Applications of systems synthesis techniques to industrial systems

Digitized by Kansas Correctional Industrie

Attrition and abrasion models for oil shale process modeling

reportAs oil shale is processed, line particles, much smaller than the original shale are created. This process is called attrition or more accurately abrasion. In this paper, models of abrasion are presented for oil shale being processed in several unit operations. Two of these unit operations, a fluidized bed and a lift pipe are used in the Lawrence Livermore National Laboratory Hot-Recycle-Solid (HRS) process being developed for the above ground processing of oil shale. Abrasion occurs so commonly in the handling and processing of particulate materials that numerous studies have been conducted to first characterize the phenomena and secondly to attempt to minimize it. In the review of the literature, materials which have been studied for attrition potential are examined as are the specific unit operations for which either experimental or modeling studies have been conducted. Several papers are discussed in which attrition in fluidized beds or lift pipes is addressed. In two reports, studies were conducted on the attrition of oil shale in unit operations which are used in the ERS process. Carley reported results for attrition in a lift pipe for oil shale which had been pre-processed either by retorting or by retorting then burning. The second paper, by Taylor and Beavers, reported results for a fluidized bed processing of oil shale. Taylor and Beavers studied raw, retorted, and shale which had been retorted and then burned. In this paper, empirical models are derived, from the experimental studies conducted on oil shale, for the processes occurring in the HRS process. The derived models are presented along with comparisons with experimental results

Solar-Supplemented, Natural Air Drying of Shelled Corn: The Economic Limitations

It is not economically feasible to supplement natural air drying of high-moisture shelled corn by adding heat (solar and otherwise). In some cases, that drying method speeds product deterioration. A simulatiton analysis of the west central Great Plains determined that benefits from adding solar heat to batch-in-bin and layer~in-bin grain drying. methods failed to offset the solar heat installation costs and product deterioration losses. Findings also suggest that high-speed, high temperature drying is necessary to avoid field losses and to ensure marketable corn of high quality

European evidence-based guidelines on pancreatic cystic neoplasms

Evidence-based guidelines on the management of pancreatic cystic neoplasms (PCN) are lacking. This guideline is a joint initiative of the European Study Group on Cystic Tumours of the Pancreas, United European Gastroenterology, European Pancreatic Club, European-African Hepato-Pancreato-Biliary Association, European Digestive Surgery, and the European Society of Gastrointestinal Endoscopy. It replaces the 2013 European consensus statement guidelines on PCN. European and non-European experts performed systematic reviews and used GRADE methodology to answer relevant clinical questions on nine topics (biomarkers, radiology, endoscopy, intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), serous cystic neoplasm, rare cysts, (neo)adjuvant treatment, and pathology). Recommendations include conservative management, relative and absolute indications for surgery. A conservative approach is recommended for asymptomatic MCN and IPMN measuring < 40 mm without an enhancing nodule. Relative indications for surgery in IPMN include a main pancreatic duct (MPD) diameter between 5 and 9.9 mm or a cyst diameter >= 40 mm. Absolute indications for surgery in IPMN, due to the high-risk of malignant transformation, include jaundice, an enhancing mural nodule > 5 mm, and MPD diameter > 10 mm. Lifelong follow-up of IPMN is recommended in patients who are fit for surgery. The European evidence-based guidelines on PCN aim to improve the diagnosis and management of PCN

Alirocumab and cardiovascular outcomes after acute coronary syndrome

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Alirocumab and Cardiovascular Outcomes after Acute Coronary Syndrome

BACKGROUN