The potential of CO2 laser photoacoustic spectrometry for?detection of methanol in alcoholic beverage

The first use of CO₂ laser photoacoustic measurements for detecting the methanol contents in alcohol-like solutions is presented. With an intracavity cell configuration, the minimum detectable concentration was ∼200 ppm for methanol and the linear range of the calibration curve for methanol was from 200 to 70000 ppm. For demonstrating the reliability of analysis in alcoholic beverages, a series of different concentrations of two-component samples was prepared and measured by the same procedures. The results showed the feasibility on determining methanol and ethanol contents accurately within a specific tolerance, limited mainly by background signal and laser stability. This potential method with no pre-treatment of samples takes only ∼10 min to finish one single measurement. It suggests that the PA detection is suitable for routine diagnosis of adulterated wines in commercial products.     

An analysis of the role of nonreactive plasticizers in the crosslinking reactions of a rigid resin

A uniform dispersion of reactants is necessary to achieve a complete reaction involving multiple components. Using a combination of infrared spectroscopy, thermal analysis, and low field NMR, we have elucidated the role of a new class of nonreactive plasticizers on the crosslinking reaction between hexamethylenetetramine (HMTA) and phenol formaldehyde resin. These two seemingly dissimilar reactants are responsible for the exceptionally high mechanical strength in a number of organic–inorganic composites. The efficiency of the curing reaction is characterized by the changing functionality of HMTA. Infrared active vibrations are used to characterize the changing molecular structures as a function of temperature. The T₁ spin‐lattice relaxation time is used for the characterization of segmental dynamics of the chains in the formation of the crosslinked product. The segmental mobility depends on the amount of crosslinking and the stiffness of the chain. This study shows that this new class of nonreactive plasticizer can induce highly crosslinked structures without any of the environmental impact of the current technology. An efficient crosslinking reaction in phenolic resin can be achieved by using methyl benzoate as a nonreacting plasticizer. Low field NMR, in conjunction with infrared spectroscopy (mid and near) and DSC, clarified the crosslinking reaction mechanism and the ensuing structure. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 206–213     

Interparticle interaction and gel characterization of PE microgels using small- and large-strain viscoelastic response

PE microgels were prepared from mechanical fragmentation and from immiscible blends of PS and PE. The surface topology of microgels obtained from mechanical fragmentation was hypothesized to consist of long linear PE chains that are capable of interparticle co-crystallization as suggested by low-strain oscillatory shear experiment results. To investigate this hypothesis, PE microgels with a smooth surface and a PS corona were prepared using immiscible blends of PE and PS, followed by removal of the PS matrix. The rheological response of suspensions of PE microgels with a PS corona in squalane was similar to suspensions of PE microgels with crystallizable surface chains whereby the system would gel and exhibit hysteresis upon a cooling and heating cycle. Suspensions of PE microgels without any surface chains, however, were reversible over multiple cooling and heating cycles. It was determined that the PS corona and the cross-link density of the microgels had an effect (p < 0.01) on the reversibility whereas the microgel concentration in the suspension did not (p = 0.82).     

Designing a recovery-orientated system of care: A community operational research perspective

Theory suggests health focused Community Operational Research (COR) projects and their participants can benefit from balancing a “glass half empty” concern for deficits, problems and weaknesses with a “glass half full” concern for identifying health assets and bringing them into use. We present a COR systemic intervention in the care of persons with addiction and substance use/ misuse problems in Clydeplace, Scotland (anonymised). Our research reveals how the Whole Person Recovery System is situated within a wider General Community Recovery System that offers a variety of health assets that can be mobilised to create and increase recovery capital. The project involved 20 semi-structured interviews, two asset mapping workshops, a certificated “health issues” course completed by seven “champions”, and action planning and implementation. In the interviews participants found gaps were more easily identified than assets. During the workshops participants identified 388 discrete assets and gaps, prioritised these using a simple voting system and developed a series of actions to mobilise health assets including bringing into use local facilities and amenities and involving a number of individuals and groups in local events and activities. Our study suggests that even in the impoverished system of Clydeplace, a “Community Catalyst” in the form of a Community Operational Researcher can act to stimulate the co-development of health assets, build relationships and enable the creation of social capital. It is not clear though when such systems become “self-catalysing.”     

Fragment Assembly: An Alternative Approach to Generating Complex Polyketides

A new approach to the preparation of complex polyketide natural products has been outlined in which the products of biosynthesis are used as starting materials for chemical synthesis of difficult‐to‐obtain natural products.     

A Stereospecific Route to 6-Substituted-7-Azabicyclo[3.2.1]Oct-2-Ones

N-carbethoxy-3-exo- or 3-endo-substituted-2-azabicyclo-[2.2.2]oct-5-enes 1 provide the title compounds 2 by a stercospecific route involving bromohydrin formation, reductive dehalogenation and oxidation.