Porcine reproductive and respiratory syndrome virus (PRRSV) causes disease in swine and economic losses for swine producers. An inexpensive and effective method for removing PRRSV from air is required to reduce aerosol transmission of PRRSV. A laboratory study was used to assess the performance of air ionization at removing bioaerosols contaminated with PRRSV. Aerosol properties were measured with an Aerosol Particle Size Spectrometer and air samples were collected with SKC biosamplers. PRRSV RNA was quantified with RNA extraction and quantitative reverse transcription polymerase chain reaction. Reduction in aerosol concentrations ranged from 61 – 93% by number count and 68 – 96% by mass. Initial particle size distribution and airflow rate affected the performance of EPI Air at reducing aerosol concentrations. Air ionization was effective at removing PRRSV from the air. The PRRSV RNA concentrations were reduced by 68 – 90% and the average PRRSV RNA after ionization ranged from 154 – 4594 VGCN/m3.

by Kwok Chiu Nga. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 1-3 (4th gp.)). / Abstract also in Chinese. / TABLE OF CONTENTS --- p.i / ABSTRACT --- p.iv / 摘要 --- p.vi / LIST OF FIGURES --- p.vii / LIST OF TABLES --- p.x / ABBREVIATION --- p.xi / Chapter CHAPTER ONE --- RESEARCH BACKGROUND / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.1.1 --- Alkaloids --- p.1 / Chapter 1.1.2 --- Diterpenoid alkaloids --- p.2 / Chapter 1.1.3 --- Aconitine-type alkaloids --- p.2 / Chapter 1.1.4 --- Toxicity --- p.4 / Chapter 1.1.5 --- Safety concerns --- p.4 / Chapter 1.2 --- Summary of the Previous Work --- p.8 / Chapter 1.3 --- Objectives and Outline of the Present Work --- p.13 / Chapter CHAPTER TWO --- INSTRUMENTATION AND EXPERIMENTAL / Chapter 2.1 --- Instrumentation --- p.15 / Chapter 2.1.1 --- High performance liquid chromatography (HPLC) --- p.15 / Chapter 2.1.2 --- Triple-stage quadrupole (TSQ) mass spectrometer --- p.17 / Chapter 2.1.2.1 --- Atmospheric pressure chemical ionization (APCI) --- p.17 / Chapter 2.1.2.2 --- Electrospray ionization (ESI) --- p.20 / Chapter 2.1.2.3 --- Quadrupole system --- p.20 / Chapter 2.1.2.4 --- Ion detection system --- p.22 / Chapter 2.1.2.5 --- Data system --- p.22 / Chapter 2.2 --- Experimental --- p.22 / Chapter 2.2.1 --- Sample and reagents --- p.22 / Chapter 2.2.2 --- Sample preparation --- p.23 / Chapter 2.2.3 --- High performance liquid chromatography conditions --- p.23 / Chapter 2.2.4 --- Mass spectrometry conditions --- p.25 / Chapter 2.2.4.1 --- Atmospheric pressure chemical ionization conditions --- p.25 / Chapter 2.2.4.2 --- Electrospray ionization conditions --- p.25 / Chapter CHAPTER THREE --- SELECTION AND OPTIMIZATION OF HPLC/MS METHOD / Chapter 3.1 --- Introduction --- p.26 / Chapter 3.2 --- Experimental --- p.29 / Chapter 3.3 --- Results and Discussion --- p.29 / Chapter 3.3.1 --- Triethylamine concentration --- p.31 / Chapter 3.3.2 --- Ammonium acetate concentration --- p.34 / Chapter 3.3.3 --- Acetic acid concentration --- p.37 / Chapter 3.3.4 --- HPLC/MS interface --- p.40 / Chapter 3.3.5 --- MS/MS conditions --- p.40 / Chapter 3.4 --- Conclusions --- p.43 / Chapter CHAPTER FOUR --- DETERMINATION OF ACONITINE-TYPE ALKALOIDS IN ACONITE ROOTS / Chapter 4.1 --- Introduction --- p.48 / Chapter 4.2 --- Experimental --- p.48 / Chapter 4.3 --- Results and Discussion --- p.50 / Chapter 4.3.1 --- Selection of internal standard --- p.50 / Chapter 4.3.2 --- Method validation --- p.50 / Chapter 4.3.2.1 --- Precision of measurement --- p.50 / Chapter 4.3.2.2 --- Accuracy of measurement --- p.50 / Chapter 4.3.2.3 --- Limits of detection and quantitation --- p.58 / Chapter 4.3.3 --- Determination of aconitine-type alkaloids in aconite roots --- p.58 / Chapter 4.4 --- Conclusions --- p.60 / Chapter CHAPTER FIVE --- CONCLUSIONS AND FUTURE WORK / Chapter 5.1 --- Conclusions --- p.67 / Chapter 5.2 --- Future Work --- p.68 / ACKNOWLEDGMENT --- p.A1 / APPENDIX --- p.A2 / REFERENCES --- p.R1

Neste trabalho foi estabelecido um sistema padrão primário para raios X de energias baixas (10 kV a 50 kV), utilizando uma câmara de ionização de ar livre de cilindros concêntricos da marca Victoreen (modelo 481-5) no Laboratório de Calibração de Instrumentos (LCI) do Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP). Para isso foi desenvolvido um novo protocolo de alinhamento da câmara de ionização no sistema de radiação e foi feita uma modificação no suporte dos micrômetros utilizados para o movimento dos cilindros internos. Os resultados obtidos nos testes de estabilidade e de caracterização ficaram dentro dos limites estabelecidos pelas normas IEC 61674 e IEC 60731. Foram determinados também os fatores de correção para atenuação de fótons no ar, transmissão e espalhamento no diafragma, espalhamento e fluorescência, e recombinação iônica. Esses valores foram comparados com os valores obtidos pelo laboratório padrão primário alemão,Physikalisch-Technische Bundesanstalt (PTB), mostrando boa concordância. Por último, foi determinado o valor absoluto da grandeza taxa de kerma no ar para as qualidades padronizadas de mamografia de feixes diretos WMV28 e WMV35 e feixes atenuados WMH28 e WMH35; os resultados são compatíveis, com diferença máxima de 3,8% com os valores obtidos utilizando o sistema padrão secundário do LCI. / In this work a primary standard system was established for low energy X-rays (10 kV to 50 kV), using a free air ionization chamber with concentric cylinders, Victoreen (Model 481-5), at the Calibration Laboratory of Instruments (LCI) of the Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP). For this, a new ionization chamber alignment protocol was developed for the radiation system and a modification on the micrometer housing used for the movement of the internal cylinders was made. The results obtained for the stability and characterization tests showed to be within the limits established by the standards IEC 61674 and IEC 60731. The correction factors for photon attenuation in the air, transmission and scattering in the diaphragm, scattering and fluorescence and ion recombination were also determined. These values were compared with those obtained by the German primary standard laboratory, Physikalisch-Technische Bundesanstalt (PTB), showing good agreement. Finally, the absolute values of the quantity air kerma rate for the standard qualities direct beams MWV28 and WMV35 and the attenuated beams WMH28 and WMH35 were determined; the results are in agreement, with a maximum difference of 3,8% with the values obtained using the secondary standard system of LCI.

Neste trabalho foi estabelecido um sistema padrão primário para raios X de energias baixas (10 kV a 50 kV), utilizando uma câmara de ionização de ar livre de cilindros concêntricos da marca Victoreen (modelo 481-5) no Laboratório de Calibração de Instrumentos (LCI) do Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP). Para isso foi desenvolvido um novo protocolo de alinhamento da câmara de ionização no sistema de radiação e foi feita uma modificação no suporte dos micrômetros utilizados para o movimento dos cilindros internos. Os resultados obtidos nos testes de estabilidade e de caracterização ficaram dentro dos limites estabelecidos pelas normas IEC 61674 e IEC 60731. Foram determinados também os fatores de correção para atenuação de fótons no ar, transmissão e espalhamento no diafragma, espalhamento e fluorescência, e recombinação iônica. Esses valores foram comparados com os valores obtidos pelo laboratório padrão primário alemão,Physikalisch-Technische Bundesanstalt (PTB), mostrando boa concordância. Por último, foi determinado o valor absoluto da grandeza taxa de kerma no ar para as qualidades padronizadas de mamografia de feixes diretos WMV28 e WMV35 e feixes atenuados WMH28 e WMH35; os resultados são compatíveis, com diferença máxima de 3,8% com os valores obtidos utilizando o sistema padrão secundário do LCI. / In this work a primary standard system was established for low energy X-rays (10 kV to 50 kV), using a free air ionization chamber with concentric cylinders, Victoreen (Model 481-5), at the Calibration Laboratory of Instruments (LCI) of the Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP). For this, a new ionization chamber alignment protocol was developed for the radiation system and a modification on the micrometer housing used for the movement of the internal cylinders was made. The results obtained for the stability and characterization tests showed to be within the limits established by the standards IEC 61674 and IEC 60731. The correction factors for photon attenuation in the air, transmission and scattering in the diaphragm, scattering and fluorescence and ion recombination were also determined. These values were compared with those obtained by the German primary standard laboratory, Physikalisch-Technische Bundesanstalt (PTB), showing good agreement. Finally, the absolute values of the quantity air kerma rate for the standard qualities direct beams MWV28 and WMV35 and the attenuated beams WMH28 and WMH35 were determined; the results are in agreement, with a maximum difference of 3,8% with the values obtained using the secondary standard system of LCI.

The presence of molds on the surface of salami may bring undesirable effects during the maturation process of salami, causing negative effects on the development of color, aroma and flavor. Where there is often the need for removal of this gut, the final product, resulting in losses in production, reducing yield and increasing the cost of the product. This way, this study is justified the search of a new technology in the market to control fungal. With this objective was to follow the evolution of mold surface of salami (Ф=42 mm) and the italian salami (Ф=75 mm), observing the effect of the application of antifungal natamycin, UV, ozone and air ionization. Evaluate the physico-chemical, microbiological and sensory and monitor the shelf life of salami in different decontamination methods followed.The main fatty acids found after treatments were oleic acid, palmitic acid, linoleic acid and stearic acid, causing an increase in saturated fatty acids after the storage period (120 days), proving that there was an increase in lipid oxidation without differ in storage time. All the procedures affected thesensorial quality, which has been evaluated by the attributes color, odor, flavor and texture after 120 days.When evaluating different methods for the control of mold surface of salami, observed that treatment of natamycin 0,5% (SLS5) and ionization (SLSION) had a maximum growth of 103 CFU/cm2 being that the most effective method for the salami was treatment with natamycin 0.5% had a maximum growth of 1.90 x102 CFU/cm2. As for, the Italian salami treatments using natamycin 0.5% (SIG5), ozonizer (SIGOZO) and ionizer (SIGION) were the most effective methods, had a maximum growth of 103 CFU/cm2. Therefore, this study showed that treatments using natamycin 0.5% and ionization in air is an alternative to control mould salami thin and thick gauge of salamis providing the highest microbiological safety and sensory acceptance. / A presença dos mofos na superfície do salame pode trazer efeitos indesejáveis durante o processo de maturação, causando efeitos negativos no desenvolvimento de cor, aroma e no sabor. Muitas vezes há a necessidade de remoção desta tripa, ao final do processo, resultando em perdas na produção, reduzindo o rendimento e elevando o custo de produto. Dessa forma, o presente trabalho justifica-se pela busca de uma nova tecnologia no mercado para o controle fúngico. Com isso, objetivo do trabalho foi acompanhar a evolução do mofo em superfície de salaminho (Ф=42 mm) e dos salames tipo italiano (Ф=75 mm) observando o efeito antifúngico na aplicação de natamicina, ultravioleta, ozônio e ionização do ar. Foi avaliado as características físico-químicas, microbiológicas e sensoriais e acompanhar a vida de prateleira dos salames produzidas com diferentes métodos de descontaminação. Observou-se que em todos os tratamentos não houve comprometimento do processo tecnológico, nem dos parâmetros legais físico-químicos e microbiológicos. Os principais ácidos graxos encontrados foram ácido oléico, ácido palmítico, ácido linoléico e o ácido esteárico (18:0), observando aumento nos ácidos graxos saturados após no período de armazenamento, demonstrando que houve um aumento na oxidação lipídica, sem diferir no tempo de armazenamento. Todos os tratamentos afetaram a qualidade sensorial que foi avaliada através dos atributos cor, odor, sabor e textura após os 120 dias. Ao avaliar os diferentes métodos para o controle de mofos em superfície de salaminho, conclui-se que os tratamentos utilizando natamicina 0,5% e ionização foram os métodos mais efetivo, que apresentou baixa carga fúngica (1,90 x102 UFC/cm2). Já para o salame tipo italiano os tratamentos utilizando natamicina 0,5% (SIG5), ozonizador (SIGOZO) e o ionizador (SIGION) foram os métodos mais efetivos, mantendo-se 103 UFC/cm2. Portanto, este estudo indicou que os tratamentos utilizando natamicina 0,5% e ionização em ar é uma alternativa para controle fúngicos em salame de calibre fino e grosso proporcionando salames de maior segurança microbiológica e com aceitação sensorial.

Air ionization is a method used at air treatment of closed spaces. Properly applied air ionization improves health condition of bred animals, lowers the costs of pharmaceuticals and increases their efficiency. Negative ions attach themselves to particles of dust causing them to drop to the ground. The aim of the thesis was to analyse the influence of air ionization on air dustiness in a relation to temperature changes and relative air humidity in a farrowing house for sows. The farm used litter in the lairage pens. Sows were fed with dampened mixture. By the help of a data logger was measured the temperature [°C] and the relative air humidity [%]. The readings were recorded at hourly interval. Speed of the air circulation [m.s-1] in the stall and the cooling power [mcal.cm-2.s-1] were measured in the resting stage. The air dustiness in the stall was measured on the level of a lying sow in the state of resting, activity and after an activity. The data of the concentration of dust molecules in the air were recorded at interval of 10 seconds. The length of the measuring for each period was set for 8 minutes. The size adjustment of the dust molecules wasn?t specified. On selected days was applied the air ionization. At high temperature and relative humidity it came to binding of ions to the molecules of dust. At low temperature, high relative humidity and reduced intensity of air change in the stall the ionization didn?t have any influence on the dustiness because the dust settled as a result of the relative air humidity.

No description available.