Digital Commons Network^™

Nano-Injection Molding With Resin Mold Inserts For Prototyping Of Nanofluidic Devices For Single Molecular Detection, Farhad Shiri, Junseo Choi, Chad Vietz, Chathurika Rathnayaka, Anishkumar Manoharan, Suresh Shivanka, Guoqiang Li, Chengbin Yu, Michael C. Murphy, Steven A. Soper, Sunggook Park

Faculty Publications

While injection molding is becoming the fabrication modality of choice for high-scale production of microfluidic devices, especially those used for in vitro diagnostics, its translation into the growing area of nanofluidics (structures with at least one dimension <100 >nm) has not been well established. Another prevailing issue with injection molding is the high startup costs and the relatively long time between device iterations making it in many cases impractical for device prototyping. We report, for the first time, functional nanofluidic devices with dimensions of critical structures below 30 nm fabricated by injection molding for the manipulation, identification, and detection of single …

Are We There Yet?, Marion S. Freistadt

LSU Master's Theses

To solve the Climate Crisis, a global Energy Transition is required. The primary contemporary tool for tackling these two massive problems is modeling, both biophysical climate models and IAMS (Integrated Assessment Models) which combine socioeconomic and technological progress with Climate Change. However, the proliferation and complexity of modeling systems make it difficult for most people to contribute substantively to solutions. In particular, stakeholders, policymakers, nonspecialists and activists require sufficient understanding of modeling to impact outcomes.

In this thesis, after summarizing the Climate Crisis and potential Energy Transition solutions, I review current modeling approaches. Models can be considered in terms of …

First-Principles And Machine Learning Investigation Of Refractory High Entropy Alloys And Conventional Alloys., Uttam Bhandari

LSU Doctoral Dissertations

Refractory high entropy alloys (RHEAs) are gaining prominence because of their balanced mechanical properties and are regarded as suitable alloys for a variety of applications such as aerospace, structural material, nuclear, and hydrogen storage. The first part of the dissertation explored the mechanical and thermal properties of RHEAs, specifically HfNbTaTiZr and Hf_0.5Nb_0.5Ta_0.5Ti_1.5Zr, which have potential uses in the health industry. The first-principles method using 100 atom supercell was carried out to compute the lattice constant, density, elastic modulus, Poisson ratio, and Vickers hardness. These calculated results were consistent with the available experimental …

Lrtransformer: Learn-Region Transformer For Object-Agnostic Point Cloud Segmentation, Dipesh Gyawali

LSU Master's Theses

3D point cloud segmentation segments the 3D point cloud data into different regions/instances depending on their features that have numerous applications in robotics, autonomous driving, digital twinning, augmented reality, etc. The majority of the existing point cloud segmentation methods depend on class labels to identify 3D objects in the surroundings. Our work focuses on segmenting point clouds into different regions/instances in an object-agnostic manner for any number of objects in the environment. Given the point cloud, our method can segment the entire scene into multiple instances without depending on object shape and size. We leverage the power of the self-attention …

Deconvoluting Charge-Transfer, Mass Transfer, And Ohmic Resistances In Phosphonic Acid-Sulfonic Acid Ionomer Binders Used In Electrochemical Hydrogen Pumps, Karthik Arunagiri, Andrew Jark Wah Wong, Luis Briceno-Mena, Hania Mohamed Gaber Hassan Elsayed, José A. Romagnoli, Michael J. Janik, Christopher G. Arges

Faculty Publications

Ion-pair high-temperature polymer electrolyte membranes (HT-PEMs) paired with phosphonic acid ionomer electrode binders have substantially improved the performance of HT-PEM electrochemical hydrogen pumps (EHPs) and fuel cells. Blending poly(pentafluorstyrene-co-tetrafluorostyrene phosphonic acid) (PTFSPA) with Nafion™, and using this blend as an electrode binder, improved proton conductivity in the electrode layer resulting in a 2 W cm−2 peak power density of fuel cells at 240 °C (a HT-PEM fuel cell record). However, much is unknown about how phosphonic acid ionomers blended with perfluorosulfonic acid materials affect electrode kinetics and gas transport in porous electrodes. In this work, we studied the proton conductivity, …

Evaluation Of Novel Jointless Engineered Cementitious Composites Ultrathin Whitetopping (Ecc-Utw), Ricardo Hungria

LSU Doctoral Dissertations

Ultrathin Whitetopping (UTW) is a rehabilitation technique that consists of placing a thin layer of concrete over a damaged asphalt pavement. While UTWs have demonstrated satisfactory performance in field tests, the inherent brittleness of concrete has led to the appearance of distresses. To address these distresses, Engineered Cementitious Composites (ECC) have been proposed for UTW applications, thanks to their exceptional attributes, including tensile ductility, flexural performance, and fatigue resistance. In this study, an ECC-UTW was constructed to investigate its potential as a viable solution. The project comprised two 18.3 m ECC sections with different thicknesses, namely 63.5 mm and 101.6 …

Ready Worker One? High-Res Vr For The Home Office, Anastasia Ruvimova, Felipe Fronchetti, Boden A. Kahn, Luiz Henrique Susin, Zekeya Hurley, Thomas Fritz, Mark Hancock, David Shepherd

Faculty Publications

Many employees prefer to work from home, yet struggle to squeeze their office into an already fully-utilized space. Virtual Reality (VR) seemingly offered a solution with its ability to transform even modest physical spaces into spacious, productive virtual offices, but hardware challenges - such as low resolution - have prevented this from becoming a reality. Now that hardware issues are being overcome, we are able to investigate the suitability of VR for daily work. To do so, we (1) studied the physical space that users typically dedicate to home offices and (2) conducted an exploratory study of users working in …

Continuous Spin Excitations In The Three-Dimensional Frustrated Magnet K2ni2 (So4)3, Weiliang Yao, Qing Huang, Tao Xie, Andrey Podlesnyak, Alexander Brassington, Chengkun Xing, Ranuri S.Dissanayaka Mudiyanselage, Haozhe Wang, Weiwei Xie, Shengzhi Zhang, Minseong Lee, Vivien S. Zapf, Xiaojian Bai, D. Alan Tennant, Jian Liu, Haidong Zhou

Faculty Publications

Continuous spin excitations are widely recognized as one of the hallmarks of novel spin states in quantum magnets, such as quantum spin liquids (QSLs). Here, we report the observation of such kind of excitations in K2Ni2(SO4)3, which consists of two sets of intersected spin-1 (Ni2+) trillium lattices. Our inelastic neutron scattering measurement on single crystals clearly shows a dominant excitation continuum, which exhibits a distinct temperature-dependent behavior from that of spin waves, and is rooted in strong quantum spin fluctuations. Further using the self-consistent-Gaussian-approximation method, we determine that the fourth- and fifth-nearest-neighbor exchange interactions are dominant. These two bonds together …

Backward Stochastic Differential Equations In A Semi-Markov Chain Model, Robert J. Elliott, Zhe Yang

Journal of Stochastic Analysis

No abstract provided.

Fall Facts, 2023, Louisiana State University

Fall Facts

No abstract provided.

Fall 2023 Catalog, Lsu Press

LSU Press Seasonal Catalogs

No abstract provided.

Potential Impact Of Wearables On Physical Activity Guidelines And Interventions: Opportunities And Challenges, Jason M.R. Gill, Timothy J. Chico, Aiden Doherty, Jessilyn Dunn, Ulf Ekelund, Peter T. Katzmarzyk, Karen Milton, Marie H. Murphy, Emmanuel Stamatakis

Population and Public Health Science Faculty Publications

No abstract provided.

Genetic Deletion Of Dnajb3 Using Crispr-Cas9, Produced Discordant Phenotypes, Shadi Nejat, Kalhara R. Menikdiwela, Aliyah Efotte, Shane Scoggin, Bolormaa Vandanmagsar, Paul J. Thornalley, Mohammed Dehbi, Naima Moustaid-Moussa

Division of Basic Science Faculty Publications

Several pathways and/or genes have been shown to be dysregulated in obesity-induced insulin resistance (IR) and type 2 diabetes (T2D). We previously showed, for the first time, impaired expression of DNAJB3 mRNA and protein in subjects with obesity, which was concomitant with increased metabolic stress. Restoring the normal expression of DNAJB3 attenuated metabolic stress and improved insulin signaling both in vivo and in vitro, suggesting a protective role of DNAJB3 against obesity and T2D. The precise underlying mechanisms remained, however, unclear. This study was designed to confirm the human studies in a mouse model of dietary obesity-induced insulin resistance, and, …

Toward Food Security In 2050: Gene Pyramiding For Climate-Smart Rice, Isnaini Isnaini, Yudhistira Nugraha, Niranjan Baisakh, Nono Carsono

Faculty Publications

The decline in crop productivity due to climate change is a major issue that threatens global food security and is the main challenge for breeders today in developing sustainable varieties with a wider tolerance to abiotic and biotic stresses. Breeding climate-smart rice (CSR) cultivars may be the best adaptation to climate change, with the potential to improve future food security and profitability for farmers in many nations. The main objective of this review is to highlight the direction of development of superior rice breeding from time to time, and various studies of new techniques of breeding methods for pyramiding various …

Multimessenger Diagnostics Of The Engine Behind Core-Collapse Supernovae, Christopher L. Fryer, Eric Burns, Aimee Hungerford, Samar Safi-Harb, R. T. Wollaeger, Richard S. Miller, Michela Negro, Samalka Anandagoda, Dieter H. Hartmann

Faculty Publications

Core-collapse supernova explosions play a wide role in astrophysics by producing compact remnants (neutron stars or black holes) and the synthesis and injection of many heavy elements into their host galaxy. Because they are produced in some of the most extreme conditions in the universe, they can also probe physics in extreme conditions (matter at nuclear densities and extreme temperatures and magnetic fields). To quantify the impact of supernovae on both fundamental physics and our understanding of the universe, we must leverage a broad set of observables of this engine. In this paper, we study a subset of these probes …

Engineering Super-Poissonian Photon Statistics Of Spatial Light Modes, Mingyuan Hong, Ashe Miller, Roberto De J. León-Montiel, Chenglong You, Omar S. Magaña-Loaiza

Faculty Publications

The nature of light sources is defined by the statistical fluctuations of the electromagnetic field. As such, the photon statistics of light sources are typically associated with distinct emitters. Here, the possibility of producing light beams with various photon statistics through the spatial modulation of coherent light is demonstrated. This is achieved by the sequential encoding of controllable Kolmogorov phase screens in a digital micromirror device. Interestingly, the flexibility of this scheme allows for the shaping of spatial light modes with engineered photon statistics at different spatial positions. The performance of this scheme is assessed through the photon-number-resolving characterization of …

Sexually Dimorphic Oxytocin Receptor-Expressing (Oxtr) Neurons In The Anteroventral Periventricular Nucleus (Avpv) In The Postpartum Female Mouse Are Involved In Maternal Behavior, Kaustubh Sharma, Armita A. Govar, Bandana Ghimire, Katsuhiko Nishimori, Elizabeth Hammock, Ryoichi Teruyama

Faculty Publications

Maternal care is crucial for the survival and development of offspring. Oxytocin modulates maternal behavior by binding to oxytocin receptors (OXTRs) in various parts of the brain. Previously, we showed that OXTRs are expressed in the anteroventral periventricular nucleus (AVPV) of female, but not male mice. Because the AVPV is involved in the regulation of maternal behavior and oxytocin enhances its induction, this finding leads to the hypothesis that the female specific population of OXTR neurons in the AVPV regulates maternal behavior. To address this hypothesis, OXTR-Venus reporter mice were used to assess if expression levels of OXTR in the …

U-Net-Lstm: Time Series-Enhanced Lake Boundary Prediction Model, Lirong Yin, Lei Wang, Tingqiao Li, Siyu Lu, Jiawei Tian, Zhengtong Yin, Xiaolu Li, Wenfeng Zheng

Faculty Publications

Change detection of natural lake boundaries is one of the important tasks in remote sensing image interpretation. In an ordinary fully connected network, or CNN, the signal of neurons in each layer can only be propagated to the upper layer, and the processing of samples is independent at each moment. However, for time-series data with transferability, the learned change information needs to be recorded and utilized. To solve the above problems, we propose a lake boundary change prediction model combining U-Net and LSTM. The ensemble of LSTMs helps to improve the overall accuracy and robustness of the model by capturing …

Coir/Glass Hybrid Fiber Reinforced Thermoset Polymer Composite Laminates With Room-Temperature Self-Healing And Shape Memory Functions, Sakil Mahmud, John Konlan, Jenny Deicaza, Guoqiang Li

Faculty Publications

Natural fibers have a lot of potentials as renewable reinforcements for polymers. However, their lower load-carrying capacity compared with synthetic fibers made it a challenge to use them as polymer reinforcements. When a laminated composite beam is bent, the normal stress is the highest on the top and bottom layers and zero in the midplane due to the (non)linear distribution of normal strain. Even though the shear stress is the highest in the midplane, most polymers can tolerate the high shear stress. Therefore, hybrid composite laminates with strong synthetic glass fibers stacked over the core of weak natural coir fiber …

Machine-Learning-Based Thermal Conductivity Prediction For Additively Manufactured Alloys, Uttam Bhandari, Yehong Chen, Huan Ding, Congyuan Zeng, Selami Emanet, Paul R. Gradl, Shengmin Guo

Faculty Publications

Thermal conductivity (TC) is greatly influenced by the working temperature, microstructures, thermal processing (heat treatment) history and the composition of alloys. Due to computational costs and lengthy experimental procedures, obtaining the thermal conductivity for novel alloys, particularly parts made with additive manufacturing, is difficult and it is almost impossible to optimize the compositional space for an absolute targeted value of thermal conductivity. To address these difficulties, a machine learning method is explored to predict the TC of additive manufactured alloys. To accomplish this, an extensive thermal conductivity dataset for additively manufactured alloys was generated for several AM alloy families (nickel, …

Additive Friction Stir Deposition Of Metallic Materials: Process, Structure And Properties, Jiayun Shao, Arash Samaei, Tianju Xue, Xiaoyu Xie, Shengmin Guo, Jian Cao, Eric Macdonald, Zhengtao Gan

Faculty Publications

Additive friction stir deposition (AFSD) is a relatively new additive manufacturing technique to fabricate parts in solid state below the melting temperature. Due to the solid-state nature, AFSD benefits from lower residual stresses as well as significantly lower susceptibility to porosity, hot-cracking, and other defects compared to conventional fusion-based metallic additive manufacturing. These unique features make AFSD a promising alternative to conventional forging for fabricating large structures for aerospace, naval, nuclear, and automotive applications. This review comprehensively summarizes the advances in AFSD, as well as the microstructure and properties of the final part. Given the rapidly growing research in AFSD, …

The Standard For Assessing Water Resistance Properties Of Lubricating Grease Using Contact Angle Measurements, Koottaparambil Lijesh, Roger A. Miller, Raj Shah, Khosro Shirvani, Michael M. Khonsari

Faculty Publications

Many grease-lubricated machines operate in wet environments, and are vulnerable to contamination because of water exposure. Reports suggest that even the presence of 1% water in grease reduces the life of a bearing by 90%. Nevertheless, only a few qualitative tests and standards are available to characterize the water resistance properties of greases. In this paper, we propose a standard for evaluating the water resistance properties of greases by studying their hydrophobic and hydrophilic nature via a custom-designed apparatus for measuring the grease contact angle. In this approach, a water droplet is dispensed onto the surface of the grease and …

In Situ Prediction Of Metal Fatigue Life Using Frequency Change, Ali Mahmoudi, Mohammad A. Amooie, Lijesh Koottaparambil, Michael M. Khonsari

Faculty Publications

A reliable technique for rapid prediction of the remaining useful life (RUL) of components experiencing fatigue degradation is introduced. The approach is based on measuring the temperature signature of a component upon rapidly changing its operating frequency for a short period of time. The temperature variations caused by alterations in plastic work rate are correlated to the loading history. The efficacy of the approach is investigated by conducting a series of axial fatigue tests on stainless steel 316 specimens. The material characterization involves subjecting the material to a constant amplitude fatigue load at 4 Hz and 12 Hz frequencies. The …

Comparative Analyses Of Covariance Matrix Adaptation And Iterative Ensemble Smoother On High-Dimensional Inverse Problems In High-Resolution Groundwater Modeling, Shuo Yang, Frank T.C. Tsai, Peter Bacopoulos, Christopher E. Kees

Faculty Publications

Parameter estimation is an inverse problem which is crucial to reliable groundwater model predictions and management. Numerous techniques have been developed to address this challenging problem. This study aims to compare the performance of a stochastic optimization method, covariance matrix adaptation-evolution strategy (CMA-ES), and a data assimilation method, Levenberg-Marquardt based iterative ensemble smoother (ES-LM), on solving inverse problems in groundwater modeling. This study also presents a parallelization strategy to accelerate their implementation. The comparative analysis involves synthetic inverse problems and a real-world case study of calibrating a high-resolution groundwater model. Results from the synthetic problems suggest that both the CMA-ES …

Coupled Wellbore-Reservoir Modelling To Evaluate Co2 Injection Rate Distribution Over Thick Multilayer Storage Zones, Mohamed Abdelaal, Mehdi Zeidouni

Faculty Publications

Technical and economic feasibility of Geologic CO2 Storage (GCS) projects requires maximizing the amount of stored CO2 per unit pore space of the storage zone per well. Considering injection through a fully penetrating vertical well in a multi-layer thick aquifer, CO2 would be unevenly distributed over the aquifer thickness, underutilizing the available pore space. In this work, we use coupled wellbore-reservoir modelling to investigate the interplay between the parameters that control CO2 pore-space filling. Flow capacity profile and gravity/buoyancy override are the primary factors controlling CO2 flux into a layered system. In addition, a higher fraction of CO2 would flow …

Quantification Of Solution-Free Red Blood Cell Staining By Sorption Kinetics Of Romanowsky Stains To Agarose Gels, Chae Yun Bae, Hamid Esmaeili, Syed A. Zamin, Min Jeong Seol, Eunmi Hwang, Suk Kyung Beak, Younghoon Song, Bhuvnesh Bharti, Jangwook P. Jung

Faculty Publications

The imaging and quantification of stained red blood cells (RBCs) are important for identifying RBCs in hematology and for diagnosing diseased RBCs or parasites in cytopathology. Romanowsky staining has been used traditionally to produce hues in blood cells using a mixture of anionic eosin Y and cationic methylene blue and azure B. While Romanowsky stains have been widely used in cytopathology, end-users have experienced problems with varying results in staining due to the premature precipitation or evaporation of methanol, leading to the inherent inconsistency of solution-based Romanowsky staining. Herein, we demonstrate that the staining and destaining of blood smears are …

Greater Male Variability In Daily Energy Expenditure Develops Through Puberty, Lewis G. Halsey, Vincent Careau, Philip N. Ainslie, Heliodoro Alemán-Mateo, Lene F. Andersen, Liam J. Anderson, Leonore Arab, Issad Baddou, Linda Bandini, Kweku Bedu-Addo, Ellen E. Blaak, Stephane Blanc, Alberto G. Bonomi, Carlijn V.C. Bouten, Pascal Bovet, Soren Brage, Maciej S. Buchowski, Nancy Butte, Stephan G. Camps, Regian Casper, Graeme L. Close, Lisa H. Colbert, Jamie A. Cooper, Richard Cooper, Prasangi Dabare, Sai Krupa Das, Peter S.W. Davies, Sanjoy Deb, Christine Delisle Nyström, William Dietz, Lara R. Dugas, Simon Eaton, Ulf Ekelund

Faculty Publications

There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at …

Highly Flexible, Self-Bonding, Self-Healing, And Conductive Soft Pressure Sensors Based On Dicarboxylic Cellulose Nanofiber Hydrogels, Ragab Abouzeid, Mohammad Shayan, Tongyao Wu, Jaegyoung Gwon, Timo A. Kärki, Qinglin Wu

Faculty Publications

Conductive hydrogels have gained a great deal of interest in the flexible electronics industry because of their remarkable inherent properties. However, a significant challenge remains for balancing hydrogel’s conductivity, self-healing, and strength properties. Herein, double network ionic hydrogels were fabricated by concurrently introducing borax into dicarboxylic cellulose nanofiber (DCNFs) and polyacrylamide (PAM) hydrogels. The incorporation of borax provided a superabsorbent feature to the PAM/DCNF hydrogels (without borax) with the equilibrium water absorption rate increased from 552 to 1800% after 42 h. The compressive strength of the prepared hydrogel was 935 kPa compared to 132 kPa for the PAM hydrogel, with …

Chitosan-Coated Lignin Nanoparticles Enhance Adsorption And Proliferation Of Alcanivorax Borkumensis At The Hexadecane-Water Interface, Amber J. Pete, Jin Gyun Lee, Michael G. Benton, Bhuvnesh Bharti

Faculty Publications

Bioremediation of oil spills occurs when indigenous microbes metabolize petroleum hydrocarbons. Rapid proliferation of hydrocarbon-consuming bacteria near the oil-water interface is vital to optimizing the oil biodegradation rate. Adding nanoparticles (NPs) to microbial systems can enhance the bacterial growth rate. However, the role of NP source material and surface charge on their ability to impact bacterial growth and oil-water interface characteristics is poorly understood. Here, we investigate the role of NP composition and surface chemistry on the growth rate of hydrocarbon-consuming bacteria and its attachment to the oil-water interface. We use Alcanivorax borkumensis as a model organism because of its …

Structured Ethical Review For Wastewater-Based Testing In Support Of Public Health, Devin A. Bowes, Amanda Darling, Erin M. Driver, Devrim Kaya, Rasha Maal-Bared, Lisa M. Lee, Kenneth Goodman, Sangeet Adhikari, Srijan Aggarwal, Aaron Bivins, Zuzana Bohrerova, Alasdair Cohen, Claire Duvallet, Rasha A. Elnimeiry, Justin M. Hutchison, Vikram Kapoor, Ishi Keenum, Fangqiong Ling, Deborah Sills, Ananda Tiwari, Peter Vikesland, Ryan Ziels, Cresten Mansfeldt

Faculty Publications

Wastewater-based testing (WBT) for SARS-CoV-2 has rapidly expanded over the past three years due to its ability to provide a comprehensive measurement of disease prevalence independent of clinical testing. The development and simultaneous application of WBT measured biomarkers for research activities and for the pursuit of public health goals, both areas with well-established ethical frameworks. Currently, WBT practitioners do not employ a standardized ethical review process, introducing the potential for adverse outcomes for WBT professionals and community members. To address this deficiency, an interdisciplinary workshop developed a framework for a structured ethical review of WBT. The workshop employed a consensus …