Practical Method for Burner Staging Turbine Forced Response Evaluation

2021 ◽  
Author(s):  
Nikola Kafedzhiyski ◽  
Maria Mayorca
Keyword(s):  
Parametric Method ◽  
Practical Method ◽  
Forced Response ◽  
Base Case ◽  
Inlet Temperature ◽  
Before And After ◽  
Efficiency Increase ◽  
Annular Combustor ◽  
Time Marching ◽  
To Come

Abstract Decarbonization and sustainability efforts challenge gas turbine engineers to come up with creative strategies for reduction of emissions and efficiency increase over the whole operating range. Burner staging at part loads presents a flexible solution to achieve these goals through selective burner deactivation. Shutting off burners could also be required for combustion of increased H2 content at some conditions. Burner staging will create circumferential unevenness with patterns of hot and cold streaks that could excite blade rows through the entire turbine. This paper presents a parametric method for annular combustor staging patterns profile generation intended for use for forced response predictions from a limited number of combustor CFD calculations while keeping the key phenomenological features. Two cases with burner staging turbine inlet temperature distributions are considered and compared to a base case with uniform temperature distribution. The unsteady aerodynamic forcing was obtained from full wheel time marching unsteady computational fluid dynamics calculations. The results show that the hot streaks generate important and noticeable excitation sources. Additionally, the results show that the pattern generator could be used extensively before and after the unsteady calculations phase to minimize the excitation levels and the computational load.

Practical Method for Burner Staging Turbine Forced Response Evaluation

2021 ◽  
Author(s):  
Nikola Kafedzhiyski ◽  
Maria Mayorca
Keyword(s):  
Parametric Method ◽  
Practical Method ◽  
Forced Response ◽  
Base Case ◽  
Inlet Temperature ◽  
Before And After ◽  
Efficiency Increase ◽  
Annular Combustor ◽  
Time Marching ◽  
To Come

Abstract Decarbonization and sustainability efforts challenge gas turbine engineers to come up with creative strategies for reduction of emissions and efficiency increase over the whole operating range. Burner staging at part loads presents a flexible solution to achieve these goals through selective burner deactivation. Shutting off burners could also be required for combustion of increased H2 content at some conditions. Burner staging will create circumferential unevenness with patterns of hot and cold streaks that could excite blade rows through the entire turbine. This paper presents a parametric method for annular combustor staging patterns profile generation intended for use for forced response predictions from a limited number of combustor CFD calculations while keeping the key phenomenological features. Two cases with burner staging turbine inlet temperature distributions are considered and compared to a base case with uniform temperature distribution. The unsteady aerodynamic forcing was obtained from full wheel time marching unsteady computational fluid dynamics calculations. The results show that the hot streaks generate important and noticeable excitation sources. Additionally, the results show that the pattern generator could be used extensively before and after the unsteady calculations phase to minimize the excitation levels and the computational load.

Twenty Years After the Hype

2015 ◽  
Vol 2 (2) ◽  
pp. 1-21 ◽  
Author(s):  
Alois Paulin
Keyword(s):  
Performance Indicators ◽  
The State ◽  
Government Performance ◽  
Before And After ◽  
To Come ◽  
And Performance ◽  
Government Reforms

In this study the authors analyze the effects of e-government reforms that began in mid-90ies by confronting the promises which these reforms made to government performance in the period before and after the reforms took place. The authors use fiscal and performance indicators of the Slovenian government and courts to argue that e-government did not yield any notable effects on the state performance. Finally, the authors analyze the reasons why e-government technology cannot be regarded as sustainable and suggest a different approach towards researching how to sustainably improve governance for generations to come.

scholarly journals A Secure Two Factor Authentication Protocol for Cloud-Assisted Wireless Body Area Network Using Blockchain

2021 ◽  
Vol 9 (1) ◽  
pp. 71-79
Author(s):  
Jacqualine Cristhy Ujil
Keyword(s):  
Cloud Computing ◽  
Wireless Body Area Network ◽  
Practical Method ◽  
Security And Privacy ◽  
Body Area Network ◽  
Area Network ◽  
Body Area ◽  
Secure Protocol ◽  
Confidential Data ◽  
To Come

The recent advancements in technologies have allowed us to come so far and resulted in many breakthroughs. One of the various examples is internet of things, wireless communication, and cloud computing which can be useful if utilize in many fields. In the field of medical, these advancements allowed any medical centres to improve patient’s health remotely simply by using wearable devices on patients that then will amalgamate with the wireless body area network (WBAN). However, WBAN has limited resources which limits its services. To solve this problem, cloud computing is used to provide storage and computation. Unfortunately, these methods allow the system to be vulnerable to various malicious attacks. Attackers can easily gain access to the medical records of patients hence the integrity of security and privacy of confidential data have been compromised. In this paper, we presented a secure protocol for cloud-assisted database using multi-factor authentication and blockchain as an added measure to ensure security. Accordingly, we prove that the presented scheme offers more security and privacy. Therefore, it is the most practical method to be applied in the medical field.

scholarly journals Cryo-electron microscopy of vitrified specimens

1988 ◽  
Vol 21 (2) ◽  
pp. 129-228 ◽  
Author(s):  
Jacques Dubochet ◽  
Marc Adrian ◽  
Jiin-Ju Chang ◽  
Jean-Claude Homo ◽  
Jean Lepault ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Practical Method ◽  
New Technique ◽  
Biological Matter ◽  
Cryo Electron Microscopy ◽  
To Come

Cryo-electron microscopy of vitrified specimens was just emerging as a practical method when Richard Henderson proposed that we should teach an EMBO course on the new technique. The request seemed to come too early because at that moment the method looked more like a laboratory game than a useful tool. However, during the months which ellapsed before the start of the course, several of the major difficulties associated with electron microscopy of vitrified specimens found surprisingly elegant solutions or simply became non-existent. The course could therefore take place under favourable circumstances in the summer of 1983. It was repeated the following years and cryo-electron microscopy spread rapidly. Since that time, water, which was once the arch enemy of all electronmicroscopists, became what it always was in nature – an integral part of biological matter and a beautiful substance.

Study on the planarization behaviour of copper CMP utilizing a dense pattern and a global step

2005 ◽  
Vol 867 ◽  
Author(s):  
Tilo Bormann ◽  
Johann W. Bartha
Keyword(s):  
Removal Rate ◽  
Specific Pattern ◽  
Constant Density ◽  
Large Area ◽  
Before And After ◽  
Contour Evolution ◽  
Copper Cmp ◽  
To Come ◽  
Dense Pattern

AbstractThe major aim of CMP is not the removal of excess material but the planarization of the surface. Therefore the determination of the planarization length appears to be more important than the removal rate itself. It has been shown, that the planarization length is not a constant process parameter, but is related to the removal respectively to the polish time in a square root behaviour. Founded on models proposed by Boning, Ouma, et. al. we applied a sequential polish on a single quasi infinite step. The resulting profile could be simulated by a sequential convolution of the surface contour with a Gaussian transfer function.To come closer to the situation on a chip pattern we investigated the planarization behaviour on a specific pattern of the MIT854AZ copper CMP test chip, where a large area of unpatterned surface touches a pattern with a specific constant density.The 200 mm wafer samples consisted of RIE structured oxide films covered with 850 nm ECD copper. The polish was performed on a standard semiconductor manufacturing tool, using a commercial consumables set. The surface profiles were determined by a high resolution profiler within the polishing sequence. The densely patterned areas are removed within a certain polishing time while the transition point between the unpatterned and patterned area appears as a global step. The deposited copper thickness is sufficient to study the contour evolution in both phases, before and after removal of the dense pattern. The paper presents the experimental results on the contour evolution for the patterned fields as well as the global step.

The Application of Autogenic Feedback Training in a Smoking Termination Program

1980 ◽  
Vol 10 (4) ◽  
pp. 331-341
Author(s):  
Jean K. Boullion ◽  
W. William Chen
Keyword(s):  
Practical Method ◽  
Anxiety Reduction ◽  
Control Group ◽  
Feedback Training ◽  
Before And After ◽  
The Relationship ◽  
Effective Adjunct ◽  
Experimental Group

The tremendous potential for autogenic feedback training in helping smokers to deal with their anxiety before and after termination as well as the need to make autogenic feedback training in a practical method for smoking termination prompted this study which: (1) investigated the changes in smoking activity in subjects who have had autogenic feedback training and those who have not; (2) investigated the relationship between the success in performing autogenic feedback and the success in smoking termination; and (3) investigated the effect of autogenic feedback training on anxiety reduction before and after smoking termination. Twenty-three subjects were randomly assigned to two groups. The first group received the autogenic feedback training initially while the second group served as the control. This control group became a second experimental group upon the completion of the first phase. The results of the study revealed that the autogenic feedback training was an effective adjunct to a smoking termination program. Eighty-one per cent reduction in smoking activity was found for the subjects that received the training.

Modelling and Characterization of Submicron P-Channel MOSFET's Locally Degraded by Hot Carrier Injection

1991 ◽  
Vol 225 ◽  
Author(s):  
A. Hassein-Bey ◽  
S. Cristoloveanu
Keyword(s):  
Practical Method ◽  
Parameter Extraction ◽  
Carrier Injection ◽  
Hot Carrier ◽  
Hot Carrier Injection ◽  
Strong Inversion ◽  
Before And After ◽  
Basic Characteristics ◽  
Channel Region

ABSTRACTThe influence of the localized defective channel region formed by hot carrier injection on the basic characteristics of P-channel transistors is systematically investigated and modeled. A practical method of parameter extraction in stressed P-MOSFET's is proposed. It is based on the comparison of Ids(Vg) characteristics before and after stress in weak and strong inversion.

scholarly journals Betting on Canada: the immigration trajectories of Mexican professionals as international students

2021 ◽  
Author(s):  
Claudia Iveth Suarez Zamora
Keyword(s):  
International Students ◽  
Qualitative Approach ◽  
Financial Investment ◽  
The Past ◽  
Professional Careers ◽  
Before And After ◽  
Research Findings ◽  
To Come ◽  
Inclusive Society ◽  
Push Factor

Canada has positioned itself as a destination for thousands of international students from all over the world. Arguably, by offering a relatively affordable education, and an inclusive society. Over the past two decades, the number of international students to Canada has not just increased, but also become more diverse by places of birth, age, marital status, education, and prior occupation. Even though many international students come to Canada when they are single young adults, some arrive with their families leaving behind professional careers back home. Using a qualitative approach, this research explores the motivations that prompt Mexican professionals to come to Canada as international students with their families. The research findings demonstrate that high levels of insecurity in Mexico was the number one push factor that motivated participants to make the decision to immigrate. Furthermore, for many this represents a significant financial investment that can require sacrifices both before and after immigrating. Key words: Mexico; international students; insecurity; immigration; professionals

scholarly journals Art, Nature, and Culinary as Leverage of Village Branding at the Foot of the Mountain

2021 ◽  
Vol 16 (2) ◽  
pp. 67-74
Author(s):  
Soerjo Wido Minarto ◽  
Rully Aprilia Zandra ◽  
Adzrool Idzwan Ismail
Keyword(s):  
Development Research ◽  
Mountain Communities ◽  
Individual Interviews ◽  
Tourist Destinations ◽  
Government Documents ◽  
Before And After ◽  
Beach Tourism ◽  
To Come ◽  
Viable Approach ◽  
Hybrid Art

Beach tourism and seaside settlements are perennially popular. Nature's potential as well as the coast's characteristic hybrid art may always entice visitors. The settlements at the foot of the mountain, on the other hand, have their own unique environmental, gastronomic, and cultural identities. Bedugul village (Indonesia), Albarracin village (Spain), Reine village (Norway), Wengen village (Switzerland), Panglipuran village (Indonesia), Hallstatt village (Austria), Patiangan village (Indonesia), and Ora village (Indonesia) are some of the names given to the villages in Indonesia (Greece). They're all mountain communities that have successfully marketed themselves as tourist destinations at the foot of the mountain. The goal of this research is to come up with a viable approach for village branding at the foot of the mountain. This study is a hybrid of action research and development research, with a focus on tourism village acceleration. The Benjor village residents, Benjor village administrators, and a sample of potential visitors were polled for information. The community around Benjor village, the Malang Regency community, and persons outside the Malang Regency were all surveyed for potential visitors. Individual interviews or focus groups, environmental observations, and archives of village office records and Malang Regency government documents were used to gather data. The purpose of this study is to understand the tourism village process before and after therapy. Mining potential excavation yields eleven environmental assets in the form of waterfalls, five culinary assets in the form of chilli sauce, grilled rice, and other similar dishes, and three cultural assets in the form of hadrah, jaranan, and dancing. The development research yielded seven goods that Benjor villagers found to be the most effective in terms of branding. For mountain slope communities, the greatest method is to combine branded items that showcase their artistic, natural, and gastronomic potential.

scholarly journals Notification and Communication Technology: An Observational Study of Call Light Systems in Nursing Homes

2019 ◽  
Author(s):  
Haneen Ali ◽  
Huiyang Li
Keyword(s):  
Nursing Home ◽  
Nursing Homes ◽  
Observational Study ◽  
Standard Procedure ◽  
The Elderly ◽  
Nursing Home Staff ◽  
Before And After ◽  
Long Time ◽  
To Come

Abstract Background and Objectives: The call light system is one of the major communication technologies that links the nursing home staff to the needs of the residents. By providing residents with the ability to request assistance, the system becomes an indispensable resource for patient-focused healthcare. However, there is little known about how the call light systems are being used in nursing homes and how the system contributes to the safety and the quality of care for seniors. Therefore, the aims of this study are to understand the nursing home staff experience while using the call light systems and to uncover the usability issues associated with the implemented systems. Method: A mix of 150 hours of hypothetic-deductive (unstructured) and 90 hours of standard-procedure (structured) observational study were conducted in four different nursing homes. The data collected includes insights into the nursing homes work system and the process of locating and responding to call lights. Results: The data shows that the highest alarm rate is before and after meal times. The nursing staff exceeded the allotted time set by administration 50% of the time. Additionally, the staff canceled 10% of the call lights and did not immediately assist residents due to high workloads. Further, the staff forgot to come back to assist residents over 3% of the time. Usability issues such as broken parts, lack of feedback, lack of prioritization, and low/no discriminability are contributing to the long response time. More than 8% of the time, residents notified the staff about call lights after they waited for a long time, as these residents were left unattended. Conclusion: Nursing homes that are still using old call light systems risk the continuation of usability issues that can affect performance of the staff and contribute to a decline in staff and resident outcomes. While the healthcare industry has been at the forefront of technological advancements and implementation, it is important to recognize the influence of technology in the quality of service delivery for the elderly population in nursing homes and to the nursing homes staff working conditions.

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