Partial Consolidation Research Articles

Friction stir consolidation of aluminum machining chips

Friction stir consolidation (FSC) is a solid-phase manufacturing process that consolidates metal powder, chips, or scraps into solid blocks via severe plastic deformation and solid state welding. It has the potential to be a more economical and “green” process to recycle metal waste. In this study, solid discs were made from AA6061 aluminum alloy machining chips by FSC. The progression of the process was revealed by analyzing the motion of the tool, consolidating force, power history, and macro/microstructure of discs produced from a series of partial consolidation experiments. A bowl-shaped recrystallized zone in the vertical cross-sections of the disc products was observed and considered as the fully consolidated region. Design of experiments was conducted to quantify the effect of die rotational speed, compressive force, and processing time on the volume of fully consolidated material. A numerical model was used to predict the evolution of the main field variables such as density and temperature.

Berlin Symposium on Post-culturalist Art History

‘Post-culturalist art history’ doesn’t take for granted the ontological fact of culture as the context and content in dealing with the concrete material things and aesthetic practices which make up the putative ‘objects’ of art history. And therefore it doesn’t take for granted the epistemological primacy of cultural history in interpretation and explanation of its objects. It means offering a nontautological analysis of the social emergence and partial consolidation of visual culture, including traditions of pictorial art. What this analysis claims and does in its terms and details is less important than the very fact of a strenuous effort to provide it. Precisely because post-culturalist thinking doesn’t take for granted the fact of culture and the primacy of cultural history, potentially it can situate itself in productive and practical ways in relation to non-cultural inquiries in art history and in studies of art. The present essays began as presentations given at a symposium organized by Jakub Stejskal at the Dahlem Humanities Center, Freie Universitat Berlin, in April 2016.

The Social Costs of Uber

The rise of the car-sharing company Uber will likely have mixed effects on labor standards. On the one hand, Uber’s partial consolidation of the car-hire sector and its compilation of data on passenger and driver behavior could enable the company and regulators to ensure safety and root out discrimination against passengers with relative ease. In that regard, Uber may be an improvement over the existing taxi sector, which is quite difficult to regulate. Uber’s longer-term impact on labor standards is quite unclear, however, and it may have dark implications for the future of low-wage work more generally.

INCREASE IN EFFICIENCY OF THE CYCLIC DRIVING OF WELLS IN SOIL

Processing methods of a cyclic driving of wells with a diameter over 300 mm by methods of vibro-impact pushing and combined with partial consolidation and excavation of soil on the basis of use of pneumo-percussive mashines (pneumatic bore-hole driver) are given in work. The results of researches received with use of the ground intake devices physical models have allowed to establish characteristics of change of force of resistance to the return transportation of the equipment with the taken soil core in process of his removal from a face. Analytical expressions for engineering calculation of the winch tractive force are received. Technical characteristics of the created number of the winches of scraper type working at the uniform energy carrier with shock cars – compressed air are given.The schematic diagram winch with hybrid pneumatic drive, the having variable traction and high-speed characteristic is offered at a limited expense of the energy carrier which realization of a design at vibroshock breakdown and a combined method allows to reduce time of a production cycle of formation of wells and to increase productivity of driving works. A schematic diagram of a winch with a hybrid pneumatic drive is proposed, which has variable traction and speed characteristics with a limited energy carrier consumption, the implementation of the design which in vibro-impact pushing and combined method allows to reduce time of process of formation of wells and improve the performance of the tunneling works.

INVESTIGATING EXPRESSION OF AUTOPHAGY-ASSOCIATED PROTEINS LEVEL IN RATS WITH ACUTE LUNG INJURY INDUCED BY REMOTE LIMB ISCHEMIA-REPERFUSION

Objective: To explore the early expression of autophagy-associated proteins in lung tissues in acute lung injury (ALI) induced by remote limb ischemia-reperfusion (LIR) by using rats as our test specimens. Method: A total of 48 adult male Sprague-Dawley (SD) rats with weights in the range of 220–250[Formula: see text]g were designated as LIR models, and divided randomly into two groups of 24 each: Sham group and ischemia-reperfusion (I/R) group. Then, each group was divided into four subgroups at the end of 0, 2, 4, 8[Formula: see text]h of reperfusion, after 3[Formula: see text]h of ischemia. The rats were anesthetized by pentobarbital sodium. The serum lactate dehydrogenases (LDH) were detected with enzyme linked immunosorbent assay (ELISA), and the pathological changes of lung tissues were observed by using immunofluorescence techniques. The expression of Beclin1 protein and Atg5 mRNA in the lung tissues were detected by using reverse transcription polymerase chain reaction (RT-PCR), and analyzed by 2[Formula: see text] method; Microtubules associated protein light chain 3 (LC3) in the lung tissues were detected by Western blot test. Result: The levels of serum LDH in I/R groups were much higher than those in Sham groups ([Formula: see text]), which showed that the rats models of LIR were successful. Immunofluorescence examination demonstrated injuries of lung tissues, thickening of alveolar septum and partial consolidation in I/R groups; however, this damage was not observed significantly in Sham groups. The expression of Beclin1 and Atg5 mRNA, LC3-II and the ratio of LC3-II/GAPDH in lung tissues were very much higher at 4 and 8[Formula: see text]h in IR groups ([Formula: see text] or [Formula: see text]), and were significantly higher at the same time compared with Sham groups ([Formula: see text] or [Formula: see text]). Conclusion: LIR causes ALI to induce increased autophagy and high expression of its relevant proteins; while continuous I/R can also cause autophagy inhibition.

Estimating consolidation parameters from field piezoball tests

The piezoball, a ball penetrometer featuring pore pressure measurements, is a relatively new device that is potentially superior to the more commonly used piezocone for profiling fine-grained soils. This is due to lower uncertainty in how to derive soil strength from the net penetration resistance and the option of measuring consolidation characteristics during pauses in the penetration, potentially more quickly than in a piezocone test. This paper presents results from a series of piezoball tests undertaken at a soft clay test site using a piezoball that measures pore pressure concurrently at the ball equator, tip and half-way between the tip and equator, the so-called mid-face position. Analysis of the test data provides strong arguments for measuring pore pressure at both the equator and mid-face positions. The coefficient of consolidation derived from piezoball dissipation data using recently developed numerical solutions is shown to be highly comparable to that deduced from a piezocone dissipation test. This paper shows that the penetration resistance varies significantly with the rate of penetration due to either viscous rate effects or increasing degrees of partial consolidation during penetration, both of which influence the estimation of undrained shear strength and hamper interpretation of dissipation data. Guidance on assessing the drainage response during a piezoball penetration test is provided. Finally, dissipation test data presented in the paper are added to a database formed from centrifuge and field tests that is used to form a new empirical method for estimating the coefficient of consolidation.

Selective arterial Embolisation of Aneurysmal Bone Cysts ofthe Sacrum: a promising Alternative to Surgery.

The sacrum is a rare but unfavourable location for Aneurysmal Bone Cysts (ABCs), surgical procedures aiming to achieve local tumour control can be mutilating. Aim of this study was to evaluate whether selective arterial embolisation (AE) of ABC of the sacrum is an effective treatment and might be an alternative to surgical treatment options. Between 2007 and 2011 six patients (mean age 13.7 years, range 8 - 18 years) with an ABC of the sacrum were treated by AE. Follow-up was performed by MRI-scans as well as clinical examination (mean 36.5 months, range 14 - 56 months). No treatment related complications have been observed. AE resulted in devascularisation of ABC and led to local tumour control in all patients. A partial consolidation was noticed in three patients. Pain relief was achieved in five of six patients, neurological deficits dissolved. In two patients more than one embolization was necessary. In one of these patients due to exacerbation of pain a surgical decompression was performed. AE of sacral ABCs can serve as an effective and safe treatment option. Thus it might be an alternative to potentially harmful surgical procedures. In case of ongoing tumour growth or pain recurrence AE can be repeated. In case of treatment failure surgical interventions are still possible. • transarterial embolisation enables local tumour control in sacral ABCs. • transarterial embolisation of sacral ABCs is a safe procedure. • in case of tumour progression repetitive embolisations are possible and effective.

Inhalation of Pin - A Rare Case Report

A boy aged 1year presented with persistent cough, sputum and fever for last two months which is did not subside in spite of empirical mediacal therapy. For last 15 days symptoms started to aggravate and not responding to medical management. Chest X-ray showed a pin in the right main bronchus with more radiolucency of right lung. CT scan of chest revealed radiodense linear opacity in the right lower lobe primary and secondary bronchus with partial collapse consolidation of right lower lobe medial basal and lateral basal segment. Rigid bronchoscopic removal was tried but failed. Ultimately thoracotomy was done to remove the foreign body.

¿De la Primavera al Verano Arabe?

Este artículo explora los factores políticos (participación ciudadana), sociales (capital social), educativos (alfabetismo) y económicos (infraestructura e inversión) que se considera han permitido la consolidación de la democracia en Túnez y una parcial de la misma en Egipto. Para sustentar estas afirmaciones se han empleados índices como el Democratic Index, Doing Business o Global Competitiveness, mismos que han sido de apoyo para los factores antes mencionados. Los argumentos de que la consolidación democrática de Túnez, y la parcial de Egipto, resultan del capital social, alfabetismo, infraestructura o participación ciudadana, están basadas principalmente en procesos similares iniciados en distintas latitudes, demostrando la validez de los mismos.

Morphological assessment of sulfur mustard-induced acute lung injury in rats through different routes

To establish an animal model of sulfur mustard (SM)-induced acute lung injury in rats through different routes and compare the morphological changes in lung tissue and cells. One hundred and thirty-six male rats were selected and randomly divided into 5 groups, namely peritoneal cavity SM group (n=32), trachea SM group (n=32), peritoneal cavity propylene glycol group (n=32), trachea propylene glycol group (n=32), and normal control group (n=8). The rats in peritoneal cavity SM group were injected intraperitoneally with diluted SM (0.1 ml, 8 mg/kg), and the rats in trachea SM group were injected intratracheally with diluted SM (0.1 ml, 2 mg/kg). Once the rats were sacrificed at 6, 24, 48, and 72 h after SM treatment, morphological changes in lung tissue and cells were observed by light and electron microscopy. In the peritoneal cavity SM group, the epithelial cells of bronchioles maintained intact with increased exudate and bleeding in alveolar cavity and large areas of pulmonary consolidation under the light microscope. In the tracheal SM group, focal ulcer formed in the epithelial cells of bronchioles with increased exudate and bleeding in alveolar cavity, partial pulmonary consolidation, and compensatory emphysema in peripheral alveolar space under the light microscope. The alveolar interval areas were widened obviously in both groups in a time-dependent manner. Under the electron microscope, we observed local loss of cellular membrane in type I alveolar epithelium, broken or lost microvilli in cells of typeⅡalveolar epithelium and fuzzy mitochondrial crista as well as the appearance of ribosome detached from rough endoplasmic reticulum in both two groups. Compared with those in the trachea SM group and the control group, the ratio of the alveolar septum average area to the visual field area in the peritoneal cavity SM group at 6, 24, 48, and 72 h was significantly higher (P<0.05). The lung tissue injury through the intraperitoneal route is more severe than that through the tracheal route, while focal ulceration of bronchioles epithelial cells appears in the case of tracheal route. The degree of injury increases over time in both groups, and the cellular damage is approximately the same in both groups.

Determining scaphoid waist fracture union by conventional radiographic examination: an analysis of reliability and validity.

Conventional radiographic imaging is the first imaging tool of choice in scaphoid fractures. The majority of undisplaced scaphoid waist fractures unite after 6weeks of cast immobilization. We hypothesized that conventional radiographic imaging at 6weeks after injury can both accurately and reliably predict union in undisplaced scaphoid waist fractures. Fleiss' kappa statistics were used concerning the opinions of four observers reviewing 47 sets of good-quality scaphoid radiographs of undisplaced scaphoid waist fractures. As reference standard for union, radiographs were taken at a minimum of 6months after injury to determine validity. Overall agreement was defined as moderate. (κ=0.583) "No consolidation" (κ=0.816), "full consolidation" (κ=0.517) and "partial consolidation" (κ=0.390) were defined as good, moderate and fair agreement, respectively. The average sensitivity and specificity of diagnosing scaphoid waist fracture union on standard scaphoid radiographs were 0.65 and 0.67, respectively. The positive predictive value for diagnosing union was 0.93 and the negative predictive value was 0.22. Conventional radiographic imaging is accurate and moderately reliable in diagnosing union, and reliable but inaccurate in diagnosing nonunion of scaphoid waist fractures at 6weeks follow-up.

Numerical simulation of piezocone dissipation test in clays

The piezocone is one of the most widely used in-situ tools with which to characterise the soil profile, distinguishing different types of sediment, and to provide quantitative data on the soil strength and consolidation characteristics. For fine-grained soils where penetration occurs under nominally undrained conditions, consolidation characteristics are obtained from dissipation tests conducted with the piezocone brought to rest. Dissipation testing is interpreted to yield a coefficient of consolidation, by comparison of the excess pore pressure decay with theoretical solutions. It is generally acknowledged that the coefficient of consolidation derived from in-situ dissipation tests will be greater, by a factor of perhaps 2 to 10, than values derived from oedometer tests on samples recovered from the corresponding depth. Apart from potential differences in horizontal and vertical permeability, differences arise from the influence of the rigidity index on the initial excess pore pressure field and the more complex stress paths undergone by soil elements surrounding the piezocone by comparison with an oedometer test. In order to advance the science underlying interpretation of dissipation testing, a careful parametric study has been undertaken using finite-element analysis, with the soil modelled as modified Cam Clay. The aim has been to derive an ‘operative' coefficient of consolidation, linked to the consolidation and swelling parameters of the soil model, thus allowing quantitative treatment of the difference in coefficients of consolidation derived from laboratory oedometer or in-situ dissipation testing. The effect of partial consolidation during the penetration phase is also considered.

Electron-microscopic examination of the transition zone of aluminum-tantalum bimetallic joints (explosion welding)

A study of the structure of an aluminum-tantalum joint and a comparison of this structure with the structures of iron-silver and copper-tantalum joints have revealed the following processes of the interpenetration of the materials that occur during explosion welding: the formation of protrusions, the injection of particles of one material into the other, and the formation of zones of local melting. Regardless of the mutual solubility of the metals being welded, two types of fragmentation occur, i.e., (1) a granulating fragmentation (GF), which includes the formation, explosion-governed (EG) dispersion, and partial consolidation of particles, and (2) the fragmentation that is usually observed during severe plastic deformation. It is important that this traditional fragmentation is not accompanied by the formation and EG dispersion of particles. This feature allows one to easily distinguish these types of fragmentation (traditional and GF fragmentation).

Penetrometer Testing: Effect of Partial Consolidation on Subsequent Dissipation Response

AbstractPartial drainage during a penetration test increases the penetration resistance, and also affects the excess pore pressures generated and the form of any subsequent dissipation test. This complicates interpretation of such tests, particularly in soils of intermediate consolidation characteristics, because it is difficult to obtain an accurate estimate of the coefficient of consolidation from which to assess the degree of consolidation during penetration. The effect of partial consolidation during penetration on subsequent dissipation tests is investigated here through a number of model piezocone and piezoball tests conducted in a single soil sample under centrifuge conditions. Backbone curves of penetration resistance and excess pore pressure are devised, and comparisons are made of the form of the dissipation response for the two types of penetrometers and for two different pore pressure monitoring positions on the piezoball. Different methods are proposed for assessing the degree of consolidatio...

Tibial tubercle osteotomy with absorbable suture fixation in revision total knee arthroplasty: a report of 23 cases

Tibial tubercle osteotomy (TTO) is a well-known technique for improving exposure in difficult total knee arthroplasty (TKA). We have performed 23 revision TKAs with TTO. The tibial tubercle was fixated with only absorbable sutures afterwards. The aim of this study is to report on the clinical results and complications of this procedure. We retrospectively evaluated 23 patients (mean age 69.6years, range 43-84years) who underwent TTO with only absorbable suture fixation. Clinic charts were reviewed to identify any complications that occurred. Obvious proximal migration and union of the tibial tubercle was evaluated on the postoperative radiographs. Knee Society scores and SF-36 were assigned at latest follow-up. The mean follow-up was 16.1months (1-43). Two patients died of causes unrelated to surgery. In one case a fracture of the TTO occurred. No obvious migration of the osteotomy was detected. In two cases there was partial consolidation of the osteotomy, but without clinical consequences of pain or extension lag. In five patients a tibial plateau fracture occurred intraoperative which allowed partial weight bearing during 6weeks. These fractures were not related to the surgical technique of the TTO. In 15 out of 23 patients a Knee Society Score could be assigned. The mean total knee score (maximum 200 points) after revision was 99.5 (17-166) (clinical KSS 52.1, functional KSS 47.3) at latest follow-up. SF-36 scores could be assigned to 16 patients; the mean SF-36 (maximum 100) was 88 (range 74-98). Tibial tubercle osteotomy with only absorbable suture fixation is a reliable and simple method of fixation and provides adequate stability. It is a straightforward surgical technique which is less time-consuming and expensive compared with screw and cerclage wire fixation and no hardware removal will be necessary. Therefore, this method is a beneficial technique for the enhancement of surgical exposure in difficult revision TKA.

Defining existence domains in geopolymers through their physicochemical properties

Geopolymeric material is a new type of cement that is synthesized through the alkali activation of aluminosilicates. To improve the properties of the aluminosilicates, the composition is greatly modified. However, through numerous possible synthetic routes to form geopolymers, the determination that the final material has a geopolymer network cannot be ensured, despite the apparent or partial consolidation of material. This work proposes a definition that a domain in the geopolymeric material exists that can be correlated using different techniques to quantify the amount of silicon, potassium and aluminum. Two sources of potassium silicate and various clays with different degrees of amorphous character were compared to determine the importance of the starting materials. The existence domain is an important tool to determine if the synthesized material is a geopolymer network independent of the raw materials used.

Novel Human Enterovirus C Infection in Child with Community-Acquired Pneumonia

Novel Human Enterovirus C Infection in Child with Community-Acquired Pneumonia

Comparing CPTU Q–F and Q–Δu2/σv0′soil classification charts

This paper extends a framework for classifying soil using normalised cone resistance (qt) and porewater pressure (u2) data from piezocone tests (CPTU) to include the friction ratio. Analytical predictions of normalised cone tip resistance ([Formula: see text]) and friction ratio (F = fs/qn) for a range of overconsolidation ratios are compared to databases of piezocone measurements during undrained penetration at clay sites, as well as to data from sands, silts and mixed soil types having partial to full drainage. Aspects of soil behaviour that result in data plotting in different zones of the complementary charts are discussed. It is concluded that Q–F classification charts are useful in the absence of high-quality pore pressure data. However, when attempting to separate the effects of yield stress ratio from partial consolidation during penetration in soils that may have some degree of sensitivity, structure or cementation, additional site-specific calibration may be required.

A numerical study of cone penetration in fine-grained soils allowing for consolidation effects

This paper presents results from a numerical study performed to examine cone penetration response that spans fully undrained to fully drained conditions. Coupled-consolidation finite-element analyses, which accounted for large deformation and finite sliding effects, were carried out using Abaqus/Standard v6.6 at various rates of cone penetration. The model assumed a smooth soil/cone interface, with the soil idealised as a homogeneous elastic-perfectly plastic material obeying a non-dilatant Drucker–Prager yield criterion. The results for the limiting undrained and drained conditions are compared with published strain path and cone factor solutions. The significant advance of this work is the establishment of the theoretical backbone curves arising from the effects of partial consolidation during cone penetration. The factors affecting the backbone curves are examined, and a simplified procedure for deriving these curves is proposed using a hyperbolic fit. An example is then presented to illustrate how the data from measured field cone tests performed at different penetration rates may be used to estimate the strength, deformation and consolidation characteristics of a soil.

6-Year follow-up of ventral monosegmental spondylodesis of incomplete burst fractures of the thoracolumbar spine using three cortical iliac crest bone grafts

Autologous bone graft is the gold standard for vertebral body replacement. Currently, after modern implants for vertebral body replacement are available, controversies exist regarding the optimal implant strategy. Between 2002 and 2003, 17 patients were included in this study, all suffering from incomplete burst fractures of the thoracolumbar spine. All of them were treated by ventral monosegmental spondylodesis using iliac crest bone graft. The individual treatment strategy depended on the fracture situation and patient's condition. After an average of 74 months (range 66-84) a clinical and computer tomographic follow-up examination was performed in 14 patients (average age, 35.2 years) including VAS spine score and SF 36 score. Nine patients were treated ventral only five patients dorsoventrally. Complete osseous consolidation was visible in nine, partial consolidation (>30 %) in four, and lysis in one patient, without any significant differences between ventral only or dorsoventral approach. After removal of the fixateur interne the level of consolidation improved in all patients, treated dorsoventrally. There was no significant correlation between percentage of osseous consolidation and the clinical follow-up parameters. After 6 years, 71 % of the patients suffered from persistent pain associated with the approach to the iliac crest. Two revision surgeries have been necessary. High rates of osseous consolidation are visible 6 years after ventral spondylodesis by iliac crest bone grafts. A further improvement of consolidation can be expected after dorsal implant removal. But the surgical approach to the iliac crest is accompanied with a relevant complication rate.