Density modeling of polyurethane box foam

A model based on about a dozen fundamental differential equations is used to evaluate and simulate the urethane reactions and physical processes of urethane box foaming. This work focuses on quantitative modeling of foam density for foams using water and physical blowing agents. The final densities of foams range from 30 to 90% of the density as projected with full utilization of the blowing agent. The primary sources of inefficient use of blowing agent are loss of the physical blowing during open‐air mixing and degassing—basically, physical blowing agents with boiling points between 25 and 80°C will evaporate and experience cell rupture in box foams. This loss of blowing agent would not apply to in‐line mixers used for commercial production and should be taken into account with scaling up box or cup foams commercial processes. POLYM. ENG. SCI., 54:1503–1511, 2014. © 2013 Society of Plastics Engineers     

Qualitative Axioms of Uncertainty as a Foundation for Probability and Decision-Making

Although the concept of uncertainty is as old as Epicurus’s writings, and an excellent quantitative theory, with entropy as the measure of uncertainty having been developed in recent times, there has been little exploration of the qualitative theory. The purpose of the present paper is to give a qualitative axiomatization of uncertainty, in the spirit of the many studies of qualitative comparative probability. The qualitative axioms are fundamentally about the uncertainty of a partition of the probability space of events. Of course, it is common to speak of the uncertainty, or randomness, of a random variable, but only the partition defined by the values of the random variable enter into the definition of uncertainty, not the actual values. It is straightforward to add axioms for decision making following the general line of Savage from the 1950s. Indeed, in the spirit of Epicurus, it is really our intuitive feeling about the uncertainty of the future that motivates much of our thinking about decisions. Here, the distinction between the concepts of probability and uncertainty can be made by citing many familiar examples. Without spelling out the technical details, the axiomatization of qualitative probability with uncertainty as the most important primitive concept, it is possible to raise a different kind of question about bounded rationality. This new question is whether or not one should bound the uncertainty in thinking and investigating any detailed framework of decision making. Discussion of this point is certainly different from the question of bounding rationality by not maximizing expected utility. In practice, we naturally bound uncertainty in our analysis of decision-making problems. As in the case of formulating an alternative for maximizing expected utility, so is the case of rational alternatives to maximizing uncertainty. There are several issues to consider. In the spirit of my other work in qualitative probability, I explore alternatives rather than attempt to give a definitive argument for one single solution.     

New low-cost storage in air conditioning

This paper describes the development of a new low-cost phase-change material packaging concept for air conditioning systems.

The realization of the promise of storage assisted air conditioning for saving oil and money is dependent upon the successful development of a low-cost storage subsystem and the adoption of time-of-day electricity rates. Time-of-day rates are currently under consideration or have been adopted in 27 different states and consideration of these rates has been required by federal legislation.

The adoption of this low-cost thermal energy storage technology for storage assisted air conditioning and other storage assisted heat pump applications has the potential of saving 100 million barrels of oil over the next ten years and 12 million barrels of oil per year by 1985. These savings would accrue from a change in the summer air conditioning peak electricity load from oil and gas-fired peak electrical generators to the base load electrical generators fired by coal, nuclear and hydroelectric.

This low-cost air conditioning storage concept is based on hydrated salt phase change material, specifically a mixture based on sodium sulphate decahydrate and a new low-cost packaging technology which uses a film laminate as the phase change material mixture's package and heat exchanger.

In this paper. the relative economics of various technological options for air conditioning storage are compared. It is demonstrated that this economic analysis leads to the necessity to develop a low-cost film package and heat exchanger. An analysis of savings to homeowners based on current and planned off-peak rates is included. Since this is the first product developed utilizing this new low-cost material as a packaging film, it is anticipated that major improvements in both cost and performance specifically related to individual systems will be developed and implemented over the next ten years, with significant improvements coming in the next several years.     

Modeling reaction kinetics of rigid polyurethane foaming process

A theoretical model was developed to simulate the polyurethane foaming process for a rigid foam. In the model, multiple ordinary differential equations were solved by MATLAB and the model was able to predict temperature profiles by inputting foam recipe information. This initial study on foam modeling focusses on reaction kinetic parameters that were fitted to experimental temperature data as a function of time. The modeling was able to accurately model temperature profiles of single‐polyol polyurethane formulations and was able to accurately predict temperature profiles of mixtures based on pure component kinetic parameters. A primary goal of this work is to expedite the ability to develop new foam formulations by simulation—especially for incorporation of new bio‐based polyols into formulations. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1131‐1138, 2013     

Supporting solar power in renewables portfolio standards: Experience from the United States

Renewables portfolio standards (RPS) have become an increasingly popular option for encouraging the deployment of renewable electricity. It is a relatively new policy mechanism, however, and experience with its use is only beginning to emerge. One key concern is whether RPS policies offer adequate support to a wide range of renewable energy technologies and applications or whether, alternatively, they will favor a small number of the currently least-cost forms of renewable energy. This article documents the design of and early experience with state-level RPS programs in the United States that have been specifically tailored to encourage a wider diversity of renewable energy technologies, and solar energy in particular. As shown here, state-level RPS programs specifically designed to support solar have already proven to be an important driver for solar energy deployment, and those impacts are projected to build in the coming years. State experience in supporting solar energy with RPS programs is mixed, however, and full compliance with existing requirements has not been achieved. The comparative experiences described herein highlight the opportunities and challenges of applying an RPS to specifically support solar energy, as well as the importance of policy design details to ensuring that program goals are achieved.     

Noncatalytic polymerization of ethylene glycol and epoxy molecules for rigid polyurethane foam applications

The study investigated an approach to incorporate modified epoxidized soy‐based vegetable oil polyol as a replacement for petroleum‐based polyether polyol and to substantially reduce the isocyanate loading in the rigid foam formulation. Noncatalytic polymerization of epoxidized bodied soybean oil and ethylene glycol (EG) was carried out in a closed batch reaction. Cleavage of the oxirane rings and hydroxyl group attachment at optimum conditions provided the desired polyol products. The polyols were characterized based on its hydroxyl numbers, acidity, viscosity, iodine number, and Gardner color index for quality purposes. Reactions of oxirane ring and EG were verified by spectroscopic FTIR. Crosslinking performance was evaluated by extractability analysis on the polyurethane (PU) elastomer wafers. Rigid foaming performed at 50 and 75% petroleum‐based polyether polyol replacements have shown excellent thermoinsulating and mechanical properties compared with epoxidized soybean oil (ESBO) alone or petroleum‐based polyether polyol alone. A reduction of up to 8% of the polymeric diphenylmethane diisocyanate was achieved using the synthesized ESBO‐EG‐based polyols. A higher average functionality polyol is key component to the reduction of isocyanate in PU synthesis. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Managing carbon regulatory risk in utility resource planning: Current practices in the Western United States

Concerns about global climate change have substantially increased the likelihood that future policy will seek to minimize carbon dioxide emissions. As such, even today, electric utilities are making resource planning and investment decisions that consider the possible implications of these future carbon regulations. In this article, we examine the manner in which utilities assess the financial risks associated with future carbon regulations within their long-term resource plans. We base our analysis on a review of the most recent resource plans filed by 15 electric utilities in the Western United States. Virtually all of these utilities made some effort to quantitatively evaluate the potential cost of future carbon regulations when analyzing alternate supply- and demand-side resource options for meeting customer load. Even without federal climate regulation in the US, the prospect of that regulation is already having an impact on utility decision-making and resource choices. That said, the methods and assumptions used by utilities to analyze carbon regulatory risk, and the impact of that analysis on their choice of a particular resource strategy, vary considerably, revealing a number of opportunities for analytic improvement. Though our review focuses on a subset of US electric utilities, this work holds implications for all electric utilities and energy policymakers who are seeking to minimize the compliance costs associated with future carbon regulations.     

应对人口流失的景观设计改进方法:以美国宾夕法尼亚州约翰斯敦的 城市更新为例

Over the last 50 years, 370 large cities worldwide have severely depopulated, or shrunk, by at least 10%. Johnstown, Pennsylvania, is the third fastest U.S. shrinking city. Primarily a victim of deindustrialization, Johnstown faces severe decline issues related to depopulation, including social disorder and lowered quality of life. This project develops a framework for urban design for shrinking cities, integrating permanent functions into high development potential areas but temporary functions into declining areas. This approach allows for future development to occur through time as the city recovers. Using a GIS-based weighted overlay model to assess the threat level of decline, 4 sites were identified and strategies for each were developed. Master plans to retrofit new functions integrating residents' desire and demands into vacant / abandoned properties were then generated for each site. Rather than chasing hefty attempted quick-hitting developmental incentives, this approach will bring new long-term economic engines and lifestyles to the city due to a diversity in the economic base; it also pays attention to the social dimension of urban regeneration by providing a structured way to promoting social justice and equity in shrinking cities.