91 research outputs found
Length Effects of a Built-in Flapping Flat Plate on the Flow Over a Traveling Wavy Foil
Flow over the traveling wavy foil with a built-in rigid flapping plate at its trailing edge has been numerically studied using the multi-relaxation-time Lattice Boltzmann method and immersed boundary method. The effect of the plate length on the propulsive performance such as the thrust force, energy consumption, and propeller efficiency has been investigated. Three modes (body force dominated, body and tail force competing and tail force dominated modes) have been identified that are associated with different hydrodynamics and flow structures. It is revealed that there exists a better performance plate length region and, within this region, a high propeller efficiency (close to its maximum value) is achieved due to a great increase in propulsive force at a cost of a slight increase in energy consumption. Furthermore, a weak stabilizing effect on locomotion movement is indicated by the slight decrease in the root-mean-square (rms) values of drag and lateral forces. Β© 2014 American Physical Society
Flow Over a Traveling Wavy Foil With a Passively Flapping Flat Plate
Flow over a traveling wavy foil with a passively flapping flat plate has been investigated using a multiblock lattice Boltzmann equation and the immersed boundary method. The foil undergoes prescribed undulations in the lateral direction and the rigid flat plate has passive motion determined by the fluid structure interaction. This simplified model is used to study the effect of the fish caudal fin and its flexibility on the locomotion of swimming animals. The flexibility of the caudal fin is modeled by a torsion spring acting about the pivot at the conjuncture of the wavy foil and the flat plate. The study reveals that the passively oscillating flat plate contributes half of the propulsive force. The flexibility, represented by the nondimensional natural frequency F, plays a very important role in the movement and propulsive force generation of the whole body. When the plate is too flexible, the drag force is observed. As the flat plate becomes more rigid, the propulsive force that is generated when the undulation is confined to last part of the wavy foil becomes larger. The steady movement occurs at F=5. These results are consistent with the observations of some swimming animals in nature. Β© 2012 American Physical Society
A deformable plate interacting with a non-Newtonian fluid in three dimensions
We consider a deformable plate interacting with a non-Newtonian fluid flow in three dimensions as a simple model problem for fluid-structure-interaction phenomena in life sciences (e.g., red blood cell interacting with blood flow). A power-law function is used for the constitutive equation of the non-Newtonian fluid. The lattice Boltzmann equation (the D3Q19 model) is used for modeling the fluid flow. The immersed boundary (IB) method is used for modeling the flexible plate and handling the fluid-plate interaction. The plate drag and its scaling are studied; the influences of three dimensionless parameters (power-law exponent, bending modulus, and generalized Reynolds number) are investigated
Unlocking the key to successful commercialization by coupling the power of biocatalysis, strain engineering, and application studies
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Nonlinear Analysis of Dynamic Stability and the Prediction of Wing Rock
Nonlinear analysis of dynamic stability for a delta wing in rolling motion at high angles of attack is presented based on a modeled differential equation for wing rolling motion. A method for determining the aerodynamic coef cients up to third-order approximation in the modeled equation, which are functions of the amplitude of wing rolling oscillation at a xed high angle of attack, is proposed by use of the Fourier expansion approach. Using the modeled equations of motion combined with the aerodynamic coef cients determined by the conical Eulerian computations of supersonic ow past a forced rolling delta wing, we predicted the rock motion of a delta wing that was set into a free-to-roll motion. The results were compared with those obtained by direct coupling calculations based on solving the unsteady ow equations and the wing motion equations simultaneously, which proved to be in fairly good agreement with each other. A numerical investigation of active control technique of the wing rock was also performed by use of the present method
Antibacterial performance of a porous Cu-bearing titanium alloy by laser additive manufacturing
Porphyromonas gingivalis (P. gingivalis) is the most common species that causes peri-implantitis. It forms an irreversible dense biofilm and causes inflammation. A novel 3D-printed porous TC4-6Cu alloy was fabricated using selective laser melting (SLM) technology for the dental implant, which is anticipated to inhibit biofilm formation. We attempted to investigate the antibacterial ability and antibacterial mechanism of the 3D-printed porous TC4-6Cu alloy against P. gingivalis. This work used scanning electron microscopy (SEM) and laser confocal microscopy (CLSM) to detect the antimicrobial ability of the alloy against sessile P. gingivalis. The results indicated that the 3D-printed porous TC4-6Cu alloy could cause bacterial fragmentation and deformation. Plate antimicrobial counting experiments showed that the antibacterial rates of the alloy against adherent bacteria and planktonic bacteria after 24Β h were 98.05% and 73.92%, respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Cu2+ were tested to appraise the antibacterial property of the alloy against planktonic P. gingivalis. The relationship between the antibacterial mechanism of the alloy with oxidative stress was evaluated through ROS fluorescence intensity and protein leakage concentration. The results revealed that the alloy significantly eliminated adherent bacteria and inhibited biofilm formation. Moreover, 3D-printed porous TC4-6Cu alloy demonstrated significant bactericidal ability by inducing the production of reactive oxygen species (ROS), which could result in protein leakage from the bacterial cell membrane. This research may open a new perspective on the development and biomedical applications for dental implantation
Impaired tumor angiogenesis and VEGF-induced pathway in endothelial CD146 knockout mice
This research aims to develop mathematical teaching materials based on sharia economy for madrasah tsanawiyah students with good quality. The method used in the study is the development model adapted from Borg & Gall is the preliminary stage, development, and validation. The preliminary stage includes literature studies, analysis of the needs and characteristics of students, and to plan and choose the design of teaching materials. The development phase includes determining the competence standard, basic competence, indicators, and the subject matter, compiling teaching materials math, and prepare research instruments. The validation phase includes validation expert and revisions. Results of the study are social arithmetic teaching materials based on sharia economy. Each material begins with the problem of economic comparison of Islamic and conventional. The feasibility of the value of teaching materials is Very Good for aspects of the look and Very Good for the material aspects. With these criteria very well, teaching materials are feasible for use in the learning of mathematics in the social arithmetic material
A Novel Anti-CEACAM5 Monoclonal Antibody, CC4, Suppresses Colorectal Tumor Growth and Enhances NK Cells-Mediated Tumor Immunity
Carcinoembryonic antigen (CEA, CEACAM5, and CD66e) has been found to be associated with various types of cancers, particularly colorectal carcinoma, and developed to be a molecular target for cancer diagnosis and therapy. In present study, we generated a novel anti-CEACAM5 monoclonal antibody, namely mAb CC4, by immunizing mice with living colorectal cancer LS174T cells. Immunohistochemical studies found that mAb CC4 specifically and strongly binds to tumor tissues, especially colorectal adenocarcinoma. In xenografted mice, mAb CC4 is specifically accumulated in tumor site and remarkably represses colorectal tumor growth. In vitro functional analysis showed that mAb CC4 significantly suppresses cell proliferation, migration and aggregation of colorectal cancer cells and also raises strong ADCC reaction. More interestingly, mAb CC4 is able to enhance NK cytotoxicity against MHC-I-deficient colorectal cancer cells by blocking intercellular interaction between epithelial CEACAM5 and NK inhibitory receptor CEACAM1. These data suggest that mAb CC4 has the potential to be developed as a novel tumor-targeting carrier and cancer therapeutic
Down-regulation of miR-675-5p contributes to tumor progression and development by targeting pro-tumorigenic GPR55 in non-small cell lung cancer
Steganography techniques and implementation - for hiding information in digital images
A continuous boost in the amount of information exchanged and stored in a variety of
digital media has been brought by the increasing use of the Internet brings about. This
has resulted in certain unusual consequences involving both helpful and harmful
usage of data.
Steganography is a beautiful art of concealing the fact that when communication is
happening, it conceals data in other forms of data. Because of their prevalent usage on
the Internet, digital images and pictures are the most well-known, despite the various
available file formats. For hiding secret information in images, you could find quite a
number of steganographic methods which are either simple or complicated and also
with respective advantages and disadvantages. Different steganography techniques are
used for different programs. For instance, some programs may require a greater
capacity for secret data to be hidden, while others require complete imperceptibility of
the secret data.
This paper attempts to elaborate on the technique of LSB substitution steganography
by specifying the criteria of a good steganographic techniques after providing a
summary of the uses and techniques of image steganography. The threshold for
human eye to distinguish between the stegoimage and the cover image would also be
discussed later in this report, for cover image of different sizes and RGB/grayscale
property. This is to ensure that the programme I designed provides no suspicion to
human visual system. Possible improvement of the programme would be suggested
and the LSB substitution technique would be review in the final part of the report.
Full MATLAB codes for GUI and other related algorithm provided in the appendix
would be available for public use for reference and further improvement.Bachelor of Engineerin
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