Exploring the grand-canonical phase diagram of interacting bosons in optical lattices by trap squeezing

In this paper we theoretically discuss how quantum simulators based on trapped cold bosons in optical lattices can explore the grand-canonical phase diagram of homogeneous lattice boson models, via control of the trapping potential independently of all other experimental parameters (trap squeezing). Based on quantum Monte Carlo, we establish the general scaling relation linking the global chemical potential to the Hamiltonian parameters of the Bose-Hubbard model in a parabolic trap, describing cold bosons in optical lattices; we find that this scaling relation is well captured by a modified Thomas-Fermi scaling behavior - corrected for quantum fluctuations - in the case of high enough density and/or weak enough interactions, and by a mean-field Gutzwiller Ansatz over a much larger parameter range. The above scaling relation allows to control experimentally the chemical potential, independently of all other Hamiltonian parameters, via trap squeezing; given that the global chemical potential coincides with the local chemical potential in the trap center, measurements of the central density as a function of the chemical potential gives access to the information on the bulk compressibility of the Bose-Hubbard model. Supplemented with time-of-flight measurements of the coherence properties, the measurement of compressibility enables one to discern among the various possible phases realized by bosons in an optical lattice with or without external (periodic or random) potentials -- e.g. superfluid, Mott insulator, band insulator, and Bose glass. We theoretically demonstrate the trap-squeezing investigation of the above phases in the case of bosons in a one-dimensional optical lattice, and in a one-dimensional incommensurate superlattice.Comment: 27 pages, 26 figures. v2: added references and further discussion of the local-density approximation

The supernova cosmology cookbook: Bayesian numerical recipes

Theoretical and observational cosmology have enjoyed a number of significant successes over the last two decades. Cosmic microwave background measurements from the Wilkinson Microwave Anisotropy Probe and Planck, together with large-scale structure and supernova (SN) searches, have put very tight constraints on cosmological parameters. Type Ia supernovae (SNIa) played a central role in the discovery of the accelerated expansion of the Universe, recognised by the Nobel Prize in Physics in 2011. The last decade has seen an enormous increase in the amount of high quality SN observations, with SN catalogues now containing hundreds of objects. This number is expected to increase to thousands in the next few years, as data from next-generation missions, such as the Dark Energy Survey and Large Synoptic Survey Telescope become available. In order to exploit the vast amount of forthcoming high quality data, it is extremely important to develop robust and efficient statistical analysis methods to answer cosmological questions, most notably determining the nature of dark energy. To address these problems my work is based on nested-sampling approaches to parameter estimation and model selection and neural networks for machine-learning. Using advanced Bayesian techniques, I constrain the properties of dark-matter haloes along the SN lines-of-sight via their weak gravitational lensing effects, develop methods for classifying SNe photometrically from their lightcurves, and present results on more general issues associated with constraining cosmological parameters and testing the consistency of different SN compilations.Comment: 119 pages, 29 figures, Doctoral Thesis in Theoretical Physics, ISBN 978-91-7447-953-

Modelling volume change and deformation in food products/processes: An overview

Volume change and large deformation occur in different solid and semi-solid foods during processing, e.g., shrinkage of fruits and vegetables during drying and of meat during cooking, swelling of grains during hydration, and expansion of dough during baking and of snacks during extrusion and puffing. In addition, food is broken down during oral processing. Such phenomena are the result of complex and dynamic relationships between composition and structure of foods, and driving forces established by processes and operating conditions. In particular, water plays a key role as plasticizer, strongly influencing the state of amorphous materials via the glass transition and, thus, their mechanical properties. Therefore, it is important to improve the understanding about these complex phenomena and to develop useful prediction tools. For this aim, different modelling approaches have been applied in the food engineering field. The objective of this article is to provide a general (non-systematic) review of recent (2005–2021) and relevant works regarding the modelling and simulation of volume change and large deformation in various food products/processes. Empirical-and physics-based models are considered, as well as different driving forces for deformation, in order to identify common bottlenecks and challenges in food engineering applications.Fil: Purlis, Emmanuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Cevoli, Chiara. Università di Bologna; ItaliaFil: Fabbri, Angelo. Università di Bologna; Itali

Understanding effect of filtration and washing on dried product : paracetamol case study

One of the key challenges that the pharmaceutical industry is trying to address is to maintain particle properties across the entire purification and isolation process. This research focuses on the effect of slurry properties, wash solvent, filtration and washing mechanisms on API agglomeration/granulation during the processes of downstream isolation and the impact on the physical properties of the product. In this investigation, each isolation step was analysed to identify factors that have the potential to affect the final product qualities using a multivariate statistical design of experiments approach. The factors which were most detrimental in increasing particle agglomeration, were found to be the particle size of the input material, the quantity and identity of wash solvent and the drying mode. Low boiling point aliphatic hydrocarbons are shown to be desirable final wash solvents to reduce the extent and strength of agglomerates and to produce free flowing powder/readily disrupted agglomerates

Unit Operations of Particulate Solids

Suitable for practicing engineers and engineers in training, this book covers the most important operations involving particulate solids. Through clear explanations of theoretical principles and practical laboratory exercises, the text provides an understanding of the behavior of powders and pulverized systems. It also helps readers develop skills for operating, optimizing, and innovating particle processing technologies and machinery in order to carry out industrial operations. The author explores common bulk solids processing operations, including milling, agglomeration, fluidization, mixing, and solid-fluid separation

The Computational and Experimental Study of the Freeze-Drying Process for a Monoclonal Antibody

Freeze-drying for biopharmaceuticals is widely used in industry to fabricate the final therapeutic product intended for administration to patients. Freeze-drying is a highly complex subject area, thus spurring research to make this process more applicable for various products and processes. This thesis first studies the production of a typical mAb therapeutic. A 50L Single-use Bioprocessing run was conducted by small research team (in which the author of this thesis was part of) at UCL to produce a purified mAb substance. The relevant stages detailing the methods and results for the downsteam process have been defined. In particular, this offers a deep dive into three chromatography trains comparing CEX (Cation Exchange Chromatography) methods to SMB (Simulated Bed) Chromatography. These polishing trains are: CEX to AEX (anion exchange chromatography) for main peak eluted mAb, CEX to AEX for shoulder peak eluted mAb) and SMB to AEX for pooled mAb sample. It was seen the Cation exchange to Anion exchange (shoulder peak mAb)) produced the lowest yield of 17.5% whereas the Cation Exchange to Anion Exchange (main peak mAb) produced the highest yield of 57%. The process was successful as it was scaled up from 5L to 50L and purified to a final titre of 0.8 g/L. However, it was concluded that a possible compromise needed to be made between the overall yield and product quality. Next, the freeze-drying of the mAb produced in the bioprocess run is investigated. The mAb substance was formulated and freeze-dried, according to different temperature/time run schemes, vial placement, protein concentrations and two freeze-dryers – SP Scientific LyoStar3 freeze-dryer and a Telstar LyoBeta freeze-dryer. Analyses done on the freeze-dried samples showed interesting results dependent on the specific parameters. It was observed that this mAb product showed little change and degradation in the aggressive freeze-drying run cycles adopted in this research. Finally, the experimental results and the obtained temperature readings to support the development of a novel one-dimensional computational model for the primary drying phase. A novel method to measure the movement of the drying interface was also developed to validate the model simulations. From observing these results, new novel one-dimensional based on heat transfer for the primary drying phase was investigated. This model was adapted from a previous model that studied the solidification of superheated metal

A proposed cost accounting method for sugar refinery

Thesis (M.B.A.)--Boston University, 1940 Page numbers 166 and 203 are missing; content flow indicates this to be a problem of incorrect pagination rather than missing content