<p dir="ltr">While electrospray ionization facilitates the mass determination of smaller analytes, ESI of macromolecular native protein complexes is complicated by narrow charge state distributions and overlapping charge states, hindering mass analysis. This problem is further exacerbated with heterogeneous protein mixtures that yield ions of similar <i>m/z</i> values. Charge-reduction of a selected precursor population via ion/ion reaction provides further <i>m/z</i> separation and utilizes an extended mass range, allowing for mass determination. All experiments were performed on a TripleTOF 5600 quadrupole TOF mass spectrometer (SCIEX), modified for ion/ion reactions. Alternatively pulsed nano-electrospray ionization allowed for sequential injection of reagent and analyte ions. Selected cations were reacted with different anions, and charge-reduced product ions were mass analyzed on a TOF with modifications and tuning for an extended <i>m/z</i> range of 200,000+. Charge reduction via proton transfer reaction (PTR) involves a perfluorinated anion reacting with a multiply charged cation and results in the loss of one proton removal at a time. Through multiple iterations of PTR, the overlapping charge states of protein ions (from an unstained protein standard mixture consisting of 12 recombinant proteins of masses10kDa-200kDa) within the <i>m/z</i> 6500-8500 and <i>m/z</i> 4000-5000 ranges, generated under native conditions by ESI, transforms to a product spectrum with single-digit charge states, thereby deconvoluting the precursor “blob”.</p>

This dissertation elucidates a greater understanding of protein folding and unfolding processes during the lifetimes of electrospray and nano-spray droplets in laser electrospray mass spectrometry (LEMS) and nano-laser electrospray mass spectrometry (nano-LEMS) measurements, respectively. The similarity in mass spectral features obtained from conventional electrospray measurements for supercharged proteins with those of LEMS measurements suggested that supercharging phenomena occurs in the electrospray droplets during the droplet desolvation process. It was observed that the laser vaporization of protein from condensed phase into the electrospray droplets containing denaturing electrospray solution and a supercharging reagent resulted in the increase in ion abundance of higher charge states in comparison with electrospray measurements. Conversely, the addition of solution additives with varying gas phase basicity in the electrospray solvent resulted in charge reduction for unfolded protein upon laser vaporization from condensed phase into the charged electrospray droplets. The extent of charge reduction and the fraction of folded protein within the electrospray droplets was found to be dependent upon both the extent of protein denaturation in the solution prior to laser vaporization and the gas phase basicity of solution additives. The ability of the LEMS technique to analyze molecules from solution with high matrix effects was established by the successful detection of protein molecules from solution with high salt concentration. Experiments with LEMS enabled the detection of a protonated protein feature as the dominating peak in the mass spectra for up to 250 mM sodium chloride while conventional electrospray resulted in predominantly salt-adducted features, with suppression of the protonated protein ions for the salt concentration of 5 mM. This dissertation also expanded upon the use of a reaction system to measure the lifetimes of laser vaporized liquid droplets coupled with electrospray and nano-spray postionization mass spectrometry. Electrospray and nanospray droplet lifetimes were measured to be 4.5±0.6 ms and 1.4±0.3 ms using LEMS and nano-LEMS measurements, respectively. Time dependent protein folding measurements using LEMS revealed intermediate states during protein folding processes which are often limited in conventional electrospray measurements where bulk solution in manipulated (change in pH) to achieve protein folding. / Chemistry

Battery energy storage systems are a key factor for enabling a continuous increase of the fraction of photovoltaics in the Swedish electricity grid. One big challenge is to utilise all potential services of such a storage system. The aim of this study was to improve the supervisory controller for an existing battery storage and photovoltaic solution marketed by the Swedish company Ferroamp AB. This has been done by developing a combined peak reduction and time-of-use bill management algorithm, together with a simulation and evaluation software for optimisation of algorithm parameters. The algorithms and tools were evaluated using an installation made by Ferroamp AB and Vattenfall Eldistribution AB as a case study. Sensitivity analyses has been performed on economic parameters and length of the algorithm training data set. Improvement of economic profit, in this case study, were 300 % compared to the currently used algorithm and 32 % compared to a conventional threshold peak reduction algorithm. Despite this improvement, the battery energy storage system is shown to be non-profitable, with the economic profit only covering 36 % of the investment costs, not taking interest rate into account. Like in many other studies, power storage was found more profitable than energy storage. An increase of the grid power tariff and the grid energy fee of 30 % to 40 % is found to make the system viable. One interesting finding is that by using the proposed optimal algorithm, 55 % of the cycle life of the battery storage is still accessible for other services when considering 10 years of economic depreciation time for the system.