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The fixed bed drying of western hemlock and Douglas-fir biomass particles at temperatures ranging from 50��C to 200��C and air velocities from 0.3 to 0.9 m/s was investigated. The objectives were to describe the drying characteristics of the particles, fit a model for thin-layer drying, and develop and test a deep bed drying model based on the thin-layer model. The effects of temperature and air velocity were determined in a bed approximately 1.3 cm in depth and a model for the drying curve was developed. The thin-layer model was then used to predict what would happen in a deeper bed. Model results were compared to drying curves measured in a 23-cm-deep bed. The deep bed model predicted both the experimental drying times and the moisture and temperature profiles in the bed. / Graduation date: 2013

Call number: LD2668 .T4 1978 C5 / Master of Science

For African farmers, proper drying is considered to be the biggest single factor in determining whether grain can be effectively stored without deterioration. The primary goal of the project is to develop and test the Pico solar crOp Dryer (POD). The overall goal is to improve the POD’s performance, making it acceptable to small holder farmers in Kenya and other developing countries, and positioning it for commercialization. In the POD tests shelled maize was placed in wooden or plastic trays and that were covered with plastic sheets. In the final design, seven small fans of the type used for cooling electronics moved air through the dryer. Power was supplied by a 12 volt, 30 Watt Solar Panel and a 12 volt 7 ampere hour lead acid battery. A charge controller allowed the fans to draw energy from both the solar panel and the battery. The POD was tested at Purdue from 2017 to 2019. The most recent Purdue test on freshly harvested maize was conducted in September 2018. The POD was able to dry 142 kg of 30.1% mc maize to 13.3% in 24.5 hours of drying over 3 calendar days giving an overall drying rate of 0.68 percentage points per hour. The POD dried the maize in 0.84 of the time required to dry maize on a tarp. In the summer of 2018, the components for assembling 5 POD’s were prepared and sent to Kenya for testing. The tests were conducted in Nakuru county in November 2018, and in Trans-Nzoia, Uasin Gishu, and Nandi counties in March 2019. Overall average drying rates for the tests varied, depending on weather conditions, from 0.58 to 0.97 percentage points per hour. A thin layer drying equation was adapted for use in investigating the effects of weather conditions and the airflow rate on the POD drying rate. Adoption of the POD by small holder farmers in Kenya and other developing countries should lead to a reduction in post-harvest losses caused by improper drying. Although testing has been primarily focused on drying maize, it could be adapted for drying other crops.

A liberação local de fármacos na cavidade oral apresenta muitas aplicações, incluindo o controle da dor pós-cirúrgica, tratamento de doenças periodontais e anestesia local. Micropartículas carregadas com anti-inflamatórios não-esteroidais (AINEs) produzidas para a liberação sustentada é útil em Odontologia, uma vez que mantém o fármaco em níveis terapêuticos, promove o controle da dor e maior adesão do paciente ao tratamento.Uma vez que o sistema é biodegradável, o paciente não precisa ir ao consultório do dentista para removê-lo. Spray drying, é um dos vários métodos de microencapsulação, é rápido, de fácil operação, ampliação de escala e apresenta condições moderadas de operação. Assim, o objetivo deste trabalho é determinar as especificações do processo de spray-drying na obtenção de micropartículas biodegradáveis para a liberação sustentada de fármacos com aplicação odontológica. Quitosana foi utilizada como polímero de revestimento, uma vez que é biodegradável, biocompatível e mucoadesivo. Cetoprofeno foi utilizado como AINE modelo.Testes de qualificação de operação do spray-dryer foram conduzidos em conformidades com os requisitos da ANVISA e FDA. O método de análise de teor de cetoprofeno também foi validado, apresentando precisão, exatidão, linearidade e especificidade adequados ao seu propósito. Com relação ao processo de microencapsulação, a melhor condição operacional no spray-dryer apresenta 100 ºC de temperatura de entrada, 5,7 g/min de vazão da bomba peristáltica, 49,2 m3/h de vazão do ar de secagem, 1 mm de diâmetro do bico atomizador e 1,3 de pressão do ar comprimido. As micropartículas obtidas apresentam boa esfericidade e uma superfície lisa. A distribuição granulométrica é estreita, variando de 2,11 a 3,27m. Os estudos de liberação in vitro mostram um comportamento linear de dissolução do cetoprofeno encapsulado nas micropartículas, sugerindo que a cinética de liberação do fármaco é governada pela dissolução do fármaco e difusão através da matriz polimérica. Quitosana apresentou influência sobre a liberação do cetoprofeno, uma vez que foi encontrado um T50 de 36,0 h para o fármaco microencapsulado, ao passo que para o fármaco livre o T50 é de apenas 7,84 h. / Local release of drugs at oral cavity tissues shows several uses, including postsurgery pain control, periodontal disease treatment and local anesthesia. NSAID loaded-biodegradable microparticles made for a sustained drug release is useful in Dentistry since they keep the drug therapeutic level sustained, promote pain control and patient compliance. Since the system is biodegradable, the patient do not need to go to the dentistry office to remove it. Spray-drying (SD) , one of the several microencapsulation methods, is fast, has easy operation and scale-up and shows mint operating conditions. Thus the aim of this work is to design the spraydrying specifications of manufacturing dental drug loaded-biodegradable microparticles for sustained release purposes. Chitosan was used as the microencapsulation polymer due to its biodegradability, biocompatibility and mucoadhesiveness. Ketoprofen was used as the model NSAID. Operation qualification tests were performed with the spray-dryer as required by ANVISA and FDA. The analytical method for ketoprofen assay was also validated, showing accuracy, precision, linearity and specificity suitable for its purpose. Concerning microencapsulation process, the best SD operating conditions was 100 º C (inlet), 5,73 g/min (pump flow rate), 49,19 m3/h (air flow rate), 1 mm (nozzle), 1,3 (compressed air). The microparticles delivered show good sphericity and a smooth surface. The size distribution is narrow, ranging from 2,11 to 3,27 m. In vitro release studies show a linear dissolution behavior of cetoprofen-loaded microparticules suggesting the kinetic of drug release is driven by drug dissolution and diffusion through polymer matrix. Chitosan has an influence over the cetoprofen release since a T50 of 36,0 h was found to microparticles while the cetoprofen only has a T50 of 7,84 h.

Typescript. / Digitized by Kansas Correctional Industries

The aim of this work has been to minimize the thermal energy required to dry malt in deep beds while maintaining malt quality, and without increasing the drying time more than one hour. Malt drying usually takes place in deep bed (. 7-1 m) driers by forcing hot air through the bed. Measurements of inlet and outlet relative humidity, temperature, and airflow at a drier at Great Western Malting Company's Vancouver, Washington facility were made to find average moisture content versus time. The measurements were used to develop a wetted surface model of a malt bed. However, the model was not detailed enough to accurately fit the drying data taken from the kiln. Thus it was necessary to consider a more complex model. A diffusion based mathematical model of malt drying was coded using malt properties and drying equations found in the research of Bala (Ph.D. thesis, 1983). This program calculates moisture content and malt temperature in horizontal layers of a malt bed. Energy saving drying tests by airflow reduction methods were simulated with the program. The methods were designed to take advantage of the malt's internal drying mechanism, and they were effective at reducing energy consumption. However, model verification was necessary, and maintaining malt quality was essential. A deep bed experimental malt drier was built at Portland State University to allow malt temperature and average moisture content data collection. Drying experiments were performed at constant airflow, for several different drying temperature cases, and the highest experimental temperature with acceptable malt quality was found to be 7 5 C. Drying at 70 C (158 F) rather than at 63 C (145 F) was found to cause a 20% reduction in the thermal energy consumption, but higher temperatures did not significantly improve efficiency. The experimental moisture contents and grain temperatures generally compared well with diffusion model simulations of the experiments. Airflow reduction experiments decreased thermal consumption by 20% compared to typical drying schedules. These experiments were based on the airflow reduction methods learned from the diffusion model. However, diffusion model simulations using the experimental conditions showed thermal energy reductions of 11 %.