Development of Gas-Chromatographic Method for Simultaneous Determination of Cannabinoids and Terpenes in Hemp

An original gas chromatographic method has been developed for simultaneous determination of major terpenes and cannabinoids in plant samples and their extracts. The main issues to be addressed were the large differences in polarity and volatility between both groups of analytes, but also the need for an exhaustive decarboxylation of cannabinoid acidic forms. Sample preparation was minimised, also by avoiding any analyte derivatisation. Acetone was found to be the most appropriate extraction solvent. Successful chromatographic separation was achieved by using a medium polarity column. Limits of detection ranged from 120 to 260 ng/mL for terpenes and from 660 to 860 ng/mL for cannabinoids. Parallel testing proved the results for cannabinoids are comparable to those obtained from established HPLC methods. Despite very large differences in concentrations between both analyte groups, a linear range between 1 and 100 µg/mL for terpenes and between 10 and 1500 µg/mL for cannabinoids was determined.     

Optimal Expansion Planning for an Electric Distribution Network with the NLP Solver WORHP

This paper shows how an electrical distribution network can be modeled as constraints of a continuous nonlinear optimization problem. The objective is to minimize the deviation from a given nominal voltage. We explain how this setup can be used to optimize wire diameters within the network. Thus we find the optimal expansion of the network by identifying wires which should be enforced. The results are shown by applying the functionality to a real world example. (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Heat transfer study in rotating cascade using IR thermography and CFD analyses

This paper presents an experimental and CFD numerical study of convective heat transfer in a rotating cascade. Infrared thermography was used to measure surface temperature distribution on a rotating hollow blade, heated internally by secondary air. A CFD numerical model was made according to the actual test rig geometry and operating conditions. Tests were carried out in an iposonic flow regime at relatively low fluid temperatures, with the rotational and Reynolds numbers varied and hot-to-cool air mass flow ratio kept constant. Experimental and numerical results for the blade pressure side are compared in terms of surface temperature 2D distribution and Nusselt number one-dimensional distribution along the blade midspan, providing a reasonable agreement.     

LQR control for a Diesel engine's air system

Due to more and more restrictive emission standards, the air system of Diesel engines has evolved into a complex system with several coupled actuating and controlled variables. In this paper, a linear-quadratic regulator (LQR) is used as a model-based, multivariable, optimal control of the air system. This technique is validated by results of an on-board test. (© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)