The Mechanical Design of Large Turbogenerators

1987 ◽  
Vol 201 (2) ◽  
pp. 91-103
Author(s):  
B A Marlow
Keyword(s):  
High Speed ◽  
Mechanical Design ◽  
Rotating Machinery ◽  
Design Problems ◽  
Detail Design ◽  
Insight Into

Experience shows that the reliability of large turbogenerators depends substantially on the quality of detail design, particularly the quality of the mechanical design. In addition to the design problems common to all high-speed rotating machinery, the mechanical design of generators must take account of certain electrical requirements. This paper gives an insight into the detail mechanical design of large turbogenerators paying particular attention to the interaction of electrical requirements on the mechanical design.

scholarly journals An eye-tracking study examining information search in transit maps

2021 ◽  
Author(s):  
Zheng Wang ◽  
Maria dos Santos Lonsdale ◽  
Vien Cheung
Keyword(s):  
Eye Tracking ◽  
Information Search ◽  
High Speed ◽  
Performance Test ◽  
User Centered Design ◽  
Design Quality ◽  
Design Problems ◽  
In Transit ◽  
Design Guidance

Abstract This study investigates the legibility of China’s high-speed railway map through eye-tracking measurement. The information searching process was identified by conducting: (1) Scoping stage – a user performance test and interview to inform the design of the eye-tracking study; (2) In-depth stage – an eye-tracking study. A number of visual design problems with the map have been identified. This research explores user-centered design map solutions and provides detailed design guidance for transit maps. It also demonstrates that eye-tracking is an effective method of evaluating the design quality of a transit map as it can identify design limitations and user needs.

Attitudes of Elderly People in the South Moravian Region to Further Education

2014 ◽  
Vol 4 (2) ◽  
pp. 54-78
Author(s):  
Petr Adamec ◽  
Marián Svoboda
Keyword(s):  
Quality Of Life ◽  
Elderly People ◽  
Further Education ◽  
The South ◽  
The Third ◽  
Interesting Insight ◽  
Survey Results ◽  
Insight Into ◽  
Demographic Features

This paper deals with the results of sociological survey focused on identification of the attitudes of elderly people to further education. The research was carried out in September 2010. Experience of elderly people with further education, their readiness (determination) for further education as well as their motivation and barriers in further education were also subjects of this research. Detecting elderly population’s awareness of universities of the third age and finding out their further education preferences were an integral part of the research. Research sample consisted of citizens over 55 years living in the South Moravian region. The survey results are structured by socio-demographic features e.g.: age, sex, educational attainment etc. and provide an interesting insight into the attitudes of the target group to one of the activities that contributes to improvement of their quality of life.

scholarly journals Comparisons among rainbow trout, Oncorhynchus mykiss, populations of maternal transcript profile associated with egg viability

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gregory M. Weber ◽  
Jill Birkett ◽  
Kyle Martin ◽  
Doug Dixon ◽  
Guangtu Gao ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Egg Quality ◽  
Transcript Abundance ◽  
Differentially Expressed ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Analysis Group ◽  
Maternal Transcripts ◽  
Single Batch ◽  
Insight Into

Abstract Background Transcription is arrested in the late stage oocyte and therefore the maternal transcriptome stored in the oocyte provides nearly all the mRNA required for oocyte maturation, fertilization, and early cleavage of the embryo. The transcriptome of the unfertilized egg, therefore, has potential to provide markers for predictors of egg quality and diagnosing problems with embryo production encountered by fish hatcheries. Although levels of specific transcripts have been shown to associate with measures of egg quality, these differentially expressed genes (DEGs) have not been consistent among studies. The present study compares differences in select transcripts among unfertilized rainbow trout eggs of different quality based on eyeing rate, among 2 year classes of the same line (A1, A2) and a population from a different hatchery (B). The study compared 65 transcripts previously reported to be differentially expressed with egg quality in rainbow trout. Results There were 32 transcripts identified as DEGs among the three groups by regression analysis. Group A1 had the most DEGs, 26; A2 had 15, 14 of which were shared with A1; and B had 12, 7 of which overlapped with A1 or A2. Six transcripts were found in all three groups, dcaf11, impa2, mrpl39_like, senp7, tfip11 and uchl1. Conclusions Our results confirmed maternal transcripts found to be differentially expressed between low- and high-quality eggs in one population of rainbow trout can often be found to overlap with DEGs in other populations. The transcripts differentially expressed with egg quality remain consistent among year classes of the same line. Greater similarity in dysregulated transcripts within year classes of the same line than among lines suggests patterns of transcriptome dysregulation may provide insight into causes of decreased viability within a hatchery population. Although many DEGs were identified, for each of the genes there is considerable variability in transcript abundance among eggs of similar quality and low correlations between transcript abundance and eyeing rate, making it highly improbable to predict the quality of a single batch of eggs based on transcript abundance of just a few genes.

A Study on the Mineral Depletion of the Foods Available to us as a Nation over the Period 1940 to 1991

2003 ◽  
Vol 17 (2) ◽  
pp. 85-115 ◽  
Author(s):  
David Thomas
Keyword(s):  
Mineral Content ◽  
Dietary Habits ◽  
Medical Research Council ◽  
Significant Loss ◽  
King's College ◽  
Compare And Contrast ◽  
Insight Into ◽  
Mineral Constituents ◽  
Mineral Depletion

In 1927 a study at King's College, University of London, of the chemical composition of foods was initiated by Dr McCance to assist with diabetic dietary guidance. The study evolved and was then broadened to determine all the important organic and mineral constituents of foods, it was financed by the Medical Research Council and eventually published in 1940. Over the next 51 years subsequent editions reflected changing national dietary habits and food laws as well as advances in analytical procedures. The most recent (5th Edition) published in 1991 has comprehensively analysed 14 different categories of foods and beverages. In order to provide some insight into any variation in the quality of the foods available to us as a nation between 1940 and 1991 it was possible to compare and contrast the mineral content of 27 varieties of vegetable, 17 varieties of fruit, 10 cuts of meat and some milk and cheese products. The results demonstrate that there has been a significant loss of minerals and trace elements in these foods over that period of time. It is suggested that the results of this study cannot be taken in isolation from recent dietary, environmental and disease trends. These trends are briefly mentioned and suggestions are made as to how the deterioration in the micronutrient quality of our food intake may be arrested and reversed.

scholarly journals Dialogical research to open up new narrative patterns among young women living with severe anxiety

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
L Cantarero Arevalo ◽  
S Fejfer Olsen
Keyword(s):  
Young Women ◽  
Population Group ◽  
Patient Experiences ◽  
Constructivist Approach ◽  
Patient’S Perspective ◽  
Healthcare Needs ◽  
Narrative Patterns ◽  
Severe Anxiety ◽  
Insight Into

Abstract Background 16,889 new cases of severe anxiety (SA) were diagnosed in Denmark in 2019. Incidence rate is highest among 16 to 24 year-old women, a population group with 64% risk of being diagnosed with SA. Experiences of stigma and shame are common among this group, affecting negatively their quality of life and opportunity to recover. The aim is 1) to gain insight into the digital narratives young women with SA share through social networking websites, and 2) to open up the possibility to develop new narrative patterns using dialogical research as a method rooted in Bakhtin (1895-1975) and further developed by Frank (2005). Methods Netnography of four large Facebook groups focused on anxiety was used to gain insight into the patients' narratives and to build guiding themes for the off-line dialogical interviews (DI). Biographical narrative patterns were analyzed in light of a narrative-constructivist approach. Participants were invited to sign an informed consent prior to the DI and received ample information about the project aims and their rights. Results 8 young women diagnosed with SA participated in the off-line DI. They had experienced stress, loss, betrayal or violation against them prior to the trigger of SA. All had constructed a narrative that explained why they were suffering from SA. Patient experiences were dominated by the struggle to control intrusive thoughts and to live in a threatening world. Some felt stigmatized and tried to hide their condition from colleagues, friends and family. They had different preferences regarding healthcare needs and were active in their search for alternative ways to cope with SA. Conclusions Participants perceived DI as beneficial. It thus has the potential to not only explore the patient's perspective in depth, but also serve as therapy during the process of inquiry. Key messages Dialogical research has the potential to not only explore the patient’s perspective in depth, but also serve as therapy during the process of inquiry. Young women suffering with severe anxiety experience shame and stigma, which worsen their condiction and hinder their opportunity to recover.

High-Speed Imaging to Study an Auto-Oscillating Vocal Fold Replica for Different Initial Conditions

2017 ◽  
Vol 09 (05) ◽  
pp. 1750064 ◽  
Author(s):  
A. Van Hirtum ◽  
X. Pelorson
Keyword(s):  
Vocal Fold ◽  
High Speed ◽  
Initial Conditions ◽  
Vocal Folds ◽  
High Speed Imaging ◽  
Human Voice ◽  
Manual Intervention ◽  
Geometrical Features ◽  
Upstream Pressure

Experiments on mechanical deformable vocal folds replicas are important in physical studies of human voice production to understand the underlying fluid–structure interaction. At current date, most experiments are performed for constant initial conditions with respect to structural as well as geometrical features. Varying those conditions requires manual intervention, which might affect reproducibility and hence the quality of experimental results. In this work, a setup is described which allows setting elastic and geometrical initial conditions in an automated way for a deformable vocal fold replica. High-speed imaging is integrated in the setup in order to decorrelate elastic and geometrical features. This way, reproducible, accurate and systematic measurements can be performed for prescribed initial conditions of glottal area, mean upstream pressure and vocal fold elasticity. Moreover, quantification of geometrical features during auto-oscillation is shown to contribute to the experimental characterization and understanding.

scholarly journals Earth’s Time-Variable Gravity from GRACE Follow-On K-Band Range-Rates and Pseudo-Observed Orbits

2021 ◽  
Vol 13 (9) ◽  
pp. 1766
Author(s):  
Igor Koch ◽  
Mathias Duwe ◽  
Jakob Flury ◽  
Akbar Shabanloui
Keyword(s):  
Gravity Field ◽  
Time Variable ◽  
Time Variable Gravity ◽  
Gravity Field Recovery ◽  
Variable Gravity ◽  
Earth’S System ◽  
Grace Mission ◽  
Insight Into ◽  
K Band

During its science phase from 2002–2017, the low-low satellite-to-satellite tracking mission Gravity Field Recovery And Climate Experiment (GRACE) provided an insight into Earth’s time-variable gravity (TVG). The unprecedented quality of gravity field solutions from GRACE sensor data improved the understanding of mass changes in Earth’s system considerably. Monthly gravity field solutions as the main products of the GRACE mission, published by several analysis centers (ACs) from Europe, USA and China, became indispensable products for quantifying terrestrial water storage, ice sheet mass balance and sea level change. The successor mission GRACE Follow-On (GRACE-FO) was launched in May 2018 and proceeds observing Earth’s TVG. The Institute of Geodesy (IfE) at Leibniz University Hannover (LUH) is one of the most recent ACs. The purpose of this article is to give a detailed insight into the gravity field recovery processing strategy applied at LUH; to compare the obtained gravity field results to the gravity field solutions of other established ACs; and to compare the GRACE-FO performance to that of the preceding GRACE mission in terms of post-fit residuals. We use the in-house-developed MATLAB-based GRACE-SIGMA software to compute unconstrained solutions based on the generalized orbit determination of 3 h arcs. K-band range-rates (KBRR) and kinematic orbits are used as (pseudo)-observations. A comparison of the obtained solutions to the results of the GRACE-FO Science Data System (SDS) and Combination Service for Time-variable Gravity Fields (COST-G) ACs, reveals a competitive quality of our solutions. While the spectral and spatial noise levels slightly differ, the signal content of the solutions is similar among all ACs. The carried out comparison of GRACE and GRACE-FO KBRR post-fit residuals highlights an improvement of the GRACE-FO K-band ranging system performance. The overall amplitude of GRACE-FO post-fit residuals is about three times smaller, compared to GRACE. GRACE-FO post-fit residuals show less systematics, compared to GRACE. Nevertheless, the power spectral density of GRACE-FO and GRACE post-fit residuals is dominated by similar spikes located at multiples of the orbital and daily frequencies. To our knowledge, the detailed origin of these spikes and their influence on the gravity field recovery quality were not addressed in any study so far and therefore deserve further attention in the future. Presented results are based on 29 monthly gravity field solutions from June 2018 until December 2020. The regularly updated LUH-GRACE-FO-2020 time series of monthly gravity field solutions can be found on the website of the International Centre for Global Earth Models (ICGEM) and in LUH’s research data repository. These operationally published products complement the time series of the already established ACs and allow for a continuous and independent assessment of mass changes in Earth’s system.

SUITABILITY OF ACID-SOLUBLE AND ACID-INSOLUBLE LEATHER FRACTIONS IN RADIOCARBON DATING

Radiocarbon ◽  
2020 ◽  
pp. 1-8
Author(s):  
Alyssa M Tate ◽  
Brittany Hundman ◽  
Jonathan Heile
Keyword(s):  
Radiocarbon Dating ◽  
Insoluble Fraction ◽  
Economic Life ◽  
Chemical Pretreatment ◽  
Acid Base ◽  
The Past ◽  
Acid Soluble Collagen ◽  
Method Of Production ◽  
Insight Into

ABSTRACT Leather has been produced by a variety of methods throughout human history, providing researchers unique insight into multiple facets of social and economic life in the past. Archaeologically recovered leather is often fragile and poorly preserved, leading to the use of various conservation and restoration efforts that may include the application of fats, oils, or waxes. Such additives introduce exogenous carbon to the leather, contaminating the specimen. These contaminants, in addition to those accumulated during interment, must be removed through chemical pretreatment prior to radiocarbon (14C) dating to ensure accurate dating. DirectAMS utilizes organic solvents, acid-base-acid (ABA) and gelatinization for all leather samples. Collagen yield from leather samples is variable due to the method of production and the quality of preservation. However, evaluating the acid-soluble collagen fraction, when available, provides the most accurate 14C dates for leather samples. In instances where gelatinization does not yield sufficient material, the resulting acid-insoluble fraction may be dated. Here we examine the effectiveness of the combined organic solvent and ABA pretreatment with gelatinization for leather samples, as well as the suitability of the acid-insoluble fraction for 14C dating.

Machining quality of high speed helical milling of carbon fiber reinforced plastics

2021 ◽  
pp. 095440622199673
Author(s):  
Adel Abidi ◽  
Sahbi Ben Salem ◽  
Mohamed Athmane Yallese
Keyword(s):  
Surface Roughness ◽  
Carbon Fiber ◽  
High Speed ◽  
Hole Diameter ◽  
Feed Speed ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Machining Quality ◽  
Fiber Reinforced Plastics

Among advanced cutting methods, High Speed Milling (HSM) is often recommended to improve the productivity and to reduce the costs of machining parts. As every cutting process, HSM is characterized by some defects like surface roughness and delamination are the main defects generated in composite materials. The aim of this experimental work is the studying of the machining quality of woven Carbon fiber reinforced plastics (CFRP) using the HSM technology. Experiments were done using different machining parameters combinations to make opened holes in CFRP laminates. This study investigated the effect of cutting speed, orbital feed speed, hole diameter on the delamination defect and surface roughness responses generated in the drilled holes. The design of experimental tests was generated using the approach of Central Composite Design (CCD). The characterization of these responses was treated with the Analysis of variance (ANOVA) and Response surface methodology (RSM). Results showed that the surface roughness is highly affected by the orbital feed speed (F) with contribution of 22.45%. The delamination factor at entry and exit of holes is strongly influenced by the hole diameter D (25.97% and 57.43%) respectively. The developed model equations gave a good correlation between the empirical and predicted results. The optimization of the milling parameters was treated using desirability function to minimize the surface roughness (Ra) and the delamination factor simultaneously.

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