Split torque transmission load sharing

Split torque transmissions are attractive alternatives to conventional planetary designs for helicopter transmissions. The split torque designs can offer lighter weight and fewer parts but have not been used extensively for lack of experience, especially with obtaining proper load sharing. Two split torque designs that use different load sharing methods have been studied. Precise indexing and alignment of the geartrain to produce acceptable load sharing has been demonstrated. An elastomeric torque splitter that has large torsional compliance and damping produces even better load sharing while reducing dynamic transmission error and noise. However, the elastomeric torque splitter as now configured is not capable over the full range of operating conditions of a fielded system. A thrust balancing load sharing device was evaluated. Friction forces that oppose the motion of the balance mechanism are significant. A static analysis suggests increasing the helix angle of the input pinion of the thrust balancing design. Also, dynamic analysis of this design predicts good load sharing and significant torsional response to accumulative pitch errors of the gears

Vibration Analysis of a Split Path Gearbox

Split path gearboxes can be attractive alternatives to the common planetary designs for rotorcraft, but because they have seem little use, they are relatively high risk designs. To help reduce the risk of fielding a rotorcraft with a split path gearbox, the vibration and dynamic characteristics of such a gearbox were studied. A mathematical model was developed by using the Lagrangian method, and it was applied to study the effect of three design variables on the natural frequencies and vibration energy of the gearbox. The first design variable, shaft angle, had little influence on the natural frequencies. The second variable, mesh phasing, had a strong effect on the levels of vibration energy, with phase angles of 0 degrees and 180 degrees producing low vibration levels. The third design variable, the stiffness of the shafts connecting the spur gears to the helical pinions, strongly influenced the natural frequencies of some of the vibration modes, including two of the dominant modes. We found that, to achieve the lowest level of vibration energy, the natural frequencies of these two dominant modes should be less than those of the main excitation sources.https://engagedscholarship.csuohio.edu/scholbks/1128/thumbnail.jp

Early Recognition of Burn- and Trauma-Related Acute Kidney Injury: A Pilot Comparison of Machine Learning Techniques.

Severely burned and non-burned trauma patients are at risk for acute kidney injury (AKI). The study objective was to assess the theoretical performance of artificial intelligence (AI)/machine learning (ML) algorithms to augment AKI recognition using the novel biomarker, neutrophil gelatinase associated lipocalin (NGAL), combined with contemporary biomarkers such as N-terminal pro B-type natriuretic peptide (NT-proBNP), urine output (UOP), and plasma creatinine. Machine learning approaches including logistic regression (LR), k-nearest neighbor (k-NN), support vector machine (SVM), random forest (RF), and deep neural networks (DNN) were used in this study. The AI/ML algorithm helped predict AKI 61.8 (32.5) hours faster than the Kidney Disease and Improving Global Disease Outcomes (KDIGO) criteria for burn and non-burned trauma patients. NGAL was analytically superior to traditional AKI biomarkers such as creatinine and UOP. With ML, the AKI predictive capability of NGAL was further enhanced when combined with NT-proBNP or creatinine. The use of AI/ML could be employed with NGAL to accelerate detection of AKI in at-risk burn and non-burned trauma patients

Derjaguin-Landau-Verwey-Overbeek Energy Landscape of a Janus Particle with a Nonuniform Cap

A colloidal particle is often termed “Janus” when some portion of its surface is coated by a second material which has distinct properties from the native particle. The anisotropy of Janus particles enables unique behavior at interfaces. However, rigorous methodologies to predict Janus particle dynamics at interfaces are required to implement these particles in complex fluid applications. Previous work studying Janus particle dynamics does not consider van der Waals interactions and realistic, nonuniform coating morphology. Here we develop semianalytic equations to accurately calculate the potential landscape, including van der Waals interactions, of a Janus particle with nonuniform coating thickness above a solid boundary. The effects of both nonuniform coating thickness and van der Waals interactions significantly influence the potential landscape of the particle, particularly in high ionic strength solutions, where the particle samples positions very close to the solid boundary. The equations developed herein facilitate more simple, accurate, and less computationally expensive characterization of conservative interactions experienced by a confined Janus particle than previous methods

Psychological disorders inwomen with spontaneous preterm delivery

Background: Preterm delivery is a major cause of mortality in infants. The prevalence of preterm delivery is rising over time. Psychological disorders have been associated with preterm delivery. In this study, we aimed to compare the frequency of psychological disorders among women with spontaneous preterm versus term delivery. Methods: In this cross-sectional study, psychological disorders in 60 women, who experienced spontaneous term delivery and in 60 women who had spontaneous preterm delivery (gestational age of less than 37 weeks) were examined, using symptom checklist-90-revised questionnaire (SCL-90-R) in Akbarabadi teaching hospital during 2014. The question scales were compared between the two groups, using Chi 2 test and independent t-test. Results: The mean age of the participants was 23.58±4.26, and 23.90±4.71 in preterm-delivery and term-delivery groups, respectively (P value = 0.22). The mean score of Symptom checklist-90-revised questionnaire (SCL-90-R) was 102.21 (±35.81) in women with preterm delivery, and it was 59.14±22.17 in women with term delivery, which was significantly different (P value < 0.001). In addition, the total score and the score for all the subscales of psychological disorder were higher in women with preterm delivery (P value < 0.001). Conclusions: Psychological disorders in pregnancy are associated with an increased risk of preterm delivery. Therefore, future studies should focus on finding ways to lower psychological disorders in late pregnancy. © 2016, Shiraz University of Medical Sciences

SAT based Enforcement of Domotic Effects in Smart Environments

The emergence of economically viable and efficient sensor technology provided impetus to the development of smart devices (or appliances). Modern smart environments are equipped with a multitude of smart devices and sensors, aimed at delivering intelligent services to the users of smart environments. The presence of these diverse smart devices has raised a major problem of managing environments. A rising solution to the problem is the modeling of user goals and intentions, and then interacting with the environments using user defined goals. `Domotic Effects' is a user goal modeling framework, which provides Ambient Intelligence (AmI) designers and integrators with an abstract layer that enables the definition of generic goals in a smart environment, in a declarative way, which can be used to design and develop intelligent applications. The high-level nature of domotic effects also allows the residents to program their personal space as they see fit: they can define different achievement criteria for a particular generic goal, e.g., by defining a combination of devices having some particular states, by using domain-specific custom operators. This paper describes an approach for the automatic enforcement of domotic effects in case of the Boolean application domain, suitable for intelligent monitoring and control in domotic environments. Effect enforcement is the ability to determine device configurations that can achieve a set of generic goals (domotic effects). The paper also presents an architecture to implement the enforcement of Boolean domotic effects, and results obtained from carried out experiments prove the feasibility of the proposed approach and highlight the responsiveness of the implemented effect enforcement architectur

Diagnosing students' difficulties in learning mathematics

This study considers the results of a diagnostic test of student difficulty and contrasts the difference in performance between the lower attaining quartile and the higher quartile. It illustrates a difference in qualitative thinking between those who succeed and those who fail in mathematics, illustrating a theory that those who fail are performing a more difficult type of mathematics (coordinating procedures) than those who succeed (manipulating concepts). Students who have to coordinate or reverse processes in time will encounter far greater difficulty than those who can manipulate symbols in a flexible way. The consequences of such a dichotomy and implications for remediation are then considered