bluuebunny/crossref_metadata_2025 huggingface dataset:
The Residency Match: Interview Experiences, Postinterview Communication, and Associated Distress
Authors: Berriochoa Camille , Reddy Chandana A. , Dorsey Steven , Campbell Steven , Poblete-Lopez Christine , Schlenk Richard , Spencer Abby , Lee John , Eagleton Matthew , Tendulkar Rahul D.
Published: July 2018

Background 

Interview experiences and postinterview communication during the residency match process can cause distress for applicants, and deserve further study.

Objective 

We both quantified and qualified the nature of various interview behaviors during the 2015–2016 National Resident Matching Program (NRMP) Match and collected applicant perspectives on postinterview communication and preferences for policy change.

Methods 

An anonymous, 31-question survey was sent to residency candidates applying to 8 residency programs at a single academic institution regarding their experiences at all programs where they interviewed.

Results 

Of 6693 candidates surveyed, 2079 (31%) responded. Regarding interview experiences, applicants reported being asked at least once about other interviews, marital status, and children at the following rates: 72%, 38%, and 17%, respectively, and such questions arose at a reported mean of 25%, 14%, and 5% of programs, respectively. Female applicants were more frequently asked about children than male applicants (22% versus 14%, P < .0001). Overall, 91% of respondents engaged in postinterview communication. A total of 70% of respondents informed their top program that they had ranked it highly; 70% of this subset reported associated distress, and 78% reported doing this to improve match success. A total of 71% would feel relief if postinterview communication was actively discouraged, and 51% would prefer applicants to be prohibited from notifying programs of their rank.

Conclusions 

Applicants to several residency programs reported being asked questions that violate the NRMP Code of Conduct. The majority of applicants would prefer postinterview communication to be more regulated and less prevalent.
Validity issues in the application of selected qualitative social research methods
Authors: Boateng William
Published: July 2018

This paper investigated the validity concerns in the application of Focus Group Discussions (FGDs) and One-on-one Qualitative Interviews as forms of qualitative social research methods with the objective of unraveling the validity concerns embedded in their application.In order to reach this objective, theeffectiveness of qualitative social research methods – FGDs and One-on-one Qualitative Interviews– is put on the line by empirically  comparing and contrasting data from two FGD sessions and one-on-one interviews to ascertain the consistency in terms of data retrieved from participants using these two data collection methods. The study is guided by the hypothesis that data obtained via FGDs may be influenced by groupthink rather than individual participant’s perspectives. A critical scrutiny of the data that emanated from the two organized FGDs  departed quite  significantly from the data that was elicited from the one-on-one qualitative interviews. The difference in responses confirms that FGDs are not fully insulated from the shackles of groupthink. It is recommended, among others,that though FGD can stand  unilaterally as a research methodology for non-sensitive topics with no direct personal implications forparticipants; researchers should be encouraged to adopt FGD in league with other methods in a form of triangulation or mixed methodological approach for amore quality data, bearing in mind the central role occupied by data in the social scientific research process.Key Words: Focus Group Discussion, One-on-One Qualitative Interview, Social Research Methodology, Qualitative Data, and Groupthink.
Local institutions and adaptive capacity of rural households in the Niger Delta
Authors: Jack Jackson , Eke Paul
Published: July 2018

The study examined the role local institutionsplay in promoting adaptive capacity of households to environmental degradation in the Niger Delta region of Nigeria.The survey was conducted amongst 610 households across Rivers, Delta and Bayelsa states. The questionnaire instrument was employed ineliciting data from the respondents. The study shows that respondents belonged to about 106 formal and informal local institutions spreadacross the study communities. Findings revealed that local institutions serves as safety nets and sources of local insurance as they provide households opportunities for resources and materials exchange as well as galvanizing collective action that promotes livelihoods and adaptive capacity. The hypothesis test result indicated that  membership to local institutions has a significant effect on  adaptive capacity. The study hence concluded that membership to local institutions significantly promote the capacity of households to adapt to environmental degradation in the Niger Delta. The study hence recommends that the institutional capacities of these institutions should be enhanced through knowledge and resource sharing by means ofincreasingly engaging with external actors like the government and civil society who can provide external support to the communities.Keywords: LocalInstitutions, Adaptive Capacity, Rural  Households, Niger Delta.
Nigerian Pidgin(NP) for Peace, Unity and Sustainable Development in Nigeria
Authors: Ezekwe Angela Chitoo
Published: July 2018

The need for peace, unity and development that is sustained is one that has continually been reverberated throughout the nation for a number of decades now. Absence of peace and unity hinders sustainable development, as the existence of these is a prerequisite to achieving sustainable economic development in any nation. Multilingual and multiethnic nature of Nigeria has promoted the divide among Nigerians in this decade more than ever before. There is need for the adoption of a common language acceptable to all. In contemporary Nigeria, we see pidgin bridging the gap incommunication between people of different social status, tribes and religious affiliations, thereby building the right atmosphere for peace, unity and sustainable development to thrive. This papertherefore discussed contexts where Nigerian Pidgin is already in use and advocated that its acceptability in these context indicates that it can be turned to a language for wider communication and a panacea for peace and development in Nigeria
Repenser la Sorcellerie dans les Romans Antillais: Une étude Sociocritique de Moi, Tituba Sorcière. . . Noire de Salem de Maryse Condé, Chair Piment de Gisèle Pineau et Hadriana dans tous mes Rêves de René Depestre
Authors: Obidiegwu Vincent Nnaemeka , Ugwu Evaristus Nkemdilim
Published: July 2018

Sorcery is a subject that always creates heated debate in our  contemporary society. That’s why we aim to examine sorcery within the specific context of Caribbean writer’s literary creations. Therefore, this study looks at witch crafting as one of the major themes that continue to occupy a major place in the Antillean literary discourse. It seems to us that irrespective of the presence of this theme, very rare are literary critics especially from Nigeria that is based on sorcery. That forms our reason of venturinginto these literary works to unveil and show how witch crafting is represented. What are the reasons behind this? The overall  assessment is it negative or positive? What is the way forward? These are basic questions that this study tries to resolve under social critic approach.Key Words: Rethink, witch crafting, Antillean, social critic
Extreme temperature and precipitation response to solar dimming and stratospheric aerosol geoengineering
Authors: Ji Duoying , Fang Songsong , Curry Charles L. , Kashimura Hiroki , Watanabe Shingo , Cole Jason N. S. , Lenton Andrew , Muri Helene , Kravitz Ben , Moore John C.
Published: July 2018

Abstract. We examine extreme temperature and precipitation under two
potential geoengineering methods forming part of the Geoengineering Model
Intercomparison Project (GeoMIP). The solar dimming experiment G1 is designed
to completely offset the global mean radiative forcing due to a
CO2-quadrupling experiment (abrupt4 × CO2), while in
GeoMIP experiment G4, the radiative forcing due to the representative
concentration pathway 4.5 (RCP4.5) scenario is partly offset by a simulated
layer of aerosols in the stratosphere. Both G1 and G4 geoengineering
simulations lead to lower minimum temperatures (TNn) at higher latitudes and
on land, primarily through feedback effects involving high-latitude processes
such as snow cover, sea ice and soil moisture. There is larger cooling of TNn
and maximum temperatures (TXx) over land compared with oceans, and the
land–sea cooling contrast is larger for TXx than TNn. Maximum 5-day
precipitation (Rx5day) increases over subtropical oceans, whereas warm spells
(WSDI) decrease markedly in the tropics, and the number of consecutive dry
days (CDDs) decreases in most deserts. The precipitation during the tropical
cyclone (hurricane) seasons becomes less intense, whilst the remainder of the
year becomes wetter. Stratospheric aerosol injection is more effective than
solar dimming in moderating extreme precipitation (and flooding). Despite the
magnitude of the radiative forcing applied in G1 being ∼ 7.7 times
larger than in G4 and despite differences in the aerosol chemistry and
transport schemes amongst the models, the two types of geoengineering show
similar spatial patterns in normalized differences in extreme temperatures
changes. Large differences mainly occur at northern high latitudes, where
stratospheric aerosol injection more effectively reduces TNn and TXx. While
the pattern of normalized differences in extreme precipitation is more
complex than that of extreme temperatures, generally stratospheric aerosol
injection is more effective in reducing tropical Rx5day, while solar dimming
is more effective over extra-tropical regions.
Correction of CCI cloud data over the Swiss Alps using ground-based radiation measurements
Authors: Jeanneret Fanny , Martucci Giovanni , Pinnock Simon , Berne Alexis
Published: July 2018

Abstract. The validation of long-term cloud data sets retrieved from
satellites is challenging due to their worldwide coverage going back as far
as the 1980s. A trustworthy reference cannot be found easily at every
location and every time. Mountainous regions present a particular problem
since ground-based measurements are sparse. Moreover, as retrievals from
passive satellite radiometers are difficult in winter due to the presence of
snow on the ground, it is particularly important to develop new ways to
evaluate and to correct satellite data sets over elevated areas. In winter for ground levels above 1000 m (a.s.l.) in Switzerland, the cloud
occurrence of the newly released cloud property data sets of the ESA Climate
Change Initiative Cloud_cci Project (Advanced Very High Resolution Radiometer afternoon
series (AVHRR-PM) and Moderate-Resolution Imaging Spectroradiometer (MODIS) Aqua series) is
132 to 217 % that of surface synoptic (SYNOP)
observations, corresponding to a rate of false cloud detections between 24 and 54 %. Furthermore, the overestimations
increase with the altitude of the sites and are associated with particular
retrieved cloud properties. In this study, a novel post-processing approach is proposed to reduce the
amount of false cloud detections in the satellite data sets. A combination of
ground-based downwelling longwave and shortwave radiation and temperature
measurements is used to provide independent validation of the cloud cover
over 41 locations in Switzerland. An agreement of 85 % is obtained when the
cloud cover is compared to surface synoptic observations (90 % within ± 1 okta difference). The validation data are then co-located with the satellite
observations, and a decision tree model is trained to automatically detect the
overestimations in the satellite cloud masks. Cross-validated results show
that 62±13 % of these overestimations can be identified by the model,
reducing the systematic error in the satellite data sets from 14.4±15.5 % to 4.3±2.8 %. The amount of errors is lower, and, importantly, their
distribution is more homogeneous as well. These corrections happen at the
cost of a global increase of 7±2 % of missed clouds. Using this model,
it is possible to significantly improve the cloud detection reliability in
elevated areas in the Cloud_cci AVHRR-PM and MODIS-Aqua products.
A lattice grain model of hillslope evolution
Authors: Tucker Gregory E. , McCoy Scott W. , Hobley Daniel E. J.
Published: July 2018

Abstract. This paper describes and explores a
new continuous-time stochastic cellular automaton model of hillslope
evolution. The Grain Hill model provides a computational framework with which
to study slope forms that arise from stochastic disturbance and rock
weathering events. The model operates on a hexagonal lattice, with cell
states representing fluid, rock, and grain aggregates that are either
stationary or in a state of motion in one of the six cardinal lattice
directions. Cells representing near-surface soil material undergo stochastic
disturbance events, in which initially stationary material is put into
motion. Net downslope transport emerges from the greater likelihood for
disturbed material to move downhill than to move uphill. Cells representing
rock undergo stochastic weathering events in which the rock is converted into
regolith. The model can reproduce a range of common slope forms, from fully
soil mantled to rocky or partially mantled, and from convex-upward to planar
shapes. An optional additional state represents large blocks that cannot be
displaced upward by disturbance events. With the addition of this state, the
model captures the morphology of hogbacks, scarps, and similar features. In
its simplest form, the model has only three process parameters, which
represent disturbance frequency, characteristic disturbance depth, and
base-level lowering rate, respectively. Incorporating physical weathering of
rock adds one additional parameter, representing the characteristic rock
weathering rate. These parameters are not arbitrary but rather have a direct
link with corresponding parameters in continuum theory. Comparison between
observed and modeled slope forms demonstrates that the model can reproduce
both the shape and scale of real hillslope profiles. Model experiments
highlight the importance of regolith cover fraction in governing both the
downslope mass transport rate and the rate of physical weathering.
Equilibrium rocky hillslope profiles are possible even when the rate of
base-level lowering exceeds the nominal bare-rock weathering rate, because
increases in both slope gradient and roughness can allow for rock weathering
rates that are greater than the flat-surface maximum. Examples of transient
relaxation of steep, rocky slopes predict the formation of a regolith-mantled
pediment that migrates headward through time while maintaining a sharp slope
break.
Long-term groundwater recharge rates across India by in situ measurements
Authors: Bhanja Soumendra N. , Mukherjee Abhijit , Ramaswamy Rangarajan , Scanlon Bridget R. , Malakar Pragnaditya , Verma Shubha
Published: July 2018

Abstract. Groundwater recharge sustains groundwater discharge, including natural discharge through springs and base flow to surface water as well as anthropogenic discharge through pumping wells. Here, for the first time, we compute long-term (1996–2015) groundwater recharge rates using data retrieved from several groundwater level monitoring locations across India (3.3 million km2 area), the most groundwater-stressed region globally. Spatial variations in groundwater recharge rates (basin-wide mean: 17 to 960 mm/yr) were estimated in the 22 major river basins across India. The extensive plains of the Indus–Ganges–Brahmaputra (IGB) river basins are subjected to prevalence of comparatively higher recharge. This is mainly attributed to occurrence of coarse sediments, higher rainfall, and intensive irrigation-linked groundwater abstraction inducing recharge by increasing available groundwater storage and return flows. Lower recharge rates (
Profesional de Instrumentación Quirúrgica frente a la aplicación de los Principios y Valores Bioéticos de acuerdo a la Ley de Talento Humano en Salud en Colombia
Authors: Carrillo González Stephanye , Lorduy-Gómez Jaime , Muñoz-Baldiris Ruby
Published: July 2018

El instrumentador quirúrgico es un miembro activo del equipo quirúrgico, que tiene como esencia y objeto formal del ejercicio mantener la vida con todo el respeto y la dignidad inherentes al ser humano, y debe acompañar sus acciones de forma coherente a fin de proteger y preservar la vida, de esta manera le otorga significado a la enfermedad, el sufrimiento y el dolor. El objetivo del presente estudio descriptivo, de corte transversal y prospectivo, es determinar el conocimiento del instrumentador quirúrgico frente a los principios y valores bioéticos según la Ley 1164 de 2007. La población objeto fueron instrumentadores quirúrgicos de la ciudad de Cartagena. Participaron profesionales de tres instituciones de salud. Se encontró que los principios éticos y bioéticos que conocen y aplican estos profesionales son: veracidad, igualdad y beneficencia. Los que menos conocen son mal menor, no maleficencia, de totalidad y de causa de doble efecto. Los valores más aplicados son: humanidad, dignidad, responsabilidad, prudencia y secreto. Se concluye que la gran mayoría de los instrumentadores quirúrgicos encuestados aplican los principios y valores éticos en su quehacer profesional, pero desconocen el nombre o la definición de los mismos. Se propone ahondar más desde la academia en el fortalecimiento de estos temas para lograr un nivel integral y de mayor cuidado.
Missing inflectional features and missing exponents in DP-internal agreement asymmetries
Authors: Bonet Eulàlia
Published: July 2018

This paper focuses on different types of agreement asymmetries within the DP in which postnominal modifiers exhibit full agreement while in prenominal modifiers agreement can fail in different ways. The main lines of the optimality-theoretic proposal in Bonet, Lloret & Mascaró (2015) are followed, but it is shown, through a comparison of two Northern Italian varieties, that their constraint set cannot account for varieties of Friulian, where the plural exponent fails to surface in plural contexts. It is argued that one of their constraints must be split into two separate ones, a strictly phonological constraint, Max(segment), on the one hand, and, on the other, a constraint on exponence, Max-M[F], proposed by Wolf (2008).
Georganiseerde houtcriminaliteit in de Braziliaanse Amazone
Authors: Boekhout van Solinge Tim
Published: July 2018

Organized timber crime in the Brazilian Amazon

That criminal networks are active in the illegal exploitation of timber is increasingly acknowledged. The degree of organization of these networks, and the way in which they use (threats of) violence and corruption, is less known. This article describes and analyses, on the basis of various, including local, sources, how organized criminal groups in the Amazon rainforest illegally harvest trees which they sell on the (international) market and how they try to stay immune from the law by using threats, violence, fraud and corruption. This article also discusses the first results of a three-year pilot (2014-2017) of community-based forest monitoring and protection with waterproof GPS-camera’s, developed with communities and with support of the Brazilian Public Prosecutor’s Office.
Wildlife crime als een complex systeem: hoe agent-gebaseerde modellen gebruikt kunnen worden om stroperij te bestuderen en bestrijden
Authors: van der Ploeg Jacob , van Doormaal Nick , Mäs Michael , Lemieux Andrew M.
Published: July 2018

Wildlife crime as a complex system: how agent-based models can be used to study and prevent poaching

Developing effective anti-poaching strategies is difficult because of complex interactions between animals, poachers, and rangers. This study shows the utility of agent-based models (ABM) for unraveling these interactions, and their underlying mechanisms, to identify relevant components for planning ranger operations. Here, two patrol strategies were simulated using an ABM for wildlife crime to quantify their effectiveness under different circumstances. The model showed border patrols to be more effective than search patrols in protecting both solitary and herd animals. Furthermore, the model suggests that rangers catch fewer poachers when patrols are overly focused on locations where poaching was detected previously. The study illustrates that disciplined model development and testing is required for useful conclusions to be drawn, from a fully understood ABM.
Sana que sana. Ciudadanía dominicana. El proyecto multimedia de Rita Indiana.
Authors: Martínez Hernández Lina
Published: July 2018

En este artículo propongo una lectura de los diferentes componentes audio-visuales y textuales de la obra de la artista dominicana Rita Indiana Hernández, enfatizando su intervención en los debates sobre ciudadanía y frontera entre la República Dominicana y Haití. Propongo que a partir del uso de la yuxtaposición y la (re) mediación –pasar de un medio audiovisual a otro– el proyecto multimedia de Rita Indiana puede entenderse como una exploración de las posibilidades discursivas y críticas tanto dentro de los confines de la nación, como en respuesta a las redes de producción y circulación artísticas globales. Esta posibilidad de intervenir en lo nacional y lo transnacional se da de la mano con una crítica a la naturaleza racializada del discurso nacional dominicano, así como también de las formas de producción neoliberales. El llamado “problema haitiano” cobra centralidad en la obra de Rita como epicentro de imaginarios, prácticas e identidades que permiten entender la construcción de la ciudadanía de manera retro-activa, es decir, como un contrapunteo conflictivo entre los legados del pasado histórico y las demandas de la actualidad.
La relación arte-política en Cuba: Entre el silencio y el susurro. El arte como lugar de acción y repolitización de la vida.
Authors: Ibarra Cáceres Anaeli
Published: July 2018

Este artículo indaga cómo se expresa la relación arte-política en Cuba en el contexto de un cambio de perspectiva en la dirección del país. Se precisa cómo lo político atraviesa el arte, politizándolo y constituyendo nudos esenciales que permiten situar y revalorizar conceptos como gestión ciudadana y activismo artístico. El lapso 2006-2014 marca un periodo muy interesante en la historia cubana. Primero, porque hay una transferencia de poderes. Segundo, porque a partir de esa transición comienzan a manifestarse transformaciones que denotan un punto de giro en el enfoque socialista. El susurro de Tatlin (2014) es una performance de Tania Bruguera que marca este lapso y traza una parábola del socialismo cubano en el siglo XXI, planteando algunas preguntas, desde “¿hacia dónde vamos?”, “¿hay hacia dónde ir?”, “¿cómo llegar?”, sobre todo, cómo llegar después del camino desandado; hasta la constatación de una inminente gravitación hacia el norte.
Identidades en tránsito: Reformulando el Caribe desde España a través de la obra de Gertrudis Rivalta y Brenda Cruz.
Authors: Alcaide Ramírez Aurora
Published: July 2018

Este artículo analiza las obras Soy Cuba y Verano de la artista cubana Gertrudis Rivalta y Soy: un cuerpo tatuado y Fronteras de la puertorriqueña Brenda Cruz, en las que ambas creadoras, que emigraron a España hace casi dos décadas, problematizan acerca de los movimientos migratorios, la raza, la identidad cultural y la ciudadanía en el Caribe hispano, profundizando en nociones como la de “mulata”, “transculturación” y “otredad” desde una perspectiva de género, decolonial y autobiográfica. Teniendo en cuenta su condición de mujeres, mulatas, caribeñas, migrantes y artistas, utilizan sus proyectos creativos como altavoz desde cual reivindicar visibilidad e igualdad para los sujetos afrodescendientes, tanto dentro como fuera del Caribe, especialmente de las mujeres, reconociendo a la mulata como símbolo de la hibridez de sus naciones, en donde la herencia africana es tan importante como la española/europea; a la par que critican la imagen estereotipada y prejuiciosa que de la mujer caribeña se tiene en Occidente, así como de todos sus ciudadanos y del Caribe en general -especialmente perceptible cuando se vive en la diáspora, como ellas. Asimismo, en dos de las obras objeto de estudio cuestionan la eficacia de los gobiernos ante el problema de la inmigración, criticando la insensibilidad de la sociedad receptora hacia el drama de sus protagonistas, así como los abusos y precariedad a la que éstos son sometidos para optar a un futuro mejor, y nuevamente al estatus de “ciudadano”.
El cine que emigra: la transnacionalidad en la cinematografía dominicana.
Authors: Iturriza Mendía Aitor , Pimentel Mendoza Raisa
Published: July 2018

El presente trabajo es una revisión de las categorías de transnacionalidad propuestas por Deborah Shaw, Andrew Higson y Mette Hjort para analizar la línea evolutiva del cine dominicano y establecer las dinámicas mediante las cuales las películas nacionales han superado el contexto de lo local para coexistir con aspectos que condicionan “lo nacional”. El estudio se centra en dos filmes de la producción cinematográfica sobre migración –Un pasaje de ida (1988) y Nueba Yol (1995)- y tiene como objetivo establecer un nuevo punto de vista sobre algunos rasgos de transnacionalidad presentes en el cine dominicano.
PYRANOCHROMENES, THIOPYRANOCHROMENILIUM SALTS. PERSPECTIVES OF SYNTHESIS
Authors: Mazhukina Olga A. , Shkel Andreiy A. , Fedotova Olga V.
Published: July 2018

The reactions of propanonilchromenes with protonic and aprotonic acids were investigated. The possibility of aromatisation of thiopyranochromen-2-ones’ 4Н-thiopiranic fragment was demonstrated using NMR 1Н spectroscopy method in time and new chromenothiopyrilium perchlorates (thriftoracetates) were discovered.
SYNTHESIS OF STYRENE BUTADIENE RUBBER IN PRESENCE OF GRINDED VULCANIZATE
Authors: Makarov Vladimir M. , Guryleva Nadezhda L.
Published: July 2018

The method for recycling of rubber of different composition in granular state by introducing them into the polymerization medium at the synthesis of butadiene-styrene rubber was considerd. It was shown that rubber made on basis of such rubber, exhibits better physical and mechanical properties than at introducing grinded vulcanizate at producing these mixtures on rolls as well as through rubbers thermomechanical regeneration.
SORPTION OF AMINO ACID AND CHANGES IN HYDRATION OF HETEROGENEOUS CATION- AND ANION-EXCHANGE MEMBRANES FUMASEP
Authors: Maiygurova Nina I. , Roessner Frank , Eliseeva Tatiana V. , Selemenev Vladimir F.
Published: July 2018

Hydration of heterogeneous cation-exchange membranes Fumasep FTCM and anion-exchange membranes Fumasep FTAM in hydrogen and hydroxyl forms, respectively, sorbing tyrosine as well as of the samples being used in electrodialysis concentration of tyrosine solution was studied using the methods of thermogravimetry and IR-spectroscopy. It was revealed that tyrosine sorption and membranes application in electrodialysis of this amino acid solution causes membranes hydration decrease. The decrease in membrane hydration after its contact with tyrosine leads to membrane surface hydrophobicity grow up and, consequently, make significant influence on amino acid’s mass transfer.
SPECTRAL CHARACTERISTICS OF CONFORMATION ISOMERS OF MESO-OCTAMETHYL-CALIX(4)PYRROLE BASED ON QUANTUM-CHEMICAL CALCULATIONS
Authors: Surov Oleg V. , Krestianinov Mikhail A. , Mamardashvili Nugzar Zh.
Published: July 2018

The structure optimization and calculation of electronic absorption spectra of meso-octa-methylcalix(4)pyrrole conformers was performed  by density- functional theory using hybrid B3LYP functional in cc-pVTZ basis set of Gaussian 09 package. Analysis of experimental UV-Vis spectra of solutions of calix(4)pyrrole was carried out in various solvents. The conclusion on the existence of a dynamic equilibrium between conformers in solutions of meso-octamethylcalix(4)pyrrole was made.
EFFECT OF NANO- AND MICROPARTICLES OF IRON (III) OXIDE ON VISCOSITY OF LAMELLAR LIQUID CRYSTALS OF LECITHIN
Authors: Murashova Nataliya M. , Dambieva Ayuna A. , Yurtov Evgeniy V.
Published: July 2018

The addition of low concentrations (0.001 – 0.1 wt. %) of iron (III) oxide nanoparticles with diameter of 10-20 nm was shown to result in the increase in a viscosity of lamellar liquid crystals in the systems of lecithin – water and lecithin – dodecane – water by 35-60% and 15-20%, respectively, whereas the addition of 1-5 µm microparticles does not affect the viscosity. An increase in a viscosity of the liquid crystals with the growth of the nanoparticles concentration from 0.001 to 0.1 wt. % is observed. It is assumed that the nanoparticles act as "bridges" between the bilayers of the lamellar liquid crystal.
LiF – NaF – KCl SYSTEM
Authors: Verdiev Nadinbeg N. , Arbukhanova Patimat A. , Alkhasov Alibek B. , Magomedbekov Ukhmaali G. , Verdieva Zaira N. , Iskenderov Eldar G.
Published: July 2018

The stable cross section of LiF - NaF - KCl quadruple mutual system Li, Na, K // F, Cl was studied with the differential thermal (DTA) and X-ray fluorescence (XRF) methods. It was established that in a system the eutectic composition crystallizing at 591 ° C is realized.  Temperatures of starting solid-phase reactions were revealed in the ternary systems mutual Na, K // F, Cl and Li, Na // F, Cl, (715 and 650 °C, respectively) corresponding to the conversion of reactants of metastable diagonals into products of stable diagonals.
STUDY OF PURIFICATION PROCESS OF VEGETABLE OIL BY PINK CLAY
Authors: Razgovorov Pavel B. , Nagornov Roman S. , Grishina Yuliya N. , Silanteva Anna D.
Published: July 2018

The phase composition of natural pink clay was studied and influence of sorption properties on purification of mustard oil was investigated.  The clay was activated by treatment with oxalic acid and sodium carbonate before using. The acid-base activation of natural material was shown to promote the creation of the new centers on its surface. The new materials demonstrated a positive effect on the oil purification process from fatty acids, peroxide compounds and no effect on the concentrations of carotenoids.
WATER QUALITY IN TRIBUTARIES OF VOLGA RIVER IN WATER AREA OF GORKY WATER-STORAGE BASIN
Authors: Marchenko Tatyana A. , Izvekova Tatyana V. , Gushchin Andrey A. , Grinevich Vladimir I. , Golovkina Elena A
Published: July 2018

In article the results of complex study of water quality for tributaries of Volga river in a water area of Gorky water-storage basin. Study methods included both the chemical and biological methods of pollution level control.  For all water flows the excess of MPC   on heavy metals (by 1-27 times), partially on copper by 1-27, on iron –by 3-9, on manganese by 1-8, as well as on ammonium cations – by 1-6, and difficult-oxidizing organic compounds (COD)-by 2-4 is observed.  It was established by the bio-testing method (test-objects are the chlorella algae and Daphnia) that water samples taken in the region of river mouths of Gorky water-storage basin (Sunzha, Kazokha, Elnat, Kineshemka) don’t posses acute toxicity but they are slightly toxicity.
STUDY OF CADMIUM OCTA(4-METHOXYPHENYL)PORPHYRINATE IN REACTION OF METAL EXCHANGE WITH TIN CHLORIDE IN DMF
Authors: Zvezdina Svetlana V. , Chizhova Natalya.V. , Mamardashvili Nugzar Zh. , Koifman Oskar I.
Published: July 2018

Metal-exchange reaction for complexes with macrocyclic ligands refers to a special type of complex coordination interactions. The reaction of metal exchange has founded wide application for the synthesis of complexes of natural and synthetic porphyrins. In the general form, the metal-exchange reaction may be written as follows:MР + M/Xn(Solv)m-n® M/Р + MXn(Solv)m-nwhere МP and M/P are metalloporphyrins, M/Xn(Solv)m-n are metal salts of solvate complexes. Cd-octa(4-methoxyphenyl)porphyrin was obtained by the reaction of octa(4-methoxyphenyl)-porphyrin-ligand with cadmium chloride in the presence of potassium acetate in dime-thylformamide. The obtained compound was identified by the methods of UV-VIS spectroscopy, 1H NMR and mass-spectrometry. The reaction order on the salt and the complex of cadmium in the case of the reactions of the Cd-octa(4-methoxyphenyl)porphyrin metal-exchange with tin chloride in dimethylformamide is equal to 1. Thus, the metal-exchange reaction is bimolecular and its total rate obeys to the second-order kinetic equation. It is suggested that the metal-exchange reaction of Cd-оcta(4-methoxyphenyl)porphyrin with tin chloride in dimethyl-formamide proceeds through a bimolecular associative mechanism.
RELATIONSHIP BETWEEN MOLAR PARAMETERS OF VISCOUS FLOW AND ULTRASONIC WAVE PROPAGATION IN AQUEOUS SOLUTIONS OF AMINO ACIDS
Authors: Tyunina Elena Yu. , Badelin Valentin G.
Published: July 2018

Quantitative structure-property relationship (QSPR) correlations have been widely applied in biological active solutes over several decades. Many new descriptors (parameters) have been developed. Of the many parameters reported in literature, it is argued that the volume (constitutional, geometrical, compressibility) properties play an important role in determining the overall state of proteins consisting of the various amino acids residuals. On basis of experimental data on density, viscosity and ultrasound velocity for aqueous solutions of amino acids, the volume effects in characteristics of impulse transfer and ultrasound wave were studied. The analysis on the correlations between molar parameters of viscosity and ultrasound velocity and molar volume for aqueous solutions of glycine, alanine, aminobutanoic acid, valine, leucine and serine has been carried. It was shown, that the temperature and the concentration dependences of viscosity and ultrasound velocity in the aqueous amino acids solutions may be represented using the molar approach of Krestov-Afanas`ev. An evaluation of the degree of correspondence of the correlation dependences to the experimental data was performed with the minimum distribution dispersion (SD), which was also called the sample standard deviation for regression, and the correlation coefficient (rcorr). It was shown that on basis of the correlations obtained, the densities or the molar volumes can be successfully used for the estimation of unknown values of the viscosities and sound speeds for the amino acid solutions.
MODIFICATION OF POLYESTER FIBERS TO CREATE COMPOSITE MATERIALS WITH ADJUSTABLE RIGIDITY
Authors: Koksharov Sergey A. , Kornilova Nadezda L. , Fedosov Sergey V.
Published: July 2018

Research aims at experimental study of an effective method of creating polymer-fiber composite materials with a comb structure of an interfacial layer. To change the surface micro-relief of polyester fiber method of surface saponification in the presence of a quaternary ammonium compound was used. This method provides localized hydrolysis reacting of polymer to form dotted etch wells. Fiber modification allows synthesizing comb polymer chains of the binder with the penetration of the lateral branches into the formed pore spaces of the textile carrier. Condition of polyester fiber after saponification estimated by indices: a loss of fiber mass, specific breaking load of the material, the content of carboxyl groups, the sorption of acrylic dispersion. The criterion for the rapid assessment of the quality of the fiber modification to change the micro-relief of its surface can serve the magnitude of the fiber mass loss, which must not exceed 3 %. Estimating the size of the formed voids was carried out according to the nitrogen adsorption data using a sorption analyzer NOVA 1200e. In moderate alkaline hydrolysis conditions, the main increase in the internal free volume provides mesopores with a diameter of 35...40 nm. The formations of a sub microscopic size 7...8 nm are the most numerous. Assessment of nanosized condition of reinforcing polymer dispersion by dynamic light scattering method allows recommending the necessary depth of polyester fiber hydrolysis to ensure the effects of the composite material stiffness controlled increase in 10...16 times.
MECHANOCHEMICAL SYNTHESIS OF CALCIUM TITANATE AND RESEARCH OF ITS PHOTOCATALYTIC ACTIVITY
Authors: Ivanov Konstantin V. , Agafonov Alexandr V. , Alexeeva Olyga V.
Published: July 2018

Recently much attention is paid to the synthesis and study of the properties of inorganic materials, based on alkaline earth titanates with a perovskite structure that have various polymorphic forms depending on the temperature. Calcium titatanat (CaTiO3) can be selected from the variety of perovskites because of its relatively high dielectric constant, unique photochemical properties, chemical stability, and compatibility with biological tissues, which leads to its application in microelectronics, photocatalysis and biomedicine as bone implants. In this paper, a solid-phase synthesis of calcium titanate was carried out by ceramic technology using mechanochemistry methods. This method allows to obtain calcium titanate directly by mechanochemical activation from the initial mixture of Ca (OH)2 and TiO2, which significantly reduces the energy consumption for its production. Structural changes in the synthesized material during calcination at 120 °C, 200 °C, 400 °C, 600 °C, and 800 °C were studied. The particle size and specific surface area of powders synthesized and calcined at 800 °C was measured by laser diffraction ("Analysette 22") and the low temperature (77K) nitrogen adsorption-desorption vapor, respectively. The phase composition of the obtained materials was studied by X-ray diffraction. It was found on the basis of studies of the particle size distribution that synthesized and calcined powders contain nanoparticles with sizes of 377 and 422 nm. The samples of CaTiO3 calcined at 120 °C and 800 °C have a mesoporous structure, the specific surface area was 46 and 7 m2/g, respectively, and average pore size in powders was 4 nm. It was found by the X-ray diffraction technique that the uncalcined sample contains admixtures of CaCO3 and TiO2 that can be removed completely at 600 °C.The photocatalytic activity of the synthesized material has been studied by the example of Rhodamine B dye decoloration on the calcium titanate calcined at 800°C. It was found that the decomposition degree of dye in solution was 77% for 80 min at a 6.7% shadow adsorption.
FEATURES OF X-RAY ANALYSIS OF CRYSTALLINITY DEGREE OF POLYPROPYLENE FIBRES
Authors: Zavadskii Aleksandr Ye.
Published: July 2018

The need to take into account the anisotropy of compact samples pressed from grinded polypropylene (PP) fibres at a determination of the degree of polymer crystallinity by X-ray method was shown. It was proved that the breach of the spherical scattering symmetry of X-rays by PP fiber samples is not connected with an amorphous phase of polymer. The method for calculating the degree of crystallinity of fibres from the normalized intensity of the diffuse halo of preparations under study and standard powder PP samples was proposed.
INVESTIGATION OF THERMAL PROCESSES OCCURING AT HEATING OF CAPROLACTAM SOLUTIONS AND ITS CYCLIC OLIGOMERS IN AMORPHOUS AREAS OF POLYAMIDE-6
Authors: Barannikov Mikhail V. , Bazarov Yuriy M. , Koifman Oscar I.
Published: July 2018

Samples of caprolactam and polyamide-6 granules of different composition prepared by drying methods, sublimation and extraction were investigated by thermogravimetry and differential scanning calorimetry. The temperature range for the process of de-monomerization-drying of polyamide-6 granules was determined on the basis of the thermogravimetry and differential scanning calorimetry data of submitted samples.
ENTHALPY OF INTERACTION OF ION-EXCHANGE HETEROGENEOUS MEMBRANES AND THEIR GRANULAR ANALOGUES WITH AMMONIUM NITRATE SOLUTION
Authors: Niftaliev Sabukhi I. , Peregudov Yuriy S , Kozaderova Olga A. , Kim Kseniya B.
Published: July 2018

Ion-exchange membranes are widely used for extraction, separation and concentration of aqueous nitrogen-containing solutions. In the study the heterogeneous ion-exchange membranes of cationic type- MK-40, Ralex CM (H) -PP, MK-41 – and anionic type - MA-41, Ralex AM (H) -PP and also their granular analogues – cation exchanger  KУ-2·8 and anion exchanger AB-17·8 were used. Sorption of nitrate ions and ammonium ions was conducted from the ammonium nitrate solution with concentration of 0.012 mole / dm³. To determine sorption thermochemical characteristics of the studied ions the calorimetric method was used. It was found that for all the studied types of membranes and ion exchangers the processes were accompanied by heat evolution. From the calorimetric measurements the thermokinetic interaction curves of cation-exchange membranes and KУ-2×8 with the ammonium nitrate solution and anion-exchange membranes and AB-17×8 with the solution of the same salt were obtained. According to the curves the power of heat evolution and time of the process were determined. It was shown that the ion exchangers KУ-2·8 and AB-17·8 are characterized by a longer time to achieve the maximum of heat evolution and process time than for the similar membranes. This fact is explained by the different number and accessibility of the functional groups in the membranes and ion exchangers. From the thermo-kinetic curves the enthalpies of interaction were calculated. The process of the interaction between the granular ion exchangers and ions is characterized by higher values of the enthalpy than for the membranes which large steric effects are common for. Saline concentration, nature of exchangeable ions and type of functional groups of the ion exchanger and also its moisture content influence the enthalpy value. Experimental calorimetric data indicated that the energy costs connected with the effects of dehydration and conformational changes in the sorbent polymer chains do not overlap the exothermic sorption effect. The calorimetric method is informative to determine the nature and mechanism of sorption.
PERSPECTIVE DIRECTION OF CALCULATION AND DESIGN OF REINFORCING CARCASSES OF TENSION FIRE HOSES ON BASIS OF SYNTHETIC FIBERS
Authors: Aripbaeva Akerke E. , Myrkhalykov Zhumakhan U. , Koifman Oscar I. , Bazarov Yuriy M. , Stepanov Sergey G.
Published: July 2018

The physical and chemical properties of synthetic fibers of various compositions for reinforcing carcasses of pressure fire fibers, and their appointment and structure were denoted. It is noted that due to the effect of negative factors (mechanical wear, impact of low and high temperatures, the action of sunlight, aging of the material, accidental release of chemically active substances, etc..) on pressure fire hoses at their exploitation, increased demands are imposed on the material of synthetic fibers of pressure fire hoses, the most important of which is resistant to abrasion. The use of pressure fire hoses from polyester fibers based on PET shows that the main reason for breaking up the fibers at their exploitation is abrasion of the surface. In this regard, the use fibers of ultrahigh molecular weight polyethylene (UHMWPE fibers) and fibers of PET, polyamide 66 (PA-66) having high strength and abrasion resistance as a material of reinforcing carcass of pressure fire hoses was proposed. It is extremely important to  develop and improve of the calculation theory and design of fire hoses in hydraulic impact, which will be demand in the calculation and design of new types of pressure fire hoses on the basis of synthetic fibers, as well as to identify reasons for breaking of pressure fire hoses to extinguish the fire, to create a new high-pressure fire hoses. In this regard, the brief analysis of publications on their strength calculation at the hydraulic impact was carried out and achievements in the field of calculation and design of reinforcing carcasses of fire hoses were denoted.
HIGH-PERFORMANCE MICROPOROUS MEMBRANES IN TECHNOLOGIES OF SEA WATER PURIFICATION
Authors: Desyatov Andreiy V. , Kruchinina Nataliya E. , Landyrev Alekseiy M.
Published: July 2018

Now the microfiltration are widely used for treatment of surface waters (sea, river) from the fine suspended solids, colloidal and organic compounds including their preparation for reverse osmosis desalination and for purification of waste and water processing at the creation of closed systems of water use. The process of water purification using microfiltration elements of roll type on the basis of micro porous membranes with cylindrical pores of 0.2 microns size at laboratory and industrial plants was studied. The technology for pretreatment of water prior to microfiltration by coagulant dosing to increase the specific productivity of microfiltration elements and the quality of the filtrate was proposed. The optimal dose of ferric chloride coagulant and the time of contact with water and water quality parameters (color, turbidity, total iron content, the index of density of sediment) were determined. The resulting indicators of the quality of the filtrate for water at input of the reverse osmosis systems were: the average value of the filtrate turbidity - 0.2 NTU, the average SDI15 value -3.5. The obtained high value of specific performance in working mode was 260 l/ (m2×bar×h)( average value).
ELECTRICALLY CONDUCTIVE POLYCRYSTALLINE SUPER HARD MATERIAL BASED ON DIAMOND AND n-LAYER GRAPHENES
Authors: Shul’zhenko Alexandr A. , Jaworska Lucyna , Sokolov Alexandr N. , Gargin Vladislav G. , Romanko Ludmila A.
Published: July 2018

The electrical and physical properties of the electrically conductive super hard material on the basis of polycrystalline diamond and n-layered graphenes obtained at high pressures and temperatures were studied. It was established that the increase in graphene in a polycrystalline diamond compact leads to a sharp decrease in resistance. Wherein the hardness of the samples is slightly inferior to the hardness of diamond poly crystals obtained without the use of graphene.
RECEIVING AND PROPERTIES OF NEW NANO COMPOSITE CARBON MATERIALS
Authors: Yafarov Ravil K.
Published: July 2018

The effect of self-organization of diamond nanocrystallites in graphite and in the polymer-like carbon films was discovered for the first time at deposition from vapors of ethanol of low pressure with the use of non-equilibrium high-ionized microwave plasma. The technology of receiving nanocomposite diamond-graphite covers with adjustable thresholds of field emission in the range from 5-7 to 20 V/mm and density of currents higher than 100A/cm2 was developed. The possibility of receiving of insular carbon coverings with super high surface density on crystals of silicon as well as   the quasi-closed cellular macro cell structures with transparent graphene-like "windows" in the visible spectral range was shown.
MODIFICATION OF SURFACE OF DOUBLE WALL CARBON NANO TUBES BY FULLERENE C60
Authors: Karaeva Aida R. , Zhukova Ekaterina A. , Urvanov Sergei A. , Senatulin Boris R. , Skryleva Elena A. , Mordkovich Vladimir Z.
Published: July 2018

The composite samples based on double-wall carbon nano tubes and fullerenes followed by laser treatment were prepared. XPS confirmed existence of essential contact between two components of the composite. The differential charging effect disappears after laser processing, which induces photopolymerization of fullerene clusters.  The TEM showed close-packed continuous coating of cross-linked C60 clusters formed on the surface of nano tubes after laser irradiation.
DEVELOPING MANUFACTURING TECHNOLOGY OF COMPOSITE CATHODES WITH METHOD OF PRESSING PYROLYTIC GRAPHITE WITH TRIPLE CARBONATE
Authors: Lobanov Svyatoslav V. , Fedorov Ivan A. , Sheshin Evgeniy P.
Published: July 2018

In this work a manufacturing technology for a composite cathode is described. In this cathode draphite and emission-active substance forms intercalated chemical compound. These cathodes were studied in a mode of field thermo electrone emission at temperatures of 0-1100 ° C and anode voltages of 1 – 15 kV. The article contains results of determination of optimal pressing parameters, different methods of cathode surface processing and field emission current-voltage characteristics.