Terminal Blocks Research Articles

A study of bottom-up electroplated copper filling by the potential difference between two rotating speeds of a working electrode

In order to achieve a bottom-up plated copper filling with a minimal surface thickness, an additive system containing a pluronic triblock copolymers, ethylene oxide terminal blocks termed EPE as a suppressor, bis(3-sulfopropyl) disulfide (SPS) as accelerator, Janus Green B (JGB) as leveler, and Cl− was used to investigated bottom-up filling by galvanostatic measurements method and cross-sectional OM observation. The EPE-8000 not only was a stronger inhibition for electrodeposition copper reaction, but also had a stronger forced convection with JGB and Cl− in copper electroplating solution than PEG-8000 for copper deposition. The potential difference obtained from two different rotating speeds of a copper working electrode by galvanostatic measurements reached positive 20mV with an addition of the EPE-8000 and was much higher than that with an addition of PEG-8000 (about 12mV), which led to a high filling performance with a minimal surface copper thickness. The effects of additives SPS, JGB, and Cl− on the potential difference and bottom-up filling behavior were investigated in detail. With an addition of EPE-8000, the filling performance of the plating copper solution was enhanced, the surface thickness of deposited copper film was reduced, but also the operation windows of four additives were widened extensively.

Higher-order repeat structure in alpha satellite DNA is an attribute of hominoids rather than hominids

Alpha satellite DNA (AS), a major DNA component of primate centromeres, is composed of a tandem array of repeat units of approximately 170 bp. The AS of hominids (family Hominidae; humans and great apes) includes sequences organized into higher-order repeat (HOR) structures, with a periodic appearance of multiple copies of the basic repeat units. Here, we identified an HOR in AS of the siamang, a small ape phylogenetically distinct from hominids but included in hominoids (superfamily Hominoidea). We sequenced long stretches of genomic DNA, and found a repetition of blocks consisting of six and four basic repeat units. Thus, AS organization into HOR is an attribute of hominoids, rather than, as currently postulated, hominids. In addition to centromeres, siamangs carry AS in terminal heterochromatin blocks, and it cannot be determined at present whether these HOR-containing AS sequences originate from the centromere or from the terminal heterochromatin. Even if the latter is the case, these sequences might affect the composition of centromeric AS by being transferred to the centromere.

Application of infrared thermography for predictive/preventive maintenance of thermal defect in electrical equipment

Internal heat of electrical equipment rises due to various reasons such as contact problems, unbalance loading, cracks in insulation, defective relays or terminal blocks, etc until eventual failure which can cause unplanned outages and possible injuries. Therefore, early prevention of thermal abnormalities in electrical equipment is necessary to avoid failure. Nowadays a fast, reliable, non-contact and cost effective infrared thermographic inspection system is being utilized widely for detecting where and how internal and external defects occur in equipment. The system collects data for investigating thermal condition through the analysis of thermal image of equipment. The image is captured by infrared camera without interrupting the running operation of system. Both preventive and predictive maintenance programs are adopted for defect diagnosis. Actually, the frequency and sequence of thermographic inspection depend on various factors including thermal condition, expense of a failure, type of production and age of equipment, etc. The objectives of this article are to discuss about preventive and predictive maintenance, thermal defects in electrical equipment and also an intelligent thermal defect identification system for accelerating the predictive defect diagnosis technique. The intelligent system proposes the application of artificial neural network and statistical features to detect the existence of defect within equipment by monitoring its thermal condition. Using discriminant analysis, the optimum features were chosen as the inputs of the neural network. The performances of the neural network were compared with the performances of discriminant analysis classifier. The comparison results showed that discriminant analysis classifier produced better performance with accuracy 82.40%.

Identification of Location and Orientation for Terminal Blocks Based on Template Matching

A template matching method based on a vision system is proposed to get the location of terminal blocks. Gaussian pyramid decomposition is used to get the source image and template image samples, which will reduce the matching time and thus fulfill the requirement of real time application. The positioning screws used as mark points can be obtained by binarization, erosion, and dilation, and then the location of them can be worked out by the centre-of-gravity method. Finally, the location and the rotation angle of terminal blocks can be obtained with least square method. Experimental results show that this method is convenient to be operated with high recognition rate and efficiency.

Reliability of Bi-2223/AgAu Current Leads for Cryocooled Superconducting Magnet

A current lead for a cryocooled superconducting magnet (CSM) was designed and fabricated using a high-temperature superconductor (HTS) tape, which could easily facilitate modification of the transport current capacity. The current lead was constructed of two terminal blocks, a support tube, and five Bi2223/AgAu HTS tapes. The Bi2223/AgAu HTS tapes with a critical current of 100 A at 77 K in self-fields were used for the current leads. The critical current value of the current lead was 390 A at 77 K in self-fields. The initial critical current at 77 K was maintained after four thermal cycles. The transport current of 170 A was continuously applied at 75 K, 0.27 T by conduction cooling. The voltage between two terminal blocks was 0.28 mV, even after 930 cycles of electromagnetic force (Lorentz force). The heat leakage through the current lead was 0.21 W from 55 K stage to 4.5 K stage. The experimental results showed that the current lead for CSM had sufficient strength against thermal stress and Lorentz force. The current lead has been operated in a CSM to demonstrate a stable excitation and reliability after thermal cycles from room temperature to 4 K. During the excitation and thermal cycle test, overall voltage of the current lead was maintained at an operational condition of 155 A, 55 K, and 0.26 T.

Novel supramolecular block copolymer containing organic–inorganic pentablock copolymer by ATRP of styrene and vinyl acetate using polydimethylsiloxane/cyclodextrin inclusion complexes as macroinitiator

Organic–inorganic pentablock copolymers have been synthesized via atom transfer radical polymerization (ATRP) of styrene (St) and vinyl acetate (VAc) monomers at 60 °C using CuCl/N,N,N′,N″,N″-pentamethyldiethylenetriamine as a catalyst system initiated from boromoalkyl-terminated poly(dimethylsiloxane) (PDMS)/cyclodextrins macroinitiator (Br-PDMS/γ-CD). Br-PDMS-Br was reacted with γ-CD in different conditions with inclusion complexes being characterized through hydrogen nuclear magnetic resonance (1H NMR) and differential scanning calorimetry (DSC). Resulting Br-PDMS-Br/γ-CD inclusion complexes were taken as macroinitiators for ATRP of St and VAc. Well-defined poly(styrene)-b-poly(vinyl acetate)-b-poly(dimethylsiloxane/γ-cyclodextrin)-b-poly(vinyl acetate)-b-poly(styrene) (PSt-b-PVAc-b-PDMS/γ-CD-b-PVAc-b-PSt) pentablock copolymer was characterized by 1H NMR, gel permeation chromatograph (GPC) and DSC. There was a good agreement between the number-average molecular weight calculated from 1H NMR spectra and that of theoretically calculated. Pentablock copolymers consisting of Br-PDMS-Br/γ-CD inclusion complex as central blocks (inorganic block) and PVAc and PSt as terminal blocks were synthesized by this technique. PSt-b-PVAc-b-PDMS/γ-CD-b-PVAc-b-PSt pentablock copolymer can undergo a temperature-induced reversible transition upon heating of the copolymer complex from white complex at 22 °C to green complex in 55 °C which characterized with XRD and 1H NMR. XRD showed a change in crystallinity percent of St peak with changing the temperature which calculated by Origin75 software.

Amphiphilic ABC Triblock Copolymers Tailored via RAFT Polymerization as Textile Surface Modifiers with Dual-Action Properties

We present the synthesis and characterization of two different kinds of triblock copolymers prepared via RAFT polymerization by only two synthetic steps applying a sequential monomer addition approach. Both triblock copolymers consist of a hydrophilic, a hydrophobic and an anchor block which is located in the middle or at the end of the polymer chains. In both triblock copolymer systems the hydrophobic blocks consist of randomly polymerized tert-butylstyrene (tBS) and n-hexyl acrylate (nHA) monomers in a ratio of approximately 2:1, respectively, whereas the hydrophilic blocks were accomplished by polymerization of N,N-dimethylacrylamide (DMA). As a result of the employed synthetic approach, every anchor block contains several N-acryloxysuccinimide (NAS) units besides tBS and nHA units in the case of the triblock copolymer with the central anchor block and DMA units in the case of the triblock copolymer with the terminal anchor block. The structures as well as the compositions of all synthesized polymers w...

Theory of self-assembly of triblock ter-polymers in selective solvent towards corona-compartmentalized (Janus) micelles

We present a scaling theory of self-assembly of triblock ter-polymer ABC in selective solvent which is good or theta for both terminal blocks A and C, but poor for the middle block B. It is demonstrated that depending on the level of incompatibility between blocks A and C of the ter-polymer, equilibrium micelle has either laterally homogeneous (mixed) or segregated (“Janus”) corona.

Directed formation of tri-connected Cu(i) coordination polymers

Two new tri-connected copper(I) coordination polymers have been synthesized, featuring a 1D staircase-like structure and an interpenetrating 2D polycyclohexane framework. The geometries are controlled by steric factors that are generated from the terminal blocking ligand 2-diphenylphosphino-n-methyl pyridine (n = 3, 6) with the methyl group at different substituted positions.

Silicone Macroinitiator in Atom Transfer Radical Polymerization of Styrene and Vinyl Acetate: Synthesis and Characterization of Pentablock Copolymers

Poly(dimethylsiloxane) (PDMS) based pentablock copolymers has been synthesized via atom transfer radical polymerization (ATRP) of styrene (St) and vinyl acetate (VAc) telomer at 60 °C in the presence of CuCl/PMDETA as a catalyst system. Vinyl acetate telomer was prepared from controlled radical telomerization with Co(acac)2/DMF with PDI ≈ 1.3. Poly(vinyl acetate-b-styrene-b- dimethylsiloxane- b- styrene-b-vinyl acetate) (PVAc-b-PSt-b-PDMS-b-PSt-b-PVAc) pentablock copolymers provided a method to design block copolymer with PDMS segment, allowing us for the adjustments in the flexibility by PDMS with a large effect from its softening point (Tg), or rigidity of styrene monomer and a higher melting temperature (Tm). Penta-block copolymers were characterized by FTIR, 1HNMR, DSC, and GPC techniques. Meanwhile, the number-average molecular weights calculated from 1HNMR spectra were in very good agreement with the theoretically calculated value. It could be concluded from the 1HNMR and DSC spectrum that the pentablock copolymers of PVAc-b-PSt-b-PDMS-b-PSt-b-PVAc consisting of a PDMS center block and PSt and PVAc terminal blocks were synthesized.

Monte-carlo simulations of the order-disorder transition depression in ABA triblock copolymers with a short terminal block

Although most ABA triblock copolymers are molecularly symmetric (i.e., the terminal blocks possess the same mass), molecularly asymmetric A1BA2 triblock copolymers are of greater fundamental interest in that they can be used to explore the transition from diblock to triblock copolymer in systematic fashion. In this study, we use a lattice Monte Carlo method known as the cooperative motion algorithm to simulate molten ABA triblock copolymers possessing a short terminal block to explore the effect of molecular asymmetry on the copolymer order–disorder transition (ODT). Reduced ODT temperatures, discerned by simultaneously analyzing several features of the simulation results, are found to compare favorably with experimental data. Of particular interest here is the initial depression in the ODT temperature for A1BA2 copolymers possessing a relatively short terminal (A2) block. This signature feature is successfully captured by the simulations and is found to be strongly dependent on composition, but weakly dependent on copolymer chain length. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013

Phosphoglycerate mutase deficiency with tubular aggregates in a patient from panama

Phosphoglycerate mutase deficiency (PGAM) is a rare metabolic myopathy that results in terminal block in glycogenolysis. Clinically, patients with PGAM deficiency are asymptomatic, except when they engage in brief, strenuous efforts, which may trigger myalgias, cramps, muscle necrosis, and myoglobinuria. An unusual pathologic feature of PGAM deficiency is the association with tubular aggregates. We report an African-American patient from Panama with partial deficiency of PGAM who presented with asymptomatic elevation of creatine kinase levels and tubular aggregates on muscle biopsy. Muscle biopsies showed subsarcolemmal and sarcolemmal tubular aggregates in type 2 fibers. Muscle PGAM enzymatic activity was decreased and gene sequencing revealed a heterozygous mutation in codon 78 of exon 1 of the PGAM2 gene, which is located on the short arm of chromosome 7. PGAM deficiency has been reported in 14 patients, 9 of whom were of African-American ethnicity, and in 5 (36%) tubular aggregates were seen on muscle biopsy. Contrary to previously reported cases, our patient was initially asymptomatic. This further expands the PGAM deficiency phenotype.

Cyanide-bridged complexes based on dinuclear Cu(II)-M(II) [M = Pb and Cu] building blocks: Synthesis, crystal structures and magnetic properties

Four cyanide-bridged heterometallic complexes {[CuPb(L1)][FeIII(bpb)(CN)2]}2·(ClO4)2·2H2O·2CH3CN (1), {[CuPb(L1)]2[FeII(CN)6](H2O)2}·10H2O (2), {[Cu2(L2)][FeIII(bpb)(CN)2]2}·2H2O·2CH3OH (3) and {[Cu2(L2)]3[FeIII(CN)6]2(H2O)2}·10H2O (4) have been synthesized by treating K[FeIII(bpb)(CN)2] [bpb2−=1,2-bis(pyridine-2-carboxamido)benzenate] and K3[FeIII(CN)]6 with dinuclear compartmental macrocyclic Schiff-base complexes [CuPb(L1)]·(ClO4)2 or [Cu2(L2)]·(ClO4)2, in which H2L1 was derived from 2,6-diformyl-4-methyl-phenol, ethylenediamine, and diethylenetriamine in the molar ratio of 2:1:1 and H2L2 from 2,6-diformyl-4-methyl-phenol and propylenediamine in the molar ratio of 1:1. Single crystal X-ray diffraction analysis reveals that compound 1 displays a cyclic hexanuclear heterotrimetallic molecular structure with alternating [FeIII(bpb)(CN)2]− and [CuPb(L1)]2+ units. Complex 2 is of a neutral dumb-bell-type pentanuclear molecular configuration consisting of one [Fe(CN)6]4− anion sandwiched in two [CuPu(L1)]2+ cations, and the pentanuclear moieties are further connected by the hydrogen bonding to give a 2D supramolecular framework. Heterobimetallic complex 3 is a tetranuclear molecule composed of a centrosymmetric [Cu2(L2)]2+ segment and two terminal cyanide-containing blocks [FeIII(bpb)(CN)2]−. Octanuclear compound 4 is built from two [Fe(CN)6]3− anions sandwiched in the three [Cu2L2]2+ cations. Investigation of their magnetic properties reveals the overall antiferromagnetic behavior in the series of complexes except 2.

C terminal block of the Pannexin 1 channel pore and its relief by proteolytic cleavage

Pannexin‐1 (PANX1) channels release ATP, a “find‐me” signal that recruits macrophages to apoptosing cells. Cleavage of the PANX1 C terminus by caspases represents a new mechanism of ion channel opening, but how the C terminus regulates channel activity is unclear. We provide evidence suggesting that the C terminal residues of PANX1 block the pore and removing this block activates the channel. Silent channels could be activated directly by C terminal cleavage, in the absence of additional apoptotic factors. We identified a region immediately downstream of the caspase site required for inhibition of PANX1. Consistent with the C terminus acting as a pore blocker, we found that constitutively active channels could be inhibited, in trans, by the isolated C terminus. Furthermore, using a cysteine crosslinking approach, we show that relief of inhibition following cleavage requires dissociation of the C terminus from the channel pore. Together, these data suggest a ball & chain mechanism of PANX1 activation, wherein the C terminus blocks the full length channel and a remarkably well placed caspase cleavage site allows effective removal of inhibitory C terminal residues to facilitate channel opening.

Test bench for ITER gyrotrons. Measurements of the RF power value during tests of the ITER-prototype gyrotrons

An increase of the industrial production and population in the world requires search and introduction of the new energy sources. Controlled thermonuclear fusion is one of the most promising sources of obtaining energy. At present, the international experimental thermonuclear reactor ITER is built in France (Cadarache). For additional plasma heating in ITER twenty four gyrotrons generating RFpower at the 170 GHz frequency will be used. Russian Federation within the framework of ITER obligations, must supply eight gyrotrons [1]. Before delivery, the gyrotrons must be tested on the test bench, which was built in Institute of tokamak physics, NRC “Kurchatov Institute”. Test bench for the work in the continuous (CW) regime is equipped with the high-voltage power supplies, water cooling and vacuum pumping systems, evacuated transmission line, which connects gyrotron with the terminal load, the protection and blocking system, technological diagnostics, the systems of the experimental data acquisition, processing and archiving.

Thermoreversible high-temperature gelation of an ionic liquid with poly(benzyl methacrylate-b-methyl methacrylate-b-benzyl methacrylate) triblock copolymer

In this paper, we describe a novel thermosensitive triblock copolymer in an ionic liquid (IL) that shows a low-temperature-sol–high-temperature-gel transition. A well-defined ABA triblock copolymer consisting of poly(benzyl methacrylate) as the terminal A blocks and poly(methyl methacrylate) as the middle B block (P(BnMA-b-MMA-b-BnMA), BMB) was successfully synthesized using atom transfer radical polymerization (ATRP) from a bifunctional initiator. The number-average molecular weights of the PBnMA blocks and the PMMA block were estimated to be 25 kDa and 33 kDa, respectively. The temperature dependence of the hydrodynamic radius obtained from dynamic light scattering showed that in dilute solutions (0.1 wt%) the triblock copolymer exhibited lower critical micellization temperature (LCMT)-type aggregation behaviour around 135 °C in a common hydrophobic IL, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C2mim][NTf2]). Dynamic viscoelastic measurements for a 20 wt% BMB solution in [C2mim][NTf2] confirmed that a viscous liquid at low temperature (G′ (storage elastic modulus) G′′) upon heating above the aggregation temperature of the PBnMA terminal blocks. No gelation was observed when the triblock copolymer concentration was below 10 wt%. Furthermore, the thermoreversible ion gel exhibited excellent sol–gel transition reversibility for multiple heating/cooling cycles performed over several days.

Current controlled current differential current conveyor: a novel building block for analog signal processing

In this paper, a novel active block for analog signal processing is presented, namely the current controlled current differential current conveyor (CCCDCC). This multi terminal block has most features of the well-known CCII (Second Generation Current Conveyor) and CCCDTA (Current Controlled Current Differencing Tranconductance Amplifier) to simplify the realization of current-mode analog filters suitable for signal processing. The proposed block and its applications were simulated in 0.18µm CMOS process at ±0.9V supply voltages. All of results were obtained by Hspice and with a high detailed transistor library.

Heterochromatin heterogeneity in Hypostomus prope unae (Steindachner, 1878) (Siluriformes, Loricariidae) from Northeastern Brazil

Cytogenetic analyses using C-banding and chromosomal digestion by several restriction enzymes were carried out in four populations (named A, B, C and D) of Hypostomus prope unae (Loricariidae, Hypostominae) from Contas river basin, northeastern Brazil. These populations share 2n=76 and single NORs on the second metacentric pair but exclusive karyotype forms for each locality. Populations A and B presented conspicuous terminal and interstitial heterochromatic blocks on most of acrocentric chromosomes and equivalent to NORs with differences in both position and bearing pair. Population D showed evident marks at interstitial regions and interspersed with nucleolar region while population C presented interstitial and terminal heterochromatin segments, non-coincident with NORs. The banding pattern after digestion with the endonucleases Alu I, Bam HI, Hae III and Dde I revealed a remarkable heterogeneity within heterochromatin, allowing the identification of distinctive clusters of repeated DNA in the studied populations, besides specific patterns along euchromatic regions. The analysis using restriction enzymes has proved to be highly informative, characterizing population differences and peculiarities in the genome organization of Hypostomus prope unae.

Specific Interactions of Sodium Salts with Alanine Dipeptide and Tetrapeptide in Water: Insights from Molecular Dynamics

We examine computationally the dipeptide and tetrapeptide of alanine in pure water and solutions of sodium chloride (NaCl) and iodide (NaI), with salt concentrations up to 3 M. Enhanced sampling of the configuration space is achieved by the replica exchange method. In agreement with other works, we observe preferential sodium interactions with the peptide carbonyl groups, which are enhanced in the NaI solutions due to the increased affinity of the less hydrophilic iodide anion for the peptide methyl side-chains and terminal blocking groups. These interactions have been associated with a decrease in the helicities of more complex peptides. In our simulations, both salts have a small effect on the dipeptide, but consistently stabilize the intramolecular hydrogen-bonding interactions and "α-helical" conformations of the tetrapeptide. This behavior, and an analysis of the intermolecular interaction energies show that ion-peptide interactions, or changes in the peptide hydration due to salts, are not sufficient determining factors of the peptide conformational preferences. Additional simulations suggest that the observed stabilizing effect is not due to the employed force-field, and that it is maintained in short peptides but is reversed in longer peptides. Thus, the peptide conformational preferences are determined by an interplay of energetic and entropic factors, arising from the peptide sequence and length and the composition of the solution.

Isolation and characterization of a new repetitive DNA family recently amplified in the Mesoamerican gene pool of the common bean (Phaseolus vulgaris L., Fabaceae)

The common bean (Phaseolus vulgaris) is one of the most important crop plants. About 50% of its genome is composed of repetitive sequences, but only a little fraction was isolated and characterized so far. In this paper, a new repetitive DNA family from the species, named PvMeso, was isolated and characterized in both gene pools of P. vulgaris (Andean and Mesoamerican) and related species. Two fragments, 1.7 and 2.3 kb long, were cloned from BAC 255F18, which has previously shown a repetitive pattern. The subclone PvMeso-31 showed a terminal block in chromosome 7. This subclone contains a 1,705 bp long, AT-rich repeat with small internal repeats and shares a 1.2 kb region with PvMeso-47, derived from the 2.3 kb fragment. The presence of this repetitive block was restricted to Mesoamerican accessions of the common bean. In P. acutifolius, P. leptostachyus and Andean P. vulgaris, only a faint, 2.3 kb fragment was visualized in Southern experiments. Moreover, in Mesoamerican accessions, two other fragments (1.7 kb and 3.4 kb) were strongly labelled as well. Taken together, our results indicate that PvMeso is a recently emerged, repeat family initially duplicated in chromosome 11, on ancestral Mesoamerican accession, and later amplified in chromosome 7, after the split of the two major gene pools of the common bean.