A method of treating boundary singularities in time-dependent problems

A method is presented for treating singularities which occur in solutions of Parabolic partial differential equations due to sharp corners in the boundary. The method is essentially an extension of the method due to Motz (1946) for solving Elliptic problems and approximates to the analytical form of the singularity in terms of neighbouring function values at each time step. It is used in conjunction with the simple explicit finite-difference scheme and subsequently the overall method is explicit

A simple finite-difference modification for improving accuracy near a corner in heat flow problems

Traditional numerical methods of solution of heat flow problems are subject to inaccuracies near sharp corners, where the derivatives of the exact solution may "become unbounded (Jeffreys1). 2Previous methods of overcoming this difficulty (Motz, Woods3

Impact of Driving Cycles on Greenhouse Gas (GHG) Emissions, Global Warming Potential (GWP) and Fuel Economy for SI Car Real World Driving

The transport sector is one of the major contributors to greenhouse gas emissions. This study investigated three greenhouse gases emitted from road transport: CO2, N2O and CH4 emissions as a function of engine warm up and driving cycles. Five different urban driving cycles were developed and used including free flow driving and congested driving. An in-vehicle FTIR (Fourier Transform Inferred) emission measurement system was installed on a EURO2 emission compliant SI (Spark Ignition) car for emissions measurement at a rate of 0.5 HZ under real world urban driving conditions. This emission measurement system was calibrated on a standard CVS (Constant Volume Sampling) measurement system and showed excellent agreement on CO2 measurement with CVS results. The N2O and CH4 measurement was calibrated using calibration gas in lab. A MAX710 real time in-vehicle fuel consumption measurement system was installed in the test vehicle and real time fuel consumption was then obtained. The temperatures across the TWC (Three Way Catalyst) and engine out exhaust gas lambda were measured. The GHG (greenhouse gas) mass emissions and consequent GWP (Global Warming Potential) for different urban diving conditions were analyzed and presented. The results provided a better understanding of traffic related greenhouse gas emission profile in urban area and will contribute to the control of climate change

Warp-X: a new exascale computing platform for beam-plasma simulations

Turning the current experimental plasma accelerator state-of-the-art from a promising technology into mainstream scientific tools depends critically on high-performance, high-fidelity modeling of complex processes that develop over a wide range of space and time scales. As part of the U.S. Department of Energy's Exascale Computing Project, a team from Lawrence Berkeley National Laboratory, in collaboration with teams from SLAC National Accelerator Laboratory and Lawrence Livermore National Laboratory, is developing a new plasma accelerator simulation tool that will harness the power of future exascale supercomputers for high-performance modeling of plasma accelerators. We present the various components of the codes such as the new Particle-In-Cell Scalable Application Resource (PICSAR) and the redesigned adaptive mesh refinement library AMReX, which are combined with redesigned elements of the Warp code, in the new WarpX software. The code structure, status, early examples of applications and plans are discussed

Inhalation of high-concentration hydrogen gas attenuates cognitive deficits in a rat model of asphyxia induced-cardiac arrest.

Cognitive deficits are a devastating neurological outcome seen in survivors of cardiac arrest. We previously reported water electrolysis derived 67% hydrogen gas inhalation has some beneficial effects on short-term outcomes in a rat model of global brain hypoxia-ischemia induced by asphyxia cardiac arrest. In the present study, we further investigated its protective effects in long-term spatial learning memory function using the same animal model. Water electrolysis derived 67% hydrogen gas was either administered 1 hour prior to cardiac arrest for 1 hour and at 1-hour post-resuscitation for 1 hour (pre- & post-treatment) or at 1-hour post-resuscitation for 2 hours (post-treatment). T-maze and Morris water maze were used for hippocampal memory function evaluation at 7 and 14 days post-resuscitation, respectively. Neuronal degeneration within hippocampal Cornu Ammonis 1 (CA1) regions was examined by Fluoro-Jade staining ex vivo. Hippocampal deficits were detected at 7 and 18 days post-resuscitation, with increased neuronal degeneration within hippocampal CA1 regions. Both hydrogen gas treatment regimens significantly improved spatial learning function and attenuated neuronal degeneration within hippocampal CA1 regions at 18 days post-resuscitation. Our findings suggest that water electrolysis derived 67% hydrogen gas may be an effective therapeutic approach for improving cognitive outcomes associated with global brain hypoxia-ischemia following cardiac arrest. The study was approved by the Animal Health and Safety Committees of Loma Linda University, USA (approval number: IACUC #8170006) on March 2, 2017

SOLVING TRAFFIC CONGESTION FROM THE DEMAND SIDE

It is nowadays widely accepted that solving traffic congestion from the demand side is more important and more feasible than offering more capacity or facilities for transportation. Following a brief overview of evolution of the concept of Travel Demand Management (TDM), there is a discussion on the TDM foundations that include demand-side strategies, traveler choice and application settings and the new dimensions that ATDM (Active forms of Transportation and Demand Management) bring to TDM, i.e. active management and integrative management. Subsequently, the authors provide a short review of the state-of-the-art TDM focusing on relevant literature published since 2000. Next, we highlight five TDM topics that are currently hot: traffic congestion pricing, public transit and bicycles, travel behavior, travel plans and methodology. The paper closes with some concluding remarks

Parallel Unsmoothed Aggregation Algebraic Multigrid Algorithms on GPUs

We design and implement a parallel algebraic multigrid method for isotropic graph Laplacian problems on multicore Graphical Processing Units (GPUs). The proposed AMG method is based on the aggregation framework. The setup phase of the algorithm uses a parallel maximal independent set algorithm in forming aggregates and the resulting coarse level hierarchy is then used in a K-cycle iteration solve phase with a $\ell^1$-Jacobi smoother. Numerical tests of a parallel implementation of the method for graphics processors are presented to demonstrate its effectiveness.Comment: 18 pages, 3 figure

5-Meth­oxy-3-[(5-meth­oxy-1H-indol-3-yl)(phen­yl)meth­yl]-1H-indole

In the title compound, C25H22N2O2, the indole rings are individually almost planar [with maximum deviations of 0.0116 (19) and 0.0113 (18) Å] and are almost orthogonal to each other, making a dihedral angle of 84.49 (6)°. The benzene ring is inclined at 72.83 (9) and 80.85 (9)° with respect to the indole rings. In the crystal, mol­ecules are linked by N—H⋯O inter­actions into chains running parallel to the c axis. The crystal structure is further stabilized by C—H⋯π inter­actions

Angry responses to infant challenges: parent, marital, and child genetic factors associated with harsh parenting

This study examined genetic and environmental influences on harsh parenting of 9-month-olds. We examined whether positive child-, parent-, and family-level characteristics were associated with harsh parenting in addition to negative characteristics. We were particularly interested in examining evocative gene-environment correlation (rGE) by testing the effect of birth parent temperament on adoptive parents’ harsh parenting. Additionally, we examined associations among adoptive parents’ own temperaments, their marital relationship quality, and harsh parenting. Adoptive fathers’ (but not adoptive mothers’) harsh parenting was inversely related to an index of birth mother positive temperament (reward dependence), indicating evocative rGE. Higher marital quality was associated with less harsh parenting, but only for adoptive fathers. Adoptive parents’ negative temperamental characteristics (harm avoidance) were related to hostile parenting. Findings suggest the importance of enhancing positive family characteristics in addition to mitigating negative characteristics, as well as engaging multiple levels of the family system to prevent harsh parenting. Children have the potential to evoke strong positive and negative affective responses from parents, which then influence and organize caregiving behavior (Dix, 1991). All young children demonstrate challenging behaviors, such as prolonged crying that may be difficult to soothe, uncooperativeness with bathing or dressing, or difficulty with eating or sleeping. The degree to which parental negative emotion is evoked by these challenges and expressed in interactions with children is often characterized as harsh or overreactive parenting. Harsh parenting is a function of a complex interplay of risk and protective factors that operate at multiple levels of the family system (i.e., characteristics of the parent, child, and family environment; Belsky, 1984; Boivin et al., 2005; DiLalla & Bishop, 1996; Neiderhiser et al., 2004, 2007; Towers, Spotts, & Neiderhiser, 2002). The long-term maladaptive developmental outcomes associated with harsh, negative parenting during infancy (Bayer, Ukoumunne, Mathers, Wake, Abdi, & Hiscock, 2012; Bradley & Corwyn, 2008; Lorber & Egeland, 2009) underscore the need for improved understanding of risk and protective factors associated with early harsh parenting. The current study aims to extend on the research on harsh parenting in infancy in two ways. First, although risk factors for early harsh parenting are well documented, we know little about factors that buffer parents from harsh parenting during infancy; this study examines independent and differential effects of positive and negative characteristics on harsh parenting. Second, although interest in child effects on parenting, including harsh parenting, has been present in the field for decades (Bell, 1979; Bell & Chapman, 1986; Rutter et al., 1997) we know very little about the degree to which the effects found in the literature truly reflect evocative effects of infants’ genetically influenced characteristics. The current study used an adoption design to test the hypothesis that genetically influenced temperamental characteristics of 9-month-olds would influence adoptive parents’ harsh parenting. Previous research has identified many correlates of harsh parenting, including negative characteristics of the parent (e.g., maternal depression; Lovejoy, Graczyk, O’Hare, & Neuman, 2000), family (e.g., marital hostility, Rhoades et al., 2011), and child (e.g., difficult temperament, Plomin, Loehlin & DeFries, 1985; poor regulation, Bridgett et al., 2009). Previous research has identified risk factors for harsh parenting, but very little is known about how positive parent, child, and family characteristics might mitigate it. For example, a positive marital relationship could buffer the impact of high levels of depressive symptoms on parenting, and thus have implications for prevention and intervention efforts. The current study examined positive and negative parent, child, and family factors in association with harsh parenting. A second emphasis centered on understanding the role of infants’ genetically influenced characteristics on harsh parenting. Much of the previous work on child effects on parenting has examined child temperament. In general, child positivity is related to positive parenting, while child negativity is related to negative parenting (Putnam, Sanson, & Rothbart, 2002; Wilson & Durbin, 2012). However, the general lack of genetically sensitive designs in this research makes it impossible to determine whether these associations exist because (1) harsh parenting leads to negative child characteristics, (2) specific child characteristics evoke harsh parenting (evocative gene-environment correlation, rGE; Plomin, Loehlin & DeFries, 1977; Scarr & McCartney, 1983) or (3) children and parents share genes that contribute to both parenting and temperament (passive gene-environment correlation). Therefore, genetically-sensitive research designs are needed to disentangle these influences to understand specific mechanisms underlying relations between child characteristics and parent behavior