scholarly journals Almost étale extensions of Fontaine rings and log-crystalline cohomology in the semi-stable reduction case

2011 ◽  
Vol 61 (5) ◽  
pp. 1875-1942
Author(s):  
Rémi Shankar Lodh
Keyword(s):  
Crystalline Cohomology ◽  
Stable Reduction ◽  
Reduction Case

Strategic Scripts and Nuclear Disarmament

2018 ◽  
Author(s):  
Matthew Harries ◽  
Benedict Wilkinson
Keyword(s):  
Nuclear Weapons ◽  
Analytical Tool ◽  
The Other ◽  
Nuclear Disarmament ◽  
Stable Reduction ◽  
The Way

This chapter spans Freedman’s earliest focus on nuclear weapons and his development of strategic scripts as an analytical tool over three decades later. It discusses the way in which opposing logics of disarmament and armament co-existed in relation to nuclear weapons. It deploys the notion of strategic scripts to explain the contradictions inherent in approaches to nuclear disarmament, developing the concept of strategic scripts as it does so. The notion of scripts can be used to explore and even to promote nuclear disarmament. Two scripts, one of ‘stable reduction’, the other of ‘disarmament’, each serve to frame thinking. These scripts and the interactions they generate facilitate understanding of the way in which opposite instinctive reactions and, stemming from these, scripts about nuclear weapons co-exist, but are fragile as either an analytical or a strategic tool.

scholarly journals Investigation of Water Composition on Formation Damage and Related Energy Recovery from Geothermal Reservoirs: Geochemical and Geomechanics Insights

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7415
Author(s):  
Ilyas Khurshid ◽  
Imran Afgan
Keyword(s):  
Geothermal Energy ◽  
Water Injection ◽  
Formation Damage ◽  
Breakdown Pressure ◽  
Geothermal Reservoirs ◽  
Water Composition ◽  
Porosity Reduction ◽  
Reduction Case ◽  
Formation Porosity

The main challenge in extracting geothermal energy is to overcome issues relating to geothermal reservoirs such as the formation damage and formation fracturing. The objective of this study is to develop an integrated framework that considers the geochemical and geomechanics aspects of a reservoir and characterizes various formation damages such as impairment of formation porosity and permeability, hydraulic fracturing, lowering of formation breakdown pressure, and the associated heat recovery. In this research study, various shallow, deep and high temperature geothermal reservoirs with different formation water compositions were simulated to predict the severity/challenges during water injection in hot geothermal reservoirs. The developed model solves various geochemical reactions and processes that take place during water injection in geothermal reservoirs. The results obtained were then used to investigate the geomechanics aspect of cold-water injection. Our findings presented that the formation temperature, injected water temperature, the concentration of sulfate in the injected water, and its dilution have a noticeable impact on rock dissolution and precipitation. In addition, anhydrite precipitation has a controlling effect on permeability impairment in the investigated case study. It was observed that the dilution of water could decrease formation of scale while the injection of sulfate rich water could intensify scale precipitation. Thus, the reservoir permeability could decrease to a critical level, where the production of hot water reduces and the generation of geothermal energy no longer remains economical. It evident that injection of incompatible water would decrease the formation porosity. Thus, the geomechanics investigation was performed to determine the effect of porosity decrease. It was found that for the 50% porosity reduction case, the initial formation breakdown pressure reduced from 2588 psi to 2586 psi, and for the 75% porosity reduction case it decreased to 2584 psi. Thus, geochemical based formation damage is significant but geomechanics based formation fracturing is insignificant in the selected case study. We propose that water composition should be designed to minimize damage and that high water injection pressures in shallow reservoirs should be avoided.

scholarly journals Influence of Ulnar Bow Sign on Surgical Treatment of Missed Bado Type I Monteggia Fracture in Children

2020 ◽  
Author(s):  
Shijie Liao ◽  
Tiantian Wang ◽  
Qian Huang ◽  
Yun Liu ◽  
Rongbin Lu ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Radial Head ◽  
Monteggia Fracture ◽  
Type I ◽  
Ulnar Osteotomy ◽  
Group A ◽  
The Mean ◽  
Group B ◽  
Stable Reduction

Abstract PurposeThe present study aimed to explore the influence of ulnar bow on the surgical treatment of Bado type I missed Monteggia fracture in children.MethodsThis study is a retrospective review of 24 patients between November 2010 and March 2019. All patients were treated with open reduction of the radial head and ulnar opening wedge osteotomy without annular ligament reconstruction. The mean interval between injury onset and surgery was five months (range: 2–12 months). The average age of participants at the time of surgery was 6.4 years (range: 3–10 years). We evaluated the maximum ulnar bow (MUB) and MUB position (P-MUB) via radiography. The patients were divided into middle group (group A: 14 cases, MUB located at 40% to 60% of the distal ulna) and distal group (group B: 10 cases, MUB located at 20% to 40% from the distal end of the ulna) based on P-MUB. The mean period of follow-up was 37 months (range: 6–102 months).ResultsAt the last follow-up, all the children showed stable reduction of the radial head, and the flexion function of elbow joint improved after operation (P<0.05). Group A presented a larger the ratio of maximum ulnar bow(R-MUB) and angle of ulnar osteotomy(OA) than group B (P<0.05). There was statistically significant difference between group A and Group B in the P-MUB (P < 0.05). The osteotomy angle was positively correlated with the R-MUB (R2 =0.497,P=0.013), The osteotomy angle was positively correlated with the P-MUB (R2=0.731,P=0.000), The R-MUB is proportional to the P-MUB (R2 =0.597,P=0.002). The regression equation of P-MUB and osteotomy angle: Angle=7.064+33.227* P-MUB (R2=0.459, P =0.000).ConclusionWhen the ulnar bow is positioned at the middle ulna, a stable reduction of radial head need to be achieved through a larger angle in the ulnar osteotomy. If the position of maximum ulnar bow (P-MUB) is closer to the middle of the ulna or the ratio of maximum ulnar bow (R-MUB) is larger, the osteotomy angle is larger.

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