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Indentation onto Stishovite (SiO<sub>2</sub>), MgO, and a Covered Superalloy: “Pop-In” Repair, Phase-Transition Onsets, Polymorph Energies, and Transition-Energies

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Advances in Materials Physics and Chemistry 2020年第3期10卷 77-95页

作者： gerd Kaupp University of Oldenburg Oldenburg Germany

The Berkovich indentation loading curves of the initially only extraterrestrial available polymorphs of SiO2 are physically analyzed by applying the now well established FN-h3/2 plots for conical/pyramidal indentations, in view of determining the phase-transition onset forces, indentation energies, and transition energies. Two phase-transitions of synthesized Stishovite yielding 2 polymorphs (one of them is Seifertite) with these properties are characterized. A third post-Stishovite polymorph is safely projected for higher load indentation. Both of them are now available at room temperature on earth for further investigation and the projected third of them is waiting. The published “pop-ins” had to be removed by self-evident repair of the force-depth curve. The meaning of published “pop-ins” is elucidated, apparently for the first time. The reasons for them and their avoidance are manifold. They are not materials’ properties but mechanical artefacts. Published pop-ins are not at all connected to phase-transitions, despite theoretical considerations claiming elastic-plastic conversion at the start of “pop-ins”. Spherical indentation analyses before them are obsolete. Final support is inter alia that one of the two new MgO twinning transitions is within a published “pop-in excursion”. The putting of a pop-in arrow at smooth loading curve without discontinuities is criticized, as the transfer between chemically different phases is neither phase transition nor “pop-in”. The polymorph’s onset forces, their energies and their endo- or exo-thermic phase-transition energies are reported. The development of the Stishovite, post-Stishovite and MgO polymorphs is mechanochemical analyzed. High pressure polymorph energetic properties are important for the earth’s sub mantel investigations and for public safety of technical materials such as MgO for constructions, or covered superalloys for e.g. airplanes, turbines, etc. Breakage and catastrophic cracks are more easily initiated

关键词： Berkovich Indentation Catastrophic Cracking Covered-Superalloy False Historical Concepts MgO Phase-Transition-Energy “Pop-In” Post-Stishovite Stishovite

Phase-Transition Energies, New Characterization of Solid Materials and Anisotropy

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Advances in Materials Physics and Chemistry 2019年第4期9卷 57-70页

作者： gerd Kaupp University of Oldenburg Oldenburg Germany

Non-iterative analysis of indentation results allows for the detection of phase transitions under load and their transition energy. The closed algebraic equations have been deduced on the basis of the physically founded normal force ?depth3/2 relation. The precise transition onset position is obtained by linear regression of the FN = kh3/2 plot, where k is the penetration resistance, which also provides the axis cuts of both polymorphs of first order phase transitions. The phase changes can be endothermic or exothermic. They are normalized per μN or mN normal load. The analyses of indentation loading curves with self-similar diamond indenters are used as validity check of the loading curves, also from calibration standards that exhibit previously undetected phase-transitions and are thus incorrect. The phase-transition energies for fused quartz are determined from the loading curves from instrument provider handbooks. The anisotropic behavior of phase transition energies is studied for the first time. Quartz is a useful test object. The reasons for the packing-dependent differences are discussed on the basis of the local crystal structure under and around the inserting tip.

关键词： Instrumented Indentation Loading Curve Phase Transition Onset and Energy Iteration-Less Plot Physical Exponent Present ISO Standard Energy Law Violations Physical Hardness Error Detections

Valid Geometric Solutions for Indentations with Algebraic Calculations

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Advances in Pure Mathematics 2020年第5期10卷 322-336页

作者： gerd Kaupp University of Oldenburg Oldenburg Germany

This paper analyzes the force vs depth loading curves of conical, pyramidal, wedged and for spherical indentations on a strict mathematical basis by explicit use of the indenter geometries rather than on still world-wide used iterated “contact depths” with elastic theory and violation of the energy law. The now correctly analyzed loading curves provide as yet undetectable phase-transition. For the spherical indentations, this includes an obvious correction for the varying depth/radius ratio, which had previously been disregarded. Only algebraic formulas are now used for the calculation of material’s properties without data-fittings, or simplifications, or false simulations. Penetration resistance differences of materials’ polymorphs provide precise intersection values as kink unsteadiness by equalization of linear regression lines from mathematically linearized loading curves. These intersections indicate phase transition onset values for depth and force. The precise and correct determination of phase-transition onsets allows for energy and phase-transition energy calculations. The unprecedented algebraic equations are most simply and mathematically reproducibly deduced. There are no restrictions for elastic and/or plastic behavior and no use of different formulas for different force ranges. The novel indentation formulas reveal unprecedented access to the onset, energy and transition energy of phase-transitions. This is now also achieved for spherical indentations. Their formula as deduced for plotting is reformulated for integrations. The distinction of applied work (Wapplied) and indentation work (Windent) allows now for comparing spherical with pyramidal indentation phase-transitions. Only low energy phase-transitions from pyramidal indentation may be missed in spherical indentations. The rather low penetration depths of sphere calottes calculate very close for cap and flat area values. This allows for the calculation of the indentation phase-transition onset pr

关键词： Geometry of Indenters Algebraic Solutions False Mathematic Concepts Germanium Pyramidal Conical Indentation Spherical Indentation

Global standard names for the Lowermost Cambrian Series and Stage

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Episodes 2007年第4期30卷 287-289页

作者： Ed Landing Shanchi Peng Loren E. Babcock gerd Geyer Malgorzata Moczydlowska- Vidal New York State Museum Madison Avenue Albany New York 12230 USA. State Key Laboratory of Stratigraphy and Palaeobiology Nanjing Institute of Geology and Palaeontology 39 East Beijing Road Nanjing 210008 China School of Earth Sciences The Ohio State University Columbus Ohio 43210 USA Institut für Palaiontologie Bayerische Julius-Maximillians-Universitat Pleicherwall 1 D97070 Würzburg Germany Department of Earth Sciences Uppsala University Norbyvaigen 22 Sweden.

The GSSP marking the base of the Cambrian System was ratified by the lUGS in 1992. Ratification of the GSSP point at the base of the Trichophycus pedum Ichnozone in the Fortune Head section, eastern Newfoundland, Canada, automatically defined the conterminant base of the lowermost series and stage of the Cambrian although names for those subdivisions were not proposed at the time of the decision. In 2007, the lUGS ratified the names Terreneuvian Series and Fortunian Stage for these previously unnamed chronostratigraphic subdivisions. The Terreneuvian Series replaces the provisional name ＂Series 1,＂ and the Fortunian Stage replaces the provisional name ＂Stage 1,＂ of the Cambrian System.

关键词：寒武纪全球标准地质学测量方法

Descemet-membrane endothelial keratoplasty in patients with retinal comorbidity -a prospective cohort study

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International Journal of Ophthalmology(English edition) 2016年第3期9卷 390-394页

作者： Kristina Spaniol Christoph Holtmann Jan-Hendrik Schwinde Sophia Deffaa Rainer Guthoff gerd Geerling University Eye Hospital Dusseldorf Moorenstraβe 5Dusseldorf 40225 Germany

AIM： To investigate indications, surgical challenges, and outcome of Descemet -membrane endothelial keratoplasty （DMEK） in patients with retinal comorbidities （RC）. METHODS： In a prospective cohort study, 8 eyes of 8 DMEK-patients with known RC were compared to 38 eyes of 38 DMEK-patients without RC. The duration of surgery, the degree of difficulty graded by the surgeon, and the complications through DMEK-surgery were analyzed for each patient. The best-corrected visual acuity （BCVA）, the endothelial cell count, the intraocular pressure, and the subjective satisfaction was evaluated after a 6-month follow-up. Data were compared applying the non-parametric Wilcoxon-, Chi-square- and Fisher＇s-exact-test with P≤ 0. 05 as level of significance. RESULTS： RC-patients had dry age-related macular degeneration （n=4） or history of pars-plana vitrectomy （n=4）. The main indication for DMEK was pain due to bullous keratopathy for the RC-patlents （n=7, 88%） and visual impairment due to Fuchs endothelial keratoplasty for the non-RC-patients （n=33, 87% ）. The BCVA increased for both groups （P=0.01, P〈0.001） and all corneas cleared. For the RC-patients, the subjective satisfaction improved significantly （P=0.02）. Oil-filling and missing support of the vitreous body complicated surgery in vitrectomized eyes. CONCLUSION： DMEK is a favorable technique to treat endothelial disorders even if patients suffer from a retinal comorbidity. By enhancing the corneal clarity, it enables retinal examination or intraocular surgery and increases the patients satisfaction. However, in vitrectomized or silicone-oil filled eyes, the duration of surgery and degree of complexity are increased. An experienced surgeon should perform DMEK in these patients. Clinical trial registration number： DRKS00007566.

关键词： Descemet-membrane endothelial keratoplasty age-related macular degeneration pars plana vitrectomy

The Loading Curve of Spherical Indentions Is Not a Parabola and Flat Punch Is Linear

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Advances in Materials Physics and Chemistry 2019年第8期9卷 141-157页

作者： gerd Kaupp University of Oldenburg Oldenburg Germany

The purpose of this paper is the physical deduction of the loading curves for spherical and flat punch indentations, in particular as the parabola assumption for not self-similar spherical impressions appears impossible. These deductions avoid the still common first energy law violations of ISO 14577 by consideration of the work done by elastic and plastic pressure work. The hitherto generally accepted “parabolas’” exponents on the depth h (“2 for cone, 3/2 for spheres, and 1 for flat punches”) are still the unchanged basis of ISO 14577 standards that also enforce the up to 3 + 8 free iteration parameters for ISO hardness and ISO elastic indentation modulus. Almost all of these common practices are now challenged by physical mathematical proof of exponent 3/2 for cones by removing the misconceptions with indentation against a projected surface (contact) area with violation of the first energy law, because the elastic and inelastic pressure work cannot be obtained from nothing. Physically correct is the impression of a volume that is coupled with pressure formation that creates elastic deformation and numerous types of plastic deformations. It follows the exponent 3/2 only for the cones/pyramids/wedges loading parabola. It appears impossible that the geometrically not self-similar sphere loading curve is an h3/2 parabola. Hertz did only deduce the touching of the sphere and Sneddon did not get a parabola for the sphere. The radius over depth ratio is not constant with the sphere. The apparently good correlation of such parabola plots at large R/h ratios and low h-values does not withstand against the deduced physical equation for the spherical indentation loading curve. Such plots are unphysical for the sphere and so tried regression results indicate data-treatments. The closed physical deduction result consists of the exponential factor h and a dimensionless correction factor that is depth dependent. The non-parabola against force plot using published data is concav

关键词： Closed Formula for Spherical Indentation Challenge of ISO14577 Mathematical Proofs Volume Instead of Area Correct Flat Indentations Physical Indentation Hardness Hardness Dependence on Indenter Shape Data Treatment Detection

Erratum to “Valid Geometric Solutions for Indentations with Algebraic Calculations”, [Advances in Pure Mathematics, Vol. 10 (2020) 322-336]

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Advances in Pure Mathematics 2020年第9期10卷 545-546页

作者： gerd Kaupp University of Oldenburg Oldenburg Germany

The original online version of this article (gerd Kaupp 2020) Valid Geometric Solutions for Indentations with Algebraic Calculations, (Volume, 10, 322-336, https://***/10.4236/apm.2020.105019) needs some further amend... 详细信息

关键词： erratum

Hepatocellular carcinoma recurrence after acute liver allograft rejection treatment: A multicenter European experience

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Hepatobiliary & Pancreatic Diseases International 2019年第6期18卷 517-524页

作者： Quirino Lai Samuele Iesari Armin Finkenstedt Maria Hoppe-Lotichius Maxime Foguenne Konrad Lehner gerd Otto Jan Lerut Starzl Unit of Abdominal Transplantation University Hospitals Saint LucUniversitécatholique LouvainBrusselsBelgium Hepato-biliary Surgery and Liver Transplantation Unit Sapienza University of RomeUmberto I HospitalRomeItaly Department of Bio-technological and Applied Clinical Sciences University of L’AquilaL’AquilaItaly Department of Internal Medicine I Innsbruck Medical UniversityInnsbruckAustria Department of Transplantation and Hepatobiliary Surgery University of MainzMainzGermany

Background:During the last decades,several risk factors for the recurrence of hepatocellular carcinoma(HCC)after liver transplantation(LT)have been ***,the impact of two important drivers of oncogenesis,namely the immunosuppression and the treatment of acute cellular rejection(ACR)have been marginally *** study aimed at investigating the impact of ACR treatment on the incidence of tumor recurrence in a large European HCC-LT ***:Seven hundred and eighty-one adult patients transplanted between February 1,1985 and June 30,2016 were retrospectively *** propensity score match,116 patients treated for ACR using steroid boluses were compared with 115 patients who did not present any ACR or a histologic but clinical irrelevant ***:Steroid boluses treated patients had a 18-fold higher overall incidence of HCC recurrence than those non-treated patients(16.4%vs.0.9%;P<0.0001).At multivariate Cox regression analysis,steroid boluses used to treat ACR were an independent risk factor for HCC recurrence(HR=14.2;95%CI:1.8–110.4;P=0.010).Conclusions:The decision to treat ACR as well as to reinforce immunosuppression load should be cautiously taken in view of the presented *** studies are needed to further elucidate the clinical impact of immunosuppression on HCC recurrence after transplantation.

关键词： Liver transplantation Recurrence Steroid biopsy Acute rejection

Stigma and its impact on the families of former soldiers of the German Armed Forces: An exploratory study

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Military Medical Research 2019年第2期6卷 143-158页

作者： Katrin Schuy Simone Dors Loni Brants Marie Horzetzky gerd Willmund Andreas Strohle Peter Zimmermann Heinrich Rau Stefan Siegel Department of Psychiatry and Psychotherapy Campus ChariteMitteCharite-Universitatsmedizin Berlin10117BerlinGermany Psychotraumazentrum Military Hospital10115BerlinGermany

Background: Military families who have a family member with a mental illness see themselves confronted with many demands. Stigmatization is one of these challenges. Stigmatization affects not only the individual who suffers from a mental illness but also other family members via stigma by association and vicarious stigma. Stigma by association occurs when mental illness stigma spills over to individuals associated with an individual with a mental illness. Vicarious stigma describes the suffering of family members when they note the impact of stigma on their relative with mental illness. As a societal phenomenon, stigma plays out in social interactions and might therefore influence the social networks of families. It is also associated with healthcare ***: Narrative interviews were conducted with 15 family members(partners, spouses, parents and children) of former soldiers of the German Armed Forces with a service-induced mental illness. The transcribed interview data were analyzed using a thematic analysis approach, in which codes were formed and emerging themes were systemized. Relationships between stigma, the families’ reactions to it, its effects on their social relationships and its interference with their healthcare utilization were ***: This study provides a detailed description of how relatives of former German soldiers with mental health problems experience stigma by association and vicarious stigma. Their perceptions are shown in a model that describes stigma-related attitudes, reactions to them and their effects on the social relationships of former soldiers’ families. These families felt stigmatized because of the former soldiers’ mental illness(mental illness stigma) and the military context in which it occurred(former soldier stigma). They reacted with nondisclosure, anger, acceptance and self-blame. Stigma was associated with smaller and weaker social networks that were characterized by social exclusion, self-segregation a

关键词： Stigma by association Vicarious stigma Families Mental illness Veteran German Armed Forces