Graduate Student

Title: Design of an Electrical Gelation Chamber to Synthesize Alginate Microparticles for Inhalational Delivery of Anti-tubercular Drug

Department: Mechanical Engineering

Email: athukocd@clarkson.edu

Advisor: Suresh Dhaniyala

Abstract: Inhalational delivery of antitubercular drugs using polymeric carrier particles is emerging as an attractive therapeutic option for pulmonary tuberculosis (TB). For such approach to be successful, the size of the particles needs to be optimized for their delivery to the lung alveoli and enhanced uptake by macrophages, where TB bacteria reside. Previous reports suggest nebulized particles in the size range of 500-700 nm are most effective in reaching the alveolar region. The objective of the present work is to synthesize alginate microspheres within a narrow size range and relevant for pulmonary drug delivery application using a custom-designed electrical gelation chamber. Aerosols of alginate were first generated by atomization, which were collected in a chamber under electrostatic precipitation, and cross-linked to gel by exposure to CaCl2 solution. The chamber was designed to collect alginate aerosols of <1 µm in size under an electric field of 5 kV/cm. Flow behavior and collection of alginate aerosols in the chamber was estimated by CFD simulations and its design was optimized for improved collection efficiency. The collection efficiency of the gelation chamber was examined as a function of the electric field and ionization of alginate aerosols. We achieved a collection efficiency of >90 % for aerosol of size <1 µm as estimated by APS measurements. Collected particles were further characterized by microscopy and dynamic light scattering experiments. We will present the design and performance details of the gelation chamber from our ongoing work.

Graduate Student

Title: Study of Airborne Microbes in University Environment Using a Portable Electrostatic Bioaerosol Collection Device

Department of Biology

Email: kumarakk@clarkson.edu

Advisors: Shantanu Sur and Suresh Dhaniyala

Abstract: We have developed a portable, low-power, and low-cost device for environmental bioaerosol monitoring. Our device called Trace Real-time Aerosol Concentration sensor and Biological sampler (TRAC- B), is capable of real-time air quality monitoring and capturing airborne particles for offline analysis. TRAC-B uses a low-cost sensor for real-time aerosol measurements and an electrostatic precipitator for the collection of bioaerosol for offline analysis. We have performed detailed characterization of the electrostatic precipitator-based bio-sampler section of the device, such as the impact of an ionizer on collection efficiency, effect of precipitation voltage on viability, and dependency of particle capture and recovery on the collection substrate used. We have deployed multiple TRAC-B units for a year-long study in various indoor and outdoor locations on Clarkson University campus. A culture and sequencing-based analysis of the collected samples was conducted to determine the diversity, abundance, and seasonal variation of the airborne microbial population in various indoor and outdoor environments. Our preliminary results (Sanger sequencing) show that bacterial species belonging to the genus Bacillus are the most abundant cultivable bacteria in the collected samples. Furthermore, our data suggests the highest microbial abundance in the spring and the summer seasons for both indoor and outdoor sampling locations.

Keywords: Bioaerosol, low-cost sensor, electrostatic precipitator

Research Associate

Title: Explore the Transmission of COVID-19 by Respiratory Aerosol and Droplet Emission during Speech

Department of Mechanical and Aeronautical Engineering

Email: abdolla@clarkson.edu

Phone: 315-268-6586

Advisors: Brian Helenbrook, Goodarz Ahmadi, Byron Erath, Andrea Ferro & Deborah Brown

Abstract: Despite the lack of understanding of aerosol transmission at the beginning of the COVID-19 pandemic, recently, more attention has been given to the role of expiratory aerosol in spreading the SARS-CoV-2 virus. In addition to coughing and sneezing, speaking is considered a generator of airborne aerosol and droplets with the number and size distribution comparable to that of coughing. Since the velocity field and the droplet concentration and size distribution at the mouth exit have not been fully understood, this investigation focuses on the numerical simulation of the velocity field and of the trajectories of respiratory droplets at the mouth exit. Based on some preliminary study, it is known that fricative consonants, such as “f†and “thâ€, that form very narrow occlusions at the mouth produce the largest exit velocities, which could spread expiratory droplets to large distances from the speaker. In this study, a two-dimensional idealized geometry of the human mouth pronouncing “f†and “th†consonants based on the MRI measurements of the mouth was generated. The airflow velocities in the mouth cavity and at the mouth exit were simulated using the laminar model of the ANSYS-Fluent software. To investigate the spread of expiratory aerosol, particles with diameters between 1 to 200 microns were introduced in the mouth cavity, and the discrete phase model of the ANSYS-Fluent code, including the gravitational sedimentation effects, was used to evaluate their trajectories. The simulations results were used to assess the risk of airborne human-to-human virus transmission from an infected person to other individuals in both the near and far-field.

Graduate Student

Title: Flocculation and Removal of Harmful Cyanobacteria from Water using Surface-Engineered Polymer Additives

Department of Chemical Engineering

Email: orimoltj@clarkson.edu

Advisor: Sitaraman Krishnan

Temitope Orimolade,¹ Ngoc-Tram Le,¹ Michael Twiss,² Bandaru V. Ramarao,³ Sitaraman Krishnan¹*

¹Department of Chemical and Biomolecular Engineering and ²Department of Biology, Clarkson University; ³SUNY College of Environmental Science and Forestry

Abstract: Harmful algae blooms (HABs) are uncontrolled growth of colonies of microalgae that are harmful because they can produce toxins that can kill fish, birds, and mammals, and affect the nervous system and organs such as liver and skin in humans. HABs are a growing problem in all coastal regions of the world. Among the several methods developed to tackle HABs, the Harmful Algal Bloom Interception, Treatment, and Transformation System (HABITATS) designed by the U.S. Army Engineer Research & Development Center (ERDC) is quite promising, and is based on the removal of algae by flocculation and converting the collected biomass into useful products such as biofuels and fertilizer. Alum is an effective chemical coagulant for this process, but its use in large quantities could have a detrimental effect on the aquatic biosystem because of aluminum toxicity effects. In this project, we are developing alternative biobased coagulants, e.g., Moringa oleifera lectin and some natural polysaccharides. The biocoagulants are evaluated for their ability to flocculate and remove Microcystis aeruginosa, a species of freshwater cyanobacteria that produces neurotoxins and peptide hepatotoxins, such as microcystin and cyanopeptolin. The cyanobacteriacoagulant system’s surface and colloidal properties are investigated using a range of techniques, including rheometry, centrifugation, laser diffraction, electrophoretic mobility, and jar tests. The results from these studies are used to control the flocculation process such that coagulant dosing can be adjusted in real-time. Polymer latex particles with well-defined particle sizes and surface properties are used as controls. The algal flocs are buoyed to the surface by tiny air bubbles in the HABITATS process. Accordingly, air floatation tests in the presence of the biobased coagulants are also of interest. Preliminary results show that the biobased coagulants are highly effective as cyanobacteria coagulants.

Sitaraman Krishnan and Bandaru V. Ramarao gratefully acknowledge a Seed Grant from the ESF-Clarkson Center of Excellence in Healthy Water Solutions for this project.

Graduate Student

Title: Bio-aerosol source localization in an indoor environment using low cost particle measuring sensors

Department of Electrical and Computer Engineering

Email: sahuc@clarkson.edu

Advisors: Mahesh Banavar and Suresh Dhaniyala

Abstract: Indoor air quality has been of global concern from a human health perspective. In particular, exposure to indoor particulate matter, has been identified as one of top 5 contributors to the global burden of disease. To help mitigate the problem of indoor air pollution, it is critical to identify the source of pollutants in real-time. Here, we use a network of low-cost sensors to measure particle concentrations in a classroom and investigate the ability of the source identification models - maximum monitoring value point approach (MPA), Earliest detection point approach (EPA), Fused MPA-EPA model, and modified time difference of arrival (mTDOA) model - to determine the particle source location. Using different sensor layout configurations, we determine the minimum number of sensors required to accurately identify the source location. We show that all models predict source location to within 5\% locational accuracy with just 4 sensors placed in the corners of a room. Source prediction accuracy improves with number of sensors in the facility.

Graduate Student

Title: Dynamic Covalent Exchange of Polyanhydride Copolymers for Potential Bone Cement Applications

Department of Chemistry & Biomolecular Science

Email: floydal@clarkson.edu

Advisor: Devon Shipp

Abstract: This work will investigate the dynamic covalent exchange of polyanhydrides and their ability to undergo surface erosion degradation for the potential implementation as a bone cement. Polyanhydrides are an excellent option for the inclusion in bone cements due to the ability to undergo dynamic covalent exchange, surface erosion hydrolysis, and exhibits a tensile modulus comparable to bone. In this study the polymer composition was altered via the addition of comonomers to probe the effect on the thermomechanical behaviors, degradation profiles, and dynamic covalent exchange as assessed through recyclability. It was found through the introduction of methyl methacrylate and butyl acrylate the conversion and degradation profiles can be extended while maintaining recyclability at the cost of modulus and Tg.

Graduate Student

Title: Development and validation of a method for measuring the contact pressure of the vocal folds

Department of Mechanical Engineering

Email: motiesm@clarkson.edu

Advisor: Byron Erath

Abstract: The production of voiced speech arises from vibrations of the vocal folds (VFs), two elastic band of tissues that stretch across the airway. The air flow that is supplied by the lungs passes through the VFs, imparts energy to them, and induces self-sustained oscillations of the VFs. It is believed that abnormally high contact pressures applied to the VF tissues during collision play the main role in initiating some VF pathologies such as emergence of VF polyps and nodules. Therefore, measuring the contact pressure of the VFs as a function of different speech parameters provides insight into the cause of some VF disorders. Measuring the contact pressure is highly challenging to be performed in vivo. Synthetic models of the VFs have been developed as reliable surrogates for the VF studies. However, the prior efforts to investigate the contact pressure with these models have not been successful, mainly because the accuracy of the employed pressure sensors was not examined. A novel pressure measurement technique is introduced in this study by placing a Millar Mikro-Cath pressure sensor in a groove that is cut into an aluminum cylindrical plate. The validation of this method is performed by pressing silicone disks with a known load on the surface of the plate and comparing the measured pressure by the pressure sensor with the ground-truth pressure calculated from the applied load and the contact area. It was found that the contact pressure is highly sensitive to sensor insertion depth in the groove and the stiffness of the silicone disks. A one-to-one correspondence between the measured and the ground-truth pressures was only obtained when the pressure sensor is completely embedded in the groove and the groove is filled with stiff silicone such that it creates a flat surface with the aluminum plate. This provides a reliable technique to be employed for investigating the contact pressure of the VFs by using synthetic silicone models in a hemilaryngeal flow facility.