Uranium oxide weathering: spectroscopy and kinetics

Particles of UO_2+x (x≅0.16 ± 0.06) exposed to the atmosphere react by oxidation and formation of complexes (hydrates, hydroxides and carbonates). Surface reactions alter and erode the UO₂ particles. This paper outlines results for measurements of oxidation rates on uranium oxide particles using in situ photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). Phosphorescence spectra observed during oxidation of UO_2+x were attributed to U(VI) in uranyl-type coordination and in octahedral coordination. Uranyl-type spectra formed during wet oxidation of UO_2+x, and U(VI) octahedral spectra formed during dry oxidation of UO_2+x. The uranyl-type species, although more stable, is more kinetically labile for vacuum reduction than is the octahedral U(VI). Oxidation of U(IV) species are diffusion controlled. Vacuum reduction of uranyl U(VI) in UO₃ follows a field-enhanced cationic diffusion rate law, while re-oxidation follows a diffusion rate law. Post-oxidation core and valence band XPS and SIMS measurements provided qualitative and quantitative measures of uranium oxidation states near uranium oxide surfaces.     

Dairy farmers with larger herd sizes adopt more precision dairy technologies

An increase in the average herd size on Australian dairy farms has also increased the labor and animal management pressure on farmers, thus potentially encouraging the adoption of precision technologies for enhanced management control. A survey was undertaken in 2015 in Australia to identify the relationship between herd size, current precision technology adoption, and perception of the future of precision technologies. Additionally, differences between farmers and service providers in relation to perception of future precision technology adoption were also investigated. Responses from 199 dairy farmers, and 102 service providers, were collected between May and August 2015 via an anonymous Internet-based questionnaire. Of the 199 dairy farmer responses, 10.4% corresponded to farms that had fewer than 150 cows, 37.7% had 151 to 300 cows, 35.5% had 301 to 500 cows; 6.0% had 501 to 700 cows, and 10.4% had more than 701 cows. The results showed that farmers with more than 500 cows adopted between 2 and 5 times more specific precision technologies, such as automatic cup removers, automatic milk plant wash systems, electronic cow identification systems and herd management software, when compared with smaller farms. Only minor differences were detected in perception of the future of precision technologies between either herd size or farmers and service providers. In particular, service providers expected a higher adoption of automatic milking and walk over weighing systems than farmers. Currently, the adoption of precision technology has mostly been of the type that reduces labor needs; however, respondents indicated that by 2025 adoption of data capturing technology for monitoring farm system parameters would be increased.     

Phase transition in V3O5

A phase transition at 420°K previously unreported, has been discovered in V₃O₅. The transition is characterized by an endothermic DTA peak on heating and an abrupt change in the electrical resistivity at the same temperature. Results from X-ray analysis of the V₃O₅ samples exhibiting the transition agree very well with the values reported by Andersson (1). Powder diffraction analysis of the high temperature phase indicates that there is a small change in the cell volume but the crystal apparently conserves its symmetry through the transition.     

Mobility using IEEE 802.21 in a heterogeneous IEEE 802.16/802.11-based, IMT-advanced (4g) network

Industry is defining a new generation of mobile wireless technologies, called in cellular terminology "fourth generation" or "4G." This article shows that a system combining extensions of two radio access technologies, IEEE 802.11 and IEEE 802.16, meets the ITU-R's "IMT-Advanced" or 4G requirements. The extensions are 802.16 m (100 Mb/s, 250 km/h) and 802.11VHT (1 Gb/s, low velocity). The focus of this article is to show how IEEE 802.21 (the emerging IEEE standard for media-independent handover services) supports ";seamless"; mobility between these two radio access technologies. This mobility integrates the two radio access technologies into one system. We conclude that an 802.11VHT + 802.16 m + 802.21 system is likely to be proposed to the ITU-R for IMT- Advanced 4G.     

Dietary fibre: The use of in-vitro and rat models to predict action on stool output in man

An in-vitro model (fermentation and water holding capacity measurement) and a rat model were compared for their ability to predict the action of dietary fibre on stool output in man. A range of different purified or semipurified fibres were studied: wheat bran, pectin, carboxymethylcellulose, xanthan, guar, karaya, tragacanth and gellan. Using equations derived from previous studies, prediction indices from in-vitro studies were compared with the effects of these fibres on stool output in rat and man. The rat model was better as a predictor for stool output (r = 0.94, P < 0.005) in man but the log in-vitro predictive index was significantly correlated with stool output in both rat (r = 0.87, P < 0.02) and man (r = 0.84, P < 0.04). Since in-vitro methods are less expensive and time consuming than animal studies, the log in-vitro predictive index may provide a useful pre-screening device for new dietary fibre sources or detecting changes in the action of dietary fibres during the manufacturing process.     

Implementing mass customization

Total Customer Satisfaction today can mean embarking on “Mass Customization”: giving every customer a product tailored specifically to his or her needs. In the past, manufacturing was usually “high volume, low mix”, characterized by keeping costs down with economies of scale, or “low volume, high mix”, incurring costs and time for changeovers and special handling. Today's mass customization, however, can result in a challenging manufacturing environment with both high volume and high mix, where customers expect individualized products at the same price they paid for mass-produced items. Meeting this challenge requires changes in the manufacturing processes. Equipment must be more flexible. Most important are the computer systems which support the manufacturing enterprise. Never has data been so essential to define, control, and monitor manufacturing as with mass customization. Motorola's product lines — from the pagers with millions of possible options, to the cellular phones and semiconductors — are all experiencing the move to mass customization. This presentation will describe some Motorola examples and the methods used to achieve world-class manufacturing under these conditions.     

An investigation into the dietary fibre content of named varieties of carrot at different developmental ages

The carrot, Daucus carota, is a commonly used vegetable which has changed in appearance due to plant breeding programmes. The development of the carrot can be divided into a period of rapid increase in fresh weight, a stage of constant fresh weight and a stage of floral development and decrease in fresh weight. An analysis of the dietary fibre content of the carrot and its chemical composition has been made, using the varieties Altrincham, Chantenay, Nantes and Scarlet Perfection, at different developmental stages. Fibre was measured as prepared fibre, NDF, ADF, cellulose and lignin. No differences were found between varieties except those due to the different developmental rates of each variety. Within each variety the ADF content increased during late stage 2 and the increase was apparently due to the cellulose component of the ADF. Despite the differences, however, in carrot fresh weight between varieties and also within each variety there is no difference in any fibre component of carrot per 100 g fresh weight.