scholarly journals Effects of Organ-Pipe Chamber Geometry on the Frequency and Erosion Characteristics of the Self-Excited Cavitating Waterjet

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 978
Author(s):  
Tengfei Cai ◽  
Yan Pan ◽  
Fei Ma ◽  
Pingping Xu
Keyword(s):  
Mass Loss ◽  
Natural Frequency ◽  
Pressure Sensors ◽  
The Self ◽  
Effective Length ◽  
Resonance Amplitude ◽  
Equivalent Length ◽  
Contraction Ratio ◽  
Organ Pipe ◽  
The Impact

Erosion experiments were performed to uncover the impact of organ-pipe chamber geometry on the frequency and erosion characteristics of self-excited cavitating waterjets. Jets emanating from self-excited nozzles with various organ-pipe geometries were investigated. The upstream and downstream contraction ratios of the organ-pipe resonator were changed respectively from 1.5 to 6 and 2 to 12. Pressure sensors and hydrophone were used to characterize jets’ frequency characteristics. Mass loss was also obtained in each of the configurations to assess the erosion performance. By tuning the self-excited frequency, the peak resonance was achieved using the nozzles with different geometries. Accordingly, the acoustic natural frequencies of various chamber geometries were obtained precisely. Results show that with increasing upstream and downstream contraction ratio of the organ-pipe chamber, the acoustic natural frequency increases monotonically due to the reduction of equivalent length, while the resonance amplitude and mass loss first increase and then decrease. There are optimum geometric parameters to reach the largest resonance amplitude and erosion mass loss: the upstream contraction ratio being between two and four, and downstream ratio being between four and seven. The effective length of the organ pipe can be calculated by the sum of the physical length and equivalent length to accurately obtain the acoustic natural frequency. Under the optimized parameters, the equivalent length can be estimated as 0.35D.

scholarly journals Erosion Characteristics and the Corresponding Self-Resonating Oscillations of Cavitating Jet on Oblique Surfaces

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2563
Author(s):  
Boshen Liu ◽  
Fei Ma
Keyword(s):  
Surface Morphology ◽  
Mass Loss ◽  
Intermediate State ◽  
Spectral Decomposition ◽  
The Self ◽  
Cavitation Noise ◽  
Fluctuating Pressure ◽  
Erosion Damage ◽  
Organ Pipe ◽  
Cavitating Jet

The erosion and the corresponding self-resonating oscillations of the cavitating jet were experimentally investigated on the oblique surfaces. To evaluate the intensities of erosion and self-resonating oscillations of the jet, mass loss, surface morphology of the eroded specimens, upstream fluctuating pressure and unsteady cavitation noise were obtained at a series of stand-off distance ratios l d / d t in the cases where the oblique angles are α = 0°, 5°, 15° and 30°. In the low l d / d t range, with the increase of α , the erosion gradually transforms from two isolated circular erosion rings at α = 0° into irregular oval shaped rings at α = 5° and separated horseshoe shaped rings at α = 15°. The self-resonating oscillations and cavitation were weak in this range because the dominating frequency f 0 is away from the design frequency of the organ-pipe nozzle, resulting in the depressed aggressive ability in the low l d / d t range. With increasing l d / d t , the cavitation is enhanced before the self-resonating oscillations achieving more energy. The spectral decomposition reveals the existence of an intermediate state at the optimum standoff distance, where the energy of self-resonating oscillations and the cavitation reach a balance to realize the severest erosion damage.

Self-Compassion and Quality of Life in Adults Who Stutter

2020 ◽  
Vol 29 (4) ◽  
pp. 2097-2108
Author(s):  
Robyn L. Croft ◽  
Courtney T. Byrd
Keyword(s):  
Quality Of Life ◽  
Social Connectedness ◽  
The Self ◽  
Future Research ◽  
Self Compassion ◽  
Adults Who Stutter ◽  
And Gender ◽  
Relationship Of ◽  
The Impact

Purpose The purpose of this study was to identify levels of self-compassion in adults who do and do not stutter and to determine whether self-compassion predicts the impact of stuttering on quality of life in adults who stutter. Method Participants included 140 adults who do and do not stutter matched for age and gender. All participants completed the Self-Compassion Scale. Adults who stutter also completed the Overall Assessment of the Speaker's Experience of Stuttering. Data were analyzed for self-compassion differences between and within adults who do and do not stutter and to predict self-compassion on quality of life in adults who stutter. Results Adults who do and do not stutter exhibited no significant differences in total self-compassion, regardless of participant gender. A simple linear regression of the total self-compassion score and total Overall Assessment of the Speaker's Experience of Stuttering score showed a significant, negative linear relationship of self-compassion predicting the impact of stuttering on quality of life. Conclusions Data suggest that higher levels of self-kindness, mindfulness, and social connectedness (i.e., self-compassion) are related to reduced negative reactions to stuttering, an increased participation in daily communication situations, and an improved overall quality of life. Future research should replicate current findings and identify moderators of the self-compassion–quality of life relationship.

Influence of the distribution of the shear walls on the seismic response of the buildings

2020 ◽  
Vol 15 (1) ◽  
pp. 37-44
Author(s):  
El Mehdi Echebba ◽  
Hasnae Boubel ◽  
Oumnia Elmrabet ◽  
Mohamed Rougui
Keyword(s):  
Structural Analysis ◽  
Seismic Response ◽  
Natural Frequency ◽  
Structural Design ◽  
Structural Response ◽  
Shear Walls ◽  
Structural Elements ◽  
Analysis Software ◽  
Ansys Apdl ◽  
The Impact

Abstract In this paper, an evaluation was tried for the impact of structural design on structural response. Several situations are foreseen as the possibilities of changing the distribution of the structural elements (sails, columns, etc.), the width of the structure and the number of floors indicates the adapted type of bracing for a given structure by referring only to its Geometric dimensions. This was done by studying the effect of the technical design of the building on the natural frequency of the structure with the study of the influence of the distribution of the structural elements on the seismic response of the building, taking into account of the requirements of the Moroccan earthquake regulations 2000/2011 and using the ANSYS APDL and Robot Structural Analysis software.

Effect of Parental Modernity on Rejection Sensitivity and Self-Esteem of Adolescents

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Ritu ◽  
Madhu Anand
Keyword(s):  
Social Development ◽  
Rejection Sensitivity ◽  
Self Esteem ◽  
The Self ◽  
Negatively Associated ◽  
Individual Modernity ◽  
The Impact ◽  
The Relationship

Parental Modernity is an important aspect for the psycho-social development of the child. The present study aims to study the effect of parental modernity on rejection sensitivity and self-esteem of adolescents and the relationship between rejection sensitivity and self-esteem. The research is carried out on a sample of 240 parents (including 120 fathers and 120 mothers) and their 120 children. For observing the impact of modernity of parents on their children, Individual Modernity Scale was used and administered on father and mother. Rejection Sensitivity Questionnaire and Self-Esteem Inventory were used to measure the rejection sensitivity and self-esteem of children (age ranges from 14 to 19 years). The results suggest that parental modernity has an effect on the rejection sensitivity and personally perceived self of the self – esteem of adolescents. Furthermore, the rejection sensitivity has been found negatively associated with self-esteem.

Fluxus and the Absurd (1961–62)

2017 ◽  
Author(s):  
Benjamin R. Levy
Keyword(s):  
Second Life ◽  
The Self ◽  
Major Work ◽  
The Future ◽  
To Come ◽  
The Impact

After John Cage’s 1958 Darmstadt lectures, many European composers developed an interest in absurdity and artistic provocation. Although Ligeti’s fascination with Cage and his association with the Fluxus group was brief, the impact it had on his composition was palpable and lasting. A set of conceptual works, The Future of Music, Trois Bagatelles, and Poème symphonique for one hundred metronomes, fall clearly into the Fluxus model, even as the last has taken on a second life as a serious work. This spirit, however, can also be seen in the self-satire of Fragment and the drama and irony of Volumina, Aventures, and Nouvelles Aventures. The sketches for Aventures not only show the composer channeling this humor into a major work but also prove to be a fascinating repository of ideas that Ligeti would reuse in the years to come.

scholarly journals Windblown Sand-Induced Degradation of Glass Panels in Curtain Walls

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 607
Author(s):  
Yuxi Zhao ◽  
Rongcheng Liu ◽  
Fan Yan ◽  
Dawei Zhang ◽  
Junjin Liu
Keyword(s):  
Visible Light ◽  
Mass Loss ◽  
Effective Area ◽  
Area Ratio ◽  
Light Transmittance ◽  
Relative Mass ◽  
Impact Time ◽  
Windblown Sand ◽  
Glass Panels ◽  
The Impact

The windblown sand-induced degradation of glass panels influences the serviceability and safety of these panels. In this study, the degradation of glass panels subject to windblown sand with different impact velocities and impact angles was studied based on a sandblasting test simulating a sandstorm. After the glass panels were degraded by windblown sand, the surface morphology of the damaged glass panels was observed using scanning electron microscopy, and three damage modes were found: a cutting mode, smash mode, and plastic deformation mode. The mass loss, visible light transmittance, and effective area ratio values of the glass samples were then measured to evaluate the effects of the windblown sand on the panels. The results indicate that, at high abrasive feed rates, the relative mass loss of the glass samples decreases initially and then remains steady with increases in impact time, whereas it increases first and then decreases with an increase in impact angle such as that for ductile materials. Both visible light transmittance and effective area ratio decrease with increases in the impact time and velocities. There exists a positive linear relationship between the visible light transmittance and effective area ratio.

scholarly journals Effect of Storage Conditions on Storability and Antioxidant Potential of Pears cv. ‘Conference’

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 545
Author(s):  
Grzegorz P. Łysiak ◽  
Krzysztof Rutkowski ◽  
Dorota Walkowiak-Tomczak
Keyword(s):  
Mass Loss ◽  
Strong Influence ◽  
Storage Conditions ◽  
Quality Parameters ◽  
Soluble Solids ◽  
Controlled Atmosphere ◽  
Postharvest Diseases ◽  
Market Prices ◽  
Long Period ◽  
The Impact

Late pear cultivars, such as ‘Conference’, can be stored for a long period if kept in good storage conditions. A three-year study (2011–2013) compared the impact of six-month storage using four technologies—normal atmosphere, normal atmosphere + 1-methylcyclopropene (1-MCP), controlled atmosphere, and controlled atmosphere + 1-MCP—on the quality parameters of ‘Conference’ pears, such as mass loss, firmness, total soluble solids, acidity, antioxidant capacity, and the incidence of diseases and disorders. Additionally, the study analysed different storage conditions in terms of profitability, based on the market prices for pears in the seasons during which the pears were stored. The storage conditions had a very strong influence on the fruit quality parameters, and were found to affect most visibly the mass loss and the incidence of postharvest diseases and disorders. The storage of ‘Conference’ pears for 180 days in normal atmosphere is not economically viable, even if the fruit is subjected to 1-MCP treatment; at the same time, it is profitable to store ‘Conference’ pears in controlled atmosphere for the same period, no matter whether 1-MCP was applied or not.

scholarly journals The “Christology” of Bely the Anthroposophist: Andrei Bely, Rudolf Steiner, and the Apostle Paul

Religions ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 519
Author(s):  
Monika Spivak
Keyword(s):  
The Self ◽  
Apostle Paul ◽  
Rudolf Steiner ◽  
2 Corinthians ◽  
History Of ◽  
The Impact

The article focuses on R. Steiner’s perception of the Gospels and the impact of that view on Bely’s works. The latter had always valued Steiner’s lectures on Christ and the Fifth Gospel, the “Anthroposophic” (relating to the philosophy of human genesis, existence, and outcome) Gospel, the knowledge of which had been received in a visionary way. In addition, Bely was an esoteric follower of Steiner and often quoted from Apostle Paul’s 2 Corinthians, “Ye are our epistle written in our hearts, known and read of all men”. The citation occurs in Bely’s philosophical works (The History of the Formation of the Self-Conscious Soul, “Crisis of Consciousness”), autobiographic prose (Reminiscences of Steiner), the essay “Why I Became a Symbolist…”, and letters (to Ivanov-Razumnik and Fedor Gladkov). Bely’s own anthroposophic and esoteric ideas relating to the gospel sayings are also examined. The aim of the research is to show through the example of one quotation the specifics of Bely the Anthroposophist’s perception of Christian texts in general. This provides a methodological meaning for understanding other Biblical quotations and images in the works of Bely because anthroposophical Christology is also the key to their deciphering.

scholarly journals The effect of heat treatment and impact angle on the erosion behavior of nickel-tungsten carbide cold spray coating using response surface methodology

2021 ◽  
Author(s):  
Marios Kazasidis ◽  
Elisa Verna ◽  
Shuo Yin ◽  
Rocco Lupoi
Keyword(s):  
Heat Treatment ◽  
Response Surface Methodology ◽  
Mass Loss ◽  
Tungsten Carbide ◽  
Response Surface ◽  
Spray Coating ◽  
Impact Angle ◽  
Control Factors ◽  
Heat Treated ◽  
The Impact

AbstractThis study elucidates the performance of cold-sprayed tungsten carbide-nickel coating against solid particle impingement erosion using alumina (corundum) particles. After the coating fabrication, part of the specimens followed two different annealing heat treatment cycles with peak temperatures of 600 °C and 800 °C. The coatings were examined in terms of microstructure in the as-sprayed (AS) and the two heat-treated conditions (HT1, HT2). Subsequently, the erosion tests were carried out using design of experiments with two control factors and two replicate measurements in each case. The effect of the heat treatment on the mass loss of the coatings was investigated at the three levels (AS, HT1, HT2), as well as the impact angle of the erodents (30°, 60°, 90°). Finally, the response surface methodology (RSM) was applied to analyze and optimize the results, building the mathematical models that relate the significant variables and their interactions to the output response (mass loss) for each coating condition. The obtained results demonstrated that erosion minimization was achieved when the coating was heat treated at 600 °C and the angle was 90°.

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