From Strain to Loads: Development of a Measurement Solution for Wind Turbine Transmission Input Loads during Drivetrain Testing.

As wind energy is paving the way for the energy transition from fossil to renewable energy sources, the ongoing trend of increasing the rated power of wind turbines aims to reduce the overall cost of wind energy. The resulting increase in drivetrain loads motivates the need for wind turbine (WT) drivetrain testing in the development phase of critical components such as the WT main gearbox (GB). While several WT system test benches allow for the application of emulated rotor loads in six degrees of freedom (6-DOF), the drivetrain input loads can significantly differ from the GB 6-DOF input loads due to the design of the drivetrain under test. However, currently available load measurement solutions are not capable of sensing GB input loads in 6-DOF. Thus, this work aims to develop a methodology for converging signals from a purposely designed sensor setup and turbine specific design parameters to compute the GB 6-DOF input loads during WT testing. Strain gauges (SG) and accelerometers have been installed on the low-speed shaft (LSS) of a WT drivetrain under test at the 4MW WT system test bench at the Center for Wind Power Drives. Using the data of the aforementioned sensors, a methodology for computing the GB input loads is developed. The methodology is validated through comparison to the applied loads data provided by the aforementioned test bench. The results demonstrate the high promise of the proposed method for estimating the GB input loads during WT drivetrain testing.

Sensor Screening Methodology for Virtually Sensing Transmission Input Loads of a Wind Turbine Using Machine Learning Techniques and Drivetrain Simulations.

The ongoing trend of building larger wind turbines (WT) to reach greater economies of scale is contributing to the reduction in cost of wind energy, as well as the increase in WT drivetrain input loads into uncharted territories. The resulting intensification of the load situation within the WT gearbox motivates the need to monitor WT transmission input loads. However, due to the high costs of direct measurement solutions, more economical solutions, such as virtual sensing of transmission input loads using stationary sensors mounted on the gearbox housing or other drivetrain locations, are of interest. As the number, type, and location of sensors needed for a virtual sensing solutions can vary considerably in cost, in this investigation, we aimed to identify optimal sensor locations for virtually sensing WT 6-degree of freedom (6-DOF) transmission input loads. Random forest (RF) models were designed and applied to a dataset containing simulated operational data of a Vestas V52 WT multibody simulation model undergoing simulated wind fields. The dataset contained the 6-DOF transmission input loads and signals from potential sensor locations covering deformations, misalignments, and rotational speeds at various drivetrain locations. The RF models were used to identify the sensor locations with the highest impact on accuracy of virtual load sensing following a known statistical test in order to prioritize and reduce the number of needed input signals. The performance of the models was assessed before and after reducing the number of input signals required. By allowing for a screening of sensors prior to real-world tests, the results demonstrate the high promise of the proposed method for optimizing the cost of future virtual WT transmission load sensors.

Development and validation of a parametric human mandible model to determine internal stresses for the future design optimization of maxillofacial implants.

Large segmental mandible bone defects still represent a challenge for endogenous regeneration. Despite the bone's capacity to heal in many clinical situations, bone defects over a critical size do not heal spontaneously. An emerging treatment of critically sized mandibular defects is the implantation of individually manufactured scaffolds consisting of biodegradable magnesium alloys. Biomedical engineers faced the challenge of developing a scaffold structure that not only provides sufficient stability, but also stimulates and promotes bone growth while considering the degradation of the magnesium alloy. The porosity of the scaffold must also support bone ingrowth and neovascularization. For an optimal design and subsequent structural optimization knowledge of external load cases is essential. However, currently the muscle and joint forces of the mandible cannot be measured directly. The aim of our study was therefore the development of a parametric human mandible model to determine the relevant boundary conditions for the subsequent structural optimization of individual jawbone implants. Using a model-based approach, determining the essential external load of the mandible as a function of the age and sex of a patient individually and the realistic simulation of the mechanical stress for patient-specific loads and anatomies has been realized. The developed model is successfully validated by evaluating the deformations and stresses of the lower jaw of a possible patient and comparing them with the results of dental research. Based on the results of the modelling, in a subsequent optimization process section forces at the interface between the bone tissue and jawbone implant can be determined and used to optimize the design of the jawbone implant.

Model-Based Estimation of the Strength of Laser-Based Plastic-Metal Joints Using Finite Element Microstructure Models and Regression Models.

Plastic-metal joints with a laser-structured metal surface have a high potential to reduce cost and weight compared to conventional joining technologies. However, their application is currently inhibited due to the absence of simulation methods and models for mechanical design. Thus, this paper presents a model-based approach for the strength estimation of laser-based plastic-metal joints. The approach aims to provide a methodology for the efficient creation of surrogate models, which can capture the influence of the microstructure parameters on the joint strength. A parametrization rule for the shape of the microstructure is developed using microsection analysis. Then, a parameterized finite element (FE) model of the joining zone on micro level is developed. Different statistical plans and model fits are tested, and the predicted strength of the FE model and the surrogate models are compared against experiments for different microstructure geometries. The joint strength is predicted by the FE model with a 3.7% error. Surrogate modelling using half-factorial experimental design and linear regression shows the best accuracy (6.2% error). This surrogate model can be efficiently created as only 16 samples are required. Furthermore, the surrogate model is provided as an equation, offering the designer a convenient tool to estimate parameter sensitivities.

Prognostic model for newly diagnosed CLL patients in Binet stage A: results of the multicenter, prospective CLL1 trial of the German CLL study group.

The heterogeneity of early stage CLL challenges prognostication, and refinement of prognostic indices for risk-adapted management in this population is essential. The aim of the multicenter, prospective CLL1 trial was to explore a novel prognostic model (CLL1-PM) developed to identify risk groups, separating patients with favorable from others with dismal prognosis. A cohort of 539 clinically, biochemically, and genetically characterized Binet stage A patients were observed until progression, first-line treatment, or death. Multivariate analysis identified six independent factors associated with overall survival (OS) and time-to-first treatment (TTFT): del(17p), unmutated IGHV, del(11q), ß2-microglobulin >3.5 mg/dL, lymphocyte doubling time (LDT) <12 months, and age >60 years. These factors were integrated into the CLL1-PM, which stratified patients into four risk groups. The CLL1-PM was prognostic for OS and TTFT, e.g., the risk of treatment at 5 years was 85.9, 51.8, 27.6, and 11.3% for very low (0-1.5), low (2-4), high (4.5-6.5), and very high-risk (7-14) scores, respectively (P < 0.001). Notably, in addition to factors comprising CLL-IPI, we substantiated del(11q) and LDT as prognostic factors in early CLL. Altogether, our findings would be useful to effectively stratify Binet stage A patients, particularly within the scope of clinical trials evaluating novel agents.

Life cycle assessment and sustainable engineering in the context of near net shape grown components: striving towards a sustainable way of future production.

Technical product harvesting (TEPHA) is a newly developing interdisciplinary approach in which bio-based production is investigated from a technical and ecological perspective. Society's demand for ecologically produced and sustainably operable goods is a key driver for the substitution of conventional materials like metals or plastics through bio-based alternatives. Technical product harvesting of near net shape grown components describes the use of suitable biomass for the production of technical products through influencing the natural shape of plants during their growth period. The use of natural materials may show positive effects on the amount of non-renewable resource consumption. This also increases the product recyclability at the end of its life cycle. Furthermore, through the near net shape growth of biomass, production steps can be reduced. As a consequence such approaches may save energy and the needed resources like crude oil, coal or gas. The derived near net shape grown components are not only considered beneficial from an environmental point of view. They can also have mechanical advantages through an intrinsic topology optimization in contrast to common natural materials, which are influenced in their shape after harvesting. In order to prove these benefits a comprehensive, interdisciplinary scientific strategy is needed. Here, both mechanical investigations and life cycle assessment as a method of environmental evaluation are used.

Observational study of adjuvant therapy with capecitabine in colon cancer.

OBJECTIVE: This observational study was conducted to document the safety of capecitabine-based adjuvant therapy in patients with resected colon cancer under routine clinical conditions. RESEARCH AND DESIGN METHODS: ML20431 was a prospective, multicenter, non-interventional, observational study. It was designed to answer five research questions relating to safety, dosage and administration, and discontinuation from capecitabine-based adjuvant therapy. Patients were required to have R0 resected stage III colon cancer and have started treatment with capecitabine-based adjuvant therapy based on a decision by the investigator. Patients were followed over an observation period of ≤6 months after initiation of therapy. Investigators were required to complete the study case report form at study entry, each treatment cycle, and at the final examination. MAIN OUTCOME MEASURES: A total of 1485 patients were included in the study, and 1481 patients were treated with capecitabine and formed the analysis population. Most patients had colon cancer (78.3%), followed by rectal cancer (16.4%). Most patients had stage III disease (69.3%); the remaining patients had stage II disease (30.7%). The most common all-grade adverse reactions were hand-foot syndrome (46.9%), diarrhea (34.4%), and hemoglobin decreases (31.5%). Grade 3/4 adverse reactions were infrequent (<4%). Serious adverse events were reported in 96 patients (6.5%). Six or more cycles of treatment were completed by 77.9% of patients. Approximately two-thirds of patients (67.3%) received capecitabine monotherapy and the remainder (32.7%) received capecitabine in combination with ≥1 drugs, most commonly oxaliplatin (460 cases). Discontinuation of capecitabine was documented in 344 patients (23.2%). STUDY LIMITATIONS: no efficacy data were collected; the questionnaires for patients' expectations and satisfaction were not formally validated; and a few patients (<1.5%) had some retrospective data. CONCLUSIONS: The safety profile of capecitabine-based adjuvant therapy in a broad patient population with colon cancer is similar to that previously documented in phase III clinical trials.

Solitary pulmonary plasmacytoma: report of two cases.

We report two cases of solitary plasmacytoma of the lung. Computed tomographic scan disclosed in case A a solid tissue formation in a cystic pulmonary lesion and in case B a solitary nodule. Suggesting aspergilloma in A and pulmonary malignancy in B diagnostic thoracotomies were performed and the respective findings were resected. In both cases a diagnosis of plasmacytoma was made. Postoperatively multiple myeloma was ruled out. Solitary pulmonary plasmacytoma is a very rare condition and to the best of our knowledge plasmacytoma within a cystic lung lesion has not been described so far. After curative resection treatment the prognosis of these circumscript lesions should be excellent.

Low sensitivity of the ki-ras polymerase chain reaction for diagnosing pancreatic cancer from pancreatic juice and bile: a multicenter prospective trial.

PURPOSE: Early detection of pancreatic cancer using molecular markers may improve outcome. Mutations of the ki-ras oncogene are detected in 70% to 90% of pancreatic adenocarcinomas. A prospective, partially blinded, multicenter diagnostic trial was performed to test the sensitivity and specificity of the ki-ras polymerase chain reaction (PCR) analysis of pancreatic juice and bile specimens. PATIENTS AND METHODS: Specimens of pancreatic juice and bile were collected from 532 consecutive patients. Mutations in codon 12 of the ki-ras gene were identified by two independent enrichment PCRs and confirmed by direct sequencing. RESULTS: One hundred seventy-four of 532 patients were excluded from the final analysis (reasons: no amplifiable DNA, no specimen or only duodenal juice sent, lost to follow-up). Sixty-three of 358 patients had ductal pancreatic cancer. In 24 (38.1%) of 63 patients, a mutated ki-ras gene was identified in pancreatic juice and/or bile. Ki-ras mutations were found in four (8%) of 50 cases of chronic pancreatitis, in 10 (18.7%) of 53 cases of other malignancies of the pancreaticobiliary tree, and in 14 (7.3%) of 192 cases of benign diseases or normal findings. Sensitivity and specificity of the ki-ras PCR analysis for the detection of pancreatic cancer was 38.1% and 90.5%, respectively. CONCLUSION: In this prospective trial performed in nonselected patients, mutations of the ki-ras gene were detected in 38.1% of cases with pancreatic cancer. This test in its present form is not appropriate to confirm or screen for pancreatic cancer. More sensitive and/or quantitative PCR tests may improve the molecular diagnosis of pancreatic cancer.

Nitric oxide pathways in human bladder carcinoma. The distribution of nitric oxide synthases, soluble guanylyl cyclase, cyclic guanosine monophosphate, and nitrotyrosine.

BACKGROUND: Nitric oxide (NO) is produced by a group of synthase enzymes (NOS). By means of different pathways, NO exerts several functions in benign and malignant human bladder tissues. The current paper describes the NO/guanylate cyclase (sGC)/cyclic guanosine monophosphate (cGMP) and the NO/oxidative pathways in human bladder tissues. METHODS: Bladder carcinoma tissues were collected from 18 patients by transurethral resection procedures. Normal benign vesical tissue specimens from a further eight patients with benign diseases served as controls. Immunohistochemistry was conducted for localization of sGC, cGMP, and nitrotyrosine in benign and malignant vesical tissues, evaluating two-three tissue sections per patient. RESULTS: Positive immunolabeling for sGC and cGMP was detected in vascular endothelial cells of normal and malignant vesical tissues. Those signals were most intense in bladder carcinoma tissues. Immunolabeling for sGC and cGMP was also detected in normal urothelial cells. In bladder carcinoma cells, a heterogeneous immunolabeling for sGC and cGMP was seen, with a wide spectrum of signal intensity. Positive immunostaining for sGC and cGMP was also observed in stromal round cells in benign and malignant bladder tissues. Immunolabeling for nitrotyrosine was mainly observed in endothelial cells, with a much stronger immunolabeling in bladder carcinoma tissues compared to normal benign controls. A weak immunolabeling for nitrotyrosine was also observed in bladder carcinoma cells. Normal urothelial cells did not show such nitrotyrosine expression. CONCLUSIONS: The current report provides evidences that NO play several roles through different pathways in benign and malignant vesical tissues. The influences generated by NO molecules can be divided into cGMP-mediated effects (those resulting from the NO/sGC/cGMP pathway) and non-cGMP-mediated effects (those resulting from the NO/oxidative pathway). Increased angiogenesis is a cGMP-mediated effect, while nitrotyrosine production is a non cGMP-mediated oxidative effect. Such an NO/oxidative pathway is observed more often in bladder carcinoma.