1,093 research outputs found

    Thermodynamic modeling of the NbeB system

    Get PDF
    In the present work, the Nb–B binary system was thermodynamically optimized. The stable phases in this system are BCC (niobium), Nb3B2, NbB, Nb3B4, Nb5B6, NbB2, B (boron) and liquid L. The borides Nb3B2, NbB, Nb3B4 and Nb5B6 and the B (boron) were modeled as stoichiometric phases and the liquid L, BCC (niobium) and NbB2 as solutions, using the sublattices model, with their excess terms described by the Redlich–Kister polynomials. The Gibbs energy coefficients were optimized based on the experimental values of enthalpy of formation, low temperature specific heat, liquidus temperatures and temperatures of invariant transformations. The calculated Nb–B diagram reproduces well the experimental values from the literature

    Modeling drivers of biodiversity change emphasizes the need for multivariate assessments and rescaled targeting for management

    Get PDF
    The current policy and goals aimed to conserve biodiversity and manage biodiversity change are often formulated at the global scale. At smaller scales however, biodiversity change is more nuanced leading to a plethora of trends in different metrics of alpha diversity and temporal turnover. Therefore, large-scale policy targets do not translate easily into local to regional management decisions for biodiversity. Using long-term monitoring data from the Wadden Sea (Southern North Sea), joining structural equation models and general dissimilarity models enabled a better overview of the drivers of biodiversity change. Few commonalities emerged as birds, fish, macroinvertebrates, and phytoplankton differed in their response to certain drivers of change. These differences were additionally dependent upon the biodiversity aspect in question and which environmental data were recorded in each monitoring program. No single biodiversity metric or model sufficed to capture all ongoing change, which requires an explicitly multivariate approaches to biodiversity assessment in local ecosystem management

    7β-Hydroxy­artemisinin

    Get PDF
    Crystals of the title compound [systematic name: (3R,6R,7S,8aR,9R,12aR)-7-hydr­oxy-3,6,9-trimethyl­octa­hydro-3,12-ep­oxy[1,2]dioxepino[4,3-i]isochromen-10(3H)-one], C15H22O6, were obtained from microbial transformation of artemisinin by a culture of Cunninghamella elegans. The stereochemistry of the compound is consistent with the spectroscopic findings in previously published works. A weak O—H⋯O hydrogen bond occurs in the crystal structure, together with intermolecular C—H⋯O hydrogen bonds

    Membrane Bioreactors for Waste gas Treatment

    Get PDF
    Producción CientíficaIn the chapter on “Membrane Bioreactors for Waste Gas Treatment” an overview of recent progress in this field is given. In contrast with waste water treatment, membrane systems for waste gas treatment are still in the exploratory stage, although advantages are obvious: in membrane systems the air and aqueous phase are separated, which allows better performance for hydrophobic compounds. The bottleneck, however, is the scaling up of the system. In this chapter the basics of membrane permeation; reactor configuration; results of lab and pilot scale membrane waste gas treatment studies; microbiological aspects and modeling are discussed and future perspectives are presented

    Anomalous tqÎłtq\gamma coupling effects in exclusive radiative B-meson decays

    Full text link
    The top-quark FCNC processes will be searched for at the CERN LHC, which are correlated with the B-meson decays. In this paper, we study the effects of top-quark anomalous interactions tqγtq\gamma in the exclusive radiative B→K∗γB\to K^*\gamma and B→ργB\to\rho\gamma decays. With the current experimental data of the branching ratios, the direct CP and the isospin asymmetries, bounds on the coupling κtcRγ\kappa_{tcR}^{\gamma} from B→K∗γB\to K^*\gamma and κtuRγ\kappa_{tuR}^{\gamma} from B→ργB\to \rho\gamma decays are derived, respectively. The bound on ∣κtcRγ∣|\kappa_{tcR}^{\gamma}| from B(B→K∗γ){\mathcal B}(B\to K^{*}\gamma) is generally compatible with that from B(B→Xsγ){\mathcal B}(B\to X_{s}\gamma). However, the isospin asymmetry Δ(K∗γ)\Delta(K^{*}\gamma) further restrict the phase of κtcRγ\kappa_{tcR}^{\gamma}, and the combined bound results in the upper limit, B(t→cγ)<0.21\mathcal B(t\to c\gamma)<0.21%, which is lower than the CDF result. For real κtcRγ\kappa_{tcR}^{\gamma}, the upper bound on B(t→cγ)\mathcal B(t\to c\gamma) is about of the same order as the 5σ5\sigma discovery potential of ATLAS with an integrated luminosity of 10fb−110 {\rm fb}^{-1}. For B→ργB\to\rho\gamma decays, the NP contribution is enhanced by a large CKM factor ∣Vud/Vtd∣|V_{ud}/V_{td}|, and the constraint on tuγtu\gamma coupling is rather restrictive, B(t→uγ)<1.44×10−5\mathcal B(t\to u\gamma)<1.44\times 10^{-5}. With refined measurements to be available at the LHCb and the future super-B factories, we can get close correlations between B→VγB\to V \gamma and the rare t→qγt\to q\gamma decays, which will be studied directly at the LHC ATLAS and CMS.Comment: 25 pages, 15 figures, pdflate

    Complex in vitro 3D models of digestive system tumors to advance precision medicine and drug testing: Progress, challenges, and trends

    Get PDF
    Digestive system cancers account for nearly half of all cancers around the world and have a high mortality rate. Cell culture and animal models represent cornerstones of digestive cancer research. However, their ability to en- able cancer precision medicine is limited. Cell culture models cannot retain the genetic and phenotypic heteroge- neity of tumors and lack tumor microenvironment (TME). Patient-derived xenograft mouse models are not suitable for immune-oncology research. While humanized mouse models are time- and cost-consuming. Suitable preclinical models, which can facilitate the understanding of mechanisms of tumor progression and develop new therapeutic strategies, are in high demand. This review article summarizes the recent progress on the establish- ment of TME by using tumor organoid models and microfluidic systems. The main challenges regarding the translation of organoid models from bench to bedside are discussed. The integration of organoids and a microflu- idic platform is the emerging trend in drug screening and precision medicine. A future prospective on this field is also provided.This study was supported by the National Natural Science Foundation of China (Grant No.82073148), the Guangdong Provincial Key Laboratory of Digestive Cancer Research (No. 2021B1212040006), the Sanming Project of Medicine in Shenzhen (SZSM201911010), the Shenzhen Key Medical Discipline Construction Fund (SZXK016), the Shenzhen Sustainable Project (KCXFZ202002011010593), and the Shenzhen-Hong Kong-Macau Technology Research Programme (Type C) (Grant No. SGDX2020110309260100)

    High-power low spatial coherence random fiber laser

    Get PDF
    A high-power multi-transverse modes random fiber laser (RFL) is investigated by combining a master oscillator power-amplifier (MOPA) configuration with a segment of extra-large mode area step-index multimode fiber (MMF). Spatial coherence of the high-power multi-transverse modes RFL has been analyzed, which shows that speckle contrast is reduced dramatically with the output power increasing. In this way, considerably low speckle contrast of ~0.01 is achieved under high laser power of ~56 W, which are the records for multi-transverse modes RFLs in both spatial coherence and output power. This work paves a way to develop high-power RFLs with very low spatial coherence for wide-range speckle-free imaging and free-space communication applications
    • …
    corecore