Summary: A process is under investigation for the manufacture of dicalcium phosphate by the hydrolosis of concentrated superphosphate containing recycled monocalcium phosphate. The hydrolysis also results in the formation of an aqueous solution of monocalcium phosphate and free phosphoric acid. The phases are separated, followed by washing and drying of the solid dicalcium phosphate. The wash water is used in the hydrolyzer. The solution is returned to the superphosphate production step, where phosphate rock and additional phosphoric acid are added, and where water is evaporated to form the solid superphosphate.Pilot plant results have indicated that filtration rates vary widely under almost identical mixing conditions, presumably due to variations in particle size ranges. It was thought worthwhile, therefore, to study the effects of different mixing variables on the relative particle sizes as indicated by the settling rates of the mixture.

This study has analyzed particel size distribution and needle content in chipped logging residuals (branches and tops) delivered to the district heating plant Ryaverket in city of Borås, Sweden. Two fuel assortments has been analyzed: Chipped logging residuals from pure softwood and from mixed fuel (connifers and broadleaves). The samples has been sieved at Linneaus University laboratory. The study of particle sizes indicates that only 53,2 % of delivered fuel is within the fuels specification (7– 45 mm). The needle content is in this study 12,4 % (dry mass) which is higher than expected. / Sedan oljekriserna på 1970 talet har den svenska energiförsörjningen ändrats i grunden. Idag har stora delar av de tidigare petroleumbaserade bränslena ersatts med olika förnybara biobränslen. Skogsbränsle delas upp i olika bränslesortiment utifrån trädslag samt olika fysikaliska och tekniska egenskaper. Till Borås Energi & Miljö Ab´s värmeverk Ryaverket levereras det årligen ungefär 550000 kubikmeter skogsbränsle fördelat på cirka 30 olika sortiment. Fraktionsfördelningen, det vill säga storleken på bitarna i materialet, samt barrinnehåll är två viktiga kvalitetsfaktorer på bränslet. Denna rapport är en redovisning av en fraktionsanalysstudie på två av bränslesortimenten till Ryaverket. Dels flisad grot av rent barrträ och dels blandsortimentet flisad grot av barr och lövträ. I studien har också gjorts en analys av barrinnehållet i bränslet. Studien har gjorts genom sållning av prover från inkommande bränsleleveranser. Analysen visar att stora delar av det, till värmeverket, inkomna bränslet ligger utanför uppsatta bränslespecifikationer. Av materialet finns 53,2 % inom storleksområdet 7 -45 mm (acceptflis). Delvis bekräftar detta resultat tidigare forskning på området. Barrandelen är hög: 12,4%. Detta är en högre siffra än vad som var förväntat och högre än vad som framkommit i tidigare studier. Slutsatsen är att det troligen krävs omtänkande/nytänkande för att dagens grotbränsle skall fungera optimalt i moderna värmeverk. Skall flisningsutrustningen konstrueras om? Skall ny teknik för online och kontinuerlig mätning av bland annat fraktionsfördelning införas? Vilket är optimalt: att köpa in olika bränslesortiment lassvis och blanda själv på värmeverket? Eller är det mest optimalt att köpa färdigblandat bränsle från leverantör?

Hazel (Corylus avellana L.) is a common feature of meadows and pastures where it can grow in large populations and become very old. Is it possible to use the size of hazel stools for age determination and is it possible to use the size distribution of a population to provide information about how the land has been used? Hazel populations on ground where the lake-water level had been lowered, has been studied to validate an already developed growth model of hazel clones. Different hazel populations, on wooded meadows affected by mowing or grazing or overgrown meadows, were studied to evaluate the method utilizing hazel as land use indicator. The growth model was used to compare the size distributions of hazel populations with historical periods, which has been important for changes in agriculture or demography. The results show that the current growth model needs to be refined, but the method itself with a growth model based on the circumference of hazel bushes seems feasible. Additional studies about the influence of, for example, soils of different fertility are needed. The results also show that the size distribution in a population depends on how much meadows have been affected by mowing or grazing and that areas with similar land use have similar size distribution. Finally, some examples are reported about how a growth model can be used to compare historical periods of changes in agriculture, for example reduced livestock, with variations of the size distribution in a hazel population.

This thesis describes the development of an empirical model of focus beam reflectance measurements (FBRM) and the application of the model to monitoring batch cooling crystallization and extracting information on crystallization kinetics. Batch crystallization is widely used in the fine chemical and pharmaceutical industries to purify and separate solid products. The crystal size distribution (CSD) of the final product greatly influences the product characteristics, such as purity, stability, and bioavailability. It also has a great effect on downstream processing. To achieve a desired CSD of the final product, batch crystallization processes need to be monitored, understood, and controlled. FBRM is a promising technique for in situ determination of the CSD. It is based on scattering of laser light and provides a chord-length distribution (CLD), which is a complex function of crystal geometry. In this thesis, an empirical correlation between CSDs and CLDs is established and applied in place of existing first-principles FBRM models. Built from experimental data, the empirical mapping of CSD and CLD is advantageous in representing some effects that are difficult to quantify by mathematical and physical expressions. The developed model enables computation of the CSD from measured CLDs, which can be followed during the evolution of the crystal population during batch cooling crystallization processes. Paracetamol, a common drug product also known as acetaminophen, is selected as the model compound in this thesis study. The empirical model was first established and verified in a paracetamol-nonsolvent (toluene) slurry, and later applied to the paracetamol-ethanol crystallization system. Complementary to the FBRM measurements, solute concentrations in the liquid phase were determined by in situ infrared spectra, and they were jointly implemented to monitor the crystallization process. The framework of measuring the CSD and the solute concentration allows the estimation of crystallization kinetics, including those for primary nucleation, secondary nucleation, and crystal growth. These parameters were determined simultaneously by fitting the full population balance model to process measurements obtained from multiple unseeded paracetamol-ethanol crystallization runs. The major contributions of this thesis study are (1) providing a novel methodology for using FBRM measurements to estimate CSD; (2) development of an experimental protocol that provided data sets rich in information on crystal growth and primary and secondary nucleation; (3) interpretation of kinetics so that appropriate model parameters could be extracted from fitting population balances to experimental data; (4) identification of the potential importance of secondary nucleation relative to primary nucleation. The protocol and methods developed in this study can be applied to other systems for evaluating and improving batch crystallization processes.

Σε προβλήματα ερμηνείας βιολογικών δεδομένων όπου οι υπό μελέτη μονάδες εμφανίζονται κατά συστάδες (cluster) τυχαίου μεγέθους και πλήθους, ιδιαίτερο ρόλο παίζουν οι επιγενείς κατανομές. Συγκεκριμένα ως επιγενής Poisson κατανομή μπορεί να παρασταθεί κάθε μονοδιάστατη διακριτή κατανομή η οποία είναι άπειρα διαιρετή. Έχει μελετηθεί, η περίπτωση στην οποία η κατανομή του μεγέθους της συστάδας (csd) είναι μια γενικευμένη (εισάγεται νέα παράμετρος) εξαρτώμενη μεγέθους (gsb) λογαριθμική κατανομή. Παίρνοντας τα όρια αυτής της παραμέτρου ως οριακές κατανομές προκύπτουν η ΝΝΒD και η Pόlya-Aeppli. Στη παρούσα διπλωματική μελετάται η κατανομή που προκύπτει όταν ως csd χρησιμοποιείται η gsb μιας οιασδήποτε κατανομής. Δίνεται η πιθανογεννήτρια και προσδιορίζονται οι ασυμπτωτικές κατανομές στη γενικότερη περίπτωση. Μελετώνται επίσης, οι ιδιότητες της κατανομής και δίνονται εκτιμητές με τις μεθόδους των ροπών και της μέγιστης πιθανοφάνειας. Ειδικότερα, παρουσιάζεται η περίπτωση της ακρότμητης Poisson που δίνει ως οριακές κατανομές τις Νeyman και Thomas και προσομοιώνονται δεδομένα. Εξάγονται επίσης, ως ειδική περίπτωση των γενικών τύπων, τα αποτελέσματα που έχουν αποδειχθεί για τη λογαριθμική κατανομή. Στη συνέχεια αναπτύσσονται αντίστοιχα γενικευμένα διδιάστατα μοντέλα τέτοιων κατανομών. Δίνονται επίσης οι περιθώριες και οι δεσμευμένες κατανομές τους, υπολογίζονται οι ροπές, και χρήσιμες σχέσεις για τα διδιάστατα μοντέλα. Τέλος, παρουσιάζονται ειδικές περιπτώσεις, όπως οι Sum-Symmetric Power-Series και δίνονται εφαρμογές των διδιαστάτων κατανομών που μελετήθηκαν. / In biological data interpretation domains, where the units we exam come along as clusters of random size and number, generalized distributions have a very major role. In particular, every univariate discrete distribution that is infinite divisible can be formed like a generalized Poisson distribution. The case where the cluster-size distribution is a generalized (a new parameter has been inserted) size-biased log-series distribution has been studied. Taking the limits of this parameter, as limited cases we have the NNBD and Polya-Aeppli distribution. In this diplomatic work, we study the distribution which arises when as a csd we use the gsb of a random distribution. We give the pgf and we see the asymptotic distributions in the general case. We also see the attributes of the distribution and we give estimators with the method of moments and maximum likelihood estimators. Specially, we report the case of Truncated Poisson, which gives Neyman and Thomas as limiting cases and we simulate some data. Likewise, we also see the results that have been proofed for the Log-Series distribution as a special case of the general formulas. Then, we see correspond generalized Bivariate models of these distributions. We also give the marginals and the conditional distributions, we find the moments and some useful relations about the Bivariate models. Final, we present special cases, like Sum-Symmetric Power-Series and we give applications of the Bivariate distributions that we saw. In biological data interpretation domains, where the units we exam come along as clusters of random size and number, generalized distributions have a very major role. In particular, every univariate discrete distribution that is infinite divisible can be formed like a generalized Poisson distribution. The case where the cluster-size distribution is a generalized (a new parameter has been inserted) size-biased log-series distribution has been studied. Taking the limits of this parameter, as limited cases we have the NNBD and Polya-Aeppli distribution. In this diplomatic work, we study the distribution which arises when as a csd we use the gsb of a random distribution. We give the pgf and we see the asymptotic distributions in the general case. We also see the attributes of the distribution and we give estimators with the method of moments and maximum likelihood estimators. Specially, we report the case of Truncated Poisson, which gives Neyman and Thomas as limiting cases and we simulate some data. Likewise, we also see the results that have been proofed for the Log-Series distribution as a special case of the general formulas. Then, we see correspond generalized Bivariate models of these distributions. We also give the marginals and the conditional distributions, we find the moments and some useful relations about the Bivariate models. Final, we present special cases, like Sum-Symmetric Power-Series and we give applications of the Bivariate distributions that we saw.

Pressurized metered dose inhalers (pMDIs) are widely utilized to manage diseases of the lungs, such as asthma and chronic obstructive pulmonary disease. They can be formulated such that the drug and/or nonvolatile excipients are dissolved or dispersed in the formulation, rendering a solution or suspension formulation, respectively. While the formulation process for solution pMDIs is well defined, the formulation process of pMDIs with any type of suspended entity can be lengthy and empirical. The use of suspended drug or the addition of a second drug or excipient in a suspension pMDI formulation may non-linearly impact the product performance of the drug of interest in the formulation; this requires iterative testing of a series of pMDIs in order to identify a formulation with the most potential for success. One of the primary attributes used to characterize the product performance and quality control of inhaled medications is the residual aerodynamic particle size distribution (APSD) of the aerosolized drug. Along with clinical factors, formulation and device parameters have a significant impact on APSD. In this study, a computational model was developed using the principles of statistics and physical chemistry to predict the residual APSD generated by suspension pMDIs based on formulation, device, and raw drug or excipient substance considerations. The formulations modeled and experimentally evaluated consist of a suspended drug or excipient with/without a dissolved drug or excipient in a cosolvent-propellant system. The in silico model enables modeling a process that is difficult to delineate experimentally and contributes to understanding the link between pMDI formulation and device to product performance. The ability to identify and understand the variables that affect atomization and/or aerosol disposition , such as initial droplet size, suspended micronized drug or excipient size, and drug or excipient concentration, facilitates defining the design space for suspension pMDIs during development and improves recognizing the sensitive of the APSD is on each hardware and formulation variable. This model can later be applied to limit batch-to-batch variation in the manufacturing process and selecting plausible suspension pMDI formulations with quality design as the end goal.

No description available.

No description available.

The most important criterion in industrial production processes is to control the required product quality and comply with the standards pre-described for the application during any stage of the process. This control begins from the entry of raw material to the plant and continues with pre-determined points. Mainly two different types of inspection and analyses are used to examine the material quality and content. These are physical and chemical analysis.In most of the production plants above mentioned analyses are made in related laboratories of the plant. Therefore, it is necessary to have &amp / #65533 / sample&amp / #65533 / to be analyzed. This &amp / #65533 / sample&amp / #65533 / should have a real &amp / #65533 / representative&amp / #65533 / property, which must carry all of the physical and chemical characteristics of the material at the point where this &amp / #65533 / sample&amp / #65533 / is taken.The present methods and systems used to take samples from any required point have some disadvantages and present some problems especially for not being &amp / #65533 / representative&amp / #65533 / . These problems are discussed in detail within this thesis study and aimed to reach a new concept and system with: - Low cost of investment - Low cost of operation - Less requirement of maintenance and calibration - The achievement of &amp / #65533 / correct&amp / #65533 / and &amp / #65533 / representative&amp / #65533 / sample As a result of the theoretical studies together with practical application works and experiments, a new concept in sampling, namely &amp / #65533 / Sampling System with Air Cannons&amp / #65533 / was introduced. The new system of sampling was tested to give better performance and practical use.

Athabasca asphaltenes were characterized using small-angle X-ray scattering (SAXS) with synchrotron radiation. Two methods were used to separate asphaltenes from Athabasca bitumen. Conventional chemical separation by precipitation with n-pentane, and physical separation realized by passing bitumen through a zirconia membrane with a 20 nm average pore size. The Athabasca permeates and chemically separated samples were dispersed in 1-methylnaphtalene and n-dodecane, with temperature and asphaltene concentration ranges of 50-310 C and 1-8 wt. %, respectively. Two approaches were also taken in the analysis of the SAXS emissions. A model-independent approach provided radii of gyration and scattering coefficients. A model-dependent fit provided size distributions for asphaltenes aggregates assuming that they are dense and spherical. Physically and chemically separated asphaltenes showed significant differences in nominal size and structure, and their structural properties exhibited different temperature dependencies. The results challenge the merits of using chemically separated asphaltene properties as a basis for asphaltene property prediction in crude oil/bitumen.