Solute-Solute Interactions in Jet Fuel by Ultralow Conductance Measurement

Solute-solute interactions in pure organic liquids are much easier to determine than solute-solute interactions in a complex organic mixture such as a middle distillate fuel. This paper presents a method for the determination of solute-solute interaction and infinite dilution diffusion coefficient of hydrogen bond donor-acceptor species using ultralow conductance measurement. A theoretical framework was developed to obtain both complexation equilibrium constant (K) and infinite dilution diffusion coefficient, D° from a single set of measurements. These equations were applied for the study in hexadecane, a model hydrocarbon, and in jet fuel. The D° for methanol in jet fuel, 1.38 × 10^-4 cm² s^-1, is indicative of hydrophobic environments for the polar solutes in hydrocarbons media. The conditional equilibrium constant, K', was found to be maximum for methanol in jet fuel, which indicates the presence of strong hydrogen bond acceptors in jet fuel. The present method is fairly general and applicable to polar and polarizable species in hydrocarbon media.     

Multi-Criteria Approach for Evaluating Long Term Water Strategies

Abstract

Long-term national water strategies, which are formulated to cope with the socio-economic development plans, have either positive or negative impacts in several domains including environment, economy, and social life. Intuitive evaluation of policies and actions on the basis of their social, economic, and environmental utilities is ambiguous and very complex. Setting water resources policies for a country like Egypt is a good example of this type of complexity due to its multisectoral, interdisciplinary, interrelated environment. There is a classical assumption in water resources planning and management that stipulates decisions based on optimization of a well-defined single objective. In reality, the decision-making process is much more complex. Decision makers seek an optimal compromise among several objectives or try to achieve satisfying levels of their goals. Therefore, the present study proposes the multi-criteria analysis as an approach for evaluating Egypt's long term plans to reveal their rank and behavior throughout the foreseen planning horizon. Several evaluation criteria (indicators) have been articulated and grouped into four main categories: water, environment, social, and economy. A simple empirical simulation model was used to score different criteria. Four cases have been compared and evaluated by the suggested approach. Each case represents an anticipated national water-related development plan. This is carried out under specific scenarios for uncontrolled variables such as population growth rate, hydrological river flow into the system, and others. The application showed that a multi-criteria approach could contribute significantly to the decision making process in Egypt. It provides a systematic way of presenting the tradeoffs among policy choices considering many issues.     

Design of a lightweight authentication scheme for IEEE 802.11p vehicular networks

With the growing popularity of vehicle-based mobile devices, vehicular networks are becoming an essential part of wireless heterogeneous networks. Therefore, vehicular networks have been widely studied in recent years. Because of limited transmission range of wireless antennas, mobile vehicles should also switch their access points to maintain the connections as conventional mobile nodes. Considering the inherent characteristics of vehicular networks such as dynamic topology and high speed, the question of how to implement handoff protocol under real-time scenarios is very important. IEEE 802.11p protocol is designed for vehicular networks for the long distance transmission. To reduce handoff latency for 802.11p protocol, the authentication phase is waived during the handoff. However, security is also very important for wireless communications, and authentication can forbid access from malicious nodes and prevent wireless communications from potential attacks. Thus, in this paper, a lightweight authentication scheme is introduced to balance the security requirements and the handoff performance for 802.11p vehicular networks. In our scheme, the access points are divided into different trust groups, and the authentication process is completed in a group-based method. Once a vehicle is authenticated by an access point group, during the handoff within the same group, few extra authentication operations are needed. As a result, there is no extra overhead introduced to the authentication servers. Simulation results demonstrate that our authentication scheme only introduces small handoff latency and it is ideal for vehicular networks.     

Structural Insights into the Substrate Transport Mechanisms in GTR Transporters through Ensemble Docking

Glucosinolate transporters (GTRs) are part of the nitrate/peptide transporter (NPF) family, members of which also transport specialized secondary metabolites as substrates. Glucosinolates are defense compounds derived from amino acids. We selected 4-methylthiobutyl (4MTB) and indol-3-ylmethyl (I3M) glucosinolates to study how GTR1 from Arabidopsis thaliana transports these substrates in computational simulation approaches. The designed pipeline reported here includes massive docking of 4MTB and I3M in an ensemble of GTR1 conformations (in both inward and outward conformations) extracted from molecular dynamics simulations, followed by clustered and substrate–protein interactions profiling. The identified key residues were mutated, and their role in substrate transport was tested. We were able to identify key residues that integrate a major binding site of these substrates, which is critical for transport activity. In silico approaches employed here represent a breakthrough in the plant transportomics field, as the identification of key residues usually takes a long time if performed from a purely wet-lab experimental perspective. The inclusion of structural bioinformatics in the analyses of plant transporters significantly speeds up the knowledge-gaining process and optimizes valuable time and resources.     

An analysis of the framings of water scarcity in the Jordanian national water strategy

This viewpoint analyzes the Jordanian water strategy to investigate how water scarcity is framed, and what solutions are suggested. It also analyzes how the framings and discourses have changed in the two versions of the strategy, why, and their implications. The Jordanian national water strategy has been overlooked by the literature of hydropolitics. The analysis here also contributes by showing the interplay between discourses of scarcity and policy solutions.     

Spatial and Temporal Quantification of Community Resilience: Gotham City under Attack

Mitigating the impact of disasters on communities requires not only a deep understanding of the essential features of infrastructure, social, and economical components that make a community resilient; but also the development of mathematical models that can seamlessly integrate these features. This article lays the foundation for an integrative model that captures interaction between these components. The underlying fundamentals of the proposed model hinges on the principle of a damped harmonic oscillator by assuming the behavior of a community in response to a hazard is equivalent to the response of a vibrating mass of finite stiffness and damping. We implemented the dynamic model by developing a novel finite element formulation capable of quantifying resilience both temporally and spatially. We then used the developed model to devise a suitable hazard‐agnostic definition of community resilience. This was realized through a set of demonstration and logical verification tests conducted on Gotham City, the fictional city of the infamous character, Batman. It was observed that the model can be used to identify sensitive and vulnerable areas in a community, provide a spatial and temporal quantification of community resilience, and accommodate various types of hazards such as physical disruptions, economic downtimes, and even social disorders.     

Global Genome Conformational Programming during Neuronal Development Is Associated with CTCF and Nuclear FGFR1—The Genome Archipelago Model

During the development of mouse embryonic stem cells (ESC) to neuronal committed cells (NCC), coordinated changes in the expression of 2851 genes take place, mediated by the nuclear form of FGFR1. In this paper, widespread differences are demonstrated in the ESC and NCC inter- and intra-chromosomal interactions, chromatin looping, the formation of CTCF- and nFGFR1-linked Topologically Associating Domains (TADs) on a genome-wide scale and in exemplary HoxA-D loci. The analysis centered on HoxA cluster shows that blocking FGFR1 disrupts the loop formation. FGFR1 binding and genome locales are predictive of the genome interactions; likewise, chromatin interactions along with nFGFR1 binding are predictive of the genome function and correlate with genome regulatory attributes and gene expression. This study advances a topologically integrated genome archipelago model that undergoes structural transformations through the formation of nFGFR1-associated TADs. The makeover of the TAD islands serves to recruit distinct ontogenic programs during the development of the ESC to NCC.     

The Synthesis of Biarylmonophosphonates via Palladium-Catalyzed Phosphonation,Iridium-Catalyzed C-H Borylation,Palladium-Catalyzed Suzuki–Miyaura Cross-Coupling

Catalysis Letters - The iridium-catalyzed C-H borylation of diethyl phenylphosphonate results in nonselective mono and bisborylation to afford a near statistical mixture of 3-, 3,5- and 4-boryl...     

Min–max control using parametric approximate dynamic programming

This study presents a computationally efficient approximate dynamic programming approach to control uncertain linear systems based on a min–max control formulation. The optimal cost-to-go function, which prescribes an optimal control policy, is estimated using piecewise parametric quadratic approximation. The approach requires simulation or operational data only at the bounds of additive disturbances or polyhedral uncertain parameters. This strategy significantly reduces the computational burden associated with dynamic programming and is not limited to a particular form of performance criterion as in previous approaches.