Detection of chemical warfare-related species on complex aerosol particles deposited on surfaces using an ion trap-based aerosol mass spectrometer

A new type of aerosol mass spectrometer was developed by minimal modification of an existing commercial ion trap to analyze the semivolatile components of aerosols in real time. An aerodynamic lens-based inlet system created a well-collimated particle beam that impacted into the heated ionization volume of the commercial ion trap mass spectrometer. The semivolatile components of the aerosols were thermally vaporized and ionized by electron impact or chemical ionization in the source. The nascent ions were extracted and injected into the ion trap for mass analysis. The utility of this instrument was demonstrated by identifying semivolatile analytes in complex aerosols. This study is part of an ongoing effort to develop methods for identifying chemical species related to CW agent exposure. Our efforts focused on detection of CW-related species doped on omnipresent aerosols such as house dust particles vacuumed from various surfaces found in any office building. The doped aerosols were sampled directly into the inlet of our mass spectrometer from the vacuumed particle stream. The semivolatile analytes were deposited on house dust and identified by positive ion chemical ionization mass spectrometry up to 2.5 h after deposition. Our results suggest that the observed semivolatile species may have been chemisorbed on some of the particle surfaces in submonolayer concentrations and may remain hours after deposition. This research suggests that identification of trace CW agent-related species should be feasible by this technique.     

A New Underwater Floodlight

The inhibitory effect of polyethylene oxides (PEO) on development by hydroquinone is analyzed. Inhibition is observed when the compounds are added to the emulsion or to a liquid emulsion-developer system. It is shown that PEa is irreversibly adsorbed to silver holide but that the port so adsorbed is not responsible for the effect. PEO does not influence the diffusion of developer components through a gelatingel. A technique was devised, whereby it was possible to demonstrate that addition ofquinone to a component of a sulphite-free alkaline hydroquinone developer overcomes the inhibition. It is concluded that PEa interferes in some way with the accumulation of semiquinone development catalyst at the grain surface. Possible factors are the presence of Oxidizing groups or free radical centres in PEO or oxonium salt formation.     

A New Technique for High Contrast Development in Rapid Processing

A rapid developing system with a high contrast comparable to that of the lith system is described. The mechanism of the high contrast development has been investigated by using a model system. It has been found that a considerable amount of semiquinone is formed in a high pH and high-sulphite developer and a specific retardation effect by some antifogging agents enhances a contrast of a characteristic curve. By use of this system “fine line reproduction in superimposition” and other contact printing works can be better achieved with rapid access.     

The high‐speed measurement of a partial area imaging system applied to photoresist development processing

Abstract

Among the parameters that affect photolithography, the most important are exposure and development time which affect the coating photoresist characteristics. This study further researches the relationship between the exposure and development time using a high speed image inspection system, and the relationship between the development time and photoresist depth using a Scanning Probe Microscope (SPM). A partial scan CCD camera and high speed frame capture card were used to obtain the photoresist development processing parameters. The experimental results verified that this imaging system provides an economical and effective method for producing a micro‐photo‐etched product. It is expected that these experiments can also offer some good references useful in the micro electro mechanical industrial field.     

Methodology for determining the radiation efficiency and contrast characteristics in the case of electron and ion lithography, using positive polymer resists

In this paper we propose a methodology for calculating the radiation efficiency and the contrast characteristics for an arbitrary couple of positive resist-developer in the field of electron and ion lithography.

The methodology uses a Monte Carlo calculation technique. It is based on the knowledge of the solubility rate as a function of the exposure dose. The proposed method allows profile modelling and the evaluation of the most important relations in the case of exposure and development conditions that differ from the conditions for which the solubility rate dependence on the exposure dose is known.

The radiation efficiency and the contrast characteristic values are calculated for some particular cases of electron and ion lithography. Using these values, some development process characteristics such as developed depth as a function of the exposure dose and the developing time, and developed profiles are calculated.

Comparisons are carried out and a good agreement is observed between our results, the experimental data and the modelling results, given by other researchers.     

Model Experiments with Polyethylene Okides

A cell, producing measurable currents, is used as a model in further studies on the inhibitory action of polyethylene oxides (PEO) on development by hydroquinone (Hq). The cell reaction is found to be inhibited when PEO is in contact with the anode (silver), but not when in contact with the cathode (silver bromide). There is in general a parallel between the behaviour of substances in the cell and in a photographic emulsion test. Polymers and substituted hydroquinones which do not show the PEO-Hq effect with emulsion are inactive in the cell. The resistance of some Hq derivatives to PEO inhibition may be associated with their demonstrated adsorption to silver, but an exception suggests an alternative, that they may have more active semiquinones. The results of the cell experiments are believed to be applicable to the case of photographic development. The hypothesis that PEO inhibits Hq development by interfering with the adsorption of developing agent (semiquinone) at latent image specks thus receives some support.     

Effect of some cement components on ion contents in different brain areas of adult male albino mice

The aim of this study is to investigate the chronic effect of some cement components on the content of ions in different brain areas in adult male albino mice. It is clear that chronic intraperitoneal administration of 0.0013 mg/g aluminum ion caused a significant increase in aluminum, calcium and sodium ions and significant decrease in iron ions, the chronic intraperitoneal administration of 0.00065 mg/g iron caused a significant increase in iron, calcium, and sodium ions but No significant change in potassium and aluminum ions. Chronic intraperitoneal administration of 0.0013 mg/g silicon caused no significant change in calcium, potassium, sodium, aluminum and iron. Chronic intraperitoneal administration of 0.0013 mg/g aluminum, 0.0013 mg/g silicon and 0.00065 mg/g iron, respectively, --using separating time interval 30 min between each--caused a higher elevation in calcium, sodium, aluminum and iron concentrations than the elevation in other groups and no significant change in potassium ions. This may be due to the elevation in glutamate which leads to increase in the intracellular of calcium concentration and the inhibition of membrane-bound Na(+), K(+), Ca(2+) ATPase activity which lead to cellular alterations and may be death. So long-term exposure to cement components as environmental pollutants may lead to neurodegenerative diseases.     

Study of the direct current breakage process in an external nonuniform magnetic field

We study experimentally the influence of an external nonuniform magnetic field with transverse and longitudinal components on the electric characteristics, plasma configuration, and cathode spot arrangement of vaccum-arc discharge. It is revealed that for a cylindrical cathode, cathode spots are nonuniformly distributed on the cathode surface, the spot configuration has no axial symmetry, and the arrangement of spots changes in time depending on the induction value of the external pulsed magnetic field. With an increase in induction, spots (on average) are arranged closer to the cathode, i.e., displaced to the region of weaker transverse field. For two cathode geometries, the probabilities of direct current breakage depending on the induction of the external nonuniform magnetic field are experimentally determined. To determine the conditions of current breakage, a three-dimensional mathematical model of ion motion is suggested and the current breakage criterion is formulated. The trajectories of fast cathode ions in an electrode system with a ring cathode have been calculated using the model. Calculations were performed in a nonuniform magnetic field, the radial and axial components of which have been measured experimentally. It is shown that conditions of current breakage determined with this criterion agree with the results of experiment.     

The Photographic Implications of the Chemistry of Quinone*

The data obtained in the investigation of the chemistry of quinone were used in conjunction with sensitometric data to relate fog, accelerated, contagious, infectious and superadditive development. Latensification and desensitization were studied. The photographic experiments have been summarized and discussed. It was concluded that hydroxyhydroquinone or its precursors were the prime cause of development fog and aerial fog. It was also suggested that hydroxyhydroquinone is the cause of accelerated, contagious and infectious development. It was further shown that the best anti-foggants against hydroxyhydroquinone were the superadditive components of developers, namely Phenidone and Elon. It was suggested that Phenidone and Elon react with hydroxyhydroquinone to form a powerful non-fogging developer. Furthermore, it appeared from the data that benzotriazole also reacted with hydroxyhydroquinone to form a non-fogging compound, whereas 6-nitrobenzimidazole was merely strongly adsorbed to fogged areas and thus inhibited development, it was shown that Fremy's salt, potassium nitrosodisulphonate, may be used to give reproducible latensification without aerial drying. This suggested that the usual latensifying agents must be aerially oxidized to free radicals before they latensify. This also explained the irreproducibility of latensification by perborate and metabisulphite. The work on latensification led to experiments which showed that inhibition by the products of development in paraphenylenediamine developers was due to the destruction of latent image and small development centres by the semiquinone and the diimine of the paraphenylenediamine. It was found that Wurster's Slue and methylpyridinium iodide could desensitize exposed film. It was also found that a dilute solution of Wurster’s Blue could completely desensitize unexposed film.     

Inverted magnetron manometer with enhanced operating time

If a cold-cathode ionization gauge is operated in a gas atmosphere with a high content of hydrocarbons at high pressures, the pressure reading of the gauge is disturbed by the contamination after a certain time of operation. Since in the most cases it is not possible to eliminate these disturbing residual gas components, one has to demand that the measuring process may not be substantially influenced by these gas components. To enhance the time of reliable pressure reading of a cold-cathode gauge we have equipped the entrance of an inverted magnetron gauge head with an ion baffle. By this measure the time of a reliable operation of the gauge is increased at least by a factor 3. The construction of this ion baffle is rather simple. It does not require any additional voltage supply or additional magnets. An additional feedthrough is only necessary for the measurement of the discharge current of the measuring system. The gauge has a range of pressure measurement from 10⁻⁹ to 3×10⁻³ mbar.     

On the UV-induced polymeric behavior of Chinese lacquer

To dry Chinese lacquer rapidly for the protection and restoration of archeological findings coated by lacquer or excavated lacquer wares and the development of new application of this lacquer, we carried out UV curing technology to improve its curing rate using a high-pressure mercury lamp as a UV source in the absence of any additional photoinitiator. The effects of mainly specific components in Chinese lacquer sap and the role of each reactive group of urushiol, namely hydroxyl groups, hydrogen on the phenyl ring, and olefins in the side chain, in the course of UV exposure were well-investigated. The UV-cured Chinese lacquer films were also characterized by FT-IR, (1)H NMR, SEM, TGA, and Py-GC/MS. The results showed that urushiol was the main component to form Chinese lacquer films, and decomposed to generate the urushiol semiquinone radicals, which sequentially induced the polymerization of Chinese lacquer by radical polymerization, as well as radical substitution under UV irradiation. In addition, the TG analysis suggested that polysaccharide and glycoproteins were integrated with the UV-cured films by covalent bonding. Furthermore, this method could be suitable to fast cure other phenol bearing long aliphatic unsaturated chain, such as CNSL.     

Evaluation of long-term exposure to the magnetic field produced from power lines

For some years, the Italian Regional Agencies for Environmental Protection (ARPA) have been engaged in the evaluation of long-term exposure to 50 Hz magnetic fields for receptors close to power lines. In this study, experiences and procedures are suggested in order to estimate long-term exposure levels in the case of magnetic induction produced contemporaneously by different power lines. In the simplest cases, the influence of a single line is evaluated by verifying the correlation factor between the variation of the current in each line and the measured magnetic induction. When the prevalence of a single line is not clear and systematic, much additional data (voltage, current, phases and geometrical configuration) have to be considered. The case of a school in Livomo near two lines. placed on the same supports, is described and a range of the most probable exposure values is given, corresponding to the phase change of the two current fluxes.     

Induction of DNA DSB and its rejoining in clamped and non-clamped tumours after exposure to carbon ion beams in comparison to X rays

We studied double-strand breaks (DSB) induction and rejoining in clamped and non-clamped transplanted tumours in mice leg after exposure to 80 keV μm(-1) carbon ions and X rays. The yields of DSB in the tumours were analysed by a static-field gel electrophoresis. The OER of DSB after X rays was 1.68±0.31, and this value was not changed after 1 h rejoining time (1.40±0.26). These damages in oxygenated conditions were rejoined 60-70% within 1 h in situ. No difference was found between the exposure to X rays and carbon ions for the induction and rejoining of DSB. Thus, the values of OER and rejoined fraction after exposure to carbon ions were similar to those after X rays, and the calculated relative biological effectivenesses of carbon ion were around 1 under both oxygen conditions. The yields of DSB in vivo depend on exposure doses, oxygen conditions and rejoining time, but not on the types of radiation quality.     

C/C复合材料在原子氧辐照下的结构性能演变

通过分析失重率、显微形貌变化讨论了原子氧辐照对C/C复合材料以及SiC基体改性C/C复合材料(C/C-SiC)的损伤机制; 并通过热膨胀系数(CTE)、热扩散率(TD)以及弯曲强度等性能的变化, 进一步讨论了原子氧辐照损伤对材料热物理及力学性能影响。结果表明, C/C复合材料受原子氧辐照损伤是物理化学综合作用, 属于冲击诱发-增强表面化学刻蚀; SiC组元表现出良好的抗原子氧侵蚀性能, 阻碍了原子氧向材料内部侵蚀, 但是SiC组元在更长时间辐照后出现机械破损; C/C复合材料在原子氧辐照下失重率呈线性增加, 而C/C-SiC复合材料失重率小于C/C复合材料且增长幅度越来越小; C/C复合材料和C/C-SiC复合材料的整体结构性能在辐照损伤后发生了一定变化。     

Failure time distributions for complex equipment

The exponential distribution is inadequate as a failure time model for most components; however, under certain conditions (in particular, that component failure rates are small and mutually independent, and failed components are immediately replaced or perfectly repaired), it is applicable to complex repairable systems with large numbers of components in series, regardless of component distributions, as shown by Drenick in 1960. This result implies that system behavior may become simpler as more components are added. We review necessary conditions for the result and present some simulation studies to assess how well it holds in systems with finite numbers of components. We also note that Drenick's result is analogous to similar results in other systems disciplines, again resulting in simpler behavior as the number of entities in the system increases.     

Superadditive Black and White Developing Agents: A Review

The relationship between chemical structure and superadditive effectiveness in photographic development was systematically investigated for different classes of substances. The existence of a stable radical is a pre-requisite for a strong superadditivity. The formation of a stable semiquinone demands a chemical structure which allows a high resonance stabilization. In phenidone, the resonance stabilization (as well as the superadditive effect) disappears for example through displacement of the phenyl ring by alkyl substitution or by the introduction of strongly electrophilic groups. Negative charge or non-coplanar structures also reduce the stability of the semiquinone and the superadditivity. Beyond that, a definite redox potential difference is necessary for superadditive effectiveness on photographic development. The results equally well support the regeneration theory and the charge barrier model as the cause of super-additivity.     

Active Polyethylene Oxides: Mechanism of Development

A group of graft co-polymers of polyethylene oxide (PEO) and vinyl acetate (VA) is shown to have a particularly strong inhibiting effect on hydroquinone development, whether added to the emulsion or to the developer. Data are also provided for substituted hydroquinones; much less inhibition is noticed against 2-(N,N-diethylamino-methyl) hydroquinone. Adsorption of the latter and of an integrally coloured PEO to silver powder is demonstrated. The paradoxical difference between the effect of PEO on hydroquinone developer (inhibition) and on a mixed developer, e.g., MQ (acceleration) is discussed The situation is thought to be inexplicable on the charge-barrier theory. An attempt is made to base an hypothesis of PEO action on the following concepts. The active agent of a hydroquinone developer is the semiquinone ion, and this is inhibited by PEO; metol is unaffected by PEO; developing agents are operative by reason of adsorption to latent image silver.     

Monte Carlo simulation analysis of the effects of different system performance levels on the importance of multi-state components

In the present paper, we consider some frequently used importance measures, in their generalized form proposed by the authors for application to multi-state systems constituted by multi-state components. To catch the dynamics of multi-state systems, Monte Carlo simulation has been utilized. A simulation approach has been presented which allows estimating of all the importance measures of the components at a given performance level in a single simulation, provided that the components are independent. The effects of different performance demands made on the system on the importance of its multi-state components have been examined with respect to a simple multi-state series–parallel system. The results have shown that a performance level of a component may be more critical for the achievement of a system performance and less critical for another.     

Rechargeable Seawater Batteries—From Concept to Applications

Harvesting energy from natural resources is of significant interest because of their abundance and sustainability. Seawater is the most abundant natural resource on earth, covering two‐thirds of the surface. The rechargeable seawater battery is a new energy storage platform that enables interconversion of electrical energy and chemical energy by tapping into seawater as an infinite medium. Here, an overview of the research and development activities of seawater batteries toward practical applications is presented. Seawater batteries consist of anode and cathode compartments that are separated by a Na‐ion conducting membrane, which allows only Na⁺ ion transport between the two electrodes. The roles and drawbacks of the three key components, as well as the development concept and operation principles of the batteries on the basis of previous reports are covered. Moreover, the prototype manufacturing lines for mass production and automation, and potential applications, particularly in marine environments are introduced. Highlighting the importance of engineering the cell components, as well as optimizing the system level for a particular application and thereby successful market entry, the key issues to be resolved are discussed, so that the seawater battery can emerge as a promising alternative to existing rechargeable batteries.