324 research outputs found

    Design and Manufacturing of the Carbon Fiber Roll Table

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    Backpacking and exploration of the great outdoors has surged in popularity in the 21st century, especially after the COVID-19 pandemic called for many to change their hobbies and interests. Additionally, many people explore new, remote locations as a way of breaking free from the chains of addiction to media and reliance on technology. Our team experienced this shift firsthand as our interest in backpacking and exploration has grown in recent years. Upon our reflection of this newfound hobby, we realized that the camping equipment market was missing one thing: a “do it all” backpacking table. Our team wanted to address this need in the backpacking community by creating a versatile, lightweight, and durable camping table that will help people experience the beauty found in nature. The product design, cost, and manufacturing process were all developed and chosen with these criteria in mind. In spring of 2022, we conducted market research through public polls and think tanks. From this research, we established a target market of individuals between the ages of 18-30 years old that are active backpackers and outdoor enthusiasts. This target market is a niche sub-category of the camping equipment and accessory market. Additionally, market research identified four consumer considerations: durability, versatility, weight, and affordability, all of which were considered during each phase of the design and production process. After establishing a market for our product concept, an outline of future work and procedures was established to manufacture our product. To begin, we would need to convert our drawings and ideas into an initial prototype. This phase of the manufacturing process was critical for success because it served as the foundation of what our product would be down the road. Additionally, this initial prototype was a proof of concept to prove that our design drawing was feasible. Next, our timeline called for product design and material changes based on our review of the initial prototype. These changes factored in physical limitations and manufacturing process restrictions that would be problematic in the future. For example, the primary design change was related to the coupler that holds all three table legs together at a single point. The initial design was bulky and expensive, so creating a more efficient coupler was necessary. All three previous stages of our process lead to a final product that resembled the product we set out to create. The final product was lightweight, versatile, and strong. The product itself was nearly flawless. In review of our final product, the next stage was completing a holistic profitability analysis of the end product since the primary mission of all businesses is to create income for stakeholders. We were able to complete this holistic analysis by combining data from processing time studies, material purchase orders, industry research, and target market surveys. Although we utilized this same data when making design and material decisions, the result of this end-stage financial study proved that our final product and design would be profitable

    Unilateral total hip replacement patients with symptomatic leg length inequality have abnormal hip biomechanics during walking

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    BACKGROUND Symptomatic leg length inequality accounts for 8.7% of total hip replacement related claims made against the UK National Health Service Litigation authority. It has not been established whether symptomatic leg length inequality patients following total hip replacement have abnormal hip kinetics during gait. METHODS Hip kinetics in 15 unilateral total hip replacement patients with symptomatic leg length inequality during gait was determined through multibody dynamics and compared to 15 native hip healthy controls and 15 'successful' asymptomatic unilateral total hip replacement patients. FINDING More significant differences from normal were found in symptomatic leg length inequality patients than in asymptomatic total hip replacement patients. The leg length inequality patients had altered functions defined by lower gait velocity, reduced stride length, reduced ground reaction force, decreased hip range of motion, reduced hip moment and less dynamic hip force with a 24% lower heel-strike peak, 66% higher mid-stance trough and 37% lower toe-off peak. Greater asymmetry in hip contact force was also observed in leg length inequality patients. INTERPRETATION These gait adaptions may affect the function of the implant and other healthy joints in symptomatic leg length inequality patients. This study provides important information for the musculoskeletal function and rehabilitation of symptomatic leg length inequality patients

    A flash heating method for measuring thermal conductivity at high pressure and temperature: application to Pt

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    The transport properties of matter at high pressure and temperature are critical components in planetary interior models, yet are challenging to measure or predict at relevant conditions. Using a novel flash-heating method for in-situ high-temperature and high-pressure thermal conductivity measurement, we study the transport properties of platinum to 55 GPa and 2300 K. Experimental data reveal a simple high-pressure and high-temperature behavior of the thermal conductivity that is linearly dependent on both pressure and temperature. The corresponding electrical resistivity evaluated through the Wiedemann–Franz–Lorenz law is nearly constant along the melting curve, experimentally confirming the prediction of Stacey for an ideal metal. This study together with prior first-principles predictions of transport properties in Al and Fe at extreme conditions suggests a broad applicability of Stacey’s law to diverse metals, supporting a limit on the thermal conductivity of iron at the conditions of Earth’s outer core of 90 W/mK or less

    Cultured lymphocytes’ mitochondrial genome integrity is not altered by cladribine

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    Cladribine tablets are a treatment for multiple sclerosis with effects on lymphocytes, yet its mode of action has not been fully established. Here, we analyzed the effects of cladribine on mitochondrial DNA integrity in lymphocytes. We treated cultured human T-cell lines (CCRF-CEM and Jurkat) with varying concentrations of cladribine to mimic the slow cell depletion observed in treated patients. The CCRF-CEM was more susceptible to cladribine than Jurkat cells. In both cells, mitochondrial protein synthesis, mitochondrial DNA copy number, and mitochondrial cytochrome-c oxidase-I mRNA mutagenesis was not affected by cladribine, while caspase-3 cleavage was detected in Jurkat cells at 100 nM concentration. Cladribine treatment at concentrations up to 10 nM in CCRF-CEM and 100 nM in Jurkat cells did not induce significant increase in mitochondrial DNA mutations. Peripheral blood mononuclear cells from eight multiple sclerosis patients and four controls were cultured with or without an effective dose of cladribine (5 nM). However, we did not find any differences in mitochondrial DNA somatic mutations in lymphocyte subpopulations (CD4+, CD8+, and CD19+) between treated versus nontreated cells. The overall mutation rate was similar in patients and controls. When different lymphocyte subpopulations were compared, greater mitochondrial DNA mutation levels were detected in CD8+ (P = 0.014) and CD4+ (P = 0.038) as compared to CD19+ cells, these differences were independent of cladribine treatment. We conclude that T cells have more detectable mitochondrial DNA mutations than B cells, and cladribine has no detectable mutagenic effect on lymphocyte mitochondrial genome nor does it impair mitochondrial function in human T-cell lines

    Litigation after hip and knee replacement in the national health service

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    The results of hip and knee replacement surgery are generally regarded as positive for patients. Nonetheless, they are both major operations and have recognised complications. We present a review of relevant claims made to the National Health Service Litigation Authority. Between 1995 and 2010 there were 1004 claims to a value of ÂŁ41.5 million following hip replacement surgery and 523 claims to a value of ÂŁ21 million for knee replacement. The most common complaint after hip surgery was related to residual neurological deficit, whereas after knee replacement it was related to infection. Vascular complications resulted in the highest costs per case in each group.Although there has been a large increase in the number of operations performed, there has not been a corresponding relative increase in litigation. The reasons for litigation have remained largely unchanged over time after hip replacement. In the case of knee replacement, although there has been a reduction in claims for infection, there has been an increase in claims for technical errors. There has also been a rise in claims for non-specified dissatisfaction. This information is of value to surgeons and can be used to minimise the potential mismatch between patient expectation, informed consent and outcome
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