1,844 research outputs found
Model-based evaluation of stormwater management alternatives for a new development
This is the final version of the article. Available from NOVATECH via the URL in this record.This case study analyses and compares the performance of different stormwater management options for a future residential development located in the Czech Republic. The drainage alternatives are developed from the original design proposed earlier by a team of consultants using conventional drainage design approaches. The potential shortcomings of the original design as well as the performance of its alternatives are analysed with the use of a rainfall-runoff simulation model built specifically for this purpose. Four design scenarios were considered: design provided by the consultancy with oversized sewer and source control measures; modified design with on-line detention tank and source control measures; conventional drainage with on-line detention tank; conventional drainage without any detention facilities. All design scenarios are compared and evaluated in terms of their hydraulic performance and construction costs. The results indicate that even when the system layouts are adjusted for the same level of service given by the return period of the rainfall, they can perform differently under extreme rainfall conditions. Moreover, present findings suggest that a decentralized distribution of storage capacity within the catchment could contribute to cost savings when compared to centralized downstream flow control
Single-Channel Flow Injection Spectrophotometric Determination of Nickel Using Furildioxime in Micellar Solution
A very simple, selective, and fast flow injection spectrophotometeric method is developed for determination of nickel using furildioxime as complexing agent. Micellar solution of brij-35 is employed to solubilize the sparingly soluble complex of Ni-furildioxime in buffered aqueous system (pH-9.00). Under optimized conditions, absorbance is linear from 0.02 to 10 μg mL−1 using 500 μL sample volume and from 10 to 30 μg mL−1 using 50 μL sample volume of nickel at 480 nm, with R2 = 0.9971 and 0.9916, respectively. The molar absorption coefficient and Sandell's sensitivity were 6.0 × 103 L mol−1 cm−1 and 0.01 ng cm−2, respectively. The sample throughput of the method is 120 samples per hour with RSD of 0.01–0.2% for 0.02 to 10 μg mL−1 nickel (n = 5), indicating that the method is highly precise and reproducible. Interference from cobalt is removed by Nitroso R-salt-modified XAD-16. The developed method is validated by analysing certified reference materials and is applied to assess nickel content of commercially available cigarettes
Representation of Septic Tanks in Stormwater Management Model (SWMM)
This is the author accepted manuscript.Septic tank systems are commonly used for treating domestic wastewater and an essential part of decentralized wastewater management systems. Many studies have considered septic tanks in terms of their design, performance and their impact on the environment. However, studies that have modelled septic tanks to test their performance for the removal of biochemical oxygen demand (BOD) and total suspended solids (TSS) are scant. This paper presents an approach to model septic tanks using the Stormwater Management Model (SWMM).The developed approach has been then applied to assess the influence of septic tank design configurations on pollution reduction.The authors are grateful to the Ministry of Higher Education and Scientific Research in Libya for the financial support to this PhD studies
Management of Iron-Deficiency Anemia on Inpatients and Appropriate Discharge and Follow-Up.
Background:The aims of the study were to identify appropriate supplementation of iron for inpatients and to identify factors involved in appropriate discharge documentation and follow-up. Methods:This was a retrospective analysis of 103 patients at a community hospital in New York City. Results:A total of 57 (57/103, 55.3%) patients were admitted due to symptomatic anemia. Twenty (20/103, 19.4%) of those with iron-deficiency anemia had either esophagogastroduodenoscopy or colonoscopy. Gastroenterologist or hematologist was consulted for 45/103 (43.7%). Inpatient iron supplementation was given for 62/103 (60.2%) of patients; and 43/103 (41.7%) had blood transfusion. Upon discharge, 50/103 (48.5%) had appropriate documentation of iron-deficiency anemia on discharge paperwork. Appropriate follow-up was done for 54/103 (52.4%). Iron supplementation was provided for 53/103 (51.5%) of patients. Having inpatient esophagogastroduodenoscopy or colonoscopy, blood transfusion, or symptomatic anemia had a statistical significance for likelihood of appropriate discharge documentation. Conclusions:Iron-deficiency anemia can have high rates of mortality and morbidity in the population. Appropriate discharge of patients with iron-deficiency anemia and factors related to this are paramount for clinicians in order to have the best patient outcomes
Modification of cellulose ether with organic carbonate for enhanced thermal and rheological properties: Characterization and analysis
Reduction in viscosity at higher temperatures is the main limitation of utilizing cellulose ethers in high thermal reservoir conditions for petroleum industry applications. In this study, cellulose ether (hydroxyethyl methyl cellulose (HEMC)) is modified using organic carbonates, i.e., propylene carbonate (PC) and diethyl carbonate (DEC), to overcome the limitation of reduced viscosity at high temperatures. The polymer composites were characterized through various analytical techniques, including Fourier-transform infrared (FTIR), H-NMR, X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), -potential measurement, molecular weight determination, and rheology measurements. The experimental results of structural and morphological characterization confirm the modification and formation of a new organic carbonate-based cellulose ether. The thermal analysis revealed that the modified composites have greater stability, as the modified samples demonstrated higher vaporization and decomposition temperatures. -potential measurement indicates higher stability of DEC- and PC-modified composites. The relative viscometry measurement revealed that the modification increased the molecular weight of PC- and DEC-containing polymers, up to 93,000 and 99,000 g/moL, respectively. Moreover, the modified composites exhibited higher levels of stability, shear strength and thermal resistance as confirmed by viscosity measurement through rheology determination. The observed increase in viscosity is likely due to the enhanced inter- and intramolecular interaction and higher molecular weight of modified composites. The organic carbonate performed as a transesterification agent that improves the overall properties of cellulose ether (HEMC) at elevated temperatures as concluded from this study. The modification approach in this study will open the doors to new applications and will be beneficial for substantial development in the petroleum industry
A Novel Micellar Electrokinetic Chromatographic Method for Separation of Metal-DDTC Complexes
Micellar electrokinetic chromatography (MEKC) was examined for the separation and determination of Mo(VI), Cr(VI), Ni(II), Pd(II), and Co(III) as diethyl dithiocarbamate (DDTC) chelates. The separation was achieved from fused silica capillary (52 cm × 75 μm id) with effective length 40 cm, background electrolyte (BGE) borate buffer pH 9.1 (25 mM), CTAB 30% (100 mM), and 1% butanol in methanol (70 : 30 : 5 v/v/v) with applied voltage of −10 kV using reverse polarity. The photodiode array detection was achieved at 225 nm. The linear calibration for each of the element was obtained within 0.16–10 μg/mL with a limit of detection (LOD) 0.005–0.0167 μg/mL. The separation and determination was repeatable with relative standard deviation (RSD) within 2.4–3.3% (n = 4) in terms of migration time and peak height/peak area. The method was applied for the determination of Mo(VI) from potatoes and almond, Ni(II) from hydrogenated vegetable oil, and Co(III) from pharmaceutical preparations with RSD within 3.9%. The results obtained were checked by standard addition and rechecked by atomic absorption spectrometry
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