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Nonaccidental head injury, as seen in domestic child abuse cases, is often associated with spinal injury, and spinal subdural hematoma is the most frequent diagnosis. While spinal epidural hematomas are a rare occurrence, the incidence of spontaneous epidural hematomas occurring in nonaccidental head injury patients is even lower. Epidural hematomas often result in acute focal neurological deficits necessitating emergent neurosurgical intervention. In patients without focal neurological deficits, conservative management may allow for spontaneous resolution of the epidural hematoma. The authors present the case of a 2-year-old boy with a large spinal epidural hematoma resulting after an event of nonaccidental injury, specifically, domestic child abuse. This patient exhibited no focal neurological deficits and was managed conservatively without surgical clot evacuation. On a follow-up visit, repeat imaging studies demonstrated a stable resolution of spinal epidural hematoma, providing further support for the safety of conservative management in these patients.

The MicroBlower Sustainable Soil Vapor Extraction System is a cost-effective device specifically designed for remediation of organic compounds in the vadose zone. The system is applicable for remediating sites with low levels of contamination and for transitioning sites from active source technologies such as active soil vapor extraction to natural attenuation. It can also be a better choice for remediating small source zones that are often found in “tight zones” that are controlled by diffusion rate. The MicroBlower was developed by the Savannah River National Laboratory at the US Department of Energy's Savannah River Site to address residual volatile organic compound (VOC) contamination after shutdown of active soil vapor extraction systems. In addition, the system has been deployed to control recalcitrant sources that are controlled by diffusion rates. © 2012 Wiley Periodicals, Inc.

Fire protection of pressure vessels for transport and storage of dangerous goods is an active topic of research around the world. In many cases, organizations are conducting theoretical analysis followed by fire testing of thermal protection systems to determine how long they delay thermally induced failure, or if they eliminate failure. In most recent cases the organizations chose to do small scale fire testing because of the obvious cost savings. The question then is – are small scale experiments representative of highway tank truck and rail tank car scales? This paper discusses the scale issues involved. It goes on to show how identical fire heating conditions can give dramatically different failure times and modes of failure for small and large scale tanks if the conditions are not truly similar.

Laser transmission welding, a technique to join thermoplastic components, involves a laser beam passing through a laser-transmitting part being absorbed by a laser-absorbing part at the weld interface. The heat generated at the interface melts a thin layer of the plastic in both parts and forms a joint. Laser-absorbing agents such as dyes or soot particles are added to the laser-absorbing part to make it absorbing to the laser beam. Thermal and optical interaction of the soot particles and polymer with laser beam determines heating, melting, and, consequently, welding of plastics. To form a strong bond, it is important that the weld interface be exposed to sufficient heat to melt the polymer without degrading it. This paper investigates the thermal response of soot particles to a diode laser heat source. A thermal model is presented herein for a soot particle that is surrounded by a semicrystalline material (PA6) and solved using finite volume technique. The results are then compared to the ones obtained from a finite element analysis solved with a commercial software (ANSYS®). The microscale model predictions for the peak temperature of the soot particle appear to be reasonable when compared with the results of the macroscale finite element models for the same process parameters and set up developed in the previous work of the authors.

While laser beam profiling techniques are available for the measurement of a laser beam power profile, such techniques are difficult or impossible to use in order to characterize the power profile of the beam which has passed through the light-scattering semi-crystalline polymer (such as nylon). This paper presents a technique for measuring the scattering of the laser beam caused by the laser-transparent part in laser transmission welding. The technique is easy to implement and does not require specialized or expensive equipment. It relies on measurements of line widths for a sequence of lines left on the polymer surface by a rapidly moving laser beam at progressively increasing powers. The line width and power information is then used to obtain the distribution of the laser energy across the weld line. An application for a case of a high-power diode laser and (glass-reinforced and natural) polyamide 6 is presented.

Laser transmission welding (LTW), a technique to join thermoplastic components, involves a laser beam passing through a laser-transmitting part and then being absorbed by the laser-absorbing part at the weld interface. To form a strong bond, it is important that the weld interface be exposed to sufficient heat to melt the polymer without degrading it. A lap-joint geometry was investigated and the interaction between a stationary laser beam and the plastic was observed using a thermal imaging camera. Several coatings on the surface observed by the camera were evaluated. Time histories and temperature distribution on the sample surface transverse to the joint interface were obtained. Soot-coated surface was found to heat up in response to the scattered laser light, providing means for estimation of the scattered light intensity. The LTW welding process was modeled in three dimensions using a commercial finite element solver. This thermal model addresses the heating and cooling stages in a laser welding process in detail, including the effects of laser beam profile and laser beam scattering in a semicrystalline material. The model matched well the temperature distributions obtained by thermal imaging observations on the laser-absorbing part.

The objective of this work was to determine if the Kachanov one-state variable continuum damage mechanics technique and the MPC omega method could accurately model SA 455 steel’s high-temperature creep behaviour. The steps required for extracting needed material constants from the creep rupture experimental data were presented. Uniaxial finite element analyses were performed using the material constants found for each of the two creep damage techniques. The results of the analyses were carefully compared with the experimental data to show that both CDM and MPC Omega techniques can accurately predict SA 455 steel’s high-temperature creep behaviour. Analyses were performed using commercial finite element analysis computer codes, ABAQUS and ANSYS. It was found that both creep damage techniques were able to accurately predict failure time but that the MPC Omega method was more accurate at predicting creep failure strain.

Experiments have shown that pressure vessels made of ASME SA 455 steel can fail by high-temperature stress rupture in less than 100 min when exposed to accidental fire heat loads. The objective of this work is to develop a three dimensional finite element analysis (FEA) model capable of predicting structural failure in pressure vessels to assess the effects that various parameters have on vessel failure. These parameters included wall thickness, vessel dimensions, wall temperature and vessel internal pressure. Also, the effect of local hot spots on failure time was investigated. The finite element analyses were conducted on 500, 1000 and 33,000 US gallon pressure vessels using ABAQUS. From the results of the three dimensional finite element analyses it was found that shorter and/or thicker walled (with respect to vessel diameter) pressure vessels have greater fire survivability then longer and/or thinner walled pressure vessels. It was also found that if peak wall temperature and internal pressure were the same, pressure vessels exposed to fully engulfing fires would fail sooner than pressure vessels exposed to a local fire impingement. Also, it was shown that the MPC Omega method could be used to predict fast stress ruptures.

Recent years have seen wider application of laser transmission welding (LTW) as a means for joining plastic parts. This paper presents a three-dimensional (3D) transient thermal model of LTW solved...

Vascular endothelial growth factor (VEGF) is a key molecule that orchestrates the formation and function of vascular networks. Impaired regulation of angiogenesis is implicated in a number of pathologic states. For instance, neoplasias exhibit uncontrolled angiogenesis, whereas ischemia and states of vascular insufficiency involve reduced VEGF activity. As the role of VEGF has been elucidated in these disease processes, its therapeutic role has been developed. The Food and Drug Administration has approved several anti-VEGF agents for treating colorectal, lung, and kidney cancer. VEGF-inducing agents have also been used experimentally to induce angiogenesis in patients with critical limb ischemia. As more knowledge is gathered about the biology of VEGF and its receptors, there is greater promise for therapeutic modulation of VEGF expression. The purpose of this review is to describe the various therapeutic and biologic factors that regulate the expression of VEGF.

For over three decades, products made from expanded aluminum have been available for explosion suppression in fuel tanks and containers. You can find various products on the internet with names like Explosafe, Deto-Stop, Ex-Co or Explo Control, No-Ex, EM2, and others. It appears that Explosafe was the first product to appear in the late 1970s. The expanded aluminum consists of thin aluminum foil that is sliced, stretched and stacked or rolled to produce a highly porous matrix of low-density expanded aluminum. This matrix can be inserted into a fuel tank and it only takes up 1–3% of the tank volume. The matrix has been shown to dramatically reduce overpressures generated by ignition of fuel–air mixtures in a closed space if the closed space is nearly 100% filled with the matrix. The matrix has also been promoted as having other beneficial properties that reduce slosh pressures in dropped fuel tanks, suppression of algae growth, enhanced discharge of static electricity, corrosion protection for steel fuel tanks, and some state it reduces the risk of a BLEVE (boiling liquid expanding vapor explosion) in pressure liquefied gas tanks and pressure vessels. This paper reviews the history of some of these products and presents a summary of the testing that has been performed to prove some of the benefits. It also includes some limited installation experience that shows some of the penalties associated with the products.

The great number of hip revision arthroplasties and the cementless fixation of arthroplasties has led to more and cementless hip revision operations with bone transplantation. This retrospective study shows the results of a clinical and radiological follow-up of 34 patients with an average age of 71 years and 4 months at their hip revision arthroplasty. The subjective and clinical result in the Harris-Hip-Score 3 years and 9 months (1 year 4 months-6 years 3 months) after surgery shows 67% of the patients content with the result of the revision arthroplasty. The Harris-Hip-Score shows an average of 41.1 points preoperatively and 73.2 points at the follow-up examination. The loosening-rate was 11.8%, all arthroplasties which seemed loosened radiologically had also a bad result clinically. No correlation could be shown between the age of the patients and the clinical results as well as between an additional stem revision (15 patients) and the clinical result in the Harris-Hip-Score. All revision operations were done with bone transplantation and demonstrate, that the concept of cementless fixation of acetabular component gives satisfactory results.

198 Phonoarthrographic examinations of the knee joint are reported on. An analysis was then carried out on the noise in knee joints with clinically and operatively demonstrated gonarthritis, chondromalacia of the patella, meniscus lesion and complex ligament injuries of the knee joint. Our results show that statistically, due to the division of the noise peaks into frequency groups, the four examined conditions could be separately identified. A practical use is possible now, in diagnosis as well as in examining the progress in knee joint disease. The representation of pathological-anatomical changes by phonoarthrograhy allows the effectiveness of therapeutical measures to be checked. This simple painless examination method provides an additional aid to diagnosis.

Fire exposure of pressurized tanks may lead to their catastrophic rupture due to internal pressure build-up and reduction of allowable stress of the metallic shell due to temperature increase. Hence, the assessment of the thermal behavior of pressurized equipment exposed to fires is a critical issue to prevent the escalation of accident scenarios in the process industry. The present study was aimed at comparing two modeling approaches for the assessment of the heat transfer in pressurized vessels exposed to fire. In particular, two simplified lumped models based on thermal nodes were compared with a CFD (computational fluid dynamics) model implemented on ANSYS FLUENT. The models were aimed at reproducing the initial phase of the vessel heat-up, before the opening of the pressure relief valve (PRV). The models were applied to case studies of industrial interest in order to assess the expected internal pressure build-up in different fire scenarios. The comparison among model results confirmed the importance of the use of advanced simulation tools for a more precise assessment of failure conditions of vessels engulfed in fires.

MIPAS on ENVISAT performed almost continuously measurements of the atmospheric composition for almost 10 years, from June 2002 to April 2012. These ten years cover a period when the first effect of the dismiss of the emission of the CFCs after the Montreal protocol ratification in 1987can be measured. Even if ten years constitute a short period to derive trends, it has been proven that useful information on time variation of atmospheric constituents can be derived from the analysis of these measurements. However, previous versions of MIPAS on ENVISAT dataset were characterized by an instrumental drift due to the fact that some detectors used by MIPAS were affected by non-linearities, which change with time due to the ageing of the detectors and this was cause of a non negligible systematic error in the trend estimation. The new full mission reprocessed dataset V7 that will be released very soon uses L1 files where the impact of the ageing of the detectors on non-linearities has been corrected. Furthermore, also the L2 processor has been upgraded with new functionalities improving the performances of the processor. We present the results of study of trends derived from the analysis of the new MIPAS V7 products on several MIPAS target species including ozone depleting species, like CFC-11, CFC-12, CCl4 and HCFC-22.

The measured blast overpressures from recent tests involving boiling liquid expanding vapour explosions (BLEVE) has been studied. The blast data came from tests where 0.4 and 2 m 3 ASME code propane tanks were exposed to torch and pool fires. In total almost 60 tanks were tested, and of these nearly 20 resulted in catastrophic failures and BLEVEs. Both single and two-step BLEVEs were observed in these tests. This paper presents an analysis of the blast overpressures created by these BLEVEs. In addition, the blast overpressures from a recent full scale fire test of a rail tank car is included in the analysis. The results suggest that the liquid energy content did not contribute to the shock overpressures in the near or far field. The liquid flashing and expansion does produce a local overpressure by dynamic pressure effects but it does not appear to produce a shock wave. The shock overpressures could be estimated from the vapour energy alone for all the tests considered. This was true for liquid temperatures at failure that were below, at and above the atmospheric superheat limit for propane. Data suggests that the two step type BLEVE produces the strongest overpressure. The authors give their ideas for this observation. The results shown here add some limited evidence to support previous researchers claims that the liquid flashing process is too slow to generate a shock. It suggests that liquid temperatures at or above the Tsl do not change this. The expansion of the flashing liquid contributes to other hazards such as projectiles, and close in dynamic pressure effects. Of course BLEVE releases in enclosed spaces such as tunnels or buildings have different hazards.

Laser transmission welding (LTW) is a relatively new technology for joining plastic parts. This paper presents a three-dimensional (3D) transient thermal model of LTW solved with the finite element method. A lap-joint geometry was modeled for unreinforced polyamide (PA) 6 specimens. This thermal model addressed the heating and cooling stages in a laser welding process with a stationary laser beam. This paper compares the temperature distribution of a lap-joint geometry exposed to a stationary diode laser beam, obtained from 3D thermal modeling with thermal imaging observations. It is shown that the thermal model is capable of accurately predicting the temperature distribution when laser beam scattering during transmission through the polymer is included in the model. The weld dimensions obtained from the model have been compared with the experimental data and are in good agreement.

This paper presents a three-dimensional (3-D) transient thermal model of spot Laser Transmission Welding (LTW) solved with the finite element method (FEM). Unreinforced nylon 6 temperature-dependant properties were employed for a lap joint geometry. The heating and cooling stages in a spot laser welding process were addressed. The spot weld dimensions obtained from the model were compared with the experimental weld dimension data, and were in good agreement. It is shown that the thermal model is capable of accurately predicting the temperature distribution.

The number of peripheral nerve stimulation (PNS) indications, targets, and devices is expanding, yet the development of the technology has been slow because many devices used for PNS do not have formal regulatory approval. Manufacturers have not sought Food and Drug Administration (FDA) approval for PNS devices because of a perceived lack of interest amongst practitioners and patients. Without FDA approval, companies cannot invest in marketing to educate the implanters and the patients about the benefits of PNS in the treatment of chronic pain. Violation of this has resulted in governmental investigation and prosecution. Most of the PNS devices currently used to treat chronic pain are FDA approved for epidural spinal cord stimulation. Many of the complications seen in PNS surgery can be attributed to the lack of purpose-built hardware with FDA approval. Despite the lack of regulatory approval, there are insurance companies that approve PNS procedures when deemed medically necessary. As the targets and indications for PNS continue to expand, there will be an even greater need for customized technological solutions. It is up to the medical device industry to invest in the design and marketing of PNS technology and seek out FDA approval. Market forces will continue to push PNS into the mainstream and physicians will increasingly have the choice to implant devices specifically designed and approved to treat chronic peripheral nerve pain.

The number of peripheral nerve stimulation (PNS) indications, targets, and devices is expanding, yet the development of the technology has been slow because many devices used for PNS do not have formal regulatory approval. Manufacturers have not sought Food and Drug Administration (FDA) approval for PNS devices because of a perceived lack of interest amongst practitioners and patients. Without FDA approval, companies cannot invest in marketing to educate the implanters and the patients about the benefits of PNS in the treatment of chronic pain. Violation of this has resulted in governmental investigation and prosecution. Most of the PNS devices currently used to treat chronic pain are FDA approved for epidural spinal cord stimulation. Many of the complications seen in PNS surgery can be attributed to the lack of purpose-built hardware with FDA approval. Despite the lack of regulatory approval, there are insurance companies that approve PNS procedures when deemed medically necessary. As the targets and indications for PNS continue to expand, there will be an even greater need for customized technological solutions. It is up to the medical device industry to invest in the design and marketing of PNS technology and seek out FDA approval. Market forces will continue to push PNS into the mainstream and physicians will increasingly have the choice to implant devices specifically designed and approved to treat chronic peripheral nerve pain.

Square tabs were placed on the base of an ellipsoidal center-body (CB) in short annular diffusers. Tests were conducted in subsonic swirling flow with an inlet Reynolds number of 1 × 105. The tabs, with a projected height equivalent to the boundary layer thickness, reduced the outlet distortion and incurred a pressure penalty in the three smaller diffusers whose designs were not expected to stall. The largest area ratio (AR = 6.18) diffuser improved back pressure coefficient 4.6% with four tabs that blocked 4.7% of the inlet cross section over its bare diffuser but was 42% lower than that obtained by the AR = 2.73 diffuser with no tabs. Computational fluid dynamics (CFD) was useful for capturing relevant flow features that corroborated with experimental data and literature. Tabs oriented normal to the diffuser axis were less effective at influencing the flow as swirl angle increased but similar elongated wakes oriented with the flow direction were observed at all simulated swirl angles. The CFD either predicted equivalent performance due to the over-prediction associated with diffusion equaling the under-prediction associated with vorticity or over-predicted performance.

Peristomal skin lesions are frequent complications of ostomy; however, there is no generally accepted nomenclature and classification system.An interdisciplinary German expert panel (GESS) composed of ten members, developed an innovative semiquantitative classification system for peristomal skin lesions for further stratification of ostomy therapy. This score is based on criteria which can be assessed by stomal therapists and treating physicians.The new peristomal skin lesion score grades three categories: lesion (L), status of ostomy (S) and disease (D). The L category describes the integrity of the skin as normal (L0), lesion with sustained integrity of skin (L1), integrity destroyed (L2) and local infection (L3). The S category rates the complexity of ostomy therapy as normal (S0), increased (S1) and high but not sufficiently effective (S2). The additional letters for categorization O. R. P. H. E. US describe anatomical pathologies of the stoma itself: ostomy stenosis (O), retraction (R), prolapse (P), hernia (H), edema (E) and unfavorable site (US). A systemic disorder is either absent (D0), irrelevant (D1) or relevant (D2). The LSD score is the basis for a management algorithm.The LSD score is comprehensive, standardized and holistic. Its straightforward use by health professionals can improve the consistency of the description of skin lesions and enhance the quality of ostomy therapy.

Ring vanes were recognized as being beneficial for increasing pressure recovery and reducing stall in wide-angled diffusers. Augmentation devices can also reduce swirl-induced flow distortion. A three-point ring vane was inserted into a short annular diffuser with a length-to-inlet-height ratio of 14.5 and area ratio of 4. Numerical optimization studies were completed using the realizable k-e turbulence model at zero and 12 deg inlet swirl that established a preferential location of the ring vane leading edge. Parametric computational fluid dynamics studies evaluated the influence of the dominant variables — overall length and angle — at 0 to 12 deg inlet swirl. Performance was dependent on the ability of the ring vane to reduce outer wall stall without swirl or the central toroidal recirculation zone with swirl and the ring vane wake. Shorter vanes angled towards the centre reduced back pressure with no swirl whereas longer outward-angled vanes were preferred with 12 deg swirl.Copyright © 2015 by ASME

A set of numerical simulations were performed on an asymmetric, two dimensional diffuser using ANSYS Fluent 14.0, a commercially available RANS based CFD code. The Display Formulaν′2¯-f turbulence model, which has previously been shown to be a good model for this geometry, was implemented through a user defined function, and the influence of inlet boundary conditions was evaluated. It was shown that the inlet velocity and turbulence profiles had a significant effect on the calculated performance of the diffuser, especially in terms of the onset of diffuser stall. It was shown that when the boundary conditions were set appropriately, excellent agreement with LES and experimental data was obtained.Copyright © 2015 by ASME

The current paper presents a cold flow simulation study of a low Mach number air-air ejector with a four ring entraining diffuser that is used in a variety of applications including infrared (IR) suppression of exhaust from helicopters and fixed wing aircraft. The main objectives of this investigation were to identify key issues that must be addressed in successful CFD modelling of such devices, and recognize opportunities to improve the performance of these devices. Two-dimensional CFD simulations were carried out using commercial software, Ansys14. Studies of mesh and domain size sensitivity were made to ensure the CFD results were independent of both factors. A turbulence model independence study using k-ε, k-ω and RSM turbulence models was performed to figure out the appropriate turbulence model that produced the best agreement with the experimental data for several of ejector performance criteria. The measured flow properties in the annulus were used as input boundary conditions for the CFD simulations. However, in the comprehensive turbulence model study, the measured flow parameters at the nozzle exit were also applied as inlet boundary conditions for the CFD simulations. The measured flow velocity at the nozzle exit, at one centerline section inside the mixing tube and at the diffuser exit and the system pressure recovery were compared with the CFD predictions. The ejector pumping ratios, back pressure coefficient and diffuser gap velocities were also compared. It was found that the RANS-based CFD predictions were sensitive to the changes in the ejector domain size, mesh refinement and inlet boundary condition locations. With the annulus inlet boundary conditions, the tested turbulence models under predicted the size of the core separation downstream of the system, back pressure, pumping ratio and pressure recovery in the mixing tube and diffuser. However, the ability of the RNG turbulence model to predict the ejector performance parameters was better than that of the other turbulence models at all inlet flow conditions. Nevertheless, applying the inlet boundary conditions at the nozzle exit enhanced the capability of the RANS-based turbulence model particularly in predicting the ejector pumping ratios, pressure recovery and the size of the core separation. Finally, the acceptable agreement between the experimental data and the CFD predictions provides a valid tool to continue improving these devices using CFD techniques.

The flow and heat transfer inside a short airfoil shaped turbine exhaust strut was studied experimentally and computationally. A combination of transient and steady IR thermographic techniques were used to measure the heat transfer, and showed that the streamwise evolution of the heat transfer could be reliably described using a power law type relationship. Steady RANS CFD using the realizable k-epsilon was unable to accurately predict the observed heat transfer, with the main limitations of the model being a) a fundamental inability to calculate secondary flows and b) an underestimation of the restriction on boundary layer growth rates imposed by the opposing walls. The experiments showed that heat transfer rates were much higher in thinner regions of the strut, and lower in thicker regions. The CFD predicted an essentially uniform heat transfer rate, independent of the local strut thickness.Copyright © 2015 by ASME

International audience; BLEVE Blast wave Overpressure Modeling Moving shock Stationary shock a b s t r a c t The overpressure produced by the boiling liquid expanding vapor explosion (BLEVE) is still not well understood. Various methods have been published on the overpressure modeling in the far field. They mostly differ by the modeling of the expansion energy, used to scale the distance to the source where the overpressure needs to be calculated. But these methods usually include a experimentally fitted reduction factor, and are mostly overestimating the overpressures. Today there is a growing interest in modeling the BLEVE overpressure in the near field, for studying the blast effect on critical infrastructure such as bridges and buildings. This requires a much better understanding of the BLEVE blast. This paper goes deeper in the understanding of the physical phenomenon leading to the BLEVE blast wave generation and propagation. First, mid-scale BLEVE experiments in addition to new experimental data for near field blast from a small scale supercritical BLEVE are analyzed. And second, an analysis method of the shocks observed in the experiments is presented based on fundamental gas dynamics, and allows the elaboration of a new modeling approach for BLEVE overpressure, based on the calculation of the initial overpressure and radius of the blast.

Given the frequent incidences of Non-Accident Releases (NARs) of hazardous materials from tank cars, there in an increasing interest in transporting hazardous materials in total containment conditions (i.e., no pressure relief devices). However, the ability of tank cars to meet thermal protection requirements provided in the Code of Federal Regulations under conditions of total containment has not been established. Also, the modeling tool commonly used by industry to evaluate thermal protection, AFFTAC, has not been validated under these conditions. The intent of this effort was to evaluate through a series of third-scale fire tests, the ability of tank cars to meet the thermal protection requirements under total containment conditions, and also, to validate AFFTAC for such conditions. This paper describes the test design and planning effort associated with this research, including the design and evaluation of a fire test setup to simulate a credible, fully engulfing, pool fire that is consistent and repeatable, and the design and hydro-static testing of a third-scale tank specimen. The fire design includes controls on the spatial distribution and temperature variation of the flame temperature, the heat flux, and the radiative balance, to best reflect large liquid hydrocarbon pool fire conditions that may be experienced during derailment scenarios.

This paper describes the results from a series of fire tests that were carried out to measure the effect of defects in thermal protection systems on fire engulfed propane pressure vessels. In North America thermal protection is used to protect dangerous goods rail tank-cars from accidental fire impingement. They are designed so that a tank-car will not rupture for 100 min in a defined engulfing fire, or 30 min in a defined torching fire. One common system includes a 13 mm blanket of high-temperature ceramic fibre thermal insulation covered with a 3 mm steel jacket. Recent inspections have shown that some tanks have significant defects in these thermal protection systems. This work was done to establish what levels of defect are acceptable from a safety standpoint. The tests were conducted using 1890 l (500 US gallon) ASME code propane pressure vessels (commonly called tanks in the propane industry). The defects tested covered ∼8% and 15% of the tank surface. The tanks were 25% engulfed in a fire that simulated a hydrocarbon pool fire with an effective blackbody temperature of ∼870 °C. The fire testing showed that even relatively small defects can result in tank rupture if the defect area is engulfed in a severe fire, and the defect area is not wetted by liquid from the inside. A wall failure prediction technique based on uniaxial high-temperature stress rupture test data has been developed and agrees well with the observed failure times.

This paper presents detailed data on the thermal response of two 500 gal ASME code propane tanks that were 25% engulfed in a hydrocarbon fire. These tests were done as part of an overall test programme to study thermal protection systems for propane-filled railway tank-cars. The fire was generated using an array of 25 liquid propane-fuelled burners. This provided a luminous fire that engulfed 25% of the tank surface on one side. The intent of these tests was to model a severe partially engulfing fire situation. The paper presents data on the tank wall and lading temperatures and tank internal pressure. In the first test the wind reduced the fire heating and resulted in a late failure of the tank at 46 min. This tank failed catastrophically with a powerful boiling liquid expanding vapour explosion (BLEVE). In the other test, the fire heating was very severe and steady and this tank failed very quickly in 8 min as a finite rupture with massive two-phase jet release. The reasons for these different outcomes are discussed. The different failures provide a range of realistic outcomes for the subject tank and fire condition.

This paper contains tension and stress-rupture test data on sample railroad tank-car steels at room temperature and temperatures between 500 and 720 °C. The paper describes the test facility, applicable standards, and procedures that were followed during the tests of tension and stress rupture. The paper also contains a simple correlation for the data and gives examples of how it can be used to predict tank failure times when exposed to fire heating. The stress-rupture testing was conducted at constant load (tensile force) conditions. A sample was heated to a specified temperature and the load was applied. The time to failure was then recorded. This testing was needed due to a general lack of available data for the high-temperature stress rupture of tank-car steels. These data are needed for the purposes of predicting tank failure when tank-cars are exposed to heating by fire. The steel samples were obtained from a recent train derailment in Ontario, Canada, and the steel samples included both new and older steels. Samples were cut in both the hoop and longitudinal directions to see if the stress-rupture properties were isotropic. Excellent data were obtained with very little data scatter in each sample. The results show that stress-rupture properties vary from sample to sample. Some older steels were as good as new steels, and some were not. However, all samples were nearly isotropic when it came to high-temperature stress rupture.

Recent years have seen wider application of laser transmission welding (LTW) as a means for joining of plastic components. Advantages of LTW arise from it being a contact-free method for delivering precisely controlled energy to the surfaces of the welded components and from flexibility with regard to welding geometry afforded by the laser being under computer control. LTW involves a laser beam passing through a laser-transparent component being absorbed by the laser-absorbent component at the weld interface. Heat generated at the interface melts a thin layer of plastic in both components and thus forms a joint through molecular interdiffusion. To form a strong bond, it is important that the weld interface is exposed to sufficient heat to melt the polymer without degrading it. Delivery of the thermal energy by the laser beam is affected by process parameters, such as laser power, scan speed, beam spot size, and material properties, such as absorptivity, presence of reinforcements, and other additives. Dev...

A series of fire tests were conducted on nine, 1.8m3(500USgal) ASME code propane pressure vessels to study the significance of pressure relief valve behavior on tank survivability to fire impingement. In these tests three tanks ruptured (i.e., finite failure) and six boiling liquid expanding vapor explosion (BLEVEd) (total loss of containment). The difference between the BLEVE and non-BLEVE failures was due to a difference in the fire conditions. It is believed that these tests show some insight into the BLEVE process. In all tests the fire consisted of an array of nominal 590kW(2MBTU∕h) liquid propane burners. A pool fire was not used because of the uncontrolled nature of open pool fires. It was believed that very repeatable fire conditions could be achieved by using a series of burners. In the tests where the outcome was a non-BLEVE there were two burners mounted 30cm above the tank on the tank vapor space. These burners were used to weaken the steel and to initiate a failure. To heat the liquid, there were between 4 and 12 burners applied below the liquid level. When one burner was added on the vapor space, all of the remaining tanks BLEVEd. This was true over a range of fill levels (at failure) of between 10% and 50% by volume. It is believed this added burner was just enough to weaken the tank so that any initial rupture would grow towards a total loss of containment and BLEVE. This paper presents the details of this test series and shows how severely heated length and liquid energy affected the outcome.

This chapter describes the application of social network analysis to evaluate the knowledge capacity of a business initiative program at a government-owned national laboratory.

Many railway tank-cars carrying hazardous materials are thermally protected from fire impingement by thermal insulation and a steel jacket applied to the outside of the tank-car shell. Over time, it is possible that the thermal insulation will sag, rip, degrade, or be crushed under the steel jacket. A thermographic technique to determine whether or not a tank has insulation deficiencies has been developed, but it is necessary to determine which thermal deficiencies do not affect a tank’s survivability in a fire and which thermal deficiencies must be repaired. In order to develop a guideline in assessing thermal defects, a thermal model and experimental data would be beneficial. A series of fire tests were performed on a quarter-section tank-car mock-up to assist in developing a guideline and to provide validation data for a thermal model. Twelve fire tests, with constant, credible, simulated pool fire conditions, were performed on the tank-car mock-up with various insulation deficiencies. An infrared thermal imaging camera was used to measure the tank wall temperature. The thermal images were useful in determining the temperature profiles across the defects at different times and the transient temperature behaviour at different locations. It was seen that the properly installed thermal protection system significantly reduced the heat transfer from the fire to the tank wall. It was also seen that the steel jacket alone (i.e. 100% defect) acted as a radiation shield and provided a significant level of protection. With small defects, it was observed that the surrounding protected material provided a cooling effect by thermal conduction. A square defect greater than about 40 cm on each side should be considered significant, because unlike smaller defects, there is little benefit from the surrounding material as far as the peak defect temperature is concerned.

All pressure cylinders in North America used for liquefied petroleum gases (LPG) must meet the standards set by the Compressed Gas Association (CGA), regardless of whether they are made of steel or aluminum. However, there is anecdotal evidence from accidents that suggests that an aluminum propane cylinder is much more likely to fail than a steel one when exposed to fire in an accident. In order to test and quantify this, a series of fire tests were performed on standard 33.5 lb (DOT 4E240) propane cylinders. Three aluminum cylinders and three steel cylinders were tested under three different fire conditions, covering a range of fire engulfment severity. In all cases, the cylinders were horizontal and the fire was directed onto the side and top of the cylinders. In matching tests, all 3 aluminum cylinders failed in less than 10 minutes, including one boiling liquid expanding vapor explosion (BLEVE), while all 3 steel cylinders did not fail even after more than 40 minutes in the fire. This paper presents the results and an analysis of the fire test data.

International human rights law provides a comprehensive framework for the protection of persons in detention, notably by means of the absolute prohibition of torture and other forms of ill-treatment and the right to respect for human dignity. Furthermore, this law offers a wide set of safeguards, including the right to an effective remedy and fair trial guarantees. Nevertheless, there is a considerable gap between human rights norms and their practical implementation. By widening the knowledge on human rights norms and mechanisms, it is to be hoped that there will be a concurrent advancement of the protection and promotion of the rights of persons in detention, to ensure a dignified existence for those too often forgotten by society and their reintegration into society after their release.

Recent studies have shown that the hazards associated with loss of containment and BLEVEs (boiling liquid expanding vapor explosions) are strongly tied to the energy stored in the liquid phase of a pressure vessel. This stored energy is affected by heat transfer with the surroundings (e.g., fire exposure) and pressure relief valve (PRV) action. Since it would be desirable to minimize this stored energy to reduce hazards, a study was initiated by Transport Canada and Queen’s University to quantify the effect of various PRV parameters on the thermal energy storage of a pressure vessel. A fully automated state-of-the-art test facility has been constructed to perform 2-phase blowdown tests using steam and water. This paper describes the Queen’s University/Transport Canada PRV Test Program and the test procedures and facilities used. It goes on to show some preliminary results from 2-phase testing currently underway to determine the optimal PRV operating characteristics from a hazard mitigation standpoint. The results of this study may be useful for standards-writing bodies to set experimentally determined optimal behavior criteria for PRVs and acceptable tolerances for deviation from this.

Neurosurgical treatment for chronic abdominal pain ranges from destructive spinal cord lesioning to ablate the ascending pain pathways to nondestructive therapies with the use of opioid pumps and electrical stimulation. Existence of unwanted side effects, socioeconomic factors, and the cost of long-term treatment, sometimes make opioid and neurostimulation therapies not feasible for the management of such pain. Consequently, destructive neurosurgical interventions may become the best option to manage chronic and malignant abdominal pain refractory to other treatment modalities. Although destruction of the thalamic nuclei was frequently performed decades ago for treatment of intractable pain, this approach is rarely used today, mainly due to advancements made in the surgeon’s ability to create targeted lesions within the spinal cord. The targets of such therapy are the spinothalamic tracts in the ventral spinal cord as well as another ascending pain pathway located in the center and dorsal midline of the spinal cord. Both of these locations are easily accessible and extremely amenable to procedures such as anterolateral cordotomy, commissurotomy, and midline myelotomy. While considered the last resort for the management of intractable abdominal pain, neuroablative procedures provide permanent pain relief with minimal side effects and low morbidity to those patients who have otherwise run out of treatment options.

The objective of the current paper is to gain an understanding of the effects of inlet swirling flow on the flow field through short annular transition diffusers and nozzles. These devices are representative of the primary driving nozzles for certain exhaust ejector systems. It is known that strongly swirling flow can degrade ejector performance due to core separation. It is believed that minor changes in driving nozzle shape can improve ejector performance significantly. Two configurations of a diffuser/nozzle were tested experimentally and numerically under different swirl strengths. The two configurations were mounted on an annular flow wind tunnel. Two shapes of the annulus’ centre body end; square and elliptical, were used. Based on the hydraulic inlet diameter, average velocity and temperature in the annulus of the wind tunnel, the measurements were carried out at Mach range of 0.21 to 0.26 with Reynolds number of 2.3 to 2.7×105. Ansys14 was used for the CFD simulations. The measured velocity profiles in the annulus were used as input flow conditions in the CFD investigation. The RNG k-ε turbulence model was used in the CFD simulations. The measured velocity profiles at the device exit, and measured surface pressures on the annulus, duct and nozzle walls were compared with the CFD predictions. The measured back pressure coefficient and total pressure loss through the diffuser systems were compared with the CFD predictions. A reasonable agreement between the experimental data and numerical predictions was observed. It was found computationally that the size of the central recirculation zone behind the annulus centre body has negative effects on the diffuser performance under different swirl numbers. The square shape of the annulus’ centre body end increased the back pressure and total pressure loss coefficients over the elliptical shape. However, the flow uniformity at the duct and nozzle exits improved with the square shape over the elliptical end. These differences may have a significant effect on ejector pumping.

Square tabs were placed on the base of an ellipsoidal centre body in annular diffusers with length to inlet height of 12. Tests were completed with an inlet Reynolds number of 1 × 105, swirl number of 0.71, and inlet flow blockage of 0.02–0.04. Four outer walls were manufactured with area ratios of 1.61, 1.91, 2.73, and 6.18. The tabs with a projected height equivalent to the boundary layer thickness were effective at reducing the outlet distortion but at a pressure penalty for the three smaller diffusers. The largest diffuser improved back pressure coefficient 4.6% with four tabs providing a blockage of 4.7% over its bare diffuser but was 42% lower than that obtained by the AR = 2.73 diffuser with no tabs.Copyright © 2014 by ASME

The flow around a NACA 0020 airfoil strut placed in the centre of a rectangular duct has been studied. The performance of the strut was characterized in terms of its effect on the mean flow, as well as in terms of overall losses. It was shown that the main influences of increasing the confined mixing length downstream of the airfoil wake were to reduce the total system dump loss (kinetic energy loss) through the use of a Carnot diffuser, and to slightly increase the wake spreading rate. In addition to creating a reference dataset for CFD comparison and validation, some phenomenon were particularly identified for future CFD investigation. It was shown that there may be some benefit to adjusting the turbulent Prandtl number for Turbulent Kinetic Energy during CFD simulations of this same problem. It was also shown that studying the particular effects of the Carnot diffuser on the development and migration of the wall-airfoil interface vortices would give useful insight into the physical mechanisms driving this change in performance.

Passive augmentation devices are typically added to diffusers to increase pressure recovery; however, applications such as infrared suppression exist where more uniform outlet velocity profiles are also desirable. Square tabs were added to a short annular diffuser system with diffuser effectiveness of 80% in strong swirling subsonic turbulent flow. The number, axial position, width, and height were varied for the tabs with a 135° orientation angle. Results showed that back pressure increased linearly with increasing tab projected area blockage but outlet velocity uniformity was maximum with 7% tab blockage. Tabs placed on the centre body base recovered more dynamic pressure than tabs placed downstream on the centre body with similar tab area blockage.Copyright © 2014 by ASME

Short annular diffuser systems consisting of a conical expansion section with negative wall angles and a solid (full outer diameter) diffusing section were tested experimentally at several inlet swirl angles of 0–40°. Tests analyzed were completed over a range of inlet Reynolds number of Ret = 0.9–2.2 × 105 and considered fully turbulent. Performance — back pressure coefficient, outlet velocity uniformity, and total pressure loss — were appreciably depreciated for inlet swirl number larger than 0.7 and the average 10° curved vane swirler out-performed its straight vaned equivalent. Three centre bodies with length half that of the diffuser and different curvatures were manufactured. Similar performance was achieved but each centre body provided marginal improvements to a particular objective. Most notably, the centre body that gave an initial flow expansion angle of 14° resulted in 1–4% lower back pressure than the other two whose expansion angles were 12° and 16°.Copyright © 2014 by ASME

This paper presents the results of an experimental study of passive effusion cooling in an S-bend channel with a diffuser. A previous paper showed the results for cold primary flow [1]. This paper deals with hot primary flow. The results show that different levels and locations of effusion injection significantly affect the primary flow field and the pressure recovery in the downstream diffuser. This leads to a significant increase in static pressure at the inlet of the S-bend section, and reduces the driving pressure for the passive effusion cooling air. This effect then leads to reduced effusion mass flow, momentum and cooling effectiveness. The paper presents data on the static pressure distributions in the device, flow distortion at the diffuser exit, flow rate of effusion injection, and effusion cooling effectiveness.Copyright © 2014 by ASME