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السجلات المعروضة 4021 -- 4030 من 4191
Vibration of Periodic Drill-Strings with Local Sources of Resonance
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Multidisciplinary Digital Publishing Institute (MDPI)
, 2021 , Article)
A new class of drill-strings is proposed for attenuating undesirable vibrations to ensure effective operation. The drill-string is provided with passive periodic inserts, which are integrated with sources of local resonance ...
Comparative chloroplast genomics of endangered euphorbia species: Insights into hotspot divergence, repetitive sequence variation, and phylogeny
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Multidisciplinary Digital Publishing Institute (MDPI)
, 2020 , Article)
Euphorbia is one of the largest genera in the Euphorbiaceae family, comprising 2000 species possessing commercial, medicinal, and ornamental importance. However, there are very little data available on their molecular ...
Psychological impact of the COVID-19 pandemic within institutional quarantine and isolation centres and its sociodemographic correlates in Qatar: A cross-sectional study
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BMJ Publishing Group
, 2021 , Article)
Setting The State of Qatar has had one of the highest COVID-19 infection rates globally and has used state-managed quarantine and isolation centres to limit the spread of infection. Quarantine and isolation have been shown ...
Fetal lung maturity assessment: A historic perspective and Non – invasive assessment using an automatic quantitative ultrasound analysis (a potentially useful clinical tool)
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Elsevier
, 2021 , Article)
Immature fetal lung is associated with many adverse outcomes including respiratory distress syndrome and transient tachypnoea of the newborn. Several methods/tools have been used over several decades to assess fetal lung ...
Impact of the COVID-19 Pandemic on Mental Health Law in the State of Qatar
(
Elsevier
, 2021 , Article Review)
Accumulating evidence exploring the impact of the pandemic on mental health has been published as the Covid-19 pandemic has evolved and reflect how shock, anxiety, and fear of the early periods of the pandemic are giving ...
Optimization of piezoelectric sensor-actuator for plate vibration control using evolutionary computation: Modeling, simulation and experimentation
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Institute of Electrical and Electronics Engineers Inc.
, 2021 , Article)
The development of lightweight, stronger, and more flexible structures has received the utmost interest from many researchers. For this reason, piezoelectric materials, with their inherent electromechanical coupling, have ...
Combined effects of treated domestic wastewater, fly ash, and calcium nitrite toward concrete sustainability
(
Elsevier
, 2021 , Article)
The drastic increase in freshwater and ordinary Portland cement (OPC) consumption poses severe environmental and economic challenges worldwide. This study; therefore, explores the mechanical and durability properties of ...
Thermal integrity testing of cast in situ piles: An alternative interpretation approach
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SAGE Publications Ltd
, 2021 , Article)
Integrity testing of deep cast in situ concrete foundations is challenging due to the intrinsic nature of how these foundations are formed. Several integrity test methods have been developed and are well established, but ...
First principle study of transition metals codoped MoS2 as a gas sensor for the detection of NO and NO2 gases
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Elsevier B.V.
, 2021 , Article)
Exposure to nitrogen oxides (NOx) has been reported to seriously affect the respiratory systems. More precisely, breathing NOx may lead to the appearance of asthma symptoms, and may also result in the infection with asthma ...
Inefficiency source tracking: evidence from data envelopment analysis and random forests
(
Springer Nature
, 2021 , Article)
In the present era of complex environments, banks operate in a more dynamic environment, which in turn, affects their relative efficiency. Traditional Data envelopment analysis (DEA) models are widely used to measure ...