The aim of the ongoing research is (i) to develop a new biodegradation landfill technique so that the landfill gas production could be controlled and the utilisation of the landfill gas could economically be optimized, (ii) to plan the energy utilisation of the landfill including individual and combined solutions (solar, wind, geothermal energy, energy storage using methanol etc.). [1, 2, 3]
After summarizing the previous measurements made on the ongoing research, the first results of the oedometer tests are presented. The compression curves were determined, the measured data are evaluated by two simple models, the parameters are identified, the reliability of the parameters is tested.
The simple models make possible the separation of the three major components of the settlement: the immediate settlement, the creep settlement and the primary consolidation settlement. The degradation induced strains were not considered since the tests were short term. Using these components, three different oedometric moduli are defined.
The identified parameters are presented and compared with the parameters previously identified from some CPTu dissipation test data, and with the parameters measured by some recent seismic tests. The parameters are used to estimate the settlement of the landfill.
Robert-Alexandru Vlad, Lenard Farczadi, Silvia Imre, Adriana Daniela Ciurba, Nicoleta Todoran, Emoke Redai, Paula Antonoaea and Daniela Lucia Muntean
Objectives: The aim of the study was to propose a new UHPLC method for the determination of cannabidiol (CBD) from supplements and drugs available on the Romanian market.
Materials and methods: The HPLC assay of CBD was achieved by using a Phenomenex Gemini NX-C18 column. The mobile phase consisted of 70% acetonitrile and 30% water. Elution was performed in isocratic mode and the detection was done at 208 nm. The method was tested on hard capsules containing 150 mg of CBD.
Results and discussions: The retention time of CBD was 2.8 minutes. Regression analysis showed good linearity over the 1-100 ug/ml concentration range. The lowest limit of quantification was established at 1 µg/ml. The method was developed by using reconstituted capsules. The substance proved low stability in solution at room temperature and stability at temperatures between 2-8°C. The recovery of reconstituted samples was 96.77%. The commercial capsules had a very low content of 15-20% from declared content.
Conclusions: The proposed method can be used for CBD determination in different pharmaceutical formulations – hard and soft capsules with coconut oil as excipient.