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Publication Editorial: Insights in biomaterials 2022 / 2023-novel developments, current challenges and future perspectives(Frontiers, 2024-01-23) Vasudev, Milana C; Kothapalli, Chandra; Tamerler, Candan; Vrana, Nihal Engin; Wang, Yunbing; Uludağ, HasanPublication Microgravity Spherical Droplet Evaporation and Entropy Effects(Entropy, 2023-08-18) Depcik, ChristopherRecent efforts to understand low-temperature combustion (LTC) in internal combustion engines highlight the need to improve chemical kinetic mechanisms involved in the negative temperature coefficient (aka cool flame) regime. Interestingly, microgravity droplet combustion experiments demonstrate this cool flame behavior, allowing a greater focus on chemistry after buoyancy, and the corresponding influence of the conservation of momentum is removed. In Experimental terms, the LTC regime is often characterized by a reduction in heat transfer losses. Novel findings in this area demonstrate that lower entropy generation, in conjunction with diminished heat transfer losses, could more definitively define the LTC regime. As a result, the simulation of the entropy equation for spherical droplet combustion under microgravity could help us to investigate fundamental LTC chemical kinetic pathways. To provide a starting point for researchers who are new to this field, this effort first provides a comprehensive and detailed derivation of the conservation of entropy equation using spherical coordinates and gathers all relevant information under one cohesive framework, which is a resource not readily available in the literature. Subsequently, the well-known d law analytical model is determined and compared to experimental data that highlight shortcomings of the law. The potential improvements in the d law are then discussed, and a numerical model is presented that includes entropy. The resulting codes are available in an online repository to ensure that other researchers interested in expanding this field of work have a fundamental starting point.Publication Cutaneous Hypervascularization Treatment Using Photo-Mediated Ultrasound Therapy(Elsevier, 2023-09-22) Wang, Mingyang; Singh, Rohit; Zhang, Wei; Orringer, Jeffrey S.; Paulus, Yannis M.; Yang, Xinmai; Wang, XuedingPhoto-mediated ultrasound therapy (PUT) is a cavitation-based, highly selective antivascular technique. In this study, the effectiveness and safety of PUT on cutaneous vascular malformation was examined through in vivo experiments in a clinically relevant chicken wattle model, whose microanatomy is similar to that of port-wine stain and other hypervascular dermal diseases in humans. Assessed by optical coherence tomography angiography, the blood vessel density in the chicken wattle decreased by 73.23% after one session of PUT treatment in which 0.707 J/cm2 fluence laser pulses were applied concurrently with ultrasound bursts (n = 7, P < .01). The effectiveness of removing blood vessels in the skin at depth up to 1 mm was further assessed by H&E-stained histology at multiple time points, which included days 1, 3, 7, 14, and 21 after treatment. Additional immunohistochemical analyses with CD31, caspase-3, and Masson’s trichrome stains were performed on day 3 after treatment. The results show that the PUT-induced therapeutic effect was confined and specific to blood vessels only, whereas unwanted collateral damage in other skin tissues such as collagen was avoided. The findings from this study demonstrate that PUT can efficiently and safely remove hypervascular dermal capillaries using laser fluence at a level that is orders of magnitude smaller than that used in conventional laser treatment of vascular lesions, thus offering a safer alternative technique for clinical management of cutaneous vascular malformations.Publication Microgravity Spherical Droplet Evaporation and Entropy Effects(MDPI, 2023-08-18) Madani, Seyedamirhossein; Depcik, ChristopherRecent efforts to understand low-temperature combustion (LTC) in internal combustion engines highlight the need to improve chemical kinetic mechanisms involved in the negative temperature coefficient (aka cool flame) regime. Interestingly, microgravity droplet combustion experiments demonstrate this cool flame behavior, allowing a greater focus on chemistry after buoyancy, and the corresponding influence of the conservation of momentum is removed. In Experimental terms, the LTC regime is often characterized by a reduction in heat transfer losses. Novel findings in this area demonstrate that lower entropy generation, in conjunction with diminished heat transfer losses, could more definitively define the LTC regime. As a result, the simulation of the entropy equation for spherical droplet combustion under microgravity could help us to investigate fundamental LTC chemical kinetic pathways. To provide a starting point for researchers who are new to this field, this effort first provides a comprehensive and detailed derivation of the conservation of entropy equation using spherical coordinates and gathers all relevant information under one cohesive framework, which is a resource not readily available in the literature. Subsequently, the well-known d2 law analytical model is determined and compared to experimental data that highlight shortcomings of the law. The potential improvements in the d2 law are then discussed, and a numerical model is presented that includes entropy. The resulting codes are available in an online repository to ensure that other researchers interested in expanding this field of work have a fundamental starting point.Publication Data-driven prognosis of failure detection and prediction of lithium-ion batteries(Elsevier, 2023-10-15) Kouhestani, Hamed Sadegh; Liu, Lin; Wang, Ruimin; Chandra, AbhijitBattery prognostics and health management predictive models are essential components of safety and reliability protocols in battery management system frameworks. Overall, developing a robust and efficient fault diagnostic battery model that aligns with the current literature is an essential step in ensuring the safety of battery function. For this purpose, a multi-physics, multi-scale deterministic data-driven prognosis (DDP) is proposed that only relies on in situ measurements of data and estimates the failure based on the curvature information extracted from the system. Unlike traditional applications that require explicit expression of conservation principle to represent the system's behavior, the proposed method devices a local conservation functional in the neighborhood of each data point which is represented as the minimization of curvature in the system. Pursuing such a deterministic approach, DDP eliminates the need for offline training regimen by considering only two consecutive time instances to make the prognostication that are sufficient to extract the behavioral pattern of the system. The developed framework is then employed to analyze the health of lithium ion batteries by monitoring the performance and detecting faults within the system's behavior. Based on the outcomes, the DDP exhibits promising results in detection of anomaly and prognostication of batteries' failure.Publication Output force and ratio of laparoscopic graspers: an evaluation of operating room ergonomics(Elsevier, 2023-05-15) Olig, Emily M.; Wilson, Sara; Reddy, MadhuriBackground “Laparoscopist's thumb,” or thenar paresthesia, can result from prolonged or excessive grip force during laparoscopy, as can more general syndromes, such as carpal tunnel syndrome. This is particularly relevant in gynecology, where laparoscopic procedures are standard. Although this method of injury is well known, there is a paucity of data to guide surgeons in selecting more efficient, ergonomic instruments. Objective This study compared the ratio of applied tissue force and required surgeon input in a sample of common ratcheting laparoscopic graspers in a small-handed surgeon, to provide potential metrics applicable to surgical ergonomics and surgeon instrument choice. Study Design Laparoscopic graspers with varied ratcheting mechanisms and tip shapes were evaluated. Brands included Snowden-Pencer, Covidien, Aesculap, and Ethicon. A Kocher was used as an open instrument comparison. Flexiforce A401 thin-film force sensors were used to measure applied forces. Data were collected and calibrated using an Arduino Uno microcontroller board with Arduino and MATLAB software. Single-handed, complete closure of each device’s ratcheting mechanism was performed 3 times. The maximum required input force in Newtons was recorded and averaged. The average output force was measured with a bare sensor and the same sensor between 2 different thicknesses of LifeLike BioTissue. Results The most ergonomic ratcheting grasper for a small-handed surgeon was identified by the output ratio: the highest output force relative to the required surgeon input (the most force for the least amount of effort). The Kocher required an average input force of 33.66 N, with its highest output ratio of 3.46 (112 N output). The Covidien Endo Grasp was the most ergonomic, with an output ratio of 0.96 on the bare force sensor (31.4 N output). The Snowden-Pencer Wavy grasper was the least ergonomic, with an output ratio of 0.06 when applied to the bare force sensor (5.9 N output). All graspers except for the Endo Grasp had improving output ratios as tissue thickness and subsequent grasper contact area increased. Input force above that provided by the ratcheting mechanisms did not increase output force in a clinically relevant amount for any of the instruments evaluated. Conclusion Laparoscopic graspers vary widely in their ability to provide reliable tissue force without requiring excessive input by the surgeon, and a point of diminishing returns often exists with increased surgeon input over designed ratcheting mechanisms. Output force and output ratio are potential quantitative measures of the efficiency of laparoscopic instruments. Providing users with this type of data could assist in optimizing instrument ergonomics.Publication Production of the cylinder head and crankcase of a small internal combustion engine using metal laser powder bed fusion(Elsevier, 2023-05-03) Gray, Jamee; Depcik, Christopher; Sietins, Jennifer M.; Kudzal, Andelle; Rogers, Ryan; Cho, KyuThis effort investigates the use of metal additive manufacturing, specifically laser powder bed fusion (LPBF) for the automotive and defense industries by demonstrating its feasibility to produce working internal combustion (IC) engine components. Through reverse engineering, model modifications, parameter selection, build layout optimization, and support structure design, the production of a titanium crankcase and aluminum cylinder head for a small IC engine was made possible. Computed tomography (CT) scans were subsequently used to quantify whether defects such as cracks, geometric deviations, and porosity were present or critical. Once viability of the parts was established, machining and other post-possessing were completed to create functional parts. Final X-ray CT and micro-CT results showed all critical features fell within ±0.127 mm of the original equipment manufacturer (OEM) parts. This allowed reassembly of the engine without any issues hindering later successful operation. Furthermore, the LPBF parts had significantly reduced porosity percentages, potentially making them more robust than their cast counterparts.Publication Water-Responsive Self-Repairing Superomniphobic Surfaces via Regeneration of Hierarchical Topography(American Chemical Society, 2021-10-13) Ezazi, Mohammadamin; Shrestha, Bishwash; Maharjan, Anjana; Kwon, GibumSuperomniphobic surfaces that can self-repair physical damage are desirable for sustainable performance over time in many practical applications that include self-cleaning, corrosion resistance, and protective gears. However, fabricating such self-repairing superomniphobic surfaces has thus far been a challenge because it necessitates the regeneration of both low-surface-energy materials and hierarchical topography. Herein, a water-responsive self-repairing superomniphobic film is reported by utilizing cross-linked hydroxypropyl cellulose (HPC) composited with silica (SiO2) nanoparticles (HPC-SiO2) that is treated with a low-surface-energy perfluorosilane. The film can repair physical damage (e.g., a scratch) in approximately 10 s by regenerating its hierarchical topography and low-surface-energy material upon the application of water vapor. The repaired region shows an almost complete recovery of its inherent superomniphobic wettability and mechanical hardness. The repairing process is driven by the reversible hydrogen bond between the hydroxyl (−OH) groups which can be dissociated upon exposure to water vapor. This results in a viscous flow of the HPC-SiO2 film into the damaged region. A mathematical model composed of viscosity and surface tension of the HPC-SiO2 film can describe the experimentally measured viscous flow with reasonable accuracy. Finally, we demonstrate that the superomniphobic HPC-SiO2 film can repair physical damage by a water droplet pinned on a damaged area or by sequential rolling water droplets.Publication BattX: An equivalent circuit model for lithium-ion batteries over broad current ranges(Elsevier, 2023-06-01) Biju, Nikhil; Fang, HuazhenAdvanced battery management is as important for lithium-ion battery systems as the brain is for the human body. Its performance is based on the use of fast and accurate battery models. However, the mainstream equivalent circuit models and electrochemical models have yet to meet this need well, due to their struggle with either predictive accuracy or computational complexity. This problem has acquired urgency as some emerging battery applications running across broad current ranges, e.g., electric vertical take-off and landing aircraft, can hardly find usable models from the literature. Motivated to address this problem, we develop an innovative model in this study. Called BattX, the model is an equivalent circuit model that draws comparisons to a single particle model with electrolyte and thermal dynamics, thus combining their respective merits to be computationally efficient, accurate, and physically interpretable. The model design pivots on leveraging multiple circuits to approximate major electrochemical and physical processes in charging/discharging. Given the model, we develop a multipronged approach to design experiments and identify its parameters in groups from experimental data. Experimental validation proves that the BattX model is capable of accurate voltage prediction for charging/discharging across low to high C-rates.Publication Photo-Mediated Ultrasound Therapy for the Treatment of Corneal Neovascularization in Rabbit Eyes(Association for Research in Vision and Ophthalmology, 2020-12-09) Qin, Yu; Yu, Yixin; Fu, Julia; Xie, Xinyi; Wang, Tao; Woodward, Maria A.; Paulus, Yannis M.; Yang, Xinmai; Wang, XuedingPurpose: Corneal neovascularization (CNV) is the invasion of new blood vessels into the avascular cornea, leading to reduced corneal transparency and visual acuity, impaired vision, and even blindness. Current treatment options for CNV are limited. We developed a novel treatment method, termed photo-mediated ultrasound therapy (PUT), that combines laser and ultrasound, and we tested its feasibility for treating CNV in a rabbit model. Methods: A suture-induced CNV model was established in New Zealand White rabbits, which were randomly divided into two groups: PUT and control. For the PUT group, the applied light fluence at the corneal surface was estimated to be 27 mJ/cm2 at 1064-nm wavelength with a pulse duration of 5 ns, and the ultrasound pressure applied on the cornea was 0.43 MPa at 0.5 MHz. The control group received no treatment. Red-free photography and fluorescein angiography were utilized to evaluate the efficiency of PUT. Safety was evaluated by histology and immunohistochemistry. For comparison with the PUT safety results, conventional laser photocoagulation (LP) treatment was performed with standard clinical parameters: 532-nm continuous-wave (CW) laser with 0.1-second pulse duration, 450-mW power, and 75-µm spot size. Results: In the PUT group, only 1.8% ± 0.8% of the CNV remained 30 days after treatment. In contrast, 71.4% ± 7.2% of the CNV remained in the control group after 30 days. Safety evaluations showed that PUT did not cause any damage to the surrounding tissue. Conclusions: These results demonstrate that PUT is capable of removing CNV safely and effectively in this rabbit model. Translational Relevance: PUT can remove CNV safely and effectively.Publication Cavitation induced shear and circumferential stresses on blood vessel walls during photo-mediated ultrasound therapy(American Institute of Physics, 2020-12-29) Singh, Rohit; Wang, Xueding; Yang, XinmaiPhoto-mediated ultrasound therapy (PUT) is a novel technique using combined laser and ultrasound to generate enhanced cavitation activity inside blood vessels. The stresses produced by oscillating bubbles during PUT are believed to be responsible for the induced bio-effects in blood vessels. However, the magnitudes of these stresses are unclear. In this study, a two-dimensional axisymmetric finite element method-based numerical model was developed to investigate the oscillating bubble-produced shear and circumferential stresses during PUT. The results showed that increased stresses on the vessel wall were produced during PUT as compared with ultrasound-alone. For a 50-nm radius bubble in a 50-μm radius blood vessel, the produced circumferential and shear stresses were in the range of 100 kPa–400 kPa and 10 Pa–100 Pa, respectively, during PUT with the ultrasound frequency of 1 MHz, ultrasound amplitude of 1400 kPa–1550 kPa, and laser fluence of 20 mJ/cm2, whereas the circumferential and shear stresses produced with ultrasound-alone were less than 2 kPa and 1 Pa, respectively, using the same ultrasound parameters. In addition, the produced stresses increased when the ultrasound pressure and laser fluence were increased but decreased when the ultrasound frequency and vessel size were increased. For bubbles with a radius larger than 100 nm, however, the stresses produced during PUT were similar to those produced during ultrasound-alone, indicating the effect of the laser was only significant for small bubbles.Publication Effect of Grade III Lumbar Mobilization on Back Muscles in Chronic Low Back Pain: A Randomized Controlled Trial(Association of Schools of Allied Health Professions, 2020) Mehyar, Fahed; Santos, Marcio; Wilson, Sara E.; Staggs, Vincent S.; Sharma, Neena K.BACKGROUND: Lumbar mobilization is a standard intervention for lower back pain (LBP). However, its effect on the activity of back muscles is not well known. OBJECTIVES: To investigate the effects of lumbar mobilization on the activity/contraction of erector spinae (ES) and lumbar multifidus (LM) muscles in people with LBP. DESIGN: Randomized controlled study. METHODS: 21 subjects with LBP received either grade III central lumbar mobilization or placebo (light touch) intervention on lumbar segment level 4 (L4). Surface electromyography (EMG) signals of ES and ultrasound (US) images of LM were captured before and after the intervention. The contraction of LM was calculated from US images at L4 level. The normalized amplitude of EMG signals (nEMG) and activity onset of ES were calculated from the EMG signals at both L1 and L4 levels. RESULTS: Significant differences were found between the mobilization and placebo groups in LM contraction (p=0.03), nEMG of ES at L1 (p=0.01) and L4 (p=0.05), and activity onset of ES at L1 (p=0.02). CONCLUSION: Lumbar mobilization decreased both the activity amplitude and the activity onset of ES in people with LBP. However, the significant difference in LM contraction was small and may not have clinical significance.Publication Consistency and Validity of the Mathematical Models and the Solution Methods for BVPs and IVPs Based on Energy Methods and Principle of Virtual Work for Homogeneous Isotropic and Non-Homogeneous Non-Isotropic Solid Continua(Scientific Research Publishing, 2020-07-16) Surana, Karan S.; Alverio, Emilio N.Energy methods and the principle of virtual work are commonly used for obtaining solutions of boundary value problems (BVPs) and initial value problems (IVPs) associated with homogeneous, isotropic and non-homogeneous, non-isotropic matter without using (or in the absence of) the mathematical models of the BVPs and the IVPs. These methods are also used for deriving mathematical models for BVPs and IVPs associated with isotropic, homogeneous as well as non-homogeneous, non-isotropic continuous matter. In energy methods when applied to IVPs, one constructs energy functional (I) consisting of kinetic energy, strain energy and the potential energy of loads. The first variation of this energy functional (δI) set to zero is a necessary condition for an extremum of I. In this approach one could use δI = 0 directly in constructing computational processes such as the finite element method or could derive Euler’s equations (differential or partial differential equations) from δI = 0, which is also satisfied by a solution obtained from δI = 0. The Euler’s equations obtained from δI = 0 indeed are the mathematical model associated with the energy functional I. In case of BVPs we follow the same approach except in this case, the energy functional I consists of strain energy and the potential energy of loads. In using the principle of virtual work for BVPs and the IVPs, we can also accomplish the same as described above using energy methods. In this paper we investigate consistency and validity of the mathematical models for isotropic, homogeneous and non-isotropic, non-homogeneous continuous matter for BVPs that are derived using energy functional consisting of strain energy and the potential energy of loads. Similar investigation is also presented for IVPs using energy functional consisting of kinetic energy, strain energy and the potential energy of loads. The computational approaches for BVPs and the IVPs designed using energy functional and principle of virtual work, their consistency and validity are also investigated. Classical continuum mechanics (CCM) principles i.e. conservation and balance laws of CCM with consistent constitutive theories and the elements of calculus of variations are employed in the investigations presented in this paper.Publication Thermodynamic Consistency of Plate and Shell Mathematical Models in the Context of Classical and Non-Classical Continuum Mechanics and a Thermodynamically Consistent New Thermoelastic Formulation(Scientific Research Publishing, 2020-06) Surana, Karan S.; Mathi, Sri Sai CharanInclusion of dissipation and memory mechanisms, non-classical elasticity and thermal effects in the currently used plate/shell mathematical models require that we establish if these mathematical models can be derived using the conservation and balance laws of continuum mechanics in conjunction with the corresponding kinematic assumptions. This is referred to as thermodynamic consistency of the mathematical models. Thermodynamic consistency ensures thermodynamic equilibrium during the evolution of the deformation. When the mathematical models are thermodynamically consistent, the second law of thermodynamics facilitates consistent derivations of constitutive theories in the presence of dissipation and memory mechanisms. This is the main motivation for the work presented in this paper. In the currently used mathematical models for plates/shells based on the assumed kinematic relations, energy functional is constructed over the volume consisting of kinetic energy, strain energy and the potential energy of the loads. The Euler’s equations derived from the first variation of the energy functional for arbitrary length when set to zero yield the mathematical model(s) for the deforming plates/shells. Alternatively, principle of virtual work can also be used to derive the same mathematical model(s). For linear elastic reversible deformation physics with small deformation and small strain, these two approaches, based on energy functional and the principle of virtual work, yield the same mathematical models. These mathematical models hold for reversible mechanical deformation. In this paper, we examine whether the currently used plate/shell mathematical models with the corresponding kinematic assumptions can be derived using the conservation and balance laws of classical or non-classical continuum mechanics. The mathematical models based on Kirchhoff hypothesis (classical plate theory, CPT) and first order shear deformation theory (FSDT) that are representative of most mathematical models for plates/shells are investigated in this paper for their thermodynamic consistency. This is followed by the details of a general and higher order thermodynamically consistent plate/shell thermoelastic mathematical model that is free of a priori consideration of kinematic assumptions and remains valid for very thin as well as thick plates/shells with comprehensive nonlinear constitutive theories based on integrity. Model problem studies are presented for small deformation behavior of linear elastic plates in the absence of thermal effects and the results are compared with CPT and FSDT mathematical models.Publication Evolution of Network Structure and Mechanical Properties in Autonomous-Strengthening Dental Adhesive(MDPI, 2020-09-12) Sarikaya, Rizacan; Song, Linyong; Ye, Qiang; Misra, Anil; Tamerler, Candan; Spencer, PauletteThe inherent degradation property of most dental resins in the mouth leads to the long-term release of degradation by-products at the adhesive/tooth interface. The by-products increase the virulence of cariogenic bacteria, provoking a degradative positive-feedback loop that leads to physicochemical and mechanical failure. Photoinduced free-radical polymerization and sol‒gel reactions have been coupled to produce a novel autonomous-strengthening adhesive with enhanced hydrolytic stability. This paper investigates the effect of network structure on time-dependent mechanical properties in adhesives with and without autonomous strengthening. Stress relaxation was conducted under 0.2% strain for 8 h followed by 40 h recovery in water. The stress‒time relationship is analyzed by nonlinear least-squares data-fitting. The fitted Prony series predicts the sample’s history under monotonic loading. Results showed that the control failed after the first loading‒unloading‒recovery cycle with permanent deformation. While for the experimental sample, the displacement was almost completely recovered and the Young’s modulus increased significantly after the first test cycle. The experimental polymer exhibited higher degree of conversion, lower leachate, and time-dependent stiffening characteristics. The autonomous-strengthening reaction persists in the aqueous environment leading to a network with enhanced resistance to deformation. The results illustrate a rational approach for tuning the viscoelasticity of durable dental adhesives.Publication Synthesis of oxygen functionalized carbon nanotubes and their application for selective catalytic reduction of NOx with NH3(Royal Society of Chemistry, 2020-04-28) Ye, Bora; Kim, Sun-I; Lee, Minwoo; Ezazi, Mohammadamin; Kim, Hong-Dae; Kwon, Gibum; Lee, Duck HyunOxygen functionalized carbon nanotubes synthesized by surface acid treatment were used to improve the dispersion properties of active materials for catalysis. Carbon nanotubes have gained attention as a support for active materials due to their high specific surface areas (400–700 m2 g−1) and chemical stability. However, the lack of surface functionality causes poor dispersion of active materials on carbon nanotube supports. In this study, oxygen functional groups were prepared on the surface of carbon nanotubes as anchoring sites for decoration with catalytic nanoparticles. The oxygen functional groups were prepared through a chemical acid treatment using sulfuric acid and nitric acid, and the amount of functional groups was controlled by the reaction time. Vanadium, tungsten, and titanium oxides as catalytic materials were dispersed using an impregnation method on the synthesized carbon nanotube surfaces. Due to the high density of oxygen functional groups, the catalytic nanoparticles were well dispersed and reduced in size on the surface of the carbon nanotube supports. The selective catalytic reduction catalyst with the oxygen functionalized carbon nanotube support exhibited enhanced NOx removal efficiency of over 90% at 350–380 °C which is the general operating temperature range of catalysis in power plants.Publication Selective Wettability Membrane for Continuous Oil−Water Separation and In Situ Visible Light-Driven Photocatalytic Purification of Water(Wiley Open Access, 2020-04-16) Ezazi, Mohammadamin; Shrestha, Bishwash; Kim, Sun-I.; Jeong, Bora; Gorney, Jerad; Hutchison, Katie; Lee, Duck Hyun; Kwon, GibumMembrane-based technologies are attractive for remediating oily wastewater because they are relatively energy-efficient and are applicable to a wide range of industrial effluents. For complete treatment of oily wastewater, removing dissolved contaminants from the water phase is typically followed by adsorption onto an adsorbent, which complicates the process. Here, an in-air superhydrophilic and underwater superoleophobic membrane-based continuous separation of surfactant-stabilized oil-in-water emulsions and in situ decontamination of water by visible-light-driven photocatalytic degradation of dissolved organic contaminants is reported. The membrane is fabricated by utilizing a thermally sensitized stainless steel mesh coated with visible light absorbing iron-doped titania nanoparticles. Post annealing of the membrane can enhance the adhesion of nanoparticles to the membrane surface by formation of a bridge between them. An apparatus that enables continuous separation of surfactant-stabilized oil-in-water emulsion and in situ photocatalytic degradation of dissolved organic matter in the water-rich permeate upon irradiation of visible light on the membrane surface with greater than 99% photocatalytic degradation is developed. The membrane demonstrates the recovery of its intrinsic water-rich permeate flux upon continuous irradiation of light after being contaminated with oil. Finally, continuous oil−water separation and in situ water decontamination is demonstrated by photocatalytically degrading model toxins in water-rich permeate.Publication Technical and Economic Analysis of Fuel Cells for Forklift Applications(American Chemical Society, 2022-05-26) Metzger, Nathan; Li, XianglinThis study compared the life cycle cost (LCC) of LiFePO4 battery, proton exchange membrane fuel cell (PEMFC), and direct methanol fuel cell (DMFC) as the main power source of electric forklifts. The battery showed the lowest LCC over 10 years ($14,935) among the three power sources, thanks to the significant price reduction in recent years. The fuel cost accounted for more than 70% of the total LCC of PEMFC ($36,682) when the hydrogen price was $8/kg. The LCC of DMFC ($41,819) with the current performance and catalyst loading (0.2 W/cm2, 6 mgPGM/cm2) was 12% higher than the LCC of PEMFC ($36,682). The LCC of DMFC ($25,050) will be 28.9% lower than that of PEMFC if both PEMFC and DMFC reach the target performance and catalyst loading set by the U.S. Department of Energy (1 W/cm2, 0.125 mgPGM/cm2 for PEMFC and 0.3 W/cm2, 3 mgPGM/cm2 for DMFC). The smaller fleet size will significantly increase the LCC of PEMFC due to the high cost of hydrogen fueling and storage infrastructure. For forklift users with less than 50 units, which account for 80% of forklift users, DMFC will be even more cost-effective due to the significantly lower cost of methanol infrastructure.Publication Anthropogenic impacts on phytosociological features and soil microbial health of Colchicum luteum L. an endangered medicinal plant of North Western Himalaya(Elsevier, 2022-01-10) Rather, Rauoof Ahmad; Bano, Haleema; Padder, Shahid Ahmad; Perveen, Kahkashan; Al Masoudi, Luluah M.; Alam, Shah Saud; Hong, Seung HoColchicum luteum is currently a rare and threatened medicinal plant species in the Kashmir Himalaya. Due to the subsequent increase in anthropogenic pressure on medicinal plant species, it is imperative to understand the phytosociological and conservational status of the plant in its natural habitat. The objectives of this study were analysed in year 2018–2019 on the phytosociological data, viz. density, frequency, and abundance, as well as the rhizospheric soil microbial diversity of C. luteum in disturbed and undisturbed areas of the Kashmir Himalaya. We examined the distribution pattern, phytosociological data, and conservation status of C. luteum by analysing ecological features like abundance, frequency, and density in all three selected locations in Kashmir, Northern India and were found maximum values at Undisturbed areas. The highest values of density (3.24 ± 0.69 m2), frequency (57.77 ± 13.55%), and abundance (5.49 m2) were recorded at undisturbed site Harwan. The total bacterial count (CFU) and Vesicular Arbuscular Mycorrhiza (VAM) spore population from the rhizospheric soil of C. luteum were also analysed, with higher bacterial count i.e., Pseudomonas, Azatobacter, Rhizobium and PSB were (26.2 ± 0.648) (21.88 ± 0.675) (30.11 ± 0.576) and (14.11 ± 0.671) and VAM spore population (g−1) of soil recorded 6.36 ± 0.550 at undisturbed areas viz. Harwan. The bacteria and fungi are likely keystone organisms that form an interface between soils and plant roots. Mutualistic associations with host plants have been observed in various natural and agricultural ecosystems. The present findings could be helpful in formulating conservation strategies for C. Luteum threatened and endangered medicinal plant present in North western Himalayan regions. The plant in disturbed areas that are affected by anthropogenic activities like tourism, grazing, deforestation, urbanization, transport etc. impacts on phytosociological and soil microbial patterns in the area. Because of these abiotic pressures, causes a reduction in plant cover in forest regions, soils become exposed, affecting soil microbial health. Therefore, the study shows the necessity for best practices for medicinal plant and forest management that provide effective monitoring and regulation of human activities in the offshore forest regions and avoid the intrusion of existing reserves.Publication Thermodynamic modeling of in-situ rocket propellant fabrication on Mars(Cell Press, 2022-04-28) Alam, Shah Saud; Depcik, Christopher; Burugupally, Sindhu Preetham; Hobeck, Jared; McDaniel, EthanIn-situ resource utilization (ISRU) to refuel rockets on Mars will become critical in the future. The current effort presents a thorough feasibility analysis of a scalable, Matlab-based, integrated ISRU framework from the standpoint of the second law of thermodynamics. The ISRU model is based on existing technology that can utilize Martian resources (regolith and atmosphere) to produce rocket propellants. Model simulations show that the system analysis is theoretically consistent with a positive entropy generation, and the achievable mass flow rates of liquid methane and liquid oxygen can potentially meet the 16-month rocket refueling deadline (on Mars) as desired by the National Aeronautics and Space Administration. However, the model is sensitive to liquid oxygen storage temperatures, and lower temperatures are necessary to minimize compressor work. This proof-of-concept model can open avenues for further experimental evaluation of the system to achieve a higher technology readiness level.