Bag Failures Research Articles

Power Morcellation Using a Contained Bag System.

Background and Objectives:The well-known advantages of minimally invasive surgery make the approach well suited for hysterectomy and other gynecological procedures. The removal of specimens excised during surgery has been a challenge that has been answered by the use of power morcellation. With this study we sought to assess the feasibility of power morcellation within a specimen bag.Methods:This was a retrospective cohort study including patients from a private practice in suburban Chicago, Illinois, who underwent contained electromechanical power morcellation during a laparoscopic or robot-assisted hysterectomy or myomectomy from May 2014 through December 2015. Contained power morcellation was performed with the Espiner EcoSac 230 (Espiner Medical Ltd., North Somerset, United Kingdom) specimen bag. Descriptive statistics were performed for both categorical and continuous data.Results:Of the 187 procedures performed, 73.8% were myomectomies, and 26.2% were hysterectomies. The patients' mean age was 40 (range, 25–54) years and mean body mass index was 28.7 (range, 17.3–57.6). The average specimen weight was 300 g, with the largest weighing 2134 g. Estimated blood loss averaged 98.4 mL. The postoperative admission rate was 12.3%, most of which were due to nausea and urinary retention. Seventeen patients (9.1%) had postoperative complications, most of which were minor, and 4 (2.1%) were readmitted. There were no bag failures or complications that were due to the use of the specimen bag or to power morcellation.Conclusions:Performing electromechanical power morcellation within the Espiner EcoSac 230 specimen bag was successfully performed in 187 patients with no bag-related complications. This method of contained power morcellation is feasible, reliable, and reproducible, even for a large specimen.

Reasons for Filter Bag Failure and Method Development to Improve its Life Span

AbstractReasons for filter bag failure at steel plants were analyzed and a suitable approach to overcome such problems is proposed. Clean and used filter bags were tested to evaluate tensile and bursting strengths and air permeability properties. In order to simulate the behavior of the filter bags under acidic conditions normally encountered in actual working environment, an acid dew point test was conducted on the clean bags. The structural changes in all bags were determined by scanning electron microscopy. A significant reduction in tensile and bursting strengths was observed after acidic treatment. In order to improve the durability of the bags, they were coated with a mixture of acrylic binder and nanoclay. Commercial filter bags as well as the developed samples showed improved resistance without any failure behavior.

Mechanics of filled jute bag

A simplified model of a filled-in jute bag in the form of composite shell of three segments, each of which is generated by surface of revolution, is assumed. The development and distribution of stresses in the different portions of the composite shell under the action of uniform internal pressure is calculated using membrane theory. The portion subjected to maximum stress and the controlling factors in the failure of bag, such as bag dimension and width/length ratio of bag, are identified. These findings corroborate the observations related to failure of filled jute bags in actual use.

Failure to Ventilate with the Dräger Apollo® Anesthesia Workstation

Failure to Ventilate with the Dräger Apollo® Anesthesia Workstation

Mrs. GH, A Resident Who Challenged Us

Mrs. GH, A Resident Who Challenged Us

Performance of the Packed-Foamed Cement Milk and Its Applicability as Base Material

It is often being used for construction works such as backfill, void packing and widening of embankment because the foamed cement milk (FCM) consisting of cement, water and air bubble is a lighter and more fluid material. On one hand, the geotextile which has function to strengthen earth structure with a tensile resisting force of fiber has been employed in the reinforcing construction of banking and reinforced soil wall method from the past. In the present study, we have devised a material combining these advantages namely the geotextile-made bag (hereinafter referred to as “FCM bag”) which was filled with FCM, and have ascertained its efficiency as pavement materials by examining the bending strength of square column specimen and the elastic modulus of slab sized to actual execution.According to result obtained from the laboratory test, both bending strength and deformation before reaching a failure of FCM bag tended to become larger than those of specimen without bag. This is considered to be the effect of adhesion between solidified FCM and an inner side of bag on increase of a tensile stress due to bending occurring in specimen. Secondly, we carried out the non-destructive bearing capacity test by dropping a weight as to the slablike FCM bags (a length of 5m, a width of 2m and thickness of 0.15 to 0.2m) which were laid on improved ground and conventional ground. Having executed the inverse analysis with measurement records following the site investigation, it was found that the elastic moduli of FCM bags were equal to or greater than those of about 0.5m thick stabilized layers. Moreover, the output consequences of the structural calculations of asphalt pavement using multi-layer elasticity theory indicated that the appropriating of FCM bag to subbase course brought a reduction in thickness of pavement, providing elastic modulus of subgrade exceeded 40MPa.Based on such results, it can be concluded that the FCM bag is particularly suitable for material of the subbase course built on soft subgrade, because of its superior lightness and its prominent attendantness against flexural tension.

Prediction of Particulate Loading in Exhaust from Fabric Filter Baghouses with One or More Failed Bags

Loss of filtration efficiency in a fabric filter baghouse is typically caused by bag failure, in one form or another. The degree of such failure can be as minor as a pinhole leak or as major as a fully involved baghouse fire. In some cases, local air pollution regulations or federal hazardous waste laws may require estimation of the total quantity of particulate matter released to the environment as a result of such failures. In this paper, a technique is presented for computing the dust loading in the baghouse exhaust when one or more bags have failed. The algorithm developed is shown to be an improvement over a previously published result, which requires empirical knowledge of the variation in baghouse pressure differential with bag failures. An example calculation is presented for a bag-house equipped with 200 bags. The prediction shows that a small percentage of failed bags can cause a relatively large proportion of the gas flow to bypass the active bags, which, in turn, leads to high outlet dust loading and low overall collection efficiency from the baghouse.

Analytical model for residual stresses in polymeric containers during cryogenic storage of hematopoietic stem cells

Hematopoietic stem cell (HSC) therapy can significantly lower instances of infection in chemotherapy patients by accelerating the recovery of white blood cells in the body. However, therapy requires that HSCs be stored at cryogenic temperatures to retain the cells’ ability to proliferate. Currently, cells are stored in polymeric blood bags that are subject to fracture at the extremely low storage temperatures, which leads to cell contamination, thereby reducing their effectiveness. Therefore, we have developed an analytical model to predict the accumulation of stresses that ultimately lead to crack initiation and bag fracture during cryogenic storage. Our model gives explicit relationships between stress state in the container and thermoelastic properties of the container material, container geometry, and environmental factors that include temperature of the system and pressure induced by excess gas evolving from the stored medium. Predictions based on the model are consistent with experimental observations of bag failures that occurred during cryogenic storage applications. Finally, the model can provide guidance in material selection and bag design to fabricate bags that will be less susceptible to fracture.

Cryopreservation of hematopoietic and non-hematopoietic stem cells

Recent studies illustrate the potential for improving the cryopreservation of stem cells. Reduced DMSO concentrations in the cryopreservation medium, post thaw washing of cells and increased cell concentration have been actively studied. Standardization of cell processing has led to the study of liquid storage prior to cryopreservation, validation of mechanical (uncontrolled rate freezing) freezing, and cryopreservation bag failure. Finally, the need for the systematic study and optimization of preservation processes has not been fulfilled. As the sources and applications of stem cells (hematopoietic and non-hematopoietic) continue to be developed, the need for effective preservation methods will only grow.

Effect of Flow Distributors on Uniformity of Velocity Profile in a Baghouse

In recent years, the utility industry has turned to bag-houses as an alternative technology for particulate emission control from pulverized-coal–fired power plants. One of the more significant issues is to improve poor gas distribution that causes bag failures in baghouse operation. Bag failures during operation are almost impossible to prevent, but proper flow design can help in their prevention. This study investigated vertical velocity profiles below the bags in a baghouse (the hopper region) to determine whether flow could be improved with the installation of flow distributors in the hopper region. Three types of flow distributors were used to improve flow distribution and were compared with the original baghouse without flow distributors. Velocity profiles were measured by a hot-wire anemometer at an inlet velocity of 18 m/sec. Uniformity of flow distribution was calculated by the uniformity value U for the velocity profile of each flow distributor. Experimental results showed that the velocity profile of the empty configuration (without flow distributors) was poor because the uniformity value was 2.048. The uniformity values of type 1 (flow distributor with three vertical vanes), type 2 (flow distributor with one vertical and one inclined vane), and type 3 (flow distributor with two inclined vanes) configurations were reduced to 1.051, 0.617, and 0.526, respectively. These results indicate that the flow distributors designed in this study made significant improvements in the velocity profile of a baghouse, with the type 3 configuration having the best performance.

Catastrophic failures of freezing bags for cellular therapy products: description, cause, and consequences.

Container integrity is critical for maintaining sterility of cryopreserved cellular therapy products. We investigated a series of catastrophic bag failures, first noticed in early 2001. Process records were reviewed for all PBPC and lymphocyte products cryopreserved in bags from January 2000 through April 2002. Patient charts were also reviewed. One thousand two hundred and four bags were removed from storage for infusion to 261 patients. All products had been cryopreserved in Cryocyte poly(ethylene co-vinyl acetate) (EVA) bags in either 10% DMSO or 5% DMSO and 6% pentastarch. Product volumes were 25-75 mL, and bags were stored with overwrap bags in a liquid nitrogen tank. From January 2000 to April 2001, failure occurred in 10 of 599 (1.7%) bags. From May 2001 to April 2002, 58 of 605 (9.6%) bags failed, typically with extensive fractures that were visible before thaw. Of the 58 that failed, 24 were salvaged by aseptic methods and infused to patients under antibiotic coverage; 10 of those 24 (42%) had positive bacterial cultures. Bag failures were not related to product type, cryoprotectant solution, liquid versus vapor storage, or freezer location. Failures were linked to use of four Cryocyte bag lots manufactured in 2000 and 2001. After replacing these lots with a 1999 Cryocyte lot and with KryoSafe polyfluoroethylene polyfluoropropylene (FEP) bags, no more failures occurred in 75 and 102 bags, respectively, thawed through April 2002. High rates of bag failure were associated with four Cryocyte bag lots. No serious adverse patient effects occurred, but bag failures led to microbial contamination, increased product preparation time, increased antibiotic use, and increased resource expenditure to replace products.

Using sonic cleaning to improve dry scrubber operation

At Noranda Aluminum, implementation of sonic cleaning has allowed the company to improve the efficiency and reliability of its shaker dust collector operation. Using this method of bag cleaning permits the use of a more efficient bag fabric and eliminates bag failures caused by abrasion of the bag at the tube sheet thimble. Bag life has increased substantially as has the efficiency of the scrubber operation. Time requirements for production personnel have been reduced as constant cleaning of the tube sheets has been eliminated. This system has become stable and reliable.

Baghouse on a Glass Furnace Provides Lesson in Filter Bag Specification

This paper, directed toward Individuals who specify filter bags for industrial dust collectors, is a case history illustrating the need for a complete bag specification. The case history documents Owens- Corning Fiberglas' solution to a glass bag failure that occurred during the start-up of a new baghouse on a gas fired glass furnace. Based on the chemical and physical testing described in this paper, the conclusion was reached that the early problems were due to a lack of process understanding and attention to the bag specification. The process has operated satisfactorily with the respecified glass bag.

Results of a Baghouse Operation and Maintenance Survey on Industry and Utility Coal-Fired Boilers

In 1979, the results of an operation and maintenance fabric filter survey conducted by APAC were presented. In view of the potential usefulness of such information, Manhattan college was requested by APAC to follow up the initial survey with another improved version. To maximize the usefulness and insure a greater degree of validity to the conclusions, it was decided to limit the participants to users of coal-fired boilers only. A more comprehensive questionaire and one more suitable to computer interpretation than that used in the first study was developed and employed. In this paper, the results of an analysis of these data are presented. Some of the conclusions and opinions of the authors include: (1) Bag life may well be greater than the 2-3 yr reported in the literature, a fact that could reduce projected operating costs for proposed units. (2) Abrasion/erosion difficulties, once a major factor for baghouse users, apparently has been resolved by the equipment manufacturers. (3) Compliance is not a problem with the baghouse. (4) Both utilities and industry would recommend a baghouse to control fly ash for other boilers. (5) O and M problems are more severe with pulse-jet than with reverse-air systems. (6) The threemore » most prevalent O and M problems appear to be higher than design pressure drop, bag failure, and the fly ash handling system.« less

Elk River Completes Second Year With Zero Bag Failures Reported

Elk River Completes Second Year With Zero Bag Failures Reported

Operating characteristics of a fabric filter on a peaking/cycling boiler without auxiliary preheat or reheat

A fabric filter has been on-line for one year on a coal-fired boiler that is primarily a peaking unit within the power schedule. For the first six months, Eastern Kentucky coal with 2.5% sulfur was the fuel source for 30% of the time, with low-sulfur Montana coal constituting the remaining fuel during the operation period. Bag life has been excellent with no bag failures reported to date, and the pressure drops have been low. There has never been an auxilliary heat source to preheat the fabric filter for start-up, nor to reheat the fabric filter when operating at reduced load with associated low back-end temperatures. Conclusions are that the filter cake formed does protect the bags from blinding at low load conditions, and a special acid-resistant finish applied to the glass fibers protects the bags when high-sulfur coal is burned at low temperatures. Overall, this installation provides an excellent data base for cycling service and high-sulfur coal usage with a fabric filter.

Effect of Bag Failure on Baghouse Outlet Loading

One of the most important considerations in baghouse operation is the effect of bag failure on outlet loading. This information would be Of use to equipment manufacturers, users, and regulatory officials. Unfortunately, little information is available in the literature on this aspect of baghouse performance. Equations describing changes in outlet loading resulting from the sudden rupture of one or more bags are developed from first principles. Calculated results from these equations are presented in the form of a chart which can very quickly and simply be used to obtain a numerical value for a revised outlet loading resulting from bag failure(s) for a variety of system conditions. Due to an assumption made in the derivation, the new outlet loading thus obtained represents the maximum increase (worst case conditions) to be expected from the rupture of one or more bags. The following variables are included in the analysis: inlet loading, outlet loading (prior to bag failure), number of bag failures, bag diameter, system pressure drop; and gas temperature.

New high‐speed tensile tester for polymer films

AbstractDesign characteristics are described of a rotating‐wheel tensile tester suitable for stressing a vertical specimen with a force of 115 kg. through a distance of 15 cm. in a velocity range of 10 to 730 m./min. with no more than 1% loss in velocity, thereby assuring constant speed of grip separation. Provision is made for specimens up to 7.5 cm. width in order to achieve multiaxial distributions of stresses which are important in bag failure and leading to the determination of critical strain rates. Instrumentation provides reliable triggering of stress and strain traces on a double‐beam oscilloscope. Straight‐line travel of the moveable specimen grip is assured by the use of tracks which restrain horizontal motions without hindering the desired vertical motion.

331. Mutual diffusion of pairs of rare gases at different temperatures: B. N. Srivastova and K. P. Srivastova, J. Chem. Phys.30, 984–990, April 1959

Container integrity is critical for maintaining sterility of cryopreserved cellular therapy products. We investigated a series of catastrophic bag failures, first noticed in early 2001.Process records were reviewed for all PBPC and lymphocyte products cryopreserved in bags from January 2000 through April 2002. Patient charts were also reviewed.One thousand two hundred and four bags were removed from storage for infusion to 261 patients. All products had been cryopreserved in Cryocyte poly(ethylene co-vinyl acetate) (EVA) bags in either 10% DMSO or 5% DMSO and 6% pentastarch. Product volumes were 25–75 mL, and bags were stored with overwrap bags in a liquid nitrogen tank. From January 2000 to April 2001, failure occurred in 10 of 599 (1.7%) bags. From May 2001 to April 2002, 58 of 605 (9.6%) bags failed, typically with extensive fractures that were visible before thaw. Of the 58 that failed, 24 were salvaged by aseptic methods and infused to patients under antibiotic coverage; 10 of those 24 (42%) had positive bacterial cultures. Bag failures were not related to product type, cryoprotectant solution, liquid versus vapor storage, or freezer location. Failures were linked to use of four Cryocyte bag lots manufactured in 2000 and 2001. After replacing these lots with a 1999 Cryocyte lot and with KryoSafe polyfluoroethylene polyfluoropropylene (FEP) bags, no more failures occurred in 75 and 102 bags, respectively, thawed through April 2002.High rates of bag failure were associated with four Cryocyte bag lots. No serious adverse patient effects occurred, but bag failures led to microbial contamination, increased product preparation time, increased antibiotic use, and increased resource expenditure to replace products.