Quantitative Modeling of Entangled Polymer Rheology: Experiments, Tube Models and Slip-Link Simulations.

Rheology properties are sensitive indicators of molecular structure and dynamics. The relationship between rheology and polymer dynamics is captured in the constitutive model, which, if accurate and robust, would greatly aid molecular design and polymer processing. This dissertation is thus focused on building accurate and quantitative constitutive models that can help predict linear and non-linear viscoelasticity. In this work, we have used a multi-pronged approach based on the tube theory, coarse-grained slip-link simulations, and advanced polymeric synthetic and characterization techniques, to confront some of the outstanding problems in entangled polymer rheology. First, we modified simple tube based constitutive equations in extensional rheology and developed functional forms to test the effect of Kuhn segment alignment on a) tube diameter enlargement and b) monomeric friction reduction between subchains. We, then, used these functional forms to model extensional viscosity data for polystyrene (PS) melts and solutions. We demonstrated that the idea of reduction in segmental friction due to Kuhn alignment is successful in explaining the qualitative difference between melts and solutions in extension as revealed by recent experiments on PS. Second, we compiled literature data and used it to develop a universal tube model parameter set and prescribed their values and uncertainties for 1,4-PBd by comparing linear viscoelastic G’ and G” mastercurves for 1,4-PBds of various branching architectures. The high frequency transition region of the mastercurves superposed very well for all the 1,4-PBds irrespective of their molecular weight and architecture, indicating universality in high frequency behavior. Therefore, all three parameters of the tube model were extracted from this high frequency transition region alone. Third, we compared predictions of two versions of the tube model, Hierarchical model and BoB model against linear viscoelastic data of blends of 1,4-PBd star and linear melts. The star was carefully synthesized and characterized. We found massive failures of tube models to predict the terminal relaxation behavior of the star/linear blends. In addition, these blends were also tested against a coarse-grained slip-link model, the “Cluster Fixed Slip-link Model (CFSM)” of Schieber and coworkers. The CFSM with only two parameters gave excellent agreement with all experimental data for the blends.PHDMacromolecular Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/120764/1/psdesai_1.pd

TECHNIQUES TO ENHANCE USER PLANE FUNCTION (UPF) LOAD METRICS TO IMPROVE UPF SELECTION

Mobile network architectures, such as Fifth Generation Core (5GC) architectures are designed to serve a variety of use cases in which each of the use cases can demand very different network resource allocation and traffic treatment. The introduction of the Control and User Plane separation (CUPS) architecture in the Evolved Packet Core (EPC) mobile network architecture, requires the control plane (CP) to select an appropriate User Plane Function (UPF) to serve a service request from a user equipment (UE) with a desired Quality of Service (QoS). This proposal provides techniques through which optimum UPF usage can be determined by considering multiple load factors, which can aid in performing UPF selection for 5GC and CUPS/EPC mobile network architectures

Association of Inflammatory Markers with Outcome and Prognosis of COVID-19 Pneumonia

The COVID-19 pandemic, which was brought on by the SARS-CoV-2 virus, has created serious problems for global health. It is essential to comprehend the elements that affect the prognosis and severity of an illness. The results of COVID-19 pneumonia may be predicted by inflammatory markers such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), serum lactate dehydrogenase (LDH), serum ferritin, and serum D-dimer. Methods: To examine the relationship between these inflammatory markers and unfavourable outcomes in COVID-19 pneumonia, we carried out an 18-month observational research (February 2021 to August 2022) with 100 COVID-19-positive patients. We gathered demographic information, clinical information, and marker levels. Chi-squared tests and logistic regression were used in the statistical analysis. Results: Patients with COVID-19 pneumonia had elevated levels of CRP, ESR, LDH, ferritin, and D-dimer. Increased levels of these markers were strongly linked to unfavourable results. The odds ratios, which varied from 2.12 to 2.59, showed that patients with increased markers were more likely to experience negative outcomes. Conclusion: The clinical importance of tracking inflammatory markers in COVID-19 pneumonia patients is highlighted by our study, in its conclusion. Elevated levels of CRP, ESR, LDH, ferritin, and D-dimer may act as early markers of illness development and predictors of unfavourable results. During the ongoing COVID-19 epidemic, these markers may help with risk stratification and clinical decision-making, thereby enhancing patient care. These findings need to be expanded upon and validated by additional study

Effect of hydrodynamic cavitation on zooplankton: a tool for disinfection

Application of hydrodynamic cavitation for disinfection of water is gaining momentum, as it provides environmentally and economically sound options. In this effort, the effect of cavitating conditions created by differential pump valve opening and that created by flowing through a cavitating element (orifice plates) on the microbes (zooplankton in sea water) is described. The experimental results are compared with modelling of cavitating conditions that includes cavity dynamics, turbulence generated by individual oscillating cavity, cell wall strength and geometrical and operating parameters of cavitation device. Theoretical model for quantifying the cavitationally generated turbulent shear and extent of microbial disinfection has been developed. Experimental results indicated that cavitation and/or turbulent fluid shear dominantly originating from cavitation are effective tools for sea water disinfection as more than 80% of the zooplankton present in the sea water were killed. It was also observed that shock waves generated due to cavitation is not the sole cause for zooplankton disruption. A correct physical mechanism accounting fluid turbulence and shear, generated from stable oscillation of cavity, significantly contribute towards the disruption. Further refinement of the model presented will serve as a basis for higher degree of disinfection and provide a practical tool for sea water disinfection

An inter-site study of biofouling recruitment on static immersion panels in major ports of South East Asia and India

Limited knowledge of native marine biodiversity hinders effective biodiversity management to safeguard South and Southeast Asia’s marine coastal environment against the threat of invasive species transfer through shipping. In particular, sessile marine biofouling organisms in South East Asian ports are poorly known. Through the support of the ASEAN-India Cooperation Project on the Extent of Transfer of Alien Invasive Organisms in South/South East Asia Region by Shipping, a coordinated effort to examine diversity of biofouling organisms in major port areas in Southeast Asia and India was made using polyvinylchloride (PVC) panels as recruitment surfaces in a static immersion study for a period of 12 months. Not surprisingly, the study revealed that fouling patterns differed between ports possibly as a result of dissimilar hydrographic conditions. However, there were also underlying similarities that reflected a regional uniformity in the composition of fouling communities. At the same time, the alien Caribbean bivalve Mytilopsis sallei was detected in Manila Bay (Philippines), Songkhla Port (Thailand) and Singapore. This is a first simultaneous biofouling survey involving scientists and government stakeholders from India and ASEAN nations of Brunei Darussalam, Indonesia, Lao PDR, Malaysia, Myanmar, Singapore, Thailand, Philippines and Vietnam

Biodegradation of textile dye Direct Blue 71 using root nodulating Rhizobium sp.

532-539Textile dye pollution  is an issue of environmental concern. . Though microbes have been widely explored for their dye degrading abilities, little work has been reported using root nodulating bacteria. In the present study, an attempt has been made to use a non-pathogenic, nitrogen fixing soil bacteria for biodegradation of textile dye, Direct Blue 71 (DB71). The 11 isolates of Rhizobium showed potential to decolourize the triazo dye DB71. Of these, isolate TUR2 (GenBank accession no. JF820124) showed the highest (95%) ability to decolourize the dye. Over expression of oxidative and reductive enzymes in the presence of the dye indicated their role in degradation which was confirmed using analytical techniques like HPLC, FTIR and GC-MS. Phytotoxicity studies have shown these dye metabolites to be non-toxic. Results of this study indicate potential use of Rhizobium sp. in biodegradation of textile dye, and suggest further investigation towards developing a dual technology of biofertilization coupled with bioremediation

Hairy root induction and phytoremediation of textile dye, Reactive green 19A-HE4BD, in a halophyte, Sesuvium portulacastrum (L.) L.

In this study, we report phytoremediation of textile dyes using hairy roots derived through Agrobacterium rhizogenes (NCIM 5140) infection of in vitro leaf and stem explants of a halophyte Sesuvium portulacastrum (L.) L. Leaf explants showed higher frequency of hairy root induction (70%) than stem explants (30%), and maximum number of roots (leaf 42.3 ± 2.4 and stem 50.3 ± 1.7). Transformed nature of hairy roots was ascertained by amplifying 970 bp region of T-DNA of Ri plasmid. Hairy roots were screened for phytoremediation of various textile dyes and results showed that HRs were able to degrade Reactive green 19A HE4BD upto 98% within 5 days of incubation. Spectrophotometric analysis showed decrease in dye concentration while HPLC and FTIR analysis confirmed its degradation. Seed germination assay demonstrated non-toxic nature of the extracted metabolites. This is the first report on induction of hairy root culture in Sesuvium portulacastrum and phytoremediation of textile dyes