Cannabis through the looking glass: chemo- and enantio-selective separation of phytocannabinoids by enantioselective ultra high performance supercritical fluid chromatography

By using the Inverted Chirality Columns Approach (ICCA) we have developed an enantioselective UHPSFC method to determine the enantiomeric excess (ee) of (-)-Δ(9)-THC in medicinal marijuana (Bedrocan®). The ee was high (99.73%), but the concentration of the (+)-enantiomer (0.135%) was not negligible, and it is worth a systematic evaluation of bioactivity

Impact of localization on Dyson's circular ensemble

A wide variety of complex physical systems described by unitary matrices have been shown numerically to satisfy level statistics predicted by Dyson's circular ensemble. We argue that the impact of localization in such systems is to provide certain restrictions on the eigenvalues. We consider a solvable model which takes into account such restrictions qualitatively and find that within the model a gap is created in the spectrum, and there is a transition from the universal Wigner distribution towards a Poisson distribution with increasing localization.Comment: To be published in J. Phys.

Effect of pmma-mwnts loading on Co2 separation performance of thin film nanocomposite membrane

Nanocomposite membrane, especially the thin film nanocomposite (TFN) fabricated via interfacial polymerization (IP) is a relatively new class of membrane which features good separation performance and practical processing. This study investigated on the effects of multi-walled carbon nanotubes (MWNTs) loading on the gas separation performance of the resultant TFNs. TFNs were tested with pure CO2, N2 and CH4 gases at feed pressure of 2 bar. The findings from this study suggested that the optimum fillers loading was around 0.25 g/L in the coating solution which gives TFN with CO2 permeance of 53.5 gas permeation unit (GPU) (12% higher than base membrane without filler), CO2/N2 selectivity of 61 and CO2/CH4 selectivity of 35. The enhancement in CO2 permeance without sacrificing the membrane selectvities was attributed to the good dispersion and compatibility of the MWNTs with the polymer matrix while the nanotubes serve as rapid diffusion channels to facilitate transport of gases. TFN embedded with polymethyl methacrylate (PMMA)-MWNTs showed potential for low pressure carbon capture and storage application

Coherent Time Evolution and Boundary Conditions of Two-Photon Quantum Walks

Multi-photon quantum walks in integrated optics are an attractive controlled quantum system, that can mimic less readily accessible quantum systems and exhibit behavior that cannot in general be accurately replicated by classical light without an exponential overhead in resources. The ability to observe time evolution of such systems is important for characterising multi-particle quantum dynamics---notably this includes the effects of boundary conditions for walks in spaces of finite size. Here we demonstrate the coherent evolution of quantum walks of two indistinguishable photons using planar arrays of 21 evanescently coupled waveguides fabricated in silicon oxynitride technology. We compare three time evolutions, that follow closely a model assuming unitary evolution, corresponding to three different lengths of the array---in each case we observe quantum interference features that violate classical predictions. The longest array includes reflecting boundary conditions.Comment: 7 pages,7 figure

On factorization of q-difference equation for continuous q-Hermite polynomials

We argue that a customary q-difference equation for the continuous q-Hermite polynomials H_n(x|q) can be written in the factorized form as (D_q^2 - 1)H_n(x|q)=(q^{-n}-1)H_n(x|q), where D_q is some explicitly known q-difference operator. This means that the polynomials H_n(x|q) are in fact governed by the q-difference equation D_qH_n(x|q)=q^{-n/2}H_n(x|q), which is simpler than the conventional one.Comment: 7 page

Intelligent Optimization Systems for MaintenanceScheduling of Power Plant Generators

This paper presents a Genetic Algorithm (GA) and Ant-Colony (AC) optimization model for power plant generators’ maintenance scheduling. Maintenance scheduling of power plant generators is essential for ensuring the reliability and economic operation of a power system. Proper maintenance scheduling prolongs the shelf life of the generators and prevents unexpected failures. To reduce the cost and duration of generator maintenance, these models are built with various constants, fitness functions, and objective functions. The Analytical Hierarchy Process (AHP), a decision-making tool, is implemented to aid the researcher in prioritizing and re-ranking the maintenance activities from the most important to the least. The intelligent optimization models are developed using MATLAB and the developed intelligent algorithms are tested on a case study in a coal power plant located at minjung, Perak, Malaysia. The power plant is owned and operated by Tenaga Nasional Berhad (TNB), the electric utility company in peninsular Malaysia. The results show that GA outperforms ACO since it reduces maintenance costs by 39.78% and maintenance duration by 60%. The study demonstrates that the proposed optimization method is effective in reducing maintenance time and cost while also optimizing power plant operation

Semiclassical Double-Pomeron Production of Glueballs and η′\eta'

A semiclassical theory of high energy scattering based on interrupted tunneling (instantons) or QCD sphaleron production has been recently developed to describe the growing hadronic cross section and properties of the soft Pomeron. In this work we address double-pomeron processes in this framework for the first time. We specifically derive the cross section for central production of parity even and odd clusters, scalar and pseudoscalar glueballs, and $\eta'$ in parton-parton scattering at high energy. We show that the specific dependence of the production cross section on all its kinematical variables compares favorably with the UA8 data on inclusive cluster production, as well as the WA102 data on exclusive central production of scalar glueball and $\eta'$, in double-pomeron exchange $pp$ scattering. The magnitude of the cross section and its dependece on kinematic variables is correct, explaining in particular a large deviation from the Pomeron factorization at cluster masses in the range $M_X<8$ GeV reported by UA8