DOE/ORNL demonstrations of load management by controlled customer-side thermal energy storage

The Division of Electric Energy Systems of the Department of Energy is funding a nationwide demonstration of electric load management through the use of utility-controlled customer-side thermal energy storage for residential space conditioning. These demonstration projects, which are being conducted by utilities under contract to ORNL, are designed to (1) collect reliable load-research data for assessing the impact on the utility system, (2) delineate and solve installation problems, (3) establish maintainability, (4) illuminate customer and utility acceptance, and (5) generate cost data. Ten demonstrations, 5 heat storage and 5 cool storage, are underway. The thermal energy storage systems being demonstrated include ceramic brick, pressurized water, and building structural heat-storage systems, and ice-cool-storage systems. The demonstrations will cover two full conditioning seasons. The results obtained from these demonstrations are expected to be useful to utilities in making local load management decisions, to assist DOE in establishing priorities for R and D efforts in load management, and to provide objective information related to electric-system impact, energy conservation, and the cost-effectiveness of this form of load management

Engineering the Surface Properties of Poly(dimethylsiloxane) Utilizing Aqueous RAFT Photografting of Acrylate/Methacrylate Monomers

Polymeric surface grafting offers a tunable way to control the interfacial interactions between a material’s surface and its environment. The ability to tailor the surface properties of poly­(dimethylsiloxane) elastomer (PDMSe) substrates with functional chemistry, wettability, and roughness can enhance the fields of biofouling, microfluidics, and medical implants. We developed a reversible addition–fragmentation chain transfer (RAFT) polymerization technique to synthesize a host of copolymers composed of acrylamide, acrylic acid, hydroxyethyl methacrylate, and (3-acrylamidopropyl)­trimethylammonium chloride with targetable molecular weight from ∼5 to 80 kg/mol and low dispersity of <i>Đ</i> ≤ 1.13. This RAFT strategy was used in conjunction with photografting to chemically engineer the surface of PDMSe with hydrophilic, hydrophobic, and anionic groups. Varying grafting time and copolymer composition allowed for targetable molecular weight, chemical functionality, and water contact angles ranging from 112° to 14°. These new material surfaces will be evaluated for their antifouling and fouling release potential

3D Microtissue Models to Analyze the Effects of Ultralow Dose LPS on Vascular Sprouting Dynamics in the Tumor Microenvironment

Lipopolysaccharide (LPS) plays a major role in innate immune responses and has been shown to impact vascular dynamics when present at high concentrations. However, the impact of ultralow levels of LPS (<100 pg/mL), present in the body during states of chronic inflammation, on vascular dynamics is unclear. In this study, we have integrated a 3D collagen hydrogel tissue mimic with advanced imaging and cell characterization assays to assess the potential impact of chronic inflammation on vascular dynamics, and uncover any alterations in the vascular response to low vs high dose LPS in the context of tumor progression. Accounting for both frequency of sprouting and invasiveness of the sprouts, the treatments of ultralow dose LPS with vascular endothelial growth factor (VEGF), a potent angiogenic promoter and present in excess in the tumor microenvironment, produced enhanced vascular development of human brain microvascular endothelial cells (HBMECs) in our in vitro model. There was no evidence of altered proliferation or apoptosis among the various VEGF treatment groups, indicating an enhanced migratory endothelial cell phenotype results from exposure to ultralow dose LPS with VEGF. The lack of enhanced vascular development upon treatments of high doses of LPS in the presence of VEGF could be partially attributed to an LPS dose-dependent increase in the activation of NF-κB. This study provides insight into the dynamic regulation of vascular development by varying levels of LPS and the potential role of chronic inflammation to prime a pro-angiogenic microenvironment and contribute to tumor progression