Measurement and Modeling of the Acoustic Response in a High Pressure Combustor

In this paper, a one dimensional acoustic network model is presented which can be used as a design tool to predict the limit cycle pressure oscillations in a gas turbine combustor. Analytically represented models are combined with measured flame transfer functions and well defined boundary conditions. Additionally acoustic damping due to turbulence, acoustic reflection at contractions, modification of the acoustic speed of sound due to a mean flow and effect of temperature gradient that play a role in the acoustic modeling of combustion systems have been included in this network model. The model is applied on a high-pressure laboratory combustor. Finally, the measured and predicted dynamic behaviour in the combustor is compared. The results indicate the network modelling approach is a promising design tool for gas turbine combustion application

Markiz is back in business!

Taha Toros Arşivi, Dosya No: 112-Lokantalarİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

Can Management Practices Make a Difference? Nonprofit Organization Financial Performance during Times of Economic Stress

The economic crisis presented unprecedented challenges to nonprofit organizations to sustain their services. In this study, we examined both financial and management factors that influence the financial performance of nonprofit organizations during times of economic stress. In particular, we investigated whether strategic planning and plan implementation, revenue diversification, and board involvement help nonprofit organizations deal with financial uncertainty and strengthen financial performance. Despite the negative impacts that the economic downturn had on nonprofit organizations, we found that the implementation of strategic plans can help nonprofit organizations reduce financial vulnerability. Our findings call attention to key management factors that influence the financial performance of nonprofit organizations

TITLE EMPHASIZING THE SENSE OF NUMBER IN CARTOONS: THE EXAMPLE OF THE CARTOON NAMED "YADE YADE"

In this research, the cartoon "Yade Yade" broadcasted on TRT Çocuk, Turkey's national channel where programs for children's education are broadcast, was examined in terms of number sense components. In this context, 52 episodes of the cartoon "Yade Yade", which has been broadcast on TRT Çocuk since 2020, were used as data sources. Document analysis method was used in data analysis. The 52 episodes of the cartoon "Yade Yade" were examined in terms of number sense components (counting aloud, measuring concepts, nonverbal calculation, number identification, and quantity discrimination) used by Lago and DiPerna (2010). When the number components were analyzed for each section, it was seen that the measuring concepts component was mostly emphasized. This number sense component was followed by number determination, recognizing quantity, counting aloud and nonverbal calculation components. Various suggestions were developed in line with the results of the study. "Yade Yade" cartoon can be used for educational purposes in mathematics lessons in schools to emphasize the number sense, especially the component of measuring concepts. This and similar cartoons can be analyzed in terms of content and concept teaching can be realized in lessons.  Article visualizations

Disaster Policies and Governance: Promoting Community Resilience

This brief editorial introduction highlights the importance of policies and effective governance for disaster resilience including communities, individuals, institutions, and organizations through the execution of deliberate choice and collective action. Effective facilitation of development and implementation of disaster policies can lead to more resilient communities in the aftermath of disasters. The success of design, development, and execution of disaster resilience policies require engagement of the “whole community”

The effect of using animations on pre-service science teachers’ science achievement

AbstractIn this study, the effect of animation technique on the learning of properties of electromagnetic waves (EMWs) for pre-service science teachers has been investigated. The research has been carried out for two weeks on 2nd grade pre-service science teachers. This study has been carried out with experimental and control groups consisted of 70 students in total. 35 students were randomly assigned to experimental group and control group respectively. The achievement test was given to both groups before and after the treatment. Significant difference has been found between the experimental group and control group (p<0,05)

A robust motion design technique for flexible-jointed manipulation systems

This paper presents a robust input shaping technique that significantly reduces (almost eliminates) the residual vibration of manipulation systems typified by a flexiblejointed robot manipulator. The technique consists of two stages. In the first stage, a ramp function is superimposed onto the main trajectory to be preshaped. In the second stage, the outcome of the first stage is convolved with a sequence of two impulses. The robustness of the technique to the uncertainties in the system natural frequency and damping ratio are quantified through simulation and experimental evaluation. Simulation and experimental results demonstrate that the technique is not only effective in reducing the residual vibrations, but also it is robust to the uncertainties of as high as∓35% from the ideal value of the system natural frequency. Further, it has been found that the proposed input shaping technique is insensitive to the uncertainties in the damping ratio. The results allow us to suggest that the proposed technique is versatile and robust enough to apply it to the motion design of any flexible-jointed manipulation system making a point-to-point motion