safety margin
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Frederic Trillaud ◽  
Edgar Berrospe-Juarez ◽  
Vı́ctor M. R. Zermeño ◽  
Francesco Grilli

Abstract Second-Generation High Temperature Superconducting (2G HTS) tapes are considered to be the main candidates for the development of future ultra high DC magnetic field magnets. In such application, the usability of the HTS magnets can be strongly impaired by large screening currents developed in the flat strip of the tapes. These currents lead to the generation of a Screening Current Induced Field (SCIF) that can deteriorate the performance by affecting the stability and the homogeneity of the magnetic field. Besides the SCIF, there is also the likely mechanical degradation of the tapes under the action of large Lorentz forces. The mechanical degradation and the presence of large screening currents intertwine to affect the reliable operation of 2G HTS magnets. To study those combined issues, an electromagneto-mechanical model based on tensile mechanical characterization of short samples was built to simulate the coupled electromagnetic and mechanical behaviour of insert magnets made of 2G HTS tapes under very high magnetic field. The coupling is carried out by considering the dependence of the n index and the critical current density Jc on the local relative deformation in addition to the magnetic flux density. The case study is the Little Big Coil (LBC, version 3) which broke the world record of the strongest continuous magnetic field achieved to this date. An analysis of the electromagneto-mechanical behavior of the LBC is conducted on the basis of information extracted from literature to show that the proposed model can assess the current magnitude at which the insert magnet quenched. Additionally, it is shown that the model can also provide some insights on the impact of the mechanical degradation of the tape on the SCIF hysteresis loop. The studies are conducted on the original LBC and on versions that include additional modifications such as harnessing and co- winding with rigid metallic tapes. These modifications are employed to limit the mechanical degradation of the HTS insert magnet under ultra high magnetic field. They are expected to deliver extra safety margin to 2G HTS insert magnets.

Chenxing Hu ◽  
Xue Li ◽  
Siyu Zheng

The increasing demand for compression systems with high pressure ratio and wide safety margin has set new prerequisites for designers to meet the industrial needs without increasing the manufacturing costs excessively. In this work, the turbulent stability of the vaneless diffuser of the centrifugal compressor was analyzed. Unsteady Reynolds-averaged numerical simulations of the isolated diffuser and full annular diffuser with or without circumferential asymmetric boundary conditions downstream were performed. And a continuous adjoint approach was adopted, which is rarely applied in the stability analysis of compressor flow. Then, the origin of instability under different inflow and outflow conditions was sought with a sensitivity analysis. The prediction of the growth rate reveals that the flow near the shroud dominates the global stability of the diffuser. When connected with an impeller in the upstream direction, the most unstable region is localized at the backflow regions near the outlet. The wave number, however, is altered under the impact of the jet-wake flow. When connected to a circumferential asymmetric condition, the structural sensitivity of the vaneless diffuser with a radius ratio of 1.53 indicates that the interaction between the inlet reverse flow and outlet backflow is responsible for the occurrence of stall. The most unstable regions are localized at the region 90°–135° away from the volute tongue. The present work mainly contributes to the instabilities identification with novel sensitivity methods under asymmetric boundary conditions.

Palvi Banotra

Background: Preeclampsia, a serious pregnancy complication which is commonly characterized by high blood pressure, presence of protein in the urine and sometimes swelling in women's feet, legs and hands. With this condition, patient’s high blood pressure often results in seizures. Generally, the outcome remains good, however, eclampsia can be life threatening and disastrous.Methods: This cross-sectional study considered 114 patients who meet inclusion criteria and agreed to will-fully participate in the study were evaluated for different parameters. Patients who developed eclampsia during intra-natal and postnatal period were included in the study. The aim of the study was to evaluate the maternal outcome among all patients of eclampsia treated with low magnesium sulphate dosage therapy.  Results: The present study revealed, very low fit recurrence rate, low mortality rate, zero treatment failure rate, no toxicity and (99.12%) success rate.Conclusions: Apart from zero percent treatment failure rate, Low maternal mortality and fit recurrence rate encouraged us to continue the treatment with low dose MGSO4 regimen. Thus, low dose magnesium sulphate has been found very effective in treating the eclmpsia and at the same time maintains the high safety margin.

2022 ◽  
Vol 9 ◽  
Zhiyi Yang ◽  
Fengchen Li ◽  
Guohan Chai

The significant impact brought by a severe nuclear accident at the Fukushima Daiichi Nuclear Power Plant (NPP) in Japan in March 2011 has made global regulators to review the requirements against severe accidents. In China, comprehensive safety inspection and external hazard safety margin assessment on NPPs were carried out, regulatory requirements on improvement measures for NPPs based on the inspection were given, the nuclear safety 5-year plan was made and executed, and the safety requirements on the new NPP design were drafted. The Nuclear Safety Law came into effect in 2018. The “Code on the Safety of Nuclear Power Plant Design” (HAF102) was revised in 2016, and relevant safety guides were developed. In this article, improvement actions and requirements about NPP safety in China over the past 10 years were reviewed, and the nuclear safety philosophy and requirements including practical elimination, classification of accident conditions, and defense in depth portable equipment were elaborated. In summary, some suggestions of NPP safety in China in the future were provided.

2022 ◽  
Vol 42 ◽  
Antonio W.O. Silva ◽  
Múcio F.F. Mendonça ◽  
Moisés D. Freitas ◽  
Antonio L. Ribeiro Filho ◽  
Ricardo D.G. Silva ◽  

ABSTRACT: Monensin is an ionophore antibiotic (IA) widely used for growth promotion and weight gain in the production of ruminants. However, it has caused intoxication in several species, including buffaloes, mainly because of the ignorance or disrespect of the recommendations for use in each animal species. The objective of this study was to describe, for the first time, clinical-epidemiological and anatomopathological data of an outbreak of accidental poisoning by monensin in buffalos and rediscuss the recommendation of the use of IA in the production of this species. The outbreak affected 21 adult buffaloes after consumption of remains from a feed formulated on the farm and whose constituents were mixed by hand. Clinical and first death signs were observed 24 hours after ingestion of this food. In general, the clinical picture was characterized by muscle weakness, tremors, difficulty in locomotion, and decubitus. Fifteen buffaloes presented clinical signs of poisoning (71.5% morbidity), followed by death (100% lethality), after acute to subacute evolution (<24h to 96h). Laboratory tests indicated elevated serum activity of creatine phosphokinase and aspartate aminotransferase enzymes. Three buffaloes underwent necropsy, and samples from several organs were collected for histopathological examination. The main injuries found were hyaline degeneration and multifocal segmental necrosis in the skeletal and cardiac striated muscles (myopathy and degenerative-necrotic multifocal multifocal-necrotic cardiopathy). The diagnosis was confirmed by the toxicological evaluation of suspected ration remains, which detected 461.67mg/kg of monensin. The death of 71.5% buffaloes in this lot occurred due to a succession of errors, which included faults in the formulation of the ration and, above all, due to the use of monensin in a highly sensitive species. Despite the possible beneficial effects of IA use as a dietary supplement for buffaloes, we are of the opinion that IAs should never be used in bubalinoculture since any increment in production does not compensate for the imminent risk of death due to a small safety margin for this species and the absence of antidotes.

2021 ◽  
Vol 34 (06) ◽  
pp. 1667-1676
Ilya V. Chepurchenko ◽  
Svetlana V. Korkina

The use of modern means of mechanization of loading and unloading operations in places of mass processing of bulky loads in railway and water connection allows to increase the efficiency and productivity of various types of transport, to ensure the safety of load and rolling stock. The most common method of unloading open wagons in ports, mining enterprises, thermal power plants, etc. is the use of special rotary car dumpers. However, it should be noted that unloading on the car dumpers leads to damage of the carriages structural elements. The article presents the results of strength calculations of the car dumper body under the influence of specified dynamic loads from the expiring cargo. They show that the safety margin of the load-bearing elements of the car body is not enough at critical corners of rotation of the car dumper rotor. The studies were carried out using modern computer modeling methods used in the development of new-generation freight car designs. The software package took into account the effects of dynamic loading as external factors that occur at different corners of the car dumper rotor. The implementation of the results obtained at the design stage of innovative structures of open wagon car bodies will allow predicting the operational parameters of load-bearing structures. The presented studies are aimed at improving the safety and operational reliability of the cargo car fleet.

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Jianqing Zhang ◽  
Ruikun Zhang ◽  
Yihua Zeng

In this paper, a statistical analysis of the tensile strength of FRP composites is conducted. A relatively large experimental database including 58 datasets is first constructed, and the Normal, Lognormal, and Weibull distributions are fitted to the data using a tail-sensitive Anderson–Darling statistic as the measure of goodness of fit. Fitting results show that the Normal, Lognormal, and Weibull distributions can be used to model the tensile strength of FRP composites. Then, the characteristic value for the tensile strength of FRP composites at a fixed percentile is analyzed. It is found that the Weibull distribution results in a higher safety margin in comparison to either the Normal or the Lognormal distribution. When the experimental justification, the theoretical justification, as well as the design conservativeness are taken into consideration, the Weibull distribution is the most recommended distribution to model the tensile strength of FRP composites. Furthermore, a probabilistic model considering the statistical uncertainty for the tensile strength for FRP composites is proposed. It is believed that the statistical uncertainty can be modeled as a reduction factor, and the recommended value of such factor for engineering design practices is provided based on regression analysis.

2021 ◽  
Maurizio Chioccioli ◽  
Subhadeep Roy ◽  
Kevin Rigby ◽  
Rachel Newell ◽  
Oliver Dansereau ◽  

AbstractmicroRNAs are non-coding RNAs that negatively regulate gene networks. Previously, we reported a systemically delivered miR-29 mimic MRG-201 that reduced fibrosis in animal models, but at doses prohibiting clinical translation. Here, we generated MRG-229, a next-gen miR-29 mimic with improved chemical stability, conjugated with the internalization moiety BiPPB (PDGFbetaR-specific bicyclic peptide). In TGF-b-treated human lung fibroblasts and precision cut lung slices, MRG-229 decreased COL1A1 and ACTA2 gene expression and reduced collagen production. In bleomycin-treated mice, intravenous or subcutaneous delivery of MRG-229 downregulated profibrotic gene programs at doses more than ten-fold lower than the original compound. In rats and non-human primates, and at clinically relevant doses, MRG-229 was well tolerated, with no adverse findings observed. In human peripheral blood decreased mir-29 concentrations were associated with increased mortality in two cohorts potentially identified as a target population for treatment. Collectively, our results provide support for the development of MRG-229 as a potential therapy in humans with IPF.One Sentence SummaryOne Sentence Summary: A stabilized, next-generation miR-29 mimic has been developed that demonstrates efficacy at commercially viable doses with a robust safety margin in non-human primates.

2021 ◽  
Vol In Press (In Press) ◽  
Eric Y. Chen ◽  
Sascha S. Beutler ◽  
Alan D. Kaye ◽  
Amber N. Edinoff ◽  
Seyed-Hossein Khademi ◽  

: Neuropathic pain has presented a challenge for physicians to treat and often requires a multimodal approach with both pharmacologic and lifestyle interventions. Mirogabalin, a potent, selective ligand of the α2δ-1 and α2δ-2 subunits of voltage-gated calcium channels (VGCCs), provides analgesia by inhibiting neurotransmitter release at the presynaptic end of the neuron. Mirogabalin offers more sustained analgesia than its gabapentinoid counterparts in addition to a wider safety margin for adverse events. Recent clinical trials of mirogabalin have demonstrated both efficacy and tolerability of the drug for the treatment of diabetic peripheral neuropathic pain and postherpetic neuralgia, leading to its approval in Japan. While still not yet FDA approved, mirogabalin is still in its infancy and offers potential into the treatment of neuropathic pain and its associated comorbidities.

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