During the preparation of nanocomposite phase change material (nanoCPCM), more attentions are focused on thermal conductivity. In fact, adding nanomaterial not only affects thermal conductivity, but ...also changes the other thermophysical properties of PCM and causes complicated effects on latent heat storage performance. In present study, melting behavior of pure phase change material and its four kinds of nanocomposites in a horizontal concentric tube were investigated and a new evaluation index was developed to examine the effects of nanomaterial on heat storage performance of nanoCPCM. The results show that both thermal conductivity and melting temperature have significant effects on nanoCPCM melting behavior and heat storage rate. Sometimes, although the thermal conductivity is enhanced, the heat storage rate is decreased due to its melting temperature increasing caused by nanomaterial. Especially, when the heat source temperature and PCM melting temperature is close, the variation of melting temperature is more significant. For example, nanoCPCM with SWCNT has the higher thermal conductivity, but its heat storage rate is slower than nanoCPCM with MWCNT, because of its higher melting temperature. Therefore, more attention must be paid to the variation of melting temperature caused by nanomaterial during the preparation and application of nanoCPCMs.
•Details of NanoCPCM melting and LHS process are revealed.•Thermal conductivity and melting temperature are key factors for LHS rate.•More attention must be paid to melting temperature variation.•An evaluation index for LHS performance is proposed.•NanoCPCM with MWCNT has the optimum LHS performance.
Sarcosaprophagous flesh flies are insect species frequently found on corpses, and their developmental patterns can be used as reliable indicators for estimating minimum postmortem interval (PMImin). ...In this study, the Boettcherisca peregrina Robineau-Desvoidy was reared at seven constant temperatures ranging from 16 to 34 °C to investigate the indexes of development duration and larval body length. Using these results, we generated three development models, including isomorphen diagram, isomegalen diagram, and thermal summation model. Regression analysis was conducted to obtain simulation equations of the variation in larval body length with time after larviposition, and variation in time after larviposition with body length. The developmental durations of B. peregrina from larviposition to adult eclosion under 16, 19, 22, 25, 28, 31 and 34 °C were 1,064.7 ± 34.8, 756.0 ± 19.0, 559.6 ± 5.5, 414.3 ± 3.9, 315.0 ± 2.0, 278.0 ± 4.0, and 258.0 ± 3.5 h, respectively. The developmental threshold temperature of B. peregrina was 10.87 ± 0.49 °C, and the thermal summation constant was 5,809.7 ± 291.4 degree days. The results of this study provide basic data for the use of B. peregrina for estimating PMImin.
ObjectiveFaecal microbiota transplantation (FMT) is effective for the treatment of recurrent Clostridium difficile infection (CDI). Studies have shown bacterial colonisation after FMT, but data on ...viral alterations in CDI are scarce. We investigated enteric virome alterations in CDI and the association between viral transfer and clinical outcome in patients with CDI.DesignUltra-deep metagenomic sequencing of virus-like particle preparations and bacterial 16S rRNA sequencing were performed on stool samples from 24 subjects with CDI and 20 healthy controls. We longitudinally assessed the virome and bacterial microbiome changes in nine CDI subjects treated with FMT and five treated with vancomycin. Enteric virome alterations were assessed in association with treatment response.ResultsSubjects with CDI demonstrated a significantly higher abundance of bacteriophage Caudovirales and a lower Caudovirales diversity, richness and evenness compared with healthy household controls. Significant correlations were observed between bacterial families Proteobacteria, Actinobacteria and Caudovirales taxa in CDI. FMT treatment resulted in a significant decrease in the abundance of Caudovirales in CDI. Cure after FMT was observed when donor-derived Caudovirales contigs occupied a larger fraction of the enteric virome in the recipients (p=0.024). In treatment responders, FMT was associated with alterations in the virome and the bacterial microbiome, while vancomycin treatment led to alterations in the bacterial community alone.ConclusionsIn a preliminary study, CDI is characterised by enteric virome dysbiosis. Treatment response in FMT was associated with a high colonisation level of donor-derived Caudovirales taxa in the recipient. Caudovirales bacteriophages may play a role in the efficacy of FMT in CDI.Trial registration numberNCT02570477
Abstract
We study the spectral evolution of the black hole candidate EXO 1846−031 during its 2019 outburst, in the 1–150 keV band, with the Hard X-ray Modulation Telescope. The continuum spectrum is ...well modeled with an absorbed disk-blackbody plus cutoff power law, in the hard, intermediate, and soft states. In addition, we detect an ≈6.6 keV Fe emission line in the hard intermediate state. Throughout the soft intermediate and soft states, the fitted inner disk radius remains almost constant; we suggest that it has settled at the innermost stable circular orbit (ISCO). However, in the hard and hard intermediate states, the apparent inner radius was unphysically small (smaller than the ISCO), even after accounting for the Compton scattering of some of the disk photons by the corona in the fit. We argue that this is the result of a high hardening factor,
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≈ 2.0–2.7, in the early phases of the outburst evolution, well above the canonical value of 1.7 suitable for a steady disk. We suggest that the inner disk radius was already close to the ISCO in the low/hard state. Furthermore, we propose that this high value of the hardening factor in the relatively hard state was probably caused by the additional illuminating of the coronal irradiation onto the disk. Additionally, we estimate the spin parameter using the continuum-fitting method, over a range of plausible black hole masses and distances. We compare our results with the spin measured using the reflection-fitting method and find that the inconsistency of the two results is partly caused by different choices of
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ABSTRACT
The High Energy (HE) X-ray telescope on board the Hard X-ray Modulation Telescope (Insight-HXMT) can serve as a wide field of view (FOV) gamma-ray monitor with high time resolution (μs) and ...large effective area (up to thousands cm2). We developed a pipeline to search for gamma-ray bursts (GRBs), using the traditional signal-to-noise ratio (SNR) method for blind search and the coherent search method for targeted search. By taking into account the location and spectrum of the burst and the detector response, the targeted coherent search is more powerful to unveil weak and sub-threshold bursts, especially those in temporal coincidence with gravitational wave (GW) events. Based on the original method in literature, we further improved the coherent search to filter out false triggers caused by spikes in light curves, which are commonly seen in gamma-ray instruments (e.g. Fermi/GBM, POLAR). We show that our improved targeted coherent search method could eliminate almost all false triggers caused by spikes. Based on the first two years of Insight-HXMT/HE data, our targeted search recovered 40 GRBs, which were detected by either Swift/BAT or Fermi/GBM but too weak to be found in our blind search. With this coherent search pipeline, the GRB detection sensitivity of Insight-HXMT/HE is increased to about 1.5E-08 erg cm−2 (200 keV–3 MeV). We also used this targeted coherent method to search Insight-HXMT/HE data for electromagnetic counterparts of LIGO-Virgo GW events (including O2 and O3a runs). However, we did not find any significant burst associated with GW events.
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