Methanol-induced biological nutrient removal kinetics in a full-scale sequencing batch reactor

The primary goal of this research was to determine the potential for denitrification and phosphorus removal of a full-scale sequencing batch reactor (SBR), with and without the use of methanol as an external carbon source. The control SBR, without methanol addition, achieved negligible denitrification. Two denitrification rates were observed in the experimental SBR, with methanol addition, an initial fast rate and a slower second rate. The denitrification rate during the first rate period increased with increasing methanol concentration, until a maximum denitrification rate of approximately 19 mg NOx-N/g MLVSS/day was attained. Following the depletion of the methanol, denitrification reactions probably continued by using the available natural carbon in the influent, resulting in a slower, second denitrification rate. Biological phosphorus uptake and release was significant only in the SBR with methanol addition. Methanol was probably not utilized as the carbon source for the enhanced biological phosphorus removal (EBPR) process. However, methanol addition was critical, since it depleted the available nitrates and thus allowed EBPR to take place.     

Average-current-mode control of two-input buck postregulators usedin power-factor correctors

The use of the average-current-mode control in the two-input buck postregulator is studied in this paper. Using this type of control, the attenuation of the input voltage ripple (100-120 Hz) increases in relation to the one obtained when a conventional voltage-mode control (with or without feedforward) is used and, therefore, lower bulk capacitors can be used to obtain a very low voltage ripple at the output, which is very important when a battery is connected at the output. This is very common in distributed power supply systems     

Study of a Nitinol Stent Deployed into Anatomically Accurate Artery Geometry and Subjected to Realistic Service Loading

Realistic simulation of a stent in service loading is necessary for the design of Nitinol stents. This type of analysis is complicated by several issues: artery geometry and material properties are largely unknown and may vary from person to person; the loading on the stent is due to interactions between pulsatile blood flow, the artery, and stent. This study addresses the first issue by obtaining realistic artery geometry from magnetic resonance imaging (MRI) scans of a patient in the fetal and supine positions, and comparing deformation of the stent deployed into the two different artery configurations. The second issue is addressed by investigating two different methods of applying service loading. The first method applies sinusoidal pressure waves directly to the artery wall. The second method considers the effect of blood flow within the artery by performing a fluid-structure interaction (FSI) simulation. Simulation of expansion, annealing, crimping, and deployment of a Nitinol stent into the two artery configurations was performed using Abaqus. Following the deployment, sinusoidal pressure pulses, emulating systolic and diastolic blood pressures, were applied to the inner surface of the artery. To simulate the effect of blood within the artery, the coupled Eulerian-Lagrangian method in Abaqus was used. The blood was modeled as a partially filled Eulerian domain, whose material boundary contacted the Lagrangian artery. Transient inlet velocity and outlet pressure conditions were applied to the Eulerian domain to simulate blood flow. Since fatigue life calculations are important for the design of Nitinol stents, the maximum principal strains at the diastolic pressure troughs and the difference between the maximum principal strains at diastolic and systolic pressure were investigated for five cycles. Different maximum principal strains resulted for the different artery geometries (fetal or supine), while the difference between maximum principal strains was similar. For the simulations including the effect of blood flow, the maximum principal strains at the diastolic pressure troughs were somewhat higher than the simulations in which pressure was directly applied to the artery. In conclusion, this study established and compared various methods of improving the service loading in the simulation of Nitinol stents, specifically including anatomically correct artery geometry and the effect of blood flow.     

Unveiling the Metabolic Effects of Glycomacropeptide

For many years, the main nitrogen source for patients with phenylketonuria (PKU) was phenylalanine-free amino acid supplements. Recently, casein glycomacropeptide (GMP) supplements have been prescribed due to its functional and sensorial properties. Nevertheless, many doubts still persist about the metabolic effects of GMP compared to free amino acids (fAA) and intact proteins such as casein (CAS). We endeavour to compare, in rats, the metabolic effects of different nitrogen sources. Twenty-four male Wistar rats were fed equal energy density diets plus CAS (control, n = 8), fAA (n = 8) or GMP (n = 8) for 8 weeks. Food, liquid intake and body weight were measured weekly. Blood biochemical parameters and markers of glycidic metabolism were assessed. Glucagon-like peptide-1 (GLP-1) was analysed by ELISA and immunohistochemistry. Food intake was higher in rats fed CAS compared to fAA or GMP throughout the treatment period. Fluid intake was similar between rats fed fAA and GMP. Body weight was systematically lower in rats fed fAA and GMP compared to those fed CAS, and still, from week 4 onwards, there were differences between fAA and GMP. None of the treatments appeared to induce consistent changes in glycaemia, while insulin levels were significantly higher in GMP. Likewise, the production of GLP-1 was higher in rats fed GMP when compared to fAA. Decreased urea, total protein and triglycerides were seen both in fAA and GMP related to CAS. GMP also reduced albumin and triglycerides in comparison to CAS and fAA, respectively. The chronic consumption of the diets triggers different metabolic responses which may provide clues to further study potential underlying mechanisms.     

Synergistic Interaction of CPP2 Coupled with Thiazole Derivates Combined with Clotrimazole and Antineoplastic Drugs in Prostate and Colon Cancer Cell Lines

Cell-penetrating peptides (CPPs) are small peptide sequences used mainly as cellular delivery agents that are able to efficiently deliver cargo into cells. Some CPPs also demonstrate intrinsic anticancer properties. Previously, our group developed a new family of CPP2-thiazole conjugates that have been shown to effectively reduce the proliferation of different cancer cells. This work aimed to combine these CPP2-thiazole conjugates with paclitaxel (PTX) and 5-fluorouracil (5-FU) in PC-3 prostate and HT-29 colon cancer cells, respectively, to evaluate the cytotoxic effects of these combinations. We also combined these CPP2-thiazole conjugates with clotrimazole (CLZ), an antifungal agent that has been shown to decrease cancer cell proliferation. Cell viability was evaluated using MTT and SRB assays. Drug interaction was quantified using the Chou–Talalay method. We determined that CPP2 did not have significant activity in these cells and demonstrate that N-terminal modification of this peptide enhanced its anticancer activity in both cell lines. Our results also showed an uneven response between cell lines to the proposed combinations. PC-3 cells were more responsive to the combination of CPP2-thiazole conjugates with CLZ than PTX and were more sensitive to these combinations than HT-29 cells. In addition, the interaction of drugs resulted in more synergism in PC-3 cells. These results suggest that N-terminal modification of CPP2 results in the enhanced anticancer activity of the peptide and demonstrates the potential of CPPs as adjuvants in cancer therapy. These results also validate that CLZ has significant anticancer activity both alone and in combination and support the strategy of drug repurposing coupled to drug combination for prostate cancer therapy.     

Multi-stage optimization in a pilot scale gasification plant

A 2-D multiphase CFD model was coupled with advanced statistical methods to find the best operating conditions to maximize a set of selected responses that characterize the normal operation of a pilot scale fluidized bed gasifier running Municipal Solid Waste. After using CFD simulations to compute 7 responses at 27 different operating conditions, a single response optimization based on the response surface method was carried out to identify the best operating conditions. Then, the desirability concept was advantageously used to proceed with a multiple optimization where all the responses were targeted under normal industrial conditions. The operating conditions that set the optimized responses not always coincide with the most stable process. To target both optimized and robust conditions a multiple optimization combining the response surface and the propagation of error methods were employed. Finally, the tolerance intervals were reduced to increase the process Cpk and six sigma standards about 20%. New measures to further increase the process performance were identified and the transmitted variation to the response from input factors was computed.     

Evaluation of Tribological Behaviour of Polymeric Materials for Hip Prostheses Application

The tribological (friction and wear) behaviour of different polymeric materials was evaluated for hip prostheses applications. First, three polymeric materials were tested with fixed conditions of contact stress and sliding velocity. In a second phase, the material which presented the best results was selected. Its frictional behaviour under dynamic conditions of contact stress and sliding velocity was evaluated.     

Spatiotemporal Saliency in Dynamic Scenes

A spatiotemporal saliency algorithm based on a center-surround framework is proposed. The algorithm is inspired by biological mechanisms of motion-based perceptual grouping and extends a discriminant formulation of center-surround saliency previously proposed for static imagery. Under this formulation, the saliency of a location is equated to the power of a predefined set of features to discriminate between the visual stimuli in a center and a surround window, centered at that location. The features are spatiotemporal video patches and are modeled as dynamic textures, to achieve a principled joint characterization of the spatial and temporal components of saliency. The combination of discriminant center-surround saliency with the modeling power of dynamic textures yields a robust, versatile, and fully unsupervised spatiotemporal saliency algorithm, applicable to scenes with highly dynamic backgrounds and moving cameras. The related problem of background subtraction is treated as the complement of saliency detection, by classifying nonsalient (with respect to appearance and motion dynamics) points in the visual field as background. The algorithm is tested for background subtraction on challenging sequences, and shown to substantially outperform various state-of-the-art techniques. Quantitatively, its average error rate is almost half that of the closest competitor.     

MPF6D: masked pyramid fusion 6D pose estimation

Pattern Analysis and Applications - Object pose estimation has multiple important applications, such as robotic grasping and augmented reality. We present a new method to estimate the 6D pose of...