Convection in Rotating Spherical Fluid Shell

t has been recently observed that there is a change in the length of day with a period of roughly six years, while a longer period in the change of length of day is attributed to action within Earth’s core, the six year period is theorized to be a product of the Earth’s dynamo generation. It is conjectured that a torsional wave with a six year periodicity, i.e. an oscillation in the azimuthal velocity of the outer core that propagates radially outward could explain the change in the length of the day via conservation of angular momentum. Previous simulations have identified torsional waves in both dynamo simulations and purely hydrodynamical simulations. Here we explore torsional waves as a purely hydrodynamical process, modeling Boussinesq fluids in arotating spherical shell, with no-slip boundary condition. The numerical simulations are doneby solving the Navier-Stokes equation sets using spherical Dedalus, a pseudo-spectral partial differential equation solver. There were no successful identification of torsional waves for the rapidly rotating parameter regime Ek ~10^{-6} and Ra ~ 10^8

Multipartite entanglement groups

We propose to define multipartite entanglement of pure states as transformations acting on some parts of a system that can be undone by transformations acting on other parts. This leads to a definition of multipartite entanglement in terms of groups, namely certain quotients of the stabilizer group and its subgroups. We analyze properties of these entanglement groups and show that they lead to restrictions which give a precise meaning to monogamy of entanglement. We use these groups to propose a finite classification of entanglement types in multi-partite quantum systems and we show that this characterization of entanglement underlies several well-known quantum tasks.Comment: 36 page

Arsenic transformation behaviour during thermal decomposition of P. vittata, an arsenic hyperaccumulator

Thermal treatment of P. vittata, an arsenic hyperaccumulator harvested from contaminated land is a promising method of achieving volume reduction, energy production and arsenic (As) recovery simultaneously. In this paper, the arsenic transformation characteristics of field-harvested P. vittata were investigated during its pyrolysis and gasification process. The produced solid residue and flue gas were analysed by a high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) to determine both the arsenic concentration and speciation. Moreover, the occurrence of arsenic in the solid residues was further identified as soluble and insoluble, which can feed information to the next arsenic recovery step. Results show that the fuel arsenic into gas phase increases firstly from 400 °C to 600 °C, but then drops from 600 °C to 800 °C, probably due to the self-retention of arsenic by CaO enriched in this P. vittata. Further increasing temperature to 900 °C will result in fast arsenic release. Gasification results in slightly higher arsenic release into the gas phase compared with pyrolysi

Experimental and kinetic study of thermal decomposition behaviour of phytoremediation derived Pteris vittata

Combustion and gasification for biomass to energy conversion is often suggested for the management of residual Pteris vittata from phytoremediation. In this study, the thermal behaviour of P. vittata was studied on a thermogravimetric analyser, and the kinetic triplet of biomass sample was further determined for different stages of the thermochemical processes using the Ozawa and KAS methods, subsequently modified by an iterative procedure. Results show that thermal decomposition under combustion condition was complete at a lower temperature of ~500 °C compared to ~700 °C for gasification, indicating the both easily complete conversion of P. vittata by combustion and gasification. Kinetic study shows that although activation energy for each stage under combustion condition is mostly larger than that under gasification, the reaction rate of thermal decomposition of P. vittata under combustion condition is still great larger than that under gasification condition. These findings strongly suggest that thermochemical processes offer suitable methods for the volume reduction and energy production of P. vittata

Influence of the Process Parameters on the Microhardness and the Wear Resistance of Friction Stir Processed H65 Copper Alloy

Friction stir processing (FSP) was used to modify a larger-size surface of H65 copper alloy. The influence of the traverse speed and the rotation speed on the microstructure, the microhardness and the wear resistance of the modified surface were analyzed. The wear mechanism of the modified H65 copper alloy was revealed. The results indicate that the grain size was greatly refined after FSP compared with the parent metal and that the grain size increased with the increment of the rotation speed. The average microhardness of the modified surface was higher than that of the parent metal. The average microhardness had a highest value of 174.13 HV when the traverse speed was 200 mm/min and the rotation speed was 200 rpm, i.e., 21% higher than that of the parent metal. The average microhardness decreased with the increase of the rotation speed. When the traverse speed was 200 mm/min and the rotation speed was 600 rpm, the average friction coefficient of the modified surface was the smallest (0.3213), which was lower than that of the parent metal (0.3810). The wear mechanism of the H65 copper alloy modified by FSP was mainly adhesive wear accompanied by local abrasive wear

Inference of transcriptional regulation in cancers

We developed an efficient and accurate computational framework, RABIT (regression analysis with background integration), and comprehensively integrated public transcription factor (TF)-binding profiles with TCGA tumor-profiling datasets in 18 cancer types. To systematically search for cancer-associated TFs, RABIT controls the effect of tumor-confounding factors on transcriptional regulation, such as copy number alteration, DNA methylation, and TF somatic mutation. Our predicted TF regulatory activity in tumors is highly consistent with the knowledge from cancer gene databases and reveals many previously unidentified cancer-associated TFs. We also analyzed RNA-binding protein regulation in cancer and demonstrated that RABIT is a general platform for predicting oncogenic gene expression regulators

Effects of S. cerevisiae strains on the sensory characteristics and flavor profile of kiwi wine based on E-tongue, GC-IMS and 1H-NMR

The fermentation of kiwifruit into kiwi wine (KW) can represent a strategy to reduce the economic losses linked to fruits imperfections, spoilage, over production and seasonality. In the study, Pujiang kiwifruit, a China National Geographical Indication Product, was used as raw material to produce KW fermented by four commercial S. cerevisiae strains, namely Drop Acid Yeast, DV10, SY and RW. The sensory characteristics and flavor profile of KW were assessed by means of sensory evaluation, E-tongue, GC-IMS and 1H-NMR. KW fermented by RW strain obtained the higher sensory evaluation score. E-tongue could clearly distinguish the taste differences of KW fermented by distinct S. cerevisiae strains. A total of 128 molecules were characterized by GC-IMS and 1H-NMR, indicating that the combinations of multiple technologies could provide a comprehensive flavor profile of KW. The main flavor compounds in KW pertained to the classes of esters and alcohols. Several pathways were found to be differently altered by the fermentation with the different yeast strains, namely butanoate metabolism, glycerolipid metabolism, alanine, aspartate and glutamate metabolism, arginine biosynthesis, arginine and proline metabolism. The present study will facilitate screening suitable S. cerevisiae strains for KW production and provide a theoretical basis for large-scale production of KW

Catalytic oxidation of chlorinated organics over lanthanide perovskites: effects of phosphoric acid etching and water vapor on chlorine desorption behavior

In this article, the underlying effect of phosphoric acid etching and additional water vapor on chlorine desorption behavior over a model catalyst La3Mn2O7 was explored. Acid treatment led to the formation of LaPO4 and enhanced the mobility of lattice oxygen of La3Mn2O7 evidenced by a range of characterization (i.e., X-ray diffraction, temperature-programmed analyses, NH3–IR, etc.). The former introduced thermally stable Brönsted acidic sites that enhanced dichloromethane (DCM) hydrolysis while the latter facilitated desorption of accumulated chlorine at elevated temperatures. The acid-modified catalyst displayed a superior catalytic activity in DCM oxidation compared to the untreated sample, which was ascribed to the abundance of proton donors and Mn­(IV) species. The addition of water vapor to the reaction favored the formation and desorption of HCl and avoided surface chlorination at low temperatures. This resulted in a further reduction in reaction temperature under humid conditions (T90 of 380 °C for the modified catalyst). These results provide an in-depth interpretation of chlorine desorption behavior for DCM oxidation, which should aid the future design of industrial catalysts for the durable catalytic combustion of chlorinated organics

MindShift: Leveraging Large Language Models for Mental-States-Based Problematic Smartphone Use Intervention

Problematic smartphone use negatively affects physical and mental health. Despite the wide range of prior research, existing persuasive techniques are not flexible enough to provide dynamic persuasion content based on users' physical contexts and mental states. We first conduct a Wizard-of-Oz study (N=12) and an interview study (N=10) to summarize the mental states behind problematic smartphone use: boredom, stress, and inertia. This informs our design of four persuasion strategies: understanding, comforting, evoking, and scaffolding habits. We leverage large language models (LLMs) to enable the automatic and dynamic generation of effective persuasion content. We develop MindShift, a novel LLM-powered problematic smartphone use intervention technique. MindShift takes users' in-the-moment physical contexts, mental states, app usage behaviors, users' goals & habits as input, and generates high-quality and flexible persuasive content with appropriate persuasion strategies. We conduct a 5-week field experiment (N=25) to compare MindShift with baseline techniques. The results show that MindShift significantly improves intervention acceptance rates by 17.8-22.5% and reduces smartphone use frequency by 12.1-14.4%. Moreover, users have a significant drop in smartphone addiction scale scores and a rise in self-efficacy. Our study sheds light on the potential of leveraging LLMs for context-aware persuasion in other behavior change domains

Effects of biochar-amended alkali-activated slag on the stabilization of coral sand in coastal areas

Coral sand is widely encountered in coastal areas of tropical and subtropical regions. Compared with silica sand, it usually exhibits weaker performance from the perspective of engineering geology. To improve the geomechanical performance of coral sand and meet the requirement of foundation construction in coastal areas, a novel alkali activation-based sustainable binder was developed. The alkali-activated slag (AAS) binder material was composed of ground granulated blast-furnace slag (GGBS) and hydrated lime with the amendment of biochar, an agricultural waste-derived material. The biochar-amended AAS stabilized coral sand was subjected to a series of laboratory tests to determine its mechanical, physicochemical, and microstructural characteristics. Results show that adding a moderate amount of biochar in AAS could improve soil strength, elastic modulus, and water holding capacity by up to 20%, 70%, and 30%, respectively. Moreover, the addition of biochar in AAS had a marginal effect on the sulfate resistance of the stabilized sand, especially at high biochar content. However, the resistance of the AAS stabilized sand to wet-dry cycles slightly deteriorated with the addition of biochar. Based on these observations, a conceptual model showing biochar-AAS-sand interactions was proposed, in which biochar served as an internal curing agent, micro-reinforcer, and mechanically weak point