Network modelling of underground mine layout: two case studies

The dominant working structure of an underground mine is a set of interconnected tunnels which provides access to ore zones and haulage of ore from the designated ore zones to the mill. This set of interconnected tunnels forms a network. We describe a mathematical network model and the modelling features of our two software tools for designing underground mine layouts that minimise associated costs. The application of these techniques is illustrated in two industry case studies. In the first, we apply the underground network optimisation tool to design an extension to an Australian gold mine where 15 new distinct orebodies are located in a 3 km long region, several hundred metres underground. In a second case study, we design a single decline for accessing a large orebody where a turning circle constraint is a significant factor. An efficient decline is found using the decline optimisation tool.     

Polyurethane adhesives containing Diels–Alder‐based thermoreversible bonds

A facile two‐step process is developed to obtain polyester urethanes that contain various concentrations of thermoreversible Diels–Alder adduct–based bonds for the development of adhesives. Besides linear systems thermoreversible networks have been included in the study. The reactions are verified using IR‐spectroscopy and gel permeation chromatography analysis. The material properties are characterized with solvent exposure tests, dynamic scanning calorimetry, microindentation and rheology and the potential for application as adhesives is tested with an elcometer. Material properties have been found highly tunable for the system, and high adhesive strengths (off‐scale) are found for polyester urethanes that are doped with an intermediate level Diels–Alder functional groups. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44972.     

Use of auricular chondrocytes for lining artificial surfaces: a mathematical model

Auricular elastic cartilage is a potential source for lining of luminal surfaces of implantable vascular devices, such as stents and left ventricular assist devices with the purpose to improve their biocompatibility. Auricular chondrocytes are easily accessible, harvested, and isolated, and they have been shown to provide a strong adherent cell lining for left ventricular assist devices. Additionally, Dr. Rosenstrauch have shown that it is possible to genetically engineer auricular chondrocytes to produce antithrombogenic factors. Thus, implantable vascular devices, such as coronary stents covered with genetically engineered auricular chondrocytes might lower restenosis rates and provide a long-lasting biocompatible prosthesis. In this paper, to optimize the process of lining of artificial surfaces with auricular cartilage, we devise a mathematical model that describes the rate of cell division and growth of extracellular matrix as a function of the initial cell count, proximity to other cells, and the type of artificial surface. Our mathematical model was experimentally tested using two different cell cultures (auricular chondrocytes and dermal fibroblasts) seeded on different artificial surfaces (tc-treated polystyrene and aluminum foil). Excellent agreement between the model and experiment was obtained. This mathematical model can be used to, for example, determine the optimum number of initially seaded cells that would provide fastest coverage of a given artificial surface.     

Remote sensing of the terrestrial environment using middle infrared radiation (3.0–5.0 µm)

The middle infrared (MIR) spectral region, between 3.0 and 5.0?µm in the electromagnetic spectrum, features a myriad of atmospheric windows. The favourable atmospheric penetration of electromagnetic radiation at MIR wavelengths has been readily noted. To exploit this atmospheric window, there have been several remote sensing instruments acquiring radiation from the terrestrial environment. However, these data remain under-utilized for terrestrial environmental studies. The principal reason for this is the hybrid nature of this spectral region, as it comprises a combination of both reflected and emitted radiation during daytime measurement. Despite this, there are many attributes of the MIR spectral region that should encourage its use. Studies focusing on a wide range of terrestrial environment characteristics using MIR radiation have advocated that these data be used. Moreover, there has been a progressive maturation of the methods for processing the radiation acquired by instruments in the MIR spectral region, allowing the informed use of the unique information provided by this part of the spectrum. In particular, these methods have allowed the retrieval of MIR reflectance from the full MIR radiation acquired by a sensor and this information has been demonstrated to be particularly useful for the study of the terrestrial environment and its change. It would appear that the full potential of MIR radiation is unrealized. This paper is a review that aims to motivate and advise of future research using MIR radiation, and in particular MIR reflectance. The paper outlines the physical principles determining MIR radiation interactions with the terrestrial environment; reviews current status of processing methods of MIR radiation to retrieve MIR reflectance; and how the retrieved data have been used. In conclusion, future research priorities are suggested.     

Polyphenol oxidase activity in white tan‐plant‐type sorghums: An important determinant of the relatively dark colour of their porridges

The relatively dark colour of food products from white tan‐plant (food‐grade) sorghums can compromise their acceptability. The relationship between white tan‐plant sorghum polyphenol oxidase activity (PPO) and porridge colour was investigated, primarily using lines grown in the same locality over two seasons. Sorghum was intermediate in PPO between wheat and maize. White tan‐plant sorghum and white maize whole grain flours were similar in colour. However, with white tan‐plant sorghum, the transition from flour to porridge caused a much larger reduction in L* value. Further, the correlation between white tan‐plant sorghum PPO activity and porridge L* values was highly significantly negative (P < 0.001), the relationship accounting for 40–50% of variation. PPO in white tan‐plant‐type sorghums is therefore an important determinant of the relatively dark colour of porridges. Breeding to reduce PPO activity could improve consumer appeal. Cultivar Sima (IS 23520) that had low PPO activity and produced light‐coloured porridge could be useful for breeding.     

Building signatures: A holistic approach to the evaluation of heating and cooling concepts

A sustainable and environmentally responsible building concept aims at a high workplace comfort, a significantly reduced heating and cooling demand, a high-efficient plant system, and the use of renewable energy sources to condition the built environment. This paper presents a comprehensive analysis of the heating and cooling concepts of 11 low-energy buildings in terms of energy use, efficiency and occupant thermal comfort. All buildings investigated employ environmental energy sources and sinks – such as the ground, ground water, rainwater and the ambient air – in combination with thermo-active building systems. A limited primary energy use of about 100 kWh_prim/(m²_neta) as a target for the complete building service technology (HVAC and lighting) was postulated for all buildings presented. With respect to this premise, a comprehensive long-term monitoring in high time resolution was carried out for two to five years, with an accompanying commissioning of the building performance. Measurements include the useful heating and cooling energy use, auxiliary energy use for the hydraulic system, as well as end and primary energy use, occupant thermal comfort and local meteorological conditions. A new methodology is proposed for a holistic approach to the evaluation of heating and cooling concepts, which not only considers the occupants thermal comfort, but also the useful energy consumption and the efficiency of the generation, distribution and delivery of heating and cooling energy.     

The electronic conductivity of Ba0.5Sr0.5CoxFe1?xO3?δ (BSCF: x?=?0?～?1.0) under different oxygen partial pressures

The electronic conductivity of sintered BSCF ceramics (Ba_0.5Sr_0.5Co _x Fe_1−x O_3−δ, 0 ≤  x  ≤ 1) was measured as a function of temperature up to 1273 K in air. The conductivity of BSC is thermally activated over 298–1273 K with an activation energy of 0.21 eV. The conductivity of BSF and BSCF (0.2 ≤  x  ≤ 0.8) is thermally activated below ∼673 K with activation energies of 0.21 eV–0.40 eV. Above 673 K, the formation of oxygen vacancies results in a decrease in p-type carrier concentration and a decrease in electronic conductivity. Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ (BSCF5582) was also measured under 10⁻⁵ atm ≤ pO₂ ≤ 1 atm. Below ∼673 K, the electronic conductivity of BSCF 5582 shows no dependence on pO₂. Above 673 K, the conductivity of BSCF5582 increases with increasing pO₂ for pO₂ ≥ 0.01 (p-type conduction) and decreases slightly with increasing pO₂ for pO₂  ≤ 0.01 atm. The activation energy for conduction above ∼673 K and at pO₂ ≥ 0.1 is ∼0.07 eV. Above ∼823K and at pO₂ ≥ 0.01 atm, the activation energy for conduction is ∼0.2 eV.     

Left-ear superiority in dichotic perception of vocal nonverbal sounds.

In 2 experiments, a total of 96 right-handed college students were asked to identify 2 dichotic sounds in recordings of (a) hummed melodic patterns; or (b) vocal nonspeech sounds, e.g., laughing or crying. In both cases a significant left-ear superiority was found. Data indicate that voice quality does not independently engage left or right hemisphere mechanisms since verbal and nonverbal vocal stimuli may be processed in different hemispheres. (French summary) (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Photoacoustic Spectroscopy for the Study of the Adsorption of Dyes on Wool Fabrics

Dyes have been applied to different wool fabrics and measurements by photoacoustic spectroscopy showed well-defined absorption bands. Differences were found in the spectral properties of dyes, which appeared visually to be very similar, indicating that photoacoustic spectroscopy may be useful for the identification of dyes on wool fabrics. Photoacoustic spectroscopy was also shown to be capable of measuring two-dye and three-dye combinations and very dark colours. Comparisons with reflectance spectroscopy showed that photoacoustic spectroscopy might usefully complement the results obtained from reflectance measurements.