2,569 research outputs found
Numerical Modeling of Geyser Formation by Release of Entrapped Air from Horizontal Pipe into Vertical Shaft
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive
Withanolides from Jaborosa caulescens var. bipinnatifida
Two new withanolides 2,3-dihydrotrechonolide A (1) and 2,3-dihydro-21-hydroxytrechonolide A (2) were isolated along with two known withanolides trechonolide A (3) and jaborosalactone 39 (4) from Jaborosa caulescens var. bipinnatifida (Solanaceae). The structures of 1-2 were elucidated through 2D NMR and other spectroscopic techniques. In addition, the structure of withanolide 1 was confirmed by X-ray crystallographic analysis
A breakthrough dynamic-osmotic membrane bioreactor/nanofiltration hybrid system for real municipal wastewater treatment and reuse.
This study designed a Dynamic-Osmotic membrane bioreactor/nanofiltration (OsMBR/NF) system for municipal wastewater treatment and reuse. Results indicated that a continuously rotating FO module with 60 RPM in Dynamic-OsMBR system could enhance shear stress and reduce cake layer of foulants, leading to higher flux (50%) compared to Traditional-OsMBR during a 40-operation day. A negligible specific reverse salt flux (0.059 G/L) and a water flux of 2.86 LMH were recorded when a mixture of 0.1Ā M EDTA-2Na/0.1Ā M Na2CO3/0.9Ā mM Triton114 functioned as draw solution (DS). It was found that the Dynamic-OsMBR/NF hybrid system could effectively remove pollutants (ā¼98% COD, ā¼99% PO43-P, ā¼93% NH4+-N, > 99% suspended solids) from wastewater. In short, this developed system can be considered a breakthrough technology as it successfully minimizes membrane fouling by shear force, and achieves high water quality for reuse by two membrane- barriers
Free vibration analysis of laminated composite plates based on FSDT using one-dimensional IRBFN method
This paper presents a new effective radial basis function (RBF) collocation technique for the free vibration
analysis of laminated composite plates using the first order shear deformation theory (FSDT). The plates, which can be rectangular or non-rectangular, are simply discretised by means of Cartesian grids. Instead of using conventional differentiated RBF networks, one-dimensional integrated RBF networks (1D-IRBFN) are employed on grid lines to approximate the field variables. A number of examples concerning various thickness-to-span ratios, material properties and boundary conditions are considered. Results obtained are compared with the exact solutions and numerical results by other techniques in the literature to
investigate the performance of the proposed method
Antibiotic Use and Bacterial Infection in COVID-19 Patients in the Second Phase of the SARS-CoV-2 Pandemic: A Scoping Review
This scoping review aimed to explore the prevalence and patterns of global antibiotic use and bacterial infection in COVID-19 patients from studies published between June 2020 and March 2021. This review was reported in line with the Preferred Reporting of Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews, and the protocol is registered with the Open Science Framework. Compared with our previously-published review of the period (December 2019āJune 2020), the antibiotic prescribing rate for COVID-19 patients (June 2020āMarch 2021) was found to have declined overall (82.3% vs. 39.7%), for mild and moderate patients (75.1% vs. 15.5%), and for severe and critical patients (75.3% vs. 48.3%). The seven most frequently prescribed antibiotics in COVID-19 patients were all on the āWatchā list of the WHO AWaRe antibiotics classification. The overall reported bacterial infection rate in COVID-19 patients was 10.5%, and the most frequently reported resistant pathogen in COVID-19 patients was Staphylococcus aureus, followed by Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. There is an urgent need to establish comprehensive and consistent guidelines to assist clinicians in selecting appropriate antibiotics for COVID-19 patients when needed. The resistance data on the most frequently used antibiotics for COVID-19 patients for certain resistant pathogens should be closely monitored
Distinct magnetic regimes through site-selective atom substitution in the frustrated quantum antiferromagnet CsCuClBr
We report on a systematic study of the magnetic properties on single crystals
of the solid solution CsCuClBr (0 x 4), which
include the two known end-member compounds CsCuCl and CsCuBr,
classified as quasi-two-dimensional quantum antiferromagnets with different
degrees of magnetic frustration. By comparative measurements of the magnetic
susceptibility () on as many as eighteen different Br concentrations,
we found that the inplane and out-of-plane magnetic correlations, probed by the
position and height of a maximum in the magnetic susceptibility, respectively,
do not show a smooth variation with x. Instead three distinct concentration
regimes can be identified, which are separated by critical concentrations
x = 1 and x = 2. This unusual magnetic behavior can be explained
by considering the structural peculiarities of the materials, especially the
distorted Cu-halide tetrahedra, which support a site-selective replacement of
Cl- by Br- ions. Consequently, the critical concentrations x (x)
mark particularly interesting systems, where one (two) halidesublattice
positions are fully occupied.Comment: 15 pages, 4 figure
The stable phases of the Cs2CuCl4-xBrx mixed systems
Starting from Cs2CuCl4 and Cs2CuBr4 our project focuses on the growth of the
Cs2CuCl4-xBrx mixed crystals from aqueous solution and the investigation of the
occurring structural variations. The well known orthorhombic structure (space
group Pnma) of the end members of this system is interrupted within the
intermediate composition range Cs2CuCl3Br1 - Cs2CuCl2Br2, if the growth takes
place at room temperature. Within this range a new tetragonal phase is found
(space group I4/mmm). However, in case the growth temperature will be increased
to 50 {\deg}C, the existence of the orthorhombic structure can be extended over
the whole Cs2CuCl4-xBrx mixed system. A detailed analysis of the composition
dependence of the lattice parameters is used to draw conclusions on the
incorporation of Cl- and Br-ions at different sites which is important for the
magnetic interactions between the Cu-ions.Comment: 16 pages,8 figure
Determining Heavy Hybrid Masses via QCD Sum Rules
The masses of charmonium and bottomonium hybrids are evaluated in
terms of QCD sum rules. We find that the ground state hybrid in charm sector
lies in GeV, while in bottom sector the hybrid may
situated in GeV. Since the numerical result on
charmonium hybrid mass is not compatible with the charmonium spectra, including
structures newly observed in experiment, we tempt to conclude that such a
hybrid does not purely exist, but rather as an admixture with other states,
like glueball and regular quarkonium, in experimental observation. However, our
result on bottomonium hybrid coincide with the "exotic structure" recently
observed at BELLE.Comment: 15 pages, 5 figures, version to appear in J.Phys.
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