Building a community one block at a time : VISTA.

Mode of access: Internet.

The Poly-Olbion: a chorographicall description of Great Britain.

Each of the thirty songs is preceded by a double map of the countries referred to, in which the towns, rivers, etc. are represented by allegorical figures.

Logica Martini Smiglecii Societatis Iesu, S. Theologi Doctoris : selectis disputationibus & qustionibus illustrata, et in duos tomos distributa: in qua quicquid in Aristotelico organo vel cognitu necessarium, vel obscuritate perplexum, tam claráe & perspicuáe, quam solidáe ac nervosáe pertractur. Cum indice rerum copioso. Ad perillustrem ac magnificum dominum, Dm Thomam Zamoyscium, &c.

Mode of access: Internet.

1980 census of population and housing. finders' guide to block statistics reports.

"Population Division"--T.p. verso.

Organizational, direct support, and general support maintenance repair parts and special tools list (including depot maintenance repair parts and special tools) for training set, guided missile system M76 6920-00-809-0399 (block III) (Redeye Air Defense Guided Missile System).

Includes index.

Postcard, Block M Card Section, Ferry Field

[Hugh C. Leighton Co., Portland Oregon, made in Germany.]

Implementing community development : a study of the Community Development Block Grant Program /

Item 582

1970 census of housing : block statistics : San Bernardino-Riverside, Calif. urbanized area.

"Issued September 1971."

1970 census of housing : block statistics, San Diego, Calif. urbanized area.

"Issued October 1971."

Chain scission and branching in irradiated poly(tetrafluoroethylene-co-hexafluoropropylene)

The radiation chemistry of poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) with a TFE mole fraction of 0.90 has been studied under vacuum using Co-60 gamma-radiation over a range of temperatures and absorbed doses. The radiolysis temperatures were 300, 363, 423, 523 and 543 K. New structure formation in the copolymers was analysed by solid-state F-19 NMR spectroscopy. The new structures formed in the copolymers have been identified and the G-values for the formation of new chemical structures have been investigated at 363 and 523 K. These two temperatures are just above and just below the polymer T-g and T-m, respectively. At the lower temperature, there was no evidence for any chain branching and an estimate of G(S) of 1.0 was obtained. A value of G(S) of 1.3 and a minimum value of G(X)(Y) of 1.3 were obtained at 523 K. (C) 2003 Society of Chemical Industry.

Poly(hydroxyether of phenolphthalein) and its blends with poly(ethylene oxid)

Poly(hydroxyether of phenolphthalein) (PPH) was synthesized through the polycondensation of phenolphthalein with epichlorohydrin. It was characterized by Fourier transform infrared (FTIR) spectroscopy, NMR spectroscopy, and differential scanning calorimetry (DSC). The miscibility of the blends of PPH with poly(ethylene oxide) (PEO) was established on the basis of the thermal analysis results. DSC showed that the PPH/PEO blends prepared via casting from N,N-dimethylformamide possessed single, composition-dependent glass-transition temperatures. Therefore, the blends were miscible in the amorphous state for all compositions. FTIR studies indicated that there were competitive hydrogen-bonding interactions with the addition of PEO to the system, which were involved with (OHO)-O-. . .=C

Nanostructures, Semicrytalline Morphology, and Nanoscale Confinement Effect on the Crystallization Kinetics in Self-Organized Block Copolymer/Thermoset Blends

This work reports the first instance of self-organized thermoset blends containing diblock copolymers with a crystallizable thermoset-immiscible block. Nanostructured thermoset blends of bisphenol A-type epoxy resin (ER) and a low-molecular-weight (M-n = 1400) amphiphilic polyethylene-block-poly(ethylene oxide) (EEO) symmetric diblock copolymer were prepared using 4,4'-methylenedianiline (MDA) as curing agent and were characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), small-angle X-ray scattering (SAXS), and differential scanning calorimetry (DSC). All the MDA-cured ER/EEO blends do not show macroscopic phase separation but exhibit microstructures. The ER selectively mixes with the epoxy-miscible PEO block in the EEO diblock copolymer whereas the crystallizable PE blocks that are immiscible with ER form separate microdomains at nanoscales in the blends. The PE crystals with size on nanoscales are formed and restricted within the individual spherical micelles in the nanostructured ER/EEO blends with EEO content up to 30 wt %. The spherical micelles are highly aggregated in the blends containing 40 and 50 wt % EEO. The PE dentritic crystallites exist in the blend containing 50 wt % EEO whereas the blends with even higher EEO content are completely volume-filled with PE spherulites. The semicrystalline microphase-separated lamellae in the symmetric EEO diblock copolymer are swollen in the blend with decreasing EEO content, followed by a structural transition to aggregated spherical micellar phase morphology and, eventually, spherical micellar phase morphology at the lowest EEO contents. Three morphological regimes are identified, corresponding precisely to the three regimes of crystallization kinetics of the PE blocks. The nanoscale confinement effect on the crystallization kinetics in nanostructured thermoset blends is revealed for the first time. This new phenomenon is explained on the basis of homogeneous nucleation controlled crystallization within nanoscale confined environments in the block copolymer/thermoset blends.

Long-term in vivo biostability of poly(dimethylsiloxane) / poly(hexamethylene oxide) mixed macrodiol-based polyurethane elastomers

The long-term biostability of a novel thermoplastic polyurethane elastomer (Elast-Eon(TM) 2 80A) synthesized using poly(hexamethylene oxide) (PHMO) and poly(dimethylsiloxane) (PDMS) macrodiols has been studied using an in vivo ovine model. The material's biostability was compared with that of three commercially available control materials, Pellethane(R) 2363-80A, Pellethane(R) 2363-55D and Bionate(R) 55D, after subcutaneous implantation of strained compression moulded flat sheet dumbbells in sheep for periods ranging from 3 to 24 months. Scanning electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy were used to assess changes in the surface chemical structure and morphology of the materials. Gel permeation chromatography, differential scanning calorimetry and tensile testing were used to examine changes in bulk characteristics of the materials. The results showed that the biostability of the soft flexible PDMS-based test polyurethane was significantly better than the control material of similar softness, Pellethane(R) 80A, and as good as or better than both of the harder commercially available negative control polyurethanes. Pellethane(R) 55D and Bionate(R) 55D. Changes observed in the surface of the Pellethane(R) materials were consistent with oxidation of the aliphatic polyether soft segment and hydrolysis of the urethane bonds joining hard to soft segment with degradation in Pellethane(R) 80A significantly more severe than that observed in Pellethane(R) 55D. Very minor changes were seen on the surfaces of the Elast-Eon(TM) 2 80A and Bionate(R) 55D materials. There was a general trend of molecular weight decreasing with time across all polymers and the molecular weights of all materials decreased at a similar relative rate. The polydispersity ratio, M-w/M-n, increased with time for all materials. Tensile tests indicated that UTS increased in Elast-Eon(TM) 2 80A and Bionate(R) 55D following implantation under strained conditions. However, ultimate strain decreased and elastic modulus increased in the explanted specimens of all three materials when compared with their unimplanted unstrained counterparts. The results indicate that a soft, flexible PDMS-based polyurethane synthesized using 20% PHMO and 80% PDMS macrodiols has excellent long-term biostability compared with commercially available polyurethanes. (C) 2004 Elsevier Ltd. All rights reserved.

Determination of domain sizes in blends of poly(ethylene) and poly(styrene) formed in the presence of supercritical carbon dioxide

Well-mixed blends of poly(ethylene) and poly(styrene) have been synthesized using supercritical carbon dioxide as a solvent. The morphology of the blends has been conclusively characterized using differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), Raman microprobe microscopy, and C-13 solid-state cross-polarization magic angle spinning NMR (C-13 CPMAS NMR). DSC measurements demonstrate that poly(styrene) in the blends resides solely in the amorphous regions of the poly(ethylene) matrix; however, corroborative evidence from the SAXS experiments shows that poly(styrene) resides within the interlamellar spaces. The existence of nanometer-sized domains of poly(styrene) was shown within a blend of poly(styrene) and poly(ethylene) when formed in supercritical carbon dioxide using Raman microprobe microscopy and C-13 CPMAS NMR spectroscopy coupled with a spin diffusion model. This contrasts with blends formed at ambient pressure in the absence of solvent, in which domains of poly(styrene) in the micrometer size range are formed. This apparent improved miscibility of the two components was attributed to better penetration of the monomer prior to polymerization and increased swelling of the polymer substrate by the supercritical carbon dioxide solvent.

Miscibility and phase separation in blends of phenolphthalein poly(aryl ether ketone) and poly(ethylene oxide): a differential scanning calorimetric study

Miscibility and phase separation in the blends of phenolphthalein poly(aryl ether ketone) (PPAEK) and poly(ethylene oxide) (PEO) were investigated by means of differential scanning calorimetry (DSC). The PPAEK/PEO blends prepared by solution casting from N,N-dimethylformamide (DMF) displayed single composition-dependent glass transition temperatures (T-g), intermediate between those of the pure components, suggesting that the blend system is miscible in the amorphous state at all compositions. All the blends underwent phase separation at higher temperatures and the system exhibited a lower critical solution temperature (LCST) behavior. A step-heating thermal analysis was designed to determine the phase boundaries with DSC. The significant changes in the thermal properties of blends were utilized to judge the mixing status for the blends and the phase diagram was thus established. (C) 2004 Elsevier B.V. All rights reserved.