2,416 research outputs found

    Experimental characterisation of fatigue damage in single Z-pins

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    Z-pins have been shown to significantly improve delamination resistance and impact strength of carbon fibre reinforced (CFRP) composites. In this paper, an experimental investigation of the influence of different fatigue parameters (mean opening/sliding displacement, amplitude, frequency, number of cycles) on the through-thickness reinforcement (TTR) is presented. For mode I, it is shown that the degradation on pin behaviour during fatigue is mostly affected by the applied displacement amplitude. The degradation is primarily caused by surface wear. Due to the brittleness of the Z-pins, mode II fatigue does not have a significant effect for very small sliding displacements. Exceeding a critical displacement causes the pin to rupture within the very first cycles

    Analisis Peranan Perempuan Pada Rantai Nilai Pemasaran Tuna Cakalang Di Tempat Pelelangan Ikan (Tpi) Aertembaga Kota Bitung

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    Penelitian ini dilaksanakan di Tempat Pendaratan Ikan (TPI) Aertembaga Kota Bitung Provinsi Sulawesi Utara dengan tujuan (1) Untuk menganalisis peran, akses dan kotrol atas asset dan sumberdaya dan kekuatan pengambilan kepeutusan perempuan pedagang ikan (2) Untuk menganalisis peranan perempuan pedagang ikan pada rantai nilai pemasaran tuna-cakalang. Manfaat yang diharapkan dari penelitian ini yaitu: (1) Menerapkan ilmu pengetahuan yang telah diperoleh selama kuliah melalui penelitian yang dilakukan di lapangan. (2) Menambah pengetahuan sebagai bekal dalam mengaplikasikan pengetahuan teoritik terhadap masalah praktis. (3) Memberikan sumbangan yang berarti bagi pemerintah dan berbagai pihak juga sebagai bahan tambahan informasi pada yang membutuhkan.Hasil penelitian menunjukkan bahwa peranan perempuan pada rantai nilai pemasaran tuna cakalang sangat besar yaitu mulai dari membeli hingga memasarkan. Laki-laki berperan hanya pada kegiatan mengangkut ikan, baik dari atas kapal maupun ke pasar. Hasil analisis juga menunjukkan perempuan pedagang ikan memiliki peran yang lebih dalam kegiatan domestik, publik dan sosial kemasyarakatan. Perempuan pedagang ikan juga memiliki peran terhadap akses dan kontrol atas aset dan sumber daya perikanan, sedangkan untuk pengambilan keputusan mengenai USAha memasarkan ikan, hal ini sebagian besar dilakukan oleh perempuan. Laki-laki hanya berperan dalam pengambilan keputusan mengenai penetapan dan peminjaman modal

    Assessing the relationship between markers of glycemic control through flexible copula regression models

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    Glycated haemoglobin (HbA1c) is a sensitive marker of blood glucose in patients with diabetes. However, levels can vary considerably, even amongst individuals with similar mean blood glucose concentrations. Other glycated proteins, such as fructosamine, can also act as blood sugar markers, but estimating HbA1c and fructosamine via independent models may lead to errors of interpretation regarding disease severity. From a clinical standpoint, it would be of great interest to know the factors that affect the mean concentration of both HbA1c and fructosamine, which influence the variability in the concentrations of these glycated markers and cause HbA1c/fructosamine discordance. Flexible models are required to illustrate the behaviour of these variables as well as the association between them. This work reviews existing models that might serve in this regard. Flexible copula regression models using splines were used to provide a better understanding of the behaviour of both glycated proteins and the relationship between them under the possible influence of different covariates. This work shows the usefulness of this type of models in practise and provides a basis for their clinical interpretation by means of an understandable case study. Ultimately, to better understand the effects of each continuous covariate, they are represented at the true scale of the response variables

    Advanced computational fluid dynamics (CFD)–multi-body simulation (MBS) coupling to assess low-frequency emissions from wind turbines

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    The low-frequency emissions from a generic 5 MW wind turbine are investigated numerically. In order to regard airborne noise and structure-borne noise simultaneously, a process chain is developed. It considers fluid–structure coupling (FSC) of a computational fluid dynamics (CFD) solver and a multi-body simulations (MBSs) solver as well as a Ffowcs-Williams–Hawkings (FW-H) acoustic solver. The approach is applied to a generic 5 MW turbine to get more insight into the sources and mechanisms of low-frequency emissions from wind turbines. For this purpose simulations with increasing complexity in terms of considered components in the CFD model, degrees of freedom in the structural model and inflow in the CFD model are conducted. Consistent with the literature, it is found that aeroacoustic low-frequency emission is dominated by the blade-passing frequency harmonics. In the spectra of the tower base loads, which excite seismic emission, the structural eigenfrequencies become more prominent with increasing complexity of the model. The main source of low-frequency aeroacoustic emissions is the blade–tower interaction, and the contribution of the tower as an acoustic emitter is stronger than the contribution of the rotor. Aerodynamic tower loads also significantly contribute to the external excitation acting on the structure of the wind turbine.</p

    Clinical Performance Feedback Intervention Theory (CP-FIT): a new theory for designing, implementing, and evaluating feedback in health care based on a systematic review and meta-synthesis of qualitative research

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    Background: Providing health professionals with quantitative summaries of their clinical performance when treating specific groups of patients (“feedback”) is a widely used quality improvement strategy, yet systematic reviews show it has varying success. Theory could help explain what factors influence feedback success, and guide approaches to enhance effectiveness. However, existing theories lack comprehensiveness and specificity to health care. To address this problem, we conducted the first systematic review and synthesis of qualitative evaluations of feedback interventions, using findings to develop a comprehensive new health care-specific feedback theory. Methods: We searched MEDLINE, EMBASE, CINAHL, Web of Science, and Google Scholar from inception until 2016 inclusive. Data were synthesised by coding individual papers, building on pre-existing theories to formulate hypotheses, iteratively testing and improving hypotheses, assessing confidence in hypotheses using the GRADE-CERQual method, and summarising high-confidence hypotheses into a set of propositions. Results: We synthesised 65 papers evaluating 73 feedback interventions from countries spanning five continents. From our synthesis we developed Clinical Performance Feedback Intervention Theory (CP-FIT), which builds on 30 pre-existing theories and has 42 high-confidence hypotheses. CP-FIT states that effective feedback works in a cycle of sequential processes; it becomes less effective if any individual process fails, thus halting progress round the cycle. Feedback’s success is influenced by several factors operating via a set of common explanatory mechanisms: the feedback method used, health professional receiving feedback, and context in which feedback takes place. CP-FIT summarises these effects in three propositions: (1) health care professionals and organisations have a finite capacity to engage with feedback, (2) these parties have strong beliefs regarding how patient care should be provided that influence their interactions with feedback, and (3) feedback that directly supports clinical behaviours is most effective. Conclusions: This is the first qualitative meta-synthesis of feedback interventions, and the first comprehensive theory of feedback designed specifically for health care. Our findings contribute new knowledge about how feedback works and factors that influence its effectiveness. Internationally, practitioners, researchers, and policy-makers can use CP-FIT to design, implement, and evaluate feedback. Doing so could improve care for large numbers of patients, reduce opportunity costs, and improve returns on financial investments
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