The objective of this study was to encapsulate cell lines that secrete marker proteins that cover a large molecular weight range (M^r from 45,000 to 300,000) and monitor the secretion of the marker proteins from alginate-poly-L-lysine-alginate (APA) microcapsules and hydroxyethyl methacrylatemethyl methacrylate (HEMA-MMA) thermoplastic capsules. Different parameters for the APA microcapsules, such as the duration of poly-L-lysine (PLL) and sodium citrate treatment, the initial cell density for encapsulation was studied, and their effects on secretion rate and cell proliferation were closely examined. Cell lines used for encapsulation secreted human growth hormone (hGH) (M^r 45,000), β-hexosaminidase (β-hexo.) (M^r 120,000) and β-glucuronidase (β-gluc.) (M^r 300,000). Monitoring the secretion rates, as well as the distribution of the marker proteins within the microcapsules following encapsulation enabled the permeability of the membrane to be assessed over one month in culture. Encapsulation of cell lines in both types of capsules was effective in producing viable cells capable of proliferating within a semi-permeable membrane. Encapsulating cells in single-coated APA microcapsules at 4°C, treated with 10 minutes PLL, 20 minutes sodium citrate and at a cell density of 2x10^6 cells/ml alginate was found to provide the most optimal conditions for prolonged viability of and stable secretion by the recombinant cells. Human growth hormone diffused readily across the capsule membrane into the culture media from both APA and HEMA-MMA capsules, at rates similar to the non-encapsulated cells. Human growth hormone did not accumulate in the intracapsular space in significant quantities. β-glucuronidase and β-hexosaminidase could diffuse across APA capsule membrane, but not across HEMA-MMA capsule membrane into surrounding media. β-glucuronidase secretion from APA microcapsules was 8-fold lower than non-encapsulated cells. β-hexosaminidase secretion from APA microcapsules was 4.5-fold lower than non-encapsulated cells. Slight retention of both β-glucuronidase and β-hexosaminidase was observed in the intracapsular space of APA capsules. HEMA-MMA capsules completely blocked the secretion of both β-glucuronidase and β-hexosaminidase out of the capsule. Massive accumulation of both kinds of secretory enzymes was found in the intracapsular space of HEMA-MMA capsules. This indicated APA microcapsules have a molecular weight cut-off of >300,000 whereas HEMA-MMA microcapsules have a molecular weight cut-off of <120,000. / Thesis / Master of Science (MS)

The purpose of this study is to determine the specific reaction or velocity constants and the equilibrium constant in a system of methyl alcohol and acetic acid, a bimolecular reaction of the second order.

Yes / Synthesis of methyl palmitate (MP) has not been considered in the past using a reactive distillation process (continuous or batch) due to the challenge of keeping the reactants palmitic acid (PA) and methanol (MeOH) together in the reactive zone. MeOH, being the lightest in the reaction mixture, travels up the distillation column as distillation proceeds and will be removed from the system via the distillate in a conventional batch reactive distillation (CBRD) column and thus will limit the conversion of PA. Therefore, in this work semi-batch reactive distillation (SBRD) column is proposed where additional methanol will be fed at the bottom of the column in a continuous mode allowing the chemical reaction to continue. However, as water (H2O) is one of the reaction products and is the second lightest component in the mixture, it will travel up the column next and will be removed in the distillate tank. Also due to wide difference in the boiling points of the reaction products and due to diminishing amount of water in the reboiler, the backward reaction will not be a dominating factor and therefore ignored in this work. With this backdrop, optimal performance of the SBRD column is evaluated in terms of conversion of PA to MP and energy consumption via minimization of the operating batch time for a wide range on MP purity.

No / The performance of batch reactive distillation process involving the esterification of acetic acid with methanol to produce methyl acetate and water is considered in this work. Two cases studies with varying amount of the reactants are considered. The reflux ratio (single time interval) is selected as the control variable to be optimised (treated as piecewise constant) for different but fixed batch time ranging from 5 to 15 h, so as to maximise the conversion of methanol subject to product purity of methyl acetate. The dynamic optimisation problem is converted to a nonlinear programming problem by Control Vector Parameterization (CVP) technique and is solved by using efficient SQP method. The optimisation results show that as the methanol and methyl acetate are wide boiling, the separation of methyl acetate is easier without losing much of methanol reactant. The conversion improves by 6.4 % due to sufficient amount of acetic acid being reacted with methanol. Moreover an excess of acetic acid leads to high operation temperature and therefore high reflux operation (to reduce loss of methanol from the top of the column) to maximise the conversion.

Statistical copolymers of acrylonitrile (AN) and methyl acrylate (MA) were successfully prepared and characterized using reversible addition-fragmentation chain transfer (RAFT) copolymerization. A typical copolymer was charged with 15 wt. % MA content. This thesis describes a systematic variation of the RAFT copolymerization variables to optimize this system. In particular, the effects of chain transfer agent, initiator, temperature, and solvent on the copolymer properties were studied. / Master of Science

Yes / Exposure to DNA-damaging agents produces a range of stress-related responses. These change the expression of genes leading to mutations that cause cell cycle arrest, induction of apoptosis and cancer. We have examined the contribution of haploid and diploid DNA damage and genes involved in the regulation of the apoptotic process associated with exposure, The Comet assay was used to detect DNA damage and quantitative RT-PCR analysis (qPCR) to detect gene expression changes in lymphocytes and sperm in response to methyl methanesulfonate. In the Comet assay, cells were administered 0–1.2 mM of MMS at 37 °C for 30 min for lymphocytes and 32 °C for 60 min for sperm to obtain optimal survival for both cell types. In the Comet assay a significant increase in Olive tail moment (OTM) and % tail DNA indicated DNA damage at increasing concentrations compared to the control group. In the qPCR study, cells were treated for 4 h, and RNA was isolated at the end of the treatment. qPCR analysis of genes associated with DNA stress responses showed that TP53 and CDKN1A are upregulated, while BCL2 is downregulated compared with the control. Thus, MMS caused DNA damage in lymphocytes at increasing concentrations, but appeared not to have the same effect in sperm at the low concentrations. These results indicate that exposure to MMS increased DNA damage and triggered the apoptotic response by activating TP53, CDKN1A and BCL2. These findings of the processing of DNA damage in human lymphocytes and sperm should be taken into account when genotoxic alterations in both cell types are produced when monitoring human exposure. / Libyan Government

A double modulation microwave spectrometer is used to evaluate the linewidth parameters for some excited rotational components in the bending vibration v_8 of 13CH3 13C 15N and 13CH3C15N isotopomers of methyl cyanide. The linewidth parameters for self-broadening of the ΔJ=2←1 rotational components for the ground v_8 , 1v_8, and the 2v_8 vibrations were determined over a pressure range of 1 to 13 mtorr and at a temperature of 300 K. The double modulation technique is used to explore the high eighth derivative of the line shape profile of the spectral line. This technique proved to give good signal-to-noise ratios and enabled the recovery of weak signals. An experimental method is developed to correct for source modulation broadening. The tests of the ratios of the two inner peak's separation of the eighth derivative of the line showed that they were up to 95% similar to those for a Lorentzian line shape function. The line shapes were assumed to be Lorentzian for the theoretical analysis of the derivative profiles and comparisons were made between experiment and theory on this basis. Dipole moments for vibrationally excited states were calculated from linewidth parameters and show systematic decrease with the increase of excitation. Impact parameters were calculated using the "hard sphere" model of the kinetic theory of gases. The results were many times larger than the size of the molecule itself. This suggests that the dominant interaction is a long range dipole-dipole force interaction.

The phenomenon of depropagation or reverse polymerization for multicomponent polymerizations has been studied in detail. The monomer Alpha-Methyl Styrene (AMS) has been copolymerized with Methyl Methacrylate (MMA) and Butyl Acrylate (BA) at temperatures ranging from 60oC to 140oC and the kinetics have been studied in the form of propagation/cross propagation and depropagation parameters. There have been multiple attempts with varying amounts of success in the past to determine the kinetic parameters for depropagating systems including work by Lowry and Wittmer as well as other modelling methodologies that are not as mechanistic. The most recent development of the mechanistic terminal model is that of the Kruger model. The model is robust and can take into account all special cases as well as all reactions being reversible. The kinetic parameters have been estimated for each of the three binary systems using the Kruger model (MMA/AMS, MMA/BA, BA/AMS). The Alfrey-Goldfinger model is inadequate to describe depropagating terpolymer systems and in order to study them, a new model was developed based upon the binary Kruger model. This new model takes into account a fully depropagating terpolymer system leading to a total of 15 parameters to be estimated. These 15 parameters have the same definitions as those estimated from the binary Kruger model, thus making accurate analysis of the binary systems crucial since these will be used as first estimates for the terpolymer system. Extensive experimental data (composition, conversion and molecular weights) was collected and analysed for the MMA/AMS and BA/AMS systems. For the BA/AMS system both the bulk and solution copolymerizations were studied in detail with the results from the Kruger model not showing a significant difference in the reactivity ratios between the two types of polymerization. For the MMA/AMS system, a bulk study only was done which revealed an interesting phenomenon that points toward a break down of the long chain approximations used for all of the models being studied. For both of these systems, extensive ¹H NMR analysis was done to determine the copolymer composition. Data collected in previous research for the MMA/BA system was reanalysed using the Kruger model and it was found that the parameter estimates did not differ significantly from the published values. Extensive benchmarking was done with the newly developed terpolymer model on non-depropagating systems using data from the literature to ensure it worked for the simplest cases. It was found that the model matched the parameter estimates from the literature and in some cases improving upon them to fit the data better. Along with the benchmarking a sensitivity analysis was done which revealed some interesting information. For the MMA/BA/AMS terpolymer system a set of experiments (based upon practical considerations) were performed and the composition of the polymer was determined using ¹³C NMR instead of the usual ¹H NMR due to the difficulty of peak separation for the complex terpolymer. Using the depropagating terpolymer composition data in conjunction with the parameter estimates from the three binary systems allowed for estimation of the 15 kinetic parameters, which showed only minor variation from the binary estimates.

The phenomenon of depropagation or reverse polymerization for multicomponent polymerizations has been studied in detail. The monomer Alpha-Methyl Styrene (AMS) has been copolymerized with Methyl Methacrylate (MMA) and Butyl Acrylate (BA) at temperatures ranging from 60oC to 140oC and the kinetics have been studied in the form of propagation/cross propagation and depropagation parameters. There have been multiple attempts with varying amounts of success in the past to determine the kinetic parameters for depropagating systems including work by Lowry and Wittmer as well as other modelling methodologies that are not as mechanistic. The most recent development of the mechanistic terminal model is that of the Kruger model. The model is robust and can take into account all special cases as well as all reactions being reversible. The kinetic parameters have been estimated for each of the three binary systems using the Kruger model (MMA/AMS, MMA/BA, BA/AMS). The Alfrey-Goldfinger model is inadequate to describe depropagating terpolymer systems and in order to study them, a new model was developed based upon the binary Kruger model. This new model takes into account a fully depropagating terpolymer system leading to a total of 15 parameters to be estimated. These 15 parameters have the same definitions as those estimated from the binary Kruger model, thus making accurate analysis of the binary systems crucial since these will be used as first estimates for the terpolymer system. Extensive experimental data (composition, conversion and molecular weights) was collected and analysed for the MMA/AMS and BA/AMS systems. For the BA/AMS system both the bulk and solution copolymerizations were studied in detail with the results from the Kruger model not showing a significant difference in the reactivity ratios between the two types of polymerization. For the MMA/AMS system, a bulk study only was done which revealed an interesting phenomenon that points toward a break down of the long chain approximations used for all of the models being studied. For both of these systems, extensive ¹H NMR analysis was done to determine the copolymer composition. Data collected in previous research for the MMA/BA system was reanalysed using the Kruger model and it was found that the parameter estimates did not differ significantly from the published values. Extensive benchmarking was done with the newly developed terpolymer model on non-depropagating systems using data from the literature to ensure it worked for the simplest cases. It was found that the model matched the parameter estimates from the literature and in some cases improving upon them to fit the data better. Along with the benchmarking a sensitivity analysis was done which revealed some interesting information. For the MMA/BA/AMS terpolymer system a set of experiments (based upon practical considerations) were performed and the composition of the polymer was determined using ¹³C NMR instead of the usual ¹H NMR due to the difficulty of peak separation for the complex terpolymer. Using the depropagating terpolymer composition data in conjunction with the parameter estimates from the three binary systems allowed for estimation of the 15 kinetic parameters, which showed only minor variation from the binary estimates.

Environmentally friendly processing of materials is becoming an increasingly important consideration in a wide variety of emerging technologies. Polymer processing,in particular, has benefited tremendously in this venue from numerous advances achievedusing high-pressure carbon dioxide (CO2) as a viscosity modifier, plasticizing agent,foaming agent, and reaction medium. Polymer processing in supercritical fluids has been a major interest for a portfolio of materials processing applications including their impregnation into porous matrices. Also, SCF solvents are being examined as a media for polymerization processes, polymer purification and fractionation, and as environmentally preferable solvents for solution coatings. Pressurized CO2 isinexpensive, sustainable, relatively benign, and versatile due to its gas-like viscosity and liquid-like densities, which can be controllably tuned through appropriate choice of temperature and pressure. Addition of high-pressure CO2 to polymer systems can have a profound impact on their thermodynamic properties and phase behavior, since the number of interacting species increases due to the high-pressures, so that the compressibility also increases, as well as the plasticity effects. Even then, polymers are only sparingly soluble in CO2 unless one uses an entrainer or surfactant. An addition of a liquid monomer co-solvent results in greatly enhanced polymer solubility in the supercritical fluid at rather mild conditions of lower temperatures and reduced pressures.The focus of this research is to measure, evaluate and model the phase behavior of the methyl methacrylate-CO2 and the poly (methyl methacrylate)-CO2-methyl methacrylatesystem, where methyl methacrylate plays role of a co-solvent. Cloud-point data are measured in the temperature range of 30-80ʻC, pressures as high as 300 bar, co-solvent concentrations of 27 and 48.4 wt% MMA, and varying PMMA concentrations of 0.1, 0.2,0.5, and 2.5 wt%. Solubility data is reported for these systems. The experimental results are modeled accurately using the Statistical Associating Fluid Theory (SAFT) for multi component polymer/solvent mixtures. The measured solubility data appears to be significantly different than previously published results by McHugh et al, Fluid Phase Equilibria, 1999. Thorough investigation, re-calibration of the equipment, and repetition of the measurements has proved that the measured data is entirely correct and the reference data is significantly off, which indirectly gives credit to this work and opens room for amendments of those results.