Towards real-time understanding of processes in pharmaceutical powder technology

There is a need for better understanding of the processes and new ideas to develop traditional pharmaceutical powder manufacturing procedures. Process analytical technology (PAT) has been developed to improve understanding of the processes and establish methods to monitor and control processes. The interest is in maintaining and even improving the whole manufacturing process and the final products at real-time. Process understanding can be a foundation for innovation and continuous improvement in pharmaceutical development and manufacturing. New methods are craved for to increase the quality and safety of the final products faster and more efficiently than ever before. The real-time process monitoring demands tools, which enable fast and noninvasive measurements with sufficient accuracy. Traditional quality control methods have been laborious and time consuming and they are performed off line i.e. the analysis has been removed from process area. Vibrational spectroscopic methods are responding this challenge and their utilisation have increased a lot during the past few years. In addition, other methods such as colour analysis can be utilised in noninvasive real-time process monitoring. In this study three pharmaceutical processes were investigated: drying, mixing and tabletting. In addition tablet properties were evaluated. Real-time monitoring was performed with NIR and Raman spectroscopies, colour analysis, particle size analysis and compression data during tabletting was evaluated using mathematical modelling. These methods were suitable for real-time monitoring of pharmaceutical unit operations and increase the knowledge of the critical parameters in the processes and the phenomena occurring during operations. They can improve our process understanding and therefore, finally, enhance the quality of final products.

BaSnO3 fine powders from hydrothermal preparations

Attempts to prepare BaSnO3 by the hydrothermal method starting from SnO2·xH2O gel and Ba (OH)2 solution in teflonlined autoclaves at 150–260°C invariably lead to the formation of a hydrated phase, BaSn(OH)6·3H2O. On heating in air or on releasing the pressure Image at ≈260°C, BaSN (OH)6·3H2O converts to BaSnO3 fine powder which involves the formation of an intermediate oxyhydroxide, BaSnO(OH)4. TEM studies show that particle size of the resulting BaSnO3 ranges from 0.2–0.6 μm. Solid solutions of Ba(Ti, Sn) O3 were prepared from (TiO2+SnO2)·xH2O mixed gel and Ba(OH)2 solutions. Single-phase perovskite Ba(Ti, Sn)O3 was obtained up to 35 atom % Sn. Above this composition, the hydrothermal products are mixtures of BaTiO3 (cubic) and BaSn(OH)6·3H2O which on heating at ≈260°C give rise to BaTiO3+BaSnO3. Annealing at 1000°C results in monophasic Ba(Ti, Sn)O3, in the complete range of Sn/Ti. Formation of the hydrated phase is attributed to the amphoteric nature of SnO2·xH2O gel which stabilises Sn(OH)62− anions under higher H2O-pressures and elevated temperatures. The sintering characteristics and dielectric properties of ceramics prepared from these fine powders are presented.

Absorption of electromagnetic radiation by superconducting YBa2Cu3O7: an oxygen-induced phenomenon

In the superconducting state, YBa2Cu3O7 absorbs electromagnetic radiation over a wide range of frequencies (8 MHz-9 GHz). The absorption is extremely sensitive to temperature, particle size and the magnetic field and depends crucially on the presence of oxygen. A possible explanation for the phenomenon based on the formation of Josephson junctions is suggested.

Assessing for genetic and environmental effects on ruminant feed quality in barley ( Hordeum vulgare )

Grain samples from a combined intermediate and advanced stage barley breeding trial series, grown at two sites in two consecutive years were assessed for detailed grain quality and ruminant feed quality. The results indicated that there were significant genetic and environmental effects for “feed” traits as measured using grain hardness, acid detergent fibre (ADF), starch and in-sacco dry matter digestibility (ISDMD) assays. In addition, there was strong genotypic discrimination for the regressed feed performance traits, namely Net Energy (NE) and Average Daily Gain (ADG). There was considerable variation in genetic correlations for all traits based on variance from the cultivars used, sites or laboratory processing effects. There was a high level of heritability ranging from 89% to 88% for retention, 60% to 80% for protein and 56% to 68% for ADF. However, there were only low to moderate levels of heritability for the feed traits, with starch 30–39%, ISDMD 55–63%, ADF 56–68%, particle size 47–73%, 31–48% NE and ADG 44–51%. These results suggest that there were real differences in the feed performance of barleys and that selection for cattle feed quality is potentially a viable option for breeding programs.

Thermal polymerization of acrylamide in the solid state

The role of imperfections in thermal polymerization of acrylamide in the solid state was studied. The polymer yield and the degree of polymerization are highly dependent on the particle size and on the pressure to which the monomer is subjected prior to polymerization reaction. There is an enhancement in the rate of polymerization in air unlike in the case of radiation-induced polymerization. Thermal polymerization of acrylamide in pelletized form results in the formation of water-soluble linear polymer and water-insoluble cross-linked product with the evolution of ammonia. The activation energy (E) values obtained in the present investigation reveal that basically there are two processes taking place, one with E = 34–36 kcal/mole, corresponding to the initiation process, and the other with E = 19 ± 3 kcal/more for the propagation process.

Magnesium/Copper Nanocomposite through Digestive Ripening

Composing nanocomposites: Co-digestive ripening of as-prepared Mg and Cu colloids prepared by the solvated metal atom dispersion method results in a highly monodisperse colloid of Mg/Cu nanocomposite with an average particle size of 3.0 +/- 0.5 nm. Annealing of these samples at 300 degrees C gives the Cu/MgO nanocomposite.

Studies on vacuum pyrolysis of ammonium perchlorate and ammonium perchlorate/polystyrene propellant in the presence of transition metal oxides

Vacuum pyrolysis of ammonium perchlorate (AP) and ammonium perchlorate/polystyrene (PS) propellant has been studied by differential thermal analysis (DTA) in order to observe the effect of transition metal oxides on sublimation. Sublimation and decomposition being competitive processes, their proportions depend on the pressure of the pyrolysis chamber. The enthalpies for complete decomposition and complete sublimation are available from the literature and by using these data together with DTA area measurements, the extents of sublimation and decomposition have been calculated for AP and the propellant system. The effect of the metal ions on the extent and rate of sublimation depends on their nature. For AP the extent of sublimation increases with a decrease in particle size. For the propellants the powder sublimes more readily than the bulk material, but in the presence of metal ions the bulk material sublimes more readily than the powder. To substantiate this finding, the effect of MnO2 on AP sublimation as a function of particle size was examined, and it was observed that the extent of sublimation decreases as the particle size decreases.

Traffic and nucleation events as main sources of ultrafine particles in high-insolation developed world cities

Road traffic emissions are often considered the main source of ultrafine particles (UFP, diameter smaller than 100 nm) in urban environments. However, recent studies worldwide have shown that - in high-insolation urban regions at least - new particle formation events can also contribute to UFP. In order to quantify such events we systematically studied three cities located in predominantly sunny environments: Barcelona (Spain), Madrid (Spain) and Brisbane (Australia). Three long term datasets (1-2 years) of fine and ultrafine particle number size distributions (measured by SMPS, Scanning Mobility Particle Sizer) were analysed. Compared to total particle number concentrations, aerosol size distributions offer far more information on the type, origin and atmospheric evolution of the particles. By applying k-Means clustering analysis, we categorized the collected aerosol size distributions in three main categories: “Traffic” (prevailing 44-63% of the time), “Nucleation” (14-19%) and “Background pollution and Specific cases” (7-22%). Measurements from Rome (Italy) and Los Angeles (California) were also included to complement the study. The daily variation of the average UFP concentrations for a typical nucleation day at each site revealed a similar pattern for all cities, with three distinct particle bursts. A morning and an evening spike reflected traffic rush hours, whereas a third one at midday showed nucleation events. The photochemically nucleated particles burst lasted 1-4 hours, reaching sizes of 30-40 nm. On average, the occurrence of particle size spectra dominated by nucleation events was 16% of the time, showing the importance of this process as a source of UFP in urban environments exposed to high solar radiation. On average, nucleation events lasting for 2 hours or more occurred on 55% of the days, this extending to >4hrs in 28% of the days, demonstrating that atmospheric conditions in urban environments are not favourable to the growth of photochemically nucleated particles. In summary, although traffic remains the main source of UFP in urban areas, in developed countries with high insolation urban nucleation events are also a main source of UFP. If traffic-related particle concentrations are reduced in the future, nucleation events will likely increase in urban areas, due to the reduced urban condensation sinks.

Mobile assessment of on-road air pollution and its sources along the East-West Highway in Bhutan

Human exposures in transportation microenvironments are poorly represented by ambient stationary monitoring. A number of on-road studies using vehicle-based mobile monitoring have been conducted to address this. Most previous studies were conducted on urban roads in developed countries where the primary emission source was vehicles. Few studies have examined on-road pollution in developing countries in urban settings. Currently, no study has been conducted for roadways in rural environments where a substantial proportion of the population live. This study aimed to characterize on-road air quality on the East-West Highway (EWH) in Bhutan and identify its principal sources. We conducted six mobile measurements of PM10, particle number (PN) count and CO along the entire 570 km length of the EWH. We divided the EWH into five segments, R1-R5, taking the road length between two district towns as a single road segment. The pollutant concentrations varied widely along the different road segments, with the highest concentrations for R5 compared with other road segments (PM10 = 149 µg/m3, PN = 5.74 × 104 particles/cm-3, CO = 0.19 ppm), which is the final segment of the road to the capital. Apart from vehicle emissions, the dominant sources were road works, unpaved roads and roadside combustion activities. Overall, the highest contributions above the background levels were made by unpaved roads for PM10 (6 times background), and vehicle emissions for PN and CO (5 and 15 times background, respectively). Notwithstanding the differences in instrumentation used and particle size range measured, the current study showed lower PN concentrations compared with similar on-road studies. However, concentrations were still high enough that commuters, road maintenance workers and residents living along the EWH, were potentially exposed to elevated pollutant concentrations from combustion and non-combustion sources. Future studies should focus on assessing the dispersion patterns of roadway pollutants and defining the short- and long-term health impacts of exposure in Bhutan, as well as in other developing countries with similar characteristics.

Determining and quantifying components of an aquaculture soundscape.

Recirculating aquaculture systems have a unique anthropogenic-based soundscape which is characterized by the type of equipment utilized, the structural configuration of walls, tanks, equipment, the substrate the tanks are situated on and even the activities of the personnel operating the facility. The soundscape of recirculation facilities is inadequately understood and remains poorly characterized, although it is generally accepted that the dominant sounds found in such facilities are within the hearing range of fish. The objective of this study was to evaluate the soundscape in a recirculating aquaculture facility from an intra-tank perspective and determine how the soundscape is shaped by a range of characteristics within the facility. Sounds were recorded across an operating aquaculture facility including different tank designs. The sounds recorded fell within previously measured pressure level ranges for recirculating systems, with the highest maximum sound pressure level (SPL) recorded at 124 dB re 1 mu Pa-2/Hz (with an FFT bin width of 46.9 Hz, centered at 187.5 Hz). The soundscape within the tanks was stratified and positively correlated with depth, the highest sound pressure occurring at the base of the tanks. Each recording of the soundscape was dominated by a frequency component of 187.5 Hz (corresponding centre of the 4th 46.9 Hz FFT analysis bin) that produced the highest observed SPL Analysis of sound recordings revealed that this peak SPL was associated with the acoustic signature of the pump. The soundscape was also evaluated for impacts of tank hood position, time of day, transient sounds and airstone particle size types, all of which were found to appreciably influence sound levels and structure within the tank environment. This study further discusses the distinctiveness of the soundscape, how it is shaped by the various operating components and considers the aquaculture soundscape in relation to natural soundscapes found within aquatic tropical environments.

Stream power criterion and design of sand bed channels at incipient motion

The critical stream power criterion may be used to describe the incipient motion of cohesionless particles of plane sediment beds. The governing equation relating ``critical stream power'' to ``shear Reynolds number'' is developed by using the present experimental data as well as the data from several other sources. Simultaneously, a resistance equation, relating the ``particle Reynolds number'' to the``shear Reynolds number'' is developed for plane sediment beds in wide channels with little or no transport. By making use of these relations, a procedure is developed to design plane sediment beds such that any two of the four design variables, including particle size, energy/friction slope, flow depth, and discharge per unit width in the channel should be known to predict the remaining two variables. Finally, a straightforward design procedure using design tables/design curves and analytical methods is presented to solve six possible design problems.

Defect Sensitization of Combustion and Thermal Decomposition of Ammonium Perchlorate: Effect of Pelletizing Pressure and Dwell Time

A systematic study was undertaken on the combustion and thermal decomposition of pelletized Ammonium Perchlorate (AP) to investigate the effects of pelletizing pressure and dwell time. At constant pressure, increasing the dwell time results in an increase in the burning rate up to a maximum and thereafter decreases it. The dwell time required for the pellets to have maximum burning rate is a function of pressure. The maximum burning rate is the same for all the pressures used and is also unaffected by increasing, to the range 90-250 μ, the particle size of AP used. In order to explain the occurrence of a maximum in burning rate, pellets were examined for their thermal sensitivities, physical nature and the changes occurring during pelletization with dwell time and pressure. The variations are argued in terms of increasing density, formation of defects such as dislocations leading to an increase in the number of reactive sites, followed by their partial annihilation at longer dwell times due to flow of material during pelletization.

Effect of experimental parameters on non-isothermal TG

The effect of some experimental parameters, namely sample weight, particle size and its distribution, heating rate and flow rate of inert gas, on the fractional decomposition of calcium carbonate samples have been studied both experimentally and theoretical. The general conclusions obtained from theoretical analysis are corroborated qualitatively by the experimental data. The analysis indicates that the kinetic compensating effect may be partly due to the variations in experimental parameters for different experiments.

Rate capability of graphite materials as negative electrodes in lithium-ion capacitors

The lithium-ion exchange rate capability of various commercial graphite materials are evaluated using galvanostatic charge/discharge cycling in a half-cell configuration over a wide range of C-rates (0.1 similar to 60C). The results confirm that graphite is capable of de-intercalating stored charge at high rates, but has a poor intercalating rate capability. Decreasing the graphite coating thickness leads to a limited rate performance improvement of the electrode. Reducing the graphite particle size shows enhanced C-rate capability but with increased irreversible capacity loss (ICL). It is demonstrated that the rate of intercalation of lithium-ions into the graphite is significantly limited compared with the corresponding rate of de-intercalation at high C-rates. For the successful utilisation of commercially available conventional graphite as a negative electrode in a lithium-ion capacitor (LIC), its intercalation rate capability needs to be improved or oversized to accommodate high charge rates.

Quantifying differences between treated and untreated coir substrate

The aim of this project was to quantify differences between treated and untreated coir (coconut industrial residues) products and to identify differences in growth, yield and quality of cut flowers grown in different coir products. This has been brought about largely by the concern that some coir products, washed in low quality (saline) water may have detrimental effects on plant productivity and quality. There is concern in the flower production industry and among media suppliers, that lower quality products are favoured due to price alone, which as this project shows is a false economy. Specifically the project examined: • Differences in physical and chemical properties of treated and untreated coir along with another commonly used growing media in the flower industy; • Potential improvements in yield and quality of Gerbera (Gerbera jamesonii); • Potential differences in vase life of Gerbera as a result of the different growing media; and • Cost-benefit implications of treated (more expensive) coir substrate products versus untreated (less expensive) coir including any subsequent differences in yield and quality. By first examining the physical and some chemical properties of different coir substrates and other industry standard media, the researchers have been able to validate the concerns raised about the potential quality issues in coir based growing media. There was a great deal of variation in both the electrical conductivity and sodium contents. Physical properties were also variable as expected since manufacturers are able to target the specific physical preferences of plants through manipulation of the particle size distribution. A field trial was conducted under protected cropping practices in which three growing media were compared in terms of total productivity and also flower quality parameters such as stem length, flower diameter and vase life. The trial was a completely randomised design with the three growing media comprising treated coir discs, untreated coir discs and a pine bark coir mix. Four cultivars of Gerbera were assessed: Balance®; Carambole®; Dune® and Picobello®, all new products from Florist de Kwakel B.V., Denmark. Initial expansion from tissue culture was conducted at the Highsun Express Facility, Ormiston, Queensland. The trial included 12 replications of each cultivar in each media (a total of 144 plants) to ensure all data collected, and the derived conclusions were statistically rigorous. The coir supplied with no pre-treatment or buffering produced significantly less flowers than those grown in a pine bark coir mix or the pre-treated coir. Interestingly, the pine bark coir mix produced a greater number of flowers. However, the flowers produced in the pine bark coir mix were generally a shorter length stem. Productivity data, combined with flower quality data and component costs were all analysed through a cost/benefit economic model which showed that the greater revenue from better stem length outweighed the stem numbers, giving a cost benefit ratio of 2.58 for treated coir, 2.49 for untreated coir and 2.52 for pine bark coir mix. While this does not seem a large difference, when considering the number of plants a producer maintains can be upwards of 50,000 the difference in revenue would be, at a minimum $60,000 in this example. In conclusion, this project has found that there are significant effects on plant health, growth, yield and quality between those grown in treated and untreated coir. The outcome being growers can confidently invest in more expensive treated products with the assurance that benefits will outweigh initial cost. It is false economy to favour untreated coir products based on price alone. Producers should ensure they fully understand the production processes when purchasing growing media. Rather than targeting lower priced materials, it is recommended that quality be the highest priority in making this management decision. In making recommendations for future research and development it was important to consider conclusions from other researchers as well as those of the current project. It has been suggested that the media has greater longevity, which although not captured in this study could also lead to further cost efficiencies. Assessment of the products over a longer time period, and using a wider range of plant species are the major recommendations for further research to ensure greater understanding as to the importance in choosing the right growing media to meet specific needs.