6 research outputs found

    Reaction of small olefins on zeolite H-ZSM-5. A thermogravimetric study at low and intermediate temperatures Citation for published version (APA): Reaction of Small Olefins on Zeolite H-ZSM-5. A Thermogravimetric Study at Low and Intermediate Temperatures

    No full text
    Oligomerization and cracking reactions of ethene, propene, and isobutene on zeolite H-ZSM-5 (300 5 T < 600K) were investigated using temperature-programmed adsorption and desorption experiments, high-resolution r3C-NMR spectroscopy, and gas chromatographic product analysis. Evidence is gained that at 300K only the stronger part of the Bronsted-acid sites are active in ethene oligomerization, while at increased temperatures more sites become active. On the contrary, in propene and isobutene oligomerization all sites are already active at 300K. This results in completely analogous products formed upon oligomerization of ethene, propene, and isobutene above 373K. The rate of oligomerization increases sharply with increasing reaction temperatures, resulting in a hindered transport of reactant molecules through the pores due to pore mouth blocking. The reactions on the outer surface become more important, which results in an increased branching of the oligomers formed at higher reaction temperatures. At 400K cracking of the oligomers starts, and at 490K the rate of cracking equals the rate of oligomerization. At this temperature desorption products show considerable branching, while at 573K only highly branched products are desorbed. At temperatures above SOOK zeolite H-ZSM-5 becomes a dynamically operating catalytic system in the conversion of small olefins

    Victorian Specialist Immunisation Services (VicSIS) – bolstering adult clinics for COVID-19 vaccines

    No full text
    The Victorian Specialist Immunization Services (VicSIS) was established in Victoria, Australia, in February 2021, aiming to enhance vaccine safety services for Coronavirus disease (COVID-19) vaccines. VicSIS supports practitioners and patients with complex vaccine safety questions, including those who experience adverse events following immunization (AEFI) after COVID-19 vaccines. VicSIS provides individual vaccination recommendations, allergy testing, vaccine challenges, and vaccination under supervision. VicSIS initially comprised of eight adult COVID-19 specialist vaccination clinics, subsequently, expanding to better support pediatric patients as the Australian vaccine roll-out extended to adolescents and children. Since their establishment to September 2021, the inaugural VicSIS clinics received a total of 26,401 referrals and reviewed 6,079 patients. Consults were initially predominantly for pre-vaccination reviews, later predominantly becoming post-vaccination AEFI reviews as the program progressed. Regardless of the type of consult, the most common consult outcome was a recommendation for routine vaccination (73% and 55% of consult outcomes respectively). VicSIS is an integral component of the COVID-19 vaccination program and supports confidence in COVID-19 vaccine safety by providing consistent advice across the state. VicSIS aims to strengthen the health system through the pandemic, bolstering specialist immunization services beyond COVID-19 vaccines, including training the next generation of vaccinology experts
    corecore