期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
Multiplication with the Factor One, a Rare Mathematic Tool for Simplification and Unrevised DIN-ISO-ASTM-14577
1
作者 Gerd Kaupp 《Advances in Pure Mathematics》 2025年第1期91-105,共15页
The search for mechanical properties of materials reached a highly acclaimed level, when indentations could be analysed on the basis of elastic theory for hardness and elastic modulus. The mathematical formulas proved... The search for mechanical properties of materials reached a highly acclaimed level, when indentations could be analysed on the basis of elastic theory for hardness and elastic modulus. The mathematical formulas proved to be very complicated, and various trials were published between the 1900s and 2000s. The development of indentation instruments and the wish to make the application in numerous steps easier, led in 1992 to trials with iterations by using relative values instead of absolute ones. Excessive iterations of computers with 3 + 8 free parameters of the loading and unloading curves became possible and were implemented into the instruments and worldwide standards. The physical formula for hardness was defined as force over area. For the conical, pyramidal, and spherical indenters, one simply took the projected area for the calculation of the indentation depth from the projected area, adjusted it later by the iterations with respect to fused quartz or aluminium as standard materials, and called it “contact height”. Continuously measured indentation loading curves were formulated as loading force over depth square. The unloading curves after release of the indenter used the initial steepness of the pressure relief for the calculation of what was (and is) incorrectly called “Young’s modulus”. But it is not unidirectional. And for the spherical indentations’ loading curve, they defined the indentation force over depth raised to 3/2 (but without R/h correction). They till now (2025) violate the energy law, because they use all applied force for the indenter depth and ignore the obvious sidewise force upon indentation (cf. e.g. the wood cleaving). The various refinements led to more and more complicated formulas that could not be reasonably calculated with them. One decided to use 3 + 8 free-parameter iterations for fitting to the (poor) standards of fused quartz or aluminium. The mechanical values of these were considered to be “true”. This is till now the worldwide standard of DIN-ISO-ASTM-14577, avoiding overcomplicated formulas with their complexity. Some of these are shown in the Introduction Section. By doing so, one avoided the understanding of indentation results on a physical basis. However, we open a simple way to obtain absolute values (though still on the blackbox instrument’s unsuitable force calibration). We do not iterate but calculate algebraically on the basis of the correct, physically deduced exponent of the loading force parabolas with h3/2 instead of false “h2” (for the spherical indentation, there is a calotte-radius over depth correction), and we reveal the physical errors taken up in the official worldwide “14577-Standard”. Importantly, we reveal the hitherto fully overlooked phase transitions under load that are not detectable with the false exponent. Phase-transition twinning is even present and falsifies the iteration standards. Instead of elasticity theory, we use the well-defined geometry of these indentations. By doing so, we reach simple algebraically calculable formulas and find the physical indentation hardness of materials with their onset depth, onset force and energy, as well as their phase-transition energy (temperature dependent also its activation energy). The most important phase transitions are our absolute algebraically calculated results. The now most easily obtained phase transitions under load are very dangerous because they produce polymorph interfaces between the changed and the unchanged material. It was found and published by high-enlargement microscopy (5000-fold) that these trouble spots are the sites for the development of stable, 1 to 2 µm long, micro-cracks (stable for months). If however, a force higher than the one of their formation occurs to them, these grow to catastrophic crash. That works equally with turbulences at the pickle fork of airliners. After the publication of these facts and after three fatal crashing had occurred in a short sequence, FAA (Federal Aviation Agency) reacted by rechecking all airplanes for such micro cracks. These were now found in a new fleet of airliners from where the three crashed ones came. These were previously overlooked. FAA became aware of that risk and grounded 290 (certainly all) of them, because the material of these did not have higher phase-transition onset and energy than other airplanes with better material. They did so despite the 14577-Standard that does not find (and thus formally forbids) phase transitions under indenter load with the false exponent on the indentation parabola. However, this “Standard” will, despite the present author’s well-founded petition, not be corrected for the next 5 years. 展开更多
关键词 Instrumental Indentation One-Point Spherical Arithmetic Formulas Reformulation Factor One Twinning Standards Zerodur undue Fittings Erroneous Standards DIN-ISO-ASTM-14577 Revision Petition Energy-Law-Violation Faked Data
在线阅读 下载PDF
Unexpected Twinning and Phase-Transition of the Indentation Standards, Their Transition Energies, and Scientific Dichotomy
2
作者 Gerd Kaupp 《Journal of Applied Mathematics and Physics》 2024年第6期2119-2159,共41页
The general use of aluminium as an indentation standard for the iteration of contact heights for the determination of ISO-14577 hardness and elastic modulus is challenged because of as yet not appreciated phase-change... The general use of aluminium as an indentation standard for the iteration of contact heights for the determination of ISO-14577 hardness and elastic modulus is challenged because of as yet not appreciated phase-changes in the physical force-depth standard curve that seemed to be secured by claims from 1992. The physical and mathematical analyses with closed formulas avoid the still world-wide standardized energy-law violation by not reserving 33.33% (h2 belief) (or 20% h3/2 physical law) of the loading force and thus energy for all not depth producing events but using 100% for the depth formation is a severe violation of the energy law. The not depth producing part of the indentation work cannot be done with zero energy! Both twinning and structural phase-transition onsets and normalized phase-transition energies are now calculated without iterations but with physically correct closed arithmetic equations. These are reported for Berkovich and cubecorner indentations, including their comparison on geometric grounds and an indentation standard without mechanical twinning is proposed. Characteristic data are reported. This is the first detection of the indentation twinning of aluminium at room temperature and the mechanical twinning of fused quartz is also new. Their disqualification as indentation standards is established. Also, the again found higher load phase-transitions disqualify aluminium and fused quartz as ISO-ASTM 14577 (International Standardization Organization and American Society for Testing and Materials) standards for the contact depth “hc” iterations. The incorrect and still world-wide used black-box values for H- and Er-values (the latter are still falsely called “Young’s moduli” even though they are not directional) and all mechanical properties that depend on them. They lack relation to bulk moduli from compression experiments. Experimentally obtained and so published force vs depth parabolas always follow the linear FN = kh3/2 + Fa equation, where Fa is the axis-cut before and after the phase-transition branches (never “h2” as falsely enforced and used for H, Er and giving incorrectly calculated parameters). The regression slopes k are the precise physical hardness values, which for the first time allow for precise calculation of the mechanical qualities by indentation in relation to the geometry of the indenter tip. Exactly 20% of the applied force and thus energy is not available for the indentation depth. Only these scientific k-values must be used for AI-advises at the expense of falsely iterated indentation hardness H-values. Any incorrect H-ISO-ASTM and also the iterated Er-ISO-ASTM modulus values of technical materials in artificial intelligence will be a disaster for the daily safety. The AI must be told that these are unscientific and must therefore be replaced by physical data. Iterated data (3 and 8 free parameters!) cannot be transformed into physical data. One has to start with real experimental loading curves and an absolute ZerodurR standard that must be calibrated with standard force and standard length to create absolute indentation results. . 展开更多
关键词 Aluminium Fused Quartz Copper TWINNING Structural Phase-Transitions undue Indentation Standards Data Manipulation ZerodurR Absolute Hardness
在线阅读 下载PDF
即食沙虫干加工工艺优化河北省部分水产品市场价格 被引量:1
3
作者 郭峰君 《河北渔业》 2021年第11期36-38,43,共4页
为优化即食沙虫(方格星虫Sipunculs undus)干加工工艺,在单因素试验的基础上,采用Box-Benhnken设计原理,选定腌制时间、烘干时间、烘干温度、油炸时间4个因素对即食沙虫干加工工艺进行优化。结果显示,最佳配方为腌制时间20 min,烘干温度... 为优化即食沙虫(方格星虫Sipunculs undus)干加工工艺,在单因素试验的基础上,采用Box-Benhnken设计原理,选定腌制时间、烘干时间、烘干温度、油炸时间4个因素对即食沙虫干加工工艺进行优化。结果显示,最佳配方为腌制时间20 min,烘干温度100℃,烘干时间38.39 min,油炸时间15.94 s。用此方法制备出的即食沙虫干色泽金黄,口感香脆,无其他明显的异味。 展开更多
关键词 方格星虫(Sipunculs undus) 即食 响应面法
在线阅读 下载PDF
The Non-Equivalence of Pyramids and Their Pseudo-Cones: Important New Insights
4
作者 Gerd Kaupp 《Journal of Applied Mathematics and Physics》 2022年第4期1158-1166,共9页
The simulation of indentations with so called “equivalent” pseudo-cones for decreasing computer time is challenged. The mimicry of pseudo-cones having equal basal surface and depth with pyramidal indenters is exclud... The simulation of indentations with so called “equivalent” pseudo-cones for decreasing computer time is challenged. The mimicry of pseudo-cones having equal basal surface and depth with pyramidal indenters is excluded by basic arithmetic and trigonometric calculations. The commonly accepted angles of so called “equivalent” pseudo-cones must not also claim equal depth. Such bias (answers put into the questions to be solved) in the historical values of the generally used half-opening angles of pseudo-cones is revealed. It falsifies all simulations or conclusions on that basis. The enormous errors in the resulting hardness H<sub>ISO</sub> and elastic modulus E<sub>r-ISO</sub> values are disastrous not only for the artificial intelligence. The straightforward deduction for possibly ψ-cones (ψ for pseudo) without biased depths’ errors for equal basal surface and equal volume is reported. These ψ-cones would of course penetrate much more deeply than the three-sided Berkovich and cube corner pyramids (r a/2), and their half-opening angles would be smaller than those of the respective pyramids (reverse with r > a/2 for four-sided Vickers). Also the unlike forces’ direction angles are reported for the more sideward and the resulting downward directions. They are reflected by the diameter of the parallelograms with length and off-angle from the vertical axis. Experimental loading curves before and after the phase-transition onsets are indispensable. Mimicry of ψ-cones and pyramids is also quantitatively excluded. All simulations on their bases would also be dangerously invalid for industrial and solid pharmaceutical materials. 展开更多
关键词 Basic Mathematics Extreme Errors False Cone Angles INDENTATION Unphysical Cone Models for Pyramids undue Simulations
在线阅读 下载PDF
Incentivization and the moral problem of involuntary consent in medical research
5
作者 Victor Chidi Wolemonwu 《History & Philosophy of Medicine》 2023年第1期30-34,共5页
The legal and moral permissibility of clinical research entails that researchers must secure the voluntary,informed consent of prospective research participants before enrolling them in studies.In seeking the consent ... The legal and moral permissibility of clinical research entails that researchers must secure the voluntary,informed consent of prospective research participants before enrolling them in studies.In seeking the consent of potential participants,researchers are also allowed to incentivise the recruitment process because many studies would fail to meet enrollment goals without a financial incentive for participation.Some philosophers and bioethicists contend that the use of incentives to secure consent from research subjects is problematic because it constitutes undue inducement and a coercive offer.Some proponents of this view are Ruth Macklin(1981,1989)and Joan McGregor(2005).Macklin claims that it is ethically inappropriate to pay research subjects.The payment is likely to coerce the research subject,thereby violating the ethical requirement on the voluntariness of research participation.Also,such offers can prompt subjects to lie,deceive or conceal information that,if known,would disqualify them as participants.For McGregor,incentives could be undue and coercive because they make offerees better off relative to their baseline as well as constrain them to accept the offer of incentives as the only eligible choice or option.I argue that coercive offers are distinct from undue inducement.Coercive offers are essentially morally objectionable because by making people accept an offer through threats for the sake of some interests or ends,the offeror vitiates the offeree’s capacity to make informed,voluntary,and rational decisions and choices.I further claim that the quantity of an incentive does not render an inducement undue.I contend that the only condition under which incentives are regarded as an undue inducement and as such vitiates an agent’s voluntary consent is if they are offered through deceptive or manipulative means. 展开更多
关键词 VOLUNTARINESS informed consent INCENTIVES coercive offers undue inducement human rights
在线阅读 下载PDF
Variation Analysis of mtDNA D-loop Sequence of Cheilinus undulatus
6
作者 Jing HU Shaowu YIN +2 位作者 Le YE Kaichang WU Yu WANG 《Agricultural Biotechnology》 CAS 2013年第4期42-46,共5页
[ Objective] The aim of this paper was to investigate the genetic diversity of mitochondrial DNA D-loop sequences of Cheilinus undulatus populations. [Method] Twenty-five individuals of C. undu/atus were collected fro... [ Objective] The aim of this paper was to investigate the genetic diversity of mitochondrial DNA D-loop sequences of Cheilinus undulatus populations. [Method] Twenty-five individuals of C. undu/atus were collected from the offshore area of Hainan Province. PCR and cloning techniques were used to clone and purify the mtDNA D-loop sequences of C. undu/atus populations (n =25), about 1 400 bp long PCR product was obtained. ClustalX software was adopted for sequence alignment, and results were imported into MEGAS. 0. [ Result] According to experimental results, 66 mutation sites were detected from 25 individuals, including 0 deletion, 4 inserts, 59 transition sites, 2 transversion sites and 1 transition-transversion site. Pairwise genetic distances of these 25 individuals were calcu- lated by using MEGA5.0 software. Based on that, NJ phylogenetic tree of these 25 individuals was constructed. Analysis of C. undulatus populations using DNASP software showed that the polymorphic site number (S) was 62, nucleotide diversity (Pi) was 0.006 06, and average number of nucleotide differences (K) was 6. 907. [ Conclusion] Overall, there was no significant variation among mtDNA D-loops of C. undulatus populations. Key words 展开更多
关键词 Cheilinus undu/atus Mitochondrial DNA D-leep Genetic diversity
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部