Melting processes and mantle sources of lavas on Mercury

peer reviewe

Productive and Destructive Entrepreneurship in a Political Economy Framework

Recent research has highlighted the role of institutions in channeling entrepreneurs into activities with positive or negative effects on overall productivity. Embedding central elements from these theories into a political economy framework reveals the bilateral causal relation between entrepreneurs and institutions. Core features of the entrepreneur force us to view its effects on institutions as more than mechanic general equilibrium adjustments. Three analytically separate channels of influence are isolated, analyzed and exemplified. Entrepreneurs influence formal economic institutions through direct involvement in politics, by using their entrepreneurial talent to wield de facto political power and by altering the effect of formal institutions. We propose a parsimonious framework that incorporates these effects as well as the role of institutions in channeling entrepreneurial talent. We use examples from modern history as a real-world context to illustrate our framework

Das Nachspiel der Bopparder Fehde : Darstellung der Streitigkeiten im Erzstift Trier bei Gelegenheit der Coadjutorwahl des Markgrafen Jacob (II.) von Baden

vom Oberlehrer Dr. HoltzProgr. Nr. 15

Der Konflikt zwischen dem Erzstift Trier und der Reichsstadt Boppard insbesondere im Jahre 1497

Max HoltzGreifswald, Univ., Diss., 188

Melting processes and mantle sources of lavas on Mercury

© 2016 Elsevier B.V. The MESSENGER spacecraft provided geochemical data for surface rocks on Mercury. In this study, we use the major element composition of these lavas to constrain melting conditions and residual mantle sources on Mercury. We combine modelling and high-temperature (1320-1580 °C), low- to high-pressure (0.1 to 3 GPa) experiments on average compositions for the Northern Volcanic Plains (NVP) and the high-Mg region of the Intercrater Plains and Heavily Cratered Terrains (High-Mg IcP-HCT). Near-liquidus phase relations show that the S-free NVP and High-Mg IcP-HCT compositions are multiply saturated with forsterite and enstatite at 1450 °C - 1.3 GPa and 1570 °C - 1.7 GPa, respectively. For S-saturated melts (1.5-3 wt.% S), the multiple saturation point (MSP) is shifted to 1380 °C - 0.75 GPa for NVP and 1480 °C - 0.8 GPa for High-Mg IcP-HCT. To expand our experimental results to the range of surface compositions, we used and calibrated the pMELTS thermodynamic calculator and estimated phase equilibria of ~5800 compositions from the Mercurian surface and determined the P-T conditions of liquid-forsterite-enstatite MSP (1300-1600 °C; 0.25-1.25 GPa). Surface basalts were produced by 10 to 50% partial melting of variably enriched lherzolitic mantle sources. The relatively low pressure of the olivine-enstatite-liquid MSP seems most consistent with decompression batch melting and melts being segregated from their residues near the base of Mercury's ancient lithosphere. The average melting degree is lower for the young NVP (0.27 ± 0.04) than for the older IcP-HCT (0.46 ± 0.02), indicating that melt productivity decreased with time. The mantle potential temperature required to form Mercurian lavas and the initial depth of melting also decreased from the older High-Mg IcP-HCT terrane (1650 °C and 360 km) to the younger lavas covering the NVP regions (1410 °C and 160 km). This evolution supports strong secular cooling of Mercury's mantle between 4.2 and 3.7 Ga and explains why very little magmatic activity occurred after 3.7 Ga.status: publishe

Geschäftsmodelle zur Einbindung dezentraler Anlagen auf Haushaltsebene in Virtuelle Kraftwerke

Virtuelle Kraftwerke (VKW) bieten die Möglichkeit, den steigenden Flexibilitätsbedarf des Stromsystems durch die Bündelung dezentraler Erzeugungsanlagen, Speicher und steuerbarer Verbraucher zu decken. Insbesondere die Hebung noch unerschlossener dezentraler Flexibilitätspotenziale auf Haushaltsebene, die durch die Digitalisierung und die Verfügbakeit smarter Technologien ermöglicht wird, eröffnet voraussichtlich zukünftige Geschäftsfelder. In diesem Artikel werden die zu erwartenden technologischen und ökonomischen Entwicklungen skizziert und darauf aufbauend ein Analyserahmen für Geschäftsmodelle Virtueller Kraftwerke vorgestellt

Geschäftsmodelle zur Einbindung dezentraler Anlagen auf Haushaltsebene in Virtuelle Kraftwerke

Virtuelle Kraftwerke (VKW) bieten die Möglichkeit, den steigenden Flexibilitätsbedarf des Stromsystems durch die Bündelung dezentraler Erzeugungsanlagen, Speicher und steuerbarer Verbraucher zu decken. Insbesondere die Hebung noch unerschlossener dezentraler Flexibilitätspotenziale auf Haushaltsebene, die durch die Digitalisierung und die Verfügbakeit smarter Technologien ermöglicht wird, eröffnet voraussichtlich zukünftige Geschäftsfelder. In diesem Artikel werden die zu erwartenden technologischen und ökonomischen Entwicklungen skizziert und darauf aufbauend ein Analyserahmen für Geschäftsmodelle Virtueller Kraftwerke vorgestellt

EFEITO DE DIFERENTES CONCENTRAÇÕES DE BIODIESEL NO DESEMPENHO DE UM TRATOR EM OPERAÇÃO DE PREPARO DO SOLO - DOI: 10.12971/2179-5959.v02n02a05

O uso de combustíveis derivados de petróleo tem sido a maior fonte de energia mundial. Porem com as previsões de termino desse recurso tem se buscado novas fontes de energia que substituam parcialmente ou totalmente essa fonte. O presente estudo objetivou avaliar o desempenho de um trator agrícola com motor de ciclo Diesel utilizando misturas de biodiesel de soja e óleo diesel em conjunto trator/grade pesada realizando na operação de preparo do solo. O experimento foi realizado em Latossolo Vermelho Amarelo, onde o mesmo foi montado no delineamento de blocos casualizados em esquema de parcelas subdivididas com três repetições, onde as parcelas foram constituídas pelas misturas de biodiesel e óleo diesel (B5, B10, B25, B50, B75 e B100) e as subparcelas as profundidades de atuação da grade aradora (0,11; 0,13; 0,16; 0,18 m). Foram avaliadas as variáveis de desempenho força de tração, potência na barra de tração, consumo horário e específico e patinagem das rodas motrizes. Os resultados obtidos mostraram que a patinagem aumenta com o aumento da profundidade de trabalho, devido à maior exigência de potência do trator. O consumo específico diminuiu com o aumento da profundidade de trabalho. A força de tração e a potência na barra de tração reduzem quando há o aumento combinado dos fatores concentração de biodiesel na mistura e profundidade de trabalho