Liquid Line Research Articles

Experimental investigation on the start-up performance of a novel flat loop heat pipe with dual evaporators

Thermal management for multiple heat sources has been becoming increasingly important, especially under high heat flux conditions. As a passive heat transfer device, loop heat pipes (LHP) with multiple evaporators does not consume extra energy, demonstrating a great potential in thermal management. This paper proposed a flat plate LHP with dual evaporators for the first time. Two flat plate evaporators were adopted, and both of them had their own porous wick, compensation chamber (CC) and vapor line. The condensed liquid converged, then moved along the main liquid line. The CC of two evaporators was joined by a tube, which can ensure the sharing of the returning liquid. To verify the performance of novel flat plate LHP, the start-up test was investigated under different heat load arrangements, involving only a single evaporate was applied heat load, two evaporators were applied with the equal or unequal heat load. Meanwhile, the operation stability was determined by testing the performance with the successionally variable heat load. This system has been shown to operate successfully at heating source temperature below 100 °C with heat load ranging from 10 W–10 W to 130 W–130 W (corresponding to the maximum heat flux of 13.52 W/cm2).

Charge-separated electron-hole liquid in transition metal dichalcogenide heterostructures

The possibility of the formation of an electron-hole liquid in the type II heterostructures based on monolayers (bilayers) of transition metal dichalcogenides is considered. It is indicated that additional valleys in the conduction band, which are present in bilayers, are required for its observation. The binding energy of the interlayer exciton is found by the variation method. An analytical formula is found for the shape of the recombination line of the electron-hole liquid.

Making Andesites and the Continental Crust: Mind the Step When Wet

ABSTRACT Andesites are iconic of subduction zone magmatism. Yet intermediate magmas (57–66 wt % SiO2) are less abundant than generally thought in arc settings. A comparison of experimental hydrous liquid lines of descent, melt inclusions and bulk-rock compositions demonstrates the importance of polybaric crystallization–differentiation in producing the compositional range and dictating the relative abundance of arc melts, but also highlights the preponderant role of mixing (sensu lato) in producing andesitic magmas. Based on their P2O5 contents, at least 74% of the arc magmas with around 64 wt % SiO2 are inferred to be mixing products. In addition to their surprisingly low abundance, andesitic melt inclusions are characterized by relatively low H2O, Al2O3, ± Na2O contents compared to the ranges measured in mafic and silicic melt inclusions. These compositional characteristics suggest that there is a sweet spot for the production of andesitic melts delimited by the low-pressure stability limit of amphibole (<150 MPa) and the adiabatic ascent path of mafic melts, but that this low-pressure differentiation pathway plays a minor role in the production of silicic arc magmas that principally form along high-pressure hydrous liquid line of descents (>700 MPa) before decompression. The compositional bimodality recorded by the melt inclusions and in well-preserved intra-oceanic arc crustal sections is a fundamental characteristic of differentiation in transcrustal arc magmatic systems, with important consequences for the chemical evolution of the continental crust. We propose that the overall bimodality shown by arc melts does not relate to a compositional gap in the differentiation mechanisms but results from a combination of (1) the disparity in volume of differentiated magmas produced by low and high-pressure crystallization–differentiation and (2) the strong nonlinearity of the high-pressure liquid lines of descent in composition–temperature–crystallinity space related to crystallization of amphibole-rich assemblages. In this context, the compositional characteristics shared by andesitic magmas and the continental crust principally depict the central role of mixing and mass balance processes in producing andesitic compositions. The step in differentiation efficiency encountered by hydrous magmas entering the amphibole stability field at high pressure plays an important role in defining the silicic component involved in these scenarios.

Pre-Eruptive Magma Configurations and Petrogenetic Relationships of the Rattlesnake Tuff, Oregon–Insights From Spectacularly Banded High-Silica Rhyolite Pumices

The 7.1 Ma Rattlesnake Tuff (RST) of eastern Oregon is a widespread and voluminous (>300 km3) ignimbrite composed of 99% crystal poor (≤1%) high-silica rhyolite (HSR) and <1% dacites. Basaltic andesitic to basaltic inclusions within dacites are samples of underpinned mafic magmas. The RST HSR is comprised of five increasingly evolved compositional Groups (E–A), and HSR pumices range from white to dark grey, often co-mingled in spectacular banded pumices. Previously, Groups were interpreted as rhyolites generated by crystal fractionation within a single reservoir, where more evolved rhyolite melts formed from relatively less evolved rhyolite parents. To reassess compositional HSR Groups and their implications for tapping a single or multiple rhyolite reservoirs as well as reevaluating the petrological relationships among groups, we focus on large banded pumices for geochemical analysis. Statistical analysis of existing and new data verified these five compositional Groups and gaps, best characterized by variations in Ba, Eu/Eu*, Eu, FeO*, Hf, and Zr. Wet-liquidus temperatures, storage temperatures, and storage pressures calculated for all HSR Groups indicate similar pre-eruptive conditions (∼6.1–7.5 km depth; storage temperatures of ∼805–895°C). Differentiation trends, trends in storage pressure and temperature, and lack of crystal-rich tuff or country rock corroborate existing models for HSRs that involve a single, density-stratified magma reservoir prior eruption. Density differences are sufficient to prevent convection between layers of HSRs in a single reservoir when water content increases from 2–4 wt% from Groups E–A. However, if HSRs do not represent a liquid line, it is possible to generate HSRs through batch melting of various regional country rock. Yet, HSRs would still accumulate within the same storage zone, where density variations kept HSRs from mixing until eruption when these banded pumices formed. In either scenario, our study underscores the significance of water content and density variations for accumulating rhyolite magmas in a contiguous magma body without mixing. This has implications for other compositionally heterogenous rhyolitic ignimbrites where natural samples do not provide comparable evidence to argue for pre-eruptive confocal storage of different rhyolite magmas as is the case for the Rattlesnake Tuff.

The Economics of Liquidity Lines Between Central Banks

Liquidity lines between central banks are a key part of the international financial safety net. In this review article, we lay out some of the economic questions that they pose. Research has provided answers to some of these questions, but many more require further research.

Introduction of the liquid nitrogen transfer line for TPS beamline endstation

At Taiwan Photon Source (TPS), the main liquid-nitrogen (LN2) transfer line of length 600 m for beamline endstations was installed in 2015. It formerly supplied LN2 to maximum 24 beamline endstations. Beamline endstation 13A, of which the aim is advanced and general studies of biological structures and structural kinetics in solution or condensed forms under environmental simulations, from atomic to micrometre scale and time resolution from microsecond to minute, was installed during 2018 and 2019. We designed and self-manufactured one LN2 transfer line according to the requirement of beamline endstation 13A, to supply LN2 into the double-crystal monochromator (DCM), to solve the problem of thermal deformation of the crystal. Otherwise the keep-full device was designed to replace the phase separator of the chiller. In this paper we present the pipeline design, performance testing, keep-full device, pressure reducer, noise reduction and heat-load measurement.

Antiproliferative Activities of Lipophililic Fluoroquinolones- Based Scaffold Against a Panel of Solid and Liquid Cancer Cell Lines

Objectives:In this work, 9 lipophilic-acid chelating FQs (fluoroquinolones) comprising chelating groups have been prepared, characterized and screened for in vitro cytotoxicity, radical scavenging and antiinflammation propensities.Methods:Using sulforhodamine B colorimetric bioassay vs. cisplatin; FQs-inflicted reductions’ of viability against breast T47D and MCF7, Pancreatic PANC-1, colorectal HT29, HCT116, SW620, CACO2, SW480 and Leukaemia K562 cancer cell lines were examined in quadruplicates/dose/cell line. Parameters including potency, toxicity, and selectivity (potency/toxicity) have been reported along with DPPH- and NO- radicals’ scavenging capacities -as their molecular action mechanism- in comparison to ascorbic acid and indomethacin respectively. Using Griess assay in Lipopolysaccharide (LPS) prompted RAW264.7 macrophages; mitigation of inflammation was investigated. Results:nitroFQ 3b, unlike the rest of FQs in PANC1 and MCF7 cells, exhibited remarkably superior NO-radical scavenging/antiinflammation capacity to indomethacin with respective antiproliferative IC50 values (<50µM) 49 vs. cisplatin’s 122 and 6 vs. cisplatin’s 28 (p<0.01-0.001; n=4). Reduced FQ 4b of significantly dual DPPH-NO scavenging propensities exerted exceptionally substantial micromolar antiproliferation in colorectal cancer cells with respective antiproliferative IC50 values (<50µM) of HCT116 0.84< HT29 1.6<PANC1 5.7<SW620 9.2 vs. cisplatins’, (p<0.01-0.001; n=4). FQ 5a of superb NO radical reduction effect had antiproliferative IC50 value (<50µM) of 37.6 in PANC1 cells. In breast cancer T47D the ascending order of pronounced nano-micromolar antiproliferative IC50 values (<50µM) was 4d<3d<4a<4b<3b (0.009<0.59<10<15<41 vs. cisplatins’, p<0.01-0.001; n=4). Both 4d and 4b displayed both DPPH-NO radicals reduction –related cytotoxicities. NO radical scavengers 3d and 3b as well as DPPH radical scavenger 4a exerted highly appreciably relevant antineoplastic affinities. Conclusion:Acidic groups and C8-C7 ethylene diamine Chelation Bridge along with bulky dual halogenations can be substantially associated with molecular action mechanisms of FQs cytotoxicities, antioxidative and antiinflammation effects, collectively.

Style of Fractional Crystallization in Basalts from the Paleoarchean Western Iron Ore Group of Singhbhum Craton, Eastern India: Implications from One Atmosphere Experimental Studies

Abstract One atmosphere experimental study on fresh basaltic rocks of Paleoarchean western Iron Ore Group (IOG) basin of Singhbhum Craton, Eastern India gives insight of the crystallization behavior of the parent magma, liquid lines of descent and appearance of the different constituent phases. The natural starting material is sufficiently ferroan (FeOt: 14.28 wt%) and corresponds to ‘ferro-basalt’. Regarding the experimental run products, clinopyroxene shows Al2O3 rich character (ranging from 2.23 – 6.94 wt%; formed due to fluctuating silica activities in the magma) while plagioclase reveals typical Fe-Mg enrichment (that corresponds to higher KdFe-Mg between plagioclase and the parent liquid caused due to immiscible silicate melt inclusion in plagioclase where Mg enters more readily in plagioclase than Fe). The run-product glass corresponds to both high and low iron contents suggesting liquid immiscibility in the parent magma at particular temperature-domains. This study suggests that the crystallization of the western Iron Ore Group basalts represents a broad ‘Skaergaard analogue’ involving depression/shift of eutectic point in the diopside-anorthite system during crystallization.

Numerical investigation of two-phase fluid-transient induced cavitation in the cryogenic propellant feedlines

Rapid changes in fluid-flow conditions, whether purposeful or accidental, may result in generation of a pressure surge in the fluid handling equipment followed by oscillations of pressure, which is known as the fluid transient (or fluid hammer). Fluid transient occurs very often during the filling of the dry liquid lines as well as during the valving operation in the cryogenic propellant feed systems. The maximum amplitude of fluid transient induced pressure oscillations may exceed the strength of the material, which results in the rupture of the flow components. Sometimes, due to its oscillatory nature, when the pressure wave amplitude falls below the vapour pressure of the fluid it may lead to cavity generation resulting in two-phase fluid transients. The pressure generated due to the collapse of the cavity will be higher than the pressure in the single-phase fluid transients that may lead to the structural failure of the fluid handling equipment.In this study, a one–dimensional numerical model has been proposed using the Method of Characteristics (MOC) scheme to investigate the fluid transient induced cavitation due to sudden closure of the valve in the propellant feedlines. Different two-phase models namely Discrete Vapour Cavity Model (DVCM) and Discrete Gas Cavity Model (DGCM) have been used to predict the vapour volume in the pipe. The applicability of the developed model has been evaluated by validating its predictions with the results available in the literature. It has been observed that both the models are in good agreement with experiments, but DGCM can be preferred due to its ability to handle larger void fractions as compared to DVCM.

The formation of three-grain junctions during solidification. Part I: observations

The thermodynamic equilibrium dihedral angle at grain junctions in crystalline rocks is set by the grain boundary interfacial surface energies, but the long times required to attain equilibrium mean that the observed dihedral angles in igneous rocks are generally set by the kinetics of crystallisation. We distinguish three types of augite–plagioclase–plagioclase dihedral angle in mafic igneous rocks. In the first, augite grows in the pores of a pre-existing plagioclase framework accompanied by little to no inwards-growth of the plagioclase pore walls. In the second, the plagioclase pore walls grow inwards simultaneously with the augite, and the dihedral angle is generally larger than the original angle at which the two plagioclase grains impinged except when the impingement angle itself is large. The first type is seen in rapidly crystallised rocks, whereas the second is observed in slowly cooled rocks. The third type is highly asymmetric and resembles (and so we call) an eagle’s beak: it is only seen in slowly cooled rocks. It is common in gabbroic cumulates, and is also present in strongly orthocumulate troctolites. Using the mode of interstitial phases to calculate the amount of interstitial liquid present in a series of mafic cumulates from the Rum and Skaergaard layered intrusions, we show that the asymmetry of three-grain junctions in troctolites increases as the rocks progress from adcumulate to orthocumulate (i.e. as the olivine–plagioclase crystal mush becomes more liquid-rich), with eagles’ beaks becoming the dominant three-grain junction geometry for troctolitic mushes containing ∼ 12 vol.% interstitial material (corresponding to ∼ 30 vol.% liquid in the mush). The geometry of three-grain junctions in mafic rocks is thus a function not only of cooling rate, but also of the progression along the liquid line of descent during fractionation. The first two types of junction are formed in relatively primitive liquids, during which the crystal mushes on the margins of the solidifying magma body are formed predominantly of plagioclase and olivine, whereas the eagle’s beak geometry occurs once augite forms an important component of the crystal framework in the accumulating mush, either because it is a framework-forming primocryst phase or because it grows from highly abundant interstitial liquid.

Experimental Crystallization of the Lunar Magma Ocean, Initial Selenotherm and Density Stratification, and Implications for Crust Formation, Overturn and the Bulk Silicate Moon Composition

AbstractEleven isobaric experimental series simulate the fractional crystallization of 1,150 km deep lunar magma ocean. Crystallization begins at 1,850°C with olivine (to 32 per cent solidified, pcs), followed at 1,600°C by olivine + opx ± Cr‐spinel (to 62 pcs), at 1,210°C cpx + plagioclase ± olivine ± Ti‐spinel (to 97 pcs) and at 1,060°C quartz + cpx + plagioclase + Ti‐spinel, leaving 1.8 wt% residual magma that crystallizes minor K‐feldspar and apatite in addition. Melt compositions remain near 45 wt% SiO2, while FeO increases from 11 to 26 wt%, TiO2 peaks at 4 wt% at Ti‐spinel saturation. The available experimental liquid lines of descent yield an overall fractional crystallization sequence of olivine→opx→cpx + plagioclase→quartz→FeTi‐oxide. Plagioclase appears concomitantly with cpx, a result of the low magma ocean floor pressures (≤1 GPa) after 66%–76% of olivine + opx‐fractionation. A few wt% of FeTi‐oxides form mostly once the quartz + plagioclase + cpx‐cotectic is reached, cumulate densities remain ≤3,740 kg/m3. Scaled to a full magma ocean, plagioclase appears at 210–120 km depth, mainly as a function of bulk Al2O3. As buoyancy driven plagioclase‐cpx separation is likely limited, these depths may correspond to the primordial lunar crustal thickness. Allowing for complete plagioclase flotation to the quartz + plagioclase + cpx + FeTi‐oxide ± olivine cotectic yields 95–70 km primordial crust of anorthosite and quartz‐gabbro, far in excess of the 35–50 km observed. This supports an overturn of primordial layers, remelting of dense gabbroic cumulates in the harzburgitic cumulate mantle leading to further mixing and differentiation. We posit that such complex density induced convection led to a lunar marble cake mantle with primitive and fairly evolved reprocessed cumulates next to each other.

Petrogenetic evolution of early Paleozoic trachytic rocks in the South Qinling Belt, Central China: Insights from mineralogy, geochemistry, and thermodynamic modeling

Early Paleozoic volcanic–intrusive rocks in the South Qinling Belt, central China, consist of bimodal alkaline suites ranging in composition from basalt to trachyte, with an apparent scarcity of intermediate silicic components (the so-called “Daly gap”). A series of trachytic rocks have been identified in the Quanxi area of the South Qinling Belt. In this work, we combine mineralogical evidence with whole-rock major- and trace-element data, Sr–Nd–Pb isotope data, and the results of thermodynamic modeling to gain a better understanding of the petrogenesis and evolutionary process of the Quanxi trachytic rocks, as well as their compositional discontinuity with coeval mafic rocks. Our samples can be clearly classified into two lithological groups based on their phenocryst content: Group 1, phenocryst-poor trachytes (<5 vol% phenocrysts; SiO2 = 63.91–66.13 wt%) and Group 2, trachytic tufflavas (30–45 vol% pyroclasts; SiO2 = 53.34–59.03 wt%). All of the samples exhibit typical oceanic island basalt-like enrichment in light rare earth elements and high field strength elements, as well as marked depletion of Ba, Sr, and Ti. A cogenetic metasomatized lithosphere source for the Quanxi trachytic rocks and contemporaneous mafic rocks is indicated by their homogeneous isotopic features (εNd(t) = +2.3 to +3.4; initial 206Pb/204Pb = 17.92–18.69; initial 207Pb/204Pb = 15.53–15.57; initial 208Pb/204Pb = 37.96–38.99) and linear geochemical variations, with protracted fractional crystallization regarded as the key mechanism for the compositional variations among these cogenetic rocks. The results of Rhyolite-MELTS modeling predict 72%–80% crystallization involving plagioclase, pyroxene, biotite, apatite, and FeTi oxide, to yield the magmatic compositions from an evolved mafic progenitor to the Quanxi trachytes under conditions of low pressure (1.5–2 kbar), high H2O content (2–3 wt%), and high fO2 (FMQ–0.5). Some incompatible elements in trachytic tufflavas deviate markedly from the liquid lines of descent from coeval mafic rocks to the Quanxi trachytes: this deviation is attributed to a combination of the involvement of large proportions of alkali-feldspar pyroclasts and post-magmatic hydrothermal alteration. The presence of the “Daly gap” in early Paleozoic alkaline suites can be explained by an accelerated differentiation rate (i.e., dSiO2/dt) in the SiO2-intermediate field, which is driven by the simultaneous separation of a considerable scale of SiO2-poor phases.

Mechanical-capillary-driven two-phase loop: Feedback control for thin-film evaporation and capillary limit enhancement

• Feedback control can transition boiling modes in hybrid two-phase loop. • Capillary pumping head was used for feedback control as control variable. • Pump flow rate and evaporator liquid pressure were varied to extend capillary mode. • Pumping power consumption was reduced by feedback control of pump flow rate. • Feedback control was robust under transient heat inputs. Capillary-driven thin-film evaporation in the evaporator was modulated using feedback control of the mechanical pump flow rate and capillary pumping head in a mechanical-capillary-driven two-phase loop. The shift from cold-start (forced-convection dominant condition) to post cold-start (boiling dominant condition) was signified by a sudden drop in the evaporator thermal resistance at relatively low heat inputs. In the post cold-start, positive capillary pressure head resulted in another important transition of boiling conditions in the evaporator transitioning from mechanically-driven flooded boiling (flooded mode) to the capillary-driven thin-film evaporation (capillary mode) showing a small but continuous decrease in the thermal resistance. The feedback control significantly expanded the range of the capillary mode by 285% and reduced the mechanical pumping power consumption by 48% compared to a constant flow case. In this study using a monolayer wick in the evaporator, the highest capillary limit was measured to be 227.2 W/cm 2 with a thermal resistance of 0.190 K-cm 2 /W for the highest pump flow rate of 7.5 g/s and the highest flow restriction in the liquid return line from the evaporator.

Oscillatory dynamics of immiscible liquids with high viscosity contrast in a rectangular Hele–Shaw channel

The dynamics of the interface of liquids with a high viscosity contrast, performing harmonic oscillations with zero mean in a straight slot channel, is experimentally investigated. The boundary is located across the channel and oscillates along the channel with a harmonic change in the flow rate of the fluid pumped through the channel. Owing to the high contrast of viscosities, the motion of the more viscous liquid obeys Darcy's law, while the low-viscosity liquid performs “inviscid” oscillations. The oscillations of the interface occur in the form of an oscillating flat tongue of low-viscosity liquid that periodically penetrates into the more viscous one. The interface oscillations lead to the manifestation of two effects. One of these consists of changes in the averaged shape of the interface and the liquid contact line. The interface in the cell plane takes the form of a “hill,” the dynamical equilibrium of which is maintained by oscillations, while the deformation of the boundary is proportional to the amplitude of the oscillations and vanishes in their absence. The second effect consists of the development of finger instability of the oscillating boundary, which manifests itself in the periodic development of fingers of low-viscosity liquid at part of a period. The instability develops in a threshold manner when the relative amplitude of the interface oscillations reaches a critical value. It is found that the instability has a local character and manifests itself in those regions of the interface where the amplitude of the oscillations reaches a critical value. The stability threshold decreases with the dimensionless frequency.

Olivine Melt Inclusion Constraints on Some Intensive Properties of Subvolcanic Crystal Mushes and Their Evolution through Boundary Layer Fractionation in Northern Japan

Abstract Magma differentiation in arc settings has usually been attributed to an interplay of processes (fractional crystallization, assimilation, and magma mixing). Homogeneous fractional crystallization has been widely used to model the magmatic evolution of volcanic systems in arc settings due to its simplicity, even though boundary layer fractionation (BLF) has been proposed as a preponderant process of differentiation in hydrous magmatic systems. Both models produce distinct compositional paths and the application of the wrong model yields erroneous estimates of parameters like pressure–temperature-H2O conditions and primary melt compositions. Melt inclusion (MI) populations corrected for post-entrapment processes have the potential to help discriminate between these two types of fractional crystallization, as their compositions are not affected by crystal accumulation and should capture the magmatic evolution as crystallization occurs. In this study, olivine-hosted MIs are used to assess the differentiation trends of basic arc magmas in northern Japan. Differentiation trends from five arc volcanic systems in northern Japan show that BLF is ubiquitous. Homogeneous fractionation models are unable to explain the liquid lines of descent of minor elements, like TiO2 and P2O5. To reproduce these differentiation trends, the presence of accessory phases like titanomagnetite or apatite are required, which in many cases are not equilibrated by the melt or need to be fractionated in amounts that are incompatible with homogeneous fractionation. The prevalence of BLF in all studied arc magmas of northern Japan indicates that solidification fronts are key environments in the crustal evolution of some hydrous subduction zone magmas.

Eoarchean subduction-like magmatism recorded in 3750\xa0Ma mafic\u2013ultramafic rocks of the Ukaliq supracrustal belt (Qu\xe9bec)

Our understanding of the nature of crustal formation in the Eoarchean is limited by the scarcity and poor preservation of the oldest rocks and variable and imperfect preservation of protolith magmatic signatures. These limitations hamper our ability to place quantitative constraints on thermomechanical models for early crustal genesis and hence on the operative geodynamic regimes at that time. The recently discovered ca. 3.75 Ga Ukaliq supracrustal enclave (northern Québec) is mainly composed of variably deformed and compositionally diverse serpentinized ultramafic rocks and amphibolitized mafic schists whose metamorphic peak, inferred from phase equilibria modeling, was below 720 °C. Inferred protoliths to the Ukaliq ultramafic rocks include cumulative dunites, pyroxenites, and gabbros, whereas the mafic rocks were probably picrites, basalts, and basaltic andesites. The bulk-rock and mineral chemistry documents the partial preservation of cumulative pyroxenes and probably amphiboles and demonstrates the occurrence of a clinopyroxene-dominated, tholeiitic suite and an orthopyroxene-dominated, boninite-like suite. Together with the presence of negative μ142Nd anomalies in the boninitic basalts, two liquid lines of descent are inferred: (i) a damp tholeiitic sequence resulting from the fractionation of a basaltic liquid produced by mantle decompression; and (ii) a boninitic suite documenting the evolution of an initially primitive basaltic andesite liquid produced by flux melting. Petrographic observations, thermodynamic modeling, bulk-rock and mineral chemistry, and 142Nd isotopic compositions identify the Ukaliq supracrustal belt as the remnant of an Eoarchean arc crust produced by the recycling of Hadean crust in a similar way as modern-style subduction.

Thin diffusion bonded flat loop heat pipes for electronics: Fabrication, modelling and testing

Diffusion bonding process was used to manufacture three different thin flat loop heat pipes (LHP), two with 1.52 mm and one with 0.92 mm of thickness. The proposed LHPs were designed to be candidates for thin electronics cooling applications, such as smartphones. The devices attended to the following heat transfer requirements, based on recent electronic technologies: dissipation of both low (2 W/cm2) and high heat fluxes (8 W/cm2) at natural air convection. A workbench, capable of evaluating the LHP thermal performance, was developed to simulate the operating condition of a chip processor with 1 cm2. The LHPs were investigated experimentally using ethanol as the working fluid in three orientations: horizontal, gravity-assisted and against-gravity. As the main problem of operating thin LHPs with low heat fluxes is the heat leakages from the evaporator, a theoretical model was proposed to predict the conduction heat transfer between the evaporator and the liquid line. The minimum thermal resistance of 0.2 °C/W was achieved for the 1.52 mm thick device at 8 W/cm2. Experimental results confirmed that the thickness reduction of heat pipes leads to a decrease in their thermal performance. The heat leakage of the thinner LHP to the liquid line was approximate 17% of the total heat transferred, while the thicker LHP showed a heat leakage of 10%. Although still demands development, two of the three proposed loop heat pipes showed good heat transfer capacity, keeping the evaporator temperature, supposedly in contact with the electronic component in actual applications, below 100 °C. This device is shown to be suitable for the thermal management of thin electronic devices, especially mobile phones.

Modeling and test of a thermosyphon loop for the cooling of a megawatt-range power electronics converter

A thermosyphon loop, designed for the thermal management of a large Medium voltage power converter 5 MW overall, corresponding to a 2.4 kW thermal load per cooling unit) is presented. The device is mainly made of an evaporator, a condenser and a reservoir connected with plastic liquid and vapor lines. Novec 649 (3M) has been chosen as the working fluid due to environmental and electrical concerns. A model of the loop is described, and its predictions are compared with experiments. A first comparison yields a maximum mean deviation of 20 % between experimental results and numerical simulation at the maximum coolant temperature. The main sources of errors are identified, and improvements are proposed for better model accuracy. • Selection of an environment-friendly fluid (Novec 649). • Entire model of the loop thermo-syphon is presented. • Experimental validation on a full-scale protype (up to 2400 W thermal load) shows < 20% deviation.

Evolution of the magma system of Pantelleria (Italy) from 190 ka to present

The eruptive history of Pantelleria has been marked by the eruption of nine peralkaline ignimbrites, with inter-ignimbrite episodes from small, local volcanic centres. New whole-rock geochemical data are presented for seven ignimbrites and used with published data for younger units to track compositional changes with time. From ∼190 ka, silicic magmatism was dominated by comenditic trachyte to comendite compositions, evolving along generally similar liquid lines of descent (LLOD). The final ignimbrite, the Green Tuff (∼46 ka), was tapped from a compositionally zoned pantelleritic upper reservoir to a trachytic mush zone. Younger (20–7 ka) silicic magmatism has been relatively small scale, with compositions similar to the earliest pre-Green Tuff pantelleritic ignimbrite (Zinedi). These data suggest that the comenditic reservoirs may have been emplaced at deeper levels than the pantelleritic reservoirs. While both types of series evolved along similar LLOD dominated by fractionation of alkali feldspar, it is the fractionation of iron that determines whether comendite or pantellerite is produced. The deeper reservoirs were more oxidizing and wetter, thus leading to the crystallization of magnetite and therefore the fractionation of iron.

Lateral terahertz wave emission from laser induced plasma in liquid water line

Laser ionized liquid has been considered as a promising broadband terahertz (THz) source recently. The ponderomotive force induced dipole model can be used to describe the mechanism of THz generation, implying that the lateral THz emission is stronger than the forward emission. Thus, we systemically investigate the lateral THz emission from laser induced plasma in liquid water line. THz energy about 4.4-times of that from the forward emission is achieved from the lateral emission scheme. Results on the angular distribution of coherent THz radiation indicate that the maximal THz radiation falls between 120° and 150° with respect to the pump laser propagation direction. Moreover, dependence of collected THz energy on the relative position between laser focus and the water line shows a counterintuitive “two peaks” trend, which can be explained by the impact of cylindrical water surface on the divergence angle of the generated THz wave. Therefore, the enhancement in THz energy can be attributed to the high-efficiency lateral collection scheme and the tradeoff between the THz wave converging effect of the cylindrical surface and the absorption in water. Our work helps to further optimize the coupling efficiency of generated THz wave out of liquid samples.