Hard Floor Research Articles

A Nonconformist Compound

W ild temperature swings can crack a plate as surely as dropping it on a hard kitchen floor. A ceramic dish taken from the freezer and thrust into a hot oven splits apart because some parts heat up and expand faster than others. This problem isn't unique to dishes. Computer chips, fiber optic cables, and dental fillings, for example, all risk failure when they expand differently from the materials around them. An unusual compound called zirconium tungstate, however, might make these annoyances a thing of the past. Although most materials grow when they get hot, zirconium tungstate does the exact opposite-it shrinks. A few other compounds have this characteristic, but they tend to shrink in one direction while they stretch out in others in order to preserve an overall volume. Zirconium tungstate, a blend of zirconium, tungsten, and oxygen, stands out from its peers because it shrinks equally in all directions. Moreover, zirconium tungstate exhibits this behavior over a huge temperature range-from near absolute zero to 777?C. Although scientists have known about zirconium tungstate's weird behavior for 30 years, they have only recently begun to explain why the material acts so contrarily. With this new understanding, researchers are also beginning to learn how to blend zirconium tungstate with other compounds so as to make new composite materials resistant to thermal shock.

Near-Bottom Sedimentation Processes Revealed by Echo-Character Mapping Studies, Northwestern Mediterranean Basin

Subbottom echoes recorded on 3.5 kHz echo sounders in the northwestern Mediterranean Basin from 1978 to 1991 can be classified into five main categories of echo character: (1) Continental shelf (CS) echo character characterizes the continental platform and areas of shallow relief and commonly is related to consolidated sediments. (2) Hyperbolic (H) echo character is recorded from areas with rough bottom morphology. Echo type H1 corresponds to steep slopes; echo type H2 reflects very coarse grained sediments deposited by energetic turbidity currents. (3) Bedded (B) echo character is widely observed throughout the study area and corresponds to terrigenous deposits distributed by turbidity currents. Echo type B1 is related to thin turbidites deposited on overbank portions of channel levees by lateral overflow of turbiditic currents moving down the channels; echo type B2 corresponds to coarser turbiditic materials. (4) Rugged (R) echo character is observed in the axes of submarine canyons and channels and characterizes hard sea floor with coarse heterogeneous turbiditic deposits subjected to energetic gravity-flow processes. (5) Transparent (T) echo character is ubiquitous in the study area and is attributed to mass-movement deposits. The widespread occurrence of those deposits testifies to the general instability of the study area. Types and distribution of echo character throughout the study area show the importance of gravity-dominated depositional processes (turbidity currents and mass wasting) in this region. This remobilization of siliciclastic sediments, induced by high sediment rates, steep slopes, and halotectonics, theoretically could create potential hydrocarbon reservoirs within the deep-water portions of the continental margin.

Epidemiologic evaluation of decubital ulcers in farrowing sows

Objective— To define temporal patterns and risk factors for development of decubital ulcers over the tuber of the spine of the scapula (tuber) of lactating sows. Design— Prospective study. Animals— 147 late-gestation sows and gilts. Procedure— Females were examined for skin lesions over the tubers, and body condition score, depth of back fat and depth of soft tissues over the tuber (tuber depth) were determined (day 0). On days 5, 12, 18,40, 54, and 68, sows were examined for lesions over the tubers. Data on sow parity, date of farrowing, total number of pigs born/litter, and number of stillborn pigs/litter were obtained from farm records. Results— Ulcers were recorded for 33 of 206 (16%) shoulders by day 5. Peak prevalence (99/206; 48% of shoulders) was on day 12, and all ulcers had resolved by day 68. Ulcers were more common on the right shoulder. Considerable resolution of ulcers was evident between days 12 and 18, when sows still were housed in farrowing crates. Parity and tuber depth were significantly associated with ulcers and ulcer severity (size) on day 12. Clinical Implications— Decubital ulcers in lactating sows are a multifactorial condition. Factors such as floor type are important, but other physiologic and behavioral factors of periparturient swine, including body weight, body condition and mobility of lategestation animals, duration of farrowing, and patterns of recumbency and activity, appear to be important in the pathogenesis of lesions. Housing sows on hard floors is not a sufficient cause of decubital ulcers over the scapula. (J Am Vet Med Assoc 1997;210:1173–1178)

Repetitive strain injury to the foot in elite women kendoka.

OBJECTIVE: To account for the apparent high incidence of pain in the feet of elite women kendo players. METHODS: A clinical evaluation was done by a chiropractor, the women were...

Detailed Elastic Modelling to Characterise Noise Contributions to Seismic Data from the Gippsland Basin

Strong noise contributions currently prevent adequate definition of deep exploration targets in marine seismic data from the Gippsland Basin. We computed an elastic synthetic seismogram (Kennett, 1979, 1980) from a highly detailed depth model to match the raw field records with considerable accuracy. As part of a sensitivity analysis, we computed additional synthetics to gauge the effects of poorly known parts of the depth model upon the elastic synthetic. These synthetics also helped us to identify noise events in the field records. Subsequent processing of the synthetics led to the identification of persistent noise contributions to stacked data from the Gippsland Basin. Noise contributions in the target zone consist of resulting from strong mode conversion occurring at the Miocene channels and the Latrobe Group coal/shale sequence. These formations then reconvert the S-waves to P-waves so that they are recorded by the hydrophones. The timing and curvature of the shear reflections is such that they strongly interfere with primary reflections in the target zone stack response. At greater depths, the stack response is dominated by long-period multiples associated with the coal sequence, the Miocene channels, the hard sea floor and the sea surface. Lateral variation of these noise interferences is due to structural variation in the Miocene channels and the lower part of the coal sequence. Strong interbed multiples (including mode converted peglegs) are generated in the coal sequence and constitute a second type of noise interference by preventing direct interpretation of the target zone primary reflections. Our elastic synthetics also characterised shear refractions in the field data using a compactional trend to derive the shallow depth model. The modelled shear refractions were highly sensitive to the shallow shear velocity profile and this makes them an important elastic modelling constraint. Further variation of the shear velocity model also revealed the insensitivity of stacked elastic synthetics to our 'artificial Vs log' based on approximate formation s values. The amplitude and timing of prominent reflections barely changed as we adjusted their formation s values.

Dereverberation of marine reflection seismic data by a spatial combination of predictive deconvolution and velocity filtering

Contamination of seismic reflection records at early times by first-order water reverberations can be especially severe during survey operations over hard and flat sea floors on the continental shelf or in lake environments. A new dereverberation scheme based on two classical techniques — predictive deconvolution and velocity filtering — has been developed to address this problem. The techniques are combined spatially to take advantage of their complementary offset- and time-dependent properties. Stage I of the scheme consists of applying predictive deconvolution at short offset. The data are previously conditioned by a normal moveout correction with the water velocity which restores the periodicity of the reverberations in the offset-time plane and enhances the performance of deconvolution. Stage II of the scheme involves velocity filtering in the common-midpoint domain which is particularly effective at long offset where the moveout difference between primary reflections and reverberations is largest. The dereverberation scheme is well suited for the initial processing of large volumes of data due to the general availability of cost-effective deconvolution and velocity filtering algorithms in seismic processing software packages. Practical implementation issues are illustrated by a field example from the GLIMPCE survey in Lake Superior.

Cleaning methods, their effectiveness and airborne dust generation

The effectiness of dry and wet methods for cleaning furniture and hard floors was studied. Dust on surfaces was sampled with gelatine foils, and the % area covered by particles was measured with a laser extinction meter. Airborne dust generation during furniture cleaning was measured with an optical particle counter. Good cleaning effectiveness was obtained with some dry floor cleaning methods. On furniture, wet cloth was best at high dust levels, but at low levels the relative differences between dry and wet methods were low. The use of dry cleaning methods is encouraged. The contribution to the airborne dust concentration of movement of the cleaning operator is of the same order of magnitude as is the cleaning operation.

Haemorrhages of the Sole Horn of Dairy Cows as a Retrospective Indicator of Laminitis: An Epidemiological Study

Eleven herds with clinical laminitis problems and 11 control herds were studied for 2 consecutive years. All the claws were trimmed and photographically recorded once each year, 2 to 6 months after the cows had calved. The haemorrhages of the sole horn were evaluated and scored for each digit, and data relevant to the factors associated with an increased risk of laminitis for each herd were collected and related to these scores for sole haemorrhages. It was found that the laminitic herds were more prone to the sole lesions than the control herds, the hind claws were more prone than the front claws, the primiparous cows were more prone than the multiparous cows and the Swedish Friesian cows were more prone than the Swedish Red and White cows. High scores were also correlated with hard floors (ie concrete) in the cow stalls, with fewer than 4 daily feedings of concentrates, with a short time allocated for the cows to eat concentrates, with feeding concentrates only at the first meal in the morning and in the afternoon and with the interaction between these last 2 variables.

A Large Hemi-anechoic Enclosure for Community-Compatible Aeroacoustic Testing of Aircraft Propulsion Systems

A large hemi-anechoic (absorptive walls and acoustically hard floor) noise control enclosure has been erected around a complex of test stands at the NASA Lewis Research Center in Cleveland, Ohio. This new state-of-the-art Aeroacoustic Propulsion Laboratory (APL) provides an all-weather, semisecure test environment while limiting noise to acceptable levels in surrounding residential neighborhoods. The 39.6 m (130 ft) diameter geodesic dome structure houses the new Nozzle Aeroacoustic Test Rig (NATR), an ejector-powered M = 0.3 free jet facility for acoustic testing of supersonic aircraft exhaust nozzles and turbomachinery. A multi-axis, force-measuring Powered Lift Facility (PLF) stand for testing of Short Takeoff Vertical Landing (STOVL) vehicles is also located within the dome. The design of the Aeroacoustic Propulsion Laboratory efficiently accomodates the research functions of two separate test rigs, one of which (NATR) requires a specialized environment for taking acoustic measurements. Absorptive fiberglass wedge treatment on the interior surface of the dome provides a hemi-anechoic interior environment for obtaining the accurate acoustic measurements required to meet research program goals. The APL is the first known geodesic dome structure to incorporate transmission-loss properties as well as interior absorption into a free-standing, community-compatible, hemi-anechoic test facility.

北海道大学「医学部文化村」について

There, since 1922, lived several professors of the newly founded School of Medicine, Hokkaido University, in Kita 10-11 Nishi 3 blocks, Kita-ku, Sapporo. In the community called "Igakubu-bunkamura", they had certain relationship to the activities of the Bunka-Seikatsu Kenkyukai (Modern Life Society) promoted by Dr. Kokichi Morimoto, and wrote some essays on the society's jounal "Bunka-Seikatsu". We could, by statements and photographs of their relatives, observe that they achieved some improvements in their houses : the use of hard floors for drawing rooms, studies and dining rooms, and of glass window panes, the improvement of engawa, the utilization of space between ceiling and roof.

Optimum solutions for cold-storage flooring and central frost-heave protective heating systems

The author has developed, tested and widely applied new effective solutions for cold-store floorings over the last 18 years, including frost-heave protective systems. The low-joint or monolithically joined single-layer hard concrete floor and the central frost-heave protective heating system are of special importance because these two solutions can easily be combined.

Stance duration under sensory conflict conditions in patients with hemiplegia.

Standing balance was evaluated in ten subjects with hemiplegia using a sensory organization balance test (SOT). The SOT is a timed balance test which evaluates somatosensory, visual, and vestibular function for maintenance of upright posture. The duration of bilateral stance was assessed using combinations of three visual and two support surface conditions. Stance time was measured with eyes open, eyes closed, and with each patient wearing a visual dome to produce inaccurate visual information. The support surface conditions involved stance on a hard flat floor followed by attempted stance on a compliant foam surface. Visual deprivation or visual conflict conditions did not cause a loss of balance when stance was performed on a stable surface. However, a lower stance duration was found when patients stood on a compliant surface (p less than .05). Visual compensation was evident during the compliant-surface condition because stance duration showed the greatest reductions with eyes closed and with the visual dome. These findings suggest that the ability to integrate somatosensory information from the lower extremities for balance is compromised after cerebrovascular disease. The implications for diagnosing the specific cause of balance dysfunction and for developing sensory-specific therapeutic interventions are discussed.

A longitudinal study relating carpeting with sick building syndrome

A longitudinal questionnaire study was performed among personnel in two Swedish primary schools with wall-to-wall carpets and four schools with hard floor covering. The study groups consisted of all primary schools equipped with wall-to-wall carpets in the town of Uppsala, plus a random sample of two newer and two elderly primary schools with hard floor covering. In an initial cross-sectional study, the wall-to-wall carpet group reported an enhanced prevalence of eye and airway symptoms, face rashes, headache, abnormal tiredness and a sensation of being electrostatically charged in comparison with personnel in schools with hard floor covering. Since the enhanced prevalence of symptoms in the wall-to-wall carpets versus the hard floor covering group was also observed among persons without signs of atopy it was concluded that wall-to-wall carpets are not exclusively a problem for the sensitive atopic individual. The type of ventilation system (mechanical ventilation versus natural ventilation) had no significant effect on the symptom frequencies. After the removal of the wall-to-wall carpets, many of the reported symptoms decreased to a level similar to the group without previous or present exposure to such carpets. However, the frequency of airway symptoms remained enhanced among the wall-to-wall carpet group.

Measurement of airborne mite antigen in homes of asthmatic children

The airborne concentration of major house dust mite antigen Der p1 was measured by low volume sampling (2 litres/min) in the homes of 68 allergic, asthmatic children. The presence of detectable airborne antigen was strongly associated with sensitivity to the mite, whereas there was no significant relation between sensitivity and the previously recommended threshold level of 2 μg Der p1 per g carpet dust. There was a significant association with lower threshold levels in carpet dust (0·5 μg/g) but at no level was the association as strong as that with air measurements. Concentrations of airborne antigen were higher in rooms with wool carpets than in those with synthetic carpets or hard floors, but there was no significant difference between the dust levels of Der p1 in the two carpet types. Air sampling is a more appropriate method of assessing antigen exposure than dust sampling for asthmatic patients.

Hard public access floors: A problem for the industry – Part 2

Discusses some of the extent and consequences of failures of hard public access floors, affecting among other building types: hospitals, airports, railway stations and shopping centres. Describes the attitudes taken by clients and project managers, with reference to the growth of new and refurbished façadism and themes, and to conservative outlooks by proprietors of superstores and transport industries. Outlines solutions to problems with respect to changing trends, such as client requirements for designers to accept design liability for fitness for purpose of flooring systems, performance specifications incorporated in contract documentation and the increasing proportion of value of work being done in the building industry by specialist sub‐contractors. Discusses methods, quality assurance and quality control, giving examples from the industry. Compares and contrasts some differing approaches to the ways in which the industry deals with the generation and provision of information and advice about standards and techniques, and particular materials and systems. Suggests that more explanation needs to be given to the reasoning behind the failure of some techniques and the creation of design guidances.

Hard public access floors: A problem for the industry – Part 1

Discusses some aspects of composite construction and composite materials in the flooring industry, in particular relation to failures in the construction of hard public access flooring. Outlines the background to the increase in investigations into problems in two types of floor, namely: hard public access floors in malls and transport buildings, and raised platform floors in offices. Details the main points to emerge from investigation into complaints of defective flooring, concentrating on ill‐considered integration of engineering and architectural design skills in relation to new and existing structures and finishes and the problem of using new methods and materials without considering how they differ from those that went before. Suggests that the industry is taking considerable risks with clients′ money during its learning process.

An indoor sound-power test for light vehicles

There is a need to develop sound-power tests as standards for the noise of manufactured products, such as automobiles. For uniformity of testing, the tests have to be independent of the test location. Sound-intensity measurements can be used for this, as has been demonstrated in tests with six automobiles. The sound power of each vehicle was measured for different loads and engine speeds, using a semicircular array of sound-intensity probes rotated around the vehicle on a dynamometer roll. The tests were conducted at Clark Laboratory Services in a large work area with a hard floor and high ceiling, with partially absorbent material on the walls. There were no room resonances apparent in the A-weighted vehicle sound-power spectra. Also, theoretical estimates with point sources in a reverberant room showed that the presence of the walls and ceiling has a negligible effect on the A-weighted sound power of the vehicles. Good agreement was obtained with a standard reference source. The results with the six vehicles indicated that the peaks in narrow-band sound-power spectra can be used to identify noisy components in a vehicle power train. [Work supported by the United States Office of Naval Research.]

ABC of child abuse. Head injuries.

Head injuries with or without fracture ofthe skull feed. Serious intracranial injury is extremely are the commonest cause ofdeath from battering, unlikely. but abdominal injury to the gut or solid organs The force entailed in physical abuse-for can mimic the signs ofhead injury and can lead to example, in swinging the child, in violent death if they are unrecognised. uncontrolled shaking, and in hitting the child's head with a fist or-foot or against a wall-is so much greater that the pattern ofinjury is Detecting head injuries due to physical abuse different.-Fractures are more likely to be When an infant rolls off a changing table, extensive, multiple, complex or branched, hospital trolley, or bed, even on to a hard floor, he depressed, wide, separated, and growing and to is unlikely to sustain a fracture of the skull and is affect several of the individual skull bones. The almost certainly assured of escaping from major occipital bone and base of the skull, which are intracranial injury. Falls from greater heights hardly ever fractured in simple falls, are common (between 1 and 2 m), as, for example, from a sites of injury. standing adult's shoulder, may result in a single These differences are shown in the table. linear parietal hairline fracture of the skull, and Children who have been shaken but have not the infant may be irritable, vomit, or refuse a suffered blunt trauma to the head will have no

A longitudinal study relating carpeting with sick building syndrome

A longitudinal questionnaire study was performed among personnel in two Swedish primary schools with wall-to-wall carpets and four schools with hard floor covering. The study groups consisted of all primary schools equipped with wall-to-wall carpets in the town of Uppsala, plus a random sample of two newer and two elderly primary schools with hard floor covering. In an initial cross-sectional study, the wall-to-wall carpet group reported an enhanced prevalence of eye and airway symptoms, face rashes, headache, abnormal tiredness and a sensation of being electrostatically charged in comparison with personnel in schools with hard floor covering. Since the enhanced prevalence of symptoms in the wall-to-wall carpets versus the hard floor covering group was also observed among persons without signs of atopy it was concluded that wall-to-wall carpets are not exclusively a problem for the sensitive atopic individual. The type of ventilation system (mechanical ventilation versus natural ventilation) had no significant effect on the symptom frequencies. After the removal of the wall-to-wall carpets, many of the reported symptoms decreased to a level similar to the group without previous or present exposure to such carpets. However, the frequency of airway symptoms remained enhanced among the wall-to-wall carpet group.

Suspended particulate matter transport through the Vema Channel

Sixteen-month time-series measurements of water velocity and light scattering were coupled with hydrographic and suspended particulate matter sections to determine the flux and the variability in flux of suspended particulate matter through the Vema Channel. The northward flux of SPM through the Vema Channel ranged from 3 to 10.5 × 10 4 g s −1 with a mean of 6.5 × 10 4 g s −1. The largest fluxes were measured in the deepest and eastern portions of the channel with maximum fluxes of suspended particulate matter at specific sites being roughly two to four times the mean flux. Some of the suspended particulate matter in the channel may be eroded from the channel itself by the swift currents or eddy-like features, however, the known manganese encrustation and hard floor of the channel suggest that the deep channel floor is not a likely source of sediment. A primary source of the suspended particulate matter in the channel may be the sediment drifts in the Argentine Basin with their associated high standing crops of resuspended particulate matter. This resuspended material would then be transported by the Antarctic Bottom Water into and through the Vema Channel into the Brazil Basin. The northward flux of suspended particulate matter through the Vema Channel is presently a significant, but not dominant, influence on sedimentation in the Brazil Basin.