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This paper presents an effective way to control the temperature of bio-reactors (fermenters) used in ethanol production and to reduce the volume of cooling water required per square meter of ethanol produced. This paper specifically focuses on the fermentation of cassava starch using Saccharomyces cerevisiae at 32ºC. The flow across tube banks model is employed as the cooling mechanism of the bio-reactor. Cooling water at 28°C enters a shell containing five rows of fifteen (15) bio-reactors in a square in-line arrangement and exits the shell at 31.84°C. The total working volume of all fifteen (15) bio-reactors in the bank equals 180m^3. Each bio-reactor in the bank is designed to have an effective heat transfer area to volume ratio of two (2) to enhance heat transfer. The total quantity of cooling water required per cubic meter of ethanol produced is found to be 97.833m^3. A total amount of 1.303kW is required to power anchor impellers placed in each bio-reactor to provide mixing. The rotation speed of the impeller in each bio-reactor is 0.2〖rev·s〗^(-1). A total of 3.453*10^(-6) W is required to move cooling water through the bio-reactor bank at a speed of 3.942*10^(-5) ms^(-1). An overall heat transfer coefficient of 11.345W·m-2°C-1 was found for the bio-reactor cooling system. Employing flow across tube banks model in cooling ethanol bio-reactors required significantly less amount of cooling water per cubic meter of ethanol produced compared to using internal cooling coils.

Low Rolling Resistance (LRR) conveyor systems are generally preferred over traditional conveyors because of better overall efficiency lesser energy consumption required to operate. In this work, the design development and analysis path in the process of downscaling the size of an existent LRR test rig to a compact, portable and desktop-sized model is presented. Simulation has been developed using SolidWorks and finite element analysis is conducted using ANSYS to obtain the deformation, stress and strain of each part of the new design.

The objective of this paper is to calculate fatigue reliability of the new design of universal upright for the James Cook University Formula SAE car. The upright design is the back bone of the unsprung mass on the car as it provides connection points for many necessary components. Several different forms of analysis were used to ensure the upright design is capable of handling the frequent loading from different load cases. The main form of analysis was computational modelling using finite element method (FEM) to determine and apply loads to the initial upright design. Using these results the upright was further optimised to save weight and improve cooling effects to the upright and surrounding components. Also, in order to maintain the minimum amount of reliability at a certain value, the number of variable components is defined at each time of inspection. The results showed that reducing the time interval between periodic inspections and increasing the number of replaced components at each stage of the inspection can keep the system reliability as expected.

The sugar industry is an ideal sector for electricity cogeneration due to a large amount of burnable bagasse produce as a by-product. Bagasse produced in the sugar industry always consists of moisture affecting the efficiency of a boiler in the cogeneration plant. In our case study, a cogeneration plant run by bagasse burning found with bagasse moisture problem and suffocating with low power generation for the last few years. The boiler efficiency per tonne of bagasse is currently lower than optimal due to the substantial percentage of water present in the bagasse. A bagasse dryer design for this industry can improve the efficiency of a boiler as well as the cogeneration plant. In this paper, a pneumatic bagasse drying system is proposed to reduce the moisture content of bagasse from 48% to 30%. This work provides a full analysis of bagasse dryer design parameters, including specifications for dryer system components, such as feeders, fan, drying tube, and cyclone. The total bagasse drying system proposed is expected to be fitted within a 6 x 6 x 25 m space to dry 60 tph of bagasse, reducing the moisture content from 48% to 30%, in full compliance with all relevant Australian and company standards. Resumen La industria azucarera es un sector ideal para la cogeneración eléctrica debido a la gran cantidad de bagazo que se produce como subproducto. El bagazo producido en la industria azucarera siempre consiste en humedad que afecta la eficiencia de una caldera en la planta de cogeneración. En nuestro caso de estudio, una planta de cogeneración operada por la quema de bagazo se encontró con un problema de humedad del bagazo y asfixiada con baja generación de energía durante los últimos años. La eficiencia de la caldera por tonelada de bagazo es actualmente inferior a la óptima debido al porcentaje sustancial de agua presente en el bagazo. Un diseño de secador de bagazo para esta industria puede mejorar la eficiencia de una caldera y de la planta de cogeneración. En este trabajo, se propone un sistema de secado neumático de bagazo para reducir el contenido de humedad del bagazo del 48% al 30%. Este trabajo proporciona un análisis completo de los parámetros de diseño del secador de bagazo, incluidas las especificaciones de los componentes del sistema del secador, como alimentadores, ven tiladores, tubos de secado y ciclones. Se espera que el sistema de secado total de bagazo propuesto se instale en un espacio de 6 x 6 x 25 m para secar 60 tph de bagazo, reduciendo el contenido de humedad del 48% al 30%, en total cumplimiento con todas las normas relevantes de Australia y de la empresa.

The purpose of this paper is to numerically investigate the fatigue life and the fatigue crack growth path of 2024 aluminum plate riveted joints. For this purpose, according to field observations, the parameters affecting fatigue life are obtained. Relevant geometric parameters such as rivet shank length, hole diameter and dimensional tolerances, as well as the location pattern of the rivets and the material of the rivet joints are studied. In this study, modeling is performed to calculate the equivalent plastic strain using the finite element method. For this purpose, a three-dimensional elastoplastic model is used for simulation. The information obtained from the finite element method in this study made it possible to place the rivets in this type of joint for use in high safety structures such as the aerospace industry. Given the importance of the problem of crack growth in 2024 aluminum plates, having the geometrical and physical parameters of the problem, the goal is to achieve the exact path of crack growth and fatigue life of riveted joints. Fatigue crack growth simulation is performed on the samples using the boundary element method. The stress intensity factor for different loading modes is determined using the boundary element method. The results showed that the geometric parameters and the rivet material have a significant effect on fatigue cracking in aluminum plates.

The present study aims to implement a non-destructive approach to determine the tensile properties of magnesium-based nanocomposites reinforced with ZrO2 and TiO2 nanoparticles. Micron-sized magnesium particles were blended with 0, 1.5, 3, and 5 volume percentage of ZrO2 and TiO2 nanoparticles and hot-pressed at 450 °C under the pressure of 600 MPa. Next, the spherical indentation test was performed on the produced composites to obtain the load–penetration curves. A finite element model of the indentation test was then developed using the Hollomon material model with randomly chosen materials constants. At the next stage, load–penetration curves were obtained for each composite using simulations. A Levenberg–Marquardt neural network was then trained and utilized to find the correct material constants by minimizing the differences between the experimental and simulated load–penetration curves. The results indicated that there is a linear relationship between the tensile strength and content of the reinforcement phase, while it is inversely proportional to the size of the reinforcing particles. Magnesium composites reinforced with 5 volume percentage of ZrO2 and TiO2 nanoparticles showed tensile strengths 2.5 and 2.1 times greater than that of unreinforced magnesium, respectively. It was shown that the proposed method is able to calculate the tensile properties of magnesium-based composites in an accurate and inexpensive manner.

In this article, a case study of a load-carrying vehicle chassis with various loading conditions in six maneuvers has been conducted. These maneuvers include acceleration and deceleration in a loaded and un-loaded situation, drops, pothole, turn, and sinusoidal obstacles. Finite element analysis has been implemented in order to calculate stress distribution and fatigue life. Stress analysis indicated that the joints stiffness is higher where the auxiliary profiles were utilized. However, this procedure is cumbersome and auxiliary plates would be a more efficient strategy. The effects of using auxiliary plates have been investigated in the fatigue and stress distribution of the aforementioned chassis. The analysis revealed that the 300 mm drop has the maximum tension and accordingly embodies the shortest fatigue life. Furthermore, for welding joints, three different strategies for geometry configuration including welding bead, reinforcing plates, and extra auxiliary profiles under the welded joints were assumed.

Improving the performance of idlers is paramount to the performance of the conveyor system in various industries since belt conveyors can be many kilometers in length and consequently there are a huge number of rollers in use. The key intention of this work is the development of a light-weight composite idler roller. Critical design considerations are strength-to-weight ratio and performance. Most importantly, the design must reduce the weight of the roller as compared to standard steel rollers. The final design provides a significant reduction in weight of about 47 % over that of traditional steel rollers of a similar size.

This paper involves the design and construction of the intake manifold system of the FSAE car including the air shroud, air filter, throttle body, restrictor plenum, fuel injectors, fuel rail and runners. To ensure the quality, the proposed system is designed based on the FSAE rules. The design process of the intake manifold system will consist of the usual engineering processes including computer modelling, Finite Element Analysis and finally Computational Fluid Dynamics testing in order to determine the validity of the model and to tune the design in order to obtain the optimum performance out of the intake manifold system as a whole.

Investigation on a designed and modified standard automatic transmission for a 2017 Yamaha Grizzly All-Terrain Vehicle was carried out to allow it to be controlled remotely and autonomously while maintaining its ability to be manually operated. The vehicle is a part of a project named AutoWeed. This project aims at developing a vehicle which can be used in the Australian outback to control and eradicate weeds. Preliminary tests were conducted on the vehicle to determine the performance parameters required to replace the movement supplied by the operator. Several devices used to achieve this motion were explored. It was concluded that the Motion Dynamics HB-DJ806 - LALI10010 electromechanical linear actuator be used as a proof of concept device for this application. This device is capable of exerting 200 N at 35 mm/seconds. It has a stroke length of 50 mm and was powered by a 12V DC motor, which drew 3 amps at maximum load. Through testing, it was found that the selected actuator did not have enough stroke length to cycle through the five gears on the ATV. This error was rectified allowing the system to function as intended. To achieve a reliable design, however, the Linak LA14 actuator was purchased as a final design as it was stronger, faster and had feedback capabilities. Before procurement, the new actuator was digitally modelled using SolidWorks 2017 and 3D printed to confirm the mounting position and method. An ANSYS FEA was conducted on all the custom-made components including the actuator bracket and mounting plate to ensure reliability. The bracket model was manufactured using 3D printing from ABS. It was recommended that for reliability, the bracket should be constructed from a stronger material such as aluminium. The results gained from testing proved that the autonomous transmission system implemented was reliable and repeatable. This was justified as the system achieved a 100% success rate when cycling through gears.

This project was aimed at modelling the stress and deformation profile of a 6061-T6 aluminium suspension upright of a formula society of automotive engineers style vehicle with a double wishbone suspension under the loading conditions of a 1.5G corner. With these results, it would need to be determined whether the design is fit for use. Using remote displacement boundary conditions for the upper and lower wishbone connections and the control arm connection with a remote force at the centre of the wheel patch acting on the bearing surfaces the maximum stress, overall stress profile and maximum deformation of the upright was calculated. These results after, undertaking a verification and validation study, were a maximum equivalent von-Mises stress of 87.358MPa and a maximum bearing surface deflection of 0.21 mm. The maximum von-Mises stress calculated was less than the fatigue limit of 90MPa signalling infinite life and also less than the yield stress of 240MPa signalling a safe design. Verification and validation techniques were used to ensure the final result was accurate and reflected the real – life system. Structural error was used to verify the results where it was found that maximum structural error in the upright was 0.052mJ and at the location of maximum stress was between 0.0058-1.0782e-8 mJ. Validation of the model was achieved by comparing the reaction forces calculated in ANSYS to theoretical values and was found that the magnitudes were within 2.5% of the theoretical values, thus the model was considered valid.

The aim of this paper is to design the steering system of the formula racing car. This includes the designing of its main components in solidworks, its analysis by calculation and finite element simulation. Load acting on the wheels of formula car are calculated and input in the analysis wherever necessary. The cars steering rack is repositioned to avoid any collision with a-arms. The force acting on the bolts at tie rod, clevis and mounting bracket is found below its yield strength. The clevis attached at the end of the rack is subject to load and fatigue analysis in ANSYS and all results were found satisfactory. Similar analysis is done for rack arm at critical areas and its was found that region where the rack arm can withstand fluctuations ranging for almost whole life till failure. Later the whole steering system was split into three major components (Steering column assembly, steering rack assembly, Tie rod assemblies) and each component is designed separately in SolidWorks and then assembled into whole one. SKF SAKAC 10 M ends are selected rod ends for steering arm assembly allowing rigid force transfer between rack arms and upright assembly as well as vertical motion of wheel assembly in operation. In the assembly 6 x M8 and 4 x M10 exist with the associated washers and nuts. The universal joint connecting the two steering column was machined according to Australian standards with splines at both ends. Two splined steering columns was machined in order to complete the steering column assembly. In order to stop the clevis colliding with the steering with the rack on full lock and to restrict the steering of the vehicle two locking collars were manufactured.

This paper outlines the design, analysis and physical testing of the material for the front impact attenuator for the Motorsports car. The material selected was a 20 mm thick panel of veiled polypr...

The suspension assembly of a vehicle is a vital component in its ability to function safely and effectively. This paper details the design and simulation of the James Cook University Motorsports 2nd generation vehicle for the Formula Society of Automotive Engineers competition. After in-depth research it was decided that a pull-rod suspension system would be the most effective assembly for the Gen 2 car. Contrary to the current push-rod suspension on the Gen 1 car, the pull-rods allow the centre of gravity to be lowered, which is ideal. Working closely with the rear drive train, cockpit and upright teams, a design was conceived and developed. After several redesigns a final model was able to be created. SolidWorks was the tool used to generate the components created in the design phase. This is an extremely powerful program that allows the user to not only produce a three-dimensional component but also allow future modifications to be made to the component to change its dimensions. It was decided this was a vitally important ability, as future modifications will be needed when less conservative loading cases are discovered and then applied. The SolidWorks models where then transported to a computational simulation program, ANSYS. ANSYS, like SolidWorks, was an important tool in verifying design assumptions and concepts. With this program loading cases where able to be applied to the system to understand how they would react and if they would fail under the stresses applied.

Resin tubes made of epoxy base material and fibers are widely used in the transportation, and aeronautics industries due to their high mechanical properties. Different reinforcing fibers and resins are usually used in making these tubes and lead to various properties. In this study, tubes made by using a 45-degree unilateral winding method and reinforced by Glass, Carbon, and Kevlar fibers and their hardness and wear behaviors were investigated. The results showed that the highest hardness was obtained for the carbon fiber reinforced composite tube (CFR), equal to 65HV, which was 109% more than the Kevlar fiber reinforced composite tube (KFR). Higher hardness indicates greater resistance of the material to local deformation and also stronger bonding between the base material and the reinforcing fibers. The wear test results showed that the wear rate of CFR was 6 mg/m, which was 26% and 55% lower than the glass fiber reinforced composite tube (GFR) and KFR, respectively. The obtained result can be explained as a result of good bonding and compatibility between carbon fibers and used resin. Scanning electron microscope (SEM) images were taken to evaluate the results.

This article includes the design procedure and the Finite Element Analysis (FEA) that was undertaken to design a chassis to be used in a Formula Society of Automotive Engineers (FSAE) racecar competition. After conducting an audit on the previous chassis design, major design goals were created for optimization and improvement, some of which included removing the rear box section to allow a 52-tooth sprocket, increasing the torsional stiffness, and decreasing the weight. Computer software ANSYS and SolidWorks were used to analyze the major performance indicators of the chassis design. The torque of the car was increased by approximately 30%, torsional stiffness was increased by 10%, the chassis was shortened by 12.8%, and the weight was reduced by 3.5%. The results from the analysis suggest that there are many improvements in the new chassis design, and it will be highly beneficial to the new FSAE car.

High density polyethylene (HDPE) is a thermoplastic polymer which is classified as one of the highly consumed types of plastics. One major advantage of thermoplastic materials is their ability of recycling and reprocessing which will bring considerable economicand environmental benefits. The present paper, therefore, endeavours to explore the practical possibility of using recycled HDPE hollow section as a replacement of virgin HDPE made by the extrusion process. The main focus of the study was to evaluate the mechanical performance of the recycled HDPE and compare the results with virgin or non-recycled HDPE. The modulus of elasticity, tensile yield and ultimate strength, compressive yield and ultimate strength, flexural yield and ultimate strength and the coefficient of thermal expansion were the main parameters to be checked against the respective mechanical properties. Thus, pursuant to the rsults, it was found out that the modulus of elasticity and the tensile yield strength are lower in recycled HDPE compared to the non-recycled HDPE. However, there is no significant difference between the recycled and non-recycled HDPE for the tensile ultimate strength, compressive yield strength and compressive ultimate strength. The flexural yield strength and flexural ultimate strength properties of the recycled HDPE proved to be superior to those of the non-recycled HDPE. The coefficient of linear thermal expansion of the recycled HDPE sample was 130 μm/(m.°C) and that for the non-recycled HDPE was 142 μm/(m.°C).

This paper was commissioned for the design and analysis of an entire rear suspension system befitting a Formula Society of Automotive Engineers (FSAE) vehicle. The paper includes a literature review to gain a full understanding of the workings and design decisions applied to the rear suspension in the Society of Automotive Engineers (SAE) competition. After completing the design development process, a final analysis of the designed system was done to ensure the minimum two years-of-life requirement is met. It was found that due to constraints, a major design change was necessary that involves mounting the A-arms further forward on the chassis body than previous generation vehicles. This design increased the stresses present in the system compared to previous designs. As such, careful consid-eration had been given to the analysis aspect of the paper. Full fatigue analysis performed individually on each component proved that the lower A-arm was the most critical component, with a predicted failure at 1466 laps. However, with the given lifespan of two years, this design procured a conservative Factor of Safety of above two years.Notable mention should be given to the complete develop-ment of an FSAE uniaxial force determination code that was produced by Team Recoil. This code greatly improved the confidence in component forces and thus allowed less conservative design choices in several other aspects.

The proposed Gen2 rear subframe is an all-new concept designed to be a complete rear-end subassembly, which replaces the conventional rear frame of a car. A reliable, lightweight, simple, and cost-effective design has been developed to improve the James Cook University (JCU)'s Formula Society of Automotive Engineers (FSAE) car performance in competition.Through the use of numerical simulation, theoretical computations, and research, refinement of the concept was conducted until a compromise between reliability and light-weight design was found. Taking into consideration accurate loadings acting on the assembly, critical areas of stress were found in the solid drive axle with a maximum Von Mises stress of 151 MPa and overall Factor of Safety (FOS) of 2.11 located on the drive splines of the shaft. All simulations are verified with the use of theoretical calculations, making the results reliable and accurate. Off-the-shelf items are verified to withstand all loads, and the designs meet the relevant guidelines (Australian Standard [AS] or other) and FSAE requirements. Simplicity has been kept in mind throughout the entire project to help reduce manufacturing costs yet make a reliable model.

This paper details the design of rear upright for a JCU Tec-NQ (JTR) Racing Motorsport, Formula Society of Automotive Engineers (FSAE) race car using Aluminium Alloy 7075-T6 through the use of a track simulator developed by RMIT Racing, forces on the upright were calculated and an upright was designed in SolidWorks. To ensure optimal design with the aid of Finite Element Analysis using ANSYS workbench, three main load cases with combination of drive cases (acceleration, braking, and left and right turn) were used to evaluate performance of the rear upright. They include fatigue of upright, single bump loads and the zero-based fatigue loading of the calliper-mounting bracket. For the fatigue loading of the whole upright, it was observed that the greatest stress throughout the four drive cases occurred in a left hand turn. For single bump loads, the upright could withstand a vertical bump load of stress value significantly lower than the ultimate tensile strength. For the fatigue analysis on the brake calliper mount, the resulting safety factor plot presented a minimum factor of three for infinite life. Other relevant analysis were presented, such as sphere of influence and exaggerated deformation which showed that the upright will experience a maximum deformation of 0.132mm during the worst case lap scenario (left hand turn). The material considered for the design of the rear upright was Aluminium Alloy 7075-T6 as it has superior mechanical properties in terms of stiffness, fatigue and tensile strength for the application compared to both the Alumec alloy and Aluminium Alloy 6061-T6 considered in this paper.

Growing quantities of end-of-life batteries, increasing demand for critical metals and the depleting reserve of high grade ores have necessitated the need to explore secondary sources such as spent lithium ion batteries (LiBs). Among various processes developed for the recovery of materials from the LiBs, the hydrometallurgical approach is mainstream due to its flexibility and efficiency. However, the cost and environmental impacts of hydrometallurgical approaches depend on the reagents used. Organic compounds such as organic acids and biomasses as lixiviants and reductants are considered cheaper and more eco-friendly alternatives to their inorganic counterparts conventionally used. This review summarises the progresses made in the use of organic based substances as reductants in reductive leaching of spent LiBs and low grade ores. It also discusses factors affecting leaching mechanisms, possible reaction chemistries and kinetics. Analysis of the available data in the literature suggests that the use of organic-based compounds could achieve comparable recovery but with much reduced adverse environmental impacts in the extraction of metals from spent LiBs. Further, technology development in the area will benefit from application of key knowledge on the recovery of metals from low grade ores. The review concludes with a summary of current challenges facing the industrial application of organic compounds and highlights future perspectives on organic acids as lixiviants in a mixed acid leaching system.

The purpose of this paper is to numerically and experimentally investigate with optimized parameters laser thermal bending of aluminum-copper two-layer sheet. Due to the fact that laminated sheets have more ductility and lower manufacturing costs, in this article, the thermal bending behavior of this type of sheet is investigated. For this purpose, the optimal model is obtained using the Taguchi and finite element methods, with respect to the cost functions and the defined levels for the parameters. The effective parameters of the laser forming process such as the scanning speed, the laser beam power, and the laser beam diameter on the aluminum-copper two-layer sheet are optimally determined and subsequently the laser thermal bending of the aluminum-copper two-layer sheet is obtained by experimental tests. The Taguchi method is used to optimize the simulations required for the analysis. The Taguchi method with its own algorithm reduced the number of experiments to 9 design points. These experiments are simulated by the finite element method with a three-dimensional elastoplastic model. Then, to verify the numerical results of these optimized parameters, the samples are fabricated and the effect of optimal parameters on the behavior of this type of the aluminum-copper two-layer sheet is evaluated under experimental tests. The results showed that the laser beam power has a direct relation and the laser beam diameter and scanning speed have an inverse relation with the final bending angle.

Polymeric tubes, including epoxy and reinforcing fibers, are widely used in the petroleum and aerospace industries due to their high strength and corrosion resistance. In this study, corrosion and creep properties of resin-based tubes reinforced by Glass fibers (GFR), Carbon fibers (CFR), and Kevlar fibers (KFR) were investigated using tubes made by using a 45-degree unilateral winding method. The highest creep strain was obtained for the CFR equal to 0.7445 and the lowest was obtained for KFR with the Kevlar fibers being severely damaged. The lowest corrosion rate per year was for the CFR sample, equal to 113in/year×1000. The corroded samples were subjected to a tensile test and a 2% improvement in ultimate tensile strength was achieved for GFR. To evaluate the results and the quality of adhesions between fibers and resins, SEM images were taken of the samples.

BACKGROUND: Damage control resuscitation (DCR) with early plasma in combat casualties requiring massive transfusion (MT) decreases early deaths from bleeding. METHODS: To ascertain the potential role of early plasma DCR in civilian MT, we queried a prospective traumatic shock database of 383 civilians. RESULTS: Ninety-three (24%) of the traumatic shock civilians received a MT, of which 26 (28%) died early, predominantly from bleeding within 6 hours. Comparatively, this early MT death cohort arrived in more severe shock and were coagulopathic (mean INR 2.4). In the critical period of MT (ie, the first 3 hours), these patients received 20 U of packed red blood cells (PRBCs) but only 4 U of fresh frozen plasma (FFP). They remained severely acidotic and their coagulopathy worsened as they exsanquinated. CONCLUSION: Civilians who arrived in traumatic shock, required a MT, and died early had worsening coagulopathy, which was not treated. DCR with FFP may have a role in civilian trauma.

Many aircraft inspections currently require personnel to access difficult or hazardous areas. The inspections also require removal of structure, sealant often must be removed and restored with the commensurate damage to structure, ventilation must take place, etc. An automated inspection method that does not have reduced accuracy and that could take place with personnel remote to the inspection area is desirable. permanently mounted sensors in the inspection areas that could be remotely interrogated would be the simplest option. A CVM portable system is currently available for this purpose. Boeing, FAA, Airbus, Northwest Airlines, US Navy and RAAF are currently conducting independent verification trials with Structural Monitoring Systems Ltd (SMS). These trials involve laboratory, environmental and on-aircraft tests. The validation trial with the US Navy has involved an on-aircraft installation for the last 18 months and recently, successfully detected a crack. SMS is now conducting a joint Boeing/Northwest Airlines/FAA validation trial on a flying DC-9. The wing spar in the fuel tank area of the wing is to be monitored. The current inspection requires four days for completion and will be reduced to five minutes by CVM. The system has been installed and should result in CVM being approved as an alternate means of compliance (AMOC).

The aim of this study was to investigate the effects of a single tensile overload on subsequent fatigue crack growth in a 316L stainless steel. Fatigue tests were conducted under the plane stress condition, and further supplemented with compliance measurements and field emission scanning electron microscopy (FESEM) observations. Effects of a tensile overload, e.g. initial acceleration and subsequent retardation of fatigue crack growth, were explained and quantified by FESEM and compliance measurements. The FESEM observations suggest that the initial crack growth acceleration stems from void and quasi-cleavage fracture within the fatigue damage zone in the vicinity of the crack tip. Systematic compliance measurements taken during fatigue crack growth suggest that the overall crack growth retardation is related to strain hardening and residual compressive stress produced by the plastic deformation associated with the tensile overload.

The aim of this study was to investigate the effect of an overload on the rate of crack growth (da/dN) in a 316L stainless steel. Fatigue testing was carried out under plain stress condition. Parameters of the Paris Law were identified. The effect of a static overload, viz. an overall decrease in the crack growth rate, could be quantified. An initial, short-lived crack tip acceleration could also be detected. Compliance measurements taken concurrently to the crack growth measurements suggest that crack closure is not responsible for the initial acceleration or subsequent retardation of the crack growth rate.

Severely bleeding trauma patients requiring massive transfusion (MT) often experience poor outcomes. Our purpose was to determine the potential role of near infrared spectrometry derived tissue hemoglobin oxygen saturation (StO2) monitoring in early prediction of MT, and in the identification of those MT patients who will have poor outcomes.Data from a prospective multi-institution StO2 monitoring study were analyzed to determine the current epidemiology of MT (defined as transfusion volume/=10 units packed red blood cells in 24 hours of hospitalization). Multivariate logistic regression was used to develop prediction models.Seven US level I trauma centers (TC) enrolled 383 patients. 114 (30%) required MT. MT progressed rapidly (40% exceeded MT threshold 2 hours after TC arrival, 80% after 6 hours). One third of MT patients died. Two thirds of deaths were due to early exsanguination and two thirds of early exsanguination patients died within 6 hours. One third of the early MT survivors developed multiple organ dysfunction syndrome. MT could be predicted with standard, readily available clinical data within 30 minutes and 60 minutes of TC arrival (area under the receiver operating characteristic curve = 0.78 and 0.80). In patients who required MT, StO2 was the only consistent predictor of poor outcome (multiple organ dysfunction syndrome or death).MT progresses rapidly to significant morbidity and mortality despite level I TC care. Patients who require MT can be predicted early, and persistent low StO2 identifies those MT patients destined to have poor outcome. The ultimate goal is to identify these high risk patients as early as possible to test new strategies to improve outcome. Further validation studies are needed to analyze appropriate allocation and study appropriate use of damage control interventions.

Near-infrared spectroscopy (NIRS) can continuously and noninvasively monitor tissue oxygen saturation (StO2) in muscle and may be an indicator of shock severity. Our purpose was to evaluate how well StO2 predicted outcome in high-risk torso trauma patients presenting in shock.The primary outcome in this prospective study was multiple organ dysfunction syndrome (MODS). StO2 data were obtained upon hospital arrival and for 24 hours along with other known predictors of hypoperfusion and clinical outcomes. Clinicians were blinded to StO2 measurements.Seven Level I trauma centers enrolled 383 patients, 50 of whom developed MODS. Minimum StO2 performed similarly to maximum base deficit (BD) in discrimination of MODS patients. The sensitivity for both measures (StO2 cutoff = 75%; BD cutoff = 6 mEq/L) was 78%, the specificity was 34% to 39%, the positive predictive value was 18% to 20% and the negative predictive value was 88% to 91%. StO2 and BD were also comparable in predicting death.NIRS-derived muscle StO2 measurements perform similarly to BD in identifying poor perfusion and predicting the development of MODS or death after severe torso trauma, yet have the additional advantages of being continuous and noninvasive.

The following paper provides a summary of the design and operating parameters for the Dynamic Belt Clamp. The Dynamic Clamp is hydraulically controlled to apply braking force on a belt via referenc...