109 research outputs found
Phase relationships in grunerite-garnet-bearing amphibolites in the systemCFMASH, with applications to metamorphic rocks from the Central Zone of the Limpopo Belt, South Africa.
No full textA petrogenetic grid in the model system CaO–FeO–MgO–Al2O3–SiO2–H2O is presented, illustrating the phase relationships among the minerals grunerite, hornblende, garnet, clinopyroxene, chlorite, olivine, anorthite, zoisite and aluminosilicates, with quartz and H2O in excess. The grid was calculated with the computer softwarethermocalc, using an upgraded version of the internally consistent thermodynamic dataset HP98 and non-ideal mixing activity models for all solid solutions. From this grid, quantitative phase diagrams (P–T pseudosections) are derived and employed to infer a P–T path for grunerite–garnet-bearing amphibolites from the Endora Klippe, part of the Venetia Klippen Complex within the Central Zone of the Limpopo Belt. Agreement between calculated and observed mineral assemblages and garnet zonation indicates that this part of the Central Zone underwent a prograde temperature and pressure increase from c. 540 °C/4.5 kbar to 650 °C/6.5 kbar, followed by a post-peak metamorphic pressure decrease. The inferred P–T path supports a geotectonic model suggesting that the area surrounding the Venetia kimberlite pipes represents the amphibolite-facies roof zone of migmatitic gneisses and granulites that occur widely within the Central Zone. In addition, the P–T path conforms to an interpretation that the Proterozoic evolution of the Central Zone was controlled by horizontal tectonics, causing stacking and differential heating at c. 2.0 Ga
Ottaviano/Augusto e la Venetia nelle fonti letterarie: quale rapporto?
No full textThis article analyses Octavian/Augustus’ relationship with the Venetia region, as described by
literary sources. The author first examines the problem of Caesar’s legacy in the Transpadana, shedding
light on Octavian’s and Antony’s different attitudes towards the so-called causa Transpadanorum and
different components of the local society. Further insight is offered on the switching role of the Venetia
from strategic region for controlling Italy to staging area for military campaigns across the Alps (Germany,
Illyricum and Pannonia). Finally, the author makes an attempt to discern the exact periods when Augustus
resided in the Venetia region.
Keywords: Octavian/Augustus
Delle cose fatte da M. Pietro Mocenico capitano generale di mare della serenissima signoria di Venetia libri tre /
No full textIncludes index.Signatures: *⁸(-*8) A-G⁸.Guerra device on t.p. (eagle shedding feathers as it rises toward sun). Initials.Mode of access: Internet.Binding: later vellum. Abbreviated author and title in gilt on red goatskin spine label. Page edges blue. Green silk place marker
The Effect of Glutamine Supplementation on Microbial Invasion in Surgical Infants Requiring Parenteral Nutrition: Results of a Randomized Controlled Trial
No full textBackground: To determine whether parenteral plus enteral glutamine supplementation influences microbial invasion in surgical infants who require parenteral nutrition (PN). Methods: An prospective double-blind randomized controlled trial studying surgical infants receiving PN for at least 5 days for congenital or acquired intestinal anomalies (2009–2012) was used. Infants were randomized to receive either glutamine supplementation (parenteral plus enteral; total 400 mg/kg/d) or isonitrogenous control. The primary end point was microbial invasion evaluated after 5 days of supplementation and defined as: (i) positive conventional blood culture, (ii) evidence of microbial DNA in blood (polymerase chain reaction), (iii) plasma endotoxin level ≥50 pg/mL, or (iv) plasma level of lipopolysaccharide binding protein ≥50 ng/mL. Data are given as median (range) and compared by logistic regression. Results: Sixty infants were randomized and reached the primary end point. Twenty-five patients had intestinal obstruction, 19 had abdominal wall defects, and 13 had necrotizing enterocolitis. Thirty-six infants showed evidence of microbial invasion during the study, and 17 of these were not detected by conventional blood culture. There was no significant difference between the 2 groups in the primary outcome; evidence of microbial invasion after 5 days was found in 9/31 (control group) and 8/29 (glutamine group) (odds ratio 0.83 [0.24–2.86; P = 0.77]). Conclusion: More than half of surgical infants requiring PN showed evidence of microbial invasion. Approximately half of this was not detectable by conventional blood cultures. Parenteral plus enteral glutamine supplementation had no effect on incidence of microbial invasion
The Fables of Moronia
No full textSee my comments on the hardbound edition.Signed by the authorHerbert C. Holdridg
Le lettre di M. Pietro Aretino
No full textColophon: In Venetia, per Venturino de Roffinelli, del mese di decembre. MDXXXVIII. ; Publisher's devices on t.p. verso & on verso of last leaf, (recto blank) ; Woodcut portrait of the author on t.p. ; Signatures: A-Z⁸ AA-FF⁸ (FF8 blank) ; Index Aurenliensis 107.056 ; Publisher's device cut away from last leaf ; leaves 201-208 (DD [sic], CC[sup]2-[CC⁸]) duplicated in error between leaves 208 and 217
The Fables of Moronia
No full textOne of the weirdest books I own. Heavily political fables directed at the stupidity of U.S. policies. There is nothing really Aesopic here in the content. The prose is a mishmash of cliche, biblical image, King James prose, and who knows what else! Note that the author published his own book. I have tried reading it twice. Good luck!This is a hardbound book (hard cover)This book has a dust jacket (book cover)Signed by the authorHerbert C. Holdridg
Geotechnical optimisation of the Venetia open pit
No full textVenetia Mine is situated south of the confluence of the Shashi and Limpopo rivers, 80 km West of Musina and 36 km North-east of Alldays in South Africa. Venetia is an open pit, truck and shovel operation which commenced full production in 1993. Mining began on the Cut 4 design in 2006 with a final planned open pit depth of approximately 500m below surface at a maximum waste stripping rate of approximately 50 million tonnes per annum.
The country rock assemblages at Venetia are part of the Limpopo Mobile Belt and mainly consist of metamorphic and intrusive igneous rocks. The stability of the pit is structurally controlled and the structure can be divided into two main components, ductile structure (foliation) and brittle structures (major structures and joints). A dominant metamorphic foliation cross cuts all the geology which results in an anisotropic rock mass strength. The interaction between the brittle jointing and foliation also locally impacts on bench stability and subsequent bench performance. The slope design is therefore highly dependent on the orientation of the pit slopes relative to structural features.
Up to 2009 Venetia mine employed high energy blasting techniques, mainly focused on achieving high production rates and optimum fragmentation, to develop the final walls of the pit. Excavating the highwalls with conventional production blasting techniques resulted in extremely poor highwall conditions. In 2009 this practice was ceased and the mine started experimenting with limit blasting techniques on the final pit limits. The benefit of the limit blasting was however not quantified. That same year a revision and optimisation of the business plan was undertaken of which one aspect was the review of the slope angles and design sectors. The acceptance criteria, as recommended by the Guidelines for Open Pit Slope Design (Read and Stacey, 2009) were used by De Beers to determine the acceptable level of risk for the optimisation programme.
Rigorous reviews of actual pit slope performance were conducted for the North and Southern slopes. This indicated that the bench performance in the Southern slopes can be isolated to distinct areas. The South-western portion of the slope had the highest incidence of complete bench failures (43%) followed by the Southern section (17%). See Figure 2.1. In turn rock
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falls were prevalent in the North domain. This was aggravated by poor blasting resulting in the catch berms not being retained and thus not being effective at retaining rock falls. The mechanisms that initiated the variable bench performance and rock fall risk were not well understood at that stage.
The first Cut 4 slope stability design was conducted in 2008 and defined only two major domains [North: 56⁰ stack angle, South: 40⁰ stack angle] (Contreras, 2008). The South slope design assumed a slope striking parallel to the orientation of the foliation. The analysis indicated that steeper stack angles are achievable in the North domain however a lower slope angle was recommended due to the perceived rock fall risk and mining practices at the mine. The rock fall risk was however not quantified. Review of the data supplied by the operation to the consultant indicated that the orientation of the S2 foliation and joint populations were extrapolated from old exposures in Cut 2. In addition to the above no groundwater table was available for the first design in 2008.
Thus considering the improvement in mining practices, lack of understanding regarding the actual slope performance and extrapolated data that was used in the design the author deemed it appropriate to re-evaluate the Cut 4 design in 2009. The optimisation study was scoped by the author and consisted of various phases (1 – 3).
Phase 1 was aimed at providing initial input parameters into the strategic business plan (SBP) regarding slope angles (savings on waste stripping) (Strouth, 2009; Gomez, 2010) and bench heights (potential to increase productivity) (Contreras, 2010; Steffen and Terbrugge, 2009). The only new data for this phase was limited scan line mapping that was collected by the mine in the South-western quadrant of the pit and thus similar constraints relating to the orientation of the S2 foliation, joint sets and groundwater applied.
Phase 2 ran concurrently with the above work and was aimed at defining the orientation of the S2 foliation, joint data and pore pressures in the toe of the slope. This phase consisted of structural mapping, drilling, instrumentation installation; and modelling of the geology and ground water table by Basson (2011a) and Liu et al. (2011) respectively.
For the final phase of the optimisation (Phase 3) the Geotechnical domain model and slope design was updated using the results from Phase 2 of the study. The updated design incorporated the updated groundwater table and considered the orientation of the pit slopes relative to the foliation; and consisted of bench, inter-ramp and overall slope analyses.
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Probabilistic limit equilibrium bench analyses were conducted by the author for every practical orientation of each domain, at various bench heights, using SWISA™ and PFISA™. For the inter-ramp and overall slope design limit equilibrium probabilistic analysis were conducted using the programme SLIDE™. The anisotropic strength model in SLIDE™ was used to account for the S2 foliation.
The bench and inter-ramp analyses indicated that steeper angles are viable in a number of domains. The stability of the pit walls in the Southern domains is mainly controlled by their orientation in relation to the major S2 foliation. In contrast the stack angle in the North domain is not controlled by the S2 foliation and/or rock mass strength. Here the interaction between brittle jointing controls the maximum catch berm and subsequent stack angle. The numerical finite difference code, FLAC™, was used to validate the results of the limit equilibrium stack analysis. The validation indicated that the limit equilibrium modelling is conservative when compared to numerical modelling and it is recommended that future studies use the response surface methodology by Chiwaye and Stacey (2010), whereby numerical modelling is used, to estimate the risk (probability of failure).
Strategies to monitor the quality of mining practices and related rock fall risk have also been developed and incorporated into the Code of Practice and related standard operating procedures for the operation.
The results of the optimisation project was included into the mine’s strategic business plan in 2011 and resulted in significant financial savings
Mobile Press-Register sleeve MP0053760
No full textDinner party given by Billie Goodloe, honoring author Roy Simmonds / (2151 Venetia Road
Le imprese illvstri : con espositioni et discorsi /
No full textReference to Christopher Columbus and Sebastian Cabot, leaf 22.Includes "Tavola de personaggi di cvi sono l'imprese," [dagger]3v-[dagger]4r.Engraved t.p. and double-page ill. on 2L2v-2L3r signed by Domenico Zenoi. The t.p. incorporates the arms of Philip II, to whom the work is dedicated. The ill. on 2L2v-2L3r depicts the army of Charles V crossing the Elbe at Mühlberg and is adapted from an engraving by Enea Vico; see Mortimer. Engraved port. of author, [dagger]4v. Special engraved t.p.'s for libri 2-3. Decorated and historiated initials.Signatures: [dagger]⁴ A-3D⁴ 3E² ²3C-4C⁴.Printer from colophon.Originally published: Venice, 1566. For a comparison with that ed. see Mortimer.Scanned copy bound with: Il qvarto libro delle imprese illvstri / con figvre di stampe di rame aggivnto da Vincenzo Rvscelli da Viterbo. In Venetia : [F. de Franceschi], l'anno MDLXXXIII 1583.Mortimer, R. Italian 16th-cent.,Mode of access: Internet.The letters MB written on t.p. verso, with a continuation now covered by mounted paper slip. Partial impression in red ink of two inverted lines of type at foot of G3r. Inscription in blue ink on back pastedown: Inc Leonard Baskin.Modern rebinding, retaining the old vellum. Title and author written on spine. Holes for 2 pairs of ties at foredge. Page edges gilt.Bound with: Il qvarto libro delle imprese illvstri / con figvre di stampe di rame aggivnto da Vincenzo Rvscelli da Viterbo. In Venetia : [F. de Franceschi], l'anno MDLXXXIII 1583. (2928-626
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