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Currently, light-based three-dimensional (3D) printing with submicron features is mainly developed based on photosensitive polymers or inorganic-polymer composite materials. To eliminate polymer/organic additives, a strategy for direct 3D assembly and printing of metallic nanocrystals without additives is presented. Ultrafast laser with intensity in the range of 1 × 1010 to 1 × 1012 W/cm2 is used to nonequilibrium heat nanocrystals and induce ligand transformation, which triggers the spontaneous fusion and localized assembly of nanocrystals. The process is due to the operation of hot electrons as confirmed by a strong dependence of the printing rate on laser pulse duration varied in the range of electron-phonon relaxation time. Using the developed laser-induced ligand transformation (LILT) process, direct printing of 3D metallic structures at micro and submicron scales is demonstrated. Facile integration with other microscale additive manufacturing for printing 3D devices containing multiscale features is also demonstrated.

The carrier excitation, relaxation, energy transport, and conversion processes during light-nanocrystal (NC) interactions have been intensively investigated for applications in optoelectronics, photocatalysis, and photovoltaics. However, there are limited studies on the non-equilibrium heating under relatively high laser excitation that leads to NCs sintering. Here, the authors use femtosecond laser two-pulse correlation and in-situ optical transmission probing to investigate the non-equilibrium heating of NCs and transient sintering dynamics. First, a two-pulse correlation study reveals that the sintering rate strongly increases when the two heating laser pulses are temporally separated by

Er3+/Yb3+ co-doped fluorotellurite glasses were prepared. Intense green and red upconversion (UC) emissions corresponding to the transitions of 2H11/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 were observed under 980 nm laser excitation, benefiting from the advantages of low phonon energy and good stability of fluorotellurite glasses. Temperature-dependent UC luminescence was carried on glasses with different doping concentration of Er3+ in the range of 298–568 K. Fluorescence intensity ratios (FIR) and absolute sensitivities (Sa) were calculated, and the maximal sensitivity value of 54.09 × 10−4 K−1 was obtained at 531 K in the glass with the lowest Er3+ concentration at 0.1 mol%. This study indicates that Er3+/Yb3+ co-doped fluorotellurite glasses can be promising materials applied to non-touching temperature sensors.

The occupy of Eu3+ ions in the crystal lattice of NZPO:Eu3+ ions are studied by theoretical calculation and experimental. The electric structure and density of states of NZPO and NZPO:Eu3+ were comparatively studied by the first-principles, which indicated that the band gap of NZPO decreased after doping Eu3+ ions. The XRD patterns and PL spectra of NZ1-xPO:xEu3+ or N1-yZPO:yEu3+ phosphorare measured in the sake of prove the occupy of Eu3+ ions. The optimal sintering temperature are confirmed by the PL spectra and XRD patterns of a series NZPO:0.04Eu3+ phosphors prepared at different temperature.The effect of the charge compensator and different matrix component on the emission intensity of the phosphors was investigated. Moderate Na+ ions substitute for Zn2+ ions will enhance the emission intensity.The thermal quenching measurement revealed that NZPO:Eu3+ phosphor had better thermal stability. The results indicated that this phosphor can be used as a red supply light material for UV or blue based white LED.

The superconducting ECR source magnet for the Facility for Rare Isotope Beams at Michigan State University was designed and built by the Superconducting Magnet Group at Lawrence Berkeley National Laboratory (LBNL). The 28-GHz NbTi ion source magnet features a sextupole-in-solenoids configuration, which is comparable to the VENUS ECR magnet operated at LBNL. A shell-based support structure using bladders and keys has been incorporated into the design to allow for adjustments of the preload and reversibility of the magnet assembly process. The magnet has been assembled and successfully tested to operational currents at LBNL. This paper describes the basic design of the magnet and the passive quench protection system. The test results are also presented, including the quench behavior of the magnet, the training performance, and the magnetic measurement results.

The High Luminosity (HiLumi) Large Hadron Collider (LHC) project has, as the main objective, to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new interaction region layout, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the interaction points by a factor of two, which requires doubling the aperture of the low-β (or inner triplet) quadrupole magnets. The use of Nb3Sn superconducting material and, as a result, the possibility of operating at magnetic field levels in the windings higher than 11 T will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the U.S. LHC Accelerator Research Program and the Conseil Europeen pour la Recherche Nucleaire (CERN), has now entered the construction and test phase of the short models. Concurrently, the preparation for the development of the full-length prototypes has been initiated. This paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.

Motivation A series of Eu2+ (0.0025≤ × ≤0.025) activated Sr2SiO4:xEu2+ (SSO:xEu2+) phosphors were synthesized via a sol-gel method. The phosphors were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. The differences between α’ and β phase of SSO in the density of states and energy band gap were investigated. Results The energy gap of α’-SSO and β-SSO are 4.489 and 4.106 eV, respectively. While, two samples showed similar total and partial densities of states. Under the excitation by the ultra violet (UV) light (365 nm), the SSO:xEu2+ phosphor exhibited a green emission band from 400 to 700 nm, which was corresponding to the transition of 5 d → 4 f of Eu2+ ions. Two emission peaks at 464 and 532 nm could be obtained through Gauss fitting curves. The ratio of the blue to green emission peak decreased with the Eu2+ concentration and the peaks shifted regularly with it. The thermal quenching property was investigated and its activation energy was calculated. The results indicated that this phosphor could be a candidate of green phosphor for UV-based light-emitting diodes (LEDs).

A novel bifunctional catalyst, [PYD]@Cu–Pd composite, was synthesized for the first time and used as a cathode for electrochemical reduction of CO2. Methanol with 26% and ethanol with 12% Faradaic efficiency were obtained at the same [PYD]@Cu–Pd cathode using different potentials. Under both conditions, the [PYD]@Cu–Pd cathode shows remarkable stability and reusability.

Manipulating and tuning nanoparticles by means of optical field interactions is of key interest for nanoscience and applications in electronics and photonics. We report scalable, direct, and optically modulated writing of nanoparticle patterns (size, number, and location) of high precision using a pulsed nanosecond laser. The complex nanoparticle arrangement is modulated by the laser pulse energy and polarization with the particle size ranging from 60 to 330 nm. Furthermore, we report fast cooling-rate induced phase switching of crystalline Si nanoparticles to the amorphous state. Such phase switching has usually been observed in compound phase change materials like GeSbTe. The ensuing modification of atomic structure leads to dielectric constant switching. Based on these effects, a multiscale laser-assisted method of fabricating Mie resonator arrays is proposed. The number of Mie resonators, as well as the resonance peaks and dielectric constants of selected resonators, can be programmed. The programmable light-matter interaction serves as a mechanism to fabricate optical metasurfaces, structural color, and multidimensional optical storage devices.

Copper nanoparticles were prepared in an aqueous solution, compacted into a coin, and used as a cathode for asymmetric hydrogenation by the electrochemical method for the first time. A good ee value and excellent yield were obtained under mild conditions. Electrochemical conditions were crucial for alkaloid adsorption on metallic Cu, which is a key process of asymmetric induction. Furthermore, the ee value was linear with an adsorption amount. Keywords: Copper nanoparticles, Asymmetric hydrogenation, Electrochemical conditions, Alkaloids, Adsorption

Background Gross deformity of the foot in Charcot neuroarthropathy can lead to foot collapse and subsequent ulceration, infection, amputation, or premature death. Total-contact casting (TCC) is a well-established treatment for neuropathic diabetic plantar foot ulcers. It was hypothesized that arthrodesis plus TCC may have advantages over TCC alone. This pilot study compared the effectiveness of arthrodesis plus TCC with TCC alone for the prevention, treatment, and recurrence of midfoot ulcerations associated with Charcot neuroarthropathy. Material/Methods Twenty-one subjects with plantar ulcers associated with unilateral diabetic Charcot midfoot neuroarthropathy were randomly assigned to ADS or TCC groups. The ADS group underwent an extended medial column arthrodesis procedure and TCC; ulcers were sutured directly. The TCC group underwent TCC alone with dressing changes. All patients underwent nerve conduction studies and quantitative sensory testing at baseline and during follow-up (6 and 12 months). Healing time and ulcer relapse rate were evaluated. Result Compared with the TCC group, there were fewer lesions in the ADS group after treatment (P0.05). There was no ulcer recurrence after 12 months in the ADS group compared with 33.3% in the TCC group. Conclusions An extended medial column arthrodesis may partly improve sensory impairments and restore protective sensation in patients with Charcot neuroarthropathy.

A highly stable and reusable Cu NP cathode was prepared by a simple method and used for the electrosynthesis of cyclic carbonates by electroreduction of CO2 in the presence of epoxides under mild conditions. No added metal catalyst is required and the yields vary from moderate to very good. Furthermore, the activity of the cathode was shown to depend on the size of the Cu NPs.

Laser processing (sintering, melting, crystallization and ablation) of nanoscale materials has been extensively employed for electronics manufacturing including both integrated circuit and emerging printable electronics. Many applications in semiconductor devices require annealing step to fabricate high quality crystalline domains on substrates that may not intrinsically promote the growth of high crystalline films. The recent emergence of FinFETs (Fin-shaped Field Effect Transistor) and 3D Integrated Circuits (3D-IC) has inspired the study of crystallization of amorphous materials in nano/micro confined domains. Using Molecular Dynamics (MD) simulation, we study the characteristics of unseeded crystallization within nano/microscale confining domains. Firstly, it is demonstrated that unseeded crystallization can yield single crystal domains facilitated by the confinement effects. A phenomenological model has been developed and tailored by MD simulations, which was applied to quantitatively evaluate the effects of domain size and processing laser pulse width on single crystal formation. Secondly, to predict crystallization behaviors on confining walls, a thermodynamics integration scheme will be used to calculate interfacial energies of Si-SiO2 interfaces.

International audience; Mechanical Design Studies of the MQXF Long Model Quadrupole for the HiLumi LHC 520__ $The Large Hadron Collider Luminosity upgrade(HiLumi) program requires new low-β triplet quadrupole magnets, called MQXF, in the Interaction Region (IR) to increase the LHC peak and integrated luminosity. The MQXF magnets, designed and fabricated in collaboration between CERN and the U.S. LARP, will all have the same cross section. The MQXF long model, referred as MQXFA, is a quadrupole using the Nb3Sn superconducting technology with 150 mm aperture and a 4.2 m magnetic length and is the first long prototype of the final MQXF design. The MQXFA magnet is based on the previous LARP HQ and MQXFS designs. In this paper we present the baseline design of the MQXFA structure with detailed 3D numerical analysis. A detailed tolerance analysis of the baseline case has been performed by using a 3D finite element model, which allows fast computation of structures modeled with actual tolerances. Tolerance sensitivity of each component is discussed to verify the actual tolera nces to be achieved by vendors. Tolerance stack-up analysis is presented in the end of this paper.

This paper presents an ultrathin stretchable device capable of soft lamination onto the skin with a releasable film for wireless measurement of biophysiological signal on skin. The device contains metallic electrodes and graphite strips, and can be attached to multiple skin locations in a conformal manner. Experimental results demonstrate that the device offers ease of skin releasing with reliable biopotential and strain measurement capability. This device when combined with other sensing mechanisms can yield a comprehensive sleep evaluation system capable of revealing influencing factors that are specific to a person, allowing highly individualized treatment plans for patients with sleep disorders.

Direct writing using single or multiple energized beams (e.g. laser, ion or electron beams) provides high feature resolution (

Currently, bioresorbable electronic devices are predominantly fabricated by complex and expensive vacuum-based integrated circuit (IC) processes. Here, a low-cost manufacturing approach for bioresorbable conductors on bioresorbable polymer substrates by evaporation-condensation-mediated laser printing and sintering of Zn nanoparticle is reported. Laser sintering of Zn nanoparticles has been technically difficult due to the surface oxide on nanoparticles. To circumvent the surface oxide, a novel approach is discovered to print and sinter Zn nanoparticle facilitated by evaporation-condensation in confined domains. The printing process can be performed on low-temperature substrates in ambient environment allowing easy integration on a roll-to-roll platform for economical manufacturing of bioresorbable electronics. The fabricated Zn conductors show excellent electrical conductivity (≈1.124 × 106 S m-1 ), mechanical durability, and water dissolvability. Successful demonstration of strain gauges confirms the potential application in various environmentally friendly sensors and circuits.

A solid understanding and accurate analysis of the voltage transients in the quench process of superconducting magnets is the basis for verifying quench protection system design. This paper presents an analysis of the voltage spike that triggered a quench in a serially connected set of superconducting solenoid magnets, which are protected by a stack of cold diodes and dump resistors. The voltage development associated with the normal zone growth is analyzed. The magnets were trained close to the full design current and all the terminal voltages of the coils were captured by a specialized quench detection system. In the analyses described in this paper, the different stages of the voltage transient development will be detailed. Comparisons of simulations and the training results are provided to substantiate the mechanism of the quench voltage behavior in this passive protection scheme.

In this paper, the one-step synthesis of enantiomerically pure cyclic carbonates has been developed by electrolyzing the chiral epoxides and CO2 (0.1 MPa, rt) in an undivided cell with a 316 stainless steel (SS) cathode and a Mg sacrificial anode containing TEAI–MeCN as supporting electrolyte and solvent with a constant current. To deeply understand this reaction, the effects of various synthesis conditions were investigated using R-styrene oxide as the model compound. Under the optimized conditions, the maximum conversion is 67% with 96% selectivity and 98.8% ee value for R-styrene carbonate. Finally, the reaction mechanism has been proposed by comparative electrolysis and DFT calculation. Keywords: Electrosynthesis, Cyclic carbonates, CO2, Chiral epoxides

A novel NaZnPO 4 :Eu 3+ (NZPO:Eu 3+ ) phosphors were successfully synthesized via solid state reactions for the first time. The XRD analysis confirms that single orthorhombic phase of NZPO was obtained at 850 °C for 4 h. In NZPO:Eu 3+ phosphor, the 7 F 0 → 5 L 6 transitions resulted in the strongest near UV excitation centered at 395 nm and this phosphor shows strong magnetic-dipole transition dominant red emission at 595 nm. The decay lifetime and the CIE coordinate were investigated, respectively. The results suggest that NZPO:Eu 3+ red-emitting phosphor was a potential candidate for UV based white LEDs applications.

The feasibility of the enantioselective electroreduction of pro-chiral acetophenone was investigated at the silver cathode in an undivided cell for the first time. Electroreduction of acetophenone in the presence of cinchonidine (CD) yielded two main products: the optically active alcohol, and the dimer product pinacol with no optical rotation. The influence of water in the co-solvent (MeCN/H 2 O), supporting electrolyte, electrode material, current density, and the alkaloid type on the enantiomeric excesses (ee) and yield was investigated. Under the optimized conditions, the alcohol was obtained with a 21.6% ee and a 3.6% yield, whereas, an 83.2% yield and a 5.5 dl/meso ratio were obtained for pinacol. The electrochemical behavior of the samples was also studied through cyclic voltammetry (CV). Finally, we proposed a possible induction mechanism based on the results of the electrolysis and CV.

The US LHC Accelerator Research Program (LARP) has been developing $Nb_3Sn$ quadrupoles of progressively increasing performance for the high luminosity upgrade of the Large Hadron Collider. The 120 mm aperture High-field Quadrupole (HQ) models are the last step in the R&D; phase supporting the development of the new IR Quadrupoles (MQXF). Three series of HQ coils were fabricated and assembled in a shell-based support structure, progressively optimizing the design and fabrication process. The final set of coils consistently applied the optimized design solutions, and was assembled in the HQ03a model. This paper reports a summary of the HQ03a test results, including training, mechanical performance, field quality and quench studies. The U.S. LHC Accelerator Research Program (LARP) has been developing Nb_3Sn quadrupoles of increasing performance for the high-luminosity upgrade of the large hadron collider. The 120-mm aperture high-field quadrupole (HQ) models are the last step in the R&D; phase supporting the development of the new IR Quadrupoles (MQXF). Three series of HQ coils were fabricated and assembled in a shell-based support structure, progressively optimizing the design and fabrication process. The final set of coils consistently applied the optimized design solutions and was assembled in the HQ03a model. This paper reports a summary of the HQ03a test results, including training, mechanical performance, field quality, and quench studies.

© 2015 IEEE. In preparation for the high-luminosity upgrade of the Large Hadron Collider (LHC), the LHC Accelerator Research Program (LARP) in collaboration with CERN is pursuing the development of MQXF: a 150-mm-aperture high-field Nb3Sn quadrupole magnet. The development phase starts with the fabrication and test of several short models (1.2-m magnetic length) and will continue with the development of several long prototypes. All of them are mechanically supported using a shell-based support structure, which has been extensively demonstrated on several RD models within LARP. The first short model MQXFS-AT has been assembled at LBNL with coils fabricated by LARP and CERN. In this paper, we summarize the assembly process and show how it relies strongly on experience acquired during the LARP 120-mm-aperture HQ magnet series. We present comparison between strain gauges data and finite-element model analysis. Finally, we present the implication of the MQXFS-AT experience on the design of the long prototype support structure.

The maneuvering target tracking with the tracking in military and civil fields has important application value. Based on the design of single maneuvering target tracking algorithm the problem for the following research work. By preliminary analysis of the data to determine the target for frequent low-speed movement of maneuvering targets, in the actual movement model under the premise of the unknown, we adopted the "current" statistical model to describe the movement of the target, and selects the volume kalman filter (CKF) solved the problem of the nonlinear observation model. Using the algorithm of target tracking online, real-time estimate target position, velocity and acceleration, and to determine whether a filter divergence passed to real time to determine whether the target maneuvering, the goal set in radar observation period 1two mobile time (36734.4 s, 36734.4 s), and subsequent class 12 times in the process of the elliptical motion motor turning time. To estimate location in space remains relatively obvious fluctuation phenomenon, we used FFT digital filter for filtering the data obtained by real-time track filtering, finally get the target track is smooth, as an ideal track estimates, calculate radar measurements relative ideal track measurement error, the results show that the radar Angle measurement error average approximation is zero, and variance and radar performance index approximation, verify the tracking accuracy of the model.

The Laser Direct Synthesis and Patterning (LDSP) technology has advantages in terms of processing time and cost compared to nanomaterials-based laser additive microfabrication processes. In LDSP, a scanning laser on the substrate surface induces chemical reactions in the reactive liquid solution and selectively deposits target material in a preselected pattern on the substrate. In this study, we experimentally investigated the effect of the processing parameters and type and concentration of the additive solvent on the properties and growth rate of the resulting metal film fabricated by this LDSP technology. It was shown that reactive metal ion solutions with substantial viscosity yield metal films with superior physical properties. A numerical analysis was also carried out the first time to investigate the coupled opto-thermo-fluidic transport phenomena and the effects on the metal film growth rate. To complete the simulation, the optical properties of the LDSP deposited metal film with a variety of thicknesses were measured. The characteristics of the temperature field and the thermally induced flow associated with the moving heat source are discussed. It was shown that the processing temperature range of the LDSP is from 330 to 390 K. A semi-empirical model for estimating the metal film growth rate using this process was developed based on these results. From the experimental and numerical results, it is seen that, owing to the increased reflectivity of the silver film as its thickness increases, the growth rate decreases gradually from about 40 nm at initial to 10 nm per laser scan after ten scans. This self-controlling effect of LDSP process controls the thickness and improves the uniformity of the fabricated metal film. The growth rate and resulting thickness of the metal film can also be regulated by adjustment of the processing parameters, and thus can be utilized for controllable additive nano/microfabrication.

Indium tin oxide (ITO) coatings are widely used as transparent electrodes for optoelectronic devices. The most common preparation methods are sputtering, evaporation, and wet chemical deposition. ITO coatings can also be manufactured by solution deposition of ITO nanoparticles followed by furnace thermal annealing with the major motivation to reduce equipment investment. However, conventional furnace annealing is energy intensive, slow, and limited by the peak processing temperature. To overcome these constraints, we suggest using a laser beam for ITO nanoparticle annealing over a large area. It is shown in the present study that a low cost, high power, and high efficiency laser can yield large area functional ITO films in a process that carries substantial promise for potential industrial implementation. Furthermore, laser annealing generates higher electrical conductivity than conventional, thermally annealed nanoparticle films. The optical and electrical properties of the annealed ITO films can also be altered by adjusting laser parameters and environmental gases.

This paper describes how a passive quench protection system can be applied to long superconducting solenoid magnets. When a solenoid coil is long compared to its thickness, the magnet quench process will be dominated by the time needed for quench propagation along the magnet length. Quench-back will permit a long magnet to quench more rapidly in a passive way. Quench-back from a conductive (low resistivity) mandrel is essential for spreading the quench along the length of a magnet. The mandrel must be inductively coupled to the magnet circuit that is being quenched. Current induced in the mandrel by di/dt in the magnet produces heat in the mandrel, which in turn causes the superconducting coil wound on the mandrel to quench. Sub-division is often employed to reduce the voltages to ground within the coil. This paper explores when it is possible for quench-back to be employed for passive quench protection. The role of sub-division of the coil is discussed for long magnets.

This paper describes the passive quench protection system selected for the muon ionization cooling experiment (MICE) cooling channel coupling magnet. The MICE coupling magnet will employ two methods of quench protection simultaneously. The most important method of quench protection in the coupling magnet is the subdivision of the coil. Cold diodes and resistors are put across the subdivisions to reduce both the voltage to ground and the hot-spot temperature. The second method of quench protection is quench-back from the mandrel, which speeds up the spread of the normal region within the coils. Combining quench back with coil subdivision will reduce the hot spot temperature further. This paper explores the effect on the quench process of the number of coil sub-divisions, the quench propagation velocity within the magnet, and the shunt resistance.

Nanoparticle solutions are considered promising for realizing low cost printable high performance flexible electronics. In this letter, excimer laser annealing (ELA) was employed to induce melting of solution-deposited ZnO nanoparticles and form electrically conductive porous films. The properties of the films were characterized by scanning electron microscopy, high-resolution transmission electron microscopy, DC conductance, and photoluminescence measurements. Thin-film field-effect transistors have been fabricated by ELA without the use of conventional vacuum or any high temperature thermal annealing processes. The transistors show n-type accumulation mode behavior with mobility greater than 0.1 cm2/V s and current on/off ratios of more than 104. Optimization and control of the laser processing parameters minimized thermal impact on the substrate. This technique can be beneficial in the fabrication of metal oxide based electronics on heat sensitive flexible plastic substrates using low-cost, large-area solution processing combined with direct printing techniques.

Inkjet direct writing of functional materials provides a promising pathway towards realization of ultra-low-cost, large-area printed electronics, albeit at the expense of lowered resolution (∼20–50 μm). We demonstrate that selective laser sintering and ablation of inkjet-printed metal nanoparticles enables low-temperature metal deposition as well as high-resolution patterning. Combined with an air-stable carboxylate-functionalized polythiophene, all-inkjet-printed and laser-processed organic field effect transistors with micron to submicron critical feature resolution were fabricated in a fully maskless sequence, eliminating the need for any lithographic processes. All processing and characterization steps were carried out at plastic-compatible low temperatures and in air under ambient pressure.

According to the security requirement of the short message service (SMS) industry application, a secure short message communication protocol is proposed. This is an application level protocol constructed on the standard SMS communication protocol using public key authentication and key agreement without the need of wireless public key infrastructure (WPKI). Secure short message transmission and dynamic key agreement between mobile terminals and the accessing gateway are realized. The security of the proposed protocol is validated through the BAN logic. Compared with the standard SMS protocol, the effective payload rate of our protocol can reach 91.4%, and subscriber identity module (SIM) tool kit (STK) applications based on our protocol suit well for all kinds of mobile terminals in practical application.

Laser aided deposition process offers the ability to make a metal component directly from CAD drawings. Analysis of metallic powder flow in the feeding system is of particular significance to researchers in order to optimize this technique. Powder flow simulation holds a critical role in understanding flow phenomenon so as to ensure proper design and sound functionality of the coaxial nozzle. Numerical study of metallic powder flow in the coaxial nozzle for laser aided deposition is, however, barely existent. This is partially because not all of gas-atomized powders and none of water-atomised powders can be considered spheres and an accurate and economic modeling approach in describing non-spherical powder dispersion behavior can rarely be seen. To quickly simulate realistic powder flow and also meet the practical requirement for design optimization of the coaxial nozzle, a stochastic model, which considers particle shape effects, is developed. The validity of the model is demonstrated through comparison with experiment. The application of the model to the evaluation of various nozzle geometrical configurations is shown.

Seeded crystallization and solidification in nanoscale confinement volumes has become an important and complex topic in nanomanufacturing. Due to the complexity and limitations in observing nanoscale crystallization, computer simulation can provide valuable details for supporting and interpreting experimental observations. In this article, seeded crystallization from nano-confined liquid, as represented by the crystallization of a suspended gold nano-droplet seeded by a pre-existing gold nanocrystal seed, was investigated using molecular dynamics simulations in canonical (NVT) ensemble. We found that the crystallization temperature depends on nano-confinement volume, crystal orientation and seed size as explained by classical two-sphere model and Gibbs-Thomson effect.Copyright © 2014 by ASME

Additive manufacturing has shown potential for manufacturing parts out of metals, plastics and even ceramics. This paper reports on Selective Laser Melting (SLM) for depositing glass which has significantly different material properties from metals, ceramics or polymers. A CO2 laser is used to locally melt portions of a powder bed to explore the effects of process parameters on stationary particle formation as well as continuous line quality. Numerical modeling is also applied to gain insight into the physical process. The experimental and numerical results indicate that the absorptivity of the glass powder is nearly constant with respect to the processing parameters. Finally we show that higher quality parts can be created using a wire-fed instead of powder-bed process. Industrially, the additive manufacturing of glass is potentially relevant for gradient index optics, systems with embedded optics and applications where glass is used to form a hermetic seal.

Two 2.7-m long solenoid magnets with a cold mass of 1400 kg were fabricated in between 2007 and 2010. The magnet cryostat outside diameter is ∼1.4 meters and the cryostat length is ∼2.73 meters. The magnet warm bore is 0.4 meters. The magnet was designed to be cooled using three 1.5 W two-stage coolers. In both magnets, three coolers could not keep the cryostat filled with liquid helium. The temperatures of the shield and the tops of the HTS leads were too warm. A 140 W single stage cooler was added to magnet 2 to cool the HTS leads, the shield and the cold mass support intercepts. When the magnet 2 was retested in 2010, the net cooling at 4.2 K was −1.5 W with first-stage temperatures of the four coolers at ∼42 K. The tops of the HTS leads were

The technique of subdivision protection is extensively applied to protect large superconducting solenoid magnets such as accelerator magnets and MRI magnets. The number of subdivision and the parameters of protection circuit are usually decided by the quench simulation results. The accurate current data during quench process is important to verify the quench simulation code and estimate the magnet performance. But not like voltage signal, the acquisition of which just needs to attach a pair of voltage taps on both side of each protection resistor, current signal is very difficult to be obtained from cryogenic environment. This paper presents an algorithm to calculate the quench current from the quench voltage measurement result. By this algorithm the temperature rise history of protection resistor is obtained simultaneously.

We report direct printing of micro/sub-micron structures by femtosecond laser excitation of semiconductor nanocrystals (NCs) in solution. Laser excitation with moderate intensity (1011–1012 W/cm2) induces 2D and 3D deposition of CdTe nanocrystals in aqueous solution, which can be applied for direct printing of microstructures. It is believed that laser irradiation induces charge formation on nanocrystals leading to deposition. Furthermore, it is demonstrated that the charged nanocrystals can respond to external electrical bias, enabling a printing approach based on selective laser induced electrophoretic deposition. Finally, energy dispersive X-ray analysis of deposited structures shows oxidation occurs and deposited structure mainly consists of CdxO.

MICE Note-420 Eddy-currents and the Force Analysis for the Thermal Shields of the MICE Spectrometer Solenoids H. Pan 1 , S. O. Prestemon 1 , S. Virostek 1 , R. Preece 2 and M. A. Green 1 Abstract—The MICE spectrometer solenoids contain five superconducting solenoids with different structural parameters. Two coils are each separately powered. The other three coils are connected in series. The five coils are wound on a single 6061- aluminum mandrel. If one of the coils quenches, the quench will propagate by quench-back and cause other coils quench sequentially. The decaying field will induce a significant eddy current and Lorentz force on the surrounding shields. Shield eddy current heating is non-issue for the spectrometer solenoids, but the Lorentz force becomes an important aspect for designing because the five coils are not symmetric. In this paper, the detailed eddy current simulations were performed. The net lateral forces on each part of shields and the stress distribution were analyzed. Based on the Finite-element analysis, adding cuts on shields is an effective way to avoid the collapse of the shield due to changing current path direction. The shield cuts layout is presented in detail. the radiation heat from the room temperature. The main structure of shields consist of two 9.5 mm thick neck copper shields and a 6.35 mm thick main aluminum shields including main cylinder, endplates and inner bore. Based on the previous test results, the main shields are expected to use 1100 aluminum to enhance the thermal uniformity [5]. Index Terms—Eddy current, force, quench, superconducting magnets, shields, transient stress. I. I NTRODUCTION T HE objective off the Muon Ionization Cooling Experiment (MICE) is to demonstrate the designing and engineering on a section of cooling channel capable of giving the desired performance for a Neutrino Factory [1]. Two spectrometer solenoids in the MICE cooling channel will provide a uniform magnetic field for five plane scintillating fiber trackers to analyze the changing of the muon beam emittance in the cooling channel [2]. Each of the spectrometer magnet consists of five coils wound on a 2543-mm long 6061-Al mandrel as represented in Fig.1 (not drawn to scale). The center and end coils are the tracker section of the spectrometer solenoids, providing a uniform magnetic field (0.3 percent) over a length of 1000 mm and in a diameter of 300 mm; The two match coils are to match the muon beam from the Absorber Focus Coil module (AFC) into the tracker section [3,4]. All the coils are bath-cooled in liquid helium and use cryocoolers to re-condense helium vapor. In order to reduce the heat load to the cold mass, a set of shields cooled by the first-stages of thee coolers were adopted to intercept most of Manuscript received October 9, 2012. This work was supported in part by the U.S. Department of Energy under contract DE-AC02-05CH11231. H. Pan, S. O. Prestemon, S. Virostek and M. A. Green are with Lawrence Berkeley National Laboratory, Berkeley, CA, 94720 USA (phone: 510-612- 7137; e-mail: hengpan@lbl.gov). R. Preece is with Rutherford Appleton Laboratory, Didcot, OX11 0QX UK. (e-mail: Roy.Preece@stfc.ac.uk). Fig. 1. The cold mass and shields cross section of the spectrometer solenoids Because the cold mass is asymmetric, the interaction of its local magnetic field with the eddy current induced on the conductive parts of the cryostat during a quench could introduce significant lateral forces on the mandrel and the shields. Eddy currents don’t affect the mandrel mechanical stability due to a high electrical resistivity of 6061-Al. The big concern is with the shields where their low electrical resistivity causes a large-forces during a quench. One must reduce the eddy current impact by redesigning the shields. II. MICE S PECTROMETER S OLENOIDS P ARAMETERS The Spectrometer solenoid consists of five coils wound on the slotted aluminum 6061 bobbin, and covered by Al bandage wound on top of each coil to avoid separation between coil and mandrel. Table I represents the parameters of coils for this study. TABLE I D ESIGN P ARAMETERS FOR C OILS Parameter No. turns/layer No. layers Inner radius (mm) Outer radius (mm) Axial coil build (mm) Initial current (A) M1 M2 E1 C E2

A novel method for head detection was proposed in video sequences captured with fixed vertical mono-camera, which integrated hough transformation, hair-color distribution model and circle existence model. Target area was firstly detected using fast gradient hough transformation (FGHT). In order to overcome head area mis-detection and incapability of locating head area introduced by FGHT, hair-color classification was used to filter the candidate targets through modeling hair-color distribution. Furthermore, based on non-parameter probability theory, the probability of circle existence model was established, which finalized the stages of head detection by locating the head. Compared with average circle detection algorithm, experimental results indicate that the proposed head detection algorithm can eliminate false targets and greatly increase accuracy.

MRI magnets and other magnets that have a low current and high self-inductance are passively quench-protected with a system that includes sub-divided coils with resistors and diodes that are in parallel with sections of the coils. The primary purpose of coil sub-division is to protect the coil from the high voltages that can occur during a quench. In the event of a lead failure (conventional or superconducting) between the coil and its power supply or its persistent switch, the total current in the coil flows through the diodes and resistors in parallel with the coil. When a lead fails, the current decay time constant for the coil current can be quite long. It is desirable that the coil quench in a time that is short compared to the coil current decay time constant. Experience shows that the heating from the resistors and diodes will eventually quench the magnet. This paper presents methods for shortening the time between a lead failure or a persistent switch failure and the eventual magnet quench. © 2011 IEEE.

Low average power fiber lasers are being used for an ever expanding range of applications, most of these employ near infrared wavelengths in the 1070 nm range. Substituting erbium or thulium doped active media for ytterbium dopants enables the manufacture of fiber lasers emitting in the mid infra-red 1.5 and 2 um regime. Some details on these lasers that are now available at average powers relevant for industrial applications are presented. Furthermore, a novel application for a 1.5 um fiber laser is explored; localized thermal treatment of solution deposited ITO nanoparticle film for large area and low cost manufacturing of Transparent Conducting Oxide. These doped metal oxide films are widely used in a range of optoelectronic devices such as flat panels and PV cells as they allow light transmission whilst providing high electrical conductivity. Substantial technical benefits are presented and the consequent commercial benefits for this process are also explored.Low average power fiber lasers are being used for an ever expanding range of applications, most of these employ near infrared wavelengths in the 1070 nm range. Substituting erbium or thulium doped active media for ytterbium dopants enables the manufacture of fiber lasers emitting in the mid infra-red 1.5 and 2 um regime. Some details on these lasers that are now available at average powers relevant for industrial applications are presented. Furthermore, a novel application for a 1.5 um fiber laser is explored; localized thermal treatment of solution deposited ITO nanoparticle film for large area and low cost manufacturing of Transparent Conducting Oxide. These doped metal oxide films are widely used in a range of optoelectronic devices such as flat panels and PV cells as they allow light transmission whilst providing high electrical conductivity. Substantial technical benefits are presented and the consequent commercial benefits for this process are also explored.

This article presents an analog multilayer perceptron (MLP) neural network circuit with on‐chip back propagation learning. This low power and small area analog MLP circuit is proposed to implement as a classifier in an electronic nose (E‐nose). Comparing with the E‐nose using microprocessor or FPGA as a classifier, the E‐nose applying analog circuit as a classifier can be faster and much smaller, demonstrate greater power efficiency and be capable of developing a portable E‐nose [1]. The system contains four inputs, four hidden neurons, and only one output neuron; this simple structure allows the circuit to have a smaller area and less power consumption. The circuit is fabricated using TSMC 0.18 μm 1P6M CMOS process with 1.8 V supply voltage. The area of this chip is 1.353×1.353 mm2 and the power consumption is 0.54 mW. Post‐layout simulations show that the proposed analog MLP circuit can be successively trained to identify three kinds of fruit odors.

In this study, we have developed a prototype of a portable electronic nose (E-Nose) comprising a sensor array of eight commercially available sensors, a data acquisition interface PCB, and a microprocessor. Verification software was developed to verify system functions. Experimental results indicate that the proposed system prototype is able to identify the fragrance of three fruits, namely lemon, banana, and litchi.

Organic material direct writing was demonstrated based on nanomaterial enabled laser transfer (NELT). Through proper nanoparticle size and type, and the laser wavelength choice, a single laser pulse could transfer well defined and arbitrarily shaped tris-(8-hydroxyquinoline)Al patterns ranging from several microns to millimeter size. The unique properties of nanomaterials allow the laser induced forward transfer process to be effected at irradiation energies and temperatures lower than commonly used. The technique may be well suited for the mass production of temperature sensitive devices.

All-printed electronics is the key technology to ultra-low-cost, large-area electronics. As a critical step in this direction, we demonstrate that femtosecond laser processing (sintering and ablation) of solution deposited metal nanoparticles enables direct metal patterning at low-temperature with ultra high resolution (∼300nm) to overcome the resolution limitation of the current inkjet direct writing processes.This could be explained by the combined effects of novel properties of metal nanoparticles such as melting temperature drop, strong absorption of the incident laser beam at surface plasmon mode, lower conductive heat transfer loss, and the relatively weak bonding between nanoparticles. Local thermal control of the laser sintering process could minimize the heat-affected zone and the thermal damage to the substrate and further enhance the resolution of the process. This local nanoparticle deposition and energy coupling enable an environmentally friendly and cost-effective process as well as a low-temperature manufacturing sequence to realize large-area, flexible electronics on polymer substrates.

The muon ionization cooling experiment (MICE) consists of a target, a beam line, a pion decay channel, the MICE cooling channel. Superconducting magnets are used in the pion decay channel and the MICE cooling channel. This report describes the MICE cooling channel magnets and the progress in the design and fabrication of these magnets. The MICE cooling channel consists of three types of superconducting solenoids; the spectrometer solenoids, the coupling solenoids and the focusing solenoids. The three types of magnets are being fabricated in the United States, China, and the UK respectively. The spectrometer magnets are used to analyze the muon beam before and after muon cooling. The coupling magnets couple the focusing sections and keep the muon beam contained within the iris of the RF cavities that are used to recover the muon momentum lost during ionization cooling. The focusing magnets focus the muon beam in the center of a liquid hydrogen absorber. The first of the cooling channel magnets will be operational in MICE in the spring of 2010. © 2010 IOP Publishing Ltd.

The portable electronic nose system is composed of a sensor array (sensor head) part and an electronics part. The sensors are made of polymer/mesoporous carbon composite materials for high sensitivity and selectivity. The electronics are sensor interface circuitry together with a microprocessor.

MICE Note-238 The Calculated and Measured Resistance for Splices between Conductors in a MICE Superconducting Coil Michael A. Green a , Dan Dietderich a , Hugh C. Higley a , Heng Pan b , Darren G. Tam a , Frederic Trillaud a , Li Wang b , Hong Wu b , and Feng Yu Xu b a )Lawrence Berkeley Laboratory, Berkeley CA 94720, USA b) Institute for Cryogenics and Superconductive Technology, HIT, Harbin China 1 March 2009* Abstract The resistance of superconducting joints within MICE coils is an important issue particularly for the coupling coils. The MICE tracker solenoids have only two superconducting joints in the three spectrometer set (end coil 1, the center coil and end coil 2). The AFC magnets may have only a single joint within the coil. The coupling coils may have as many as fifteen joints within the coil, due to relatively short piece lengths of the superconductor. LBNL and ICST looked at three types of coil joints. They are; 1) cold fusion butt joints, 2) side-by-side lap joints, and 3) up-down lap joints. A theoretical calculation of the joint resistance was done at LBNL and checked by ICST. After looking at the theoretical resistance of the three types of joints, it was decided that the cold welded butt joint was not an attractive alternative for joints within a MICE superconducting magnet coil. Side-by-side and up-down lap joints were fabricated at ICST using two types of soft solder between the conductors. These conductor joints were tested at LBNL at liquid helium temperatures over a range of magnetic fields. The joint resistance was compared with the theoretical calculations. Measurements of splice strength were also made at 300 K and 77 K. TABLE OF CONTENTS Abstract Theoretical Calculations of MICE Coil Joint Resistance Fabrication of Superconductor Joints at ICST Conductor Joint Resistance Measurement Technique Measured Joint Resistance Compared with Calculated Joint Resistance Measurements of the Joint Breaking Strength Some Concluding Comments Acknowledgements References * Last revision 8 March 2009 Page