Thermotropic polyester: the influence of the spacer on the physical properties

Thermotropic polyesters prepared from series of 4,4-dihydroxy-,w-diphenoxy alkanes and 4,4-dichloroformyl-,w-diphenoxy alkanes are well known. The substitution of a methylenic spacer by an oxyethylenic spacer in the main chain of these polyesters drastically modifies their physical properties, particularly the mesogenic transition temperatures, as can be observed by DSC and thermooptical analysis. The thermal stability and the polymer solubility in common organic solvents of these polymers did not show a significant change. The physical properties of the two thermotropic polyesters prepared in diphenyl ether were evaluated.     

Prediction of Cognitive Abilities 1 Year Following Traumatic Brain Injury From Inpatient Rehabilitation Cognitive Screening.

Objective: To evaluate the ability of the Cognitive Log (Cog-Log) to predict neuropsychological outcome at 1 year after traumatic brain injury (TBI). Study Design: The Orientation Log (O-Log) and Cog-Log were administered during morning rounds, and a battery of neuropsychological tests was administered at 1 year postinjury. Setting: Acute rehabilitation hospital. Participants: Fifty rehabilitation inpatients. Main Outcome Measures: Composite scores for processing speed, attention, language, memory, executive functioning, and visuospatial abilities. Results: The Cog-Log was found to significantly predict 1-year outcome in attention, executive functioning, and visuospatial abilities. The O-Log contributed significantly to memory outcome. The Disability Rating Scale was not a significant predictor. Conclusions: The Cog-Log has utility as a predictor of neuropsychological outcome, particularly when used with its companion instrument, the O-Log. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamic mechanical behavior of vinylester matrix composites reinforced by Luffa cylindrica modified fibers

Currently, there is a demand for new engineering materials presenting a combination of strength, low density, processing easiness, and reduced costs. In this context, polymer matrix composites reinforced by natural fibers have been studied in recent years due to their ecological and economic advantages. Some fibers are still little explored in literature despite presenting a great potential as reinforcement like Luffa cylindrica. The present work aims at the preparation and characterization of a vinylester thermoset matrix composite material reinforced by fibers of the natural L. cylindrica fruit after modification treatments. In this study, extraction treatments in organic solvents, mercerization, and a quite new esterification with BTDA dianhydrides were used and the results showed that in all cases, the composite materials reinforced by Luffa fibers have showed improvements in mechanical and thermal properties compared to the vinylester matrix. As an example, 50% tensile increase was obtained for the composite reinforced by fibers esterified with benzophenone tetracarboxylic dianhydride when compared with thermoset matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Disability determination for the mentally impaired: Conflicts and changes.

Reports that the Social Security Administration (SSA) has been criticized for its handling of mentally impaired disability claimants. Requirements by the SSA for objective evidence of disability and the presumption that mentally impaired individuals are capable of unskilled work have been deemed prejudicial by those critical of the SSA. The 5-step process employed in determining whether disability benefits will be granted is outlined. Since reviews of existing disability cases began in 1981, a disproportionate number of mentally disabled beneficiaries have been selected for review and subsequent termination of benefits. Consequently, the disability programs of the SSA, particularly as they apply to mentally impaired claimants, have been challenged in federal courts and have been the subject of congressional scrutiny. Partly as a result, the SSA has suspended the review of disability cases and is in the process of modifying the determination and review process for disability claims involving mental disorders. Legislation pending in Congress indicates that sections of the Social Security Act pertaining to mental disorder are to be revised, and there will be increasing emphasis on determining the vocational impact of mental disorders. (69 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Novel garnet then film optical waveguides

Two epitaxial thin film garnet compositions Gd₃Sc_.13Gal_4.87012 and Y₃Sc₂.0A1.9lGa_2.090012, have been developed and operated as otpical waveguides. The refractive index of the solid solution films is shown to be linear with respect to mole fraction of the end member garnets. Compositions of twelve additional solid solutions are proposed which will allow selection of film-substrate combinations from among a wide range of refractive index differences.     

Three-dimensional phase step profilometry with a multicore optical fiber

This paper demonstrates the feasibility of using phase stepping and a multicore optical fiber to calculate an object's depth profile. An interference pattern is projected by an optical fiber onto the object. The distorted interference pattern containing the object information is captured by a CCD camera and processed using a phase step interferometry method. The phase step method is less computationally intensive compared to two-dimensional Fourier transform profilometry and provides more accuracy when measuring objects of high frequency spatial variations.