Sacrificial Element Research Articles

Cyclic behavior of reinforced concrete bridge bent retrofitted with buckling restrained braces

The cyclic behavior of a deficient reinforced concrete bridge bent retrofitted using buckling restrained braces (BRBs) was experimentally evaluated using large scale experiments and quasi-static cyclic loading that reflected subduction zone earthquake demands. The retrofitted reinforced concrete bent specimen consisted of two circular cross section columns, a rectangular cap beam and a buckling restrained brace in a diagonal configuration. The brace was secured to the bent using steel gusset plates and post-installed adhesive anchors. The retrofitted bent was designed to perform elastically or with minor damage under different seismic hazards design levels. Two BRB designs were considered in an effort to assess the influence of the BRB design on the overall bent performance. The data from these large-scale experiments were analyzed considering bent hysteretic response, observed damage, component curvatures, internal member loads, as well as the overall stiffness and energy dissipation characteristics. The results successfully demonstrated the effectiveness of utilizing buckling restrained braces for achieving high displacement ductility of the retrofitted structure, while also controlling the damage of the existing vulnerable reinforced concrete bent. No damage was observed in the connection regions of the brace throughout the loading history, leaving the potential for rapid replaceability of the sacrificial BRB element.

Effects of Cobalt Nanoparticles Addition on Shear Strength, Wettability and Interfacial Intermetallic Growth of Sn−3.0Ag−0.5Cu Solder during Thermal Cycling

In the present study, Cobalt nanoparticles were synthesized and mixed with Sn-3.0Ag-0.5Cu solder (SAC305). The effect of 0.05 wt.%, 0.2 wt.%, 0.5 wt.% and 1.0 wt.% Co nanoparticles on the wettability, the shear strength as well as the growth of intermetallic compounds (IMCs) at composite solder/Cu interface during thermal cycling were investigated. Results show that Co nanoparticle addition can considerably improve wettability, increase the shear strength and suppress the growth of interfacial IMCs. The addition amount of Co nanoparticles have the consistent relation with the improvement extent of the wettability, shear strength and the growth rate of interfacial IMCs. Slight addition (0.05 wt.% and 0.2 wt.%) can significantly improve the properties of nanocomposite solder in all the three aspects. However, with excessive addition amount (0.5 wt.% and 1.0 wt.%) of Co nanoparticles, the improvement extent will decline. The Cross-section images of the interface of nanocomposite solder/Cu joint show that Co can form reinforcement particles in the solder and can act as the sacrificial element to substitute Cu to react with Sn. Excessive Co nanoparticles would form large amount of hard and brittle intermetallics which leads to decreasing shear strength of the composite solder.

Corrosion protection with hard coatings on steel: Past approaches and current research efforts

This work gives a review on published results on the corrosion behavior of hard coatings deposited on steel substrates by mainly physical vapor deposition (PVD) or in some cases by plasma-assisted chemical vapor deposition (PACVD). Corrosion investigations of our own lab have been added at several sites to complete missing knowledge or to introduce new non-published data. A detailed discussion of thin film growth, microstructure and the kind of defects inherent in hard coatings has been given. Then the influence of coating thickness and some processing parameters on the corrosion resistance of coated steel is demonstrated. After this incipient part, the corrosion behavior of hard nitride coatings, multilayer coatings, alloyed or modified nitride coatings, insulating nitride, oxide or oxynitride coatings and duplex treated steel is being presented. Own investigations and published results show that single layered, conducting nitride coatings can protect steel to some extent only if very thick coatings (≥10μm) are applied or if energetic deposition methods (e.g. ion-assisted deposition) are used. Distinct improvements of the corrosion behavior of hard coatings can be obtained by a proper multilayer structure deposited by deposition methods allowing energetic condensation, i.e. possessing a high ion-to-atom flux ratio. Alloying TiN by a sacrificial element, like magnesium, is also capable of significantly improving the corrosion resistance of low alloyed steel. Amazing improvements have also been reported for insulating coatings like AlN, oxynitride coatings or oxide coatings. However, the most significant improvement seems to be the application of duplex treatments. Plasma nitriding+PVD coating or PVD coating+atomic layer deposition (ALD) prolonged the time to red rust in neutral salt spray test for >2days up to one week, respectively. The only disadvantage of the duplex treatments is the higher cost. Recently, mapping by a confocal microscope of TiN coating surfaces before and after salt spray testing showed that open porosities in micro- and macro-scale growth defects mainly govern the corrosion behavior of hard coatings on steel. The coating microstructure – i.e. the submicron-scale morphology – seems to play only a secondary role in the corrosion behavior.

Electroless Deposition By Surface Limited Redox Replacement in One Cell Configuration

The deposition of thin noble metal films is an area of wide interest for many different industrial applications. These films allow for an application to take advantage of the beneficial properties of said metal of interest while minimizing cost. Thusly, thin films are currently being applied as low-cost, high-activity fuel cell catalysts, photovoltaic semiconductors, and protective coatings in circuitization of electronic devices.Surface limited redox replacement (SLRR) is a technique that has been applied to depositing ultra thin films of metals and alloys and has also shown the ability to grow epitaxial metal layers utilizing the monolayer limited nature of underpotential deposition (UPD). In SLRR an UPD monolayer of a sacrificial element is formed via a potential pulse. This layer is sequentially replaced by a more noble metal at free corrosion conditions. This sequence of events ultimately yields the deposition of one layer of the more noble metal 1. This technique can be then applied to subsequent events resulting in perfectly controlled layer by layer metal growth 2-6.During SLRR the potential pulse that is applied to form the UPD layer has conventionally been performed by an external power device (potentiostat). In this work instead of the application of external power, a corrosion pair scenario is realized in a three-electrode configuration with a Pb wire in solution serving as the “executive” electrode, a Hg/Hg2SO4 reference electrode and a Au polycrystalline disc used as working electrode. The difference in equilibrium potentials of the executive and working electrode coupled with specific aspects of the kinetics of the Pb-Au corrosion pair allow for efficient control of the potential applied to the Au substrate. More specifically, electrical contact between executive and working electrodes results in the application of a potential to the Au electrode, nearly identical to the Pb equilibrium potential. This ultimately leads to the formation of a sacrificial Pb UPD layer on the Au surface. Subsequent disconnection of the electrical contact allows for the electroless, in nature, SLRR to occur. This technique can consequentially be used to coat a substrate metal surface with another metal or alloy of interest as illustrated in Figure 1. In the present report, the proposed approach has been applied to an ideal system in the plating of Ag on Au in order to ascertain the protocol’s applicability for metal deposition. The work has also been extended to the industrially more relevant system of Pt on Au. Adopting the herein presented routine, SLRR can be simplified and prove even more cost effective with no need for external power source and little to no energy cost, ultimately improving industrial viability.

A combined additive manufacturing and micro-syringe deposition technique for realization of bio-ceramic structures with micro-scale channels

This article presents a novel rapid layered manufacturing approach based on a combined additive manufacturing (AM) process and a UV-based micro-syringe deposition (μSD) technique to be used in the fabrication of bio-ceramic structures with controlled micro-sized channels for bone and osteochondral tissue regeneration. In the proposed rapid manufacturing method, micro-scale sacrificial photopolymer networks are integrated within the manufactured part by depositing the photopolymer on selected bio-ceramic powder layers using an injection system. This AM–μSD method along with a post-processing protocol can potentially overcome current limitations of traditional powder-based AM approaches that are restricted in terms of complexity of internal architecture and feature size. For bone or osteochondral repair applications, the material system composed of the bio-ceramic and sacrificial photopolymer, along with the post-processing protocol, must ensure that the final implants are free from manufacturing residuals that could trigger an immune response post-implantation. In this study, calcium polyphosphate bio-ceramic was used as the substrate material based on prior art, polyvinyl alcohol solution was used as the powder binding agent, and ethoxylated (10 bisphenol A diacrylate) photopolymer solution was used as the sacrificial photopolymer element. Material characterization suggests that the proposed material system along with heat treatment protocol is suitable for the targeted applications where micro-scale channels within the implant are produced by AM–μSD.

Electrochemical Atomic Layer Deposition (E-ALD) of Pt Nanofilms Using SLRR Cycles

This paper describes platinum nanofilm formation via the electrochemical form of atomic layer deposition (E-ALD), where the E-ALD cycles are based on surface limited redox replacement (SLRR) reaction. SLRR is where an atomic layer (AL) of a reactive (sacrificial) metal is exchanged for a more noble metal. In the present study both Cu and Pb AL were investigated as sacrificial atomic layers for replacement with both Pt(II) and Pt(IV) precursors. 25 E-ALD cycles were used to form Pt nanofilm deposits. Initial deposits contained an order of magnitude more Pt than expected, evidenced by a factor of 7 increase in surface roughness. Overly positive potentials achieved during the exchange promoted excess deposition and surface roughening. It is proposed that anionic Pt precursors adsorbed more strongly at high potentials, making them difficult to rinse from the cell. Those remaining adsorbed Pt anions are then reduced to Pto when the potential was shifted negative for deposition of the sacrificial element. The result was Pto formation at a large overpotential, which, contributed to excessive Pt deposits and roughening. Increased rinsing of the anionic Pt precursors from the cell eliminated the excess Pt deposition and roughening, resulting in the expected layer by layer growth of an ALD process.

Self-Standing Polyelectrolyte Multilayer Films Based on Light-Triggered Disassembly of a Sacrificial Layer

In the present article, we present a new and convenient optical method for the preparation of self-standing polyelectrolyte multilayer films. This method employs the disassembly of a sacrificial layer stratum composed of five poly(acrylate, merocyanine) PMC/poly(diallyldimethylammonium chloride) PDADMAC bilayers, which is triggered by the irradiation with visible light. This leads to the conversion of the zwitterionic PMC to its neutral isomer poly(acrylate, spiropyran) PSP, whereby the attractive ionic interactions between the neighboring bilayers vanish. The disassembly of the sacrificial layers in deionized water was completed within 47 s, when in-situ monitored at the maximum absorbance of PSP (λ = 360 nm), employing UV/visible spectrometry. Surprisingly, the disassembly duration of the sacrificial layers increased very little with an upper target film composed of 75 PDADMAC/PSS bilayers. The quick release of a thick target film (d ∼ 232 nm) composed of 100 (PDADMAC)/(PSS) bilayers in a large scale (7 × 18 mm(2)) could be ascribed not only to the vanished electrostatic attractive interaction between the layer pairs but also to increased hydrophobicity of the sacrificial layer element due to the photoisomerization of zwitterionic ionic PMC to neutral PSP. The unique advantages of this method as compared to the conventional approaches are demonstrated with the fast release (~2 min) of self-standing film combined with a well-defined, thin sacrificial layer (d ~ 30 nm). Moreover, harsh release conditions are also avoided, which significantly broadens the choice of materials that can be incorporated into the free-standing film.

Carbon as a sacrificial alloying element in processing Fe-P soft magnetic alloys

The present investigation deals with designing Fe-P based binary alloy produced by in-house developed powder metallurgical technique based on ‘Hot Powder Preform Forging’. Proper soaking of preforms at high temperature (1050°C) eliminates iron-phosphide eutectic and brings entire phosphorus into solution in iron. Attempting hot forging thereafter completely eliminates hot as well as cold shortness and thereby helps to form these preforms into very thin sheets of 0.5mm. The use of costly hydrogen atmosphere during sintering has been eliminated by use of addition of carbon. The glassy ceramic coating applied over the compact serves as a protective coating to avoid atmospheric oxygen attack over the compact held at high temperature. The alloy so formed was subjected to density examination at various stages. Microstructural study has been carried out to estimate the grain size, volume percentage porosity in the alloy and uniform distribution of phosphorus in iron matrix. Fe-0.07wt% C-0.3wt% P alloy so formed yielded coercivity as low as 0.45 Oe, resistivity as high as 17.4 μΩcm and total loss as low as 0.176 W/Kg. The alloy which is drawn to thin sheets could find its possible application in manufacturing transformer cores.

Sheet‐Metal Assessment at Medium Strain‐Rates by Digital Image Correlation

Abstract: The aim of the paper is to present an experimental test methodology able to investigate the strain‐rate influence on the mechanical behaviour of thin sheet metals at large strains. Dynamic tensile tests at medium strain rate were carried out using an electromechanical material testing machine and a specifically developed clamping device, which is able to create a traction pulse on the specimen by releasing the energy stored in a set of preloaded viscoelastic springs by means of the rupture of a sacrificial element. A numerical model of the testing system has been created to optimise the shape of the strain rate pulse. Due to sheet metal anisotropic behaviour, it is advisable to measure both axial and transverse strains and to assure that the stress field is purely axial. To fulfil both requirements, digital image correlation technique has been used for strain measurement on specimen surface. In fact, this method is capable to return full‐field maps of all in‐plane strain components. In addition, strain map analysis allows to detect when transverse stress components arise. To make use of image processing for strain and strain rate measurement, the specimen surface has been speckle‐prepared and, because of the dynamic nature of the phenomenon in exam, a high speed camera, able to grab and store 1024 × 1024 pixel images at 1000 fps, was used. To verify the functionality of the testing system, tests on DP 600 and AISI 304 steels have been run in which strain rates up to 150 s−1 have been reached.

Toughness of fibre reinforced hydraulic lime mortar. Part-1: Quasi-static response

There are several stone masonry structures of historical importance in Canada that lie in regions of varying degrees of seismicity. Hydraulic lime mortars are used in the repair of such heritage buildings. While this mortar works as a sacrificial element in the stone masonry system, a tougher and more durable mortar is expected to offer the best repointing binder. This paper reports the results of a study on the compressive, flexural and shear toughness of plain and fibre reinforced hydraulic lime mortar. Polypropylene micro-fibres were incorporated at 0, 0.25 and 0.5% volume fraction. As expected, hydraulic lime mortar was seen to be weakest in flexure. However, fibres were effective in increasing the flexural toughness as well as the shear strength.

On‐demand three‐dimensional freeform fabrication of multi‐layered hydrogel scaffold with fluidic channels

One of the challenges in tissue engineering is to provide adequate supplies of oxygen and nutrients to cells within the engineered tissue construct. Soft-lithographic techniques have allowed the generation of hydrogel scaffolds containing a network of fluidic channels, but at the cost of complicated and often time-consuming manufacturing steps. We report a three-dimensional (3D) direct printing technique to construct hydrogel scaffolds containing fluidic channels. Cells can also be printed on to and embedded in the scaffold with this technique. Collagen hydrogel precursor was printed and subsequently crosslinked via nebulized sodium bicarbonate solution. A heated gelatin solution, which served as a sacrificial element for the fluidic channels, was printed between the collagen layers. The process was repeated layer-by-layer to form a 3D hydrogel block. The printed hydrogel block was heated to 37 degrees C, which allowed the gelatin to be selectively liquefied and drained, generating a hollow channel within the collagen scaffold. The dermal fibroblasts grown in a scaffold containing fluidic channels showed significantly elevated cell viability compared to the ones without any channels. The on-demand capability to print fluidic channel structures and cells in a 3D hydrogel scaffold offers flexibility in generating perfusable 3D artificial tissue composites.

Electrodeposition of Ru by atomic layer deposition (ALD)

Studies are presented describing attempts to form a cycle for the growth of Ru nanofilms using the electrochemical form of atomic layer deposition (ALD). Au substrates have been used to form Ru nanofilms, based on layer by layer growth of deposits, using surface limited reactions. These deposits were formed using surface limited redox replacement (SLRR), where an atomic layer of a sacrificial element is first deposited by underpotential deposition (UPD), and is then exchanged for the element of interest. The use of the UPD atomic layer limits subsequent growth by limiting the number of electrons available for deposition. In the present study, Pb atomic layers were used, and exposed to solutions of Ru 3+ ions at open circuit. This process can then be repeated to grow films of the desired thickness. It was shown that less than an at.% of Pb was evident in the deposits, using electron probe microanalysis (EPMA), and even that could be removed if a stripping step was added to the ALD cycle. The deposits displayed the expected Ru voltammetry, as well as the Ru hcp XRD pattern. There were some differences in the first 20 cycles, compared with subsequent, suggesting some nucleation process that must be investigated. However, after 20 cycles, the deposit showed the linear growth with the number of cycles expected for an ALD process. The morphology of Ru films, deposited on template-stripped Au was studied using ex situ scanning tunneling microscopy (STM), and showed no evidence of 3D growth.

Fabrication of microfluidic hydrogels using molded gelatin as a sacrificial element

This paper describes a general procedure for the formation of hydrogels that contain microfluidic networks. In this procedure, micromolded meshes of gelatin served as sacrificial materials. Encapsulation of gelatin meshes in a hydrogel and subsequent melting and flushing of the gelatin left behind interconnected channels in the hydrogel. The channels were as narrow as approximately 6 microm, and faithfully replicated the features in the original gelatin mesh. Fifty micrometre wide microfluidic networks in collagen and fibrin readily enabled delivery of macromolecules and particles into the channels and transport of macromolecules from channels into the bulk of the gels. Microfluidic gels were also suitable as scaffolds for cell culture, and could be seeded by human microvascular endothelial cells to form rudimentary endothelial networks for potential use in tissue engineering.

Behaviour of Multi-Layered Corrugated Paperboard Cushioning Systems under Impact Loads

This paper presents some of the latest results of a research project aimed at using composite corrugated paperboard structures for protection of products against mechanical shocks and vibration during transportation and handling. Specifically, the behaviour of multi-layered corrugated paperboard (MCPB) under shock loading is investigated. Conventionally, packaging cushion design requires the determination of the maximum expected shock levels or equivalent drop which are usually determined from statistical analysis of original field measurements. With this approach, it is generally acknowledged that the cushioning element is engineered to provide adequate protection for statistically likely events but not for extreme events with low statistical likelihood. It is reluctantly accepted that, should it occur, the latter will result in damage to the product. MCPB can be formed with a broad range of compressive characteristics and with various proportions of elastic and plastic behaviour. The objective of this experimental investigation was to determine the optimum elastic/plastic proportion to extend the protective range to include large shock levels. The experimental results obtained include the effects of compression history on the stress-strain properties of MCPB as well as the behaviour of the material in both virgin and pre-compressed form under impulsive loads. The mechanism of deformation of the corrugations (flutes) was studied using high-speed video equipment. The complex acceleration signals produced during deformation of the composite corrugated paperboard cushions under shock loading were analysed by means of the shock response spectrum. Experiments have shown that inserting a sacrificial crumple element of virgin corrugated paperboard at the optimum contact area ratio dramatically lowers the overall level of the resulting shock response spectrum. This has the effect of increasing the allowable drop height for a limited number of extreme events. The main conclusion of the research is that MCPB in both virgin and pre-compressed forms can be combined to provide significantly enhanced protection to products against mechanical hazards during distribution.

Polymer investment molding: Method for fabricating hollow, microscale parts

Polymer investment molding combines traditional injection molding with investment casting to create hollow parts on the microscale. Silicon mold inserts are manufactured using reactive ion etching or anisotropic wet etching. Then, a sacrificial element is placed in the mold. Plastic is injected into the mold and around the sacrificial element using an injection molding press. After removing the plastic part from the mold, liquid etchant dissolves the sacrificial element leaving a hollow plastic part. To demonstrate the process microneedles were formed by injection molding Cyclic Olefin Copolymer (Ticona Topas ®) around 32 μm diameter aluminum bond wire. Hollow, in-plane, microneedles were then achieved by dissolving the bond wire away in liquid aluminum etchant. Rectangular cross-section needles were created with dimensions of 130 μm × 100 μm, overall lengths of 280 μm, and approximate inner diameter of 35 μm. Tapered needles were also created having an approximately triangular cross-section with two 105 μm sides and one 150 μm side. These needles had a base-to-tip length of 300 μm and approximate inner diameter of 35 μm.

Essai de sociographie de la messe, 1200-1700

Max Weber a pu croire que le grand apport de la tradition judéo-chrétienne avait été de remplacer par une morale universelle, « rationnelle », kantienne, les liens moraux qui auparavant étaient fonction de la parenté et qui, au niveau de l'individu, divisaient le monde en deux catégories morales : il y avait d'abord les frères, qui avaient droit aux plus hauts égards, et puis les autres. Il voyait quatre étapes dans le processus conduisant à cette transcendance : chez les Juifs d'abord, la mise en place d'un monopole du culte public à Jérusalem qui interdisait les sacrifices privés et instituait un clergé professionnel ; l'intégration de Juifs et de Gentils dans les premières communautés chrétiennes ; le culte dans la cité médiévale qui, à rencontre de la cité antique, n'était plus une confédération de groupes de parenté mais une association d'individus ; et pour finir, l'économie morale des sectes protestantes de tendance « ascétique et morale » dont le puritanisme était à ses yeux un exemple.

Christian Marriage

The importance of the Christian family as the corner-stone of any social rebuilding in the future is recognised by all; and Blackfriars cannot hope to do more than produce a few pointers to some of the more significant elements in its constitution. Thus we may note the vocation of marriage. For Christian marriage, no less than the religious life or the priesthood, is a ‘calling,’ a divine calling to specific functions, responsibilities and joys. Indeed, it involves the spirit of a religious vocation, since it involves the spirit of the three vows of religion. Married life usually implies a greater degree of actual poverty than living single, and must always mean a certain detachment from wealth and possessions. In this it stands out against the standards of those whose ideal of conjugal happiness is summed up in a service flat and a car. Married life demands a chastity that is constantly selfless in face of the selfish way out by birth prevention. It requires obedience, without which the family collapses in a chaotic group of warring relatives. All this necessarily implies sacrifice. The poverty, chastity and obedience of marriage are consecrated in a special way by the sacrament, which links them with Calvary : every sacrament represents the Passion of Christ. By his analogy between the union of the Church with Christ and that of husband with wife St. Paul shows how central this sacrificial element must be, for Christ was wedded to his Church on Calvary. In these days it might perhaps prove more helpful to insist on this aspect of married life rather than on the union of married love or the importance of children as its primary end. These latter are the natural elements of the marriage bond, whereas the sacrificial, and sometimes heroic, element should be essentially supernatural.

The Sacrificial Element in Christian Ethics

Previous articleNext article FreeThe Sacrificial Element in Christian EthicsGeorge Henry HubbardGeorge Henry Hubbard Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 31, Number 5May, 1908 Article DOIhttps://doi.org/10.1086/474051 Views: 92 Citations: 1Citations are reported from Crossref Journal History This article was published in The Biblical World (1893-1920), which is continued by The American Journal of Theology (1897-1920). PDF download Crossref reports the following articles citing this article:Ilsup Ahn BETWEEN MT. MORIAH AND MT. GOLGOTHA: How Is Christian Ethics Possible?, Journal of Religious Ethics 40, no.44 (Oct 2012): 629–652.https://doi.org/10.1111/j.1467-9795.2012.00541.x

The Sacrificial Element in Hopi Worship

The Sacrificial Element in Hopi Worship