EFFECT OF COMPOSITION AND PROCESSING CONDITION ON MICROSTRUCTURAL PROPERTIES AND DURABILITY OF FLUOROPOLYMER/ACRYLIC BLENDS

Fluoropolymer blends have been widely used as binders for exterior coatings because of their excellent resistance to ultra-violet (UV) radiation as well as to many corrosive chemical agents.It is known that the fluorinated component usually has a lower glass transition temperature and easily crystallizes in the final structure depending upon the blend composition and sample annealing condition.We investigated the effect of blend composition and annealing process (slow and fast cooling) on the surface mor...     

Characterization of a sealed Americium–Beryllium (AmBe) source by inductively coupled plasma mass spectrometry

Two Americium–Beryllium neutron sources were dismantled, sampled (sub-sampled) and analyzed via inductively coupled plasma mass spectrometry (ICP-MS). Characteristics such as “age” since purification, actinide content, trace metal content and inter and intra source composition were determined. The “age” since purification of the two sources was determined to be 25.0 and 25.4 years, respectively. The systematic uncertainties in the “age” determination were ±4% 2σ. The amount and isotopic composition of U and Pu varied substantially between the sub-samples of Source 2 (n = 8). This may be due to the physical means of sub-sampling or the way the source was manufactured. Source 1 was much more consistent in terms of content and isotopic composition (n = 3 sub-samples). The Be–Am ratio varied greatly between the two sources. Source 1 had an Am–Be ratio of 6.3 ± 52% (1σ). Source 2 had an Am–Be ratio of 9.81 ± 3.5% (1σ). In addition, the trace element content between the samples varied greatly. Significant differences were determined between Sources 1 and 2 for Sc, Sr, Y, Zr, Mo, Ba and W.     

Structure-based design of supercharged, highly thermoresistant antibodies

Mutation of surface residues to charged amino acids increases resistance to aggregation and can enable reversible unfolding. We have developed a protocol using the Rosetta computational design package that "supercharges" proteins while considering the energetic implications of each mutation. Using?a homology model, a single-chain variable fragment antibody was designed that has a markedly enhanced resistance to thermal inactivation and displays an unanticipated ≈30-fold improvement in affinity. Such supercharged antibodies should prove useful for assays in resource-limited settings and for developing reagents with improved shelf lives.     

Power-excitation diffraction tomography with partially coherent light

Some consequences of using partially coherent fields in the recently proposed method of power-extinction diffraction tomography are analyzed. It is found that the method is very tolerant of short spectral coherence lengths. The spectral coherence length of the field is shown to set the scale of a low-pass filter that acts on the subject. The implications of these results for implementation of the method are discussed.     

Transverse momentum distributions for meson resonances at central rapidity andP T≧2 GeV/c

The transverse momentum distributions for and (1020) have been studied in thep _t region between 2 and 4 GeV/c and central rapidity. The data analysed come from the WA77 experiment at CERN with a 300 GeV/c ^– beam incident on a Be target. These distributions are well described by the functionp _t ^–n withn8. A sample of simulated events from the Lund Monte Carlo in the same experimental conditions reproduces well the data.     

Low reflectivity and high flexibility of tin-doped indium oxide nanofiber transparent electrodes

Tin-doped indium oxide (ITO) has found widespread use in solar cells, displays, and touch screens as a transparent electrode; however, two major problems with ITO remain: high reflectivity (up to 10%) and insufficient flexibility. Together, these problems severely limit the applications of ITO films for future optoelectronic devices. In this communication, we report the fabrication of ITO nanofiber network transparent electrodes. The nanofiber networks show optical reflectivity as low as 5% and high flexibility; the nanofiber networks can be bent to a radius of 2 mm with negligible changes in the sheet resistance.     

Investigation of the configurational stabilities of chiral isocyanoacetates in multicomponent reactions

Isocyanoacetates are uniquely reactive compounds characterized by an ambivalent isocyano functional group and an enolizable α-carbon. It is widely believed that chiral α-substituted isocyanoacetates are configurationally unstable in some synthetically useful isocyanide-based multicomponent reactions. Herein, we demonstrate that chiral isocyanoacetates can be used with minimal to negligible epimerization in a variety of canonical Ugi four-component condensations as well as Joullié-Ugi three-component condensations, reactions that are particularly useful for constructing complex peptide structures in a single synthetic operation.     

The reactionsK − p→π ∓ Σ(1385)± at 8.25 GeV/c

The reactionsK ^? p→π ^? Σ(1385)^± are studied at an incident laboratory momentum of 8.25 GeV/c using data from a high statistics (?180 events/μb) bubble chamber experiment. In the case of the reactionK ^? p→π ^? Σ(1385)⁺ an amplitude analysis is performed and the complete Σ(1385)⁺ spin density matrix is extracted as a function oft′. The results are compared with the predictions of the additive quark model. In the case of the reactionK ^? p→π ⁺ Σ(1385)^? the cross-sections for forward and backward production are determined.