Interfacial Phenomena in Pharmaceutical Low Moisture Content Powder Processing

Powders are essential materials in the pharmaceutical industry, being involved in majority of all drug manufacturing. Powder flow and particle size are central particle properties addressed by means of particle engineering. The aim of the thesis was to gain knowledge on powder processing with restricted liquid addition, with a primary focus on particle coating and early granule growth. Furthermore, characterisation of this kind of processes was performed. A thin coating layer of hydroxypropyl methylcellulose was applied on individual particles of ibuprofen in a fluidised bed top-spray process. The polymeric coating improved the flow properties of the powder. The improvement was strongly related to relative humidity, which can be seen as an indicator of a change in surface hydrophilicity caused by the coating. The ibuprofen used in the present study had a d50 of 40 μm and thus belongs to the Geldart group C powders, which can be considered as challenging materials in top-spray coating processes. Ibuprofen was similarly coated using a novel ultrasound-assisted coating method. The results were in line with those obtained from powders coated in the fluidised bed process mentioned above. It was found that the ultrasound-assisted method was capable of coating single particles with a simple and robust setup. Granule growth in a fluidised bed process was inhibited by feeding the liquid in pulses. The results showed that the length of the pulsing cycles is of importance, and can be used to adjust granule growth. Moreover, pulsed liquid feed was found to be of greater significance to granule growth in high inlet air relative humidity. Liquid feed pulsing can thus be used as a tool in particle size targeting in fluidised bed processes and in compensating for changes in relative humidity of the inlet air. The nozzle function of a two-fluid external mixing pneumatic nozzle, typical for small scale pharmaceutical fluidised bed processes, was studied in situ in an ongoing fluidised bed process with particle tracking velocimetry. It was found that the liquid droplets undergo coalescence as they proceed away from the nozzle head. The coalescence was expected to increase droplet speed, which was confirmed in the study. The spray turbulence was studied, and the results showed turbulence caused by the event of atomisation and by the oppositely directed fluidising air. It was concluded that particle tracking velocimetry is a suitable tool for in situ spray characterisation. The light transmission through dense particulate systems was found to carry information on particle size and packing density as expected based on the theory of light scattering by solids. It was possible to differentiate binary blends consisting of components with differences in optical properties. Light transmission showed potential as a rapid, simple and inexpensive tool in characterisation of particulate systems giving information on changes in particle systems, which could be utilised in basic process diagnostics.

Precursor Dependent Microstructure Evolution and Nonstoichiometry in Nanostructured Cerium Oxide Coatings Using the Solution Precursor Plasma Spray Technique

A solution precursor plasma spray (SPPS) technique has been used for direct deposition of cerium oxide nanoparticles (CNPs) from various cerium salt solutions as precursors. Solution precursors were injected into the hot zone of a plasma plume to deposit CNP coatings. A numerical study of the droplet injection model has been employed for microstructure development during SPPS. The decomposition of each precursor to cerium oxide was analyzed by thermogravimetric-differential thermal analysis and validated by thermodynamic calculations. The presence of the cerium oxide phase in the coatings was confirmed by X-ray diffraction studies. Transmission electron microscopy studies confirmed nanocrystalline (grain size <14 nm) characteristic of the coatings. X-ray photoelectron spectroscopy studies indicated the presence of a high concentration of Ce3+ (up to 0.32) in the coating prepared by SPPS. The processing and microstructure evolution of cerium oxide coatings with high nonstoichiometry are reported.

Information Technology Development Needs in Community Pharmacies : A Strategic Approach

In the context of health care, information technology (IT) has an important role in the operational infrastructure, ranging from business management to patient care. An essential part of the system is medication management in inpatient and outpatient care. Community pharmacists strategy has been to extend practice responsibilities beyond dispensing towards patient care services. Few studies have evaluated the strategic development of IT systems to support this vision. The objectives of this study were to assess and compare independent Finnish community pharmacy owners and staff pharmacists priorities concerning the content and structure of the next generation of community pharmacy IT systems, to explore international experts visions and strategic views on IT development needs in relation to services provided in community pharmacies, to identify IT innovations facilitating patient care services and to evaluate their development and implementation processes, and to assess community pharmacists readiness to adopt innovations. This study applied both qualitative and quantitative methods. A qualitative personal interview of 14 experts in community pharmacy services and related IT from eight countries and a national survey of Finnish community pharmacy owners (mail survey, response rate 53%, n=308), and of a representative sample of staff pharmacists (online survey, response rate 22%, n=373) were conducted. Finnish independent community pharmacy owners gave priority to logistical functions but also to those related to medication information and patient care. The managers and staff pharmacists have different views of the importance of IT features, reflecting their different professional duties in the community pharmacy. This indicates the need for involving different occupation groups in planning the new IT systems for community pharmacies. A majority of the international experts shared the vision of community pharmacy adopting a patient care orientation; supported by IT-based documentation, new technological solutions, access to information, and shared patient data. Community pharmacy IT innovations were rare, which is paradoxical because owners and staff pharmacists perception of their innovativeness was seen as being high. Community pharmacy IT systems development processes usually had not undergone systematic needs assessment research beforehand or evaluation after the implementation and were most often coordinated by national governments without subsequent commercialization. Specifically, community pharmacy IT developments lack research, organization, leadership and user involvement in the process. Those responsible for IT development in the community pharmacy sector should create long-term IT development strategies that are in line with community pharmacy service development strategies. This could provide systematic guidance for future projects to ensure that potential innovations are based on a sufficient understanding of pharmacy practice problems that they are intended to solve, and to encourage strong leadership in research, development of innovations so that community pharmacists potential innovativeness is used, and that professional needs and strategic priorities will be considered even if the development process is led by those outside the profession.

Recent advances in radar technology

The technical developments and advances that have taken place thus far are reviewed in those areas impacting future phased array active aperture radar systems. The areas covered are printed circuit antennas and antenna arrays, GaAs MMIC design and fabrication leading to affordable transmitter-receiver (T-R) modules, and novel hardware and software developments. The use of fiber-optic distribution networks to interconnect the monolithically integrated optical components with the T-R modules is discussed. Beamforming and sidelobe control techniques for active phased array systems are also examined.

Biomass gasification: Environmentally sound technology for decentralized power generation, a case study from India

This study aims at understanding the need for decentralized power generation systems and to explore the potential, feasibility and environmental implications of biomass gasifier-based electricity generation systems for village electrification. Electricity needs of villages are in the range of 5–20 kW depending on the size of the village. Decentralized power generation systems are desirable for low load village situations as the cost of power transmission lines is reduced and transmission and distribution losses are minimised. A biomass gasifier-based electricity generation system is one of the feasible options; the technology is readily available and has already been field tested. To meet the lighting and stationary power needs of 500,000 villages in India the land required is only 16 Mha compared to over 100 Mha of degraded land available for tree planting. In fact all the 95 Mt of woody biomass required for gasification could be obtained through biomass conservation programmes such as biogas and improved cook stoves. Thus dedication of land for energy plantations may not be required. A shift to a biomass gasifier-based power generation system leads to local benefits such as village self reliance, local employment and skill generation and promotion of in situ plant diversity plus global benefits like no net CO2 emission (as sustainable biomass harvests are possible) and a reduction in CO2 emissions (when used to substitute thermal power and diesel in irrigation pump sets).

Novel mechanism for high speed growth of transparent and conducting tin oxide thin films by spray pyrolysis

A novel mechanism is proposed for efficient manipulation of transport forces acting on the droplets during spray pyrolytic deposition of thin films. A ‘‘burst mode’’ technique of spraying is used to adjust the deposition conditions so as to transport the droplets under the new mechanism. Transparent, conducting thin films of undoped tin oxide prepared by this method showed significant improvement in growth rate. The films are found to be of fairly good quality with optical transmission of 82% and sheet resistance of 35 Ω/☒. The films are chemically homogeneous and grow preferentially along 〈200〉 direction.

Solar pond technology

Solar pond technology has made substantial progress in the last fifteen years. This paper reviews the basic principles of solar ponds and the problems encountered in their operation and maintenance. The factors which influence the technical and economic viability of solar ponds for thermal applications and power generation have been discussed.

Some features of spray breakup in effervescent atomizers

The near orifice spray breakup at low GLR (gas to liquid ratio by mass) values in an effervescent atomizer is studied experimentally using water as a simulant and air as atomizing gas. From the visualizations, the near orifice spray structures are classified into three modes: discrete bubble explosions, continuous bubble explosions and annular conical spray. The breakup of the spray is quantified in terms of the mean bubble bursting distance from the orifice. The parametric study indicates that the mean bubble bursting distance mainly depends on airflow rate, jet diameter and mixture velocity. It is also observed that the jet diameter has a dominant effect on the bubble bursting distance when compared to mixture velocity at a given airflow rate. The mean bubble bursting distance is shown to be governed by a nondimensional two-phase flow number consisting of all the aforementioned parameters. The location of bubble bursting is found to be highly unsteady spatially, which is influenced by flow dynamics inside the injector. It is proposed that this unsteadiness in jet breakup length is a consequence of varying degree of bubble expansion caused due to the intermittent occurrence of single phase and two-phase flow inside the orifice.

Electro-magnetically Actuated Minute Polymer Pump Fabricated using Packaging Technology

Design, fabrication and preliminary testing of a flat pump with millimetre thickness are described in this paper. The pump is entirely made of polymer materials barring the magnet and copper coils used for electromagnetic actuation. The fabrication is carried out using widely available microelectronic packaging machinery and techniques. Therefore, the fabrication of the pump is straightforward and inexpensive. Two types of prototypes are designed and built. One consists of copper coils that are etched on an epoxy plate and the other has wound insulated wire of 90 mu m diameter to serve as a coil. The overall size of the first pump is 25 mm x 25 mm x 3.6 mm including the 3.1 mm-thick NdFeB magnet of diameter 12 mm. It consists of a pump chamber of 20 mm x 20 mm x 0.8 mm with copper coils etched from a copper-clad epoxy plate using dry-film lithography and milled using a CNC milling machine, two passive valves and the pump-diaphragm made of Kapton film of 0.089 mm thickness. The second pump has an overall size of 35 mm x 35 mm x 4.4 mm including the magnet and the windings. A breadboard circuit and DC power supply are used to test the pump by applying an alternating square-wave voltage pulse. A water slug in a tube attached to the inlet is used to observe and measure the air-flow induced by the pump against atmospheric pressure. The maximum flow rate was found to be 15 ml/min for a voltage of 2.5 V and a current of 19 mA at 68 Hz.

Ultrasonic spray pyrolysis of CZTS solar cell absorber layers and characterization studies

CZTS (Copper Zinc Tin Sulphide) is a wide band gap quartnery chalcopyrite which has a band gap of about 1.45 eV and an absorption coefficient of 10(4) cm(-1); thus making it an ideal material to be used as an absorber layer in solar cells. Ultrasonic Spray Pyrolysis is a deposition technique, where the solution is atomized ultrasonically, thereby giving a fine mist having a narrow size distribution which can be used for uniform coatings on substrates. An Ultrasonic Spray Pyrolysis equipment was developed and CZTS absorber layers were successfully grown with this technique on soda lime glass substrates using aqueous solutions. Substrate temperatures ranging from 523 K to 723 K were used to deposit the CZTS layers and these films were characterized using SEM, EDAX and XRD. It was observed that the film crystallized in the kesterite structure and the best crystallites were obtained at 613 K. It was observed that the grain size progressively increased with temperature. The optical band gap of the material was obtained as 1.54 eV.

Integrated optics � technology and applications

The emergence of optoelectronics and photonics as viable alternatives to electronics in many key areas of engineering relevance is indeed significant. This paper presents a tutorial review of integrated optics � a technologically important development in photonics. Materials, processes, device technology and applications are highlighted.