163 research outputs found

    The societal costs of femoral neck fracture patients treated with internal fixation

    Get PDF
    __Abstract__ The study rationale was to provide a detailed overview of the costs for femoral neck fracture treatment with internal fixation in the Netherlands. Mean total costs per patient at 2-years follow-up were €19,425. Costs were higher for older, less healthy patients. Results are comparable to internationally published costs. Introduction The aim of this study was to provide a detailed overview of the cost and healthcare consumptio

    Business Rules on Trial: Exploring hindrances in validation of Natural Language Business Rules

    Get PDF
    The ability for organizations to respond to change has become ever more important in today's rapidly changing macro environment. The Business Rules Approach, a relatively new Information Systems Development methodology, promises business agility through the focus on and use of Business Rules. Business Rules are to be stated in natural language, so that they can be accessed and validated by people without technical experience. The easy validation of Business Rules by non-technical business users is a fundamental, but largely untested, claim and assumption in the Business Rules Approach. This thesis employs an experiment where eight librarian business experts were exposed to natural language Business Rules in order to find out if any problems arise when the said business experts attempted validation. The data was collected by conducting interviews in conjunction with the experiment, resulting in the conclusion that there were no major hindrances to validation of natural language Business Rules. The business experts in the study were able to go beyond validation of Business Rules by correcting erroneous Business Rules, suggesting corrections to Business Rules and in rare cases suggest structural changes to Business Rules

    Experimental evaluation of a solid oxide fuel cell system exposed to inclinations and accelerations by ship motions

    Get PDF
    Solid Oxide Fuel Cell (SOFC) systems have the potential to reduce emissions from seagoing vessels. However, it is unknown whether ship motions influence the system's operation. In this research, a 1.5 kW SOFC module is operated on an inclination platform that emulates ship motions, to evaluate the influence of static and dynamic inclinations on the system's safety, operation, and lifetime. The test campaign consists of a static inclination test, a dynamic test, a degradation test, and a high acceleration test. There were no interruptions in the power supply during the different tests, and no detectable gas leakages or safety hazards. Although the SOFC does not fail in any test condition, dynamic inclinations result in forced oscillations in the fuel regulation, which propagate through the system by different feedback loops in the control architecture, leading to significant deviations in the operational parameters of the system. Additionally, for motion periods from 16 to 26 s, reoccurring exceedance of the fuel utilisation results in a gradual reduction of the power supply. Several enhancements are recommended to improve the design of SOFCs and marine fuel cell regulations to ensure their safe operation on ships.</p

    Component sizing and dynamic simulation of a low-emission power plant for cruise ships with solid oxide fuel cells

    Get PDF
    Solid oxide fuel cell systems are considered for the power plant of ships, because of their high efficiency, low pollutant emissions, and fuel flexibility. This research compares the volume, mass, fuel consumption, and emissions of different hybrid power plants for cruise ships using solid oxide fuel cells, fuelled with marine gas oil and liquefied natural gas. A component sizing model allocates the installed power over the selected power plant components and determines their size and weight. The components and energy management strategy are simulated with a cruise ship for five years of operation. A simple method is implemented to estimate the degradation and its effect on component operation. The combined component sizing and time-domain model highlights the importance of dynamic simulation for battery sizing. The results show that using solid oxide fuel cells for the auxiliary consumers can reduce greenhouse gas emissions by 21% and pollutants by 38% to 46% with only 17.5% installed power, which has limited consequences for the cost and size of the power plant. With 31% installed power, the ship can operate in low-emission zones while reducing greenhouse gas emissions by 33% and pollutants by 60% to 70%. Performing all cruise operations requires 51% installed fuel cell power and reduces greenhouse gas emissions by 49% and pollutants by 94% to 96%. In conclusion, the study affirms that solid oxide fuel cell systems, with proper sizing and energy management, can be used to reduce shipping emissions and reach IMO's 30% GHG emission reduction target for 2030.</p

    Enhanced Fusarium head blight resistance in bread wheat and durum by alien introgression

    Get PDF
    PURPOSE: In the Netherlands, over 20,000 patients sustain a hip fracture yearly. A first hip fracture is a risk factor for a second, contralateral fracture. Data on the similarity of the treatment of bilateral femoral neck fractures is only scarcely available. The objectives of this study were to determine the cumulative incidence of non-simultaneous bilateral femoral neck fractures and to describe the patient characteristics and treatment characteristics of these patients. METHODS: A database of 1,250 consecutive patients with a femoral neck fracture was available. Patients with a previous contralateral femoral neck fractures were identified by reviewing radiographs and patient files. Patient characteristics, previous fractures, hip fracture type and details on treatment were collected from the patient files. RESULTS: One hundred nine patients (9%, 95% confidence interval 7-10%) had sustained a non-simultaneous bilateral femoral neck fracture. The median age at the first fracture was 81 years; the median interval between the fractures was 25 months. Overall, 73% was treated similarly for both fractures in terms of non-operative treatment, internal fixation or arthroplasty. In patients with identical Garden classification (30%), treatment similarity was 88%. CONCLUSIONS: The cumulative incidence of non-simultaneous bilateral femoral neck fractures was 9%. Most patients with identical fracture types were treated similarly. The relatively high risk of sustaining a second femoral neck fracture supports the importance of secondary prevention, especially in patients with a prior wrist or vertebral fracture

    Advancements and prospects of thermal management and waste heat recovery of PEMFC

    Get PDF
    Despite that the Proton Exchange Membrane Fuel Cell (PEMFC) is considered to be an efficient power device; around half of the energy produced from the electrochemical reaction is dissipated as heat due to irreversibility of the cathodic reaction, Ohmic resistance, and mass transport overpotentials. Effective heat removal from the PEMFC, via cooling, is very important to maintain the cell/stack at a uniform operating temperature ensuring the durability of the device as excessive operating temperature may dry out the membrane and reduces the surface area of the catalyst hence lowering the performance of the cell. In addition to cooling, capturing the produced heat and repurposing it using one of the Waste Heat Recovery (WHR) technologies is an effective approach to add a great economic value to the PEMFC power system. Global warming, climate change, and the high cost of energy production are the main drivers to improve the energy efficiency of PEMFC using WHR. This paper presents an overview of the recent progress concerning the cooling strategies and WHR opportunities for PEMFC. The main cooling techniques of PEMFCs are described and evaluated with respect to their advantages and disadvantages. Additionally, the potential pathways for PEMFC-WHR including heating, cooling, and power generation are explored and assessed. Furthermore, the main challenges and the research prospects for the cooling strategies and WHR of PEMFCs are discussed

    Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

    Get PDF
    Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

    Retention of first aid and basic life support skills in undergraduate medical students

    Get PDF
    Contains fulltext : 139233.pdf (publisher's version ) (Open Access)BACKGROUND: Undergraduate medical students follow a compulsory first aid (FA) and basic life support (BLS) course. Retention of BLS seems poor and only little information is provided on the retention of FA skills. This study aims at evaluating 1- and 2-year retention of FA and BLS training in undergraduate medical students. METHODS: One hundred and twenty students were randomly selected from first year (n=349) medical students who successfully followed a compulsory FA and BLS course. From these 120 students, 94 (78%) and 69 (58%) participated in retention tests of FA and BLS skills after 1 and 2 years, respectively. The assessment consisted of two FA stations and one BLS station. RESULTS: After 1 year, only 2% passed both FA and BLS stations and 68% failed both FA and BLS stations. After 2 years, 5% passed and 50% failed both FA and BLS stations. Despite the high failure rate at the stations, 90% adequately checked vital signs and started cardiopulmonary resuscitation appropriately. CONCLUSIONS: The long-term retention of FA and BLS skills after a compulsory course in the first year is poor. Adequate check of vital signs and commencing cardiopulmonary resuscitation retained longer

    Impact of additional extracranial injuries on outcome after mild traumatic brain injury.

    Get PDF
    Contains fulltext : 51324.pdf (publisher's version ) (Open Access)Many patients with mild traumatic brain injury (MTBI) concurrently sustain extracranial injuries; however, little is known about the impact of these additional injuries on outcome. We assessed the impact of additional injuries on the severity of postconcussional symptoms (PCS) and functional outcome 6 months post-injury. A questionnaire (including the Rivermead Post-Concussion Questionnaire and SF-36) was sent to consecutive MTBI patients (hospital admission Glasgow Coma Score 13-15; age range 18-60 years) admitted to the emergency department of a level-I trauma center, and, to serve as a baseline for PCS, a control group of minor-injury patients (ankle or wrist distortion). Of the 299 MTBI respondents (response rate 52%), 89 had suffered additional injuries (mean Injury Severity Score [ISS] of 14.5 +/- 7.4). After 6 months, 44% of the patients with additional injuries were still in some form of treatment, compared to 14% of patients with isolated MTBI and 5% of the controls. Compared to patients with isolated injury, MTBI patients with additional injuries had resumed work less frequently and reported more limitations in physical functioning. Overall, they did not report higher levels of PCS, despite somewhat more severe head injury. Regardless of the presence of additional injuries, patients that were still in treatment reported significantly more severe PCS, with highest rates in patients with isolated MTBI. In conclusion, many patients with additional extracranial injuries are still in the process of recovery at 6 months after injury. However, despite more severe impact to the head and inferior functional outcomes, these patients do not report more severe PCS

    Solid oxide fuel cells for ships: System integration concepts with reforming and thermal cycles

    No full text
    For decades, ships have been propelled by diesel engines. However, there are increasing concerns about their environmental impact. Fuel cells can provide an alternative to convert fuels directly into electricity, with high efficiencies and without hazardous emissions.Solid oxide fuel cells have a ceramic membrane, which functions at high temperatures. This makes them less prone to contamination, allows internal conversion of various fuels and enables integration with thermal cycles to achieve high combined efficiencies.So are ships and solid oxide fuel cells a match made in heaven? This dissertation breaks ground on the challenges and opportunities regarding the application of solid oxide fuel cells in ships, internal fuel reforming and integration with thermal cycles.How do solid oxide fuel cells compare to other power plants? How can we compare different system integration options? Does internal fuel reforming affect the efficiency and lifetime? Can cell experiments provide useful information on overall system performance? These are among the questions addressed in this dissertation.The reader will learn how solid oxide fuel cell integration with reforming and thermal cycles can provide power on ships with high efficiency and reliability, no pollutant emissions and low noise, but also about the challenges and opportunities of this potentially budding love.Ship Design, Production and Operation
    corecore