scholarly journals Lightweight alumina refractory aggregate: Phase 3, Full-scale demonstration

1996 ◽  
Author(s):  
T.G. Swansiger ◽  
A. Pearson
Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 779
Author(s):  
David Zemánek ◽  
Karel Lang ◽  
Lukáš Tvrdík ◽  
Dalibor Všianský ◽  
Lenka Nevřivová ◽  
...  

The presented study is focused on optimization and characterization of a high-alumina refractory aggregate based on natural raw materials—kaolins, claystone, and mullite dust by-product (used to increase the alumina and mullite contents, respectively). In total, four individual formulas with the Al2O3 contents between 45 and 50 wt.% were designed; the samples were subsequently fired, both in a laboratory oven and an industrial tunnel furnace. The effects of repeated firing were examined during industrial pilot tests. Mineral and chemical compositions and microstructures, of both the raw materials and designed aggregates, were thoroughly investigated by the means of X-ray fluorescence spectroscopy, powder X-ray diffraction, and optical and scanning electron microscopies. Porosity, mineral composition, and mullite crystal-size development during the firing process were also studied. Based on the acquired results, the formula with the perspective to be used as a new mullite grog, featuring similar properties as the available commercial products, however, with reduced production expenses, was selected. The quality of grog determines to a large extent the properties of the final product. Hence, optimization of aggregates for specific refractories is of a great importance. The production of engineered aggregates provides the opportunity to utilize industrial by-products.


2005 ◽  
Vol 2005 (1) ◽  
pp. 831-836 ◽  
Author(s):  
Tharaid M. Brekne ◽  
Gry Asheim Eide ◽  
Geir M. Skeie

ABSTRACT The Norwegian Clean Seas Association for Operating Companies (NOFO) has recently completed a comprehensive Research & Development (R&D) program. The main objective of this program was to provide a basis for decisions regarding selection of equipment in the next generation of NOFO's oil spill response. The R&D program was initiated in 2000 and the results from the preliminary phase of the program were presented at the 2003 IOSC in Vancouver. In the summer of 2003, NOFO successfully carried out an Oil-on-water exercise. This exercise encompassed a full scale testing of new equipment developed in the second phase of the program. A series of experiments were performed where oil was released to the sea and subsequently recovered. In total, 170 cubic meters of oil emulsion was released, and approximately 80 % recovered. Based on the experiences from the Oil-on-water exercise, NOFO implemented Phase 3 of the R&D program. This phase comprised of redesign and modifications to two types of booms, and of a high capacity skimmer. Final testing of the Phase 3 results was completed in the first quarter of 2004, and concluded that the design criteria were met. Concurrently, NOFO has embarked on a three-year replacement plan, in which existing booms and skimmers are replaced by the new equipment types. Phase 2 included a feasibility study on enhanced detection of oil spills under conditions of low light and reduced visibility. Based on results from this study, a project has been initiated to develop and implement a ship based radar system for detection of oil spills. This project is considered the first step towards the goal of achieving an oil spill response that is independent of light and visibility. This paper outlines the conclusions of the R&D program and the 2003 Oil-on-water exercise, as well as the results from the final performance tests of the new equipment. Further, the new oil spill response is comprehensive, in terms of total capability and geographical coverage.


2000 ◽  
Vol 16 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Louis M. Hsu ◽  
Judy Hayman ◽  
Judith Koch ◽  
Debbie Mandell

Summary: In the United States' normative population for the WAIS-R, differences (Ds) between persons' verbal and performance IQs (VIQs and PIQs) tend to increase with an increase in full scale IQs (FSIQs). This suggests that norm-referenced interpretations of Ds should take FSIQs into account. Two new graphs are presented to facilitate this type of interpretation. One of these graphs estimates the mean of absolute values of D (called typical D) at each FSIQ level of the US normative population. The other graph estimates the absolute value of D that is exceeded only 5% of the time (called abnormal D) at each FSIQ level of this population. A graph for the identification of conventional “statistically significant Ds” (also called “reliable Ds”) is also presented. A reliable D is defined in the context of classical true score theory as an absolute D that is unlikely (p < .05) to be exceeded by a person whose true VIQ and PIQ are equal. As conventionally defined reliable Ds do not depend on the FSIQ. The graphs of typical and abnormal Ds are based on quadratic models of the relation of sizes of Ds to FSIQs. These models are generalizations of models described in Hsu (1996) . The new graphical method of identifying Abnormal Ds is compared to the conventional Payne-Jones method of identifying these Ds. Implications of the three juxtaposed graphs for the interpretation of VIQ-PIQ differences are discussed.


1996 ◽  
Vol 12 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Louis M. Hsu

The difference (D) between a person's Verbal IQ (VIQ) and Performance IQ (PIQ) has for some time been considered clinically meaningful ( Kaufman, 1976 , 1979 ; Matarazzo, 1990 , 1991 ; Matarazzo & Herman, 1985 ; Sattler, 1982 ; Wechsler, 1984 ). Particularly useful is information about the degree to which a difference (D) between scores is “abnormal” (i.e., deviant in a standardization group) as opposed to simply “reliable” (i.e., indicative of a true score difference) ( Mittenberg, Thompson, & Schwartz, 1991 ; Silverstein, 1981 ; Payne & Jones, 1957 ). Payne and Jones (1957) proposed a formula to identify “abnormal” differences, which has been used extensively in the literature, and which has generally yielded good approximations to empirically determined “abnormal” differences ( Silverstein, 1985 ; Matarazzo & Herman, 1985 ). However applications of this formula have not taken into account the dependence (demonstrated by Kaufman, 1976 , 1979 , and Matarazzo & Herman, 1985 ) of Ds on Full Scale IQs (FSIQs). This has led to overestimation of “abnormality” of Ds of high FSIQ children, and underestimation of “abnormality” of Ds of low FSIQ children. This article presents a formula for identification of abnormal WISC-R Ds, which overcomes these problems, by explicitly taking into account the dependence of Ds on FSIQs.


2018 ◽  
Vol 86 (08) ◽  
pp. 456-457
Keyword(s):  
Phase 2 ◽  
Phase 3 ◽  

Die Blockade von Serotoninrezeptoren, insbesondere des Serotonin-Rezeptortyps 5-HT6, als Zusatztherapie in Kombination mit Cholinesterasehemmer, hat in experimentellen Versuchen sowie in einer Phase-2-Studie positive Effekte bei Demenz gezeigt. Im Rahmen eines Phase-3 Entwicklungsprogramms wurde nun die Effektivität des selektiven Serotoninrezeptor-Antagonisten Idalopirdin bei leichter bis mittelschwerer Alzheimer Demenz geprüft.


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