The first ambient measurements using nitrate ion based Chemical Ionization with the Atmospheric Pressure interface Time-Of-Flight mass spectrometer (CI-APi-TOF) for sulphuric acid and neutral cluster ...detection are presented. We have found CI-APi-TOF a highly stable and sensitive tool for molecular sulphuric acid detection. The lowest limit of detection for sulphuric acid was determined to be 3.6 × 104 molecules cm−3 for 15 min averaging. Signals from sulphuric acid clusters up to tetramer containing ammonia were also obtained but these were found to result from naturally charged clusters formed by ion induced clustering in the atmosphere during nucleation. Opposite to earlier studies with cluster mass spectrometers, we had no indication of neutral clusters. The reason is either less efficient charging of clusters in comparison to molecular sulphuric acid, or the low concentration of neutral clusters at our measurement site during these particular nucleation events. We show that utilizing high resolution mass spectrometry is crucial in separating the weak sulfuric acid cluster signal from other compounds.
In order to develop and validate the high performance tungsten monoblock technology, the full-tungsten divertor qualification program was defined. As the first step, small-scale mock-ups were ...manufactured and successfully tested under the required high heat flux loads. The test results demonstrated that the technology is available in Japan and Europe. Post-tests observation of the loaded W monoblocks showed generation of self-castellation – a crack along coolant tube axis. The cause of the self-castellation was discussed and a tungsten material characterization program is being developed with the objective to understand mechanical properties that influence the occurrence of the self-castellation.
Oxidation processes in Earth's atmosphere are tightly connected to many environmental and human health issues and are essential drivers for biogeochemistry. Until the recent discovery of the ...atmospheric relevance of the reaction of stabilized Criegee intermediates (sCIs) with SO2, atmospheric oxidation processes were thought to be dominated by a few main oxidants: ozone, hydroxyl radicals (OH), nitrate radicals and, e.g. over oceans, halogen atoms such as chlorine. Here, we report results from laboratory experiments at 293 K and atmospheric pressure focusing on sCI formation from the ozonolysis of isoprene and the most abundant monoterpenes ( alpha -pinene and limonene), and subsequent reactions of the resulting sCIs with SO2 producing sulfuric acid (H2SO4). The measured total sCI yields were (0.15 plus or minus 0.07), (0.27 plus or minus 0.12) and (0.58 plus or minus 0.26) for alpha -pinene, limonene and isoprene, respectively. The ratio between the rate coefficient for the sCI loss (including thermal decomposition and the reaction with water vapour) and the rate coefficient for the reaction of sCI with SO2, k(loss) /k(sCI + SO2), was determined at relative humidities of 10 and 50%. Observed values represent the average reactivity of all sCIs produced from the individual alkene used in the ozonolysis. For the monoterpene-derived sCIs, the relative rate coefficients k(loss) / k(sCI + SO2) were in the range (2.0-2.4) 1012 molecules cm-3 and nearly independent of the relative humidity. This fact points to a minor importance of the sCI + H2O reaction in the case of the sCI arising from alpha -pinene and limonene. For the isoprene sCIs, however, the ratio k(loss) / k(sCI + SO2) was strongly dependent on the relative humidity. To explore whether sCIs could have a more general role in atmospheric oxidation, we investigated as an example the reactivity of acetone oxide (sCI from the ozonolysis of 2,3-dimethyl-2-butene) toward small organic acids, i.e. formic and acetic acid. Acetone oxide was found to react faster with the organic acids than with SO2; k(sCI + acid) / k(sCI + SO2) = (2.8 plus or minus 0.3) for formic acid, and k(sCI + acid) / k(sCI + SO2) = (3.4 plus or minus 0.2) for acetic acid. This finding indicates that sCIs can play a role in the formation and loss of other atmospheric constituents besides SO2.
Formation of new aerosol particles from trace gases is a major source of cloud condensation nuclei (CCN) in the global atmosphere, with potentially large effects on cloud optical properties and ...Earth's radiative balance. Controlled laboratory experiments have resolved, in detail, the different nucleation pathways likely responsible for atmospheric new particle formation, yet very little is known from field studies about the molecular steps and compounds involved in different regions of the atmosphere. The scarcity of primary particle sources makes secondary aerosol formation particularly important in the Antarctic atmosphere. Here, we report on the observation of ion-induced nucleation of sulfuric acid and ammonia-a process experimentally investigated by the CERN CLOUD experiment-as a major source of secondary aerosol particles over coastal Antarctica. We further show that measured high sulfuric acid concentrations, exceeding 10
molecules cm
, are sufficient to explain the observed new particle growth rates. Our findings show that ion-induced nucleation is the dominant particle formation mechanism, implying that galactic cosmic radiation plays a key role in new particle formation in the pristine Antarctic atmosphere.
•Detailed design development plan for the ITER tungsten divertor.•Latest status of the ITER tungsten divertor design.•Brief overview of qualification program for the ITER tungsten divertor and status ...of R&D activity.
In November 2011, the ITER Council has endorsed the recommendation that a period of up to 2 years be set to develop a full-tungsten divertor design and accelerate technology qualification in view of a possible decision to start operation with a divertor having a full-tungsten plasma-facing surface. To ensure a solid foundation for such a decision, a full tungsten divertor design, together with a demonstration of the necessary high performance tungsten monoblock technology should be completed within the required timescale. The status of both the design and technology R&D activity is summarized in this paper.
Background
Poor agreement between observers on whether an unusual event is a seizure drives the need for a specific diagnostic tool provided by video‐electroencephalography (video‐EEG) in human ...pediatric epileptology.
Objective
That successful classification of events would be positively associated with increasing EEG recording length and higher event frequency reported before video‐EEG evaluation; that a novel wireless video‐EEG technique would clarify whether unusual behavioral events were seizures in unsedated dogs.
Animals
Eighty‐one client‐owned dogs of various breeds undergoing investigation of unusual behavioral events at 4 institutions.
Methods
Retrospective case series: evaluation of wireless video‐EEG recordings in unsedated dogs performed at 4 institutions.
Results
Electroencephalography achieved/excluded diagnosis of epilepsy in 58 dogs (72%); 25 dogs confirmed with epileptic seizures based on ictal/interictal epileptiform discharges, and 33 dogs with no EEG abnormalities associated with their target events. As reported frequency of the target events decreased (annually, monthly, weekly, daily, hourly, minutes, seconds), EEG was less likely to achieve diagnosis (P < 0.001). Every increase in event frequency increased the odds of achieving diagnosis by 2.315 (95% confidence interval: 1.36–4.34). EEG recording length (mean = 3.69 hours, range: 0.17–22.5) was not associated (P = 0.2) with the likelihood of achieving a diagnosis.
Conclusions and Clinical Importance
Wireless video‐EEG in unsedated dogs had a high success for diagnosis of unusual behavioral events. This technique offered a reliable clinical tool to investigate the epileptic origin of behavioral events in dogs.
Background
Chiari‐like malformation (CM) and syringomyelia (SM) are widely reported in Cavalier King Charles Spaniels and Griffon Bruxellois dogs. Increasing evidence indicates that CM and SM also ...occur in other small and toy breed dogs, such as Chihuahuas.
Objectives
To describe the presence of SM and craniocervical junction (CCJ) abnormalities in Chihuahuas and to evaluate the possible association of CCJ abnormalities with SM. To describe CM/SM‐related clinical signs and neurologic deficits and to investigate the association of CM/SM‐related clinical signs with signalment, SM, or CCJ abnormalities.
Animals
Fifty‐three client‐owned Chihuahuas.
Methods
Prospective study. Questionnaire analyses and physical and neurologic examinations were obtained before magnetic resonance and computed tomography imaging. Images were evaluated for the presence of SM, CM, and atlantooccipital overlapping. Additionally, medullary kinking, dorsal spinal cord compression, and their sum indices were calculated.
Results
Scratching was the most common CM/SM‐related clinical sign and decreased postural reaction the most common neurologic deficit in 73 and 87% of dogs, respectively. Chiari‐like malformation and SM were present in 100 and 38% of dogs, respectively. Syringomyelia was associated with the presence of CM/SM‐related clinical signs (P = 0.034), and medullary kinking and sum indices were higher in dogs with clinical signs (P = 0.016 and P = 0.007, respectively).
Conclusions and Clinical Importance
Syringomyelia and CCJ abnormalities are prevalent in Chihuahuas. Syringomyelia was an important factor for the presence of CM/SM‐related clinical signs, but many dogs suffered from similar clinical signs without being affected by SM, highlighting the clinical importance of CCJ abnormalities in Chihuahuas.
Sulfuric acid is known to be a key component for atmospheric nucleation. Precise determination of sulfuric-acid concentration is a crucial factor for prediction of nucleation rates and subsequent ...growth. In our study, we have noticed a substantial discrepancy between sulfuric-acid monomer concentrations and total-sulfate concentrations measured from the same source of sulfuric-acid vapor. The discrepancy of about 1–2 orders of magnitude was found with similar particle-formation rates. To investigate this discrepancy, and its effect on nucleation, a method of thermally controlled saturator filled with pure sulfuric acid (97% wt.) for production of sulfuric-acid vapor is applied and rigorously tested. The saturator provided an independent vapor-production method, compared to our previous method of the furnace (Brus et al., 2010, 2011), to find out if the discrepancy is caused by the production method itself. The saturator was used in a H2SO4–H2O nucleation experiment, using a laminar flow tube to check reproducibility of the nucleation results with the saturator method, compared to the furnace. Two independent methods of mass spectrometry and online ion chromatography were used for detecting sulfuric-acid or sulfate concentrations. Measured sulfuric-acid or total-sulfate concentrations are compared to theoretical predictions calculated using vapor pressure and a mixing law. The calculated prediction of sulfuric-acid concentrations agrees very well with the measured values when total sulfate is considered. Sulfuric-acid monomer concentration was found to be about 2 orders of magnitude lower than theoretical predictions, but with a temperature dependency similar to the predictions and the results obtained with the ion-chromatograph method. Formation rates are reproducible when compared to our previous results with both sulfuric-acid or total-sulfate detection and sulfuric-acid production methods separately, removing any doubts that the vapor-production method would cause the discrepancy. Possible reasons for the discrepancy are discussed and some suggestions include that the missing sulfuric acid is in clusters, formed with contaminants found in most laboratory experiments. One-to-two-order-of-magnitude higher sulfuric-acid concentrations (measured as total sulfate in this study) would contribute to a higher fraction of particle growth rate than assumed from the measurements by mass spectrometers (i.e. sulfuric-acid monomer). However, the observed growth rates by sulfate-containing vapor in this study does not directly imply a similar situation in the field, where sources of sulfate are much more diverse.
Background
Lagotto Romagnolo (LR) dogs with benign juvenile epilepsy syndrome often experience spontaneous remission of seizures. The long‐term outcome in these dogs currently is unknown. In humans, ...behavioral and psychiatric comorbidities have been reported in pediatric and adult‐onset epilepsies.
Hypothesis/Objectives
The objectives of this study were to investigate possible neurobehavioral comorbidities in LR with a history of benign familial juvenile epilepsy (BFJE) and to assess the occurrence of seizures after the remission of seizures in puppyhood.
Animals
A total of 25 LR with a history of BFJE and 91 control dogs of the same breed.
Methods
Owners of the LR dogs in the BFJE and control groups completed an online questionnaire about each dog's activity, impulsivity, and inattention. Principal component analysis (PCA) served to extract behavioral factors from the data. We then compared the scores of these factors between the 2 groups in a retrospective case–control study. We also interviewed all dog owners in the BFJE group by telephone to inquire specifically about possible seizures or other neurological problems after remission of seizures as a puppy.
Results
Lagotto Romagnolo dogs with BFJE showed significantly higher scores on the factors Inattention and Excitability/Impulsivity than did the control group (P = .003; P = .021, respectively). Only 1 of the 25 BFJE LR exhibited seizures after remission of epilepsy in puppyhood.
Conclusions and Clinical Importance
Although the long‐term seizure outcome in BFJE LR seems to be good, the dogs exhibit behavioral abnormalities resembling attention deficit hyperactivity disorder (ADHD) in humans, thus suggesting neurobehavioral comorbidities with epilepsy.
Atmospheric amines may play a crucial role in formation of new aerosol particles via nucleation with sulfuric acid. Recent studies have revealed that concentrations below 1 pptV can significantly ...promote nucleation of sulfuric acid particles. While sulfuric acid detection is relatively straightforward, no amine measurements to date have been able to reach the critical sub-pptV concentration range and atmospheric amine concentrations are in general poorly characterized. In this work we present a proof-of-concept of an instrument capable of detecting dimethyl amine (DMA) with concentrations even down to 70 ppqV (parts per quadrillion, 0.07 pptV) for a 15 min integration time. Detection of ammonia and amines other than dimethyl amine is discussed. We also report results from the first ambient measurements performed in spring 2013 at a boreal forest site. While minute signals above the signal-to-noise ratio that could be attributed to trimethyl or propyl amine were observed, DMA concentration never exceeded the detection threshold of ambient measurements (150 ppqV), thereby questioning, though not excluding, the role of DMA in nucleation at this location.
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