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In this article, the author presents the evolution in the European Union of different borrowing models going through a path which starts out with a purely national model, passes through stages of h...

We proposed previously that aqueous non-covalent barriers arise from solute-induced perturbation of the H-bond network of solvating water (“the solvation field”) relative to bulk solvent, where the association barrier equates to enthalpic losses incurred from incomplete replacement of the H-bonds of expelled H-bond enriched solvation by inter-partner H-bonds, and the dissociation barrier equates to enthalpic + entropic losses incurred during dissociation-induced resolvation of H-bond depleted positions of the free partners (where dynamic occupancy is powered largely by the expulsion of such solvation to bulk solvent during association). We went on to analyze blockade of the human ether-a-go-go-related gene potassium channel (hERG) based on these principles, the results of which suggest that blockers: 1) project a single rod-shaped R-group (denoted as “BP”) into the pore at a rate proportional to the desolvation cost of BP, with the largely solvated remainder (denoted as “BC”) occupying the cytoplasmic “antechamber” of hERG; and 2) undergo second-order entry to the antechamber, followed byfirst-orderassociation of BP to the pore. In this work, we used WATMD to qualitatively survey the solvation fields of the pore and a representative set of 16 blockers sampled from the Redfern dataset of marketed drugs spanning a range of pro-arrhythmicity. We show that the highly non-polarporeis solvated principally by H-bond depleted and bulk-like water (incurring zero desolvation cost), whereasblocker BP moietiesare solvated by variable combinations of H-bond enriched and depleted water. With a few explainable exceptions, theblockersolvation fields (and implied desolvation/resolvation costs) are qualitatively well-correlated with both blocker potency and Redfern safety classification.

The golden chests bearing the emblem of the Macedonian Royal family contained in two marble sarcophagi found in 1977 in the main chamber and antechamber of the unlooted Royal Tomb II at Aegae, Greece, contained the remains of two individuals, a man and a woman. The man in the main chamber has been identified as King Philip II of Macedon, father of Alexander the Great. A pair of unequal gilded greaves, the left one shorter by 2.6 cm and narrower by 3.5 cm compared to the right one, an indication of the lameness of their owner, was found in the antechamber. There is not enough evidence that they belong to the woman buried and the possibility they are part of the ceremonial armor found in the main chamber cannot be excluded. The woman’s age remains disputed, following criticism of the method used in estimating it. Whether she is King Philip’s seventh wife/concubine, daughter of Scythian king Atheas, or Cleopatra, King Philip’s wife, remains still open to discussion and any uncertainties need to be further explored.

Newer generation circular light sources shall radiate at even higher brightness, requiring a reduction of their emittance. Furthermore, high-energy photons are needed for research in materials science, biology, and chemistry. These requirements can be met by using superconducting longitudinal gradient bend magnets, foreseen for the upgrade of the Swiss light source. The design of this kind of magnets is challenging due to the need of a quasi-hyperbolic field profile with a peak around 6 T and providing a warm bore with an antechamber to extract synchrotron radiation. In this paper, we present an overview of the simulations of the electro-thermo-mechanical magnet behavior in operation and during a quench using multiphysics FEM tools.

Background: Health care systems in the United States are continuously expanding and contracting spaces to treat patients with coronavirus disease 2019 (COVID-19) in intensive care units (ICUs). As a result, hospitals must effectively decontaminate and contain severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in constructed and deconstructed ICUs that care for patients with COVID-19. We assessed decontamination of a COVID-19 ICU and examined the containment efficacy of combined contact and droplet precautions in creating and maintaining a SARS-CoV-2–negative ICU “antechamber”. Methods: To examine the efficacy of chemical decontamination, we used high-density, semi-quantitative environmental sampling to detect SARS-CoV-2 on surfaces in a COVID-19 ICU and COVID-19 ICU antechamber. Quantitative real-time polymerase chain reaction was used to measure viral RNA on surfaces. Viral location mapping revealed the distribution of viral RNA in the COVID-19 ICU and COVID-19 ICU antechamber. Results were further assessed using loop-mediated isothermal amplification. Results: We collected 224 surface samples pre-decontamination and 193 samples post-decontamination from a COVID-19 ICU and adjoining COVID-19 ICU antechamber. We found that 46% of antechamber objects were positive for SARS-CoV-2 pre-decontamination despite the construction of a swinging door barrier system, implementation of contact precautions, and installation of high-efficiency particulate air filters. The object positivity rate reduced to 32.1% and viral particle rate reduced by 95.4% following decontamination. Matched items had an average of 432.2 ± 2729 viral copies/cm2 pre-decontamination and 19.2 ± 118 viral copies/cm2 post-decontamination, demonstrating significantly reduced viral surface distribution (p &lt, 0.0001). Conclusions: Environmental sampling is an effective method for evaluating decontamination protocols and validating measures used to contain SARS-CoV-2 viral particles. While chemical decontamination effectively removes detectable viral RNA from surfaces, our approach to droplet/contact containment with an antechamber was not highly effective. These data suggest that hospitals should plan for the potential of aerosolized virions when creating strategies to contain SARS-CoV-2.

Background: The COVID-19 pandemic has revealed deficiencies in the adequacy of personal protective equipment (PPE) forhealth care workers. Endoscopic endonasal skull base surgery (ESBS) is thought to be among the highest risk aerosol-generating procedures (AGPs) for surgeons and operating room personnel. Objective: To validate the efficacy and clinical feasibility of a novel surgical device. Methods: A low-cost, modifiable, and easily producible negative pressure, face-mounted antechamber was developedutilizing 3D printing and silicone molding. Efficacy was evaluated using an optical particle sizer (OPS) to quantify aerosolsgenerated during both cadaver and intraoperative human use with high-speed drilling. Results: Particle counts in the cadaver showed that drilling led to a 2.49-fold increase in particles ≤5 μm ( p = 0.001), andthat the chamber was effective at reducing particles to levels not significantly different than baseline. In humans, drillingled to a 37-fold increase in in particles ≤5 μm ( p < 0.001), and the chamber was effective at reducing particles to a level notsignificantly different than baseline. Use of the antechamber in 6 complex cases did not interfere with the ability to performsurgery. Patients did not report any facial discomfort after surgery related to antechamber use. Conclusions: The use of a negative pressure facial antechamber can effectively reduce aerosolization from endoscopicdrilling without disturbing the flow of the operation. The antechamber, in conjunction with appropriate PPE, will be usefulduring the COVID-19 pandemic, as well as during flu season and any future viral outbreaks.

OBJECTIVE The authors developed a negative-pressure, patient face-mounted antechamber and tested its efficacy as a tool for sequestering aerated particles and improving the safety of endonasal surgical procedures. METHODS Antechamber prototyping was performed with 3D printing and silicone-elastomer molding. The lowest vacuum settings needed to meet specifications for class I biosafety cabinets (flow rate ≥ 0.38 m/sec) were determined using an anemometer. A cross-validation approach with two different techniques, optical particle sizing and high-speed videography/shadowgraphy, was used to identify the minimum pressures required to sequester aerosolized materials. At the minimum vacuum settings identified, physical parameters were quantified, including flow rate, antechamber pressure, and time to clearance. RESULTS The minimum tube pressures needed to meet specifications for class I biosafety cabinets were −1.0 and −14.5 mm Hg for the surgical chambers with (“closed face”) and without (“open face”) the silicone diaphragm covering the operative port, respectively. Optical particle sizing did not detect aerosol generation from surgical drilling at these vacuum settings; however, videography estimated higher thresholds required to contain aerosols, at −6 and −35 mm Hg. Simulation of surgical movement disrupted aerosol containment visualized by shadowgraphy in the open-faced but not the closed-faced version of the mask; however, the closed-face version of the mask required increased negative pressure (−15 mm Hg) to contain aerosols during surgical simulation. CONCLUSIONS Portable, negative-pressure surgical compartments can contain aerosols from surgical drilling with pressures attainable by standard hospital and clinic vacuums. Future studies are needed to carefully consider the reliability of different techniques for detecting aerosols.

La domus de la rue Saint-Symphorien à Reims (Marne), fouillée en 2006 par l’Inrap, a livré plusieurs lots de peintures, dont les principaux posent notamment la question du décor de deux pièces contiguës. Les peintures, en place sur les murs ou effondrées au sol, laissent penser que la grande salle de réception ainsi qu’une plus petite étaient ornées d’un même décor, à fond noir et rouge audessus d’une haute plinthe rose mouchetée. Mêlé à ces fragments, un ensemble à fond blanc, agrémenté de bandes de rouge cinabre et d’imagines clipeatae de belle facture, vestige d’un état antérieur, semble avoir orné un des murs de la petite salle, en coexistence avec le décor polychrome. The domus in rue Saint-Symphorien in Reims (Marne), which was excavated in 2006 by the Institut national de recherches archéologiques preventives (Inrap), was found to contain sets of paintings, the most important of which raised the question of the decoration in two adjacent rooms. The paintings, which were either still in situ on the walls or in pieces on the ground, suggest that the large and smaller reception room were decorated with the same decor, that is to say, a black and red ground above a high, flecked pink socle. Coexisting with this polychrome decoration and mixed with these fragments, it seems that one of the walls in the smaller room featured a series of elements on a white ground, embellished with beautifully created imagines clipeatae and bands in cinnabar red, the vestiges of an earlier period. Die 2006 vom Inrap ausgegrabene domus der Rue Saint-Symphorien in Reims (Marne) hat mehrere Ensembles von Wandmalereien geliefert. Die Hauptwerke stellen insbesondere die Frage nach dem Dekor aus zwei aneinander grenzenden Räumen. Die noch an den Wänden haftenden oder am Boden liegenden Malereien legen nahe, dass das gleiche Dekor sowohl den großen Empfangsaal als auch einen kleineren Nebenraum schmückte : schwarz-und rotgrundige Felder über einer hohen rosa gesprenkelten Sockelzone. Unter den Fragmenten befand sich ein zu einer älteren Phase gehöriges Ensemble, dessen Dekor auf weißem Grund mit zinnoberroten Streifen und qualitätvollen imagines clipeatae gemeinsam mit dem polychromen Dekor eine der Wände des kleinen Raumes geschmückt zu haben scheint.

International audience; The future Europa Clipper NASA mission to Europa will carry the MAss Spectrometer for Planetary EXploration (MASPEX), which will analyze the compounds making up Europa's exosphere, and plumes, if present. Europa's exosphere is likely to feature abundant atomic oxygen, a product of sputtering of Europa's surface by energetic particles from Jupiter's radiation belts, or photolysis of oxygen-bearing molecules in the exosphere. Due to its very high reactivity, this atomic oxygen could induce chemical processes within MASPEX. These processes could involve materials composing the instrument, or other compounds from Europa's exosphere. In both cases, the possible effect on the instrument's measurements is a concern. In this work we first review previous relevant experiments on the effect of atomic oxygen on several candidate metals and conclude that stainless steel with a gold coating is the most satisfactory choice for MASPEX's antechamber walls, and alumina for the impact plate. We then perform simulations of adsorption/desorption processes within the instrument's antechamber to bound the effect of atomic oxygen on other compounds from Europa's exosphere. We find that the accumulation of atomic oxygen during a flyby would lead to a reduction of the apparent abundance of water by as much as 0.125% (Δ[H2O]/[H2O] = -1.25 × 10-3). Evaluating the exact extent of this effect during data post-processing would require constraining the atomic oxygen abundance, which would have to be achieved with other instruments, such as the ultraviolet spectrometer.

First published online: 30 March 2019 This article examines the ‘integration discourse’ that characterises migrants’ governance in the Centre for the Temporary Stay of Immigrants (CETI) in the Spanish enclave of Melilla. Beyond observing the incongruous character of the integration discourse, the article unpacks the ways in which this framing fulfils a specific function within the broader setup of migration control and the gendered modalities of migrant governance on a daily basis. The article argues that life in the CETI presents the fundamental characteristics of an existence inscribed within a total institution, implying the use of discipline as a technology of power and a structure of relations based on deference, in the specific guise of residents’ condition as ‘subjects to be integrated’. Furthermore, the article identifies three forms of dispossession – material, role and time-related – carried out against the background of a fictional integration, each bringing its share of gendered implications. This article draws on fieldwork conducted in Melilla over three months, with regular visits to the CETI that entailed participant observation inside the Centre as well as semi-structured interviews with migrant women on the one hand, and social, healthcare, and administrative workers on the other.

The first (Phase-1) commissioning of SuperKEKB—an electron-positron collider with asymmetric energies located at KEK, in Tsukuba, Japan—started in February 2016, after more than five years of upgrading work on KEKB, and successfully ended in June of the same year. This paper describes one major task of Phase-1 commissioning: beam scrubbing the surface of the beam pipes, to prepare them for a sufficiently long beam lifetime and low background noise in the next commissioning, when a new particle detector will be installed. The pressure rises per unit beam current ( dP / dI [Pa A −1 ]) were continuously monitored, and the coefficient of photon-stimulated desorption (PSD), η [molecules photon −1 ], was evaluated in the arc sections. The value of η decreased steadily with the beam dose, as expected. For arc sections in the positron ring, where most of the beam pipes were newly fabricated, the decrease in η against the photon dose ( D ) was similar to that previously reported; that is: η ∝ D −0.5 ∼ 0.8 . At high storage beam currents, the evolution of η was affected by gas desorption resulting from the multipacting of electrons—that is, the electron cloud effect (ECE), which is a phenomenon particular to high-intensity positron rings. For the arc sections in the electron ring, η also decreased smoothly with the photon dose D , approximately as ∝ D −0.8 . Given that most of these beam pipes were reused from KEKB, the value of η was much lower than that of the positron ring, and also lower than that of the electron ring of KEKB from the early stages of D . This implies that the surface of the reused beam pipes remembered the conditions in the KEKB, which is a known memory effect. The results obtained for η are compared with those obtained in various other accelerators.

In this article itisconcidereddiscusses current flow forebays and the conditions for its entry into the water inlet chamber at different numerical combinations of pumping units. The results of laboratory tests on model water inlet pumping station installations to determine the pressure loss coefficients and hydraulic resistances and optimum operating conditions.

The General AMBER Force Field (GAFF) has been broadly used by researchers all over the world to perform in silico simulations and modelings on diverse scientific topics, especially in the field of computer-aided drug design whose primary task is to accurately predict the affinity and selectivity of receptor–ligand binding. The atomic partial charges in GAFF and the second generation of GAFF (GAFF2) were originally developed with the quantum mechanics derived restrained electrostatic potential charge, but in practice, users usually adopt an efficient charge method, Austin Model 1-bond charge corrections (AM1-BCC), based on which, without expensive ab initio calculations, the atomic charges could be efficiently and conveniently obtained with the ANTECHAMBER module implemented in the AMBER software package. In this work, we developed a new set of BCC parameters specifically for GAFF2 using 442 neutral organic solutes covering diverse functional groups in aqueous solution. Compared to the original BCC parameter set, the new parameter set significantly reduced the mean unsigned error (MUE) of hydration free energies from 1.03 kcal/mol to 0.37 kcal/mol. More excitingly, this new AM1-BCC model also showed excellent performance in the solvation free energy (SFE) calculation on diverse solutes in various organic solvents across a range of different dielectric constants. In this large-scale test with totally 895 neutral organic solvent–solute systems, the new parameter set led to accurate SFE predictions with the MUE and the root-mean-square-error of 0.51 kcal/mol and 0.65 kcal/mol, respectively. This newly developed charge model, ABCG2, paved a promising path for the next generation GAFF development.

The exploration of new materials, novel quantum phases, and devices requires ways to prepare cleaner samples with smaller feature sizes. Initially, this meant the use of a cleanroom that limits the amount and size of dust particles. However, many materials are highly sensitive to oxygen and water in the air. Furthermore, the ever-increasing demand for a quantum workforce, trained and able to use the equipment for creating and characterizing materials, calls for a dramatic reduction in the cost to create and operate such facilities. To this end, we present our cleanroom-in-a-glovebox, a system that allows for the fabrication and characterization of devices in an inert argon atmosphere. We demonstrate the ability to perform a wide range of characterization as well as fabrication steps, without the need for a dedicated room, all in an argon environment. Finally, we discuss the custom-built antechamber attached to the back of the glovebox. This antechamber allows the glovebox to interface with ultra-high vacuum equipment such as molecular-beam epitaxy and scanning tunneling microscopy.

The current study describes the vacuum system of ILSF storage ring. The design uses the stainless steel vacuum chambers with a continuing keyhole profile all around the storage ring. The NEG cartridge and Ion pumps which are installed in the antechamber will pump all the vacuum sectors. Using Monte-Carlo simulation proved that the machine could reach an average pressure of 1 nTorr after the commissioning phase, which could guarantee a vacuum life time of about 13 h. The general layout of the vacuum system and the construction steps for the vacuum chambers will also be elaborated on. Several discrete photon absorbers which are designed in three types will absorb all the synchrotron radiations . For the heat load study, a simulation with Synrad is performed to calculate the power distribution on the absorber surfaces. Then the result is used to calculate the stress and strain on the absorbers by Finite Element Analysis (FEA).

Публикация представляет собой первый перевод на русский язык краткой редакции учебника Яна Амоса Коменского Vestibulum («Преддверие»), созданного как введение к учебнику Janua Lnguarum («Дверь Языков») и в окончательном виде напечатанного в первом томе собрания его сочинений (Амстердам, 1657–1658). Постепенная демонстрация грамматических явлений латинского языка дается в книге как описание предметов и явлений окружающего мира, которое можно рассматривать как краткую энциклопедию, содержащую основные слова и понятия, необходимые на первом этапе обучения латыни., Статья, предваряющая перевод учебника Я.А. Коменского «Физика» (переводчик — А.И. Золотухина) посвящена выявлению троичности и многомерности в его тексте. В ней показано, как эти пансофические начала в контексте метафизической традиции параллельного чтения учебника и Священного Писания формируют метод, который позволяет выстроить на едином фундаменте порядок познания вещей в материальном и духовном мире, объединить знания о Боге, природе и человеке в целостную систему., This is the first translation into Russian of shorter version of Johan Amos Comenius's textbook “Vestibulum”, which was planned as an introduction to the textbook “Janua Linguarum” (“The Door to Languages") and finally printed in the first volume of his collected works (Amsterdam, 1657–1658). A gradual demonstration of Latin grammar is given in the book on the basis of objects and phenomena of the surrounding world, which can be regarded as a brief encyclopedia containing the basic words and concepts needed in the first stage of Latin teaching., №4 (2018)

The exploration of habitable environments on or inside icy moons around the gas giants in the solar system is of major interest in upcoming planetary missions. Exactly this theme is addressed by the JUpiter ICy moons Explorer (JUICE) mission of ESA, which will characterise Ganymede, Europa and Callisto as planetary objects and potential habitats. We developed a prototype of the Neutral Gas and Ion Mass spectrometer (NIM) of the Particle Environment Package (PEP) for the JUICE mission intended for composition measurements of neutral gas and thermal plasma. NIM/PEP will be used to measure the chemical composition of the exospheres of the icy Jovian moons. Besides direct ion measurement, the NIM instrument is able to measure the inflowing neutral gas in two different modes: in neutral mode, where the gas enters directly the ion source (open source), and in thermal mode, where the gas gets thermally accommodated to the wall temperature by several collisions inside an equilibrium sphere, called antechamber, before entering the ion source (closed source). We performed measurements with the prototype NIM using a neutral gas beam of 1 up to 4.5 km s−1 velocity in the neutral and thermal mode. The current trajectory of JUICE foresees a flyby velocity of 4 km s−1 at Europa; other flybys are in the range of 1 up to 7 km s−1 and orbital velocity in Ganymede orbits is around 2 km s−1. Different species are used for the gas beam, such as noble gases Ne, Ar, Kr as well as molecules like H2, methane, ethane, propane and more complex ones. The NIM prototype was successfully tested under realistic JUICE mission conditions. In addition, we find that the antechamber (closed source) behaves as expected with predictable density enhancement over the specified mass range and within the JUICE mission phase velocities. Furthermore, with the open source and the closed source we measure almost the same composition for noble gases, as well as for molecules, indicating no additional fragmentation of the species recorded with the antechamber for the investigated parameter range.

The SuperKEKB, the upgrade of the KEKB, is an electron-positron collider with asymmetric energies, that is, 4.0 GeV positrons and 7.0 GeV electrons, aiming an unprecedentedly high luminosity of 8 × 10 35 cm −2 s −1 . The construction of the new vacuum system for SuperKEKB has been in progress since 2010, as a key item of the upgrade project. The major challenges in the vacuum system are the reduction of beam impedances of various components and the suppression of the electron cloud effects (ECE) in the positron ring, as well as the realization of ultra-high vacuum, under the high beam current. New beam pipes and bellows chambers basically have an antechamber structure. The main pump is a strip-type NEG installed in an antechamber of beam pipes. Various countermeasures against the electron cloud effect, such as coating of TiN film, grooved surfaces and so on, are prepared for the positron ring. Most of new components have been already ordered and delivered. All the new beam pipes are baked at 150 °C for one day before the installation into the tunnel. Approximately 73% of the beam pipes have been installed. The evacuation of beam pipes in the tunnel has also begun. The vacuum system will be almost completed by the end of this March.

A compact lattice and small magnet apertures will be the main characteristics of future diffraction-limited storage rings, adding difficulties for the design of the vacuum system of these machines. The use of NEG coatings and distributed absorbers could provide a solution to overcome these challenges., Some of the characteristics of recent ultralow-emittance storage-ring designs and possibly future diffraction-limited storage rings are a compact lattice combined with small magnet apertures. Such requirements present a challenge for the design and performance of the vacuum system. The vacuum system should provide the required vacuum pressure for machine operation and be able to handle the heat load from synchrotron radiation. Small magnet apertures result in the conductance of the chamber being low, and lumped pumps are ineffective. One way to provide the required vacuum level is by distributed pumping, which can be realised by the use of a non-evaporable getter (NEG) coating of the chamber walls. It may not be possible to use crotch absorbers to absorb the heat from the synchrotron radiation because an antechamber is difficult to realise with such a compact lattice. To solve this, the chamber walls can work as distributed absorbers if they are made of a material with good thermal conductivity, and distributed cooling is used at the location where the synchrotron radiation hits the wall. The vacuum system of the 3 GeV storage ring of MAX IV is used as an example of possible solutions for vacuum technologies for diffraction-limited storage rings.

Cold-cathode ionization gauges were used for rocket-borne measurements of total neutral density and temperature in the aurorally forced lower thermosphere between 90 and 200 km. A commercial gauge was adapted as a low-cost instrument with a spherical antechamber for measurements in molecular flow conditions. Three roll-stabilized payloads on different trajectories each carried two instruments for measurements near the ram flow direction along the respective upleg and downleg segments of a flight path, and six density profiles were obtained within a period of 22 min covering spatial separations up to 200 km. The density profiles were integrated below 125 km to yield temperatures. The mean temperature structure was similar for all six profiles with two mesopause minima near 110 and 101 km, however, for the downleg profiles, the upper minimum was warmer and the lower minimum was colder by 20–30 K indicating significant variability over horizontal scales of 100–200 km. The upper temperature minimum coincided with maximum horizontal winds speeds, exceeding 170 m/s.

Elevator evacuation of high-rise building fire has become an urgent problem. Based on the problems of general elevator evacuation, this paper offers some measures of smoke-proof measures, such as setting up pressure ventilation in elevator car, setting up pressure ventilation in elevator shaft, setting elevator antechamber and setting smoke preventing air curtain etc. This paper provides some practical ways of elevator evacuation on high-rise building fire.

Antechamber which composes the arc vacuum chamber of storage rings is one of the key devices of BEPCII. It has the characteristic of various specifications, large size, complex structure, and high dimension accuracy. This paper gives a review on the structure features and the procedure of production, including the mechanical machining process, cleaning and welding process of high vacuum aluminum alloy, ultrahigh vacuum test and so on. In view of the occurrence of the concave deformation, the reasons are analyzed and the correction method developed is introduced too.

Protein S-nitrosation is common in cells under nitrosative stress. In order to model proteins with S-nitrosocysteine (CysSNO) residues, we first developed an Amber force field for S-nitrosoethanethiol (EtSNO) and then transferred it to CysSNO. Partial atomic charges for EtSNO and CysSNO were obtained by a restrained electrostatic potential approach to be compatible with the Amber-99 force field. The force field parameters for bonds and angles in EtSNO were obtained from a generalized Amber force field (GAFF) by running the Antechamber module of the Amber software package. The GAFF parameters for the CC-SN and CS-NO dihedrals were not accurate and thus determined anew. The CC-SN and CS-NO torsional energy profiles of EtSNO were calculated quantum mechanically at the level of B3LYP/cc-pVTZ//HF/6-31 G * . Torsional force constants were obtained by fitting the theoretical torsional energies with those obtained from molecular mechanics energy minimization. These parameters for EtSNO reproduced, to a reasonable accuracy, the corresponding torsional energy profiles of the capped tripeptide ACE-CysSNO-NLVIE as well as their structures obtained from quantum mechanical geometry optimization. A molecular dynamics simulation of myoglobin with a CysSNO residue produced a well-behaved trajectory demonstrating that the parameters may be used in modeling other S-nitrosated proteins.

The design, fabrication and performance of a vacuum system for the BEPCII storage ring are described in this paper. The arc beam pipes and their antechambers are made by machining upper and lower chamber halves, then welding them at the periphery to form a complete chamber. The photon absorbers and the pumping stations are located in the antechambers. The special vacuum components, such as photon absorbers, RF shielding bellows, and the in-vacuum wiggler, have been manufactured according to the characteristics of the BEPCII storage ring and shown to perform well. The vacuum systems of the BEPCII storage ring have been assembled and run over a two years period, and they had accumulated 1000 A h of beam dose in the colliding mode as of the end of July 2009. On average, the dynamic pressure rise of the BEPCII storage ring is less than 3 x 10(-7) Pa/A. The effect of a cloud of photoelectrons around the positron beam was not found in the high beam current, because the beam pipe with an antechamber in the positron ring was coated by a TiN layer of about 100 nm in thickness. Ion currents of a few specially positioned ion pumps were slight high in the high beam current, which can be explained as an effect of electron multiplying. (C) 2010 Elsevier B.V. All rights reserved.

There has been continuous progress at the High Energy Accelerator Research Organization (KEK) in R&D on vacuum beam ducts adaptable to future high-current particle storage rings. Here we proposed copper beam ducts with antechambers to deal with the severe issues attributed to the high beam currents. The proposed antechamber scheme can withstand intense synchrotron radiation (SR), provide a beam duct with low beam impedance, and effectively reduce the electron cloud effect (ECE) in positron/proton rings. Several trial models were manufactured by a pressing or cold-drawn method, and assembled with electron beam welding. Special vacuum components, such as connection flanges, distributed pumps, and gate valves, were customized for the beam ducts. TiN coating on the inner surface of the beam duct was also investigated as a mitigating measure for the ECE. Trial models of the copper beam ducts were installed into the KEK B-factory (KEKB), and their performances were evaluated using real positron and electron beams.

N termini of auxiliary beta subunits that produce inactivation of large-conductance Ca(2+)-activated K(+) (BK) channels reach their pore-blocking position by first passing through side portals into an antechamber separating the BK pore module and the large C-terminal cytosolic domain. Previous work indicated that the beta2 subunit inactivation domain is protected from digestion by trypsin when bound in the inactivated conformation. Other results suggest that, even when channels are closed, an inactivation domain can also be protected from digestion by trypsin when bound within the antechamber. Here, we provide additional tests of this model and examine its applicability to other beta subunit N termini. First, we show that specific mutations in the beta2 inactivation segment can speed up digestion by trypsin under closed-channel conditions, supporting the idea that the beta2 N terminus is protected by binding within the antechamber. Second, we show that cytosolic channel blockers distinguish between protection mediated by inactivation and protection under closed-channel conditions, implicating two distinct sites of protection. Together, these results confirm the idea that beta2 N termini can occupy the BK channel antechamber by interaction at some site distinct from the BK central cavity. In contrast, the beta 3a N terminus is digested over 10-fold more quickly than the beta2 N terminus. Analysis of factors that contribute to differences in digestion rates suggests that binding of an N terminus within the antechamber constrains the trypsin accessibility of digestible basic residues, even when such residues are positioned outside the antechamber. Our analysis indicates that up to two N termini may simultaneously be protected from digestion. These results indicate that inactivation domains have sites of binding in addition to those directly involved in inactivation.

In the VUV spectrum we see a significant decrease in reflection due to organic contamination on the surface of mirrors. To study VUV mirrors it is requisite to have calibration standards. Such standards are useless as calibration tools if the surface has organic contamination. For our standard, we use a thermally oxidized silicon wafer with a 27 nm oxide overlayer. We found that silicon wafer samples capped with native oxide acquire 0.1 to 0.2 nm of organic contamination within two hours of being cleaned with stored in closed, but nonvacuum, conditions. After a week there is an additional 0.2 to 0.5 nm deposition after which no further significant deposition is measured up to 90 days. We place the samples in air within one cm of a xenon excimer lamp that radiates 7.2 eV photons which remove half of the remaining contamination every minute. Five minutes exposure is sufficient to clean both fresh and stored samples. Data are determined using spectroscopic ellipsometry (SE) and X-ray photoelectron spectroscopy (XPS). Additionally this paper addresses the need to ensure that these characterization tools are not a source of organic contamination. We determined that the antechamber of our XPS was contaminating samples at a rate of 0.6 nm/30 min as they waited for transfer to the analysis chamber. This contamination was virtually eliminated by attaching an oxygen radical source (ORS) device (Evactron® C De-Contaminator RF Plasma Cleaning System) directly to the antechamber.

ALBA will be a third generation synchrotron light facility to be built near Barcelona (Spain). The design phase of ALBA is almost completed and the first components are ready to be ordered. Commissioning of the storage ring is foreseen to start at the end of 2008. The circumference of the storage ring of ALBA is 268.8 m and it will be divided into 16 vacuum sections by ultra high vacuum (UHV) gate valves. The vacuum chamber will be made of stainless steel with vertical aperture of 28 mm and 72 mm width. The vacuum chamber will be connected to an antechamber with a slot of 10 mm height. The antechamber will have the crotch absorbers which will absorb the unwanted synchrotron radiation. The pumping will be by sputter ion pumps (SIP), NEG pumps and titanium sublimation pumps (TSP), with an overall pumping speed from SIP of 57,400 l/s. This will maintain an average dynamic pressure of around 1 × 10 −9 mbar to achieve a beam lifetime >15 h at the designed current.

A tired‐looking man appears out of a corridor of scuffed linoleum and steps tentatively on to the sombre carpet of a waiting room. He has entered the antechamber to a headteacher's office. Framed m...

In order to obtain a method to suppress electron-cloud instability (ECI), the photoelectron and the secondary electron yields (PEY and SEY) of a TiN coating and an NEG (Ti–Zr–V) coating on copper have been studied so far by using the KEK B-factory (KEKB) positron ring. Recently, test chambers with these coatings were installed at a straight section of the ring where the irradiated photon density was considerably smaller than that at the arc section of a previous experiment. The number of electrons around beams was measured by an electron current monitor; this measurement was performed up to a stored beam current of approximately 1700 mA (1389 bunches). For the entire range of the beam current, the electron currents of the NEG-coated and the TiN-coated chambers were clearly smaller as compared to those of the uncoated copper chamber by the factors of 2–3 and 3–4, respectively. The small photon density, that is, the weak effect of photoelectrons, elucidated the differences in the SEYs of these coatings when compared to the measurements at the arc section. By assuming almost the same PEY (ηe) values obtained in the previous study, the maximum SEY (δmax) for the TiN and NEG coatings and the copper chamber was again estimated based on a previously developed simulation. The evaluated δmax values for these three surfaces were in the ranges of 0.8–1.0, 1.0–1.15, and 1.1–1.25, respectively. These values were consistent with the values obtained so far. As an application of the simulation, the effective ηe, ηe−eff (which included the geometrical effect of the antechamber) and δmax values were also estimated for copper chambers with one or two antechambers. These chambers were installed in an arc section and a wiggler section, respectively. The evaluated ηe−eff and δmax values were approximately 0.008 and 1.2, and 0.04 and 1.2, respectively, where ηe=0.28 was assumed on the side wall. As expected, the ηe−eff values were considerably smaller than those obtained in the case of a simple circular chamber (ηe=0.28–0.3). Further, the δmax values were consistent with those obtained so far. With regard to the uncertainty in the simulation, the effect of the SEY spectrum on the estimation of δmax values is briefly discussed. As the next step in our study, we plan to combine beam ducts with antechambers and TiN coatings; this combination is the most promising solution to ECI at present.

In order to investigate a way to suppress the electron-cloud instability (ECI), the secondary electron and photoelectron yields (SEY and PEY) of a TiN coating were studied with an intense positron beam at the KEK B-Factory (KEKB), following up our previous study on a NEG (Ti–Zr–V) coating. A TiN-coated chamber was installed at an arc section of the KEKB positron ring, where photons with a line density of 6.5×1014 photons m−1 s−1 mA−1 were directly irradiated. The number of electrons around the positron bunches was measured by a special electron-current monitor, up to a stored beam current of about 1700 mA (1284 bunches). The electron current of the TiN-coated chamber was clearly smaller than those of the NEG-coated and the non-coated copper chambers by a factor of 2 for all beam currents. Using the previous results of the NEG-coated and the non-coated copper chambers as well as the TiN-coated one here, the maximum SEY (δmax) and the PEY (ηe) of the TiN coating, the NEG coating and the copper were again estimated based on a simulation. The evaluated δmax values for these three surfaces were 0.8–1.0, 0.9–1.1 and 1.1–1.3, and the ηe values were 0.13–0.15, 0.22–0.27 and 0.28–0.31, respectively. It was found that the TiN coating had an SEY (δmax∼0.9) as low as the NEG coating (δmax∼1.0), but the electron current was clearly smaller than that of the NEG coating, due to its lower photoelectron yield (ηe∼0.14). This study again indicated that the suppression of photoelectrons is required to make effective use of a surface with a low SEY, such as a TiN or a NEG coating. As an application of the simulation code, the electron current of a beam duct with an antechamber was calculated for the case of a NEG coating or a TiN coating ( δ max = 0.9 – 1.0 ). The calculated electron current for a copper duct with an antechamber was about 1/4 of that of a simple circular copper duct ( δ max = 1.2 for both cases) at a high current (∼1700 mA, 1284 bunches), which was in good agreement with the measurement. By combining with a surface with a low SEY ( δ max = 1.0 – 0.9 ), that is, a TiN coating or a NEG coating, a further reduction of the electron current by a factor of about 2 was obtained.

A beam duct coated with NEG materials (Ti, Zr, V), which had been known to have a low secondary electron yield (SEY), was studied for the first time under intense photon irradiation using a positron beam at the KEK B-Factory (KEKB) to investigate a way to suppress the electron cloud instability (ECI). A 2.56 m test copper chamber was coated with the NEG materials (we call it NEG coating here) by magnetron sputtering. It was installed at an arc section of the KEKB positron ring, where the chamber was irradiated by direct photons with a line density of 6.5×10 14 photons m −1 s −1 mA −1 . The vacuum pressure around the test chamber during a usual beam operation was lower than the case of non-coated copper chambers by a factor of 4–5. The number of electrons around positron bunches was measured by a special electron monitor up to a stored beam current of 1600 mA. The measured electron current, however, was almost the same as a non-coated copper chamber, especially at low-beam currents, and the effect of the NEG coating was smaller than expected. A simulation explained the result that abundant photoelectrons in the positron ring reduce the effect of the low SEY. The maximum SEYs of the NEG coating and non-coated copper were evaluated using a simulation as about 0.9–1.0 and 1.1–1.3, respectively, which were consistent with the values after a sufficient electron bombardment. Their photoelectron yields were also estimated as 0.22–0.28 and 0.26–0.34, respectively, and were in good agreement with the previous experimental results. The study indicates that the suppression of photoelectrons, by a beam duct with an antechamber, for example, is indispensable to make effective use of a surface with a low SEY, such as the NEG coating.