Integrated Framework for Process and Product Synthesis/Design

Future growth within the chemical process industries depends on various factors such as raw material and energy availability, sustainability etc. A systematic process synthesis and design framework integrated with molecular design is needed to synthesize processes that perform this efficiently. Hence, this dissertation describes the development of a novel hybrid method for Computer Aided Flowsheet Design (CAFD) and its effective integration with molecular design. The interactions among process synthesis, process design and molecular design is through a common set of properties that are employed to analyze the processes as well as external agents involved in the process. Knowledge of these specific properties is needed to establish the feasibility of a unit operation in a process and the corresponding conditions of operation. The same information is needed for design of a component as an appropriate external agent. This forms the very basis of the proposed hybrid methodology for flowsheet synthesis/design integrated with molecular design. Both the Computer Aided Flowsheet Design (CAFD) and Computer Aided Molecular Design (CAMD) frameworks developed are group contribution (GC) based approaches. CAFD makes use of functional process groups, characterized by the type of unit operation/process and their corresponding driving force, to generate and represent flowsheets; process group contribution based property models to predict flowsheet properties from a-priori regressed contributions of process groups; a notation system (called SFILES) for storing the flowsheet structural information; and a synthesis method to generate and identify the feasible flowsheets. The identified candidate flowsheets are ranked based on flowsheet properties (like energy consumption, amount (mass) of external agents used and/or cost/profit) representing flowsheet performance in a quantitative sense. Once the promising flowsheet structures are identified, the flowsheet design parameters that describe the process will be estimated. The reverse simulation method is used to calculate the design variables of the unit operations involved in the process. This also gives a good estimate of the important design parameters. Some alternatives may involve unit operations that require an external agent. Conventional agents may not always meet the property constraints set by the reverse simulation design problem of such operations. Novel agents can be identified by solving a product design problem satisfying the property constraints. This is done by integrating the flowsheet design problem with a molecular design problem. Depending on the type of unit operation in the process where an external agent is required, the CAMD problem is formulated accordingly and the effect of the solution alternatives from the CAMD problem on the process is evaluated by the process models. CAMD includes building blocks (atoms and functional groups) to generate and represent molecules; group contribution based property models to predict target properties; a standard molecular structure notation system to store and visualize the molecular structure information; and a synthesis method to generate and screen molecules that match the target (design) properties. Once a set of near optimal flowsheet alternatives have been identified, rigorous simulation is used to verify the predicted performance and select the best flowsheet. The framework also aims at maintaining a good accuracy of solutions and large application range. A completely automated tool to perform the above tasks is also developed

Real-Time Byzantine-Resilient Power Grid Infrastructure

The power grid, critical to society and the economy, is increasingly targeted by sophisticated cyber attacks, especially from nation-state actors. These threats, at both system and network levels, aim to compromise key grid components, risking severe disruptions and blackouts. While much of the existing research focuses on isolated security concerns, it neglects complex threats to the broad grid infrastructure, especially in substations. This gap undermines grid resilience and endangers both lives and billions of dollars. This thesis takes a step towards resilient grid infrastructure by introducing a novel comprehensive threat model and pioneering real-time, Byzantine-resilient solutions for grid infrastructure. We present the first real-time Byzantine-resilient architecture and protocols for the substation, ensuring correct protective operations even in the face of protective relay compromises and network attacks. We evaluate our implementation across a comprehensive range of fault-free and faulty operating conditions in relevant testbeds, demonstrating its ability to meet strict real-time latency requirements even in the worst operating conditions. We introduce the first end-to-end Byzantine-resilient system framework for the broad grid infrastructure from the control center to the substation and field devices under the comprehensive threat model. We demonstrate the proposed system frame- work’s ability to support real-time grid operations in a Byzantine-resilient manner. To enhance situational awareness, we integrate unsupervised machine learning models for anomaly detection. The solutions we propose satisfy other critical domain needs, including continu- ous availability over a long system lifetime and seamless integration with the grid. We implemented all modules and protocols and made them available to the commu- nity within the open-source Spire Toolkit. The system has successfully withstood a purple team exercise and has been transitioned to SCADA manufacturers GE and Siemens, as well as two national laboratories PNNL and SANDIA. Finally, we pro- pose a practical incremental deployment strategy for large-scale real-world power grid topologies

Real-Time Byzantine-Resilient Power Grid Infrastructure

The power grid, critical to society and the economy, is increasingly targeted by sophisticated cyber attacks, especially from nation-state actors. These threats, at both system and network levels, aim to compromise key grid components, risking severe disruptions and blackouts. While much of the existing research focuses on isolated security concerns, it neglects complex threats to the broad grid infrastructure, especially in substations. This gap undermines grid resilience and endangers both lives and billions of dollars. This thesis takes a step towards resilient grid infrastructure by introducing a novel comprehensive threat model and pioneering real-time, Byzantine-resilient solutions for grid infrastructure. We present the first real-time Byzantine-resilient architecture and protocols for the substation, ensuring correct protective operations even in the face of protective relay compromises and network attacks. We evaluate our implementation across a comprehensive range of fault-free and faulty operating conditions in relevant testbeds, demonstrating its ability to meet strict real-time latency requirements even in the worst operating conditions. We introduce the first end-to-end Byzantine-resilient system framework for the broad grid infrastructure from the control center to the substation and field devices under the comprehensive threat model. We demonstrate the proposed system frame- work’s ability to support real-time grid operations in a Byzantine-resilient manner. To enhance situational awareness, we integrate unsupervised machine learning models for anomaly detection. The solutions we propose satisfy other critical domain needs, including continu- ous availability over a long system lifetime and seamless integration with the grid. We implemented all modules and protocols and made them available to the commu- nity within the open-source Spire Toolkit. The system has successfully withstood a purple team exercise and has been transitioned to SCADA manufacturers GE and Siemens, as well as two national laboratories PNNL and SANDIA. Finally, we pro- pose a practical incremental deployment strategy for large-scale real-world power grid topologies

Broken Promises: Prolonged Diminished Quality-of-Life among Liberian Ebola Survivors Half a Decade after the 2014-16 West African Outbreak

The 2014–2016 Ebola outbreak left thousands of Liberian survivors with severely diminished quality of life. Applying a social determinants framework, this mixed method study investigates to what extent Ebola virus disease (EVD) survivors suffer long-haul psychosocial stress, diminished quality-of-life factors, and the impact of EVD-related service provisions on their ongoing healing. We present the results of a quantitative analysis survey of data collected from 19 Liberian EVD survivors in 2022 using snowball sampling. Additionally, a qualitative analysis of survivor statements helps triangulate key statistical findings and inform causal mechanisms. Survivors report experiencing 5.25 of a total of 7 ongoing stressors (95% CI 4.65–5.85). Higher satisfaction rates of government service provision are negatively correlated with experiencing long-term stigmatization (r = -0.55), eviction (-0.45), and the inability to pay school fees (-0.33). However, most survivors rate service provisions as low, frustrated that promised services such as resettlement and scholarships often have gone unfulfilled. All survivors feel the world has forgotten about them. All suffer financial hardships. The inability to fund their children’s schooling is statistically linked to experiencing 43 percent higher (2.96 points) stress than that of peers (p \u3c 0.05). Due to ongoing EVD-related health complications, all survivors volunteered as human participants in the clinical trials mounted by Partnership for Research on Ebola Vaccines in Liberia (PREVAIL). Statements reflect diminishing implementation quality over time, along with instances of unethical mistreatment. Being treated poorly or being discriminated against by PREVAIL staff appears to have an 18 percent (1.27 points) higher rate of stress (p \u3c 0.05). This research is one of the first studies that examines the long-term social adversities threatening survivors’ long-term well-being

Pericyte dynamics in the mouse germinal matrix angiogenesis.

Germinal matrix-intraventricular hemorrhage (GM-IVH) is the most devastating neurological complication in premature infants. GM-IVH usually begins in the GM, a highly vascularized region of the developing brain where glial and neuronal precursors reside underneath the lateral ventricular ependyma. Previous studies using human fetal tissue have suggested increased angiogenesis and paucity of pericytes as key factors contributing to GM-IVH pathogenesis. Yet, despite its relevance, the mechanisms underlying the GM vasculature's susceptibility to hemorrhage remain poorly understood. To gain better understanding on the vascular dynamics of the GM, we performed a comprehensive analysis of the mouse GM vascular endothelium and pericytes during development. We hypothesize that vascular development of the mouse GM will provide a good model for studies of human GM vascularization and provide insights into the role of pericytes in GM-IVH pathogenesis. Our findings show that the mouse GM presents significantly greater vascular area and vascular branching compared to the developing cortex (CTX). Analysis of pericyte coverage showed abundance in PDGFRβ-positive and NG2-positive pericyte coverage in the GM similar to the developing CTX. However, we found a paucity in Desmin-positive pericyte coverage of the GM vasculature. Our results underscore the highly angiogenic nature of the GM and reveal that pericytes in the developing mouse GM exhibit distinct phenotypical and likely functional characteristics compared to other brain regions which might contribute to the high susceptibility of the GM vasculature to hemorrhage.S