Performance of a non‐load‐bearing steel stud gypsum board wall assembly: Experiments and modelling

A gypsum wall assembly was exposed to an intense real‐scale compartment fire. For the wall assembly, temperatures were measured at the exposed face, within the stud cavity, and at the unexposed face during the fire exposure. Total heat flux gauges were used to measure the temporal variation of the energy incident on the walls, and cameras, both visual and infrared, were used to image the unexposed face of the wall assembly during the fire exposure. The behaviour of the wall assembly under the fire load is discussed as are current model results for a simulation of the fire test. Copyright © 2006 John Wiley & Sons, Ltd.     

Organochlorine Contaminants of Wintering Ducks Foraging on Detroit River Sediments

Organochlorine analysis was performed on carcasses of 13 diving ducks from a 1981 wintering population that foraged on contaminated sediments in the lower Detroit River. Mean total PCB concentrations were 10 mg/kg for seven lesser scaups (Aythya affinis), 11 mg/kg for three greater scaups (A. marila), and 7.6 mg/kg for three goldeneyes (Bucephala clangula). Highest mean levels of other residues were measured for hexachlorobenzene (1.7 mg/kg) in goldeneyes, and transnonachlor (0.33 mg/kg) and 4,4’-DDE (1.3 mg/kg) in greater scaup. Quantitative analysis of 72 PCB congeners also was applied to water, seston, sediment, benthie oligochaetes, and carp from the same site. Principal congeners in most of the samples included some of the more toxic and persistent PCBs. Results of a multivariate analysis indicated that ratios of more conservative to less conservative PCBs did not vary significantly among ducks (α = .05), but differed from those in carp, oligochaetes, and sediment. For the February through March period of fat mobilization, concentrations of total PCB in lipid were inversely correlated with percent lipid (r = 0.76) in ducks. The percentage of conservative PCBs increased slightly. The distribution and partitioning of organochlorines, including toxic PCB congeners, varied considerably within this water column-sediment-fauna ecosystem. Estimates of toxic exposure based on total PCB values may be unreliable.     

Variations in software development practices

Research on over 18 years of software projects reveals that developing large systems involves substantially more activities and a greater variety of specialized personnel than developing smaller systems. Perhaps the most significant observation is that good quality control is the best overall indicator of a successful project. Schedule delays and cost overruns most often occur when you discover during testing that the application has so many bugs that it doesn't work. Projects using QA teams, formal design and code inspections, and pretest defect tracking always had shorter testing cycles and therefore were more likely to be deliverable on schedule.     

Human papillomavirus investigation of patients with cervical intraepithelial neoplasia 3, some of whom progressed to invasive cancer

Unstable expansion of the CTG repeats in the 3' untranslated region encoding a member of the protein kinase family in the q13.3 band on chromosome 19 is a mutation specific for myotonic dystrophy. To examine the correlation between clinical expression and CTG trinucleotide repeat length, we carried out Southern blot analysis in a family with myotonic dystrophy. In this pedigree, the expanded CTG repeats were transmitted maternally. The mother had three female children. The mother had about 200 CTG repeats, and the number of repeats for each child was about 800, 1500 and 1600 in birth order. The mother and the patient with 800 repeats were unaware of muscle weakness or myotonia. Symptoms were present from age 3 years in the patient with 1500 repeats and from birth in the one with 1600 repeats. Although the mother menstruated regularly, the patients with 800 and 1500 repeats both menstruated irregularly, and the one with 1600 repeats has never menstruated. The age of onset and severity of the disease were correlated with the size of the expanded repeats. Endocrinological studies revealed that the basal levels of the gonadotropins, PRL and E2 were within normal range, and a pituitary response to LHRH was observed. These data suggest that the amenorrhea and menstrual irregularities were caused by a suprahypophyseal dysfunction. When expanded CTG repeats are transmitted maternally, abnormal products resulting from the metabolic disturbance in the affected mother may harm the fetus in utero. A heterozygous fetus, who has more CTG repeats, may be unable to metabolize the pathologic products sufficiently and therefore may become more severely affected. This may explain the exclusive maternal transmission of congenital myotonic dystrophy.     

Dynamic elastic-plastic buckling phenomena in a rod due to axial impact

Dynamic elastic-plastic buckling phenomena which might develop in a rod from an axial impact loading are studied in order to identify the conditions for quasi-static behaviour. A discrete model for dynamic elastic-plastic buckling, which retains the axial and the lateral inertia forces, is proposed, and the relationship between the model parameters and the characteristics of an actual structure is given. Examples of different external loadings and boundary conditions are considered in order to clarify the influence of elastic-plastic axial wave propagation on the buckling process. The critical time for the initiation of buckling is obtained and the post-buckling behaviour of the model is analysed. Particular attention is paid to the role of the striking mass on the characteristics of the buckling process and on the development of the buckling shape. The numerical study reveals that the inertia of the striking mass affects considerably the development of the buckling shape causing different patterns of axial strain distributions at the initiation of buckling. The comparisons which are made between the model predictions and some previously published experimental data show that the buckling process is governed by the impact velocity as well as by the external loading history provided by the experimental technique.     

Lung function measurement in general practice: a comparison of the Escort spirometer with the Micromed turbine spirometer and the mini-Wright peak flow meter

It is important that new types of spirometer for widespread clinical use are pragmatically evaluated in primary care. This study compared measurements taken by a new portable Fleisch pneumotachograph spirometer (known as the Escort) with those of the commonly used mini-Wright peak flow meter and the Micromed Pocket turbine spirometer. A pragmatic study was conducted in two phases during routine surgeries at Aldermoor Health Centre, Southampton. Phase I compared the new spirometer with the mini-Wright peak flow meter and Phase 2 compared the new spirometer and the turbine spirometer. One hundred patients aged 5-88 years (56 patients with a history of chronic respiratory complaints and 44 patients without) entered Phase 1, and 100 patients aged 6-82 years (62 patients with a history of chronic respiratory complaints and 38 patients without) entered Phase 2. Each patient contributed only once to each phase, but some entered both phases on separate occasions. Ninety-five percent limits of agreement (mean +/- SD) were wide for all comparisons. Graphical plots revealed trends towards higher Escort values as mean values rose compared with both mini-Wright and turbine readings for peak expiratory flow rate and forced expiratory volume in one second. Possible over-reading of peak expiratory flow rate with the mini-Wright meter at low mean values was also seen. Readings taken with these different types of meter cannot be interchanged with confidence in clinical practice. The clinical significance of the theoretically more accurate measures of lung function produced with the new meter, and indeed of spirometry itself, needs further investigation.     

An X-ray photoelectron spectroscopic investigation into the chemical structure of deposits formed from hexamethyldisiloxane/ oxygen plasmas

The effect of oxygen addition to microwave-sustained plasmas of hexamethyldisiloxane (HMDSO) has been investigated. Attention was directed to the solid products formed on aluminium substrates (plasma deposits). To enable a quantitative analysis of these, X-ray photoelectron spectroscopy (XPS) of standard silicon-containing materials was carried out. When suitable charge correction is applied to the XP spectra of HMDSO/O₂ plasma deposits, a number of very clear trends emerge. From changes in elemental composition, core line binding energies (Si2p, C 1s, and O 1s) and widths, we show how oxygen addition to the plasma affects the chemical nature of the plasma deposit. The data reported also provide (some limited) information on the reactions taking place in the plasma.     

Effect of titanium substitution on the structure and properties of Fe3Al-based intermetallic alloys

Substitutions (0–16 at%) of titanium for iron in Fe₃Al-based alloys rapidly solidified by chill-block melt-spinning stabilize the D0₃ and B2 ordered structures. Rapid solidification results in total suppression of D0₃ order in binary alloys, whereas alloys containing titanium have D0₃ structure. D0₃ and B2 antiphase domain size, lattice parameter and hardness increase with increasing titanium content of the alloy. The deformation mode changes from single (unit) bcc dislocation in binary alloys to two-fold superdislocation configuration in D0₃Fe₃Al-Ti alloys. Mechanical antiphase boundaries are generated by the movement of these imperfect configurations. All the alloys exhibited cleavage tensile failure. The mechanical properties are correlated with the observed structural changes.     

Evaluation of a commercial process for collection and cooling of beef offals by a temperature function integration technique.

The hygienic adequacy of a commercial process for the collection and cooling of beef offals was assessed by a temperature function integration technique. The diverse operations for collection of offals were inspected. The rates of product movement through those operations, and the temperatures of products at the time of their being packed, were determined. From that information, four of the nine product types were selected for examination of their temperature histories during the assembly and cooling of the cartoned products. The products selected encompassed product at near-body and near-air-ambient temperatures at the time of packaging, product in the largest and smallest cartons used in the process, and product with relatively short and long residence times in an unchilled carton stack assembly area. Twenty-one temperature histories were collected for each of the products, and the possible proliferation of an indicator organism, Escherichia coli, calculated for each temperature history. The results were assessed against a temperature function integration criterion derived from studies of beef carcass and cartoned meat cooling processes. Products packaged at near-ambient temperature readily met with the criterion, but products packed at near-body temperatures did not comply. The latter non-compliance was extreme for product packaged in large cartons. However, the principal cause of non-compliance was identified as highly variable cooling conditions in the carton freezing facility. A brief survey of air speeds and temperatures within that facility indicated means by which product cooling could be better controlled.