Stripes of Partially Fluorinated Alkyl Chains: Dipolar Langmuir Monolayers

Stripe-like domains of Langmuir monolayers formed by surfactants with partially fluorinated lipid anchors (F-alkyl lipids) are observed at the gas-liquid phase coexistence. The average periodicity of the stripes, measured by fluorescence microscopy, is in the micrometer range, varying between 2 and 8 microns. The observed stripe-like patterns are stabilized due to dipole-dipole interactions between terminal -CF3 groups. These interactions are particularly strong as compared with non-fluorinated lipids due to the low dielectric constant of the surrounding media (air). These long-range dipolar interactions tend to elongate the domains, in contrast to the line tension that tends to minimize the length of the domain boundary. This behavior should be compared with that of the lipid monolayer having alkyl chains, and which form spherical micro-domains (bubbles) at the gas-liquid coexistence. The measured stripe periodicity agrees quantitatively with a theoretical model. Moreover, the reduction in line tension by adding traces (0.1 mol fraction) of cholesterol results, as expected, in a decrease in the domain periodicity.Comment: 20 pages, 4 fig

Computer recommendations for an automatic approach and landing system for V/STOL aircraft. Volume 1 - Computer recommendations

Evaluation of digital computer for V/STOL aircraft automatic approach and landing syste

Parents And Children Thriving Together: A Framework For Two-Generation Policy And System Reform

This brief explores the lessons learned from the 2016 Parents and Children Thriving Together: Two Generation State Policy Network (PACTT Network), a collaboration between the National Governors Association (NGA) and the Center for Law and Social Policy (CLASP) with funding from the Doris Duke Charitable Foundation, W.K. Kellogg Foundation and the Annie E. Casey Foundation. Through this initiative, five states explored how to use the two-generation approach to improve their state systems that serve children and parents. This brief summarizes the lessons learned from the two-year initiative and provides a framework to help guide state leaders trying to implement two-generation strategies

Companion Diagnostics for Breast Cancer Chemotherapeutics

Chemotherapy plays a major role in breast cancer treatment. However, not every chemotherapeutics is appropriate for each cancer due to the person’s individual cancer characteristics and whether the patient has developed chemoresistance to a particular drug. In this research, the InVitro-Q is used to detect subtle differences in tumor cell proliferation post-treatment with four-breast cancer chemotherapeutics used: paclitaxel, docetaxel, nocodazole, and cytochalasin B. Our multi-well cell-based sensor that can monitor real-time biological changes in living cells, such as mass redistribution, and viscoelasticity. This system provides unique kinetic information regarding the phenotypic change in the cells post treatment. Each drug induces apoptosis by targeting a different mechanism of action. Each drug was assayed for 48h with MCF-7 or SK-Br-3 breast cancer cells, and data collected. Post analysis we created quantitative projection regarding the efficacy of each drug on the specific cancer type

Ultrathin epitaxial Fe films in vicinal GaAs(001): A study by spin-resolved photoelectron spectroscopy

Thin epitaxial Fe films have been grown on vicinal GaAs(001) substrates and their remanent magnetic properties and the degree of substrate atom diffusion investigated using synchrotron-based photoelectron spectroscopy. The vicinal Fe films, though exhibiting greater As diffusion than their singular homologues, displayed better film quality both from the structural and the magnetic points of view. The spin-resolved valence spectra of the vicinal films resemble those for crystalline bulk Fe at lower film thicknesses than for singular films

Computer recommendations for an automatic approach and landing system for V/STOL aircraft. Volume 2 - Equations

Automatic approach and landing system for V/STOL aircraf

Rodents as receptor species at a tritium

New methods are being employed on the Department of Energy’s Savannah River Site to deal with the disposal of tritium, including the irrigation of a hardwood/pine forest with tritiated water from an intercepted contaminant plume to reduce concentrations of tritium outcropping into Fourmile Branch, a tributary of the Savannah River. The use of this system has proven to be an effective means of tritium disposal. To evaluate the impact of this activity on terrestrial biota, rodent species were captured on the tritium disposal site and a control site during two trapping seasons in order to assess tritium exposure resulting from the forest irrigation. Control site mice had background levels of tritium, 0.02 Bq/mL, with disposal site mice having significantly higher tritium concentrations, meanZ34.86 Bq/mL. Whole body tritium concentrations of the mice captured at the disposal site were positively correlated with tritium application and negatively correlated with precipitation at the site

The use of small angle neutron scattering with contrast matching and variable adsorbate partial pressures in the study of porosity in activated carbons

The porosity of a typical activated carbon is investigated with small angle neutron scattering (SANS), using the contrast matching technique, by changing the hydrogen/deuterium content of the absorbed liquid (toluene) to extract the carbon density at different scattering vector (Q) values and by measuring the p/p0 dependence of the SANS, using fully deuterated toluene. The contrast matching data shows that the apparent density is Q-dependent, either because of pores opening near the carbon surface during the activation processor or changes in D-toluene density in nanoscale pores. For each p/p0 value, evaluation of the Porod Invariant yields the fraction of empty pores. Hence, comparison with the adsorption isotherm shows that the fully dry powder undergoes densification when liquid is added. An algebraic function is developed to fit the SANS signal at each p/p0 value hence yielding the effective Kelvin radii of the liquid surfaces as a function of p/p0. These values, when compared with the Kelvin Equation, show that the resultant surface tension value is accurate for the larger pores but tends to increase for small (nanoscale) pores. The resultant pore size distribution is less model-dependent than for the traditional methods of analyzing the adsorption isotherms