Comparisons of predicted steady-state levels in rooms with extended- and local-reaction bounding surfaces

A combined beam-tracing and transfer-matrix model for predicting steady-state sound-pressure levels in rooms with multilayer bounding surfaces was used to compare the effect of extended- and local-reaction surfaces, and the accuracy of the local-reaction approximation. Three rooms—an office, a corridor and a workshop—with one or more multilayer test surfaces were considered. The test surfaces were a single-glass panel, a double-drywall panel, a carpeted floor, a suspended-acoustical ceiling, a double-steel panel, and glass fibre on a hard backing. Each test surface was modeled as of extended or of local reaction. Sound-pressure levels were predicted and compared to determine the significance of the surface-reaction assumption. The main conclusions were that the difference between modeling a room surface as of extended or of local reaction is not significant when the surface is a single plate or a single layer of material (solid or porous) with a hard backing. The difference is significant when the surface consists of multilayers of solid or porous material and includes a layer of fluid with a large thickness relative to the other layers. The results are partially explained by considering the surface-reflection coefficients at the first-reflection angles.     

XPS and resistive studies on thin films of a copper(II)‐based coordination polymer deposited on functionalized interdigital electrodes

A symmetrical 2‐thiopyrimidine based molecule with an expanded π‐electron system is synthesized and used to form a self‐assembled monolayer (SAM) on gold surfaces. Utilizing chemical vapor deposition a monolayer of (3‐mercaptopropyl)triethoxysilane is formed on silicon dioxide substrates. Both of these SAM coated substrates are characterized by X‐ray photoelectron spectroscopy and the growth of a coordination polymer built up from 5,5′‐(ethyne‐1,2‐diyl)bis(2‐hydroxyacetophenone) and copper(II) on dual SAM coated transducers is studied. After the deposition procedure on interdigital electrodes the electrical properties of the polymer are investigated performing resistive measurements. A significant change of the resistance, which depends on the surrounding atmosphere, proves the sensing behavior of the synthesized coordination polymer. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 335–344     

Phase-sensitivity measurement of a 10-sensor array with erbium-doped fiber amplifier telemetry

We report what are believed to be the first measurements of the phase sensitivity of a fiber sensor array using multiple low-gain remotely pumped amplifiers with an interferometric sensor inserted. The measured phase sensitivities for individual rungs average 5.7 microrad(rms)/ radicalHz and exhibit no dependence on rung number, in agreement with predictions.     

Alternative organic solvents for HILIC separation of cisplatin species with on-line ICP-MS detection

Several low volatile organic solvents were evaluated as organic modifiers in eluents for HILIC separations of cisplatin species to optimize the on-line coupling of HILIC to inductively coupled plasma MS (ICP-MS). The aim was to identify a solvent giving low solvent vapor loading of the ICP, to maximize analyte sensitivity and minimize carbon depositions on instrumental parts, while retaining chromatographic performance. The best overall performance of the HILIC-ICP-MS system for the analysis of cisplatin was achieved using 1,4-dioxane as eluent, yielding high retention and an HILIC type retention mechanism, at the expense of a 50% drop in column efficiency due to the higher viscosity of 1,4-dioxane compared to the more commonly used HILIC solvent ACN. Using 1,4-dioxane as solvent in HILIC provides the best compromise between carbon deposition and separation efficiency among a series of high-boiling water-miscible solvents tested.     

Dehydroalkylation of toluene with ethane in a packed-bed membrane reactor with a bifunctional catalyst and a hydrogen-selective membrane

The dehydroalkylation of toluene with ethane to form isomeric ethyltoluenes has been carried out in a packed-bed membrane reactor under mild conditions of 350 degrees C, where it is shown that ethyltoluene yields significantly increase with increasing sweep gas flow rate and pressure.     

Use of an electrochemically synthesised metabolite of a selective androgen receptor modulator for mass spectrometry-based sports drug testing

The elucidation of the metabolism of new therapeutics is a major task for pharmaceutical companies and of great interest for drug testing laboratories. The latter in particular need to determine the presence or absence of drugs or their metabolic products in urine to test for a misuse of these compounds. Commonly, in vitro or animal models are used to mimic the human metabolism and produce potential targets in amounts allowing for method development. An alternative route based on electrochemical reactions of drugs was reported to allow for the generation of selected metabolites. The utility of this approach for doping control purposes was demonstrated with a novel class of anabolic agents termed selective androgen receptor modulators (SARMs). An arylpropionamide- derived drug candidate was subjected to electrochemical "metabolism" and a major phase-I- metabolite, resulting from the elimination of a substituted phenol residue as identified in in vitro experiments, was generated and characterised using liquid chromatography/nuclear magnetic resonance spectroscopy and high resolution/high accuracy mass spectrometry. The metabolite was included in routine doping control procedures based on liquid chromatography/tandem mass spectrometry and has served as a reference compound for 5000 doping control specimens.     

Porphyrin complexes containing coordinated BOB groups: synthesis, chemical reactivity and the structure of [BOB(tpClpp)]2+

The reactions of boron halides with free base porphyrins under conditions where partial hydrolysis of the boron halides can occur give diboron porphyrin complexes containing BOB moieties in which each boron is bonded to two porphyrin nitrogen atoms. BF(3).OEt(2) with H(2)(por) gives B(2)OF(2)(por) (por = tpp, ttp, tpClpp, oep) which has an asymmetric structure in which one boron lies in the porphyrin plane (B(ip)) while the other lies above it (B(oop)). BCl(3).MeCN with H(2)(por) gives B(2)O(2)(BCl(3))(2)(por) which contains a four-membered B(2)O(2) ring and is stable only in the presence of excess BCl(3). BBr(3) with Li(2)(tpClpp) gives the dicationic complex [B(2)O(tpClpp)](2+) as its [BBr(4)](-) salt, and is the first example of a boron porphyrin containing three-coordinate boron to be structurally characterised. B(2)O(2)(BCl(3))(2)(por) can be chromatographed on basic alumina to give the hydroxyboron complex B(2)O(OH)(2)(por), which is deduced from its NMR spectra and DFT calculations to have a structure analogous to B(2)OF(2)(por). The OH protons are shifted upfield to near delta -4 (B(oop)-OH) and -10 (B(ip)-OH) by the diamagnetic porphyrin ring current. The reaction of either B(2)O(2)(BCl(3))(2)(por) or B(2)O(OH)(2)(por) (por = ttp, tpClpp) with alcohols (ROH, R = Et, 4-C(6)H(4)CH(3)) gives B(2)O(OR)(2)(por), which can in turn be converted to B(2)O(OR)(OH)(por) by repeated chromatography. The reaction of PhBCl(2) with H(2)(por) (por = ttp, tpClpp) gives B(2)O(Ph)(OH)(por) which has been characterised by spectroscopy in concert with DFT calculations. It is a further example of the B(2)OF(2)(por) structural type, in which the phenyl group is coordinated to the out-of-plane boron and the OH group to the in-plane boron, as are its derivatives B(2)O(Ph)(X)(tpClpp) (X = F, OEt). Steric drivers for the facile hydrolysis of haloboron porphyrins relative to their dipyrromethene and expanded porphyrin counterparts are discussed.     

Synthesis and absolute configuration of a constitutionally-new [5.6] spiroacetal from B. tryoni (Queensland fruit fly)

A novel spiroacetal, (2S,6R,8S)-2-methyl-8-ethyl-1,7-dioxaspiro[5.6]dodecane (1), has been identified from the volatile secretions of female B. tryoni by mass spectral analysis and synthesis of an authentic, enantioenriched sample.