Early stage disentanglement and non-Markovianity

We have studied an early stage disentanglement by solving an exactly solvable spin bath model in the Markovian and non-Markovian regimes. In the Markovian regime, the central two qubit spins are non-interacting in which entanglement strongly depends on mean number of photon. In the non-Markovian regime, we solved by considering and ignoring the interaction between central two spins and observe that the entanglement strongly depends on the spin bath interaction, qubit spin interaction, bath spin interaction, thermal temperature and the initial state. Further, the concurrence of an initially unentangled state mixed with an entangled state also depends on the initial state.     

On damage tolerance design of fuselage structure (longitudinal cracks)

Aircraft structure is the most obvious example where functional requirements demand light weight and, therefore, high operating stresses. An efficient structural component must have three primary attributes; namely, the ability to perform its intended function, adequate service life and the capability of being produced at reasonable cost. To ensure the safety of aircraft structures, the Air Force requires damage tolerance analysis. This paper focuses its attention on designing a fail-safe fuselage structure. Two types of damage most frequently associated with the structural integrity of the fuselage are longitudinal cracks under high hoop stresses induced by cabin pressurization and circumferential cracks under stresses from vertical bending of the fuselage. The analysis of these types of cracks is complex, first due to the complex structural configuration (i.e. frames, skin longeron and crack stopper straps) and secondly due to the influence of the curvature of the shell. Various analytical and empirical approaches have been used to study the damage tolerance capability of the fuselage structure. Due to the lack of a comprehensive model to calculate the stress intensity factors for the complex structure, experiments usually have been performed to measure the crack growth rates and to demonstrate the residual strength of fuselage-type structural components containing circumferential and longitudinal cracks.

In this paper various analytical and empirical approaches used in evaluating the damage tolerance capability of the fuselage structure are critically evaluated and compared. A model which accounts for the influence of frames, straps and curvature is developed. This model is then used in an example problem having typical military cargo aircraft fuselage structural elements. The Air Force damage tolerance requirements are discussed in detail.     

Effect of semi-drying on the antioxidant components of tomatoes

Three tomato cultivars (Excell, Tradiro, and Flavourine) grown under hydroponic conditions in a commercial greenhouse in New Zealand were semi-dried at 42 °C. The semi-dried tomatoes contained low levels of 5-hydroxymethyl-2-furfural and were significantly (p < 0.05) darker (lower CIELAB L* values) and had a higher mean a*/b* value (1.6) than the fresh tomatoes (1.2). The mean total phenolics in the semi-dried samples of tomatoes (300 mg gallic acid equivalents, GAE/100 g dry matter (DM)) was significantly lower than that of fresh tomatoes (404 mg GAE/100 g DM). The mean total flavonoid, and lycopene contents in the fresh samples (206 mg rutin equivalents/100 g DM, 63 mg/100 g DM, respectively) also showed a significant decrease after semi-drying (179 mg rutin equivalents/100 g, 54 mg/100 g DM, respectively). Ascorbic acid content in fresh tomatoes (284 mg/100 g DM) decreased to 223 mg/100 g DM after drying. The total antioxidant activity of the semi-dried tomatoes (1783 μmole trolox equivalents antioxidant capacity (TEAC)/100 g DM) was significantly (p < 0.05) lower than that of the fresh samples (2730 μmole TEAC/100 g DM).     

A review of some damage tolerance design approaches for aircraft structures

Damage tolerance design is becoming a necessity in the design of modern aircraft although its importance was recognized as long as four centuries ago by Leonardo da Vinci. Two decades ago structural design engineers and research workers felt the need of incorporating damage tolerance in the design of aircraft structure. Due to a lack of comprehensive damage tolerance methodology large scale component test results were used to develop empirical damage tolerance methods. Recently, linear elastic fracture mechanics has been used in predicting residual strength and crack growth rates in damaged structure. As a result of these efforts significant developments in cracked structure analytical methodology have been achieved. The recent Air Force requirement to apply linear elastic fracture mechanics approach in damage tolerance design of aircraft structures, warrants and critical review of various approaches. In this paper an attempt has been made to critically review some damage tolerance design approaches and their application to aircraft structures.

The paper consists of three main sections: The first section reviews the residual strength analysis methodology, assumptions and limitations of each method are discussed through a simple example. The second part surveys the various crack propagation laws, including linear and non-linear ranges and spectrum loading effects. In the third and last section, fracture mechanics methodology is applied to several types of built-up structural components under spectrum loading conditions. The comparison of test results and analysis of complex structures indicate that simple methods of fracture mechanics can be applied to find the damage tolerant strength and rate of crack growth.

The review presented in this paper indicates that the majority of work done in development of fracture mechanics analytical methodology has been based on data obtained from small scale laboratory specimens tested under closely controlled conditions of damage and environment. The validity of the methodology for complex structure under complex loading conditions has not been established. Before the results of a fracture mechanics analytical methodology can be accepted with a high degree of confidence many realism factors must be properly accounted for in the analysis.     

Absorption of solar radiation in ponds

Analysis is presented to predict the local rate of solar energy absorption in a pond using the radiative transfer theory. The physical model considers absorption and scattering by the water and internal reflection of radiation from the air-water interface as well as the bottom. A forward scattering approximation and a discrete-coordinate approximation of the radiative transfer equation are discussed. Numerical results for the local volumetric rate of solar energy absorption in the water are presented in the paper for a range of parameters of physical interest. The effects of the directional distribution of solar radiation incident on the water surface, the attenuation of solar radiation by the atmosphere during the diurnal cycle and the modification of the spectral radiation characteristics of water by impurities and additives on the absorption and distribution of the absorbed energy in the pond are investigated.     

Thermal remote sensing of temperature distribution in glass

A numerical method is developed for recovering the temperature distribution in glass from spectral radiation emission data. The desired temperature distribution is obtained using an optimization scheme which determines the best temperature profile from the data in a form of discrete points or Legendre polynomials. In order to evaluate the accuracy and validity of the thermal remote sensing method, the recovered temperatures are compared with independent measurements in three different experiments, one of which uses a Mach-Zehnder interferometer. Experimental results are reported for Corning Code 7940 fused silica using a Perkin-Elmer spectrometer to measure the spectral radiant energy emerging from the glass. The recovered and interferometrically measured temperatures are found to be in good agreement, i.e. within about $\text{1}\text{1}\text{2}$ per cent at temperatures up to about 800 K. Results are also presented for a parabolic temperature profile commonly encountered in glass manufacturing.     

Soil carbon pools under poplar-based agroforestry,rice-wheat,and maize-wheat cropping systems in semi-arid India

Labile fractions of soil organic C are considered important indicators of soil quality as these can respond rapidly to land-use changes and agricultural management. We studied the impact of three different land-use systems viz. poplar-based agroforestry involving wheat-legume rotation, rice-wheat and maize-wheat agroecosystems, on dynamics of total organic C (TOC), oxidisable soil organic C (SOC), very labile, labile, less labile, and recalcitrant C fractions, water extractable organic carbon (WEOC), hot water soluble C (HWC), microbial biomass C (MBC), and mineralizable C in the semi-arid subtropical India. The maize-wheat and agroforestry systems had 65–88% higher SOC stocks than the rice-wheat system and were characterized by predominantly labile C. About 56–60% of the total organic C in maize-wheat and agroforestry systems occurred as labile and very labile C compared to 37% under rice-wheat rotation. Contrarily, the majority of organic C (63%) in rice-wheat soils was stabilized in less labile and recalcitrant forms. The HWC and MBC were also higher in maize-wheat and agroforestry systems as opposed to the rice-wheat system. In the discriminant function analysis, a composite of indicators involving TOC, recalcitrant C and total N correctly distinguished the soils under the three systems. The results suggested that in agroforestry and maize-wheat systems the organic C in soils was less stable and thus could be lost following the land-use change.     

Hydrothermal liquefaction of biomass: A review of subcritical water technologies

This article reviews the hydrothermal liquefaction of biomass with the aim of describing the current status of the technology. Hydrothermal liquefaction is a medium-temperature, high-pressure thermochemical process, which produces a liquid product, often called bio-oil or bi-crude. During the hydrothermal liquefaction process, the macromolecules of the biomass are first hydrolyzed and/or degraded into smaller molecules. Many of the produced molecules are unstable and reactive and can recombine into larger ones. During this process, a substantial part of the oxygen in the biomass is removed by dehydration or decarboxylation. The chemical properties of bio-oil are highly dependent of the biomass substrate composition. Biomass constitutes of various components such as protein; carbohydrates, lignin and fat, and each of them produce distinct spectra of compounds during hydrothermal liquefaction. In spite of the potential for hydrothermal production of renewable fuels, only a few hydrothermal technologies have so far gone beyond lab- or bench-scale.     

Positive Psychological Capital as a Source of Sustainable Competitive Advantage for Organizations

Psychological capital (PsyCap) has gained prominence as an important construct in leadership research. Comprising four factors (self-efficacy, hope, optimism, and resiliency), PsyCap is considered to be a vital factor for authentic leadership development and influence. The current study reports the results of a questionnaire survey that was conducted in the construction industry of Singapore. The survey explored the correlations of PsyCap with authenticity, leadership, and leadership outcomes. The results show that PsyCap significantly correlates with authenticity and transformational leadership. It was also found that transformational leadership plays a mediating role for PsyCap to predict leadership outcomes (effectiveness, extra effort, and satisfaction). The discussion in the paper also considers the implications of PsyCap for leadership development and effectiveness in general and in the context of the construction industry.