Air/Water Oxygen Transfer in a Biological Aerated Filter

The oxygen-transfer characteristics of an upflow biological aerated filter filled with angular clay media were determined over a wide range of gas and liquid flow rates. Liquid-side, oxygen-transfer coefficients (KLa) were measured using a nitrogen gas stripping method under abiotic conditions and were found to increase as both gas and liquid superficial velocity increases, with values ranging from 12 to 110?h?1 based on empty bed volume. The effect of gas and liquid velocity, wastewater to clean water ratio, and temperature dependence was correlated to within ±20% of the experimental KLa value. Stagnant gas holdup is roughly double in wastewater compared to clean water, but the dynamic gas holdup is the same. The oxygen-transfer coefficient is directly proportional to the dynamic gas holdup. Stagnant gas holdup does not influence the rate of oxygen transfer. The results suggest that dynamic gas holdup largely determines the specific interfacial area (a), whereas the interstitial liquid velocity largely controls the oxygen-transfer coefficient (KL).     

Government housing policy in New South Wales 1788–1900

This paper discusses the development of housing policy in Australia through a study of New South Wales. Throughout the 19th century the government became increasingly involved in housing. Its involvement was reluctant and not always welcomed. It was principally concerned with relationships between landlords and tenants and the quality of housing, and this paper examines the factors influencing the emerging pattern of intervention.     

Effects of prognostic information on global ratings of psychotherapy outcome.

30 graduate students in clinical psychology (raters) viewed a videotape recording of an interview with a patient after having read 1 of 3 types of posttherapy information about the patient. One group of raters was presented information associated with a good prognosis, one group was presented information associated with a poor prognosis, and the last group received neutral information about the patient. Half of the members of each group were told that the interview was made at the termination of therapy, the other half were told that it was a 1-yr follow-up interview. All raters then completed scales regarding patient's level of adjustment, psychic distress, amount of change, and success of patient's therapy. Only ratings of pre- to posttherapy patient change varied as a function of prognostic information. Results suggest that although poor prognosis patients are perceived as exhibiting more change than good prognosis patients, only final level of functioning determines global judgments of psychotherapy outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dual source fourier transform polarization modulation spectroscopy: an improved method for the measurement of circular and linear dichroism

It is shown that the use of two sources in a four-port interferometer equipped with cube-corner mirrors leads to increased signal-to-noise ratios in Fourier transform (FT-IR) circular and linear dichroism spectra. The output beam to the sample is a superposition of two interferograms, one from each source, having opposite Fourier phases. These two interferograms cancel one another to the degree that the two sources are matched in intensity. If the radiation from each of the two sources is first polarized orthogonally with respect to the other and passed through a polarization modulator before reaching the sample, the resulting polarization-modulation interferograms are out of Fourier phase and out of polarization-modulation phase. As a result, the polarization-modulation interferograms, due to circular or linear dichroism in the sample, from the two sources combine positively rather than negatively. An improvement in signal-to-noise ratio of up to two (or a factor of four in scan-time reduction for the same signal-to-noise ratio) compared to single source operation can be realized, while at the same time, the potential for saturation of the detector signal is significantly reduced due to the reduction in magnitude of the combined ordinary infrared transmission interferogram. Absorption and circular dichroism spectra from a dual-source FT-IR spectrometer are presented and analyzed.     

Optimizing Transportation Problems with Multiple Objectives

Virtually all models developed for transportation problems have focused upon the optimization of a single objective criterion, namely the minimization of total transportation costs. They have generally neglected or often ignored the multiple conflicting objectives involved in the problem, the priority structure of these objectives, various environmental constraints, unique organizational values of the firm, and bureaucratic decision structures. However, in reality these are important factors which greatly influence the decision process of transportation problems. In this study the goal programming approach is utilized in order to allow for the optimization of multiple conflicting goals while permitting an explicit consideration of the existing decision environment.     

The role of rehabilitation psychologists in the treatment of disease and disability.

It is contended that rehabilitation psychologists have remained content to continue using the same techniques for the same types of problems that they used more than a decade ago. Because of a temerity of thought, rehabilitation psychologists have not extended their particular research and technological expertise into the more major areas of health care. Examples are presented in which such psychological techniques as conditioning and biofeedback were employed to treat successfully a variety of serious health problems. Rather than leave the major areas of investigation and treatment to others, as has traditionally been the case, rehabilitation psychologists are urged to utilize their skills in studying and treating the major physical problems of their patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduction of poliovirus 1, bacteriophages,Salmonella montevideo,and Escherichia coli O157:H7 on strawberries by physical and disinfectant washes

The efficacy levels of different physical and chemical washing treatments in the reduction of viral and bacterial pathogens from inoculated strawberries were evaluated. Escherichia coli O157:H7, Salmonella Montevideo, poliovirus 1, and the bacteriophages PRD1, phiX174, and MS2 were used as model and surrogate organisms. Chemicals readily available to producers and/or consumers were evaluated as antimicrobial additives for the production of washes. The gentle agitation of contaminated strawberries in water for 2 min led to reductions in microbial populations ranging from 41 to 79% and from 62 to 90% at water temperatures of 22 and 43 degrees C, respectively. Significant reductions (> 98%) in numbers of bacteria and viruses were obtained with sodium hypochlorite (50 to 300 ppm of free chlorine), Oxine or Carnebon (200 ppm of product generating "stabilized chlorine dioxide"), Tsunami (100 ppm of peroxyacetic acid), and Alcide (100 or 200 ppm of acidified sodium chlorite) washes. Overall, 200 ppm of acidified sodium chlorite produced the greatest reductions of microorganisms. Hydrogen peroxide (0.5%) was slightly less effective than free chlorine in a strawberry wash and caused slight fruit discoloration. Cetylpyridinium chloride (0.1%) was effective in the reduction of bacterial species, while trisodium phosphate (1%) was effective against viruses. The consumer-oriented produce wash Fit was very effective (> 99%) in reducing the numbers of bacteria but not in reducing the numbers of viruses. Another wash, Healthy Harvest, was significantly less effective than Fit in reducing bacterial pathogens but more effective for viruses. The performance of automatic dishwashing detergent was similar to that of Healthy Harvest and significantly better than that of liquid dishwashing detergent. Solutions containing table salt (2% NaCl) or vinegar (10%) reduced the numbers of bacteria by about 90%, whereas only the vinegar wash reduced the numbers of viruses significantly (ca. 95%).     

Controlled modification and direct characterization of multimode-fiber refractive-index profiles

A combination of controlled annealing and characterization by scanning probe microscopy (SPM) is used to demonstrate that the refractive-index proffle of a commercially available silica-based optical fiber can be accurately reconfigured for use as an evanescent field sensor. The process relies on the controlled relocation of the silica glass dopants across the fiber cross section through heat treatment and the accurate measurement of the resulting dopant redistribution with SPM and differential etching techniques. The effect of variable annealing along a length of fiber is to produce a mode transformer to couple light from a laser source into the sensing region of the fiber.