bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Determination of Polymers and Polymer-Based Composite Materials Diffusion Properties
Authors: Dmitriev V. , Baronin G. , Sergeeva E.
Published: February 2019

The widespread use of polymer composite materials makes it necessary to study their physical properties. Particular attention is given to polymers reacted with water and other low molecular weight compounds in their preparation as well as during operation. Most studies have been devoted in the diffusion properties of materials in the form of films, while operating materials often have a different shape, for example pellets. Well at small sizes of granules is impossible to use stationary methods. In this paper, the diffusion coefficient is determined by the zonal method based on the integration of the diffusion equation. A significant increase in the effective diffusion coefficient with an increase in the diffusant concentration associated with the plasticizing action of water was detected. Temperature-humidity dependence of diffusion effective coefficient is approximated by the refined formula which helps to calculate mass transfer process kinetics and carry out theoretical analysis of water diffuse properties in polymer matrix. With the movement of individual particles of polymer materials in real dryers, it is expedient to break the kinetic problem of mass transfer into external and internal one. The validity of the two-level consideration of the kinetic problem of granular polymer materials deep drying and the applicability of the data obtained for their diffusion properties are shown. The microkinetics of a single particle drying is considered, it is the determining condition for the accuracy of the kinetic calculation.
Investigation of the Plasticizer Content Effects on the Operability of the Epichlorohydrin Rubber Based Elastomeric Material during Full-Scale Test under Cold Climate Conditions and Hydrocarbon Medium Influence
Authors: Mukhin V.V. , Petrova Natalia N. , Portnyagina V.V. , Fedorov A.L. , Baisheva A.V.
Published: February 2019

Sealing rubbers used in the climatic conditions of the Far North and the Arctic, based on butadiene-nitrile rubbers contain significant amounts of plasticizers, which increase their frost resistance. They lose low-temperature and operational properties when they contact with the hydrocarbon medium due to intensive plasticizer washing out. Zeon Hydrin T6000 epichlorohydrin rubber, has a low glass transition temperature (Tg = -60 °C) and resistance to aggressive media. The model rubber was developed that minimally meets the requirements for sealing rubbers. Samples were exposed in oil, for 2 years, in climate of Yakutsk, the Republic of Sakha (Yakutia), Russia. The climate is characterized by significant average daily temperature fluctuations with a transition through the 0 °C and low temperatures below-60 °C. For comparison, simultaneously rubbers based on butadiene-nitrile rubbers was investigated. Every two months, the main parameters were measured: swelling degree, tensile strength, elongation, frost resistance coefficient for elastic recovery after compression at-50 °C and-30 °C, compression set and plasticizer content by means of IR spectroscopy. Model rubber showed excellent frost resistance while retaining the other properties, regardless of the plasticizer content, while rubber based on butadiene-nitrile rubber irreversibly lost low-temperature properties in the first months. Similar results were obtained earlier in the study propylene oxide rubber produced in Russia (Tg = -74°C). During full-scale exposure, a small dependence of its low-temperature characteristics on the amount of plasticizer in the elastomeric material was also revealed. Thus, epichlorohydrin rubber Hydrin T6000 can be used as a sealing rubber.
Building Ceramics with Organic-Mineral Modifiers
Authors: Vasyunina S.V. , Momot V.O. , Kondratyev M.S.
Published: February 2019

The paper presents the results of the study dealing with improving the physical and mechanical properties of building ceramics samples: mean density, compressive strength, wear resistance, impact resistance, water absorption, thermal conductivity coefficient, and frost resistance. In the study the organic-mineral additive based on industrial wollastonite with the superplasticizer S-3 was used. The most functional amount of the applied additive, as well as the optimal volume of water in the molding mixture and the firing temperature were determined with the method of experiment mathematical planning. In the course of the studies the specifics of the organic-mineral additive influence on the properties and structure of building ceramics are revealed. The findings are attested by electron microscopy data. The application of the organic-mineral additive improves the performance characteristics of building ceramics samples.
Influence of 6PPD Stabilizer on Climatic Stability of Rubbers Based on Butadiene-Nitrile and Epichlorohydrin Rubbers
Authors: Sokolova M.D. , Fedorova A.F. , Davydova M.L.
Published: February 2019

The present paper outlines the results of full-scale tests of climatic stability and the study of resistance to the action of hydrocarbon media of rubbers based on BNKS-18-18 (butadiene-nitrile rubber) and Hydrin T6000 epichlorohydrin rubber containing one of 6PPDstabilizerwith an aromatic amine moiety widely used in synthetic rubbers. Samples are exposed in an open ground under natural conditions of exposure to climatic external factors of Yakutsk in the Republic of Sakha (Yakutia), as well as in the oil environment of Talakanskoye field and I-50A hydraulic fluid in an unheated room. Such indexes of the samples as conditional tensile strength, elongation at rupture, hardness and degree of swelling are measured to determine the resistance of rubbers to aging after the first, third, and sixth months of exposing. The results of the study reveal the contribution of 6PPD stabilizer in maintaining the stability of the physical and mechanical properties of BNKS-18: rubber containing 6PPD has less property changes both in the open air and in hydrocarbon media compared to rubber without a stabilizer. It should be noted that the oil environment is the most aggressive environment, the swelling of rubbers in oil leads to a significant reduction in strength due to a decrease in intermolecular interaction.6PPD stabilizer occurred less effective for the rubber based on Hydrin T6000: changes in properties of the samples containing the stabilizer are larger than those of the samples without the stabilizer. However, unlike BNKS-18-18-based rubber, the swelling of rubber based on Hydrin T6000 led to the greatest stability of the physical and mechanical properties in the oil environment compared to the open air and hydraulic fluids.
Properties of Particleboards Manufactured from Low-Grade Wood by Using a Shungite Modified Binder
Authors: Panov Nikolai Gennadievich , Pitukhin Aleksandr Vasilyevich , Vasilyev Sergey Borisovich
Published: February 2019

The results of testing one-ply and three-ply particleboards manufactured by using a shungite modified binder are presented. Stress limits under bending and stretching, as well as parameters of water resistance were determined. The particle boards were manufactures from low-grade wood shavings. Ultradispersed powder of nanoscaled shungite was used as a modifying agent for the urea-formaldehyde resin based binder. Properties of particleboards samples were determined by standard methods. Best parameter values of physical and mechanical properties were observed for samples of one-ply and three-ply boards when the modifying agent mass fraction at binder was 10 %. At this concentration the ultimate stress limits under static bending increased by 41% and 12% for one-ply and three-ply boards, respectively. The increase of ultimate stress limits under stretching was 104% and 12% for one-ply and three-ply boards, respectively. Addition of ultradispersed powder of nanoscaled shungite increases boards’ water resistance. The modifying agent reduces 24-hour swelling of one-ply and three-ply boards by 32% and by 20%, respectively. The water absorption of all types of particle boards reduced up to 50%
Synthesis of 2,5-Furandicarboxylic Acid from Natural Raw Materials
Authors: Boldyreva E.V. , Chus U.A. , Klushin V.A.
Published: February 2019

2,5-Furandicarboxylic acid (FDCA) and polyethylene furanoate are now considered as an alternative to terephthalic acid and polyethylene terephthalate (PET), which are produced from fossil sources. FDCA can be obtained by dehydration of polysaccharides and biomass feedstock to 5-hydroxymethylfurfural (5-HMF) with its following catalytic oxidation. A procedure for obtain 2,5-furandicarboxylic acid with using jerusalem artichoke rhizomes as raw materials for the 5-HMF preparation without prior isolation of inulin has been shown. In first step jerusalem artichoke rhizomes dehydration in a two-phase system of «aqueous solution of Na2SO4 · 10 H2O – methyl isobutyl ketone» 40% 5-HMF yield has been achieved. In second step 5-HMF was oxidized by KMnO4 in alkaline medium to FDCA with 100% yield according to HPLC and 89% yield (99% purity) after isolation. The optima time of intervals and amount of oxidizer - potassium permanganate and importance of maintaining the exact pH= 10.5 ± 0.5 of the reaction mixture have been shown. A perspective of using this approach to create the FDCA synthesis technology by oxidizing the product from 5-HMF raw material with 60% main product content, avoiding expensive and long-term 5-HMF purification steps have been proved.
Investigation of the Stages of Damage Accumulation in Polymer Composite Materials
Authors: Bashkov O.V. , Bryansky A.A. , Belova I.V. , Solovev Denis B.
Published: February 2019

This paper presents the results of the study of strength and fracture processes of FRP samples, obtained by vacuum and vacuum-autoclave molding methods. The experimental studies consisted of a three-point bending test with step loading, accompanied by an acoustic emission method. Based on the acoustic emission data recorded using the acoustic-emission software and hardware complex during the experiments, a method for estimating the accumulated damage using various techniques for analyzing acoustic emission parameters was tested. The results of methods for analyzing the power-law coefficient of accumulation of total AE, b-value and density distribution of amplitudes and median frequencies are considered. An estimate of the power-law coefficient of accumulation of the total AE made it possible to determine the bearing capacity of PCM samples. Using the techniques for analyzing the amplitude distribution of the AE signals and the distribution density of the amplitudes and median frequencies of the AE signals, destructive processes in the volume of samples were described and the stages of their damaging were revealed.
Carbon Nanotubes in Composite Hydrogels Based on Plant Carbohydrates
Authors: Zueva O.S. , Makarova A.O. , Zuev Yu.F.
Published: February 2019

Due to the physical, chemical, biological characteristics and high biocompatibility, the hydrogels based on plant polysaccharides and proteins became a sought-after material in many fields. Such hydrogels are the water swelling biopolymer matrices that react reversibly on minor changes in composition and in the external environment. However, the mechanical and electrical properties of "pure" hydrogels inhibit their wide practical application. One of approachs to improve their properties is the usage of carbon nanotubes, which provide good electrical conductivity and can significantly improve the characteristics of materials. The effects of carbon nanotubes on electric conductivity and mechanic properties of hydrogels based on natural biopolymers (gelatin and κ-carrageenan) of different composition were investigated. The electrical conductivity of the gels was studied using InoLab Cond 7310 SET1 conductometer. The rheological properties of hydrogels were investigated by Anton Paar MCR 302 rheometer. Such characteristics as temperature, frequency and amplitude dependencies of the storage modulus and the loss modulus of hydrogels were obtained. It was found that the addition of carbon nanotubes led to the increase in electrical conductivity of hydrogels. The morphology and rheological properties of studied hydrogels alter significantly in the presence of carbon nanotubes. The obtained data indicate the possibility of a purposeful change in electrical and mechanical properties of hydrogels by the addition of carbon nanotubes.
The Development of New Materials and Modes of Casting Metal Powder Mixtures (MIM Technology)
Authors: Korotchenko A.Yu. , Khilkov D.E. , Tverskoy M.V.
Published: February 2019

In the present work, to reduce the cost of production of the parts with MIM technology, proposed to use a new metal powder mixture (feedstock are presented) with the increased size of the powder to 50 microns. New feedstock are presented recommended for use in the manufacture of parts with a wall thickness of 5 mm. Shows the main physical and technological properties of new metal powder mix (feedstock) 40ХМА of steel intended for the manufacture of parts via MIM technology. Given the results of determination of granulometric composition and particle shape. The obtained values of tensile strength, hardness and roughness. The results of determining the dependence of viscosity on shear rate. For simulation of rheological properties of selected elastic-visco-plastic model of Bingham type with nonlinear dependence of viscosity on shear rate and temperature. The example of the calculation of feedstock fill the cavity of the mold. The analysis of defects in green part, associated with an irregular velocity field in the flow channels feedstock form.
Use of a Reductive Carbon Monoxide Atmosphere in Arc Welding of Microalloyed Steels
Authors: Ivanaysky E.A. , Ishkov A.V. , Ivanaysky A.A.
Published: February 2019

The possibility of making welded steel joints using arc welding in a reducing medium of carbon monoxide was studied. A method was proposed to eliminate its negative biological effect by heating the feed gas above its flash point, followed by oxidation till carbon dioxide was obtained. Welding modes have been selected to ensure the formation of a quality welded joint. Comparative studies of welded joints obtained using an oxidizing atmosphere of carbon dioxide and a reducing atmosphere of carbon monoxide were carried out. A chemical and metallographic analysis of welded joints was performed. The thermodynamic substantiation of chemical reactions in which carbon and microalloying additives can participate was presented. It was established that the main difference between the proposed welding method and those used at present was the suppression of oxidative processes in liquid metal due to the presence of a reducing atmosphere.
Effect of Severe Plastic Deformation and Hardening on the Properties and Failure Mechanisms of Constructional Steel
Authors: Borisova Maria Z.
Published: February 2019

The influence of severe plastic deformation on structural materials has been actively studied in recent years. Undoubtedly is the positive influence of this method on strength characteristics of materials. In addition, it is very interesting to influence of the severe plastic deformation on the mechanisms of fracture. One of the most common methods of severe plastic deformation is equal-channel angular pressing (ECAP). In this paper, the influence of different modes of ECAP on the strength of structural steel was studied. Also, the destruction of steel at different test temperatures was studied in detail. It is shown that the ECAP increases the strength of steel almost twice, but the plasticity of steel is reduced, which leads to fragility. Quenching can remove the negative impact of the ECAP on toughness of the steel and will increase the impact strength several times.
The Strength and Ductility of Low Carbon Steel Subjected to Equal Channel Angular Pressing and Extrusion at a Low Temperature
Authors: Ivanov Afanasiy M. , Kovalenko N.D.
Published: February 2019

The deformation treatment of Fe360 low carbon steel by extrusion, equal-channel angular pressing, and equal-channel angular pressing with extrusion in one pass at a temperature of 673 K is considered.The strength increase in steel is shown for all methods of hardening. It is noted that in the range of temperature under consideration, the strength characteristics and the relative residual constriction of hardened steel samples are the parameters of low sensitivity to temperature decrease. The material destruction mechanism in various states under uniaxial tension under conditions of room and low temperature is analyzed.
Concretes with Unique Properties for Special Building Structures
Authors: Solovyova V. , Solovyov D. , Stepanova I.
Published: February 2019

The paper presents new results in the building materials area. One of the solutions of the thin-walled elements obtaining can be achieved due to new additive using. The main purpose of the paper was improvement concrete properties for thin-walled constructive elements. The experimental and standard methods have been used and new complex additive for concrete. The research shows that a comprehensive additive consisting of aqueous solution of polycarboxilate polymer, silica sol and potassium nitrite is effective and makes it possible to produce high-efficiency concrete with unique properties: higher compression strength, higher crack resistance, frost resistance, water resistance, abrasion resistance. The study shows that the concrete is chemical resistant. Modified concrete can be recommended for manufacturing critical concrete structures of special purpose, for example high-rise constriction.
Effect of Electrolysis Modes on Physico-Mechanical Properties of Composite Coatings Based on Nickel
Authors: Arzumanova A.V. , Starunov A.V.
Published: February 2019

The receiving method and some properties of the composite nickel containing galvanic coating on base nickel-cobalt-oxide silicon-carbide silicon system were discussed. Chloride electrolyte for the application of the composite electroplating coating with firmness to wear and corrosion properties of nickel-cobalt-oxide silicon-carbide silicon system was elaborated. Influence of electrolysis and electrolyte composition on physico-mechanical properties (firmness to wear, corrosion resistance, hardness, internal tensions, porosity, adhesion) of the composite electrolytic coating of nickel-cobalt-silicon oxide system, electroplated from chloride electrolyte, and on the properties of electrolyte (diffusing ability, output current draught) were investigated. The possibility of using for composite electroplating of nickel-cobalt-silicon oxide-carbide silicon system as a firmness to wear coating in instead of chrome was showed.
Distribution of Magnetic Field Parameters in the Surface Layer of the Material of Reaction Furnace Coils after Operation Period
Authors: Naumkin E.A. , Shermatov J.N. , Gaysina A.I.
Published: February 2019

One of the main reasons for the limited service life period of the reaction furnace coils is the carburization of the surface layers, which leads to a decrease in the performance characteristics of the pipe material, decrease in plasticity, generation of internal stresses, change in the metal structure. Therefore, monitoring the state of coils surface in order to detect critical parameters of the carburized layer thickness, using non-destructive methods of control is relevant. The results of the distribution of magnetic parameters over the depth of the carburized layer in the fragments of pipes made of steel 20Х25Н20C2, operated under furnace conditions at high temperatures, for 1300, 6000, 8000, 10000 hours are presented in the article. Analysis of the results showed that the magnetic properties are manifested only in the surface layers of the reaction furnace tubes. At the same time, the longer the service life period, the deeper is the layer exercising the magnetic properties and the higher in this layer the values ​of the constant magnetic field intensity. Analysis of magnetic properties distribution in all studied pipe fragments, both from the inner and from the outer side, showed the non-uniformity of the constant magnetic field intensity distribution, while zones of extremely high values ​are observed. The layer-by-layer surface removal in these zones with the determination of the resultant constant magnetic field intensity showed that there are critical values of the carburization depth, after which a sharp increase of this parameter is registered. These results can be used as a method for carburization depth determination, and also used to develop criterion for rejecting coils of reaction furnaces.
Control of Cement Grout Plastic Properties
Authors: Kondrashchenko Valerii I. , Nikolaev A.P. , Kondrashchenko E.V.
Published: February 2019

A unique apparatus is described combining properties of plastometer and Vicat apparatus. A possibility is substantiated of cement properties plastometric determination, peculiarities are found of its compatibility with different action type modifiers in operation range of W/C values.
Efficiency of Hybrid Sintering Technology for Cemented Carbide Diamond-Containing Composites with Impregnation, Including Thermal Diffusion Metallization of Diamonds
Authors: Sharin P.P. , Akimova M.P. , Yakovleva S.P.
Published: February 2019

For the enhancement of chemical and mechanical adhesion of natural diamond particles with a hard-alloy matrix during the synthesis of diamond-abrasive composites the hybrid technology which combined in one technological process the thermal diffusion metallization of diamond particles and sintering by the developed scheme of the self-dosed impregnation is proposed. This technology does not include a reheating of the metallized coating that causes its destruction and enhances graphitization of diamond thus limiting the application of metallization method for improvement of diamond retention and creation of high-functional composites for diamond tools. Formation and preservation of adhesion-durable metallized coating is confirmed by experiments simulating the conditions of high temperature interaction of diamond with a carbide-forming metal and a hard-alloy matrix during the sintering of special samples using the regimes of developed technological process. The structural and phase state of the transition zone is studied by scanning electron microscopy, X-ray structure analysis and X-ray phase analysis of the partition surfaces of the contact zone between the diamond and the matrix obtained by tensile testing of special samples. Comparative service properties tests of prototype and control samples of diamond dressers confirmed efficiency of the developed hybrid technology for the creation of diamond tools.
Noncontact Control by Laser Conoscopy of Optical Homogeneity of Heavily Doped LiNbO3: Zn
Authors: Pikoul O. , Sidorov Nikolay V. , Palatnikov Mikhail N.
Published: February 2019

A non-contact method using laser conoscope the studies of optical homogeneity of a series of heavily doped LiNbO3crystals (4.46–4.69 mol. % ZnO). For all crystals not detected additional anomalies in сonoscopic patterns at increase of laser radiation power up to 90 mW, due to the presence of static and fluctuating defects induced in the photorefractive crystal by laser radiation.
Spherically Symmetric Shock Waves in Materials with a Nonlinear Stress-Strain Dependence
Authors: Ragozina Victoria E. , Ivanova Yulia E.
Published: February 2019

The paper considers the dynamic deformation features of constructional materials with nonlinear stress-strain dependence. For the one-dimensional shock waves with nonzero curvature arising in constructions under dynamic loading the propagation regularities are studied on the basis of the matched asymptotic expansions method. In the nonstationary problem with the longitudinal spherical shock wave the relations for simultaneous consideration of dynamic properties in the outer and inner problem of the perturbation method are obtained. The solution in the front-line area is constructed on the basis of the evolution equation different from ones for a plane longitudinal wave. The need for a solving of an additional ODE system for matching outer and inner expansions is shown. It is obtained that the outer solution asymptotics in the spherically symmetric problem contains waves reflected from the leading front in contrast to the solution behavior behind the front of the plane shock wave.
Technique for the Development of the Technological Process for the Tightening of Aircraft Parts on CNC Presses
Authors: Feoktistov S.I. , Pogartseva M.M.
Published: February 2019

A method for creating a control program has been developed, which ensures the manufacturing of the details-cladding of the required accuracy and quality in the automated mode. The method is based on the choice of the optimal loading scheme, under which the deformation program is created, the values of the control coordinates of the press are calculated in accordance with the kinematic model of the press. As a result, a control program is obtained, which ensures a more accurate manufacturing of the part, with a minimum amount of finishing work. The presented method of calculation of the tightening process allows, on the basis of the details of the part, to determine the shape of the tightening punch, and also, if necessary, to adjust the existing tightening punch in order to ensure a more precise manufacturing of the part.
The Method of Prediction Climatic Loads on the Building Enclosures
Authors: Zheldakov D.Y.
Published: February 2019

Based on the numerical solution of the differential equation that determines one-dimensional heat transfer under unstable conditions with constant coefficients, a method was developed to calculate the temperature distribution over the cross section of the enclosing structure. Based on the developed method, a method of determining the number of cycles of freezing and thawing of moisture in the cross sections of the outer wall of the building was calculated. This method was tested in the experiment on the exterior walls of operating buildings. The results showed good convergence of the real and calculated temperature values. The calculation of the number of cycles of freezing and thawing on the cross section of the outer wall of the building according to the developed methodology and the experiment showed the same results. The method of numerical assessment was developed to show the impact of global climate change on enclosed structures. The parameter of temperature load of enclosing structures was introduce. The method uses meteorological data of outdoor air temperature over the last 50 years and the results of calculation of temperature fluctuation of the enclosed structures. The use of this method allowed to calculate the number of cycles of freezing and thawing in cross sections of the outer wall at any given time period, and, therefore, more accurately predict the durability of enclosed structures. In addition, the developed technique allows quantitative comparison of different designs of external structures on the thermal load, taking into account global climate change.
Effective Fine-Grained Concrete with High-Dispersed Additive Based on the Natural Mineral Wollastonite
Authors: Karpikov E.G. , Lukutsova N.P. , Bondarenko E.A. , Klyonov V.V. , Zajcev A.E.
Published: February 2019

Micro-fillers based on natural mineral wollastonite, modifying fine-grained concrete and improving its physical and mechanical characteristics, are developed and studied. The influence of the most common stabilizers on the aggregate stability of wollastonite-based microdispersed systems in the aquatic dispersion environment is considered. The optimal parameters, ensuring the production of micro-fillers in the form of stable suspensions, are developed. The application efficiency of the wollastonite-based filler due to its micro-reinforcing properties is revealed. These properties are specified by the formation of needle-shaped crystals by the ultrasonic dispersion in the aquatic environment, chemically related to cement-containing raw materials and contributing to the active selective adsorption of the binder hydration products. It has a significant influence on the rheological parameters of cement composites, on structure formation, as well as on their strength and deformation properties.
Fracture Mechanics when Studying the Long-Term Strength of Concrete
Authors: Shubin I.L. , Dorkin V.V. , Sultygova P.S.
Published: February 2019

The results of experimental and theoretical studies of the process of destruction of concrete by the methods of fracture mechanics are considered. Results of studies of long-term strength, durability and deformability of concrete subjected to a preliminary short-term temperature action up to 300° C and 400° C under load and without load are presented. It is shown that after short-term heating up to 300о С the long-term strength of concrete decreases insignificantly. It is established that heating up to 400° C can be considered the boundary of the structural integrity of concrete. The conditions for using the results of these studies in determining the values of a function that characterizes the change in the long-term strength of a material in the mechanics of heterogeneous structures are formulated. The function of the material destruction measure is introduced to describe the nature of the structural changes in the material at a given constant continuous load, and its change for different levels of a continuous load is considered.
Energy Parameters of the Binder during Activation in the Vortex Layer Apparatus
Authors: Ibragimov Ruslan A. , Korolev Evgeniy V. , Deberdeev T.R. , Leksin V.V. , Solovev Denis B.
Published: February 2019

Improving the efficiency of construction composites is a relevant problem for modern-day material science. One of the ways to solve the problem consists in activating the binders by means of vortex-layer devices. Mathematical transformations produced a formula for calculating the dependency of the number of ferromagnetic-particle collision on the number and velocity of such particles, as well as on the device chamber fill factor. The results obtained by applying the proposed formula differ from D.D. Logvinenko's model by 10% at max. We calculated the impact force, the impulse of the grinding body in the vortex-layer device, as well as the amount of applied energy per unit of mass of the ground material. It was found out that the impact force and the impulse of force were maximized in the test device. At the same time, energy applied over the grinding time necessary to even out the binder dispersion in the vortex-layer device was 2 to 4.8 times greater compared to conventional devices.
Psicanálise e Literatura: Uma Proposta de Análise do Conto Berenice
Authors: Pereira Ana Alice Da Silva , Próchno Caio César Souza Camargo
Published: February 2019

Este artigo trata de uma análise do conto Berenice, de Edgar Allan Poe. O conto faz parte de uma coletânea de histórias de terror e mistério, e está inserido no que se chama de literatura fantástica. A análise proposta tem por base a psicanálise, considerando seu entendimento como método de conhecimento a partir da interpretação, sem, contudo, desconsiderar elementos da crítica literária. Foram pontos marcantes nos resultados deste estudo o surgimento da psicanálise e da literatura fantástica, a questão do duplo, o espaço na narrativa, o onírico, as fantasias acerca da cena aterrorizante e a literatura de terror como possibilidade de acessar o estranho e o desamparo, assim como realizar o desejo de transgressão do sujeito.
O Dispositivo Clínica da Urgência na Atenção Hospitalar: Sofrimento, Escuta e Sujeito
Authors: Costa Maico Fernando , Costa-Rosa Abílio Da
Published: February 2019

O objetivo do presente artigo é considerar os aspectos psíquicos do sofrimento do sujeito que chega ao estabelecimento hospitalar relatando ou apresentando tipos de lesão física no corpo.  Essa perspectiva passa pela definição de clínica da urgência no campo da atenção à saúde hospitalar. Para tanto, apresentamos aos psicólogos e trabalhadores, inseridos nos estabelecimentos hospitalares e que possuem interesse na escuta ao sujeito do sofrimento, um posicionamento num horizonte técnico-teórico e ético-político pautado na orientação da Psicanálise de Freud e Lacan. No hospital, as concepções de doença, tratamento e diagnóstico são consideradas, a priori, por uma equipe de médicos e enfermeiros, como um fator biológico do humano. No discurso médico, o sujeito se torna objeto e passivo a sua condição de “doente”. Respaldados pelas noções de sujeito e subjetividade, o psicólogo, precavido pela Psicanálise, aposta e apreende, mediante a experiência em uma Unidade de Pronto Atendimento, a possibilidade, nesse contexto, de uma direção de tratamento não excludente ao sujeito do inconsciente. De maneira que, o sujeito, ao falar de sua história, daquilo que mais o angustia e o assusta, ao perceber a saúde abalada por um acidente, pode se reposicionar diante da “doença”.
As Máscaras e a Estrutura Mítica: Verdade Ficcional e Hiância Subjetiva
Authors: Krinski Sthefan Dos Santos , Madeira Manoel Luce , Moschen Simone Zanon
Published: February 2019

O trabalho procura delinear uma reflexão sobre a noção de máscara em Lacan, tecendo-a as noções de mito e semblante, a partir do aforismo segundo o qual a verdade tem uma estrutura de ficção. Para tanto, o texto divide-se em três seções. Inicialmente, dedica-se ao estudo do mito em sua função estruturante, articulando-o à origem e à verdade do sujeito. Na segunda seção, o texto situa o mito como produção que confere sentido e suporte subjetivo às máscaras. Ademais, calcados nos seminários As Formações do Inconsciente e Os Quatro Conceitos Fundamentais, o artigo lança a hipótese de que a máscara opera a partir da inscrição de certa hiância constitutiva que se dá entre ela e o sujeito – hiância que, caso desfeita, estaria articulada à eclosão de angústia. Por fim, contrapondo noções tanto cotidianas como hermenêuticas sobre verdade, mentira e dissimulação, o escrito desdobra a noção de máscara à conceitualização de semblante, situando-a ao nível do discurso e de seus matemas.
Objetos (In)visíveis: Psicanálise, Espetáculo e a Arte de Vik Muniz
Authors: Zancan Frantz Marília , De Sousa Edson Luiz André
Published: February 2019

As questões propostas neste ensaio nascem de três encontros: o primeiro, com a teoria lacaniana a respeito da constituição do sujeito a partir do campo do Outro; o segundo, com a obra de Guy Debord sobre A Sociedade do Espetáculo; o terceiro, com o trabalho do artista brasileiro Vik Muniz. O que une esses três encontros é o desejo de pensar nas relações do sujeito com o social e nas questões que suscitam a respeito do laço social em nossa sociedade capitalista, na qual visibilidade e cidadania se confundem com a capacidade de consumo. Se o sujeito depende do olhar do outro para se estruturar, e é o poder aquisitivo que, nesse contexto, lhe dá lugar no espaço público, já não basta consumir, é preciso mostrar aquilo que se consome, transformando a si mesmo em objeto consumível. Este ensaio propõe que o espetáculo, conforme o definiu Debord, é o modo como o laço social se apresenta a partir da estrutura que Lacan definiu como discurso capitalista, e que produz efeitos de reificação e de apagamento da singularidade do sujeito através da antecipação de respostas para as questões que o desejo coloca. No entanto, nem todas as imagens que vemos são iguais, nem todas estão submetidas à lógica espetacular. A arte propõe imagens a partir de outro lugar, compartilhado com a psicanálise: aquele que busca desestabilizar o eixo dos discursos prontos e das produções de sentido. E é esta também a proposta de trabalho de Vik Muniz ao criar ilusões que não iludem, mas revelam os elementos que as constituem. Assim, diante dos imperativos do espetáculo, da arte e da psicanálise, ao sustentarem a potência do nome que falta, possibilitam que o sujeito de desejo encontre brechas por onde resistir.
Ficção e Memória na Clínica Psicanalítica Contemporânea: Uma Leitura a partir de Black Mirror
Authors: Triska Vitor Hugo Couto , Mano Gustavo Caetano de Mattos
Published: February 2019

Este artigo investiga uma forma específica de sofrimento na contemporaneidade a partir de uma narrativa comum extraível de duas obras: o conto Funes, o memorioso, de Jorge Luis Borges, e o episódio The entire story of you, do seriado televisivo Black Mirror. Em ambos se reconhece um ideal maquínico que, ao reduzir a história a um passado perfeitamente objetivável, promove um rebaixamento da dimensão ficcional que toda narrativa implica e impede a produção de uma verdade singular do sujeito. Analisa-se a relação entre memória e ficção em Freud e Lacan, reconhecendo-se a impossibilidade da realização do ideal maquínico da memória perfeita e permitindo uma diferenciação entre passado e história. Finalmente, propõe-se uma comparação com questões que interrogam a clínica psicanalítica contemporânea, como as patologias baseadas em déficits narrativos, assim como a necessidade da ampliação da diagnóstica psicanalítica para que esta reconheça novas modalidades de sofrimento.
Chemical characterisation of water-soluble ions in atmospheric particulate matter on the east coast of Peninsular Malaysia
Authors: Farren Naomi J. , Dunmore Rachel E. , Mead Mohammed Iqbal , Mohd Nadzir Mohd Shahrul , Samah Azizan Abu , Phang Siew-Moi , Bandy Brian J. , Sturges William T. , Hamilton Jacqueline F.
Published: February 2019

Abstract. Air quality on the east coast of Peninsular Malaysia is influenced by local
anthropogenic and biogenic emissions as well as marine air masses from the
South China Sea and aged emissions transported from highly polluted East
Asian regions during the winter monsoon season. An atmospheric observation
tower has been constructed on this coastline at the Bachok Marine Research Station. Daily PM2.5 samples were collected from
the top of the observation tower over a 3-week period, and ion chromatography
was used to make time-resolved measurements of major atmospheric ions present
in aerosol. SO42- was found to be the most dominant ion present
and on average made up 66 % of the total ion content. Predictions of
aerosol pH were made using the ISORROPIA II
thermodynamic model, and it was estimated that the aerosol was highly acidic,
with pH values ranging from −0.97 to 1.12. A clear difference in aerosol
composition was found between continental air masses originating from
industrialised regions of East Asia and marine air masses predominantly
influenced by the South China Sea. For example, elevated SO42-
concentrations and increased Cl− depletion were observed when
continental air masses that had passed over highly industrialised regions of
East Asia arrived at the measurement site. Correlation analyses of the ionic
species and assessment of ratios between different ions provided an insight
into common sources and formation pathways of key atmospheric ions, such as
SO42-, NH4+ and C2O42-. To our
knowledge, time-resolved measurements of water-soluble ions in PM2.5 are
virtually non-existent in rural locations on the east coast of Peninsular
Malaysia. Overall this dataset contributes towards a better understanding of
atmospheric composition in the Maritime Continent, a region of the tropics
that is vulnerable to the effects of poor air quality, largely as a result of
rapid industrialisation in East Asia.
Relative humidity effect on the formation of highly oxidized molecules and new particles during monoterpene oxidation
Authors: Li Xiaoxiao , Chee Sabrina , Hao Jiming , Abbatt Jonathan P. D. , Jiang Jingkun , Smith James N.
Published: February 2019

Abstract. It has been widely observed around the world that the frequency and intensity
of new particle formation (NPF) events are reduced during periods of high
relative humidity (RH). The current study focuses on how RH affects the
formation of highly oxidized molecules (HOMs), which are key components of
NPF and initial growth caused by oxidized organics. The ozonolysis of
α-pinene, limonene, and Δ3-carene, with and without OH
scavengers, were carried out under low NOx conditions under
a range of RH (from ∼3 % to ∼92 %) in a
temperature-controlled flow tube to generate secondary organic aerosol (SOA).
A Scanning Mobility Particle Sizer (SMPS) was used to measure the size
distribution of generated particles, and a novel transverse ionization
chemical ionization inlet with a high-resolution time-of-fight mass
spectrometer detected HOMs. A major finding from this work is that neither
the detected HOMs nor their abundance changed significantly with RH, which
indicates that the detected HOMs must be formed from water-independent
pathways. In fact, the distinguished OH- and O3-derived peroxy
radicals (RO2), HOM monomers, and HOM dimers could mostly be
explained by the autoxidation of RO2 followed by bimolecular
reactions with other RO2 or hydroperoxy radicals (HO2),
rather than from a water-influenced pathway like through the formation of a
stabilized Criegee intermediate (sCI). However, as RH increased from ∼3 % to ∼92 %, the total SOA number concentrations decreased by
a factor of 2–3 while SOA mass concentrations remained relatively constant. These observations show that, while
high RH appears to inhibit NPF as evident by the decreasing number
concentration, this reduction is not caused by a decrease in
RO2-derived HOM formation. Possible explanations for these phenomena
were discussed.
Biomarker evidence for the occurrence of anaerobic ammonium oxidation in the eastern Mediterranean Sea during Quaternary and Pliocene sapropel formation
Authors: Rush Darci , Talbot Helen M. , van der Meer Marcel T. J. , Hopmans Ellen C. , Douglas Ben , Sinninghe Damsté Jaap S.
Published: February 2019

Abstract. The eastern Mediterranean Sea sedimentary record is characterised by intervals of organic rich sediment (sapropels), indicating periods of severe anoxia triggered by astronomical forcing. It has been hypothesized that nitrogen fixation was crucial in injecting the Mediterranean Sea with bioavailable nitrogen (N) during sapropel events. However, the evolution of the N biogeochemical cycle of sapropels is poorly understood. For example, the role of the complementary removal reaction, anaerobic ammonium oxidation (anammox), has not been investigated because the traditional lipid biomarkers for anammox, ladderane fatty acids, are not stable over long periods in the sedimentary record. The recent development of an alternative lipid biomarker for anammox (bacteriohopanetetrol stereoisomer; BHT isomer) allowed for the investigation of anammox during sapropel deposition in this marginal sea. We present here the first application of a lipid biomarker for N removal throughout the progression (e.g. formation, propagation, and termination) of basin-wide anoxic events. In this study, BHT isomer and ladderanes were analysed in sapropel records taken from three Eastern Mediterranean sediment cores, spanning the most recent (S1) to Pliocene sapropels. Ladderanes were rapidly degraded in sediments, as recently as the S5 sapropel (ca. 125 ka). BHT isomer, however, was present in all sapropel sediments, as far back as the Pliocene (2.97 Ma), and clearly showed the response of anammox bacteria to marine water column redox shifts in high-resolution records. Two different N removal scenarios were observed in Mediterranean sapropels. During S5, anammox experienced Black Sea-like water column conditions, with the peak of BHT isomer coinciding with the core of the sapropel. Under the alternative scenario observed in the Pliocene sapropel, the anammox biomarker peaked at onset and termination of said sapropel, which may indicate sulphide inhibition of anammox during the core of sapropel deposition. This study shows the use of BHT isomer as a biomarker for anammox in the marine sediment record and highlights its potential in reconstructing anammox during past anoxic events that are too old for ladderanes to be applied (e.g. the history of oxygen minimum zone expansion and oceanic anoxic events).
Limitations of the 1 % experiment as the benchmark idealized experiment for carbon cycle intercomparison in C4MIP
Authors: MacDougall Andrew Hugh
Published: February 2019

Abstract. Idealized climate change simulations are used as benchmark experiments to facilitate the
comparison of ensembles of climate models. In the fifth phase of the Coupled Model
Intercomparison Project (CMIP5), the 1 % per yearly compounded change in atmospheric
CO2 concentration experiment was used to compare Earth system models with full
representations of the global carbon cycle in the Coupled Climate–Carbon Cycle Model
Intercomparison Project (C4MIP). However, this “1 % experiment” was never
intended for such a purpose and implies a rise in atmospheric CO2 concentration
at double the rate of the instrumental record. Here, we examine this choice by using an
intermediate complexity climate model to compare the 1 % experiment to an idealized
CO2 pathway derived from a logistic function. The comparison shows three key
differences in model output when forcing the model with the logistic experiment. (1) The
model forced with the logistic experiment exhibits a transition of the land biosphere
from a carbon sink to a carbon source, a feature absent when forcing the model with the
1 % experiment. (2) The ocean uptake of carbon comes to dominate the carbon cycle as
emissions decline, a feature that cannot be captured when forcing a model with the
1 % experiment, as emissions always increase in that experiment. (3) The permafrost
carbon feedback to climate change under the 1 % experiment forcing is less than half
the strength of the feedback seen under logistic experiment forcing. Using the logistic
experiment also allows smooth transition to zero or negative emissions states, allowing
these states to be examined without sharp discontinuities in CO2 emissions. The
protocol for the CMIP6 iteration of C4MIP again sets the 1 % experiment as the
benchmark experiment for model intercomparison; however, clever use of the Tier 2
experiments may alleviate some of the limitations outlined here. Given the limitations of
the 1 % experiment as the benchmark experiment for carbon cycle intercomparisons,
adding a logistic or similar idealized experiment to the protocol of the CMIP7 iteration
of C4MIP is recommended.