Yes,More Decoherence: A Reply to Critics

Recently I published an article in this journal entitled “Less interpretation and more decoherence in quantum gravity and inflationary cosmology” (Crull in Found Phys 45(9):1019–1045, 2015). This article generated responses from three pairs of authors: Vassallo and Esfeld (Found Phys 45(12):1533–1536, 2015), Okon and Sudarsky (Found Phys 46(7):852–879, 2016) and Fortin and Lombardi (Found Phys, 2017). In what follows, I reply to the criticisms raised by these authors.     

The role of pore size and structure on the thermal stability of gold nanoparticles within mesoporous silica

Highly dispersed gold particles (<2 nm) were synthesized within the pores of mesoporous silica with pore sizes ranging from 2.2 to 6.5 nm and different pore structures (2D-hexagonal, 3D-hexagonal, and cubic). The catalysts were reduced in flowing H2 at 200 degrees C and then used for CO oxidation at temperatures ranging from 25 to 400 degrees C. The objective of this study was to investigate the role of pore size and structure in controlling the thermal sintering of Au nanoparticles. Our study shows that sintering of Au particles is dependent on pore size, pore wall thickness (strength of pores), and pore connectivity. A combination of high-resolution TEM/STEM and SEM was used to measure the particle size distribution and to determine whether the Au particles were located within the pores or had migrated to the external silica surface.     

The dark side of disulfide-based dynamic combinatorial chemistry

During the last two decades, disulfide-based dynamic combinatorial chemistry has been extensively used in the field of molecular recognition to deliver artificial receptors for molecules of biological interest. Commonly, the nature of library members and their relative amounts are provided from HPLC-MS analysis of the libraries, allowing the identification of potential binders for a target (bio)molecule. By re-investigating dynamic combinatorial libraries generated from a simple 2,5-dicarboxy-1,4-dithiophenol building block in water, we herein demonstrated that multiple analytical tools were actually necessary in order to comprehensively describe the libraries in terms of size, stereochemistry, affinity, selectivity, and finally to get a true grasp on the different phenomena at work within dynamic combinatorial systems.

We show that multiple analytical tools are necessary in order to describe the different phenomena within disulfide-based dynamic combinatorial libraries in terms of size, stereochemistry, affinity and selectivity.     

Two- and three-body photodissociation of gas phase I(3) (-)

The photodissociation dynamics of I3- from 390 to 290 nm (3.18 to 4.28 eV) have been investigated using fast beam photofragment translational spectroscopy in which the products are detected and analyzed with coincidence imaging. At photon energies < or = 3.87 eV, two-body dissociation that generates I- + I2(A 3Pi1) and vibrationally excited I2- (X 2Sigmau+) + I(2P(3/2)) is observed, while at energies > or = 3.87 eV, I*(2P(1/2)) + I2- (X 2Sigmau+) is the primary two-body dissociation channel. In addition, three-body dissociation yielding I- +2I(2P(3/2)) photofragments is seen throughout the energy range probed; this is the dominant channel at all but the lowest photon energy. Analysis of the three-body dissociation events indicates that this channel results primarily from a synchronous concerted decay mechanism.     

The H method: hydrogen atoms with a fictitious nuclear charge. A versatile theoretical tool for study of atom and group properties as substituents: electronegativity and partition of σ and π contributions

We present a preliminary work for a general method of computing the partition of σ and π electronic effects of a given atom A or substituent R on a given substrate. In this aim, the nuclear charge Z^* of a fictitious hydrogen atom H^* is fitted in order that the A–H^* (or R–H^*) bond be purely covalent, i.e. the Mulliken electron population be one electron on H^*. We obtain this way entities of the same electronegativity as A or R, thus having a comparable σ effect, without any π effect.

The values of Z^* obtained for A–H^* diatomic molecules (A=H–Br) exhibit a good linear correlation with the Allred–Rochow scale of electronegativity, as it could be expected on theoretical grounds. The method, applied to R–H^* molecules, allows a determination of the electronegativity of a variety of polyatomic R substituents, and provides H^*(R) having the same inductive effect as R. These results are discussed by comparison with some previous theoretical and experimental data.

As an example of application, the partition of σ and π contributions of R on the ¹³C chemical shifts in a series of monosubstituted benzenes RC₆H₅ has been computed.     

Inductively Coupled Plasma Zoom–Time-of-Flight Mass Spectrometry

A zoom–time-of-flight mass spectrometer has been coupled to an inductively coupled plasma (ICP) ionization source. Zoom–time-of-flight mass spectrometry (zoom-TOFMS) combines two complementary types of velocity-based mass separation. Specifically, zoom-TOFMS alternates between conventional, constant-energy acceleration (CEA) TOFMS and energy-focused, constant-momentum acceleration (CMA) (zoom) TOFMS. The CMA mode provides a mass-resolution enhancement of 1.5-1.7× over CEA-TOFMS in the current, 35-cm ICP-zoom-TOFMS instrument geometry. The maximum resolving power (full-width at half-maximum) for the ICP-zoom-TOFMS instrument is 1200 for CEA-TOFMS and 1900 for CMA-TOFMS. The CMA mode yields detection limits of between 0.02 and 0.8 ppt, depending upon the repetition rate and integration time—compared with single ppt detection limits for CEA-TOFMS. Isotope-ratio precision is shot-noise limited at approximately 0.2% relative-standard deviation (RSD) for both CEA- and CMA-TOFMS at a 10 kHz repetition rate and an integration time of 3–5 min. When the repetition rate is increased to 43.5 kHz for CMA, the shot-noise limited, zoom-mode isotope-ratio precision is improved to 0.09% RSD for the same integration time.

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Graphical Abstract ?

     

Comprehensive two-dimensional gas chromatography analysis of high-ethanol containing motor fuels

A comprehensive 2-D GC (GC x GC) instrument equipped with a flow-switching modulator was used to determine the concentration of ethanol and eight other alcohols in a retail pump sample of E85 fuel. E85 is a mixture of ethanol and gasoline where the ethanol concentration can range from 70 to 85 vol%. The increased peak capacity and selectivity generated by GC x GC analysis allowed the alcohols to be fully resolved from the gasoline hydrocarbons. GC x GC analysis was compared to the performance obtained with the standard analytical method for determining ethanol in fuel ethanol (ASTM D5501) and the standard method for determining oxygenate concentrations in gasoline (ASTM D4815). The GC x GC analysis required 14 min while the combined ASTM D5501 and ASTM D4815 analyses required more than 60 min. The ethanol concentration obtained by GC x GC was in excellent agreement with the value obtained by the D5501 method. Poorer agreement was observed between the GC x GC and D4815 concentrations for the other alcohols present in E85. In all cases, the differences could be attributed to deficiencies in the D4815 method that led to coelutions between the alcohols and gasoline hydrocarbons.