Integration of Shading Device and Semi-Circle Horizontal Light Pipe Transporter for High-Rise Office Building in Tropical Climate

The blooming of a deep open plan in office buildings is accelerated due to economic profit reasons. This hinders the utilisation of daylight despite having abundance of daylight in tropical climate. Although a light pipe (LP) provides a means to illuminate the deep interior of the space, non-uniform daylight distribution still occurs due to the high illumination contrast across the room. The integration of a shading device (SD) in a room with an LP offers a solution to create a uniform daylight distribution. In this study, daylighting performances of 5 different types of an SD with different angles were analysed through a computer simulation software, namely Integrated Environment Solution Virtual Environment. The simulation was done using overcast and intermediate sky with sun conditions. The results showed that all SD cases improved the daylight uniformity across the room. A horizontal Venetian blind with an angle of +45o and −45o showed the best qualitative performance among all the cases. However, further shading and illumination are needed respectively to increase the potential daylight utilisation in an open plan office room. This study also concluded that a vertical Venetian blind did not provide a good daylight uniformity due to the vertical nature of the SD. A design recommendation guide for building designers is proposed at the end of this study to promote the integration of an SD and an LP in deep open plan high-rise office building.

Theory of Figures to the Seventh Order and the Interiors of Jupiter and Saturn

Interior modeling of Jupiter and Saturn has advanced to a state where thousands of models are generated that cover the uncertainty space of many parameters. This approach demands a fast method of computing their gravity field and shape. Moreover, the Cassini mission at Saturn and the ongoing Juno mission delivered gravitational harmonics up to J 12. Here we report the expansion of the theory of figures, which is a fast method for gravity field and shape computation, to the seventh order (ToF7), which allows for computation of up to J 14. We apply three different codes to compare the accuracy using polytropic models. We apply ToF7 to Jupiter and Saturn interior models in conjunction with CMS-19 H/He equation of state. For Jupiter, we find that J 6 is best matched by a transition from an He-depleted to He-enriched envelope at 2–2.5 Mbar. However, the atmospheric metallicity reaches 1 × solar only if the adiabat is perturbed toward lower densities, or if the surface temperature is enhanced by ∼14 K from the Galileo value. Our Saturn models imply a largely homogeneous-in-Z envelope at 1.5–4 × solar atop a small core. Perturbing the adiabat yields metallicity profiles with extended, heavy-element-enriched deep interior (diffuse core) out to 0.4 R Sat, as for Jupiter. Classical models with compact, dilute, or no core are possible as long as the deep interior is enriched in heavy elements. Including a thermal wind fitted to the observed wind speeds, representative Jupiter and Saturn models are consistent with all observed J n values.

High 3He/4He in central Panama reveals a distal connection to the Galápagos plume

It is well established that mantle plumes are the main conduits for upwelling geochemically enriched material from Earth's deep interior. The fashion and extent to which lateral flow processes at shallow depths may disperse enriched mantle material far (>1,000 km) from vertical plume conduits, however, remain poorly constrained. Here, we report He and C isotope data from 65 hydrothermal fluids from the southern Central America Margin (CAM) which reveal strikingly high 3He/4He (up to 8.9RA) in low-temperature (≤50 °C) geothermal springs of central Panama that are not associated with active volcanism. Following radiogenic correction, these data imply a mantle source 3He/4He >10.3RA (and potentially up to 26RA, similar to Galápagos hotspot lavas) markedly greater than the upper mantle range (8 ± 1RA). Lava geochemistry (Pb isotopes, Nb/U, and Ce/Pb) and geophysical constraints show that high 3He/4He values in central Panama are likely derived from the infiltration of a Galápagos plume–like mantle through a slab window that opened ∼8 Mya. Two potential transport mechanisms can explain the connection between the Galápagos plume and the slab window: 1) sublithospheric transport of Galápagos plume material channeled by lithosphere thinning along the Panama Fracture Zone or 2) active upwelling of Galápagos plume material blown by a “mantle wind” toward the CAM. We present a model of global mantle flow that supports the second mechanism, whereby most of the eastward transport of Galápagos plume material occurs in the shallow asthenosphere. These findings underscore the potential for lateral mantle flow to transport mantle geochemical heterogeneities thousands of kilometers away from plume conduits.

Philosophical Reflections on Facilitating Paradigm Shifts

A paradigm shift by definition is a major change in scientific understanding that upends and replaces a prior paradigm. Over the past 47 years, I have made a number of paradigm shifts in the geosciences, planetary sciences, and astrophysical sciences. These include the composition of the inner core and deep interior of Earth, recognizing that Earth’s early formation as a Jupiter-like gas giant makes it possible to derive virtually all the geological and geodynamic behavior of our planet, including the origin of mountains characterized by folding, the primary initiation of fjords and submarine canyons, the origin and typography of ocean floors and continents (described in Whole-Earth Decompression Dynamics), which upends and replaces plate tectonics theory, Earth’s previously unanticipated, powerful, and variable energy sources, namely, a terra-centric nuclear fission georeactor and the stored energy of protoplanetary compression, the nuclear georeactor origin of Earth’s magnetic field and the reasons for its variability. I also revealed a new concept that explains the thermonuclear ignition of stars and, concomitantly, the dark matter surrounding galaxies, the origin of heavy elements, and the reason why the vast multitude of galaxies in the universe display just a few prominent patterns of luminous stars. Recently, I discovered that particulate pollution, not carbon dioxide, is the primary cause of anthropogenic global warming. These are paradigm shifts which, unless successfully refuted, provide new, more-correct logical pathways for future discoveries. Here I reflect on some aspects of my personal science philosophy that has facilitated these fundamental paradigm shifts.

Tracing the subducting Pacific slab to the mantle transition zone with hydrogen isotopes

Hydrogen isotopes have been widely used as powerful tracers to understand the origin of terrestrial water and the water circulation between the surface and the deep interior of the Earth. However, further quantitative understanding is hindered due to a lack of observations about the changes in D/H ratios of a slab during subduction. Here, we report hydrogen isotope data of olivine-hosted melt inclusions from active volcanoes with variable depths (90‒550 km) to the subducting Pacific slab. The results show that the D/H ratio of the slab fluid at the volcanic front is lower than that of the slab fluid just behind the volcanic front. This demonstrates that fluids with different D/H ratios were released from the crust and the underlying peridotite portions of the slab around the volcanic front. The results also show that the D/H ratios of slab fluids do not change significantly with slab depths from 300 to 550 km, which demonstrates that slab dehydration did not occur significantly beyond the arc. Our estimated δD‰ value for the slab materials that accumulated in the mantle transition zone is > − 90‰, a value which is significantly higher than previous estimates.

Calcium isotope compositions as a means to trace carbonate recycling

Marine carbonate, an important CO2 reservoir, is continuously sent to the Earth's deep interior at subduction zones, forming an essential part of the global carbon cycle. The pros and cons of using calcium isotope compositions to trace marine carbonates recycled into the mantle are discussed in this Perspective.