1,453 research outputs found
Optimization of organics and nitrogen removal in intermittently aerated vertical flow constructed wetlands: Effects of aeration time and aeration rate
© 2016 Elsevier Ltd In this study, to optimize aeration for the enhancement of organics and nitrogen removal in intermittently aerated vertical flow constructed wetlands (VF CWs) for treating domestic wastewater, the experimental VF CWs were operated at different aeration time (1 h d−1, 2 h d−1, 4 h d−1, 6 h d−1, 8 h d−1 and 10 h d−1) and aeration rate (0.1 L min−1, 0.2 L min−1, 0.5 L min−1, 1.0 L min−1 and 2.0 L min−1) to investigate the effect of artificial aeration on the removal efficiency of organics and nitrogen. The results showed that the optimal aeration time and aeration rate were 4 h d−1 and 1.0 L min−1, which could create the appropriate aerobic and anoxic regions in CWs with the greater removal of COD (97.2%), NH4+-N (98.4%) and TN (90.6%) achieved simultaneously during the experiment. The results demonstrate that the optimized intermittent aeration is reliable option to enhance the treatment performance of organics and nitrogen at a lower operating cost
Digital twins of plant and forest
This is the author accepted manuscriptIn forestry and plantation management, digital twins can improve viable business insights and reduce operating costs. The application of digital twins is still expanding. This Research Topic hopes to collect the application models and key technologies of digital twins in forest management and plant cultivation to lay the foundation for expanding the application scope of visual intelligence solutions
Intensified organics and nitrogen removal in the intermittent-aerated constructed wetland using a novel sludge-ceramsite as substrate
© 2016 Elsevier Ltd. In this study, a novel sludge-ceramsite was applied as main substrate in intermittent-aerated subsurface flow constructed wetlands (SSF CWs) for treating decentralized domestic wastewater, and intensified organics and nitrogen removal in different SSF CWs (with and without intermittent aeration, with and without sludge-ceramsite substrate) were evaluated. High removal of 97.2% COD, 98.9% NH4+-N and 85.8% TN were obtained simultaneously in the intermittent-aerated CW system using sludge-ceramsite substrate compared with non-aerated CWs. Moreover, results from fluorescence in situ hybridization (FISH) analysis revealed that the growth of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in the intermittent-aerated CW system with sludge-ceramsite substrate was enhanced, thus indicating that the application of intermittent aeration and sludge-ceramsite plays an important role in nitrogen transformations. These results suggest that a combination of intermittent aeration and sludge-ceramsite substrate is reliable to enhance the treatment performance in SSF CWs
Mapping and neuromodulation of lower urinary tract function using spinal cord stimulation in female rats
Spinal cord epidural stimulation (SCS) represents a form of neuromodulation for the management of spasticity and pain. This technology has recently emerged as a new approach for potentially augmenting locomotion and voiding function in humans and rodents after spinal cord injury. However, the effect of SCS on micturition has not been studied extensively. Here, SCS was first applied as a direct stimulus onto individual segmental levels of the lumbar spinal cord in rats to map evoked external urethral sphincter (EUS) electromyography activity and SCS-induced voiding contractions. SCS of L2-3 inhibited EUS tonic activity, and SCS on L3 (L3/SCS) inhibited EUS tonic activity and elicited EUS bursting. In contrast, SCS of L1 and L4-6 evoked EUS tonic contractions, which resembled the urethral guarding reflex during bladder storage. Next, the effects of a bilateral pelvic nerve crush (PNC) injury on urodynamic function were examined at 14 days post-operatively. The PNC injury resulted in decreased voiding efficiency and maximum intravesical pressure, whereas the post-voiding residual volume was increased, suggestive of an underactive bladder. Finally, L3/SCS was performed to induce a voiding contraction and enable voiding in rats with a PNC injury. Voiding efficiency was significantly increased, and the residual volume was decreased by L3/SCS in rats after the PNC injury. We conclude that L3/SCS may be used to induce micturition reflexes in a partially filled bladder, reduce urethral resistance, and augment bladder emptying after PNC injury
Polarization and temperature dependence of photoluminescence from zincblende and wurtzite InP nanowires
We use polarization-resolved and temperature-dependent photoluminescence of single zincblende (ZB) (cubic) and wurtzite (WZ) (hexagonal) InPnanowires to probe differences in selection rules and bandgaps between these two semiconductor nanostructures. The WZ nanowires exhibit a bandgap80meV higher in energy than the ZB nanowires. The temperature dependence of the PL is similar but not identical for the WZ and ZB nanowires. We find that ZB nanowires exhibit strong polarization parallel to the nanowire axis, while the WZ nanowires exhibit polarized emission perpendicular to the nanowire axis. This behavior is interpreted in terms of the different selection rules for WZ and ZB crystal structures.A.M., L.V.T., T.B.H., H.E.J., L.M.S., and J.M.Y.-R. acknowledge
support from the Institute for Nanoscale Science
and Technology of the University of Cincinnati and the
National Science Foundation through Grant Nos. EEC/NUE
0532495 and ECCS 0701703. The Australian authors acknowledge
support from the Australian Research Council.
Y.K. acknowledges support by the Korean Science and
Engineering Foundation KOSEF through Grant No. F01-
2007-000-10087-0
Anodic-oxide-induced intermixing in GaAs-AlGaAs quantum-well and quantum-wire structures
Anodic oxides of GaAs were shown to enhance the intermixing in GaAs-AlGaAs quantum wells (QW) during rapid thermal processing. Proximity of the anodic oxide to the QW has been shown to influence the photoluminescence (PL) energy shift due to intermixing. Anodic oxide induced intermixing has been used to enhance quantum-wire PL in the structures grown on V-groove patterned GaAs substrates. This has been attributed to enhanced lateral confinement in these structures. Injection of defects such as group-III vacancies or interstitials was considered to be driving force for the intermixing.published_or_final_versio
From error bounds to the complexity of first-order descent methods for convex functions
This paper shows that error bounds can be used as effective tools for
deriving complexity results for first-order descent methods in convex
minimization. In a first stage, this objective led us to revisit the interplay
between error bounds and the Kurdyka-\L ojasiewicz (KL) inequality. One can
show the equivalence between the two concepts for convex functions having a
moderately flat profile near the set of minimizers (as those of functions with
H\"olderian growth). A counterexample shows that the equivalence is no longer
true for extremely flat functions. This fact reveals the relevance of an
approach based on KL inequality. In a second stage, we show how KL inequalities
can in turn be employed to compute new complexity bounds for a wealth of
descent methods for convex problems. Our approach is completely original and
makes use of a one-dimensional worst-case proximal sequence in the spirit of
the famous majorant method of Kantorovich. Our result applies to a very simple
abstract scheme that covers a wide class of descent methods. As a byproduct of
our study, we also provide new results for the globalization of KL inequalities
in the convex framework.
Our main results inaugurate a simple methodology: derive an error bound,
compute the desingularizing function whenever possible, identify essential
constants in the descent method and finally compute the complexity using the
one-dimensional worst case proximal sequence. Our method is illustrated through
projection methods for feasibility problems, and through the famous iterative
shrinkage thresholding algorithm (ISTA), for which we show that the complexity
bound is of the form where the constituents of the bound only depend
on error bound constants obtained for an arbitrary least squares objective with
regularization
The statistical analysis of a clinical trial when a protocol amendment changed the inclusion criteria
Abstract Background Sometimes, protocol amendments that change the inclusion and exclusion criteria are required in clinical trials. Then, the patient populations before and after the amendment may differ. Methods We propose to perform separate statistical tests for the different phases, i.e. for the patients recruited before and after the amendment, and to combine the tests using Fisher's combination test. After a significant combination test a multiple testing procedure can be applied to identify the phase(s) to which a proof of efficacy refers. We assume that the amendment(s) are not based on any type of unblinded data. The proposed method is investigated within a simulation study. Results The proposed combination approach is superior to the 'naïve' strategy to ignore the differences between the phases and pooling the data to perform just one statistical test. This superiority disappears when there are hardly any differences between the two phases. Conclusion When one or more protocol amendments change the inclusion and exclusion criteria, one should realize that the populations may differ. In this case, separate tests for the different phases together with a combination test are a powerful method that can be applied in a variety of settings. The (first) amendment should specify the combination test to be applied in order to combine the different phases.</p
Resolved Psychosis after Liver Transplantation in a Patient with Wilson’s Disease
A psychiatric involvement is frequently present in Wilson’s disease. Psychiatric symptoms are sometimes the first and only manifestation of Wilson’s disease. More often a psychiatric involvement is present beside a neurologic or hepatic disease
Does antihypertensive treatment with renin-angiotensin system inhibitors prevent the development of diabetic kidney disease?
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