Simple and fast methods based on solid-phase extraction coupled to liquid chromatography with UV detection for the monitoring of caffeine in natural and waste waters as marker of anthropogenic impact

Two concentration methods for fast and routine determination of caffeine (using HPLC-UV detection) in surface, and wastewater are evaluated. Both methods are based on solid-phase extraction (SPE) concentration with octadecyl silica sorbents. A common “offline” SPE procedure shows that quantitative recovery of caffeine is obtained with 2 mL of an elution mixture solvent methanol-water containing at least 60% methanol. The method detection limit is 0.1 μg L−1 when percolating 1 L samples through the cartridge. The development of an “online” SPE method based on a mini-SPE column, containing 100 mg of the same sorbent, directly connected to the HPLC system allows the method detection limit to be decreased to 10 ng L−1 with a sample volume of 100 mL. The “offline” SPE method is applied to the analysis of caffeine in wastewater samples, whereas the “on-line” method is used for analysis in natural waters from streams receiving significant water intakes from local wastewater treatment plants

Iowa Construction Site Erosion Control Manual, 2006

The purpose of this Iowa manual is to serve as a guide, provide solutions, and offer suggestions on construction sites to comply with Iowa's current soil erosion and storm water runoff regulations. This need is particularly important when land undergoes a land use change. Information provided in this manual will be helpful to land owners, developers, consultants, contractors, planners, local government, as well as the general public. This manual is intended to provide techniques that will meet the mandates of current legislation. Innovations that will benefit the user and still provide effective control are encouraged.

Can smaller-scale comprehensive cancer centers provide outstanding care in abdominal and thoracic pediatric solid tumor surgery? Results of a 14-year retrospective single-center analysis.

PURPOSE: Quality of care and its measurement represent a considerable challenge for pediatric smaller-scale comprehensive cancer centers (pSSCC) providing surgical oncology services. It remains unclear whether center size and/or yearly case-flow numbers influence the quality of care, and therefore impact outcomes for this population of patients. PATIENTS AND METHODS: We performed a 14-year, retrospective, single-center analysis, assessing adherence to treatment protocols and surgical adverse events as quality indicators in abdominal and thoracic pediatric solid tumor surgery. RESULTS: Forty-eight patients, enrolled in a research-associated treatment protocol, underwent 51 cancer-oriented surgical procedures. All the protocols contain precise technical criteria, indications, and instructions for tumor surgery. Overall, compliance with such items was very high, with 997/1,035 items (95 %) meeting protocol requirements. There was no surgical mortality. Twenty-one patients (43 %) had one or more complications, for a total of 34 complications (66 % of procedures). Overall, 85 % of complications were grade 1 or 2 according to Clavien-Dindo classification requiring observation or minor medical treatment. Case-sample and outcome/effectiveness data were comparable to published series. Overall, our data suggest that even with the modest caseload of a pSSCC within a Swiss tertiary academic hospital, compliance with international standards can be very high, and the incidence of adverse events can be kept minimal. CONCLUSION: Open and objective data sharing, and discussion between pSSCCs, will ultimately benefit our patient populations. Our study is an initial step towards the enhancement of critical self-review and quality-of-care measurements in this setting.

Características geológicas y geotécnicas de los lodos de flotación de la Sierra Minera de Cartagena-La Unión (SE España)

We present the results of a geological and geotechnical characterization of the metallurgic waste from the Sierra Minera de Cartagena-La Union. We have studied eight tailings dams from which we collected and analysed 42 samples of metallurgic waste. We measured grainsize distribution, the specific gravity of solid particles, plasticity index, permeability, both in situ and in the laboratory, direct shear characteristicsand moisture content. According to size distribution the tailings can be classified as sandy silt. Their plasticity index ranges from medium to nil. The internal friction angle varies between 28 and 42 degrees. Cohesion is between 0 and 2.2 t/m2. The specific gravity of the solid particles ranges widely from 1.8 to 4 g/cm3. The saturated hydraulic conductivity values vary between 1.3x 10-5 and 3.2x 10-9 m/s.The water content measured in situ shows that the degree of saturation remains relatively high despite low rainfall and high evaporation rates. Several tailings dams have failed. The leading causes of tailings-dam failure are: 1) slope instability; 2) overflow; 3) erosion; and 4) subsidence or collapse. The main factor leading to dam failure is that the tailings stored in the ponds are highly saturated

Reconsolidation of the soil surface after tillage discontinuity, with and without cultivation, related to erosion and its prediction with RUSLE

Site-specific regression coefficient values are essential for erosion prediction with empirical models. With the objective to investigate the surface-soilconsolidation factor, Cf, linked to the RUSLE's prior-land-use subfactor, PLU, an erosion experiment using simulated rainfall on a 0.075 m m-1 slope, sandy loam Paleudult soil, was conducted at the Agriculture Experimental Station of the Federal University of Rio Grande do Sul (EEA/UFRGS), in Eldorado do Sul, State of Rio Grande do Sul, Brazil. Firstly, a row-cropped area was excluded from cultivation (March 1995), the existing crop residue removed from the field, and the soil kept clean-tilled the rest of the year (to get a degraded soil condition for the intended purpose of this research). The soil was then conventional-tilled for the last time (except for a standard plot which was kept continuously cleantilled for comparison purposes), in January 1996, and the following treatments were established and evaluated for soil reconsolidation and soil erosion until May 1998, on duplicated 3.5 x 11.0 m erosion plots: (a) fresh-tilled soil, continuously in clean-tilled fallow (unit plot); (b) reconsolidating soil without cultivation; and (c) reconsolidating soil with cultivation (a crop sequence of three corn- and two black oats cycles, continuously in no-till, removing the crop residues after each harvest for rainfall application and redistributing them on the site after that). Simulated rainfall was applied with a Swanson's type, rotating-boom rainfall simulator, at 63.5 mm h-1 intensity and 90 min duration, six times during the two-and-half years of experimental period (at the beginning of the study and after each crop harvest, with the soil in the unit plot being retilled before each rainfall test). The soil-surface-consolidation factor, Cf, was calculated by dividing soil loss values from the reconsolidating soil treatments by the average value from the fresh-tilled soil treatment (unit plot). Non-linear regression was used to fit the Cf = e b.t model through the calculated Cf-data, where t is time in days since last tillage. Values for b were -0.0020 for the reconsolidating soil without cultivation and -0.0031 for the one with cultivation, yielding Cf-values equal to 0.16 and 0.06, respectively, after two-and-half years of tillage discontinuation, compared to 1.0 for fresh-tilled soil. These estimated Cf-values correspond, respectively, to soil loss reductions of 84 and 94 %, in relation to soil loss from the fresh-tilled soil, showing that the soil surface reconsolidated intenser with cultivation than without it. Two distinct treatmentinherent soil surface conditions probably influenced the rapid decay-rate of Cf values in this study, but, as a matter of a fact, they were part of the real environmental field conditions. Cf-factor curves presented in this paper are therefore useful for predicting erosion with RUSLE, but their application is restricted to situations where both soil type and particular soil surface condition are similar to the ones investigate in this study.

Surface and subsurface decomposition of a desiccated grass pasture biomass related to erosion and its prediction with RUSLE

Erosion is deleterious because it reduces the soil's productivity capacity for growing crops and causes sedimentation and water pollution problems. Surface and buried crop residue, as well as live and dead plant roots, play an important role in erosion control. An efficient way to assess the effectiveness of such materials in erosion reduction is by means of decomposition constants as used within the Revised Universal Soil Loss Equation - RUSLE's prior-land-use subfactor - PLU. This was investigated using simulated rainfall on a 0.12 m m-1 slope, sandy loam Paleudult soil, at the Agriculture Experimental Station of the Federal University of Rio Grande do Sul, in Eldorado do Sul, State of Rio Grande do Sul, Brazil. The study area had been covered by native grass pasture for about fifteen years. By the middle of March 1996, the sod was mechanically mowed and the crop residue removed from the field. Late in April 1996, the sod was chemically desiccated with herbicide and, about one month later, the following treatments were established and evaluated for sod biomass decomposition and soil erosion, from June 1996 to May 1998, on duplicated 3.5 x 11.0 m erosion plots: (a) and (b) soil without tillage, with surface residue and dead roots; (c) soil without tillage, with dead roots only; (d) soil tilled conventionally every two-and-half months, with dead roots plus incorporated residue; and (e) soil tilled conventionally every six months, with dead roots plus incorporated residue. Simulated rainfall was applied with a rotating-boom rainfall simulator, at an intensity of 63.5 mm h-1 for 90 min, eight to nine times during the experimental period (about every two-and-half months). Surface and subsurface sod biomass amounts were measured before each rainfall test along with the erosion measurements of runoff rate, sediment concentration in runoff, soil loss rate, and total soil loss. Non-linear regression analysis was performed using an exponential and a power model. Surface sod biomass decomposition was better depicted by the exponential model, while subsurface sod biomass was by the power model. Subsurface sod biomass decomposed faster and more than surface sod biomass, with dead roots in untilled soil without residue on the surface decomposing more than dead roots in untilled soil with surface residue. Tillage type and frequency did not appreciably influence subsurface sod biomass decomposition. Soil loss rates increased greatly with both surface sod biomass decomposition and decomposition of subsurface sod biomass in the conventionally tilled soil, but they were minimally affected by subsurface sod biomass decomposition in the untilled soil. Runoff rates were little affected by the studied treatments. Dead roots plus incorporated residues were effective in reducing erosion in the conventionally tilled soil, while consolidation of the soil surface was important in no-till. The residual effect of the turned soil on erosion diminished gradually with time and ceased after two years.

Audit report on the Shelby County Area Solid Waste Agency for the year ended June 30, 2009

Audit report on the Shelby County Area Solid Waste Agency for the year ended June 30, 2009

Effluent particle removal by microirrigation system filters

The aim of this work was to determine whether the filters used in microirrigation systems can remove potentially emitter-clogging particles. The particle size and volume distributions of different effluents and their filtrates were established, and the efficiency of the removal of these particles and total suspended solids by screen, disc and sand filters determined. In most of the effluents and filtrates, the number of particles with a diameter > 20 μm was minimal. By analysing the particle volume distribution it was found that particles larger than the disc and screen filter pores appeared in the filtrates. However, the sand filter was able to retain particles larger than the pore size. The filtration efficiency depended more on the type of effluent than on the filter. It was also found that the particle size distribution followed a potential law. Analysis of the β exponents showed that the filters did not significantly modify the particle size distribution of the effluents

Audit report on the Butler County Solid Waste Commission for the year ended June 30, 2009

Audit report on the Butler County Solid Waste Commission for the year ended June 30, 2009

Audit report on the Hardin County Sanitary Solid Waste Disposal Commission for the year ended June 30, 2009

Audit report on the Hardin County Sanitary Solid Waste Disposal Commission for the year ended June 30, 2009

Audit report on the Wayne-Ringgold-Decatur County Solid Waste Management Commission for the year ended June 30, 2009

Audit report on the Wayne-Ringgold-Decatur County Solid Waste Management Commission for the year ended June 30, 2009

Audit report on the Jones County Solid Waste Management Commission for the year ended June 30, 2009

Audit report on the Jones County Solid Waste Management Commission for the year ended June 30, 2009

Audit report on the Pocahontas County Solid Waste Commission for the year ended June 30, 2009

Audit report on the Pocahontas County Solid Waste Commission for the year ended June 30, 2009