911 research outputs found
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 0.1 M EDTA-2Na/0.1 M Na2CO3/0.9 mM Triton114 functioned as draw solution (DS). It was found that the Dynamic-OsMBR/NF hybrid system could effectively remove pollutants (∼98% COD, ∼99% PO43-P, ∼93% 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
Research on hot extrusion forming of 7075 aluminum alloy wheel profile
Design the wheel mold according to the cross-sectional view of the lightweight aluminum alloy wheel profile, determine the length of its working belt and use HyperXtrude software to simulate it, verify the rationality of the working belt design, analyze the flow velocity and temperature of the mold outlet, and determine the 7075 aluminum alloy The alloy wheel profile is most reasonable to be produced on a 10 MN extruder. Finally, the optimized working belt length is used for production. The quality of hot extrusion profile is qualified, which proves the accuracy of the simulation
New radiodonts with gnathobase-like structures from the Cambrian Chengjiang biota and implications for the systematics of Radiodonta
On Metric Dimension of Functigraphs
The \emph{metric dimension} of a graph , denoted by , is the
minimum number of vertices such that each vertex is uniquely determined by its
distances to the chosen vertices. Let and be disjoint copies of a
graph and let be a function. Then a
\emph{functigraph} has the vertex set
and the edge set . We study how
metric dimension behaves in passing from to by first showing that
, if is a connected graph of order
and is any function. We further investigate the metric dimension of
functigraphs on complete graphs and on cycles.Comment: 10 pages, 7 figure
Ageing in rural China: migration and care circulation
This article applies the concept of care circulation (Baldassar and Merla, Transnational families, migration and the circulation of care: understanding mobility and absence in family life, 2013) to the processes involved in the care of old people in rural China,an area which has hitherto been predominantly located in a quantitatively based intergenerational transfer framework. Drawing upon a qualitative study of rural families in the context of rural to urban migration, this article examines the multidirectional and asymmetrical exchanges of caregiving and care-receiving and seeks to provide a more nuanced understanding of the impact of migration upon ageing and familial care in rural China. First, going beyond a unidirectional flow or two-way transfer, this article reveals that care circulates between different family members, in different locations, to differing degrees, over the life course. This circulation framework enables an examination of intra-generational dynamics as well as intergenerational relations. Second, this article draws attention to the mediating factors that impact upon the ways in which adult children care for the older generation. It reveals how the employment status of migrating adult children, the temporal dimension of migration and family life cycle of migrating children as well as family relations between the older generation and adult child generation are critical factors. These factors also contribute to the quality of care provided. Finally, while confirming existing scholarship that gender is an important dimension in structuring old age support in rural China, this article calls for a more differentiated approach among generations of women and between regions, revealing the ways in which local migration history interacts with intergenerational dynamics to determine the cohort of women that endure the greatest burden of care
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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Warming-induced permafrost thaw exacerbates tundra soil carbon decomposition mediated by microbial community.
BACKGROUND:It is well-known that global warming has effects on high-latitude tundra underlain with permafrost. This leads to a severe concern that decomposition of soil organic carbon (SOC) previously stored in this region, which accounts for about 50% of the world's SOC storage, will cause positive feedback that accelerates climate warming. We have previously shown that short-term warming (1.5 years) stimulates rapid, microbe-mediated decomposition of tundra soil carbon without affecting the composition of the soil microbial community (based on the depth of 42684 sequence reads of 16S rRNA gene amplicons per 3 g of soil sample). RESULTS:We show that longer-term (5 years) experimental winter warming at the same site altered microbial communities (p < 0.040). Thaw depth correlated the strongest with community assembly and interaction networks, implying that warming-accelerated tundra thaw fundamentally restructured the microbial communities. Both carbon decomposition and methanogenesis genes increased in relative abundance under warming, and their functional structures strongly correlated (R2 > 0.725, p < 0.001) with ecosystem respiration or CH4 flux. CONCLUSIONS:Our results demonstrate that microbial responses associated with carbon cycling could lead to positive feedbacks that accelerate SOC decomposition in tundra regions, which is alarming because SOC loss is unlikely to subside owing to changes in microbial community composition. Video Abstract
Terahertz communications for 5G and beyond
A brief discussion about the exclusive properties and applications of terahertz technology is provided in this chapter. The frequency spectrum terahertz (THz) is also discussed. The applications of terahertz in the field of sensors and terahertz for communications are covered. State-of-the-art literature starting from the early to the latest research conducted is provided and analyzed in terms of the performance of terahertz systems. Terahertz, known as Tera waves or T-waves rather than submillimeter wave, has approximately a fraction of a wavelength less than 30 μm. T-wave is heavily used in sensing and imaging applications, and has no ionization hazards and is an excellent candidate frequency band to defeat the multipaths interference problems for pulse communications. The lower quantum energy of T-waves identifies its potential applications toward near-field imaging, telecommunications, spectroscopy, and sensing, including medical diagnoses and security screening. Identification of DNA signatures including complex real-time molecular dynamics through dielectric resonance is a good example of terahertz spectroscopy instruments nowadays. This concluding chapter will not only address the practical applications of terahertz communications, but also identify the research challenges that lie ahead in terms of terahertz antenna desig
On the Validation of a Multiple-Network Poroelastic Model Using Arterial Spin Labeling MRI Data
The Multiple-Network Poroelastic Theory (MPET) is a numerical model to characterize the transport of multiple fluid networks in the brain, which overcomes the problem of conducting separate analyses on individual fluid compartments and losing the interactions between tissue and fluids, in addition to the interaction between the different fluids themselves. In this paper, the blood perfusion results from MPET modeling are partially validated using cerebral blood flow (CBF) data obtained from arterial spin labeling (ASL) magnetic resonance imaging (MRI), which uses arterial blood water as an endogenous tracer to measure CBF. Two subjects—one healthy control and one patient with unilateral middle cerebral artery (MCA) stenosis are included in the validation test. The comparison shows several similarities between CBF data from ASL and blood perfusion results from MPET modeling, such as higher blood perfusion in the gray matter than in the white matter, higher perfusion in the periventricular region for both the healthy control and the patient, and asymmetric distribution of blood perfusion for the patient. Although the partial validation is mainly conducted in a qualitative way, it is one important step toward the full validation of the MPET model, which has the potential to be used as a testing bed for hypotheses and new theories in neuroscience research
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