682 research outputs found
Lattice Boltzmann modelling of bacterial colony patterns
Full text linkThe formation of branches in bacterial colonies is influenced by both chemical interactions (reactions) and the movement of substances through space (diffusion). These colonies can exhibit a variety of fascinating branching patterns due to the interplay of nutrient transport, bacterial growth, and chemotaxis. To understand this complex process, researchers have developed several mathematical models based on solving reaction-diffusion equations. In this letter, we introduce an innovative application of the lattice Boltzmann method to investigate the diverse morphological patterns observed in bacterial colonies. This method is concise, compact, and easy to implement. Our study demonstrates its effectiveness in accurately predicting various types of bacterial colony patterns, offering a new tool to obtain insights into the dynamics of bacterial growth andpattern formation
Utilizing biomarkers in colorectal cancer: an interview with Ajay Goel
No full text Ajay Goel speaks to Rachel Jenkins, Commissioning Editor. Ajay Goel, PhD, is a Professor and Director, Center for Gastrointestinal Research, and Director, Center for Translational Genomics and Oncology, at the Baylor Scott & White Research Institute, Baylor University Medical Center in Dallas, Texas. Dr Goel has spent more than 20 years researching cancer and has been the lead author or contributor to over 240 scientific articles published in peer-reviewed international journals and several book chapters. He is also a primary inventor on more than 15 international patents aimed at developing various biomarkers for the diagnosis, prognosis and prediction of gastrointestinal cancers. He is currently using advanced genomic and transcriptomic approaches to develop novel DNA- and miRNA-based biomarkers for the early detection of colorectal cancers. In addition, he is researching the prevention of gastrointestinal cancers using integrative and alternative approaches, including botanical products such as curcumin (from turmeric) and boswellia. Dr Goel is a member of the American Association for Cancer Research (AACR) and the American Gastroenterology Association (AGA) and is on the international editorial boards of several journals including Gastroenterology, Clinical Cancer Research, Carcinogenesis, PLoS ONE, Scientific Reports, Epigenomics, Future Medicine, Alternative Therapies in Heath and Medicine and World Journal of Gastroenterology. He is also actively involved in peer-reviewing activities for more than 100 international scientific journals and various grant review panels of various national and international funding organizations. His research has been actively funded by various private and federal organizations, including funding from the National Cancer Institute (NCI) at the NIH, American Cancer Society (ACS) and other state organizations. He has won more than dozen awards and honors, including the Union of European Gastroenterology Federation's Distinguished Researcher Award, multiple Poster of Distinction Awards from the AGA, and Visiting Professorships from various national and international academic institutions and academic bodies. Some of his key research interests include: Understanding the basic genetics and epigenetic basis of gastrointestinal cancers; Use of epigenetic markers, both DNA and RNA, for the early detection of colorectal, pancreatic and other gastrointestinal cancers; Personalized medicine and treatment of gastrointestinal cancers; Chemoprevention, using complementary and alternative approaches using nutraceuticals such as curcumin, green tea, resveratrol and other botanicals. </jats:p
Mathematics of stable tensegrity structures
Full text linkTensegrity structures have been extensively studied over the last years due
to their potential applications in modern engineering like metamaterials,
deployable structures, planetary lander modules, etc. Many of the form-finding
methods proposed continue to produce structures with one or more soft/swinging
modes. These modes have been vividly highlighted and outlined as the grounds
for these structures to be unsuitable as engineering structures. This work
proposes a relationship between the number of rods and strings to satisfy the
full-rank convexity criterion as a part of the form-finding process. Using the
proposed form-finding process for the famous three-rod tensegrity, the work
proposes an alternative three-rod ten-string that is stable. The work
demonstrates that the stable tensegrities suitable for engineering are feasible
and can be designed
OpenFOAM v2306
No full textThis repository houses a specialized version of OpenFOAM 2306 that has been meticulously tailored and optimized for the unique needs of ajaylab. OpenFOAM, an open-source computational fluid dynamics (CFD) software, is a powerful tool for simulating and solving complex fluid flow problems. The customized version here is crafted by the experts at ajaylab to enhance performance, provide additional features, and streamline workflows to cater specifically to our research and engineering endeavors. More information on running (for users), modification (for developers), version history is available in the README-v2306.md file.
Version history
1.0.0:
openfoam-2306-arm-v100.tar.gz: Currently deprecated. Please do not us
Experimental evaluation of long term evolution-based NC OFDM secondary-to-secondary interference
No full textScarcity of spectrum resources, inefficient spectrum usage and the inflexibility of the current spectrum assignment are few of the major roadblocks in the development of new wireless communication standards. Secondary spectrum sharing has become a viable solution to alleviate this problem. Secondary users are unlicensed devices that use opportunistic spectrum access to identify vacant frequency bins and thereby utilize the spectrum. For advanced wireless communication standards like the Long Term Evolution (LTE) which primarily calls for higher data rates, evaluation of design parameters for ensuring efficient coexistence of heterogeneous secondary users and guaranteeing acceptable minimum level of performance becomes essential. Additionally, the understanding of the interference between secondary users occupying adjacent frequency bands for their transmission is imperative. This thesis focuses on the coexistence of secondary users in the same band assuming that the primary spectrum is found available. By Implementing two Non Contiguous Orthogonal Frequency Division Multiplexing ( NC-OFDM) based secondary transmitters on a real time platform, the design parameters that need to be considered to ensure efficient coexistence have been identified and investigated. The performance degradations observed at a particular secondary link due to presence of another interfering secondary link occupying adjacent frequency bands for its transmission have also been studied. This thesis also focuses on implementation of algorithms to modify the existing NC-OFDM transmission at the secondary transmitter end to reduce its Interference effects on the other secondary links operating within the same band. The focus is on an LTE-based Secondary Non Contiguous Orthogonal Frequency Division Multiplexing Transceiver on a Real Time Platform developed by National Instruments. The various blocks needed to design a real time LTE based communications links are discussed. An experimental LTE-to-LTE interference analysis based on the Real Time Platform and the designed system is presented.M.S.Includes bibliographical referencesby Ajay Ramkumar Iye
Automated image-based detection and grading of lymphocytic infiltration in breast cancer histopathology:
No full textThe identification of phenotypic changes in breast cancer (BC) histopathology is of significant clinical importance in predicting disease outcome and prescribing appropriate therapy. One such example is the presence of lymphocytic infiltration (LI) in histopathology, which has been correlated with a variety of prognoses and theragnoses (i.e. response to treatment) in BC patients. In this thesis work a computer-aided diagnosis (CADx) system is detailed for quantitatively measuring the extent of LI from hematoxylin and eosin (H & E) stained histopathology. The CADx system is subsequently applied to BC patients expressing the HER2 gene (HER2+ BC), where LI extent has been found to correlate with nodal metastasis and distant recurrence. Although LI may be graded qualitatively by BC pathologists, there is currently no quantitative and reproducible method for measuring LI extent in HER2+ BC histopathology. Hence, a CADx system that performs this task will potentially help clinicians predict disease outcome and allow them to make better therapy recommendations for HER2+ BC patients. The CADx methodology comprises three key steps. First, a combination of region-growing and Markov Random Field algorithms is used to detect individual lymphocyte nuclei and isolate areas of LI in digitized H & E stained histopathology images. The centers of individual detected lymphocytes are used as vertices to construct a series of graphs (Voronoi Diagram, Delaunay Triangulation, and Minimum Spanning Tree) and a total of 50 architectural features describing the spatial arrangement of lymphocytes are extracted from each image. By using Graph Embedding, a non-linear dimensionality reduction method, to project the high-dimensional feature vectors into a reduced 3D embedding space, it is possible to visualize the underlying manifold that represents the continuous nature of the LI phenotype. Over a set of 100 randomized cross-validation trials, a Support Vector Machine classifier shows that the architectural feature set distinguishes HER2+ BC histopathology samples containing high and low levels of LI with a classification accuracy greater than 90%.M.S.Includes bibliographical references (p. 35-35)by Ajay Basavanhall
UMAT routines for Abaqus CAE
No full textYoutube link to video: https://www.youtube.com/watch?v=-uZH1F4QX2M
Abstract of the lecture
Dr. Jha will present a methodology for the development of UMAT in Abaqus CAE. In this regard, the lecture will focus on modeling of the damage in hyperelastic materials. In addition, the lecture will also demonstrate the development of UMAT as well. Over the course of the lecture, he will present theoretical formulations followed by code review. The intended audience of this lecture is Master / Ph.D. / Industry participants who are beginning to use UEL routines in Abaqus CAE
Pointwise contact numerical models and applications
No full textYoutube link to the video: https://www.youtube.com/watch?v=3VpkVH2osxk
Abstract of the lecture
In this lecture, an overview of computational modeling of pointwise contact will be given. Beam-to-beam contact will be addressed, such as contact involving rigid/flexible bodies, modeled by beams/shells. An overview of the master-master contact strategy will be provided, presenting its pros/cons, such as numerous examples.
Related publications
Gay Neto, A.; Wriggers, P.; Master-master frictional contact and applications for beam-shell interaction. Computational Mechanics, Published Online, 2020.
Gay Neto, A.; Wriggers, P.; Numerical method for solution of pointwise contact between surfaces. Computer Methods in Applied Mechanics and Engineering, v. 365,112971, 2020.
Gay Neto, A.; Wriggers, P.; Computing pointwise contact between bodies: a class of formulations based on master-master approach. Computational Mechanics, Published Online, 2019.
Campos, P.R.R.; Gay Neto, A.; Rigid body formulation in a finite element context with contact interaction. Computational Mechanics, 62:1369, 2018.
Gay Neto, A.; Pimenta, P. M.; Wriggers, P.; Contact between spheres and general surfaces. Computer Methods in Applied Mechanics and Engineering, v. 328, p. 686-716, 2018.
Gay Neto, A.; Campello, E. M. B.; Granular materials interacting with thin flexible rods. Computational Particle Mechanics, v. 4, p. 229-247, 2017.
Gay Neto, A.; Pimento, P. M.; Wriggers, P.; A master-surface to master-surface formulation for beam to beam contact. Part II: Frictional interaction. Computer 8. Methods in Applied Mechanics and Engineering, v. 319, p. 146-174, 2017.
Gay Neto, A.; Simulation of mechanisms modeled by geometrically-exact beams using Rodrigues rotation parameters. Computational Mechanics, v. 59, p. 459-481, 2017.
Gay Neto, A.; Pimento, P. M.; Wriggers, P.; A master-surface to master-surface formulation for beam to beam contact. Part I: Frictionless interaction. Computer Methods in Applied Mechanics and Engineering, v. 303, p. 400–429, 2016
Machine intelligence in mechanical and aerospace sciences: Today & beyond
No full textIn this lecture, the application of AI / ML and the upcoming trends are discussed, particularly in reference to mechanical and aerospace industries. AI and ML have been topics of huge interest in recent times. Machine learning techniques are being applied vastly to understand the uncertainties in the models - both solid and fluid mechanics. During the lecture, we will discuss on how artificial intelligence is being used in the aerospace industry
Chaotic footprints of a flapping wing: A computational perspective
No full textThe lecture will discuss the investigations made on the complex vortex interactions in a flapping wing. The flow-field transitions from periodic to chaotic through a quasi-periodic route as the plunge amplitude is gradually increased. This study unravels the role of the complex interactions that take place among the main vortex structures in making the unsteady flow-field transition from periodicity to chaos.
The lecture is available for viewing through youtube at: https://www.youtube.com/watch?v=aQZxxe8YUR
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