Characterization of surface functional groups present on laboratory-generated and ambient aerosol particles by means of heterogeneous titration reactions

A Knudsen flow reactor has been used to quantify surface functional groups on aerosols collected in the field. This technique is based on a heterogeneous titration reaction between a probe gas and a specific functional group on the particle surface. In the first part of this work, the reactivity of different probe gases on laboratory-generated aerosols (limonene SOA, Pb(NO3)2, Cd(NO3)2) and diesel reference soot (SRM 2975) has been studied. Five probe gases have been selected for the quantitative determination of important functional groups: N(CH3)3 (for the titration of acidic sites), NH2OH (for carbonyl functions), CF3COOH and HCl (for basic sites of different strength), and O3 (for oxidizable groups). The second part describes a field campaign that has been undertaken in several bus depots in Switzerland, where ambient fine and ultrafine particles were collected on suitable filters and quantitatively investigated using the Knudsen flow reactor. Results point to important differences in the surface reactivity of ambient particles, depending on the sampling site and season. The particle surface appears to be multi-functional, with the simultaneous presence of antagonistic functional groups which do not undergo internal chemical reactions, such as acid-base neutralization. Results also indicate that the surface of ambient particles was characterized by a high density of carbonyl functions (reactivity towards NH2OH probe in the range 0.26-6 formal molecular monolayers) and a low density of acidic sites (reactivity towards N(CH3)3 probe in the range 0.01-0.20 formal molecular monolayer). Kinetic parameters point to fast redox reactions (uptake coefficient ?0>10-3 for O3 probe) and slow acid-base reactions (?0<10-4 for N(CH3)3 probe) on the particle surface. [Authors]

Waste Authority of Jackson County (formerly known as the Jackson County Sanitary Disposal Agency) independent auditor's reports, basic financial statements, required supplementary information, schedule of findings, June 30, 2012

Audit report on the Waste Authority of Jackson County (formerly known as the Jackson County Sanitary Disposal Agency) for the year ended June 30, 2012

Deicer Scaling Resistance of Concrete Mixtures Containing Slag Cement Phase 2: Evaluation of Different Laboratory Scaling Test Methods, TPF-5(100), 2012

With the use of supplementary cementing materials (SCMs) in concrete mixtures, salt scaling tests such as ASTM C672 have been found to be overly aggressive and do correlate well with field scaling performance. The reasons for this are thought to be because at high replacement levels, SCM mixtures can take longer to set and to develop their properties: neither of these factors is taken into account in the standard laboratory finishing and curing procedures. As a result, these variables were studied as well as a modified scaling test, based on the Quebec BNQ scaling test that had shown promise in other research. The experimental research focused on the evaluation of three scaling resistance tests, including the ASTM C672 test with normal curing as well as an accelerated curing regime used by VDOT for ASTM C1202 rapid chloride permeability tests and now included as an option in ASTM C1202. As well, several variations on the proposed draft ASTM WK9367 deicer scaling resistance test, based on the Quebec Ministry of Transportation BNQ test method, were evaluated for concretes containing varying amounts of slag cement. A total of 16 concrete mixtures were studied using both high alkali cement and low alkali cement, Grade 100 slag and Grade 120 slag with 0, 20, 35 and 50 percent slag replacement by mass of total cementing materials. Vinsol resin was used as the primary air entrainer and Micro Air® was used in two replicate mixes for comparison. Based on the results of this study, a draft alternative test method to ASTM C762 is proposed.

Laboratory and Field Testing of an Accelerated Bridge Construction Demonstration Bridge: US Highway 6 Bridge over Keg Creek, RB02-012, 2013

The US Highway 6 Bridge over Keg Creek outside of Council Bluffs, Iowa is a demonstration bridge site chosen to put into practice newly-developed Accelerated Bridge Construction (ABC) concepts. One of these new concepts is the use of prefabricated high performance concrete (HPC) bridge elements that are connected, in place, utilizing advanced material closure-pours and quick-to-install connection details. The Keg Creek Bridge is the first bridge in the US to utilize moment-resisting ultra-high performance concrete (UHPC) joints in negative moment regions over piers. Through laboratory and live load field testing, performance of these transverse joints as well as global bridge behavior is quantified and examined. The effectiveness of the structural performance of the bridge is evaluated to provide guidance for future designs of similar bridges throughout the US.

Laboratory Testing of Precast Paving Notch System, RB01-005, 2008

The Iowa State University (ISU) Bridge Engineering Center (BEC) performed full-scale laboratory testing of the proposed paving notch replacement system. The objective of the testing program was to verify the structural capacity of the proposed precast paving notch system and to investigate the feasibility of the proposed solution. This report describes the laboratory testing procedure and discusses its results

Audit report on the Rathbun Area Solid Waste Commission for the year ended June 30, 2013

Audit report on the Rathbun Area Solid Waste Commission for the year ended June 30, 2013

Reaudit report on the North Central Iowa Regional Solid Waste Agency for the period July 1, 2011 through June 30, 2012

Reaudit report on the North Central Iowa Regional Solid Waste Agency for the period July 1, 2011 through June 30, 2012

Treatment of ruptured abdominal aortic aneurysm, a permanent challenge or a waste of resources? Prediction of outcome using a multi-organ-dysfunction score.

OBJECTIVES: in a retrospective study, attempts have been made to identify individual organ-dysfunction risk profiles influencing the outcome after surgery for ruptured abdominal aortic aneurysms. METHODS: out of 235 patients undergoing graft replacement for abdominal aortic aneurysms, 57 (53 men, four women, mean age 72 years [s.d. 8.8]) were treated for ruptured aneurysms in a 3-year period. Forty-eight preoperative, 13 intraoperative and 34 postoperative variables were evaluated statistically. A simple multi-organ dysfunction (MOD) score was adopted. RESULTS: the perioperative mortality was 32%. Three patients died intraoperatively, four within 48 h and 11 died later. A significant influence for pre-existing risk factors was identified only for cardiovascular diseases. Multiple linear-regression analysis indicated that a haemoglobin <90 g/l, systolic blood pressure <80 mmHg and ECG signs of ischaemia at admission were highly significant risk factors. The cause of death for patients, who died more than 48 h postoperatively, was mainly MOD. All patients with a MOD score >/=4 died (n=7). These patients required 27% of the intensive-care unit (ICU) days of all patients and 72% of the ICU days of the non-survivors. CONCLUSION: patients with ruptured aortic aneurysms from treatment should not be excluded. However, a physiological scoring system after 48 h appears justifiable in order to decide on the appropriateness of continual ICU support.

A Laboratory Evaluation of Asphaltic Concrete Containing Asphadur, MLR-78-2, 1978

This report describes a laboratory evaluation of three asphaltic concrete, plant produced mixtures containing Asphadur. The mixtures represent a type A asphaltic concrete and two type B asphaltic concretes. The type A and one of the type B mixtures were used in pavements and will be evaluated later for durability and serviceability. The second type B mixture was made only for laboratory testing. In each instance, control batches of the same mixtures but without Asphadur were made for comparison. Type A is a high type asphaltic concrete, requires a minimum of 65 percent crushed particles and is generally used for higher traffic volume roads. Type B is used for intermediate or lower traffic volumes and requires a minimum of 30 percent crushed particles.

Laboratory Evaluation of Polymer and Multi-Grade Asphalt Binders, MLR-90-5, 1992

A number of claims have been made that polymer modified asphalt cements, multi-grade asphalt cements, and other modifications of the liquid asphalt will prevent rutting and other deterioration of asphalt mixes, thereby, extending the service life of asphalt pavements. This laboratory study evaluates regular AC-20 asphalt cement, PAC-30 polymer modified asphalt cement and AC-10-30 multi-grade asphalt cement. PAC-30 was also evaluated with 15% Gilsonite and 15% Witcurb in a 75% crushed stone - 25% sand mix. These mixtures were evaluated for all Marshall properties along with indirect tensile, resilient modulus, and creep resistance.

Audit report on the Crawford County Area Solid Waste Agency Commission for the year ended June 30, 2013

Audit report on the Crawford County Area Solid Waste Agency Commission for the year ended June 30, 2013

Audit report on the Shelby County Area Solid Waste Agency for the year ended June 30, 2013

Audit report on the Shelby County Area Solid Waste Agency for the year ended June 30, 2013

Field Demonstration and Laboratory Evaluation of Foamed Asphalts - Muscatine County, HR-233, 1985

In view of the energy, environmental, and economic advantages of the foamed asphalt process using local aggregates in cold mixes and the promising results from Research Project HR-212, a 4.2-mile section of county road in Muscatine County was built with foamed asphalt and local aggregates during August-September 1983. Extensive laboratory evaluation was carried out on five plant mixes representing foamed mixes used in the nine test sections, a laboratory prepared foamed mix, and a laboratory prepared hot mix similar to Plant Mix 1. The foamed mixes were compacted, cured under 15 curing conditions and tested for bulk specific gravity, Marshall stability at 77° F and at 140° F, cured moisture content, resilient modulus and effects of moisture damage due to freeze-thaw cycles, water soaking, and vacuum saturation. In addition, four sets of 83 core samples were taken at 1 to 15 months and tested for moisture content, specific gravity, Marshall stability, and resilient modulus. In summary, the test road has performed satisfactorily for almost two years. The few early construction problems encountered were to be expected for experimental projects dealing with new materials and technologies. Overall results to date are encouraging and foamed asphalt mixes have proved to have the potential as a viable base material in areas where marginal aggregates are available. It is hoped and expected that performance evaluation of the test sections will be continued and that more foamed asphalt trial projects will be constructed and monitored so that experiences and findings from this project can be verified and mix design criteria can be gradually established. For future foamed asphalt projects it is recommended that anti-stripping additives, such as hydrated lime, be added in view of the potential moisture susceptibility of foamed mixes observed in the laboratory evaluation.

Audit report on the Wayne-Ringgold-Decatur County Solid Waste Management Commission for the year ended June 30, 2013

Audit report on the Wayne-Ringgold-Decatur County Solid Waste Management Commission for the year ended June 30, 2013