Fire performance of sandwich panels in a modified ISO 13784-1 small room test: the influence of increased fire load for different insulation materials

Four sandwich panel rooms were constructed as prescribed in the ISO 13784-1 test. However, the construction followed normal industry practice, and the panels were also subjected to the kinds of damage typically found in commercial premises, although such damage may not typically be concentrated in such a small room. The fire load was increased to simulate fires actually occurring in commercial premises by stepping up the propane burner output from the usual maximum of 300–600 kW, and by placing a substantial wooden crib in two of the rooms. The results showed significant differences in fire growth rate and burning behaviour between those panels filled with polyisocyanurate (PIR) and those filled with stone wool in both the experiments without and with the wooden crib. Most significantly, the PIR pyrolysis products caused earlier ignition (by radiation from above) of the wooden crib 11 min into the experiment (1 min after the burner was stepped up to 300 kW), whereas the crib ignited 22 min into the test (2 min after the burner had been stepped up to 600 kW, which is beyond the test standard both in time and heat input) for the stone wool panels. This interaction between building and contents is most often ignored in fire safety assessments. After a few minutes, the PIR pyrolysis products that escaped outside the room, from between the panels, ignited. The extra thermal exposure from the PIR-fuelled flames distorted the panels, which in turn exposed more PIR, resulting in large flames on both the inside and outside of the enclosure. From a fire safety perspective this is most important as it shows that with the large fire loads that are commonly found in commercial premises, steel-faced PIR filled panels are not capable of acting as fire barriers, and may support flame spread through compartment walls and ceilings. In addition, the PIR panelled rooms produced very large quantities of dense smoke and toxic effluents, whereas the stone wool panelled rooms produced small amounts of light smoke of lower toxicity. Furthermore, the experiments showed that modifications to the standard test can lead to extremely different outcomes for some of the products. As the modifications simulated real-life situations, it seems important to discuss whether the standard is robust enough for property safety scenarios encountered in industrial premises

Experimental Results and Integrated Modeling of Bacterial Growth on an Insoluble Hydrophobic Substrate (Phenanthrene)

Metabolism of a low-solubility substrate is limited by dissolution and availability and can hardly be determined. We developed a numerical model for simultaneously calculating dissolution kinetics of such substrates and their metabolism and microbial growth (Monod kinetics with decay) and tested it with three aerobic phenanthrene (PHE) degraders: Novosphingobium pentaromativorans US6-1, Sphingomonas sp. EPA505, and Sphingobium yanoikuyae B1. PHE was present as microcrystals, providing non-limiting conditions for growth. Total PHE and protein concentration were tracked over 6-12 days. The model was fitted to the test results for the rates of dissolution, metabolism, and growth. The strains showed similar efficiency, with v(max) values of 12-18 g dw g(-1) d(-1), yields of 0.21 g g(-1), maximum growth rates of 2.5-3.8 d(-1), and decay rates of 0.04-0.05 d(-1). Sensitivity analysis with the model shows that (i) retention in crystals or NAPLs or by sequestration competes with biodegradation, (ii) bacterial growth conditions (dissolution flux and resulting chemical activity of substrate) are more relevant for the final state of the system than the initial biomass, and (iii) the desorption flux regulates the turnover in the presence of solid-state, sequestered (aged), or NAPL substrate sources

Long-term monitoring of nitrate transport to drainage from three agricultural clayey till fields

The application of nitrogen (N) fertilisers to crops grown on tile-drained fields is required to sustain most modern crop production, but it poses a risk to the aquatic environment since tile drains facilitate rapid transport pathways with no significant reduction in nitrate. To maintain the water quality of the aquatic environment and the provision of food from highly efficient agriculture in line with the EU's Water Framework Directive and Nitrates Directive, field-scale knowledge is essential for introducing water management actions on-field or off-field and producing an optimal differentiated N-regulation in future. This study strives to provide such knowledge by evaluating on 11 years of nitrate-N concentration measurements in drainage from three subsurface-drained clayey till fields (1.3–2.3 ha) representing approximately 71 % of the surface sediments in Denmark dominated by clay. The fields differ in their inherent hydrogeological field settings (e.g. soil-type, geology, climate, drainage and groundwater table) and the agricultural management of the fields (e.g. crop type, type of N fertilisers and agricultural practices). The evaluation revealed three types of clayey till fields characterised by: (i) low net precipitation, high concentration of nitrate-N, and short-term low intensity drainage at air temperatures often below 5 °C; (ii) medium net precipitation, medium concentration of nitrate-N, and short-term medium-intensity drainage at air temperatures often above 5 °C; and (iii) high net precipitation, low concentration of nitrate-N and long-term high intensity drainage at air temperatures above 5 °C. For each type, on-field water management actions, such as the selection of crop types and introduction of catch crops, appeared relevant, whereas off-field actions only seemed relevant for the latter two field types given the temperature-dependent reduction potential of nitrate off-field. This initial well-documented field-scale knowledge from fields that are representative of large areas in Denmark is a first step towards establishing a differentiated N-regulation for clayey till areas. Additionally, it provides a unique starting point by identifying important parameters for future mapping of catchment-scale variations in nitrate concentrations and fluxes

Morphological diversities and ecozones of Ethiopian horse populations

Using standard survey approaches, we carried out a nationwide survey to morphologically characterize and identify ecozones of Ethiopian horse populations. Accordingly, we explored one new feral horse population previously unreported and seven other distinct horse populations. A total of 17 selected morphological variables were recorded on 503 horses (293 stallions and 210 mares) that belong to five out of eight identified horse populations. Pair-wise multiple mean comparisons (PMMC) using one-way analysis of variance and multivariate analyses were performed separately for each sex and least-squares means was used in the case of aggregated sexes. Results of PMMC showed that there were significant differences (P < 0.05) between the means for most of the variables recorded. Principal component analysis showed that height at wither, height at back, height at rump, body length, back length and barrel length jointly account for about 80 percent of the variations. All squared Mahalanobis distance between populations were significant (P < 0.01). The greatest phenotypic divergence was observed between Bale and Selale horse populations and the least phenotypic divergence was between Horro and Kafa populations. Canonical discriminant function analysis showed that 77.05 percent of individuals were correctly categorized into their respective populations. Moreover, cluster analysis based on squared Mahalanobis distances grouped the five measured Ethiopian horse populations into three major breed groups and five distinct horse populations

Discordances between morphological systematics and molecular taxonomy in the stem line of equids: A review of the case of taxonomy of genus Equus

This paper revises the evolutionary history of the stem root of the genus Equus from Eocene period (54 million years before present, MYBP) to present. It also assesses molecular taxonomy and evolutionary relationships of this line since the first appearance of fossil records in terrestrial deposits. Combining these two lines of evidences, we outline a more informative and consensus phylogeny in a more understandable context. We also compare and contrast evolutionary histories and phylogenetic relationships of equids inferred from paleontological as well as varieties of molecular data and their implications. Using pair-wise coalescence time estimates, we draw a consensus speciation order in the stem root of the genus Equus. With the help of molecular data, we suggest the reasons for enigmatic speciation events between asses and zebras as well as the backgrounds for genetic dissimilarities between hemiones of Asia and asses of Africa regardless their phenotypic similarities. Based on the evidences from molecular data and review of late Pleistocene megafauna extinction in the Americas, we believe that horses were certainly domesticated in the Eurasian Steppe or elsewhere that survived late Pleistocene megafauna's extinction than in the Americas. We discuss the true wild horse that was involved in horse domestication processes in line with recent evidences that unraveled multi-geographic origins and multi-maternal lineages in the present day domestic horses

Genetic diversity and matrilineal genetic signature of native Ethiopian donkeys (Equus asinus) inferred from mitochondrial DNA sequence polymorphism

We investigated mitochondrial DNA (mtDNA) sequence polymorphism of six morphologically diverse domestic donkey (Equus asinus) populations in Ethiopia. These populations include: Abyssinian (AB), Afar (AF), Hararghe (HR), Ogaden (OG), Omo (OM) and Sinnar (SI). Genetic relationships and other diversity parameters were inferred from 39 randomly selected mtDNA D-loop partial sequences, characterized by 29 polymorphic sites defining 19 distinct haplotypes. Moreover, haplotype and nucleotide diversity in Ethiopian donkey populations were 0.903±0.032 and 0.020±0.003, respectively. A network analysis produced moderate star-like patterns suggesting past population demographic and spatial expansion. Population subdivision estimates demonstrated that Sinnar donkeys are considerably divergent from the other donkey populations. To trace the matrilineal genetic origin of Ethiopian donkeys, we retrieved 221 previously published domestic donkeys' mtDNA D-loop sequences from the GenBank (146 from Chinese and 75 from worldwide domestic donkeys). The haplogroup derived from the Ethiopian sources formed the center of the network from which most of the worldwide domestic donkey populations emerged. This suggests that Ethiopia could be one of the centers of diversities for domestic donkeys in the Horn of Africa. The present study also overrides some previous reports that claims donkeys were solely an Egyptian domesticate

Positive effect of protein-supplemented hospital food on protein intake in patients at nutritional risk: a randomised controlled trial

BackgroundNew evidence indicates that increased dietary protein ingestion promotes health and recovery from illness, and also maintains functionality in older adults. The present study aimed to investigate whether a novel food service concept with protein-supplementation would increase protein and energy intake in hospitalised patients at nutritional risk. MethodsA single-blinded randomised controlled trial was conducted. Eighty-four participants at nutritional risk, recruited from the departments of Oncology, Orthopaedics and Urology, were included. The intervention group (IG) received the protein-supplemented food service concept. The control group (CG) received the standard hospital menu. Primary outcome comprised the number of patients achieving 75% of energy and protein requirements. Secondary outcomes comprised mean energy and protein intake, body weight, handgrip strength and length of hospital stay. ResultsIn IG, 76% versus 70% CG patients reached 75% of their energy requirements (P=0.57); 66% IG versus 30% CG patients reached 75% of their protein requirements (P=0.001). The risk ratio for achieving 75% of protein requirements: 2.2 (95% confidence interval=1.3-3.7); number needed to treat=3 (95% confidence interval=2-6). IG had a higher mean intake of energy and protein when adjusted for body weight (CG: 82kJkg(-1) versus IG: 103kJkg(-1), P=0.013; CG: 0.7g proteinkg(-1) versus 0.9g proteinkg(-1), P=0.003). Body weight, handgrip strength and length of hospital stay did not differ between groups. ConclusionsThe novel food service concept had a significant positive impact on overall protein intake and on weight-adjusted energy intake in hospitalised patients at nutritional risk