Simultaneous measurement of spatially resolved particle emissions in a pilot plant scale baghouse filter applying distributed low-cost particulate matter sensors

Baghouse filters are widely applied in industrial gas cleaning, for example in waste incineration plants and the cement industry, to meet particle emission standards and for product recovery. The global particle emission of pulse-jet cleaned surface filters is typically monitored end of pipe (e.g. in the stack). Since the particulate matter emission of baghouse filters originates often from leaks and incorrectly installed or damaged filter bags, operators would greatly profit from online measurement technology that monitors the emission contribution of individual filter bags or at least a subset of all installed filter elements to the total emission. Low-cost particulate matter sensors can be deployed inside filter houses in larger quantities due to their compact design and low asset cost compared to conventional aerosol measurement technology. The ability of several low-cost sensors to detect the characteristic PM emission behavior of surface filters has been shown in previous investigations in a filter test rig. This study shows first results regarding the emission contribution of individual filter bags of a pilot plant scale baghouse filter employing distributed low-cost sensors of the model OPC-N3 from the manufacturer Alphasense. A Promo® 2000 aerosol spectrometer with a welas® 2100 sensor serves as reference regarding the particulate matter concentration detected by the low-cost sensors and as end of pipe measurement equipment to monitor the global emission. The selected filter medium was a membrane filter medium with sealed seams to provide low emission levels and defined conditions on the clean gas side. The employed low-cost sensors detect an emission peak right after cleaning of the corresponding filter bag only. The global emission measured in the clean gas duct consists of the overlay of the individual emission peaks detected locally at the corresponding filter bags. By exchanging one filter bag with a filter bag made from a non-membrane filter medium without sealed seams, an increase of the total continuous emission can be detected, both end of pipe in the clean gas duct and locally via the low-cost particulate matter sensor. This demonstrates the applicability of the measurement technology for the detection and identification of leaks and damaged filter bags that serve as emission hotspots in baghouse filters

Intermittency and Exotic Channels

It is pointed out that accurate measurements of short-range two-particle correlations in like-charge $K\pi$ and in $\pi^ 0\pi^ 0$ channels should be very helpful in determining the origin of the \lq\lq intermittency\rq\rq\ phenomenon observed recently for the like-charge pion pairs.Comment: 5 p., plain tex, preprint T94/078(Saclay), LPTHE 94/58(Orsay

Impact of ambient air filters on PM concentration levels at an urban traffic hotspot (Stuttgart, Am Neckartor)

Air pollution can have severe impacts on public health. A novel approach to lower the local particle concentrations at urban hotspots is ambient air filtration. This study presents experimental investigations into the effectiveness of air filters to lower ambient particle concentration levels at two different locations. Seventeen outdoor filtration devices with a total flow rate of 170.000 m³/h were installed beside federal highway B14 at Stuttgart “Am Neckartor” targeting to reduce PM10 concentration levels within a 300 m × 50 m area around the urban pollution hotspot. Further measurements were conducted at the residential area “Bleyle quarter” to show the capabilities of a single filter device under relatively defined conditions. By periodically switching the filters on and off while monitoring the particle mass concentrations with optical particle counters, the effects of the filters on the PM10 and PM2.5 concentration levels were determined. A long term investigation at the Neckartor installation site (466 h) yielded an average PM10 reduction of 10.4% (6.3 μg/m³) at the official Neckartor measurement station. Additional in situ measurement campaigns showed that the PM reduction effect decreases with increasing distance to the filter devices. However, the effect is clearly measurable in the walkway areas across the installation site

Charge Particle Multiplicity and Transverse Energy Measurements in Au-Au collisions in PHENIX at RHIC

We present results on charged particle and transverse energy densities measured at mid-rapidity in Au-Au collisions at sqrt(s_{NN})=200 GeV. The mean transverse energy per charged particle is derived. The results are presented as a function of centrality, which is defined by the number of participating nucleons, and compared to results obtained in Au-Au collisions at sqrt{s_{NN})=130 GeV. A comparison with calculations from various theoretical models is performed.Comment: 4 pages, 5 figures. Talk presented at Quark Matter 2002, Nantes, France, July 18-24, 2002. To appear in the proceedings (Nucl. Phys. A

Relativistic Heavy--Ion Collisions in the Dynamical String--Parton Model

We develop and extend the dynamical string parton model. This model, which is based on the salient features of QCD, uses classical Nambu-Got\=o strings with the endpoints identified as partons, an invariant string breaking model of the hadronization process, and interactions described as quark-quark interactions. In this work, the original model is extended to include a phenomenological quantization of the mass of the strings, an analytical technique for treating the incident nucleons as a distribution of string configurations determined by the experimentally measured structure function, the inclusion of the gluonic content of the nucleon through the introduction of purely gluonic strings, and the use of a hard parton-parton interaction taken from perturbative QCD combined with a phenomenological soft interaction. The limited number of parameters in the model are adjusted to $e^+e^-$ and $p$--$p$ data. Utilizing these parameters, the first calculations of the model for $p$--$A$ and $A$--$A$ collisions are presented and found to be in reasonable agreement with a broad set of data.Comment: 26 pages of text with 23 Postscript figures placed in tex

Thermal analysis of hadron multiplicities from relativistic quantum molecular dynamics

Some questions arising in the application of the thermal model to hadron production in heavy ion collisions are studied. We do so by applying the thermal model of hadron production to particle yields calculated by the microscopic transport model RQMD(v2.3). We study the bias of incomplete information about the final hadronic state on the extraction of thermal parameters.It is found that the subset of particles measured typically in the experiments looks more thermal than the complete set of stable particles. The hadrons which show the largest deviations from thermal behaviour in RQMD(v2.3) are the multistrange baryons and antibaryons. We also looked at the influence of rapidity cuts on the extraction of thermal parameters and found that they lead to different thermal parameters and larger disagreement between the RQMD yields and the thermal model.Comment: 12 pages, 2 figures, uses REVTEX, only misprint and stylistic corrections, to appear in Physical Review

Energy dependence of kaon production in central Pb+Pb collisions

Recent results from the NA49 experiment on the energy dependence of charged kaon production in central Pb+Pb collisions are presented. First results from the new data at 80 AGeV beam energy are compared with those from lower and higher energies. A difference in the energy dependence of the / and / ratios is observed. The / ratio shows a non-monotonic behaviour with a maximum near 40 AGeV.Comment: 8 pages, 7 figures, proceedings of talk at SQM2001, Frankfurt, Germany, to appear in J. Phys.

Criticality, Fractality and Intermittency in Strong Interactions

Assuming a second-order phase transition for the hadronization process, we attempt to associate intermittency patterns in high-energy hadronic collisions to fractal structures in configuration space and corresponding intermittency indices to the isothermal critical exponent at the transition temperature. In this approach, the most general multidimensional intermittency pattern, associated to a second-order phase transition of the strongly interacting system, is determined, and its relevance to present and future experiments is discussed.Comment: 15 pages + 2 figures (available on request), CERN-TH.6990/93, UA/NPPS-5-9

Is Anomalous Production of Omega and anti-Omega Evidence for Disoriented Chiral Condensates?

No conventional picture of nucleus-nucleus collisions has yet been able to explain the abundance of Omega and anti-Omega hyperons in central collisions between Pb nuclei at 158 A GeV at the CERN SPS. We argue that this is evidence that they are produced as topological defects arising from the formation of disoriented chiral condensates (DCC) with an average domain size of about 2 fm.Comment: version 2 containing formulas, accepted by PR