Floor Line Research Articles

Should Smoke Yield be Regulated for Wall, Ceiling and Floor Linings?

A major issue in fire safety engineering is the control and regulation of smoke production from wall linings. When a material burns it produces smoke. Smoke production has two attributes, its volume and its concentration. The smoke volume is the total amount of smoke per unit time, and is proportional to the heat release rate. The smoke concentration depends on the smoke yield of the material, which is defined as grams of smoke produced per gram of material burnt. Current two-zone models, generally accepted in fire safety design, determine whether tenability conditions are met based on smoke volume. In these models a distinct interface between the smoke and the clear layer is assumed. This paper focuses on the impact of smoke yield on tenability. Two issues are discussed (a) the variation of smoke yield with ventilation conditions and (b) the influence of smoke density gradients between the smoke and clear layer on tenability conditions. Two examples are presented to illustrate the significance of these issues.

A Valley Following Method

We present a procedure to follow the "path along the valley floor" of a hypersurface. The aim is either to find minima, or to go from a minimum to a saddle point of index one, if the saddle is at the top of the valley floor. The motivation is that of taking into account local nonconvexity of the hypersurface and possibly to determine valleys. The method uses a projector technique where the projector is built by the tangent of the valley floor line. The projector is applied to the gradient and Hessian matrix of a given function, and it is used for predictor and corrector steps in path following. The resulting path is the "valley floor gradient extremal" which corresponds to the smallest (absolute) eigenvalue of the Hessian. Convergence properties are analysed.

Ultrafast MR imaging of the pelvic floor.

The aim of this study was to compare pelvic floor anatomy and laxity at rest and on straining (Valsalva's maneuver) using dynamic ultrafast MR imaging in women who were continent versus those with stress incontinence differing in obstetric history. Thirty continent women were divided into three equal groups (nulliparous, previous cesarean delivery, previous vaginal delivery) and compared with 10 women with stress-incontinence with a history of at least one vaginal delivery. MR imaging of the pelvic floor at rest and on maximal strain was performed, using axial T2-weighted fast spin-echo images followed by sagittal ultrafast T2-weighted single-shot fast spin-echo sequences. Mean population age (age range, 22-45 years; mean +/- SD, 36 +/- 5.4 years), was similar in the four groups, as was parity in the three parous groups. Mean distances between the bladder floor and pubococcygeal line at rest did not differ between the four groups. On straining, bladder floor descent was 1.1 +/- 0.9, 1.0 +/- 1.1, and 1.9 +/- 0.9 cm in continent nulliparous, cesarean delivery, and vaginal delivery women, respectively, versus 3.2 +/- 1.0 cm in incontinent women (p = 0.0005). Cervical descent was greater in incontinent versus nulliparous women (p = 0.0019). Bladder floor descent was greater in the continent vaginal delivery group than in continent cesarean delivery control patients (p = 0.04). In patients with stress incontinence, symptoms did not correlate with amplitude of descent. The right levator muscle was thinner overall than the left, regardless of frequency direction (p = 0.001). Ultrafast MR imaging using the T2-weighted single-shot fast spin-echo sequence allows dynamic evaluation of the pelvic compartments at maximal strain with no need for contrast medium. Pelvic floor laxity and supporting fascia abnormalities were most common in patients with stress incontinence followed by continent women with a history of vaginal delivery. The results are therefore compatible with the hypothesis of vaginal delivery as a contributory factor to stress incontinence in older parous women.

The usefulness of orbital lines in detecting blow-out fracture on plain radiography.

The purpose of this study was to assess the diagnostic value of orbital line changes on plain radiographs in detecting blow-out fracture. 92 cases of surgically confirmed blow-out fracture were retrospectively analysed in regard to plain radiographs and CT. Anterior and posterior lamina papyracea lines (ALPL and PLPL, respectively) of the orbital medial wall as well as the posteromedial floor line (PMFL) were assessed on orbital posteroanterior projections. The inferomedial orbital line (IMOL) and the inferior wall line were assessed on Waters projections. Orbital lines on plain radiographs were compared with CT findings. Of 53 cases of lamina papyracea fracture, 47 cases showed orbital line changes on plain radiographs (sensitivity 88.7%). Changes of PLPL (41/47), IMOL (29/47), ALPL (4/47) and PMFL (2/47) were demonstrated as depression, loss, discontinuity and irregularity. In four cases showing normal radiographs, the fractures measured less than 9 mm in size on CT. All 25 cases with orbital floor fracture accompanying medial wall fracture demonstrated orbital line changes of PMFL (16/25), PLPL (14/25), ALPL (3/25) and IMOL (2/25) (sensitivity 100%). 12 of 14 cases with orbital floor fracture demonstrated changes of inferior wall line (7/12) and PMFL (6/12) (sensitivity 85.7%). Two cases demonstrated asymmetric focal soft tissue density without orbital line changes. Orbital line changes on plain radiographs corresponded well with CT findings, confirming the usefulness of plain radiographs in detecting blow-out fracture.

GenRad announces availability of Shop Floor Line Manager software

GenRad announces availability of Shop Floor Line Manager software

Reducing formaldehyde exposure in office environments using plants.

Formaldehyde is a toxic substance with adverse health effects detectable at low concentrations. Formaldehyde causes irritation of the eyes, skin and respiratory tract, wheezing, nausea, coughing, diarrhoea, vomiting, dizziness and lethargy at levels as low as 50 parts per billion (ppb) (0.05 ppm) (Horvath et al, 1988). Formaldehyde has also been associated with aggravation of asthma, emphysema, hayfever and allergy problems at low levels (EPA, 1987). Formaldehyde is currently considered a potential carcinogen to humans (EPA, 1987). Formaldehyde is a ubiquitous gas found in elevated concentrations in indoor environments. Concentrations of formaldehyde are typically an order of magnitude greater inside buildings compared to outdoor air (Godish, 1990). Formaldehyde concentrations are particularly high in portable buildings due to the presence of more formaldehyde emitting materials and the relatively smaller interior volumes of air (Sexton et al, 1983). Major sources of formaldehyde indoors are pressed wood products, such as particle board and plywood (Elbert, 1995: Myer and Hermans, 1985), and urea formaldehyde foam insulation (Spengler and Sexton, 1983). Other sources include carpets, curtains, floor linings, paper products, cosmetics and soaps, tobacco smoke and gas combustion (Spengler and Sexton, 1983: Godish, 1990). Methods to reduce indoor formaldehyde include source removal or use of non- polluting materials, emission reduction through physical or chemical treatments and dilution through ventilation and air purification. While most solutions involve dilution through ventilation, increased interest in the scientific literature (Wolverton et al, 1989: Godish and Guindon, 1989) as well as in the popular media has been given to the use of plants to purify air in buildings . Most studies however, have been conducted in the laboratory (Levin J, 1992: Godish T and Guindon C, 1989) and are difficult to extrapolate to real life situations (Wolverton et al, 1989: Godish and Guindon, 1989).

The National Electronics Manufacturing Initiative (NEMI) plug and play factory project

The National Electronics Manufacturing Initiative (NEMI) plug and play factory project addressed the issues of how to quickly integrate new pieces of electronics assembly equipment into a shop floor line management system and how to manage the vast amounts of data available in today's electronics manufacturing environment. The necessary technical infrastructure was designed, developed, and demonstrated over a two-year period. New standards activities for electronics manufacturing were initiated where existing standards were either non-existent or insufficient to achieve the project goals.

Load floor lining having integrated sound insulation

There is provided a one-piece, removable load floor lining having sound insulation properties, for motor vehicles, having an upper shell (2) and a lower shell (1). The upper shell (2) is substantially flat and is hingeably connected with the lower shell (1) which is adapted to the contours of the trunk region, so that a complete unit is obtained which because of the double-wall principle achieves a large acoustic effect. The upper shell (2) further includes coverings (19, 20) which can be folded open by means of hinge means, whereby together with the contour-following configuration of the lower shell (1) there are provided closed hollow spaces (4, 5, 6, 7) of different depths, in particular as storage compartments for receiving accessory parts, baggage or the like, such as e.g. a so-called active noise control system.

Meatpackers: An Oral History of Black Packinghouse Workers and Their Struggle for Racial and Economic Equality.

Meatpackers provides an important window into race and racism in the American workplace. In their own words, male and female packinghouse workers in the Midwest-mostly African-American-talk of their experiences on the shop floor and picket lines. They tell of their fight between the 1930s and 1960s for economic advancement and racial equality. In cities like Chicago, Kansas City, Omaha, Fort Worth, and Waterloo, Iowa, meatpackers built a union that would defend their interests as workers-and their civil rights.

Using agents to make and manage markets across a supply Web

One of the triumphs of computerization in the middle of the 20th century has been materials resource planning (MRP) software. Plants using MRP loaded their anticipated orders in, and the system “exploded” the requirements to cover every gasket and grommet needed, transmitting the requirements to suppliers under contract and managing the scheduling of the shop floor or assembly line. MRP created a sort of clockwork universe in manufacturing. Today, General Electric is experimenting with a system whereby its needs will be met by posting requirements on an electronic bulletin board and letting any accredited supplier bid. General Motors is letting paint booths “decide” the order in which trucks roll off the line. The clockwork mechanism has turned into a rainforest ecology. What's going on?

"Stalin over Wisconsin": The Making and Unmaking of Militant Unionism, 1900-1950.

During the first half of this century, Allis-Chalmers was Wisconsin's largest employer. The firm hired a variety of workers, including the native-born, immigrants, the skilled, the unskilled, and eventually women and a small number of blacks. Stephen Meyer presents a history of the Allis-Chalmers workers, and of the growth and destruction of the militant, left-wing union they built. The story of these workers and their union serves as a microcosm of the history of American labor in the twentieth century. Meyer describes how skilled workers, fearful of mechanization, worked to develop a robust union in the 1930s. He details the battle for unionization among the more militant CIO, the conservative AFL, Communists, and Allis-Chalmers management officials. Meyer tells us about several of the key players in this battle--Harold Story, the Allis-Chalmers vice president and chief labor strategist, and Harold Christoffel, the electrical worker who became the powerful first president of the union. Meyer also analyzes the technical and social transition from batch to mass production, the social and cultural world of the ordinary workers at the workplace, and the factional struggles on the shop floor and picket line. He concludes by examining the CIO's entry into Wisconsin politics, the subsequent campaign against union leftists, the rise of Joseph McCarthy, the consolidation of Walter Reuther's position as UAW president, and the passage of the Taft-Hartley law.

病的骨吸収 特に慢性腎不全にみられる腎性骨異栄養症（ＲＯＤ）の顎骨Ｘ線写真の評価に関する研究

Renal osteodystrophy (ROD) was first reported by Virchow in 1855 and Lucas in 1883, but in the field of the oral and maxillofacial regions were reported for the first time in 1945 by Weinmann. ROD is one of the pathologic bone resorption' as in inflammatory bone resorption and tumor bone resorption. This study is carried out for purpose of finding a method by which bone lesions shown on mandibular roentgenogram can be evaluated objectively. There are very few methods that permit quantitative evaluation of the lesions. Therefore, this study is performed for objective and quantitative evaluation by correlating changes on the dental/mandibular roentgenogram with the duration of haemodialysis and clinical laboratory tests. Subjects consisted of 80 patients (54 male and 26 female patients) on haemodialysis 3 times weekly but without bone lesions in the measured region. Their age ranged between 24 and 65 years (average 45, 5 years). The patients were assigned to subgroups according to haemodialysis duration. Abnormal findings obtained in the study are summarized below.1) In clinical laboratory tests, abnormal levels of P, PTH, Al, Mg and HCO-3 weredetected, showing the condition in which ROD could occur.2) According to the interpretation of radiogram, lesions tend to increase in lamina dura, trabecula, mandibular canal and maxillary sinus floor line with the increase in duration of haemodialysis.3) Significant difference in metacarpal index (MCI) were observed from 4 years after initiation of haemodialysis. As compared with control group, mandibular lower cortical thickness (MLCT) value of molar region decreased significantly from 2 years after initiation of haemodialysis, indicating that MLCT values can reveal ROD induced bone lesions earlier than MCI.4) As compared with control group, mandibular trabecular width (MTW) values in the patients became more significant from 1 year after initiation of haemodialysis, showing that trabecular structure is affected earlier than cortical bone. It was thus suggested that the changes in trabecular structure occur at 2 year intervals after initiation of haemodial-ysis.

Dentin-polymer bond in resin fillings tested in vitro by thermo- and load-cycling.

The effect of stress applied by thermo- and load-cycling to the bond between composite- and bonding-agent-treated dentin was tested. Cylindrical cavities in extracted human teeth, approximately one-half of the margins in dentin, were etched and treated with two bonding agents - Gluma and Clearfil Bond - before being filled with Silux composite. Forty specimens, some provided with cavity floor lining, were cycled several hundred times between 15 degrees and 50 degrees C, either immediately after light-curing or upon 24 hr of water storage. In all cases, microscopic inspection revealed unchanged adaptation at the dentin margins. Teeth with Class 3 and Class 5 cavities, ten of each and with the gingival margins entirely in dentin, were pre-treated and filled as above. The teeth were covered with a dye during loading and unloading in a manner simulating biting and chewing. Inspection of the cavity margins revealed absence of percolation at the dentin margins. It is concluded that effective bonding agents are necessary to prevent contraction gaps in resin-filled cavities where the margins are partly or entirely located in dentin.

Age differences in the effect of lateral displacing prisms (base left/20 diopter) on perception and walking

Effects of short-term exposure to 11-deg lateral displacing prisms (base left/20 diopter) on perception and sensorimotor behavior (walking) was assessed in 24 5- to 7- year-old children and 24 adults. Walking tasks involved variation of feedback (walking along a straight line painted on the floor, walking toward a target) and carrying weight. Under prisms, it was found that: (1) three features of perception are affected significantly-physical horizontal appears rotated so that the left side is lower than the right, physical straight-ahead appears shifted to the right, and physical fronto-parallel plane appears rotated with right side closer to the subject than left; (2) relative to children, for adults the shifts are greater for both straight-ahead and fronto-parallel plane; (3) relative to children, adults walk rightward of the floor line to a differentially and progressively greater degree; (4) independent of age, walking rightward of the line is differentially greater when walking toward the target and walking without weight.

Ultra-Violet Lighting

MR. R. H. FINCH of the Lighting Section of the British Thomson-Houston Co. Ltd., has written a paper published in the Electrical Review for August 25 on the use in generating stations in war-time of ultra-violet lighting. The whole station could be bathed in ultra-violet energy and light produced only where needed, as, for example, on the handles of switches, meter scales, push buttons, telephones, doors, keyholes, tables, stairs, fire-extinguishers, etc., by the application to them of a dab of fluorescent paint or dye. Small press buttons should be surrounded by circles. Fuse positions can be delineated by outlining them, or by spotting the carriers with paint on the floor. In front of every switchboard a line should be painted about 12 inches away. The shape of every obstruction near an open switchboard or in a control room should be delineated by floor lines or patches of paint. Fluorescent chalks are also available for writing emergency warnings. The waves given off by the black lamps used are of a definite wave-length and produce no sun-burning or other dangerous effects. They are used in connexion with invisible fluorescent laundry marking systems and have been in constant operation for several years without a single case of ill effects to operators. Ultra-violet lighting is recommended for the emergency lighting in generating stations and similar premises in the Home Office A.R.P. Department pamphlet entitled ‘War Time Lighting Restrictions for Industrial and Commercial Premises’.