Gold Bridges Research Articles

Jewish "Iron Rangers": Jewish Settlement on Minnesota's Iron Range

Jewish "Iron Rangers"Jewish Settlement on Minnesota's Iron Range Marilyn J. Chiat (bio) I. Introduction A small red brick building stands on the corner of 4th Avenue and 5th Street South in Virginia, Minnesota. On the day of its dedication, April 8, 1910, the front page of the local newspaper, The Virginia Enterprise, featured a photo of the building and an article describing it as a beautiful, well-built temple that cost approximately $10,000, a goodly sum for the time.1 Constructed for the town's small Jewish community, the temple was given the name B'nai (sons of) Abraham. Beautifully restored and rededicated in 2010, the building, now known as the B'nai Abraham Cultural Center and Museum, is used for a variety of community events and houses a permanent display of photographs, artifacts, and other material documenting the history of the Iron Range's once-vibrant Jewish community. The recipient of a Minnesota Preservation Award in 2019, B'nai Abraham is the only surviving visual evidence of the Range's Jewish settlers who, in the face of many challenges, were able to maintain their faith and its traditions, while adapting to life as "Iron Rangers." At one time the Range was home to over one thousand Jews who organized congregations in four towns: Chisholm, Eveleth, Hibbing, and Virginia. This essay traces the history of their founders who established homes and opened shops on the Range's developing main streets. It recounts the challenges facing them, including their interactions with their neighbors in what was and still is Minnesota's most diverse religious and ethnic region. The uncertain economy of the Range also had an impact on the Jewish community. As the demand for iron ore began to diminish in the 1950s, so too did the region's population. Many young people left to seek [End Page 1] their fortune elsewhere, including Robert Zimmerman, a.k.a. Bob Dylan, whose maternal great-grandparents, Lyba and Benjamin Edelstein, were among the Range's earliest settlers. The departure of members of Dylan's generation spelled doom for the Jewish community and its synagogues. By the 1980s only one synagogue survived, B'nai Abraham, and its doors closed a decade later. Jews no longer have a presence on the Range.2 Long before iron ore was discovered in northeastern Minnesota, the land was covered with a verdant forest of white pine and home to Native peoples living off its bounty. By the early nineteenth century, as the nation began to expand westward, cities like Chicago and St. Louis were developing, and lumber was needed for construction. Fifty years after timber cruisers first discovered the region's vast forest, the land was reduced to tree stumps, revealing the red earth that lay below its surface.3 Minnesota's pine forests were gone, but the region soon contributed a second natural resource to the building of America, iron ore. Geologists were aware of the region's lode, but it was not until the development of the modern blast furnace in the 1850s that iron could be economically transformed into steel. Soon after, speculators and explorers began to stake out claims for mining rights, first on the Vermillion Range, opening in 1882, and ten years later on the larger and more productive Mesabi Range. Laborers, skilled and unskilled, were needed. Among the first to arrive were experienced mine operators, often Scandinavians, and Cornish miners from the mines of Michigan. Recruiters in impoverished regions of eastern and southern Europe found a ready supply of unskilled laborers seeking a ticket to the "promised land." By 1910, the Range's total population was 77,655, representing twenty-five different ethnic and/or national groups, each carving out a place in the region, in hopes it would be their "bridge of gold" to a better life. Finns were the dominant nationality, then Slavs and Italians, and following them, Swedes, Norwegians, and a diversity of others including Jews.4 The Iron Range was representative of the nation's "mosaic" celebrated in a speech delivered by former Vice President Hubert H. Humphrey in 1972: "Some see the United States as a vast melting pot where our particular ethnic traditions...

Continuous wave vertical emission from terahertz microcavity lasers with a dual injection scheme.

Quantum cascade lasers (QCLs) represent a most promising compact source at terahertz (THz) frequencies, but efficiency of their continuous wave (CW) operation still needs to be improved to achieve large-scale exploitation. Here, we demonstrate highly efficient operation of a subwavelength microcavity laser consisting of two evanescently coupled whispering gallery microdisk resonators. Exploiting a dual injection scheme for the laser cavity, single mode CW vertical emission at 3.3 THz is obtained at 10 K with 6.4 mA threshold current and 145 mW/A slope efficiency up to 320 μW emitted power measured in quasi-CW mode. The tuning of the laser emission directionality is also obtained by independently varying the pumping strength between the microdisks. By connecting the resonators through a suspended gold bridge, the laser out-coupling efficiency in the vertical direction is strongly enhanced. Owing to the high brightness, low-power consumption and CW operation, the proposed microcavity laser design could allow the realization of high-performance CW THz QCLs ready for massive parallelization.

Cryoplasma-mediated fabrication of Au-TiO2 composite film using freezing ice front templated structures

Ice-templating is a powerful technique that exploits self-organized ice structures formed during the freezing of colloidal suspensions as templates to fabricate microstructured materials. However, the active introduction of reactivity to the ice-templating process remains limited. In this study, a Au-TiO2 composite film composed of gold and titanium oxide (TiO2) was fabricated on a frozen aqueous colloidal suspension, using cryoplasma to introduce reactive species to the frozen suspension. Auric ions and TiO2 nanoparticles were segregated on the ice body by one-directional freezing of the aqueous colloidal suspension from the lower side. Meanwhile, a cryoplasma, in which the gas temperature was controlled to be lower than the melting point of water, was irradiated onto the frozen aqueous colloidal suspension to facilitate the chemical reduction of gold ions and the formation of gold bridges between TiO2 nanoparticles. The face of the fabricated Au-TiO2 composite film that had been adjacent to the ice structure during its formation was shown to possess both greater roughness and higher photocatalytic activity for methylene blue degradation when the aqueous colloidal suspension was frozen at a higher temperature during the fabrication of the composite film. The temperature dependence of the roughness and photocatalytic activity indicates a potential of the combination of cryoplasma irradiation and ice-templating processes for structure-controlled fabrication of composite film materials, suggesting that alterations in the structure of the freezing ice front that occur with changes in temperature can be harnessed.

PENGGUNAAN SISTEM KOMPUTERISASI PADA KINERJA PROCUREMENT DEPARTMENT DI GOLD BRIDGE SHIPPING LTD

ABSTRAK
 Indonesia dikelilingi beberapa negara maju dengan sistem teknologi canggih dan terstruktur, yangmempengaruhi teknologi di Indonesia. Demikian juga suatu organisasi perusahaan terdapat banyak asetpenting dan harus dicatat dengan rinci serta diolah secara tepat sehingga dibutuhkan penggunaan sistemkomputerisasi. Pada era pelayanan prima, Gold Bridge Shipping Ltd harus memberikan pelayanan yang cepat,terbuka, dan professional kepada mitra-mitra kerjanya. Oleh karena itu, proses purchasing harusmenggunakan teknologi informatika agar proses pelayanan procurement terlaksana dengan sitematis. Namunsayangnya sistem komputerisasi belum seluruhnya diterapkan di Procurement Department sehinggamenghambat kegiatan di Procurement department. Penelitian ini bertujuan untuk mengetahui perbandingankinerja Procurement Department menggunakan dan tidak menggunakan sistem komputerisasi. Metodepenelitian yang digunakan yaitu kualitatif deskriptif. Adapun sumber data yang digunakan yaitu riset pustaka,wawancara dan dokumentasi. Hasil penelitian ini menemukan beberapa kendala yang dihadapi dalampenggunaan sistem komputerisasi diantaranya spesifikasi komputer yang belum diperbarui, gangguan sistemcomputer, gangguan system Manajemen database kerusakan komponen komputer, dan kurangnya SDM 
 
 

On the electrostatic actuation of capacitive RF MEMS switches on GaAs substrate

The electrostatic actuation behaviour of the gold bridge in capacitive radio frequency microelectromechanical system switches, fabricated on GaAs substrate, is investigated. An unconventional imaging technique, based on the out-of-focus reflection, was used to evaluate the topographic profile of the suspended bridge and its lowering as a function of the voltage. Important parameters for the switch actuation, such as the pull-down voltage and the air gap between the bridge and the actuator, are estimated. Capacitance-voltage curves allow to evaluate the capacitance associated to the bridge in the up and down states as well as the dielectric constant of the Si3N4 layer, which covers the actuator. The experimental values of the pull-down voltage and the dielectric constant are used to extract from the theoretical equations the residual stress of the fabricated gold membrane. Finally, the current through the dielectric Si3N4 layer was measured as a function of the voltage applied to the actuator, finding that the Poole–Frenkel effect is the dominant conduction mechanism when the switch is actuated.

Reverse engineering of mandible and prosthetic framework: Effect of titanium implants in conjunction with titanium milled full arch bridge prostheses on the biomechanics of the mandible

This study aimed at investigating the effects of titanium implants and different configurations of full-arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology.

Design and development of a surface micro-machined push–pull-type true-time-delay phase shifter on an alumina substrate for Ka-band T/R module application

A radio frequency micro-electro-mechanical system (RF-MEMS) phase shifter based on the distributed MEMS transmission line (DMTL) concept towards maximum achievable phase shift with low actuation voltage with good figure of merit (FOM) is presented in this paper. This surface micro-machined analog DMTL phase shifter demonstrates low power consumption for implementation in a Ka-band transmit/receive (T/R) module. The push–pull-type switch has been designed and optimized with an analytical method and validated with simulation, which is the fundamental building block of the design of a true-time-delay phase shifter. Change in phase has been designed and optimized in push and pull states with reference to the up-state performance of the phase shifter. The working principle of this push–pull-type DMTL phase shifter has been comprehensively worked out. A thorough detail of the design and performance analysis of the phase shifter has been carried out with various structural parameters using commercially available simulation tools with reference to a change in phase shift and has been verified using a system level simulation. The phase shifter is fabricated on the alumina substrate, using a suspended gold bridge membrane with a surface micromachining process. Asymmetric behaviour of push–pull bridge configuration has been noted and a corresponding effect on mechanical, electrical and RF performances has been extensively investigated. It is demonstrated 114° dB−1 FOM over 0–40 GHz band, which is the highest achievable FOM from a unit cell on an alumina substrate reported so far. A complete phase shifter contributes to a continuous differential phase shift of 0°–360° over 0–40 GHz band with a minimum actuation voltage of 8.1 V which is the highest achievable phase shift with the lowest actuation voltage as per till date on the alumina substrate with good repeatability and return loss better than 11.5 dB over 0–40 GHz band.

Advanced characterization of a W-band phase shifter based on liquid crystals and MEMS technology

In this paper, we present a continuously tunable phase shifter realized in MEMS technology. Varactors with liquid crystal as a tunable dielectric layer underneath gold bridges are used to build a loaded line phase shifter. Measurements show that the phase shifter has a differential phase shift of 92°, a figure of merit (FoM) of 42°/dB and an input matching of −19 dB at 76 GHz.The tuning speed of the phase shifter is measured at different temperatures between 10 and 50°C. The realized phase shifter can be used in combination with MEMS switches in order to build a 360° tunable reflection phase shifter.

A Density Functional Investigation on C2Aun+ (n = 1, 3, 5) and C2Aun (n = 2, 4, 6): from Gold Terminals, Gold Bridges, to Gold Triangles

A systematic density functional theory investigation on C2Aun+ (n = 1,3,5) and C2Aun (n = 2,4,6) indicates that gold atoms serve as terminals (–Au) in the chain-like Cs C2Au+ (C=C–Au+) and D∞h C2Au2 (Au–C≡C–Au) and as bridges (–Au–) in the side-on coordinated C2v C2Au3+ ([Au–C≡C–Au]Au+) and Cs C2HAu2+([H–C≡C–Au]Au+). However, when the number of gold atoms reaches four, they form stable gold triangles (–Au3) in the head-on coordinated C2v C2Au4 (Au–C≡C–Au3) and the side-on coordinated C2v C2Au5+ ([Au–C≡C–Au]Au3+). Similar –Au3 triangular units exist in the head-on coordinated C2v C2HAu3 (H–C≡C–Au3) and D2d C2Au6 (Au3–C≡C–Au3). The existence of stable –Au3 triangular units in small dicarbon aurides is significant and intriguing. The high stability of Au3 triangles originates from the fact that an equilateral D3h Au3+ cation possesses a completely delocalized three-center-two-electron (3c–2e) σ bond and therefore is σ-aromatic in nature. The extension from H/Au analogy to H/Au3 analogy established in this work may have important implications in designing new gold-containing catalysts and nano-materials.

Direct current effects on 1/f noise in patterned Permalloy films

Detailed investigations of 1/f noise were performed in patterned Permalloy films. The gold bridges for the four probe measurement setup were deposited on a quartz substrate. Pattern geometry, bias current, and transverse magnetostatic field effects on the material’s 1/f noise were studied. The normalized Hooge parameter and frequency slope were analyzed in the framework of the empirical Hooge relation. Different dependences of the noise versus bias current generated Oersted field and the magnetostatic field were observed. The normalized Hooge parameter and frequency slope were pattern width and field configuration dependent.

Influence of Parameters of Fabrication on Quality and Performance of Superconducting MEM Switches

In earlier work a capacitively shunted superconducting MicroElectroMechanical (MEM) switch has been designed and fabricated. The switch is composed of high temperature superconducting (HTS) YBa/sub 2/Cu/sub 3/O/sub 7/ coplanar waveguide structure with a gold bridge membrane suspended above an area of the center conductor covered with BaTiO/sub 3/ dielectric. The switch demonstrated an insertion loss of less than 0.007 dB with 30 dB isolation at 3 GHz. These switches have been shown to be viable, however, issues of the dielectric material deposition and gold bridge release process posed limitations on the yield and switch cycling. In this work we report on the issues encountered and improvements made in the development of HTS MEMS switches for use in tunable RF devices.

Effect of Temperature on Impedance Behavior of Insulation Layer in a HTS MEMS Switch for RF Applications

We have successfully developed High Temperature Superconducting (HTS) MicroElectroMechanical (MEM) switches for RF applications. A typical switch is composed of a superconducting Yttrium Barium Copper Oxide (YBa/sub 2/Cu/sub 3/O/sub 7/) coplanar waveguide structure with a gold bridge membrane suspended above an area of the center conductor covered with Barium Titinate (BaTiO/sub 3/) ferroelectric. A control voltage applied between the membrane and transmission line causes the membrane to collapse on top of the dielectric layer by electrostatically induced force; this in turn allows the RF signal to capacitively shunt to ground. Initial testing of switches showed very promising RF behavior with insertion losses less than 0.1dB with 30 dB isolation at 3 GHz. These switches rely on the "ON/OFF" impedance ratio to achieve switching; this is determined by the dielectric constant of the BaTiO/sub 3/ ferroelectric. These switches will be operated at cryogenic temperatures; we have investigated the impedance behavior vs. temperature of the HTS/ferroelectric/metal heterostructure to better understand the behavior of the insulating layer at cryogenic temperatures.

Design of a superconducting MEM shunt switch for RF applications

We have designed, simulated and optimized a capacitively shunted RF MicroElectroMechanical (MEM) superconducting switch. The switch consists of a High Temperature Superconducting (HTS) YBa/sub 2/Cu/sub 3/O/sub 7/ coplanar waveguide (CPW) structure with a gold membrane bridge suspended above the center conductor and anchored at the ground planes (air gap 3 /spl mu/m). A thin layer of BaTiO/sub 3/, in the shape of a patch, lies on top of the center conductor and underneath the suspended gold membrane. Under an applied voltage, the gold bridge membrane actuates downwards and collapses on top of the dielectric layer of BaTiO/sub 3/ thereby capacitively shunting the RF signal to ground. Using Sonnet, simulations were conducted to optimize the switch design. An analysis of these results revealed interesting relationships between the switch mechanical and electrical parameters; this paper discusses and analyzes these results, along with measured data.

Continuous anti-stiction coatings using self-assembled monolayers for gold microstructures

We have experimented with using continuous self-assembled monolayer (SAM) coatings on different surfaces, such as gold and silicon nitride, as anti-stiction coatings for radio-frequency microelectromechanical systems (RF MEMS). SAMs are coated on gold and silicon nitride surfaces in order to fabricate stiction-free gold structures after the wet release process. SAM coatings on gold and silicon nitride surfaces change the contact angle of a water droplet from 70.6° to 112.6° and from 36.7° to 115.8°, respectively. From atomic force microscopy, we can see that there is little change in the roughness of the gold and silicon nitride before and after the SAM coating. Using the electroplating technique and the wet release process, we have fabricated 4 μm thick gold cantilevers and bridges on a gold surface with a 6.5 μm gap from the substrate. Cantilevers and bridges are fabricated with different lengths in the range of 100–1000 μm with separations of 100 μm. It is observed that cantilevers and bridges with a length of 1000 μm on a gold substrate are released and standing free. A 1000 μm long gold cantilever has only 16.5 μm tip end deflection after the wet release process and SAM coating, much smaller compared with the 120 μm tip end deflection with the dry release process. Gold cantilevers, 100–500 μm long, on silicon nitride are released free and gold bridges on silicon nitride are released with a length of 1000 μm with continuous SAMs. The SAMs are coated on gold and silicon nitride surface in order. This method enables the gold cantilever and bridge on the gold or silicon nitride surface to be released with low deflection.

Joined at the Hip

![Graphic][1] Hip1R (gold) bridges actin and clathrin. A direct link between clathrin cages and actin is described on [page 1209][2] by Engqvist-Goldstein et al. The protein that forms the link is huntingtin interacting protein 1 related (Hip1R), which was characterized previously

Interactions between molecular wires and a gold surface

The thiol group attaches strongly to gold surfaces and can thus be used as interconnects of molecular wires in nano electronics. A phenyl molecule attached to gold via a thiol group has been investigated by ab initio Hartree–Fock calculations in order to understand electronic transport through the sulfur–gold bridge. In our analysis of the coupling between gold and the molecule, we found that the electronic system of the gold substrate interacts directly with the conducting states of the molecule and thus forms an ohmic contact to the molecular wire.

Influence of a new energy scale on conductance fluctuations and weak localization in ultrasmall metallic nanobridges.

Conductance fluctuations and weak localization in ultrasmall gold bridges with all dimensions smaller than the elastic mean free path have been studied as a function of magnetic field and applied bias voltage. In addition to the well known Thouless energy we observe a new energy scale in the dependence of both quantum interference effects on the bias voltage. This new energy scale agrees well with the level separation estimated for the states in the corresponding closed system.

Geochronometry of the Bridge River Camp, southwestern British Columbia

Mineralization at the Bralorne mesothermal gold vein deposit is closely related to a suite of early Late Cretaceous to early Tertiary dykes. Premineral albitite dykes (91.4 ± 1.4 Ma by U–Pb on zircons) and postmineral lamprophyre dykes (43.5 ± 1.5 Ma by K–Ar on biotite) set definite age limits on the mineralizing event. A late intra- to post-mineral green hornblende dyke set (85.7 ± 3.0 Ma by K–Ar on hornblende) that forms a transitional series to the albitites may further restrict the age. Thus, mineralization occurred long after emplacement of the host Bralorne intrusions, dated as Early Permian (minimum age of approximately 270 ± 5 Ma by U–Pb on zircons, 284 ± 20 Ma by K–Ar on hornblende, and 40Ar/39Ar plateau at 276 ± 31 Ma). Lithologically similar intrusions 20 km to the north near Gold Bridge are also Early Permian (287 ± 20 Ma by K–Ar on hornblende and 320 ± 80 Ma by a Rb–Sr whole-rock isochron). Geochronology, radiogenic and stable isotopes, and fluid-inclusion studies suggest that there were several pulses of mineralizing activity adjacent to and east of the Coast Plutonic Complex (CPC). Decreasing temperatures and younger age of mineralization with increasing distance from the CPC imply that plutons of the CPC were the main heat source responsible for mineralization. The main pulses were about 90 Ma for mesothermal Au–Ag–As ± W,Mo mineralization at Bralorne near the CPC, ranging outwards to 65 Ma for Ag–Au–Sb–As ± Hg mineralization at the Minto and Congress deposits, to 45 Ma for Ag–Au epithermal mineralization at Blackdome, 100 km east of the CPC.The Bralorne intrusions may have been emplaced below the sea floor in a spreading-ridge oceanic environment, as suggested by the petrology of the intrusive suite, which includes serpentinized ultramafite, hornblende diorite, and soda granite (trondhjemite), typical of an ophiolite association. The chemistry of volcanic rocks mapped as Cadwallader Group, which host these intrusive bodies, is transitional from mid-ocean-ridge basalts to island-arc tholeiite, suggesting a back-arc-basin setting. Gradational contact relations between the hornblende diorite and the volcanic rocks suggest that the diorite intruded its own volcanic products. Intrusive contacts of the diorite with adjacent elongate ultramafic bodies imply that the ultramafic rocks are of Permian or older age and had been structurally emplaced into crustal levels by the time of diorite intrusion. In the Bralorne fault block the Bralorne intrusions appear to cut the adjacent Cadwallader and Bridge River groups, implying an Early Permian or older age for at least parts of these groups. Thus, rocks mapped as Cadwallader Group in the Bralorne area could be distinct from and older than lithologic equivalents exposed elsewhere, although they are similar in terms of their petrology and major- and trace-element chemistry.

Gold–boron chemistry. Part 2. The interaction of {AuP(C6H11)3} bridges with decaboranyl cages: the accurate structure of [5,6-µ-{AuP(C6H11)3}-nido-B10H13], and the synthesis and molecular and electronic structures of its conjugate base [5,6,9,10-µ4-{AuP(C6H11)3}-nido-B10H12]–

Analysis of the results of an accurate, low-temperature redetermination of the molecular structure of [5,6-µ-{AuP(C6H11)3}-nido-B10H13](1a) implies an interaction, albeit weak, between the bridging gold atom and the B(9)H(9,10)B(10) moiety, and extended Huckel molecular orbital (EHMO) calculations reveal that the nature of this bonding is interaction of the three-centre two-electron–B(9)HB(10) unit with a previously vacant 6sp-hybrid orbital on gold. Mossbauer parameters obtained for (1a) are consistent with an sp-hybridised gold (I) atom which makes a supplementary weak interaction. Deprotonation of (1a) or of its P(C6H4Me-2)3 analogue removes the H(9,10) atom, and affords species (2) in which the gold–phosphine unit has slipped from µ to µ4 on a decaboranyl framework, the molecular structure of [NHEt3][nido-{AuP(C6H11)3}B10H12], (2a), having been established by a crystallographic stydy. For (2), a combination of Mossbauer spectroscopic studies and EHMO calculations indicates that the orbital number of the metal atom is again somewhat greater than 2, i.e. that the formal co-ordination geometry of the gold (I) bridge is intermediate bewteen linear and trigonal, but more so than in (1). The deprotonation of (1) is fully reversible, and its reaction with HCl results in cleavage of the remaining gold–boron connectivities to afford B10H14.

A clinical evaluation of fixed bridges, 10 years following insertion.

In this long-term clinical study, the condition of extensive fixed bridges was investigated 10 years after cementation. From the records of the Swedish Insurance System (Gothenburg branch) the individuals were randomly selected. All restorative treatment had been performed by private general practitioners. The investigation comprised a total of 238 bridges making 1606 units, 944 abutment and 662 pontics. Seven bridges had been removed and in a further nine cases the bridge had been separated and units removed. Loose retainers were detected at thirty (3%) abutments. In 14.5% of the surfaces a deficiency in marginal adaptation was found. An open margin seemed to be the most serious defect and was often related to caries in contact with the margin of the crown. Caries and fillings in relation to the margin were detected in 8.1% of the surfaces. Porcelain bonded to gold restorations were significantly more often overcontoured in the interproximal space compared with acrylic resin veneer gold bridges. In the investigation the caries status has been also thoroughly reported. Abutment teeth, presumed to be vital, had a prevalence of 10% radiographically visible periapical lesions. Finally, 93.3% of the bridges cemented 10 years prior to the investigation were still in function without any parts being removed.