Non-conducting Substances Research Articles

Enhancing electricity-driven methanogenesis by assembling biotic-abiotic hybrid system in anaerobic membrane bioreactor

Biotic-abiotic hybrid systems are promising technologies to enhance methane production in anaerobic wastewater treatment. However, the dense structure of the extracellular polymeric substances (EPS) present in anaerobic granular sludge (AGS) poses challenges with respect to the implementation of hybrid systems and efficient interspecies electron transfer. In this study, the use of AGS with a Ni/Fe layered double hydroxide@activated carbon (Ni/Fe LDH@C-AGS) was investigated in an anaerobic membrane bioreactor (AnMBR). The hybrid system showed a significant increase of 82% in methane production. Further research revealed that Ni/Fe LDH@C regulated the dense structure of EPS, stimulated the production of cytochromes, and facilitated the decomposition of nonconductive substances. Surprisingly, the hybrid system also promoted resistance to membrane fouling and extended membrane life by 81%. This study provides insights into the operation of a biotic-abiotic hybrid system by regulating the dense structure of EPS ultimately resulting in an enhanced methane production.

Study of Plasma Arc Underwater Penetration Processes in Steel Structures Covered with Non-conductive Materials

Recently, plenty of offshore platforms have faced decommissioning. Offshore steel structures covered with rust, mud, and barnacles require suitable cutting methods for their removal. The non-transferred plasma arc is highly efficient in cutting both conductive and non-conductive materials and is expected to play an important role in offshore demolition operations. This work aims to investigate the underwater penetration process of non-transferred plasma arcs on steel structures covered with non-conductive substances. The workpiece consisted of a 5 mm cement layer and a 10 mm steel plate, whose removal mass and hole morphology were recorded at several moments. It was found that the hole of the cement layer was larger than that of the steel plate, while the mass removal rate of the steel plate was much higher than that of the cement layer. The hole in the cement layer gradually changes from an inverted cone to a drum, and the hole in the steel plate is always an inverted cone. A combined heat source model with time variation is proposed based on the experimental results, and a 2D axisymmetric simulation model is developed. The error between the simulated and experimental hole dimensions was within 3.1%, proving that the proposed heat source model can reflect the heat process of the workpiece well.

Study of underwater plasma arc ignition and cutting process for surface nonconductive steel structures for offshore decommissioning

Plasma cutting is expected to play a significant role as a highly efficient thermal cutting method in offshore decommissioning. Offshore steel structures get covered with nonconductive substances such as rust, mud, and barnacles, which affect the ignition and maintenance of the plasma arcs. This study aimed to determine a suitable method for cutting steel structures covered with nonconductive substances. The entire process of the underwater plasma arc, including ignition, piercing, and cutting, was systematically studied experimentally. A multi-arc root state occurred during the ignition of the transferred plasma arc. In this state, the workpiece current is a significant signal for characterizing the piercing of nonconductive substances on the steel structure. The composite plasma arc exhibits better resistance to interference and a longer ignition distance. In lateral water flow, which was used to simulate ocean currents, the composite plasma arc pierced through 12-mm thick mild steel. Based on the experimental results, a novel cutting strategy was proposed, and a double-layered workpiece consisting of 8-mm thick cement and 12-mm thick mild steel was successfully cut. These findings may drive the application of plasma arc cutting in offshore decommissioning.

Review of acoustical and optical techniques to measure absolute salinity of seawater

The salinity of seawater is of fundamental importance in climate studies, and the measurement of the variable requires high accuracy and precision in order to be able to resolve its typically small variations in the oceans with depth and over long-time scales. This is currently only possible through the measurement of conductivity, which has led to the definition of a Practical Salinity scale. However, seawater is also composed of a large number of non-conducting substances that constitute salinity anomalies. Differences of the ratios of the constituents of sea salt from the Reference Composition may also change salinity anomalies. The establishment of formulae for calculating the thermodynamic properties of seawater has led to the definition of the concept of Absolute Salinity (SA), which includes such anomalies and is similar in approach to the notion of density. Although the routine in situ measurement of SA is still a huge challenge, numerous developments based on acoustic techniques, but above all, refractometry, interferometry or complex fiber optic assemblies, have been tested for this purpose. The development of monolithic components has also been initiated. The measurement of the refractive index by these techniques has the advantage of taking into account all the dissolved substances in seawater. This paper reviews the difficulties encountered in establishing theoretical or empirical relations between SA and the sound velocity, the refractive index or the density, and discusses the latest and most promising developments in SA measurement with a particular focus on in situ applications.

Fabrication and study of properties in metallized ABS plastic

ABSTRACTCoating metal on non-conductive substrates is known as metallization. Metallization became quite popular method these days owing to the fact the demand of metallic properties on non-conductive substances has grown. Acrylonitrile butadiene styrene is a plastic which is being used by various industries mainly because it has a unique combination of toughness, strength and light weight when compared to other plastics. Need of metallization crops up when the industries desire for a material that is light in weight, yet is thermally and electrically conductive. Industries like automotive, textile and electronic are popularly consuming metallized plastic. This paper throws light on a successful method of metallization that deposits thick layer of copper metal on the plastic. This work includes the study of micrograph, qualitative assessment of adhesive strength by Tape test method and electrical performance measurement of the coating in order to understand its nature. The work demonstrates a less complex method as compared to conventional ones. Hence, demanding less time and money when performed in bulk.

Characterization of protein-immobilized polystyrene nanoparticles using impedance spectroscopy.

A novel approach for characterization of non-conductive protein-immobilized nanoparticles using AC impedance spectroscopy combined with conductive atomic force microscopy was examined. As AC impedance spectroscopy can provide information on diverse electrical properties such as capacitance and inductance, it is applicable to the characterization of non-conductive substances. Several non-conductive protein-immobilized polystyrene nanoparticles were analyzed using AC impedance spectroscopy, and their impedance spectra were used as markers for nanoparticle identification. Analyses of impedance signals using an electrical circuit model established that the capacitance and inductance of each nanoparticle changed with the adsorbed protein and that impedance spectral differences were characteristic properties of the proteins. From this study, AC impedance spectroscopy was shown to be a useful tool for characterization of non-conductive nanoparticles and is expected to be applicable to the development of sensors for nanomaterials.

A fiber-array probe technique for measuring the viscosity of a substance under shock compression

A fiber-array probe is designed to measure the damping behavior of a small perturbed shock wave in an opaque substance, by which the effective viscosity of substance under the condition of high temperature and high pressure can be constrained according to the flyer-impact technique. It shows that the measurement precision of the shock arrival time by using this technique is within 2 ns. To easily compare with the results given by electrical pin technique, the newly developed method is used to investigate the effective viscosity of aluminum (Al). The shear viscosity coefficient of Al is determined to be 1700 Pa·s at 71 GPa with a strain rate of 3.6 × 106 s−1, which is in good agreement with the results of other methods. The advantage of the new technique over the electrical pin one is that it is applicable for studying the non-conductive substances.

Synthesis of UV-curable chitosan derivatives and palladium (II) adsorption behavior on their UV-exposed films

Novel chitosan derivatives with UV-curable functional groups, such as 3-methoxy-4-(2-hydroxy-3-methacryloyloxypropoxy)benzyl, 3,4-bis(2-hydroxy-3-methacryloyloxypropoxy)benzyl, 3-methoxy-4-methacryloyloxybenzyl, and 3,5-dimethacryloyloxybenzyl groups, were prepared. Introduction of photosensitive functional groups to chitosan was accomplished by reductive N-alkylation via Schiff’s bases using corresponding photosensitive aldehydes. Compared to starting chitosan, UV-curable chitosan derivatives showed better solubility in several organic solvents, such as DMSO and 70% methacrylic acid. The solubility of these compounds increased with an increase in the degree of substitution of the N-alkyl side chains. After UV irradiation for 20 s under a high-pressure mercury lamp at a distance of 15 cm from the samples, acidic methanol solutions of these derivatives were transformed to gels in the presence of photo-initiator, and their dried films adsorbed palladium (II) at pH 1.1 and pH 5.3. The UV-curable chitosan derivatives were successfully used as coating materials for electroless plating on non-conductive substances.

Visualisation of gas–oil two-phase flows in pressurised pipes using electrical capacitance tomography

Electrical capacitance tomography (ECT) was used to image various two-phase gas–oil horizontal flows on a 7.62 cm (3 in.) pressurised test loop. ECT is a novel non-invasive technique for imaging mixtures of electrically non-conducting substances. One of its most promising applications is the visualisation of gas–oil flows. This work presents a series of imaging experiments using a pressure-resistant ECT sensor. By varying the oil and gas flow rates, different flow regimes were established in the test loop. ECT images were obtained for each case and compared with (a) the flow observed through a transparent section in the loop and (b) the prediction of the Taitel–Duckler flow map. The results confirm the suitability of ECT for imaging gas–oil flows.

Origin of changes in electrical impedance during the growth and fermentation process of yeast in batch culture

The electrical impedance of the culture medium shows complex changes during the growth and fermentation process of yeast, and this prevents its possible application for the monitoring of certain yeast activities. Clarification of the mechanism of such changes is thus essential for practical use. As a first step toward this aim, the impedance, yeast concentration, and pH of a batch culture medium were measured using special cells with two compartments and also the usual type of cell with one compartment. In the special cells, the yeast was cultured in one compartment only. Conducting ions and nonconducting substances diffused through an intermediate porous membrane sandwiched between the two compartments. The impedances of the two compartments were measured simultaneously by the four-electrode method. The main mechanism responsible for increasing the impedance was the conducting ions produced by the yeast extract added as a nutrient to the culture broth by certain nonconducting substances during the process of growth. The increase in the yeast concentration was also a minor factor increasing the impedance. These increases surpassed the impedance decrease caused by the increase of H(+) ions produced by some accumulated acidic substances, and the impedance thus increased.

Adhesion of Rime and Glaze on Conductors Protected by Various Materials

A layer of about 2 cm of either glaze or rime was accumulated on a stranded aluminum conductor covered by various non-conducting substances. This ice accretion was formed by exposing the conductor ...

The unsuitability of gold as a standard for non-conducting samples in X-ray photoelectron spectroscopy

The bombardment of non-conducting substances with X-rays causes charging which alters the kinetic energies of the ejected photoelectrons. Some means of

Eine Apparatur zum Verdampfen hochschmelzender Erdalkalichalkogenide

An apparatus is described, which permits the evaporation of nonconducting substances with high melting points by electron bombardment.

Transmission Electron Microscopy of Sodium Chloride Films Prepared by Electron Beam Flashing Thinning Technique

A new method of electron beam flashing for preparing thin single crystal films of non-conducting substances has been developed. With use of the method, mechanically introduced and grown-in dislocations and precipitates in NaCl containing 0.00 to 2.3 mole % of CaCl 2 are observed by transmission electron microscopy. The Burgers vectors of dislocations are determined by observing their contrast change which occurs when the crystal is set for different Bragg reflections. Characteristic climb of them into helical form due to electron irradiation is observed. The rate of climb expressed by the number of vacancy pairs causing climb per incident electron of 100–150 keV is found to be of the order of 10 -5 in the films of NaCl containing 0.1 mole % of CaCl 2 about 5000A in thickness. Observations on incipient and final precipitates in NaCl containing more than 0.3 mole % of CaCl 2 are compared with the results of previous X-ray studies.

不傳導體物質の接觸による高クロム不銹鐵の孔又は洞侵蝕とその防止

In the acidic oxidizing solution containing chlorine ion, for example in aqueous solution of ferric chloride, the entire surface of 14% Cr stainless iron or steel corrodes, whereas that of 21%_??_35% Cr stainless iron, being in the passive state, does not corrode at all. When the surface of this high chromium stainless iron comes in contact with non-conductive substances, such as glass, cork or rubber, or noble metals like platinum or gold, a narrow crevice is formed, and the corrosion takes place, making pit or cavity at the point of contact. On 22% Cr, 22%Cr-3%Mo, 22%Cr-7%Mo, and 35% Cr stainless iron, two kinds of specimen, namely those annealed at 900° and those quenched in the water from 1000° or 1300°. were tested in 5% ferric chloride aqueous solution to ascertain whether pit or cavity corrosion takes place by bringing them in contact with non-conductive substances. The mechanism which gives rise to the phenomenon is also discussed. It has been ascertained that while 22% Cr stainless iron is affectfd by the contact, the said effect is greatly reduced when it is alloyed with 3_??_7% molybdenum and quenched in the water, The author discusses briefly the method of prevention of the contact effects based upon the foregoing, experiments

酸性溶液中に於ける21% Cr不銹鋼の表面の不働性と内部洞侵蝕に就て

An experiment of surface-passivity is made on 14% and 21% Cr stainless steels in a solution of 10% FeCl3, the former is severely attacked while the latter unattacked, retaining metallic lustre provided that the portion of the contact surface of the specimen and glass supporter is attacked to form a pit. When the specimen of 21% Cr stainless steel was immersed in the solution for a long time, the portion severely attacked formed a cavity, while the passive film on the surface of the inner-corroded portion slacken ed. The “inner-corrosion” of the 21% Cr steel occurs also in the case of the surface of the specimen in contact with non-cond uctive substances other than glass supporter, and a discussion of this phenomenon is also made, taking the non-metallic inclusions, pits and fissures on the surface of the specimen into account. These undesirable inclusions, pits and contact portion with non-conductive substances act as capillary crevices on the surface which becomes anodic while the other portions of the surface is subjected only to the action of oxidation and remain in a passive state. It is also ascertained that when the surface of the specimen is covered with glass cylinder having a capillary crevice and the specimen is held vertically, all the surface of the specimen was attacked and no passive film was formed. The interesting phenomenon of inner-corrosion occurs also in the solutions of (75g/L CuSO4+50g/L HCl) and 10% CuCl2, while in the solution of 10% FeCl2, the surface of the specimen was attacked, and in the solutions of (CuSO4+H2SO4) and (_??_M K2Cr2O7+10g/L HCl) all the surfaceof the specimen became passive state. The activity or passivity of the specimen is, of course, depends on the amount of chromium content in the specimen and the kind of acidic solution, however, the cause of the passivity of the surface and the inner-corrosion on a special portion of 21% Cr stainless steel is due to the following factors, - (1) the passivity depends on the strengths of the acidity and oxidation-power of the solution used on the surface of the specimen. In this experiment the existence of metallic cations of higher valency in the solutions of HCl and H2SO4, for example, Cu++, Fe+++, Cr+++ and Hg++ give an oxidizing power to the solution, and therefore the passivity of the 21% Cr steel in the solutions of FeCl3, CuCl2, (CuSO4+HCl) and (CuSO4+H2SO4) is produced. (2) The inner-corrosion of the specimen in which its surface is passive state is caused by the presence of capillary crevice on the surface which is in contact with the glass supporter, and it is also due to the existence of some amounts of chlorine ions in the solution. (3) The mechanism of the deep attack in the process of the inner-corrosion is elucidated by an experiment that if the portion on the surface, on which a capillary crevice is existing, is attacked by chlorine ions on account of poor oxidation of the solution, it will be dissolved by the solution and afterwards it cannot be so oxidized to form a passive state by the formation of reducing hydrogen, i.e. due to the impossibility of the formation of passive film on the portion of the specimen.

Societies and Academies

PARIS Academy of Sciences, August 16.—M. Wurtz in the chair.—The following papers were read:—Summary report of the cruise of Le Travailleur (continued), by M. Alph. Milne-Edwards. He describes the various animal species obtained.—On the establishment of hospital stations in Equatorial Africa, by M. de Lesseps. This reports the progress of Capt. Bloyet in the East (who reached Usagara on July 2) and M. de Brazza in the West (who is seeking a suitable position on one of the affluents of the Ogowé).—On the embryos accompanying cysti-cersi in pork, by M. Poincaré. Pork may contain microscopic germs of Tsenia which may quite escape ordinary inspection. Raw meat of any kind should be avoided.—On some formulse relative to hypergeometric functions of two variables, by M. Appell.—On various attempts at demonstration of the theorem of Fermat, by M. Pépin.—Observation on a group of lines in the solar spectrum, by M. Thollon. With the centre of the solar image, on his apparatus (on a mountain near Nice) he notes four lines, a, b, c, d, of which a and b are close to each other, and similarly c and d; b and c are of iron, a and d are telluric. On directing the apparatus to the two ends of the equatorial diameter, the iron lines are displaced relatively to the others, conformably to theory.—On the cause of variations of fixed points in thermometers, by M. Crafts. He describes experiments which reduce to nil, or a very small amount, the rôle of pressure in permanent elevation of the zero point. Glass blown at the lamp and long exposed to heat diminishes in volume through interior work.—On rapid alcoholic fermentation, by M. Boussingault. This relates to fermentation in a liquid that is boiling under a pressure so weak that the heat does not alter the organism of the ferment, while yet it is sufficient to expel the alcohol and the carbonic acid. Glycerine appears during this rapid fermentation.—Spectral examination of thulium, by M. Thalén.—On the absorption spectra of metals forming part of the groups of yttria and of cerite, by M. Soret.—On erbine, by M. Clève. The atomic weight of the metal he finds to be 166 (ytterbium 173).—Measurement of the intensity of some dark lines of the solar spectrum, by M. Gony. His method shows clearly the telluric nature of the group B (between 6866 and 6880), by reason of their greater intensity.—On polar electricity in hemihedric crystals with inclined faces, by MM. Jacques and Curie. They show that in all the non-conducting substances studied the direction of the electric poles is connected with the position of the hemihedric facettes. M Thenard recalled experiments bearing on the subject made by his son fifteen years ago. -New results of utilisation of solar heat obtained at Paris, by M. Pifre. He succeeds in utilising 80 per cent, of the solar heat as against 50 (Mouchot). The reflector is made of three truncated cones, so that the generating line is a broken one. The focus is thus concentrated in much less length, and the height of the boiler may be diminished one half (without increasing its diameter). When the sky is clear the boiling of fifty litres is obtained in less than forty minutes, and the pressure rises 1 atm. every seven or eight minutes. The steam-engine is specially adapted for solar receivers.—Production of crystals of sesquichloride of chromium of persistent green colour, by M. Mengeot.—On the inconveniences presented, with regard to physiological reactions, in cases of poisoning with morphine, by the substitution of amylic alcohol for ether in the process of Stas, by MM, Bergeron and L'Hote.—On the experiment of the great cervical sympathetic, by MM. Dastre and Morat. They demonstrate the existence of vaso-dilator as well as vaso-constrictor nerves in the cervical sympathetic.—Morphological signification of the appendices serving for suspension of chrysalides, by M. Kiinckel. They are (in Lepidoptera) hooks of membranous anal legs modified and adapted to special biological conditions.—On a new station of the age of stone at Hanaweh, near Tyre (Syria), by M. Lortet. Myriads of flints (of very primitive form), along with numerous fragments of bone and teeth, were found in a kind of conglomerate or breccia. -On the falling stars of August 9, 10, and II, 1880, by M. Chapelas. The mean horary number is only 53.7, making a difference of 69.3 with that last year. This seems to limit the return of the maximum of August between 1848 and 1879, giving a period of thirty-two or thirty-three years, quite like that of the phenomenon of November 12 and 13.

An enquiry concerning the nature of heat, and the mode of its communication

The importance of the investigation here entered into,—inasmuch as it applies to most of the operations of nature as well as art,—appears so manifest, that we shall not recapitulate what the author advances on that subject. Before he proceeds to the detail of his experiments for the purpose of computing the emissions of heat from various bodies under a variety of circumstances, he finds it necessary to premise a minute description of the principal part of the apparatus he contrived for his purpose. This instrument consists of a hollow cylindrical vessel of brass, four inches long, and as many in diameter. It is closed at both ends; but has at one end a cylindrical neck about eight-tenths of an inch in diameter, by which it is occasionally filled with water of different temperatures, and through which also a thermometer, constructed for the purpose, is occasionally introduced, in order to ascertain the changes of temperature in the fluid. As it was in the first instance only meant to observe the quantity of heat that escapes through the sides of the vessel, two boxes were contrived, filled and covered with non-conducting substances, such as eiderdown, fur, &c., which were fitted to the two ends or flat surfaces of the cylinder. Six of these instruments, with proper stands, and auxiliary implements of obvious construction, were prepared for the sake of comparative experiments. A previous trial was made with two of the cylinders, the vertical polished sides of the one being naked, and those of the other covered with one thickness of fine white Irish linen, strained over the metallic surface. Here it was found, contrary to expectation, that in a certain space of time the covered cylinder had lost considerably more heat than the naked one.