Expandable bladder

A bladder or diaphragm-type aeeumulator should be supplied to provide proper lube oil supply to the bearings during expander-eompressor eoast-down in the event lube oil pressure is lost. The aeeumulator must be fitted with a preload filling system and neeessary bleed and bloek valves. 

An update of a previous study (Axelson et al. 1978), Axelson (1986) evaluated an expanded cohort of 1,424 men (levels of trichloroethylene exposure inferred from measured urinary metabolite concentrations) and found a significant increase in incidences of bladder cancer and lymphomas, and a lower than expected incidence of total cancer mortality. A further update of this work (Axelson et al. 1994) expanded the cohort to include 249 women, tracking cancer morbidity over 30 years, and found no correlation between exposure concentration or exposure time and cancer incidence at any site. The highest standardized incidence ratio noted in this study was 1.56 (95% Cl of 0.51-3.64) for 5 cases of non-Hodgkin s lymphoma observed in men. Although four of these cases occurred in persons exposed for at least 2 years, and 3 cases had a latency of 10 years or more, urinary levels of TCA showed that 4 of the 5 cases were exposed to the lowest levels of trichloroethylene (urinary levels of TCA 0-49 mg/L). The study authors mentioned that a urinary TCA level below 50 mg/L corresponds to a trichloroethylene exposure concentration of about 20 ppm. The study authors concluded that "this study provides no evidence that trichloroethylene is a human carcinogen, i.e., when the exposure is as low as for this study population."... 

Concurrent with the injection of iron is the injection of the inert chemical tracer sulfur hexafluoride (SFg). By presaturating a tank of sea water with SFg and employing an expandable displacement bladder, a constant molar injection ratio of Fe SFg can be achieved (Figure 6). In this way, both conservative and nonconservative removal of iron can be quantified. Sulfur hexafluoride traces the physical properties of the enriched patch the relatively rapid shipboard detection of SFg can be used to track and... 

As opposed to the relatively thick silicone bladders that have to be removed from the component, thinner bladders may remain inside without negative effect on mechanical properties. Thin imstretched tubular polyamide films appear to offer best drapability and, at an air pressure of 0.5 MPa, they could expand into the edges of the component. Good results were obtained with these with braided glass fiber textile tubes, with the following process parameters ... 

As the metal parts are heated to above the melting point of the thermoplastic, the material at the joint softens and melts. However, it is totally constrained and a melt pressure is built up because of thermal expansion. For pipes, the molten material is prevented from extruding into the bore by using an inflatable bladder, which is expanded at the joint line prior to welding. After a predetermined time, related to the thickness of the thermoplastic part, the heat supply is switched off and the joint is allowed to cool. 

The individual layers are laminated together by heated hydraulic presses. TypicaUy, isostatic pressure is achieved on the three-dimensional pattern with isostatic pressing or through the use of molds or conformal bladders or bags. Finally, the laminates are green cut to final or near-net expanded dimensions. The multilayer parts are then heated in a burnout and firing process to remove organics and densify the ceramic and metal materials. 

Cell-based scaffold systems for bladder regeneration that are based on the use of isolated urothelial and smooth muscle cells, which are the key cellular components of the native bladder, have shown promise in early studies. In order to engineer bladder tissue in vitro, these cell types can be cultured and expanded in vitro, seeded on scaffolds, and allowed to adhere to the scaffold. They then form cellular structures on the scaffold, and this construct can be implanted into the patient. It is hypothesized that the tissue engineered 3D bladder, will exhibit fully differentiated cell populations after implantation in vivo and the presence of these cells will reduce the inflammatory immune response to the matrix as well as prevent graft contraction and shrinkage. 

Cilento, B. G., M. R. Freeman, F. X. Schneck, A. B. Retik, and A. Atala. 1994. Phenotypic and cytogenetic characterization of human bladder urothelia expanded in vitro. J Urol 152 665-670. 

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