Search results for "Onium"

Evidence for eta(c) -> gamma gamma and measurement of J/psi -> 3 gamma

2013

The decay of J/psi to three photons is studied using psi (3686) -> pi(+) pi(-) J/psi in a sample of 1.0641 X 10(8) psi (3686) events collected with the BESIII detector. Evidence of the direct decay of eta(c) to two photons, eta(c) -> gamma gamma, is reported, and the product branching fraction is determined to be B(J/psi -> gamma eta(c,) eta(c) -> gamma gamma = (4.5 +/- 1.2 +/- 0.6) X 10(-6), where the first error is statistical and the second is systematic. The branching fraction for J/psi -> 3 gamma is measured to be (11.3 +/- 1.8 +/- 2.0) X 10(-6) with improved precision.

Subsurface nitrate reduction under wetlands takes place in narrow superficial zones

2017

This study aims to investigate the depth distribution of the Nitrate Reduction Potential (NRP) on a natural and a re-established wetland. The obtained NRP provides a valuable data of the driving factors affecting denitrification, the Dissimilatory Nitrate Reduction to Ammonium (DNRA) process and the performance of a re-established wetland. Intact soil cores were collected and divided in slices for the determination of Organic Matter (OM) through Loss of Ignition (LOI) as well as Dissolved Organic Carbon (DOC) and NRP spiking nitrate in batch tests. The Nitrate Reduction (NR) was fitted as a pseudo-first order rate constant (k) from where NRPs were obtained. NR took place in a narrow superfi…

High Nitrogen Removal in a Constructed Wetland Receiving Treated Wastewater in a Cold Climate

2018

Constructed wetlands provide cost-efficient nutrient removal, with minimal input of human labor and energy, and their number is globally increasing. However, in northern latitudes, wetlands are rarely utilized, because their nutrient removal efficiency has been questioned due to the cold climate. Here, we studied nutrient retention and nitrogen removal in a boreal constructed wetland (4-ha) receiving treated nitrogen-rich wastewater. On a yearly basis, most of the inorganic nutrients were retained by the wetland. The highest retention efficiency was found during the ice-free period, being 79% for ammonium-nitrogen (NH4+-N), 71% for nitrate-nitrogen (NO3--N), and 88% for phosphate-phosphorus…

N2O emission in maize-crops fertilized with pig slurry, matured pig manure or ammonium nitrate in Brittany

2008

International audience; N2O is a potent greenhouse gas and solutions have to be sought to reduce its emission from agriculture. This work evaluates N2O emission from maize-crop (Zea mays) fields submitted to different organic or mineral fertilizers (pig slurry, matured pig manure or ammonium nitrate) in Brittany (France). N2O emission was evaluated along a year in two experimental sites receiving 110 or 180 kg N ha−1 as ammonium nitrate or pig slurry and 180 or 132 kg N ha−1 as ammonium nitrate or matured pig manure at Champ Noel and Le Rheu experimental plots, respectively. N2O emission was evaluated by interpolation method of periodic fluxes on the field scale and by simulation with NOE a…

Optimization of Nitrification Process by a Bacterial Consortium in the Submerged Biofiltration System with Ceramic Bead Carrier

2014

Laboratory-scale solid phase submerged system was developed to study the process of ammonium biodegradation. Ceramic beads were found to be an appropriate carrier material for the attachment of thePNN bacterial consortium (Pseudomonas sp., Nitrosomonas sp., Nitrobacter sp.) exhibiting nitrification/denitrification activity. This consortium was previously isolated from a biological activated sludge process at a fish factory wastewater treatment plant. Three organic amendments - molasses, humic acid extract, and malt extract - were used for the ceramic bead pretreatment. Molasses significantly enhanced (p<0.05) the process of bacteria attachment onto the ceramic carrier and further ammonium r…

2019

The in-medium dynamics of heavy particles are governed by transport coefficients. The heavy quark momentum diffusion coefficient, $\ensuremath{\kappa}$, is an object of special interest in the literature, but one which has proven notoriously difficult to estimate, despite the fact that it has been computed by weak-coupling methods at next-to-leading order accuracy, and by lattice simulations of the pure SU(3) gauge theory. Another coefficient, $\ensuremath{\gamma}$, has been recently identified. It can be understood as the dispersive counterpart of $\ensuremath{\kappa}$. Little is known about $\ensuremath{\gamma}$. Both $\ensuremath{\kappa}$ and $\ensuremath{\gamma}$ are, however, of foremo…

A Prospective Noninterventional Study to Evaluate Survival and Success of Reduced Diameter Implants Made From Titanium-Zirconium Alloy

2015

Narrow diameter implants may be at increased risk of overload due to occlusal forces; therefore, implants with higher fatigue strength may be beneficial. The aim of this observational study was to evaluate survival and success of narrow diameter (Ø 3.3 mm) TiZr alloy (Roxolid, Institut Straumann AG, Basel, Switzerland) implants for 2 years in daily dental practice. This was a prospective, non-interventional, multicenter study; no specific patient inclusion or exclusion criteria were applied. Each patient received at least one TiZr implant; the treatment plan, including implant loading and final restoration, was at the investigator's discretion. The primary outcome was implant survival and s…

A prospective evaluation of zirconia anterior partial fixed dental prostheses: Clinical results after seven years.

2014

Abstract Statement of problem Because of the high mechanical strength of zirconium dioxide, the metal in fixed partial prostheses can now be replaced. However, the material is susceptible to aging or hydrothermal degradation and to chipping of the feldspathic veneer. Purpose The purpose of this prospective study was to evaluate the survival (without failure) and success (survival without any complication or failure) rate and clinical efficacy of anterior zirconia partial fixed dental prostheses. Material and methods Twenty-seven anterior partial fixed dental prostheses of 3 to 6 units were fabricated. All participants were examined after 1 month and 6 months, then annually for 7 years. Resu…

Mechanical resistance of zirconium implant abutments: A review of the literature

2010

The increase of aesthetic demands, together with the successful outcome of current implants, has renewed interest in the search for new materials with enough mechanical properties and better aesthetic qualities than the materials customarily used in implanto-prosthetic rehabilitation. Among these materials, zirconium has been used in different types of implants, including prosthetic abutments. The aim of the present review is to analyse current scientific evidence supporting the use of this material for the above mentioned purposes. We carried out the review of the literature published in the last ten years (2000 through 2010) of in vitro trials of dynamic and static loading of zirconium ab…

Comparative fracture behavior of monolithic and veneered zirconia posterior fixed dental prostheses

2017

The purpose of this study was to evaluate and to compare the fracture load and the fracture pattern of monolithic and veneered zirconia posterior fixed dental prostheses (FDPs). Twenty standardized steel dies were prepared to receive posterior 3-unit FDPs. Specimens were randomly divided into 2 groups (n=10): (1) Lava Zirconia, and (2) Lava Plus. All FDPs were cemented using glass ionomer cement and subjected to thermal and mechanical cycling at 5-55ºC with a 30-s dwell time for 120,000 masticatory cycles. All specimens were subjected to a three-point bending test until fracture. Data were statistically analyzed using Student's t test, paired t-test and Weibull statistics (α=0.05). No diffe…