Energy Conversion and Resource Management

The United States has 5 percent of the world\u27s population, yet consumes 35 percent of the total energy. This statistic reflects the availability of unlimited and cheap energy that has been enjoyed in this country. Unfortunately, this energy has been provided without much regard for the future, so that plentiful and cheap energy may not be possible much longer. A carefully formulated energy policy will be required to manage our remaining natural resources wisely and extend their longevity until other sources of energy can be developed. There are five basic forms of energy: chemical, thermal, electrical, mechanical and radiant. Energy is consumed primarily in the thermal, electrical and mechanical forms. However, the source of almost all of our energy is chemical (petroleum or coal); so that conversions of chemical energy are necessary steps in our energy economy

Process Optimization By Flow Sheet Simulation

Optimization of large or complex chemical processes often requires simplifying the system to reduce the mathematics to a form manageable by available algorithms or to reduce the time required to perform the computations. In many cases, such simplification alters the solution of the problem. Flow sheet simulation programs are ideally suited to the study of chemical processes, although the computational time is generally considered excessive for detailed optimization of complex systems by the usual procedures. This paper discusses the modifications needed to apply flow sheet simulation programs to the optimization of chemical processes. The advantages and disadvantages of the use of several optimization algorithms, including stochastic procedures, in this modified program are discussed and examples compared. © 1976, American Chemical Society. All rights reserved

Synthesis Of Heat Exchange Networks By Mixed Integer Optimization

Process synthesis involves manipulation of the process arrangement, while studying the variables of each arrangement, to arrive at the optimal process. If each process arrangement is treated as a discrete variable, process synthesis becomes a mixed integer optimization problem. This paper examines the synthesis of heat exchanger networks using the adaptive random search procedure, which can be used to search continuous and discrete independent variables simultaneously. The means of handling the heat exchanger arrangement as a discrete variable is discussed, and the incorporation of various synthesis heuristics is presented. The results of synthesis of 2 x 2, 2 x 3, and 3 x 3 networks are presented and compared with other methods of synthesis. Copyright © 1977 American Institute of Chemical Engineer

An Examination Of The Adaptive Random Search Technique

Random search procedures have recently been successfully applied to the optimization of a variety of chemical engineering problems, including optimization of chemical processes by flow sheet simulation. These procedures represent the independent variables as random variables described by probability distributions. The adaptive random search procedure centers the distribution for each variable about the best search point found and examines this region for a better point. Thus, this technique has the ability of continuously moving the search region toward the optimum, which is particularly advantageous in following constraints. This study examines the efficiency of the adaptive random search technique as applied to six different problems, which have been previously solved by various other techniques. Copyright © 1976 American Institute of Chemical Engineer

The PAS Domain-Containing Protein HeuR Regulates Heme Uptake in Campylobacter jejuni

Campylobacter jejuni is a leading cause of bacterially derived gastroenteritis. A previous mutant screen demonstrated that the heme uptake system (Chu) is required for full colonization of the chicken gastrointestinal tract. Subsequent work identified a PAS domain-containing regulator, termed HeuR, as being required for chicken colonization. Here we confirm that both the heme uptake system and HeuR are required for full chicken gastrointestinal tract colonization, with the hour mutant being particularly affected during competition with wild-type C. jejuni. Transcriptomic analysis identified the chu genes—and those encoding other iron uptake systems—as regulatory targets of HeuR. Purified HeuR bound the chuZA promoter region in electrophoretic mobility shift assays. Consistent with a role for HeuR in chu expression, heuR mutants were unable to efficiently use heme as a source of iron under iron-limiting conditions, and mutants exhibited decreased levels of cell-associated iron by mass spectrometry. Finally, we demonstrate that an heuR mutant of C. jejuni is resistant to hydrogen peroxide and that this resistance correlates to elevated levels of catalase activity. These results indicate that HeuR directly and positively regulates iron acquisition from heme and negatively impacts catalase activity by an as yet unidentified mechanism in C. jejuni

Energy From Biochemical Sources

As available energy reserves decline, renewable sources must be utilized. Organic matter, grown agriculturally, represents a renewable energy source, which is readily available. This paper reviews the methods by which organic matter can be converted to energy sources by biochemical processes. The economics of conversion of agricultural crops and byproducts to alcohols by fermentation and conversion of these agricultural materials to methane by anaerobic digestion are examined. Projections of the potential of this energy source are quite promising

Design of lipid nanoparticle delivery agents for multivalent display of recombinant Env trimers in HIV vaccination

Background: Immunization strategies that elicit antibodies capable of neutralizing diverse strains of the virus will likely be an important part of a successful vaccine against HIV. The envelope trimer is the only neutralizing target on the virus, and strategies to promote durable, high avidity antibody responses against the native intact trimer structure are lacking. We recently developed chemically-crosslinked lipid nanocapsules as carriers of molecular adjuvants and encapsulated or surface-displayed antigens, which promote follicular helper T-cell responses and elicited high-avidity, durable antibody responses to a candidate malaria antigen (Moon et al. Nat. Mater. 10 243 (2011); Moon et al. PNAS 109 1080 (2012)). Methods: To apply this system to the delivery of HIV antigens, we developed a strategy to anchor recombinant envelope trimers to the surfaces of these particles under conditions preserving the antigenic integrity of the trimers, allowing multivalent display of these immunogens for immunization. To anchor trimers in their native orientation, gp140 trimers with terminal his-tags were anchored to the surface of lipid nanocapsules via Ni-NTA-functionalized lipids. Results: Owing to their significant size (409 kDa) and heavy glycosylation, we found that liquid-ordered and/or gel-phase lipid compositions were required to stably anchor trimers to particle membranes. Trimer-loaded nanocapsules carrying monophosphoryl lipid A elicited durable antibody responses with titers comparable to a Complete Freund’s Adjuvant (CFA)-like emulsion in mice, without the toxic inflammation associated with the latter adjuvant. Further, nanocapsules elicited strong helper T-cell responses associated with a steadily increasing avidity of trimer-binding antibody over 90 days, which was not replicated by other adjuvants. Conclusion: These results suggest that nanoparticles displaying HIV trimers in an oriented, multivalent presentation can promote key aspects of the humoral response against Env immunogens.National Institutes of Health (U.S.) (AI095109)Massachusetts Institute of Technology. Ragon Institute of MGH, MIT, and Harvar

Energy from Agriculture

During the past few years, the demand for energy and petrochemicals has grown at a pace so rapid that our reserves of fossil fuels, once considered inexhaustible, are now being quickly depleted. To help lessen this impending problem, alternative sources of energy must be rapidly developed. Of the many new sources of energy being studied, solar energy, undisputedly, is the most inexhaustible. Energy from the sun, incident upon the earth\u27s surface, exceeds by nearly three orders of magnitude the total energy consumption today. Furthermore, it is not subject to nationalistic boundaries and its use would be compatible with our environmental goals. Several methods of using solar energy are under investigation

Developing Two-Generation Approaches in Communities: Final Report from Family-Centered Community Change

The Annie E. Casey Foundation launched its Family-Centered Community Change (FCCC) initiative with a goal of integrating two-generation strategies into existing place-based community initiatives. The innovative effort, which ran from 2012 to 2019, focused on supporting local partners in three neighborhoods with low economic resources: Buffalo, New York; Columbus, Ohio; and San Antonio, Texas.Over the course of the initiative, the sites worked to promote the healthy development and academic success of children while simultaneously delivering adult services focused on parenting and financial stability. In year three, the community partners also received training and technical assistance — provided by the Casey Foundation — aimed at enhancing racial and ethnic equity and inclusion.The Urban Institute conducted a formative evaluation of this effort, which included: 1) qualitative data collection from interviews and focus groups with partner staff and participants; 2) descriptive analysis of program data; and 3) a cost study