Development of a control algorithm for air‐scour reduction in membrane bioreactors for wastewater treatment

BACKGROUND: Membrane bioreactors are used in an increasing number of wastewater treatment facilities because of their compactness and efficiency in solid‐liquid separation, but energy requirements are still higher than other competitive technologies such as conventional activated sludge. RESULTS: In this paper the development of an air‐scour control algorithm based on short‐term and long‐term membrane permeability evolution is presented. An open loop calibration and partial validation was carried out in a semi‐industrial scale pilot plant where manual changes in air‐scour flow had been previously carried out. The control system was successfully tested in closed loop in an industrial scale pilot plant, defining a maximum daily air‐scour decrease or increase of 6% of the air‐scour recommended by membranes suppliers. An average air‐scour saving of 13% and a maximum of 20%, calculated in terms of air flow saved, were achieved during the validation test without any apparent long‐term effect on membrane permeability. CONCLUSION: It was proven that the air‐scour control system is an important tool capable of reducing operational costs in MBR systems. Copyright © 2011 Society of Chemical Industry     

Synthesis of Nanocompositites Containing Tantalum or Molybdenum Nitride with Silicon Imidonitride

Ammonolysis of solutions containing tetrakis(methylamido)silane and either pentakis(dimethylamido)tantalum(V) or tetrakis(dimethylamido)molybdenum(IV) results in gels that can be pyrolysed in ammonia to yield metal-containing amorphous silicon nitride compositions. The tantalum-containing samples remain amorphous to 1000?°C, though there is evidence of some metal clustering, whereas the molybdenum-containing samples crystallise molybdenum nitride nanorods at 1000?°C.     

Fluorescence‐based fouling prediction and optimization of a membrane filtration process for drinking water treatment

A novel fluorescence‐based approach is proposed for modeling, predicting, and optimizing different fouling dynamics in an ultrafiltration (UF) process for drinking water treatment. Principal component analysis (PCA) was used to extract information in terms of principal components (PCs), related to major membrane foulant groups, from fluorescence excitation–emission matrix measurements captured during UF of natural river water. The evolution of PC scores during the filtration process was then related to membrane fouling using dynamic balances of latent variable values (PC scores). This approach was found suitable for forecasting fouling behaviors with good accuracy based solely on fluorescence data collected 15 min from the start of the filtration. The proposed approach was tested experimentally through model‐based optimization of backwashing times with the objective of minimizing the energy consumption per unit amount of water produced during the filtration process. This approach was also useful for identifying fouling groups contributing to reversible and irreversible fouling. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

International Society of Sports Nutrition position stand: Nutrient timing

Background

The present experiment examined the responses of peripheral modulators and indices of brain serotonin (5-HT) and dopamine (DA) function and their association with perception of effort during prolonged exercise in the heat after creatine (Cr) supplementation.

Methods

Twenty one endurance-trained males performed, in a double-blind fashion, two constant-load exercise tests to exhaustion at 63 ± 5% O _{2 max} in the heat (ambient temperature: 30.3 ± 0.5 °C, relative humidity: 70 ± 2%) before and after 7 days of Cr (20 g·d^-1 Cr + 140 g·d^-1 glucose polymer) or placebo (Plc) (160 g·d^-1 glucose polymer) supplementation.

Results

3-way interaction has shown that Cr supplementation reduced rectal temperature, heart rate, ratings of perceived leg fatigue (P < 0.05), plasma free-tryptophan (Trp) (P < 0.01) and free-Trp:tyrosine ratio (P < 0.01) but did not influence the ratio of free-Trp:large neutral amino acids or contribute in improving endurance performance (Plc group, n = 10: 50.4 ± 8.4 min vs. 51.2 ± 8.0 min, P > 0.05; Cr group, n = 11: 47.0 ± 4.7 min vs. 49.7 ± 7.5 min, P > 0.05). However, after dividing the participants into "responders" and "non-responders" to Cr, based on their intramuscular Cr uptake, performance was higher in the "responders" relative to "non-responders" group (51.7 ± 7.4 min vs.47.3 ± 4.9 min, p < 0.05).

Conclusion

although Cr influenced key modulators of brain 5-HT and DA function and reduced various thermophysiological parameters which all may have contributed to the reduced effort perception during exercise in the heat, performance was improved only in the "responders" to Cr supplementation. The present results may also suggest the demanding of the pre-experimental identification of the participants into "responders" and "non-responders" to Cr supplementation before performing the main experimentation. Otherwise, the possibility of the type II error may be enhanced.     

Colorimetry technique on BaTiO3 and KNbO3 ceramics to determine the phase transition

In this work, colorimetry was used in order to identify the phase transition of BaTiO₃ and KNbO₃ ceramic. The transition of the structure produces a change of color of the ceramic bulks because their optical properties change. The transition phase was detected with a color sensor and reflectance method on ceramic bulks. CIE L*a*b* and CIE L*u*v* color spaces were used to measure the color changes reported. Experimental results showed that the changes of color are suitable for detecting the phase transition in both perovskite structures. The phase transition in the proposed ferroelectric materials was also measured by means of the dielectric constant method and the results obtained were in agreement with the temperatures reported for phase transition changes on BaTiO₃ and KNbO₃. Therefore, the colorimetry technique proposed in this paper proved to be suitable for detecting structure changes as a relationship between color properties and temperature.     

Stages of Change Among Chinese People With Mental Illness: A Preliminary Study.

Objective: To determine the effect of self-efficacy and outcome expectancy on the readiness for rehabilitation among Chinese people with mental illness. Participants: Fifty-eight men and 62 women with chronic mental illness. Outcome Measures: Change Assessment Questionnaire for People With Severe and Persistent Mental Illness, Task-Specific Self-Efficacy Scale for People With Mental Illness, and Outcome-Expectancy Scale for People With Mental Illness. Results: Chinese people with mental illness can be meaningfully classified into 4 stages of change (SOC) groups: precontemplation, contemplation, ambivalent-conforming, and action-maintenance. SOCs are related to self-efficacy in interpersonal, symptoms management, and help-seeking skills as well as expectations about the benefit of social and coping skills. Conclusion: The SOC concept is useful for tailoring culturally sensitive psychiatric rehabilitation interventions for Chinese people with mental illness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Color image ownership protection based on spectral domain watermarking using QR codes and QIM

Some watermarking authentication methods based on spectral domain using QR codes and Quantization Index Modulation (QIM) are proposed for ownership protection in color images. The QR code is created with the owners’ information and used as binary watermark sequence, which is permuted using Arnold Permutation to increase the security before embedding it. Once the watermark sequence is generated, the original color image is transformed from RGB to YCbCr color space where the Luminance Channel (Y) is processed by the Singular Value Decomposition (SVD), Discrete Wavelet Transform (DWT) and Discrete Cosine Transform (DCT) to embed the binary watermark sequence using Quantization Index Modulation (QIM). The experimental results show the effectiveness of the proposed method.     

State Estimation Using Non-uniform and Delayed Information: A Review

The study and application of methods for incorporating nonuniform and delayed information in state estimation techniques are important topics to advance in soft sensor development.Therefore, this paper presents a review of these methods and proposes a taxonomy that allows a faster selection of state estimator in this type of applications. The classification is performed according to the type of estimator, method, and used tool. Finally, using the proposed taxonomy, some applications reported in the literature are described.     

Segmentation and adaptive assimilation for detail-preserving display of high-dynamic range images

Realistic display of high-dynamic range images is a difficult problem. Previous methods for high-dynamic range image display suffer from halo artifacts or are computationally expensive. We present a novel method for computing local adaptation luminance that can be used with several different visual adaptation-based tone-reproduction operators for displaying visually accurate high-dynamic range images. The method uses fast image segmentation, grouping, and graph operations to generate local adaptation luminance. Results on several images show excellent dynamic range compression, while preserving detail without the presence of halo artifacts. With adaptive assimilation, the method can be configured to bring out a high-dynamic range appearance in the display image. The method is efficient in terms of processor and memory use.     

Impairment in shifting attention in autistic and cerebellar patients.

Magnetic resonance imaging (MRI) and autopsy evidence of early maldevelopment of cerebellar vermis and hemispheres in autism raises the question of how cerebellar maldevelopment contributes to the cognitive and social deficits characteristic of autism. Compared with 18 normal controls, 8 autistic patients (mean age 13.9 yrs) and 6 patients (mean age 8.6 yrs) with acquired cerebellar lesions were similarly impaired in a task requiring rapid and accurate shifts of attention between auditory and visual stimuli. Neurophysiologic and behavioral evidence rules out motor dysfunction as the cause of this deficit. These findings are consistent with the proposal that in autism cerebellar maldevelopment may contribute to an inability to execute rapid attention shifts, which in turn undermines social and cognitive development. Findings support the proposal that the human cerebellum is involved in the coordination of rapid attention shifts in a fashion analogous to its role in the coordination of movement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)