Landslide hazard assessment and mitigation measures in Philippine geothermal fields

Simple, yet reliable, field criteria have been developed and are being used to qualitatively assess slope instability and slope failure potential in Philippine geothermal fields. Based on a hazard assessment classification of slopes along corridor facilities, sites for implementation of engineering measures are selected. Two case studies are presented. In Mindanao field, the “very high-risk” classification of an area resulted in the installation of pipe shelters, which subsequently shielded a section of a pipeline from landslides. Follow-up monitoring is also conducted using cheap, locally fabricated tools, such as surface extensometers. This is being done in Leyte field, where a landslide has threatened a transmission line tower.     

Water and heat transport in boreal soils: implications for soil response to climate change

Soil water content strongly affects permafrost dynamics by changing the soil thermal properties. However, the movement of liquid water, which plays an important role in the heat transport of temperate soils, has been under-represented in boreal studies. Two different heat transport models with and without convective heat transport were compared to measurements of soil temperatures in four boreal sites with different stand ages and drainage classes. Overall, soil temperatures during the growing season tended to be over-estimated by 2-4 °C when movement of liquid water and water vapor was not represented in the model. The role of heat transport in water has broad implications for site responses to warming and suggests reduced vulnerability of permafrost to thaw at drier sites. This result is consistent with field observations of faster thaw in response to warming in wet sites compared to drier sites over the past 30 years in Canadian boreal forests. These results highlight that representation of water flow in heat transport models is important to simulate future soil thermal or permafrost dynamics under a changing climate.     

Oil Migration in 2-Component Confectionery Systems

ABSTRACT:  Oil migration from high oil content centers into chocolate coatings results in product quality changes. The objective of this study was to monitor and model peanut oil migration in 2-layer systems of increasing phase complexity. Three 2-layer systems were prepared: peanut oil/cocoa butter; peanut butter paste/cocoa butter; and peanut butter paste/chocolate. Magnetic resonance imaging was used to measure liquid oil signal as a function of position over a storage time of 193 days at 25 °C. The 3 types of samples exhibited appreciably different patterns of oil migration. The peanut oil/cocoa butter samples had mass transfer typical of oil being absorbed into a liquid/solid region. The peanut butter paste/cocoa butter magnetic resonance profiles were characterized by mass transfer with a partition coefficient greater than unity. The peanut butter paste/chocolate samples exhibited a time-dependent peanut oil concentration at the interface between the chocolate and peanut butter paste. The spatial and temporal experimental data of the peanut butter paste/chocolate samples were modeled using a Fickian diffusion model, fitting for the effective diffusivity. Values of the diffusivity for the 6 chocolate formulations ranged from 1.10 to 2.01 × 10⁻¹³ m²/s, with no statistically significant differences.     

Ultrathin Lithiophilic 3D Arrayed Skeleton Enabling Spatial-Selection Deposition for Dendrite-Free Lithium Anodes

Lithium metal batteries are promising to become a new generation of energy storage batteries. However, the growth of Li dendrites and the volume expansion of the anode are serious constraints to their commercial implementation. Herein, a controllable strategy is proposed to construct an ultrathin 3D hierarchical host of honeycomb copper micromesh loaded with lithiophilic copper oxide nanowires (CMMC). The uniquely designed 3D hierarchical arrayed skeletons demonstrate a surface-preferred and spatial-selective effect to homogenize local current density and relieve the volume expansion, effectively suppressing the dendrite growth. Employing the constructed CMMC current collector in a half-cell, >400 cycles with 99% coulombic efficiency at 0.5 mA cm⁻² is performed. The symmetric battery cycles stably for >2000 h, and the full battery delivers a capacity of 166.6 mAh g⁻¹. This facile and controllable approach provides an effective strategy for constructing high-performance lithium metal batteries.     

Unusual Post Modulation of Pore Size,Nanostructure, and Composition of Metal–Organic Frameworks via Cooperative Ozone/Water Co-Etching

Rational engineering of pore structure and size, nanostructure, and local composition of metal-organic frameworks (MOFs) plays a crucial role for their applications. Herein, a facile O₃/H₂O co-etching strategy is reported to treat ZIF-67 to synthesize derivatives with novel and hard-to-acquire structures and properties, including mesoporous ZIF-67 dodecahedra with variable mesopore sizes (3–30 nm), core–shell and core-void-shell mesoporous ZIF-67@amorphous cobalt hydroxide dodecahedra, and hollow dodecahedral frameworks. In the cooperative etching mechanism, O₃ diffuses into the hydrophobic ZIF-67 to progressively oxidize the ligand to create functional groups, mesopores and voids, while the enhanced hydrophilicity and pore size allow H₂O to diffuse inside to hydrolyze the metal centers to form cobalt hydroxide shells. The co-etching boosts the performance of ZIF-67 in the electrocatalytic oxygen evolution reaction. The derived core-void-shell material possesses a highly attractive performance (an overpotential of 286 mV, a Tafel slope of 59.5 mV dec⁻¹, and a stability of >20 h) because of the presence of amorphous cobalt species, large pores, hierarchal structure, and high hydrophilicity. This work provides a general approach for post engineering of MOFs to create novel structures and functionalities.     

A miniaturized uniplanar MIMO antenna for n79/n46/millimeter-wave applications

This research suggests a compact uniplanar multiple-input multiple-output (MIMO) with four ports for n79/n46/millimeter-wave (mm-wave) applications. The size of the quad MIMO is only 30 × 30 × 0.8 mm³. MIMO system consists of four identical Z-shaped radiators and common ground on the same plane and no decoupling structures are used for isolation. The system covers the bandwidth of 1.9 GHz (4.4–6.3 GHz) with a mid-frequency of 5.6 GHz and also covers the high-band frequencies ranging from 18 to 30 GHz with a bandwidth of 12 GHz. The suggested quad MIMO is fabricated on an FR-4 board, and the measured outcomes are well in line with the simulated results. An isolation value of −11 dB has been achieved for mid-band frequency and −24 dB has been attained for mm-wave bands. Through the value of DG = 10 dB, ECC < 0.07, TARC < −3 dB, MEG < −5 dB, and the ratio of MEG = 1 dB, uniplanar quad MIMO shows acceptable MIMO diversity performance. The entire system was evaluated for the users' hand specific absorption rate (SAR) impacts and is within the limits. After the complete analysis of the miniature quad MIMO antenna, an 8-port, and a 16-port uniplanar MIMO are simulated for smartphone-sized dielectric substrates and the performances were examined. The suggested MIMO system provides an efficient single-layer MIMO antenna to 5G smartphones with high bandwidth and low SAR. The proposed quad MIMO systems are suitable for both the sub-6 GHz band and the mm-wave band.