scholarly journals Failure Mechanism of Multilayer Ceramic Capacitors under Transient High Impact

2020 ◽  
Vol 10 (23) ◽  
pp. 8435
Author(s):  
Da Yu ◽  
Keren Dai ◽  
Jinming Zhang ◽  
Benqiang Yang ◽  
He Zhang ◽  
...  
Keyword(s):  
Leakage Current ◽  
High Impact ◽  
Capacitance Change ◽  
Current Increase ◽  
Parameter Drift ◽  
Ceramic Capacitor ◽  
Current Change ◽  
Multilayer Ceramic ◽  
The Impact ◽  
Main Factor

In recent years, penetrating weapons have been used more and more to attack increasingly hard targets; therefore, the impact of such a penetrating process has increased to an extremely high level. As an important component of a fuze, the reliability of the ceramic capacitor in high-impact environments is key for the normal working of the fuze. In this paper, we found that a high-impact causes parameter drift of the multilayer ceramic capacitor (MLCC), which further causes the fuze to misfire. This paper mainly studies the internal mechanism of the MLCC’s parameter drift during high impact. Firstly, transient physical phenomena, such as capacitance fluctuation and the leakage current increase of the ceramic capacitor under a high acceleration impact, were studied experimentally by a Machete hammer, revealing the relationship between the capacitance change, leakage current change, and acceleration under different working conditions. Secondly, a mechanical model of the ceramic capacitor is established to simulate the change in capacitance value, which shows that the main factor of the capacitance change is the deformation-derived change in the facing area between the electrodes. Lastly, an equivalent circuit model is established to simulate the change in the leakage current, which shows that the main factor of the leakage current change is the piezoelectric resistance of the ceramic dielectric.

Larvae of the blow fly Caiusa testacea (Diptera: Calliphoridae) as egg predators of Polypedates cruciger Blyth, 1852 (Amphibia: Anura: Rhacophoridae)

2020 ◽  
Vol 12 (17) ◽  
pp. 17374-17379
Author(s):  
W.G.D. Chathuranga ◽  
K. Kariyawasam ◽  
Anslem De Silva ◽  
W.A.Priyanka P. De Silva
Keyword(s):  
Sri Lanka ◽  
High Impact ◽  
Tree Frog ◽  
Blow Fly ◽  
Breeding Habitats ◽  
The Family ◽  
Water Container ◽  
The Common ◽  
Natural Breeding ◽  
The Impact

We investigated the impact of dipteran predators on eggs in foam nests of the Common Hour-glass Tree Frog Polypedates cruciger Blyth, 1852 (Anura: Rhacophoridae) in central Sri Lanka.  Foam nests (n=24) of P. cruciger were examined at their natural breeding habitats and infected (n=8) and uninfected spawns (n=16) were identified.  Emerging tadpoles were collected in a water container hung under each spawn and the average number of tadpoles (N) hatched from infected spawns (N=0) was compared with that of uninfected spawns (N=354 ± 67).  Three severely infected spawns were brought to the laboratory and the fly larvae were reared until they metamorphosed to adults.  Morphological and molecular identification of the flies confirmed them as belonging to Caiusa testacea Senior-White, 1923 of the family Calliphoridae.  The infected spawns were completely destroyed and an estimated average of 400 P. cruciger eggs per spawn were lost.  The results revealed a high impact of Caiusa testacea on egg and embryo mortality of P. cruciger.

scholarly journals Numerical simulation of the impact of an integrated renovation project on the Maowei Sea hydrodynamic environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cui Wang ◽  
Ling Cai ◽  
Yaojian Wu ◽  
Yurong Ouyang
Keyword(s):  
Water Exchange ◽  
Land Reclamation ◽  
Three Dimensional ◽  
Exchange Capacity ◽  
Reclamation Project ◽  
Hydrodynamic Environment ◽  
Sea Area ◽  
Water Quality Models ◽  
The Impact ◽  
Main Factor

AbstractIntegrated renovation projects are important for marine ecological environment protection. Three-dimensional hydrodynamics and water quality models are developed for the Maowei Sea to assess the hydrodynamic environment base on the MIKE3 software with high resolution meshes. The results showed that the flow velocity changed minimally after the project, decreasing by approximately 0.12 m/s in the east of the Maowei Sea area and increasing by approximately 0.01 m/s in the northeast of the Shajing Port. The decrease in tidal prism (~ 2.66 × 106 m3) was attributed to land reclamation, and accounted for just 0.86% of the pre-project level. The water exchange half-life increased by approximately 1 day, implying a slightly reduced water exchange capacity. Siltation occurred mainly in the reclamation and dredging areas, amounting to back-silting of approximately 2 cm/year. Reclamation project is the main factor causing the decrease of tidal volume and weakening the hydrodynamics in Maowei Sea. Adaptive management is necessary for such a comprehensive regulation project. According to the result, we suggest that reclamation works should strictly prohibit and dredging schemes should optimize in the subsequent regulation works.

scholarly journals Spatio-Temporal Variation Characteristics of Snow Depth and Snow Cover Days over the Tibetan Plateau

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 307
Author(s):  
Chi Zhang ◽  
Naixia Mou ◽  
Jiqiang Niu ◽  
Lingxian Zhang ◽  
Feng Liu
Keyword(s):  
Tibetan Plateau ◽  
Snow Cover ◽  
Snow Depth ◽  
Feedback Effect ◽  
Effect Of Temperature ◽  
The Tibetan Plateau ◽  
Reanalysis Dataset ◽  
Spatio Temporal ◽  
The Impact ◽  
Main Factor

Changes in snow cover over the Tibetan Plateau (TP) have a significant impact on agriculture, hydrology, and ecological environment of surrounding areas. This study investigates the spatio-temporal pattern of snow depth (SD) and snow cover days (SCD), as well as the impact of temperature and precipitation on snow cover over TP from 1979 to 2018 by using the ERA5 reanalysis dataset, and uses the Mann–Kendall test for significance. The results indicate that (1) the average annual SD and SCD in the southern and western edge areas of TP are relatively high, reaching 10 cm and 120 d or more, respectively. (2) In the past 40 years, SD (s = 0.04 cm decade−1, p = 0.81) and SCD (s = −2.3 d decade−1, p = 0.10) over TP did not change significantly. (3) The positive feedback effect of precipitation is the main factor affecting SD, while the negative feedback effect of temperature is the main factor affecting SCD. This study improves the understanding of snow cover change and is conducive to the further study of climate change on TP.

Qualitŕ della vita e invecchiamento della popolazione. Materiali per un'ipotesi alternativa alla questione pensionistica

2009 ◽  
pp. 67-91
Author(s):  
Adele Bianco
Keyword(s):  
Quality Of Life ◽  
Life Quality ◽  
Main Idea ◽  
Living Condition ◽  
Climate And Environmental Change ◽  
Safety And Health ◽  
Positive Ageing ◽  
The Impact ◽  
Main Factor

The topic of this article is quality of life and ageing process specially focused on today young generations and their coming retirement situation. The main idea is that quality of life is increasing, that means longer, safer and better living condition; consequently positive ageing processes mean also reforming retirement sector. The hypothesis carried out in this paper is an alternative one. Despite of the positive trends, we describe how three main factor of nowadays life are, on the contrary, turning into worse condition the future of young generations and their coming life situation. Firstly we consider the socio-economic aspects, the impact on health and the implications connected with precarious work. Secondly we consider pollution and its effects on health, life quality and life expectation. Thirdly we pay attention about climate and environmental change and their effect on health, life quality and expectation. In conclusion, the retirement future of today young generations may be very different (worse) than expected. The paper in based on WHO, IPCC and European Agency for Safety and Health at Work data and reports.Key words: Young generations; Coming quality of life; Population ageing and future of retirement question.Parole chiave: Giovani generazioni; Qualitŕ della vita; Invecchiamento della popolazione e pensioni.

Impact of extreme hydrological perturbation on sediment distribution from source to sink, PETM, Spain.

2021 ◽  
Author(s):  
Marine Prieur ◽  
Alexander C. Whittaker ◽  
Fritz Schlunegger ◽  
Tor O. Sømme ◽  
Jean Braun ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Adaptation ◽  
Global Climate ◽  
Depositional Environments ◽  
Lead Author ◽  
Current Increase ◽  
Sediment Distribution ◽  
Current Climate ◽  
Source To Sink ◽  
The Impact

<p>Sedimentary dynamics and fluxes are influenced by both autogenic and allogenic forcings. A better understanding of the evolution of sedimentary systems through time and space requires us to decipher, and therefore to characterise, the impact of each of these on the Earth’s landscape. Given the current increase in the concentration of atmospheric carbon, studying the impact of rapid and global climate changes is of particular importance at the present time. Such events have been clearly defined in the geologic record. Among them, the Paleocene-Eocene Thermal Maximum (PETM) has been extensively studied worldwide and represents a possible analogue of the rapid current climate warming.</p><p>The present project focuses on the Southern Pyrenees (Spain) where excellent exposures of the Paleocene-Eocene interval span a large range of depositional environments from continental to deep-marine. These conditions allow us to collect data along the whole depositional system in order to document changes in sediment fluxes and paleohydraulic conditions. Because hydrological conditions have an impact on sediment transport through hydrodynamics, paleoflow reconstructions can shed light on changes in sediment dynamics. This information is reconstructed from the statistical distributions of channel morphologies, characteristic system dimensions including bankfull channel depth and width, and grain-sizes.</p><p>With this approach, our aim is to provide both qualitative and quantitative assessments of the magnitude and extent of the perturbation of sedimentary fluxes along an entire source-to-sink system during an episode of extreme climate change. This will lead to a better understanding of the impact of abrupt climate change on earth surface systems in mid-latitudinal areas, with possible implications for current climate adaptation policy.</p><p>This research is carried out in the scope of the lead author’s PhD project and is part of the S2S-FUTURE European Marie Skłodowska-Curie ITN (Grant Agreement No 860383).</p>

HR Management in Russia: concepts of a new Normality. Book 8

2021 ◽  
Author(s):  
Yuliya Dolzhenkova ◽  
Galina Rudenko ◽  
Fedor Mihaylov ◽  
Svetlana Sotnikova ◽  
Anatoliy Zhukov ◽  
...  
Keyword(s):  
Personnel Management ◽  
Health Management ◽  
Well Being ◽  
Teaching Staff ◽  
Economic Determinants ◽  
Higher Education System ◽  
Statics And Dynamics ◽  
The Impact ◽  
Labor Success ◽  
Main Factor

The monograph contains the results of research, systematized in five groups. The first group is presented with information about the current vectors of the development of the personnel management system, the harmonization of its statics and dynamics, the benchmarking of human resources, the impact of personnel management on the growth of labor productivity as the main factor of efficiency. The content of the second group is the specifics of health management in the workplace. The third group presents issues of social well-being and social interaction of employees, najing, and corporate remuneration. The fourth group includes the problems of personnel aging, the biological and socio-economic determinants of the phenomenon, and the idea of maintaining labor success. The content of the fifth group focuses on the representation of parental labor, as well as the readiness of the domestic higher education system to respond to the requirements of the modern economy and perceive it as a new normality. For postgraduates, undergraduates, students, researchers who are engaged in research in the field of personnel management, as well as the teaching staff of universities and employers.

Impactul inundaţiilor pluviale din Republica Moldova și măsurile de diminuare a lui

2019 ◽  
Author(s):  
Galina Mindru ◽  
Keyword(s):  
Statistical Data ◽  
Negative Effects ◽  
Digital Map ◽  
Republic Of Moldova ◽  
Significant Damage ◽  
Annual Frequency ◽  
The Republic ◽  
Favorable Conditions ◽  
The Impact ◽  
Main Factor

In the Republic of Moldova, the main factor contributing to the floods is the torrential rains from the warm semester of the year, which create favorable conditions for triggering strong, sometimes catastrophic floods in the rivers of the republic, especially in the smaller ones. During the study period, 40 floods with significant damage were recorded in the country, with an annual frequency ranging from 0 to 12 cases. In the administrativeterritorial profile, the damages caused by the aforementioned floods varied greatly. Based on the statistical data, a digital map was developed reflecting the degree of exposure of the territory of the Republic of Moldova in the administrative-territorial aspect to the mentioned risk, expressed by the value of the damages caused. In order to reduce the impact caused by the flood floods, measures have been developed to prevent, reduce and combat the negative effects of that risk.

scholarly journals Evolution of mantis shrimp telson armour and its role in ritualized fighting

2019 ◽  
Vol 16 (157) ◽  
pp. 20190203 ◽  
Author(s):  
Jennifer R. A. Taylor ◽  
Nina I. Scott ◽  
Greg W. Rouse
Keyword(s):  
Comparative Analysis ◽  
Impact Resistance ◽  
High Impact ◽  
Mantis Shrimp ◽  
Impact Forces ◽  
Drop Tests ◽  
Impact Parameters ◽  
Ritualized Combat ◽  
Stiff Spring ◽  
The Impact

Mantis shrimp possess both formidable weapons and impact-resistant armour that clash during ritualized combat. The telson is one of few biological structures known to withstand the repeated high impact forces of smashing mantis shrimp strikes, and it is hypothesized that this pairing of armour and weapon is associated with the evolution of telson sparring. We carried out a comparative analysis of telson impact mechanics across 15 mantis shrimp species to assess if the telsons of sparring species (i) are consistently specialized for impact-resistance, (ii) are more impact-resistant than those of non-sparring species, and (iii) have impact parameters that correlate with body size, and thereby useful for assessment. Our data from ball drop tests show that the telsons of all species function like a stiff spring that dissipates most of the impact energy, but none of the measured impact parameters are correlated with the occurrence of sparring behaviour. Impact parameters were correlated with body mass for only some species, suggesting that it is not broadly useful for size assessment during ritualized fighting. Contrary to expectation, sparring mantis shrimp do not appear to have coevolved telson armour that is more robust to impact than non-sparring species. Rather, telson structure is inherently impact-resistant.

Perinatal Profile of Twin Pregnancies: A Retrospective Review of 11 Years (1969–1979) at Hôpital Notre-Dame, Montréal, Canada

1982 ◽  
Vol 31 (3-4) ◽  
pp. 157-163 ◽  
Author(s):  
Marie-Françoise Desgranges ◽  
Xavier De Muylder ◽  
Jean-Marie Moutquin ◽  
Francisco Lazaro-Lopez ◽  
Bernard Leduc
Keyword(s):  
Perinatal Mortality ◽  
Perinatal Care ◽  
Fetal Mortality ◽  
Ultrasound Technique ◽  
Intrauterine Growth ◽  
Before And After ◽  
The Impact ◽  
Second Period ◽  
Twin Pregnancies ◽  
Main Factor

Four hundred and thirty four twins occurring in 220 women were studied during a period of 11 years (1969–1979) at Notre-Dame Hospital.Perinatal mortality (< 28 days) was compared before and after 1974, and the impact of ultrasound technique upon perinatal outcome was assessed during the second period (1974–1979). The main factor associated with perinatal mortality was low birth weight caused by either prematurity or intrauterine growth retardation.While fetal mortality remained unchanged within the two study periods, neonatal mortality decreased from 68.2/1,000 to 28.9/1,000 mainly due to increased survival rate of twins below 1,500 g at birth.With identical perinatal care during the same period, perinatal mortality and incidence of intrauterine growth-retarded twins remained unchanged despite early diagnosis by ultrasound.

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