Types Of Tiles Research Articles

Rotational displacement on the sagittal plane in unstable pelvic fractures: a clinical case study

Objective To investigate the clinical significance and distribution of different rotational displacements on the sagittal plane in unstable pelvic fractures radiologically. Methods We retrospectively reviewed 82 patients with unilateral pelvic fracture who had been treated at our department from June 2005 to June 2015. They were 48 men and 34 women, with an average age of 43±18 years. By Tile classification, there were 48 cases of type B and 34 cases of type C. Their rotational displacements on the sagittal plane of the pelvic ring were determined on the anteroposterior X-ray films of the pelvis by measuring the changed distances from the top of iliac crest to the lowest point of ischial tuberosity and to the pubic tubercle. The data were recorded for analysis of different displacements and their clinical significance. Results Of all the 82 patients, based on the preoperative radiographic evidence, 36 (43.9%) showed sagittal plane rotational displacement. Of them, 28 (77.8%) showed supination displacement and 8 (22.2%) pronation displacement. The preoperative CT three-dimensional reconstruction confirmed the findings from the X-ray films. Twenty-one of the 48 cases of Tile type B (43.8%) and 15 of the 34 cases of Tile type C (44.1%) showed sagittal plane rotational displacement. The success rate of closed reduction was, respectively, 66.7% (24/36) in the 36 cases with sagittal plane rotational displacement, 62.5% (5/8) in those with pronation displacement and 67.9% (19/28) in those with supination displacement, all significantly lower than the total success rate of closed reduction in this cohort (84.1%). Conclusions The sagittal plane rotational (pronation and supination) displacement of pelvic fracture can be determined by measuring special points and lines on the anteroposterior radiographs of the pelvis. The supination displacement on the sagittal plane is more common. The unstable pelvic fracture with sagittal plane rotational displacement is more difficult to reduce. Key words: Pelvis; Fractures, bone; Closed reduction; X-ray; Rotation

Tratamento das lesões instáveis do anel pélvico com fixador supra‐acetabular e parafusos sacroilíacos: resultados preliminares em 20 pacientes

ObjectiveTo analyze the treatment results from 20 patients who underwent an alternative osteosynthesis method as definitive treatment for pelvic ring fractures. MethodsA retrospective analysis was conducted on a series of 20 patients with pelvic ring fractures (Tile type C) and a high risk of postoperative infection, who were treated at Santa Casa de Misericórdia de São Paulo between August 2004 and December 2012. The patients underwent percutaneous supra‐acetabular external fixation in association with cannulated 7.0mm iliosacral screws. ResultsThe patients’ mean age was 40 years (range 22‐77 years) and the mean length of follow‐up was 18.5 months (range 3‐69 months). At the end of the treatment, ten patients (50%) were classified as having good results, nine patients (45%) had fair results and one patient (5%) did not have any improvement. Six patients presented complications, and paresthesia of the lateral femoral cutaneous nerve was the most frequent of these (two patients). ConclusionSupra‐acetabular external fixation in association with iliosacral percutaneous osteosynthesis is a good definitive treatment method for patients with a high risk of postoperative infection.

外装タイル剥離診断装置の開発に関する基礎研究

Exterior tile cladding can suffer debonding or adhesive failures as it ages. Failures that lead to cladding tiles falling from the building are highly dangerous for people passing beneath, and consequently it is vital to be able to identify debonding defects at an early stage to prevent tiles falling. This study was performed to develop high-precision apparatus for the efficient debonding detection of debonding. This paper presents the results of investigations into detection methods using impact acoustics. Initially, eight exterior-tile wall specimens were prepared with artificially debonded areas. The type of tiles, bonding materials, debonding interface and debonding depth were different for each sample. Percussion tests were carried out by three professional testers, and diagnostic tests were also performed using two types of existing debonding detecting apparatuses. The professional testers had an error rate of up to 40% in differentiating between bonded and debonded areas, while the error rate using the detecting apparatuses was up to 20 percent. These results reveal the effectiveness of using debonding detecting apparatus, but also the need for clear criteria for the apparatus, as well as the need to improve accuracy of the apparatus for objective and accurate diagnosis of debonding, Next, a prototype apparatus which has a highly efficient impact mechanism with a solenoid actuator and a microphone was manufactured. The apparatus was then used to examine suitable analysis methods, using impact acoustics, for detecting debonding and effective method for predicting depth of the debonding. As a result, relative maximum amplitude derived from impact sound waveform detected debonding areas correctly. In addition, the interval between the first and the second peaks of the recorded impact sound waveform showed the possibility of predicting debonding depth properly. Further research will be continued in order to establish more effective and accurate parameters and their criteria.

Resistance to impact of porcelain stoneware tiles

The impact resistance of ceramic tiles is an important technical requirement, especially for large size and/or low thickness slabs. The standard test for ceramic tiles (ISO 10545-5) is non-destructive: it determines the coefficient of restitution of a small sample (75×75mm2) assembled on a concrete substrate under a weak impact energy (0.27J). This method does not provide neither an impact strength nor information on the way a ceramic tile is broken by impact. In order to fill this gap, an investigation was undertaken to describe, by a phenomenological approach, how ceramic tiles break under different conditions of impact. For this purpose, unglazed porcelain stoneware tiles with different size (12×12, 25×25 and 60×60cm2) and thickness (3.5, 5 and 8mm) were assembled on a concrete basement and tested for the coefficient of restitution (ISO 10545-5) and Roesler index. Their physical and mechanical properties were determined by measuring: water absorption, porosity, bulk density (ISO 10545-3), flexural strength (EN 843-1), elastic moduli (EN 843-2), fracture toughness (SENB). The impact strength was measured by falling steel balls (50, 80, 200 and 500g) with increasing energy (from 0.2 to 6J) and with different speed at the moment of impact (from 1.9 to 5.5m/s). The effects caused by impact were visually inspected, revealing for increasing energy the formation of an impact ring, radial cracks, one or two concentric Hertzian cone fractures, a highly fractured inner zone. Such damages were quantified by measuring the impact ring diameter as well as number, length and estimated surface of radial and conical cracks. A nearly linear dependence on the impact energy was found for crack length and surface, while the ring diameter and crack number seem to follow a quadratic law. The impact strength depends on the tile thickness, but also the sample size may somehow affect the mechanical behavior under impact. A map of seven levels of damage was drawn by contrasting increasing impact energy with tile thickness: it can help to predict the tile behavior in operation and to address the correct tile type in different applications.

Comparison of Biomechanical Characteristics and Pelvic Ring Stability Using Different Fixation Methods to Treat Pubic Symphysis Diastasis

The intention of this study was to compare the biomechanical characteristics using 5 internal fixation methods used clinically to stabilize a pubic symphysis diastasis (PSD, Tile type B1).A 3-dimensional finite element model of PSD was simulated using 5 implants, including single superior plate (Single-Plate), superior and anterior plate (Dual-Plate), single cannulated screw (Single-Screw), crossed dual cannulated screws (Cross-Screw), and parallel dual cannulated screws (Para-Screw). Three loads were distributed in all models, including dual-leg standing, single-leg stance, and rotation. To evaluate the biomechanical properties, the construct stiffness, the stress distribution, and the von Misses stress were recorded and analyzed. To evaluate pelvic ring stability, the micromotion of the pubic symphysis and iliosacral joint was analyzed.Disruption of pubic symphysis dramatically decreased the pelvic ring stability. Cross-screw and Para-Screw showed higher stiffness than other methods. All implants endured the maximum von Misses stress under single-leg stance. For Plate-Screw system, the maximum stress occurred at a place where it strides over pubic symphysis and adjacent Plate-Screw interface. The single implant and Para-Screw had a tendency to fail. Para-Screw showed the best fixation effect under dual-leg conditions. Cross-screw showed superior antishearing force capacity under single-leg stance. Dual-Plate provided maximum antihorizontal rotation. Para-Screw provided the maximum stabilization for the posterior pelvic ring.This study showed the biomechanical advantages of dual-implant for PSD only from the finite element view. The Para-Screw provided high construct stiffness under 3 load conditions. The single implant and Para-Screw had a tendency to fail. The better anterior and posterior pelvic stabilization were obtained by the dual-implant fixation than other methods. Therefore, the Cross-Screw and Dual-Plate fixation methods should be preferred in the treatment of pubic symphysis from the finite element view.

Pattern overlap implies runaway growth in hierarchical tile systems

We show that in the hierarchical tile assembly model, if there is a producible assembly that overlaps a nontrivial translation of itself consistently (i.e., the pattern of tile types in the overlap region is identical in both translations), then arbitrarily large assemblies are producible. The significance of this result is that tile systems intended to controllably produce finite structures must avoid pattern repetition in their producible assemblies that would lead to such overlap. This answers an open question of Chen and Doty (SODA 2012), who showed that so-called partial-order systems producing a unique finite assembly and avoiding such overlaps must require time linear in the assembly diameter. An application of our main result is that any system producing a unique finite assembly is automatically guaranteed to avoid such overlaps, simplifying the hypothesis of Chen and Doty's main theorem.

Activatable tiles for compact robust programmable molecular assembly and other applications

Algorithmic DNA self-assembly is capable of forming complex patterns and shapes, that have been shown theoretically, and experimentally. Its experimental demonstrations, although improving over recent years, have been limited by significant assembly errors. Since 2003 there have been several designs of error-resilient tile sets but all of these existing error-resilient tile systems assumed directional growth of the tiling assembly. This is a very strong assumption because experiments show that tile self-assembly does not necessarily behave in such a fashion, since they may also grow in the reverse of the intended direction. The assumption of directional growth of the tiling assembly also underlies the growth model in theoretical assembly models such as the TAM. What is needed is a means for enforce this directionality constraint, which will allow us to reduce assembly errors. In this paper we describe a protection/deprotection strategy to strictly enforce the direction of tiling assembly growth so that the assembly process is robust against errors. Initially, we start with (1) a single "activated" tile with output pads that can bind with other tiles, along with (2) a set of "deactivated" tiles, meaning that the tile's output pads are protected and cannot bind with other tiles. After other tiles bind to a "deactivated" tile's input pads, the tile transitions to an active state and its output pads are exposed, allowing further growth. When these are activated in a desired order, we can enforce a directional assembly at the same scale as the original one. Such a system can be built with minimal modifications of existing DNA tile nanostructures. We propose a new type of tiles called activatable tiles and its role in compact proofreading. Activatable tiles can be thought of as a particular case of the more recent signal tile assembly model, where signals transmit binding/unbinding instructions across tiles on binding to one or more input sites. We describe abstract and kinetic models of activatable tile assembly and show that the error rate can be decreased significantly with respect to Winfree's original kinetic tile assembly model without considerable decrease in assembly growth speed. We prove that an activatable tile set is an instance of a compact, error-resilient and self-healing tile-set. We describe a DNA design of activatable tiles and a mechanism of deprotection using DNA polymerization and strand displacement. We also perform detailed stepwise simulations using a DNA Tile simulator Xgrow, and show that the activatable tiles mechanism can reduce error rates in self assembly. We conclude with a brief discussion on some applications of activatable tiles beyond computational tiling, both as (1) a novel system for concentration of molecules, and (2) a catalyst in sequentially triggered chemical reactions .

A manually-checkable proof for the NP-hardness of 11-color pattern self-assembly tileset synthesis

Patterned self-assembly tile set synthesis (pats) aims at minimizing the number of distinct DNA tile types used to self-assemble a given rectangular color pattern. For an integer k, k-pats is the subproblem of pats that restricts input patterns to those with at most k colors. We give an efficient [InlineEquation not available: see fulltext.] verifier, and based on that, we establish a manually-checkable proof for the NP-hardness of 11-pats; the best previous manually-checkable proof is for 29-pats.

Systematic design analysis and risk management on nanoparticles occupational exposure

Worker's health and occupational safety are critical to the development of nanotechnology applications, since some nanomaterials present a risk of adverse effect on human beings. This paper describes the application of the Systematic Design Analysis Approach based on the hazard process model (bow-tie) as well as design analysis of the production process, during a development project to produce a new type of ceramic tile with photocatalytic properties. Applying the bow-tie model together with the design analysis to the production process, it is possible to identify the emission and exposure scenarios and the related barriers based on the unit operations and the different technological options to perform them. Alternatives to the production process were considered, falling back on solutions to reduce emissions, and consequently the exposure to nanoparticles. The intervention model proposed will allow occupational safety and hygiene to be integrated into the development process that will involve a multidisciplinary team. Systematic Design Analysis Approach is a suitable method for occupational safety and hygiene risk management. This approach proved to be effective in generating relevant emission and exposure scenarios, as well as identifying possible barriers to control such emission scenarios.

Surface Mosaic Synthesis with Irregular Tiles.

Mosaics are widely used for surface decoration to produce appealing visual effects. We present a method for synthesizing digital surface mosaics with irregularly shaped tiles, which are a type of tiles often used for mosaics design. Our method employs both continuous optimization and combinatorial optimization to improve tile arrangement. In the continuous optimization step, we iteratively partition the base surface into approximate Voronoi regions of the tiles and optimize the positions and orientations of the tiles to achieve a tight fit. Combination optimization performs tile permutation and replacement to further increase surface coverage and diversify tile selection. The alternative applications of these two optimization steps lead to rich combination of tiles and high surface coverage. We demonstrate the effectiveness of our solution with extensive experiments and comparisons.

Frost Damage of Roof Tiles: A Study on Moisture Boundary Conditions

Freeze–thaw cycles are the most serious cause of roof tile deterioration; thus, it is important to know the temperature and moisture distributions in tile materials for protection against frost damage. This study focused on moisture boundary conditions for air layers under the tile. Temperature and humidity were measured using model structures with different types of roof tiles. The results showed that the temperatures around the roof were strongly influenced by solar and longwave radiation, and the humidity in the air layer was close to the outdoor. The ventilation rate between the outdoor and the air layer was estimated by numerical modelling based on the measured results.

Relation between the microstructure and technological properties of porcelain stoneware. A review

Porcelain stoneware is a strongly sintered ceramic material fabricated from ball clays-quartz-feldspar mixtures. Porcelain stoneware is characterized by its excellent technical and functional properties (low water absorption, high mechanical properties, resistant to chemical substances and cleaning agents, aesthetic possibilities …). These characteristic and technical features make that among the different types of ceramic tile, porcelain stoneware is the ceramic product that in the last years has best withstood the economic crisis in the construction sector. These properties are related to the microstructure of porcelain stoneware, which is a grain and bond type with large particles of filler (quartz), mullite crystals, a silica-rich amorphous phase and porosity. The understanding of the relationship between the microstructure and the properties of porcelain stoneware is hardly important for the development and design of these materials whose tendency is the manufacture of thinner tiles with higher dimensions but must continue to comply the specific technical requirements.

Percutaneous Ilio-Sacral Screw Fixation in Supine Position under Fluoroscopy Guidance.

Pelvic ring disruption when treated conservatively can be associated with prolonged hospital stay and immobilization, mal-union, chronic pain, limb length discrepancy if they are treated conservatively. Open reduction and fixation in an already compromised soft tissue and hemodynamically unstable patient causes more soft tissue injury, heamatoma, infection and neurovascular injury. Percutaneous iliosacral joint fixation can be an alternative technique for sacro-iliac joint injury and sacral fracture. To evaluate technique and safety of percutaneous ilio-sacral screw fixation in supine position under single fluoroscopy guidance for sacral fracture and sacro-iliac joint disruption. Twenty one patients either with sacral fracture or sacro-iliac joint disruption with percutaneous ilio-sacral screw fixation with cannulated cancellous screw fixation in between 2008 to 2014 were retrospectively evaluated including AP, inlet and outlet views of pelvis X rays and CT scan. Tile's classification and Dennis classification were used for pelvis and sacral injury. Thirty five percutaneous ilio-sacral screws were placed (Male: 6, Female: 15; range: 15 to 54) for sacral fracture involving zone 2 (8 with sacral fracture only and 5 with pelvis injury; Tile's type B in four and type C in one) and sacro-iliac joint injury (Tile's type B in three and type C in five). Commonest mode of injury was motor vehicle accidents (10) followed by fall related injury (6). Injury hospital interval and injury surgery interval was five hours to 13 days and 2 to 20 days respectively. Follow period was 3 months to 6 years. One patient developed post-operative deep vein thrombosis and another patient had post-operative haematoma. Two screws were juxtra-foramial. Good to excellent outcome were in 16 patients, fair in four and poor in one patient (Majeed Scoring). Percutaneous ilio-sacral screw fixation for sacro-iliac joint injury and sacral fracture with C arm guidance is safe and minimally invasive technique. Clear images and accurate interpretation of X-rays, CT scans and per operative C arm images are important to avoid malpositioning of screws and iatrogenic neurovascular injuries.

Combinatorial-topological modeling of the cluster self-assembly of crystal structures of zeolites of the GME, AFX, AFT, and ISC-2 family

Combinatorial-topological 3D modeling of periodic packages from T12 polyhedral clusters has been carried out (t-hpr tiles in the form of hexagonal prisms), most frequent in the crystal zeolite structures. A basic 2D microlayer L is obtained by decoding a single-node 2D grid of the 6.6.6 type of graphite and it contains cyclic hexamers (T12)6. The hexamer is located in a triple hexagonal cell with ahex = 13.90 A; the height of the layer is about 10 A. In theory, the formation of an unlimited number of structures of polytypes with cell parameters of chex = N × 10 A is possible due to the different variants of the complementary communication of the L layers with each other (both with and without a shift). For the three obtained models of skeletons, an analogy is found with the following known zeolites: GME (mineral Gmelinite, P63/mmc, chex = 10 A), which is classified as a single layer 1H-polytype from the translation-related layers L, AFX—2H-polytype (P63/mmc, chex = 20A) and AFT—3H-polytype (P63/mmc, chex = 30 A). A new 3H-polytype ISC-2 is found with parameters a = 13.90 A, c = 30.00 A, V = 5019.7 A3, and P-6m2 (187). Using a TOPOS program pack, a set of tiles Tn is determined characterizing all polyhedral zeolite cavities: t-hpr-12T, t-gme-24T, t-aft-48T, and t-isc-72T (a new type of tile). It is assumed that the synthesis of skeletonized compound Al36P36O144 can be carried out by selecting the corresponding organic structure directing agents (OSDA molecules) in order to stabilize local areas corresponding to the cavities of the largest size (t-isc-72T size).

Producibility in hierarchical self-assembly

Three results are shown on producibility in the hierarchical model of tile self-assembly. It is shown that a simple greedy polynomial-time strategy decides whether an assembly ? is producible. The algorithm can be optimized to use $$O(|\alpha | \log ^2 |\alpha |)$$O(|?|log2|?|) time. Cannon et al. (STACS 2013: proceedings of the thirtieth international symposium on theoretical aspects of computer science. pp 172---184, 2013) showed that the problem of deciding if an assembly ? is the unique producible terminal assembly of a tile system $${\mathcal {T}}$$T can be solved in $$O(|\alpha |^2 |{\mathcal {T}}| + |\alpha | |{\mathcal {T}}|^2)$$O(|?|2|T|+|?||T|2) time for the special case of noncooperative temperature 1 systems. It is shown that this can be improved to $$O(|\alpha | |{\mathcal {T}}| \log |{\mathcal {T}}|)$$O(|?||T|log|T|) time. Finally, it is shown that if two assemblies are producible, and if they can be overlapped consistently--i.e., if the positions that they share have the same tile type in each assembly--then their union is also producible .

Size-separable tile self-assembly: a tight bound for temperature-1 mismatch-free systems

We introduce a new property of tile self-assembly systems that we call size-separability. A system is size-separable if every terminal assembly is a constant factor larger than any intermediate assembly. Size-separability is motivated by the practical problem of filtering completed assemblies from a variety of incomplete garbage assemblies using gel electrophoresis or other mass-based filtering techniques. Here we prove that any system without cooperative bonding assembling a unique mismatch-free terminal assembly can be used to construct a size-separable system uniquely assembling the same shape. The proof achieves optimal scale factor, temperature, and tile types (within a factor of 2) for the size-separable system.

Predictors of mortality for complex fractures of the pelvic ring in the elderly: A twelve-year review from a German level I trauma center

Study objectiveTo document mortality rate and predictors of mortality in elderly patients with complex pelvic fractures. MethodsWe reviewed a total of 84 subjects whose ages were above 70 years with complex pelvic fractures, admitted to our hospital from January 2001 to December 2012. A multivariate linear regression model was used to determine the predictors of mortality in the study population. The median age of the patients was 80.4 years (range 70–94 years). 65 of 84 (77%) patients were females. There were 72 Tile Type B fractures (86%) and 12 Type C fractures (14%). The most common associated injuries were thoracic, extremity and head injuries, with incidence of 13 (15%), 11 (13%), and 9 (11%), respectively. ResultsThe mortality rate was 10% in our study population. The initial haemoglobin on admission (p<0.01), the presence of blood vessel injuries (p<0.01) and the number of PRBCs transfused within the first six hours after admission (p<0.01) independently predicted mortality in elderly patients with complex pelvic fractures. ConclusionAlthough there is a downward trend in mortality in elderly patients with complex pelvic fractures, haemodynamic instability still has a significant impact on survival of those patients.

Does pelvic injury trigger erectile dysfunction in men?

PurposePelvic ring fractures constitute 3%–8% of all fractures of the skeletal system and are generally related with high energy trauma. Sexual dysfunction following pelvic fracture has a high incidence, and affects the male patients both physically and psychologically. In this study, we aimed to investigate the impact and frequencies of comorbidities such as erectile dysfunction (ED) with adverse sociocultural and psychological consequences for the patient who had a pelvic ring fracture. MethodsThis study included 26 men who corresponded to the inclusion criteria and agreed to participate our study. ResultsAccording to fracture types, most of our cases were Tile type A1 and type A2. Severe and moderate ED were detected in 46.1% (12/26) of these patients via the International Index of Erectile Function-5 questionnaire. ConclusionED develops following pelvic fractures, especially in Tile type B and C pelvic fractures.

Strict Self-Assembly of Fractals Using Multiple Hands

In this paper we consider the problem of the strict self-assembly of infinite fractals within tile self-assembly. In particular, we provide tile assembly algorithms for the assembly of a Sierpinski triangle and the discrete Sierpinski carpet within a class of models we term the h-handed assembly model (h-HAM), which generalizes the 2-HAM to allow up to h assemblies to combine in a single assembly step. Despite substantial consideration, no purely growth self-assembly model has yet been shown to strictly assemble an infinite fractal without significant modification to the fractal shape. In this paper we not only achieve this, but in the case of the Sierpinski carpet are able to achieve it within the 2-HAM, one of the most well studied tile assembly models in the literature. Our specific results are as follows: We provide a 6-HAM construction for a Sierpinski triangle that works at scale factor 1, 30 tile types, and assembles the fractal in a near perfect way in which all intermediate assemblies are finite-sized iterations of the recursive fractal. We further assemble a Sierpinski triangle within the 3-HAM at scale factor 3 and 990 tile types. For the Sierpinski carpet, we present a 2-HAM result that works at scale factor 3 and uses 1216 tile types. We further include analysis showing that the aTAM is incapable of strictly assembling the Sierpinski triangle considered in this paper, and that multiple hands are needed for the near-perfect assembly of a Sierpinski triangle and the Sierpinski carpet.

Ultrafine and nanoparticle formation and emission mechanisms during laser processing of ceramic materials

The use of laser technology in the ceramic industry is undergoing an increasing trend, as it improves surface properties. The present work aimed to assess ultrafine and nanoparticle emissions from two different types of laser treatments (tile sintering and ablation) applied to two types of tiles. New particle formation mechanisms were identified, as well as primary nanoparticle emissions, with concentrations reaching up to 6.7×106particlescm−3 and a mean diameter of 18nm. Nanoparticle emission patterns were strongly dependent on temperature and raw tile chemical composition. Nucleation events were detected during the thermal treatment independently of the laser application. TEM images evidenced spherical ultrafine particles, originating from the tile melting processes. When transported across the indoor environment, particles increased in size (up to 38nm) with concentrations remaining high (2.3×106particlescm−3). Concentrations of metals such as Zn, Pb, Cu, Cr, As and TI were found in particles <250nm.