Fibre mortar composites under fire conditions: effects of ageing and moisture content of specimens

Two small scale test series were performed using the cone calorimeter heating method to detect any differences in the way various fibres affect the thermal properties of a standard mortar. The cone shaped heater of the cone calorimeter produces a uniform heat flux on the sample surface over an area of 100×100 mm². The heat flux was adjusted to 50 kW m^?2, which corresponds to the early stage of a fully developed fire. The total exposure also corresponds roughly to the ISO 834 time-temperature curve during the first 30 minutes. Short ageing of the specimens gave very clear differences in thermal properties between fibre mortars. However, no such differences were observed with oven dried samples. This shows the importance of carrying out tests in conditions as close as possible to the end use conditions of the material or product.     

Evaluation of sampling sites for detection of upper respiratory tract carriage of Streptococcus pneumoniae and Haemophilus influenzae among healthy Filipino infants

Two sampling techniques, nasal swabbing and oropharyngeal swabbing, for detection of the upper respiratory tract carriage of Streptococcus pneumoniae and Haemophilus influenzae were studied prospectively with 296 healthy Filipino infants at various ages: 6 to 8, 10 to 12, 14 to 17, 18 to 22, 32 to 39, and 46 to 65 weeks. In all age groups S. pneumoniae was isolated significantly more often (P < 0.0001) from the nasal site than from the oropharyngeal site. H. influenzae was found equally often at both sites.     

Interfacing an aspiration ion mobility spectrometer to a triple quadrupole mass spectrometer

This article presents the combination of an aspiration-type ion mobility spectrometer with a mass spectrometer. The interface between the aspiration ion mobility spectrometer and the mass spectrometer was designed to allow for quick mounting of the aspiration ion mobility spectrometer onto a Sciex API-300 triple quadrupole mass spectrometer. The developed instrumentation is used for gathering fundamental information on aspiration ion mobility spectrometry. Performance of the instrument is demonstrated using 2,6-di-tert-butyl pyridine and dimethyl methylphosphonate.     

Extractability of metals and ecotoxicity of soils from two old wood impregnation sites in Finland

Four metal-contaminated soil samples were classified using physical methods, extracted by selective extraction procedures and analyzed for chemical concentrations. De-ionized water, 0.01 mol/l barium chloride, 1 mol/l ammonium acetate and concentrated nitric acid were used as extraction solutions. Ecotoxicity of water extracts and soil samples was analyzed in order to describe the bioavailability of the contaminants. Samples from old wood impregnation plants contained high amounts of As, Cu, Cr and Zn, which originated from chromated copper arsenate, ammoniacal copper-zinc arsenate, and ammoniacal copper quaternary compound. Total As concentrations of the heavily contaminated samples varied from 752 to 4340 mg/kg, Cu concentrations from 339 to 2330 mg/kg, Cr concentrations from 367 to 2,140 mg/kg and Zn concentrations from 79 to 966 mg/kg. The extractabilities of metals differed according to soil type, extractant and element. Cu and Zn were proposed to cause the highest toxicity in the water extracts of the soils. Ecotoxicity tests displayed rather high differences in sensitivity both for water extracts and for solid soil samples. Reproduction of Enchytraeus sp. was the most sensitive and seed germination of Lactuca sativa the least sensitive and the other tests were in decreasing order of sensitivity: Folsomia candida>reverse electron transport>MetPLATE>Toxichromotest>Allium cepa root growth>Lemna sp. growth. As a conclusion, polluted soils rich in sand retain heavy metals with less firm bindings, particularly in the case of Cu and Zn, than soils rich in clay, indicating that chemical methods for measuring the bioavailability of metals need to be optimized taking into account the soil type, acidity, redox state and the individual contaminants.     

Worker allocation in make-to-order assembly cells

Assembly in the make-to-order manufacturing of large variable products is usually organized as a cell in which a team of workers operates. Several products are assembled in parallel and in sequence, so that the number of workers assembling a product may vary. The release times and due dates of products are determined by a higher level production plan. It is important to meet the due dates and use the workforce efficiently. The objective of the study described here is to optimize the allocation of workers to the products, so that the timing constraints are met, while the labor costs are minimized. Although the number of workers assembling a product can be varied, changing it involves start-up costs while the workers familiarize themselves with a new job, and a suboptimal number of workers reduce the productivity of work. These work efficiency characteristics are implemented in the optimization model presented. The developed model is a mixed integer linear program. The characteristics of the model are discussed and illustrative solutions and experimental results are provided.     

Simple and rapid synthesis of α-Fe2O3 nanowires under ambient conditions

We propose a simple method for the efficient and rapid synthesis of one-dimensional hematite (α-Fe₂O₃) nanostructures based on electrical resistive heating of iron wire under ambient conditions. Typically, 1–5 μm long α-Fe₂O₃ nanowires were synthesized on a time scale of seconds at temperatures of around 700 ° ⊂. The morphology, structure, and mechanism of formation of the nanowires were studied by scanning and transmission electron microscopies, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Raman techniques. A nanowire growth mechanism based on diffusion of iron ions to the surface through grain boundaries and to the growing wire tip through stacking fault defects and due to surface diffusion is proposed. Electronic Supplementary Material  Supplementary material is available for this article at and is accessible for authorized users.     

Antibody Responses to Transglutaminase 3 in Dermatitis Herpetiformis: Lessons from Celiac Disease

Dermatitis herpetiformis (DH) is the skin manifestation of celiac disease, presenting with a blistering rash typically on the knees, elbows, buttocks and scalp. In both DH and celiac disease, exposure to dietary gluten triggers a cascade of events resulting in the production of autoantibodies against the transglutaminase (TG) enzyme, mainly TG2 but often also TG3. The latter is considered to be the primary autoantigen in DH. The dynamics of the development of the TG2-targeted autoimmune response have been studied in depth in celiac disease, but the immunological process underlying DH pathophysiology is incompletely understood. Part of this process is the occurrence of granular deposits of IgA and TG3 in the perilesional skin. While this serves as the primary diagnostic finding in DH, the role of these immunocomplexes in the pathogenesis is unknown. Intriguingly, even though gluten-intolerance likely develops initially in a similar manner in both DH and celiac disease, after the onset of the disease, its manifestations differ widely.     

Radiant panel and air heating performance in large industrial buildings

This study determined the vertical temperature gradient in two large industrial buildings with room height close to 10 m. One of the buildings was an assembly hall with air heating system and the other was a warehouse equipped with radiant heating (primary) and air heating (secondary) system. The objective of the study was to determine the differences of vertical temperature gradient in halls during the winter. The findings from this study were used in dynamic whole-year simulations for estimating the heating and ventilation energy differences. The results showed about 0.2 K/m vertical temperature gradients in both halls, which was smaller by a factor of 5 for air heating than guidebook. This difference was likely because of the building being ventilated and well insulated. Temperature gradients kept reasonably constant at all measured outdoor temperatures. Energy simulations with measured gradient values of 0.2 K/m and with outdoor airflow rate during occupied hours 1.0 L/(s·m²), which was enough for ventilation and for air heating with simulated good insulation level, resulted in 15% to 41% higher primary energy for air heating. If it is possible to lower outdoor airflow rates to 0.5 L/(s·m²) during occupied hours, which was enough to remove pollutants from occupancy, the analyzed cases showed 23% lower primary energy for radiant heating.     

High-performance transparent conducting films of long single-walled carbon nanotubes synthesized from toluene alone

Nano Research - Single-walled carbon nanotube (SWCNT) transparent conducting films (TCFs) are attracting increasing attention due to their exceptional optoelectronic properties. Toluene is a...