Adjoint operator approach to shape design for internal incompressible flows

The problem of determining the profile of a channel or duct that provides the maximum static pressure rise is solved. Incompressible, laminar flow governed by the steady state Navier-Stokes equations is assumed. Recent advances in computational resources and algorithms have made it possible to solve the direct problem of determining such a flow through a body of known geometry. It is possible to obtain a set of adjoint equations, the solution to which permits the calculation of the direction and relative magnitude of change in the diffuser profile that leads to a higher pressure rise. The solution to the adjoint problem can be shown to represent an artificially constructed flow. This interpretation provides a means to construct numerical solutions to the adjoint equations that do not compromise the fully viscous nature of the problem. The algorithmic and computational aspects of solving the adjoint equations are addressed. The form of these set of equations is similar but not identical to the Navier-Stokes equations. In particular some issues related to boundary conditions and stability are discussed

Foundations of Quantum Discord

This paper summarizes the basics of the notion of quantum discord and how it relates to other types of correlations in quantum physics. We take the fundamental information theoretic approach and illustrate our exposition with a number of simple examples.Comment: 3 pages, special issue edited by Diogo de Oliveira Soares Pinto et a

Preterm nutritional intake and MRI phenotype at term age: a prospective observational study

Objective: To describe (1) the relationship between nutrition and the preterm-at-term infant phenotype, (2) phenotypic differences between preterm-at-term infants and healthy term born infants and (3) relationships between somatic and brain MRI outcomes. Design: Prospective observational study. Setting: UK tertiary neonatal unit. Participants: Preterm infants (<32 weeks gestation) (n=22) and healthy term infants (n=39) Main outcome measures: Preterm nutrient intake; total and regional adipose tissue (AT) depot volumes; brain volume and proximal cerebral arterial vessel tortuosity (CAVT) in preterm infants and in term infants. Results: Preterm nutrition was deficient in protein and high in carbohydrate and fat. Preterm nutrition was not related to AT volumes, brain volume or proximal CAVT score; a positive association was noted between human milk intake and proximal CAVT score (r=0.44, p=0.05). In comparison to term infants, preterm infants had increased total adiposity, comparable brain volumes and reduced proximal CAVT scores. There was a significant negative correlation between deep subcutaneous abdominal AT volume and brain volume in preterm infants (r=−0.58, p=0.01). Conclusions: Though there are significant phenotypic differences between preterm infants at term and term infants, preterm macronutrient intake does not appear to be a determinant. Our preliminary data suggest that (1) human milk may exert a beneficial effect on cerebral arterial vessel tortuosity and (2) there is a negative correlation between adiposity and brain volume in preterm infants at term. Further work is warranted to see if our findings can be replicated and to understand the causal mechanisms

Mainstreaming Underutilized Indigenous and Traditional Crops into Food Systems: A South African Perspective

Business as usual or transformative change? While the global agro-industrial food system is credited with increasing food production, availability and accessibility, it is also credited with giving birth to ‘new’ challenges such as malnutrition, biodiversity loss, and environmental degradation. We reviewed the potential of underutilized indigenous and traditional crops to bring about a transformative change to South Africa’s food system. South Africa has a dichotomous food system, characterized by a distinct, dominant agro-industrial, and, alternative, informal food system. This dichotomous food system has inadvertently undermined the development of smallholder producers. While the dominant agro-industrial food system has led to improvements in food supply, it has also resulted in significant trade-offs with agro-biodiversity, dietary diversity, environmental sustainability, and socio-economic stability, especially amongst the rural poor. This challenges South Africa’s ability to deliver on sustainable and healthy food systems under environmental change. The review proposes a transdisciplinary approach to mainstreaming underutilized indigenous and traditional crops into the food system, which offers real opportunities for developing a sustainable and healthy food system, while, at the same time, achieving societal goals such as employment creation, wellbeing, and environmental sustainability. This process can be initiated by researchers translating existing evidence for informing policy-makers. Similarly, policy-makers need to acknowledge the divergence in the existing policies, and bring about policy convergence in pursuit of a food system which includes smallholder famers, and where underutilized indigenous and traditional crops are mainstreamed into the South African food system

Work and Quantum Phase Transitions: Is there Quantum Latency?

We study the physics of quantum phase transitions from the perspective of non-equilibrium thermodynamics. For first order quantum phase transitions, we find that the average work done per quench in crossing the critical point is discontinuous. This leads us to introduce the quantum latent work in analogy with the classical latent heat of first order classical phase transitions. For second order quantum phase transitions the irreversible work is closely related to the fidelity susceptibility for weak sudden quenches of the system Hamiltonian. We demonstrate our ideas with numerical simulations of first, second, and infinite order phase transitions in various spin chain models.Comment: accepted in PR

Interaction of thiocyanate with horseradish peroxidase. <SUP>1</SUP>H and <SUP>15</SUP>N nuclear magnetic resonance studies

Interaction of thiocyanate with horseradish peroxidase (HRP) was investigated by relaxation rate measurements (at 50.68 MHz) of the 15N resonance of thiocyanate nitrogen and by following the hyperfine shifted ring methyl proton resonances (at 500 MHz) of the heme group of SCN-.HRP solutions. At pH 4.0, the apparent dissociation constant (KD) for thiocyanate binding to HRP was deduced to be 158 mM from the relaxation rate measurements. Chemical shift changes of 1- and 8-ring methyl proton resonances in the presence of various amounts of thiocyanate at pH 4.0 yielded KD values of 166 and 136 mM, respectively. From the pH dependence of KD and the 15N resonance line width, it was observed that thiocyanate binds to HRP only under acidic conditions (pH &lt; 6). The binding was found to be facilitated by protonation of an acid group on the enzyme with pKa 4.0. The pH dependence of the 15N line width as well as the apparent dissociation constant were quantitatively analyzed on the basis of a reaction scheme in which thiocyanate in deprotonated ionic form binds to the enzyme in protonated acidic form. The KD for thiocyanate binding to HRP was also evaluated in the presence of an excess of exogenous substrates such as resorcinol, cyanide, and iodide ions. It was found that the presence of cyanide (which binds to heme iron at the sixth coordination position) and resorcinol did not have any effect on the binding of thiocyanate, indicating that the binding site of the thiocyanate ion is located away from the ferric center as well as from the aromatic donor binding site. The KD in the presence of iodide, however, showed that iodide competes with thiocyanate for binding at the same site. The distance of the bound thiocyanate ion from the ferric center was deduced from the 15N relaxation time measurements and was found to be a 6.8 &#197;. From the distance as well as the change in the chemical shifts and line width of 1- and 8-methyl proton resonances, it is suggested that the binding site of thiocyanate may be located near heme, placed symmetrically with respect to 1- and 8-methyl groups of the heme of HRP. Similarity in the modes of binding of iodide and thiocyanate suggests that the oxidation of thiocyanate ion by H2O2 may also proceed via the two-electron transfer pathway under acidic conditions, as is the case for iodide

Improving pregnancy outcomes in tertiary care institution in India through obstetric intensive care unit: three-year analysis

Background: To analyse the requirement of high dependency unit (HDU)/intensive care unit (ICU) in an obstetric population in terms of utilization rate, indications for admission, interventions required and gestational outcome.Methods: Retrospective observational study was carried out from April 2015 to September 2018 at department of obstetrics and gynecology SSG Hospital, Vadodara India. Data related to indications for ICU admission, interventions required, length of stay and outcomes were collected, and results were analyzed.Results: Obstetric ICU utilization rate was 130 per 1000 deliveries.  The major obstetric indications for admission were hypertensive disorders of pregnancy (42%) followed by anemia (25%) and post-partum hemorrhage (3%). In the rest of the patient’s majority (50%) had cardiovascular problems. Maternal mortality among these critically ill women was 3.76%. The death rate in the present study was high among patients admitted for non-obstetric (74.54%) as opposed to obstetric indications (25.46%).Conclusions: Establishment of well managed high dependency and intensive care unit in health care facilities dealing with high volumes of high-risk maternity cases reduces the maternal mortality significantly and results in improved maternal outcomes

A study of the Space Station Freedom response to the disturbance environment

A relatively general formulation for studying the dynamics and control of an arbitrary spacecraft with interconnected flexible bodies has been developed. This self-contained and comprehensive numerical algorithm using system modes is applicable to a large class of spacecraft configurations of contemporary and future interest. Here, versatility of the approach is demonstrated through the dynamics and control studies aimed at the evolving Space Station Freedom

Current and near-term GHG emissions factors from electricity production for New York State and New York City

This paper reports estimates of average GHG emissions factors for New York State and marginal GHG emissions factors for interventions in New York City. A multi-regional unit commitment model was developed to simulate the behavior of the grid. The parameters defining the system operation were gathered from several publicly available data sources including historical hourly electricity production and fuel consumption from over one hundred power plants. Factors were estimated for a baseline year of 2011 and subsequently for the year 2025 considering planned power plant additions and retirements. Future scenarios are also developed considering different wind turbine installation growth rates and policies affecting the cost of generation from coal power plants. The work finds marginal GHG emissions factors for New York City could reduce between 30 and 36% from 540 kg CO2e/MWh in 2011 for all future scenarios considered. Average GHG emissions factors for New York State could reduce 9 to 39% from 215 kg CO2e/MWh depending on the wind growth rate and price burden on coal power plants