermodynamical processes change under QRF transformations. We show that thermal equilibrium is generically QRF relative and find that, remarkably, $\textit{QRF transformations not only can change a subsystem temperature, but even map positive into negative temperature states}$. We further examine how non-equilibrium notions of heat and work exchange, as well as entropy production and flow depend on the QRF. Along the way, we develop the first study of how reduced subsystem states transform under QRF changes. Focusing on physical insights, we restrict to ideal QRFs associated with finite abelian groups. Besides being conducive to rigour, the ensuing finite-dimensional setting is where quantum information-theoretic quantities and quantum thermodynamics are best developed. We anticipate, however, that our results extend qualitatively to more general groups and frames, and even to subsystems in gauge theory and gravity.Comment: 49 pages + appendices, 12 figures. Comments welcom

Actual Versus Predicted Cardiovascular Demands in Submaximal Cycle Ergometer Testing

International Journal of Exercise Science 8(1) : 4-10, 2015. The Astrand-Rhyming cycle ergometer test (ARCET) is a commonly administered submaximal test for estimating aerobic capacity. Whereas typically utilized in clinical populations, the validity of the ARCET to predict VO2max in a non-clinical population, especially female, is less clear. Therefore, the purpose of this study was to determine the accuracy of the ARCET in a sample of healthy and physically active college students. Subjects (13 females, 10 males) performed a maximal cycle ergometer test to volitional exhaustion to determine VO2max. At least 48 hours later, subjects performed the ARCET protocol. Predicted VO2max was calculated following the ARCET format using the age corrected factor. There was no significant difference (p=.045) between actual (41.0±7.97 ml/kg/min) and predicted VO2max (40.3±7.58 ml/kg/min). When split for gender there was a significant difference between actual and predicted VO2 for males, (45.1±7.74 vs. 42.7±8.26 ml/kg/min, p=0.029) but no significant difference observed for females, (37.9±6.9 vs. 38.5±6.77 ml/kg/min, p=0.675). The correlation between actual and predicted VO2 was r=0.84, p\u3c0.001 with an SEE= 4.3 ml/kg/min. When split for gender, the correlation for males was r=0.94, p\u3c0.001, SEE=2.72 ml/kg/min; for females, r=0.74, p=0.004, SEE=4.67 ml/kg/min. The results of this study indicate that the ARCET accurately estimated VO2max in a healthy college population of both male and female subjects. Implications of this study suggest the ARCET can be used to assess aerobic capacity in both fitness and clinical settings where measurement via open-circuit spirometry is either unavailable or impractical