Podcasts about dingwell

Chris Dingwell has been tattooing a long time. Chris Dingwell has been painting a long time. In today's episode, we sit down with Chris to discuss his approach to tattooing and how painting and other fine art mediums have molded him into the tattooer he is today. Enjoy! Join Chris at the Paradise Tattoo Gathering October 12-15, 2023! https://tattoogathering.com/ Join us in the Inside Fireside Tattoo Club https://explore.firesidetattoo.com/inside-fireside Or simply sign up for Tattoo Tips Tuesday! It's free! https://www.firesidetattoo.com/tattoo-library/tattoo-tips-tuesday~29102   Keep up with us at: https://firesidetattoo.com/ https://www.patreon.com/Fireside https://www.facebook.com/FiresideTattoo/ https://www.instagram.com/firesidetattoo/ Jake's Instagram: https://www.instagram.com/pluguglyart/

Chris Dingwell joins us this week to talk about his start in the industry, his upcoming seminars at the Paradise Tattoo Gathering, and explain a bit of how tattooing happens at the microscopic level and how we can use that knowledge to make better tattoos.

Blue Gum Farm's new Principal Sean Dingwall joins Michael Felgate in the studio to chat about their plans moving into the future and some exciting things they have on their agenda

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.02.24.529927v1?rss=1 Authors: Desmet, D. M., Kazanski, M. E., Cusumano, J. P., Dingwell, J. B. Abstract: Background: Walking requires frequent maneuvers to navigate changing environments with shifting goals. Humans accomplish maneuvers and simultaneously maintain balance primarily by modulating their foot placement, but a direct trade-off between these two objectives has been proposed. As older adults rely more on foot placement to maintain lateral balance, they may be less able to adequately adapt stepping to perform lateral maneuvers. Research Question: How do older adults adapt stepping to enact lateral lane-change maneuvers, and how do physical and perceived ability influence their task performance. Methods: Twenty young (21.7 {+/-} 2.6 yrs) and 18 older (71.6 {+/-} 6.0 yrs) adults walked on a motorized treadmill in a virtual environment. Following an audible and visual cue, participants switched between two parallel paths, centered 0.6m apart, to continue walking on their new path. We quantified when participants initiated the maneuver following the cue, as well as their step width, lateral position, and stepping variability ellipses at each maneuver step. Results: Young and older adults did not differ in when they initiated the maneuver, but participants with lower perceived ability took longer to do so. Young and older adults also did not exhibit differences in step width or lateral positions at any maneuver step, but participants with greater physical ability reached their new path faster. While only older adults exhibited stepping adaptations prior to initiating the maneuver, both groups traded-off stability for maneuverability to enact the lateral maneuver. Significance: Physical and perceived balance ability, rather than age per se, differentially influenced maneuver task performance. Humans must make decisions related to the task of walking itself and do so based on both physical and perceived factors. Understanding and targeting these interactions may help improve walking performance among older adults. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

What do you get when you mix two creative people, a beautiful New Mexico landscape and the magic of hat-making? Meet Charlie Overbey and Vanessa Dingwell of Lone Hawk Hats and Honey Vintage, some of the newest residents of Madrid, NM. They're story and how they ended up in Madrid is truly fascinating! Check it out in this episode. LinksLone Hawk HatsHoneywood VintageCharlie Overbey musicBunny's websiteBuy Bunny's book on AmazonI Love New Mexico InstagramI Love New Mexico FacebookOriginal Music by: Kene Terry  Original Music by: Kene Terry

In 2012 SDSU football won their first Mountain West Championship. Ten years later, the guys sit down with the QB who led the Aztecs that year and to arguably the most excitin game in San Diego State history—Adam Dingwell.

In 2012 SDSU football won their first Mountain West Championship. Ten years later, the guys sit down with the QB who led the Aztecs that year and to arguably the most excitin game in San Diego State history—Adam Dingwell.

Ms. Dingwall, Mr. Russell, and Mr. Richet, the three appellants, were convicted of aggravated assault and various firearm offences in connection to a drive-by shooting. At trial, the Crown's case was based on circumstantial evidence. The trial judge concluded that Mr. Russell and Mr. Richet were guilty as principals or aiders or abettors for all charges. Ms. Dingwall was found guilty as an aider or abettor for the charges relating to the drive-by shooting and as a principal or aider or abettor for the charges related to the burning of a truck.The three appellants appealed their respective convictions. The majority of the Court of Appeal for British Columbia dismissed the appeals. It held that the verdicts were not unreasonable. In dissent, Butler J.A. disagreed with the disposition of Ms. Dingwell's appeal related to the drive-by shooting charges. Ms. Dingwall's participation in the offences were not the only rational inference on the evidence. The verdict was therefore unreasonable.Ms. Dingwell appealed to the Supreme Court of Canada as of right.

The tragic life and death of Christine Chubbuck gets dramatized in Christine. Our pal Rebecca Dingwell joins us as we discuss this deeply sad movie, internet gore vultures, the perils of writing a bio flick, and the lack of mental health support in journalism. Warning to our listeners: This episode features a frank discussion about both suicide and depression. Box Office Bylines is a podcast about movies about journalism. How many damn Batmens do we have to learn in our lives? Email us if you know the answer at boxofficebylines@gmail.com Follow us on the old bird box (AKA Twitter): @BoxBylines (don’t ask) @rwjboon @BDingz Theme Music: Dance Movie (dancemovie.bandcamp.com) If you’re a fan of this show please consider leaving a five-star review on your favourite podcast platform so Tara can finally stop talking about Joker.

Bruce will be speaking from Luke 12, where Jesus speaks to his disciples (and us) about how to navigate difficult and anxious times, which will be an important message for us all.

I’m sure I’ve mentioned several times the perinatal depression I’ve been experiencing over the first and now second trimester of my first pregnancy. Every time I talk about this I have mixed emotions. A part of me is a little ashamed and guilty for feeling this way, but at the end of the day, it always pays off because whoever I am speaking to always has such valuable insight on what I am going through because they’ve usually gone through something similar. This week, I had the privilege of speaking with Kelly Dingwell, who is a healthcare lawyer in California and a mother of two. We talk a little bit about productivity and how that really supports our mental and professional health, and we delve into how to deal with uncontrollable barriers that not even some of the best productivity tools can help with. How do you deal with those situations? That’s what we talk about. We get real and raw, so if you are all about talking about the things that make me feel ashamed as an expecting mother and as a lawyer, this is it.   Show notes:   Instagram: @kellydingwell LinkedIn: Kelly Dingwell Email: kelly@dingwell-law.com  

Kampf um die Supercomputer - Verliert Deutschland den Anschluss? / Digitalisierter Alexander von Humboldt - Wie Forscher seine Reisetagebücher ergründen / Dreckschleudern auf hoher See - Wie können Schiffsmotoren umweltfreundlicher werden? / Ausgefragt - 180 Sekunden mit dem Vulkanologen Donald Dingwell.

Volcanic activity has been a continuous companion to mankind. A century ago, experimental Earth science began to redefine our understanding of the Earth’s interior. Although physical volcanology had been exclusively observational, new experimental science is making vast advances in the science of eruptive processes. Dr. Dingwell will guide us through some of the highlights of the last quarter century of experimental volcanology. Co-hosted by the Carnegie Institution for Science with the Embassy of Austria, the Embassy of Switzerland, and the Delegation of the European Union to the United States.

Dance on a Volcano: A Quarter Century of Experimental First Ascents Dr. Donald B. Dingwell, Secretary General of the European Research Council, President of the European Geosciences Union, Ludwig-Maximilians University Munich, Department of Earth and Environmental Science Volcanic activity has been a continuous companion to mankind. A century ago, experimental Earth science began to redefine our understanding of the Earth's interior. Although physical volcanology had been exclusively observational, new experimental science is making vast advances in the science of eruptive processes. Dr. Dingwell will guide us through some of the highlights of the last quarter century of experimental volcanology. Co-hosted by the Carnegie Institution for Science with the Embassy of Austria, the Embassy of Switzerland, and the Delegation of the European Union to the United States.

Abstract The shear viscosity, density, thermal expansivity and specific heat capacity are important factors controlling the morphology, rheology, and texture of volcanic flows and deposits. These physical properties of silicate melts largely depend on chemical composition, water content, crystal content, bubble content and stress applied to the melt. Recently, it has been recognized that the applied stress plays an important role in the so called “glass transition” area of silicate melts. This kinetic boundary between brittle and ductile behavior affects the eruptive style. Thorough knowledge of the physical processes that occur at this brittle/ductile transition can affect the decision making of governments during volcanic crises and help to reduce and/or avoid loss of life and assets. Scientific knowledge from this research can be directly applied to the geomaterial industry. In addition, natural magmatic rocks are the major raw material in the production of microfibres and continuous fibres. Compared to normal glass fibres, rock fibres have a remarkable high temperature endurance, acid and alkali resistance and anti-heat impact. Rock products can be used as substitutes for metal and timber. They are likely to become more widely used in the near future. Further use for natural magmatic rocks include crushed stone, concrete aggregate, railroad ballast, production of high quality textile fibres, floor tiles, acid-resistant equipment for heavy industrial use, rockwool, basalt pipers, basalt reinforcement bars, basalt fibre roofing felt (ruberoid), basalt laminate (used as a protective coating), heat-insulating basalt fibre materials and glass wool (fibre glass). Since Bottinga and Weill (1970) first suggested that the density of melts in two or three component systems could be used to determine partial molar volumes of oxide components in silicate liquids, several models based upon this approach have been proposed in the Earth sciences literature. Considering that knowledge the densities of 8 Zn-bearing silicate melts have been determined, in equilibrium with air, in the temperature range of 1363 to 1850 K. The compositional joins investigated [sodium disilicate (NS2)- ZnO; anorthite-diopside 1 atm eutectic (AnDi)-ZnO; and diopside-petedunnite] were chosen based on the pre-existing experimental density data set, on their petrological relevance, and in order to provide a test for significant compositionally induced variations in the structural role of ZnO. The ZnO concentrations investigated range up to 25 mol% for sodium disilicate, 20 mol% for the anorthite-diopside 1 atm eutectic, and 25 mol% for petedunnite. Molar volumes and expansivities have been derived for all melts. The molar volumes of the liquids decrease with increasing ZnO content. The partial molar volume of ZnO derived from the volumetric measurements for each binary system is the same within error. A multicomponent fit to the volumetric data for all compositions yields a value of 13.59(0.55) cm3/mol at 1500 K. I find, no volumetric evidence for compositionally induced coordination number variations for ZnO in alkali-bearing vs. alkali-free silicate melts nor for Al-free vs. Al-bearing silicate melts. The partial molar volume of ZnO determined here may be incorporated into existing multicomponent models for the prediction of silicate melt volume. High temperature density determinations on ZnO-bearing silicate melts indicate that a single value for the partial molar volume of ZnO is sufficient to describe the volumetric properties of this component in silicate melts. The presence of alkalies and Al does not appear to influence the partial molar volume of ZnO within the temperature range investigated here. There is no volumetric evidence across this temperature range presented for composition to influence the coordination polyhedron of ZnO in silicate melts. The next physical property to be studied was thermal expansivity. Ten compositions from within the anorthite-wollastonite-gehlenite (An-Wo-Geh) compatibility triangle were investigated. Due to the lack of information about the thermal expansivities at supercooled liquid temperatures this study focused on the measurement of thermal expansivity using a combination of calorimetric and dilatometric methods. The volumes at room temperature were derived from densities measured using the Archimedean buoyancy method. For each sample density was measured at 298 K using glass that had a cooling-heating history of 10-10 K min-1. The thermal expansion coefficient of the glass from 298 K to the glass transition interval was measured by a dilatometer and the heat capacity was measured using a differential scanning calorimeter from 298 to 1135 K. The thermal expansion coefficient and the heat flow were determined at a heating rate of 10 K min-1 on glasses that were previously cooled at 10 K min-1. Supercooled liquid density, molar volume and molar thermal expansivities were indirectly determined by combining differential scanning calorimetric and dilatometric measurements assuming that the kinetics of enthalpy and shear relaxation are equivalent. The data obtained on the supercooled liquids were compared to high-temperature predictions from the models of Lange and Carmichael (1987), Courtial and Dingwell (1995) and Lange (1997). The best linear fit combines the supercooled liquid data presented in this study and the high temperature data calculated using the Courtial and Dingwell (1995) model. This dilatometric/calorimetric method of determining supercooled liquid molar thermal expansivity greatly increases the temperature range accessible for thermal expansion. It represents a substantial increase in precision and understanding of the thermodynamics of calcium aluminosilicate melts. This enhanced precision demonstrates clearly the temperature independence of the melt expansions in the An-Wo-Geh system. This contrasts strongly with observations for neighboring system such as Anorthite-Diopside and raises the question of the compositional/structural origins of the temperature dependence of thermal expansivity in multicomponent silicate melts. In addition, the partial molar volumes and the thermal expansivities of 10 samples from within the An-Wo-Geh compatibility triangle have been determined. They have been incorporated into existing multicomponent models in order to predict silicate melt volume. The resulting supercooled liquid volumes near glass transition temperatures (1135 - 1200 K) and at superliquidus temperature were combined to yield temperature independent thermal expansivities over the entire temperature range. In light of results presented in this study, together with the published data, it seems that binary and ternary systems have temperature independent thermal expansivities from the supercooled liquid to the superliquidus temperature at 1 atmosphere. By combining the high temperature densitometry data (i.e., above liquidus) from the literature with volume and expansivity data obtained at Tsc, a wide temperature range is covered. There is no volumetric evidence across this temperature range for temperature independent thermal expansivities in the An-Wo-Geh compatibility triangle. Furthemore, the thermal expansivities of three multicomponent glasses and liquids have been obtained over a large temperature interval (298 - 1803 K) which involved combining the results of low and high temperature measurements. The sample compositions investigated were derived from three natural lavas; Vesuvius 1631 eruption, Etna 1992 eruption and an Oligocene-Miocene lava flow from Slapany in the Bohemian massif. The original rocks are tephri-phonolite, trachybasalt and basanite, respectively. This is the first time this calorimetric/dilatometric method has ever been applied to natural magmatic melts. The low temperature volumes were derived from measurements of the glass density of each sample after cooling at 5 K.min-1 at 298 K, followed by measurements of the glass thermal expansion coefficient from 298 K to the samples´ respective glass transition interval. Supercooled liquid volumes and molar thermal expansivities were determined by combining scanning calorimetric and dilatometric measurements, assuming that the kinetics of enthalpy and shear relaxation are equivalent (Webb, 1992). High temperature densities were measured using Pt double bob Archimedean densitometry. In addition, the oxidation state of iron was analyzed using a wet chemistry method. Small amounts of samples were taken from the liquids using a “dip” technique at regular temperature steps during high temperature densitometry. The measured high temperature densities have been compared with predicted densities across the same temperature interval calculated using the multicomponent density models of Lange and Carmichael (1987) and Lange (1997). The resulting data for liquid volumes near glass transition temperatures (993 - 1010 K) and at super-liquidus temperatures (1512 - 1803 K) are combined to yield temperature dependant thermal expansivities over the entire supercooled and stable liquid range. These results confirm the observation of Knoche et al. (1992a); Knoche et al. (1992b); Toplis and Richet (2000); Liu and Lange (2001); Gottsmann and Dingwell (2002) of the temperature dependence of thermal expansivity. The molar volumes indicate, in general, a significant negative temperature dependence of the expansivity. The thermal molar expansivity of the glasses increase from SiO2-poor (basalt-basanite composition) to relatively SiO2-rich melts (tephri-phonolite composition). The thermal molar expansivity at supercooled liquid temperatures increases in the same manner as the glasses. In contrast, the thermal molar expansivity of the superliquidus liquid decrease from SiO2-poor to relatively SiO2-rich melts. Non-linear dependency of molar volume has been observed for all studied samples above the glass transition area. Molar volume from just above the glass transition area to about 1873 K can be predicted by a non-linear logarithmic curve. This study examined the expansivities and molar volumes of relatively basic compositions. Extending such a study to more SiO2-rich, but still geologically relevant, compositions remains a challenge, because the high viscosities of such melts preclude the use of immersion techniques. This problem can be solved using a high temperature densitometry where the volume is measured on levitated sample. I would like to urge studies of this sort in the future. Results from such studies should provide important information regarding a number of geological processes, which occur in such extremely high viscous liquids. A new viscosity measurement for melts spanning a wide range of anhydrous compositions including: rhyolite, trachyte, moldavite, andesite, latite, pantellerite, basalt and basanite are discussed in the last chapters. Micropenetration and concentric cylinder viscometry measurements cover a viscosity range of 10-1 to 1012 Pas and a temperature range from 973 to 1923 K. These new measurements, combined with other published data, provide a high-quality database comprising ~800 experimental data on 44 well -characterized melt compositions. This database is used to recalibrate the model proposed by Giordano and Dingwell [Giordano, D., Dingwell, D. B., 2003a. Non-Arrhenian multicomponent melt viscosity: a model. Earth Planet. Sci. Lett. 208, 337–349] for predicting the viscosity of natural silicate melts. The recalibration shows that: a) the viscosity (η)–temperature relationship of natural silicate liquids is very well represented by the VFT equation [log η=A+B/ (T−C)] over the full range of viscosity considered here, b) the use of a constant high-T limiting value of melt viscosity (e.g., A) is fully consistent with the experimental data. There are 3 different compositional suites (peralkaline, metaluminous and peraluminous) that exhibit different patterns in viscosity, the viscosity of metaluminous liquids is well described by a simple mathematical expression involving the compositional parameter (SM) but the compositional dependence of viscosity for peralkaline and peraluminous melts is not fully controlled by SM. For these extreme compositions we refitted the model using a temperature-dependent parameter based on the excess of alkalies relative to alumina (e.g., AE/SM). The recalibrated model reproduces the entire database to within 5% relative error. On the basis of this extended database the T-variation of the viscous response of strong and fragile liquids within a wide range of compositions shows three clearly contrasting compositional suites (peralkaline, metaluminous and peraluminous). As a result, I present an extended model to calculate the viscosity of silicate melts over a wide range of temperatures and compositions. This model constitutes a significant improvement with respect to the Giordano and Dingwell (2003a) study in that: 1) The number of experimental determinations over which the model is calibrated is larger. 2) The range of investigated compositions is larger. 3) The investigated temperature range is larger. 4) The assumption is made that at infinite temperature, the viscosity of silicate melts converges to a common, but unknown value of the pre-exponential factor (A=−4.07, Equation (7.1)). In particular the compositional range involves a large number of viscosity determinations for peralkaline and peraluminous compositions in a temperature interval between 949 and 2653 K. Furthermore, it is shown that the assumption of a common value of the pre-exponential parameter A produces an equally good representation of the experimental data as that produced by each melt having its own specific A-value. This optimization also induces a strong coupling between data sets that stabilizes the range of solutions and allows the different rheological behaviour of extreme compositions (peralkaline and peraluminous vs. metaluminous) to be discriminated. It was demonstrated that, although the parameter SM (Giordano and Dingwell, 2003a) can be used to model compositional controls on the viscosities of metaluminous liquids, it does not capture the viscosity of peralkaline and peraluminous liquids. The differences in the rheological behaviour of these extreme compositions reflect important differences in the structural configuration of metaluminous, peralkaline and peraluminous melts. Subsequently, a second regression of the experimental data was performed involving a second compositional parameter (AE) that accounts for the excess of alkali oxides over the alumina. Incorporating this temperature-dependent compositional parameter (i.e., AE) into the SM-based model (Equation 7.7) appears to account for the anomalous rheological behaviour of peralkaline and peraluminous liquids. The resulting model reproduces the entire experimental database to within an average RMSE of 0.45 log units. The model presented here is recommended for the estimation of the viscosity of anhydrous multicomponent silicate melts of volcanic interest.

The main objective of this study is to investigate and model the viscosity of multicomponent natural silicate melts and constrain the compositional effects which affect such a parameter. The results of this study, relevant to all petrological and volcanological processes which involve some transport mechanism, will be applied to volcanic setting. An extensive experimental study was performed, which constituted the basis for the general modelling of Newtonian viscosity in terms of composition and temperature. Composition, viscosity and density of selected samples were investigated at different water contents. The experimental method involved measuring the viscosity of dry and hydrated melts under superliquidus and supercooled conditions. In the high temperature range (1050 – 1600 °C) viscosities from 10-0.5 to 105 Pa·s were obtained using a concentric cylinder apparatus. Measurements of both dry and hydrated samples in the low temperature (616-860 °C) - high viscosity (108.5 – 1012 Pa·s) interval, from glassy samples quenched after high temperature viscometry, were performed using the dilatometric method of micropenetration. Hydrated samples measured in the supercooled state were synthesized, using a piston cylinder apparatus, between 1100° and 1600° C at 10 kbar. Water contents were measured using the Karl Fischer Titration (KFT) method. Fourier-Transform Infrared (FTIR) spectroscopy was used before and after the experiments in order to check that the water content was homogeneously distributed in the samples and that water had not been lost. Major element compositions of the dry remelted samples were determined using an electron microprobe. Newtonian viscosities of silicate liquids were investigated in a range between 10-1 to 1011.6 Pa s and parameterised using the non-linear 3 parameter (ATVF, BTVF and T0) TVF equation. The data provided in this work are combined also with previous data from Whittington et al. (2000, 2001); Dingwell et al. (1996); Neuville et al. (1993). There are strong numerical correlations between parameters (ATVF, BTVF and T0) that mask the effect of composition. Wide ranges of ATVF, BTVF and T0 values can be used to describe individual datasets. This is true even when the data are numerous, well-measured and span a wide range of experimental conditions. In particular, “strong” liquids (liquids that are Arrhenian or slightly deviate from Arrhenian behaviour) place only minor restrictions on the absolute ranges of ATVF, BTVF and T0. Therefore, strategies for modelling the effects on compositions should be built around high-quality datasets collected on non-Arrhenian liquids. x The relationships between important quantities such as the fragility F, characterizing the deviation from Arrhenian rheological behaviour, are quantified in terms of the chemical, structure-related parameter NBO/T. Initial addition of network modifying elements to a fully polymerised liquid (i.e. NBO/T=0) results in a rapid increase in F. However, at NBO/T values above 0.4-0.5 further addition of a network modifier has little effect on fragility. This parameterisation indicates that this sharp change in the variation of fragility with NBO/T is due to a sudden change in the configurational properties and rheological regimes, owing to the addition of network modifying elements. The resulting TVF parameterisation has been also used to build up a predictive model for Arrhenian to non-Arrhenian melt viscosity. The model accommodates the effect of composition via an empirical parameter called here the “structure modifier” (SM). SM is the summation of molar oxides of Ca, Mg, Mn, half of the total iron Fetot, Na and K. This approach is validated by the highly predictive capability of the viscosity model. The model reproduces all the original data set with about 10%, of the measured values of logη over the entire range of composition in the temperature interval 700-1600 °C. The combination of calorimetric and viscosimetric data has enabled a simple expression to be used to predict shear viscosity at the glass transition, that is the temperature which defines the transition from a liquid-like to a solid-like rheological behaviour. The basis for this stems from the equivalence of the relaxation times for both enthalpy and shear stress relaxation in a wide range of silicate melt compositions (Gottsmann et al., 2002). A shift factor that relates cooling rate data with viscosity at the glass transition appears to be slightly dependent on the melt composition. Finally, the effect of water content on decreasing the viscosity of silicate melts has also been parameterised using a modified TVF expression (Giordano et al., 2000). This leads to an improvement in our knowledge of the non-Arrhenian behaviour of silicate melts over a wide compositional range from basaltic to rhyolitic and from trachytic to peralkaline phonolite compositions in the temperature interval pertaining to volcanic and subvolcanic processes. The viscosities of natural hydrous basaltic liquids are shown to be lower than those of hydrous phonolites, whereas thachytes show viscosity that are higher than those of phonolites and lower that those of rhyolites. This is consistent with the style of eruption associated with these compositions, with trachytes generating eruptions that are dominantly explosive (e.g. xi Phlegrean Fields volcano), compared to the highly explosive style of rhyolitic volcanoes, the mixed explosive-effusive style of phonolitic volcanoes (e.g. Vesuvius) and the dominantly effusive style of basalts. Variations in composition between the trachytes translate into differences in liquid viscosity of nearly two orders of magnitude in dry conditions, and less than one order of magnitude in hydrous conditions. These differences increase significantly when the estimated eruptive temperatures of different eruptions at Phlegrean Fields are taken into account. At temperatures close to those of natural magmas and in the case of low viscosity hydrous liquids the uncertainty of the calculations is large, although it cannot be quantified, due to a lack of measurements under these conditions.

Sat, 1 Jan 1994 12:00:00 +0100 http://epub.ub.uni-muenchen.de/6044/ http://epub.ub.uni-muenchen.de/6044/1/6044.pdf Mungall, Jim; Dingwell, Donald B. Mungall, Jim und Dingwell, Donald B. (1994): Effects of water content, temperature and pressure on actinide tracer diffusion in melts of haplogranitic composition. In: Mineralogical Magazine, Vol. 58A, Nr. L-Z: pp. 636-637.

Sat, 1 Jan 1994 12:00:00 +0100 http://epub.ub.uni-muenchen.de/6045/ http://epub.ub.uni-muenchen.de/6045/1/Dingwell_Donald_6045.pdf Romano, Claudia; Dingwell, Donald B.; Sterner, S. Michael Romano, Claudia; Dingwell, Donald B. und Sterner, S. Michael (1994): Kinetics of quenching of hydrous feldspathic melts: Quantification using synthetic fluid inclusions. In: American Mineralogist, Vol. 79, Nr. 11-12: pp. 1125-1134.

The effect of P2O5 on the viscosity of a haplogranitic (K2O-Na2O-Al2O3-SiO2) liquid has been determined at 1 atm pressure in the temperature interval of 700 - 1650°C. Viscosity measurements of a haplogranite, haplogranite + 5.1 wt.% P2O5 and haplogranite + 9.5 wt.% P2O5 have been performed using the concentric cylinder and micropenetration methods. The viscosity of haplogranite liquid decreases with the addition of P2O5 at all temperatures investigated. The viscosity decrease is nonlinear, with the strongest decrease exhibited at low P2O5 concentration. The temperature-dependence of the viscosity of all the investigated liquids is Arrhenian, as is the case for P2O5 liquid. The Arrhenian activation energy is slightly lower in the P2O5-bearing liquids than in the P2O5-free haplogranite with the result that the effect of P2O5 on viscosity is a (weak) function of temperature. At temperatures corresponding to the crystallization of phosphorus-rich granitic and pegmatitic systems the addition of 1 wt.% of P2O5 decreases the viscosity 0.2 log10 units. The effect of P2O5 on haplogranitic melt viscosity is much less than that for B2O3, F2O−1 on the same melt composition (Dingwell et al., 1992 and this study). This implies that P2O5 concentration gradients in high-silica melts during, for example, phosphate mineral growth or dissolution in granitic magmas, will not significantly influence melt viscosity.

Fri, 1 Jan 1993 12:00:00 +0100 http://epub.ub.uni-muenchen.de/6037/ http://epub.ub.uni-muenchen.de/6037/1/Dingwell_Donald_6037.pdf Bagdassarov, Nikolai; Dingwell, Donald B.; Webb, Sharon L. Bagdassarov, Nikolai; Dingwell, Donald B. und Webb, Sharon L. (1993): Effect of boron, phosphorus and fluorine on shear stress relaxation in haplogranite melts. In: European Journal of Mineralogy, Vol. 5, Nr. 3: pp. 409-425.

The densities of thirteen silicate liquids along the Na2SiO3-TiO2 and CaSiO3-TiO2 joins and six other titanium-bearing silicate liquids of the general formula TiSiO5 (where X = Li, Na, K, Rb, Cs, Ca, Sr, Ba) have been measured in equilibrium with air using the double Pt bob Archimedean method. The Na2SiO3-TiO2 join was investigated from 10–50 mole% TiO2 in the temperature range 1000–1150°C whereas the CaSiO3-TiO2 join was investigated from 10–80 mole% TiO2 in the temperature range of 1400–1625°C. Density increases with TiO2 content along both joins. Partial molar volumes of the binary endmembers, Na2SiO3 and CaSiO3, and of TiO2 have been computed. The partial molar volume of Na2SiO3 agrees well with that determined by Bockris et al. (1955). The partial molar volume of CaSiO3 is in disagreement with that of Tomlinson et al. (1958). The partial molar volume of TiO2 derived from a linear fit to the Na2SiO3-TiO2 join is 27.6(3) cm3/mole at 1150°C. The partial molar volume of TiO2 derived from linear extrapolation of the CaSiO3-TiO2 data to TiO2 at 1600°C is 24.3(4) cm3/mole. Comparison of the partial molar volume data from these binary joins with TiO2 liquid density data (Dingwell, 1991) requires the existence of a large positive excess volume in the Na2SiO3-TiO2 system at 1150°C.

The densitiesa nd thermal expansivitieso f boron-bearingh aplogranitic glassesa nd Iiquids have been determined using a combination of scanning .florimetry and dilatomelry. B2O3 reduces the density of haplogranitic liquids (at 750'C) from 2.295 t 0.006 g cm-r to 2.237 + 0.005 g cm-3 wirh the addition of 8.92 wt. Vo 82o,. These densities have been converted into molar volumes in the binary system haplogranite - BrO3. The partial molar volume of 8203, calculated from a linear fit to the data at 750oC, is ,10.30 + 0.77 cmr mole-r in these melts. This value compares with a molar volume of pure B2O3 at this temperature of M.36 x. 0.22 cm3 mole-l (Napolitano et ol. 1965), indicating a negative excess volume of mixing along the haplogranite - B2O3 join. In comparison, at l3moc, the addition ot Na2O to B2O3 reduces the panial molar volume of B2O3 from 46.6 to 32.3 cm3 mole-r ar 45 molego Na2O (Riebling 1966).T he densityr esultsr eported here, along with the viscosity-reducinge ffect of B2O3o n granitic melts (Dingwell et al, 1992),s hould both significantlya cceleratep rocesseso f crystal-melt fractionation and facilitate the evolution of extremely fractionated igneous systems.

Mon, 1 Jan 1990 12:00:00 +0100 http://epub.ub.uni-muenchen.de/6010/ http://epub.ub.uni-muenchen.de/6010/1/Dingwell_Donald_6010.pdf Dingwell, Donald B.; Webb, Sharon L. Dingwell, Donald B. und Webb, Sharon L. (1990): Relaxation in silicate melts. In: European Journal of Mineralogy, Vol. 2, Nr. 4: pp. 427-449. Geowissenschaften 0

Mon, 1 Jan 1990 12:00:00 +0100 http://epub.ub.uni-muenchen.de/6015/ http://epub.ub.uni-muenchen.de/6015/1/Dingwell_Donald_6015.pdf Dingwell, Donald B. Dingwell, Donald B. (1990): Shear viscosities of galliosilicate liquids. In: American Mineralogist, Vol. 75, Nr. 11-12: pp. 1231-1237. Geowissenschaften

Sun, 1 Jan 1989 12:00:00 +0100 http://epub.ub.uni-muenchen.de/6007/ http://epub.ub.uni-muenchen.de/6007/1/Dingwell_Donald_6007.pdf Dingwell, Donald B. Dingwell, Donald B. (1989): Shear viscosities of ferrosilicate liquids. In: American Mineralogist, Vol. 74, Nr. 9-10: pp. 1038-1044. Geowissenschaften

Sun, 1 Jan 1989 12:00:00 +0100 http://epub.ub.uni-muenchen.de/6005/ http://epub.ub.uni-muenchen.de/6005/1/Dingwell_Donald_6005.pdf Dingwell, Donald B. Dingwell, Donald B. (1989): Effect of fluorine on the viscosity of diopside liquid. In: American Mineralogist, Vol. 74, Nr. 3-4: pp. 333-338. Geowissenschaften

The densities of 10 melts in the CaO-FeO-Fe2O3-SiO2 system were determined in equilibrium with air, in the temperature range of 1200 to 1550°C, using the double-bob Archimedean technique. Melt compositions range from 6 to 58 wt% SiO2, 14 to 76 wt% Fe2O3 and 10 to 46 wt% CaO. The ferric-ferrous ratios of glasses drop-quenched from loop fusion equilibration experiments were determined by 57Fe Mössbauer spectroscopy. Melt densities range from 2.689 to 3.618 gm/cm3 with a mean standard deviation from replicate experiments of 0.15%. Least-squares regressions of molar volume versus molar composition have been performed and the root mean squared deviation shows that a linear combination of partial molar volumes for the oxide components (CaO, FeO, Fe2O3 and SiO2) cannot describe the data set within experimental error. Instead, the inclusion of excess terms in CaFe3+ and CaSi (product terms using the oxides) is required to yield a fit that describes the experimental data within error. The nonlinear compositional-dependence of the molar volumes of melts in this system can be explained by structural considerations of the roles of Ca and Fe3+. The volume behavior of melts in this system is significantly different from that in the Na2O-FeO-Fe2O3-SiO2 system, consistent with the proposal that a proportion of Fe3+ in melts in the CaO-FeO-Fe2O3-SiO2 system is not tetrahedrally-coordinated by oxygen, which is supported by differences in 57Fe Mössbauer spectra of glasses. Specifically, this study confirms that the 57Fe Mössbauer spectra exhibit an area asymmetry and higher values of isomer shift of the ferric doublet that vary systematically with composition and temperature (this study; Dingwell and Virgo, 1987, 1988). These observations are consistent with a number of other lines of evidence (e.g., homogeneous redox equilibria, Dickenson and Hess, 1986; viscosity, Dingwell and Virgo, 1987,1988). Two species of ferric iron, varying in proportions with temperature, composition and redox state, are sufficient to describe the above observations. The presence of more than one coordination geometry for Fe3+ in low pressure silicate melts has several implications for igneous petrogenesis. The possible effects on compressibility, the pressure dependence of the redox ratio, and redox enthalpy are briefly noted.

Thu, 1 Jan 1987 12:00:00 +0100 http://epub.ub.uni-muenchen.de/6000/ http://epub.ub.uni-muenchen.de/6000/1/6000.pdf Dingwell, Donald B.; Scarfe, Christopher M. Dingwell, Donald B. und Scarfe, Christopher M. (1987): Solubility of water in albite-melt determined by the weight-loss method: a Discussion. In: Journal of Geology, Vol. 95: pp. 583-584. Ge

Thu, 1 Jan 1987 12:00:00 +0100 http://epub.ub.uni-muenchen.de/5999/ http://epub.ub.uni-muenchen.de/5999/1/5999.pdf Dingwell, Donald B. Dingwell, Donald B. (1987): Melt viscosities in the system NaAlSi3O8-H2O-F2O-1. In: Mysen, Bjørn O. (Hrsg.), Magmatic processes: physicochemical principles. Geochemical Society: Special publication ; 1. Geochemical Soc., Dep. of Geosciences: Univ. Park, Pa., pp. 423-433. Geowissenschaften

Sun, 1 Jan 1984 12:00:00 +0100 http://epub.ub.uni-muenchen.de/5974/ http://epub.ub.uni-muenchen.de/5974/1/5974.pdf Dingwell, Donald B.; Harris, D.; Scarfe, Christopher M. Dingwell, Donald B.; Harris, D. und Scarfe, Christopher M. (1984): The solubility of water in melts in the system SiO2-Al2O3-Na2O-K2O at 1 to 2 kbars. In: Journal of Geology, Vol. 92: pp. 387-395. Geowis