Method for regeneration of electroless nickel plating solution
Eisenmann, Erhard T.
1997-01-01
An electroless nickel(EN)/hypophosphite plating bath is provided employing acetic acid/acetate as a buffer and which is, as a result, capable of perpetual regeneration while avoiding the production of hazardous waste. A regeneration process is provided to process the spent EN plating bath solution. A concentrated starter and replenishment solution is provided for ease of operation of the plating bath. The regeneration process employs a chelating ion exchange system to remove nickel cations from spent EN plating solution. Phosphites are then removed from the solution by precipitation. The nickel cations are removed from the ion exchange system by elution with hypophosphorous acid and the nickel concentration of the eluate adjusted by addition of nickel salt. The treated solution and adjusted eluate are combined, stabilizer added, and the volume of resulting solution reduced by evaporation to form the bath starter and replenishing solution.
Method for regeneration of electroless nickel plating solution
Eisenmann, E.T.
1997-03-11
An electroless nickel(EN)/hypophosphite plating bath is provided employing acetic acid/acetate as a buffer and which is, as a result, capable of perpetual regeneration while avoiding the production of hazardous waste. A regeneration process is provided to process the spent EN plating bath solution. A concentrated starter and replenishment solution is provided for ease of operation of the plating bath. The regeneration process employs a chelating ion exchange system to remove nickel cations from spent EN plating solution. Phosphites are then removed from the solution by precipitation. The nickel cations are removed from the ion exchange system by elution with hypophosphorus acid and the nickel concentration of the eluate adjusted by addition of nickel salt. The treated solution and adjusted eluate are combined, stabilizer added, and the volume of resulting solution reduced by evaporation to form the bath starter and replenishing solution. 1 fig.
METHOD OF APPLYING COPPER COATINGS TO URANIUM
Gray, A.G.
1959-07-14
A method is presented for protecting metallic uranium, which comprises anodic etching of the uranium in an aqueous phosphoric acid solution containing chloride ions, cleaning the etched uranium in aqueous nitric acid solution, promptly electro-plating the cleaned uranium in a copper electro-plating bath, and then electro-plating thereupon lead, tin, zinc, cadmium, chromium or nickel from an aqueous electro-plating bath.
Recovery process for electroless plating baths
Anderson, Roger W.; Neff, Wayne A.
1992-01-01
A process for removing, from spent electroless metal plating bath solutions, accumulated byproducts and counter-ions that have deleterious effects on plating. The solution, or a portion thereof, is passed through a selected cation exchange resin bed in hydrogen form, the resin selected from strong acid cation exchangers and combinations of intermediate acid cation exchangers with strong acid cation exchangers. Sodium and nickel ions are sorbed in the selected cation exchanger, with little removal of other constituents. The remaining solution is subjected to sulfate removal through precipitation of calcium sulfate hemihydrate using, sequentially, CaO and then CaCO.sub.3. Phosphite removal from the solution is accomplished by the addition of MgO to form magnesium phosphite trihydrate. The washed precipitates of these steps can be safely discarded in nontoxic land fills, or used in various chemical industries. Finally, any remaining solution can be concentrated, adjusted for pH, and be ready for reuse. The plating metal can be removed from the exchanger with sulfuric acid or with the filtrate from the magnesium phosphite precipitation forming a sulfate of the plating metal for reuse. The process is illustrated as applied to processing electroless nickel plating baths.
Recovery process for electroless plating baths
Anderson, R.W.; Neff, W.A.
1992-05-12
A process is described for removing, from spent electroless metal plating bath solutions, accumulated byproducts and counter-ions that have deleterious effects on plating. The solution, or a portion thereof, is passed through a selected cation exchange resin bed in hydrogen form, the resin selected from strong acid cation exchangers and combinations of intermediate acid cation exchangers with strong acid cation exchangers. Sodium and nickel ions are sorbed in the selected cation exchanger, with little removal of other constituents. The remaining solution is subjected to sulfate removal through precipitation of calcium sulfate hemihydrate using, sequentially, CaO and then CaCO[sub 3]. Phosphite removal from the solution is accomplished by the addition of MgO to form magnesium phosphite trihydrate. The washed precipitates of these steps can be safely discarded in nontoxic land fills, or used in various chemical industries. Finally, any remaining solution can be concentrated, adjusted for pH, and be ready for reuse. The plating metal can be removed from the exchanger with sulfuric acid or with the filtrate from the magnesium phosphite precipitation forming a sulfate of the plating metal for reuse. The process is illustrated as applied to processing electroless nickel plating baths. 18 figs.
Purity test for copper-plating solutions
NASA Technical Reports Server (NTRS)
Mansfeld, F. B.
1977-01-01
Electrode configuration can be used to measure extent of impurities in acid-copper plating solution. It can be inserted into any plating tank and will show whether bath is clean or contaminated, within fifteen minutes.
Method of forming oxide coatings. [for solar collector heating panels
NASA Technical Reports Server (NTRS)
Mcdonald, G. E. (Inventor)
1983-01-01
This invention is concerned with an improved plating process for covering a substrate with a black metal oxide film. The invention is particularly directed to making a heating panel for a solar collector. A compound is electrodeposited from an aqueous solution containing cobalt metal salts onto a metal substrate. This compound is converted during plating into a black, highly absorbing oxide coating which contains hydrated oxides. This is achieved by the inclusion of an oxidizing agent in the plating bath. The inclusion of an oxidizing agent in the plating bath is contrary to standard electroplating practice. The hydrated oxides are converted to oxides by treatment in a hot bath, such as boiling water. An oxidizing agent may be added to the hot liquid treating bath.
A REVIEW OF ACID COPPER PLATING BATH LIFE EXTENSION AND COPPER RECOVERY FROM ACID COPPER BATHS
Large quantities of hazardous waste, most in aqueous solution or sludges, are being produced at numerous metal plating and processing facilities in the U.S. Regulatory pressures, future liability, and limited landfill space have driven the cost of metal waste disposal to level...
Electrochemical Assay of Gold-Plating Solutions
NASA Technical Reports Server (NTRS)
Chiodo, R.
1982-01-01
Gold content of plating solution is assayed by simple method that required only ordinary electrochemical laboratory equipment and materials. Technique involves electrodeposition of gold from solution onto electrode, the weight gain of which is measured. Suitable fast assay methods are economically and practically necessary in electronics and decorative-plating industries. If gold content in plating bath is too low, poor plating may result, with consequent economic loss to user.
Installation Assessment of Frankford Arsenal.
1977-10-01
sulfate , sulfuric acid , ac ’solution 40 Hot water bath 41 Nickel plate Nickel sulfate and chloride sulfuric acid , acid ...solution 42 Chromium Copper plate Copper sulfate and sulfuric acid , acid solution 11-14 TABLE 11-2 (continued) Tank No. Plating Process Use Contents...46 Water rinse Water 47 Water rinse Water 48 Water rinse Water 49 Acid Chromic acid , acetic acid , nickel sulfate and sulfuric
NASA Technical Reports Server (NTRS)
Berkowitz, J. B.; Emerson, N. H.
1972-01-01
Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.
Collapsed heteroclinic snaking near a heteroclinic chain in dragged meniscus problems.
Tseluiko, D; Galvagno, M; Thiele, U
2014-04-01
A liquid film is studied that is deposited onto a flat plate that is inclined at a constant angle to the horizontal and is extracted from a liquid bath at a constant speed. We analyse steady-state solutions of a long-wave evolution equation for the film thickness. Using centre manifold theory, we first obtain an asymptotic expansion of solutions in the bath region. The presence of an additional temperature gradient along the plate that induces a Marangoni shear stress significantly changes these expansions and leads to the presence of logarithmic terms that are absent otherwise. Next, we numerically obtain steady solutions and analyse their behaviour as the plate velocity is changed. We observe that the bifurcation curve exhibits collapsed (or exponential) heteroclinic snaking when the plate inclination angle is above a certain critical value. Otherwise, the bifurcation curve is monotonic. The steady profiles along these curves are characterised by a foot-like structure that is formed close to the meniscus and is preceded by a thin precursor film further up the plate. The length of the foot increases along the bifurcation curve. Finally, we prove with a Shilnikov-type method that the snaking behaviour of the bifurcation curves is caused by the existence of an infinite number of heteroclinic orbits close to a heteroclinic chain that connects in an appropriate three-dimensional phase space the fixed point corresponding to the precursor film with the fixed point corresponding to the foot and then with the fixed point corresponding to the bath.
Electroless Cu Plating on Anodized Al Substrate for High Power LED.
Rha, Sa-Kyun; Lee, Youn-Seoung
2015-03-01
Area-selective copper deposition on screen printed Ag pattern/anodized Al/Al substrate was attempted using a neutral electroless plating processes for printed circuit boards (PCBs), according to a range of variation of pH 6.5-pH 8 at 70 °C. The utilized basic electroless solution consisted of copper(II) sulfate pentahydrate, sodium phosphinate monohydrate, sodium citrate tribasic dihydrate, ammonium chloride, and nickel(II) sulfate hexahydrate. The pH of the copper plating solutions was adjusted from pH 6.5 to pH 8 using NH4OH. Using electroless plating in pH 6.5 and pH 7 baths, surface damage to the anodized Al layer hardly occurred; the structure of the plated Cu-rich films was a typical fcc-Cu, but a small Ni component was co-deposited. In electroless plating at pH 8, the surface of the anodized Al layer was damaged and the Cu film was composed of a lot of Ni and P which were co-deposited with Cu. Finally, in a pH 7 bath, we can make a selectively electroless plated Cu film on a PCB without any lithography and without surface damage to the anodized Al layer.
Torras, Josep; Buj, Irene; Rovira, Miquel; de Pablo, Joan
2012-03-30
Chromium plating used for functional purposes provides an extremely hard, wear and corrosion resistant layer by means of electrolytic deposition. Typical layer thicknesses range between 2.5 and 500 μm. Chromium electroplating baths contain high concentrations of Cr(VI) with chromium trioxide (CrO(3)) as the chromium source. When because of technical or economic reasons a bath gets exhausted, a waste containing mainly chromium as dichromate as well as other heavy metals is generated. Chromium may then be purified for use in other industrial processes with different requirements. In this work, a sustainable system for using galvanic wastes as reagents in the leather tanning industry, thus reducing quantity of wastes to be treated, is presented. Metal cations present in the chromium exhausted bath were precipitated with NaOH. Then, the solution containing mainly soluble Cr(VI) was separated. By means of sodium sulphite in acidic conditions, Cr(VI) was reduced to Cr(III) as chromium (III) sulphate. From chromium (III) sulphate a basic Cr(III) sulphate may be obtained, which is one of most used compounds in the tanning industry. Cr(III) concentration in the final solution allows its reuse without concentration, but with a slight dilution. Copyright © 2012 Elsevier B.V. All rights reserved.
Nickel cobalt phosphorous low stress electroplating
NASA Technical Reports Server (NTRS)
Engelhaupt, Darell E. (Inventor); Ramsey, Brian D. (Inventor)
2002-01-01
An electrolytic plating process is provided for electrodepositing a nickel or nickel cobalt alloy which contains at least about 2% to 25% by atomic volume of phosphorous. The process solutions contains nickel and optionally cobalt sulfate, hypophosphorous acid or a salt thereof, boric acid or a salt thereof, a monodentate organic acid or a salt thereof, and a multidentate organic acid or a salt thereof. The pH of the plating bath is from about 3.0 to about 4.5. An electroplating process is also provided which includes electroplating from the bath a nickel or nickel cobalt phosphorous alloy. This process can achieve a deposit with high microyield of at least about 84 kg/mm.sup.2 (120 ksi) and a density lower than pure nickel of about 8.0 gm/cc. This process can be used to plate a deposit of essentially zero stress at plating temperatures from ambient to 70.degree. C.
The use of trivalent chromium bath to obtain a solar selective black chromium coating
NASA Astrophysics Data System (ADS)
Survilienė, S.; Češūnienė, A.; Juškėnas, R.; Selskienė, A.; Bučinskienė, D.; Kalinauskas, P.; Juškevičius, K.; Jurevičiūtė, I.
2014-06-01
Black chromium coatings were electrodeposited from a trivalent chromium bath using a ZnO additive as a second main component. Black chromium was electrodeposited on steel and copper plates and substrates plated with bright nickel prior to black chromium electrodeposition. The black chromium coatings were characterized by XRD and SEM. The XRD data suggest that the phase structure of black chromium may be defined as a zinc solid solution in chromium or a chromium solid solution in zinc depending on the chromium/zinc ratio in the deposit. The role of substrate finish was evaluated through the corrosion resistance and reflectance of black chromium. According to corrosion tests the samples plated with bright nickel prior to black chromium deposition have shown the highest corrosion resistance. The electrodeposited black chromium possesses good optical properties for the absorption of solar energy. The absorption coefficient of black chromium was found to be over 0.99 for the samples obtained without the Ni undercoat and below 0.99 for those obtained with the use of Ni undercoat. However, the use of nickel undercoat before black chromium plating is recommended because it remarkably improves the corrosion resistance of samples.
Magnetic Fe-Co films electroplated in a deep-eutectic-solvent-based plating bath
NASA Astrophysics Data System (ADS)
Yanai, T.; Shiraishi, K.; Watanabe, Y.; Ohgai, T.; Nakano, M.; Suzuki, K.; Fukunaga, H.
2015-05-01
We fabricated Fe-Co films from a deep eutectic solvent (DES)-based plating bath and investigated magnetic properties of the plated films. The plating baths were obtained by stirring the mixture of choline chloride, ethylene glycol, FeCl2.4H2O, and CoCl2.6H2O. The composition of the plated films depended on the amount of FeCl2.4H2O in the plating bath, and Fe content of the films was varied from 0 to 100 at. %. Depending on the Fe content, the saturation magnetization and the coercivity of the films varied. The Fe76Co24 film shows high saturation magnetization and smooth surface, and the change in the saturation magnetization shows good agreement with the expected change by the Slater-Pauling curve. High current efficiency (>90%) could be obtained in the wide film composition. From these results, we concluded that the DES-based plating bath is one of effective baths for the Fe-Co films with high current efficiency.
Seegmiller, R.
1957-08-01
An improved bath is reported for plating gold on other metals. The composition of the plating bath is as follows: Gold cyanide from about 15 to about 50 grams, potassium cyanide from about 70 to about 125 grams, and sulfonated castor oil from about 0.1 to about 10 cc. The gold plate produced from this bath is smooth, semi-hard, and nonporous.
NASA Technical Reports Server (NTRS)
Nelson, Mary J.; Groshart, Earl C.
1995-01-01
The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.
Electroplated Fe-Co-Ni films prepared from deep-eutectic-solvent-based plating baths
NASA Astrophysics Data System (ADS)
Yanai, Takeshi; Shiraishi, Kotaro; Akiyoshi, Toshiki; Azuma, Keita; Watanabe, Yoshimasa; Ohgai, Takeshi; Morimura, Takao; Nakano, Masaki; Fukunaga, Hirotoshi
2016-05-01
We fabricated soft magnetic films from DES-based plating baths, and investigated magnetic properties of the plated films. The plating baths were obtained by stirring the mixture of choline chloride, ethylene glycol, FeCl2 ṡ 4H2O, NiCl2 ṡ 6H2O and CoCl2 ṡ 6H2O. The composition of the electroplated film depended on the amount of the reagent in the plating bath, and we consequently obtained the films with various composition. The current efficiency of the plating process shows high values (> 88 %) in the wide composition range. The soft magnetic films with low coercivity were obtained at the Fe compositions of ≈ 30 at.% and > 80 at.%, and we found that low coercivity could be realized by the control of the film composition. We also found that the Fe-rich films prepared from DES-based plating bath have some advantages as a soft magnetic phase for a nanocomposite magnet due to their high saturation magnetization and very fine crystal structure.
A novel method of reducing agent contacting pattern for metal ceramic composite membrane fabrication
NASA Astrophysics Data System (ADS)
Agarwal, Amrita; Pujari, Murali; Uppaluri, Ramgopal; Verma, Anil
2014-11-01
Deliberating upon process modifications for surfactant induced electroless plating (SIEP), this article highlights the plating bath performance characteristics for two distinct reducing agent contacting modes (bulk and drop wise). Eventually, the effect of reducing agent concentration (50, 100, 200% excess) suitable for electroless plating bath for a nickel concentration of 0.08 mol/L was investigated. Finally, the compatibility of variation in nickel concentration (0.08-0.24 mol/L) with respect to variation in reducing agent concentration (50, 100, 200% excess) was investigated. LPSA, BET, FTIR, XRD, FESEM and nitrogen permeation experiments were used for surface and physical characterization. It was observed that for the bulk addition of reducing agent, the PPD values were 84.5% which increased to 89.3% for dropwise addition case. Thus the optimal combinations of SIEP process parameters were identified as 0.08 mol/L of nickel metal solution concentration with 100% excess drop-wise reducing agent. These conditions provided a plating rate of 5.5 × 10-5 mol/m2 s, PPD of 89.3% and a metal film thickness of 15.7 μm respectively after 12 h of sequential plating.
About one counterexample of applying method of splitting in modeling of plating processes
NASA Astrophysics Data System (ADS)
Solovjev, D. S.; Solovjeva, I. A.; Litovka, Yu V.; Korobova, I. L.
2018-05-01
The paper presents the main factors that affect the uniformity of the thickness distribution of plating on the surface of the product. The experimental search for the optimal values of these factors is expensive and time-consuming. The problem of adequate simulation of coating processes is very relevant. The finite-difference approximation using seven-point and five-point templates in combination with the splitting method is considered as solution methods for the equations of the model. To study the correctness of the solution of equations of the mathematical model by these methods, the experiments were conducted on plating with a flat anode and cathode, which relative position was not changed in the bath. The studies have shown that the solution using the splitting method was up to 1.5 times faster, but it did not give adequate results due to the geometric features of the task under the given boundary conditions.
Real time monitoring of electroless nickel plating
NASA Astrophysics Data System (ADS)
Rains, Aaron E.; Kline, Ronald A.
2013-01-01
This work deals with the design and manufacturing of the heat and chemical resistant transducer case required for on-line immersion testing, experimental design, data acquisition and signal processing. Results are presented for several depositions with an accuracy of two ten-thousandths of an inch in coating thickness obtained. Monitoring the deposition rate of Electroless Nickel (EN) plating in-situ will provide measurement of the accurate dimensions of the component being plated, in real time. EN is used as for corrosion and wear protection for automotive an - Electroless Nickel (EN) plating is commonly used for corrosion and wear protection for automotive and aerospace components. It plates evenly and symmetrically, theoretically allowing the part to be plated to its final dimension. Currently the standard approach to monitoring the thickness of the deposited nickel is to remove the component from the plating bath and physically measure the part. This can lead to plating problems such as pitting, non-adhesion of the deposit and contamination of the plating solution. The goal of this research effort is to demonstrate that plating thickness can be rapidly and accurately measured using ultrasonic testing. Here a special housing is designed to allow immersion of the ultrasonic transducers directly into the plating bath. An FFT based signal processing algorithm was developed to resolve closely spaced echoes for precise thickness determination. The technique in this research effort was found to be capable of measuring plating thicknesses to within 0.0002 inches. It is expected that this approach will lead to cost savings in many EN plating operations.
Apparatus and method for controlling plating uniformity
Hachman Jr., John T.; Kelly, James J.; West, Alan C.
2004-10-12
The use of an insulating shield for improving the current distribution in an electrochemical plating bath is disclosed. Numerical analysis is used to evaluate the influence of shield shape and position on plating uniformity. Simulation results are compared to experimental data for nickel deposition from a nickel--sulfamate bath. The shield is shown to improve the average current density at a plating surface.
Agarwal, Amrita; Pujari, Murali; Uppaluri, Ramgopal; Verma, Anil
2014-07-01
This article addresses furthering the role of sonication for the optimal fabrication of nickel ceramic composite membranes using electroless plating. Deliberating upon process modifications for surfactant induced electroless plating (SIEP) and combined surfactant and sonication induced electroless plating (SSOEP), this article highlights a novel method of contacting of the reducing agent and surfactant to the conventional electroless nickel plating baths. Rigorous experimental investigations indicated that the combination of ultrasound (in degas mode), surfactant and reducing agent pattern had a profound influence in altering the combinatorial plating characteristics. For comparison purpose, purely surfactant induced nickel ELP baths have also been investigated. These novel insights consolidate newer research horizons for the role of ultrasound to achieve dense metal ceramic composite membranes in a shorter span of total plating time. Surface and physical characterizations were carried out using BET, FTIR, XRD, FESEM and nitrogen permeation experiments. It has been analyzed that the SSOEP baths provided maximum ratio of percent pore densification per unit metal film thickness (PPDδ) and hold the key for further fine tuning of the associated degrees of freedom. On the other hand SIEP baths provided lower (PPDδ) ratio but higher PPD. For SSOEP baths with dropwise reducing agent and bulk surfactant, the PPD and metal film thickness values were 73.4% and 8.4 μm which varied to 66.9% and 13.3 μm for dropwise reducing agent and drop surfactant case. Copyright © 2014 Elsevier B.V. All rights reserved.
19. VIEW OF THE PLATING BATHS AND CONTROL PANELS. GOLD ...
19. VIEW OF THE PLATING BATHS AND CONTROL PANELS. GOLD AND SILVER WERE AMONG THE MATERIALS PLATED ONTO PARTS MADE OF COPPER, STAINLESS STEEL AND STEEL. (11/15/89) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO
NASA Astrophysics Data System (ADS)
Pang, Hongwei; Bai, Ruicheng; Shao, Qinsi; Gao, Yufang; Li, Aijun; Tang, Zhiyong
2015-12-01
A novel Ag catalyzation process using swelling impregnation pretreatment method was developed for electroless nickel (EN) deposition on Kevlar fiber. Firstly, the fiber was immersed into an aqueous dimethylsulfoxide (DMSO) solution of silver nitrate to impart silver nitrate into the inner part of the fiber near the surface. Subsequently silver nitrate was reduced to metal silver nanoparticles on the fiber surface by treatment with aqueous solution of sodium borohydride. After electroless plating, a dense and homogeneous nickel coating was obtained on the fiber surface. The silver nanoparticles formed at the fiber surface functioned as a catalyst for electroless deposition as well as an anchor for the plated layer. The study also revealed that the incorporation of surfactant sodium dodecyl sulfate (SDS) in electroless nickel plating bath can enhance the adhesion strength of EN layer with the fiber surface and minimize the surface roughness of the EN coating. The Ni plated Kevlar fiber possessed excellent corrosion resistance and high tensile strength.
PROCESS OF ELECTROPLATING METALS WITH ALUMINUM
Schickner, W.C.
1960-04-26
A process of electroplating aluminum on metals from a nonaqueous bath and a novel method of pretreating or conditioning the metal prior to electrodeposition of the aluminum are given. The process of this invention, as applied by way of example to the plating of uranium, comprises the steps of plating the uranium with the barrier inetal, immersing the barrier-coated uranium in fatty acid, and electrolyzing a water-free diethyl ether solution of aluminum chloride and lithium hydride while making the uranium the cathode until an aluminum deposit of the desired thickness has been formed. According to another preferred embodiment the barrier-coated uranium is immersed in an isopropyl alcohol solution of sterato chromic chloride prior to the fatty acid treatment of this invention.
Electrodeposited Fe-Co films prepared from a citric-acid-based plating bath
NASA Astrophysics Data System (ADS)
Yanai, T.; Uto, H.; Shimokawa, T.; Nakano, M.; Fukunaga, H.; Suzuki, K.
2013-06-01
Electrodeposited Fe-Co films are commonly prepared in a boric-acid-based bath. In this research, we applied citric acid instead of boric acid for the plating of Fe-Co films because boron in the waste bath is restricted by environmental-protection regulations in Japan. We evaluated the effect of citric acid on the magnetic and structural properties of the films. The saturation magnetization of the Fe-Co films slightly increased while the Fe content in the Fe-Co films decreased with increasing citric acid concentration. The lowest coercivity value of 240 A/m was obtained at a citric acid concentration of 100 g/L. The plating bath with this citric acid concentration enabled us to obtain Fe-Co films with high saturation magnetizations and smooth surface morphologies.
Systems and Methods for the Electrodeposition of a Nickel-cobalt Alloy
NASA Technical Reports Server (NTRS)
Ogozalek, Nance Jo (Inventor); Wistrand, Richard E. (Inventor)
2013-01-01
Systems and methods for electrodepositing a nickel-cobalt alloy using a rotating cylinder electrode assembly with a plating surface and an electrical contact. The assembly is placed within a plating bath and rotated while running a plating cycle. Nickel-cobalt alloy deposition is selectively controlled by controlling current density distribution and/or cobalt content in the plating bath while running the plating cycle to deposit an alloy of a desired yield strength onto the plating surface in a single plating cycle. In various embodiments, the rotating cylinder may be used as an insitu monitoring method to assist in obtaining the properties desired.
INVESTIGATION INTO THE REJUVENATION OF SPENT ELECTROLESS NICKEL BATHS BY ELECTRODIALYSIS
Electroless nickel plating generates substantially more waste than other metal-finishing processes due to the inherent limited bath life and the need for regular bath disposal. Electrodialysis can be used to generate electroless nickel baths, but poor membrane permselectivity, l...
40 CFR 63.341 - Definitions and nomenclature.
Code of Federal Regulations, 2013 CFR
2013-07-01
... control device or a chemical fume suppressant, that is used to reduce chromium emissions from chromium... workpiece. Bath component means the trade or brand name of each component(s) in trivalent chromium plating baths. For trivalent chromium baths, the bath composition is proprietary in most cases. Therefore, the...
40 CFR 63.341 - Definitions and nomenclature.
Code of Federal Regulations, 2014 CFR
2014-07-01
... control device or a chemical fume suppressant, that is used to reduce chromium emissions from chromium... workpiece. Bath component means the trade or brand name of each component(s) in trivalent chromium plating baths. For trivalent chromium baths, the bath composition is proprietary in most cases. Therefore, the...
Inoue, Hiroaki; Takama, Tomoko; Yoshizaki, Miwa; Agata, Kunio
2015-01-01
We detected Legionella species in 111 bath water samples and 95 cooling tower water samples by using a combination of conventional plate culture, quantitative polymerase chain reaction (qPCR) and qPCR combined with ethidium monoazide treatment (EMA-qPCR) methods. In the case of bath water samples, Legionella spp. were detected in 30 samples by plate culture, in 85 samples by qPCR, and in 49 samples by EMA-qPCR. Of 81 samples determined to be Legionella-negative by plate culture, 56 and 23 samples were positive by qPCR and EMA-qPCR, respectively. Therefore, EMA treatment decreased the number of Legionella-positive bath water samples detected by qPCR. In contrast, EMA treatment had no effect on cooling tower water samples. We therefore expect that EMA-qPCR is a useful method for the rapid detection of viable Legionella spp. from bath water samples.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hoppe, Eric W.; Aalseth, Craig E.; Brodzinski, Ronald L.
The search for neutrinoless double beta decay in 76Ge has driven the need for ultra-low background Ge detectors shielded by electroformed copper of ultra-high radiopurity (<0.1µBq/kg). Although electrodeposition processes are almost sophisticated enough to produce copper of this purity, to date there are no methods sensitive enough to assay it. Inductively-coupled plasma mass spectrometry (ICP/MS) can detect thorium and uranium at femtogram levels, but in the past, this assay has been hindered by high copper concentrations in the sample. Electrodeposition of copper samples removes copper from the solution while selectively concentrating thorium and uranium contaminants to be assayed by ICP/MS.more » Spiking 232Th and 238U into the plating bath simulates low purity copper and allows for the calculation of the electrochemical rejection rate of thorium and uranium in the electroplating system. This rejection value will help to model plating bath chemistry.« less
Image analysis for maintenance of coating quality in nickel electroplating baths--real time control.
Vidal, M; Amigo, J M; Bro, R; van den Berg, F; Ostra, M; Ubide, C
2011-11-07
The aim of this paper is to show how it is possible to extract analytical information from images acquired with a flatbed scanner and make use of this information for real time control of a nickel plating process. Digital images of plated steel sheets in a nickel bath are used to follow the process under degradation of specific additives. Dedicated software has been developed for making the obtained results accessible to process operators. This includes obtaining the RGB image, to select the red channel data exclusively, to calculate the histogram of the red channel data and to calculate the mean colour value (MCV) and the standard deviation of the red channel data. MCV is then used by the software to determine the concentration of the additives Supreme Plus Brightner (SPB) and SA-1 (for confidentiality reasons, the chemical contents cannot be further detailed) present in the bath (these two additives degrade and their concentration changes during the process). Finally, the software informs the operator when the bath is generating unsuitable quality plating and suggests the amount of SPB and SA-1 to be added in order to recover the original plating quality. Copyright © 2011 Elsevier B.V. All rights reserved.
CURRENT AND EMERGING TECHNOLOGIES FOR EXTENDING THE LIFETIME OF ELECTROLESS NICKEL PLATING BATHS
The waste treatment and rejuvenation of spent electroless nickel baths has attracted a considerable amount of interest from electroplating shops, electroless nickel suppliers, universities and regulatory agencies due to the finite life of the baths and the associated waste that t...
40 CFR 420.81 - Specialized definitions.
Code of Federal Regulations, 2013 CFR
2013-07-01
...-finished steel products by the action of molten salt baths other than those containing sodium hydride. (b... the action of molten salt baths containing sodium hydride. (c) The term batch, sheet and plate means... STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Salt Bath Descaling Subcategory § 420.81...
40 CFR 420.81 - Specialized definitions.
Code of Federal Regulations, 2014 CFR
2014-07-01
...-finished steel products by the action of molten salt baths other than those containing sodium hydride. (b... the action of molten salt baths containing sodium hydride. (c) The term batch, sheet and plate means... STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Salt Bath Descaling Subcategory § 420.81...
40 CFR 63.341 - Definitions and nomenclature.
Code of Federal Regulations, 2012 CFR
2012-07-01
... air pollution control device or a chemical fume suppressant, that is used to reduce chromium emissions... trivalent chromium plating baths. For trivalent chromium baths, the bath composition is proprietary in most... to the surface tension. Trivalent chromium means the form of chromium in a valence state of +3...
Over the last decade electrodialysis has emerged as an effective technique for removing accumulated reactant counterions (sodium and sulfate) and reaction products (orthophosphite) that interfere with the electroless nickel plating process, thus extending bath life by up to 50 me...
40 CFR 420.81 - Specialized definitions.
Code of Federal Regulations, 2012 CFR
2012-07-01
... from semi-finished steel products by the action of molten salt baths other than those containing sodium... products by the action of molten salt baths containing sodium hydride. (c) The term batch, sheet and plate... AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Salt Bath Descaling Subcategory § 420...
NASA Astrophysics Data System (ADS)
Yanai, T.; Koda, K.; Eguchi, K.; Morimura, T.; Takashima, K.; Nakano, M.; Fukunaga, H.
2018-04-01
We have already reported Fe-Ni films with good soft magnetic properties prepared by using an electroplating method. In the present study, we employed an annealing for further improvement in soft magnetic properties of the electroplated Fe-Ni films. The annealing reduces the coercivity of the films, and the reduction rate of the coercivity depended on the Cl- ion concentration in the bath. The Fe22Ni78 films prepared in the plating bath with high Cl- ion concentration showed large reduction rate of the coercivity, and we found that the annealing is more effective for high Cl- ion concentration bath since much lower coercivity value can be obtained compared with that for low Cl- ion concentration one.
Process for forming a nickel foil with controlled and predetermined permeability to hydrogen
Engelhaupt, Darell E.
1981-09-22
The present invention provides a novel process for forming a nickel foil having a controlled and predetermined hydrogen permeability. This process includes the steps of passing a nickel plating bath through a suitable cation exchange resin to provide a purified nickel plating bath free of copper and gold cations, immersing a nickel anode and a suitable cathode in the purified nickel plating bath containing a selected concentration of an organic sulfonic acid such as a napthalene-trisulfonic acid, electrodepositing a nickel layer having the thickness of a foil onto the cathode, and separating the nickel layer from the cathode to provide a nickel foil. The anode is a readily-corrodible nickel anode. The present invention also provides a novel nickel foil having a greater hydrogen permeability than palladium at room temperature.
Polyfibroblast: A Self-Healing and Galvanic Protection Additive
2011-04-25
of premature microcapsule rupture, and have shown that the microcapsules are resilient to solvent soaking. 2 Project Goals and Objectives This month...capability of Polyfibroblast microcapsules , we designed the following test. We short-circuited a A1008 steel specimen to a strip of polyurethane...pH New experiments have revealed that alkaline plating baths etch the polymer skin layer. Fresh microcapsules placed in plating baths with a pH of
40 CFR 63.11507 - What are my standards and management practices?
Code of Federal Regulations, 2010 CFR
2010-07-01
... chemistry ingredients that are added to replenish the tank bath, as in the original make-up of the tank. (iii) If a wetting agent/fume suppressant is included in the electrolytic process bath chemicals used... to be plated, as practicable. (8) Maintain quality control of chemicals, and chemical and other bath...
NASA Astrophysics Data System (ADS)
Yanai, T.; Akiyoshi, T.; Yamaguchi, T.; Takashima, K.; Morimura, T.; Nakano, M.; Fukunaga, H.
2018-05-01
Fe-Ni alloy films were electroplated in DES-based plating baths with various primary amines, and we investigated the effect of the primary amines on the magnetic and the structural properties of the films. The primary amines of ammonium sulfamate, DL-α-alanine and L-glutamic acid reduced the coercivity and the surface roughness of the Fe-rich films (Fe > 70 at.%), and the reduction tendencies of the coercivity and the roughness show good agreement with the result of our previous study on another primary amine of glycine. From the results for the TEM observation, we found that the texture of the Fe-rich film is clearly different from that for the Fe-poor one (Fe < 30 at.%), and we concluded that the primary amines are effective additives for the Fe-rich films electroplated in the DES-based plating baths.
Seal Materials Compatible with the Electroplating Solvent Used in Constellation-X Mirrors
NASA Technical Reports Server (NTRS)
Pei, Xiong-Skiba
1999-01-01
The existing gasket seals used in electroplating of the Constellation-X mirrors are difficult to assemble, and the current seal material is hydrophobic and too thick. The combination of the above problems result in: 1) non-uniform plating; 2) defect sites such as pits on the mirror edges; 3) "bear claws" on the edges of the mandrels and mirrors causing difficulties in shell-mirror separations; and 4) leakage of the plating solution past the seals into the mandrel causing chemical etching of the mandrel interior. This paper reports the results of this summer study in searching for alternate seal materials chemically compatible with the electroplating solvent. Fifteen common elastomeric rubber seal materials made-by Parker Seals were investigated including butyl, ethylene propylene, fluorosilicone, nitrile, Viton fluorocarbon, and silicone. Test results showed that Viton fluorocarbon compounds as a group were superior to the other tested compounds for chemical compatibility with the plating bath.
Cho, Young-Lae; Lee, Jung-Woo; Lee, Chang-Hyoung; Choi, Hyung-Seon; Kim, Sung-Su; Song, Young Il; Park, Chan; Suh, Su-Jeong
2015-10-01
An aluminum (Al) thin film capacitor was fabricated for a high capacitance capacitor using electrochemical etching, barrier-type anodizing, and electroless Ni-P plating. In this study, we focused on the bottom-up filling of Ni-P electrodes on Al2O3/Al with etched tunnels. The Al tunnel pits were irregularly distributed on the Al foil, diameters were in the range of about 0.5~1 μm, the depth of the tunnel pits was approximately 35~40 μm, and the complex structure was made full filled hard metal. To control the plating rate, the experiment was performed by adding polyethyleneimine (PEI, C2H5N), a high molecular substance. PEI forms a cross-link at the etching tunnel inlet, playing the role of delaying the inlet plating. When the PEI solution bath was used after activation, the Ni-P layer was deposited selectively on the bottoms of the tunnels. The characteristics were analyzed by adding the PEI addition quantity rate of 100~600 mg/L into the DI water. The capacitance of the Ni-P/Al2O3 (650~700 nm)/Al film was measured at 1 kHz using an impedance/gain phase analyzer. For the plane film without etch tunnels the capacitance was 12.5 nF/cm2 and for the etch film with Ni-P bottom-up filling the capacitance was 92 nF/cm2. These results illustrate a remarkable maximization of capacitance for thin film metal capacitors.
Electrolytically deposited Cadmium Selenide Films for Photovoltaic Applications
NASA Astrophysics Data System (ADS)
Dervos, C. T.; Palaiologopoulou, M. D.
2012-10-01
CdSe films were electrodeposited on pure nickel substrates. The nickel substrate was polished to a mirror finish by Al2O3 paste, etched in 10% HCl solution for 40 s and rinsed thoroughly by de-ionized water. The deposition bath contained solutions with excessive Cd2+ (0.2M) from CdSO4 and small amounts of SeO2 (1x10-3 M). The pH of the bath was adjusted to a value of 2.2 at RT by adding 10% H2SO4. The bath was first thermostated at the required temperature, which varied from 55°C to 65°C. Plating was accomplished at deposition potential 1000 mV (vs. Hg/Hg2SO4). The films formed had a uniform thickness and it was found to be approximately 2.0 μm thick (for 20 min electrodeposition process. The produced CdSe films were characterized by X-Ray diffraction and SEM. The induced semiconductor doping effect by thermal annealing in pure dry nitrogen gas was also investigated. Gold contacts were placed on top of the CdSe films, either by evaporation, or mechanically. Depending on the deposition parameters the electrical characteristics of the Ni/CdSe/Au structures may exhibit rectification properties. The optical excitation of the structure was investigated for various CdSe thicknesses.
Improved black nickel coatings for flat plate solar collectors
NASA Technical Reports Server (NTRS)
Lin, J. H.; Peterson, R. E.
1977-01-01
A new black nickel formula was developed which had a solar absorptance of 0.92 and an infrared emittance (at 100 C) of less than 0.10 after 14 days at 38 C and 95 percent relative humidity. The electroplating bath and conditions were changed to obtain the more stable coating configuration. The effect of bath composition, temperature, pH, and plating current density and time on the coating composition, optical properties and durability were investigated.
Study of electroless Ni-W-P alloy coating on martensitic stainless steel
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nikitasari, Arini, E-mail: arini-nikitasari@yahoo.com; Mabruri, Efendi, E-mail: efendi-lipi@yahoo.com
Electroless nickel phospor (Ni-P) is widely used in many industries due to their corrosion and wear resistance, coating uniformity, and ability to coat non-conductive surfaces. The unique properties of tungsten such as high hardness, higher melting point, lower coefficient of linear thermal expansion, and high tensile strength have created a lot of interest in developing ternary Ni-W-P alloys. This article presents the study of electroless Ni-W-P alloys coating using acid or alkaline bath on martensitic stainless steel. Nickel sulfate and sodium tungstate were used as nickel and tungsten sources, respectively, and sodium hypophosphite was used as a reducing agent. Acidmore » or alkaline bath refer to bath pH condition was adjusted by adding sulfuric acid. Martensitic stainless steel was immersed in Ni-W-P bath for 15, 30, and 60 minutes. The substrate of martensitic stainless steel was subjected to pre-treatment (polishing and cleaning) and activation prior to electroless plating. The plating characteristics were investigated for concentration ratio of nickel and hypophosphite (1:3), sodium tungstate concentration 0,1 M, immersion time (15 min, 30 min, 60 min), and bath condition (acid, alkaline). The electroless Ni-W-P plating was heat treated at 400°C for 1 hour. Deposits were characterized using scanning electron microscope (SEM) and corrosion measurement system (CMS).« less
METHOD OF APPLYING NICKEL COATINGS ON URANIUM
Gray, A.G.
1959-07-14
A method is presented for protectively coating uranium which comprises etching the uranium in an aqueous etching solution containing chloride ions, electroplating a coating of nickel on the etched uranium and heating the nickel plated uranium by immersion thereof in a molten bath composed of a material selected from the group consisting of sodium chloride, potassium chloride, lithium chloride, and mixtures thereof, maintained at a temperature of between 700 and 800 deg C, for a time sufficient to alloy the nickel and uranium and form an integral protective coating of corrosion-resistant uranium-nickel alloy.
Improved nickel plating of Inconel X-750
NASA Technical Reports Server (NTRS)
Farmer, M. E.; Feeney, J. E.; Kuster, C. A.
1969-01-01
Electroplating technique with acid pickling provides a method of applying nickel plating on Inconel X-750 tubing to serve as a wetting agent during brazing. Low-stress nickel-plating bath contains no organic wetting agents that cause the nickel to blister at high temperatures.
Thermostatic tissue platform for intravital microscopy: 'the hanging drop' model.
Pavlovic, Dragan; Frieling, Helge; Lauer, Kai-Stephan; Bac, Vo Hoai; Richter, Joern; Wendt, Michael; Lehmann, Christian; Usichenko, Taras; Meissner, Konrad; Gruendling, Matthias
2006-11-01
Intravital microscopy imposes the particular problem of the combined control of the body temperature of the animal and the local temperature of the observed organ or tissues. We constructed and tested, in the rat ileum microcirculation preparation, a new organ-support platform. The platform consisted of an organ bath filled with physiological solution, and contained a suction tube, a superfusion tube, an intestine-support hand that was attached to a micromanipulator and a thermometer probe. To cover the intestine we used a cover glass plate with a plastic ring glued on its upper surface. After a routine procedure (anaesthesia, monitoring and surgery), the intestine segment (2-3 cm long) was gently exteriorized and placed on the 'hand' of the organ support. A small part of the intestine formed a small 'island' in the bath that was filled with physiological salt solution. The cover glass was secured in place. The physiological salt solution from the superfusion tube, which was pointed to the lower surface of the cover glass, formed a 'hanging drop'. The objective of the microscope was then immersed into distilled water that was formed by the cover glass plastic ring. The 'hanging drop' technique prevented any tissue quenching, ensured undisturbed microcirculation, provided for stable temperature and humidity, and permitted a clear visual field.
NASA Astrophysics Data System (ADS)
Sengupta, Srijan; Patra, Arghya; Jena, Sambedan; Das, Karabi; Das, Siddhartha
2018-03-01
In this study, the electrodeposition of nickel foam by dynamic hydrogen bubble-template method is optimized, and the effects of key deposition parameters (applied voltage and deposition time) and bath composition (concentration of Ni2+, pH of the bath, and roles of Cl- and SO4 2- ions) on pore size, distribution, and morphology and crystal structure are studied. Nickel deposit from 0.1 M NiCl2 bath concentration is able to produce the honeycomb-like structure with regular-sized holes. Honeycomb-like structure with cauliflower morphology is deposited at higher applied voltages of 7, 8, and 9 V; and a critical time (>3 minutes) is required for the development of the foamy structure. Compressive residual stresses are developed in the porous electrodeposits after 30 seconds of deposition time (-189.0 MPa), and the nature of the residual stress remains compressive upto 10 minutes of deposition time (-1098.6 MPa). Effect of pH is more pronounced in a chloride bath compared with a sulfate bath. The increasing nature of pore size in nickel electrodeposits plated from a chloride bath (varying from 21 to 48 μm), and the constant pore size (in the range of 22 to 24 μm) in deposits plated from a sulfate bath, can be ascribed to the striking difference in the magnitude of the corresponding current-time profiles.
Electroplated Fe-Co-Ni films prepared in ammonium-chloride-based plating baths
NASA Astrophysics Data System (ADS)
Yanai, T.; Koda, K.; Kaji, J.; Aramaki, H.; Eguchi, K.; Takashima, K.; Nakano, M.; Fukunaga, H.
2018-05-01
We electroplated Fe-Co-Ni films in ammonium-chloride-based plating baths, and investigated the effect of the Co content on the magnetic properties and the structural ones of the as-plated films. The coercivity increased abruptly when the Co content become more than 60 at.%. As the rough surfaces were observed in the high Co content region, we considered that degradation of the surface is a factor of the abrupt increase in the coercivity. From the XRD analysis, we found that another factor of the abrupt increase is fcc-bcc phase transformation, and concluded that we need to keep the fcc structure to obtain Fe-Co-Ni films with low coercivity.
A REVIEW OF NICKEL PLATING BATH LIFE EXTENSION, NICKEL RECOVERY & COPPER RECOVERY FROM NICKEL BATHS
For metal finishing operations to remain competitive and in compliance with environmental requirements, companies must focus their efforts on pollution prevention to reduce waste generation and disposal costs, limit liability and restore maximum profits. By applying the pollutio...
Karpukhin, I V; Li, A A; Gusev, M A
2009-01-01
The paper reports a review of up-to-date methods for the use of white turpentine bath emulsion and yellow turpentine solution in the treatment of chronic prostatitis complicated by excretory pathospermia. The results of bath therapy are presented. It is shown that the efficiency of white turpentine bath emulsion amounted to 69.7% compared with 88.3% in patients treated with the use of yellow turpentine solution.
Method for conducting electroless metal-plating processes
Petit, George S.; Wright, Ralph R.
1978-01-01
This invention is an improved method for conducting electroless metal-plating processes in a metal tank which is exposed to the plating bath. The invention solves a problem commonly encountered in such processes: how to determine when it is advisable to shutdown the process in order to clean and/or re-passivate the tank. The new method comprises contacting the bath with a current-conducting, non-catalytic probe and, during plating operations, monitoring the gradually changing difference in electropotential between the probe and tank. It has been found that the value of this voltage is indicative of the extent to which nickel-bearing decomposition products accumulate on the tank. By utilizing the voltage to determine when shutdown for cleaning is advisable, the operator can avoid premature shutdown and at the same time avoid prolonging operations to the point that spontaneous decomposition occurs.
Characterization of Pulse Reverses Electroforming on Hard Gold Coating.
Byoun, Young-Min; Noh, Young-Tai; Kim, Young-Geun; Ma, Seung-Hwan; Kim, Gwan-Hoon
2018-03-01
Effect of pulse reverse current (PRC) method on brass coatings electroplated from gold solution was investigated by various plating parameters such as plating duration, the anodic duty cycle, the anodic current density and the cathodic current density. The reversed current results in a significant change in the morphology of electrodeposits, improvement of the overall current efficiency and reduction of deposit porosity. With longer pulses, hemispherical surface features are generated, while larger grains result from shorter pulse widths. The porosity of the plated samples is found to decrease compared with results at the same time-average plating rate obtained from DC or Pulse plating. A major impediment to reducing gold later thickness is the corrosion of the underlying substrate, which is affected by the porosity of the gold layer. Both the morphology and the hydrogen evolution reaction have significant impact on porosity. PRC plating affect hydrogen gold and may oxidize hydrogen produced during the cathodic portion of the waveform. Whether the dissolution of gold and oxidation of hydrogen occur depends on the type of plating bath and the plating conditions adapted. In reversed pulse plating, the amount of excess near-surface cyanide is changed after the cathodic current is applied, and the oxidation of gold under these conditions has not been fully addressed. The effects of the current density, pulse-reverse ratio and brightener concentration of the electroplating process were investigated and optimized for suitable performance.
Volume holographic elements in Kodak 131 plates processed with SHSG method
NASA Astrophysics Data System (ADS)
Collados, Manuel V.; Atencia, Jesus; Lopez, Ana M.; Quintanilla, Manuel M.
2001-08-01
A SHSG procedure to register volume phase holograms in Kodak 131 plates is presented. We analyze the influence on the diffraction efficiency of the developing step and the temperature of the bleaching bath of usual SHSG processes. Applying a simple 12 steps process to form phase transmission holograms developing with D-19, bleaching with R-10 at 70 degrees C and removing the sensitizing dyes that remain in the emulsion with a diluted methanol bath after the fixation step, we obtain relative efficiencies of 100 percent and effective efficiencies of 70 percent.
Pouran, Behdad; Arbabi, Vahid; Weinans, Harrie; Zadpoor, Amir A
2016-11-01
Transport of solutes helps to regulate normal physiology and proper function of cartilage in diarthrodial joints. Multiple studies have shown the effects of characteristic parameters such as concentration of proteoglycans and collagens and the orientation of collagen fibrils on the diffusion process. However, not much quantitative information and accurate models are available to help understand how the characteristics of the fluid surrounding articular cartilage influence the diffusion process. In this study, we used a combination of micro-computed tomography experiments and biphasic-solute finite element models to study the effects of three parameters of the overlying bath on the diffusion of neutral solutes across cartilage zones. Those parameters include bath size, degree of stirring of the bath, and the size and concentration of the stagnant layer that forms at the interface of cartilage and bath. Parametric studies determined the minimum of the finite bath size for which the diffusion behavior reduces to that of an infinite bath. Stirring of the bath proved to remarkably influence neutral solute transport across cartilage zones. The well-stirred condition was achieved only when the ratio of the diffusivity of bath to that of cartilage was greater than ≈1000. While the thickness of the stagnant layer at the cartilage-bath interface did not significantly influence the diffusion behavior, increase in its concentration substantially elevated solute concentration in cartilage. Sufficient stirring attenuated the effects of the stagnant layer. Our findings could be used for efficient design of experimental protocols aimed at understanding the transport of molecules across articular cartilage. Copyright © 2016 Elsevier Ltd. All rights reserved.
Electroplating Gold-Silver Alloys for Spherical Capsules for NIF Double-Shell Targets
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bhandarkar, N.; Horwood, C.; Bunn, T.
For Inertial Confinement Fusion (ICF) implosions, a design based on gradients of high and mid Z materials could potentially be more robust than single element capsule systems. To that end, gold and silver alloys were electroplated on 2.0 mm diameter surrogate brass spheres using a new flow–based pulsed plating method specifically designed to minimize surface roughness without reducing plating rates. The coatings were analyzed by scanning electron microscope (SEM) and white light interferometry for surface topography, and by energy dispersive x-ray spectroscopy (EDX) to determine near-surface gold and silver compositions. The alloy range attainable was 15 to 85 weight percentmore » gold using 1:1 and 1:3 silver to gold ratio plating baths at applied potentials of -0.7 volts to -1.8 volts. This range was bounded by the open circuit potential of the system and hydrogen evolution, and in theory could be extended by using ionic liquids or aprotic solutions. Preliminary gradient trials proved constant composition alloy data could be translated to smooth gradient plating, albeit at higher gold compositions.« less
Silver plating ensures reliable diffusion bonding of dissimilar metals
NASA Technical Reports Server (NTRS)
1967-01-01
Dissimilar metals are reliably joined by diffusion bonding when the surfaces are electroplated with silver. The process involves cleaning and etching, anodization, silver striking, and silver plating with a conventional plating bath. It minimizes the formation of detrimental intermetallic phases and provides greater tolerance of processing parameters.
In-Situ Swelling For Holographic Color Control
NASA Astrophysics Data System (ADS)
Walker Parker, Julie L.; Benton, Stephen A.
1989-05-01
Deliberate variations of the emulsion thickness between holographic exposures and reconstruction produce a range of output wavelengths from a fixed exposure wavelength, a technique known as "pseudo-color" multi-color reflection holography. Usual methods require the removal of the film or plate from the holographic setup between exposures for imbibition of a swelling agent, followed by drying and replacement, so that a retention of the swelling agent forces a physical increase in the thickness of the emulsion. The density (and hence the thickness) of the gelatin binder can also be varied by changing its electrolytic environment. By immersing the holographic emulsion in a suitable solution, allowing it to come to a new equilibrium thickness, and exposing with a long-wavelength laser, shorter wavelength reconstructions can be obtained without removing the film or plate from the setup. Accurate changes of solution can make a precise sequence of swellings possible, producing multiple reconstruction colors from a set of constant-wavelength recordings. Here we describe pre-treatments of the emulsion that make rapid and stable equilibria possible, and swelling bath sequences that produce color primaries suitable for full-color computer-graphic holographic imagery.
Fixation-free rehalogenating bleached reflection holograms recorded on BB-640 plates
NASA Astrophysics Data System (ADS)
Neipp, C.; Pascual, I.; Beléndez, A.
2000-08-01
Fixation-free rehalogenating bleaching is an interesting process for the production of phase reflection holograms. The shrinkage of the emulsion is reduced in comparison with other bleaching methods (reversal bleaching or rehalogenating bleaching with a fixation step), which is particularly interesting in the case of reflection holograms. In this communication, we present experimental results for fixation-free rehalogenating bleached holograms derived from the novel BB-640 emulsion, a red-sensitive ultra-fine grain emulsion from Holographic Recording Technologies using an R-10 type bleach bath. The influence of the potassium bromide concentrations in the bleach solution on the final quality of the holograms is also studied. The concentrations of the different components of the bleach solution are adjusted to obtain the highest diffraction efficiencies. A high diffraction efficiency of 72% is obtained.
Gill, Thomas Mark; Zhao, Jiheng; Berenschot, Erwin J W; Tas, Niels; Zheng, Xiaolin
2018-06-25
Nickel (Ni) plating has garnered great commercial interest, as it provides excellent hardness, corrosion resistance, and electrical conductivity. Though Ni plating on conducting substrates is commonly employed via electrodeposition, plating on semiconductors and insulators often necessitates electroless approaches. Corresponding plating theory for deposition on planar substrates was developed as early as 1946, but for substrates with micro- and nanoscale features, very little is known of the relationships between plating conditions, Ni deposition quality, and substrate morphology. Herein, we describe the general theory and mechanisms of electroless Ni deposition on semiconducting silicon (Si) substrates, detailing plating bath failures and establishing relationships between critical plating bath parameters and the deposited Ni film quality. Through this theory, we develop two different plating recipes: galvanic displacement (GD) and autocatalytic deposition (ACD). Neither recipe requires pretreatment of the Si substrate, and both methods are capable of depositing uniform Ni films on planar Si substrates and convex Si pyramids. In comparison, ACD has better tunability than GD, and it provides a more conformal Ni coating on complex and high-aspect-ratio Si structures, such as inverse fractal Si pyramids and ultralong Si nanowires. Our methodology and theoretical analyses can be leveraged to develop electroless plating processes for other metals and metal alloys and to generally provide direction for the adaptation of electroless deposition to modern applications.
7. INTERIOR VIEW OF THE MESTA CAROUSEL PICKLER, A SERIES ...
7. INTERIOR VIEW OF THE MESTA CAROUSEL PICKLER, A SERIES OF ACID, WATER AND LIME BATHS WHICH REMOVE RUST AND SCALE FROM THE STEEL PLATE AND LUBRICATES PLATE FOR THE SHEARING PROCESS - LaBelle Iron Works, Thirtieth & Wood Streets, Wheeling, Ohio County, WV
[Interlaboratory Study on Evaporation Residue Test for Food Contact Products (Report 1)].
Ohno, Hiroyuki; Mutsuga, Motoh; Abe, Tomoyuki; Abe, Yutaka; Amano, Homare; Ishihara, Kinuyo; Ohsaka, Ikue; Ohno, Haruka; Ohno, Yuichiro; Ozaki, Asako; Kakihara, Yoshiteru; Kobayashi, Hisashi; Sakuragi, Hiroshi; Shibata, Hiroshi; Shirono, Katsuhiro; Sekido, Haruko; Takasaka, Noriko; Takenaka, Yu; Tajima, Yoshiyasu; Tanaka, Aoi; Tanaka, Hideyuki; Tonooka, Hiroyuki; Nakanishi, Toru; Nomura, Chie; Haneishi, Nahoko; Hayakawa, Masato; Miura, Toshihiko; Yamaguchi, Miku; Watanabe, Kazunari; Sato, Kyoko
2018-01-01
An interlaboratory study was performed to evaluate the equivalence between an official method and a modified method of evaporation residue test using three food-simulating solvents (water, 4% acetic acid and 20% ethanol), based on the Japanese Food Sanitation Law for food contact products. Twenty-three laboratories participated, and tested the evaporation residues of nine test solutions as blind duplicates. For evaporation, a water bath was used in the official method, and a hot plate in the modified method. In most laboratories, the test solutions were heated until just prior to evaporation to dryness, and then allowed to dry under residual heat. Statistical analysis revealed that there was no significant difference between the two methods, regardless of the heating equipment used. Accordingly, the modified method provides performance equal to the official method, and is available as an alternative method.
Vidal, M; Amigo, J M; Bro, R; Ostra, M; Ubide, C; Zuriarrain, J
2011-05-23
Desktop flatbed scanners are very well-known devices that can provide digitized information of flat surfaces. They are practically present in most laboratories as a part of the computer support. Several quality levels can be found in the market, but all of them can be considered as tools with a high performance and low cost. The present paper shows how the information obtained with a scanner, from a flat surface, can be used with fine results for exploratory and quantitative purposes through image analysis. It provides cheap analytical measurements for assessment of quality parameters of coated metallic surfaces and monitoring of electrochemical coating bath lives. The samples used were steel sheets nickel-plated in an electrodeposition bath. The quality of the final deposit depends on the bath conditions and, especially, on the concentration of the additives in the bath. Some additives become degraded with the bath life and so is the quality of the plate finish. Analysis of the scanner images can be used to follow the evolution of the metal deposit and the concentration of additives in the bath. Principal component analysis (PCA) is applied to find significant differences in the coating of sheets, to find directions of maximum variability and to identify odd samples. The results found are favorably compared with those obtained by means of specular reflectance (SR), which is here used as a reference technique. Also the concentration of additives SPB and SA-1 along a nickel bath life can be followed using image data handled with algorithms such as partial least squares (PLS) regression and support vector regression (SVR). The quantitative results obtained with these and other algorithms are compared. All this opens new qualitative and quantitative possibilities to flatbed scanners. Copyright © 2011 Elsevier B.V. All rights reserved.
Pouran, Behdad; Arbabi, Vahid; Zadpoor, Amir A; Weinans, Harrie
2016-12-01
The metabolic function of cartilage primarily depends on transport of solutes through diffusion mechanism. In the current study, we use contrast enhanced micro-computed tomography to determine equilibrium concentration of solutes through different cartilage zones and solute flux in the cartilage, using osteochondral plugs from equine femoral condyles. Diffusion experiments were performed with two solutes of different charge and approximately equal molecular weight, namely iodixanol (neutral) and ioxaglate (charge=-1) in order to isolate the effects of solute's charge on diffusion. Furthermore, solute concentrations as well as bath osmolality were changed to isolate the effects of steric hindrance on diffusion. Bath concentration and bath osmolality only had minor effects on the diffusion of the neutral solute through cartilage at the surface, middle and deep zones, indicating that the diffusion of the neutral solute was mainly Fickian. The negatively charged solute diffused considerably slower through cartilage than the neutral solute, indicating a large non-Fickian contribution in the diffusion of charged molecules. The numerical models determined maximum solute flux in the superficial zone up to a factor of 2.5 lower for the negatively charged solutes (charge=-1) as compared to the neutral solutes confirming the importance of charge-matrix interaction in diffusion of molecules across cartilage. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.
Study on the removal of iron impurities in methanesulfonic acid tin plating bath
NASA Astrophysics Data System (ADS)
Hou-li, LIU; Jian-Jun, CHEN; Hong-Liang, PAN
2018-03-01
This thesis investigated the the influence of sodium sulfite as reducing agent on the recovery rate of tin ion. The approach is that HZ016 type cation exchange resin was used to adsorb Sn2+ and Fe2+ in electroplated tin solution first. After adsorption, the resin was removed by sulfuric acid, which was added with NaOH to adjust pH value to form precipitation and separate tin. X-ray diffraction (XRD) and energy spectrum (EDS) method were used to analyze the composition of the precipitates adjusted by pH. The results show that when the mass ratio of resin to bath is 1:2, the adsorption efficiency of resin reaches 98.3% and 97.1% respectively, and the elution efficiency of tin and iron reaches 95.1% and 94% respectively when the mass ratio of resin to eluent sulfuric acid is 1:4. Sodium sulfite was added to increase the efficiency of tin recovery by 8.1%. EDS and XRD atlas showed that after pH regulation, the main composition of the filtration precipitation was the hydroxides of tin.
Fabrication of ZnO nanorod using spray-pyrolysis and chemical bath deposition method
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ramadhani, Muhammad F., E-mail: brian@tf.itb.ac.id; Pasaribu, Maruli A. H., E-mail: brian@tf.itb.ac.id; Yuliarto, Brian, E-mail: brian@tf.itb.ac.id
2014-02-24
ZnO thin films with nanorod structure were deposited using Ultrasonic Spray Pyrolysis method for seed growth, and Chemical Bath Deposition (CBD) for nanorod growth. High purity Zn-hydrate and Urea are used to control Ph were dissolved in ethanol and aqua bidest in Ultrasonic Spray Pyrolysis process. Glass substrate was placed above the heater plate of reaction chamber, and subsequently sprayed with the range duration of 5, 10 and 20 minutes at the temperatures of 3500 C. As for the Chemical Bath Deposition, the glass substrate with ZnO seed on the surface was immerse to Zn-hydrate, HMTA (Hexa Methylene Tetra Amine)more » and deionized water solution for duration of 3, 5 and 7 hour and temperatures of 600 C, washed in distilled water, dried, and annealed at 3500 C for an hour. The characterization of samples was carried out to reveal the surface morphology using Scanning Electron Microscopy (SEM). From the data, the combination of 5 minutes of Ultrasonic Spray Pyrolysis process and 3 hour of CBD has showed the best structure of nanorod. Meanwhile the longer Spraying process and CBD yield the bigger nanorod structure that have been made, and it makes the films more dense which make the nanorod collide each other and as a result produce unsymetric nanorod structure.« less
75 FR 31691 - Safety Standard for Infant Bath Seats: Final Rule
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-04
... Preparation Comment: One commenter stated that, while it agrees with the application of the soap solution inside and outside of the tub, it believes that the soap solution should be applied once the product has... leaving children unsupervised in bath seats. To date, no practical solutions to this serious problem have...
NASA Astrophysics Data System (ADS)
Brown, Delilah A.; Morgan, Sean; Peldzinski, Vera; Brüning, Ralf
2017-11-01
Copper films for printed circuit board applications have to be fine-grained to achieve even filling of vias. Electroplated Cu films on roll annealed Cu substrates may have unacceptably large epitaxial crystals. Here galvanic films were plated on oriented single-crystal Cu substrates from an additive-free electrolyte, as well as DC plating and pulse reverse (PR) plating with additives. The distribution of crystallite orientations was mapped with XRD and compared with the microstructure determined by SEM. For the additive-free bath on [1 1 1] and [1 0 0] oriented surfaces a gradual transition from epitaxial to polycrystalline is seen, while films on [1 1 0] substrates are persistently epitaxial. Without bath additives, twinning is the main mechanism for the transition to polycrystalline texture. For DC plating, additives (carriers, accelerators and levelers) promote fine-grained films with isotropic grain orientations, with films on [1 1 0] substrates being partially isotropic. Plating with carriers and accelerators (no leveler) yields films with many distinct crystallite orientations. These orientations result from up to five steps of recursive twinning. PR plating produces isotropic films with no or very few twins (〈1 1 1〉 and 〈1 0 0〉 substrates, respectively), while on 〈1 1 0〉 oriented surfaces the deposits are about 20% epitaxial.
Characterisation of a Zn / Ni Plating Bath
2009-09-03
accelerated corrosion in the first stages which is then slowed down by its own product of corrosion, Zn(OH)212. Zinc hydroxide dehydrates in time to form ZnO ... Electrochemistry , 1991, 21, 642 [5] – Alfantasi, A.M., A study on the synthesis, characterization ans properties of pulse-plated ultrafine- grained Zn-Ni alloy
NASA Astrophysics Data System (ADS)
Meenan, B. J.; Brown, N. M. D.; Wilson, J. W.
1994-03-01
A PdCl 2/SnCl 2 metallisation catalyst system, of the type used to activate non-conducting surfaces for electroless metal deposition, has been characterised by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The substrate is a barium titanate (BaTiO 3)-based electroactive ceramic of the type used in the fabrication of multilayer ceramic capacitors (MLCC). The treatment of the substrate surface with the PdCl 2/SnCl 2 "sensitiser" solution leads to the adsorption of catalytically inactive compounds of palladium and tin. Subsequent treatment of this surface with an "accelerator" solution removes excess oxides, hydroxides and salts of tin thereby leaving the active catalyst species, Pd xSn y, on the surface. Such sites, on exposure to the appropriete electroless plating bath, are then responsible for the metal deposition. In this study, the chemical state and relative quantities of the various surface species present after each of the processing stages have been determined by XPS. The surface roughness of the substrate results in less of the tin compounds present thereon being removed on washing the catalysed surface in the accelerator solution than normally reported for such systems, thereby affecting the measured Pd: Sn ratio. SEM studies show that the accelerator solution treatment generates crystalline areas, which may be a result of coagulation of the Pd xSn y particles present, in the otherwise amorphous catalyst coating.
Osmosis in Cortical Collecting Tubules
Schafer, James A.; Troutman, Susan L.; Andreoli, Thomas E.
1974-01-01
The present experiments were designed to evaluate the effects of varying the osmolality of luminal solutions on the antidiuretic hormone (ADH)-independent water and solute permeability properties of isolated rabbit cortical collecting tubules. In the absence of ADH, the osmotic water permeability coefficient (cm s–1) Pfl→b, computed from volume flows from hypotonic lumen to isotonic bath, was 20 ± 4 x 10–4 (SEM); the value of Pfb→l in the absence of ADH, computed from volume flows from isotonic bath to hypertonic lumen, was 88 ± 15 x 10–4 cm s–1. We also measured apparent urea permeability coefficients (cm s–1) from 14C-urea fluxes from lumen to bath (P DDurea l→b) and from bath to lumen (P DDurea b→l). For hypotonic luminal solutions and isotonic bathing solutions, P DDurea l→b was 0.045 ± 0.004 x 10–4 and was unaffected by ADH. The ADH-independent values of P DDurea l→b and P urea b→l were, respectively, 0.216 ± 0.022 x 10–4 cm s–1 and 0.033 ± 0.002 x 10–4 cm s–1 for isotonic bathing solutions and luminal solutions made hypertonic with urea, i.e., there was an absolute increase in urea permeability and asymmetry of urea fluxes. Significantly, P DDurea l→b did not rise when luminal hypertonicity was produced by sucrose; and, bathing fluid hypertonicity did not alter tubular permeability to water or to urea. We interpret these data to indicate that luminal hypertonicity increased the leakiness of tight junctions to water and urea but not sucrose. Since the value of Pfb→l in the absence of ADH, when tight junctions were open to urea, was approximately half of the value of Pfl→b in the presence of ADH, when tight junctions were closed to urea, we conclude that tight junctions are negligible paracellular shunts for lumen to bath osmosis with ADH. These findings, together with those in the preceding paper, are discussed in terms of a solubility-diffusion model for water permeation in which ADH increases water solubility in luminal plasma membranes. PMID:4846768
NASA Astrophysics Data System (ADS)
Hou, Lei; Bi, Siyi; Zhao, Hang; Xu, Yumeng; Mu, Yuhang; Lu, Yinxiang
2017-05-01
High corrosion resistant Cu-Co-P coatings were firstly prepared on polyethylene terephthalate (PET) substrate by electroless plating in combination with UV/ozonolysis irradiation under optimized cobalt sulfate heptahydrate concentration, pH value, plating temperature and time. The copper polyalloy/PET composite can be obtained in three steps, namely: (i) the generation of oxygen-containing functionalities (carboxylic groups) onto PET surface through UV irradiation combined with ozone, (ii) Cu seeding catalysts were obtained after being immersed into cupric citrate and NaBH4 solutions subsequently, and (iii) Cu-Co-P polyalloy metallization using electroless plating bath. Attenuated total reflection fourier transformation infrared spectrometer (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), water contact angle measurement and energy dispersive X-ray analysis (EDAX) were utilized to track the surface changes during the whole process. The electroless plating conditions were optimized by an orthogonal experiment (L9(3)4) for Cu-Co-P coating as follows: CoSO4·7H2O addition of 0.08 M, pH value, plating temperature and time were set on 10.0, 35 °C and 25 min, respectively. Under the optimal conditions, copper polyalloy possessed high adhesive strength and the lowest surface resistance (8.06 Ω/sq), while maintaining reliability even after over 1000 times of bending and mechanical stress. The results of scanning electron microscope (SEM) and atomic force microscope (AFM) measurements showed that Cu-Co-P layer formed on PET surface was imparted with fine uniformity and high compactness. Electrochemical test revealed the optimized Cu-Co-P coatings exhibited high corrosion resistance in NaCl, NaOH and HCl solutions, respectively. The excellent electromagnetic interference shielding effectiveness (EMI SE >99.999% at frequency ranging from 30 MHz to 1000 MHz) of copper polyalloy/PET composites was confirmed by the spectrum analyzer. Therefore, this copper polyalloy will have potential applications in microelectronics packaging and coatings for anti-corrosion and electromagnetic interference shielding.
2005-01-01
Patients with chronic prostatitis complicated by sexual dysfunction took turpentine baths with yellow solution in concentration rising from 5 to 55 ml solution per 200 l water, temperature 35-40 degrees C, duration 5-16 min, daily, 12-15 procedures. Yellow turpentine baths raise efficacy of treatment of patients with copulative dysfunction to 64% due to intensive arterial blood inflow to the sexual organs including the cavernous bodies of the penis.
Ion chromatography in the manufacture of multilayer circuit boards
NASA Astrophysics Data System (ADS)
Smith, R. E.
1987-10-01
Ion chromatography (IC) has proven useful in analyzing chemical solutions used in the manufacture of multilayer circuit boards. IC provides results on ions not expected in the production solutions. Thus, solution contamination and breakdown products can be monitored in every phase of the circuit board manufacturing. During the first phase, epoxy laminates experience an etchback, first in chromic acid, which can be analyzed for trace chloride and sulfate, then in ammonium bifluoride/HCl, which can be analyzed for fluoride and chloride. Following a wet blasting to roughen up the surface, 20 mu in. of copper are deposited using an electroless bath. Again, IC is applicable for monitoring formate, tartarate, and sulfate levels. Next, an acid copper bath is used to electroplate the through holes with 0.001 in. of ductile copper. This bath is analyzed for trace chloride. Photoimaging is then performed, and the organic solvents used can be assayed for trace ionic chloride. Finally, a fluoroboric acid-based tin-lead bath is used to deposit a solderable alloy. This bath is analyzed for total fluoroborate, tin, and lead. In addition, mobile phase ion chromatography (MPIC) is used to monitor the nonionic organic brighteners in the baths.
Ion chromatography in the manufacture of multilayer circuit boards
NASA Astrophysics Data System (ADS)
Smith, Robert E.
1990-01-01
Ion chromatography (IC) has proven useful in analyzing chemical solutions used in the manufacture of multilayer circuit boards. Unlike other chemical quantification techniques, IC provides results on ions not expected in the production solutions. Thus, solution contamination and break-down products can be monitored in every phase of the circuit board manufacturing. During the first phase, epoxy laminates experience an etchback, first in chromic acid, which can be analyzed for trace chloride and sulfate, then in ammonium bifluoride/HCl, which can be analyzed for fluoride and chloride. Following a wet-blasting to roughen up the surface, 20 microinches of copper are deposited using an electroless bath. Again, IC is applicable for monitoring formate, tartarate, and sulfate levels. Next, an acid copper bath is used to electroplate the through holes with 0.001 inches of ductile copper. This bath is analyzed for trace chloride. Photoimaging is then performed, and the organic solvents used can be assayed for trace ionic chloride. Finally, a fluoroboric acid-based tin-lead bath is used to deposit a solderable alloy. This bath is analyzed for fluoroborate, tin, and lead. In addition, mobile phase ion chromatography (MPIC) is used to monitor the nonionic organic brighteners in the baths.
Metallization of Large Silicon Wafers
NASA Technical Reports Server (NTRS)
Pryor, R. A.
1978-01-01
A metallization scheme was developed which allows selective plating of silicon solar cell surfaces. The system is comprised of three layers. Palladium, through the formation of palladium silicide at 300 C in nitrogen, makes ohmic contact to the silicon surface. Nickel, plated on top of the palladium silicide layer, forms a solderable interface. Lead-tin solder on the nickel provides conductivity and allows a convenient means for interconnection of cells. To apply this metallization, three chemical plating baths are employed.
Nanocrystalline Cobalt-Phosphorous Electroplating as an Alternative to Hard Chromium Electroplating
2012-08-01
Validate pulsed electrodeposition of Nanocrystalline Cobalt-Phosphorous (nCoP) alloy coatings as a Hard Chrome electroplating alternative for DoD...limits Cr+6 Cathode Efficiency Cr Plating *Co PEL is 20 µg/m3 ≈5X faster than Chrome plating Increased throughput One nCo-P tank can...replace several hard chrome tanks Bath is Stable nCoP Plating Approaches 100% Efficiency Process Comparison CoP Technical Approach
NASA Astrophysics Data System (ADS)
Ezema, F. I.; Ekwealor, A. B. C.; Osuji, R. U.
2006-05-01
Zinc selenide (ZnSe) thin films were deposited on glass substrate using the chemical bath deposition method at room temperature from aqueous solutions of zinc sulphate and sodium selenosulfate in which sodium hydroxide was employed as complexing agents. The `as-deposited' ZnSe thin films are red in color and annealed in oven at 473 K for 1 hour and on a hot plate in open air at 333 K for 5 minutes, affecting the morphological and optical properties. Optical properties such as absorption coefficient a and extinction coefficient k, were determined using the absorbance and transmission measurement from Unico UV-2102 PC spectrophotometer, at normal incidence of light in the wavelength range of 200-1000 nm. The films have transmittance in VIS-NIR regions that range between 26 and 87%. From absorbance and transmittance spectra, the band gap energy determined ranged between 1.60 eV and 1.75 for the `as deposited' samples, and the annealed samples exhibited a band gap shift of 0.15 eV. The high transmittance of the films together with its large band gap made them good materials for selective coatings for solar cells.
2013-01-01
Environmentally friendly and cyanide-free sulfate bath under continuous current and the corrosion behavior of electrodeposits of zinc-iron alloys were studied by means of electrochemical tests in a solution of 3.5% NaCl in presence and absence of glycine. The effects of pH on the quality of Zn-Fe coatings were investigated in order to improve uniformity and corrosion protection performance of the coating films. The deposit morphology was analyzed using scanning electron microscopy (SEM), and X-ray diffraction (XRD) was used to determine the preferred crystallographic orientations of the deposits. It was found that the uniformity and corrosion resistance of Zn-Fe coating films were strongly associated with pH of the coating electrolyte. To obtain the effect of pH on the film quality and corrosion performances of the films, the corrosion test was performed with potentiodynamic anodic polarization method. It was also observed that uniformity and corrosion resistivity of the coating films were decreased towards pH = 5 and then improved with increasing pH value of the electrolyte. The presence of glycine in the plating bath decreases the corrosion resistance of Zn-Fe coatings. PMID:23844388
Study of different solutes for determination of neutron source strength based on the water bath
NASA Astrophysics Data System (ADS)
Khabaz, Rahim
2018-09-01
Time required for activation to saturation and background measurement is considered a limitation of strength determination of radionuclide neutron sources using manganese bath system (MBS). The objective of this research was to evaluate the other solutes based on water bath for presentation of the suitable replacement with MBS. With the aid Monte Carlo simulation, for three neutron sources, having different neutron spectra, immersed in six aqueous solutions, i.e., Na2SO4, VOSO4, MnSO4, Rh2(SO4)3, In2(SO4)3, I2O5, the correction factors in all nuclei of solutions for neutron losses with different process were obtained. The calculations results indicate that the Rh2(SO4)3 and VOSO4 are best options for replacing with MnSO4.
NASA Astrophysics Data System (ADS)
Benea, Lidia
2013-02-01
A series of Co/CeO2 (25 nm) nanocomposite coating materials by electrodeposition were successfully prepared containing different cerium oxide composition in the cobalt-plating bath. Stainless steel (304L) was used as support material for nanocomposite coatings. The nano-CeO2 is uniformly incorporated into cobalt matrix, and the effect on surface morphologies was identified by scanning electron microscopy with energy-dispersive X-ray analysis. Codeposition of nano-CeO2 particles with cobalt disturbs the regular surface morphology of the cobalt coatings. It should be noted that the as-prepared Co/CeO2 nanocomposite coatings were found to be much superior in corrosion resistance over those of pure cobalt coatings materials based on a series of electrochemical impedance spectroscopy measurements in simulating body fluid solution. With increase in the nano-CeO2 particles concentration in the cobalt electrolyte, it is observed that the corrosion resistance of Co/CeO2 increases. Co/CeO2 nanocomposite coatings have higher polarization resistance as compared with pure cobalt layers in simulating body fluid solution.
9 CFR 325.13 - Denaturing procedures.
Code of Federal Regulations, 2012 CFR
2012-01-01
... water, 40 parts liquid detergent, and 40 parts oil of citronella, or other proprietary substance... immersion in a water bath, then immersing it for 1 minute in a solution of 0.022 percent FD&C yellow No. 5... immersion in a water bath, then dipping it in a solution of 0.0625 percent ferric acid; and (5) When meat...
9 CFR 325.13 - Denaturing procedures.
Code of Federal Regulations, 2013 CFR
2013-01-01
... water, 40 parts liquid detergent, and 40 parts oil of citronella, or other proprietary substance... immersion in a water bath, then immersing it for 1 minute in a solution of 0.022 percent FD&C yellow No. 5... immersion in a water bath, then dipping it in a solution of 0.0625 percent ferric acid; and (5) When meat...
9 CFR 325.13 - Denaturing procedures.
Code of Federal Regulations, 2014 CFR
2014-01-01
... water, 40 parts liquid detergent, and 40 parts oil of citronella, or other proprietary substance... immersion in a water bath, then immersing it for 1 minute in a solution of 0.022 percent FD&C yellow No. 5... immersion in a water bath, then dipping it in a solution of 0.0625 percent ferric acid; and (5) When meat...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Achman, D.
1987-12-31
The company employs about forty people and operates for one or two eight hour shifts with an average of 315 racks of chrome plating per eight hour day. They plate a variety of metals including copper, nickel, gold, brass and chromium. Chromium is the major metal plated and is usually the last step in plating cycle. Most parts are copper plated and then nickel plated in preparation for chrome plating. The main difference between New Dimension Plating and other plating shops is the variety of parts plated. As New Dimension Plating is a job shop, a wide range of partsmore » such as motorcycle accessories, stove parts, and custom items are metal finished. The plating lines are manual, meaning employees dip the racks into the tanks by hand. This fact along with the fact that parts vary greatly in size and shape accounts for the significant drag-out on the chromium plating line.« less
[Interlaboratory Study on Evaporation Residue Test for Food Contact Products (Report 2)].
Ohno, Hiroyuki; Mutsuga, Motoh; Abe, Tomoyuki; Abe, Yutaka; Amano, Homare; Ishihara, Kinuyo; Ohsaka, Ikue; Ohno, Haruka; Ohno, Yuichiro; Ozaki, Asako; Kakihara, Yoshiteru; Kobayashi, Hisashi; Sakuragi, Hiroshi; Shibata, Hiroshi; Shirono, Katsuhiro; Sekido, Haruko; Takasaka, Noriko; Takenaka, Yu; Tajima, Yoshiyasu; Tanaka, Aoi; Tanaka, Hideyuki; Nakanishi, Toru; Nomura, Chie; Haneishi, Nahoko; Hayakawa, Masato; Miura, Toshihiko; Yamaguchi, Miku; Yamada, Kyohei; Watanabe, Kazunari; Sato, Kyoko
2018-01-01
An interlaboratory study was performed to evaluate the equivalence between an official method and a modified method of evaporation residue test using heptane as a food-simulating solvent for oily or fatty foods, based on the Japanese Food Sanitation Law for food contact products. Twenty-three laboratories participated, and tested the evaporation residues of nine test solutions as blind duplicates. In the official method, heating for evaporation was done with a water bath. In the modified method, a hot plate was used for evaporation, and/or a vacuum concentration procedure was skipped. In most laboratories, the test solutions were heated until just prior to dryness, and then allowed to dry under residual heat. Statistical analysis revealed that there was no significant difference between the two methods. Accordingly, the modified method provides performance equal to the official method, and is available as an alternative method. Furthermore, an interlaboratory study was performed to evaluate and compare two leaching solutions (95% ethanol and isooctane) used as food-simulating solvents for oily or fatty foods in the EU. The results demonstrated that there was no significant difference between heptane and these two leaching solutions.
Continuous process electrorefiner
Herceg, Joseph E [Naperville, IL; Saiveau, James G [Hickory Hills, IL; Krajtl, Lubomir [Woodridge, IL
2006-08-29
A new device is provided for the electrorefining of uranium in spent metallic nuclear fuels by the separation of unreacted zirconium, noble metal fission products, transuranic elements, and uranium from spent fuel rods. The process comprises an electrorefiner cell. The cell includes a drum-shaped cathode horizontally immersed about half-way into an electrolyte salt bath. A conveyor belt comprising segmented perforated metal plates transports spent fuel into the salt bath. The anode comprises the conveyor belt, the containment vessel, and the spent fuel. Uranium and transuranic elements such as plutonium (Pu) are oxidized at the anode, and, subsequently, the uranium is reduced to uranium metal at the cathode. A mechanical cutter above the surface of the salt bath removes the deposited uranium metal from the cathode.
Structure zone diagram and particle incorporation of nickel brush plated composite coatings
Isern, L.; Impey, S.; Almond, H.; Clouser, S. J.; Endrino, J. L.
2017-01-01
This work studies the deposition of aluminium-incorporated nickel coatings by brush electroplating, focusing on the electroplating setup and processing parameters. The setup was optimised in order to increase the volume of particle incorporation. The optimised design focused on increasing the plating solution flow to avoid sedimentation, and as a result the particle transport experienced a three-fold increase when compared with the traditional setup. The influence of bath load, current density and the brush material used was investigated. Both current density and brush material have a significant impact on the morphology and composition of the coatings. Higher current densities and non-abrasive brushes produce rough, particle-rich samples. Different combinations of these two parameters influence the surface characteristics differently, as illustrated in a Structure Zone Diagram. Finally, surfaces featuring crevices and peaks incorporate between 3.5 and 20 times more particles than smoother coatings. The presence of such features has been quantified using average surface roughness Ra and Abbott-Firestone curves. The combination of optimised setup and rough surface increased the particle content of the composite to 28 at.%. PMID:28300159
Structure zone diagram and particle incorporation of nickel brush plated composite coatings
NASA Astrophysics Data System (ADS)
Isern, L.; Impey, S.; Almond, H.; Clouser, S. J.; Endrino, J. L.
2017-03-01
This work studies the deposition of aluminium-incorporated nickel coatings by brush electroplating, focusing on the electroplating setup and processing parameters. The setup was optimised in order to increase the volume of particle incorporation. The optimised design focused on increasing the plating solution flow to avoid sedimentation, and as a result the particle transport experienced a three-fold increase when compared with the traditional setup. The influence of bath load, current density and the brush material used was investigated. Both current density and brush material have a significant impact on the morphology and composition of the coatings. Higher current densities and non-abrasive brushes produce rough, particle-rich samples. Different combinations of these two parameters influence the surface characteristics differently, as illustrated in a Structure Zone Diagram. Finally, surfaces featuring crevices and peaks incorporate between 3.5 and 20 times more particles than smoother coatings. The presence of such features has been quantified using average surface roughness Ra and Abbott-Firestone curves. The combination of optimised setup and rough surface increased the particle content of the composite to 28 at.%.
Structure zone diagram and particle incorporation of nickel brush plated composite coatings.
Isern, L; Impey, S; Almond, H; Clouser, S J; Endrino, J L
2017-03-16
This work studies the deposition of aluminium-incorporated nickel coatings by brush electroplating, focusing on the electroplating setup and processing parameters. The setup was optimised in order to increase the volume of particle incorporation. The optimised design focused on increasing the plating solution flow to avoid sedimentation, and as a result the particle transport experienced a three-fold increase when compared with the traditional setup. The influence of bath load, current density and the brush material used was investigated. Both current density and brush material have a significant impact on the morphology and composition of the coatings. Higher current densities and non-abrasive brushes produce rough, particle-rich samples. Different combinations of these two parameters influence the surface characteristics differently, as illustrated in a Structure Zone Diagram. Finally, surfaces featuring crevices and peaks incorporate between 3.5 and 20 times more particles than smoother coatings. The presence of such features has been quantified using average surface roughness Ra and Abbott-Firestone curves. The combination of optimised setup and rough surface increased the particle content of the composite to 28 at.%.
Optimization of formaldehyde concentration on electroless copper deposition on alumina surface
NASA Astrophysics Data System (ADS)
Shahidin, S. A. M.; Fadil, N. A.; Yusop, M. Zamri; Tamin, M. N.; Osman, S. A.
2018-05-01
The effect of formaldehyde concentration on electroless copper plating on alumina wafer was studied. The main composition of plating bath was copper sulphate (CuSO4) as precursor and formaldehyde as a reducing agent. The copper deposition films were assessed by varying the ratio of CuSO4 and formaldehyde. The plating rate was calculated from the weight gained after plating process whilst the surface morphology was observed by field emission scanning electron microscopy (FESEM). The results show that 1:3 ratio of copper to formaldehyde is an optimum ratio to produce most uniform coating with good adhesion between copper layer and alumina wafer substrate.
NASA Astrophysics Data System (ADS)
Bai, Shengchi; Wang, Haifeng; Yang, Hui; Zhang, He; Guo, Xingzhong
2018-02-01
Silver nanowires (AgNWs)-polyurethane (PU) composite transparent conductive films were fabricated via transfer method using AgNWs conductive inks and polyurethane as starting materials, and the effects of post-treatments including heat treatment, NaCl solution bath and HCl solution bath for AgNWs film on the sheet resistance and transmittance of the composite films were respectively investigated in detail. AgNWs networks are uniformly embedded in the PU layer to improve the adhesion and reduce the surface roughness of AgNWs-PU composite films. Heat treatment can melt and weld the nanowires, and NaCl and HCl solution baths promote the dissolution and re-deposition of silver and the dissolving of the polymer, both which form conduction pathways and improve contact of AgNWs for reducing the sheet resistance. Smooth and flexible AgNWs-PU composite film with a transmittance of 85% and a sheet resistance of 15 Ω · sq‑1 is obtained after treated in 0.5 wt% HCl solution bath for 60 s, and the optoelectronic properties of the resultant composite film can maintain after 1000 cycles of bending and 100 days.
Culture and long-term care: the bath as social service in Japan.
Traphagan, John W
2004-01-01
A central feature of Japan's approach to community-based care of the elderly, including long-term home health care, is the emphasis on providing bath facilities. For mobile elders, senior centers typically provide a public bathing facility in which people can enjoy a relaxing soak along with friends who also visit the centers. In terms of in-home long-term care, visiting bath services are provided to assist family care providers with the difflcult task of bathing a frail or disabled elder--a task made more problematic as a result of the Japanese style of bathing. I argue that the bath, as social service, is a culturally shaped solution to a specific problem of elder care that arises in the Japanese context as a result of the importance of the bath in everyday life for Japanese. While the services may be considered specific to Japan, some aspects of bathing services, particularly the mobile bath service, may also have applicability in the United States.
Wash Solution Bath Life Extension for the Space Shuttle Rocket Motor Aqueous Cleaning System
NASA Technical Reports Server (NTRS)
Saunders, Chad; Evans, Kurt; Sagers, Neil
1999-01-01
A spray-in-air aqueous cleaning system, which replaced 1,1,1 trichloroethane (TCA) vapor degreasing, is used for critical cleaning of Space Shuttle Redesigned Solid Rocket Motor (RSRM) metal parts. Small-scale testing demonstrated that the alkaline-based wash solution possesses adequate soil loading and cleaning properties. However, full-scale testing exhibited unexpected depletion of some primary components of the wash solution. Specifically, there was a significant decrease in the concentration of sodium metasilicate which forced change-out of the wash solution after eight days. Extension of wash solution bath life was necessary to ease the burden of frequent change-out on manufacturing. A laboratory study supports a depletion mechanism that is initiated by the hydrolysis of sodium tripolyphosphate (STPP) lowering the pH of the solution. The decrease in pH causes polymerization and subsequent precipitation of sodium metasilicate (SM). Further investigation showed that maintaining the pH was the key to preventing the precipitation of the sodium metasilicate. Implementation to the full scale operation demonstrated that periodic additions of potassium hydroxide (KOH) extended the useful bath life to more than four months.
Changes of minimal erythema dose after water and salt water baths.
Gambichler, T; Schröpl, F
1998-01-01
Knowledge about the influence of salt water baths on UV irradiation, especially balneophototherapy, is incomplete. The aim of this study was to investigate the influence of various concentrated salt solutions on the minimal erythema dose (MED). We determined the MEDdry (UVB) in 24 healthy, previously UV unexposed subjects on the inner forearm. Subjects were divided randomly into two groups of 12. Subsequently, the MEDwet was assessed on each forearm after 30 min tap water or 5% salt water bath (group A), respectively, or after 30 min 10% or 20% salt water bath (group B), respectively. Compared with the MEDdry, a significantly decreased MEDwet, was observed after all exposures (group A==>F = 18.94; P < 0.001; group B==>F = 11.73; P < 0.006). A maximal relative decrease in MEDdry of about 51.4% was observed after the 10% salt water bath. The 5% salt solution caused a modest relative decrease in MEDwet of 23.4%. We observed a markedly increased photosensitivity to UVB after all exposures, without a linear correlation between the MED and the salt water concentration. A determination of MED during balneophototherapy should be carried out after bathing in order to reduce the cumulative UV dose and to prevent acute photodamage.
Hahn, Seungyong; Kim, Seok Beom; Ahn, Min Cheol; Voccio, John; Bascuñán, Juan; Iwasa, Yukikazu
2010-01-01
This paper presents experimental and analytical results of trapped field characteristics of a stack of square YBCO thin film plates for compact NMR magnets. Each YBCO plate, 40 mm × 40 mm × 0.08 mm, has a 25-mm diameter hole at its center. A total of 500 stacked plates were used to build a 40-mm long magnet. Its trapped field, in a bath of liquid nitrogen, was measured for spatial field distribution and temporal stability. Comparison of measured and analytical results is presented: the effects on trapped field characteristics of the unsaturated nickel substrate and the non-uniform current distribution in the YBCO plate are discussed. PMID:20585463
Dichromated-gelatin hologram process for improved optical quality
NASA Technical Reports Server (NTRS)
Stewart, W. C.
1975-01-01
Optical distortions are eliminated by use of wetting agency followed by sequential immersion in several alcohol-water baths of increasing alcohol concentration. Dehydration proceeds uniformly over surface of gelatin. Dried plate is free of optically-distorting thickness variations.
The effects of tetracaine on charge movement in fast twitch rat skeletal muscle fibres.
Hollingworth, S; Marshall, M W; Robson, E
1990-02-01
1. The effects of tetracaine, a local anaesthetic that inhibits muscle contraction, on membrane potential and intramembrane charge movements were investigated in fast twitch rat muscle fibres (extensor digitorum longus). 2. The resting membrane potentials of surface fibres from muscles bathed in isotonic Ringer solution containing 2 mM-tetracaine were well maintained, but higher concentrations of tetracaine caused a time-dependent fall of potential. Muscle fibres bathed in hypertonic solutions containing 2 mM-tetracaine were rapidly depolarized. In both isotonic and hypertonic solutions, the depolarizing effect of tetracaine could not be reversed. 3. Charge movement measurements were made using the middle-of-the-fibre voltage clamp technique. The voltage dependence of charge movements measured in cold isotonic solutions was well fitted by a Boltzmann distribution (Q(V) = Qmax/(1 + exp(-(V-V)/k] where Qmax = 37.3 +/- 2.8 nC muF-1, V = -17.9 +/- 1.2 mV and k = 12.6 +/- 0.8 mV (n = 6, 2 degrees C; means +/- S.E. of means). Similar values were obtained when 2 mM-tetracaine was added to the isotonic bathing fluid (Qmax = 40.6 +/- 2.3 nC microF-1, V = -14.1 +/- 1.3 mV, k = 15.3 +/- 0.8 mV; n = 8, 2 degrees C). 4. Charge movements measured around mechanical threshold in muscle fibres bathed in hypertonic solutions were reduced when 2 mM-tetracaine was added to the bathing fluid. The tetracaine-sensitive component of charge was well fitted with an unconstrained Boltzmann distribution which gave: Qmax = 7.5 nC microF-1, V = -46.5 mV, k = 5.5 mV. The e-fold rise of the foot of the curve was 9.3 mV.
The effects of tetracaine on charge movement in fast twitch rat skeletal muscle fibres.
Hollingworth, S; Marshall, M W; Robson, E
1990-01-01
1. The effects of tetracaine, a local anaesthetic that inhibits muscle contraction, on membrane potential and intramembrane charge movements were investigated in fast twitch rat muscle fibres (extensor digitorum longus). 2. The resting membrane potentials of surface fibres from muscles bathed in isotonic Ringer solution containing 2 mM-tetracaine were well maintained, but higher concentrations of tetracaine caused a time-dependent fall of potential. Muscle fibres bathed in hypertonic solutions containing 2 mM-tetracaine were rapidly depolarized. In both isotonic and hypertonic solutions, the depolarizing effect of tetracaine could not be reversed. 3. Charge movement measurements were made using the middle-of-the-fibre voltage clamp technique. The voltage dependence of charge movements measured in cold isotonic solutions was well fitted by a Boltzmann distribution (Q(V) = Qmax/(1 + exp(-(V-V)/k] where Qmax = 37.3 +/- 2.8 nC muF-1, V = -17.9 +/- 1.2 mV and k = 12.6 +/- 0.8 mV (n = 6, 2 degrees C; means +/- S.E. of means). Similar values were obtained when 2 mM-tetracaine was added to the isotonic bathing fluid (Qmax = 40.6 +/- 2.3 nC microF-1, V = -14.1 +/- 1.3 mV, k = 15.3 +/- 0.8 mV; n = 8, 2 degrees C). 4. Charge movements measured around mechanical threshold in muscle fibres bathed in hypertonic solutions were reduced when 2 mM-tetracaine was added to the bathing fluid. The tetracaine-sensitive component of charge was well fitted with an unconstrained Boltzmann distribution which gave: Qmax = 7.5 nC microF-1, V = -46.5 mV, k = 5.5 mV. The e-fold rise of the foot of the curve was 9.3 mV. PMID:2348406
Synaptic potentials recorded by the sucrosegap method from the rabbit superior cervical ganglion
Kosterlitz, H. W.; Lees, G. M.; Wallis, D. I.
1970-01-01
1. Compound ganglionic potentials evoked by stimulation of the preganglionic nerves to the superior cervical ganglion of the rabbit were recorded by the sucrose-gap method. 2. When the distal part of the ganglion was bathed in flowing isotonic sucrose solution or sodium-deficient solutions, ganglionic action potentials were no longer evoked, only large synaptic potentials. 3. The compound synaptic potential, which remained unaltered for more than 1 h, originated in a population of cells at the interface between the Krebs and sucrose solutions. Hexamethonium reduced the size but did not alter the time course of the synaptic potential. 4. It is suggested that a higher concentration of sodium ions is required for the generation of ganglionic action potentials than for either conduction in the postganglionic axons or production of synaptic potentials. 5. When lithium replaced sodium in the solution bathing the distal part of the ganglion, the synaptic potential was greatly reduced in amplitude. Impulse propagation in the postganglionic axons was only slightly impaired when lithium replaced sodium in the solution bathing the axons. 6. A quantitative assessment of the potency of the ganglion-blocking drugs nicotine, pentolinium, hexamethonium and pempidine was made by measuring the depression of the synaptic potentials produced by bathing the distal part of the ganglion in flowing isotonic sucrose solution. The concentrations which produced a 50% depression were 8·1 μM nicotine, 26·5 μM pentolinium, 111 μM hexamethonium and 22·2 μM pempidine. PMID:5492898
Lightweight porous plastic plaque. [nickel cadmium batteries
NASA Technical Reports Server (NTRS)
Reid, M.
1978-01-01
The porosity and platability of various materials were investigated to determine a suitable substrate for nickel-plated electrodes. Immersion, ultrasonics, and flow-through plating techniques were tried using nonproprietary formulations, and proprietary phosphide and boride baths. Modifications to the selected material include variations in formulation and treatment, carbon loading to increase conductivity, and the incorporation of a grid. Problems to be solved relate to determining conductivities and porosities as a function of amount of nickel plated on the plastics; loading; charge and discharge curves of electrodes at different current densities; cell performance; and long-term degradation of electrodes.
[Turpentine baths in rehabilitation of patients with chronic obstructive pulmonary disease].
Aĭrapetova, N S; Polikanova, E B; Davydova, O B; Gosn, L D; Kulikova, O V; Ksenofontova, I V; Nikoda, N V; Rassulova, M A; Nitchenko, O V; Siziakova, L A; Doronina, Iu V; Derevnina, N A
2007-01-01
We have investigated effects of turpentine baths with white emultion, yellow solution and mixed on the course of inflammation, immunocompetent system, external respiration function, pulmonary cardiohemodynamics, physical performance in patients with chronic obstructive pulmonary disease. We developed differential indications for each bath variant depending on the features of a clinical picture of the disease, comorbid pathology and revealed contraindications to their administration.
The effect of papaine on the time course of the end-plate current.
Humar, M; Kordas, M; Melik, Z
1980-07-01
Papaine is known to detach cholinesterases from the synaptic cleft. It could be expected that this would result in an increase of the amplitude and half-time of the end-plate current. Thus, the effect of papaine on the end-plate current. Thus, the effect of papaine on the end-plate current should be similar to the effect of anticholinesterase methanesulfonylfluoride. The end-plate current was recorded in frog skeletal muscle at various levels of membrane potential, before and after papaine was added to the bath. The effect of papaine was an increase of the half-time of the end-plate current, similarly as after treatment of the muscle by methanesulfonylfluoride. It seems that both papaine and methanesulfonylfluoride have a similar mechanism of action. In either experimental condition hydrolysis of transmitter is decreased or abolished, which results in an increase of the half-time of the end-plate current.
Characterization of Polysulfone Membranes Prepared with Thermally Induced Phase Separation Technique
NASA Astrophysics Data System (ADS)
Tiron, L. G.; Pintilie, Ș C.; Vlad, M.; Birsan, I. G.; Baltă, Ș
2017-06-01
Abstract Membrane technology is one of the most used water treatment technology because of its high removal efficiency and cost effectiveness. Preparation techniques for polymer membranes show an important aspect of membrane properties. Generally, polysulfone (PSf) and polyethersulfone (PES) are used for the preparation of ultrafiltration (UF) membranes. Polysulfone (PSf) membranes have been widely used for separation and purification of different solutions because of their excellent chemical and thermal stability. Polymeric membranes were obtained by phase inversion method. The polymer solution introduced in the nonsolvent bath (distilled water) initiate the evaporation of the solvent from the solution, this phenomenon has a strong influence on the transport properties. The effect of the coagulation bath temperature on the membrane properties is of interest for this study. Membranes are characterized by pure water flux, permeability, porosity and retention of methylene blue. The low temperature of coagulation bath improve the membrane’s rejection and its influence was most notable.
Nerandzic, Michelle M.; Rackaityte, Elze; Jury, Lucy A.; Eckart, Kevin; Donskey, Curtis J.
2013-01-01
Background Removing spores of Clostridium difficile and Bacillus anthracis from skin is challenging because they are resistant to commonly used antimicrobials and soap and water washing provides only modest efficacy. We hypothesized that hygiene interventions incorporating a sporicidal electrochemically generated hypochlorous acid solution (Vashe®) would reduce the burden of spores on skin. Methods Hands of volunteers were inoculated with non-toxigenic C. difficile spores or B. anthracis spore surrogates to assess the effectiveness of Vashe solution for reducing spores on skin. Reduction in spores was compared for Vashe hygiene interventions versus soap and water (control). To determine the effectiveness of Vashe solution for removal of C. difficile spores from the skin of patients with C. difficile infection (CDI), reductions in levels of spores on skin were compared for soap and water versus Vashe bed baths. Results Spore removal from hands was enhanced with Vashe soak (>2.5 log10 reduction) versus soap and water wash or soak (~2.0 log10 reduction; P <0.05) and Vashe wipes versus alcohol wipes (P <0.01). A combined approach of soap and water wash followed by soaking in Vashe removed >3.5 log10 spores from hands (P <0.01 compared to washing or soaking alone). Bed baths using soap and water (N =26 patients) did not reduce the percentage of positive skin cultures for CDI patients (64% before versus 57% after bathing; P =0.5), whereas bathing with Vashe solution (N =21 patients) significantly reduced skin contamination (54% before versus 8% after bathing; P =0.0001). Vashe was well-tolerated with no evidence of adverse effects on skin. Conclusions Vashe was safe and effective for reducing the burden of B. anthracis surrogates and C. difficile spores on hands. Bed baths with Vashe were effective for reducing C. difficile on skin. These findings suggest a novel strategy to reduce the burden of spores on skin. PMID:23844234
Survey of Naegleria fowleri in geothermal recreational waters of Guadeloupe (French West Indies).
Moussa, Mirna; De Jonckheere, Johan F; Guerlotté, Jérôme; Richard, Vincent; Bastaraud, Alexandra; Romana, Marc; Talarmin, Antoine
2013-01-01
In 2008 a fatal case of primary amoebic meningoencephalitis, due to the amoeboflagellate Naegleria fowleri, occurred in Guadeloupe, French West Indies, after a child swam in a bath fed with geothermal water. In order to improve the knowledge on free-living amoebae in this tropical part of France, we investigated on a monthly basis, the presence of Naegleria spp. in the recreational baths, and stream waters which feed them. A total of 73 water samples, 48 sediments and 54 swabs samples were collected from 6 sampling points between June 2011 and July 2012. The water samples were filtered and the filters transferred to non-nutrient agar plates seeded with a heat-killed suspension of Escherichia coli while sediment and swab samples were placed directly on these plates. The plates were incubated at 44°C for the selective isolation of thermophilic Naegleria. To identify the Naegleria isolates the internal transcribed spacers, including the 5.8S rDNA, were amplified by polymerase chain reaction and the sequence of the PCR products was determined. Thermophilic amoebae were present at nearly all collection sites. The pathogenic N. fowleri was the most frequently encountered thermophilic species followed by N. lovaniensis. The concentration of N. fowleri was rather low in most water samples, ranging from 0 to 22 per liter. Sequencing revealed that all N. fowleri isolates belonged to a common Euro-American genotype, the same as detected in the human case in Guadeloupe. These investigations need to be continued in order to counsel the health authorities about prevention measures, because these recreational thermal baths are used daily by local people and tourists.
Survey of Naegleria fowleri in Geothermal Recreational Waters of Guadeloupe (French West Indies)
Moussa, Mirna; De Jonckheere, Johan F.; Guerlotté, Jérôme; Richard, Vincent; Bastaraud, Alexandra; Romana, Marc; Talarmin, Antoine
2013-01-01
In 2008 a fatal case of primary amoebic meningoencephalitis, due to the amoeboflagellate Naegleria fowleri, occurred in Guadeloupe, French West Indies, after a child swam in a bath fed with geothermal water. In order to improve the knowledge on free-living amoebae in this tropical part of France, we investigated on a monthly basis, the presence of Naegleria spp. in the recreational baths, and stream waters which feed them. A total of 73 water samples, 48 sediments and 54 swabs samples were collected from 6 sampling points between June 2011 and July 2012. The water samples were filtered and the filters transferred to non-nutrient agar plates seeded with a heat-killed suspension of Escherichia coli while sediment and swab samples were placed directly on these plates. The plates were incubated at 44°C for the selective isolation of thermophilic Naegleria. To identify the Naegleria isolates the internal transcribed spacers, including the 5.8S rDNA, were amplified by polymerase chain reaction and the sequence of the PCR products was determined. Thermophilic amoebae were present at nearly all collection sites. The pathogenic N. fowleri was the most frequently encountered thermophilic species followed by N. lovaniensis. The concentration of N. fowleri was rather low in most water samples, ranging from 0 to 22 per liter. Sequencing revealed that all N. fowleri isolates belonged to a common Euro-American genotype, the same as detected in the human case in Guadeloupe. These investigations need to be continued in order to counsel the health authorities about prevention measures, because these recreational thermal baths are used daily by local people and tourists. PMID:23349880
Polyurethane Filler for Electroplating
NASA Technical Reports Server (NTRS)
Beasley, J. L.
1984-01-01
Polyurethane foam proves suitable as filler for slots in parts electroplated with copper or nickel. Polyurethane causes less contamination of plating bath and of cleaning and filtering tanks than wax fillers used previously. Direct cost of maintenance and indirect cost of reduced operating time during tank cleaning also reduced.
Improvement of black nickel coatings. [product development for use in solar collectors
NASA Technical Reports Server (NTRS)
Peterson, R. E.; Lin, J. H.
1976-01-01
Selectively absorbing black nickel coatings are among the most optically efficient low cost coatings for use on flat plate solar collectors. However, a current Ni-Zn-S-O coating in use is quite susceptible to a humid environment, degrading badly in less than ten days at 38 C (100 F) at 95 percent relative humidity. Therefore, a black nickel formula was developed which can withstand such exposures with no loss of optical efficiency, solar absorption of 0.92 and an infrared emittance (at 100 C) of 1.00 were still present after 14 days of humidity exposure. This compares to a solar absorptance of only 0.72 for the previous formula after a similar time period. The electroplating bath and conditions were changed to obtain the more stable coating configuration. The effect of bath composition, temperature, pH, and plating current density and time on the coating composition, spectral optical properties and durability were investigated systematically.
NASA Technical Reports Server (NTRS)
Schwartz, Leonard W.
1999-01-01
A method of calculation is presented that allows the simulation of the time-dependent three-dimensional motion of thin liquid layers on solid substrates for systems with finite equilibrium contact angles. The contact angle is a prescribed function of position on the substrate. Similar mathematical models are constructed for substrates with a pattern of roughness. Evolution equations are given, using the lubrication approximation, that include viscous, capillary and disjoining forces. Motion to and from dry substrate regions is made possible by use of a thin energetically-stable wetting layer. We simulate motion on heterogeneous substrates with periodic arrays of high contact-angle patches. Two different problems are treated for heterogenous substrates. The first is spontaneous motion driven only by wetting forces. If the contact-angle difference is sufficiently high, the droplet can find several different stable positions, depending on the previous history of the motion. A second simulation treats a forced cyclical motion. Energy dissipation per cycle for a heterogeneous substrate is found to be larger than for a uniform substrate with the same total energy. The Landau-Levich solution for plate removal from a liquid bath is extended to account for a pattern of roughness on the plate.
Costa, P M; Fernandes, P L; Ferreira, H G; Ferreira, K T; Giraldez, F
1987-12-01
1. Membrane potential and conductances and short-circuit current were continuously measured with microelectrodes and conventional electrophysiological techniques in a stripped preparation of frog skin epithelium. The effects of the removal of chloride or sodium ions and the concentration or dilution of the serosal (inner) bathing solution were studied. 2. Chloride- or sodium-free solutions produced a cell depolarization of about 30 mV in parallel with a fall in the short-circuit current. Mucosal and serosal membrane conductances both decreased and the sodium permeability of the mucosal barrier was calculated to fall to about one-half its value in standard Ringer solution. The observed decrease in the short-circuit current is probably related to the combined effect of the decrease in sodium permeability and the decrease in the driving force across the mucosal membrane. 3. The removal of chloride or sodium ions reduced the depolarization caused by serosal perfusion with high-potassium solutions (50 mM-KCl). The ratio of the change in cell membrane potential under short-circuit conditions to the change in the potassium equilibrium potential (delta Ec(s.c.)/delta EK), was 0.59 in standard Ringer solution and 0.26 and 0.24 after the removal of chloride or sodium respectively. The depolarizing effect of barium-containing solutions (2 mM-BaCl2) was also markedly reduced in chloride- or sodium-free solutions, suggesting a decrease of the potassium selectivity of the serosal membrane in these conditions. 4. Increasing the osmolality of the serosal bathing solution produced similar effects, i.e. cell depolarization, fall in the short-circuit current and membrane conductances and reduction of the depolarizing effect of high-potassium and barium solutions. On the contrary, dilution of the serosal bath produced the opposite effects, consistent with an increase in the serosal permeability to potassium. 5. The effects of chloride- or sodium-free solutions were reversed by the dilution of the serosal bath. Cells repolarized when exposed to low-osmolality solutions after being in the absence of serosal chloride or sodium. The repolarization ran in parallel with the restoration of the short-circuit current and the potassium selectivity of the serosal membrane. 6. The results show that the effects produced by the removal of sodium or chloride ions from the serosal bathing solution are most probably mediated by a reduction in cell volume. Cell volume changes would lead to changes in the serosal membrane selectivity to potassium and thus to changes in cell membrane potential and sodium transport.(ABSTRACT TRUNCATED AT 400 WORDS)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sandoval-Paz, M.G., E-mail: myrnasandoval@udec.cl; Rodríguez, C.A.; Porcile-Saavedra, P.F.
Copper (I) selenide thin films with orthorhombic and cubic structure were deposited on glass substrates by using the chemical bath deposition technique. The effects of the solution pH on the films growth and subsequently the structural, optical and electrical properties of the films were studied. Films with orthorhombic structure were obtained from baths wherein both metal complex and hydroxide coexist; while films with cubic structure were obtained from baths where the metal hydroxide there is no present. The structural modifications are accompanied by changes in bandgap energy, morphology and electrical resistivity of the films. - Graphical abstract: “Study of themore » crystallographic phase change on copper (I) selenide thin films prepared through chemical bath deposition by varying the pH of the solution” by M. G. Sandoval-Paz, C. A. Rodríguez, P. F. Porcile-Saavedra, C. Trejo-Cruz. Display Omitted - Highlights: • Copper (I) selenide thin films were obtained by chemical bath deposition. • Orthorhombic to cubic phase change was induced by varying the reaction solution pH. • Orthorhombic phase is obtained mainly from a hydroxides cluster mechanism. • Cubic phase is obtained mainly from an ion by ion mechanism. • Structural, optical and electrical properties are presented as a function of pH.« less
Process for preparing superconducting film having substantially uniform phase development
Bharacharya, Raghuthan; Parilla, Philip A.; Blaugher, Richard D.
1995-01-01
A process for preparing a superconducting film, such as a thallium-barium-calcium-copper oxide superconducting film, having substantially uniform phase development. The process comprises providing an electrodeposition bath having one or more soluble salts of one or more respective potentially superconducting metals in respective amounts adequate to yield a superconducting film upon subsequent appropriate treatment. Should all of the metals required for producing a superconducting film not be made available in the bath, such metals can be a part of the ambient during a subsequent annealing process. A soluble silver salt in an amount between about 0.1% and about 4.0% by weight of the provided other salts is also provided to the bath, and the bath is electrically energized to thereby form a plated film. The film is annealed in ambient conditions suitable to cause formation of a superconductor film. Doping with silver reduces the temperature at which the liquid phase appears during the annealing step, initiates a liquid phase throughout the entire volume of deposited material, and influences the nucleation and growth of the deposited material.
Process for preparing superconducting film having substantially uniform phase development
Bharacharya, R.; Parilla, P.A.; Blaugher, R.D.
1995-12-19
A process is disclosed for preparing a superconducting film, such as a thallium-barium-calcium-copper oxide superconducting film, having substantially uniform phase development. The process comprises providing an electrodeposition bath having one or more soluble salts of one or more respective potentially superconducting metals in respective amounts adequate to yield a superconducting film upon subsequent appropriate treatment. Should all of the metals required for producing a superconducting film not be made available in the bath, such metals can be a part of the ambient during a subsequent annealing process. A soluble silver salt in an amount between about 0.1% and about 4.0% by weight of the provided other salts is also provided to the bath, and the bath is electrically energized to thereby form a plated film. The film is annealed in ambient conditions suitable to cause formation of a superconductor film. Doping with silver reduces the temperature at which the liquid phase appears during the annealing step, initiates a liquid phase throughout the entire volume of deposited material, and influences the nucleation and growth of the deposited material. 3 figs.
Structure, function, and long-term maintenance of the isolated turtle colon
DOE Office of Scientific and Technical Information (OSTI.GOV)
LeFevre, M.E.; Reisman, L.
1978-01-01
We describe the 5-day maintenance of sacs of turtle colonic mucosa in enriched bathing solutions. The mean maximum transepithelial potential difference (PD) developed by the sacs in Ringer solution enriched with tissue-culture medium and gassed with 95% air-5% CO/sub 2/ was 126 mV at 24 hours. Lower values were observed in other solutions. The PD of 24-hour sacs was partially or totally inhibited by ouabain, replacement of Na by choline in mucosal bathing fluids, or removal of Ca from serosal bathing fluids. The sacs transported Na in excess of H/sub 2/O forming a dilute mucosal solution. The responses of fourmore » different sac preparations (normally oriented or everted, and stripped normally oriented or everted) to long incubation were compared. Stripped normally oriented tissue developed the highest PD and maintained the lowest water content. The morphology of fresh and long-incubated tissue was examined. This investigation demonstrates that the turtle colon can be maintained in vitro for long periods, and it provides information on the morphology and physiology of this tissue.« less
Sun, H; Lau, K M; Fung, Y S
2010-05-07
Monitoring of trace impurities in electroplating bath is needed to meet EU requirements for WEEE and RoHS and for quality control of electrodeposits. Methods using IC and 100% aqueous CE buffer were found producing non-repeatable results attributed to interference of surfactants and major methanesulphonate anion. A new CE buffer containing 1.5mM tetraethylenepentaamine, 3mM 1,3,5-benzenetricarboxylic acid and 15 mM Tris in 20% (v/v) methanol at pH=8.4 was shown to enhance the separation window, reduce interaction between buffer and bath constituents, and give satisfactory repeatability with baseline separation for 14 organic and inorganic anions within 14 min, good repeatability for migration time (0.32-0.57% RSD), satisfactory peak area and peak height (2.9-4.5 and 3-4.7% respectively), low detection limit (S/N=2, 20-150 ppb), and wide working ranges (0.1-100 ppm). The CE buffer with 20% (v/v) methanol has demonstrated its capability for identifying anion impurities causing problem in aged tin bath and the use of only 10-fold dilution to produce reliable results for quality assessment in plating bath containing high surfactant additives. Copyright (c) 2010 Elsevier B.V. All rights reserved.
Bandages and difficulty with bathing: introducing Seal-Tight.
Lindsay, Ellie
2005-06-01
Patients with compression bandages experience difficulty with bathing due to the possibility that bandages may become wet and affect the wound. Bandage and dressing changes resulting from accidental wetting also cost the NHS considerable time and money. This product focus highlights the social and psychological impact on the patient when they are unable to bathe and offers a solution to the problem. Seal-Tight is a product that has been newly placed on the drug tariff, making it widely available to all patients who wear bandages (or plaster casts). Seal-Tight enables the patient to bathe, in some cases for the first time for months or even years.
2014-03-27
in a thin conductive layer, the wafer surface can be made into the cathode while using a stainless steel plate as an anode. Bath temperature, voltage...beakers with polytetrafluoroethylene (PTFE) tools while under a fume hood, as HF is known to attack glass and polystyrene [62]. Additionally
An evaluation of a manganese bath system having a new geometry through MCNP modelling.
Khabaz, Rahim
2012-12-01
In this study, an approximate symmetric cylindrical manganese bath system with equal diameter and height was appraised using a Monte Carlo simulation. For nine sizes of the tank filled with MnSO(4).H(2)O solution of three different concentrations, the necessary correction factors involved in the absolute measurement of neutron emission rate were determined by a detailed modelling of the MCNP4C code with the ENDF/B-VII.0 neutron cross section data library. The results obtained were also used to determine the optimum dimensions of the bath for each concentration of solution in the calibration of (241)Am-Be and (252)Cf sources. Also, the amount of gamma radiation produced as a result of (n,γ) the reaction with the nuclei of the manganese sulphate solution that escaped from the boundary of each tank was evaluated. This gamma can be important for the background in NaI(Tl) detectors and issues concerned with radiation protection.
Sliding enhances fluid and solute transport into buried articular cartilage contacts.
Graham, B T; Moore, A C; Burris, D L; Price, C
2017-12-01
Solutes and interstitial water are naturally transported from cartilage by load-induced interstitial fluid pressures. Fluid and solute recovery during joint articulation have been primarily attributed to passive diffusion and mechanical 'pumping' from dynamic loading. This paper tests if the sliding action of articulation is a significant and independent driver of fluid and solute transport in cartilage. The large osteochondral samples utilized in the present study preserve the convergent wedges necessary for physiological hydrodynamics. Following static load-induced fluid exudation and prior to sliding, a fluorescent solute (AlexaFluor 633) was added to the lubricant bath. In situ confocal microscopy was used to quantify the transport of solute from the bath into the buried stationary contact area (SCA) during sliding. Following static exudation, significant reductions in friction and strain during sliding at 60 mm/s were accompanied by significant solute transport into the inaccessible center of the buried contact; no such transport was detected for the 0- or 1 mm/s sliding conditions. The results suggest that external hydrodynamic pressures from sliding induced advective flows that carried solutes from the bath toward the center of contact. These results provide the first direct evidence that the action of sliding is a significant contributor to fluid and solute recovery by cartilage. Furthermore, they indicate that the sliding-induced transport of solutes into the buried interface was orders of magnitude greater than that attributable to diffusion alone, a result with critical implications for disease prevention and tissue engineering. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
Arbabi, Vahid; Pouran, Behdad; Weinans, Harrie; Zadpoor, Amir A
2016-06-14
Charged and uncharged solutes penetrate through cartilage to maintain the metabolic function of chondrocytes and to possibly restore or further breakdown the cartilage tissue in different stages of osteoarthritis. In this study the transport of charged solutes across the various zones of cartilage was quantified, taken into account the physicochemical interactions between the solute and the cartilage constituents. A multiphasic finite-bath finite element (FE) model was developed to simulate equine cartilage diffusion experiments that used a negatively charged contrast agent (ioxaglate) in combination with serial micro-computed tomography (micro-CT) to measure the diffusion. By comparing the FE model with the experimental data both the diffusion coefficient of ioxaglate and the fixed charge density (FCD) were obtained. In the multiphasic model, cartilage was divided into multiple (three) zones to help understand how diffusion coefficient and FCD vary across cartilage thickness. The direct effects of charged solute-FCD interaction on diffusion were investigated by comparing the diffusion coefficients derived from the multiphasic and biphasic-solute models. We found a relationship between the FCD obtained by the multiphasic model and ioxaglate partitioning obtained from micro-CT experiments. Using our multi-zone multiphasic model, diffusion coefficient of the superficial zone was up to ten-fold higher than that of the middle zone, while the FCD of the middle zone was up to almost two-fold higher than that of the superficial zone. In conclusion, the developed finite-bath multiphasic model provides us with a non-destructive method by which we could obtain both diffusion coefficient and FCD of different cartilage zones. The outcomes of the current work will also help understand how charge of the bath affects the diffusion of a charged molecule and also predict the diffusion behavior of a charged solute across articular cartilage. Copyright © 2016 Elsevier Ltd. All rights reserved.
Gordon, A. M.; Godt, R. E.; Donaldson, S. K. B.; Harris, C. E.
1973-01-01
The maximal calcium-activated isometric tension produced by a skinned frog single muscle fiber falls off as the ionic strength of the solution bathing this fiber is elevated declining to zero near 0.5 M as the ionic strength is varied using KCl. When other neutral salts are used, the tension always declines at high ionic strength, but there is some difference between the various neutral salts used. The anions and cations can be ordered in terms of their ability to inhibit the maximal calcium-activated tension. The order of increasing inhibition of tension (decreasing tension) at high ionic strength for anions is propionate- ≃ SO4 -- < Cl- < Br-. The order of increasing inhibition of calcium-activated tension for cations is K+ ≃ Na+ ≃ TMA+ < TEA+ < TPrA+ < TBuA+. The decline of maximal calcium-activated isometric tension with elevated salt concentration (ionic strength) can quantitatively explain the decline of isometric tetanic tension of a frog muscle fiber bathed in a hypertonic solution if one assumes that the internal ionic strength of a muscle fiber in normal Ringer's solution is 0.14–0.17 M. There is an increase in the base-line tension of a skinned muscle fiber bathed in a relaxing solution (no added calcium and 3 mM EGTA) of low ionic strength. This tension, which has no correlate in the intact fiber in hypotonic solutions, appears to be a noncalcium-activated tension and correlates more with a declining ionic strength than with small changes in [MgATP], [Mg], pH buffer, or [EGTA]. It is dependent upon the specific neutral salts used with cations being ordered in increasing inhibition of this noncalcium-activated tension (decreasing tension) as TPrA+ < TMA+ < K+ ≃ Na+. Measurements of potentials inside these skinned muscle fibers bathed in relaxing solutions produced occasional small positive values (<6 mV) which were not significantly different from zero. PMID:4543066
Dendritic Zinc Growth in Acid Electrolyte: Effect of the pH
NASA Astrophysics Data System (ADS)
Bengoa, Leandro N.; Pary, Paola; Seré, Pablo R.; Conconi, M. Susana; Egli, Walter A.
2018-03-01
In this paper, dendritic growth at the edges of electrogalvanized steel strip has been studied using a specially designed rotating washer electrode which simulates the fluid dynamic conditions and the current density distribution at the steel strip edge found in a production line. The effect of electrolyte pH and current density on dendritic growth in an acidic zinc plating bath (ZnSO4 and H2SO4) was addressed. The temperature was kept constant at 60 °C. Solution pH was adjusted to 1, 2 or 3 using different amounts of H2SO4. In addition, the influence of temperature on the pH of the solution was determined. The current density was set at 40 or 60 A/dm2, similar to that used in the industry. Deposits were characterized using SEM and XRD. The results showed that pH strongly affects dendrites shape, length and texture. Furthermore, the morphology of dendrites at the washer edge and of deposits on the flat portion of the washer changed considerably as solution pH was increased from 1 to 3. It was found that the morphology of dendrites at the washer edge stems from the morphology of the deposit on its flat portion, which in turn determines their shape.
The rejuvenation of spent electroless nickel baths by electrodialysis has received a considerable amount of attention over the past decade and the technique is being increasingly employed to extend electroless nickel bath life. However, thus far there has not been a detailed inve...
The effectiveness of a zirconium dioxide (ZrO2) membrane filter was evaluated for recycling a nonionic aqueous metal cleaning bath under real-world conditions. The pilot-scale study consisted of four 7- to 16-day filtration runs, each processed a portion of the cleaning bath duri...
Studies on the electrodeposition of tin from acidic chloride-gluconate solutions
NASA Astrophysics Data System (ADS)
Rudnik, Ewa; Włoch, Grzegorz
2013-01-01
Electrodeposition of tin from acidic chloride-gluconate baths was investigated. Equilibrium distribution of tin(II) species showed domination of Sn(II)-gluconate complexes, but for Sn2+ concentrations 50 mM or higher increased percentage of Sn(II)-chloride complexes was found. Cyclic voltammetry, anodic stripping analysis and potentiostatic measurements indicated that rate of the cathodic process is determined by the release of metal cations from gluconate complexes in diluted bath (5 mM), but for more concentrated solutions reduction of Sn(II) ions run under diffusion control. Studies of anodic response showed that it depends on the Sn(II)/Glu ratio in the bath and deposition potential due to development of different planes of metal crystal. Average effective diffusion coefficients of metal species were determined. Morphology and structure tin deposits were also presented.
Parween, Shahila; Nahar, Pradip
2013-10-15
In this communication, we report ELISA technique on an activated polypropylene microtest plate (APPµTP) as an illustrative example of a low cost diagnostic assay. Activated test zone in APPµTP binds a capture biomolecule through covalent linkage thereby, eliminating non-specific binding often prevalent in absorption based techniques. Efficacy of APPµTP is demonstrated by detecting human immunoglobulin G (IgG), human immunoglobulin E (IgE) and Aspergillus fumigatus antibody in patient's sera. Detection is done by taking the image of the assay solution by a desktop scanner and analyzing the color of the image. Human IgE quantification by color saturation in the image-based assay shows excellent correlation with absorbance-based assay (Pearson correlation coefficient, r=0.992). Significance of the relationship is seen from its p value which is 4.087e-11. Performance of APPµTP is also checked with respect to microtiter plate and paper-based ELISA. APPµTP can quantify an analyte as precisely as in microtiter plate with insignificant non-specific binding, a necessary prerequisite for ELISA assay. In contrast, paper-ELISA shows high non-specific binding in control sera (false positive). Finally, we have carried out ELISA steps on APPµTP by ultrasound waves on a sonicator bath and the results show that even in 8 min, it can convincingly differentiate a test sample from a control sample. In short, spectrophotometer-free image-based miniaturized ELISA on APPµTP is precise, reliable, rapid, and sensitive and could be a good substitute for conventional immunoassay procedures widely used in clinical and research laboratories. Copyright © 2013 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Sun, Wan-chang; Xu, Jia-Min; Wang, Yuan; Guo, Fang; Jia, Zong-Wei
2017-12-01
AZ91D magnesium alloy substrate was first pretreated in a phosphoric acid to obtain a phosphate coating, and then, the electroless ternary Ni-W-P coating was deposited using a sulfate nickel bath. The morphologies of the Ni-W-P coating were observed by using scanning electron microscope, the deposition rate of the coating was examined with the method of gravimetric analysis, and the phase analysis was identified by x-ray diffractometer. Electrochemical property was tested by means of an electrochemical analyzer. The results indicated that the addition of an optimum concentration of CeO2 (cerium oxide) particles could evidently improve the deposition rate and the stability of the plating bath. However, it acted as an inhibiting effect as the concentration of CeO2 particles exceeded to 8 mg/L in the sulfate nickel bath. The results also revealed that the morphology of Ni-W-P coating became more smooth, compact and uniform with the increase in the concentrations of CeO2 particles in the bath, but the corrosion resistance decreased due to the precipitation of crystal phases (Ni3P, Ni4W, etc.) after heat treatment.
NASA Astrophysics Data System (ADS)
Uttam, Vibha; Duchaniya, R. K.
2016-05-01
Now a days, corrosion studies are important for reducing the wastage of metals. The importance of corrosion studies is two folds i.e. first is economic, including the reduction of material losses resulting from the wasting away or sudden failure of materials and second is conservation Electroless process is an autocatalytic reduction method in which metallic ions are reduced in the solution. Nanocomposite coatings of Ni-P-TiO2 on mild steel are deposited by varying volume of TiO2 nano-powder by electroless method from Ni-P plating bath containing Nickel Sulphate as a source of nickel ions, sodium hypophosphite as the reducing agent, lactic acid as a complexing agents and TiO2 nano powder. Electroless Ni-P-TiO2 coating have been widely used in the chemical process industries, mechanical industries, electronic industries and chloroalkali industries due to their excellent corrosion with mechanical properties. In the present work, deposition of Ni-P alloy coating and Ni-P-TiO2 nanocomposited coatings were done on the mild steel and corrosion properties were studied with Potentio-dynamic polarization measurements method in 3.5 wt% sodium chloride solution. It showed in the experiments that Ni-P-TiO2 nanocomposited coating has better corrosion resistance as comparedthan Ni-P alloy coating. Morphological studies were done by field emission scanning electron microscopy (FESEM), energy-dispersive analysis of X-ray (EDAX) and X-ray diffraction (XRD). These studies confirmed the deposition of Ni-P alloy coating and Ni-P-TiO2 nanocomposited coating.
Non-Markovian decay and dynamics of decoherence in private and public environments
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dente, A. D.; Zangara, P. R.; Pastawski, H. M.
2011-10-15
We study the decay process in an open system, emphasizing the relevance of the environment's spectral structure. Non-Markovian effects are included to quantitatively analyze the degradation rate of the coherent evolution. The way in which a two-level system is coupled to different environments is specifically addressed: multiple connections to a single bath (public environment) or single connections to multiple baths (private environments). We numerically evaluate the decay rate of a local excitation by using the survival probability and the Loschmidt echo. These rates are compared to analytical results obtained from the standard Fermi golden rule (FGR) in wide band approximation,more » and a self-consistent evaluation that accounts for the bath's memory in cases where an exact analytical solution is possible. We observe that the correlations appearing in a public bath introduce further deviations from the FGR as compared with a private bath.« less
Theories of quantum dissipation and nonlinear coupling bath descriptors
NASA Astrophysics Data System (ADS)
Xu, Rui-Xue; Liu, Yang; Zhang, Hou-Dao; Yan, YiJing
2018-03-01
The quest of an exact and nonperturbative treatment of quantum dissipation in nonlinear coupling environments remains in general an intractable task. In this work, we address the key issues toward the solutions to the lowest nonlinear environment, a harmonic bath coupled both linearly and quadratically with an arbitrary system. To determine the bath coupling descriptors, we propose a physical mapping scheme, together with the prescription reference invariance requirement. We then adopt a recently developed dissipaton equation of motion theory [R. X. Xu et al., Chin. J. Chem. Phys. 30, 395 (2017)], with the underlying statistical quasi-particle ("dissipaton") algebra being extended to the quadratic bath coupling. We report the numerical results on a two-level system dynamics and absorption and emission line shapes.
Substrate spacing and thin-film yield in chemical bath deposition of semiconductor thin films
NASA Astrophysics Data System (ADS)
Arias-Carbajal Reádigos, A.; García, V. M.; Gomezdaza, O.; Campos, J.; Nair, M. T. S.; Nair, P. K.
2000-11-01
Thin-film yield in the chemical bath deposition technique is studied as a function of separation between substrates in batch production. Based on a mathematical model, it is proposed and experimentally verified in the case of CdS thin films that the film thickness reaches an asymptotic maximum with increase in substrate separation. It is shown that at a separation less than 1 mm between substrates the yield, i.e. percentage in moles of a soluble cadmium salt deposited as a thin film of CdS, can exceed 50%. This behaviour is explained on the basis of the existence of a critical layer of solution near the substrate, within which the relevant ionic species have a higher probability of interacting with the thin-film layer than of contributing to precipitate formation. The critical layer depends on the solution composition and the temperature of the bath as well as the duration of deposition. An effective value for the critical layer thickness has been defined as half the substrate separation at which 90% of the maximum film thickness for the particular bath composition, bath temperature and duration of deposition is obtained. In the case of CdS thin films studied as an example, the critical layer is found to extend from 0.5 to 2.5 mm from the substrate surface, depending on the deposition conditions.
1983-09-01
phase has a preferred orientation as most other electrodeposits, this peak found off the equatorial direction provided a way of measuring...40 (S)IoA) 1IliN3i0d , STANDARD HARD CHROM (KiC) INTERRUPTED PLATED CHROME (tC) -4’? 1001 1000X KC Chrome IC Chrome Bath Temperature *C 55 55 Current...COMMANDER ATTN: DRSNC- LC (D) I US ARMY TANK-AUTMV COWD DRSMC-LCE(D) 1 ATTN: DRSTA-RC DRSC-LCM(D) (BLDG 321) 1 WARREN, MI 48090 DRSMC- LCS (D) 1 DRSNC-LCU
Automated Chromium Plating Line for Gun Barrels
1979-09-01
consistent pretreatments and bath dwell times. Some of the advantages of automated processing include increased productivity (average of 20^) due to...when automated processing procedures’ are used. The current method of applying chromium electrodeposits to gun tubes is a manual, batch operation...currently practiced with rotary swaged gun tubes would substantially reduce the difficulties in automated processing . RECOMMENDATIONS
The Mechanism of Isotonic Water Transport
Diamond, Jared M.
1964-01-01
The mechanism by which active solute transport causes water transport in isotonic proportions across epithelial membranes has been investigated. The principle of the experiments was to measure the osmolarity of the transported fluid when the osmolarity of the bathing solution was varied over an eightfold range by varying the NaCl concentration or by adding impermeant non-electrolytes. An in vitro preparation of rabbit gall bladder was suspended in moist oxygen without an outer bathing solution, and the pure transported fluid was collected as it dripped off the serosal surface. Under all conditions the transported fluid was found to approximate an NaCl solution isotonic to whatever bathing solution used. This finding means that the mechanism of isotonic water transport in the gall bladder is neither the double membrane effect nor co-diffusion but rather local osmosis. In other words, active NaCl transport maintains a locally high concentration of solute in some restricted space in the vicinity of the cell membrane, and water follows NaCl in response to this local osmotic gradient. An equation has been derived enabling one to calculate whether the passive water permeability of an organ is high enough to account for complete osmotic equilibration of actively transported solute. By application of this equation, water transport associated with active NaCl transport in the gall bladder cannot go through the channels for water flow under passive conditions, since these channels are grossly too impermeable. Furthermore, solute-linked water transport fails to produce the streaming potentials expected for water flow through these passive channels. Hence solute-linked water transport does not occur in the passive channels but instead involves special structures in the cell membrane, which remain to be identified. PMID:14212146
NASA Astrophysics Data System (ADS)
Sofiah, A. G. N.; Kananathan, J.; Samykano, M.; Ulakanathan, S.; Lah, N. A. C.; Harun, W. S. W.; Sudhakar, K.; Kadirgama, K.; Ngui, W. K.; Siregar, J. P.
2017-10-01
This paper investigates the influence of the electrolytic bath temperature on the morphology and physical properties of nickel (Ni) nanowires electrochemically deposited into the anodic alumina oxide porous membrane (AAO). The synthesis was performed using nickel sulfate hexahydrate (NiSO4.6H2O) and boric acid (H3BO3) as an electrolytic bath for the electrochemical deposition of Ni nanowires. During the experiment, the electrolyte bath temperature varied from 40°C, 80°C, and 120°C. After the electrochemical deposition process, AAO templates cleaned with distilled water preceding to dissolution in sodium hydroxide (NaOH) solution to obtain free-standing Ni nanowires. Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDX) and X-ray Diffraction (XRD) analysis were employed to characterize the morphology and physical properties of the synthesized Ni nanowires. Finding reveals the electrodeposition bath temperature significantly influences the morphology and physical properties of the synthesized Ni nanowires. Rougher surface texture, larger crystal size, and longer Ni nanowires obtained as the deposition bath temperature increased. From the physical properties properties analysis, it can be concluded that deposition bath temperature influence the physical properties of Ni nanowires.
Code of Federal Regulations, 2010 CFR
2010-01-01
... dipping it in a solution of 0.0625 percent tannic acid, followed by immersion in a water bath, then... tannic acid for 1 minute followed by immersion in a water bath, then immersing it for 1 minute in a... establishment: Crude carbolic acid; cresylic disinfectant; a formula consisting of 1 part FD&C green No. 3...
Code of Federal Regulations, 2011 CFR
2011-01-01
... dipping it in a solution of 0.0625 percent tannic acid, followed by immersion in a water bath, then... tannic acid for 1 minute followed by immersion in a water bath, then immersing it for 1 minute in a... establishment: Crude carbolic acid; cresylic disinfectant; a formula consisting of 1 part FD&C green No. 3...
Code of Federal Regulations, 2013 CFR
2013-01-01
... coloring, 40 parts water, 40 parts liquid detergent, and 40 parts oil of citronella, or other proprietary... dipping it in a solution of 0.0625 percent tannic acid, followed by immersion in a water bath, then... tannic acid for 1 minute followed by immersion in a water bath, then immersing it for 1 minute in a...
Code of Federal Regulations, 2014 CFR
2014-01-01
... coloring, 40 parts water, 40 parts liquid detergent, and 40 parts oil of citronella, or other proprietary... dipping it in a solution of 0.0625 percent tannic acid, followed by immersion in a water bath, then... tannic acid for 1 minute followed by immersion in a water bath, then immersing it for 1 minute in a...
Code of Federal Regulations, 2012 CFR
2012-01-01
... coloring, 40 parts water, 40 parts liquid detergent, and 40 parts oil of citronella, or other proprietary... dipping it in a solution of 0.0625 percent tannic acid, followed by immersion in a water bath, then... tannic acid for 1 minute followed by immersion in a water bath, then immersing it for 1 minute in a...
de Melo, Liliane Pimenta; Salmoria, Gean Vitor; Fancello, Eduardo Alberto; Roesler, Carlos Rodrigo de Mello
2017-01-01
The purpose of this article is to present mechanical and physicochemical properties during in vitro degradation of PLGA material as craniofacial plates based on different values of injection molded temperatures. Injection molded plates were submitted to in vitro degradation in a thermostat bath at 37 ± 1°C by 16 weeks. The material was removed after 15, 30, 60, and 120 days; then bending stiffness, crystallinity, molecular weights, and viscoelasticity were studied. A significant decrease of molecular weight and mechanical properties over time and a difference in FT-IR after 60 days showed faster degradation of the material in the geometry studied. DSC analysis confirmed that the crystallization occurred, especially in higher melt temperature condition. DMA analysis suggests a greater contribution of the viscous component of higher temperature than lower temperature in thermomechanical behavior. The results suggest that physical-mechanical properties of PLGA plates among degradation differ per injection molding temperatures.
Polyelectrolyte hydrogel instabilities in ionic solutions
NASA Astrophysics Data System (ADS)
English, Anthony E.; Tanaka, Toyoichi; Edelman, Elazer R.
1996-12-01
The phase behavior of polyelectrolyte hydrogels has been examined as a function of relative charge composition, bath salt concentration, and solvent quality. Nonlinear swelling instabilities of 2-hydroxyethyl methacrylate (HEMA) and methacrylic acid (MAAc) copolymer hydrogels manifested themselves as discontinuous first order swelling transitions as a function of bath salt concentration. A modified Flory-Huggins model was used to describe the regions of instability when bath salt concentration and solvent quality are considered as control variables. The role of ion dissociation equilibrium in the change from local or smooth transitions to nonlocal or discontinuous swelling transitions is illustrated within the framework of our model.
Evolution of wave function in a dissipative system
NASA Technical Reports Server (NTRS)
Yu, Li-Hua; Sun, Chang-Pu
1994-01-01
For a dissipative system with Ohmic friction, we obtain a simple and exact solution for the wave function of the system plus the bath. It is described by the direct product in two independent Hilbert space. One of them is described by an effective Hamiltonian, the other represents the effect of the bath, i.e., the Brownian motion, thus clarifying the structure of the wave function of the system whose energy is dissipated by its interaction with the bath. No path integral technology is needed in this treatment. The derivation of the Weisskopf-Wigner line width theory follows easily.
On the Growth of Ice in Aqueous Solutions Contained in Capillaries
NASA Astrophysics Data System (ADS)
Pruppracher, H. R.
1967-06-01
The growth rate of ice in supercooled water and in dilute aqueous solutions of various salts which dissociate in water into univalent ions was studied. The solutions contained in polyethylene tubes of small bore had concentrations between 10-6 and 10-1 moles liter-1 and were investigated at bath supercoolings between 1° and 15°C. The growth rate of ice which in pure water was found to vary approximately with the square of the bath supercooling was affected in a systematic manner by the type and concentration of the salt in solution. At salt concentrations smaller than 5 × 10-2 moles liter-1 most salts did not affect the growth rate. However, the fluorides were found to increase the growth rate over and above the one in pure water. At concentrations larger than 5 × 10-2 moles liter-1 all the salts reduced the growth rate of ice below the one in pure water. By comparing solutions of salts with common anion it was found that at a particular bath supercooling and salt concentration the growth rate of ice was reduced most in lithium solutions and least in cesium and ammonium solutions. By comparing solutions of salts with common cation it was found that the growth rate of ice was reduced most in fluoride solutions and least in bromide solutions. It was concluded that in solutions with salt concentrations larger than 5 × 10-2 moles liter-1 the rate of dissipation of latent heat which controls the growth rate of ice is affected in a systematic manner by the freezing point lowering effects which result from pure mass transfer conditions prevailing at the ice-solution interface of a stagnant system. Some features of the observed growth rates are discussed in terms of the effect of dissolved salts on the growth forms of ice in aqueous solutions.
Physics of heat pipe rewetting
NASA Technical Reports Server (NTRS)
Chan, S. H.
1992-01-01
Although several studies have been made to determine the rewetting characteristics of liquid films on heated rods, tubes, and flat plates, no solutions are yet available to describe the rewetting process of a hot plate subjected to a uniform heating. A model is presented to analyze the rewetting process of such plates with and without grooves. Approximate analytical solutions are presented for the prediction of the rewetting velocity and the transient temperature profiles of the plates. It is shown that the present rewetting velocity solution reduces correctly to the existing solution for the rewetting of an initially hot isothermal plate without heating from beneath the plate. Numerical solutions have also been obtained to validate the analytical solutions.
Concept Feasibility Report for Electroplating Zirconium onto Uranium Foil - Year 2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Coffey, Greg W.; Meinhardt, Kerry D.; Joshi, Vineet V.
2015-03-01
The Fuel Fabrication Capability within the U.S. High Performance Research Reactor Conversion Program is funded through the National Nuclear Security Administration (NNSA) NA-26 (Office of Material Management and Minimization). An investigation was commissioned to determine the feasibility of using electroplating techniques to apply a coating of zirconium onto depleted uranium/molybdenum alloy (U-10Mo). Electroplating would provide an alternative method to the existing process of hot roll-bonding zirconium foil onto the U-10Mo fuel foil during the fabrication of fuel elements for high-performance research reactors. The objective of this research was to develop a reproducible and scalable plating process that will produce amore » uniform, 25 μm thick zirconium metal coating on U-10Mo foil. In previous work, Pacific Northwest National Laboratory (PNNL) established a molten salt electroplating apparatus and protocol to plate zirconium metal onto molybdenum foil (Coffey 2015). During this second year of the research, PNNL furthered this work by moving to the U-10Mo alloy system (90 percent uranium:10 percent molybdenum). The original plating apparatus was disassembled and re-assembled in a laboratory capable of handling low-level radioactive materials. Initially, the work followed the previous year’s approach, and the salt bath composition was targeted at the eutectic composition (LiF:NaF:ZrF4 = 26:37:37 mol%). Early results indicated that the formation of uranium fluoride compounds would be problematic. Other salt bath compositions were investigated in order to eliminate the uranium fluoride production (LiF:NaF = 61:39 mol% and LiF:NaF:KF = 46.5:11.5:42 mol% ). Zirconium metal was used as the crucible for the molten salt. Three plating methods were used—isopotential, galvano static, and pulsed plating. The molten salt method for zirconium metal application provided high-quality plating on molybdenum in PNNL’s previous work. A key advantage of this approach is that plating can be performed under conditions that would greatly reduce the quantity of intermetallics that form at the interface between the zirconium and U-10Mo; unlike roll bonding, the molten salt plating approach would allow for complete coverage of the U-10Mo foil with zirconium. When utilizing the experimental parameters developed for zirconium plating onto molybdenum, a uranium fluoride reaction product was formed at the Zr/U-10Mo interface. By controlling the initial plating potential, the uranium fluoride could be prevented; however, the targeted zirconium thickness (25 ±12.5 μm) could not be achieved while maintaining 100% coverage.« less
ABSTRACTS OF RESEARCH REPORTS.
Determination of the effect of cavity liner on retention of dental castings cemented in place with oxyphosphate cement; Determination of optimum pouring...on silver plating rubber base impression material in a high-speed commercial bath; Evaluation of the deterioration of carbon steel dental instruments...repairs; Evaluation of the sterilization of air-driven handpieces ; Incidence of accessory root canals in molars; Microscopic comparison of the ability of
Zhang, Daniel Y; Azrad, Maria; Demark-Wahnefried, Wendy; Frederickson, Christopher J; Lippard, Stephen J; Radford, Robert J
2015-02-20
Small-molecule fluorescent sensors are versatile agents for detecting mobile zinc in biology. Capitalizing on the abundance of validated mobile zinc probes, we devised a strategy for repurposing existing intensity-based sensors for quantitative applications. Using solid-phase peptide synthesis, we conjugated a zinc-sensitive Zinpyr-1 derivative and a zinc-insensitive 7-hydroxycoumarin derivative onto opposite ends of a rigid P9K peptide scaffold to create HcZ9, a ratiometric fluorescent probe for mobile zinc. A plate reader-based assay using HcZ9 was developed, the accuracy of which is comparable to that of atomic absorption spectroscopy. We investigated zinc accumulation in prostatic cells and zinc levels in human seminal fluid. When normal and tumorigenic cells are bathed in zinc-enriched media, cellular mobile zinc is buffered and changes slightly, but total zinc levels increase significantly. Quantification of mobile and total zinc levels in human seminal plasma revealed that the two are positively correlated with a Pearson's coefficient of 0.73.
Mechanical properties of Cr-Cu coatings produced by electroplating
NASA Astrophysics Data System (ADS)
Riyadi, Tri Widodo Besar; Sarjito, Masyrukan, Riswan, Ricky Ary
2017-06-01
Hard chromium coatings has long been considered as the most used electrodeposited coating in several industrial applications such as in petrochemistry, oil and gas industries. When hard coatings used in fastener components, the sliding contact during fastening operation produces high tensile stresses on the surface which can generate microcracks. For component used in high oxidation and corrosion environment, deep cracks cannot be tolerated. In this work, a laminated structure of Cr-Cu coating was prepared using electroplating on carbon steel substrates. Two baths of chrome and copper electrolyte solutions were prepared to deposit Cr as the first layer and Cu as the second layer. The effect of current voltages on the thickness, hardness and specific wear rate of the Cu layer was investigated. The results show that an increase of the current voltages increased the thickness and hardness of the Cu layer, but reduced the specific wear rate. This study showed that the use of Cu can be a potential candidate as a laminated structure Cr-Cu for chromium plating.
NASA Astrophysics Data System (ADS)
Xiang-Guo, Meng; Ji-Suo, Wang; Hong-Yi, Fan; Cheng-Wei, Xia
2016-04-01
We solve the fermionic master equation for a thermal bath to obtain its explicit Kraus operator solutions via the fermionic state approach. The normalization condition of the Kraus operators is proved. The matrix representation for these solutions is obtained, which is incongruous with the result in the book completed by Nielsen and Chuang [Quantum Computation and Quantum Information, Cambridge University Press, 2000]. As especial cases, we also present the Kraus operator solutions to master equations for describing the amplitude-decay model and the diffusion process at finite temperature. Project supported by the National Natural Science Foundation of China (Grant No. 11347026), the Natural Science Foundation of Shandong Province, China (Grant Nos. ZR2013AM012 and ZR2012AM004), and the Research Fund for the Doctoral Program and Scientific Research Project of Liaocheng University, Shandong Province, China.
A base-metal conductor system for silicon solar cells
NASA Technical Reports Server (NTRS)
Coleman, M. G.; Pryor, R. A.; Sparks, T. G.
1980-01-01
Solder, copper, and silver are evaluated as conductor layer metals for silicon solar cell metallization on the basis of metal price stability and reliability under operating conditions. Due to its properties and cost, copper becomes an attractive candidate for the conductor layer. It is shown that nickel operates as an excellent diffusion barrier between copper and silicon while simultaneously serving as an electrical contact and mechanical contact to silicon. The nickel-copper system may be applied to the silicon by plating techniques utilizing a variety of plating bath compositions. Solar cells having excellent current-voltage characteristics are fabricated to demonstrate the nickel-copper metallization system.
Induced Pacemaker Activity on Toad Skin
Bueno, Enrique J.; Corchs, Lelio
1968-01-01
The electrical transients produced on the isolated abdominal skin obtained from Bufo arenarum Hensel, under the influence of inward current pulses of constant intensity have been studied. When both faces of the skin are bathed with Ringer's solution, short pulses of inward current give rise to transient variations of the potential difference between both faces of the skin with "all-or-nothing" characteristics (action potentials, AP). When the outer face is bathed with a modified Ringer solution with low sodium content (2.4 mM), the transients are longer and they are only evident when the pulse is several hundred milliseconds long. With even longer pulses (several seconds) a repetitive activity can be elicited, with the electrical characteristics of a "pacemaker" activity. In all these "excitability" phenomena Na+ may be replaced by Li+ in the outer solution. The logarithm of the duration of AP's is inversely related to the logarithm of the increase in concentration of Na+ or Li+ in the solution bathing the external face of the skin. The duration of AP's is increased when the Ca++ concentration in the outer solution is raised. This effect is more evident with low sodium concentration on the outside. The evolution of the slope conductance during repetitive activity has been determined. The site and mechanisms of the "excitable" behavior of the skin and the induced repetitive activity are discussed. Under the experimental conditions employed the behavior of the skin is compared with that of normally excitable plasma membranes. PMID:5692095
DOE Office of Scientific and Technical Information (OSTI.GOV)
Uttam, Vibha, E-mail: vibhauttam74@gmail.com; Duchaniya, R. K., E-mail: rkduchaniya.meta@mnit.ac.in
2016-05-06
Now a days, corrosion studies are important for reducing the wastage of metals. The importance of corrosion studies is two folds i.e. first is economic, including the reduction of material losses resulting from the wasting away or sudden failure of materials and second is conservation Electroless process is an autocatalytic reduction method in which metallic ions are reduced in the solution. Nanocomposite coatings of Ni-P-TiO{sub 2} on mild steel are deposited by varying volume of TiO{sub 2} nano-powder by electroless method from Ni-P plating bath containing Nickel Sulphate as a source of nickel ions, sodium hypophosphite as the reducing agent,more » lactic acid as a complexing agents and TiO{sub 2} nano powder. Electroless Ni-P-TiO{sub 2} coating have been widely used in the chemical process industries, mechanical industries, electronic industries and chloroalkali industries due to their excellent corrosion with mechanical properties. In the present work, deposition of Ni-P alloy coating and Ni-P-TiO{sub 2} nanocomposited coatings were done on the mild steel and corrosion properties were studied with Potentio-dynamic polarization measurements method in 3.5 wt% sodium chloride solution. It showed in the experiments that Ni-P-TiO{sub 2} nanocomposited coating has better corrosion resistance as comparedthan Ni-P alloy coating. Morphological studies were done by field emission scanning electron microscopy (FESEM), energy–dispersive analysis of X-ray (EDAX) and X-ray diffraction (XRD). These studies confirmed the deposition of Ni-P alloy coating and Ni-P-TiO{sub 2} nanocomposited coating.« less
Rigidity of Major Plates and Microplates Estimated From GPS Solution GPS2006.0
NASA Astrophysics Data System (ADS)
Kogan, M. G.; Steblov, G. M.
2006-05-01
Here we analyze the rigidity of eight major lithospheric plates using our global GPS solution GPS2006.0. We included all daily observations in interval 1995.0 to 2006.0 collected at IGS stations, as well as observations at many important stations not included in IGS. Loose multiyear solution GPS2006.0 is based on daily solutions by GAMIT software, performed at SOPAC and at Columbia University; those daily solutions were combined by Kalman filter (GLOBK software) into a loose multiyear solution. The constrained solution for station positions and velocities was obtained without a conventional reference frame; instead, we applied translation and rotation in order to best fit the zero velocities of 76 stations in stable plate cores excluding the regions of postglacial rebound. Simultaneously, we estimated relative plate rotation vectors (RV) and the origin translation rate (OTR), and then corrected station velocities for it. Therefore, the velocities in GPS2006.0 are unaffected by the OTR error of ITRF2000 conventionally used to constrain a loose solution. The 1-sigma plate-residual velocity in a stable plate core is less than 1 mm/yr for the plates: Eurasia, Pacific, North and South Americas, Nubia, Australia, and Antarctica; it is 1.4 mm/yr for the Indian plate, most probably because of poorer data quality. Plate-residuals at other established plates (Arabia, Nazca, Caribbean, Philippine) were not assessed for lack of observations. From our analysis, an upper bound for the mobility of the plate inner area is 1 mm/yr. Plate- residual GPS velocities for several hypothesized microplates in east Asia, such as Okhotsk, Amuria, South China, are 3-4 times higher; corresponding strain rates for these microplates are an order of magnitude higher than for Eurasia, North America, and other large plates.
NASA Astrophysics Data System (ADS)
Ding, Xia; Xue, Long-fei; Wang, Xiu-chun; Ding, Kai-hong; Cui, Sheng-li; Sun, Yong-cong; Li, Mu-sen
2016-10-01
The effect of bath PH value on formation, microstructure and corrosion resistance of the phosphate chemical conversion (PCC) coatings as well as the effect on the magnetic property of the magnets is investigated in this paper. The results show that the coating mass and thickness increase with the decrease of the bath PH value. Scanning electron microscopy observation demonstrates that the PCC coatings are in a blocky structure with different grain size. Transmission electron microscope and X-ray diffractometer tests reveal the coatings are polycomponent and are mainly composed of neodymium phosphate hydrate and praseodymium phosphate hydrate. The electrochemical analysis and static immersion corrosion test show the corrosion resistance of the PCC coatings prepared at bath PH value of 0.52 is worst. Afterwards the corrosion resistance increases first and then decreases with the increasing of the bath PH values. The magnetic properties of all the samples with PCC treatment are decreased. The biggest loss is occurred when the bath PH value is 0.52. Taken together, the optimum PH range of 1.00-1.50 for the phosphate solution has been determined.
David, L M; Matos, J S
2005-01-01
Wet weather urban discharges are responsible for bathing water contamination. The proposal for a revised EU Directive concerning the quality of bathing water imposes significantly more stringent requirements for the management of bathing water quality, with particularly important repercussions on beaches subjected to short-term pollution incidents. The paper reviews the aspects from EU legislation most directly related to the problem of wet-weather discharges, placing special emphasis on the recent revision process of the Directive on bathing water quality, and evaluates the benefits of some potential solutions based on continuous modelling of a combined sewer system. Increasing the sewer system storage capacity or the STP hydraulic capacity may substantially reduce the untreated discharge volumes, but spill frequency reductions under 2 to 3 spill days per bathing season will hardly be achieved. Results show the severe strains that local rainfall patterns would place on compliance with the Commission's proposal for a revised Directive and highlight the importance of the changes introduced in the amended proposal recently approved by the Council, making it less prescriptive if adequate measures are adopted to prevent bathers' exposure to short-term pollution incidents.
NASA Astrophysics Data System (ADS)
Detrich, Kahlil T.; Goulbourne, Nakhiah C.
2009-03-01
The purpose of this research is to evaluate three polymer electroding techniques in developing a novel in situ sensor for an RO system using the electrical response of a thin film composite sensor. Electrical impedance spectroscopy (EIS) was used to measure the sensor response when exposed to sodium chloride solutions with concentrations from 0.1 M to 0.8 M in both single and double bath configurations. An insulated carbon grease sensor was mechanically stable while a composite Direct Assembly Process (DAP) sensor was fragile upon hydration. Scanning electron microscopy results from an impregnation-reduction technique showed gold nanoparticles were deposited most effectively when presoaked in a potassium hydroxide solution and on an uncoated membrane; surface resistances remained too high for sensor implementation. Through thickness carbon grease sensors showed a transient response to changes in concentration, and no meaningful concentration sensitivity was noted for the time scales over which EIS measurements were taken. Surface carbon grease electrodes attached to the polyamide thin film were not sensitive to concentration. The impedance spectra indicated the carbon grease sensor was unable to detect changes in concentration in double bath experiments when implemented with the polyamide surface exposed to salt solutions. DAP sensors lacked a consistent response to changes in concentration too. A reverse double bath experiment with the polysulfone layer exposed to a constant concentration exhibited a transient impedance response similar to through thickness carbon grease sensors in a single bath at constant concentration. These results suggest that the microporous polysulfone layer is responsible for sensor response to concentration.
PLURAL METALLIC COATINGS ON URANIUM AND METHOD OF APPLYING SAME
Gray, A.G.
1958-09-16
A method is described of applying protective coatings to uranlum articles. It consists in applying chromium plating to such uranium articles by electrolysis in a chromic acid bath and subsequently applying, to this minum containing alloy. This aluminum contalning alloy (for example one of aluminum and silicon) may then be used as a bonding alloy between the chromized surface and an aluminum can.
10. VIEW OF THE ADDITION TO BUILDING 883, REFERRED TO ...
10. VIEW OF THE ADDITION TO BUILDING 883, REFERRED TO AS SIDE C. ARMOR PLATE MADE WITH DEPLETED URANIUM WAS HEATED IN A MOLTEN SALT BATH, THEN PROCESSED THROUGH THE ROLLING MILL TO FORM LARGE SHEETS. (9/16/85) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO
NASA Astrophysics Data System (ADS)
Thoren, K. M.; Sinigalliano, C. D.
2016-02-01
Despite numerous cases of beach bacteria affecting millions of people worldwide, the persistence of the bacteria populations in coastal areas is still not well understood. The purpose of this study was to test the levels of persistence of Fecal Indicating Bacteria (FIB) of enterococci, Escherichia coli, and Human-source Bacteroidales, within the intertidal "swash zone" and the deeper waist zone in which people commonly bathe and play. In addition, the study sought to determine if these bacterial contaminants may also be found in aerosols at the beach. Measuring solar insolation in relation to bacterial persistence in seaweed wrack was used to determine if sunlight plays a role in modifying concentrations of FIB at the beach. Light intensity measured by a solar photometer and air quality measured by aerosol plate counts and qPCR Microbial Source Tracking (MST) was compared to varying locations where the beach samples were collected. Results from water samples demonstrate that bacteria measured using plate counts and qPCR were indeed higher within the swash zone than in the waist zone. This is in contrast with the way that the EPA currently measures and determines the public safety of beach waters. They commonly measure the waist zone, but disregard the swash zone. Results from beach bio-aerosol samples showed a wide variety of fungi and bacteria in the beach air, and qPCR MST analysis of these bio-aerosols showed the presence of FIBs such as enterococci on several of the aerosol collection plates. This emphasizes the need to collect samples from the entire beach instead of just measuring at an isolated area, and that exposure to microbial contaminants may include bathing water, beach sand, seaweed wrack, and bio-aerosols. Thus, the data reveals a potential way to identify harmful levels of bacteria and dangerous levels of poor air quality at recreational beaches. These results expound the need for broader assessment of potential beach contamination, not only the swimming water, but also the beach air, shoreline, and also varying depths of water, which can be extremely beneficial to reduce people's risk from microbial contamination exposure.
Microbiological Analysis in Three Diverse Natural Geothermal Bathing Pools in Iceland
Thorolfsdottir, Berglind Osk Th.; Marteinsson, Viggo Thor
2013-01-01
Natural thermal bathing pools contain geothermal water that is very popular to bathe in but the water is not sterilized, irradiated or treated in any way. Increasing tourism in Iceland will lead to increasing numbers of bath guests, which can in turn affect the microbial flora in the pools and therefore user safety. Today, there is no legislation that applies to natural geothermal pools in Iceland, as the water is not used for consumption and the pools are not defined as public swimming pools. In this study, we conducted a microbiological analysis on three popular but different natural pools in Iceland, located at Lýsuhóll, Hveravellir and Landmannalaugar. Total bacterial counts were performed by flow cytometry, and with plate count at 22 °C, 37 °C and 50 °C. The presence of viable coliforms, Enterococcus spp. and pseudomonads were investigated by growth experiments on selective media. All samples were screened for noroviruses by real time PCR. The results indicate higher fecal contamination in the geothermal pools where the geothermal water flow was low and bathing guest count was high during the day. The number of cultivated Pseudomonas spp. was high (13,000–40,000 cfu/100 mL) in the natural pools, and several strains were isolated and classified as opportunistic pathogens. Norovirus was not detected in the three pools. DNA was extracted from one-liter samples in each pool and analyzed by partial 16S rRNA gene sequencing. Microbial diversity analysis revealed different microbial communities between the pools and they were primarily composed of alpha-, beta- and gammaproteobacteria. PMID:23493033
Advances in the electrodeposition of aluminum from ionic liquid based electrolytes
NASA Astrophysics Data System (ADS)
Leadbetter, Kirt C.
Aluminum plating is of considerable technical and economic interest because it provides an eco-friendly substitute for cadmium coatings used on many military systems. However, cadmium has been determined to be a significant environmental safety and occupational health (ESOH) hazard because of its toxicity and carcinogenic nature. Furthermore, the cost of treating and disposing of generated wastes, which often contain cyanide, is costly and is becoming prohibitive in the face of increasingly stringent regulatory standards. The non-toxic alternative aluminum is equivalent or superior in performance to cadmium. In addition, it could serve to provide an alternative to hexavalent chromium coatings used on military systems for similar reasons to that of cadmium. Aluminum is a beneficial alternative in that it demonstrates self-healing corrosion resistance in the form of a tightly-bound, impervious oxide layer. A successfully plated layer would be serviceable over a wider temperature range, 925 °F for aluminum compared to 450 oF for cadmium. In addition, an aluminum layer can be anodized to make it non-conducting and colorable. In consideration of the plating process, aluminum cannot be deposited from aqueous solutions because of its reduction potential. Therefore, nonaqueous electrolytes are required for deposition. Currently, aluminum can be electrodeposited in nonaqueous processes that use hazardous chemicals such as toluene and pyrophoric aluminum alkyls. Electrodeposition from ionic liquids provides the potential for a safer method that could be easily scaled up for industrial application. The plating process could be performed at a lower temperature and higher current density than other commercially available aluminum electrodeposition processes; thus a reduced process cost could be possible. The current ionic liquid based electrolytes are more expensive; however production on a larger scale and a long electrolyte lifetime are associated with a reduction in price. Advancements of this nonaqueous aluminum plating process have the potential to lead to a novel and competitive commercial aluminum deposition process. In this investigation aluminum electrodeposition from ionic liquid based electrolytes onto steel, copper and magnesium substrates without conversion coatings or strike layers was evaluated in six different ionic liquid based electrolytes in two technical setups. Three of which are commercially available aluminum plating electrolytes, three of which, discussed in literature were created on site by research personnel in the laboratory. The three commercially available electrolytes were: 1-Butyl-3-methylimidazolium chloride ([BMIm]Cl) * 1.5 AlCl3 with proprietary additives from IoLiTec, 1-Ethyl-3-methylimidazolium chloride ([EMIm]Cl) * 1.5 AlCl3 with proprietary additives from IoLiTec, and BasionicsTM AL-02, an aluminum plating electrolyte containing [EMIm]Cl * 1.5 AlCl3 with additives from BASF. The three electrolytes created on site were based on the 1-ethyl-3-methylimidazolium chloride ionic liquid with added 1.5 AlCl3 and one with added sodium dodecyl sulfate. Small scale plating tests in a 25-mL plating cell were conducted to provide a comparative analysis of the six different electrolytes considered. From these investigations, two were chosen to be evaluated in a larger 1-liter plating cell; designed and constructed to provide a more realistic evaluation of plating parameters with selected electrolytes to better portray industrial electroplating conditions. The effect of current density (10-40 mA/cm 2), temperature (30-90° Celsius) and plating bath agitation on current efficiency, corrosion resistance by the ASTM B117 method, adhesion, microstructure, and chemical composition (evaluated with energy-dispersive x-ray spectroscopy) of the plated Al-layer was explored in both the 25-mL and 1-L plating cell investigations. In addition development of pre- and post-treatment processes for the metal substrates was attempted. While previous investigations focused on one or two of these topics, this research seeks to investigate all discussed phenomena and characteristics. Additionally, there is little research that reports on the adhesion performance of aluminum coatings from ionic liquids. Also, corrosion investigations are limited to all but a few publications. So too, the deposition of aluminum in a larger, more realistic plating cell has never been thoroughly investigated. This is key if a practical application of the technology is ever to be realized. In sum, correlations were drawn between electrolyte, current density, temperature and bath agitation with quality and characteristic of electrodeposited aluminum layers. The overriding goal to create an acceptably competitive aluminum coating process to replace cadmium and compete with other commercial aluminum deposition processes was not successful. Competitiveness was evaluated as per the discussed characteristics and so also, by a comparison to physical samples created in a more realistic plating cell to AlumiPlate aluminum coatings.
Non-Markovian decay and dynamics of decoherence in private and public environments
NASA Astrophysics Data System (ADS)
Dente, A. D.; Zangara, P. R.; Pastawski, H. M.
2011-10-01
We study the decay process in an open system, emphasizing the relevance of the environment’s spectral structure. Non-Markovian effects are included to quantitatively analyze the degradation rate of the coherent evolution. The way in which a two-level system is coupled to different environments is specifically addressed: multiple connections to a single bath (public environment) or single connections to multiple baths (private environments). We numerically evaluate the decay rate of a local excitation by using the survival probability and the Loschmidt echo. These rates are compared to analytical results obtained from the standard Fermi golden rule (FGR) in wide band approximation, and a self-consistent evaluation that accounts for the bath’s memory in cases where an exact analytical solution is possible. We observe that the correlations appearing in a public bath introduce further deviations from the FGR as compared with a private bath.
Fancello, Eduardo Alberto
2017-01-01
The purpose of this article is to present mechanical and physicochemical properties during in vitro degradation of PLGA material as craniofacial plates based on different values of injection molded temperatures. Injection molded plates were submitted to in vitro degradation in a thermostat bath at 37 ± 1°C by 16 weeks. The material was removed after 15, 30, 60, and 120 days; then bending stiffness, crystallinity, molecular weights, and viscoelasticity were studied. A significant decrease of molecular weight and mechanical properties over time and a difference in FT-IR after 60 days showed faster degradation of the material in the geometry studied. DSC analysis confirmed that the crystallization occurred, especially in higher melt temperature condition. DMA analysis suggests a greater contribution of the viscous component of higher temperature than lower temperature in thermomechanical behavior. The results suggest that physical-mechanical properties of PLGA plates among degradation differ per injection molding temperatures. PMID:29056968
Peng, Yu-Min; Wang, Jih-Wen; Liue, Chun-Ying; Yeh, Shinn-Horng
1994-01-01
A method for preparing silicon carbide particles dispersed in an electrolytic bath for composite electroplating of metals includes the steps of washing the silicon carbide particles with an organic solvent; washing the silicon carbide particles with an inorganic acid; grinding the silicon carbide particles; and heating the silicon carbide particles in a nickel-containing solution at a boiling temperature for a predetermined period of time.
2004-03-01
oxidized rapidly producing trivalent chromium and insoluble organic compounds that eventually decomposed to carbon dioxide. This behavior required...frequent or continuous WA/FS additions, making them a more temporary than permanent solution. The trivalent chromium was also a bath contaminant requiring...need for hard chromium electroplating, but is not expected to ever be able to eliminate it. • Trivalent Chromium Electroplating: Chromium can be
A rapid detection method using flow cytometry to monitor the risk of Legionella in bath water.
Taguri, Toshitsugu; Oda, Yasunori; Sugiyama, Kanji; Nishikawa, Toru; Endo, Takuro; Izumiyama, Shinji; Yamazaki, Masayuki; Kura, Fumiaki
2011-07-01
Legionella species are the causative agents of human legionellosis, and bathing facilities have been identified as the sources of infection in several outbreaks in Japan. Researchers in Japan have recently reported evidence of significant associations between bacterial counts and the occurrence of Legionella in bathing facilities and in a hot tub model. A convenient and quantitative bacterial enumeration method is therefore required as an indicator of Legionella contamination or disinfection to replace existing methods such as time-consuming Legionella culture and expensive Legionella-DNA amplification. In this study, we developed a rapid detection method (RDM) to monitor the risk of Legionella using an automated microbial analyzing device based on flow cytometry techniques to measure the total number of bacteria in water samples within two minutes, by detecting typical patterns of scattered light and fluorescence. We first compared the results of our RDM with plate counting results for five filtered hot spring water samples spiked with three species of bacteria, including Legionella. Inactivation of these samples by chlorine was also assessed by the RDM, a live/dead bacterial fluorescence assay and plate counting. Using the RDM, the lower limit of quantitative bacterial counts in the spiked samples was determined as 3.0×10(3)(3.48log)counts mL(-1). We then used a laboratory model of a hot tub and found that the RDM could monitor the growth curve of naturally occurring heterotrophic bacteria with 1 and 2 days' delayed growth of amoeba and Legionella, respectively, and could also determine the killing curve of these bacteria by chlorination. Finally, samples with ≥3.48 or <3.48log total bacterial counts mL(-1) were tested using the RDM from 149 different hot tubs, and were found to be significantly associated with the positive or negative detection of Legionella with 95% sensitivity and 84% specificity. These findings indicated that the RDM can be used for Legionella control at bathing facilities, especially those where the effectiveness of chlorine is reduced by the presence of Fe(2+), Mn(2+), NH(4)(+), skin debris, and/or biofilms in the water. Copyright © 2011 Elsevier B.V. All rights reserved.
Assessment of pollution prevention and control technology for plating operations
NASA Technical Reports Server (NTRS)
Chalmer, Paul D.; Sonntag, William A.; Cushnie, George C., Jr.
1995-01-01
The National Center for Manufacturing Sciences (NCMS) is sponsoring an on-going project to assess pollution prevention and control technology available to the plating industry and to make this information available to those who can benefit from it. Completed project activities include extensive surveys of the plating industry and vendors of technologies and an indepth literature review. The plating industry survey was performed in cooperation with the National Association of Metal Finishers. The contractor that conducted the surveys and prepared the project products was CAI Engineering. The initial products of the project were made available in April, 1994. These products include an extensive report that presents the results of the surveys and literature review and an electronic database. The project results are useful for all those associated with pollution prevention and control in the plating industry. The results show which treatment, recovery and bath maintenance technologies have been most successful for different plating processes and the costs for purchasing and operating these technologies. The project results also cover trends in chemical substitution, the identification of compliance-problem pollutants, sludge generation rates, off-site sludge recovery and disposal options, and many other pertinent topics.
Preparation of cuxinygazsen precursor films and powders by electroless deposition
Bhattacharya, Raghu N.; Batchelor, Wendi Kay; Wiesner, Holm; Ramanathan, Kannan; Noufi, Rommel
1999-01-01
A method for electroless deposition of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) precursor films and powders onto a metallic substrate comprising: preparing an aqueous bath solution of compounds selected from the group consisting of: I) a copper compound, a selenium compound, an indium compound and gallium compound; II) a copper compound, a selenium compound and an indium compound; III) a selenium compound, and indium compound and a gallium compound; IV) a selenium compound and a indium compound; and V) a copper compound and selenium compound; each compound being present in sufficient quantity to react with each other to produce Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3); adjusting the pH of the aqueous bath solution to an acidic value by the addition of a dilute acid; and initiating an electroless reaction with an oxidizing counterelectrode for a sufficient time to cause a deposit of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) from the aqueous bath solution onto a metallic substrate.
Layeni, Olawanle P; Akinola, Adegbola P; Johnson, Jesse V
2016-01-01
Two distinct and novel formalisms for deriving exact closed solutions of a class of variable-coefficient differential-difference equations arising from a plate solidification problem are introduced. Thereupon, exact closed traveling wave and similarity solutions to the plate solidification problem are obtained for some special cases of time-varying plate surface temperature.
Performance of three systems for warming intravenous fluids at different flow rates.
Satoh, J; Yamakage, M; Wasaki, S I; Namiki, A
2006-02-01
This study compared the intravenous fluid warming capabilities of three systems at different flow rates. The devices studied were a water-bath warmer, a dry-heat plate warmer, and an intravenous fluid tube warmer Ambient temperature was controlled at 22 degrees to 24 degrees C. Normal saline (0.9% NaCl) at either room temperature (21 degrees to 23 degrees C) or at ice-cold temperature (3 degrees to 5 degrees C) was administered through each device at a range of flow rates (2 to 100 ml/min). To mimic clinical conditions, the temperature of the fluid was measured with thermocouples at the end of a one metre tube connected to the outflow of the warmer for the first two devices and at the end of the 1.2 m warming tubing for the intravenous fluid tube warmer The temperature of fluid delivered by the water bath warmer increased as the flow rate was increased up to 15 to 20 ml/min but decreased with greater flow rates. The temperature of the fluid delivered by the dry-heat plate warmer significantly increased as the flow rate was increased within the range tested (due to decreased cooling after leaving the device at higher flow rates). The temperature of fluid delivered by the intravenous fluid tube warmer did not depend on the flow rate up to 20 ml/min but significantly and fluid temperature-dependently decreased at higher flow rates (>30 ml/min). Under the conditions of our testing, the dry heat plate warmer delivered the highest temperature fluid at high flow rates.
Gui, Yanghai; Zhao, Jianbo; Chen, Jingbo; Jiang, Yuanli
2016-01-01
Cubic boron nitride (cBN) is widely applied in cutting and grinding tools. cBN grains plated by pure Ni and Ni/SiC composite were produced under the same conditions from an additive-free nickel Watts type bath. The processed electroplating products were characterized by the techniques of scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermoanalysis (TG-DTA). Due to the presence of SiC particles, there are some additional nodules on the surface of Ni/SiC plated cBN compared with the pure Ni plated cBN. The unique morphology of Ni/SiC plated cBN should attain greater retention force in resin bond. Moreover, the coating weight of cBN grains could be controlled by regulating the plating time. cBN grains with 60% coating weight possess the optimum grinding performance due to their roughest and spiniest surface. In addition, Ni spines plated cBN grains show good thermal stability when temperature is lower than 464 °C. Therefore, the plated cBN grains are more stable and suitable for making resin bond abrasive tools below 225 °C. Finally, the formation mechanism of electroplating products is also discussed. PMID:28773283
Post-industrial river water quality-Fit for bathing again?
Kistemann, Thomas; Schmidt, Alexandra; Flemming, Hans-Curt
2016-10-01
For the Ruhr River, bathing has been prohibited for decades. However, along with significant improvements of the hygienic water quality, there is an increasing demand of using the river for recreational purposes, in particular for bathing. In the "Safe Ruhr" interdisciplinary research project, demands, options and chances for lifting the bathing ban for the Ruhr River were investigated. As being the prominent reason for persisting recreational restrictions, microbiological water quality was in the focus of interest. Not only the faecal indicator organisms (FIOs) as required by the European Bathing Water Directive were considered, but also pathogens such as Salmonella, Pseudomonas aeruginosa, Legionella pneumophila, Campylobacter, Leptospira, enteroviruses and protozoan parasites. In this introductory paper, we firstly relate current recreational desires to historical experiences of river bathing. After recapitulating relevant microbial river contamination sources (predominantly sewage treatment plants, combined sewer overflows, and surface runoffs), we review existing knowledge about the relationships of FIOs and pathogens in rivers designated for recreational purposes, and then trace the evolution, rationale and validity of recreational freshwater quality criteria which are, despite obvious uncertainties, mostly relying on the FIO paradigm. In particular, the representativeness of FIOs is critically discussed. The working programme of Safe Ruhr, aiming at initiating and facilitating a process towards legalisation of Ruhr River bathing, is outlined. Sources of contamination can be technically handled which leaves the actual measures to political decisions. As contaminations are transient, only occasionally exceeding legal limits, a flexible bathing site management, warning bathers of non-safe situations, may amend technical interventions and offer innovative solutions. As a result, a situation-adapted system for lifting of the bathing ban for Ruhr River appears realistic. Copyright © 2016 Elsevier GmbH. All rights reserved.
Prevention of Post-Traumatic Epilepsy by Transcranial Direct Current Stimulation
2014-09-01
epidural fluid percussion itself. As an improvement on the classic LFPI procedure, we designed and validated a new protocol, termed rapid fluid ...plated on an 8X8 micoelectrode array (left) and bathed in oxygenated artificial cerebrospinal fluid . Cortical excitability was measured as the magnitude...not be construed as an official Department of the Army position, policy or decision unless so designated by other documentation. 1 REPORT
A Comparison of Gravimetric and Photometric Aerosol Samplers
2009-03-24
the potential to cause disease (Vincent, 2007; Meldrum , 1996; and ATSDR, 2001). f) Fog – discernible mist that floats in air and usually settles to...atomization, such as spraying or arising from acid baths in chrome plating. The droplets are homogenous with the parent material and range from xvi...Contaminant Control. Boston, Butterworth Publishers. Meldrum , M. (1996). Review of fibre toxicology. H.S.E. Report, London, UK, Health and Safety
Jiang, Xiaojun; Chen, Wenchao; Xu, Hongbo
2009-01-01
A method using trivalent chromium has been used to replace hexavalent chromium for the electro-deposition of chromium. Using a tri-chamber bath system various anodic materials and membranes were evaluated to minimize the production of environmentally and health damaging chromic acid. By measuring the absorbance of Cr(VI) at 640 nm, the results indicate that the use of a titanium plated ruthenium (Ti-Ru) anode produces the least amount of chromic acid byproduct compared to lead-gold alloy and graphite anodes. The concentration of Cr(VI) in the immediate vicinity of the Ti-Ru anode decreased from 0.389 mg/L to 0 during a 40-min deposition period. The use of a Nafion(TM) quaternary cation exchange membrane portioning the buffer and anode selectively prevented Cr(III) from entering the anode compartment whilst allowing the migration of H(+) to maintain overall voltaic continuity. It has been demonstrated that the use of a Ti-Ru anode with a Nafion(TM) membrane can eliminate the production of chromic acid associated with the electro-deposition of chromium plate thereby preventing its health damaging exposure to plant operators and preventing discharge of Cr(VI) into the environment. Addition of a surfactant improved current efficiency by 34.7%.
2015-07-01
samples must be thoroughly degreased and dried to eliminate any outgassing from organic contamination and water. Samples can be cleaned ultrasonically ...in an ultrasonic bath for at least 10 minutes to ensure separation of particles (University of California, Riverside, n.d.). These solutions can...be further agitated in the ultrasonic bath to separate particles. It should be noted that excessive ultrasonic agitation can damage samples
Black chrome solar selective coating
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pettit, R.B.; Sowell, R.R.
1980-01-01
Electrodeposited black chrome solar selective coatings have frequently experienced thermal stability problems when heated to temperatures above 250/sup 0/C (480/sup 0/F) in air. By reducing the trivalent chromium concentration in the standard black chrome plating bath, coatings on nickel substrates are obtained which are stable for thousands of hours at 350/sup 0/C (660/sup 0/F) and for hundreds of hours at 400/sup 0/C (750/sup 0/F). These results have been obtained consistently on a laboratory scale, but difficulty in reproducing the results has been encountered in a production environment. A current study of the effects of known plating variables on the opticalmore » properties and thermal stability of coatings is aimed at establishing an acceptable range for each plating parameter. A preliminary process specification for electroplating mild steel substrates with a stable black chrome coating is presented.« less
Preparation and characterization of Ni-P/Ni3.1B composite alloy coatings
NASA Astrophysics Data System (ADS)
Wang, Yurong; He, Jiawei; Wang, Wenchang; Shi, Jianhua; Mitsuzaki, Naotoshi; Chen, Zhidong
2014-02-01
The preparation of Ni-P/Ni3.1B composite alloy coating on the surface of copper was achieved by co-deposition of Ni3.1B nanoparticles with Ni-P coating during electroless plating. Ni-P-B alloy coating was obtained by heat-treating the as-plated Ni-P/Ni3.1B composite coating. The effect of the concentration of sodium alginate, borax, thiourea, Ni3.1B, temperature, and pH value on the deposition rate and B content were investigated and determined to be: 30 g L-1, 10 g L-1, 2 mg L-1, 20 mg L-1, 70 °C and 9.0 , respectively. Sodium alginate and thiourea were played as surfactant for coating Ni3.1B nanoparticles and stabilizer for the plating bath, respectively. Ni-P/Ni3.1B composite coating had good performance such as corrosion resistance and solderability.
Dennis, V W; Brazy, P C
1978-08-01
Interactions among the transport systems involved with sodium, bicarbonate, glucose, phosphate, and alanine absorption in isolated segments of the rabbit proximal convoluted tubule were examined with radioisotopic techniques to measure glucose, phosphate, and fluid absorption rates. The composition of the perfusate and bath varied from normal, physiological fluids to fluids deficient in a single solute. The deletion of glucose from the perfusate increased the lumen-to-bath flux of phosphate from 5.51 +/- 1.15 to 8.32 +/- 1.34 pmol/mm-min (P less than 0.01). Similar changes occurred when glucose transport was inhibited by phlorizin 10 micron in the perfusate, The deletion of alanine from the perfusate increased the lumen-to-bath flux of phosphate from 6.55 +/- 1.08 to 9.00 +/- 1.30 pmol/mm-min (P less than 0.01) but did not affect glucose transport significantly, 80.1 +/- 10.1 vs. 72.5 +/- 5.4 pmol/mm-min. Replacement of intraluminal sodium with choline, elimination of potassium from the bath, and removal of bicarbonate from the lumen and bath each reduced glucose, phosphate, and fluid absorption. These data indicate that the proximal absorptive processes for glucose and for phosphate include elements that are dependent upon some function of sodium transport. Additionally, the effects on phosphate transport of deleting glucose or alanine occur independent of any changes in net sodium transport and are opposite the effects of deleting bicarbonate. These differences may relate to the observations that the transport of glucose and alanine is electrogenic while that of bicarbonate is not. Regardless of possible mechanisms, the data demonstrate that important changes in the absorption rates of different solutes handled significantly by the proximal convoluted tubule may occur in response to changes in specific components of proximal sodium transport.
Scanning nozzle plating system. [for etching or plating metals on substrates without masking
NASA Technical Reports Server (NTRS)
Oliver, G. D. (Inventor)
1974-01-01
A plating system is described in which a substrate to be plated is supported on a stationary platform. A nozzle assembly with a small nozzle is supplied with a plating solution under high pressure, so that a constant-flow stream of solution is directed to the substrate. The nozzle assembly is moved relative to the substrate at a selected rate and movement pattern. A potential difference (voltage) is provided between the substrate and the solution in the assembly. The voltage amplitude is modulated so that only when the amplitude is above a minimum known value plating takes place.
Comparative study of the thermal properties of mud and peat solutions applied in clinical practice.
Beer, A M; Grozeva, A; Sagorchev, P; Lukanov, J
2003-11-01
Different peloids as e.g. mud and peat have been traditionally used for therapeutic purposes successfully, especially of there thermal actions. It was the aim of the experimental study to compare the thermal properties of two peloids, mud and peat, with a view to assessing their thermal effects when they are applied in clinical practice. The studies were carried out using peat of the marsh type of peats (Hochmoor), and curative Pomorie (Bulgaria) mud. As important parameters were determined the specific thermal capacity at constant pressure (Cp), the density of solutions (rho), the cooling rate (m), the coefficient of temperature transfer (a) of solutions and the coefficient of thermal conductivity (lambda) of solutions of peat and curative mud, compared to water bath. The comparative studies of the thermal properties of water and water solutions of peat and curative mud show that the thermal effect of the water bath is substantially smaller than that of the peat and mud applications. This difference is due to a greater extent to the high values of the dynamic viscosity, not allowing cooling by convection and protecting the surface of the skin upon applications of peloid solutions with a higher temperature.
Electroless Nickel Deposition for Front Side Metallization of Silicon Solar Cells
Hsieh, Shu Huei; Hsieh, Jhong Min; Chen, Wen Jauh; Chuang, Chia Chih
2017-01-01
In this work, nickel thin films were deposited on texture silicon by electroless plated deposition. The electroless-deposited Ni layers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), X-ray diffraction analysis (XRD), and sheet resistance measurement. The results indicate that the dominant phase was Ni2Si and NiSi in samples annealed at 300–800 °C. Sheet resistance values were found to correlate well with the surface morphology obtained by SEM and the results of XRD diffraction. The Cu/Ni contact system was used to fabricate solar cells by using two different activating baths. The open circuit voltage (Voc) of the Cu/Ni samples, before and after annealing, was measured under air mass (AM) 1.5 conditions to determine solar cell properties. The results show that open circuit voltage of a solar cell can be enhanced when the activation solution incorporated hydrofluoric acid (HF). This is mainly attributed to the native silicon oxide layer that can be decreased and/or removed by HF with the corresponding reduction of series resistance. PMID:28805724
NASA Technical Reports Server (NTRS)
Solomon, S. C.
1980-01-01
The measurability of changes in plate driving or resistive forces associated with plate boundary earthquakes by laser rangefinding or VLBI is considered with emphasis on those aspects of plate forces that can be characterized by such measurements. Topics covered include: (1) analytic solutions for two dimensional stress diffusion in a plate following earthquake faulting on a finite fault; (2) two dimensional finite-element solutions for the global state of stress at the Earth's surface for possible plate driving forces; and (3) finite-element solutions for three dimensional stress diffusion in a viscoelastic Earth following earthquake faulting.
Study on Temperature Control System Based on SG3525
NASA Astrophysics Data System (ADS)
Cheng, Cong; Zhu, Yifeng; Wu, Junfeng
2017-12-01
In this paper, it uses the way of dry bath temperature to heat the microfluidic chip directly by the heating plate and the liquid sample in microfluidic chip is heated through thermal conductivity, thus the liquid sample will maintain at target temperature. In order to improve the reliability of the whole machine, a temperature control system based on SG3525 is designed.SG3525 is the core of the system which uses PWM wave produced by itself to drive power tube to heat the heating plate. The bridge circuit consisted of thermistor and PID regulation ensure that the temperature can be controlled at 37 °C with a correctness of ± 0.2 °C and a fluctuation of ± 0.1 °C.
Aluminum electroplating on steel from a fused bromide electrolyte
DOE Office of Scientific and Technical Information (OSTI.GOV)
Prabhat K. Tripathy; Laura A. Wurth; Eric J. Dufek
A quaternary bromide bath (LiBr–KBr–CsBr–AlBr3) was used to electro-coat aluminum on steel substrates. The electrolytewas prepared by the addition of AlBr3 into the eutectic LiBr–KBr–CsBr melt. A smooth, thick, adherent and shiny aluminum coating could be obtained with 80 wt.% AlBr3 in the ternary melt. The SEM photographs of the coated surfaces suggest the formation of thick and dense coatings with good aluminum coverage. Both salt immersion and open circuit potential measurement suggested that the coatings did display a good corrosionresistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminum coating inmore » preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminumcoating on both ferrous and non-ferrous metals, including complex surfaces/geometries.« less
Aluminium Electroplating on Steel from a Fused Bromide Electrolyte
DOE Office of Scientific and Technical Information (OSTI.GOV)
Prabhat Tripathy; Laura Wurth; Eric Dufek
A quaternary bromide bath (LiBr-KBr-CsBr-AlBr3) was used to electro-coat aluminium on steel substrates. The electrolyte was prepared by the addition of AlBr3 into the eutectic LiBr-KBr-CsBr melt. A smooth, thick, adherent and shiny aluminium coating could be obtained with 80 wt.% AlBr3 in the ternary melt. The SEM photographs of the coated surfaces suggest the formation of thick and dense coatings with good aluminium coverage. Both salt immersion and open circuit potential measurement suggest that the coatings did display good corrosion-resistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminium coating inmore » preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminium coating on both ferrous and non-ferrous metals, including complex surfaces/geometries.« less
ANALYTICAL METHOD FOR THE ABSORPTIOMETRIC DETERMINATION OF BORON IN AMMONIA SOLUTION
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
1962-01-01
ABS>A weighed sample is evaporated to dryness with caustic soda solution on a water bath. The residue is dissolved by addlng a solution of curcumin in acetic acid. After adding a mixture of H/sub 2/SO/sub 4/ and acetic acid, the solution is allowed to stand at room temperature for 15 minutes. The solution is then diluted to 100 ml with ethanol, and a portion is filtered and measured absorptiometrically on the residue as the curcumin complex. (P.C.H.)
Method for making thin polypropylene film
Behymer, R.D.; Scholten, J.A.
1985-11-21
An economical method is provided for making uniform thickness polypropylene film as thin as 100 Angstroms. A solution of polypropylene dissolved in xylene is formed by mixing granular polypropylene and xylene together in a flask at an elevated temperature. A substrate, such as a glass plate or microscope slide is immersed in the solution. When the glass plate is withdrawn from the solution at a uniform rate, a thin polypropylene film forms on a flat surface area of the glass plate as the result of xylene evaporation. The actual thickness of the polypropylene film is functional of the polypropylene in xylene solution concentration, and the particular withdrawal rate of the glass plate from the solution. After formation, the thin polypropylene film is floated from the glass plate onto the surface of water, from which it is picked up with a wire hoop.
The Effect of Valinomycin on the Electrical Properties of Solutions of Red Cell Lipids in n-Decane
Andreoli, Thomas E.; Tosteson, Daniel C.
1971-01-01
This paper reports the electrical properties of thick lipid membranes in the absence and presence of valinomycin. The thick lipid membranes were formed by placing a solution of sheep red cell lipids in decane between two cellophane partitions which formed the interfaces between the membrane and the two aqueous bathing solutions. The DC electrical resistance of these structures was found to be directly proportional to the reciprocal of the concentration of lipids in the decane (CL). The limiting resistance, as (CL -1) approached zero, was 3 x 108 ohm-cm2. Resistance was also found to be linearly related to membrane thickness. The limiting resistance at zero thickness was again 1–3 x 108 ohm-cm2. These data are interpreted to indicate that the DC resistance of thick lipid membranes comprises two surface resistances (RS) at each interface with the aqueous bathing solutions, and a bulk resistance (RB) of the lipid-decane solution, arranged in series. Measurements of the effect of variations of area on resistance were consistent with this interpretation. Valinomycin reduced RS but had no effect on RB. Under certain conditions, thick lipid membranes containing valinomycin behaved like highly selective K+ electrodes. PMID:5553100
Treatment of halogen-containing waste and other waste materials
Forsberg, Charles W.; Beahm, Edward C.; Parker, George W.
1997-01-01
A process for treating a halogen-containing waste material. The process provides a bath of molten glass containing a sacrificial metal oxide capable of reacting with a halogen in the waste material. The sacrificial metal oxide is present in the molten glass in at least a stoichiometric amount with respect to the halogen in the waste material. The waste material is introduced into the bath of molten glass to cause a reaction between the halogen in the waste material and the sacrificial metal oxide to yield a metal halide. The metal halide is a gas at the temperature of the molten glass. The gaseous metal halide is separated from the molten glass and contacted with an aqueous scrubber solution of an alkali metal hydroxide to yield a metal hydroxide or metal oxide-containing precipitate and a soluble alkali metal halide. The precipitate is then separated from the aqueous scrubber solution. The molten glass containing the treated waste material is removed from the bath as a waste glass. The process of the invention can be used to treat all types of waste material including radioactive wastes. The process is particularly suited for separating halogens from halogen-containing wastes.
Treatment of halogen-containing waste and other waste materials
Forsberg, C.W.; Beahm, E.C.; Parker, G.W.
1997-03-18
A process is described for treating a halogen-containing waste material. The process provides a bath of molten glass containing a sacrificial metal oxide capable of reacting with a halogen in the waste material. The sacrificial metal oxide is present in the molten glass in at least a stoichiometric amount with respect to the halogen in the waste material. The waste material is introduced into the bath of molten glass to cause a reaction between the halogen in the waste material and the sacrificial metal oxide to yield a metal halide. The metal halide is a gas at the temperature of the molten glass. The gaseous metal halide is separated from the molten glass and contacted with an aqueous scrubber solution of an alkali metal hydroxide to yield a metal hydroxide or metal oxide-containing precipitate and a soluble alkali metal halide. The precipitate is then separated from the aqueous scrubber solution. The molten glass containing the treated waste material is removed from the bath as a waste glass. The process of the invention can be used to treat all types of waste material including radioactive wastes. The process is particularly suited for separating halogens from halogen-containing wastes. 3 figs.
Ergodicity of the Stochastic Nosé-Hoover Heat Bath
NASA Astrophysics Data System (ADS)
Wei Chung Lo,; Baowen Li,
2010-07-01
We numerically study the ergodicity of the stochastic Nosé-Hoover heat bath whose formalism is based on the Markovian approximation for the Nosé-Hoover equation [J. Phys. Soc. Jpn. 77 (2008) 103001]. The approximation leads to a Langevin-like equation driven by a fluctuating dissipative force and multiplicative Gaussian white noise. The steady state solution of the associated Fokker-Planck equation is the canonical distribution. We investigate the dynamics of this method for the case of (i) free particle, (ii) nonlinear oscillators and (iii) lattice chains. We derive the Fokker-Planck equation for the free particle and present approximate analytical solution for the stationary distribution in the context of the Markovian approximation. Numerical simulation results for nonlinear oscillators show that this method results in a Gaussian distribution for the particles velocity. We also employ the method as heat baths to study nonequilibrium heat flow in one-dimensional Fermi-Pasta-Ulam (FPU-β) and Frenkel-Kontorova (FK) lattices. The establishment of well-defined temperature profiles are observed only when the lattice size is large. Our results provide numerical justification for such Markovian approximation for classical single- and many-body systems.
Adiabatic Compression Sensitivity of AF-M315E
2015-07-01
the current work is to expand the knowledge base from previous experiments completed at AFRL for AF-M315E in stainless steel U-tubes at room...addressed, to some degree, with the use of clamps and a large stainless steel plate to dissipate any major vibrations. A large preheated bath of 50:50 v/v...autocatalytic chain decomposition in the propellant. This exothermic decomposition decreases the fume -off initiation temperature of the propellant and its
Octanol reduces end-plate channel lifetime
Gage, Peter W.; McBurney, Robert N.; Van Helden, Dirk
1978-01-01
1. Post-synaptic effects of n-octanol at concentrations of 0·1-1 mM were examined in toad sartorius muscles by use of extracellular and voltage-clamp techniques. 2. Octanol depressed the amplitude and duration of miniature end-plate currents and hence depressed neuromuscular transmission. 3. The decay of miniature end-plate currents remained exponential in octanol solutions even when the time constant of decay (τD) was decreased by 80-90%. 4. The lifetime of end-plate channels, obtained by analysis of acetylcholine noise, was also decreased by octanol. The average lifetime measured from noise spectra agreed reasonably well with the time constant of decay of miniature end-plate currents, both in control solution and in octanol solutions. 5. Octanol caused a reduction in the conductance of end-plate channels. Single channel conductance was on average about 25 pS in control solution and 20 pS in octanol. 6. In most cells the normal voltage sensitivity of the decay of miniature end-plate currents was retained in octanol solutions. The lifetime of end-plate channels measured from acetylcholine noise also remained voltage-sensitive in octanol solutions. In some experiments in which channel lifetime was exceptionally reduced the voltage sensitivity was less than normal. 7. In octanol solutions, τD was still very sensitive to temperature changes in most cells although in some the temperature sensitivity of τD was clearly reduced. Changes in τD with temperature could generally be fitted by the Arrhenius equation suggesting that a single step reaction controlled the decay of currents both in control and in octanol solutions. In some cells in which τD became less than 0·3 ms, the relationship between τD and temperature became inconsistent with the Arrhenius equation. 8. As the decay of end-plate currents in octanol solutions remains exponential, and the voltage and temperature sensitivity can be unchanged even when τD is significantly reduced, it seems likely that octanol decreases τD by increasing the rate of the reaction which normally controls the lifetime of end-plate channels. PMID:203674
NASA Astrophysics Data System (ADS)
Kuzmann, E.; Stichleutner, S.; Doyle, O.; Chisholm, C. U.; El-Sharif, M.; Homonnay, Z.; Vértes, A.
2005-04-01
Constant current technique was applied to electrodeposit tin-containing coatings such as tin-cobalt (Sn-Co), tin-iron (Sn-Fe) and a novel tin-cobalt-iron (Sn-Co-Fe) from a gluconate bath. The effect of plating parameters (current density, deposition time at an electrolyte temperature of 60°C and pH=7.0) on phase composition, crystal structure and magnetic anisotropy of alloy deposits has been investigated mainly by 57Fe CEMS, 119Sn CEMS and transmission Mössbauer Spectroscopy as well as XRD. 57Fe and 119Sn CEM spectra and XRD reflect that the dominant phases of the deposits are orthorhombic Co3Sn2, tetragonal FeSn2 or amorphous Fe-Sn and amorphous Sn-Co-Fe in Sn-Co, Sn-Fe and Sn-Co-Fe coatings, respectively. Furthermore, the relative area of the 2nd and 5th lines of the sextets representing the magnetic iron containing phases decreases continuously with increasing current density in all Fe-containing deposits. At the same time, no essential change in the magnetic anisotropy can be found with the plating time. 119Sn spectra reveal the presence of small amount of β-Sn besides the main phases in Sn-Fe and in the Sn-Co coatings. Magnetically split 119Sn spectra reflecting transferred hyperfine field were observed in the case of Co-Sn-Fe coatings.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Williams, Todd O
2009-01-01
The exact solution for the history-dependent behavior of laminated plates subjected to cylindrical bending is presented. The solution represents the extension of Pagano's solution to consider arbitrary types of constitutive behaviors for the individual lamina as well as arbitrary types of cohesive zones models for delamination behavior. Examples of the possible types of material behavior are plasticity, viscoelasticity, viscoplasticity, and damaging. Examples of possible CZMs that can be considered are linear, nonlinear hardening, as well as nonlinear with softening. The resulting solution is intended as a benchmark solution for considering the predictive capabilities of different plate theories. Initial results aremore » presented for several types of history-dependent material behaviors. It is shown that the plate response in the presence of history-dependent behaviors can differ dramatically from the elastic response. These results have strong implications for what constitutes an appropriate plate theory for modeling such behaviors.« less
A maximum entropy thermodynamics of small systems.
Dixit, Purushottam D
2013-05-14
We present a maximum entropy approach to analyze the state space of a small system in contact with a large bath, e.g., a solvated macromolecular system. For the solute, the fluctuations around the mean values of observables are not negligible and the probability distribution P(r) of the state space depends on the intricate details of the interaction of the solute with the solvent. Here, we employ a superstatistical approach: P(r) is expressed as a marginal distribution summed over the variation in β, the inverse temperature of the solute. The joint distribution P(β, r) is estimated by maximizing its entropy. We also calculate the first order system-size corrections to the canonical ensemble description of the state space. We test the development on a simple harmonic oscillator interacting with two baths with very different chemical identities, viz., (a) Lennard-Jones particles and (b) water molecules. In both cases, our method captures the state space of the oscillator sufficiently well. Future directions and connections with traditional statistical mechanics are discussed.
Plating Processes Utilizing High Intensity Acoustic Beams
NASA Technical Reports Server (NTRS)
Oeftering, Richard C. (Inventor); Denofrio, Charles (Inventor)
2002-01-01
A system and a method for selective plating processes are disclosed which use directed beams of high intensity acoustic waves to create non-linear effects that alter and improve the plating process. The directed beams are focused on the surface of an object, which in one embodiment is immersed in a plating solution, and in another embodiment is suspended above a plating solution. The plating processes provide precise control of the thickness of the layers of the plating, while at the same time, in at least some incidents, eliminates the need for masking.
NASA Astrophysics Data System (ADS)
Aziz, Tengku Norazman Tengku Abd; Rosli, Aimi Bazilah; Yusoff, Marmeezee Mohd; Herman, Sukreen Hana; Zulkifli, Zurita
2018-05-01
This paper demonstrates the transfer of graphene at low temperature using water bath. Graphene in water solution (highly opaque) was transferred onto Platinum/Glass (Pt/Glass) substrate and the technique involves no additional chemicals. We obtained high transparency and large area of graphene film that is free of contaminants. The transferred graphene is characterized using FESEM, Raman spectroscopy and I-V measurements. This transfer method enables us to transfer graphene onto ZnO thin film for memristive devices.
A unified theory for laminated plates
NASA Astrophysics Data System (ADS)
Guiamatsia Tafeuvoukeng, Irene
A literature survey on plate and beam theories show how the advent of the finite element method and the variational method circa 1940 have been a great stimulant for the research in this field. The initial thin plate formulation has been incrementally expanded to treat the isotropic thick plate, the anisotropic single layer, and then laminated plates. It appears however that current formulations still fall into one of two categories: (1) The formulation is tailored for a specific laminate and/or loading case; (2) or the formulation is too complicated to be of practical relevance. In this work a new unifying approach to laminated plate formulation is presented. All laminated plates, including sandwich panels, subjected to any surface load and with any boundary conditions are treated within a single model. In addition, the fundamental behavior of the plate as a two-dimensional structural element is explained. The novel idea is the introduction of fundamental state solutions, which are analytical far field stress and strain solutions of the laminated plate subjected to a set of hierarchical primary loads, the fundamental loads. These loads are carefully selected to form a basis of the load space, and corresponding solutions are superposed to obtain extremely accurate predictions of the three dimensional solution. six,y,z =aklx,y sikl z where i = 1,..., 6; 1=1,...,l max is a substate of the kth fundamental state k=1,2,3,... Typically, a fundamental state solution is expressed as a through-thickness function (z), while the amplitudes of each fundamental load are found from two dimensional finite element solution as a function of in-plane coordinates (x,y). Three major contributions are produced in this work: (1) A complete calibration of the plate as a two-dimensional structure is performed with pure bending and constant shear fundamental states. (2) There are four independent ways to apply a constant shear resultant on a plate, as opposed to one for a beam. This makes it impossible to define a unique 2 x 2 transverse shear stiffness matrix. Therefore the traditional problem of the shear correction factor loses all relevance. It is however shown that an explicit transverse constitutive relation can be obtained for isotropic-layered laminates or single-layers. (3) Higher accuracy, three-dimensional solutions are obtained using a two-dimensional finite element model with a complexity level (degrees of freedom) similar to the Reissner-Mindlin plate. The proof of concept is realized using Pagano solution for rectangular plates under sinusoidal load, for a sandwich panel. Additional comparisons are also performed for four and six-layer symmetric and antisymmetric laminates, between the new plate theory results and full three-dimensional finite element solutions.
Exposure to buffer solution alters tendon hydration and mechanics.
Safa, Babak N; Meadows, Kyle D; Szczesny, Spencer E; Elliott, Dawn M
2017-08-16
A buffer solution is often used to maintain tissue hydration during mechanical testing. The most commonly used buffer solution is a physiological concentration of phosphate buffered saline (PBS); however, PBS increases the tissue's water content and decreases its tensile stiffness. In addition, solutes from the buffer can diffuse into the tissue and interact with its structure and mechanics. These bathing solution effects can confound the outcome and interpretation of mechanical tests. Potential bathing solution artifacts, including solute diffusion, and their effect on mechanical properties, are not well understood. The objective of this study was to measure the effects of long-term exposure of rat tail tendon fascicles to several concentrations (0.9-25%) of NaCl, sucrose, polyethylene glycol (PEG), and SPEG (NaCl+PEG) solutions on water content, solute diffusion, and mechanical properties. We found that with an increase in solute concentration the apparent water content decreased for all solution types. Solutes diffused into the tissue for NaCl and sucrose, however, no solute diffusion was observed for PEG or SPEG. The mechanical properties changed for both NaCl solutions, in particular after long-term (8h) incubation the modulus and equilibrium stress decreased compared to short-term (15min) for 25% NaCl, and the cross sectional area increased for 0.9% NaCl. However, the mechanical properties were unchanged for both PEG and SPEG except for minor alterations in stress relaxation parameters. This study shows that NaCl and sucrose buffer solutions are not suitable for long-term mechanical tests. We therefore propose using PEG or SPEG as alternative buffer solutions that after long-term incubation can maintain tissue hydration without solute diffusion and produce a consistent mechanical response. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Stein, M.; Stein, P. A.
1978-01-01
Approximate solutions for three nonlinear orthotropic plate problems are presented: (1) a thick plate attached to a pad having nonlinear material properties which, in turn, is attached to a substructure which is then deformed; (2) a long plate loaded in inplane longitudinal compression beyond its buckling load; and (3) a long plate loaded in inplane shear beyond its buckling load. For all three problems, the two dimensional plate equations are reduced to one dimensional equations in the y-direction by using a one dimensional trigonometric approximation in the x-direction. Each problem uses different trigonometric terms. Solutions are obtained using an existing algorithm for simultaneous, first order, nonlinear, ordinary differential equations subject to two point boundary conditions. Ordinary differential equations are derived to determine the variable coefficients of the trigonometric terms.
Osmosis in Cortical Collecting Tubules
Schafer, James A.; Patlak, Clifford S.; Andreoli, Thomas E.
1974-01-01
This paper reports a theoretical analysis of osmotic transients and an experimental evaluation both of rapid time resolution of lumen to bath osmosis and of bidirectional steady-state osmosis in isolated rabbit cortical collecting tubules exposed to antidiuretic hormone (ADH). For the case of a membrane in series with unstirred layers, there may be considerable differences between initial and steady-state osmotic flows (i.e., the osmotic transient phenomenon), because the solute concentrations at the interfaces between membrane and unstirred layers may vary with time. A numerical solution of the equation of continuity provided a means for computing these time-dependent values, and, accordingly, the variation of osmotic flow with time for a given set of parameters including: Pf (cm s–1), the osmotic water permeability coefficient, the bulk phase solute concentrations, the unstirred layer thickness on either side of the membrane, and the fractional areas available for volume flow in the unstirred layers. The analyses provide a quantitative frame of reference for evaluating osmotic transients observed in epithelia in series with asymmetrical unstirred layers and indicate that, for such epithelia, Pf determinations from steady-state osmotic flows may result in gross underestimates of osmotic water permeability. In earlier studies, we suggested that the discrepancy between the ADH-dependent values of Pf and PDDw (cm s–1, diffusional water permeability coefficient) was the consequence of cellular constraints to diffusion. In the present experiments, no transients were detectable 20–30 s after initiating ADH-dependent lumen to bath osmosis; and steady-state ADH-dependent osmotic flows from bath to lumen and lumen to bath were linear and symmetrical. An evaluation of these data in terms of the analytical model indicates: First, cellular constraints to diffusion in cortical collecting tubules could be rationalized in terms of a 25-fold reduction in the area of the cell layer available for water transport, possibly due in part to transcellular shunting of osmotic flow; and second, such cellular constraints resulted in relatively small, approximately 15%, underestimates of Pf. PMID:4846767
[Hydrogen peroxide, chloramine T and chlorhexidrine in the disinfection of acrylic resin].
Czerwińska, W; Kedzia, A; Kałowski, M
1978-01-01
The effectiveness of 3% h drogen peroxide, 5% chloramine T and 0,5% chlorhexidine gluconate solutions in disinfection of acrylic resine plates massively infected with oral flora was analysed. The acrylic resine plates used for investigations, were infected in vitro with mixed salivary flora characterized by small numbers of yeast-like fungi (1st group), or great number of these microorganisms (2nd group). Infected plates were exposed to solutions of analysed disinfectants during various time periods. After rinsing or inactivation of disinfectant residues, acrylic plates were put into bacteriological medium and incubated during 7 days period in 37 degrees C. The results of this study indicated the effectiveness of acrylic plates disinfection to be dependent on used disinfectant, time of exposition, and microorganisms present on the surface of acrylic resine. The solutions of disinfectants were less active in the cases of plates infected with material containing great numbers of yeast-like microorganisms. Among analysed disinfectants 0,5% solution of chlorhexidine was characterized by most effective and rapid activity, whereas 3% solution of hydrogen peroxide was found to be the least effective.
NASA Astrophysics Data System (ADS)
Ewing, Jacob; Wang, Yuzheng; Arnold, David P.
2018-05-01
This paper investigates methods for electroplating thick (>20 μm), high-coercivity CoPt films using high current densities (up to 1 A/cm2) and elevated bath temperatures (70 °C). Correlations are made tying current-density and temperature process parameters with plating rate, elemental ratio and magnetic properties of the deposited CoPt films. It also investigates how pulsed currents can increase the plating rate and film to substrate adhesion. Using 500 mA/cm2 and constant current, high-quality, dense CoPt films were successfully electroplated up to 20 μm thick in 1 hr on silicon substrates (0.35 μm/min plating rate). After standard thermal treatment (675°C, 30 min) to achieve the ordered L10 crystalline phase, strong magnetic properties were measured: coercivities up 850 kA/m, remanences >0.5 T, and maximum energy products up to 46 kJ/m3.
Metallization of Kevlar fibers with gold.
Little, Brian K; Li, Yunfeng; Cammarata, V; Broughton, R; Mills, G
2011-06-01
Electrochemical gold plating processes were examined for the metallization of Kevlar yarn. Conventional Sn(2+)/Pd(2+) surface activation coupled with electroless Ni deposition rendered the fibers conductive enough to serve as cathodes for electrochemical plating. The resulting coatings were quantified gravimetrically and characterized via adhesion tests together with XRD, SEM, TEM; the coatings effect on fiber strength was also probed. XRD data showed that metallic Pd formed during surface activation whereas amorphous phases and trace amounts of pure Ni metal were plated via the electroless process. Electrodeposition in a thiosulfate bath was the most efficient Au coating process as compared with the analogous electroless procedure, and with electroplating using a commercial cyanide method. Strongly adhering coatings resulted upon metallization with three consecutive electrodepositions, which produced conductive fibers able to sustain power outputs in the range of 1 W. On the other hand, metallization affected the tensile strength of the fiber and defects present in the metal deposits make questionable the effectiveness of the coatings as protective barriers. © 2011 American Chemical Society
Poly/vinyl alcohol/ membranes for reverse osmosis
NASA Technical Reports Server (NTRS)
Katz, M. G.; Wydeven, T., Jr.
1981-01-01
A description is presented of the results of studies of the water and salt transport properties of PVA membranes, taking into account radiation crosslinked PVA membranes, diffusive salt permeability through PVA membranes, and heat treated PVA membranes. The experimental findings support an occurrence of independent water, and salt permeation processes. It is suggested that the salt permeation is governed by a solution-diffusion transport mechanism. The preparation of thin skinned, asymmetric PVA membranes is also discussed. The employed method has a certain similarity to the classical phase inversion method, which is widely applied in the casting of asymmetric reverse osmosis membranes. Instead of using a gelling bath composed of a nonsolvent for the membrane material and miscible with the solvent from which the membrane is cast, a 'complexing' bath is used, which is a solution of a complexing agent in water.
Balcik-Canbolat, Cigdem; Sengezer, Cisel; Sakar, Hacer; Karagunduz, Ahmet; Keskinler, Bulent
2017-11-01
It has been recognized by the whole world that textile industry which produce large amounts of wastewater with strong color and toxic organic compounds is a major problematical industry requiring effective treatment solutions. In this study, reverse osmosis (RO) membranes were tested on biologically treated real dye bath wastewater with and without pretreatment by nanofiltration (NF) membrane to recovery. Also membrane fouling and reuse potential of membranes were investigated by multiple filtrations. Obtained results showed that only NF is not suitable to produce enough quality to reuse the wastewater in a textile industry as process water while RO provide successfully enough permeate quality. The results recommend that integrated NF/RO membrane process is able to reduce membrane fouling and allow long-term operation for real dye bath wastewater.
NASA Astrophysics Data System (ADS)
Santra, Siddhartha; Cruikshank, Benjamin; Balu, Radhakrishnan; Jacobs, Kurt
2017-10-01
Fermi’s golden rule applies to a situation in which a single quantum state \\vert \\psi> is coupled to a near-continuum. This ‘quasi-continuum coupling’ structure results in a rate equation for the population of \\vert \\psi> . Here we show that the coupling of a quantum system to the standard model of a thermal environment, a bath of harmonic oscillators, can be decomposed into a ‘cascade’ made up of the quasi-continuum coupling structures of Fermi’s golden rule. This clarifies the connection between the physics of the golden rule and that of a thermal bath, and provides a non-rigorous but physically intuitive derivation of the Markovian master equation directly from the former. The exact solution to the Hamiltonian of the golden rule, known as the Bixon-Jortner model, generalized for an asymmetric spectrum, provides a window on how the evolution induced by the bath deviates from the master equation as one moves outside the Markovian regime. Our analysis also reveals the relationship between the oscillator bath and the ‘random matrix model’ (RMT) of a thermal bath. We show that the cascade structure is the one essential difference between the two models, and the lack of it prevents the RMT from generating transition rates that are independent of the initial state of the system. We suggest that the cascade structure is one of the generic elements of thermalizing many-body systems.
Santos, M V; Sansinena, M; Zaritzky, N; Chirife, J
BACKGROUND: Dry ice-ethanol bath (-78 degree C) have been widely used in low temperature biological research to attain rapid cooling of samples below freezing temperature. The prediction of cooling rates of biological samples immersed in dry ice-ethanol bath is of practical interest in cryopreservation. The cooling rate can be obtained using mathematical models representing the heat conduction equation in transient state. Additionally, at the solid cryogenic-fluid interface, the knowledge of the surface heat transfer coefficient (h) is necessary for the convective boundary condition in order to correctly establish the mathematical problem. The study was to apply numerical modeling to obtain the surface heat transfer coefficient of a dry ice-ethanol bath. A numerical finite element solution of heat conduction equation was used to obtain surface heat transfer coefficients from measured temperatures at the center of polytetrafluoroethylene and polymethylmetacrylate cylinders immersed in a dry ice-ethanol cooling bath. The numerical model considered the temperature dependence of thermophysical properties of plastic materials used. A negative linear relationship is observed between cylinder diameter and heat transfer coefficient in the liquid bath, the calculated h values were 308, 135 and 62.5 W/(m 2 K) for PMMA 1.3, PTFE 2.59 and 3.14 cm in diameter, respectively. The calculated heat transfer coefficients were consistent among several replicates; h in dry ice-ethanol showed an inverse relationship with cylinder diameter.
Petit, Jean Yanique; Cavana, Paola; Thoumire, Sandra; Guillot, Jacques; Perrot, Sébastien
2016-06-01
The "hair strand test" was first developed as a model to evaluate the antifungal activity of antidandruff shampoos. To assess the residual activity of an antifungal shampoo on the hair shafts of dogs after a single application, followed by bathing with a physiological shampoo one month later. Six beagles (two males and four females) from a research colony. Dogs were bathed with a 2% climbazole shampoo. Hairs were collected before application of the shampoo and at scheduled intervals for 30 days after treatment. A physiological shampoo was then applied to all dogs and hairs were collected following the same schedule. The inhibition zone around the hair shafts was measured after incubation on Sabouraud's dextrose agar plates streaked with three Malassezia pachydermatis strains. Inhibition zones around hairs collected from dogs bathed with 2% climbazole shampoo were significantly larger than those around hairs collected before shampooing at all time points (P = 0.003). An increase in the width of the inhibition zones around climbazole treated hairs was observed following physiological shampoo on Day 30 (P = 0.005). No significant differences were observed between Malassezia pachydermatis isolates (P = 0.571). No inhibition zones were seen around the hairs of dogs bathed with physiological shampoo only. The modified hair strand test is useful for the assessment of residual antifungal activity on animal hairs. Use of a physiological shampoo following antifungal shampoo therapy may increase the efficacy of the antifungal product for the control of Malassezia overgrowth. © 2016 ESVD and ACVD.
Chou, Chung-Lin; Yu, Ming-Jiun; Kassai, Eliza M; Morris, Ryan G; Hoffert, Jason D; Wall, Susan M; Knepper, Mark A
2008-07-01
Collecting duct cells swell when exposed to arginine vasopressin (AVP) in the presence of a transepithelial osmolality gradient. We investigated the mechanisms of AVP-induced cell swelling in isolated, perfused rat inner medullary collecting ducts (IMCDs) using quantitative video microscopy and fluorescence-based measurements of transepithelial water transport. We tested the roles of transepithelial water flow, basolateral solute entry, and the cytoskeleton (actomyosin). When a transepithelial osmolality gradient was imposed by addition of NaCl to the bath, AVP significantly increased both water flux and cell height. When the osmolality gradient was imposed by addition of mannitol, AVP increased water flux but not cell height, suggesting that AVP-induced cell swelling requires a NaCl gradient and is not merely dependent on the associated water flux. Bumetanide (Na-K-2Cl cotransporter inhibitor) added to the bath markedly diminished the AVP-induced cell height increase. AVP-induced cell swelling was absent in IMCDs from NKCC1-knockout mice. In rat IMCDs, replacement of Na, K, or Cl in the peritubular bath caused significant cell shrinkage, consistent with a basolateral solute transport pathway dependent on all three ions. Immunocytochemistry using an antibody to NKCC1 confirmed basolateral expression in IMCD cells. The conventional nonmuscle myosin II inhibitor blebbistatin also diminished the AVP-induced cell height increase and cell shape change, consistent with a role for the actin cytoskeleton and myosin II. We conclude that the AVP-induced cell height increase is dependent on basolateral solute uptake via NKCC1 and changes in actin organization via myosin II, but is not dependent specifically on increased apical water entry.
Lactate metabolism and its effects on glucose metabolism in an excised neural tissue.
Larrabee, M G
1995-04-01
Chains of lumbar sympathetic ganglia, excised from 15-day-old chicken embryos, were incubated for 4 h at 36 degrees C in a bicarbonate-buffered physiological salt solution containing 5.5 mM glucose and equilibrated with 5% CO2-95% O2. [U-14C]Glucose and [U-14C]lactate were used as tracers to measure the products of glucose and lactate metabolism, respectively, including CO2, lactate, and constituents of the tissue. When 5 mM lactate was added to bathing solution containing 5.5 mM glucose, lactate carbon displaced 50-70% of the glucose carbon otherwise used for CO2 production and provided about three times as much carbon for CO2 as did glucose. The lactate addition increased the total carbon incorporated into CO2 and into constituents of the tissue above those observed with glucose alone and also increased the lactate released to the bathing solution from [U-14C]-glucose. The latter increase was evidently due to an interference with reuptake of the lactate released from the ganglion cells, not to an increase in the cellular release itself. When the volume of bathing solution was increased 10-fold relative to that of the tissue, the average output of CO2 from [U-14C]glucose during a 4-h incubation was decreased by 50% when 5 mM lactate was present but was not affected significantly in the absence of added lactate. It is concluded that the effect of changing volume in the presence of lactate was due to the effects of lactate on glucose metabolism described above and resulted from a lower average lactate concentration in the smaller volume than in the larger one, due to metabolic depletion of the added lactate.(ABSTRACT TRUNCATED AT 250 WORDS)
Dennis, V W; Brazy, P C
1978-01-01
Interactions among the transport systems involved with sodium, bicarbonate, glucose, phosphate, and alanine absorption in isolated segments of the rabbit proximal convoluted tubule were examined with radioisotopic techniques to measure glucose, phosphate, and fluid absorption rates. The composition of the perfusate and bath varied from normal, physiological fluids to fluids deficient in a single solute. The deletion of glucose from the perfusate increased the lumen-to-bath flux of phosphate from 5.51 +/- 1.15 to 8.32 +/- 1.34 pmol/mm-min (P less than 0.01). Similar changes occurred when glucose transport was inhibited by phlorizin 10 micron in the perfusate, The deletion of alanine from the perfusate increased the lumen-to-bath flux of phosphate from 6.55 +/- 1.08 to 9.00 +/- 1.30 pmol/mm-min (P less than 0.01) but did not affect glucose transport significantly, 80.1 +/- 10.1 vs. 72.5 +/- 5.4 pmol/mm-min. Replacement of intraluminal sodium with choline, elimination of potassium from the bath, and removal of bicarbonate from the lumen and bath each reduced glucose, phosphate, and fluid absorption. These data indicate that the proximal absorptive processes for glucose and for phosphate include elements that are dependent upon some function of sodium transport. Additionally, the effects on phosphate transport of deleting glucose or alanine occur independent of any changes in net sodium transport and are opposite the effects of deleting bicarbonate. These differences may relate to the observations that the transport of glucose and alanine is electrogenic while that of bicarbonate is not. Regardless of possible mechanisms, the data demonstrate that important changes in the absorption rates of different solutes handled significantly by the proximal convoluted tubule may occur in response to changes in specific components of proximal sodium transport. PMID:670399
Kumar, Raja; Sinha, Alok
2017-02-01
Influence of common dye-bath additives, namely sodium chloride, ammonium sulphate, urea, acetic acid and citric acid, on the reductive decolouration of Direct Green 1 dye in the presence of Fe 0 was investigated. Organic acids improved dye reduction by augmenting Fe 0 corrosion, with acetic acid performing better than citric acid. NaCl enhanced the reduction rate by its 'salting out' effect on the bulk solution and by Cl - anion-mediated pitting corrosion of iron surface. (NH 4 ) 2 SO 4 induced 'salting out' effect accompanied by enhanced iron corrosion by SO 4 2- anion and buffering effect of NH 4 + improved the reduction rates. However, at 2g/L (NH 4 ) 2 SO 4 concentration, complexating of SO 4 2- with iron oxides decreased Fe 0 reactivity. Urea severely compromised the reduction reaction, onus to its chaotropic and 'salting in' effect in solution, and due to it masking the Fe 0 surface. Decolouration obeyed biphasic reduction kinetics (R 2 >0.993 in all the cases) exhibiting an initial rapid phase, when more than 95% dye reduction was observed, preceding a tedious phase. Maximum rapid phase reduction rate of 0.955/min was observed at pH2 in the co-presence of all dye-bath constituents. The developed biphasic model reckoned the influence of each dye-bath additive on decolouration and simulated well with the experimental data obtained at pH2. Copyright © 2016. Published by Elsevier B.V.
Exact-solution for cone-plate viscometry
NASA Astrophysics Data System (ADS)
Giacomin, A. J.; Gilbert, P. H.
2017-11-01
The viscosity of a Newtonian fluid is often measured by confining the fluid to the gap between a rotating cone that is perpendicular to a fixed disk. We call this experiment cone-plate viscometry. When the cone angle approaches π/2 , the viscometer gap is called narrow. The shear stress in the fluid, throughout a narrow gap, hardly departs from the shear stress exerted on the plate, and we thus call cone-plate flow nearly homogeneous. In this paper, we derive an exact solution for this slight heterogeneity, and from this, we derive the correction factors for the shear rate on the cone and plate, for the torque, and thus, for the measured Newtonian viscosity. These factors thus allow the cone-plate viscometer to be used more accurately, and with cone-angles well below π/2 . We find cone-plate flow field heterogeneity to be far slighter than previously thought. We next use our exact solution for the velocity to arrive at the exact solution for the temperature rise, due to viscous dissipation, in cone-plate flow subject to isothermal boundaries. Since Newtonian viscosity is a strong function of temperature, we expect our new exact solution for the temperature rise be useful to those measuring Newtonian viscosity, and especially so, to those using wide gaps. We include two worked examples to teach practitioners how to use our main results.
A mineral separation procedure using hot Clerici solution
Rosenblum, Sam
1974-01-01
Careful boiling of Clerici solution in a Pyrex test tube in an oil bath is used to float minerals with densities up to 5.0 in order to obtain purified concentrates of monazite (density 5.1) for analysis. The "sink" and "float" fractions are trapped in solidified Clerici salts on rapid chilling, and the fractions are washed into separate filter papers with warm water. The hazardous nature of Clerici solution requires unusual care in handling.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lagier, B.; Rousset, B.; Hoa, C.
Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and themore » refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.« less
Method for controlling protein crystallization
NASA Technical Reports Server (NTRS)
Noever, David A. (Inventor)
1993-01-01
A method and apparatus for controlling the crystallization of protein by solvent evaporation including placing a drop of protein solution between and in contact with a pair of parallel plates and driving one of the plates toward and away from the other plate in a controlled manner to adjust the spacing between the plates is presented. The drop of solution forms a liquid cylinder having a height dependent upon the plate spacing thereby effecting the surface area available for solvent evaporation. When the spacing is close, evaporation is slow. Evaporation is increased by increasing the spacing between the plates until the breaking point of the liquid cylinder. One plate is mounted upon a fixed post while the other plate is carried by a receptacle movable relative to the post and driven by a belt driven screw drive. The temperature and humidity of the drop of protein solution are controlled by sealing the drop within the receptacle and mounting a heater and dessicant within the receptacle.
Nonadiabatic Dynamics of Photoinduced Proton-Coupled Electron Transfer Processes
devices and photoelectrochemical cells. Theoretical methodology for simulating the nonadiabatic dynamics of photoinduced PCET reactions in solution has...tuning and control of the ultrafast dynamics is crucial for designing renewable and sustainable energy sources, such as artificial photosynthesis...describes the solute with a multiconfigurational method in a bath of explicit solvent molecules. The transferring hydrogen nucleus is represented as a
Graphene Oxide and Thermally Exfoliated Graphene Cyanate Ester Resin Composites
2013-05-01
solution was cooled to 0 °C by placing the flask in an ice bath and 30 g of potassium permanganate was added slowly with stirring which caused the...suspension to turn to a thick paste. After the addition of potassium permanganate the solution was warmed to 35 °C and allowed to stir for 30 minutes. After
IRON COATED URANIUM AND ITS PRODUCTION
Gray, A.G.
1960-03-15
A method of applying a protective coating to a metallic uranium article is given. The method comprises etching the surface of the article with an etchant solution containlng chloride ions, such as a solution of phosphoric acid and hydrochloric acid, cleaning the etched surface, electroplating iron thereon from a ferrous ammonium sulfate electroplating bath, and soldering an aluminum sheath to the resultant iron layer.
Díaz, P; Linares, M B; Egea, M; Auqui, S M; Garrido, M D
2014-12-01
The aim was to study the effect of the incubation method and TBA reagent (concentration/solvent) on yellow pigment interference in meat products. Distillates from red sausage, sucrose, malondialdehyde and a mixture of sucrose-malondialdehyde were reacted with four different TBA solutions at five different temperature/time relations. Two TBA solutions were prepared at 20mM using 90% glacial acetic acid or 3.86% perchloric acid. In addition, an 80mM TBA solution was prepared using distilled water adjusted to pH4 and another using 0.8% TBA in distilled water. The temperature/time relations were: (1) 35min in a boiling water bath; (2) 70°C/30min; (3) 40°C/90min; (4) room temperature (r.t.) (24°C) in dark conditions for 20h; and (5) 60min in a boiling water bath. The results showed that aqueous or diluted acid solutions of TBA reagent and the application of 100°C for less than 1h provided the best conditions to minimize the presence of yellow pigments and maximize pink pigment formation in meat products. Copyright © 2014 Elsevier Ltd. All rights reserved.
Seed coat import and unloading in pisum. [Pisum sativum
DOE Office of Scientific and Technical Information (OSTI.GOV)
Grusak, M.A.; Minchin, P.E.H.
1987-08-01
Experiments were undertaken with empty, attached ovules of Pisum sativum to observe the effects of osmotic solution changes on seed coat import and unloading into the apoplast. Through the use of /sup 11/CO/sub 2/ pulse labelling along with collimated monitoring of plant sections, the authors were able to continuously and simultaneously measure total pod import, import into a single ovule, and washout from the ovule into a flow-through bathing solution. The authors results indicated that changes in bathing solution sucrose concentration had no immediate effect on tracer washout in Pisum, but did affect ovule import. Lowering the sucrose concentration decreasedmore » import and raising the concentration increased import. Furthermore, these import changes were only gradually reflected in the seed coat washout profile, suggesting a buffering capability of the non-phloem seed coat tissues. Additional results have also led them to propose that the terminal site of seed coat unloading in Pisum is the plasmalemma of an non-phloem seed coat cell type, that unloading from this site occurs via a passive membrane transport process, and that solutes move symplastically to this compartment from the phloem.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leveillee, S.Y.
1998-01-01
Two different tests were designed to evaluate the reaction of various polymers and grade-2 titanium in ozonated seawater in conjunction with a comparative analysis in an aerated seawater solution. The first was a weight loss test measuring the weight change of Polyvinyl chloride (PVC), Polyethylene and Teflon{trademark} in both ozonated and aerated artificial seawater baths. The second test was designed to induce crevice corrosion on the titanium test samples using various crevice generating materials in both ozonated and aerated solutions. The materials used to create the crevices were grade-2 titanium washers, PVC, Polyethylene, Saran and Teflon{trademark}. The weight loss testmore » showed that all three polymers lost weight in the ozonated bath. The results of the titanium washer crevice test provided no indication of corrosion or surface discoloration in either the ozonated or aerated solutions. Energy dispersive spectrometry (EDS) analysis found no fluorine, chlorine or other corrosion product. The PVC samples in the aerated bath also showed no signs of corrosion, but the PVC samples in the ozonated tank had light brown rings of surface discoloration. One of the ozonated PVC samples did show evidence of chlorine in the corrosion product. The outer circumference of the ozonated PVC washers exhibited the same type bleaching effect as in the weight loss samples, but the whitening of these samples were more pronounced. The polyethylene samples under aeration showed no discoloration or presence of fluorine or chlorine. The polyethylene crevice samples in the ozonated solution all exhibited the distinct brilliant blue color of titanium oxide. Fluorine was found in the corrosion product on only one of the samples. Chlorine was found on the surface of one of the other corrosion coupons. The results of the Teflon{trademark} crevice samples substantiated the previous Rensselaer study.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roan, M.-L.; Chen, Y.-H.; Huang, C.-Y.
2008-08-28
In this study, a variety of concentrations of chelating agents were added to obtain the anchoring effect and chelating effect in the electroless plating bath. The mechanism of the Cu{sub x(x=1,2)}S growth and the electromagnetic interference shielding effectiveness (EMI SE) of the composite were studied. It was found that the vinyl acetate residued in PAN substrate would be purged due to the swelling effect by chelating agents solution. And then, the anchoring effect occurred due to the hydrogen bonding between the pits of PAN substrate and the chelating agent. Consequently, the copper sulfide layer deposited by the electroless plating reactionmore » with EDTA and TEA. The swelling degree (S{sub d}) was proposed and evaluated from the FT-IR spectra. The relationship between swelling degree of the PAN films and EDTA (C) is expressed as: S{sub d} = 0.13+0.90xe and (-15.15C). And TEA series is expressed as: S{sub d} = 0.07+1.00xe and (-15.15C). On the other hand, the FESEM micrograph showed that the average thickness of copper sulfide increased from 76 nm to 383 nm when the concentration of EDTA increased from 0.00M to 0.20M. Consequently, the EMI SE of the composites increased from 10{approx}12 dB to 25{approx}27 dB. The GIA-XRD analyze indicated that the deposited layer consisted of CuS and Cu{sub 2}S.« less
Kandasamy, N; Venugopal, T; Kannan, K
2018-06-01
A flower like cobalt oxide nanostructured thin film (Co2O3) on Nickel (Ni) plate as have been successfully developed via alcoholic Seed Layer assisted chemical bath Deposition (SLD) process. Through the controlled alkaline electrolytes, the flower and paddles like Co2O3 nanoarchitectures were formed. The prepared thin film was characterized by X-ray diffraction (XRD), scanning electron microscope with energy dispersive X-ray (SEM and EDX), Atomic Force Microscope (AFM), Raman spectroscopy techniques. Electron micrograph reveals the flower and paddles like nanostructured Co2O3 thin film deposited on Ni plates. The electrochemical characteristics were investigated using cyclic voltammetry (CV), charge-discharge and AC impedance spectroscopy in different aqueous electrolytes such as NaOH, KOH, and LiOH. The maximum specific capacitance of 856 Fg-1 was attained with 2 M KOH electrolyte with 2 mVs-1 of the Co2O3 thin film coated Ni plate at 80 °C using SLD method. The capacitance values obtained with various electrolytes are in the order of KOH > NaOH > LiOH. The results indicate that the present method is economical and the material is ecofriendly with enhanced capacitance property.
NASA Astrophysics Data System (ADS)
Suresha, B. L.; Sumantha, H. S.; Salman, K. Mohammed; Pramod, N. G.; Abhiram, J.
2018-04-01
The ionization potential is usually found to be less in acid and more in base. The experiment proves that the ionization potential increases on dilution of acid to base and reduces from base to acid. The potential can be tailored according to the desired properties based on our choice of acid or base. The experimental study establishes a direct relationship between pH and electric potential. This work provides theoretical insights on the need for a basic media of pH 10 in chemical thin film growth techniques called Chemical Bath Deposition Techniques.
Quantum thermal diode based on two interacting spinlike systems under different excitations.
Ordonez-Miranda, Jose; Ezzahri, Younès; Joulain, Karl
2017-02-01
We demonstrate that two interacting spinlike systems characterized by different excitation frequencies and coupled to a thermal bath each, can be used as a quantum thermal diode capable of efficiently rectifying the heat current. This is done by deriving analytical expressions for both the heat current and rectification factor of the diode, based on the solution of a master equation for the density matrix. Higher rectification factors are obtained for lower heat currents, whose magnitude takes their maximum values for a given interaction coupling proportional to the temperature of the hotter thermal bath. It is shown that the rectification ability of the diode increases with the excitation frequencies difference, which drives the asymmetry of the heat current, when the temperatures of the thermal baths are inverted. Furthermore, explicit conditions for the optimization of the rectification factor and heat current are explicitly found.
A finite element analysis of viscoelastically damped sandwich plates
NASA Astrophysics Data System (ADS)
Ma, B.-A.; He, J.-F.
1992-01-01
A finite element analysis associated with an asymptotic solution method for the harmonic flexural vibration of viscoelastically damped unsymmetrical sandwich plates is given. The element formulation is based on generalization of the discrete Kirchhoff theory (DKT) element formulation. The results obtained with the first order approximation of the asymptotic solution presented here are the same as those obtained by means of the modal strain energy (MSE) method. By taking more terms of the asymptotic solution, with successive calculations and use of the Padé approximants method, accuracy can be improved. The finite element computation has been verified by comparison with an analytical exact solution for rectangular plates with simply supported edges. Results for the same plates with clamped edges are also presented.
NASA Astrophysics Data System (ADS)
Kothari, Anjana
2017-05-01
ZnO, a wide band gap semiconductor is of significant interest for a range of practical applications. One of the highly attractive features of ZnO is to grow variety of nanostructures by using low-cost techniques. In this paper, we report deposition of ZnO nanostructure rod-arrays (NRA) via low-temperature, solution-based deposition techniques such as chemical bath deposition (CBD) and microwave-assisted chemical bath deposition (MACBD). A detailed study of film deposition parameters such as variation in concentration of precursors and deposition temperature has been carried out. Compositional and structural study of the films has been done by X-ray Diffractometer to know the phase and purity of the final product. Morphological study of these structures has been carried out by Scanning Electron Microscopy. Optical study such as transmittance and diffuse reflectance of the films has been carried out as a function of growth parameters.
The Elasto-Plastic Stability of Plates
NASA Technical Reports Server (NTRS)
Ilyushin, A. A.
1947-01-01
This article explains results developed from the following research: 'The Stability of Plates and Shells beyond the Elastic Limit.' A significant improvement is found in the derivation of the relations between the stress factors and the strains resulting from the instability of plates and shells. In a strict analysis, the problem reduces to the solution of two simultaneous nonlinear partial differential equations of the fourth order in the deflection and stress function, and in the approximate analysis to a single linear equation of the Bryan type. Solutions are given for the special cases of a rectangular plate buckling into a cylindrical form, and of an arbitrarily shaped plate under uniform compression. These solutions indicate that the accuracy obtained by the approximate method is satisfactory.
Clouser, C S; Doores, S; Mast, M G; Knabel, S J
1995-04-01
This study was undertaken to determine whether the incidence of either Salmonella spp. or Listeria monocytogenes on turkeys at three commercial processors could be related to the type of defeathering system: 1) conventional, 58 C common bath scald; 2) kosher, 7 C common bath scald; or 3) steam-spray, 62 C nonimmersion scald. Flocks were sampled before defeathering, after defeathering, and after chill at each facility. The incidence of Salmonella-positive turkeys significantly increased subsequent to conventional defeathering (10 positive out of 14) as compared with before defeathering (3/14). The number of Salmonella-positive carcasses following kosher (0/14) and steam-spray (2/14) defeathering were similar to the number of Salmonella-positive carcasses found prior to defeathering (1/14 and 3/14, respectively). The incidence of Salmonella-positive carcasses following chill was slightly lower, but not significantly different than the number of Salmonella-positive carcasses found immediately following defeathering at all processors (8/14, 0/14, 1/14 for conventional, kosher, and steam-spray processors, respectively). Although L. monocytogenes was detected on turkeys sampled before chilling (2/10, kosher) and after chilling (8/14, kosher; 1/14, conventional), no L. monocytogenes was detected on turkeys at any of the processors prior to the evisceration process. Flocks with high aerobic plate counts prior to processing were more likely to contain Salmonella-positive birds throughout processing. Aerobic plate counts of all flocks were similar after chill whether or not Salmonella spp. and L. monocytogenes were detected.
Burnout Test of First- and Second-Generation HTS Tapes in Liquid-Nitrogen Bath Cooling
NASA Astrophysics Data System (ADS)
Young, M. A.; Demko, J. A.; Duckworth, R. C.; Lue, J. W.; Gouge, M. J.; Pace, M. O.
2004-06-01
A series of BSCCO-2223 and YBCO tapes were subjected to burnout tests in a liquid-nitrogen bath to observe operational stability limits when different layers of dielectric tape are added to the sample surface. In this study, the BSCCO tapes were composed of a silver/alloy sheath with nickel/copper plating, while the YBCO tapes had a 50-μm layer of copper attached to the silver surface. After attaching the tapes to a thermally insulated G-10 holder, the stability of the tapes was found by applying current greater than the critical current and holding it constant for up to 1 min. If the sample voltage increased rapidly during this period, the tape was considered unstable at this current. This was repeated at different layers of Cryoflex™, and the results were compared to a numerical simulation of the energy balance equation. This simulation was also utilized to investigate the effect of the layers on the stability limit and estimate the thermal conductivity of the Cryoflex™.
NASA Astrophysics Data System (ADS)
Barbagiovanni, E. G.; Strano, V.; Franzò, G.; Crupi, I.; Mirabella, S.
2015-03-01
Two deep level defects (2.25 and 2.03 eV) associated with oxygen vacancies (Vo) were identified in ZnO nanorods (NRs) grown by low cost chemical bath deposition. A transient behaviour in the photoluminescence (PL) intensity of the two Vo states was found to be sensitive to the ambient environment and to NR post-growth treatment. The largest transient was found in samples dried on a hot plate with a PL intensity decay time, in air only, of 23 and 80 s for the 2.25 and 2.03 eV peaks, respectively. Resistance measurements under UV exposure exhibited a transient behaviour in full agreement with the PL transient, indicating a clear role of atmospheric O2 on the surface defect states. A model for surface defect transient behaviour due to band bending with respect to the Fermi level is proposed. The results have implications for a variety of sensing and photovoltaic applications of ZnO NRs.
Rapid determination of tannins in tanning baths by adaptation of BSA method.
Molinari, R; Buonomenna, M G; Cassano, A; Drioli, E
2001-01-01
A rapid and reproducible method for the determination of tannins in vegetable tanning baths is proposed as a modification of the BSA method for grain tannins existing in literature. The protein BSA was used instead of leather powder employed in the Filter Method, which is adopted in Italy and various others countries of Central Europe. In this rapid method the tannin contents is determined by means a spectrophotometric reading and not by means a gravimetric analysis of the Filter Method. The BSA method, which belongs to mixed methods (which use both precipitation and complexation of tannins), consists of selective precipitation of tannin from a solution containing also non tannins by BSA, the dissolution of precipitate and the quantification of free tannin amount by its complexation with Fe(III) in hydrochloric solutions. The absorbance values, read at 522 nm, have been expressed in terms of tannic acid concentration by using a calibration curve made with standard solutions of tannic acid; these have been correlated with the results obtained by using the Filter Method.
NASA Astrophysics Data System (ADS)
Ismail, Abdul Hadi; Abdullah, Abdul Halim; Sulaiman, Yusran
2017-03-01
The physical and electrochemical properties of zinc oxide (ZnO) film electrode that were prepared electrochemically were studied. ZnO was electrodeposited on ITO glass substrate by applying three different highly cathodic potentials (-1.3 V, -1.5 V, -1.7 V) in a solution containing 70 mM of Zn(NO3)2.xH2O and 0.1 M KCl with bath temperatures of 70 °C and 80 °C. The presence of ZnO was asserted from XRD analysis where the corresponding peaks in the spectra were assigned. SEM images revealed the plate-like hexagonal morphology of ZnO which is in agreement with the XRD analysis. The areal capacitance of the ZnO was observed to increase when the applied electrodeposition potential is increased from -1.3 V to -1.5 V. However, the areal capacitance is found to decrease when the applied electrodeposition potential is further increased to -1.7 V. The resistance of charge transfer (Rct) of the ZnO decreased when the applied electrodeposition potential varies from -1.3 V to -1.7 V due to the decreased particle size of ZnO when more cathodic electrodeposition potential is applied.
Influence of Iterative Reconstruction Algorithms on PET Image Resolution
NASA Astrophysics Data System (ADS)
Karpetas, G. E.; Michail, C. M.; Fountos, G. P.; Valais, I. G.; Nikolopoulos, D.; Kandarakis, I. S.; Panayiotakis, G. S.
2015-09-01
The aim of the present study was to assess image quality of PET scanners through a thin layer chromatography (TLC) plane source. The source was simulated using a previously validated Monte Carlo model. The model was developed by using the GATE MC package and reconstructed images obtained with the STIR software for tomographic image reconstruction. The simulated PET scanner was the GE DiscoveryST. A plane source consisted of a TLC plate, was simulated by a layer of silica gel on aluminum (Al) foil substrates, immersed in 18F-FDG bath solution (1MBq). Image quality was assessed in terms of the modulation transfer function (MTF). MTF curves were estimated from transverse reconstructed images of the plane source. Images were reconstructed by the maximum likelihood estimation (MLE)-OSMAPOSL, the ordered subsets separable paraboloidal surrogate (OSSPS), the median root prior (MRP) and OSMAPOSL with quadratic prior, algorithms. OSMAPOSL reconstruction was assessed by using fixed subsets and various iterations, as well as by using various beta (hyper) parameter values. MTF values were found to increase with increasing iterations. MTF also improves by using lower beta values. The simulated PET evaluation method, based on the TLC plane source, can be useful in the resolution assessment of PET scanners.
Pulse electrodeposition of self-lubricating Ni-W/PTFE nanocomposite coatings on mild steel surface
NASA Astrophysics Data System (ADS)
Sangeetha, S.; Kalaignan, G. Paruthimal; Anthuvan, J. Tennis
2015-12-01
Ni-W/PTFE nanocomposite coatings with various contents of PTFE (polytetafluoroethylene) particles were prepared by pulse current (PC) electrodeposition from the Ni-W plating bath containing self lubricant PTFE particles to be co-deposited. Co-deposited PTFE particulates were uniformly distributed in the Ni-W alloy matrix. The coatings were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDAX), X-ray Diffractometry (XRD) and Vicker's micro hardness tester. Tafel Polarization and electrochemical Impedance methods were used to evaluate the corrosion resistance behaviour of the nanocomposite coatings in 3.5% NaCl solution. It was found that, the Ni-W/PTFE nanocomposite coating has better corrosion resistance than the Ni-W alloy coating. Surface roughness and friction coefficient of the coated samples were assessed by Mitutoyo Surftest SJ-310 (ISO1997) and Scratch tester TR-101-M4 respectively. The contact angle (CA) of a water droplet on the surface of nanocomposite coating was measured by Optical Contact Goniometry (OCA 35). These results indicated that, the addition of PTFE in the Ni-W alloy matrix has resulted moderate microhardness, smooth surface, less friction coefficient, excellent water repellency and enhanced corrosion resistance of the nanocomposite coatings.
The Production of Printed Circuit Boards, Photo-Anodised and Screen Printed Instrument Panels.
1981-01-01
Laboratories, Melbourne 12. RELEASE LIMITATIONS (of the document): Approved for Public Release. 12.0. OVERSEAS: N.0.1 I P.R. 1 A I I B I I C I D EI 13...solutions. 5.1 baths Required (N.B. Tanks shoula be of rigid P.V.C.) 1. Amonium persulphate solution 100 gm/L. 2. Sulphuric acid 10% (A.R. GRADE...120 degrees C for at least 10 mins. Etchant 1: 55% weight/volume solution of ferric nitrate used at 49 degrees C. This solution is made by adding
Regenerating using aqueous cleaners with ozone and electrolysis
NASA Technical Reports Server (NTRS)
Mcginness, Michael P.
1994-01-01
A new process converts organic oil and grease contaminates in used water based cleaners into synthetic surfactants. This permits the continued use of a cleaning solution long after it would have been dumped using previously known methods. Since the organic soils are converted from contaminates to cleaning compounds the need for frequent bath dumps is totally eliminated. When cleaning solutions used in aqueous cleaning systems are exhausted and ready for disposal, they will always contain the contaminates removed from the cleaned parts and drag-in from prior cleaning steps. Even when the cleaner is biodegradable these contaminants will frequently cause the waste cleaning solution to be a hazardous waste. Chlorinated solvents are rapidly being replaced by aqueous cleaners to avoid the new ozone-depletion product-labeling-law. Many industry standard halocarbon based solvents are being completely phased out of production, and their prices have nearly tripled. Waste disposal costs and cradle-to-grave liability are also major concerns for industry today. This new process reduces the amount of water and chemicals needed to maintain the cleaning process. The cost of waste disposal is eliminated because the water and cleaning compounds are reused. Energy savings result by eliminating the need for energy currently used to produce and deliver fresh water and chemicals as well as the energy used to treat and destroy the waste from the existing cleaning processes. This process also allows the cleaning bath to be maintained at the peak performance of a new bath resulting in decreased cycle times and decreased energy consumption needed to clean the parts. This results in a more efficient and cost effective cleaning process.
The Formation and Properties of Thin Lipid Membranes from HK and LK Sheep Red Cell Lipids
Andreoli, Thomas E.; Bangham, J. Andrew; Tosteson, Daniel C.
1967-01-01
Lipids were obtained from high potassium (HK) and low potassium (LK) sheep red cells by sequential extraction of the erythrocytes with isopropanol-chloroform, chloroform-methanol-0.1 M KCl, and chloroform. The extract contained cholesterol and phospholipid in a molar ratio of 0.8:1.0, and less than 1% protein contaminant. Stable thin lipid membranes separating two aqueous compartments were formed from an erythrocyte lipid-hydrocarbon solution, and had an electrical resistance of ∼108 ohm-cm2 and a capacitance of 0.38–0.4 µf/cm2. From the capacitance values, membrane thickness was estimated to be 46–132 A, depending on the assumed value for the dielectric constant (2.0–4.5). Membrane voltage was recorded in the presence of ionic (NaCl and/or KCl) concentration gradients in the solutions bathing the membrane. The permeability of the membrane to Na+, K+, and Cl- (expressed as the transference number, T ion) was computed from the steady-state membrane voltage and the activity ratio of the ions in the compartments bathing the membrane. T Na and T K were approximately equal (∼0.8) and considerably greater than T Cl (∼0.2). The ionic transference numbers were independent of temperature, the hydrocarbon solvent, the osmolarity of the solutions bathing the membranes, and the cholesterol content of the membranes, over the range 21–38°C. The high degree of membrane cation selectivity was tentatively attributed to the negatively charged phospholipids (phosphatidylethanolamine and phosphatidylserine) present in the lipid extract. PMID:6034765
Thermoelectric Mechanism and Interface Characteristics of Cyanide-Free Nanogold-Coated Silver Wire
NASA Astrophysics Data System (ADS)
Tseng, Yi-Wei; Hung, Fei-Yi; Lui, Truan-Sheng
2016-01-01
Traditional bath-plated gold contains a cyanide complex, which is an environmental hazard. In response, our study used a green plating process to produce cyanide-free gold-coated silver (cyanide-free ACA) bonding wire that has been proven to be a feasible alternative to gold bonding wire in semiconductor packaging. In this work, ACA wire annealed at 550°C was found to have stable microstructure and superior mechanical properties. Intermetallic compounds Ag2Al and AuAl2 grew from Ag-Au balls and Al pads after aging at 175°C for 500 h. After current testing, ACA wire was found to have improved electrical properties due to equiaxed grain growth. The gold nanolayer on the Ag surface increased the oxidation resistance. These results provide insights regarding the reliability of ACA wire in advanced bonding processes.
Process for metallization of a substrate by curing a catalyst applied thereto
Chen, Ken S.; Morgan, William P.; Zich, John L.
2002-10-08
An improved additive process for metallization of substrates is described whereby a catalyst solution is applied to a surface of a substrate. Metallic catalytic clusters can be formed in the catalyst solution on the substrate surface by heating the substrate. Electroless plating can then deposit metal onto the portion of the substrate surface coated with catalyst solution. Additional metallization thickness can be obtained by electrolytically plating the substrate surface after the electroless plating step.
Sodium-bicarbonate cotransport in retinal Müller (glial) cells of the salamander.
Newman, E A
1991-12-01
An electrogenic Na+/HCO3- cotransport system was studied in freshly dissociated Müller cells of the salamander retina. Cotransporter currents were recorded from isolated cells using the whole-cell, voltage-clamp technique following the block of K+ conductance with external Ba2+ and internal Cs+. At constant pHo, an outward current was evoked when extracellular HCO3- concentration was raised by pressure ejecting a HCO3(-)-buffered solution onto the surface of cells bathed in nominally HCO3(-)-free solution. The HCO3(-)-evoked outward current was reduced to 4.4% of control by 0.5 mM DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulfonate), to 28.8% of control by 2 mM DNDS (4,4'-dinitrostilbene-2,2'-disulfonate), and to 28.4% of control by 2 mM harmaline. Substitution of choline for Na+ in bath and ejection solutions reduced the response to 1.3% of control. Bicarbonate-evoked currents of normal magnitude were recorded when methane sulfonate was substituted for Cl- in bath, ejection, and intracellular solutions. Similarly, an outward current was evoked when extracellular Na+ concentration was raised in the presence of HCO3-. The Na(+)-evoked response was reduced to 16.2% of control by 2 mM DNDS and was abolished by removal of HCO3- from bath and ejection solutions. Taken together, these results (block by stilbenes and harmaline, HCO3- and Na+ dependence, Cl- independence) indicate that salamander Müller cells possess an electrogenic Na+/HCO3- cotransport system. Na+/HCO3- cotransporter sites were localized primarily at the endfoot region of Müller cells. Ejection of HCO3- onto the endfoot evoked outward currents 10 times larger than currents evoked by ejections onto the opposite (distal) end of the cell. The reversal potential of the cotransporter was determined by DNDS block of cotransport current. In the absence of a transmembrane HCO3- gradient, the reversal potential varied systematically as a function of the transmembrane Na+ gradient. The reversal potential was -0.1 mV for a [Na+]o:[Na+]i ratio of 1:1 and -25.2 mV for a Na+ gradient ratio of 7.4:1. Based on these values, the estimated stoichiometry of the cotransporter was 2.80 +/- 0.13:1 (HCO3-:Na+). Possible functions of the glial cell Na+/HCO3- cotransporter, including the regulation of CO2 in the retina and the regulation of cerebral blood flow, are discussed.
Townsend, R.G.
1959-08-25
A method is described for protectively coating beryllium metal by etching the metal in an acid bath, immersing the etched beryllium in a solution of sodium zincate for a brief period of time, immersing the beryllium in concentrated nitric acid, immersing the beryhlium in a second solution of sodium zincate, electroplating a thin layer of copper over the beryllium, and finally electroplating a layer of chromium over the copper layer.
Dilute acid pretreatment of corncob for efficient sugar production
G.S. Wang; Jae-Won Lee; Junyong Zhu; Thomas W. Jeffries
2011-01-01
Aqueous dilute acid pretreatments of corncob were conducted using cylindrical pressure vessels in an oil bath. Pretreatments were conducted in a temperature range of 160â190 °C with acid-solution-to-solid-corncob ratio of 2. The acid concentration (v/v) in the pretreatment solution was varied from 0% to 0.7%, depending on temperature. This gives acid charge on ovendry-...
LaGraff, John R; Chu-LaGraff, Quynh
2006-05-09
Unlabeled primary immunoglobulin G (IgG) antibodies and its F(ab')2 and Fc fragments were attached to oxygen-plasma-cleaned glass substrates using either microcontact printing (MCP) or physical adsorption during bath application from dilute solutions. Fluorescently labeled secondary IgGs were then bound to surface-immobilized IgG, and the relative surface coverage was determined by measuring the fluorescence intensity. Results indicated that the surface coverage of IgG increased with increasing protein solution concentration for both MCP and bath-applied IgG and that a greater concentration of IgG was transferred to a glass substrate using MCP than during physisorption during bath applications. Scanning force microscopy (SFM) showed that patterned MCP IgG monolayers were 5 nm in height, indicating that IgG molecules lie flat on the substrate. After incubation with a secondary IgG, the overall line thickness increased to around 15 nm, indicating that the secondary IgG was in a more vertical orientation with respect to the substrate. The surface roughness of these MCP patterned IgG bilayers as measured by SFM was observed to increase with increasing surface coverage. Physisorption of IgG to both unmodified patterned polydimethylsiloxane (PDMS) stamps and plasma-cleaned glass substrates was modeled by Langmuir adsorption kinetics yielding IgG binding constants of K(MCP) = 1.7(2) x 10(7) M(-1) and K(bath) = 7.8(7) x 10(5) M(-1), respectively. MCP experiments involving primary F(ab')2 and Fc fragments incubated in fluorescently labeled fragment-specific secondary IgGs were carried out to test for the function and orientation of IgG. Finally, possible origins of MCP stamping defects such as pits, pull outs, droplets, and reverse protein transfer are discussed.
NASA Astrophysics Data System (ADS)
Anawe, Paul Apeye Lucky; Fayomi, Ojo Sunday Isaac
2018-06-01
The application of rational design principles and process in electrodeposition can eliminate many engineering catastrophes related to corrosion and micromechanical failure in service. This has led to appreciate the need of surface modification on component for enhance life span. Admixed Zn-30Al-13Ti-chloride composite bath was electrolytically prepared and successfully deposited on UNS G10150 mild steel substrate by zinc dual anode deposition processes within an interval of applied current density, particle concentration and constant time. The codeposition of Zn-Al-Ti coating was studied in the presence of other bath ingredient. The effect of deposition current and particle concentration on structural property, adhesion behaviour, ideal crystal orientation, surface topography and electrochemical properties of Zn-Al-Ti alloy coating series on mild steel were analytically examined. The wear stability of the developed composite materials was examined via sliding reciprocating rig. The structural integrity was examined with scanning electron microscope equipped with EDS, X-ray diffraction; Atomic force microscope, dura scan micro-hardness tester and 3 μ metrohm Potentiostat/galvanostat. Interestingly the induced activity of the Zn-Al-Ti chloride composite alloy results into excellent structural modification and stable crystal precipitation within the structural interface as a result of Zn3Al, Zn2Ti and ZnAl3Ti2 intermetallic phase. The obtained results showed that the introduction of Ti particles in the presence of other bath additive in the plating bath mostly modified the surface and brings an increase in the microhardness, corrosion resistance and reduce wear deformation of Zn-Al-Ti chloride composite alloy.
Development of reinforced in-situ anti-corrosion and wear Zn-TiO2/ZnTiB2 coatings on mild steel
NASA Astrophysics Data System (ADS)
Fayomi, O. S. I.; Popoola, A. P. I.; Kanyane, L. R.; Monyai, T.
The development of reinforced composite coating has resulted into advanced engineering application because of the exceptional properties and increase service life. In this study, we investigated the effect of Solanum tuberosum (ST) as additive to Zn-TiO2/Zn-TiB2 sulphate bath coating by co-deposition route on mild steel. The structural characteristics and surface profile of the produced coating were examined using scanning electron microscope coupled with energy dispersive spectroscopy (SEM/EDS) and PosiTector (SPG) respectively. The anti-corrosion resistance activities of the deposited coatings were evaluated on a 101 AUTOLAB potentiostat/galvanostat device in a 3.65 wt% NaCl. The wear characteristics of the Zn-TiO2/TiB2 composite coatings were examined on a dry abrasive MTR-300 test rig. The thermal stability of the produced coatings was studied in an isothermal furnace at 600 °C and further characterized using a high tech optical microscope. From the results, it was found that Zn-TiO2/Zn-TiB2 were compassed with needle like pattern and perhaps a compact and distinctive structure was found with Zn-TiO2/Zn-TiB2/ST coatings. The microhardness deposited coatings increased with TiO2 and TiB2 interference in the plating bath, more significant improvement was noticed in the presence of natural bath-additive and the addition of ST lead to changes in the morphologies of the composite coatings. A massive decrease in corrosion and wear rate in all coatings produced as against the control sample was noticed. This was attributed to the dispersive strengthening activities of the embedded TiO2/TiB2/ST additive on the bath formed.
Analogies between Kirchhoff plates and functionally graded Saint-Venant beams under torsion
NASA Astrophysics Data System (ADS)
Barretta, Raffaele; Luciano, Raimondo
2015-05-01
Exact solutions of elastic Kirchhoff plates are available only for special geometries, loadings and kinematic boundary constraints. An effective solution procedure, based on an analogy between functionally graded orthotropic Saint-Venant beams under torsion and inhomogeneous isotropic Kirchhoff plates, with no kinematic boundary constraints, is proposed. The result extends the one contributed in Barretta (Acta Mech 224(12):2955-2964, 2013) for the special case of homogeneous Saint-Venant beams under torsion. Closed-form solutions for displacement, bending-twisting moment and curvature fields of an elliptic plate, corresponding to a functionally graded orthotropic beam, are evaluated. A new benchmark for computational mechanics is thus provided.
NASA Technical Reports Server (NTRS)
Askew, John C.
1994-01-01
An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.
NASA Astrophysics Data System (ADS)
Ventorino, V.; Pepe, O.; Sannino, L.; Blaiotta, G.; Palomba, S.
2012-04-01
Built between the walls of Herculaneum excavations, one of the world's most important archaeological sites, and the sea in the early 1st cent. AD, the Suburban Bath is one of the best thermal complexes better preserved in ancient times. The entrance opens onto a large courtyard that leads into a hallway well lit by a skylight, impluvium, with a portrait of "Apollo". From this room you can access various parts of the thermae, all beautifully preserved. A single room, mostly occupied by the pool, serving both apodyterium (dressing room) that frigidarium. Among tepidarium and frigidarium there's a room elegantly decorated with stucco and marble. The vestibule opens to the right, through a corridor, onto a waiting room with a floor in signinum opus and into a praefurnium (oven for heating). A large pool of tepidarium, connected with laconicum, a small circular room for the baths sweat, is also present. The calidarium, as usual, has a small tank for hot water and a basin for washing in cold water. Behind the calidarium is the praefurnium, an environment with the boiler for heating the bath. Although the suburban baths are well preserved, unfortunately in you can observe the development of visible microbial coatings. During the biodeterioration process, secondary colonization of wall is due to heterotrophic bacteria and fungi that induce deterioration cause structural as well as aesthetic damage such as the discoloration of materials, the formation of crusts on surfaces and the loss of material. This investigation was carried out sampling the surfaces of walls of different rooms in the Suburban Thermae according to Italian legal procedures. Depending on the samples typology, sampling was carry out using sterile nitrocellulose membranes pressed on the surface of the walls, sterile swabs or with sterile tweezers by tearing out surface material. The samples were suspended in physiological solution and immediately refrigerated until analysis. Isolated colonies grown on PCA plates were purified in the same growth medium by streaking and differentiated by assessing their morphological (phase-contrast microscopy) and biochemical characteristics (Gram-stains KOH-lysis and catalase activity). Cultural-based method allow us to identify by 16S and 26S rRNA partial sequence analysis, heterotrophic bacteria belonging to different genera as Bacillus, Pseudomonas, Aeromonas and Microbacterium. By using this approach, Bacillus-related species (B. benzoevorans, B. megaterium and B. pumilis and B. megaterium/B. simplex group) as well as Aeromonas sobria/Aeromonas salmonicida/Aeromonas hydrophila group, Pseudomonas plecoglossicida and Microbacterium esteraromaticum were isolated in different sample points analysed. DGGE analysis of PCR amplified V3 region of rDNA from DNA directly recovered from samples of biofilms and patina, enabled identification of bacterial species not found using culturable technology, as those closest related to Aeromonas, Paenibacillus, Brevibacterium, Exiguobacterium, Microbacterium, Brevibacterium, Stenothophomonas and Streptomyces. Combination of culture-dependent and independent methods provide a better characterization of heterotrophic microbiota that colonize the surface of ancient decorated walls and can contribute to understand the potential of biodeterioration activity by heterotrophic microorganisms.
1986-08-01
AD-A174 952 FINITE - DIFFERENCE SOLUTIONS FOR CONPRESSIBLE LANINAR 1/2 BOUNDARY-LAYER FLOUS (U) TORONTO UNIV DOWNSVIEW (ONTARIO) INST FOR AEROSPACE...dilute dusty gas over a semi-infinite flat plate. Details are given of the impliit finite , difference schemes as well as the boundary conditions... FINITE - DIFFERENCE SOLUTIONS FOR COMPRESSIBLE LAMINAR BOUNDARY-LAYER FLOWS OF A DUSTY GAS OVER A SEMI-INFINITE FLAT PLATE by B. Y. Wang and I. I
Device For Controlling Crystallization Of Protein
NASA Technical Reports Server (NTRS)
Noever, David A.
1993-01-01
Variable sandwich spacer enables optimization of evaporative driving force that governs crystallization of protein from solution. Mechanically more rigid than hanging-drop and sitting-drop devices. Large oscillations and dislodgment of drop of solution in response to vibrations suppressed by glass plates. Other advantages include: suitable for automated delivery, stable handling, and programmable evaporation of protein solution; controlled configuration enables simple and accurate determination of volume of solution without disrupting crystallization; pH and concentration of precipitant controlled dynamically because pH and concentration coupled to rate of evaporation, controllable via adjustment of gap between plates; and enables variation of ratio between surface area and volume of protein solution. Alternative version, plates oriented vertically instead of horizontally.
Exact analytical solution to a transient conjugate heat-transfer problem
NASA Technical Reports Server (NTRS)
Sucec, J.
1973-01-01
An exact analytical solution is found for laminar, constant-property, slug flow over a thin plate which is also convectively cooled from below. The solution is found by means of two successive Laplace transformations when a transient in the plate and the fluid is initiated by a step change in the fluid inlet temperature. The exact solution yields the transient fluid temperature, surface heat flux, and surface temperature distributions. The results of the exact transient solution for the surface heat flux are compared to the quasi-steady values, and a criterion for the validity of the quasi-steady results is found. Also the effect of the plate coupling parameter on the surface heat flux are investigated.
1983-12-01
plate quality. Dummying of chromium baths is used in the special case where high cathode-to-anode 15ea ratio has resulted in build up of trivalent ... chromium (Cr ).Dummying with a high anode -to-cat hode area ratio can be used to reoxidize the trivalent to hexavalent chromium (Cr +6 ). Proper...the trivalent state, which then can be precipitated as chromium hydroxide by alkali neutralization " Cyanide oxidation (if needed) of segregated
Apparatus and method for electroforming high aspect ratio micro-parts
Hachman, John T [Stockton, CA; Losey, Matthew W [Rancho Cucamonga, CA; McLean, Dorrance E [Manteca, CA
2009-11-27
A fixture is disclosed to more easily affix a workpiece in the proper orientation and spacing with sealed electrical interconnection within an electrochemical plating bath. The workpiece can be any planar metallic or non-metallic substrate such as a silicon wafer commonly used in LIGA or microsystem fabrication. The fixture described allows the workpiece to be submerged deep within an electrolytic cell, facing upwards, and allows easy transfer from one cell to another. The edges, backside, and electrical connections are sealed and protected from the electrolyte.
Recovering Zinc From Discarded Tires
NASA Technical Reports Server (NTRS)
Du Fresne, E. R.
1984-01-01
Zinc sulfate monohydrate sold at profit. Shredded tire material steeped in three sulfuric acid baths to extract zinc. Final product removed by evaporating part of solution until product crystallizes out. Recovered as zinc sulfate monohydrate and sold as fertilizer or for general use.
Acoustic manipulation of bacteria cells suspensions
NASA Astrophysics Data System (ADS)
GutiéRrez-Ramos, Salomé; Hoyos, Mauricio; Aider, Jean Luc; Ruiz, Carlos; Acoustofluidics Team Team; Soft; Bio Group Collaboration
An acoustic contacless manipulation gives advantages in the exploration of the complex dynamics enviroment that active matter exhibits. Our works reports the control confinement and dispersion of Escherichia coliRP437-pZA3R-YFP suspensions (M9Glu-Ca) via acoustic levitation.The manipulation of the bacteria bath in a parallel plate resonator is achieved using the acoustic radiation force and the secondary radiation force. The primary radiation force generates levitation of the bacteria cells at the nodal plane of the ultrasonic standing wave generated inside the resonator. On the other side, secondary forces leads to the consolidation of stable aggregates. All the experiments were performed in the acoustic trap described, where we excite the emission plate with a continuous sinusoidal signal at a frequency in the order of MHz and a quartz slide as the reflector plate. In a typical experiment we observed that, before the input of the signal, the bacteria cells exhibit their typical run and tumble behavior and after the sound is turned on all of them displace towards the nodal plane, and instantaneously the aggregation begins in this region. CNRS French National Space Studies, CONACYT Mexico.
Hardening parts by chrome plating in manufacture and repair
NASA Astrophysics Data System (ADS)
Astanin, V. K.; Pukhov, E. V.; Stekolnikov, Y. A.; Emtsev, V. V.; Golikova, O. A.
2018-03-01
In the engineering industry, galvanic coatings are widely used to prolong the service life of the machines, which contribute to the increase in the strength of the parts and their resistance to environmental influences, temperature and pressure drops, wear and fretting corrosion. Galvanic coatings have been widely applied in engineering, including agriculture, aircraft building, mining, construction, and electronics. The article focuses on the manufacturing methods of new agricultural machinery parts and the repair techniques of worn parts by chrome plating. The main attention is paid to the unstable methods of chromium deposition (in pulsed and reversing modes) in low-concentration electrolytes, which makes it possible to increase the reliability and durability of the hardened parts operation by changing the conditions of electrocrystallization, that is, directed formation of the structure and texture, thickness, roughness and microhardness of chromium plating. The practical recommendations are given on the current and temperature regimes of chromium deposition and composition of baths used for the restoration and hardening of the machine parts. Moreover, the basic methods of machining allowances removal are analysed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Panikkar, S.K.; Char, T.L.R.
1958-02-01
Results of studies on the electrodeposition of nickel-zinc and nickel-- molybdenum alloys in a pyrophosphate bath using platinium electrodes are presented. The fects of varying current density and metal contents of the electrolyte on alloy deposit composition, cathode efficiency, and cathode potential are presented in tabular form. (J.R.D.) l2432 A study was made of the effect of homogenization on the mechanical properties of solution-treated and aged aluminum and the quantitative effects of several variables on hardness. The effect of alloying elements on the increase in hardness of aluminum is shown. (J.E.D.)
Baum, Michel
2016-02-15
Angiotensin II (ANG II) is secreted by the proximal tubule resulting in a luminal concentration that is 100- to 1,000-fold greater than that in the blood. Luminal ANG II has been shown to stimulate sodium transport in the proximal tubule and distal nephron. Surprisingly, luminal ANG II inhibits NaCl transport in the medullary thick ascending limb (mTAL), a nephron segment responsible for a significant amount of NaCl absorption from the glomerular ultrafiltrate. We confirmed that addition of 10(-8) M ANG II to the lumen inhibited mTAL chloride transport (220 ± 19 to 165 ± 25 pmol·mm(-1)·min(-1), P < 0.01) and examined whether an interaction with basolateral norepinephrine existed to simulate the in vivo condition of an innervated tubule. We found that in the presence of a 10(-6) M norepinephrine bath, luminal ANG II stimulated mTAL chloride transport from 298 ± 18 to 364 ± 42 pmol·mm(-1)·min(-1) (P < 0.05). Stimulation of chloride transport by luminal ANG II was also observed with 10(-3) M bath dibutyryl cAMP in the bathing solution and bath isoproterenol. A bath of 10(-5) H-89 blocked the stimulation of chloride transport by norepinephrine and prevented the effect of luminal ANG II to either stimulate or inhibit chloride transport. Bath phentolamine, an α-adrenergic agonist, also prevented the decrease in mTAL chloride transport by luminal ANG II. Thus luminal ANG II increases chloride transport with basolateral norepinephrine; an effect likely mediated by stimulation of cAMP. Alpha-1 adrenergic stimulation prevents the inhibition of chloride transport by luminal ANG II. Copyright © 2016 the American Physiological Society.
NASA Technical Reports Server (NTRS)
Sucec, J.
1975-01-01
Solutions for the surface temperature and surface heat flux are found for laminar, constant property, slug flow over a plate convectively cooled from below, when the temperature of the fluid over the plate varies arbitrarily with time at the plate leading edge. A simple technique is presented for handling arbitrary fluid temperature variation with time by approximating it by a sequence of ramps or steps for which exact analytical solutions are available.
Transfer function modeling of damping mechanisms in viscoelastic plates
NASA Technical Reports Server (NTRS)
Slater, J. C.; Inman, D. J.
1991-01-01
This work formulates a method for the modeling of material damping characteristics in plates. The Sophie German equation of classical plate theory is modified to incorporate hysteresis effects represented by complex stiffness using the transfer function approach proposed by Golla and Hughes, (1985). However, this procedure is not limited to this representation. The governing characteristic equation is decoupled through separation of variables, yielding a solution similar to that of undamped classical plate theory, allowing solution of the steady state as well as the transient response problem.
NASA Astrophysics Data System (ADS)
Volchkov, Yu. M.
2017-09-01
This paper describes the modified bending equations of layered orthotropic plates in the first approximation. The approximation of the solution of the equation of the three-dimensional theory of elasticity by the Legendre polynomial segments is used to obtain differential equations of the elastic layer. For the approximation of equilibrium equations and boundary conditions of three-dimensional theory of elasticity, several approximations of each desired function (stresses and displacements) are used. The stresses at the internal points of the plate are determined from the defining equations for the orthotropic material, averaged with respect to the plate thickness. The construction of the bending equations of layered plates for each layer is carried out with the help of the elastic layer equations and the conjugation conditions on the boundaries between layers, which are conditions for the continuity of normal stresses and displacements. The numerical solution of the problem of bending of the rectangular layered plate obtained with the help of modified equations is compared with an analytical solution. It is determined that the maximum error in determining the stresses does not exceed 3 %.
Nonequilibrium Contribution to the Rate of Reaction. III. Isothermal Multicomponent Systems
DOE R&D Accomplishments Database
Shizgal, B.; Karplus, M.
1970-10-01
The nonequilibrium contribution to the reaction rate of an isothermal multicomponent system is obtained by solution of the appropriate Chapman-Enskog equation; the system is composed of reactive species in contact with a heat bath of inert atoms M.
Shannon entropic temperature and its lower and upper bounds for non-Markovian stochastic dynamics
NASA Astrophysics Data System (ADS)
Ray, Somrita; Bag, Bidhan Chandra
2014-09-01
In this article we have studied Shannon entropic nonequilibrium temperature (NET) extensively for a system which is coupled to a thermal bath that may be Markovian or non-Markovian in nature. Using the phase-space distribution function, i.e., the solution of the generalized Fokker Planck equation, we have calculated the entropy production, NET, and their bounds. Other thermodynamic properties like internal energy of the system, heat, and work, etc. are also measured to study their relations with NET. The present study reveals that the heat flux is proportional to the difference between the temperature of the thermal bath and the nonequilibrium temperature of the system. It also reveals that heat capacity at nonequilibrium state is independent of both NET and time. Furthermore, we have demonstrated the time variations of the above-mentioned and related quantities to differentiate between the equilibration processes for the coupling of the system with the Markovian and the non-Markovian thermal baths, respectively. It implies that in contrast to the Markovian case, a certain time is required to develop maximum interaction between the system and the non-Markovian thermal bath (NMTB). It also implies that longer relaxation time is needed for a NMTB compared to a Markovian one. Quasidynamical behavior of the NMTB introduces an oscillation in the variation of properties with time. Finally, we have demonstrated how the nonequilibrium state is affected by the memory time of the thermal bath.
Laser-induced selective metallization of polypropylene doped with multiwall carbon nanotubes
NASA Astrophysics Data System (ADS)
Ratautas, Karolis; Gedvilas, Mindaugas; Stankevičiene, Ina; Jagminienė, Aldona; Norkus, Eugenijus; Pira, Nello Li; Sinopoli, Stefano; Račiukaitis, Gediminas
2017-08-01
Moulded interconnect devices (MID) offer the material, weight and cost saving by integration electronic circuits directly into polymeric components used in automotive and other consumer products. Lasers are used to write circuits directly by modifying the surface of polymers followed by an electroless metal plating. A new composite material - the polypropylene doped with multiwall carbon nanotubes was developed for the laser-induced selective metallization. Mechanism of surface activation by laser irradiation was investigated in details utilising pico- and nanoseconds lasers. Deposition of copper was performed in the autocatalytic electroless plating bath. The laser-activated polymer surfaces have been studied using the Raman spectroscopy and scanning electron microscope (SEM). Microscopic images revealed that surface becomes active only after its melting by a laser. Alterations in the Raman spectra of the D and G bands indicated the clustering of carbon additives in the composite material. Optimal laser parameters for the surface activation were found by measuring a sheet resistance of the finally metal-plated samples. A spatially selective copper plating was achieved with the smallest conductor line width of 22 μm at the laser scanning speed of 3 m/s and the pulse repetition rate of 100 kHz. Finally, the technique was validated by making functional electronic circuits by this MID approach.
Muench, Falk; Schaefer, Sandra; Hagelüken, Lorenz; Molina-Luna, Leopoldo; Duerrschnabel, Michael; Kleebe, Hans-Joachim; Brötz, Joachim; Vaskevich, Alexander; Rubinstein, Israel; Ensinger, Wolfgang
2017-09-13
Metal nanowires (NWs) represent a prominent nanomaterial class, the interest in which is fueled by their tunable properties as well as their excellent performance in, for example, sensing, catalysis, and plasmonics. Synthetic approaches to obtain metal NWs mostly produce colloids or rely on templates. Integrating such nanowires into devices necessitates additional fabrication steps, such as template removal, nanostructure purification, or attachment. Here, we describe the development of a facile electroless plating protocol for the direct deposition of gold nanowire films, requiring neither templates nor complex instrumentation. The method is general, producing three-dimensional nanowire structures on substrates of varying shape and composition, with different seed types. The aqueous plating bath is prepared by ligand exchange and partial reduction of tetrachloroauric acid in the presence of 4-dimethylaminopyridine and formaldehyde. Gold deposition proceeds by nucleation of new grains on existing nanostructure tips and thus selectively produces curvy, polycrystalline nanowires of high aspect ratio. The nanofabrication potential of this method is demonstrated by producing a sensor electrode, whose performance is comparable to that of known nanostructures and discussed in terms of the catalyst architecture. Due to its flexibility and simplicity, shape-selective electroless plating is a promising new tool for functionalizing surfaces with anisotropic metal nanostructures.
Toward High-Efficiency Solution-Processed Planar Heterojunction Sb2S3 Solar Cells.
Zimmermann, Eugen; Pfadler, Thomas; Kalb, Julian; Dorman, James A; Sommer, Daniel; Hahn, Giso; Weickert, Jonas; Schmidt-Mende, Lukas
2015-05-01
Low-cost hybrid solar cells have made tremendous steps forward during the past decade owing to the implementation of extremely thin inorganic coatings as absorber layers, typically in combination with organic hole transporters. Using only extremely thin films of these absorbers reduces the requirement of single crystalline high-quality materials and paves the way for low-cost solution processing compatible with roll-to-roll fabrication processes. To date, the most efficient absorber material, except for the recently introduced organic-inorganic lead halide perovskites, has been Sb 2 S 3 , which can be implemented in hybrid photovoltaics using a simple chemical bath deposition. Current high-efficiency Sb 2 S 3 devices utilize absorber coatings on nanostructured TiO 2 electrodes in combination with polymeric hole transporters. This geometry has so far been the state of the art, even though flat junction devices would be conceptually simpler with the additional potential of higher open circuit voltages due to reduced charge carrier recombination. Besides, the role of the hole transporter is not completely clarified yet. In particular, additional photocurrent contribution from the polymers has not been directly shown, which points toward detrimental parasitic light absorption in the polymers. This study presents a fine-tuned chemical bath deposition method that allows fabricating solution-processed low-cost flat junction Sb 2 S 3 solar cells with the highest open circuit voltage reported so far for chemical bath devices and efficiencies exceeding 4%. Characterization of back-illuminated solar cells in combination with transfer matrix-based simulations further allows to address the issue of absorption losses in the hole transport material and outline a pathway toward more efficient future devices.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rodríguez, C.A.; Sandoval-Paz, M.G.; Cabello, G.
Highlights: • High quality ZnS thin films have been deposited by chemical bath deposition technique from a non-toxic precursor’s solution. • Nanocrystalline ZnS thin films with large band gap energy were synthesized without using ammonia. • Evidence that the growing of the thin films is carried out by means of hydroxide mechanism was found. • The properties of these ZnS thin films are similar and in some cases better than the corresponding ones produced using toxic precursors such as ammonia. - Abstract: In solar cells, ZnS window layer deposited by chemical bath technique can reach the highest conversion efficiency; however,more » precursors used in the process normally are materials highly volatile, toxic and harmful to the environment and health (typically ammonia and hydrazine). In this work the characterization of ZnS thin films deposited by chemical bath in a non-toxic alkaline solution is reported. The effect of deposition technique (growth in several times) on the properties of the ZnS thin film was studied. The films exhibited a high percentage of optical transmission (greater than 80%); as the deposition time increased a decreasing in the band gap values from 3.83 eV to 3.71 eV was observed. From chemical analysis, the presence of ZnS and Zn(OH){sub 2} was identified and X-ray diffraction patterns exhibited a clear peak corresponding to ZnS hexagonal phase (1 0 3) plane, which was confirmed by electron diffraction patterns. From morphological studies, compact samples with well-defined particles, low roughness, homogeneous and pinhole-free in the surface were observed. From obtained results, it is evident that deposits of ZnS–CBD using a non-toxic solution are suitable as window layer for TFSC.« less
DEFLECTION OF A HETEROGENEOUS WIDE-BEAM UNDER UNIFORM PRESSURE LOAD
DOE Office of Scientific and Technical Information (OSTI.GOV)
T. V. Holschuh; T. K. Howard; W. R. Marcum
2014-07-01
Oregon State University (OSU) and the Idaho National Laboratory (INL) are currently collaborating on a test program which entails hydro-mechanical testing of a generic plate type fuel element, or generic test plate assembly (GTPA), for the purpose of qualitatively demonstrating mechanical integrity of uranium-molybdenum monolithic plates as compared to that of uranium aluminum dispersion, and aluminum fuel plates onset by hydraulic forces. This test program supports ongoing work conducted for/by the Global Threat Reduction Initiative (GTRI) Fuels Development Program. This study’s focus supports the ongoing collaborative effort by detailing the derivation of an analytic solution for deflection of a heterogeneousmore » plate under a uniform, distributed load in order to predict the deflection of test plates in the GTPA. The resulting analytical solutions for three specific boundary condition sets are then presented against several test cases of a homogeneous plate. In all test cases considered, the results for both homogeneous and heterogeneous plates are numerically identical to one another, demonstrating correct derivation of the heterogeneous solution. Two additional problems are presents herein that provide a representative deflection profile for the plates under consideration within the GTPA. Furthermore, qualitative observations are made about the influence of a more-rigid internal fuel-meat region and its influence on the overall deflection profile of a plate. Present work is being directed to experimentally confirm the analytical solution’s results using select materials.« less
Risk of hydrocyanic acid release in the electroplating industry.
Piccinini, N; Ruggiero, G N; Baldi, G; Robotto, A
2000-01-07
This paper suggests assessing the consequences of hydrocyanic acid (HCN) release into the air by aqueous cyanide solutions in abnormal situations such as the accidental introduction of an acid, or the insertion of a cyanide in a pickling bath. It provides a well-defined source model and its resolution by methods peculiar to mass transport phenomena. The procedure consists of four stages: calculation of the liquid phase concentration, estimate of the HCN liquid-vapour equilibrium, determination of the mass transfer coefficient at the liquid-vapour interface, evaluation of the air concentration of HCN and of the damage distances. The results show that small baths operating at high temperatures are the major sources of risk. The building up of lethal air concentrations, on the other hand, is governed by the values of the mass transfer coefficient, which is itself determined by the flow dynamics and bath geometry. Concerning the magnitude of the risk, the fallout for external emergency planning is slight in all the cases investigated.
Accuracy of the QUAD4 thick shell element
NASA Technical Reports Server (NTRS)
Case, William R.; Bowles, Tiffany D.; Croft, Alicia K.; Mcginnis, Mark A.
1990-01-01
The accuracy of the relatively new QUAD4 thick shell element is assessed via comparison with a theoretical solution for thick homogeneous and honeycomb flat simply supported plates under the action of a uniform pressure load. The theoretical thick plate solution is based on the theory developed by Reissner and includes the effects of transverse shear flexibility which are not included in the thin plate solutions based on Kirchoff plate theory. In addition, the QUAD4 is assessed using a set of finite element test problems developed by the MacNeal-Schwendler Corp. (MSC). Comparison of the COSMIC QUAD4 element as well as those from MSC and Universal Analytics, Inc. (UAI) for these test problems is presented. The current COSMIC QUAD4 element is shown to have excellent comparison with both the theoretical solutions and also those from the two commercial versions of NASTRAN that it was compared to.
NASA Astrophysics Data System (ADS)
Chen, Min; Cheng, Wushan; Zhao, Zuxin; Huang, Xiaobo
2013-01-01
The major solving ways for the material wear are surface modification and lubrication. Currently, the researches at home and abroad are all limited to the single study of either nano-lubricating oil additive or electroless deposited coating. The surface coating has high hardness and high wear resistance, however, the friction reduction performance of the coating with high hardness is not good, the thickness of the coating is limited, and the coating can not regenerate after wearing. The nano-lubricating additives have good tribological performance and self-repair function, but under heavy load, the self-repair rate to the worn surface with the nano-additives is smaller than the wearing rate of the friction pair. To solve the above problems, the Ni-W-P alloy coating and deposition process with excellent anti-wear, and suitable for industrial application were developed, the optimum bath composition and process can be obtained by studying the influence of the bath composition, temperature and PH value to the deposition rate and the plating solution stability. The tribological properties as well as anti-wear and friction reduction mechanism of wear self-repair nano-ceramic lubricating additives are also studied. The ring-block abrasion testing machine and energy dispersive spectrometer are used to explore the internal relation between the coating and the nano-lubricating oil additives, and the tribology mechanism, to seek the synergetic effect between the two. The test results show that the wear resistance of Ni-W-P alloy coating (with heat treatment and in oil with nano-ceramic additives) has increased hundreds times than 45 steel as the metal substrate in basic oil, the friction reduction performance is improved. This research breaks through the bottleneck of previous separate research of the above-mentioned two methods, and explores the combination use of the two methods in industrial field.
Electrodeposition of ZnO-doped films as window layer for Cd-free CIGS-based solar cells
NASA Astrophysics Data System (ADS)
Tsin, Fabien; Vénérosy, Amélie; Hildebrandt, Thibaud; Hariskos, Dimitrios; Naghavi, Negar; Lincot, Daniel; Rousset, Jean
2016-02-01
The Cu(In,Ga)Se2 (CIGS) thin film solar cell technology has made a steady progress within the last decade reaching efficiency up to 22.3% on laboratory scale, thus overpassing the highest efficiency for polycrystalline silicon solar cells. High efficiency CIGS modules employ a so-called buffer layer of cadmium sulfide CdS deposited by Chemical Bath Deposition (CBD), which presence and Cd-containing waste present some environmental concerns. A second potential bottleneck for CIGS technology is its window layer made of i-ZnO/ZnO:Al, which is deposited by sputtering requiring expensive vacuum equipment. A non-vacuum deposition of transparent conductive oxide (TCO) relying on simpler equipment with lower investment costs will be more economically attractive, and could increase competitiveness of CIGS-based modules with the mainstream silicon-based technologies. In the frame of Novazolar project, we have developed a low-cost aqueous solution photo assisted electrodeposition process of the ZnO-based window layer for high efficiency CIGS-based solar cells. The window layer deposition have been first optimized on classical CdS buffer layer leading to cells with efficiencies similar to those measured with the sputtered references on the same absorber (15%). The the optimized ZnO doped layer has been adapted to cadmium free devices where the CdS is replaced by chemical bath deposited zinc oxysulfide Zn(S,O) buffer layer. The effect of different growth parameters has been studied on CBD-Zn(S,O)-plated co-evaporated Cu(In,Ga)Se2 substrates provided by the Zentrum für Sonnenenergie-und Wasserstoff-Forschung (ZSW). This optimization of the electrodeposition of ZnO:Cl on CIGS/Zn(S,O) stacks led to record efficiency of 14%, while the reference cell with a sputtered (Zn,Mg)O/ZnO:Al window layer has an efficiency of 15.2%.
A variational theorem for creep with applications to plates and columns
NASA Technical Reports Server (NTRS)
Sanders, J Lyell, Jr; Mccomb, Harvey G , Jr; Schlechte, Floyd R
1958-01-01
A variational theorem is presented for a body undergoing creep. Solutions to problems of the creep behavior of plates, columns, beams, and shells can be obtained by means of the direct methods of the calculus of variations in conjunction with the stated theorem. The application of the theorem is illustrated for plates and columns by the solution of two sample problems.
Approximate analytical solutions in the analysis of thin elastic plates
NASA Astrophysics Data System (ADS)
Goloskokov, Dmitriy P.; Matrosov, Alexander V.
2018-05-01
Two approaches to the construction of approximate analytical solutions for bending of a rectangular thin plate are presented: the superposition method based on the method of initial functions (MIF) and the one built using the Green's function in the form of orthogonal series. Comparison of two approaches is carried out by analyzing a square plate clamped along its contour. Behavior of the moment and the shear force in the neighborhood of the corner points is discussed. It is shown that both solutions give identical results at all points of the plate except for the neighborhoods of the corner points. There are differences in the values of bending moments and generalized shearing forces in the neighborhoods of the corner points.
Application of Laser Ranging and VLBI Data to a Study of Plate Tectonic Driving Forces
NASA Technical Reports Server (NTRS)
Solomon, S. C.
1980-01-01
The conditions under which changes in plate driving or resistive forces associated with plate boundary earthquakes are measurable with laser ranging or very long base interferometry were investigated. Aspects of plate forces that can be characterized by such measurements were identified. Analytic solutions for two dimensional stress diffusion in a viscoelastic plate following earthquake faulting on a finite fault, finite element solutions for three dimensional stress diffusion in a viscoelastic Earth following earthquake faulting, and quantitative constraints from modeling of global intraplate stress on the magnitude of deviatoric stress in the lithosphere are among the topics discussed.
ELECTRODEPOSITION OF NEPTUNIUM
Seaborg, G.T.; Wahl, A.C.
1960-08-30
A process of electrodepositing neptunium from solutions is given which comprises conducting the electrodeposition from an absolute alcohol bath containing a neptunium nitrate and lanthanum nitrate at a potential of approximately 50 volts and a current density of between about 1.8 and 4.7 ma/dm/ sup 2/.
Wave propagation in magneto-electro-elastic multilayered plates with nonlocal effect
NASA Astrophysics Data System (ADS)
Chen, Jiangyi; Guo, Junhong; Pan, Ernian
2017-07-01
In this paper, analytical solutions for propagation of time-harmonic waves in three-dimensional, transversely isotropic, magnetoelectroelastic and multilayered plates with nonlocal effect are derived. We first convert the time-harmonic wave problem into a linear eigenvalue system, from which we obtain the general solutions of the extended displacements and stresses. The solutions are then employed to derive the propagator matrix which connects the field variables at the upper and lower interfaces of each layer. Making use of the continuity conditions of the physical quantities across the interface, the global propagator relation is assembled by propagating the solutions in each layer from the bottom to the top of the layered plate. From the global propagator matrix, the dispersion equation is obtained by imposing the traction-free boundary conditions on both the top and bottom surfaces of the layered plate. Dispersion curves and mode shapes in layered plates made of piezoelectric BaTiO3 and magnetostrictive CoFe2O4 materials are presented to show the influence of the nonlocal parameter, stacking sequence, as well as the orientation of incident wave on the time-harmonic field response.
The Analysis of Metal Finishing Solutions by Ion Chromatography
1987-08-01
Chromatographic Instrumentation ...... 33 2.3 Modes of Separation .................. 35 2.4 Modes of Detection ................... 44 2.5 Method Development...Chromium Plating Solutions a and R with Added HCl ..................... 151 Table 35 . Chromium Plating Solutions a and R with Added NaOH...Dm (20) HETPld= Zd Dm / U (21) HETPsm= Zsm dp dp U / Dm (22) HETPsp= Zs dp dp U / Ds (23) where: dp- Particle diameter. Dm= Solute mobile phase
Generalized Gibbs state with modified Redfield solution: Exact agreement up to second order
DOE Office of Scientific and Technical Information (OSTI.GOV)
Thingna, Juzar; Wang, Jian-Sheng; Haenggi, Peter
A novel scheme for the steady state solution of the standard Redfield quantum master equation is developed which yields agreement with the exact result for the corresponding reduced density matrix up to second order in the system-bath coupling strength. We achieve this objective by use of an analytic continuation of the off-diagonal matrix elements of the Redfield solution towards its diagonal limit. Notably, our scheme does not require the provision of yet higher order relaxation tensors. Testing this modified method for a heat bath consisting of a collection of harmonic oscillators we assess that the system relaxes towards its correctmore » coupling-dependent, generalized quantum Gibbs state in second order. We numerically compare our formulation for a damped quantum harmonic system with the nonequilibrium Green's function formalism: we find good agreement at low temperatures for coupling strengths that are even larger than expected from the very regime of validity of the second-order Redfield quantum master equation. Yet another advantage of our method is that it markedly reduces the numerical complexity of the problem; thus, allowing to study efficiently large-sized system Hilbert spaces.« less
NASA Astrophysics Data System (ADS)
Li, Hua; Wang, Xiaogui; Yan, Guoping; Lam, K. Y.; Cheng, Sixue; Zou, Tao; Zhuo, Renxi
2005-03-01
In this paper, a novel multiphysic mathematical model is developed for simulation of swelling equilibrium of ionized temperature sensitive hydrogels with the volume phase transition, and it is termed the multi-effect-coupling thermal-stimulus (MECtherm) model. This model consists of the steady-state Nernst-Planck equation, Poisson equation and swelling equilibrium governing equation based on the Flory's mean field theory, in which two types of polymer-solvent interaction parameters, as the functions of temperature and polymer-network volume fraction, are specified with or without consideration of the hydrogen bond interaction. In order to examine the MECtherm model consisting of nonlinear partial differential equations, a meshless Hermite-Cloud method is used for numerical solution of one-dimensional swelling equilibrium of thermal-stimulus responsive hydrogels immersed in a bathing solution. The computed results are in very good agreements with experimental data for the variation of volume swelling ratio with temperature. The influences of the salt concentration and initial fixed-charge density are discussed in detail on the variations of volume swelling ratio of hydrogels, mobile ion concentrations and electric potential of both interior hydrogels and exterior bathing solution.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jayaweera, Indira; Krishnan, Gopala N.; Sanjurjo, Angel
2016-04-26
The invention provides methods for preparing an asymmetric hollow fiber, the asymmetric hollow fibers prepared by such methods, and uses of the asymmetric hollow fibers. One method involves passing a polymeric solution through an outer annular orifice of a tube-in-orifice spinneret, passing a bore fluid though an inner tube of the spinneret, dropping the polymeric solution and bore fluid through an atmosphere over a dropping distance, and quenching the polymeric solution and bore fluid in a bath to form an asymmetric hollow fiber.
Bending of Rectangular Plates with Large Deflections
NASA Technical Reports Server (NTRS)
Levy, Samuel
1942-01-01
The solution of von Karman's fundamental equations for large deflections of plates is presented for the case of a simply supported rectangular plate under combined edge compression and lateral loading. Numerical solutions are given for square plates and for rectangular plates with a width-span ratio of 3:1. The effective widths under edge compression are compared with effective widths according to von Karman, Bengston, Marguerre, and Cox and with experimental results by Ramberg, McPherson, and Levy. The deflections for a square plate under lateral pressure are compared with experimental and theoretical results by Kaiser. It is found that the effective widths agree closely with Marguerre's formula and with the experimentally observed values and that the deflections agree with the experimental results and with Kaiser's work.
Fabrication of CIGS Films by Electrodeposition Method for Photovoltaic Cells
NASA Astrophysics Data System (ADS)
Lee, Hyunju; Yoon, Hyukjoo; Ji, Changwook; Lee, Dongyun; Lee, Jae-Ho; Yun, Jae-Ho; Kim, Yangdo
2012-12-01
Cu(InGa)Se2 (CIGS) thin films were fabricated by electrochemical deposition in a single bath containing Cu, In, Ga, and Se ions. The electrolyte was prepared by dissolving CuCl2, InCl3, GaCl3, H2SeO3, and LiCl in deionized water. The potentiostatic deposition process was achieved by applying a voltage ranging from -0.5 V to -0.8 V versus Ag/AgCl. The effects of different chemical bath concentrations on the film composition and morphology were investigated. Stoichiometric CIGS film composition could be achieved by controlling the chemical compositions of the bath and the voltage. Gelatin was added to the solution to improve the surface and microstructures of the CIGS film. The as-deposited films were annealed at 500°C in Ar atmosphere for crystallization. The structural, morphological, and compositional properties of the CIGS thin films before and after annealing were examined by x-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. This study showed that the composition of the CIGS films is dependent on the bath concentration, whereas the applied potential had relatively less effect on the CIGS film composition. In addition, the use of gelatin helped in the fabrication of crack-free CIGS thin films with greatly improved surface morphology.
Controlled electrosprayed formation of non-spherical microparticles
NASA Astrophysics Data System (ADS)
Jeyhani, Morteza; Mak, Sze Yi; Sammut, Stephen; Shum, Ho Cheung; Hwang, Dae Kun; Tsai, Scott S. H.
2017-11-01
Fabrication of biocompatible microparticles, such as alginate particles, with the possibility of controlling the particles' morphology in a high-throughput manner, is essential for pharmaceutical and cosmetic industries. Even though the shape of alginate particles has been shown to be an important parameter in controlling drug delivery, there are very limited manufacturing methods to produce non-spherical alginate microparticles in a high-throughput fashion. Here, we present a system that generates non-spherical biocompatible alginate microparticles with a tunable size and shape, and at high-throughput, using an electrospray technique. Alginate solution, which is a highly biocompatible material, is flown through a needle using a constant flow rate syringe pump. The alginate phase is connected to a high-voltage power supply to charge it positively. There is a metallic ring underneath the needle that is charged negatively. The applied voltage creates an electric field that forces the dispensing droplets to pass through the metallic ring toward the collection bath. During this migration, droplets break up to smaller droplets to dissipate their energy. When the droplets reach the calcium chloride bath, polymerization happens and solidifies the droplets. We study the effects of changing the distance from the needle to the bath, and the concentration of calcium chloride in the bath, to control the size and the shape of the resulting microparticles.
A numerical solution of Duffing's equations including the prediction of jump phenomena
NASA Technical Reports Server (NTRS)
Moyer, E. T., Jr.; Ghasghai-Abdi, E.
1987-01-01
Numerical methodology for the solution of Duffing's differential equation is presented. Algorithms for the prediction of multiple equilibrium solutions and jump phenomena are developed. In addition, a filtering algorithm for producing steady state solutions is presented. The problem of a rigidly clamped circular plate subjected to cosinusoidal pressure loading is solved using the developed algorithms (the plate is assumed to be in the geometrically nonlinear range). The results accurately predict regions of solution multiplicity and jump phenomena.
Steel test panel helps control additives in pyrophosphate copper plating
NASA Technical Reports Server (NTRS)
Hollar, W. T.
1967-01-01
Test panel helps control maximum tolerance level for plating solution contaminants. It provides low, medium, and high-current density areas such as exist in production plating, and plating is examined for uniformity of texture and ductility.
Plate tectonics of the Mediterranean region.
McKenzie, D P
1970-04-18
The seismicity and fault plane solutions in the Mediterranean area show that two small rapidly moving plates exist in the Eastern Mediterranean, and such plates may be a common feature of contracting ocean basins. The results show that the concepts of plate tectonics apply to instantaneous motions across continental plate boundaries.
Gel-Filled Holders For Ultrasonic Transducers
NASA Technical Reports Server (NTRS)
Companion, John A.
1992-01-01
In new technique, ultrasonic transducer embedded in rubbery, castable, low-loss gel to enable transducer to "look" into surface of test object or human body at any desired angle. Composed of solution of water and ethylene glycol in collagen matrix. Provides total contact of water bath, also used on bodies or objects too large for water baths, even if moving. Also provides look angles of poly(methyl methacrylate) angle block with potential of reduced acoustic impedance and refraction. Custom-tailored to task at hand, and gel sufficiently inexpensive to be discarded upon completion. Easy to couple ultrasound in and out of gel, minimizing losses and artifacts of other types of standoffs employed in ultrasonic testing.
Thermosonication as a potential quality enhancement technique of apple juice.
Abid, Muhammad; Jabbar, Saqib; Hu, Bing; Hashim, Malik Muhammad; Wu, Tao; Lei, Shicheng; Khan, Muhammad Ammar; Zeng, Xiaoxiong
2014-05-01
Enzymatic browning and microbial growth lead to quality losses in apple products. In the present study, fresh apple juice was thermosonicated using ultrasound in-bath (25 kHz, 30 min, 0.06 W cm(-3)) and ultrasound with-probe sonicator (20 kHz, 5 and 10 min, 0.30 W cm(-3)) at 20, 40 and 60°C for inactivation of enzymes (polyphenolase, peroxidase and pectinmethylesterase) and microflora (total plate count, yeast and mold). Additionally, ascorbic acid, total phenolics, flavonoids, flavonols, pH, titratable acidity, (°)Brix and color values influenced by thermosonication were investigated. The highest inactivation of enzymes was obtained in ultrasound with-probe at 60°C for 10 min, and the microbial population was completely inactivated at 60°C. The retention of ascorbic acid, total phenolics, flavonoids and flavonols were significantly higher in ultrasound with-probe than ultrasound in-bath at 60°C. These results indicated the usefulness of thermosonication for apple juice processing at low temperature, for enhanced inactivation of enzymes and microorganisms. Copyright © 2013 Elsevier B.V. All rights reserved.
The USEPA has created the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. The ETV P2 Metal Finishing Technologies (ETV-MF) Prog...
Removing Biostatic Agents From Fermentation Solutions
NASA Technical Reports Server (NTRS)
Du Fresne, E. R.
1984-01-01
Liquid carbon dioxide inexpensive solvent. Inexpensive process proposed for removing such poisons as furfural and related compounds from fermentation baths of biomass hydrolysates. New process based on use of liquid carbon dioxide as extraction solvent. Liquid CO2 preferable to such other liquid solvents as ether or methylene chloride.
Neutral solute transport across osteochondral interface: A finite element approach.
Arbabi, Vahid; Pouran, Behdad; Weinans, Harrie; Zadpoor, Amir A
2016-12-08
Investigation of the solute transfer across articular cartilage and subchondral bone plate could nurture the understanding of the mechanisms of osteoarthritis (OA) progression. In the current study, we approached the transport of neutral solutes in human (slight OA) and equine (healthy) samples using both computed tomography and biphasic-solute finite element modeling. We developed a multi-zone biphasic-solute finite element model (FEM) accounting for the inhomogeneity of articular cartilage (superficial, middle and deep zones) and subchondral bone plate. Fitting the FEM model to the concentration-time curves of the cartilage and the equilibrium concentration of the subchondral plate/calcified cartilage enabled determination of the diffusion coefficients in the superficial, middle and deep zones of cartilage and subchondral plate. We found slightly higher diffusion coefficients for all zones in the human samples as compared to the equine samples. Generally the diffusion coefficient in the superficial zone of human samples was about 3-fold higher than the middle zone, the diffusion coefficient of the middle zone was 1.5-fold higher than that of the deep zone, and the diffusion coefficient of the deep zone was 1.5-fold higher than that of the subchondral plate/calcified cartilage. Those ratios for equine samples were 9, 2 and 1.5, respectively. Regardless of the species considered, there is a gradual decrease of the diffusion coefficient as one approaches the subchondral plate, whereas the rate of decrease is dependent on the type of species. Copyright © 2016 Elsevier Ltd. All rights reserved.
Convective diffusion in protein crystal growth
NASA Technical Reports Server (NTRS)
Baird, J. K.; Meehan, E. J., Jr.; Xidis, A. L.; Howard, S. B.
1986-01-01
A protein crystal modeled as a flat plate suspended in the parent solution, with the normal to the largest face perpendicular to gravity and the protein concentration in the solution adjacent to the plate taken to be the equilibrium solubility, is studied. The Navier-Stokes equation and the equation for convective diffusion in the boundary layer next to the plate are solved to calculate the flow velocity and the protein mass flux. The local rate of growth of the plate is shown to vary significantly with depth due to the convection. For an aqueous solution of lysozyme at a concentration of 40 mg/ml, the boundary layer at the top of a 1-mm-high crystal has a thickness of 80 microns at 1 g, and 2570 microns at 10 to the -6th g.
Flow of nanofluid past a Riga plate
NASA Astrophysics Data System (ADS)
Ahmad, Adeel; Asghar, Saleem; Afzal, Sumaira
2016-03-01
This paper studies the mixed convection boundary layer flow of a nanofluid past a vertical Riga plate in the presence of strong suction. The mathematical model incorporates the Brownian motion and thermophoresis effects due to nanofluid and the Grinberg-term for the wall parallel Lorentz force due to Riga plate. The analytical solution of the problem is presented using the perturbation method for small Brownian and thermophoresis diffusion parameters. The numerical solution is also presented to ensure the reliability of the asymptotic method. The comparison of the two solutions shows an excellent agreement. The correlation expressions for skin friction, Nusselt number and Sherwood number are developed by performing linear regression on the obtained numerical data. The effects of nanofluid and the Lorentz force due to Riga plate, on the skin friction are discussed.
Effect of magnetic field on the electrodeposition of nickel
NASA Astrophysics Data System (ADS)
Subhachandhar, S.; Krishnan, A. Yaadhav; Sivabalan, S.; Narayanan, R.
2012-07-01
This paper investigates the effect of an external magnetic field in the electroplating of Ni, one of the four ferromagnetic materials at the room temperature. Nickel plating is done using Watts bath with a composition of 250g/L of Nickel sulphate, 35g/L of Nickel Chloride, 25g/L of Boric acid with pH between 5 and 6 at room temperature under a current density of 0.05-0.1 A/dm2 under the presence of an external magnetic field to obtain a coherent coating. The arrangement of the coated particles is studied by SEM analysis.
Apparent Mass Nonlinearity for Paired Oscillating Plates
NASA Astrophysics Data System (ADS)
Granlund, Kenneth; Ol, Michael
2014-11-01
The classical potential-flow problem of a plate oscillating sinusoidally at small amplitude, in a direction normal to its plane, has a well-known analytical solution of a fluid ``mass,'' multiplied by plate acceleration, being equal to the force on the plate. This so-called apparent-mass is analytically equal to that of a cylinder of fluid, with diameter equal to plate chord. The force is directly proportional to frequency squared. Here we consider experimentally a generalization, where two coplanar plates of equal chord are placed at some lateral distance apart. For spacing of ~0.5 chord and larger between the two plates, the analytical solution for a single plate can simply be doubled. Zero spacing means a plate of twice the chord and therefore a heuristic cylinder of fluid of twice the cross-sectional area. This limit is approached for plate spacing <0.5c. For a spacing of 0.1-0.2c, the force due to apparent mass was found to increase with frequency, when normalized by frequency squared; this is a nonlinearity and a departure from the classical theory. Flow visualization in a water-tank suggests that such departure can be imputed to vortex shedding from the plates' edges inside the inter-plate gap.
Anodic Oxidation of Furans in Aprotic Solvents.
1984-01-06
dissolved in 70 mL acetonitrile (0.003% water , K.F. titration) containing 0.1 M tetra-n-butyl ammonium tetrafluoroborate (TBAF). The solution was...solvent evaporated on a rotary evaporator at 25°C ( water bath temperature). The residue was extracted with 3 x 20 mL portions of diethylether, and the...results for a clean electrode in the same solution after presaturation with oxygen. To make the film conductive for the electrolyses , the voltage was
Intrinsic Properties of Larval Zebrafish Neurons in Ethanol
Ikeda, Hiromi; Delargy, Alison H.; Yokogawa, Tohei; Urban, Jason M.; Burgess, Harold A.; Ono, Fumihito
2013-01-01
The behavioral effects of ethanol have been studied in multiple animal models including zebrafish. Locomotion of zebrafish larvae is resistant to high concentrations of ethanol in bath solution. This resistance has been attributed to a lower systemic concentration of ethanol in zebrafish when compared with bath solution, although the mechanism to maintain such a steep gradient is unclear. Here we examined whether the intrinsic properties of neurons play roles in this resistance. In order to minimize the contribution of metabolism and diffusional barriers, larvae were hemisected and the anterior half immersed in a range of ethanol concentrations thereby ensuring the free access of bath ethanol to the brain. The response to vibrational stimuli of three types of reticulospinal neurons: Mauthner neurons, vestibulospinal neurons, and MiD3 neurons were examined using an intracellular calcium indicator. The intracellular [Ca2+] response in MiD3 neurons decreased in 100 mM ethanol, while Mauthner neurons and vestibulospinal neurons required >300 mM ethanol to elicit similar effects. The ethanol effect in Mauthner neurons was reversible following removal of ethanol. Interestingly, activities of MiD3 neurons displayed spontaneous recovery in 300 mM ethanol, suggestive of acute tolerance. Finally, we examined with mechanical vibration the startle response of free-swimming larvae in 300 mM ethanol. Ethanol treatment abolished long latency startle responses, suggesting a functional change in neural processing. These data support the hypothesis that individual neurons in larval zebrafish brains have distinct patterns of response to ethanol dictated by specific molecular targets. PMID:23658822
NASA Astrophysics Data System (ADS)
Kumar, Prashant; Mahato, Neelima
Nanocrystalline nickel was deposited on annealed copper substrate of unit surface area (1 cm2) via pulsed electrodeposition technique using potentiostat (model 263A, Princeton Applied Research, USA) from Watts bath containing nickel sulfate, nickel chloride ,boric acid and sodium citrate. Diamond particles of three different dimensions, viz., 1, 3, and 6 micron were added separately (5 g/L) to the watts bath and co-deposited along with nanocrystalline nickel. The temperature was kept constant at 55 °C. The solution was ultrasonicated for 45-60 minutes prior to deposition to disperse the diamond particles uniformly in the bath. Depositions were carried out at different current densities, viz., 50, 100,150 and 200 mA/ cm2 for different durations, i.e.7, 14 and 21 minutes and best results are optimized for 200mA/cm2 so it is used for all process here .Scanning electron micrographs (SEM) show uniform deposition of microstructure of micron diamond on the surface of copper embedded in the nickel matrix. Elemental mapping confirmed uniform deposition of nickel and diamond with almost no cracks or pits. Mechanical properties of the sample such as, Vicker's hardness increased abruptly after the electrodeposition. Improved microstructural and mechanical properties were found in the case of electrodeposited surfaces containing followed by 3 and 6 micron diamond. The properties were also found better than those processed via stirring the solution during deposition.
A fast solution switching system with temperature control for single cell measurements
Koh, Duk-Su; Chen, Liangyi; Ufret-Vincenty, Carmen A.; Jung, Seung-Ryoung
2011-01-01
This article describes a perfusion system for biophysical single cell experiments at the physiological temperature. Our system regulates temperature of test solutions using a small heat exchanger that includes several capillaries. Water circulating inside the heat exchanger warms or cools test solutions flowing inside the capillaries. Temperature-controlled solutions are delivered directly to a single cell(s) through a multibarreled manifold that switches solutions bathing a cell in less than 1 s. This solution exchange is optimal for patch clamp, single-cell microamperometry, and microfluorometry experiments. Using this system, we demonstrate that exocytosis from pancreatic β cells and activation of TRPV1 channels are temperature sensitive. We also discuss how to measure local temperature near a single cell under investigation. PMID:21536068
Basics of Compounding: Compounding Irrigation Solutions for Sterile and Nonsterile Preparations.
Allen, Loyd V
2017-01-01
Compounding pharmacists are sometimes called upon to prepare irrigation solutions, especially in the hospital or clinical setting. Irrigations are indicated for washing or bathing surgical incisions, wounds, and body tissues, including body cavities. Some irrigation solutions coming in contact with exposed tissue, must meet stringent requirements of sterility and bacterial endotoxins. Compounded irrigation solutions may involve wound(s), the bladder, and also may be for ophthalmic, otic, and nasal application. Some vaginal douches/instillations and rectal solutions may also be used as irrigations. As with any medication administered to the body or used on body tissues, there are requirements, and these may vary depending on the type of irrigation solution involved. Copyright© by International Journal of Pharmaceutical Compounding, Inc.
Dial-A-Decon Solution Chemistry GAP Testing
2012-04-01
34 The tubes were serially diluted using Buttcrfield’s buffer solution and plated in triplicate on Tryptic Soy Agar. Plates were enumerated the...of 200 uL HD to 10 mL of the surfactant solution. The energy to create the oil in water (O/W) emulsions was provided by magnetic stirring. Solutions...emulsify a mixture of water and oil such as HD, one or more emulsifiers are required. Each surfactant system can be characterized by an HLB value
Screen test for cadmium and nickel plates as developed and used within the Aerospace Corporation
NASA Technical Reports Server (NTRS)
Phan, A. H.; Zimmerman, A. H.
1994-01-01
A new procedure described here was recently developed to quantify loading uniformity of nickel and cadmium plates and to screen finished electrodes prior to cell assembly. The technique utilizes the initial solubility rates of the active material in a standard chemical deloading solution at fixed conditions. The method can provide a reproducible indication of plate loading uniformity in situations where high surface loading limits the free flow of deloading solution into the internal porosity of the sinter plate. A preliminary study indicates that 'good' cell performance is associated with higher deloading rates.
NASA Astrophysics Data System (ADS)
Grigoryan, M. S.
2018-04-01
This paper considers two connected contact problems on the interaction of stringers with an elastic semi-infinite plate. In the first problem, an elastic half-infinite continuous plate is reinforced on its boundary by two identical stringers exposed to a tensile external force. In the second problem, in the presence of the same stringers, the plate contains a collinear system of cracks on its vertical axis. The solution of both problems is reduced to the solution of singular integral equations (SIE) that are solved by a known numerical-analytical method.
NASA Astrophysics Data System (ADS)
Toifur, M.; Yuningsih, Y.; Khusnani, A.
2018-03-01
In this research, it has been made Cu/Ni thin film produced with electroplating technique. The deposition process was done in the plating bath using Cu and Ni as cathode and anode respectively. The electrolyte solution was made from the mixture of HBrO3 (7.5g), NiSO4 (100g), NiCl2 (15g), and aquadest (250 ml). Electrolyte temperature was varied from 40°C up to 80°C, to make the Ni ions in the solution easy to move to Cu cathode. The deposition was done during 2 minutes on the potential of 1.5 volt. Many characterizations were done including the thickness of Ni film, microstructure, and sheet resistivity. The results showed that at all samples Ni had attacked on the Cu substrate to form Cu/Ni. The raising of electrolyte temperature affected the increasing of Ni thickness that is the Ni thickness increase with the increasing electrolyte temperature. From the EDS spectrum, it can be informed that samples already contain Ni and Cu elements and NiO and CuO compounds. Addition element and compound are found for sample Cu/Ni resulted from 70° electrolyte temperature of Ni deposition, that are Pt and PtO2. From XRD pattern, there are several phases which have crystal structure i.e. Cu, Ni, and NiO, while CuO and PtO2 have amorphous structure. The sheet resistivity linearly decreases with the increasing electrolyte temperature.
Feasibility of Use of Plastic Foams for Small Vessel Flotation Devices.
1976-01-01
waterproofing agents, namely, Dow Corning Silicone 200 fluid, zinc stearate, sodium silicate, Fisher Bath Wax , Carnauba wax , and paraffin wax . Some of...these materials (e.g., waxes ) did not mix well with the foam solution. None of these materials was effective in preventing water absorption by polystyrene
40 CFR Appendix C to Part 438 - Metal-Bearing Operations Definitions
Code of Federal Regulations, 2011 CFR
2011-07-01
... chromium. (1) In phosphate conversion, coatings are applied for one or more of the following reasons: to... electrolysis. The part is one of the electrodes and the electrolyte is usually alkaline. Electrolytic alkaline... during salt bath descaling includes spent process solutions, quenches, and rinses. Shot Tower—Lead Shot...
40 CFR Appendix C to Part 438 - Metal-Bearing Operations Definitions
Code of Federal Regulations, 2014 CFR
2014-07-01
... chromium. (1) In phosphate conversion, coatings are applied for one or more of the following reasons: to... electrolysis. The part is one of the electrodes and the electrolyte is usually alkaline. Electrolytic alkaline... during salt bath descaling includes spent process solutions, quenches, and rinses. Shot Tower—Lead Shot...
40 CFR Appendix C to Part 438 - Metal-Bearing Operations Definitions
Code of Federal Regulations, 2013 CFR
2013-07-01
... chromium. (1) In phosphate conversion, coatings are applied for one or more of the following reasons: to... electrolysis. The part is one of the electrodes and the electrolyte is usually alkaline. Electrolytic alkaline... during salt bath descaling includes spent process solutions, quenches, and rinses. Shot Tower—Lead Shot...
40 CFR Appendix C to Part 438 - Metal-Bearing Operations Definitions
Code of Federal Regulations, 2010 CFR
2010-07-01
... chromium. (1) In phosphate conversion, coatings are applied for one or more of the following reasons: to... electrolysis. The part is one of the electrodes and the electrolyte is usually alkaline. Electrolytic alkaline... during salt bath descaling includes spent process solutions, quenches, and rinses. Shot Tower—Lead Shot...
40 CFR Appendix C to Part 438 - Metal-Bearing Operations Definitions
Code of Federal Regulations, 2012 CFR
2012-07-01
... chromium. (1) In phosphate conversion, coatings are applied for one or more of the following reasons: to... electrolysis. The part is one of the electrodes and the electrolyte is usually alkaline. Electrolytic alkaline... during salt bath descaling includes spent process solutions, quenches, and rinses. Shot Tower—Lead Shot...
High Throughput, Polymeric Aqueous Two-Phase Printing of Tumor Spheroids
Atefi, Ehsan; Lemmo, Stephanie; Fyffe, Darcy; Luker, Gary D.; Tavana, Hossein
2014-01-01
This paper presents a new 3D culture microtechnology for high throughput production of tumor spheroids and validates its utility for screening anti-cancer drugs. We use two immiscible polymeric aqueous solutions and microprint a submicroliter drop of the “patterning” phase containing cells into a bath of the “immersion” phase. Selecting proper formulations of biphasic systems using a panel of biocompatible polymers results in the formation of a round drop that confines cells to facilitate spontaneous formation of a spheroid without any external stimuli. Adapting this approach to robotic tools enables straightforward generation and maintenance of spheroids of well-defined size in standard microwell plates and biochemical analysis of spheroids in situ, which is not possible with existing techniques for spheroid culture. To enable high throughput screening, we establish a phase diagram to identify minimum cell densities within specific volumes of the patterning drop to result in a single spheroid. Spheroids show normal growth over long-term incubation and dose-dependent decrease in cellular viability when treated with drug compounds, but present significant resistance compared to monolayer cultures. The unprecedented ease of implementing this microtechnology and its robust performance will benefit high throughput studies of drug screening against cancer cells with physiologically-relevant 3D tumor models. PMID:25411577
NASA Astrophysics Data System (ADS)
Wang, Hui-Long; Liu, Ling-Yun; Dou, Yong; Zhang, Wen-Zhu; Jiang, Wen-Feng
2013-12-01
In this paper, the protective electroless Ni-P/SiC gradient coatings on AZ91D magnesium alloy substrate were successfully prepared. The prepared Ni-P/SiC gradient coatings were characterized for its microstructure, morphology, microhardness and adhesion to the substrate. The deposition reaction kinetics was investigated and an empirical rate equation for electroless Ni-P/SiC plating on AZ91D magnesium alloy was developed. The anticorrosion properties of the Ni-P/SiC gradient coatings in 3.5 wt.% NaCl solution were evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies. The potentiodynamic polarization measurements revealed that the SiC concentration in the bath and heat treatment can influence the corrosion protection performance of electroless deposited Ni-P/SiC gradient coatings. EIS studies indicated that higher charge transfer resistance and slightly lower capacitance values were obtained for Ni-P/SiC gradient coatings compared to Ni-P coatings. The corrosion resistance of the Ni-P/SiC gradient coatings increases initially and decreases afterwards with the sustained increasing of immersion time in the aggressive medium. The electroless Ni-P/SiC gradient coatings can afford better corrosion protection for magnesium alloy substrate compared with Ni-P coatings.
NASA Astrophysics Data System (ADS)
Edwards, Devin T.; Takahashi, Susumu; Sherwin, Mark S.; Han, Songi
2012-10-01
At 8.5 T, the polarization of an ensemble of electron spins is essentially 100% at 2 K, and decreases to 30% at 20 K. The strong temperature dependence of the electron spin polarization between 2 and 20 K leads to the phenomenon of spin bath quenching: temporal fluctuations of the dipolar magnetic fields associated with the energy-conserving spin "flip-flop" process are quenched as the temperature of the spin bath is lowered to the point of nearly complete spin polarization. This work uses pulsed electron paramagnetic resonance (EPR) at 240 GHz to investigate the effects of spin bath quenching on the phase memory times (TM) of randomly-distributed ensembles of nitroxide molecules below 20 K at 8.5 T. For a given electron spin concentration, a characteristic, dipolar flip-flop rate (W) is extracted by fitting the temperature dependence of TM to a simple model of decoherence driven by the spin flip-flop process. In frozen solutions of 4-Amino-TEMPO, a stable nitroxide radical in a deuterated water-glass, a calibration is used to quantify average spin-spin distances as large as r¯=6.6 nm from the dipolar flip-flop rate. For longer distances, nuclear spin fluctuations, which are not frozen out, begin to dominate over the electron spin flip-flop processes, placing an effective ceiling on this method for nitroxide molecules. For a bulk solution with a three-dimensional distribution of nitroxide molecules at concentration n, we find W∝n∝1/r, which is consistent with magnetic dipolar spin interactions. Alternatively, we observe W∝n for nitroxides tethered to a quasi two-dimensional surface of large (Ø ˜ 200 nm), unilamellar, lipid vesicles, demonstrating that the quantification of spin bath quenching can also be used to discern the geometry of molecular assembly or organization.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhu, Jin; Li, Wenbin; Zhu, Mao
2014-03-15
The localized surface plasmon resonances (LSPRs) of gold particles assembled on a crystal plate are a powerful tool for biological sensors. Here, we prepare gold colloids in different pH solutions. We monitor the effects of the particle radius and particle coverage on the absorption spectra of AT-cut (r-face dihedral angle of about 3°) crystal plates supporting gold nanoparticles. The surface morphologies were monitored on silicon dioxide substrates using ultraviolet and visible (UV-vis) spectroscopy, and atomic force microscopy (AFM). The results showed that the gold particle coverage decreases with increasing pH value of the gold colloid solution. This phenomenon demonstrates thatmore » self-assembled gold surfaces were formed via the electrostatic adsorption of gold particles on the positively charged, ionized amino groups on the crystal plates in the acidic solution. The spectrum of gold nanoparticles with different coverage degree on the crystal plates showed that the LSPR properties are highly dependent on pH.« less
Development of LEDs-based microplate reader for bioanalytical assay measurements
NASA Astrophysics Data System (ADS)
Alaruri, Sami D.; Katzlinger, Michael; Schinwald, Bernhard; Kronberger, Georg; Atzler, Joseph
2013-10-01
The optical design for an LEDs-based microplate reader that can perform fluorescence intensity (top and bottom), absorbance, luminescence and time-resolved fluorescence measurements is described. The microplate reader is the first microplate reader in the marketplace that incorporates LEDs as excitation light sources. Absorbance measurements over the 0-3.5 optical density range for caffeine solution are presented. Additionally, fluorescence intensity readings collected at 535 and 625 nm from a green and a red RediPlateTM are reported. Furthermore, fluorescence decay lifetime measurements obtained for Eu (europium) and Sm (samarium) standard solutions using 370 nm excitation are presented. The microplate reader detection limits for the fluorescence intensity top, fluorescence intensity bottom, fluorescence polarization and time-resolved fluorescence modes are 1.5 fmol 100 µL-1 fluorescein (384-well plate), 25 fmol 100 µL-1 fluorescein (384-well plate), 5 mP at 10 nM fluorescein (black 384-well plate) and 30 amol 100 µL-1 europium solution (white 384-well plate), respectively.
Deflection of cross-ply composite laminates induced by piezoelectric actuators.
Her, Shiuh-Chuan; Lin, Chi-Sheng
2010-01-01
The coupling effects between the mechanical and electric properties of piezoelectric materials have drawn significant attention for their potential applications as sensors and actuators. In this investigation, two piezoelectric actuators are symmetrically surface bonded on a cross-ply composite laminate. Electric voltages with the same amplitude and opposite sign are applied to the two symmetric piezoelectric actuators, resulting in the bending effect on the laminated plate. The bending moment is derived by using the classical laminate theory and piezoelectricity. The analytical solution of the flexural displacement of the simply supported composite plate subjected to the bending moment is solved by using the plate theory. The analytical solution is compared with the finite element solution to show the validation of present approach. The effects of the size and location of the piezoelectric actuators on the response of the composite laminate are presented through a parametric study. A simple model incorporating the classical laminate theory and plate theory is presented to predict the deformed shape of the simply supported laminate plate.
Ovshinsky, Stanford R.; Corrigan, Dennis; Venkatesan, Srini; Young, Rosa; Fierro, Christian; Fetcenko, Michael A.
1994-01-01
A high capacity, long cycle life positive electrode for use in an alkaline rechargeable electrochemical cell comprising: a solid solution nickel hydroxide material having a multiphase structure that comprises at least one polycrystalline .gamma.-phase including a polycrystalline .gamma.-phase unit cell comprising spacedly disposed plates with at least one chemical modifier incorporated around the plates, the plates having a range of stable intersheet distances corresponding to a 2.sup.+ oxidation state and a 3.5.sup.+, or greater, oxidation state; and at least one compositional modifier incorporated into the solid solution nickel hydroxide material to promote the multiphase structure.
Process for metallization of a substrate by irradiative curing of a catalyst applied thereto
Chen, Ken S.; Morgan, William P.; Zich, John L.
1999-01-01
An improved additive process for metallization of substrates is described whereby a catalyst solution is applied to a surface of a substrate. Metallic catalytic clusters can be formed in the catalyst solution on the substrate surface by irradiating the substrate. Electroless plating can then deposit metal onto the portion of the substrate surface having metallic clusters. Additional metallization thickness can be obtained by electrolytically plating the substrate surface after the electroless plating step.
Hierarchic models for laminated plates. Ph.D. Thesis
NASA Technical Reports Server (NTRS)
Actis, Ricardo Luis
1991-01-01
Structural plates and shells are three-dimensional bodies, one dimension of which happens to be much smaller than the other two. Thus, the quality of a plate or shell model must be judged on the basis of how well its exact solution approximates the corresponding three-dimensional problem. Of course, the exact solution depends not only on the choice of the model but also on the topology, material properties, loading and constraints. The desired degree of approximation depends on the analyst's goals in performing the analysis. For these reasons models have to be chosen adaptively. Hierarchic sequences of models make adaptive selection of the model which is best suited for the purposes of a particular analysis possible. The principles governing the formulation of hierarchic models for laminated plates are presented. The essential features of the hierarchic models described models are: (1) the exact solutions corresponding to the hierarchic sequence of models converge to the exact solution of the corresponding problem of elasticity for a fixed laminate thickness; and (2) the exact solution of each model converges to the same limit as the exact solution of the corresponding problem of elasticity with respect to the laminate thickness approaching zero. The formulation is based on one parameter (beta) which characterizes the hierarchic sequence of models, and a set of constants whose influence was assessed by a numerical sensitivity study. The recommended selection of these constants results in the number of fields increasing by three for each increment in the power of beta. Numerical examples analyzed with the proposed sequence of models are included and good correlation with the reference solutions was found. Results were obtained for laminated strips (plates in cylindrical bending) and for square and rectangular plates with uniform loading and with homogeneous boundary conditions. Cross-ply and angle-ply laminates were evaluated and the results compared with those of MSC/PROBE. Hierarchic models make the computation of any engineering data possible to an arbitrary level of precision within the framework of the theory of elasticity.
Formation of a vortex at the edge of a plate
NASA Technical Reports Server (NTRS)
Anton, Leo
1956-01-01
The flow about the plate of infinite width may be represented as a potential flow with discontinuity surfaces which extend from the plate edges. For prescribed form and vortex distribution of the discontinuity surfaces, the velocity field may be calculated by means of a conformal representation. One condition is that the velocity at the plate edges must be finite. However, it is not sufficient for determination of the form and vortex distribution of the surface. However, on the basis of a similitude requirement one succeeds in finding a solution of this problem for the plate of infinite width which is correct for the very beginning of the motion of the fluid. Starting from this solution, the further development of the vortex distribution and shape of the surface are observed in the case of a plate of finite width.
NASA Technical Reports Server (NTRS)
Noor, A. K.; Burton, W. S.
1992-01-01
Analytic three-dimensional thermoelasticity solutions are presented for the thermal buckling of multilayered angle-ply composite plates with temperature-dependent thermoelastic properties. Both the critical temperatures and the sensitivity derivatives are computed. The sensitivity derivatives measure the sensitivity of the buckling response to variations in the different lamination and material parameters of the plate. The plates are assumed to have rectangular geometry and an antisymmetric lamination with respect to the middle plane. The temperature is assumed to be independent of the surface coordinates, but has an arbitrary symmetric variation through the thickness of the plate. The prebuckling deformations are accounted for. Numerical results are presented, for plates subjected to uniform temperature increase, showing the effects of temperature-dependent material properties on the prebuckling stresses, critical temperatures, and their sensitivity derivatives.
Gómez-Gutiérrez, Claudia M; Luque, P A; Castro-Beltran, A; Vilchis-Nestor, A R; Lugo-Medina, Eder; Carrillo-Castillo, A; Quevedo-Lopez, M A; Olivas, A
2015-01-01
In this work, the influence of substrate on the morphology of ZnS thin films by chemical bath deposition is studied. The materials used were zinc acetate, tri-sodium citrate, thiourea, and ammonium hydroxide/ammonium chloride solution. The growth of ZnS thin films on different substrates showed a large variation on the surface, presenting a poor growth on SiO2 and HfO2 substrates. The thin films on ITO substrate presented a uniform and compact growth without pinholes. The optical properties showed a transmittance of about 85% in the visible range of 300-800 nm with band gap of 3.7 eV. © Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Wang, Y. Y.; Cai, K. F.; Yao, X.
2009-12-01
A novel, simple, and cost-effective route to PbTe nanoparticles and films is reported in this paper. The PbTe nanoparticles and films are fabricated by a chemical bath method, at room temperature and ambient pressure, using conventional chemicals as starting materials. The average grain size of the nanoparticles collected at the bottom of the bath is ˜25 nm. The film deposited on glass substrate is dense, smooth, and uniform with silver gray metallic luster. The film exhibits p-type conduction and has a moderate Seebeck coefficient value (˜147 μV K -1) and low electrical conductivity (˜0.017 S cm -1). The formation mechanism of the PbTe nanoparticles and films is proposed.
Special features of the technology of boronizing steel in a calcium chloride melt
NASA Astrophysics Data System (ADS)
Chernov, Ya. B.; Anfinogenov, A. I.; Veselov, I. N.
1999-12-01
A technology for hardening machine parts and tools by boronizing in molten calcium chloride with amorphous-boron powder in electrode salt baths has been developed with the aim of creating a closed cycle of utilizing the raw materials and the washing water. A process of boronizing that includes quenching and tempering of the boronized articles is described. The quenching medium is an ecologically safe and readily available aqueous solution of calcium chloride. The process envisages return of the melt components to the boronizing bath. Boronizing by the suggested method was tested for different classes of steel, namely, structural and tool steels for cold and hot deformation. The wear resistance of the boronized steels was studied.
Willit, James L [Batavia, IL; Ackerman, John P [Prescott, AZ; Williamson, Mark A [Naperville, IL
2009-12-29
This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.
Topology and Function of Human P-Glycoprotein in Multidrug Resistant Breast Cancer Cells.
1995-09-01
membrane orientation and insertion process co-translationally. For the C-terminal half of Pgp, little is known about the regulatory mechanisms of...solution (in mM: 250 sucrose, 10 Tris-HC1, pH 7.5, 150 NaCl) for further processing . For experiments requiring protease digestion and endoglycosidase...steps), 40 ms after the start of the voltage pulse . Bath and pipette solution compositions were as follows (in mM): NMDG-C1 pipette (280 mosmol/kg
2013-09-01
nearly identical responses to the chemically similar odorants 2-heptanone and n-amyl acetate. The molecules differ only by a single oxygen atom in...briefly bathed in activation buffer and placed in a solution of 11.3 mM NR,NR-bis(carboxymethyl)-L-lysine hydrate (NTA- NH2) prepared with PBS (0.1 M...purity nitrogen or argon gas. A solution containing mORs in digitonin micelles or nanodiscs, prepared as described above, was de- posited on the
Thermal method for cleaning polymer quenching media
NASA Astrophysics Data System (ADS)
Sverdlin, A. V.; Blackwood, R.; Totten, G. E.
1996-06-01
Aqueous solutions of polymers are used for heat treatment, mainly for quenching steels. The most popular and universally used are quenching liquids of the UCON A, E, XT types based on various polyalkylene glycols. In the course of operation these liquids are contaminated by salts retained on the surface of the parts after their heating in salt baths, by ions of heavy metals present in the solution, etc. The paper is devoted to the most popular method for cleaning polymer quenching media, namely, the method of thermal separation.
Description of Manufacture - Optical Elements for Five Control Instruments
1951-04-01
the rotation of the mill. Pressure is applied at each turning point. When the abrasive on the mill is spent (i.e., has lost its catting efficiency...in hot water or by soaking, first in kerosene, then in alcohol. Shellac is removed by soaking in alcohol or in a dilute caustic bath, and other...room tempera- tures, the solutions are spent in just 10 min- utes. At the end of this time the residual solution is poured out and the dish is
New Engineering Solutions in Creation of Mini-BOF for Metallic Waste Recycling
NASA Astrophysics Data System (ADS)
Eronko, S. P.; Gorbatyuk, S. M.; Oshovskaya, E. V.; Starodubtsev, B. I.
2017-12-01
New engineering solutions used in design of the mini melting unit capable of recycling industrial and domestic metallic waste with high content of harmful impurities are provided. High efficiency of the process technology implemented with its use is achieved due to the possibility of the heat and mass transfer intensification in the molten metal bath, controlled charge into it of large amounts of reagents in lumps and in fines, and cut-off of remaining process slag during metal tapping into the teeming ladle.
Thermal Analysis of Antenna Structures. Part 2: Panel Temperature Distribution
NASA Technical Reports Server (NTRS)
Schonfeld, D.; Lansing, F. L.
1983-01-01
This article is the second in a series that analyzes the temperature distribution in microwave antennas. An analytical solution in a series form is obtained for the temperature distribution in a flat plate analogous to an antenna surface panel under arbitrary temperature and boundary conditions. The solution includes the effects of radiation and air convection from the plate. Good agreement is obtained between the numerical and analytical solutions.
Cadmium sulfide thin films growth by chemical bath deposition
NASA Astrophysics Data System (ADS)
Hariech, S.; Aida, M. S.; Bougdira, J.; Belmahi, M.; Medjahdi, G.; Genève, D.; Attaf, N.; Rinnert, H.
2018-03-01
Cadmium sulfide (CdS) thin films have been prepared by a simple technique such as chemical bath deposition (CBD). A set of samples CdS were deposited on glass substrates by varying the bath temperature from 55 to 75 °C at fixed deposition time (25 min) in order to investigate the effect of deposition temperature on CdS films physical properties. The determination of growth activation energy suggests that at low temperature CdS film growth is governed by the release of Cd2+ ions in the solution. The structural characterization indicated that the CdS films structure is cubic or hexagonal with preferential orientation along the direction (111) or (002), respectively. The optical characterization indicated that the films have a fairly high transparency, which varies between 55% and 80% in the visible range of the optical spectrum, the refractive index varies from 1.85 to 2.5 and the optical gap value of which can reach 2.2 eV. It can be suggested that these properties make these films perfectly suitable for their use as window film in thin films based solar cells.
Ubiquity of Beutler-Fano profiles: From scattering to dissipative processes
NASA Astrophysics Data System (ADS)
Finkelstein-Shapiro, Daniel; Keller, Arne
2018-02-01
Fano models—consisting of a Hamiltonian with a discrete-continuous spectrum—are one of the basic toy models in spectroscopy. They have been successful in explaining the line shape of experiments in atomic physics and condensed matter. These models, however, have largely been beyond the scope of dissipative dynamics, with only a handful of works considering the effect of a thermal bath. Yet in nanostructures and condensed-matter systems, dissipation strongly modulates the dynamics. We present an overview of the theory of Fano interferences coupled to a thermal bath and compare them to the scattering formalism. We provide the solution to any discrete-continuous Hamiltonian structure within the wideband approximation coupled to a Markovian bath. In doing so, we update the toy models that have been available for unitary evolution since the 1960s. We find that the Fano line shape is preserved as long as we allow a rescaling of the parameters, and an additional Lorentzian contribution that reflects the destruction of the interference by dephasings. The universality of the line shape can be traced back to specific properties of the effective Liouvillian.
Basire, Marie; Borgis, Daniel; Vuilleumier, Rodolphe
2013-08-14
Langevin dynamics coupled to a quantum thermal bath (QTB) allows for the inclusion of vibrational quantum effects in molecular dynamics simulations at virtually no additional computer cost. We investigate here the ability of the QTB method to reproduce the quantum Wigner distribution of a variety of model potentials, designed to assess the performances and limits of the method. We further compute the infrared spectrum of a multidimensional model of proton transfer in the gas phase and in solution, using classical trajectories sampled initially from the Wigner distribution. It is shown that for this type of system involving large anharmonicities and strong nonlinear coupling to the environment, the quantum thermal bath is able to sample the Wigner distribution satisfactorily and to account for both zero point energy and tunneling effects. It leads to quantum time correlation functions having the correct short-time behavior, and the correct associated spectral frequencies, but that are slightly too overdamped. This is attributed to the classical propagation approximation rather than the generation of the quantized initial conditions themselves.
ZnO/CdS bi-layer nanostructures photoelectrode for dye-sensitized solar cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dalal, Paresh V., E-mail: paresh10dalal@gmail.com; Deshpande, Milind P., E-mail: vishwadeshpande@yahoo.co.in; Solanki, Bharat G., E-mail: bhrt.solanki17@gmail.com
2016-05-06
Simple chemical deposition method for the synthesis of ZnO/CdS bilayer photoelectrode on fluorine doped tin oxide (FTO) coated glass substrate in aqueous medium at low temperature (< 373K) is described. The different preparative parameters such as deposition time, bath temperature, concentration of precursor solution and, pH of the bath etc. were optimized. Nanograined ZnO was deposited on FTO coated glass substrates by dip-coating method, whereas CdS nanorods were successfully synthesized on pre-deposited ZnO film by Chemical Bath Deposition (CBD) method. The Photovoltaic properties of FTO/ZnO/CdS bilayer photo electrodes were also studied. A maximum short circuit current density of 9.1 mA cm-2more » and conversion efficiency 1.05% are observed for ZnO/CdS-10min. Layer, which supports fast electron injection kinetics due to hetero structured nanorod, while minimum values of 0.53mA cm-2 and 0.01% respectively are observed for only ZnO deposited layer.« less
Landauer's formula breakdown for radiative heat transfer and nonequilibrium Casimir forces
NASA Astrophysics Data System (ADS)
Rubio López, Adrián E.; Poggi, Pablo M.; Lombardo, Fernando C.; Giannini, Vincenzo
2018-04-01
In this work, we analyze the incidence of the plates' thickness on the Casimir force and radiative heat transfer for a configuration of parallel plates in a nonequilibrium scenario, relating to Lifshitz's and Landauer's formulas. From a first-principles canonical quantization scheme for the study of the matter-field interaction, we give closed-form expressions for the nonequilibrium Casimir force and the heat transfer between plates of thicknesses dL,dR . We distinguish three different contributions to the Casimir force and the heat transfer in the general nonequilibrium situation: two associated with each of the plates and one to the initial state of the field. We analyze the dependence of the Casimir force and heat transfer with the plate thickness (setting dL=dR≡d ), showing the scale at which each magnitude converges to the value of infinite thickness (d →+∞ ) and how to correctly reproduce the nonequilibrium Lifshitz's formula. For the heat transfer, we show that Landauer's formula does not apply to every case (where the three contributions are present), but it is correct for some specific situations. We also analyze the interplay of the different contributions for realistic experimental and nanotechnological conditions, showing the impact of the thickness in the measurements. For small thicknesses (compared to the separation distance), the plates act to decrease the background blackbody flux, while for large thicknesses the heat is given by the baths' contribution only. The combination of these behaviors allows for the possibility, on one hand, of having a tunable minimum in the heat transfer that is experimentally attainable and observable for metals and, on the other hand, of having vanishing heat flux in the gap when those difference are of opposite signs (thermal shielding). These features turns out to be relevant for nanotechnological applications.
Markovian master equations for quantum thermal machines: local versus global approach
NASA Astrophysics Data System (ADS)
Hofer, Patrick P.; Perarnau-Llobet, Martí; Miranda, L. David M.; Haack, Géraldine; Silva, Ralph; Bohr Brask, Jonatan; Brunner, Nicolas
2017-12-01
The study of quantum thermal machines, and more generally of open quantum systems, often relies on master equations. Two approaches are mainly followed. On the one hand, there is the widely used, but often criticized, local approach, where machine sub-systems locally couple to thermal baths. On the other hand, in the more established global approach, thermal baths couple to global degrees of freedom of the machine. There has been debate as to which of these two conceptually different approaches should be used in situations out of thermal equilibrium. Here we compare the local and global approaches against an exact solution for a particular class of thermal machines. We consider thermodynamically relevant observables, such as heat currents, as well as the quantum state of the machine. Our results show that the use of a local master equation is generally well justified. In particular, for weak inter-system coupling, the local approach agrees with the exact solution, whereas the global approach fails for non-equilibrium situations. For intermediate coupling, the local and the global approach both agree with the exact solution and for strong coupling, the global approach is preferable. These results are backed by detailed derivations of the regimes of validity for the respective approaches.
Diffusion and Electric Mobility of KCI within Isolated Cuticles of Citrus aurantium 1
Tyree, Melvin T.; Wescott, Charles R.; Tabor, Christopher A.; Morse, Anne D.
1992-01-01
Fick's second law has been used to predict the time course of electrical conductance change in isolated cuticles following the rapid change in bathing solution (KCI) from concentration C to 0.1 C. The theoretical time course is dependent on the coefficient of diffusion of KCI in the cuticle and the cuticle thickness. Experimental results, obtained from cuticles isolated from sour orange (Citrus aurantium), fit with a diffusion model of an isolated cuticle in which about 90% of the conductance change following a solution change is due to salts diffusing from polar pores in the wax, and 10% of the change is due to salt diffusion from the wax. Short and long time constants for the washout of KCI were found to be 0.11 and 3.8 hours, respectively. These time constants correspond to KCI diffusion coefficients of 1 × 10−15 and 3 × 10−17 square meters per second, respectively. The larger coefficient is close to the diffusion coefficient for water in polar pores of Citrus reported elsewhere (M Becker, G Kerstiens, J Schönherr [1986] Trees 1: 54-60). This supports our interpretation of the washout kinetics of KCI following a change in concentration of bathing solution. PMID:16668971
Voltage dependence of acetylcholine receptor channel gating in rat myoballs
1992-01-01
Whole-cell currents from nicotinic acetylcholine receptor (AChR) channels were studied in rat myoballs using a light-activated agonist to determine the voltage dependence of the macroscopic opening and closing rate constants. Myoballs were bathed in a solution containing a low concentration of the inactive isomer of the photoisomerizable azobenzene derivative, cis-Bis-Q. A light flash was then presented to produce a known concentration jump of agonist, trans-Bis-Q, across a wide range of membrane potentials in symmetrical solutions (NaCl or CsCl on both sides) or asymmetrical solutions (NaCl in the bath and CsCl in the pipette). At the low agonist concentration used in this study, the reciprocal of the macroscopic time constants gives an unambiguous measure of the effective closing rate. It showed an exponential decrease with membrane hyperpolarization between +20 and - 100 mV, but tended to level off at more depolarized and at more hyperpolarized membrane potentials. The relative effective opening rate was derived from the steady-state conductance, the single-channel conductance, and the apparent closing rate; it decreased sharply in the depolarizing region and tended to level off and then turn up in the hyperpolarizing region. The two effective rate constants were shown to depend on the first, second, and third power of membrane potential. PMID:1460456
NASA Astrophysics Data System (ADS)
Maraeva, E. V.; Alexandrova, O. A.; Forostyanaya, N. A.; Levitskiy, V. S.; Mazing, D. S.; Maskaeva, L. N.; Markov, V. Ph; Moshnikov, V. A.; Shupta, A. A.; Spivak, Yu M.; Tulenin, S. S.
2015-11-01
In this study lead sulphide - cadmium sulphide based layers were obtained through chemical deposition of water solutions and cadmium sulphide quantum dots were formed through hot-injection technique. The article discusses the results of surface investigations with the use of atomic force microscopy, Raman spectroscopy and photoluminescence measurements.
To explain a carrier frequency dependence reported for radiofrequency (RF)-induced calcium-ion efflux from brain tissue, a chick-brain hemisphere bathed in buffer solution is modeled as a sphere within the uniform field of the incident electromagnetic wave. Calculations on a sphe...
Hierarchic plate and shell models based on p-extension
NASA Technical Reports Server (NTRS)
Szabo, Barna A.; Sahrmann, Glenn J.
1988-01-01
Formulations of finite element models for beams, arches, plates and shells based on the principle of virtual work was studied. The focus is on computer implementation of hierarchic sequences of finite element models suitable for numerical solution of a large variety of practical problems which may concurrently contain thin and thick plates and shells, stiffeners, and regions where three dimensional representation is required. The approximate solutions corresponding to the hierarchic sequence of models converge to the exact solution of the fully three dimensional model. The stopping criterion is based on: (1) estimation of the relative error in energy norm; (2) equilibrium tests, and (3) observation of the convergence of quantities of interest.
Stoner, L C; Kregenow, F M
1980-10-01
We describe a single-cell technique for measuring membrane potential, membrane resistance, and the efflux of rapidly penetrating solutes such as Cl and H2O. Erythrocytes from Amphiuma means were aspirated into a Sylgard (Dow Corning Corp.)-coated capillary. The aspirated cell separated a solution within the capillary from a solution in the bath. Each of these two solutions was contiguous with approximately 5% of the total membrane surface. Microelectrodes placed concentrically within the capillary permit the measurement of intracellular voltage, specific membrane resistance, and the electrical seal between the two solutions. The intracellular voltage averaged -17.7 mV (pH 7.6) and changed as either intra- or extracellular chloride was varied. The average specific membrane resistance measured by passing current across the exposed membrane surface was 110 ohm-cm2. 36Cl and tritiated H2O fluxes (0.84 +/- 0.05 x 10(-6) M . cm-2 . min-1 and 6.4 +/- 1.5 x 10(-3) M . cm-2 . min-1, respectively) were determined by noting the rate at which isotope leaves the cell and crosses the membrane exposed to the bath. Our measured values for the flux of 36Cl and tritiated H2O approximate reported values for free-floating cells. 36Cl efflux, in addition, is inhibited by 4-acetamido-4'-isothiocyano-stilbene 2,2'-disulfonic acid (SITS) and furosemide, known inhibitors of the anion exchange mechanism responsible for the rapid anion fluxes of red blood cells. One can also demonstrate directly that > 89% of 36Cl efflux is "electrically silent" by analyzing the flux in the presence of an imposed transcellular voltage.
NASA Technical Reports Server (NTRS)
Epp, L. W.; Stanton, P. H.
1993-01-01
In order to add the capability of an X-band uplink onto the 70-m antenna, a new dichroic plate is needed to replace the Pyle-guide-shaped dichroic plate currently in use. The replacement dichroic plate must exhibit an additional passband at the new uplink frequency of 7.165 GHz, while still maintaining a passband at the existing downlink frequency of 8.425 GHz. Because of the wide frequency separation of these two passbands, conventional methods of designing air-filled dichroic plates exhibit grating lobe problems. A new method of solving this problem by using a dichroic plate with cross-shaped holes is presented and verified experimentally. Two checks of the integral equation solution are described. One is the comparison to a modal analysis for the limiting cross shape of a square hole. As a final check, a prototype dichroic plate with cross-shaped holes was built and measured.
Vibro-acoustic analysis of composite plates
NASA Astrophysics Data System (ADS)
Sarigül, A. S.; Karagözlü, E.
2014-03-01
Vibro-acoustic analysis plays a vital role on the design of aircrafts, spacecrafts, land vehicles and ships produced from thin plates backed by closed cavities, with regard to human health and living comfort. For this type of structures, it is required a coupled solution that takes into account structural-acoustic interaction which is crucial for sensitive solutions. In this study, coupled vibro-acoustic analyses of plates produced from composite materials have been performed by using finite element analysis software. The study has been carried out for E-glass/Epoxy, Kevlar/Epoxy and Carbon/Epoxy plates with different ply angles and numbers of ply. The effects of composite material, ply orientation and number of layer on coupled vibro-acoustic characteristics of plates have been analysed for various combinations. The analysis results have been statistically examined and assessed.
NASA Astrophysics Data System (ADS)
Malinowski, Zbigniew; Cebo-Rudnicka, Agnieszka; Hadała, Beata; Szajding, Artur; Telejko, Tadeusz
2017-10-01
A cooling rate affects the mechanical properties of steel which strongly depend on microstructure evolution processes. The heat transfer boundary condition for the numerical simulation of steel cooling by water jets can be determined from the local one dimensional or from the three dimensional inverse solutions in space and time. In the present study the inconel plate has been heated to about 900 °C and then cooled by six circular water jets. The plate temperature has been measured by 30 thermocouples. The heat transfer coefficient and the heat flux distributions at the plate surface have been determined in time and space. The one dimensional solutions have given a local error to the heat transfer coefficient of about 35%. The three dimensional inverse solution has allowed reducing the local error to about 20%. The uncertainty test has confirmed that a better approximation of the heat transfer coefficient distribution over the cooled surface can be obtained even for limited number of thermocouples. In such a case it was necessary to constrain the inverse solution with the interpolated temperature sensors.
Fission product ion exchange between zeolite and a molten salt
NASA Astrophysics Data System (ADS)
Gougar, Mary Lou D.
The electrometallurgical treatment of spent nuclear fuel (SNF) has been developed at Argonne National Laboratory (ANL) and has been demonstrated through processing the sodium-bonded SNF from the Experimental Breeder Reactor-II in Idaho. In this process, components of the SNF, including U and species more chemically active than U, are oxidized into a bath of lithium-potassium chloride (LiCl-KCl) eutectic molten salt. Uranium is removed from the salt solution by electrochemical reduction. The noble metals and inactive fission products from the SNF remain as solids and are melted into a metal waste form after removal from the molten salt bath. The remaining salt solution contains most of the fission products and transuranic elements from the SNF. One technique that has been identified for removing these fission products and extending the usable life of the molten salt is ion exchange with zeolite A. A model has been developed and tested for its ability to describe the ion exchange of fission product species between zeolite A and a molten salt bath used for pyroprocessing of spent nuclear fuel. The model assumes (1) a system at equilibrium, (2) immobilization of species from the process salt solution via both ion exchange and occlusion in the zeolite cage structure, and (3) chemical independence of the process salt species. The first assumption simplifies the description of this physical system by eliminating the complications of including time-dependent variables. An equilibrium state between species concentrations in the two exchange phases is a common basis for ion exchange models found in the literature. Assumption two is non-simplifying with respect to the mathematical expression of the model. Two Langmuir-like fractional terms (one for each mode of immobilization) compose each equation describing each salt species. The third assumption offers great simplification over more traditional ion exchange modeling, in which interaction of solvent species with each other is considered. (Abstract shortened by UMI.)
Lubiprostone stimulates small intestinal mucin release
2012-01-01
Background Lubiprostone is a synthetic bicyclic fatty acid derivative of prostaglandin E1 (PGE1) used for chronic constipation. The best known action of lubiprostone is simulation of Cl- dependent fluid secretion. In a mouse model of the genetic disease cystic fibrosis, we previously showed that in vivo administration of lubiprostone resulted in greater mucus accumulation in the small intestine. The aim of this study was to directly test whether lubiprostone stimulates intestinal mucin release. Methods Mucin release was measured by mounting segments (4-5 cm) of mouse proximal-mid small intestine in an organ bath, allowing access to the perfusate (luminal) and the bath (serosal) solutions. Nifedipine (10-6 M) and indomethacin (10-5 M) were included in all solutions to inhibit smooth muscle activity and endogenous prostaglandin production, respectively. The tissue was equilibrated under flow for 30 min, using the perfusate collected during the final 10 min of the equilibration period to measure unstimulated release rate. Stimulus was then added to either the perfusate or the bath and the perfusate was collected for another 30 min to measure the stimulated mucin release rate. Mucin in perfusates was quantified by periodic acid-Schiff's base dot-blot assay, using purified pig gastric mucin as a standard. Results When applied luminally at 1 μM lubiprostone was ineffective at stimulating mucin release. When added to the serosal solution, 1 μM lubiprostone stimulated mucin release to ~300% of the unstimulated rate. As a positive control, serosal 1 μM prostaglandin E2 increased mucin release to ~400% of the unstimulated rate. Conclusions These results support the idea that lubiprostone has prostaglandin-like actions on the intestine, which includes stimulation of mucin release. Stimulation of mucin release by lubiprostone may be protective in gastrointestinal conditions where loss of mucus is believed to contribute to pathogenesis. Thus, in addition to chronic constipation, there is greater potential for the therapeutic applications of lubiprostone. PMID:23130661
Lubiprostone stimulates small intestinal mucin release.
De Lisle, Robert C
2012-11-06
Lubiprostone is a synthetic bicyclic fatty acid derivative of prostaglandin E1 (PGE1) used for chronic constipation. The best known action of lubiprostone is simulation of Cl- dependent fluid secretion. In a mouse model of the genetic disease cystic fibrosis, we previously showed that in vivo administration of lubiprostone resulted in greater mucus accumulation in the small intestine. The aim of this study was to directly test whether lubiprostone stimulates intestinal mucin release. Mucin release was measured by mounting segments (4-5 cm) of mouse proximal-mid small intestine in an organ bath, allowing access to the perfusate (luminal) and the bath (serosal) solutions. Nifedipine (10-6 M) and indomethacin (10-5 M) were included in all solutions to inhibit smooth muscle activity and endogenous prostaglandin production, respectively. The tissue was equilibrated under flow for 30 min, using the perfusate collected during the final 10 min of the equilibration period to measure unstimulated release rate. Stimulus was then added to either the perfusate or the bath and the perfusate was collected for another 30 min to measure the stimulated mucin release rate. Mucin in perfusates was quantified by periodic acid-Schiff's base dot-blot assay, using purified pig gastric mucin as a standard. When applied luminally at 1 μM lubiprostone was ineffective at stimulating mucin release. When added to the serosal solution, 1 μM lubiprostone stimulated mucin release to ~300% of the unstimulated rate. As a positive control, serosal 1 μM prostaglandin E2 increased mucin release to ~400% of the unstimulated rate. These results support the idea that lubiprostone has prostaglandin-like actions on the intestine, which includes stimulation of mucin release. Stimulation of mucin release by lubiprostone may be protective in gastrointestinal conditions where loss of mucus is believed to contribute to pathogenesis. Thus, in addition to chronic constipation, there is greater potential for the therapeutic applications of lubiprostone.
Adami, Chiara; d'Ovidio, Dario; Casoni, Daniela
2016-05-01
To determine a dexmedetomidine concentration, to be added to an alfaxalone-based bath solution, that will enhance the anaesthetic and analgesic effects of alfaxalone; and to compare the quality of anaesthesia and analgesia provided by immersion with either alfaxalone alone or alfaxalone with dexmedetomidine in oriental fire-bellied toads (Bombina orientalis). Pilot study followed by a prospective, randomized, experimental trial. Fourteen oriental fire-bellied toads. The pilot study aimed to identify a useful dexmedetomidine concentration to be added to an anaesthetic bath containing 20 mg 100 mL(-1) alfaxalone. Thereafter, the toads were assigned to one of two groups, each comprising eight animals, to be administered either alfaxalone (group A) or alfaxalone-dexmedetomidine (group AD). After immersion for 20 minutes, the toads were removed from the anaesthetic bath and the righting, myotactic and nociceptive reflexes, cardiopulmonary variables and von Frey filaments threshold were measured at 5 minute intervals and compared statistically between groups. Side effects and complications were noted and recorded. In the pilot study, a dexmedetomidine concentration of 0.3 mg 100 mL(-1) added to the alfaxalone-based solution resulted in surgical anaesthesia. The toads in group AD showed higher von Frey thresholds and lower nociceptive withdrawal reflex scores than those in group A. However, in group AD, surgical anaesthesia was observed in two out of eight toads only, and induction of anaesthesia was achieved in only 50% of the animals, as compared with 100% of the toads in group A. The addition of dexmedetomidine to an alfaxalone-based solution for immersion anaesthesia provided some analgesia in oriental fire-bellied toads, but failed to potentiate the level of unconsciousness and appeared to lighten the depth of anaesthesia. This limitation renders the combination unsuitable for anaesthetizing oriental fire-bellied toads for invasive procedures. © 2015 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.
Shao, Qing; White, Andrew D; Jiang, Shaoyi
2014-01-09
Polycarboxybetaine and poly(ethylene glycol) materials resist nonspecific protein adsorption but differ in influencing biological functions such as enzymatic activity. To investigate this difference, we studied the influence of carboxybetaine and oligo(ethylene glycol) moieties on hydrophobic interactions using molecular simulations. We employed a model system composed of two non-polar plates and studied the potential of mean force of plate-plate association in carboxybetaine, (ethylene glycol)4, and (ethylene glycol)2 solutions using well-tempered metadynamics simulations. Water, trimethylamine N-oxide, and urea solutions were used as reference systems. We analyzed the variation of the potential of mean force in various solutions to study how carboxybetaine and oligo(ethylene glycol) moieties influence the hydrophobic interactions. To study the origin of their influence, we analyzed the normalized distributions of moieties and water molecules using molecular dynamics simulations. The simulation results showed that oligo(ethylene glycol) moieties repel water molecules away from the non-polar plates and weaken the hydrophobic interactions. Carboxybetaine moieties do not repel water molecules away from the plates and therefore do not influence the hydrophobic interactions.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Haining; Li, Weiping; Liu, Huicong
2010-07-15
A suitable deposition method of CdS is necessary for the high performance CdS-sensitized ZnO electrodes. In this paper, chemical bath deposition (CBD) and sequential chemical bath deposition (S-CBD) methods were used to deposit CdS on ZnO mesoporous films for ZnO/CdS electrodes. The analysis results of XRD patterns and UV-vis spectroscopy indicated that CBD deposition method leaded to the dissolving of ZnO mesoporous films in deposition solution and thickness reduction of ZnO/CdS electrodes. Absorption in visible region by the ZnO/CdS electrodes with CdS deposition by S-CBD was enhanced as deposition cycles increased due to the stability of ZnO mesoporous films inmore » the S-CBD deposition solutions. The results of photocurrent-voltage (I-V) measurement showed that the performance of ZnO/CdS electrodes with CdS deposition by CBD first increased and then decreased as deposition time increased, and the greatest short-circuit current (J{sub sc}) was obtained at the deposition time of 4 min. The performance of ZnO/CdS electrodes with CdS deposition by S-CBD increased as deposition cycles increased, and both open-circuit voltage (V{sub oc}) and J{sub sc} were greater than those electrodes with CdS deposition by CBD when the deposition cycles of S-CBD were 10 or greater. These results indicated that S-CBD is a more suitable method for high performance ZnO/CdS electrodes. (author)« less
Target and method for the production of fission product molybdenum-99
Vandegrift, George F.; Vissers, Donald R.; Marshall, Simon L.; Varma, Ravi
1989-01-01
A target for the reduction of fission product Mo-99 is prepared from uranium of low U-235 enrichment by coating a structural support member with a preparatory coating of a substantially oxide-free substrate metal. Uranium metal is electrodeposited from a molten halide electrolytic bath onto a substrate metal. The electrodeposition is performed at a predetermined direct current rate or by using pulsed plating techniques which permit relaxation of accumulated uranium ion concentrations within the melt. Layers of as much as to 600 mg/cm.sup.2 of uranium can be prepared to provide a sufficient density to produce acceptable concentrations of fission product Mo-99.
Weinreich, Wenke; Acker, Jörg; Gräber, Iris
2007-03-30
In the photovoltaic industry the etching of silicon in HF/HNO(3) solutions is a decisive process for cleaning wafer surfaces or to produce certain surface morphologies like polishing or texturization. With regard to cost efficiency, a maximal utilisation of etch baths in combination with highest quality and accuracy is strived. To provide an etch bath control realised by a replenishment with concentrated acids the main constituents of these HF/HNO(3) etch solutions including the reaction product H(2)SiF(6) have to be analysed. Two new methods for the determination of the total fluoride content in an acidic etch solution based on the precipitation titration with La(NO(3))(3) are presented within this paper. The first method bases on the proper choice of the reaction conditions, since free fluoride ions have to be liberated from HF and H(2)SiF(6) at the same time to be detected by a fluoride ion-selective electrode (F-ISE). Therefore, the sample is adjusted to a pH of 8 for total cleavage of the SiF(6)(2-) anion and titrated in absence of buffers. In a second method, the titration with La(NO(3))(3) is followed by a change of the pH-value using a HF resistant glass-electrode. Both methods provide consistent values, whereas the analysis is fast and accurate, and thus, applicable for industrial process control.
A review on methods of recovery of acid(s) from spent pickle liquor of steel industry.
Ghare, N Y; Wani, K S; Patil, V S
2013-04-01
Pickling is the process of removal of oxide layer and rust formed on metal surface. It also removes sand and corrosion products from the surface of metal. Acids such as sulfuric acid, hydrochloric acid are used for pickling. Hydrofluoric acid-Nitric acid mixture is used for stainless steel pickling. Pickling solutions are spent when acid concentration in pickling solutions decreases by 75-85%, which also has metal content up to 150-250 g/ dm3. Spent pickling liquor (SPL) should be dumped because the efficiency of pickling decreases with increasing content of dissolved metal in the bath. The SPL content depends on the plant of origin and the pickling method applied there. SPL from steel pickling in hot-dip galvanizing plants contains zinc(II), iron, traces of lead, chromium. and other heavy metals (max. 500 mg/dm3) and hydrochloric acid. Zinc(II) passes tothe spent solution after dissolution of this metal from zinc(II)-covered racks, chains and baskets used for transportation of galvanized elements. Unevenly covered zinc layers are usually removed in another pickling bath. Due to this, zinc(II) concentration increases even up to 110 g/dm3, while iron content may reach or exceed even 80 g/dm3 in the same solution. This review presents an overview on different aspects of generation and treatment of SPL with recourse to recovery of acid for recycling. Different processes are described in this review and higher weightage is given to membrane processes.
Surface crack problems in plates
NASA Technical Reports Server (NTRS)
Joseph, P. F.; Erdogan, F.
1989-01-01
The mode I crack problem in plates under membrane loading and bending is reconsidered. The purpose is to examine certain analytical features of the problem further and to provide some new results. The formulation and the results given by the classical and the Reissner plate theories for through and part-through cracks are compared. For surface cracks the three-dimensional finite element solution is used as the basis of comparison. The solution is obtained and results are given for the crack/contact problem in a plate with a through crack under pure bending and for the crack interaction problem. Also, a procedure is developed to treat the problem of subcritical crack growth and to trace the evolution of the propagating crack.
Quick-Change Anode for Plating
NASA Technical Reports Server (NTRS)
Beasley, J. L.
1987-01-01
Proposed fastener for attaching electroplating anode improves quality of plating and increases productivity. Notches in twist-lock fastener mates with projections on end of anode bar. Fastener made of titanium for compatibility with copper-plating solution. Also constructed in snap-on, snap-off configuration.
Microbial contamination in intraoral phosphor storage plates: the dilemma.
de Souza, Tricia Murielly Pereira Andrade; de Castro, Ricardo Dias; de Vasconcelos, Laís César; Pontual, Andréa Dos Anjos; de Moraes Ramos Perez, Flávia Maria; Pontual, Maria Luiza Dos Anjos
2017-01-01
The aims of this study were to evaluate microbial contamination in phosphor storage plates in dental radiology services and discuss the possible origin of this contamination. The sample comprised 50 phosphor plates: 14 plates from service A, 30 from service B, and 6 in the control group, consisting of plates never used. Damp sterile swabs were rubbed on the phosphor plates, and then transferred to tests tubes containing sterile saline solution. Serial dilutions were made, and then inoculated in triplicate on Mueller Hinton agar plates and incubated at 37 °C/48 h, before counting the colony-forming units (CFU). The samples were also seeded in brain-heart infusion medium to confirm contamination by turbidity of the culture medium. All solutions, turbid and clean, were seeded in selective and non-selective media. At service A and B, 50 and 73.3 % of the phosphor plates were contaminated, respectively. This contamination was mainly due to bacteria of the genus Staphylococcus. CFU counts ranged from 26.4 to 80.0 CFU/plate. Most of the phosphor plates evaluated shown to be contaminated, mainly by Staphylococcus ssp. Quantitatively, this contamination occurred at low levels, possibly arising from handling of the plates. The use of a second plastic barrier may have diminished contamination by microorganisms from the oral cavity. There is a risk of cross-contamination by phosphor storage plates used in dental radiology services.
Armenta, Roberto E; Burja, Adam; Radianingtyas, Helia; Barrow, Colin J
2006-12-27
A variety of techniques for extracting carotenoids from the marine Thraustochytrium sp. ONC-T18 was compared. Specifically, the organic solvents acetone, ethyl acetate, and petroleum ether were tested, along with direct and indirect ultrasonic assisted extraction (probe vs bath) methods. Techniques that used petroleum ether/acetone/water (15:75:10, v/v/v) with 3 h of agitation, or 5 min in an ultrasonic bath, produced the highest extraction yields of total carotenoids (29-30.5 microg g-1). Concentrations up to 11.5 microg g-1 of canthaxanthin and 17.5 microg g-1 of beta;-carotene were detected in extracts stored for 6 weeks. Astaxanthin and echinenone were also detected as minor compounds. Extracts with and without antioxidants showed similar carotenoid concentration profiles. However, total carotenoid concentrations were approximately 8% higher when antioxidants were used. Finally, an easy-to-perform and inexpensive method to detect co-enzymes in ONC-T18 was also developed using silica gel TLC plates. Five percent methanol in toluene as a mobile phase consistently eluted co-enzyme Q10 standards and could separate the co-enzyme fractions present in ONC-T18.
Surface roughness of denture bases after immersion in fishcake vinegar solution
NASA Astrophysics Data System (ADS)
Kodir, K.; Tanti, I.; Odang, R. W.
2017-08-01
Fishcake is a common food in Palembang city and is usually eaten with fishcake vinegar sauce. Fishcake vinegar solution contains acetic acid and chloride and fluoride ions, all of which cause surface roughness on the denture base material. The objective of this study was to analyze the effect of fishcake vinegar solution on the surface roughness of heat-cured acrylic resin, thermoplastic nylon, and cobalt-chromium alloy denture bases. This laboratory-based experimental study was performed on heat-cured acrylic resins, thermoplastic nylon specimen plates formed in 15 × 10 × 1 mm shapes, and cobalt-chromium alloy specimens in cylinder forms with a 7.7 mm diameter and 17.5-mm height. Each group consisted of 10 pieces. Each specimen was immersed in a fishcake vinegar solution at 37 °C for 4 days. The surface roughness was measured using a profilometer before and after immersion. Statistical analyses showed significant (p < 0.05) changes in heat-cured acrylic resin, thermoplastic nylon, and the cobalt chromium alloy plates after immersion in a fishcake vinegar solution for 4 days. Fishcake vinegar solution affects the surface roughness of heat-cured acrylic resin, thermoplastic nylon, and cobalt-chromium alloy plates after a 4-day immersion period. The greatest surface roughness change occurred in the thermoplastic nylon plate, while the lowest change occurred in the cobalt-chromium alloy.
Hydrofluosilicic acid as a cap and can etchant
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dixon, D.S.
1953-03-17
Aluminum caps and cans are thoroughly cleaned, before being used to can slugs, to insure wetting of the metal surfaces by molten AlSi in the canning pot. An acid bath is used, as part of the cleaning operations to remove surface oxide and other surface films from the metal. Two acid solutions are authorized in the standard operating procedure; a 20% phosphoric acid solution for etching both caps and cans, and a 1% hydrofluosilicic acid solution to be used for caps only. It is desired to determine the feasibility of using hydrofluosilicic acid exclusively as an etchant for both capsmore » and cans.« less
A mixed shear flexible finite element for the analysis of laminated plates
NASA Technical Reports Server (NTRS)
Putcha, N. S.; Reddy, J. N.
1984-01-01
A mixed shear flexible finite element based on the Hencky-Mindlin type shear deformation theory of laminated plates is presented and their behavior in bending is investigated. The element consists of three displacements, two rotations, and three moments as the generalized degrees of freedom per node. The numerical convergence and accuracy characteristics of the element are investigated by comparing the finite element solutions with the exact solutions. The present study shows that reduced-order integration of the stiffness coefficients due to shear is necessary to obtain accurate results for thin plates.
Lagrangian analysis of the laminar flat plate boundary layer
NASA Astrophysics Data System (ADS)
Gabr, Mohammad
2016-10-01
The flow properties at the leading edge of a flat plate represent a singularity to the Blasius laminar boundary layer equations; by applying the Lagrangian approach, the leading edge velocity profiles of the laminar boundary layer over a flat plate are studied. Experimental observations as well as the theoretical analysis show an exact Gaussian distribution curve as the original starting profile of the laminar flow. Comparisons between the Blasius solution and the Gaussian curve solution are carried out providing a new insight into the physics of the laminar flow.
Core-coat conductor of lipid bilayer and micromachined silicon.
Fromherz, P; Klingler, J
1991-02-11
We have etched a groove into a (110) plane of silicon and have covered it with a bilayer of glycerol monooleate. We have varied the depth of the groove, the concentration of salt in the electrolyte and the density of gramicidin in the membrane. We have clamped one end of the groove at a constant voltage with respect to the bath keeping the other end sealed or electrically open with respect to the bath. We have measured (i) the voltage at the center of the groove and at the sealed distal end and (ii) the current through the system in sealed and open configuration. We have found that the spread of voltage is in quantitative agreement with the stationary solutions of Kelvin's equation for a homogeneous cable.
Theoretical analysis of a ceramic plate thickness-shear mode piezoelectric transformer.
Xu, Limei; Zhang, Ying; Fan, Hui; Hu, Junhui; Yang, Jiashi
2009-03-01
We perform a theoretical analysis on a ceramic plate piezoelectric transformer operating with thickness-shear modes. Mindlin's first-order theory of piezoelectric plates is employed, and a forced vibration solution is obtained. Transforming ratio, resonant frequencies, and vibration mode shapes are calculated, and the effects of plate thickness and electrode dimension are examined.
A Linear Theory for Inflatable Plates of Arbitrary Shape
NASA Technical Reports Server (NTRS)
McComb, Harvey G., Jr.
1961-01-01
A linear small-deflection theory is developed for the elastic behavior of inflatable plates of which Airmat is an example. Included in the theory are the effects of a small linear taper in the depth of the plate. Solutions are presented for some simple problems in the lateral deflection and vibration of constant-depth rectangular inflatable plates.
Numerical solution of acoustic scattering by finite perforated elastic plates
2016-01-01
We present a numerical method to compute the acoustic field scattered by finite perforated elastic plates. A boundary element method is developed to solve the Helmholtz equation subjected to boundary conditions related to the plate vibration. These boundary conditions are recast in terms of the vibration modes of the plate and its porosity, which enables a direct solution procedure. A parametric study is performed for a two-dimensional problem whereby a cantilevered perforated elastic plate scatters sound from a point quadrupole near the free edge. Both elasticity and porosity tend to diminish the scattered sound, in agreement with previous work considering semi-infinite plates. Finite elastic plates are shown to reduce acoustic scattering when excited at high Helmholtz numbers k0 based on the plate length. However, at low k0, finite elastic plates produce only modest reductions or, in cases related to structural resonance, an increase to the scattered sound level relative to the rigid case. Porosity, on the other hand, is shown to be more effective in reducing the radiated sound for low k0. The combined beneficial effects of elasticity and porosity are shown to be effective in reducing the scattered sound for a broader range of k0 for perforated elastic plates. PMID:27274685
Numerical solution of acoustic scattering by finite perforated elastic plates.
Cavalieri, A V G; Wolf, W R; Jaworski, J W
2016-04-01
We present a numerical method to compute the acoustic field scattered by finite perforated elastic plates. A boundary element method is developed to solve the Helmholtz equation subjected to boundary conditions related to the plate vibration. These boundary conditions are recast in terms of the vibration modes of the plate and its porosity, which enables a direct solution procedure. A parametric study is performed for a two-dimensional problem whereby a cantilevered perforated elastic plate scatters sound from a point quadrupole near the free edge. Both elasticity and porosity tend to diminish the scattered sound, in agreement with previous work considering semi-infinite plates. Finite elastic plates are shown to reduce acoustic scattering when excited at high Helmholtz numbers k 0 based on the plate length. However, at low k 0 , finite elastic plates produce only modest reductions or, in cases related to structural resonance, an increase to the scattered sound level relative to the rigid case. Porosity, on the other hand, is shown to be more effective in reducing the radiated sound for low k 0 . The combined beneficial effects of elasticity and porosity are shown to be effective in reducing the scattered sound for a broader range of k 0 for perforated elastic plates.
NASA Technical Reports Server (NTRS)
Taylor, W.
1982-01-01
Printed nickel overplated with copper and applied on top of a predeposited silicon nitride antireflective coating system for metallizing solar cells was analyzed. The ESL D and E paste formulations, and the new formulations F, G, H, and D-1 were evaluated. The nickel thick films were tested after firing for stability in the cleaning and plating solutions used in the Vanguard-Pacific brush plating process. It was found that the films are very sensitive to the leaning and alkaline copper solutions. Less sensitivity was displayed to the neutral copper solution. Microscopic and SEM observations show segregation of frit at the silicon nitride thick film interface with loose frit residues after lifting off plated grid lines.
NASA Astrophysics Data System (ADS)
Wang, Qiang; Gosselin, Louis; Fafard, Mario; Peng, Jianping; Li, Baokuan
2016-04-01
In order to understand the impact of anode change on heat transfer and magnetohydrodynamic flow in aluminum smelting cells, a transient three-dimensional (3D) coupled mathematical model has been developed. The solutions of the mass, momentum, and energy conservation equations were simultaneously implemented by the finite volume method with full coupling of the Joule heating and Lorentz force through solving the electrical potential equation. The volume of fluid approach was employed to describe the two-phase flow. The phase change of molten electrolyte (bath) as well as molten aluminum (metal) was modeled by an enthalpy-based technique, where the mushy zone is treated as a porous medium with a porosity equal to the liquid fraction. The effect of the new anode temperature on recovery time was also analyzed. A reasonable agreement between the test data and simulated results is obtained. The results indicate that the temperature of the bath under cold anodes first decreases reaching the minimal value and rises under the effect of increasing Joule heating, and finally returns to steady state. The colder bath decays the velocity, and the around ledge becomes thicker. The lowest temperature of the bath below new anodes increases from 1118 K to 1143 K (845 °C to 870 °C) with the new anode temperature ranging from 298 K to 498 K (25°C to 225°C), and the recovery time reduces from 22.5 to 20 hours.
Comparison of the susceptibility of four rainbow trout strains to cold-water disease.
Wagner, Eric J; Oplinger, Randall W
2014-09-01
Abstract Susceptibility to cold-water disease was compared among four strains of Rainbow Trout Oncorhynchus mykiss: Arlee strain from Ennis National Fish Hatchery, Montana (AL-EN), the Arlee strain from Jocko River Hatchery, Montana (AL-JR), a cold-water disease-resistant strain (WV), and the Harrison-Hofer strain (HH). Bacterial challenges were either by bath or intraperitoneal injection (50 μL of 0.65 optical density). Each strain was exposed at 75 d after hatch to either the CSF 259-93 (Idaho) or 09-104 isolate (Utah) of Flavobacterium psychrophilum. Injection controls received a phosphate-buffered saline (PBS) solution and bath controls were exposed to uninoculated sterile broth (tryptone yeast extract salts) mixed 1:1 with hatchery well water. For injected fish, the WV had significantly lower mortality (20.0-36.7%) than HH and AL-EN (76.7-96.7%) but did not significantly differ from AL-JR (46.7-56.7%). Injected fish had significantly higher mortality than bath-exposed fish. For bath-exposed fish, the WV had significantly lower mortality (0%) than the HH (10.0-26.7%), but both Arlee strains had intermediate mortality values (0-13.3%) that did not significantly differ from either the HH or WV strain. There were no significant differences between the two bacterial isolates, indicating similar virulence and similar resistance response of WV to another novel isolate of F. psychrophilum. Received November 5, 2013; accepted April 15, 2014.
NASA Astrophysics Data System (ADS)
Chakraborty, Ahana; Sensarma, Rajdeep
2018-03-01
The Born-Markov approximation is widely used to study the dynamics of open quantum systems coupled to external baths. Using Keldysh formalism, we show that the dynamics of a system of bosons (fermions) linearly coupled to a noninteracting bosonic (fermionic) bath falls outside this paradigm if the bath spectral function has nonanalyticities as a function of frequency. In this case, we show that the dissipative and noise kernels governing the dynamics have distinct power-law tails. The Green's functions show a short-time "quasi"-Markovian exponential decay before crossing over to a power-law tail governed by the nonanalyticity of the spectral function. We study a system of bosons (fermions) hopping on a one-dimensional lattice, where each site is coupled linearly to an independent bath of noninteracting bosons (fermions). We obtain exact expressions for the Green's functions of this system, which show power-law decay ˜|t - t'|-3 /2 . We use these to calculate the density and current profile, as well as unequal-time current-current correlators. While the density and current profiles show interesting quantitative deviations from Markovian results, the current-current correlators show qualitatively distinct long-time power-law tails |t - t'|-3 characteristic of non-Markovian dynamics. We show that the power-law decays survive in the presence of interparticle interaction in the system, but the crossover time scale is shifted to larger values with increasing interaction strength.
A Calorimetric Investigation of Deuterated Palladium Electrodes
1991-05-01
cells comprised either a Pd cathode in a solution of lithium hydroxide (LiOH) in water (H20) or a Pt cathode in a solution of LiOD in D2 0. 1...measuring cells mounted to TED, which in turn are mounted to a large aluminum block. This unit is then submerged in a constant- temperature water bath...Vcell - Vtn) X I, where Vtn is the thermal neutral potential of water Vtn = 1.53 V for D2 0 (1) Vtn = 1.48 V for H2 0. (2) The heat power output
Continuous production of polymethylpentene membranes
Epperson, B.J.; Burnett, L.J.; Helm, V.D.
1983-11-15
Gas separation membranes may be prepared in a continuous manner by passing a porous support which may, if so desired, be backed by a fabric through a solution of polymethylpentene dissolved in an organic solvent such as hexane. The support member is passed through the solution while one side thereof is in contact with a roller, thereby permitting only one side of the support member to be coated with the polymer. After continuously withdrawing the support member from the bath, the solvent is allowed to evaporate and the resulting membrane is recovered.
2008-04-01
conditioned fresh air. The mice were on a 12-hr light/dark full-spectrum lighting cycle . AChE +/+ and AChE -/- mice were 58.7 ± 2.9 and 51.6 ± 3.2 days old...diaphragms were excised and pinned at resting length in Sylgard (Dow Chemical Co., Midland, MI) coated dishes containing oxygenated Krebs -Ringer solution of...measurements Hemidiaphragms with attached phrenic nerves were mounted in tissue baths at 37o C and immersed in an oxygenated Krebs -Ringer solution. To
Morphology selection for cupric oxide thin films by electrodeposition.
Dhanasekaran, V; Mahalingam, T; Chandramohan, R
2011-10-01
Polycrystalline cupric oxide thin films were deposited using alkaline solution bath employing cathodic electrodeposition method. The thin films were electrodeposited at various solution pH. The surface morphology and elemental analyzes of the films were studied using scanning electron microscopy (SEM) and energy dispersive X-ray analysis, respectively. SEM studies revealed that the surface morphology could be tailored suitably by adjusting the pH value during deposition. Mesh average on multiple lattice mode atomic force microscopy image was obtained and reported. Copyright © 2011 Wiley-Liss, Inc.
NASA Astrophysics Data System (ADS)
Zhou, Hai-An; Wang, Xiao-Ming; Mei, Yu-Lin
2014-10-01
The vibro-acoustic responses and sound absorption characteristics of two kinds of periodically stiffened micro-perforated plates are analyzed theoretically. The connected periodical structures of the stiffened plates can be ribs or block-like structures. Based on fundamental acoustic formulas of the micro-perforated plate of Maa and Takahashi, semi-analytical models of the vibrating stiffened plates are developed in this paper. Approaches like the space harmonicmethod, Fourier transforms and finite elementmethod (FEM) are adopted to investigate both kinds of the stiffened plates. In the present work, the vibro-acoustic responses of micro-perforated stiffened plates in the wavenumber space are expressed as functions of plate displacement amplitudes. After approximate numerical solutions of the amplitudes, the vibration equations and sound absorption coefficients of the two kinds of stiffened plates in the physical space are then derived by employing the Fourier inverse transform. In numerical examples, the effects of some physical parameters, such as the perforation ratio, incident angles and periodical distances etc., on the sound absorption performance are examined. The proposed approaches are also validated by comparing the present results with solutions of Takahashi and previous studies of stiffened plates. Numerical results indicate that the flexural vibration of the plate has a significant effect on the sound absorption coefficient in the water but has little influence in the air.
Method of making a light weight battery plaque
NASA Technical Reports Server (NTRS)
Reid, M. A.; Post, R. E.; Soltis, D. G. (Inventor)
1984-01-01
A nickel plaque which may be coated with a suitable metal or compound to make an electrode for a fuel cell or battery is fabricated by directing nickel sensitizer, catalyst and plating solutions through a porous plastic substrate in the order named and at prescribed temperatures and flow rates. A boride compound dissolved in the plating solution decreases the electrical resistance of the plaque. Certain substrates may require treatment in an alkali solution to dissolve filler materials thereby increasing porosity to a required 65%.
A model for the motion of the Philippine Sea plate consistent with NUVEL-1 and geological data
NASA Technical Reports Server (NTRS)
Seno, Tetsuzo; Stein, Seth; Gripp, Alice E.
1993-01-01
We investigate angular velocity vectors of the Philippine Sea (PH) plate relative to the adjacent major plates, Eurasia (EU) and Pacific (PA), and the smaller Caroline (CR) plate. Earthquake slip vector data along the Philippine Sea plate are inverted, subject to the constraint that EU-PA motion equals that predicted by the global relative plate model NUVEL-1. The resulting solution fails to satisfy geological constraints along the Caroline-Pacific boundary: convergence along the Mussau Trench and divergence along the Sorol Trough. We then seek solutions satisfying both the CR-PA boundary conditions and the Philippine Sea slip vector data, by adjusting the PA-PH and EU-PH best fitting poles within their error ellipses. We also consider northern Honshu to be part of the North American plate and impose the constraint that the Philippine Sea plate subducts beneath northern Honshu along the Sagmi Trough in a NNW-NW direction. Of the solutions satisfying these conditions, we select the best EU-PH as 48.2 deg N, 157.0 deg E, 1.09 deg/my, corresponding to a pole far from Japan and south of Kamchatka, and PA-PH, 1.2 deg N, 134.2 deg E, 1.00 deg/my. Predicted NA-PH and EU-PH convergence rates in central Honshu are consistent with estimated seismic slip rates. Previous estimates of the EU-PH pole close to central Honshu are inconsistent with extension within the Bonin backarc implied by earthquake slip vectors and NNW-NW convergence of the Bonin forearc at the Sagami Trough.
Ali, Farhad; Khan, Ilyas; Shafie, Sharidan
2014-01-01
Closed form solutions for unsteady free convection flows of a second grade fluid near an isothermal vertical plate oscillating in its plane using the Laplace transform technique are established. Expressions for velocity and temperature are obtained and displayed graphically for different values of Prandtl number Pr, thermal Grashof number Gr, viscoelastic parameter α, phase angle ωτ and time τ. Numerical values of skin friction τ 0 and Nusselt number Nu are shown in tables. Some well-known solutions in literature are reduced as the limiting cases of the present solutions. PMID:24551033
Gaussian step-pressure loading of rigid viscoplastic plates. Ph.D. Thesis
NASA Technical Reports Server (NTRS)
Hayduk, R. J.; Durling, B. J.
1978-01-01
The response of a thin, rigid viscoplastic plate subjected to a spatially axisymmetric Gaussian step pressure impulse loading was studied analytically. A Gaussian pressure distribution in excess of the collapse load was applied to the plate, held constant for a length of time, and then suddenly removed. The plate deforms with monotonically increasing deflections until the dynamic energy is completely dissipated in plastic work. The simply supported plate of uniform thickness obeys the von Mises yield criterion and a generalized constitutive equation for rigid viscoplastic materials. For the small deflection bending response of the plate, the governing system of equations is essentially nonlinear. Transverse shear stress is neglected in the yield condition and rotary inertia in the equations of dynamic equilibrium. A proportional loading technique, known to give excellent approximations of the exact solution for the uniform load case, was used to linearize the problem and to obtain the analytical solutions in the form of eigenvalue expansions. The effects of load concentration, of an order of magnitude change in the viscosity of the plate material, and of load duration were examined while holding the total impulse constant.
Dynamic behaviour of thin composite plates for different boundary conditions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sprintu, Iuliana, E-mail: sprintui@yahoo.com, E-mail: rotaruconstantin@yahoo.com; Rotaru, Constantin, E-mail: sprintui@yahoo.com, E-mail: rotaruconstantin@yahoo.com
2014-12-10
In the context of composite materials technology, which is increasingly present in industry, this article covers a topic of great interest and theoretical and practical importance. Given the complex design of fiber-reinforced materials and their heterogeneous nature, mathematical modeling of the mechanical response under different external stresses is very difficult to address in the absence of simplifying assumptions. In most structural applications, composite structures can be idealized as beams, plates, or shells. The analysis is reduced from a three-dimensional elasticity problem to a oneor two-dimensional problem, based on certain simplifying assumptions that can be made because the structure is thin.more » This paper aims to validate a mathematical model illustrating how thin rectangular orthotropic plates respond to the actual load. Thus, from the theory of thin plates, new analytical solutions are proposed corresponding to orthotropic rectangular plates having different boundary conditions. The proposed analytical solutions are considered both for solving equation orthotropic rectangular plates and for modal analysis.« less
NASA Astrophysics Data System (ADS)
Zheng, Mingfang; He, Cunfu; Lu, Yan; Wu, Bin
2018-01-01
We presented a numerical method to solve phase dispersion curve in general anisotropic plates. This approach involves an exact solution to the problem in the form of the Legendre polynomial of multiple integrals, which we substituted into the state-vector formalism. In order to improve the efficiency of the proposed method, we made a special effort to demonstrate the analytical methodology. Furthermore, we analyzed the algebraic symmetries of the matrices in the state-vector formalism for anisotropic plates. The basic feature of the proposed method was the expansion of field quantities by Legendre polynomials. The Legendre polynomial method avoid to solve the transcendental dispersion equation, which can only be solved numerically. This state-vector formalism combined with Legendre polynomial expansion distinguished the adjacent dispersion mode clearly, even when the modes were very close. We then illustrated the theoretical solutions of the dispersion curves by this method for isotropic and anisotropic plates. Finally, we compared the proposed method with the global matrix method (GMM), which shows excellent agreement.
A note on the cracked plates reinforced by a line stiffener
NASA Technical Reports Server (NTRS)
Yahsi, O. S.; Erdogan, F.
1983-01-01
The problem of a cracked plate reinforced by a line stiffener is reconsidered. The original solution of this problem was given in the literature. Also, a variation of the problem with debonding between the plate and the stiffener near the cracked region was reported in the literature. However, the special case of the problem in which the crack tip terminates at the stiffener does not appear to have been studied. In practice, the solution may be necessary in order to assess the crack arrest effectiveness of the stiffener. The problem of a stiffened plate with a crack is reformulated, the asymptotic stress state near the crack tip terminating at the stiffener is examined, and numerical results are given for various stiffness constants.
NASA Technical Reports Server (NTRS)
Hyer, M. W.; Klang, E. C.; Cooper, D. E.
1987-01-01
The effects of pin elasticity, clearance, and friction on the stresses in a pin loaded orthotropic plate are studied. The effects are studied by posing the problem as a planar contact elasticity problem, the pin and the plate being two elastic bodies which interact through contact. Coulomb friction is assumed, the pin loads the plate in one of its principal material directions, and the plate is infinite in extent. A collocation scheme and interaction, in conjunction with a complex variable series solution, are used to obtain numerical results. The contact region between the plate and pin is unknown and must be solved for as part of the solution. The same is true of the region of friction induced no slip. Two pin stiffnesses, two clearance levels, two friction levels and two laminates, a (0/+ or - 45/90)s and a (02/+ or - 45)s, are studied. The effects of pin elasticity, clearance, and friction on the load capacity of the plate are assessed by comparing the load capacity of the plate with the capacity when the pin is rigid, perfectly fitting, and frictionless.
Analytical Solution for the Aeroelastic Response of a Two-Dimensional Elastic Plate in Axial Flow
NASA Astrophysics Data System (ADS)
Medina, Cory; Kang, Chang-Kwon
2017-11-01
The aeroelastic response of an elastic plate in an unsteady flow describes many engineering problems from bio-locomotion, deforming airfoils, to energy harvesting. However, the analysis is challenging because the shape of the plate is a priori unknown. This study presents an analytical model that can predict the two-way tightly coupled aeroelastic response of a two-dimensional elastic plate including the effects of plate curvature along the flow direction. The plate deforms due to the dynamic balance of wing inertia, elastic restoring force, and aerodynamic force. The coupled model utilizes the linearized Euler-Bernoulli beam theory for the structural model and thin airfoil theory as presented by Theodorsen, which assumes incompressible potential flow, for the aerodynamic model. The coupled equations of motion are solved via Galerkin's method, where closed form solutions for the plate deformation are obtained by deriving the unsteady aerodynamic pressure with respect to the plate normal functions, expressed in a Chebyshev polynomial expansion. Stability analysis is performed for a range of mass ratios obtaining the flutter velocities and corresponding frequencies and the results agree well with the results reported in the literature.
Weakly nonlinear behavior of a plate thickness-mode piezoelectric transformer.
Yang, Jiashi; Chen, Ziguang; Hu, Yuantai; Jiang, Shunong; Guo, Shaohua
2007-04-01
We analyzed the weakly nonlinear behavior of a plate thickness-shear mode piezoelectric transformer near resonance. An approximate analytical solution was obtained. Numerical results based on the analytical solution are presented. It is shown that on one side of the resonant frequency the input-output relation becomes nonlinear, and on the other side the output voltage experiences jumps.
Heat, temperature and Clausius inequality in a model for active Brownian particles
Marconi, Umberto Marini Bettolo; Puglisi, Andrea; Maggi, Claudio
2017-01-01
Methods of stochastic thermodynamics and hydrodynamics are applied to a recently introduced model of active particles. The model consists of an overdamped particle subject to Gaussian coloured noise. Inspired by stochastic thermodynamics, we derive from the system’s Fokker-Planck equation the average exchanges of heat and work with the active bath and the associated entropy production. We show that a Clausius inequality holds, with the local (non-uniform) temperature of the active bath replacing the uniform temperature usually encountered in equilibrium systems. Furthermore, by restricting the dynamical space to the first velocity moments of the local distribution function we derive a hydrodynamic description where local pressure, kinetic temperature and internal heat fluxes appear and are consistent with the previous thermodynamic analysis. The procedure also shows under which conditions one obtains the unified coloured noise approximation (UCNA): such an approximation neglects the fast relaxation to the active bath and therefore yields detailed balance and zero entropy production. In the last part, by using multiple time-scale analysis, we provide a constructive method (alternative to UCNA) to determine the solution of the Kramers equation and go beyond the detailed balance condition determining negative entropy production. PMID:28429787
Heat, temperature and Clausius inequality in a model for active Brownian particles.
Marconi, Umberto Marini Bettolo; Puglisi, Andrea; Maggi, Claudio
2017-04-21
Methods of stochastic thermodynamics and hydrodynamics are applied to a recently introduced model of active particles. The model consists of an overdamped particle subject to Gaussian coloured noise. Inspired by stochastic thermodynamics, we derive from the system's Fokker-Planck equation the average exchanges of heat and work with the active bath and the associated entropy production. We show that a Clausius inequality holds, with the local (non-uniform) temperature of the active bath replacing the uniform temperature usually encountered in equilibrium systems. Furthermore, by restricting the dynamical space to the first velocity moments of the local distribution function we derive a hydrodynamic description where local pressure, kinetic temperature and internal heat fluxes appear and are consistent with the previous thermodynamic analysis. The procedure also shows under which conditions one obtains the unified coloured noise approximation (UCNA): such an approximation neglects the fast relaxation to the active bath and therefore yields detailed balance and zero entropy production. In the last part, by using multiple time-scale analysis, we provide a constructive method (alternative to UCNA) to determine the solution of the Kramers equation and go beyond the detailed balance condition determining negative entropy production.
Lunar Surface Systems Wet-Bath Design Evaluation
NASA Technical Reports Server (NTRS)
Thompson, Shelby; Szabo, Rich; Howard, Robert
2010-01-01
The goal of the current evaluation was to examine five different wet-bath architectural design concepts. The primary means of testing the concepts required participants to physically act-out a number of functional tasks (e.g., shaving, showering, changing clothes, maintenance) in order to give judgments on the affordance of the volume as based on the design concepts. Each of the concepts was designed in such a way that certain features were exploited - for example, a concept may have a large amount of internal stowage, but minimum amount of usable space to perform tasks. The results showed that the most preferred concept was one in which stowage and usable space were balanced. This concept allowed for a moderate amount of stowage with some suggested redesign, but would not preclude additional personal items such as clothing. This concept also allowed for a greater distance to be achieved between the toilet and the sink with minimum redesign, which was desirable. Therefore, the all-in-one (i.e., toilet, sink, and shower all occupying a single volume) wet-bath concept seemed to be a viable solution in which there is a minimal amount of overall volume available with certain lunar habitat configurations.
Surface pre-treatment of aluminium by cleaning, chemical ething and conversion coating
NASA Astrophysics Data System (ADS)
Zaki, Mohammad Hafizudden Mohd; Mohd, Yusairie; Isa, Nik Norziehana Che
2017-12-01
Surface pre-treatment is one of the critical treatments for surface modification of aluminium (Al). In this study, pre-treatment of Al surface involved three stages; (1) cleaning (polishing and degreasing), (2) chemical etching (alkaline and acid) and (3) conversion coating (ie: zincate treatment). Cleaning process of Al was conducted by polishing and degreasing with acetone while etching process was done by immersion in 1.25 M NaOH solution (i.e: alkaline etching) followed with acid etching using 8 M HNO3 solution. The zincate treatment was conducted via electroless coating method by immersion of Al into a bath solution containing 0.5 M Zn(NO3)2, 0.1 M HNO3 and 0.2 M NaBH4 (reducing agent) for one hour. Different temperatures (ie: 25 °C, 50 °C, 75 °C, 90 °C) of bath solutions at pH 4 were used to investigate the effect of temperature on zincate treatment. Surface morphology and chemical composition of the pre-treated Al were characterized using Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersion X-ray analysis (EDX), respectively. The results showed that oxide layer on Al surface decreased after chemical etching process. Temperature of zincate solution has significantly affected the conversion coating process of aluminium. It was found that zinc oxide (ZnO) and zinc borate (ZnO.B2O3) were dominantly formed after zincate treatment at high temperature (ie:90 °C) with curved blade-like structure and composition of Zn, B and O with 13.70 wt.%, 3.52 wt.% and 54.39 wt.%, respectively. However, zincate treatment at low temperature (ie:<50 °C) has produced low metallic Zn.
On the distribution of Na+ pump sites in the frog skin
Mills, JW; DiBona, DR
1977-01-01
Exposure of the outside of the isolated frog skin to a Ringer's solution, made hypertonic by the addition of mannitol, causes a rapid and sustained increase in transepithelial permeability through a structural distortion-a focal blistering-of the "tight" junctions of the outermost living cell layer. [(3)H]ouabain, used as an autoradiographic marker for the Na+-pump (Na+-K+-adenosine triphosphatase), is usually unable to penetrate the frog skin from the outside solution, but when added to a hypertonic mannitol- Ringer's solution in the outside bath it readily penetrates the epithelium, presumably through the opened shunt pathway. Radioautographic analysis of [(3)H]ouabain binding sites revealed that most of ouabain enters from the outside solution binds to the sites on the cell membranes of the stratum spinosum, as was the case when it was applied from the inside bath in an earlier study. The outer living cell layer, the first to be exposed to ouabain, does not appear to be the major site for the Na+-pump, and therefore, is not likely to be responsible for most of the active pumping of Na+. This result demonstrates that previous failure to show a high density of Na+-pump sites on the cells of the outermost layer, when [(3)H]ouabain was applied from the inside solution, was not due to the inability of the marker to reach these cells at a sufficient concentration to reveal all pump sites. These results provide further support for a model of Na+-transport across the frog skin which distributes the active pump step on the inward facing membranes of all living cells. PMID:144738
Stresses in adhesively bonded joints: A closed form solution. [plate theory
NASA Technical Reports Server (NTRS)
Delale, F.; Erdogan, F.; Aydinoglu, M. N.
1980-01-01
The plane strain of adhesively bonded structures which consist of two different orthotropic adherents is considered. Assuming that the thicknesses of the adherends are constant and are small in relation to the lateral dimensions of the bonded region, the adherends are treated as plates. The transverse shear effects in the adherends and the in-plane normal strain in the adhesive are taken into account. The problem is reduced to a system of differential equations for the adhesive stresses which is solved in closed form. A single lap joint and a stiffened plate under various loading conditions are considered as examples. To verify the basic trend of the solutions obtained from the plate theory a sample problem is solved by using the finite element method and by treating the adherends and the adhesive as elastic continua. The plate theory not only predicts the correct trend for the adhesive stresses but also gives rather surprisingly accurate results.
Will Somebody do the Dishes? Weathering Analogies, Geologic Processes and Geologic Time
NASA Astrophysics Data System (ADS)
Stelling, P.; Wuotila, S.; Giuliani, M.
2006-12-01
A good analogy is one of the most powerful tools in any instructors' arsenal, and encouraging students to explore the links between an analogy and a scientific concept can cement both ideas in a student's mind. A common analogy for weathering and erosion processes is doing the dishes. Oxidation, hydration, and solution reactions can be intimidating on the chalkboard but easily understood in the context of cleaning up after dinner. Rather than present this analogy as a lecture demonstration, students are encouraged to experimentally determine which type of weathering works best on their dirty dishes. The experiment must use at least four identically dirty dishes: three experimental dishes and one control dish. The experimental dishes are subjected to simulated weathering and erosion processes of the student's design. Common techniques developed by students are cold or warm water baths, baths with and without acid (lemon juice or soda), and freeze-thaw cycles. Occasionally creative experiments result in unexpected discoveries, such the inefficiency of abrasion from wind-blown sand, especially when compared to soaking dishes in Canadian Whiskey. The effectiveness of each experimental run is determined by comparison to the control plate after loose debris is removed from each. The dish with the smallest aerial extent of remaining food is the declared the most effective. Discussion sections of the experimental write-up includes a description of which geologic processes were being simulated in each experiment, comparisons of the effectiveness of each techniques, and statements of how these experiments differ from reality. In order to advance this project, a second stage of the assignment, a direct comparison of weathering and erosion techniques on food and on geologic materials, will be added this fall. Ideally, students will empirically derive erosion rates and calculate the time required to remove the volume of material represented by a geologically important feature, such as Mt. Rainier or the Grand Canyon. In the end, students completing this project gain an understanding of how geologic processes work, the time scales required, the differences between analogies and the real thing, and arguably the most important aspect, a best-practices approach to doing the dishes.
Physiological and subjective responses to standing showers, sitting showers, and sink baths.
Ohnaka, T; Tochihara, Y; Kubo, M; Yamaguchi, C
1995-09-01
The purpose of this study was to investigate physiological and subjective responses during and after bathing in three different bathing methods. Eight healthy males bathed for 10 minutes, and then rested for 30 minutes. Three kinds of bathing methods - standing shower, sitting shower and sink bath - were adopted in this experiment. Water temperature and flow volume of the showers were kept at 41 degrees C and 11 liter/min, while water temperature of the bath was kept at 40 degrees C. Rectal temperature, skin temperatures and heart rate of the subjects were measured continuously during bathing and the subsequent 30-minute rest. Blood pressure and votes for thermal sensations were recorded before bathing, after 5 and 10 minutes of bathing, and 5, 10, 20 and 30 minutes after bathing. The following results were obtained. 1) Although rectal temperature rose, on the average, by 0.15 degrees C in all bathing methods, there were no significant differences among the three bathing methods at any time in the experiment. 2) Mean skin temperature (Tsk) during the sink bath was significantly higher than that in the standing or sitting shower. After bathing, Tsk of sink bath was slightly higher than those of the remaining conditions, but did not significantly differ among the bathing methods. 3) Heart rate increased gradually during all the bathing methods, however, only HR in the standing shower exceeded 100 beats/min which was significantly higher than those of the two remaining bathing methods. 4) Blood pressure (BP) decreased rapidly during the sink bath in contrast to an increased BP in the sitting and standing showers.
[Performance comparison of material tests for cadmium and lead in food contact plastics].
Mutsuga, Motoh; Abe, Tomoyuki; Abe, Yutaka; Ishii, Rie; Itoh, Yuko; Ohno, Hiroyuki; Ohno, Yuichiro; Ozaki, Asako; Kakihara, Yoshiteru; Kaneko, Reiko; Kawamura, Yoko; Shibata, Hiroshi; Sekido, Haruko; Sonobe, Hironori; Takasaka, Noriko; Tajima, Yoshiyasu; Tanaka, Aoi; Nomura, Chie; Hikida, Akinori; Matsuyama, Sigetomo; Murakami, Ryo; Yamaguchi, Miku; Wada, Takenari; Watanabe, Kazunari; Akiyama, Hiroshi
2014-01-01
Based on the Japanese Food Sanitation Law, the performances of official and alternative material test methods for cadmium (Cd) and lead (Pb) in food contact plastics were compared. Nineteen laboratories participated to an interlaboratory study, and quantified Cd and Pb in three PVC pellets. in the official method, a sample is digested with H2SO4, taken up in HCl, and evaporated to dryness on a water bath, then measured by atomic absorption spectrometry (AAS) or inductively coupled plasma-optical emission spectrometry (ICP-OES). Statistical treatment revealed that the trueness, repeatability (RSDr) and reproducibility (RSDr) were 86-95%, 3.1-9.4% and 8.6-22.1%, respectively. The values of the performance parameters fulfilled the requirements , and the performances met the test specifications. The combination of evaporation to dryness on a hot plate and measurement by AAS or ICP-OES is applicable as an alternative method. However, the trueness and RSDr were inferior to those of the official method. The performance parameters obtained by using the microwave digestion method (MW method) to prepare test solution were better than those of the official method. Thus, the MW method is available as an alternative method. Induced coupled plasma-mass spectrometry (ICP-MS) is also available as an alternative method. However, it is necessary to ensure complete digestion of the sample.
Enhancement of Chlorella vulgaris harvesting via the electro-coagulation-flotation (ECF) method.
Wong, Y K; Ho, Y H; Leung, H M; Ho, K C; Yau, Y H; Yung, K K L
2017-04-01
This article explores the potential of using an electro-coagulation-flotation (ECF) harvester to allow flotation of microalgae cells for surface harvesting. A response surface methodology (RSM) model was used to optimize ECF harvesting by adjusting electrode plate material, electrode plate number, charge of the electrodes, electrolyte concentration, and pH value of the culture solution. The result revealed that three aluminum electrode plates (one anode and two cathodes), brine solution (8 g/L), and acidity (pH = 4) of culture solution (optimized ECF harvester) The highest flocculant concentration was measured at 2966 mg/L after 60 min and showed a 79.8 % increase of flocculation concentration. Such results can provide a basis for designing a large-scale microalgae harvester for commercial use in the future.
High-temperature ductility of electro-deposited nickel
NASA Technical Reports Server (NTRS)
Dini, J. W.; Johnson, H. R.
1977-01-01
Work done during the past several months on high temperature ductility of electrodeposited nickel is summarized. Data are presented which show that earlier measurements made at NASA-Langley erred on the low side, that strain rate has a marked influence on high temperature ductility, and that codeposition of a small amount of manganese helps to improve high temperature ductility. Influences of a number of other factors on nickel properties were also investigated. They included plating solution temperature, current density, agitation, and elimination of the wetting agent from the plating solution. Repair of a large nozzle section by nickel plating is described.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ismail, Zulkhibri; Khan, Ilyas; Nasir, Nadirah Mohd
2015-02-03
An analysis of the exact solutions of second grade fluid problem for unsteady magnetohydrodynamic (MHD) flows past an infinite inclined plate in a porous medium is presented. It is assumed that the bounding infinite inclined plate has a constant temperature with radiation effects. Based on Boussinesq approximation the expressions for dimensionless velocity, temperature and concentration are obtained by using Laplace transform method. The derived solutions satisfying the involved differential equations, and all the boundary and initial conditions. The influence of various parameters on the velocity has been illustrated graphically and analyzed.
Thermal stresses and deflections of cross-ply laminated plates using refined plate theories
NASA Technical Reports Server (NTRS)
Khdeir, A. A.; Reddy, J. N.
1991-01-01
Exact analytical solutions of refined plate theories are developed to study the thermal stresses and deflections of cross-ply rectangular plates. The state-space approach in conjunction with the Levy method is used to solve exactly the governing equations of the theories under various boundary conditions. Numerical results of the higher-order theory of Reddy for thermal stresses and deflections are compared with those obtained using the classical and first-order plate theories.
Primary effects of metals on osmoregulatory processes
DOE Office of Scientific and Technical Information (OSTI.GOV)
DiBona, D.R.; Kendall, L.K.; Ferreria, H.G.
1995-12-31
Isolated skins of the bullfrog, Rana catesbiana, were chamber-mounted as sheets, bathed on the inside (serosa) with a Ringer`s solution but on the outside with simulations of freshwater to mimic environmental conditions. An automatic voltage-clamping protocol measured short-circuit current (I{sub sc}), an index of transepithelial Na{sup +} transport, and total tissue conductance (G{sub t}). Aluminum, cadmium, chromium, copper, lead, mercury and zinc were studied separately as additives to the outer bath and yielded qualitatively similar results. Al has been most thoroughly examined. At 200 ppB (7.4 {micro}M) or more, and at pH 5.0 or below, Al inhibits both I{sub sc}more » and G{sub t}. Effects are precluded by the addition of amiloride, a diuretic that blocks Na{sup +} transport at the level of the Na{sup +} channel. Kinetic analysis reveals that Al and amiloride compete for a single binding site on the channel protein. At levels of 10 ppM, Al addition results in amiloride-insensitive increases in G{sub t} (10-fold or more) and I{sub sc} (20+ {micro}A/cm{sup 2}). Isotopic flux measurements suggest that these effects are due to an ``opening`` of epithelial tight junctions with passive, downhill diffusion of salt from inside to outside; the polarity of the resulting current reflects enhanced paracellular permeability with specificity for Cl{sup {minus}} over Na{sup +}. Varying medium pH indicates that Al{sup 3+} is the dominant species in each of the two effects. Al addition to the inner bathing medium was without effect despite access to the Na{sup +}-K{sup +}-ATPase. Contaminant metals may interfere with osmoregulation by impairing salt accumulation and by enlarging leak pathways through which solutes are lost to the environment.« less
Sircar, S; Aisenbrey, E; Bryant, S J; Bortz, D M
2015-01-07
We present an experimentally guided, multi-phase, multi-species polyelectrolyte gel model to make qualitative predictions on the equilibrium electro-chemical properties of articular cartilage. The mixture theory consists of two different types of polymers: poly(ethylene gylcol) (PEG), chondrotin sulfate (ChS), water (acting as solvent) and several different ions: H(+), Na(+), Cl(-). The polymer chains have covalent cross-links whose effect on the swelling kinetics is modeled via Doi rubber elasticity theory. Numerical studies on equilibrium polymer volume fraction and net osmolarity (difference in the solute concentration across the gel) show a complex interplay between ionic bath concentrations, pH, cross-link fraction and the average charge per monomer. Generally speaking, swelling is aided due to a higher average charge per monomer (or a higher particle fraction of ChS, the charged component of the polymer), low solute concentration in the bath, a high pH or a low cross-link fraction. A peculiar case arises at higher values of cross-link fraction, where it is observed that increasing the average charge per monomer leads to gel deswelling. Copyright © 2014 Elsevier Ltd. All rights reserved.
Li, Huijun; Tan, Yu Jun; Leong, Kah Fai; Li, Lin
2017-06-14
A robust alginate/methylcellulose (Alg/MC) blend hydrogel, with a strategy to improve adhesion between printed layers, has been fabricated for the first time for three-dimensional (3D) bioprinting. The optimized Alg/MC blend hydrogel exhibits a highly thixotropic property, great extrudability, and stackability. With treatment by a trisodium citrate (TSC) solution, the interfacial bonding between the printed layers is significantly improved. The TSC solution acts as a chelating agent to remove the superficial calcium ions at each layer. Post-cross-linking in a CaCl 2 bath after 3D printing further enhances the adhesion strength between the layers. The key parameters affecting the interfacial strength of the Alg/MC hydrogel are found to be the concentration of TSC, the volume of TSC, and the concentration of CaCl 2 in the bath. The Alg/MC hydrogel with the aid of TSC demonstrates superior printability, high stackability (150 layers can be printed), and high shape fidelity. A good cell viability of >95% is obtained for a freshly 3D-bioprinted Alg/MC construct. The novel Alg/MC hydrogel with the aid of TSC has been shown to have a great potential as an advanced 3D bioprinting material.
Chemically Defined and Xeno-Free Cryopreservation of Human Adipose-Derived Stem Cells
López, Melany; Bollag, Roni J.; Yu, Jack C.; Isales, Carlos M.; Eroglu, Ali
2016-01-01
The stromal compartment of adipose tissue harbors multipotent cells known as adipose-derived stem cells (ASCs). These cells can differentiate into various lineages including osteogenic, chrondrogenic, adipogenic, and neurogenic; this cellular fraction may be easily obtained in large quantities through a clinically safe liposuction procedure. Therefore, ASCs offer exceptional opportunities for tissue engineering and regenerative medicine. However, current practices involving ASCs typically use fetal bovine serum (FBS)-based cryopreservation solutions that are associated with risks of immunological reactions and of transmitting infectious diseases and prions. To realize clinical applications of ASCs, serum- and xeno-free defined cryopreservation methods are needed. To this end, an animal product-free chemically defined cryopreservation medium was formulated by adding two antioxidants (reduced glutathione and ascorbic acid 2-phosphate), two polymers (PVA and ficoll), two permeating cryoprotectants (ethylene glycol and dimethylsulfoxide), a disaccharide (trehalose), and a calcium chelator (EGTA) to HEPES-buffered DMEM/F12. To limit the number of experimental groups, the concentration of trehalose, both polymers, and EGTA was fixed while the presence of the permeating CPAs and antioxidants was varied. ASCs suspended either in different versions of the defined medium or in the conventional undefined cryopreservation medium (10% dimethylsulfoxide+10% DMEM/F12+80% serum) were cooled to -70°C at 1°C/min before being plunged into liquid nitrogen. Samples were thawed either in air or in a water bath at 37°C. The presence of antioxidants along with 3.5% concentration of each penetrating cryoprotectant improved the freezing outcome to the level of the undefined cryopreservation medium, but the plating efficiency was still lower than that of unfrozen controls. Subsequently, increasing the concentration of both permeating cryoprotectants to 5% further improved the plating efficiency to the level of unfrozen controls. Moreover, ASCs cryopreserved in this defined medium retained their multipotency and chromosomal normality. These results are of significance for tissue engineering and clinical applications of stem cells. PMID:27010403
NASA Astrophysics Data System (ADS)
Luo, Keqin
1999-11-01
The electroplating industry of over 10,000 planting plants nationwide is one of the major waste generators in the industry. Large quantities of wastewater, spent solvents, spent process solutions, and sludge are the major wastes generated daily in plants, which costs the industry tremendously for waste treatment and disposal and hinders the further development of the industry. It becomes, therefore, an urgent need for the industry to identify technically most effective and economically most attractive methodologies and technologies to minimize the waste, while the production competitiveness can be still maintained. This dissertation aims at developing a novel WM methodology using artificial intelligence, fuzzy logic, and fundamental knowledge in chemical engineering, and an intelligent decision support tool. The WM methodology consists of two parts: the heuristic knowledge-based qualitative WM decision analysis and support methodology and fundamental knowledge-based quantitative process analysis methodology for waste reduction. In the former, a large number of WM strategies are represented as fuzzy rules. This becomes the main part of the knowledge base in the decision support tool, WMEP-Advisor. In the latter, various first-principles-based process dynamic models are developed. These models can characterize all three major types of operations in an electroplating plant, i.e., cleaning, rinsing, and plating. This development allows us to perform a thorough process analysis on bath efficiency, chemical consumption, wastewater generation, sludge generation, etc. Additional models are developed for quantifying drag-out and evaporation that are critical for waste reduction. The models are validated through numerous industrial experiments in a typical plating line of an industrial partner. The unique contribution of this research is that it is the first time for the electroplating industry to (i) use systematically available WM strategies, (ii) know quantitatively and accurately what is going on in each tank, and (iii) identify all WM opportunities through process improvement. This work has formed a solid foundation for the further development of powerful WM technologies for comprehensive WM in the following decade.
Float processing of high-temperature complex silicate glasses and float baths used for same
NASA Technical Reports Server (NTRS)
Cooper, Reid Franklin (Inventor); Cook, Glen Bennett (Inventor)
2000-01-01
A float glass process for production of high melting temperature glasses utilizes a binary metal alloy bath having the combined properties of a low melting point, low reactivity with oxygen, low vapor pressure, and minimal reactivity with the silicate glasses being formed. The metal alloy of the float medium is exothermic with a solvent metal that does not readily form an oxide. The vapor pressure of both components in the alloy is low enough to prevent deleterious vapor deposition, and there is minimal chemical and interdiffusive interaction of either component with silicate glasses under the float processing conditions. Alloys having the desired combination of properties include compositions in which gold, silver or copper is the solvent metal and silicon, germanium or tin is the solute, preferably in eutectic or near-eutectic compositions.
A chamber for the perfusion of in vitro tissue with multiple solutions
Covington, James A.; Wall, Mark J.
2013-01-01
There are currently no practical systems that allow extended regions (>5 mm2) of a tissue slice in vitro to be exposed, in isolation, to changes in ionic conditions or to pharmacological manipulation. Previous work has only achieved this at the expense of access to the tissue for recording electrodes. Here, we present a chamber that allows a tissue slice to be maintained in multiple solutions, at physiological temperatures, and preserves the ability to record from the slice. We demonstrate the effectiveness of the tissue bath with respect to minimizing the mixing of the solutions, maintaining the viability of the tissue, and preserving the ability to record from the slice simultaneously. PMID:23576703
Chemical Synthesis of ZnS:Cu Nanosheets
NASA Astrophysics Data System (ADS)
Bodo, Bhaskarjyoti; Kalita, P. K.
2010-10-01
ZnS thin films are synthesized through chemical bath deposition (CBD) technique from aqueous solution of ZnSO4 and thiourea mixing in equal volume and equimolar ratio. A 1% CuSO4 solution is mixed with the ZnSO4 solution for doping before the final chemical reaction. SEM image shows the formation of mainly nanosheets, teeth and comb like structures. Absorption studies show red shift of enhanced band gap on Cu doping. Photoluminescence of ZnS:Cu reveals the enhancement of blue luminescence at 468 nm and low intensity green emission at 493 nm which is attributed to more Cu2+ lying in the interstices. XRD shows that the prepared ZnS nanophosphors possess cubic zinc blende structures.
Dust-bathing behavior of laying hens in enriched colony housing systems and an aviary system
Louton, H.; Bergmann, S.; Reese, S.; Erhard, M. H.; Rauch, E.
2016-01-01
The dust-bathing behavior of Lohmann Selected Leghorn hens was compared in 4 enriched colony housing systems and in an aviary system. The enriched colony housing systems differed especially in the alignment and division of the functional areas dust bath, nest, and perches. Forty-eight-hour video recordings were performed at 3 time-points during the laying period, and focal animal sampling and behavior sampling methods were used to analyze the dust-bathing behavior. Focal animal data included the relative fractions of dust-bathing hens overall, of hens bathing in the dust-bath area, and of those bathing on the wire floor throughout the day. Behavior data included the number of dust-bathing bouts within a predefined time range, the duration of 1 bout, the number of and reasons for interruptions, and the number of and reasons for the termination of dust-bathing bouts. Results showed that the average duration of dust bathing varied between the 4 enriched colony housing systems compared with the aviary system. The duration of dust-bathing bouts was shorter than reported under natural conditions. A positive correlation between dust-bathing activity and size of the dust-bath area was observed. Frequently, dust baths were interrupted and terminated by disturbing influences such as pecking by other hens. This was especially observed in the enriched colony housing systems. In none of the observed systems, neither in the enriched colony housing nor in the aviary system, were all of the observed dust baths terminated “normally.” Dust bathing behavior on the wire mesh rather than in the provided dust-bath area generally was observed at different frequencies in all enriched colony housing systems during all observation periods, but never in the aviary system. The size and design of the dust-bath area influenced the prevalence of dust-bathing behavior in that small and subdivided dust-bath areas reduced the number of dust-bathing bouts but increased the incidence of sham dust bathing on the wire mesh. PMID:27044875
Copper Electrodeposition on a Magnesium Alloy (AZ80) with a U-Shaped Surface
Huang, Ching An; Yeh, Yu Hu; Lin, Che Kuan; Hsieh, Chen Yun
2014-01-01
Cu electrodeposition was performed on a cylindrical AZ80 substrate with a U-shaped surface. A uniform deposition of Cu was achieved on an AZ80 electrode via galvanostatic etching, followed by Cu electrodeposition in an eco-friendly alkaline Cu plating bath. Improper wetting and lower rotational speeds of the AZ80 electrode resulted in an uneven Cu deposition at the inner upper site of the U-shaped surface during the Cu electroplating process. This wetting effect could be deduced from the variation in the anodic potential during the galvanostatic etching. The corrosion resistance of the Cu-deposited AZ80 electrode can be considerably improved after Ni electroplating. PMID:28788252
Target and method for the production of fission product molybdenum-99
Vandegrift, G.F.; Vissers, D.R.; Marshall, S.L.; Varma, R.
1987-10-26
A target for the reduction of fission product Mo-99 is prepared from uranium of low U-235 enrichment by coating a structural support member with a preparatory coating of a substantially oxide-free substrate metal. Uranium metal is electrodeposited from a molten halide electrolytic bath onto a substrate metal. The electrodeposition is performed at a predetermined direct current rate or by using pulsed plating techniques which permit relaxation of accumulated uranium ion concentrations within the melt. Layers of as much as to 600 mg/cm/sup 2/ of uranium can be prepared to provide a sufficient density to produce acceptable concentrations of fission product Mo-99. 2 figs.
Wetting Hysteresis at the Molecular Scale
NASA Technical Reports Server (NTRS)
Jin, Wei; Koplik, Joel; Banavar, Jayanth R.
1996-01-01
The motion of a fluid-fluid-solid contact line on a rough surface is well known to display hysteresis in the contact angle vs. velocity relationship. In order to understand the phenomenon at a fundamental microscopic level, we have conducted molecular dynamics computer simulations of a Wilhelmy plate experiment in which a solid surface is dipped into a liquid bath, and the force-velocity characteristics are measured. We directly observe a systematic variation of force and contact angle with velocity, which is single-valued for the case of an atomically smooth solid surface. In the microscopically rough case, however, we find (as intuitively expected) an open hysteresis loop. Further characterization of the interface dynamics is in progress.
Synthesis of copper coated carbon nanotubes for aluminium matrix composites
NASA Astrophysics Data System (ADS)
Maqbool, Adnan; Khalid, F. Ahmad; Hussain, M. Asif; Bakhsh, Nabi
2014-06-01
In this investigation copper coated carbon nanotubes (CNTs) were prepared to enhance the interfacial bonding between CNTs and aluminum matrix by the molecular-level mixing process. In optimized plating bath of (1:1) by wt. CNT with Cu, thickness of coated CNTs is reduced to 100 nm to promote uniform distribution of Cu nanoparticle on the surface of pretreated CNTs. The mixing of CNTs was accomplished by ultrasonication and ball milling. Scanning electron microscope analysis revealed the homogenous dispersion of Cu-coated CNTs in nanocomposites samples compared to the uncoated CNTs. The samples were pressureless sintered under vacuum. The densification increased with the increase in the CNTs content and is more pronounced in Cu-coated CNT nanocomposites.
NASA Astrophysics Data System (ADS)
Lee, Soomin; Fujimura, Hiroko; Shimomura, Yoshihiro; Katsuura, Tetsuo
2015-09-01
Recently, a growing number in Japan are switching to taking baths in the morning (morning bathing). However, the effects of the morning bathing on human physiological functions and work efficiency have not yet been revealed. Then, we hypothesized that the effect of morning bathing on physiological functions would be different from those of night bathing. In this study, we measured the physiological functions and work efficiency during the day following the morning bathing (7:10-7:20) including showering, mist sauna bathing, and no bathing as a control. Ten male healthy young adults participated in this study as the subjects. We evaluated the rectal temperature (Tre), skin temperature (Tsk), heart rate (HR), heart rate variability (HRV), blood pressure (BP), the relative power density of the alpha wave (α-wave ratio) of electroencephalogram, alpha attenuation coefficient (AAC), and the error rate of the task performance. As a result, we found that the HR after the mist sauna bathing was significantly lower than those after no bathing rest 3 (11:00). Furthermore, we verified that the α-wave ratio of the Pz after the mist sauna bathing was significantly lower than those after no bathing during the task 6 (15:00). On the other hand, the α-wave ratio of the Pz after the mist sauna bathing was significantly higher than those after showering during the rest 3 (11:00). Tsk after the mist sauna bathing was higher than those after the showering at 9:00 and 15:00. In addition, the error rate of the task performance after the mist sauna bathing was lower than those after no bathing and showering at 14:00. This study concludes that a morning mist sauna is safe and maintains both skin temperature compared to other bathing methods. Moreover, it is presumed that the morning mist sauna bathing improves work efficiency comparing other bathing methods during the task period of the day following the morning bathing.
Lee, Soomin; Fujimura, Hiroko; Shimomura, Yoshihiro; Katsuura, Tetsuo
2015-09-01
Recently, a growing number in Japan are switching to taking baths in the morning (morning bathing). However, the effects of the morning bathing on human physiological functions and work efficiency have not yet been revealed. Then, we hypothesized that the effect of morning bathing on physiological functions would be different from those of night bathing. In this study, we measured the physiological functions and work efficiency during the day following the morning bathing (7:10-7:20) including showering, mist sauna bathing, and no bathing as a control. Ten male healthy young adults participated in this study as the subjects. We evaluated the rectal temperature (Tre), skin temperature (Tsk), heart rate (HR), heart rate variability (HRV), blood pressure (BP), the relative power density of the alpha wave (α-wave ratio) of electroencephalogram, alpha attenuation coefficient (AAC), and the error rate of the task performance. As a result, we found that the HR after the mist sauna bathing was significantly lower than those after no bathing rest 3 (11:00). Furthermore, we verified that the α-wave ratio of the Pz after the mist sauna bathing was significantly lower than those after no bathing during the task 6 (15:00). On the other hand, the α-wave ratio of the Pz after the mist sauna bathing was significantly higher than those after showering during the rest 3 (11:00). Tsk after the mist sauna bathing was higher than those after the showering at 9:00 and 15:00. In addition, the error rate of the task performance after the mist sauna bathing was lower than those after no bathing and showering at 14:00. This study concludes that a morning mist sauna is safe and maintains both skin temperature compared to other bathing methods. Moreover, it is presumed that the morning mist sauna bathing improves work efficiency comparing other bathing methods during the task period of the day following the morning bathing.
A note on the cracked plates reinforced by a line stiffener
NASA Technical Reports Server (NTRS)
Yahsi, O. S.; Erdogan, F.
1983-01-01
The problem of a cracked plate reinforced by a line stiffener is reconsidered. The original solution of this problem was given in the literature. Also, a variation of the problem with debonding between the plate and the stiffener near the cracked region was reported in the literature. However, the special case of the problem in which the crack tip terminates at the stiffener does not appear to have been studied. In practice, the solution may be necessary in order to assess the crack arrest effectiveness of the stiffener. The problem of a stiffened plate with a crack is reformulated, the asymptotic stress state near the crack tip terminating at the stiffener is examined, and numerical results are given for various stiffness constants. Previously announced in STAR as N83-21388
NASA Technical Reports Server (NTRS)
Noor, Ahmed K.; Burton, W. S.
1992-01-01
Analytic three-dimensional elasticity solutions are developed for the free vibration and buckling of thermally stressed rectangular multilayered angle-ply anisotropic plates which are assumed to have an antisymmetric lamination with respect to the middle plane. Sensitivity derivatives are evaluated and used to investigate the sensitivity of the vibration and buckling responses to variations in the different lamination and material parameters of the plate. A Duhamel-Neumann-type constitutive model is used, and the material properties are assumed to be independent of temperature. Numerical results are presented, showing the effects of variations in the material characteristics and fiber orientation of different layers, as well as the effect of initial thermal deformation on the vibrational and buckling responses of the plate.
Flow past a Flat Plate with a Vortex/sink Combination
NASA Technical Reports Server (NTRS)
Mourtos, N. J.
1984-01-01
An attempt was made to model the so called leading edge vortex which forms over the leading edge of delta wings at high angles of attack. A simplified model was considered, namely that of a two-dimensional, inviscid, incompressible steady flow around a flat plate at an angle of attack with a stationary vortex detached on top, as well as a sink to simulate the strong spanwise flow. The results appear to agree qualitatively with experiments. A comparison was also made between the lift and the drag of this model and the corresponding results for two classical solutions: (1) that of totally attached flow over the plate with the Kutta condition satisfied at the trailing edge only: and (2) the Helmholtz solution of totally separated flow over the plate.
Altitude-Limiting Airbrake System for Small to Medium Scale Rockets
NASA Technical Reports Server (NTRS)
Aaron, Robert F., III
2013-01-01
The goal of the overall internship opportunity this semester was to learn and practice the elements of engineering design through direct exposure to real engineering problems. The primary exposure was to design and manufacture an airbrake device for use with small-medium scale rocket applications. The idea was to take the presented concept of a solution and transform said concept into a reliable fully-functioning and reusable mechanism. The mechanism was to be designed as an insurance feature so that the overall altitude of a rocket with relatively undetermined engine capabilities does not unexpectedly exceed the imposed 10,000 foot ceiling, per range requirements. The airbrake concept was introduced to the Prototype Development Lab as a rotation-driven four tiered offset track pin mechanism, i.e. the airbrake was deployed by rotating a central shaft attached directly to the bottom plate. The individual airbrake fins were subsequently deployed using multiple plates with tracks of offset curvature. The fins were created with guide pins to follow the tracks in each of the offset plates, thus allowing the simultaneous rotational deployment of all fins by only rotating one plate. The concept of this solution was great; though it did not function in application. The rotating plates alone brought up problems like the entire back half of the rocket rotating according to the motion of the aforementioned base plate. Subsequently, the solution currently under development became a static linear actuator-driven spring-loaded fin release system. This solution is almost instantaneously triggered electronically when the avionics detect that the rocket has reached the calculated altitude of deceleration. This altitude will allow enough time remaining to the overall ceiling to adequately decelerate the rocket prior to reaching the ceiling.
A User’s Guide to the PLTEMP/ANL Code
DOE Office of Scientific and Technical Information (OSTI.GOV)
Olson, A. P.; Kalimullah, M.; Feldman, E. E.
2016-07-25
PLTEMP/ANL V4.2 is a program that obtains a steady-state flow and temperature solution for a nuclear reactor core, or for a single fuel assembly. It is based on an evolutionary sequence of codes originally used for plate temperatures, hence “PLTEMP”, developed at Argonne National Laboratory over several decades. Fueled and non-fueled regions are modeled. Each fuel assembly consists of one or more plates or tubes separated by coolant channels. The fuel plates may have one to five layers of different materials, each with heat generation. The width of a fuel plate may be divided into multiple longitudinal stripes, each withmore » its own axial power shape. The temperature solution is effectively 2-dimensional. It begins with a one-dimensional solution across all coolant channels and fuel plates or tubes within a given fuel assembly, at the entrance to the assembly. The temperature solution is repeated for each axial node along the length of the fuel assembly. The geometry may be either slab or radial, corresponding to fuel assemblies made of a series of flat (or slightly curved) plates, or of nested tubes. A variety of thermal-hydraulic correlations are available with which to determine safety margins such as onset-of-nucleate boiling ratio(ONBR), departure from nucleate boiling ratio (DNBR), and onset of flow instability ratio (OFIR). Coolant properties for either light or heavy water are obtained from FORTRAN functions rather than from tables. The code is intended for thermal-hydraulic analysis of research reactor performance in the sub-cooled boiling regime. Both turbulent and laminar flow regimes can be modeled. Options to calculate both forced flow and natural circulation are available. A general search capability is available (Appendix XII) to greatly reduce the reactor analyst’s time.« less
NASA Technical Reports Server (NTRS)
Anderson, Melvin S.; Kennedy, David
1992-01-01
The problem considered is the development of the necessary plate stiffnesses for use in a general purpose program for buckling and vibration of composite plate assemblies. The required stiffnesses are for the assumption of sinusoidal response along the plate length with transverse shear included. The method is based on the exact solution of the plate differential equations for a composite laminate having fully populated A, B, and D matrices which leads to a differential equation of tenth order.
Retrofit implementation of Zernike phase plate imaging for cryo-TEM
Marko, Michael; Leith, ArDean; Hsieh, Chyongere; Danev, Radostin
2011-01-01
In-focus phase-plate imaging is particularly beneficial for cryo-TEM because it offers a substantial overall increase in image contrast, without an electron dose penalty, and it simplifies image interpretation. We show how phase-plate cryo-TEM can be implemented with an appropriate existing TEM, and provide a basic practical introduction to use of thin-film (carbon) phase plates. We point out potential pitfalls of phase-plate operation, and discuss solutions. We provide information on evaluating a particular TEM for its suitability. PMID:21272647
Thermal stresses and deflections of cross-ply laminated plates using refined plate theories
DOE Office of Scientific and Technical Information (OSTI.GOV)
Khdeir, A.A.; Reddy, J.N.
1991-12-01
Exact analytical solutions of refined plate theories are developed to study the thermal stresses and deflections of cross-ply rectangular plates. The state-space approach in conjunction with the Levy method is used to solve exactly the governing equations of the theories under various boundary conditions. Numerical results of the higher-order theory of Reddy for thermal stresses and deflections are compared with those obtained using the classical and first-order plate theories. 14 refs.
Kumar, Saurav; Raman, R P; Kumar, Kundan; Pandey, P K; Kumar, Neeraj; Mallesh, B; Mohanty, Snatashree; Kumar, Abhay
2013-08-01
Argulosis hampers aquaculture production and alters the host physiology and growth. Azadirachtin is recognized as a potential antiparasitic agent against Argulus sp. The present study aimed to investigate the effect of different concentration of azadirachtin solution on haematological and serum biochemical parameters of Argulus-infested goldfish Carassius auratus. Ninety Argulus-infested goldfish were randomly divided into six equal groups. Fish of group 1-5 were treated with azadirachtin solution through bath of 1, 5, 10, 15 and 20 mg L(-1) as T1, T2, T3, T4 and T5, respectively, and group 6 was exposed to 2% DMSO solution without azadirachtin and considered as negative control T0(-). Along with six treatment groups, a positive control T0(+) of healthy goldfish free from Argulus infestation was also maintained. Parasitic mortality was evaluated after 3 days of consecutive bath treatment. After 7 days of post-treatment, the blood and serum were drawn from each of the treatment groups and haematological and serum biochemical parameters were evaluated. Total leucocyte count (TLC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), blood glucose, total protein (TP), globulin, serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) were significantly (p < 0.05) high in negative control group when compared with positive control group. It could be concluded that Argulus infestation altered marked haematological and serum biochemical parameters. However, in treated groups complete elimination of Argulus was found in T4 and T5 groups. Also significant (p < 0.05) reduction in haematological and serum biochemical parameters of all the treatment groups were recorded in comparison with negative control group. In addition, T4 and T5 groups showed significantly (p < 0.05) high superoxide dismutase (SOD), catalase, total erythrocyte count (TEC) and haemoglobin (Hb). However, higher mean corpuscular haemoglobin concentration (MCHC), blood glucose and lactate dehydrogenase (LDH) levels in T5 group revealed that higher concentration of azadirachtin have notable effects on activity of vital tissues function and physiology of the host. Argulus spp. from infested goldfish could be eliminated using bath treatment with solution of azadirachtin having concentration of 15 mg L(-1) and that also shifted haematological and serum biochemical parameters towards homeostasis.
NASA Astrophysics Data System (ADS)
Kang, Yubin; Choi, Jaeyoung; Park, Jinju; Kim, Woo-Byoung; Lee, Kun-Jae
2017-09-01
This study attempts to improve the physical and chemical adhesion between metals and ceramics by using electrolytic oxidation and a titanium organic/inorganic complex ion solution on the SS-304 plate. Surface analysis confirmed the existence of the Tisbnd Osbnd Mx bonds formed by the bonding between the metal ions and the Ti oxide at the surface of the pre-processed SS plate, and improved chemical adhesion during ceramic coating was expected by confirming the presence of the carboxylic group. The adhesion was evaluated by using the ceramic coating solution in order to assess the improved adhesion of the SS plate under conditions. The results showed that both the adhesion and durability were largely improved in the sample processed with all the pre-processing steps, thus confirming that the physical and chemical adhesion between metals and ceramics can be improved by enhancing the physical roughness via electrolytic oxidation and pre-processing using a Ti complex ion solution.
NASA Astrophysics Data System (ADS)
Azhar, Waqas Ali; Vieru, Dumitru; Fetecau, Constantin
2017-08-01
Free convection flow of some water based fractional nanofluids over a moving infinite vertical plate with uniform heat flux and heat source is analytically and graphically studied. Exact solutions for dimensionless temperature and velocity fields, Nusselt numbers, and skin friction coefficients are established in integral form in terms of modified Bessel functions of the first kind. These solutions satisfy all imposed initial and boundary conditions and reduce to the similar solutions for ordinary nanofluids when the fractional parameters tend to one. Furthermore, they reduce to the known solutions from the literature when the plate is fixed and the heat source is absent. The influence of fractional parameters on heat transfer and fluid motion is graphically underlined and discussed. The enhancement of heat transfer in such flows is higher for fractional nanofluids in comparison with ordinary nanofluids. Moreover, the use of fractional models allows us to choose the fractional parameters in order to get a very good agreement between experimental and theoretical results.
Piezoelectrically actuated flextensional micromachined ultrasound transducers--I: theory.
Perçin, Gökhan; Khuri-Yakub, Butrus T
2002-05-01
This series of two papers considers piezoelectrically actuated flextensional micromachined ultrasound transducers (PAFMUTs) and consists of theory, fabrication, and experimental parts. The theory presented in this paper is developed for an ultrasound transducer application presented in the second part. In the absence of analytical expressions for the equivalent circuit parameters of a flextensional transducer, it is difficult to calculate its optimal parameters and dimensions and difficult to choose suitable materials. The influence of coupling between flexural and extensional deformation and that of coupling between the structure and the acoustic volume on the dynamic response of piezoelectrically actuated flextensional transducer are analyzed using two analytical methods: classical thin (Kirchhoff) plate theory and Mindlin plate theory. Classical thin plate theory and Mindlin plate theory are applied to derive two-dimensional plate equations for the transducer and to calculate the coupled electromechanical field variables such as mechanical displacement and electrical input impedance. In these methods, the variations across the thickness direction vanish by using the bending moments per unit length or stress resultants. Thus, two-dimensional plate equations for a step-wise laminated circular plate are obtained as well as two different solutions to the corresponding systems. An equivalent circuit of the transducer is also obtained from these solutions.
Free vibration of functionally graded carbon-nanotube-reinforced composite plates with cutout
Mirzaei, Mostafa
2016-01-01
Summary During the past five years, it has been shown that carbon nanotubes act as an exceptional reinforcement for composites. For this reason, a large number of investigations have been devoted to analysis of fundamental, structural behavior of solid structures made of carbon-nanotube-reinforced composites (CNTRC). The present research, as an extension of the available works on the vibration analysis of CNTRC structures, examines the free vibration characteristics of plates containing a cutout that are reinforced with uniform or nonuniform distribution of carbon nanotubes. The first-order shear deformation plate theory is used to estimate the kinematics of the plate. The solution method is based on the Ritz method with Chebyshev basis polynomials. Such a solution method is suitable for arbitrary in-plane and out-of-plane boundary conditions of the plate. It is shown that through a functionally graded distribution of carbon nanotubes across the thickness of the plate, the fundamental frequency of a rectangular plate with or without a cutout may be enhanced. Furthermore, the frequencies are highly dependent on the volume fraction of carbon nanotubes and may be increased upon using more carbon nanotubes as reinforcement. PMID:27335742
High capacity adsorption media and method of producing
Tranter, Troy J.; Mann, Nicholas R.; Todd, Terry A.; Herbst, Ronald S.
2010-10-05
A method of producing an adsorption medium to remove at least one constituent from a feed stream. The method comprises dissolving and/or suspending at least one metal compound in a solvent to form a metal solution, dissolving polyacrylonitrile into the metal solution to form a PAN-metal solution, and depositing the PAN-metal solution into a quenching bath to produce the adsorption medium. The at least one constituent, such as arsenic, selenium, or antimony, is removed from the feed stream by passing the feed stream through the adsorption medium. An adsorption medium having an increased metal loading and increased capacity for arresting the at least one constituent to be removed is also disclosed. The adsorption medium includes a polyacrylonitrile matrix and at least one metal hydroxide incorporated into the polyacrylonitrile matrix.
High capacity adsorption media and method of producing
Tranter, Troy J [Idaho Falls, ID; Herbst, R Scott [Idaho Falls, ID; Mann, Nicholas R [Blackfoot, ID; Todd, Terry A [Aberdeen, ID
2008-05-06
A method of producing an adsorption medium to remove at least one constituent from a feed stream. The method comprises dissolving at least one metal compound in a solvent to form a metal solution, dissolving polyacrylonitrile into the metal solution to form a PAN-metal solution, and depositing the PAN-metal solution into a quenching bath to produce the adsorption medium. The at least one constituent, such as arsenic, selenium, or antimony, is removed from the feed stream by passing the feed stream through the adsorption medium. An adsorption medium having an increased metal loading and increased capacity for arresting the at least one constituent to be removed is also disclosed. The adsorption medium includes a polyacrylonitrile matrix and at least one metal hydroxide incorporated into the polyacrylonitrile matrix.
Elastic-plastic analysis of annular plate problems using NASTRAN
NASA Technical Reports Server (NTRS)
Chen, P. C. T.
1983-01-01
The plate elements of the NASTRAN code are used to analyze two annular plate problems loaded beyond the elastic limit. The first problem is an elastic-plastic annular plate loaded externally by two concentrated forces. The second problem is stressed radially by uniform internal pressure for which an exact analytical solution is available. A comparison of the two approaches together with an assessment of the NASTRAN code is given.
40 CFR 413.71 - Specialized definitions.
Code of Federal Regulations, 2012 CFR
2012-07-01
... deposition of conductive material from an autocatalytic plating solution without application of electrical current. (c) The term operation shall mean any step in the electroless plating process in which a metal is...
NASA Astrophysics Data System (ADS)
Nguyen Van Do, Vuong
2018-04-01
In this paper, a modified Kirchhoff theory is presented for free vibration analyses of functionally graded material (FGM) plate based on modified radial point interpolation method (RPIM). The shear deformation effects are taken account into modified theory to ignore the locking phenomenon of thin plates. Due to the proposed refined plate theory, the number of independent unknowns reduces one variable and exists with four degrees of freedom per node. The simulated free vibration results employed by the modified RPIM are compared with the other analytical solutions to verify the effectiveness and the accuracy of the developed mesh-free method. Detail parametric studies of the proposed method are then conducted including the effectiveness of thickness ratio, boundary condition and material inhomogeneity on the sample problems of square plates. Results illustrated that the modified mesh-free RPIM can effectively predict the numerical calculation as compared to the exact solutions. The obtained numerical results are indicated that the proposed method are stable and well accurate prediction to evaluate with other published analyses.
NASA Astrophysics Data System (ADS)
Liu, Lei; Wang, Xu
2017-12-01
Three-dimensional analytical solutions are derived for the structural instability of a parallel array of mutually attracting identical simply supported orthotropic piezoelectric rectangular microplates by means of a linear perturbation analysis. The two surfaces of each plate can be either insulating or conducting. By considering the fact that the shear stresses and the normal electric displacement (or electric potential) are zero on the two surfaces of each plate, a 2 × 2 transfer matrix for a plate can be obtained directly from the 8 × 8 fundamental piezoelectricity matrix without resolving the original Stroh eigenrelation. The critical interaction coefficient can be determined by solving the resulting generalized eigenvalue problem for the piezoelectric plate array. Also considered in our analysis is the in-plane uniform edge compression acting on the four sides of each piezoelectric plate. Our results indicate that the stabilizing influence of the piezoelectric effect on the structural instability is unignorable; the edge compression always plays a destabilizing role in the structural instability of the plate array with interactions.
Enhanced Dissolution of Platinum Group Metals Using Electroless Iron Deposition Pretreatment
NASA Astrophysics Data System (ADS)
Taninouchi, Yu-ki; Okabe, Toru H.
2017-12-01
In order to develop a new method for efficiently recovering platinum group metals (PGMs) from catalyst scraps, the authors investigated an efficient dissolution process where the material was pretreated by electroless Fe deposition. When Rh-loaded alumina powder was kept in aqua regia at 313 K (40 °C) for 30 to 60 minutes, the Rh hardly dissolved. Meanwhile, after electroless Fe plating using a bath containing sodium borohydride and potassium sodium tartrate as the reducing and complexing agents, respectively, approximately 60 pct of Rh was extracted by aqua regia at 313 K (40 °C) after 30 minutes. Furthermore, when heat treatment was performed at 1200 K (927 °C) for 60 minutes in vacuum after electroless plating, the extraction of Rh approached 100 pct for the same leaching conditions. The authors also confirmed that the Fe deposition pretreatment enhanced the dissolution of Pt and Pd. These results indicate that an effective and environmentally friendly process for the separation and extraction of PGMs from catalyst scraps can be developed utilizing this Fe deposition pretreatment.
NASA Astrophysics Data System (ADS)
Muench, Falk; Oezaslan, Mehtap; Svoboda, Ingrid; Ensinger, Wolfgang
2015-10-01
We present new electroless palladium plating reactions, which can be applied to complex-shaped substrates and lead to homogeneous, dense and conformal palladium films consisting of small nanoparticles. Notably, autocatalytic and surface-selective metal deposition could be achieved on a wide range of materials without sensitization and activation pretreatments. This provides a facile and competitive route to directly deposit well-defined palladium nanofilms on e.g. carbon, paper, polymers or glass substrates. The reactions proceed at mild conditions and are based on easily accessible chemicals (reducing agent: hydrazine; metal source: PdCl2; ligands: ethylenediaminetetraacetic acid (EDTA), acetylacetone). Additionally, the water-soluble capping agent 4-dimethylaminopyridine (DMAP) is employed to increase the bath stability, to ensure the formation of small particles and to improve the film conformity. The great potential of the outlined reactions for micro- and nanofabrication is demonstrated by coating an ion-track etched polycarbonate membrane with a uniform Pd film of approximately 20 nm thickness. The as-prepared membrane is then employed as a highly miniaturized flow reactor, using the reduction of 4-nitrophenol with NaBH4 as a model reaction.
[Screening and antibacterial function of Bacillus amyloliquefaciens X030].
He, Hao; Zhu, Yingling; Chi, Liqing; Zhao, Zizhao; Wang, Ting; Zuo, Mingxing; Zhang, Tong; Zhou, Fengjuan; Xia, Liqiu; Ding, Xuezhi
2015-09-04
We isolated 339 bacillus strains from 72 soil samples all over the country, then purified their antimicrobial compounds and studied the antibacterial activity, to enrich bacillus resources and explore their second metabolites. A bacillus strain with strong antibacterial activity was selected by dilution plate and water bath heating from a soil sample from a peanut plantation in Henan Province; this strain was identified according to morphological observation, physiological and biochemical characteristics, and consequences of 16S rRNA homologous analysis. Antibacterial compound from the identified strain, Bacillus amyloliquefaciens X030, was separated and purified by acetone precipitation, Sephadex chromatography, C18 reverse phase column chromatography. Its molecular weight was analyzed by LC-MS/MS. The antibacterial activity was characterized by disc diffusion and plate two-way cultivation. Bacillus amyloliquefaciens was isolated that not only has antibacterial activity against Staphylococcus aureus, Candida albican and Saccharomycetes; but also against Pyriculariaoryzae, Chili pointed cell anthrax, Gloeosporium eriobotryae speg and Phytophthora parasitica. The compound was confirmed as polypeptide. Bacillus amyloliquefaciens X030 can produce a polypeptide that inhibits pathogenic bacteria and plant pathogenic fungi.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vasil’ev, V. I.; Gagis, G. S., E-mail: galina.gagis@gmail.com; Kuchinskii, V. I.
2015-07-15
Processes are considered in which ultrathin layers of III–V ternary solid solutions are formed via the delivery of Group-V element vapors to GaAs and GaSb semiconductor plates, with solid-phase substitution reactions occurring in the surface layers of these plates. This method can form defect-free GaAs{sup 1–x}P{sup x}, GaAs{sup x}Sb{sup 1–x}, and GaP{sup x}Sb{sup 1–x} layers with thicknesses of 10–20 nm and a content x of the embedded components of up to 0.04.
Yang, Jiashi; Liu, Jinjin; Li, Jiangyu
2007-04-01
A rectangular ceramic plate with appropriate electrical load and operating mode is analyzed for piezoelectric transformer application. An exact solution from the three-dimensional equations of linear piezoelectricity is obtained. The solution simulates the real operating situation of a transformer as a vibrating piezoelectric body connected to a circuit. Transforming ratio, input admittance, and efficiency of the transformer are obtained.
Zhang, Peng; Watanabe, Kunio; Eishi, Tokida
2007-12-01
Japanese macaques (Macaca fuscata) in a free-ranging group in Jigokudani valley, Nagano prefecture, are known to bathe in a hot spring. We used scan sampling in a study aimed at elucidating the causal factors and possible social transmission of this behavior. From 1980-2003, 31% of a total 114 females in the group habitually bathed in the hot spring. The habit was more widespread in dominant matrilines than in subordinate matrilines. Infants whose mothers bathed were more likely to bathe than infants of mothers who did not bathe. The number of monkeys bathing was clearly influenced by ambient air temperature. More monkeys bathed in the hot spring in winter than in summer. The results support the thermoregulation hypothesis of hot-spring bathing. Bathing behavior varies among age and sex categories of monkeys, with adult females and juveniles bathing more often than adult males and subadults. We compared hot-spring bathing with other thermoregulatory behaviors in various primate populations. (c) 2007 Wiley-Liss, Inc.
Friebel, H.
1959-01-01
The spontaneous twitchings of isolated frog sartorius muscles in 0.7% NaCl solution have been studied. Addition of 1 mg./ml. of (±)-carnitine hydrochloride, or of (±)-carnitine base, to the bath fluid had no influence on the spontaneous activity of the muscles, their excitability or their ability to liberate potassium. This indicates that carnitine is not a natural inhibitor of striated frog muscle. Fluids enriched with potassium either from twitching muscle or by addition of KCl inhibited the activity of muscles reversibly. PMID:13825014
Production of permeable cellulose triacetate membranes
Johnson, B.M.
1986-12-23
A phase inversion process for the preparation of cellulose triacetate (CTA) and regenerated cellulose membranes is disclosed. Such membranes are useful as supports for liquid membranes in facilitated transport processes, as microfiltration membranes, as dialysis or ultrafiltration membranes, and for the preparation of ion-selective electrodes. The process comprises the steps of preparing a casting solution of CTA in a solvent comprising a mixture of cyclohexanone and methylene chloride, casting a film from the casting solution, and immersing the cast film in a methanol bath. The resulting CTA membrane may then be hydrolyzed to regenerated cellulose using conventional techniques.
Production of permeable cellulose triacetate membranes
Johnson, Bruce M.
1986-01-01
A phase inversion process for the preparation of cellulose triacetate (CTA) and regenerated cellulose membranes is disclosed. Such membranes are useful as supports for liquid membranes in facilitated transport processes, as microfiltration membranes, as dialysis or ultrafiltration membranes, and for the preparation of ion-selective electrodes. The process comprises the steps of preparing a casting solution of CTA in a solvent comprising a mixture of cyclohexanone and methylene chloride, casting a film from the casting solution, and immersing the cast film in a methanol bath. The resulting CTA membrane may then be hydrolyzed to regenerated cellulose using conventional techniques.
Baral, A; Engelken, R; Stephens, W; Farris, J; Hannigan, R
2006-05-01
This study evaluated aquatic toxicities of chromium and chromium-containing laboratory samples representative of effluents from chromium electroplating industries, and compared the aquatic environmental risks of hexavalent and trivalent chromium electroplating operations. Trivalent chromium electroplating has emerged as an acceptable alternative to hazardous hexavalent chromium electroplating. This process substitution has reduced the human health impact in the workplace and minimized the production of hazardous sludge regulated under the Resource Conservation and Recovery Act (RCRA). The thrust behind this research was to investigate whether trivalent chromium electroplating operations have lower adverse impacts on standardized toxicity test organisms. Ceriodaphnia dubia and Pimephales promelas were used to investigate toxicities of trivalent chromium (Cr (III)), hexavalent chromium (Cr (VI)), and industrial effluents. In agreement with previous studies, Cr (III) was found to be less toxic than Cr (VI). Despite having several organic and inorganic constituents in the effluents obtained from trivalent chromium plating baths, they exhibited less adverse effects to C. dubia than effluents obtained from hexavalent chromium electroplating baths. Thus, transition from hexavalent to trivalent chromium electroplating processes may be justified. However, because of the presence of organic constituents such as formate, oxalate, and triethylene glycol in effluents, trivalent chromium electroplating operations may face additional regulatory requirements for removal of total organic carbon.
NASA Astrophysics Data System (ADS)
Hsu, Chih-I.; Hou, Kung-Hsu; Ger, Ming-Der; Wang, Gao-Liang
2015-12-01
Ni-P/BN(h) composite coatings are prepared by means of the conventional electroless plating from the bath containing up to 10.0 g/l of hexagonal boron nitride particles with size 0.5 μm. The Ni-P coating is also prepared as a comparison. Cationic surfactant cetyltrimethylammonium bromide (CTAB) is used to stabilize the electrolyte, and the optimum CTAB concentration resulting in a nonagglomerated dispersion of particles is obtained using a dispersion stability analyzer. Morphology of the coatings and the effect of incorporated particles on coating structure and composition are investigated via scanning electron microscopy, field emission electron probe micro-analyzer and X-ray diffraction analysis. Hardness, roughness, friction coefficient and wear resistance of the coatings are also evaluated using Vickers microhardness tester, atomic force microscopy and ball-on disk machine. The presence of CTAB in the depositing bath has a positive effect on the surface roughness and performance of Ni-P/BN(h) composite coatings. The friction and wear tests results show that incorporation of 14.5 vol% BN(h) particles into the Ni-P coating lowers the coating friction coefficient by about 75% and the wear resistance of the Ni-P composites is approximately 10 times higher than Ni-P coating.
Staining human lymphocytes and onion root cell nuclei with madder root.
Cücer, N; Guler, N; Demirtas, H; Imamoğlu, N
2005-01-01
We performed staining experiments on cells using natural dyes and different mordants using techniques that are used for wool and silk dyeing. The natural dye sources were madder root, daisy, corn cockle and yellow weed. Ferrous sulfate, copper sulfate, potassium tartrate, urea, potassium aluminum sulfate and potassium dichromate were used as mordants. Distilled water, distilled water plus ethanol, heptane, and distilled water plus methanol were used as solvents. All dye-mordant-solvent combinations were studied at pH 2.4, 3.2 and 4.2. The generic staining procedure was to boil 5-10 onion roots or stimulated human lymphocyte (SHL) preparations in a dye bath on a hot plate. Cells were examined at every half hour. For multicolor staining, madder-dyed lymphocytes were decolorized, then stained with Giemsa. The AgNOR technique was performed following the decolorization of Giemsa stained lymphocytes. Good results were obtained for both onion root cells and lymphocytes that were boiled for 3 h in a dye bath that included 4 g madder root, 4 g ferrous sulfate as mordant in 50 ml of 1:1 (v/v) methanol:distilled water. The pH was adjusted to 4.2 with 6 ml acetic acid. We conclude that madder root has potential as an alternative dye for staining biological materials.
Methods for globally treating silica optics to reduce optical damage
Miller, Philip Edward; Suratwala, Tayyab Ishaq; Bude, Jeffrey Devin; Shen, Nan; Steele, William Augustus; Laurence, Ted Alfred; Feit, Michael Dennis; Wong, Lana Louie
2012-11-20
A method for preventing damage caused by high intensity light sources to optical components includes annealing the optical component for a predetermined period. Another method includes etching the optical component in an etchant including fluoride and bi-fluoride ions. The method also includes ultrasonically agitating the etching solution during the process followed by rinsing of the optical component in a rinse bath.
Gupta, Neeraj; Kumar, Dilip; Palla, Aparna
2017-04-01
Orthodontists are commonly faced with the decision of what to do with debonded or inaccurately positioned brackets. An economical option to this dilemma is to recycle the brackets. Many recycling methods have been proposed, but the optimal bond strength of these recycled brackets needs further evaluation. Objectives: To evaluate and compare the effect of three recycling methods: (i) Sandblasting (ii) Sandblasting / direct flaming (iii) Sandblasting /direct flaming /acid bath solution on shear bond strength (SBS) of stainless steel brackets. Eighty human premolars were bonded with premolar stainless steel brackets as per manufacturer's instructions. The teeth were divided into 4 groups (n=20): Recycling and initial debonding was not done in Control group (Group I). After initial bonding, the brackets in the rest of the three experimental groups were debonded and recycled by following methods: (i) Sandblasting (Group II) (ii) Sandblasting /direct flaming (Group III) (iii) Sandblasting /direct flaming /acid bath solution (Group IV). Further the recycled brackets were bonded. The specimens were then subjected to testing in a Universal machine. The evaluation of the variation of the shear bond strength (SBS) among test groups was done using one-way ANOVA test and inter-experimental group comparison was done by Newman-Keuls multiple post hoc procedure. Group I (8.6510±1.3943MPa) showed the highest bond strength followed by Group II (5.0185±0.9758MPa), Group IV (2.30±0.65MPa) and Group III (2.0455± 0.6196MPa). Statistically significant variations existed in the shear bond strength (SBS) in all groups analyzed except between Group III and Group IV. The following conclusions were drawn from the study: 1. Shear bond strength of new brackets is significantly higher than the recycled brackets. 2. Brackets sandblasted with 90µm aluminium oxide particle air-abrasion showed significantly higher shear bond strength compared to direct flaming/sandblasting and direct flaming/sandblasting/acid bath solution. 3. Sandblasting with 90µm aluminium oxide particle air-abrasion is the simplest, most efficient and hence, the preferred method of recycling debonded brackets. Key words: Orthodontic bracket, recycling, shear bond strength.
NASA Astrophysics Data System (ADS)
Macchiavelli, Chiara; Vergés, Jaume; Schettino, Antonio; Fernández, Manel; Turco, Eugenio; Torné, Montserrat; Casciello, Emilio
2017-04-01
We present the first high-resolution kinematic model for the southern North Atlantic since the late Cretaceous, in order to constrain the Iberian kinematics during the last 83 Myr. Assessing the detailed movements of the Iberian plate is crucial to constrain the kinematics of the Western Mediterranean region and to better understand the Pyrenees and Betic - Rif orogenic systems evolution. The new plate motions model for the Iberia - North America plate pair is accompanied by a high-resolution isochron map for the southern North Atlantic region, resulting from a re-examination of 400 ship tracks and 3 aeromagnetic tracks in the NGDC data base for the area between the Azores triple junction and 46° N. We derive a well-constrained kinematic solution for the relative motion between an independent Iberia and North America from seafloor spreading data despite the short length of the magnetic lineations and the scarcity of large-offset transform faults and fracture zones. Accurate finite reconstruction poles for the Iberia - North America conjugate plate pair between the Late Cretaceous (Chron 34, 83.5 Ma) and the present day (Chron 2A, 2.58 Ma) are calculated on the basis of a set of 100 magnetic profiles through an iterative method. Euler poles and associated angles of rotation are computed as follow. An initial rotation pole is calculated using only magnetic anomaly crossings. The initial large uncertainty associated with the first determination is reduced by generating a set of synthetic fracture zones associated with the initial pole and using points sampled along these structures in conjunction with magnetic anomaly crossings to calculate a new Euler pole and associated confidence ellipse. This procedure is repeated n times, generating a sequence of improving approximate solutions and stopped when the solution become stable excluding solutions that were inconsistent with geological constraints. We used these results to build a comprehensive kinematic model for the North America - Iberia - Europe - Africa - Morocco plate system. A set of plate reconstructions illustrates the Iberian plate kinematics and show plate boundaries and velocity fields since the Late Cretaceous attempting to reconcile the geology of Pyrenees and Betic - Rif chain and the kinematic of the southern North Atlantic Ocean. This research is supported by project ALPIMED (PIE-CSIC-201530E082)
Numerical study of large-eddy breakup and its effect on the drag characteristics of boundary layers
NASA Technical Reports Server (NTRS)
Kinney, R. B.; Taslim, M. E.; Hung, S. C.
1985-01-01
The break-up of a field of eddies by a flat-plate obstacle embedded in a boundary layer is studied using numerical solutions to the two-dimensional Navier-Stokes equations. The flow is taken to be incompressible and unsteady. The flow field is initiated from rest. A train of eddies of predetermined size and strength are swept into the computational domain upstream of the plate. The undisturbed velocity profile is given by the Blasius solution. The disturbance vorticity generated at the plate and wall, plus that introduced with the eddies, mix with the background vorticity and is transported throughout the entire flow. All quantities are scaled by the plate length, the unidsturbed free-stream velocity, and the fluid kinematic viscosity. The Reynolds number is 1000, the Blasius boundary layer thickness is 2.0, and the plate is positioned a distance of 1.0 above the wall. The computational domain is four units high and sixteen units long.
Techathuvanan, Chayapa; Draughon, Frances Ann; D'Souza, Doris Helen
2011-02-01
Novel rapid Salmonella detection assays without the need for sophisticated equipment or labor remain in high demand. Real-time reverse transcriptase PCR (RT-PCR) assays, though rapid and sensitive, require expensive thermocyclers, while a novel RT loop-mediated isothermal amplification (RT-LAMP) method requires only a simple water bath. Our objective was to compare the detection sensitivity of Salmonella Typhimurium from the pork processing environment by RT-LAMP, RT-PCR, and culture-based assays. Carcass and surface swabs and carcass rinses were obtained from a local processing plant. Autoclaved carcass rinses (500 ml) were spiked with Salmonella Typhimurium and filtered. Filters were placed in stomacher bags containing tetrathionate broth (TTB) and analyzed with or without 10-h enrichment at 37 °C. Natural swabs were stomached with buffered peptone water, and natural carcass rinses were filtered, preenriched, and further enriched in TTB. Serially-diluted enriched samples were enumerated by spread plating on xylose lysine Tergitol 4 agar. RNA was extracted from 5 ml of enriched TTB with TRIzol. RT-LAMP assay using previously described invA primers was conducted at 62 °C for 90 min in a water bath with visual detection and by gel electrophoresis. SYBR Green I-based-real-time RT-PCR was carried out with invA primers followed by melt temperature analysis. The results of RT-LAMP detection for spiked carcass rinses were comparable to those of RT-PCR and cultural plating, with detection limits of 1 log CFU/ml, although they were obtained significantly faster, within 24 h including preenrichment and enrichment. RT-LAMP showed 4 of 12 rinse samples positive, while RT-PCR showed 1 of 12 rinse samples positive. For swabs, 6 of 27 samples positive by RT-LAMP and 5 of 27 by RT-PCR were obtained. This 1-day RT-LAMP assay shows promise for routine Salmonella screening by the pork industry. Copyright ©, International Association for Food Protection
Reduction of astrometric plates
NASA Technical Reports Server (NTRS)
Stock, J.
1984-01-01
A rapid and accurate method for the reduction of comet or asteroid plates is described. Projection equations, scale length correction, rotation of coordinates, linearization, the search for additional reference stars, and the final solution are examined.
Cathodic electrodeposition of p-CuSCN nanorod and its dye-sensitized photocathodic property
NASA Astrophysics Data System (ADS)
Sun, Lina; Ichinose, Keigo; Sekiya, Tomohiro; Sugiura, Takashi; Yoshida, Tsukasa
Mechanism of cathodic electrodeposition of CuSCN from ethanolic solutions containing Cu2+ and SCN- was studied in detail. Job's plot for the absorption spectra of mixed solution in various Cu2+: SCN- ratios have revealed the presence of [Cu(SCN)2]0 as a soluble species responsible to the electrode process in SCN- rich solutions. From Levich analysis of diffusion limited current employing a rotating disc electrode (RDE), diffusion coefficients of 5.2 × 10-6 cm2 s-1 and 3.0 × 10-6 cm2 s-1 in ethanol at 298 K were determined for [Cu(SCN)2]0 and [Cu(SCN)]+, respectively. Morphology as well as crystallographic orientation of the product films significantly changed by the composition of the electrolytic baths. When the bath contains excess of Cu2+ and mixed solvent up to 50% ethanol content to water was used, strong anisotropic crystal growth along the c-axis was observed. When electrolysis was carried out under stationary conditions, the nanorod structures in high aspect ratios could be obtained, due to the limited transport of the active species to the tip of the rods. When rhodamine B was adsorbed onto such CuSCN as a sensitizer, dye-sensitized photocathodic current was observed with an incident photon to current conversion efficiency (IPCE) of 4.4% at the absorption maximum, suggesting its usefulness as the hole conducting electrode in construction of nanostructured solar cells.
Identification of proteins in renaissance paintings by proteomics.
Tokarski, Caroline; Martin, Elisabeth; Rolando, Christian; Cren-Olivé, Cécile
2006-03-01
The presented work proposes a new methodology based on proteomics techniques to identify proteins in old art paintings. The main challenging tasks of this work were (i) to find appropriate conditions for extracting proteins from the binding media without protein hydrolysis in amino acids and (ii) to develop analytical methods adapted to the small sample quantity available. Starting from microsamples of painting models (ovalbumin-based, which is the major egg white protein, and egg-based paintings), multiple extraction solutions (HCl, HCOOH, NH3, NaOH) and conditions (ultrasonic bath, mortar and pestle, grinding resin) were evaluated. The best results were obtained using a commercial kit including a synthetic resin, mortar and pestle to grind the sample in an aqueous solution acidified with trifluoroacetic acid at 1% with additional multiple steps of ultrasonic baths. The resulting supernatant was analyzed by MALDI-TOF in linear mode to verify the efficiency of the extraction solution. An enzymatic hydrolysis step was also performed for protein identification; the peptide mixture was analyzed by nanoLC/nanoESI/Q-q-TOF MS/MS with an adapted chromatographic run for the low sample quantity. Finally, the developed methodology was successfully applied to Renaissance art painting microsamples of approximately 10 microg from Benedetto Bonfigli's triptych, The Virgin and Child, St. John the Baptist, St. Sebastian (XVth century), and Niccolo di Pietro Gerini's painting, The Virgin and Child (XIVth century), identifying, for the first time and without ambiguity, the presence of whole egg proteins (egg yolk and egg white) in a painting binder.
Finite stretching of a circular plate of neo-Hookean material.
NASA Technical Reports Server (NTRS)
Biricikoglu, V.
1971-01-01
The analytical solution presented is based on the assumption that the deformed thickness of the plate is approximately constant. The nonlinear equations governing finite axisymmetric deformations of a circular plate made of neo-Hookean material are used in the analysis. The variation of circumferential extension ratio and the variation of deformed thickness are shown in graphs.
Master equation and two heat reservoirs.
Trimper, Steffen
2006-11-01
A simple spin-flip process is analyzed under the presence of two heat reservoirs. While one flip process is triggered by a bath at temperature T, the inverse process is activated by a bath at a different temperature T'. The situation can be described by using a master equation approach in a second quantized Hamiltonian formulation. The stationary solution leads to a generalized Fermi-Dirac distribution with an effective temperature Te. Likewise the relaxation time is given in terms of Te. Introducing a spin representation we perform a Landau expansion for the averaged spin
DOE Office of Scientific and Technical Information (OSTI.GOV)
McPeak, Kevin M.; Becker, Matthew A.; Britton, Nathan G.
2010-12-03
Chemical bath deposition (CBD) offers a simple and inexpensive route to deposit semiconductor nanostructures, but lack of fundamental understanding and control of the underlying chemistry has limited its versatility. Here we report the first use of in situ X-ray absorption spectroscopy during CBD, enabling detailed investigation of both reaction mechanisms and kinetics of ZnO nanowire growth from zinc nitrate and hexamethylenetetramine (HMTA) precursors. Time-resolved X-ray absorption near-edge structure (XANES) spectra were used to quantify Zn(II) speciation in both solution and solid phases. ZnO crystallizes directly from [Zn(H{sub 2}O){sub 6}]{sup 2+} without long-lived intermediates. Using ZnO nanowire deposition as an example,more » this study establishes in situ XANES spectroscopy as an excellent quantitative tool to understand CBD of nanomaterials.« less
NASA Astrophysics Data System (ADS)
Mizukami, Kohji; Satoh, Kohki; Kanayama, Hiroshi; Itoh, Hidenori; Tagashira, Hiroaki; Shimozuma, Mitsuo; Okamoto, Hiroyuki; Takasaki, Satoko; Kinoshita, Muneshige
The hydroponic culture solution contaminated by fungi is sterilised by a DC corona discharge, and the sterilisation characteristics are investigated in this work. A DC streamer corona discharge is generated at atmospheric pressure in air between needle clusters and a water bath containing contaminated solution by fungus such as Fusarium oxysporum f. sp. spinaciae or Fusarium sp.. It is found that the fungi are killed by the exposure of the corona discharge, and that the death rates of the fungi chiefly depend on the concentration of the hydroponic culture solutions. It is also found that the number densities of the fungi decrease exponentially with the energy expenditure of the corona discharge, and that damping coefficients of the fungi densities depend on the concentration of the hydroponic culture solutions. This suggests that the fungi are chiefly inactivated by electroporation.
NASA Technical Reports Server (NTRS)
Anderson, Melvin S.; Kennedy, David
1993-01-01
The problem considered is the development of the necessary plate stiffnesses for use in the general purpose program VICONOPT for buckling and vibration of composite plate assemblies. The required stiffnesses include the effects of transverse shear deformation and are for sinusoidal response along the plate length as required in VICONOPT. The method is based on the exact solution of the plate differential equations for a composite laminate having fully populated A, B, and D stiffness matrices which leads to an ordinary differential equation of tenth order.
Elastic and plastic buckling of simply supported solid-core sandwich plates in compression
NASA Technical Reports Server (NTRS)
Seide, Paul; Stowell, Elbridge Z
1950-01-01
A solution is presented for the problem of the compressive buckling of simply supported, flat, rectangular, solid-core sandwich plates stressed either in the elastic range or in the plastic range. Charts for the analysis of long sandwich plates are presented for plates having face materials of 24s-t3 aluminum alloy, 76s-t6 alclad aluminum alloy, and stainless steel. A comparison of computed and experimental buckling stresses of square solid-core sandwich plates indicates fair agreement between theory and experiment.
Retrofit implementation of Zernike phase plate imaging for cryo-TEM.
Marko, Michael; Leith, Ardean; Hsieh, Chyongere; Danev, Radostin
2011-05-01
In-focus phase-plate imaging is particularly beneficial for cryo-TEM because it offers a substantial overall increase in image contrast, without an electron dose penalty, and it simplifies image interpretation. We show how phase-plate cryo-TEM can be implemented with an appropriate existing TEM, and provide a basic practical introduction to use of thin-film (carbon) phase plates. We point out potential pitfalls of phase-plate operation, and discuss solutions. We provide information on evaluating a particular TEM for its suitability. Copyright © 2011 Elsevier Inc. All rights reserved.
Electroless metal plating of plastics
Krause, Lawrence J.
1986-01-01
Process for plating main group metals on aromatic polymers is carried out by the use of a nonaqueous solution of a salt of an alkali metal in a positive valence state and a main group metal in a negative valence state with contact between the solution and polymer providing a redox reaction causing the deposition of the main group metal and the reduction of the polymer. Products from the process exhibit useful decorative and electrical properties.
Electroless metal plating of plastics
Krause, L.J.
1982-09-20
Process for plating main group metals on aromatic polymers is carried out by the use of a nonaqueous solution of a salt of an alkali metal in a positive valence state and a main group metal in a negative valence state with contact between the solution and polymer providing a redox reaction causing the deposition of the main group metal and the reduction of the polymer. Products from the process exhibit useful decorative and electrical properties.
Electroless metal plating of plastics
Krause, Lawrence J.
1984-01-01
Process for plating main group metals on aromatic polymers is carried out by the use of a nonaqueous solution of a salt of an alkali metal in a positive valence state and a main group metal in a negative valence state with contact between the solution and polymer providing a redox reaction causing the deposition of the main group metal and the reduction of the polymer. Products from the process exhibit useful decorative and electrical properties.
Slip effects on MHD flow and heat transfer of ferrofluids over a moving flat plate
NASA Astrophysics Data System (ADS)
Ramli, Norshafira; Ahmad, Syakila; Pop, Ioan
2017-08-01
In this study, the problem of MHD flow and heat transfer of ferrofluids over a moving flat plate with slip effect and uniform heat flux is considered. The governing ordinary differential equations are solved via shooting method. The effect of slip parameter on the dimensionless velocity, temperature, skin friction and Nusselt numbers are numerically studied for the three selected ferroparticles; magnetite (Fe3O4), cobalt ferrite (CoFe2O4) and Mn-Zn ferrite (Mn-ZnFe2O4) with water-based fluid. The results indicate that dual solutions exist for a plate moving towards the origin. It is found that the slip process delays the boundary layer separation. Moreover, the velocity and thermal boundary-layer thicknesses decrease in the first solution while increase with the increase of the value of slip parameters in second solution.
Forced Convection and Sedimentation Past a Flat Plate
NASA Technical Reports Server (NTRS)
Pelekasis, Nikolaos A.; Acrivos, Andreas
1995-01-01
The steady laminar flow of a well-mixed suspension of monodisperse solid spheres, convected steadily past a horizontal flat plate and sedimenting under the action of gravity, is examined. It is shown that, in the limit as Re approaches infinity and epsilon approaches 0, where Re is the bulk Reynolds number and epsilon is the ratio of the particle radius a to the characteristic length scale L, the analysis for determining the particle concentration profile has several aspects in common with that of obtaining the temperature profile in forced-convection heat transfer from a wall to a fluid stream moving at high Reynolds and Prandtl numbers. Specifically, it is found that the particle concentration remains uniform throughout the O(Re(exp -1/2)) thick Blasius boundary layer except for two O(epsilon(exp 2/3)) thin regions on either side of the plate, where the concentration profile becomes non-uniform owing to the presence of shear-induced particle diffusion which balances the particle flux due to convection and sedimentation. The system of equations within this concentration boundary layer admits a similarity solution near the leading edge of the plate, according to which the particle concentration along the top surface of the plate increases from its value in the free stream by an amount proportional to X(exp 5/6), with X measuring the distance along the plate, and decreases in a similar fashion along the underside. But, unlike the case of gravity settling on an inclined plate in the absence of a bulk flow at infinity considered earlier, here the concentration profile remains continuous everywhere. For values of X beyond the region near the leading edge, the particle concentration profile is obtained through the numerical solution of the relevant equations. It is found that, as predicted from the similarity solution, there exists a value of X at which the particle concentration along the top side of the plate attains its maximum value phi(sub m) and that, beyond this point, a stagnant sediment layer will form that grows steadily in time. This critical value of X is computed as a function of phi(sub s), the particle volume fraction in the free stream. In contrast, but again in conformity with the similarity solution, for values of X sufficiently far removed from the leading edge along the underside of the plate, a particle-free region is predicted to form adjacent to the plate. This model, with minor modifications, can be used to describe particle migration in other shear flows, as, for example, in the case of crossflow microfiltration.
On similarity solutions of a boundary layer problem with an upstream moving wall
NASA Technical Reports Server (NTRS)
Hussaini, M. Y.; Lakin, W. D.; Nachman, A.
1986-01-01
The problem of a boundary layer on a flat plate which has a constant velocity opposite in direction to that of the uniform mainstream is examined. It was previously shown that the solution of this boundary value problem is crucially dependent on the parameter which is the ratio of the velocity of the plate to the velocity of the free stream. In particular, it was proved that a solution exists only if this parameter does not exceed a certain critical value, and numerical evidence was adduced to show that this solution is nonunique. Using Crocco formulation the present work proves this nonuniqueness. Also considered are the analyticity of solutions and the derivation of upper bounds on the critical value of wall velocity parameter.
NASA Astrophysics Data System (ADS)
Koga, Toshiaki; Hirakawa, Chieko; Takeshita, Michinori; Terasaki, Nao
2018-04-01
Bathocuproinedisulfonic acid, disodium salt (BCS) is generally used to detect Cu(I) through a color reaction. We newly found BCS fluorescence in the visible blue region in an aqueous solution. However, the fluorescence mechanism of BCS is not well known, so we should investigate its fundamental information. We confirmed that the characteristics of fluorescence are highly dependent on the molecular concentration and solvent properties. In particular, owing to the presence of the copper compound, the fluorescence intensity extremely decreases. By fluorescence quenching, we observed that a copper compound concentration of 10-6 mol/L or less could easily be measured in an aqueous solution. We also observed BCS fluorescence in copper sulfate plating solution and the possibility of detecting monovalent copper by fluorescence reabsorption.
Linear and Nonlinear Analysis of Magnetic Bearing Bandwidth Due to Eddy Current Limitations
NASA Technical Reports Server (NTRS)
Kenny, Andrew; Palazzolo, Alan
2000-01-01
Finite element analysis was used to study the bandwidth of alloy hyperco50a and silicon iron laminated rotors and stators in magnetic bearings. A three dimensional model was made of a heteropolar bearing in which all the flux circulated in the plane of the rotor and stator laminate. A three dimensional model of a plate similar to the region of a pole near the gap was also studied with a very fine mesh. Nonlinear time transient solutions for the net flux carried by the plate were compared to steady state time harmonic solutions. Both linear and quasi-nonlinear steady state time harmonic solutions were calculated and compared. The finite element solutions for power loss and flux bandwidth were compared to those determined from classical analytical solutions to Maxwell's equations.
Zha, Guo-Chun; Sun, Jun-Ying; Dong, Sheng-Jie; Zhang, Wen; Luo, Zong-Ping
2015-01-01
This study aims to assess the biomechanical properties of a novel fixation system (named AFRIF) and to compare it with other five different fixation techniques for quadrilateral plate fractures. This in vitro biomechanical experiment has shown that the multidirectional titanium fixation (MTF) and pelvic brim long screws fixation (PBSF) provided the strongest fixation for quadrilateral plate fracture; the better biomechanical performance of the AFRIF compared with the T-shaped plate fixation (TPF), L-shaped plate fixation (LPF), and H-shaped plate fixation (HPF); AFRIF gives reasonable stability of treatment for quadrilateral plate fracture and may offer a better solution for comminuted quadrilateral plate fractures or free floating medial wall fracture and be reliable in preventing protrusion of femoral head. PMID:25802849
Musuuza, Jackson S; Roberts, Tonya J; Carayon, Pascale; Safdar, Nasia
2017-01-14
Daily bathing with chlorhexidine gluconate (CHG) of intensive care unit (ICU) patients has been shown to reduce healthcare-associated infections and colonization by multidrug resistant organisms. The objective of this project was to describe the process of daily CHG bathing and identify the barriers and facilitators that can influence its successful adoption and sustainability in an ICU of a Veterans Administration Hospital. We conducted 26 semi-structured interviews with a convenience sample of 4 nurse managers (NMs), 13 registered nurses (RNs) and 9 health care technicians (HCTs) working in the ICU. We used qualitative content analysis to code and analyze the data. Dedoose software was used to facilitate data management and coding. Trustworthiness and scientific integrity of the data were ensured by having two authors corroborate the coding process, conducting member checks and keeping an audit trail of all the decisions made. Duration of the interviews was 15 to 39 min (average = 26 min). Five steps of bathing were identified: 1) decision to give a bath; 2) ability to give a bath; 3) decision about which soap to use; 4) delegation of a bath; and 5) getting assistance to do a bath. The bathing process resulted in one of the following three outcomes: 1) complete bath; 2) interrupted bath; and 3) bath not done. The outcome was influenced by a combination of barriers and facilitators at each step. Most barriers were related to perceived workload, patient factors, and scheduling. Facilitators were mainly organizational factors such as the policy of daily CHG bathing, the consistent supply of CHG soap, and support such as reminders to conduct CHG baths by nurse managers. Patient bathing in ICUs is a complex process that can be hindered and interrupted by numerous factors. The decision to use CHG soap for bathing was only one of 5 steps of bathing and was largely influenced by scheduling/workload and patient factors such as clinical stability, hypersensitivity to CHG, patient refusal, presence of IV lines and general hygiene. Interventions that address the organizational, provider, and patient barriers to bathing could improve adherence to a daily CHG bathing protocol.
Chiang, Charles; Eichenfield, Lawrence F
2009-01-01
Standard recommendations for skin care for patients with atopic dermatitis stress the importance of skin hydration and the application of moisturizers. However, objective data to guide recommendations regarding the optimal practice methods of bathing and emollient application are scarce. This study quantified cutaneous hydration status after various combination bathing and moisturizing regimens. Four bathing/moisturizer regimens were evaluated in 10 subjects, five pediatric subjects with atopic dermatitis and five subjects with healthy skin. The regimens consisted of bathing alone without emollient application, bathing and immediate emollient application, bathing and delayed application, and emollient application alone. Each regimen was evaluated in all subjects, utilizing a crossover design. Skin hydration was assessed with standard capacitance measurements. In atopic dermatitis subjects, emollient alone yielded a significantly (p < 0.05) greater mean hydration over 90 minutes (206.2% baseline hydration) than bathing with immediate emollient (141.6%), bathing and delayed emollient (141%), and bathing alone (91.4%). The combination bathing and emollient application regimens demonstrated hydration values at 90 minutes not significantly greater than baseline. Atopic dermatitis subjects had a decreased mean hydration benefit compared with normal skin subjects. Bathing without moisturizer may compromise skin hydration. Bathing followed by moisturizer application provides modest hydration benefits, though less than that of simply applying moisturizer alone.
Steinmetz, P R
1969-07-01
The acid-base relations across the two surfaces of the epithelium of the turtle bladder were examined. By means of the 5,5-dimethyl-2,4-oxazolidinedione (DMO) technique the intracellular OH(-) concentration was measured in the presence and absence of a transepithelial pH gradient. When both sides of the bladder were bathed with solutions free of exogenous CO(2) and bicarbonate at pH 7.41 ([OH(-)] = 239 nmoles/liter), the epithelial cells were alkaline, the mean intracellular [OH(-)] being 347nmoles/liter. This alkalinity of the cells was preserved in bladders that secreted H(+) against a gradient of over 2 pH units. In bathing solutions stirred with 4.85% CO(2) and buffered with 25 mM HCO(3) (-) at pH 7.41 the intracellular [OH(-)] was lower than in CO(2)-free solutions and close to the extracellular [OH(-)]. In the CO(2)-free system anaerobiosis caused increased alkalinity of the cells and inhibition of H(+) secretion presumably by decreased metabolic CO(2) production. Carbonic acid inhibitors reduced H(+) secretion, but had no significant effect on the alkalinity of the cells. An inactive analogue of acetazolamide had no effect on H(+) secretion. The results indicate that the active step in acidification is located near the mucosal surface of the epithelium and that the alkali formed within the epithelial cells moves passively into the serosal solution along an electro-chemical gradient. The inhibitory effect of certain sulfonamides on H(+) secretion by the bladder is directly correlated with their known carbonic anhydrase inhibitory activity, but not associated with a measurable change in the mean intracellular [OH(-)].
Diamond, Jared M.
1966-01-01
1. The relation between osmotic gradient and rate of osmotic water flow has been measured in rabbit gall-bladder by a gravimetric procedure and by a rapid method based on streaming potentials. Streaming potentials were directly proportional to gravimetrically measured water fluxes. 2. As in many other tissues, water flow was found to vary with gradient in a markedly non-linear fashion. There was no consistent relation between the water permeability and either the direction or the rate of water flow. 3. Water flow in response to a given gradient decreased at higher osmolarities. The resistance to water flow increased linearly with osmolarity over the range 186-825 m-osM. 4. The resistance to water flow was the same when the gall-bladder separated any two bathing solutions with the same average osmolarity, regardless of the magnitude of the gradient. In other words, the rate of water flow is given by the expression (Om — Os)/[Ro′ + ½k′ (Om + Os)], where Ro′ and k′ are constants and Om and Os are the bathing solution osmolarities. 5. Of the theories advanced to explain non-linear osmosis in other tissues, flow-induced membrane deformations, unstirred layers, asymmetrical series-membrane effects, and non-osmotic effects of solutes could not explain the results. However, experimental measurements of water permeability as a function of osmolarity permitted quantitative reconstruction of the observed water flow—osmotic gradient curves. Hence non-linear osmosis in rabbit gall-bladder is due to a decrease in water permeability with increasing osmolarity. 6. The results suggest that aqueous channels in the cell membrane behave as osmometers, shrinking in concentrated solutions of impermeant molecules and thereby increasing membrane resistance to water flow. A mathematical formulation of such a membrane structure is offered. PMID:5945254
Receptivity of the compressible mixing layer
NASA Astrophysics Data System (ADS)
Barone, Matthew F.; Lele, Sanjiva K.
2005-09-01
Receptivity of compressible mixing layers to general source distributions is examined by a combined theoretical/computational approach. The properties of solutions to the adjoint Navier Stokes equations are exploited to derive expressions for receptivity in terms of the local value of the adjoint solution. The result is a description of receptivity for arbitrary small-amplitude mass, momentum, and heat sources in the vicinity of a mixing-layer flow, including the edge-scattering effects due to the presence of a splitter plate of finite width. The adjoint solutions are examined in detail for a Mach 1.2 mixing-layer flow. The near field of the adjoint solution reveals regions of relatively high receptivity to direct forcing within the mixing layer, with receptivity to nearby acoustic sources depending on the source type and position. Receptivity ‘nodes’ are present at certain locations near the splitter plate edge where the flow is not sensitive to forcing. The presence of the nodes is explained by interpretation of the adjoint solution as the superposition of incident and scattered fields. The adjoint solution within the boundary layer upstream of the splitter-plate trailing edge reveals a mechanism for transfer of energy from boundary-layer stability modes to Kelvin Helmholtz modes. Extension of the adjoint solution to the far field using a Kirchhoff surface gives the receptivity of the mixing layer to incident sound from distant sources.
Caya, Teresa; Musuuza, Jackson; Yanke, Eric; Schmitz, Michelle; Anderson, Brooke; Carayon, Pascale; Safdar, Nasia
2015-01-01
We undertook a systems engineering approach to evaluate housewide implementation of daily chlorhexidine bathing. We performed direct observations of the bathing process and conducted provider and patient surveys. The main outcome was compliance with bathing using a checklist. Fifty-seven percent of baths had full compliance with the chlorhexidine bathing protocol. Additional time was the main barrier. Institutions undertaking daily chlorhexidine bathing should perform a rigorous assessment of implementation to optimize the benefits of this intervention.
Analysis of prestressed concrete slab-and-beam structures
NASA Astrophysics Data System (ADS)
Sapountzakis, E. J.; Katsikadelis, J. T.
In this paper a solution to the problem of prestressed concrete slab-and-beam structures including creep and shrinkage effect is presented. The adopted model takes into account the resulting inplane forces and deformations of the plate as well as the axial forces and deformations of the beam, due to combined response of the system. The analysis consists in isolating the beams from the plate by sections parallel to the lower outer surface of the plate. The forces at the interface, which produce lateral deflection and inplane deformation to the plate and lateral deflection and axial deformation to the beam, are established using continuity conditions at the interface. The influence of creep and shrinkage effect relative with the time of the casting and the time of the loading of the plate and the beams is taken into account. The estimation of the prestressing axial force of the beams is accomplished iteratively. Both instant (e.g. friction, slip of anchorage) and time dependent losses are encountered. The solution of the arising plate and beam problems, which are nonlinearly coupled, is achieved using the analog equation method (AEM). The adopted model, compared with those ignoring the inplane forces and deformations, describes better the actual response of the plate-beams system and permits the evaluation of the shear forces at the interfaces, the knowledge of which is very important in the design of prefabricated ribbed plates.
Platinum Electrodeposition for Supported ALD Templated Foam Hohlraum Liners
Horwood, Corie; Stadermann, Michael; Biener, Monika; ...
2017-12-20
Two commercially available platinum plating solutions (Platanex III and Platanex Luna) were evaluated for the electrodeposition of platinum layers on gold hohlraums and cylindrically shaped silver-gold ingots. The successful deposition of thin Pt layers on gold hohlraums as well as thick Pt layers on silver-gold alloys will allow for the integration of atomic layer deposition templated foam inside a hohlraum. We found that when the manufacturer’s recommendations for the Pt plating solutions were used, the coatings obtained were unacceptable because of cracking, poor adhesion, or thin and powdery Pt deposits. Therefore, alternative plating parameters were investigated, and the conditions resultingmore » in acceptable coatings are reported here.« less
Platinum Electrodeposition for Supported ALD Templated Foam Hohlraum Liners
DOE Office of Scientific and Technical Information (OSTI.GOV)
Horwood, Corie; Stadermann, Michael; Biener, Monika
Two commercially available platinum plating solutions (Platanex III and Platanex Luna) were evaluated for the electrodeposition of platinum layers on gold hohlraums and cylindrically shaped silver-gold ingots. The successful deposition of thin Pt layers on gold hohlraums as well as thick Pt layers on silver-gold alloys will allow for the integration of atomic layer deposition templated foam inside a hohlraum. We found that when the manufacturer’s recommendations for the Pt plating solutions were used, the coatings obtained were unacceptable because of cracking, poor adhesion, or thin and powdery Pt deposits. Therefore, alternative plating parameters were investigated, and the conditions resultingmore » in acceptable coatings are reported here.« less
Methods of removing a constituent from a feed stream using adsorption media
Tranter, Troy J [Idaho Falls, ID; Mann, Nicholas R [Rigby, ID; Todd, Terry A [Aberdeen, ID; Herbst, Ronald S [Idaho Falls, ID
2011-05-24
A method of producing an adsorption medium to remove at least one constituent from a feed stream. The method comprises dissolving and/or suspending at least one metal compound in a solvent to form a metal solution, dissolving polyacrylonitrile into the metal solution to form a PAN-metal solution, and depositing the PAN-metal solution into a quenching bath to produce the adsorption medium. The at least one constituent, such as arsenic, selenium, or antimony, is removed from the feed stream by passing the feed stream through the adsorption medium. An adsorption medium having an increased metal loading and increased capacity for arresting the at least one constituent to be removed is also disclosed. The adsorption medium includes a polyacrylonitrile matrix and at least one metal hydroxide incorporated into the polyacrylonitrile matrix.
Jasper, Ahren W; Miller, James A; Klippenstein, Stephen J
2013-11-27
The low-pressure-limit unimolecular decomposition of methane, CH4 (+M) ⇆ CH3 + H (+M), is characterized via low-order moments of the total energy, E, and angular momentum, J, transferred due to collisions. The low-order moments are calculated using ensembles of classical trajectories, with new direct dynamics results for M = H2O and new results for M = O2 compared with previous results for several typical atomic (M = He, Ne, Ar, Kr) and diatomic (M = H2 and N2) bath gases and one polyatomic bath gas, M = CH4. The calculated moments are used to parametrize three different models of the energy transfer function, from which low-pressure-limit rate coefficients for dissociation, k0, are calculated. Both one-dimensional and two-dimensional collisional energy transfer models are considered. The collision efficiency for M = H2O relative to the other bath gases (defined as the ratio of low-pressure limit rate coefficients) is found to depend on temperature, with, e.g., k0(H2O)/k0(Ar) = 7 at 2000 K but only 3 at 300 K. We also consider the rotational collision efficiency of the various baths. Water is the only bath gas found to fully equilibrate rotations, and only at temperatures below 1000 K. At elevated temperatures, the kinetic effect of "weak-collider-in-J" collisions is found to be small. At room temperature, however, the use of an explicitly two-dimensional master equation model that includes weak-collider-in-J effects predicts smaller rate coefficients by 50% relative to the use of a statistical model for rotations. The accuracies of several methods for predicting relative collision efficiencies that do not require solving the master equation and that are based on the calculated low-order moments are tested. Troe's weak collider efficiency, βc, includes the effect of saturation of collision outcomes above threshold and accurately predicts the relative collision efficiencies of the nine baths. Finally, a brief discussion is presented of mechanistic details of the energy transfer process, as inferred from the trajectories.
Degradation behaviour of LAE442-based plate-screw-systems in an in vitro bone model.
Wolters, Leonie; Besdo, Silke; Angrisani, Nina; Wriggers, Peter; Hering, Britta; Seitz, Jan-Marten; Reifenrath, Janin
2015-04-01
The use of absorbable implant materials for fixation after bone fracture helps to avoid a second surgery for implant removal and the risks and costs involved. Magnesium (Mg) is well known as a potential metallic material for degradable implants. The aim of the present in vitro study was to evaluate if degradable LAE442-based magnesium plate-screw-systems are suitable candidates for osteosynthesis implants in load-bearing bones. The corrosion behaviour was tested concerning the influence of different surface treatments, coatings and screw torques. Steel plates and screws of the same size served as control. Plates without special treatment screwed on up to a specified torque of 15cNm or 7cNm, NaOH treated plates (15cNm), magnesium fluoride coated plates (15cNm) and steel plates as control (15cNm) were examined in pH-buffered, temperature-controlled SBF solution for two weeks. The experimental results indicate that the LAE442 plates and screws coated with magnesium fluoride revealed a lower hydrogen evolution in SBF solution as well as a lower weight loss and volume decrease in μ-computed tomography (μCT). The nanoindentation and SEM/EDX measurements at several plate areas showed no significant differences. Summarized, the different screw torques did not affect the corrosion behaviour differently. Also the NaOH treatment seemed to have no essential influence on the degradation kinetics. The plates coated with magnesium fluoride showed a decreased corrosion rate. Hence, it is recommended to consider this coating for the next in vivo study. Copyright © 2015 Elsevier B.V. All rights reserved.
Williams, Rebecca M.; Farnum, Cornelia E.
2010-01-01
Ambient temperature and physical activity modulate bone elongation in mammals, but mechanisms underlying this plasticity are a century-old enigma. Longitudinal bone growth occurs in cartilaginous plates, which receive nutritional support via delivery of solutes from the vasculature. We tested the hypothesis that chronic exercise and warm temperature promote bone lengthening by increasing solute delivery to the growth plate, measured in real time using in vivo multiphoton microscopy. We housed 68 weanling female mice at cold (16°C) or warm (25°C) temperatures and allowed some groups voluntary access to a running wheel. We show that exercise mitigates the stunting effect of cold temperature on limb elongation after 11 days of wheel running. All runners had significantly lengthened limbs, regardless of temperature, while nonrunning mice had shorter limbs that correlated with housing temperature. Tail length was impacted only by temperature, indicating that the exercise effect was localized to limb bones and was not a systemic endocrine reaction. In vivo multiphoton imaging of fluoresceinated tracers revealed enhanced solute delivery to tibial growth plates in wheel-running mice, measured under anesthesia at rest. There was a minimal effect of rearing temperature on solute delivery when measured at an intermediate room temperature (20°C), suggesting that a lasting increase in solute delivery is an important factor in exercise-mediated limb lengthening but may not play a role in temperature-mediated limb lengthening. These results are relevant to the study of skeletal evolution in mammals from varying environments and have the potential to fundamentally advance our understanding of bone elongation processes. PMID:20930127
NASA Astrophysics Data System (ADS)
Adelkhani, H.; Ghaemi, M.; Jafari, S. M.
Pulse current electrodeposition (PCD) method has been applied to the preparation of novel electrolytic manganese dioxide (EMD) in order to enhance the cycle life of rechargeable alkaline MnO 2-Zn batteries (RAM). The investigation was carried out under atmospheric pressure through a systematic variation of pulse current parameters using additive free sulfuric acid-MnSO 4 electrolyte solutions. On time (t on) was varied from 0.1 to 98.5 ms, off time (t off) from 0.25 to 19.5 ms, pulse frequencies (f) from 10 to 1000 Hz and duty cycles (θ) from 0.02 to 0.985. A constant pulse current density (I p) of 0.8 A dm -2 and average current densities (I a) in the range of 0.08-0.8 A dm -2 were applied in all experiments. Resultant materials were characterized by analyzing their chemical compositions, X-ray diffractions (XRD) and scanning electron microscopy (SEM). Electrochemical characterizations carried out by charge/discharge cycling of samples in laboratory designed RAM batteries and cyclic voltammetric experiments (CV). It has been proved that specific selection of duty cycle, in the order of 0.25, and a pulse frequency of 500 Hz, results in the production of pulse deposited samples (pcMDs) with more uniform distribution of particles and more compact structure than those obtained by direct current techniques (dcMDs). Results of the test batteries demonstrated that, in spite of reduction of bath temperature in the order of 40 °C, the cycle life of batteries made of pcMDs (bath temperature: 60 °C) was rather higher than those made of conventional dcMDs (boiling electrolyte solution). Under the same conditions of EMD synthesis temperature of 80 °C and battery testing, the maximum obtainable cycle life of optimized pcMD was nearly 230 cycles with approximately 30 mAh g -1 MnO 2, compared to that of dcMD, which did not exceed 20 cycles. In accordance to these results, CV has confirmed that the pulse duty cycle is the most influential parameter on the cycle life than the pulse frequency. Because of operating at lower bath temperatures, the presented synthetic mode could improve its competitiveness in economical aspects.