scholarly journals Characterization of Shock Wave Damages in Explosion Welded Mo/Cu Clads

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 501
Author(s):  
Pradeep Kumar Parchuri ◽  
Shota Kotegawa ◽  
Kazuhiro Ito ◽  
Hajime Yamamoto ◽  
Akihisa Mori ◽  
...  

The shock wave damage during explosive welding has not been reported in a flyer Mo plate of the Mo/Cu clads. However, it would be an inevitable problem in group VI elements. This study was aimed to characterize the shock wave damage in the Mo plate, that is less brittle than a W plate, of explosive welded Mo/Cu clads. Cladding at low horizontal collision velocities leading to high collision angles was expected to enhance the shock wave damage, and the clads resulted in less elongation in bending tests. On the other hand, in the clads obtained at high horizontal collision velocities (HCVs) with low collision angles, their bending elongation increased significantly. The shock wave damage penetrated from the surface of a Mo plate to the Mo/Cu interface, and thus reducing thickness of a Mo plate of bending specimens increased bending plastic strain. The shock wave damage is associated with kinetic energy imparted to the flyer Mo plate, and thus loss of kinetic energy due to formation of an intermediate layer at the interface and reducing thickness of a flyer Mo plate would be very helpful for decrease of shock wave damage.

1982 ◽  
Vol 25 (4) ◽  
pp. 487-490
Author(s):  
Gerd Rodé

AbstractThis paper gives a new characterization of the dimension of a normal Hausdorff space, which joins together the Eilenberg-Otto characterization and the characterization by finite coverings. The link is furnished by the notion of a system of faces of a certain type (N1,..., NK), where N1,..., NK, K are natural numbers. It is shown that a space X contains a system of faces of type (N1,..., NK) if and only if dim(X) ≥ N1 + … + NK. The two limit cases of the theorem, namely Nk = 1 for 1 ≤ k ≤ K on the one hand, and K = 1 on the other hand, give the two known results mentioned above.


2015 ◽  
Vol 10 (1) ◽  
pp. 1934578X1501000
Author(s):  
Amadeo Gironés-Vilaplana ◽  
Diego A. Moreno ◽  
Cristina García-Viguera

“Pacharán” is an aniseed liquor-based beverage made with sloe berry ( Prunus spinosa L.) that has been produced in northern Spain. On the other hand, maqui berry ( Aristotelia chilensis) is a common edible berry from Chile, and currently under study because of its multiple beneficial effects on health. The aim of this work was to design a new aniseed liquor-based beverage with maqui berry, as an industrial alternative to a traditional alcoholic product with bioactive berries. The characterization of its composition, compared with the traditional “Pacharán”, and its evolution during maceration (6 and 12 months) showed that the new maqui liquor had significantly-higher anthocyanin retention over time. More studies on the organoleptic properties and bioactivity are underway.


2007 ◽  
Vol 566 ◽  
pp. 203-206
Author(s):  
Ayumi Takemoto ◽  
Toshiaki Watanabe ◽  
Hirofumi Iyama ◽  
Shigeru Itoh

The sessile organism of the oyster and the barnacle, etc. causes friction between the surface of the ship and the water. Friction causes the deterioration of fuel cost. In addition, dry dock operation with putting the ship on the land or the diving operation, are needed for the removal of the sessile organism. These works require a very high cost. Various techniques for reducing friction resistance have been proposed. On the other hand, the method for the practical use is not popular still now. Authors tried to perform an experiment to remove the sessile organism on surface of the metal by using the underwater shock wave.


2020 ◽  
Vol 2 (1-2) ◽  
pp. 181-191 ◽  
Author(s):  
Giancarlo Guizzardi

According to the FAIR guiding principles, one of the central attributes for maximizing the added value of information artifacts is interoperability. In this paper, I discuss the importance, and propose a characterization of the notion of Semantic Interoperability. Moreover, I show that a direct consequence of this view is that Semantic Interoperability cannot be achieved without the support of, on one hand, (i) ontologies, as meaning contracts capturing the conceptualizations represented in information artifacts and, on the other hand, of (ii) Ontology, as a discipline proposing formal meth- ods and theories for clarifying these conceptualizations and articulating their representations. In particular, I discuss the fundamental role of formal ontological theories (in the latter sense) to properly ground the construction of representation languages, as well as methodological and computational tools for supporting the engineering of ontologies (in the former sense) in the context of FAIR.


2007 ◽  
Vol 09 (04) ◽  
pp. 473-513 ◽  
Author(s):  
DAVID CHIRON

The purpose of this paper is to relate two notions of Sobolev and BV spaces into metric spaces, due to Korevaar and Schoen on the one hand, and Jost on the other hand. We prove that these two notions coincide and define the same p-energies. We review also other definitions, due to Ambrosio (for BV maps into metric spaces), Reshetnyak and finally to the notion of Newtonian–Sobolev spaces. These last approaches define the same Sobolev (or BV) spaces, but with a different energy, which does not extend the standard Dirichlet energy. We also prove a characterization of Sobolev spaces in the spirit of Bourgain, Brezis and Mironescu in terms of "limit" of the space Ws,p as s → 1, 0 < s < 1, and finally following the approach proposed by Nguyen. We also establish the [Formula: see text] regularity of traces of maps in Ws,p (0 < s ≤ 1 < sp).


1985 ◽  
Vol 1 (1) ◽  
pp. 69-81 ◽  
Author(s):  
Robert J. van der Veen ◽  
Philippe Van Parijs

In Anarchy, State, and Utopia, Robert Nozick contrasts entitlement theories of justice and “traditional” theories such as Rawls', utilitarianism or egalitarianism, and advocates the former against the latter. What exactly is an entitlement theory (or conception or principle) of justice? Nozick's book offers two distinct characterizations. On the one hand, he explicitly describes “the general outlines of the entitlement theory” as maintaining “that the holdings of a person are just if he is entitled to them by the principles of justice in acquisition and transfer, or by the principle of rectification of injustice (as specified by the first two principles of just acquisition and transfer)” (Nozick, 1974, p. 153). On the other hand, his famous “Wilt Chamberlain” argument against alternative theories is first said to apply to (all) “non-entitlement conceptions” (p. 160), and later to any “end-state principle or distributional patterned principle of justice” (p. 163) — which amounts to an implicit characterization of an entitlement conception (theory, principle) as a conception of justice which is neither end-state nor patterned.


2007 ◽  
Vol 18 (02) ◽  
pp. 415-431 ◽  
Author(s):  
LUDĚK CIENCIALA ◽  
LUCIE CIENCIALOVÁ ◽  
PIERLUIGI FRISCO ◽  
PETR SOSÍK

We characterize the computational power of several restricted variants of communicating P systems. We show that 2-deterministic communicating P systems with 2 membranes, working in either minimally or maximally parallel mode, are computationally universal. Considering the sequential mode, 2 membranes are shown to characterize the power of partially blind multicounter machines. Next, a characterization of the power of 1-deterministic communicating P systems is given. Finally, we show that the nondeterministic variant in maximally parallel mode is universal already with 1 membrane. These results demonstrate differences in computational power between nondeterminism, 2-determinism and 1-determinism, on one hand, and between sequential, minimally and maximally parallel modes, on the other hand.


Author(s):  
Teruki Sadasue ◽  
Satoshi Igi ◽  
Kenji Oi ◽  
Satoru Yabumoto

The reel-lay method is a fast and cost efficient installation process for offshore rigid steel pipelines. Pipelines installed by the reel-lay method are plastically deformed due to reeling, unreeling, aligning and straightening during pipeline installation. Therefore, local buckling is one of the major concerns from a view point of integrity in linepipes, especially around girth welds where strength mismatching arises due to adjacent pipes with different yield strength. One the other hand, the change in mechanical properties of linepipes during reel-lay, including coating process (e.g. 250°C) and long time exposure (e.g. 250°C aging) after installation is also important in order to guarantee safety of linepipes. Furthermore fracture toughness at girth weld Coarse-grain HAZ (CGHAZ) after reeling and aging should be clear to prevent brittle fracture of offshore linepipes in service. In this study, full scale reeling simulation tests of girth welded X60 HFW (High Frequency electric resistance Welded) linepipes with OD; 323.9mm and WT;15.9mm after full body heat treatment (coating simulation) were conducted at 5cycles and 2cycles reeling and straightening situations when yield strength mismatches are present between adjacent pipes around girth welds. Localized strain concentration was observed near girth welds by strength mismatching of adjacent pipes. DNV ovality increased with increasing reeling and straightening cycles, however the ovality did not exceed 10%, which was a criterion value for local buckling, after 5cycles reeling simulation test. The change ratio of wall thickness after full scale reeling simulation tests were about ±2% (within DNV-OS-F101 tolerance) regardless of circumferential and longitudinal direction of pipes. Longitudinal tensile properties could be characterized by axial last introduced plastic strain. That is, in the positive number of last introduced plastic strain, YS and Y/T increased, while uEl decreased by work hardening effect. On the other hand YS and Y/T decreased, while uEl increased at the negative number of last introduced plastic strain by Bauschinger effect. Circumferential tensile properties could be also characterized by axial last introduced plastic strain. Yield strength and Y/T slightly increased while uniform elongation slightly decreased by aging at longitudinal and circumferential direction. Tensile properties did not change irrespective of the number of cycles of reeling simulation tests. After 5cycles reeling simulation test and aging, girth welded CGHAZ CTOD values were over 0.4mm at −20°C and Charpy absorbed energy were over 200J at −30°V, therefore, it was considered that the brittle fracture of the girth welded linepipe unlikely occur at reeling and aging situation in this study.


2016 ◽  
Vol 880 ◽  
pp. 132-135 ◽  
Author(s):  
Selim Gürgen ◽  
Melih Cemal Kuşhan

High performance fabrics are preferable for armor systems due to their lightweight structure and flexibility. High performance fabrics are generally used in body armor design for personal protection. However, these fabrics are utilized to cover the living space in military vehicles such as helicopters and armored vehicles. Besides, pilot seats in combat helicopters are included in utilization area of high performance fabrics. On the other hand armor is defined as a defensive covering to protect body or something against attacking threats. Protection is provided by absorbing the kinetic energy of the attacking threats and stopping them before any damage occurs in the target. This paper offers an overview of high performance fabrics in armor systems.


2008 ◽  
Vol 1112 ◽  
Author(s):  
Homuro Noda ◽  
Akinobu Shibata ◽  
Masato Sone ◽  
Chiemi Ishiyama ◽  
Yakichi Higo

AbstractThe texture and microstructure of electrodeposited Ni layers formed in an additive-free Watt's bath were investigated. The microstructure of the electrodeposited Ni layer consists of fine columnar grains extending along the growth direction. The major texture components of electrodeposited Ni layers on Ni-P substrate were (112) and (110) fibers. On the other hand, electrodeposited Ni layers on Cu substrate had a strong (110) fiber texture. In the vicinity of the interface between the electrodeposited Ni layer and the Cu substrate, obvious epitaxial regions were not observed. Many twins parallel to the growth direction were observed in the electrodeposited Ni layer. It is suggested that grains with a twin relationship grew preferentially during the electrodeposition reaction.


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