Rheological properties of a dilute suspension of self-propelled particles

With a detail microscopic model for a self-propelled swimmer, we derive the rheological properties of a dilute suspension of such particles at small Peclet numbers. It is shown that, in addition to the Einstein's like contribution to the effective viscosity, that is proportional to the volume fraction of the swimmers, a contribution due to the activity of self-propelled particles influences the viscosity. As a result of the activity of swimmers, the effective viscosity would be a lower (higher) than the viscosity of the suspending medium when the particles are pushers (pullers). Such activity dependent contribution, will also results to a non-Newtonian behavior of the suspension in the form of normal stress differences

Financial Analysis of a Grid-connected Photovoltaic System in South Florida

In this paper the performance and financial analysis of a grid-connected photovoltaic system installed at Florida Atlantic University (FAU) is evaluated. The power plant has the capacity of 14.8 kW and has been under operation since August 2014. This solar PV system is composed of two 7.4 kW sub-arrays, one fixed and one with single axis tracking. First, an overview of the system followed by local weather characteristics in Boca Raton, Florida is presented. In addition, monthly averaged daily solar radiation in Boca Raton as well as system AC are calculated utilizing the PVwatts simulation calculator. Inputs such as module and inverter specifications are applied to the System Advisor Model (SAM) to design and optimize the system. Finally, the estimated local load demand as well as simulation results are extracted and analyzed.Comment: 6 Pages, IEEE PVSC 2017 Conference, Washington D.

Modeling a Grid-Connected PV/Battery Microgrid System with MPPT Controller

This paper focuses on performance analyzing and dynamic modeling of the current grid-tied fixed array 6.84kW solar photovoltaic system located at Florida Atlantic University (FAU). A battery energy storage system is designed and applied to improve the systems stability and reliability. An overview of the entire system and its PV module are presented. In sequel, the corresponding I-V and P-V curves are obtained using MATLAB-Simulink package. Actual data was collected and utilized for the modeling and simulation of the system. In addition, a grid- connected PV/Battery system with Maximum Power Point Tracking (MPPT) controller is modeled to analyze the system performance that has been evaluated under two different test conditions: (1) PV power production is higher than the load demand (2) PV generated power is less than required load. A battery system has also been sized to provide smoothing services to this array. The simulation results show the effective of the proposed method. This system can be implemented in developing countries with similar weather conditions to Florida.Comment: 6 pages, 14 figures, PVSC 201

The kinetics of update and release of polycyclic aromatic hydrocarbons in the green mussels perna viridis for biomonitoring of marine pollution

The kinetics of accumulation and depuration of polycyclic aromatic hydrocarbons (PAHs) in green mussel Perna viridis has never been investigated under field conditions. In this study, green mussels were used to assess the spatial distribution of PAH pollution along the west coast of Peninsular Malaysia, and to determine PAHs uptake and release kinetics in this species under field conditions. In addition, the effect of sex and exposure duration on the uptake and release kinetics of these contaminants were investigated. Overall more than 1500 individual mussels were collected, soft tissues were homogenized, extracted, cleaned up, fractionated and concentration of 17 individual PAH compounds were analysed using Gas Chromatography-Mass Spectrometry (GC-MS). Among the eleven stations sampled in 1997 and 1998 along the Straits of Malacca, mussels from Pasir Puteh (01˚ 26.05' N and 103˚ 55.94' E) had the highest (2855-3450 nglg lipid weight) and from Pasir Panjang (02˚ 24.96' N and 101˚ 56.54' E) the lowest (278-366 ng/g lipid weight) levels of PAHs. As a result, Pasir Puteh was selected as the "hot-spot" and Pasir Panjang as the "clean site" to further conduct the kinetics experiments. The PAH levels in mussels from Malaysian coastlines in comparison with the polluted areas worldwide were found to be relatively low. At the end of both uptake and release experiments (28 and 36 days, respectively), PAH levels in transplanted and back transplanted mussels were not significantly different (p>0.05) from those found in natives (controls in Pasir Puteh and Pasir Panjang, respectively). It was found that sex did not make a significant difference (p>0.05) in the uptake and release rates. Similarly, duration of exposure did not significantly affect the release rates. However, significant differences (p<0.05) were found both in uptake and release rates when target PAHs were divided into three, four and five to seven-ring compounds. In general, rapid rates of uptake and release of relatively less lipophilic PAHs were observed, indicating that the primary mechanism of bioaccumulation of these lipophilic pollutants in Perna viridis complies with the concept of lipid-water partitioning equilibrium. The biological half-life of individual PAHs ranged from 7 to 29 days. This study illustrated that green mussels are a useful tool in monitoring of PAHs. However, due to relatively rapid rates of uptake and release of these compounds, to get an average level of PAHs over a long period, "time-bulking" should be considered for future biomonitoring programmes using this species

Digital Holographic Microscopy of Phase Separation in Multicomponent Lipid Membranes

Lateral in-homogeneities in lipid compositions cause microdomains formation and change in the physical properties of biological membranes. With the presence of cholesterol and mixed species of lipids, phospholipid membranes segregate into lateral domains of liquid-ordered and liquid-disordered phases. Coupling of two-dimensional intralayer phase separations and interlayer liquid-crystalline ordering in multicomponent membranes has been previously demonstrated. By the use of digital holographic microscopy (DHMicroscopy), we quantitatively analyzed the volumetric dynamical behavior of such membranes. The specimens are lipid mixtures composed of sphingomyelin, cholesterol, and unsaturated phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine. DHMicroscopy in a transmission mode is an effective tool for quantitative visualization of phase objects. By deriving the associated phase changes, three-dimensional information on the morphology variation of lipid stacks at arbitrary time scales is obtained. Moreover, the thickness distribution of the object at demanded axial planes can be obtained by numerical focusing. Our results show that the volume evolution of lipid domains follows approximately the same universal growth law of previously reported area evolution. However, the thickness of the domains does not alter significantly by time; therefore, the volume evolution is mostly attributed to the changes in area dynamics. These results might be useful in the field of membrane-based functional materials

An Analysis of ‘Closure’ and ‘Equilibrium’ in Mathew Quick’s The Silver Linings Playbook in the Light of Gestalt Psychology

The present paper moves in the line of cognitive literary studies. Its project is to interpret Mathew Quick’s The Silver Linings Playbook in the light of the theories of Gestalt psychology. Quick portrays a pair of mentally unbalanced protagonists suffering from the loss of their partners. Analyzing the psychological aftermaths which befall these figures afterwards, this paper attempts to highlight some facts through Gestalt therapy. As such, this paper tries to show the role of ‘Closure’ in the psychological imbalance of Quick’s characters, arguing that in their search for ‘Equilibrium’ they pass through a phase of neurotic problems. Deciphering part of the novel’s message as such, this paper elaborates upon the life of some mentally damaged guys who come to help each other in order to pass normal and healthy lives

Bimodal network architectures for automatic generation of image annotation from text

Medical image analysis practitioners have embraced big data methodologies. This has created a need for large annotated datasets. The source of big data is typically large image collections and clinical reports recorded for these images. In many cases, however, building algorithms aimed at segmentation and detection of disease requires a training dataset with markings of the areas of interest on the image that match with the described anomalies. This process of annotation is expensive and needs the involvement of clinicians. In this work we propose two separate deep neural network architectures for automatic marking of a region of interest (ROI) on the image best representing a finding location, given a textual report or a set of keywords. One architecture consists of LSTM and CNN components and is trained end to end with images, matching text, and markings of ROIs for those images. The output layer estimates the coordinates of the vertices of a polygonal region. The second architecture uses a network pre-trained on a large dataset of the same image types for learning feature representations of the findings of interest. We show that for a variety of findings from chest X-ray images, both proposed architectures learn to estimate the ROI, as validated by clinical annotations. There is a clear advantage obtained from the architecture with pre-trained imaging network. The centroids of the ROIs marked by this network were on average at a distance equivalent to 5.1% of the image width from the centroids of the ground truth ROIs.Comment: Accepted to MICCAI 2018, LNCS 1107

Centering ability and dentin removal of rotary systems in curved root canals

INTRODUCTION: The aim of this study was to compare centering ability and dentin removal of three rotary systems in curved root canals of extracted teeth. MATERIALS AND METHODS: Sixty root canals of mandibular first molars with curvatures ranging between 25-35o were divided into three groups of 20 teeth each. Based on pre-instrumentation radiographs that assessed the angle and the radius of canal curvatures, teeth with curvatures were equally spread between the three groups. The root canals were sectioned horizontally at two levels before preparation and then remounted onto the muffle. All root canals were prepared using a low-torque control motor with Mtwo or Medin or Race instruments. Cross sectional images were obtained before and after instrumentation. Cross-sectional area and centering ability were evaluated. The data were analyzed using the one-way ANOVA and Tukey tests. RESULTS: Neither instrument fracture nor permanent deformation occurred during preparations. The best centering ability was obtained by Mtwo instruments compare to Race and Medin instruments. In the coronal and middle sections, Mtwo removed less dentin than Race and Medin; while the difference in the apical section was not significant. CONCLUSION: Under the conditions of this study, the debridement of root canals was more conservative with Mtwo. The canals prepared with these instruments were better centered in all three regions of the root