scholarly journals Thermobarometry and Geochemistry of Mantle Xenoliths from Zapolyarnaya Pipe, Upper Muna Field, Yakutia: Implications for Mantle Layering, Interaction with Plume Melts and Diamond Grade

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 755
Author(s):  
Igor Ashchepkov ◽  
Nikolay Medvedev ◽  
Nikolay Vladykin ◽  
Alexander Ivanov ◽  
Hilary Downes
Keyword(s):  
Alkali Metals ◽  
Mantle Xenoliths ◽  
Pressure Groups ◽  
Icp Ms ◽  
Melt Percolation ◽  
Pt Path ◽  
Two Stages ◽  
Diamondiferous Kimberlite ◽  
Very High ◽  
Feeding Systems

Minerals from mantle xenoliths in the Zapolyarnaya pipe in the Upper Muna field, Russia and from mineral separates from other large diamondiferous kimberlite pipes in this field (Deimos, Novinka and Komsomolskaya-Magnitnaya) were studied with EPMA and LA-ICP-MS. All pipes contain very high proportions of sub-calcic garnets. Zapolyarnaya contains mainly dunitic xenoliths with veinlets of garnets, phlogopites and Fe-rich pyroxenes similar in composition to those from sheared peridotites. PT estimates for the clinopyroxenes trace the convective inflection of the geotherm (40–45 mW·m−2) to 8 GPa, inflected at 6 GPa and overlapping with PT estimates for ilmenites derived from protokimberlites. The Upper Muna mantle lithosphere includes dunite channels from 8 to 2 GPa, which were favorable for melt movement. The primary layering deduced from the fluctuations of CaO in garnets was smoothed by the refertilization events, which formed additional pyroxenes. Clinopyroxenes from the Novinka and Komsomolskaya-Magnitnaya pipes show a more linear geotherm and three branches in the P-Fe# plot from the lithosphere base to the Moho, suggesting several episodes of pervasive melt percolation. Clinopyroxenes from Zapolyarnaya are divided into four groups according to thermobarometry and trace element patterns, which show a stepwise increase of REE and incompatible elements. Lower pressure groups including dunitic garnets have elevated REE with peaks in Rb, Th, Nb, Sr, Zr, and U, suggesting mixing of the parental protokimberlitic melts with partially melted metasomatic veins of ancient subduction origin. At least two stages of melt percolation formed the inclined PT paths: (1) an ancient garnet semi-advective geotherm (35–45 mW·m−2) formed by volatile-rich melts during the major late Archean event of lithosphere growth; and (2) a hotter megacrystic PT path (Cpx-Ilm) formed by feeding systems for kimberlite eruptions (40–45 mW·m−2). Ilmenite PT estimates trace three separate PT trajectories, suggesting a multistage process associated with metasomatism and formation of the Cpx-Phl veinlets in dunites. Heating associated with intrusions of protokimberlite caused reactivation of the mantle metasomatites rich in H2O and alkali metals and possibly favored the growth of large megacrystalline diamonds.

scholarly journals Portable DC Supply Based on SiC Power Devices for High-Voltage Marx Generator

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 313
Author(s):  
Jacek Rąbkowski ◽  
Andrzej Łasica ◽  
Mariusz Zdanowski ◽  
Grzegorz Wrona ◽  
Jacek Starzyński
Keyword(s):  
High Voltage ◽  
Specific Area ◽  
Input Voltage ◽  
Marx Generator ◽  
Power Devices ◽  
Laboratory Setup ◽  
High Voltage Gain ◽  
Main Components ◽  
Two Stages ◽  
Very High

The paper describes major issues related to the design of a portable SiC-based DC supply developed for evaluation of a high-voltage Marx generator. This generator is developed to be a part of an electromagnetic cannon providing very high voltage and current pulses aiming at the destruction of electronics equipment in a specific area. The portable DC supply offers a very high voltage gain: input voltage is 24 V, while the generator requires supply voltages up to 50 kV. Thus, the system contains two stages designed on the basis of SiC power devices operating with frequencies up to 100 kHz. At first, the input voltage is boosted up to 400 V by a non-isolated double-boost converter, and then a resonant DC-DC converter with a special transformer elevates the voltage to the required level. In the paper, the main components of the laboratory setup are presented, and experimental results of the DC supply and whole system are also shown.

scholarly journals The Electrical Conductivty Of Fe-Chitosan Schiff Base Complex

2020 ◽  
Vol 5 (2) ◽  
pp. 108
Author(s):  
Boy Chandra Sitanggang ◽  
Zainal Abidin
Keyword(s):  
Electrical Conductivity ◽  
Schiff Base ◽  
Immersion Time ◽  
Schiff Base Complex ◽  
High Electrical Conductivity ◽  
Fecl3 Solution ◽  
Icp Ms ◽  
Necked Flask ◽  
Two Stages ◽  
Chitosan Schiff Base

High electrical conductivity material Fe-Chitosan Schiff base produced via two stages mechanism, reaction of salicylaldehyde and chitosan in three necked flask following the formation of complex by soak Chitosan Schiff base in FeCl3 solution in various times. The formed Schiff base was confirmed by presence of imine at 1604.77 cm-1. Next, Fe absorption was analyzed by using ICP-MS gives highest results at 492,51 ppm at 5 hours immersion time. The electrical conductivity exhibit tendency to increase and the highest point at 3.5 x 10-6 S cm­-1

scholarly journals An Airport Knowledge-Based Method for Accurate Change Analysis of Airport Runways in VHR Remote Sensing Images

2020 ◽  
Vol 12 (19) ◽  
pp. 3163 ◽  
Author(s):  
Wei Ding ◽  
Jidong Wu
Keyword(s):  
Parallel Line ◽  
Extraction Methods ◽  
Analysis Method ◽  
Change Analysis ◽  
Multiple Features ◽  
Knowledge Based ◽  
Two Stages ◽  
Airport Runway ◽  
The Military ◽  
Very High

Due to the complexity of airport background and runway structure, the performances of most runway extraction methods are limited. Furthermore, at present, the military fields attach greater importance to semantic changes of some objects in the airport, but few studies have been done on this subject. To address these issues, this paper proposes an accurate runway change analysis method, which comprises two stages: airport runway extraction and runway change analysis. For the former stage, some airport knowledge, such as chevron markings and runway edge markings, are first applied in combination with multiple features of runways to improve the accuracy. In addition, the proposed method can accomplish airport runway extraction automatically. For the latter, semantic information and vector results of runway changes can be obtained simultaneously by comparing bi-temporal runway extraction results. In six test images with about 0.5-m spatial resolution, the average completeness of runway extraction is nearly 100%, and the average quality is nearly 89%. In addition, the final experiment using two sets of bi-temporal very high-resolution (VHR) images of runway changes demonstrated that semantic results obtained by our method are consistent with the real situation and the final accuracy is over 80%. Overall, the airport knowledge, especially chevron markings for runways and runway edge markings, are critical to runway recognition/detection, and multiple features of runways, such as shape and parallel line features, can further improve the completeness and accuracy of runway extraction. Finally, a small step has been taken in the study of runway semantic changes, which cannot be accomplished by change detection alone.

scholarly journals Two-Stage Late Jurassic to Early Cretaceous Hydrothermal Activity in the Sakar Unit of Southeastern Bulgaria

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 266
Author(s):  
Krzysztof Szopa ◽  
Anna Sałacińska ◽  
Ashley P. Gumsley ◽  
David Chew ◽  
Petko Petrov ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Late Jurassic ◽  
Hydrothermal Activity ◽  
Two Stage ◽  
Accessory Minerals ◽  
Icp Ms ◽  
Two Stages ◽  
Age Constraints ◽  
Hydrothermal Veins

Southeastern Bulgaria is composed of a variety of rocks from pre-Variscan (ca. 0.3 Ga) to pre-Alpine sensu lato (ca. 0.15 Ga) time. The Sakar Unit in this region comprises a series of granitoids and gneisses formed or metamorphosed during these events. It is cut by a series of post-Variscan hydrothermal veins, yet lacks pervasive Alpine deformation. It thus represents a key unit for detecting potential tectonism associated with the enigmatic Cimmerian Orogenic episode, but limited geochronology has been undertaken on this unit. Here we report age constraints on hydrothermal activity in the Sakar Pluton. The investigated veins contain mainly albite–actinolite–chlorite–apatite–titanite–quartz–tourmaline–epidote and accessory minerals. The most common accessory minerals are rutile and molybdenite. Apatite and titanite from the same vein were dated by U–Pb LA–ICP-MS geochronology. These dates are interpreted as crystallization ages and are 149 ± 7 Ma on apatite and 114 ± 1 Ma on titanite, respectively. These crystallization ages are the first to document two stages of hydrothermal activity during the late Jurassic to early Cretaceous, using U–Pb geochronology, and its association with the Cimmerian orogenesis. The Cimmerian tectono-thermal episode is well-documented further to the east in the Eastern Strandja Massif granitoids. However, these are the first documented ages from the western parts of the Strandja Massif, in the Sakar Unit. These ages also temporally overlap with previously published Ar–Ar and K–Ar cooling ages, and firmly establish that the Cimmerian orogeny in the studied area included both tectonic and hydrothermal activity. Such hydrothermal activity likely accounted for the intense albitization found in the Sakar Unit.

Responses to a long-chain fatty acid supplement fed to dairy cows at two stages of lactation

1991 ◽  
Vol 31 (4) ◽  
pp. 467 ◽  
Author(s):  
TM Davison ◽  
FP Vervoort ◽  
F Duncalfe
Keyword(s):  
Milk Yield ◽  
Dairy Herd ◽  
Early Lactation ◽  
Long Chain Fatty Acid ◽  
Stage Of Lactation ◽  
Holstein Friesian ◽  
Fatty Acid Supplement ◽  
Two Stages ◽  
Long Chain ◽  
Feeding Systems

A group of 36 Holstein-Friesian cows in a commercial dairy herd were used to test the effects on milk yield and composition of feeding 0.5 kg/day of a rumen-inert fat supplement containing long-chain fatty acids, given in addition to their normal ration. The group was divided into early and mid lactation cows, and the effect of the supplement was evaluated over a 12-week period of grazing predominantly kikuyu (Pennisetum clandestinum) pastures. There was a non-significant (P>0.05) trend to increased milk yield for cows in mid lactation (9% or 2.8 kg milk/kg fat supplement), no response in early lactation, and an overall response of 0.8 kg milk/kg fat supplement for all cows. There was no effect (P>0.05) of fat supplement on milk components. The lack of a milk response in the early lactation group is discussed in relation to the protein content of the diet and changes in liveweight. The varied responses with stage of lactation mean that feeding systems that can easily differentiate stages of lactation for cows would be required in dairies.

SUPER SEPARATOR SPECTROMETER FOR THE LINAG HEAVY ION BEAMS

2009 ◽  
Vol 18 (10) ◽  
pp. 2160-2168 ◽  
Author(s):  
A. DROUART ◽  
J. A. NOLEN ◽  
H. SAVAJOLS
Keyword(s):  
Electron Spectroscopy ◽  
Heavy Ion ◽  
High Energy ◽  
Ion Beams ◽  
Low Energy ◽  
Current Status ◽  
Secondary Reactions ◽  
Two Stages ◽  
Rotating Target ◽  
Very High

The Super Separator Spectrometer (S3) will receive the very high intensity heavy ion beams from the LINAG accelerator of SPIRAL2. Its privileged fields of physics are the delayed study of rare nuclei and secondary reactions with exotic nuclei. The project is presently in a phase of conceptual design. It includes a rotating target to sustain the high energy deposit, a two stages separator (momentum achromat) and spectrometer (mass spectrometer). Various detection set-ups are foreseen, especially a delayed α, γ, and electron spectroscopy array and a gas catcher coupled to a low energy branch. We present here the current status of the project and its main features.

scholarly journals Supplemental Material: Three-stage modification of lithospheric mantle: Evidence from petrology, in-situ trace elements, and Sr isotopes of mantle xenoliths in the Cenozoic basalts, northeastern North China Craton

2021 ◽  
Author(s):  
Xinran Xu ◽  
Yanjie Tang ◽  
et al.
Keyword(s):  
Trace Elements ◽  
North China Craton ◽  
North China ◽  
Major Element ◽  
Equilibrium Temperature ◽  
Mantle Xenoliths ◽  
Sr Isotopes ◽  
Temperature Estimation ◽  
Icp Ms

Table S1: Petrological information and equilibrium temperature estimation for the studied samples; Table S2: Major element compositions (wt%) of minerals; Table S3: Trace element concentrations (ppm) of Cpx in xenoliths determined by LA-ICP-MS; Table S4: In situ Sr isotopic compositions of Cpx in the xenoliths.

scholarly journals PELATIHAN PEMASARAN ONLINE DAN PENGEMBANGAN APLIKASI BERBASIS ANDROID UNTUK PENGEMBANGAN KEWIRAUSAHAAN ALUMNI

2021 ◽  
Vol 1 (1) ◽  
pp. 7-14
Author(s):  
Titis Shinta Dhewi ◽  
Syihabudhin Syihabudhin ◽  
Afwan Hariri Agus Prohimi ◽  
Dediek Tri Kurniawan
Keyword(s):  
Digital Technology ◽  
Digital Transformation ◽  
Online Marketing ◽  
Digital Marketing ◽  
The Public ◽  
Digital Era ◽  
Internet Penetration ◽  
Two Stages ◽  
Coaching Approach ◽  
Very High

Internet penetration in Indonesia has become an opportunity for business actors to increase their sales through online marketing. Especially in the field of marketing, the current digital era online marketing is becoming a very high trend among the public. In the midst of the development of digital technology, the team from Department of Management, Universitas Negeri Malang (UM) held training with a coaching approach for digital marketing. The target participants in this service are alumni of the management department on UM who own and are running a business. This training was carried out in two stages with the topics of (1) digital marketing and (2) digital business and digital transformation for its sustainability, the service team also developed an android-based application platform for the alumni of the management department on UM.

INFLUENCE OF ORGANIC MATTER ON Re-Os DATING OF SULFIDES: INSIGHTS FROM THE GIANT JINDING SEDIMENT-HOSTED Zn-Pb DEPOSIT, CHINA

2021 ◽  
Author(s):  
Shiqiang Huang ◽  
Yucai Song ◽  
Limin Zhou ◽  
David L. Leach ◽  
Zhaoshan Chang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Inductively Coupled Plasma ◽  
Elemental Mapping ◽  
Bacterial Reduction ◽  
Inductively Coupled ◽  
Hydrocarbon Reservoir ◽  
Low Concentrations ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Two Stages

Abstract This study evaluates the effect of organic matter impurities on pyrite Re-Os dating, using the giant Jinding sediment-hosted Zn-Pb deposit in China as an example. The Jinding deposit is hosted in a Paleocene evaporite dome that was a hydrocarbon reservoir before mineralization. Pyrite in Jinding formed in two stages: pre-ore (py1) and syn-ore (py2). Two types of py1 are recognized, organic matter-free and organic matter-bearing. The organic matter-free py1 contains homogeneously distributed low concentrations of Re (<2.5 ppb) that yields an isochron age of 51 ± 1 Ma (mean square of weighted deviates [MSWD] = 3.2). This date is interpreted to be the age of py1 formation. The organic matter-bearing py1 contains organic matter inclusions trapped during py1 growth and synchronous with bacterial reduction of sulfate. Elemental mapping with laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) shows that the organic matter inclusions have Re signals 1 to 4 orders of magnitude higher than those of pyrite, revealing that organic matter is the major host for Re. Such pyrite separates contain 37 to 1,145 ppb Re. The Re-Os data of organic matter-bearing py1 yield an isochron age of 72.9 ± 0.5 Ma (MSWD = 0.2). This age is older than the actual py1 formation age of 51 ± 1 Ma but overlaps with previously dated bitumen Re-Os isochron age of 68 ± 5 Ma at Jinding, indicating that organic matter inclusions can significantly influence the Re-Os dates of pyrite and likely other sulfides. This study demonstrates that in order to date sulfides formed in organic-rich environments using the Re-Os method, it is necessary to determine the distribution of Re in samples using detailed petrography and LA-ICP-MS trace element mapping plus spot analysis.

New Insights into the Origin of the World-Class Jinding Sediment-Hosted Zn-Pb Deposit, Southwestern China: Evidence from LA-ICP-MS Analysis of Individual Fluid Inclusions

2021 ◽  
Author(s):  
Lan Mu ◽  
Ruizhong Hu ◽  
Xianwu Bi ◽  
Yongyong Tang ◽  
Tingguang Lan ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Southwest China ◽  
Critical Role ◽  
Previous Suggestion ◽  
Inductively Coupled ◽  
Icp Ms ◽  
The World ◽  
World Class ◽  
Homogenization Temperatures ◽  
Very High

Abstract The Jinding deposit in the Lanping basin, southwest China, is the largest sandstone-hosted Zn deposit in the world and the second largest Zn-Pb deposit in China. However, questions related to the metal compositions and origin of the ore fluids remain. In this study, microthermometry and laser ablation-inductively coupled plasmamass spectrometry (LA-ICP-MS) were employed to determine the properties and compositions of individual fluid inclusions trapped in sphalerite and calcite. The results show that the fluid inclusions trapped in sphalerite and calcite have similar homogenization temperatures (79°–173°C with the majority 100°–130°C), salinities (10.3–29.1 wt % NaCl + CaCl2 equiv with the majority 24.5–27.4 wt % NaCl + CaCl2 equiv), and concentrations of alkali and alkali earth elements (e.g., Na, Ca, Mg, K, Sr, Ba, Li, Rb, and Cs). However, the concentrations of ore and associated metals (e.g., Pb, Sb, Ag, and Tl) in the fluid inclusions hosted by sphalerite are significantly higher than those hosted by calcite. Based on these observations, we propose that the sulfides including sphalerite were precipitated from a low-temperature, high-salinity, Ca-rich, metal-rich fluid, while the gangue minerals such as calcite crystallized subsequently from fluids depleted in metals due to prior precipitation of sulfides, and that the high salinities of the fluid inclusions are likely due to a combination of seawater evaporation and subsequent dissolution of evaporitic sequences during fluid percolation. The LA-ICP-MS analyses reveal that the fluid inclusions have K/Na, Rb/Na, and Cs/Na ratios within the range of modern basinal brines, and Li/Na, Ba/Na, and Ca/Na ratios share similar compositions with the ore fluids of basement interacted deposits in the world. The Jinding ore fluids contain ~200 to 650 ppm Pb, based on the data of fluid inclusions trapped in sphalerite. The estimated concentrations of Zn in the ore fluids are also very high at ~200 to 6,500 ppm. Our results reveal that anomalously metal rich fluids played a critical role in the formation of the giant Jinding sediment-hosted Pb-Zn deposit. We concur with the previous suggestion that sulfide precipitation at Jinding occurred when ascending metal-rich brines encountered an H2S-rich, Ca-rich fluid, which was produced by interaction of hydrocarbons with evaporites, in the cap of the Jinding dome.

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