Floor Line Research Articles

Depression of the maxillary sinus anterior wall and its influence on panoramic radiography appearance.

To clarify the depression aspect of the maxillary sinus anterior wall and to investigate its relationship with the panoramic image appearance of a diagonal line from the inferior part of the so-called panoramic innominate line to the medial portion of the orbital floor line. Based on CT data, panoramic images were simulated for two typical cases with and without anterior wall depression. Next, on axial CT images of 1689 subjects (3378 sinuses) stored in our image database, the wall depths were measured and analyzed for their relationships with the panoramic appearances of the diagonal line, classified into invisible, obscure and clear patterns. Based on the simulation study, visualization of the diagonal line was verified to alter depending on the morphology of the anterior wall and the position of the panoramic image layer. In 408 (12.1%) sinuses, the diagonal line (clear and obscure patterns) could be seen on the panoramic image. The incidences of the obscure and clear patterns increased with increasing age groups. The mean wall depths were 2.91, 4.80 and 7.28 mm for the invisible, obscure and clear patterns, respectively. The clear pattern showed the highest value for the wall depth, followed by the obscure pattern. The diagonal line on a panoramic image was verified to be related to depression of the maxillary sinus anterior wall, and its panoramic image appearance can be altered depending on the position of the tomographic image layer.

Is It Necessary to Achieve a Complete Box Isolation in the Case of Frequent Esophageal Temperature Rises? Feasibility of Shifting to a Partial Box Isolation Strategy for Patients With Non-Paroxysmal Atrial Fibrillation.

There are some cases with frequent luminal esophageal temperature (LET) rises despite titrating the radiofrequency energy while creating a linear lesion for the Box isolation of atrial fibrillation (AF). Little is known about the feasibility of redesigning the ablation lines for a modified Box isolation strategy to prevent fatal esophageal injury in those cases. Two hundred and seventeen patients who underwent a Box isolation of non-paroxysmal AF were evaluated. We divided them into 2 groups, patients in whom a box lesion set of the entire posterior left atrium had been achieved (complete Box isolation [CBI]; n = 157) and those in whom 2 additional peri-esophageal vertical lines were created at both the right and left ends of the esophagus, and those areas were left with an incomplete isolation when frequent rapid LET rises above 39.0 °C were observed while creating the floor line (partial Box isolation [PBI]; n = 60). During 20.1 ± 13.9 months of follow-up, the arrhythmia-free rates were 54.1% in the CBI group versus 48.3% in the PBI group (P = 0.62). In the second session, a complete Box isolation was highly achieved even in the PBI group (94.3% vs. 83.3%, respectively; P = 0.17) and after 2 procedures, the arrhythmia-free rates increased to 75.2% vs. 68.3%, respectively (P = 0.34). There was no symptomatic esophageal injury in the PBI group. In the case of frequent LET rises while creating the linear lesions for the Box isolation strategy for non-paroxysmal AF, shifting to the PBI strategy was feasible.

Clinical evaluation of internal axial wall divergence in inlays and casting post-and-core fabrication

Background/purposeIn the fabrication of casting post and core or inlay the line angle of the cavity floor can be seen even when the internal axial walls are parallel or slightly convergent. It is conceivable that more sighted distance will be required for internal axial walls evaluation compared with external axial walls evaluation. The aim of the study is to derive a practical and convenient method and data for the evaluation of the divergent angle of internal axial walls. Materials and methodsThrough a scientific analysis, this study derived a practical and convenient method and data for the evaluation of the divergent angle of internal axial walls. The sighted distance between occlusal line angle and the cavity floor line angle at 30-cm distance was calculated by an established formula and expressed in 6°, 12°, and 18° of internal axial walls divergent angle respectively. ResultsTables 1–3 show the value of sighted distance with cavities of 6°, 12°, and 18° tapering. Based on the data, if more divergent angle is prepared; more sighted distance will be observed. ConclusionCompared with the teeth preparation of external axial wall in a single crown, the sighted distance at 30-cm distance in the internal axial wall is 1.5 × wider. More sighted distances are required to prevent undesired undercuts.

What's to come after isolation of the pulmonary veins?

Treatment of atrial fibrillation (AF), the most prevalent tachyarrhythmia worldwide, remains a great challenge. About 15 years ago, when Haissaguerre et al. [1] first described episodes of AF triggered by focal activity originating from the pulmonary veins, the way was paved for ablative therapy of AF by pulmonary vein isolation (PVI). Despite a successful PVI, electric pulmonary vein reconnections still occur frequently requiring additional procedures. To this end new mapping, navigation, imaging and ablation techniques continue to be developed thereby facilitating and increasing success rates of PVI. In this issue of the Netherlands Heart Journal, the results of the endoscopic laser balloon ablation system (EAS) for PVI are presented by Gal et al. [2] in 50 patients with mostly paroxysmal AF (82 %). The EAS provides an elegant manner for optimal circumferential contact and ablation lesions with one device applicable in pulmonary veins of various sizes. Furthermore, an endoscope within the device provides real-time visualisation of the ablation area. This resulted in isolation of 99.5 % of the pulmonary veins during the ablation procedure. However, the long-term results were similar to other techniques and were somewhat lower compared with other studies using the EAS. The authors believe this may be due to inexperience with this novel technology, although other influential factors could be that this study, in contrast to others, also included some patients with persistent AF and had a longer follow-up period. Unfortunately, the study did not report how many pulmonary veins were in fact electrically reconnected with re-ablation procedures. This could provide more information on the long-term success of isolation with the EAS. In addition, it would give insight into the incidence of AF recurrence despite successful isolation of the pulmonary veins. For example, one study [3] using this technique reported AF recurrence in 28 % of patients with persistent pulmonary vein isolation after a median of 12-month follow-up. Moreover, three months after PVI, 14 % of ablated pulmonary veins were reconnected in 38 % of the patients, which entails that a large proportion of patients had at least one pulmonary vein electrically reconnected. We commend the authors for their contribution to optimising PVI outcomes and encourage them in their ongoing efforts to improve the PVI procedure with this refined technique. However, AF recurrences may also have aetiologies outside of our current understanding and perhaps these unknown pathological or physiological processes prevent further improvements in successful long-term outcomes. For this, it is of utmost importance to learn more about the pathophysiology of AF. The revolutionary findings of Haissaguerre et al. made it possible for a majority of patients with AF to be successfully treated with PVI. Unfortunately, another large proportion of patients continue to have AF, and PVI seems to be insufficient. For this reason different ablation strategies were implemented, such as boxlines, roof, floor and isthmus lines, complex fractionated atrial electrogram ablation and ablation of ganglionated plexi. Nonetheless, AF still recurs and the pathophysiological background to support these additional strategies is controversial. To take new steps toward successful treatments for AF, we must further understand the underlying mechanism of AF, just as Haissaguerre et al. did almost two decades ago. In previous mapping studies, we demonstrated that longitudinal dissociation in conduction and focal fibrillation waves are the key elements in persistence of AF [4, 5]. Figure 1 shows an example of an epicardial high-resolution wavemap (244 electrode, inter-electrode distance 2.5 mm) of the right atrial free wall obtained from a patient with longstanding persistent AF demonstrating a complex pattern of activation. The wavemap shows individual fibrillation waves represented by colours according to their sequence of appearance. A previously described mapping algorithm was used to classify them intoperipheral waves (entering the mapping area from outside the electrode array), breakthrough waves (appearing at the epicardial surface inside the mapping area) or discontinuous conduction waves (fibrillation waves starting with a delay of 13–40 ms from boundaries of other waves). During this AF episode of only 140 ms, the mapping area (diameter: 4 cm) is activated by as many as 15 fibrillation waves, including 5 peripheral waves, 4 epicardial breakthrough waves and 6 discontinuous waves. Hence, when patterns of activation during AF become too complex, the end stage of AF might have been reached and it is likely that PVI in these patients will be unsuccessful. We believe that by understanding the pathophysiology of AF we can come to new successful treatment strategies, which can be used when PVI just is not enough. Presumably, this will entail a tailor-made treatment determined by different mechanisms underlying AF. Fig. 1 Wavemap constructed during longstanding persistent AF. Sites of epicardial breakthroughs are indicated by white asterisks; white arrows indicate direction(s) of expansion of epicardial breakthrough or discontinuous fibrillation waves; black arrows indicate ...

Complete Isolation of the Left Atrial Posterior Wall (Box Lesion) to Treat Longstanding Persistent Atrial Fibrillation.

The left atrial posterior wall has been shown to play na important role in AF pathophysiology. Evaluate the efficacy of an ablation strategy designed to completely isolate the LA posterior wall, on top of PV isolation. Methods and Results: 25 pts (72% male age 65 ± 12 years) undergoing AF ablation for persistent or long term persistent AF. Mean AF duration was 11 ± 3 months and mean LA diameter was 4.8 ± 0.4 mm. After complete PVI, a "Roof Line" was created between the top of each contralateral set of lesions and a "floor line" closed the posterior wall in a "Box" fashion, connecting the bottom of each set of contralateral lesions. After an average follow-up of 16 ± 2 months, 20 patients (80%) were free of any atrial arrhythmia recurrences (18 of whom off drugs). Five patients (20%) had sustained atypical flutter and required a new ablation procedure. All these patients had mitral isthmus dependent flutters and no electrical conduction in the PVs or posterior wall were detected. Complete LA posterior wall isolation on top of PV is associated with good outcomes in patients with persistent and long-standing persistent AF when performed using meticulous bidirectional isolation criteria and adenosine infusion. Recurrences occur predominately as perimitral flutter, without gaps in the posterior wall.

Primary intranasal lining injury cause, deformities, and treatment plan.

Nasal membranes may be injured by immune disease, infection, trauma, or cocaine. Destruction of the septum, vault and floor lining, external skin, upper lip, and adjacent structures follows. Lining injuries caused by cocaine, Wegener granulomatosis, primary syphilis, leishmaniasis, septorhinoplasty, septal cancer excision and irradiation, corrosive inhalation, and foreign body and iatrogenic intubation injury were reviewed. The site and degree of injury were correlated with presentation and anatomical and functional abnormality. Damage may be isolated to the septum, creating a septal fistula with loss of dorsal and tip support and modest collapse of the dorsum and tip with columellar retraction, or the injury may extend onto the vaults and floor, leading to circumferential scar contracture and severe nasal shortening and lip retraction. Progressive disease, infection, or iatrogenic injury increases soft-tissue damage, causing external skin contraction or full-thickness necrosis. Repair is determined by site, depth of injury, and clinical deformity--not cause. Lining necrosis and subsequent scar contraction, rather than structural compromise of the septum, are the primary causes of the severe deformity. If vault and floor lining injury is minimal, central support alone will restore dorsal and tip projection. Extensive loss requires release of scar contracture and replacement of the vault and floor lining with composite grafts, a microvascular flap, or hinge-over lining flaps, depending on the site and extent of injury. If the external skin is destroyed by scar or a full-thickness loss, a staged forehead flap will be required to resurface the nose.

Bacterial vs. fungal spore resistance to peroxygen biocide on inanimate surfaces

A sporicidal agent formula based on a mixture of peroxyacetic acid and hydrogen peroxide was assessed for its efficacy on a representative sample of vinyl surface material. Vinyl is the construction material of wall and floor lining in pharmaceutical plants. The experimental manipulations; applied herein, simulated the actual biocidal agent preparation and were carried out using USP purified water, test temperature was 20–25°C, RH% was 40–60% and pH was 3.08 and 2.86 for 1% and 2% (v/v) respectively. Following the selection of the optimum method of antimicrobial activity neutralization, two disinfectant concentrations were examined for their sporicidal activity. The results of carrier test revealed that the disinfectant concentration (2%) (v/v) was significantly effective as a sporicidal agent after 5 and 10min for Aspergillus brasiliensis and Bacillus subtilis subsp. spizizenii, respectively, while the concentration of 1% (v/v) did not achieve even one logarithmic reduction after 20min. The agent was able to achieve more than 100 times reduction from the initial bioburden on the surfaces when used in the concentration of 2% (v/v) after 10min of contact time. The ideal kinetics of microbial death usually follows 2 parts (by averaging the responses with time for the 3 replicates): initial slow rate of death followed by higher rate. The initial sigmoidal part was only observed with B. subtilis upon exposure to 2% (v/v) sporicidal agent. Elimination time for B. subtilis spores was 15min which was about double the time required for eradication of A. brasiliensis.

Planning and visualising 3D routes for indoor and outdoor spaces using CityEngine

With the increasing size and complexity of modern buildings, 3D indoor routing is receiving more attention nowadays. Different elements such as route finding, indoor modelling, and route visualisation need to work together to achieve this goal. For this purpose, we propose a framework that makes use of existing data sources and tools that can minimise the time and effort needed for potential 3D indoor routing applications. Our 3D indoor and building models are generated from CAD files and building footprints using CityEngine and its built-in procedural modelling approach. An Americans with Disabilities Act (ADA) compatible 3D network is created by combining 3D floor lines and transitions such as staircases and elevators. The resulting routes as well as the indoor and façade models are then visualised through a 3D WebScene generated by CityEngine. Our study demonstrates the usefulness of CityEngine for 3D indoor model generation as well as 3D routing visualisation.

Offene Koloproktektomie mit ileoanaler J-Pouch-Rekonstruktion

Coloproctectomy is a visceral surgical intervention where the complete colon and rectum are removed up to the level of the pelvic floor or pectinate line and the anal canal. As a rule the anal canal and pelvic floor musculature including the anal sphincter muscle remain intact. The ileoanal J-pouch construction has become established as treatment of choice for reconstruction of the small intestine. This article presents the approach for open coloproctectomy with ileoanal J-pouch reconstruction by means of an operation video which is available on-line.

Some properties of tidal currents estimated from analytical and LES simulation studies

Some features of tidal current ellipses near the ocean floor are estimated from the bottom-limit solutions of the tidal equations with constant eddy viscosity. It is verified that a clockwise rotating ellipse becomes broad descending through the bottom boundary, whereas a counterclockwise ellipse becomes narrow except near the critical latitude. The major axis of an ellipse near the floor is directed 45° leftward (rightward) against that of the overlying tidal flow ellipse poleward from the critical latitude in the northern (southern) hemisphere. Equatorward from the critical latitude, the major axis near the floor lines up with that of the overlying tidal current ellipse in both hemispheres. The retrograde rotating hodograph against the overlying clockwise tidal hodograph appears near the floor around the critical latitude. These features are confirmed from the numerical studies using the large eddy simulation model. The deflection of the major axis poleward from the critical latitude is a little smaller, about 19°. Furthermore, the effects of nontraditional Coriolis force resulting from the horizontal component of the earth-rotating vector on the development of turbulence were investigated. When the diurnal tidal current is directed westward, the effective vertical eddy viscosity becomes maximum with developing turbulence. While in the case of a semidiurnal tide, a northward tidal current is preferred for turbulence development.

27 Sick building syndrome in public services of Eure-et-Loir’s district, France

In September 2010, a sick building syndrome occurred after the relocation of three public services of Eure-et-Loir’s district, France, in a renovated building in which foul odours have been perceived.The...

Remaining Pre-Stress Identification of Diseased Pre-Stressed Concrete Bridges Based on Neural Network

According to experimental record of bridges in use, more and more damage bridges have appeared, and the most common and severe defect is the bridge damage and cracking problem, which has seriously affected the normal usage of bridges. Analyzing the disease cause of defective bridges more effectively and deeply, in order to optimize the design and construction of bridges becomes the urgent problem in the engineering field. The study is based on the design, construction data and experimental record of the bridge.A non-linear mapping function from multiple input data (the deck elevation of each element in destructing) to multiple output data(the change of pre-stress) is constructed within BP neural networks. Based on the theory of continuous function, the convergence is disadvantageous between 0 and 1. The study shows the expected output data between 0.05 and 0.95 are better for convergence. According to the real data of bridge floor line change in process of destruction, the released pre-stresses are recognized, and the real pre-stresses in existence are calculated by scheme of cable design. The study not only offers reliable scientific basis for analyzing the disease cause in the bridges, but also is helpful to design of the bridges having same structural style.

Remedies for a high incidence of broken eggs in furnished cages: Effectiveness of increasing nest attractiveness and lowering perch height

Two remedial treatments to reduce the high incidence of broken eggs in the furnished cages of our experimental layer farm were investigated: lining the nest floor with artificial turf (to increase nest acceptance) and lowering perch height (to reduce the chance of egg breakage of outside-nest eggs). A 2 × 2 factorial design was used with low (7 cm) or high (24 cm) perches, and with nest floors lined with artificial turf or plastic mesh. Eight cages, each housing 8 hens initially (aged 40 to 56 wk), were used per treatment. Egg location and percentage of broken eggs were recorded. Hen position (cage floor, nest, or perch) was recorded by direct scan-sampling observations. In addition, 8 cages (4 high + 4 low) each containing 8 hens (aged 54 to 56 wk) were videorecorded to determine perch use and behavior during the light period. Data were mainly analyzed using logistic regression and mixed models with cage as the experimental unit. Nest floor material did not influence the percentage of eggs broken or laid outside the nest. The proportion of outside-nest eggs (2.6 vs. 10.6%, P = 0.004), and consequently also of total eggs (2 vs. 4.6%, P = 0.016) broken, was lower for low than high cages. Perch use increased during the observation period, more so for the high cages during the light period and the low cages during the dark period. Perch bout duration (P < 0.001), the likelihood of ending a perching bout voluntarily (P = 0.013), and time spent sitting during perching (P = 0.007) were lower in low vs. high cages. In this study, replacing plastic mesh nest floor lining with artificial turf was not an effective remedy for the already-high rate of broken eggs, but the prevalence of broken outside-nest eggs was lower in cages with low versus high perches. However, perching behavior during the light period was more disturbed in cages with low perches.

Ceilings and Floors

There are situations where the data or the theory suggest or require, respectively, that one estimate the boundary lines that separate regions of observations from regions of no observations. Of particular interest are ceiling or floor lines. For example, many theories use terms such as veto player, constraint, only if, and so on, which suggest ceilings. Ceiling hypotheses have a nonstandard form claiming the probability of Y will be zero for all values of Y greater than the ceiling value of Yc for a given value of X. Conversely, ceiling hypotheses make no specific prediction about the value of Y for a given value of X except that it will be less than the ceiling value. Floors work by guaranteeing minimum levels. The article gives numerous examples of theories that imply ceiling or floor hypotheses and numerous examples of data that fit such hypotheses. The article proposes quantile regression as a means of estimating the boundaries of the no-data zone as well as criteria for evaluating the importance of the boundary variable. These techniques are illustrated for ceiling and floor hypotheses relating gross domestic product/capita and democracy.

A vertical and floor line-based monocular SLAM system for corridor environments

In this paper, we propose a vertical and floor line-based monocular simultaneous localization and mapping (SLAM) system which utilizes vertical lines, floor lines, and vanishing points as sensory input to perform robust SLAM in corridor environments. By combining three map feature types, our design can help a robot to perform accurate pose estimation, repeatable loop closure, and to construct a more expressive environmental map. As a primitive element of a geometric structure, a line segment has one additional dimension compared to a point feature, thereby allowing the use of line segments to easily represent a geometric structure using a smaller number of features. This system presents map features on a 2D ground space: the vertical line as a projection point, the floor line as the original line, and the vanishing point as a directional vector. Although the vertical line, floor line, and vanishing point use different parameterization and initialization methods, their measurement models are integrated into a unified extended Kalman filter (EKF) framework. Experimental results show that our system can be deployed in a structured indoor environment as a suitable SLAM solution.

직선기반 SLAM에서의 루프결합

The loop closure problem is one of the most challenging issues in the vision-based simultaneous localization and mapping community. It requires the robot to recognize a previously visited place from current camera measurements. While the loop closure often relies on visual bag-of-words based on point features in the previous works, however, in this paper we propose a line-based method to solve the loop closure in the corridor environments. We used both the floor line and the anchored vanishing point as the loop closing feature, and a two-step loop closure algorithm was devised to detect a known place and perform the global pose correction. We propose an anchored vanishing point as a novel loop closure feature, as it includes position information and represents the vanishing points in bi-direction. In our system, the accumulated heading error is reduced using an observation of a previously registered anchored vanishing points firstly, and the observation of known floor lines allows for further pose correction. Experimental results show that our method is very efficient in a structured indoor environment as a suitable loop closure solution.

Influence of knee flexion and femoral cross-pin insertion angle on posterolateral structures of the knee and lateral fixation lengths during ACL reconstruction

Some studies have investigated knee flexion angle on the sagittal plane and insertion angle of the cross-pin on the coronal plane to evaluate proper femoral fixation. They evaluated the possibilities of injury to the posterolateral (PL) and neurovascular structures using several methods. The purposes of this study were to evaluate (1) the influence of knee flexion and femoral cross-pin insertion angles on knee PL structures and (2) the lateral fixation length of the cross-pin. Ten fresh cadaveric knees with no previous surgeries around the knee were used. Transtibial femoral tunnels (1:30 or 10:30 o'clock position) were made at three different knee flexion angles (70°, 90°, and 110°). Two cross-pin guidewires (superior and inferior pins) were drilled at three different insertion angles [downward 30°, 0° (parallel to floor line), and upward 30°] for each knee flexion position. The distances from the insertion point of the two cross-pins to the lateral collateral ligament (LCL) and popliteus tendon (PT), and the distance from the lateral wall of the femoral tunnel to the lateral cortex of the femoral condyle were measured. No significant differences were observed in the superior and inferior pin depths (p=0.56 and 0.39). The distances from the superior pin to the LCL and from the inferior pin to the LCL were significantly shorter in all knee flexions with 0° and an upward 30° insertion angle than with 70° and 90° knee flexion with a downward 30° insertion angle, respectively (superior pin: p=0.02 and 0.03; inferior pin: p=0.03 and 0.03). No significant difference was observed in the distance between the superior pin and inferior pins and the PT (p=0.25). The cross-pin was inserted close to the LCL and PT, and a downward 30° angle was the safest insertion angle. Lateral fixation length was sufficient for the cross-pin fixation in the 10:30- or 1:30-positioned femoral tunnel.

The Safe Zone for Femoral Cross-Pin Fixation –An Anatomical Study

Femoral cross-pin fixation in anterior cruciate ligament (ACL) reconstruction has a potential for neurovascular injury, thus a "safe zone" must be defined for safe pin passage with this technique. In this anatomic study, femoral-sided, arthroscopic-assisted ACL reconstruction using the TransFix system (Arthrex, Naples, Fla) was performed on five fresh extended thigh and lower leg cadavers. Using a goniometer, five cross-pin guidewires were sequentially drilled at 0 degrees, -20 degrees, -40 degrees, +20 degrees, and +40 degrees, using the parallel to floor line as 0 degrees. Negative was defined as starting the pin more posteriorly, and positive was defined as starting the pin more anteriorly. Distance from the pin to the peroneal nerve, saphenous nerve, and femoral artery was measured after pin placement, and measurements were averaged. The peroneal nerve was at minimal risk with average distance to the guide pin of 1.87, 2.13, 2.45, 2.74, and 3.05 cm at -40 degrees, -20 degrees, 0 degrees, +20 degrees, and +40 degrees, respectively. The saphenous nerve was an average distance of 2.19, 1.98, 1.41, 1.42, and 1.29 at -40 degrees, -20 degrees, 0 degrees, +20 degrees, and +40 degrees, respectively. The femoral artery was an average distance of 1.81, 1.51, 0.78, 0.46, and 0.08 cm at -40 degrees, -20 degrees, 0 degrees, +20 degrees, and +40 degrees, respectively. Based on this anatomical study, the absolute neurovascular safe zone during cross-pin guidewire placement is from +20 degrees (0 degrees parallel to floor line) and -40 degrees (lowering guide more posterior).

Determination of passenger car interior space for foot controls accommodation

This study shows that the automobile is still not well enough adapted for human beings, especially in the part of the interior where the foot controls are located. When designing passenger vehicles ergonomically, the anthropometric limitations are as important as the technical limitations. Moreover, exacting contemporary economic and ecological requirements mean that the interior of the standard passenger vehicle must be designed to reduce front surface and air resistance to a minimum. The present authors offer a new method for designing the part of the interior of standard passenger vehicles where the foot controls are located as an indivisible part of the whole interior, with interrelated functional links using anthropometric limitations. These vary according to region and country and change with time. This study uses anthropometric data for drivers from Serbia from 1976 to 2007. The objective was, taking into account vehicle interior height limitations, to accommodate the largest range of anthropometric dimensions, from the fifth-percentile woman to the 95th-percentile man, which was accomplished using a new method for model accommodation optimization. Furthermore, comfort and a safe steering position are assured. The existence of the O point is required as the origin of a coordinate system with x, y, and z axes for the man—vehicle system and this enables the mechanical and mathematical functions to be defined more accurately within the system. By applying the suggested method and processing the data acquired, an optimum space for foot controls was obtained. The space for foot control location lies horizontally along the x axis forward from the O point by 320mm and vertically along the z axis by 230mm. The space height along the z axis is 465mm. The space is determined in four segments by the anthropomeasures of the foot of the 95th-percentile man and the fifth-percentile woman, first starting from the floor line to the point (−320mm, 230mm). Also, it is determined by the height of 465mm of the 95th-percentile man to the point (50mm, 465mm), when the space as far as the lower half of the windshield glass is defined by the fifth-percentile woman. In this way, a larger space is needed for seating of the fifth-percentile woman than would be needed if only the 95th-percentile man were seated.

Delayed Ettringite Formation (DEF) Within Pre-Cast Concrete Cladding Panels on a Mid-Rise Commercial Office Building: A Case Study

Abstract This paper will present the findings of multiple forensic investigations on a fourteen-story office building located in Houston, Texas. During our initial survey, widespread cracking was observed within the concrete cladding panels that warranted a more extensive investigation. Construction of the building was completed in 1985; 17 years prior to our initial investigation. Exterior cladding components are comprised of pre-cast concrete panels over each of the floor lines, with a continuous, structurally glazed, horizontal window system at each floor level. The cladding panels are nonload bearing, pre-cast concrete panels, installed at the time of the building’s construction. The concrete panels are attached to the structure via steel plates that are welded and bolted to the building’s frame. It is intended that this paper will present the results of observations made at the site over a period of several years, as well as the results of testing conducted to assist in the evaluation. A system was developed to locate and catalog the visible anomalies on the panels; including cracks, exposed steel, spalls, pop-outs, and efflorescence on the panels. Full-depth cores were removed from select panels to perform a petrographic analysis and scanning electron microscopy/energy dispersive x-ray microanalysis (SEM/EDXA). The results revealed the presence of delayed ettringite formation (DEF) and alkali-silica reactivity (ASR), with varying degrees of severity. Specific conclusions will be derived related to the conditions at this project and how these anomalies have affected the cladding system performance. Current repair and maintenance provisions will be discussed, in addition to the necessary recladding that will be required in the future. Recommendations will be developed regarding construction practices so that the cladding panel failure observed may be avoided in the future.