bluuebunny/crossref_metadata_2025 huggingface dataset:
DRX study of the effects of aluminates and ferrites additions over bicalcium silicates formations
Authors: Triviño Vázquez F. , Ortega S.
Published: May 2012

It must be measured the height that is obtained in the peaks indicated in the diffractograms of the compounds: CaO, SÍO2, β-C2S γ-C2S, C3A, C2F and C4AF, with the finality of study their mutual influences, and also study the aluminoferrites over such bicalcic silicates, obtained from differents raw mix.
The adquired knowledges can be used to know the partial effects of such components in the elaboration of portland clinker.
Concrete blocks. Analysis of UNE, ISO en standards and comparison with other international standards
Authors: Álvarez Alonso Marina , Río Suárez Olga , Rodríguez-Monteverde Cantarell Pilar , Barbero Sánchez J. Miguel
Published: May 2012

This paper attempts to describe the recently approved UNE standards through a systematic analysis of the main specifications therein contained and the values considered for each of them, as well as the drafts for ISO and EN concrete block standards. Furthermore, the study tries to place the set of ISO standards in the international environment through a comparative analysis against a representative sample of the standards prevailing in various geographical regions of the globe to determine the analogies and differences among them. PALABRAS CLAVE: albañilería, análisis de sistemas, bloque de hormigón, muros de fábrica, normativa KEY WORDS: masonry, system analysis, concrete blocks, masonry walls, standards
Comportamiento hídrico de pizarras de techar
Authors: Ruiz de Argandoña G. , Calleja L.
Published: May 2012

The hidric behaviour of two slaty rocks from the NW of Spain (phyllite of Rande —La Coruña— and slate of Luarca —Asturias—) used as ornamental and roof slate is studied. An experimental methodology for proper interpretation of the hidric phenomena to which they can be subjected due to their particular use in the building industries is proposed. The results of the tests (swelling, slaking and wetting/drying cycles) are related to the mineralogy and texture, as well as to some physical properties related to the water movement throughout the rocks (porosity, air permeability and water absorption).
Concrete durability
Authors: Gaspar Tébar Demetrio
Published: May 2012

The evidence that the concrete is not a material for ever was noticed from the beginning of its industrial use. In the present work, the author describes the studies carried out during the last century and the early ages of the present one, mainly devoted to the study of the durability in sea water.
At the present days, and in spite of the numerous papers published from then, the study of the concrete durability continues focusing the research priorities and economical resources of researchers and industries related with this material. Moreover, the new laboratory techniques are allowing to understand old problems and even to open again the discussion on reaction mechanisms which were believed to be completely understood.
The article finalizes with a brief description of the numerous studies carried out at the Institute Eduardo Torroja on concrete durability, mainly those related with the resistance against gypsum attack (so abundant in our country land) and against sea water attack.
El vidrio en la construcción. Situación actual y orientación de la l+D
Authors: Coto José Antonio
Published: May 2012

Not available.
Cement: Administrative tender specifications and standards in Spain
Authors: Soria Santamaría Francisco
Published: May 2012

The paper describes, in chronological order, the different competent Authorities in Spain and the documents issued by them regarding Cement Regulations and Standards.
The origin of the early cement quality Rules is referred to, the issuing of Regulations by the Public Bodies and finally the adoption of National Standards on the one hand, as well as the first initiatives to establish International Standards, especially motivated by the export boom after the Second World War, on the other.
The second part of the paper offers a brief synthesis of the terms and conditions for cement in Administrative Tender Specifications from 1919 to date regarding definitions, classifications and specifications.
Finally the present state of the art is outlined in a series of Tables describing the cement standards in force in Spain.
Macroscópical morphology of deterioration of the stone in the Cathedral of Almería/Spain
Authors: Alcalde M. , Martin A.
Published: May 2012

The prevailing winds in the area, associated with an important rising damp are the main natural factors of deterioration that affect the Cathedral of Almería. Certain unfortunate maintenance Jobs carried out as well as the bombardments and machine-gunning on the building during the Civil War can be indicated as anthropogenical factors of deterioration. The only lithotype used in the construction is a dolomitic limestone of high porosity from quarries near the city. The increase in volume in capillaries and interstices, related whith the presence of salts, and the dissolution, due to the great solubility of the natural magnesium salts which can produce dedolomitization of the stone, are the main deterioration mechanisms. This leads to indicators of deterioration with a typical morphology consisting of openings in all its manifestations (pitting, alveolar erosions and craters) especially on the high and low parts of the building where the wind and humidity, respectively, are more intense. The anthropogenical deterioration also has the shape of openings, such as the impact of bullets and obuses on the Southern facade and the grooves made for electric cables throughout the building. Diverse restorations have introduced tensions in the materials which have led to decohesions at different degrees (disaggregations, disintegrations and grain disgregations) in the interior of the temple and cloister.
The building is in a state of deterioration of a certain significance which essentially affects its esthetics. The speed in the degrading process observed in some areas calls for action for its maintenance.
Mechanism of gypsum hydration
Authors: Pacheco G. , Portilla M.
Published: May 2012

There is an hypothesis that the mechanism o f gypsum hydration and dehydration is performed through two simultaneous phenomena.
In this study we try to clear up this phenomenon using chlorides as accelerators or a mixture of ethanol-methanol as retarders to carry out the gypsum setting.
Natural Mexican gypsum samples and a hemihydrate prepared in the laboratory are used. The following analytical techniques are used: MO, DRX, DTA, TG and DTG.
In agreement with the obtained results, it can be concluded: that colloid formation depends on the action of accelerators or retarders and the crystals are a consequence of the quantity of hemihydrate formed.
Influence ot the curing temperatures on the evolution of the compression strength of concretes made with different typer of cements
Authors: Fernández Cánovas Manuel
Published: May 2012

In this paper we present the results obtained in the studies carried out on evolution of the compressive strength of identical concretes made with different types of cements based on the spanish standard UNE 80 301 when they are subjected to critical temperatures (5 °C and 35 °C), compared with the same concretes cured under normalysed conditions.
The number of the different cements used was eight.
The behaviour of the concretes was analysed through the results of the compression strengths at 3, 7, 14, 28 and 90 days, determining the grades of relative maturity of these concretes subjerted to the different temperatures.
From the work it can be concluded that these concretes made of different cements fulfill with their forecasted strength at 28 days.
Petrografía, propiedades físicas y durabilidad de rocas utilizadas en el patrimonio monumental de Cataluña, España (2.ª parte)
Authors: Esbert Rosa M. , Marcos Rosa M. , Ordaz Jorge , Montoto Modesto , Alonso F. Javier , Suarez del Río Luis M. , Ruiz de Argandoña Vicente G. , Calleja Lope , Rodríguez Rey Ángel
Published: May 2012

The petrographical description and the values of some physical properties of three rocks used in the Architectonic Heritage of Catalonia (Spain) are presented. These rocks are known, in the field of the "building stones" as Sant Vicenç, El Figueró and Manresa stones. By means of accelerated ageing tests, their durability is evaluated.
A study on fiy ash: ballistic separation of a fly ash
Authors: Peris Mora Eduardo , Payá Jordi , Monzó José
Published: May 2012

The object of this study is the characterization of several sized fractions from a "spanish fly ash" originating in the thermoelectric power plant in Andorra (Teruel).
Physical (size distributions, densities) chemical (chemical composition) and mineralogical characteristics (X-ray diffractograms and infrared spectra) for those sized fractions have been analyzed.
Initial fly ash was ballistically separated (horizontal draft) into four fractions using an aerodynamic tunnel with horizontal air current The separation effectivity was adapted for our later studies.
The results obtained were interesting: in the first case, the simplicity of the separation method, by this way we will be able to use it for further studies on sized fractions. On the other hand, differences on granulometric distributions and vitreous nature will allow us to study the effect of several fractions on mechanic properties of concrete with them.
El uso de las piedras de corte en los monumentos y en la construcción. 1. Areniscas y calizas
Authors: Puche Riart O. , García de Miguel J. M. , Sánchez Castillo L. , Mata Perelló J. M. , González Aguado M. T.
Published: May 2012

Not available.
Macroscopical morphology of deterioration of the stone in the cathedral of Guadíx/Spain
Authors: Alcalde M. , Martín A.
Published: May 2012

The main factors of deterioration that affect the Cathedral of Guadíx are of a natural origin, basically thermic and hydraulic, due to its great oscillations in temperature in Summer, the frequency of frosts in Winter and the rains. The lithotypes employed are mainly calcarenite of mean porosite and slightly more compact limestones from the quarries in the area, and marbles. The corresponding deterioration mechanisms are those of differential thermic dilatations caused by thermic jumps, especially in the more compact stones, those of increase in volume in capillaries and interstices, especially by freezing, and those of dissolution. The most serious deterioration indicators are fissures and spalling that affect the most carved elements and which have taken the greater part of the most aerated elements such as the pinnacles to a state to ruin.
The use of fiy ash in concrete blocks
Authors: Álvarez Alonso Marina , Río Suárez Olga
Published: May 2012

This paper describes how fly ashes which are not prescribed by the standards can be used in the manufacturing of concrete blocks. To implement this proposal it was necessary to do tests of the constitutive materials of the blocks, and block tests. The objective of these tests is to obtain the optimum blocks. This paper presents these tests and its main results.
Durabilidad del hormigón: Acción del agua de mar sobre un cemento portland resistente a los sulfatos. Influencia de la adición de escorias y de cenizas volantes
Authors: Gaspar Tebar Demetrio , Sagrera Moreno José Luis , González Vila Victoriano , Marín Bohorouez Miguel
Published: May 2012

This article, is part of a long time ICCET investigation programs studies the variation of the mechanical resistance to flexotraction 1: 3 normalized mortar with 1 x 1 x6cm dimension, using sulphate-resistent portland cement mixed with 15-35-60 and 70% parts of a furnace slag, a fiy ash or silica sand. The samples were submitted to the action of AS.T.M. artificial sea water and filtered potable water during several time periods (3 years for the first and second addition and 1 year for the third) after the cured period (1 day at 100% R.H. and 21 days inside filtered potable water).
The evolution of the ionic concentration of the aggressive solutions were studied and also the new phases formed with its new structural composition. Finally, and account is given of the researches and first results about the behavior of the mortars and concretes made with two different industrial cements and submitted to the natural sea water at a selected area of the marine Huelva-Port.
Solid solubility of MgO in the calcium silicates of portland clinker. The effect of CaF2
Authors: Martínez S. , Puertas F. , Palomo A.
Published: May 2012

The solid solubility of MgO in the calcium silicates of portland clinker has been determined by XRD and XDS. The influence that the presence of CaF2 has on said solubility has also been verified.
The solid solution limit of MgO in C3S at 1275 ºC lies at about 1.0% wt, where the triclinic form II stabilizes. The presence of CaF2 does not alter the maximum value of the MgO solubilized in that silicate, although there does take place the stabilization of the triclinic polymorph II at lower MgO contents (between 0.3 - 0.6% wt). The maximum amount of solubilized MgO in βC2 at 1.050 ºC lies around 0.5% wt. This value does not change by the presence of CaF2.
Predicting time to failure in bending of wood particleboards under cyclic humidity conditions
Authors: Fernández-Golfín Seco J. I. , Díez Barra M. R.
Published: May 2012

Time to failure tests under constant load (30, 40, 50 and 60 % stress levels) were conducted on four different 19 mm thick particleboards with three layers. Two of them were uncoated (UF and MUF bonded) and the rest were melamine (80 g/m2) and veneer (Mukally) overlaid.
Tests were carried out in cyclic humidity conditions (30 % - 90 %), at 20º C, 7 days at each condition.
Time to failure was recorded, fitting mathematical models to predict time to failure.
Melamine coating reduces predicting errors and increases time to failure.
The effect of pozzolan additions on the shrinkage of cement pastes and mortars during their first hours of age
Authors: Ossa M. Mauricio , David D. Jorge
Published: May 2012

The traditional favour enjoyed by cement including additions and by their diverse uses in Chile calls for an extense investigation of their behaviour in order that the results may justify their utilization in specific projects. This works studies volume changes occurring in cement pastes and mortars containing pozzolan additions during their first hours of age. This investigation used cements made in the laboratory from raw materials supplied by chilean manufacturers. Two types of clinkers were used, namely; a gypsum type and a natural pozzolan type, added in proportions ranging from 0 to 30%.Tests were conducted to ascertain the shrinkage of cement pastes and mortars since the first moments following their mixing operation, employing there for moulds fitted with a special device designed and implemented at the laboratory of the IDIEM Department of Agglomerants.
The results thus gathered corroborated the fact that independently of cement characteristics, in general the deformation of pastes and mortars exhibits successive periods of first shrinkage swelling, and second shrinkage.
The first shrinkage is affected by the ambient conditions of humidity, temperature, and wind (evaporation), but also in a preponderant way by cement specific surface, which allows higher velocity in the chemical reactions occurring during that period. Moreover the compactation degree is also affecting shrinkage, here.
On the other hand, it was confirmed that with cements of like fineness, those having higher C3A contents exhibit an overall shrinkage larger than that of cements having low contents.
At last it was possible to ascertain that an increase in pozzolan contents does not affect shrinkage directly, but that its presence may eventually modify the gypsum/clinker ratio and thus give rise to changes, specially in the two States of swelling and second shrinkage.
Natural and artificial ageing for evaluating waterproofing treatments for marble
Authors: Laurenzi Tabasso Marisa , Mecchi Anna María
Published: May 2012

Exposure of samples to artificial ageing is commonly carried out to test the durability of natural and artificial stones and the effectiveness of products used for their conservation. Correlations between artificial and natural ageing, however, are not always well understood mainly because the former can only try to simulate, in a faster but simplified way, the effects of the many causes interacting ín natural environments.
In the present study, marble samples from Carrara and Proconnesion quarries, were treated with four waterproofing products (or mixtures of products) and exposed to artificial ageing while an analogous set was exposed outdoor, in the town center of Rome for two years.
Several physical parameters were measured before and after the ageing and the experimental results enabled us to compare the effects produced by the different types of ageing and to estimate the correlations between them.
As for the durability of the tested waterproofing products, the two systems are in good agreement even if two years of natural ageing resulted to be slightly more severe than 33 days of exposure to saline fog, to UV radiation and to wetting-drying cycles
Macroscopical morphology of deterioration of the stone used in the cathedral whole of Granada/Spain
Authors: Alcalde M. , Martin L. , Bello M. A. , Martin A.
Published: May 2012

The main factors of deterioration that affect the Cathedral Whole of Granada are one of natural thermic origin due to the low temperatures during the winters and the higher thermic oscillations and those of anthropogenical origin: fundamentally the oxidation of metallic elements and atmospheric pollution due to burnt products. For this reason, the more important deterioration mechanisms are the freezing ones due to the expansion produced in the water retained inside the pores and microcracks, fundamentally in the architectonic elements with high expositional surface and in their shady orientation; the main indicators produced are fissuring and spalling. In this way, a lot of elements of Santa Pudia stone located in the Royal Chapel crenellations have disappeared and the rest are very deteriorated. The more compact Sierra Elvira stone used on the upper zone of the cornices has also been affected by the freezing mechanism, which starts with the microcracks produced by differential dilatations due to the thermic oscillations which made the water access easy. The iron corrosion and later expansion of the oxidation products has provoked the cracking and fissuring of many ornamental elements like balls, pinnacles, etc, and this situation has obliged their dismantling on the upper zones due to the danger to the public.
The mechanisms of dissolution, crystallization cycles and Chemical action have led to abundant material loosening in the form of grain disgregations overcoats on the higher humidity zones, and formation of hollows (pitting, alveolar erosion, striations) in the zones more exposed to the winds. This situation is generalized in the lower zones of the monument, except on the main facade, and in the parapets and lower zones of the cornices. The grain disgregations are more important when biological crusts or unburned deposits exist, the latter being of major abundance on the surfaces near the Gran Vía and in its orientation. It is necessary to mention the pigeon dung deposits, very important in the main facade, with greater stetical repercussion.
Influence of hydroxyis, carbonates and chiorides ions on the pitting corrosión of steel in concrete
Authors: Chaussadent Thierry , Dron Roger
Published: May 2012

The electrochemical process of steel corrosion in concrete are studied by simulating its liquid phase with synthetical solutions in a large range of hydroxyls, carbonates and chlorides ions.The steel specimen is either under or without an electrical polarization.
The present analysis has made it possible to define a new relevant parameter, which is the [CΓ]/[AIK] ratio (where AIK is the total alkalinity). It characterizes the conditions of the polarized steel pitting corrosion.
Furthermore, the investigation showed out that a polarization at potentials lower than — 700 mVSCE, stops the corrosion processes.
El envejecimiento de las pastas de cemento reforzadas con fibras de vidrio
Authors: Sánchez Paradela M. L. , Del Águila A.
Published: May 2012

Cement pastes reinforced with glassfibre, popularly called GRC ("Glassfibre Reinforced Cements") are compound materials which have been widely used in the construction field for the last 30 years. Their good mechanical properties, lightness and resistance to corrosion and fire make them suitable in the process of replacing the fibrocements with asbestos base in numerous applications. For that reason, their use has been extended in recent years and they have mainly been used to manufacture panels for facades and interior decoration as well as, to a smaller extent, for plumbing installations, roofs, lost formwork and even for "fingers" at the airports (1, 2, 3, 4, 5).
Nevertheless, it has been known for over 25 years that GRC suffer deterioration with the time which affects their mechanical properties and especially their tenacity; they become fragile and crack under small deformations. The research carried out to determine the causes of the phenomenon and look for possible solutions has been intense and it would be impossible to give more details here due to the lack of space. We will try, nevertheless, to summarize some more relevant aspects of the problem and the solutions that have reached the highest point of development so far.
The refilling of pores in cement mortars treated by chemicals and desiccation at different temperatures
Authors: Menéndez Pazos Ignacio , Hernández Francisco , Triviño Vázquez Fernando
Published: May 2012

Bases under the law of solubility product, the pores of the cement mortar are refilled by impregnation with two salts that form another insoluble salt.
The number of treatments to be underdone and the drying temperatures more suitable in each case.
The calcium salts like impregnants and urea sodium oxalate and sugar like precipitates are employed, obtained in each case the corresponding pores are occupied, which depends generally on the number of treatments and in particular the drier temperature.
Characterization of alkali-metal and alkaline-earth nitrates by vibrational spectroscopy
Authors: Martínez S. , Acción F. , Puertas F.
Published: May 2012

Infrared spectra of sodium and potassium alkaline-metal nitrates and magnesium and calcium alkali-earth nitrates in solid phase had been recorded in order to assign the fundamental bands. The influence of the dispersal médium (alkaline halide), employed in the solid sample preparation have been discussed. The quantitative measurements of the band in ten sities at 1387 cm-1 (present in the I.R. spectra of the four nitrates in KBr médium) allowed us to determine the Lambert-Beer law slopes for each compound. These values are differents (bearing in mind experimental random errors), so we have could to affirm the nonexistence of solid solution between the nitrate and the alkaline halide médium. The L-B law obtained by us can be used for the Identification differentiation and quantitative analysis of these nitrates in solid phase, even if they are present in a very low concentration.
La importancia de los materiales en las viviendas de muy bajo coste
Authors: Salas Julián
Published: May 2012

This text fits into the context of the attempt to emphasize the considerable importance of the factor of the construction materials in the subsection of low cost housing in Developing Countries in general and in Latín America in particular. The author tries to quantify, in a global manner, the repercussion of the materials through different assumptions and to show how it increases as the sections of installations and finishes diminish —in fact, practically disappear—.
In accordance with this and as a consequence, the author discusses the necessity to use autochthonous materials and to support the research and technological development which lay stress on the use of alternative materials and the re-use of agro-industrial waste.
As a pan of the Chapter V reproduced here, a special Section entitled "The Industry of Construction Materials" is contemplated, a section which we omitted and which can be found in n.º 198 of this Quarterly where it was originally published.
Phase and density changes during the ''conversión'' reaction of high alumina cement
Authors: Glasser F. P. , Jappy T. G.
Published: May 2012

The basis of the conversion reaction, in which high alumina cements develop hydrogarnet subsequent to their set, is weel-established and its mineralogical features accord with phase equilibrium relations in the CaO-Al2O3-H2O system. What is less well understood is the role of silica in the conversion. Silica may substitute into hydrogarnet, which has the formula Ca3Al2Si3-XO12-4x(OH)4x. Moreover the density of the hydrogarnet phase increases rapidly with the extent of silica substitution. Nomographs showing the variation of density and X-ray d spacing with composition are presented. Although HAC contains relatively little SiO2, examination of a high alumina cement warm cured at 85ºC and containing 2.46 wt% SiO2, shows that this hydrogarnet concentrates silica. Iron is, however, present mainly as amorphous hydrated iron oxide. Implications for cement proportioning to avoid conversion are discussed.
Reactivity of high alumina cement in water: Pore solution and solid phase characterization
Authors: Gaztañaga M. T. , Goñi S. , Sagrera J. L.
Published: May 2012

The hydration reaction of high alumina cement at a temperature of 20 ºC and water/cement ratio of 0.5 has been studied over a period of one month. The changes of the solid phase were followed by X-ray diffraction and thermal analysis. Besides, pore-solution was expressed by application of high mechanical pressure (500 MPa) during different periods of the reaction in order to study its Chemical composition evolution as a result of the hydration process.
The efect of calcareous filler on portland cement mortars
Authors: Escorihuela M. José , Menéndez Ignacio , Triviño Fernando , Hernández Francisco , Hurtado Norberto , Martín M. Antonia
Published: May 2012

The present paper deals with the influence that the addition of calcareous "fillers" to a Portland cement has on the mechanical resistances of its mortars.
Taking as a basis a Portland cement to which calcareous "fillers", from 0 up to 50 percent, are added, test tubes of standardized mortars were prepared. After 7, 28 and 90 days of curing, the test tubes were submitted to breaking following flexotraction and compression; their mechanical resistances were then determined and a correlation between these and the contents of calcareous "fillers" was established. An X-ray diffracting study was also carried out on the mortars obtained.
Alteration mechanisms on the stones of the Catedral of Granada, Spain
Authors: Martin L. , Bello M. A. , Martín A.
Published: May 2012

The diverse alteration mechanisms which operate on the stony materials of the Granada Cathedral have been analized.
The water action, anthropogenic influence, thermic oscillations, incompatibility factors, seismicity and biological factors have been considered.
Escorias de alto horno: composición y comportamiento hidráulico
Authors: Puertas F.
Published: May 2012

This paper presents the state-of-the-art on hydraulic behaviour of the blast furnace slags. It analyzes different aspects such as characteristics and influence of its vitreous phase structure, its chemical composition, mechanisms that rule its hydration process, activators and activating process mechanisms, etc.
At the same time, the paper presents results obtained from a chemical and mineralogical characterization of Spanish blast furnace slags.
Determinación de la resistencia del hornnigón en viguetas fabricadas con cemento aluminóso
Authors: De la Fuente Sánchez Antonio
Published: May 2012

Not Available.
Hidration kinetics study of tlie mixed cements
Authors: Duque Fernández Gabriel . L , Díaz Quintanilla David , Zapata Sierra Manuel , Rubio Frías Ester
Published: May 2012

A study of the hydration process of cements with 10% and 20% addition of a tuff from "Las Carolinas" quarry (Cienfuegos, Cuba) by different methods was done. The results obtained by different methods showed a good agreement. It was proved an increment of the hydration products, an acceleration of alite hydration and a swelling of the fixed water in mixed cements. The resistance of the cement with 10% addition is similar to that of the pure cement for ages of 28 days, whereas with 20% addition they were similar only after 180 days.
Normas europeas de cementos
Authors: Sánchez de Rojas M. I. , Frías M. , García N.
Published: May 2012

This article is based on the lecture, by Dr. María Isabel Sánchez de Rojas (Senior Researcher at the Eduardo Torroja Institute) and it is entitled "European Cement Standars" which was given in the framework of SEMINARIOS TORROJA, Building Technology and Materials.
Correlations among plasticity, mechanical strength, water/cement ratios and limestone filler content in cement mortars
Authors: Menéndez Ignacio , Triviño Fernando , Hernández Francisco
Published: May 2012

Limestone filler addition to Portland cement does not only have an impact on the mechanical strength of mortars, but its action also alters their rheological values.
Taking a Portland cement as the basic material and incorporating different calcareous filler portions from 0 to 50 %, standard mortars were prepared, determining drainage and setting (rheological values) and establishing the correlations between these values and the respective limestone filler content. In addition, the hardened mortars were studied by X-ray diffraction and their mechanical strength was determined (1),(2), (9), (10), (11).
Study of P-350 cement setting kinetic by nuclear magnetic resonance
Authors: Duque Fernández Gabriel L. , Díaz Quintanilla David , Capote Rodríguez Rogelio , Zapata Sierra Manuel
Published: May 2012

A kinetic study of cement setting process is presented in this paper A new method which allows the microscopic research of the evolution of the cement hydration applied to the study of three P-350 cuban cements is used. The initial and final values of the specific surfaces of the hydration products and cement were obtained, and the different periods of the hydration process of cement pastes were characterized. The influence of the cement phase composition on the surface development of the hydrated cement stone is discussed.
Barriers to quality patient care in rural district hospitals
Authors: Eygelaar Johanna E. , Stellenberg Ethelwynn L.
Published: May 2012

Currently barriers exist in delivering quality health care. This study aimed to investigate such barriers in the eight rural district hospitals of the West Coast Winelands Region, three type A and five type B hospitals. A quantitative descriptive design was applied which included the total population of nursing staff (n = 340) working at the time of data collection. A self-administered questionnaire was distributed with a response rate of 82%.Reliability of the instrument was verified using the Cronbach alpha coefficient and a pilot study. The validity, specifically construct and content validity, were assured by means of an extensive literature review, pilot study and use of experts. Ethics approval was obtained from the relevant stakeholders.Results showed that 272 participants (97%) disagreed that provision of staff was adequate, with staff above 40 years of age more likely to disagree (p = <0.01). A statistically significant association was shown between availability of doctors and staff not being able to cope with emergencies (p = <0.01). Most participants (n =212; 76%) indicated that they were not receiving continuing education, with the registered nurses more likely to disagree (χ² test, p = 0.02). Participants in both hospital types A (n = 131; 82%) and B (n = 108; 91%) also disagreed that provision of equipment and consumables was adequate.The research showed that inadequacies relating to human resources, professional development, consumables and equipment influenced the quality of patient care. Urgent attention should be given to the problems identified to ensure quality of patient care in rural hospitals.
Redefining trauma in an African context: A challenge to pastoral care
Authors: Motsi Ray G. , Masango Maake J.
Published: May 2012

The article attempted to analyse critically the definition of trauma as it is used in the Western medical and psychiatry contexts in order to come up with an appropriate African definition. This was undertaken with the view to demonstrate that the Western worldview is different from the African worldview. Superimposing solutions or providing pre-packed answers to unique African problems will lead only to re-traumatisation, whereas cultural sensitivity and the right diagnosis will lead to the correct treatment. The driving force behind this article was therefore to aim to be relevant, effective and contextual in all African-based pastoral care.
Self-care practice and glycaemic control amongst adults with diabetes at the Jimma University Specialized Hospital in south-west Ethiopia: A cross-sectional study
Authors: Hailu Endalew , Mariam Wudineh H. , Belachew Tefera , Birhanu Zewdie
Published: May 2012

Background: The main goal in diabetes care is to improve the patient’s quality of life, to maintain satisfactory metabolic control and to retain minimal complications caused by diabetes mellitus (DM). Thus, this study has assessed self-care practice and glycaemic control amongst adults with diabetes mellitus. Setting: A facility-based study amongst the diabetic follow-up clinic at Jimma University Specialized Hospital in Ethiopia.Methods: A cross-sectional study was conducted from 01 April to 30 April 30 2010. A total of 343 diabetic patients were selected using a systematic sampling method. The data were collected by structured questionnaires and a medical card review; anthropometric measurement was done by trained nurses.Results: The study showed that 53% of the respondents had diabetes related knowledge. The study also found that 64% of the respondents were physically less active, and 17% of the respondents were walking on foot for less than 30 minutes per a day. Only 18.1% of the respondents were able to control their Fasting Blood Sugar (FBS) to level below 126 mg/dL.Conclusion: The present study illustrates that the level of knowledge about diabetes and selfcare practices amongst diabetic patients were meager. In addition, it showed that respondents’ level of physical activity, their educational status, and the dose of oral hypoglycaemic agents taken by the respondents significantly affected glycaemic control.
Evidence-based Medicine: Top Ten Things to Know!
Authors: Mundi Raman , Mundi Simran , Bhandari Mohit
Published: May 2012

Evidence-based medicine is the conscientious use of the current best evidence in making health care decisions. It involves the incorporation of research findings, patient values and preferences, clinical circumstances and your own clinical expertise.

This approach is not a blinkered adherence to only randomized trials, but to the best available evidence in clinical decision making. The skills of an EBM practitioner require asking clinically important questions, conducting searches for the best available evidence, appraising this evidence critically, and deciding whether to apply this evidence to patients.

How to cite this article

Mundi R, Mundi S, Bhandari M. Evidence-based Medicine: Top Ten Things to Know! J Postgrad Med Edu Res 2012;46(1):1-3.
Research made Easy: Answering Important Questions with Valid Designs
Authors: Chaudhry Harman , Bhandari Mohit
Published: May 2012

Clinical research fundamentally involves finding answers to questions. Next to asking important questions, determining what type of study design to use is arguably the most pivotal step for a researcher. In this article, we provide an overview of various clinical study designs, including case reports and series, case-control studies, observational cohort studies, randomized controlled trials and systematic reviews. We aim to elucidate the utility, advantages and drawbacks of these study designs in order to assist researchers in selecting the most valid design for their research question.

How to cite this article

Chaudhry H, Bhandari M. Research made Easy: Answering Important Questions with Valid Designs. J Postgrad Med Edu Res 2012;46(1):8-11
Sociodemographic Profile of Road Traffic Accident Victims admitted at Emergency Surgical OPD of a Tertiary Care Hospital
Authors: Aggarwal Amita , Dhillon Mandeep , Kaur Sukhpal
Published: May 2012

Objective

To assess sociodemographic profile of roadside accident victims.

Materials and methods

Using purposive sampling technique 100 patients were enrolled in the study. A questionnaire consisting of personal identification data, personal habits and details related to occurrence of accident was used to collect the data.

Results

More than half subjects (59%) were in age group of 20 to 40 years with mean age being 36.5 years ± 14.2. Majority of the accident victims (84%) were male. More than half (67%) belonged to Hindu religion, educated up to secondary level (65%), were married (54%) and were rural habitants (54%). Twenty-six percent of subjects had the history of drinking alcohol. Out of these 15 subjects (57.7%) had consumed alcohol at the time of accident. Sixty-eight percent were driving two wheeler; only 27% were wearing protective equipment (helmet/seat belt) at the time of accident. Approximately one-third (39%) had 6 to 15 years of driving experience. Half (51%) of the accidents occurred in evening hours and on Saturday and Sunday.

Conclusion

The present study reflects that there is need to plan strategies to decrease risk of accidents and inculcate healthy driving habits in the vulnerable citizens.

How to cite this article

Aggarwal A, Kaur S, Dhillon MS. Sociodemographic Profile of Road Traffic Accident Victims Admitted at Emergency Surgical OPD of a Tertiary Care Hospital. J Postgrad Med Edu Res 2012;46(1):15-18.
Time Dose Relation of Caffeine Ingestion on Muscular Strength and Endurance Performance
Authors: Shenoy Shweta , Sandhu Jaspal S , Dutt I
Published: May 2012

Background

There have been numerous studies and reviews indicating that caffeine ingested before exercise causes rapid and significant improvement in performance, especially in aerobic capacity. Even though caffeine has a half life of 4 to 6 hours that implies high level of caffeine will be in the blood for up to 3 to 4 hours after ingestion, most studies on exercise performance are at 1 hour after ingestion.

Objectives

To assess the efficacy of 300 mg of caffeine and placebo ingestion at 1 hour, 1 hour 30 minutes, 2 hours, 2 hours 30 minutes, 3 hours in improvement of isometric muscle strength in human quadriceps muscle, cardiorespiratory endurance and to find that which of the duration produce best result.

Materials and methods

Experimental study with different subject design. Twenty subjects with equal number of boys and girl (age 20-30 years, weight 60-65 kg) were recruited to participate in the study. They were randomly allocated to experimental and placebo group. Pre- and postquadriceps muscle strength and time to exhaustion at 65% of VO2max was recorded.

Results

The results showed significant improvement (p < 0.001) in strength and endurance at all five durations in experimental group. Results were significant (p < 0.05) when caffeine and placebo groups were compared. The percentage improvement for strength and endurance was higher at 1st and 2nd hours when compared to 3rd hours duration.

Conclusion

The effects of caffeine are highest till 2 hours of ingestion after that wean off effects are seen.

How to cite this article

Sandhu JS, Shenoy S, Dutt I. Time Dose Relation of Caffeine Ingestion on Muscular Strength and Endurance Performance. J Postgrad Med Edu Res 2012; 46(1):19-23.
Qualitative Assessment of Research done at Two Premier Medical Institutes in India: Some Data for Introspection
Authors: Rao KLN , Kanojia Ravi Prakash , Rathod Kirti Kumar
Published: May 2012

Aim

To perform a qualitative assessment of research publications coming from two premier medical institutes in India.

Materials and methods

Research publications from AIIMS and PGIMER published during 2004 to 2008 were analyzed. The publications were categorized into five types. A year-wise analysis was done for both the institutes. Data was obtained from Scopus. The collected data included the number of papers published in a category, total citations received by a type of publication in a year, number of publications which have no citations, number of publications with only one citation, h-index, number of zero and only one citation were added to get publications with negligible citations.

Results

A total number of 4,828 and 2,882 research publications were analyzed from AIIMS and PGIMER respectively. The original articles attracted highest no of citations that is 64 and 66% of the total citations in a year for AIIMS and PGIMER respectively. Approximately 37 to 42% of the original articles get negligible citations. The h-index for various categories of article was higher for the original articles (18/13), whereas it was very low for other category of research publications.

Conclusion

The original articles fetch more citations in long run. Close to 40% of the original research done in the studied institutes get negligible citations pointing toward their outcome utility and quality. More than 60% of the minor category publications remain uncited. This sort of data if periodically obtained should serve as a benchmark for quality analysis of scientific research.

How to cite this article

Kanojia RP, Rathod KK, Rao KLN. Qualitative Assessment of Research done at Two Premier Medical Institutes in India: Some Data for Introspection. J Postgrad Med Edu Res 2012;46(1):24-33.
A Case of Drug-induced Toxic Epidermal Necrolysis: Pharmacovigilance in Action and Lessons to learn
Authors: Shafiq Nusrat , Dogra Sunil , Malhotra Samir , Pandhi Promila , Kaur Sharonjeet , Rajagopalan Sujit
Published: May 2012

Pharmacovigilance refers to the science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other drug-related problems. During the pharmacovigilance activities undertaken by us, a case of toxic epidermal necrolysis provided us with a setting for discussing various aspects of pharmacovigilance—the process itself, important signal generators that it may yield for practice, research and policy-related matters.

How to cite this article

Kaur S, Rajagopalan S, Shafiq N, Dogra S, Pandhi P, Malhotra S. A Case of Drug-induced Toxic Epidermal Necrolysis: Pharmacovigilance in Action and Lessons to learn. J Postgrad Med Edu Res 2012;46(1):40-42.
Isolated Muscular Cysticercosis: A Rare Pseudotumor and Diagnostic Challenge, can It be treated Nonoperatively? A Report of Two Cases and Review of Literature
Authors: Prakash Mahesh , Dhillon Mandeep , Prabhakar Sharad , Dhatt Sarvdeep , Rangdal Sushil S
Published: May 2012

Cysticercosis, an infection with the larval form of pork tape worm, Taenia solium, commonly presents with multiple muscular cysts or CNS involvement. Due to vague clinical presentation and unfamiliarity of clinicians with this entity, it is difficult to diagnosis when seen as an isolated cyst. Traditional treatment is surgical excision and a course of deworming agents. We present two cases of isolated muscular cysticercosis diagnosed by USG, MRI and blood tests, who responded successfully to oral medication without need of operative intervention.

Case reports

A 45-year-old male patient had a tender 2 week swelling of 4 × 5 cm on medial right proximal calf. A 26-year male presented with discomfort and diffuse 6 cm swelling at inner left forearm. In both ultrasound showed characteristic hypoechoic cyst with hyperechoic scolex, and MRI revealed isolated cyst surrounded by inflamed muscles. FNAC confirmed cysticercosis, and the patient responded to oral albendazole (3 weeks) with oral steroids (2 weeks).

Conclusion

Although rare, possibility of isolated muscular cysticercosis should always be considered in any small musculoskeletal soft tissue swelling presenting with nonspecific clinical findings. Both our patients responded to medical therapy and were disease free, as confirmed at 3 months by follow-up MRI. These cysts can be confidently diagnosed on the basis of ultrasound and MRI, and can be very well-treated nonsurgically with an oral drug regimen consisting of albendazole and steroid.

How to cite this article

Rangdal SS, Prabhakar S, Dhatt S S, Prakash M, Dhillon MS. Isolated Muscular Cysticercosis: A Rare Pseudotumor and Diagnostic Challenge, can It be treated Nonoperatively? A Report of Two Cases and Review of Literature. J Postgrad Med Edu Res 2012;46(1):43-48.
Effect of Manganese on Discharge and Corrosion Performance of Magnesium Alloy AP65 as Anode for Seawater-Activated Battery
Authors: Wang N.-G. , Wang R.-C. , Peng C.-Q. , Feng Y.
Published: May 2012

Magnesium alloys AP65 with and without 0.3% (mass fraction) manganese additions were prepared by melting and casting. Their discharge and corrosion behavior in 3.5% sodium chloride (NaCl) solution was investigated with electrochemical measurement, immersion testing, and corrosion morphology observation. The results show that manganese promotes the grain refinement and reduces the self corrosion rate of AP65 alloy. Magnesium alloy AP65 added with manganese provides a more negative discharge potential than that without the addition of manganese, attributed to the homogeneously distributed Al11Mn4 particles, which facilitate the self-peeling of corrosion products during the discharge process. This means that the discharge and corrosion performance of AP65 alloy can be improved by adding manganese.
Corrosion Behavior of Al-Sn-Bi Alloys in Ethylene Glycol-Water Mixtures
Authors: Gama-Ferrer J.L. , Gonzalez-Rodriguez J.G. , Rosales I. , Uruchurtu J.
Published: May 2012

A study of the effect of Sn (1, 2, 3.5, 4.5, and 5 wt%) and Bi (0.5, 1.5, 3, and 4%) on the corrosion behavior of Al in ethylene glycol (C2H6O2)-40% water mixtures at 20, 40, and 60°C has been carried out using electrochemical techniques. Techniques include potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), and electrochemical noise (EN) measurements. The three techniques have shown that additions of either Sn or Bi contents increased the corrosion rate of pure Al in all cases, and that generally speaking, the corrosion rate increased by increasing the temperature except for the alloy containing 1% Sn + 4% Bi, which showed the lowest corrosion rate at 60°C. This was because of a galvanic effect from the presence of Sn and/or Bi particles on the surface alloy, which acted as local cathodes, leading to an acceleration of corrosion. Nyquist diagrams showed two semicircles at 20°C and only one at 40°C or 60°C for all the alloys, showing two different corrosion-controlling mechanisms. EN measurements showed evidence of a mixture of both localized and uniform types of corrosion for all Al-based alloys.