Force Balance Design for Educational Wind Tunnels

A typical educational wind tunnel need only measure the lift and drag forces and be able to control the angle of attack of the mounted model. This paper presents a simple design for the balance apparatus to measure lift and drag. Two load cells are used in the apparatus, one to measure the vertical force (lift) and one to measure the horizontal force (drag). This can be used for aerodynamics studies of airplane and airfoil models, as well as ground vehicles such as trucks and cars. If desired, a third load cell can be added to enable measurements of the pitching moment. A linear actuator is used to change the angle of attack of plane and airfoil models. The actuator is mounted inside the force balance apparatus, using a parallel four-bar linkage so that the angle of attack is linearly related to the actuator position. The linear actuator can be controlled by a computer, and the lift, drag, and angle of attack data recorded on the same computer. This design is simple and easy to fabricate, can be added to an old wind tunnel in need of an upgrade or replacement or included as part of a new wind tunnel built from scratch. Complete details of the design including engineering drawings are included in the paper. The design is also low cost compared to commercial wind tunnel balances and gives sufficient accuracy for educational and some research purposes. A counterweight is used to mechanically zero the force readout. The new load balance has been tested and found accurate. It has sufficient precision to perform a sting drag measurement as well. A quick-connect mechanism is used for mounting and removing models

From fruitflies to mammals: mechanisms of signalling via the Sonic hedgehog pathway in lung development

The hedgehog signalling pathway has been implicated in many different processes in fly and vertebrate development. It is now known that the hedgehog cascade is crucial for the patterning of the early respiratory system. Hedgehog signalling in the lung involves Gli transcription proteins, but their potential downstream target genes have yet to be identified. Bmp4 and Fgf10 have been shown to regulate lung branching morphogenesis but seem not to be targets of hedgehog signalling

Capstone Teams: An Industry Based Model

Project teams, a mainstay in industry practice, are being employed in many capstone design courses. This paper examines industry models for teams and their application to a specific capstone design course. Following Katzenbach and Smith’s basics of high performing teams, teams are formed based on individuals skills. The team is made accountable and committed both as a group and as individuals through the structure and format of the course. The course structure is then planned so that teams progress through Tuckman’s development stages of forming, storming, norming and performing, during their two semester capstone design project

Use of Alumni Advisory Board in Assessment of Achievement of Student Outcomes in Capstone Design

This paper discussed the use of the Alumni Advisory Board in assessment of capstone design projects. Since it is an ABET requirement that engineering programs obtain input from outside constituents on the continuous improvement processes for their programs, practically all engineering departments have established some form of external alumni advisory board which meets with the department administration and faculty on a regular basis, usually every semester. Since these boards are already in place, they can be used to assess the achievement of ABET student outcomes in the capstone design course. Specifically, the Alumni Advisory Board can be used to evaluate students’ oral presentations, if the schedule of their visit is aligned to coincide with the required presentations of the capstone design course. The Alumni Advisory Board members can also evaluate the final written project reports, which can be done anytime after the completion of the student projects, and so is not schedule dependent. At Bradley University we have conducted both of these assessments over the last ten years. An evaluation template has been developed for the final written reports that covers most of the ABET student outcomes a-k. A rubric has also been developed for evaluation of student poster presentations

Distinct Changes in Placental Ceramide Metabolism Characterize Type 1 and 2 Diabetic Pregnancies with Fetal Macrosomia or Preeclampsia

Disturbances of lipid metabolism are typical in diabetes. Our objective was to characterize and compare placental sphingolipid metabolism in type 1 (T1D) and 2 (T2D) diabetic pregnancies and in non-diabetic controls. Placental samples from T1D, T2D, and control pregnancies were processed for sphingolipid analysis using tandem mass spectrometry. Western blotting, enzyme activity, and immunofluorescence analyses were used to study sphingolipid regulatory enzymes. Placental ceramide levels were lower in T1D and T2D compared to controls, which was associated with an upregulation of the ceramide degrading enzyme acid ceramidase (ASAH1). Increased placental ceramide content was found in T1D complicated by preeclampsia. Similarly, elevated ceramides were observed in T1D and T2D pregnancies with poor glycemic control. The protein levels and activity of sphingosine kinases (SPHK) that produce sphingoid-1-phosphates (S1P) were highest in T2D. Furthermore, SPHK levels were upregulated in T1D and T2D pregnancies with fetal macrosomia. In vitro experiments using trophoblastic JEG3 cells demonstrated increased SPHK expression and activity following glucose and insulin treatments. Specific changes in the placental sphingolipidome characterize T1D and T2D placentae depending on the type of diabetes and feto-maternal complications. Increased exposure to insulin and glucose is a plausible contributor to the upregulation of the SPHK-S1P-axis in diabetic placentae

BOKASUN: a fast and precise numerical program to calculate the Master Integrals of the two-loop sunrise diagrams

We present the program BOKASUN for fast and precise evaluation of the Master Integrals of the two-loop self-mass sunrise diagram for arbitrary values of the internal masses and the external four-momentum. We use a combination of two methods: a Bernoulli accelerated series expansion and a Runge-Kutta numerical solution of a system of linear differential equations

Product shape change by internal stresses

The design of a product component may require complex processing steps such as metal forming followed by a thermal treatment. The thermal treatment may improve the functional performance of the material itself, but may result in rather unwanted changes in the shape of the product. Here it is shown that Finite Element modeling of the various processes can assist in the design of a robust and accurate production process. The modeling approach presented allows a coupling between various complex material models, in such a way that full cold forming and thermal treatment processes are calculated. This coupling of material models is key for the design and concerns the novelty of the proposed approach. Cold forming by deep drawing is calculated whereby planar anisotropy is implemented. The thermal hardening treatment consists of three contributions: creep, thermal expansion and phase transformation. All models are based on experimental data, acquired from tensile and dilatometer tests, and are implemented into the material model either directly or by a simple fit. It is shown that the effects of a complete forming and heat treatment of a cup could be successfully calculated. The predicted cup shape change was compared to experiments, and shows excellent agreement.This research was carried out under the project number T63.3.12480 in the framework of the research program of the Materials innovation institute M2i, Delft, the Netherlands; and has been part of Press Perfect project, RFSR-CT-2012-00021 funded by the Research Fund for Coal & Steel.Peer Reviewe

Congenital diaphragmatic hernia: Comparison of animal models and relevance to the human situation

Congenital diaphragmatic hernia (CDH) occurs in 1 in 3,000 newborns. Mortality and morbidity are due to the amount of pulmonary hypoplasia (PH), the response on artificial ventilation and the presence of therapy-resistant pulmonary hypertension. The pathogenesis and etiology of CDH and its associated anomalies are still largely unknown despite all research efforts over the past years. Several animal models have been proposed to study CDH. In this review we compare surgical, pharmacological and transgenic models, and discuss their strengths and limitations to study PH

General transport properties of superconducting quantum point contacts: a Green functions approach

We discuss the general transport properties of superconducting quantum point contacts. We show how these properties can be obtained from a microscopic model using nonequilibrium Green function techniques. For the case of a one-channel contact we analyze the response under different biasing conditions: constant applied voltage, current bias and microwave-induced transport. Current fluctuations are also analyzed with particular emphasis on thermal and shot-noise. Finally, the case of superconducting transport through a resonant level is discussed. The calculated properties show a remarkable agreement with the available experimental data from atomic-size contacts measurements. We suggest the possibility of extending this comparison to several other predictions of the theory.Comment: 10 pages, revtex, 8 figures, submitted to a special issue of Superlattices and Microstructure