Simulation modeling for nitrogen removal and experimental estimation of mass fractions of microbial groups in single-sludge system.

Nitrification-denitrification in a single-sludge nitrogen removal system (SSNRS; with a sufficient carbon source for denitrification) was performed. With an increase in the mixed liquor recycle ratio (R(m)) from 1 to 2, the total nitrogen (TN) removal efficiency at a lower volumetric loading rate (VLR=0.21 NH(4)(+)-N m(-3) d(-1)) increased, but the TN removal efficiency at a higher VLR (0.

Interactive fuzzy optimization for an economic and environmental balance in a river system.

An interactive fuzzy approach is applied to develop a water quality management plan in a river basin for solving multi-objective optimization problems involving vague and imprecise information related to data, model formulation, and the decision maker's preferences. This approach, originally proposed by Sakawa in 1983, is modified and presented as a sustainable water quality management strategy in which the decision makers and the environmental analysts put forward their views on three major economic and environmental factors: river water quality, assimilative capacity, and treatment cost of wastewater. This methodology is illustrated in a case study of multi-objective water quality management in the Tou-Chen River Basin in northern Taiwan.

Vibration sensitivity of the scanning near-field optical microscope with a tapered optical fiber probe.

In this paper the Rayleigh-Ritz method was used to study the scanning near-field optical microscope (SNOM) with a tapered optical fiber probe's flexural and axial sensitivity to vibration. Not only the contact stiffness but also the geometric parameters of the probe can influence the flexural and axial sensitivity to vibration. According to the analysis, the lateral and axial contact stiffness had a significant effect on the sensitivity of vibration of the SNOM's probe, each mode had a different level of sensitivity and in the first mode the tapered optical fiber probe was the most acceptive to higher levels of flexural and axial vibration.

Effects of helium-neon laser on levels of stress protein and arthritic histopathology in experimental osteoarthritis.

Objective: To investigate the effect of low-power laser therapy on levels of stress proteins (SPs) in experimental arthritis and their relation to the bioeffects on arthritic cartilage repair.

Design: A total of 42 rats with similar degrees of induced arthritis evaluated by means of bone scan were divided randomly into two groups. In the treated group, 21 rats received helium-neon laser treatment; in the control group, 21 rats received sham laser treatment.

Kinetic study on the sorption of dissolved natural organic matter onto different aquifer materials: the effects of hydrophobicity and functional groups.

The subsurface sorption of Suwannee River fulvic acid (SRFA) and humic acid (SRHA) onto a synthetic aquifer material (iron-oxide-coated quartz) and two natural aquifer materials (Ringold sediment and Bemidji soils) was studied in both batch and column experiments. The hypothesis that hydrophobic effects followed by ligand exchange are the dominant mechanism contributing to the chemical sorption happening between dissolved natural organic matter (NOM) and the mineral surfaces is supported by observations of several phenomena: nonlinear isotherms, faster sorption rates versus slower desorption rates, phosphate competition, a solution pH increase during NOM sorption, and functional groups and aromaticity-related sorption. In addition, high-pressure size exclusion chromatography (HPSEC) and carboxylic acidity showed that lower molecular weight NOM components of SRHA are preferentially sorbed to iron oxide, a result in contrast to that for SRFA.

Determination of albumin concentration by MIP-QCM sensor.

An MIP-QCM sensor able to detect micro-determine albumin concentrations was prepared by imprinting albumin with 3-dimethylaminopropyl methacrylamide-acrylate. The albumin MIP was coated on a QCM Au electrode. The adsorption characteristics of different electrodes, such as Au-OH, Au-COOH, Au-NH2 and Au electrodes, with albumin or mixture was examined.

Transport of anthracene and benz(a)anthracene through iron-quartz and three aquifer materials in laboratory columns.

In groundwater systems, dissolved natural organic matter (NOM) can influence the mobility of organic contaminants by altering the contaminant behavior in water and solid phases. The transport of anthracene and benz(a)anthracene (B(a)A) was studied in the presence and absence of NOM and/or soil organic matter (SOM) in column experiments. The results show that sorption are related to the properties of polycyclic aromatic hydrocarbons (PAHs), NOM and SOM.

Reconstruction of the temperature field for inverse ultrasound hyperthermia calculations at a muscle/bone interface.

An inverse algorithm with Tikhonov regularization of order zero has been used to estimate the intensity ratios of the reflected longitudinal wave to the incident longitudinal wave and that of the refracted shear wave to the total transmitted wave into bone in calculating the absorbed power field and then to reconstruct the temperature distribution in muscle and bone regions based on a limited number of temperature measurements during simulated ultrasound hyperthermia. The effects of the number of temperature sensors are investigated, as is the amount of noise superimposed on the temperature measurements, and the effects of the optimal sensor location on the performance of the inverse algorithm. Results show that noisy input data degrades the performance of this inverse algorithm, especially when the number of temperature sensors is small.

Optimal expansion of water quality monitoring network by fuzzy optimization approach.

River reaches are frequently classified with respect to various mode of water utilization depending on the quantity and quality of water resources available at different location. Monitoring of water quality in a river system must collect both temporal and spatial information for comparison with respect to the preferred situation of a water body based on different scenarios. Designing a technically sound monitoring network, however, needs to identify a suite of significant planning objectives and consider a series of inherent limitations simultaneously.

Elasto-optics in double-coated optical fibers induced by axial strain and hydrostatic pressure.

Stresses, microbending loss, and refractive-index changes induced simultaneously by axial strain and hydrostatic pressure in double-coated optical fibers are analyzed. The lateral pressure and normal stresses in the optical fiber, primary coating, and secondary coating are derived. Also presented are the microbending loss and refractive-index changes in the glass fiber.

Eutrophication study of twenty reservoirs in Taiwan.

Taiwan is an island off the southeastern coast of China with total area of roughly 36,000 km2. The geographic position of Taiwan is between 21degrees 45' 25" to 25 degrees 56' 31" north latitude and 119 degrees 18' 3"to 124 degrees 34' 30" east longitude and includes both tropical and subtropical areas. The study was carried out at twenty main reservoirs in Taiwan area from 1994 to 1998.