bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Flexural Strength of Ceramics Based on Zirconia Stabilized by Yttria with Ceramic Cover
Authors: Carvalho C.F. , Melo-Silva C.L. , Melo-Silva T.C.F. , Freitas R.X. , Sudré J.P.S. , Lins J.F.C.
Published: June 2015

The aim of this study was to analyze the flexural strength of ceramics based on yttria-stabilized zirconia ( Y-TZP) , used in the manufacture of dental prostheses infrastructure with different types of coating ceramics. The rectangular samples measuring 18mm x 4mm x 1.2 mm were divided into groups (n = 10): G1 = control Y-TZP, G2= Y-TZP + sintered feldspathic ceramic and G3= Y-TZP + pressable feldspathic ceramic and submitted to assay of three points with a speed of 0.5 mm / min. Compared to the control group (G1), the group that showed the greatest resistance to bending was the G2, however, not significant relative to G3. No group provided the infrastructure fracture. It was observed by means of the methodology applied to all groups are suitable for use in dental prostheses.
Phase Stability of 3Y-TSZ Ceramics after Different Surface Treatments
Authors: Heidi Calambras Pulgarin , Patricia Albano Maria , Beatriz Garrido Liliana
Published: June 2015

The ability of zirconia ceramics to develop a bioactive surface is of great importance for biomedical applications. For that, it is also required to control phase stability (i.e. to avoid the tetragonal to monoclinic phase transformation) of zirconia surfaces in order to impart a high mechanical resistance. In this work, the phase stability of dense 3 mol% yttria stabilized-zirconia (3Y-TSZ) ceramics after acid and hydrothermal treatments was examined. Ceramic discs were prepared by slip casting from well dispersed 52 vol% suspensions, and subsequently sintered to 1300-1500 °C. The effect of various synthesis parameters and 0.25 wt% alumina doping on the phase transformation after acid and hydrothermal treatments was semi-quantitatively evaluated by XRD. The 3Y-TSZ sintered to 1500°C exhibited higher t→m transformation than samples sintered at lower temperatures. The phase transformation up to10h of hydrothermal treatment occurred by nucleation and growth mechanisms in which the nucleation process predominated. The presence of 0.25 wt% alumina in 3Y-TSZ sintered at 1500°C slightly enhanced the resistance to acid treatment.
Sinterization of Alumina and of the Alumina/Zirconia System in Microwave Ovens
Authors: Maia Maria Zilda A.A. , Maia Ana Marly A. , da Silva Valmir José , Santos Renato Correia , de Araújo Neves Gelmires , Menezes Romualdo Rodrigues , de Lima Santana Lisiane Navarro
Published: June 2015

Aluminum and zirconia oxides are ceramic materials widely used in the manufacturing of dental products, however, the thermal treatment stages demand high temperatures. Aiming at the reduction of the energy consumption and of the time necessary for the thermal treatments, this work intends to evaluate the influence of the microwave energy over the thermal processes of alumina substrate and of the alumina/zirconia system. The samples were made by slip-casting and then submitted to different thermal treatments. For the microwave oven, we used powers of 1.44 and 1.66 kW and heating times of 10, 15 and 20 minutes. The samples were submitted to the determination of physico-mechanical properties: flexural strength at three points, porosity and Vickers microhardness. Based on the analysis, we conclude that the microwaves energy is promising for the processing of dental ceramic, causing a significant reduction in the firing time.
Evaluation of Organoclay Addition in Surface Modified Sintered UHMWPE Membranes for Oil Separation
Authors: Gomes Nilman D.S. , Pontes A.L. , Leite Romulo Charles Nascimento , Carvalho L.H.
Published: June 2015

Each day the water scarcity at the global level is worrying and the industries are faced with the enormous challenge to prevent contamination of existing resources. Separation processes with polymer membranes have been successfully used in separating small quantities of oil in water. The synthesis conditions of UHMWPE tubular membranes, as well as its internal coating of LDPE film with the addition of organophilic clay were evaluated for promoting the generation of micropores, which would allow a more efficient filtration. Through the techniques of flow analysis, it was found that membranes with clay were more effective for filtration. The quantification of the concentration of oil showed the benefits of the application of this technique, resulting in extremely low levels of oil in water.
PP/EPDM Blends Compatibilized by Organically Modified Clays
Authors: Ferreira Kaline Rosário Morais , Andrade D.L.A.C.S. , Canedo E.L. , Raposo C.M.O. , Silva Suédina Maria L.
Published: June 2015

In this study, the influence of type and amount of organoclay in the morphology of the polymer blend PP/EPDM is evaluated. Pure and filled mixtures were prepared by melt intercalation in an internal mixer. The morphology of the hybrids was evaluated by X-ray diffraction and scanning electron microscopy. The results showed that the incorporation of the organophyllic clay to the PP/EPDM blend resulted in new interfacial interactions between components, which contributed to a decrease in the size of the dispersed phase and the compatibility of the blends. Therefore, organoclays may be employed to compatibilize polymeric blends, replacing conventional compatibilizers.
Study of Sintering Behavior of Ceramic Composite Al2O3-TiO2 Rare Reinforcing with La2O3 Possible Application as Ceramic Cutting Tools
Authors: de Sousa Andrea G. , Ferreira R.A.S. , Yadava Y.P.
Published: June 2015

In this work, composite ceramic was produced to base Al2O3 reinforced with 35% weight TiO2 and variation 0-2% La2O3, were evaluated properties to study their microstructural characteristic and mechanical properties as applicable cutting tools. The ceramic composites were produced by thermo-mechanical process. It was observed from the results of XRD after sintering no new phase is formed, besides the characteristics of the precursor oxides. According to the result of particle size analysis before and 24 hours after milling, there was a reduction of the average diameter of agglomerate 95.25% which is suitable to assist sintering of the composite, because this reduction increases the reaction rate the raw material during firing. At microdurezavickers test it was observed that the sample with 1.5% La2O3 showed better hardness results.
Study of a Typical Soil Used for Concrete Bricks in Miracema, State of Rio de Janeiro, Brazil
Authors: Aguiar Cerqueira Niander , Alexandre Jonas , de Azevedo Afonso Rangel Garcez , de Castro Xavier Gustavo , Candido Veronica Scarpini , Vieira Carlos Maurício Fontes , Monteiro Sergio Neves
Published: June 2015

The use of natural resources for sustainable development is becoming a relevant issue in modern societies. In particular, building materials composed of local soil or available residues are considered sustainable solutions for housing construction in relatively small urban areas. In the present work a preliminary study was conducted on a typical soil in the municipal area of Miracema, state of Rio de Janeiro, Brazil. The study comprised the characterization of the particle size distribution and particle density of the soil. In addition, the application of the soil by combining with Portland cement was investigated to produce concrete blocks specified as soil-cement bricks by the Brazilian norm. The results indicated that a trace of 14 parts of soil, 6 parts of local gravel and 4 parts of cement/water produced concrete blocks that comply with the compression strength specified by the norm.
Evaluation of the Hydrophobicity on Silicon Rubber Coating with Loads of Alumina Trihydrate and Nanosilica for Use in Electrical Insulation Coatings
Authors: Bezerra Daniella Cibele , Almirall Ignat Pérez , da Costa Edson Guedes , de Melo Costa Ana Cristina Figueiredo , Araújo Edcleide Maria
Published: June 2015

This study aims to evaluate the hydrophobicity of vulcanized silicone rubber coatings at room temperature (RTV SR) with loads of alumina trihydrate (ATH) and nanosilica (NS) in the polymeric silicone rubber matrix, in order to obtain coatings ATH/NS/RTV SR to cover the surface of glass electrical insulators. The coatings were characterized by scanning electron microscopy (SEM), testing in salt spray chamber, loss test and recovery of hydrophobicity. These coatings showed varying sizes of agglomerates and heterogeneous distribution of particles within the matrix RTV SR. In the test in salt spray chamber smaller leakage current values was observed for the insulator coating with the ATH/NS loads. In the loss and recovery of the hydrophobicity test the best result was observed for insulating load RTV SR / 20: 1 (ATH: NS).
Iron-Rich Glass-Ceramics Obtained from Mill Scale
Authors: Alves Indiara Tereza , Faller Cristian , Piva Diógenes Honorato , Piva Roger Honorato , Bertan Fernando Marco , Montedo Oscar Rubem Klegues
Published: June 2015

Mill scale contains high amounts of iron and it is classified as residue Class 2 – Not Inert (ABNT NBR 10.004:2004). Considering its availability, this study aimed to investigate glass-ceramics from this residue focused on its valorization. The influence of lithium oxide and zirconia was also evaluated. Six formulations were melted at 1350 °C and obtained frits were wet ground, dried and characterized: X-ray fluorescence, X-ray diffraction, thermal differential analysis and dilatometry. Pressed bodies were dried and heat treated at 950 °C. After, crystallized samples were characterized by different techniques: X-ray diffraction, apparent and theoretical density, coefficient of thermal expansion, hardness and bending strength. Results showed that lithium oxide and zirconia significantly influenced the thermal and structural behavior of obtained glass-ceramics.
Characterization of Clayey Soils from Visconde Do Rio Branco for Fired Ceramic Bricks
Authors: de Souza Rodolfo Cretton , de Azevedo Afonso Rangel Garcez , de Castro Xavier Gustavo , Alexandre Jonas , Pedroti Leonardo Gonçalves , de Andrade Silva Flavio , Monteiro Sergio Neves
Published: June 2015

The production of conventional bricks for housing construction is worldwide carried out with either concrete or clay ceramics. In most municipalities in Brazil, bricks are produced from less expensive local clays and fired at temperatures as low as 600°C, normally using wood as fuel. Indeed, in many regions the direct use of natural clayey soils may be sufficient to fabricate bricks with properties complying with the norms. In the present work, three clayey soils from the municipal area of Visconde de Rio Branco, state of Minas Gerais, Brazil, were characterized for their physical and chemical aspects as well as the main technological properties of ceramics fired at 700, 850 and 950°C using the different soils as precursor bodies. The results indicated that these soils are acceptable for clay ceramic fabrication but only one has the strength complying with the Brazilian norm for masonry brick fired at the investigated temperatures.
Mathematical Simulation of Thermal and Moisture Gradients in Ceramic Blocks
Authors: del Puppo Pereira Fernandes Olivia , de Oliveira Geruza Rafaela , da Silva Nascimento José Jefferson , de Azevedo Afonso Rangel Garcez , Alexandre Jonas , de Andrade Silva Flavio , Monteiro Sergio Neves
Published: June 2015

Temperature and moisture substantially affect the water elimination procedure, occurring in the drying stage, of ceramic blocks used in building construction. In the present work, a modeling of the thermal gradients and moisture content during the drying process of red clayey ceramic blocks was analyzed using computer simulation by means of Mathematica®software program. Results of two-dimensional thermal gradients and variation of moisture content were predicted. This revealed that regions next to the vertices of prismatic ceramic blocks are more susceptible to structural damage due to development of cracks and deformations.
Effect of Heat Treatment on Properties of Portland Cement Pastes: Determination through Ultra-Microhardness Test
Authors: Garcia D.C.S. , Figueiredo Roberto Braga , Aguilar Maria Teresa Paulino
Published: June 2015

The aim of this paper was to investigate the influence of heat treatment on hardness evolution of cement pastes containing silica fume. The specimens were prepared with Ordinary Portland Cement, water/binder ratio of 0,40 and 25% wt. silica fume. The specimens were cast at room temperatures and after 24 hours, they were placed in a furnace for 24 hours, with heat regimes of 100°C, 200°C and 300°C and then submitted to the ultra-microhardness test. The microstructure was analyzed using optical microscopy. The results showed that the silica fume prevents the production of calcium hydroxide and the heat treatment increases the material hardness.
Granite Waste from Diamond Wire Sawing Addition into Concrete for Civil Construction
Authors: Pedroti Leonardo Gonçalves , Vieira Carlos Maurício Fontes , Alexandre Jonas , de Castro Xavier Gustavo , Candido Verônica Scarpini , Monteiro Sergio Neves
Published: June 2015

The ornamental stone industry in Brazil is a major world producer of marble and granite with a significant amount being destined to foreign countries export. A considerable amount of waste is generated at the several stages of stone processing specially the sawing with the so called diamond wire technique. In the present work a granite waste from a diamond wire sawing was added into conventional mixture of cement, gravel and sand to fabricate concrete used in civil construction. The waste was chemically and mineralogically characterized by X-ray and its pozzolanic activity was evaluated. Concretes with 0, 10 and 20 wt% of waste were tested for the water absorption and mechanical strength as well as environmental behavior. The results indicated that up to 20 wt% addition, the granite waste does not change the concrete performance and attends its environmental requirements.
Pozzolanic Activity of Wastes from Fired Clay Ceramic Industry for Incorporation into Concrete
Authors: de Souza Furriel Dias Mateus , Pedroti Leonardo Gonçalves , Vieira Carlos Mauricio Fontes , Monteiro Sérgio Neves , de Castro Xavier Gustavo , Candido Verônica Scarpini
Published: June 2015

The fired-clay ceramic industry generates relatively large amount of wastes mainly bottom ashes remaining in the firing furnaces and broken pieces, known as grog, from inappropriate products. These wastes, if inadequately disposed, may cause pollution associated with environmental degradation as well as health hazards. A viable solution for these wastes is their incorporation in concrete for civil construction, as long as they have pozzolanic activity. Therefore the present work evaluated the pozzolanic activity of three different types of wastes generated at the same ceramic industry. These wastes were a furnace remaining bottom ash from burning wood log, a similar ash from sawdust burning and a grog powder from higher firing temperature broken ceramics. The pozzolanic activity was measured by the electrical conductivity variation method. The results showed that both ashes are not provided with pozzolanic activity while the grog has a moderate activity.
Evaluation of Bentonite Clay Type in the Chocobofe Zinc Adsorption in Finite Bath System
Authors: Silva J.V. do N. , Scheibler Janaína Rafaella , Rodrigues M.G.F.
Published: June 2015

In this work the smectite clays Chocobofe from the state of Paraíba was investigated to evaluate their affinity and capacity for removal of zinc using a finite bath system. The clay was characterized by means of X-Ray Diffraction (XRD), Infrared Spectroscopy in the Region (IV) and Cation Exchange Capacity (CEC) and Physical Adsorption of Nitrogen (BET method). A 22 factorial design was conducted with three center points in a finite bath system to determine the percentage removal (% Rem) and removability (qeq) of the clay. Values of 83.35 to 98.83% and the percentage removal from 3.83 to 4.24 mg / g removal were achieved in experiments, indicating that the use of clay Chocobofe appears as a promising alternative to remove of Zn2+
Physico-Mineralogical Characterization: Bentonitic Clays Recently Found in Olivedos, Paraíba, Brazil
Authors: Sousa F.K.A. , Silva I.A. , Cavalcanti W.S. , Neves Gelmires Araújo , Ferreira Heber Carlos
Published: June 2015

Used in various branches of the industry, bentonitic clays are considered a valuable mineral, used specially in the petroleum industry for manufacturing of fluids used the drilling of petroleum wells in long depth. Recently, a deposit of this valuable mineral was discovered in the town of Olivedos-PB. There are data that prove that this is a very poor and underdeveloped town. So, this work aims at the physico-mineralogical characterization of clays recently discovered and, this way, verify if they present similar characteristics which allow them to replace the clays from Boa Vista-PB, and if they can be used by the industry, thus bringing social development for that town. The characterization was made by means of the analysis of chemical composition by X-ray fluorescence (EDX), thermogravimetric and thermal differential analyses (TG and DTA), X-ray diffraction (XRD), cation-exchange capacity (CEC) and specific area (SA). The results show that the clays recently discovered in Olivedos-PB are polycationic clays, presenting MgO, CaO and K2O content, and that they are constituted by smectitic clay mineral, by quartz and kaolinite.
Evaluation of the Presence of Aluminum Sulphate Used in the Generation of WTP Sludge when Incorporated to the Clay
Authors: Martins B.E.D.B.S. , Cunha A.C. , Yokoyama L. , Almeida Valeria C.
Published: June 2015

The WTPs generate a residue in decanters called sludge, which, despite having a similar chemical composition of clay minerals, does not behave as such when embedded in such clays. Several surveys conducted indicate a decrease in Flexural Strength for the ceramic body when incorporated. The objective of this study is to evaluate the incorporation of the sludge generated at a WTP, which uses aluminum sulfate coagulant, to clay. By the method of pressure casting, samples were prepared with different percentages of sludge containing the said coagulant. Test runs with previously calcined sludge at 700°C were also performed in order to obtain sludge without the coagulant. In both cases, the final bodies were fired at 900°C and were tested for water absorption and flexural strength. The results reveal that the incorporation of non-calcined sludge positively change the quality of the ceramics prepared.
Evaluation of the Potential of Waste from Pulp Production (Grits) in its Use in Mortar: Physical and Chemical Characterization
Authors: Carvalho Mesquita Leonardo , Sant’ana Alvarenga Rita de Cássia S. , Santos Carol Ferreira Rezende , Oliveira Alvares Adonys Natan , Rezende Ana Augusta Passos , Gravino Murilo L. , de Carvalho José Maria Franco , Pedroti Leonardo Gonçalves
Published: June 2015

The grits is an inorganic solid residue generated during the Kraft process by the pulp and paper industry, which presents in its composition the main ingredients of Portland cement. According to some authors, the grits can be classified as a non inert, non hazardous, granular solid industrial waste. With this in mind, a study was proposed with the objective of evaluating, initially, the applicability of grits in mortar, by means of physical and chemical testing. The physical evaluations were realized through the following tests: determination of bulk gravity saturated - surface - dry (SSD) and water absorption; determination of the pulverulent material content; and the determination of particle size distribution. To chemically test the grits, a reading of the metal concentrations present in the grits was realized as well as an analysis of the leaching and solubilization extracts. It was concluded that the addition of grits to mortar is a potential alternative.
Assessment of the Addition of Electric Arc Furnace Dust in Hot Metal at Temperature of 1,350 °C
Authors: de Paulo Ferreira Marques Sobrinho Vicente , de Oliveira José Roberto , Vieira Estéfano Aparecido , Telles Victor Bridi , Fardin Grillo Felipe , Tenório Jorge Alberto Soares , Espinosa Denise Crocce Romano
Published: June 2015

This research aims to assess the incorporation of mass of the electric arc furnace dust (EAFD) by addition in hot metal produced in a local foundry (1.78% Si) at a temperature of 1,350°C. The EAFD is from a steel mill producer of long steel. The EAFD was added in the form of briquettes. Previously, the EAFD was characterized using the following techniques: chemical analysis, size analysis, X-ray diffraction, scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) microanalysis. The achievement of fusion experiments in laboratory scale, took place in a vertical tubular furnace with temperature control. The fusion experiments to assess the incorporation of the EAFD mass used alumina crucibles. A flow of inert gas (argon) was maintained inside the furnace during the experiments. After cooling the furnace to room temperature, it was done the pig iron and the slag were weighed to do a mass balance to assess the efficiency of the experiments.
TiO2 Supported in Ceramic Foams Used for Photocatalytic Applications
Authors: da Silva Falk Gilberto , Machado Ênio Leandro , Rodríguez Diosnel , Acchar Wilson , de Assis Lawisch Rodriguez Adriane
Published: June 2015

The study evaluated the photocatalytic activity of TiO2 supported on ceramic foams. In order to obtain these foams it was used a polymeric spongeprocess through replica method. Alumina ceramic foams were obtained with interconnected and open cellular structures allowing access of light through the material pores. The photocatalyst used was the commercial TiO2 P25 Degussa impregnated into the ceramic foam by dip-coating method. These steps were used in the photodegradation of organic dye in an aqueous system. The photocatalytic tests showed 81 % efficiency in decolorizing the solution of Rhodamine B 20 mg L- 1 with a kinetic constant of 9.6 x 10-3 min- 1
Preparation of Membrane Zeolite MCM-22 and Evaluation Process Oil/Water Separation
Authors: Barbosa A. Santos , Barbosa A.S. , Rodrigues M.G.F.
Published: June 2015

The objective of this work was prepared by secondary growth method, and evaluate the ability of the MCM-22 zeolite membrane separation system in oil / water in a continuous flow system. The zeolite membrane MCM-22 was characterized by different techniques: X-Ray Spectrometry Energy Dispersive (EDX), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). A continuous flow was used. The test for measuring mass flow of water / oil emulsion was conducted in peristaltic pump, wherein the membrane zeolite MCM-22 was tested. Through the results, we can observe the efficiency of the method used in the preparation of zeolite membrane and was also observed that the zeolite MCM-22 membrane, obtained by secondary growth method showed removal percentages equivalent to the standards required by Resolution 392 CONAMA.
Bentonite Clays Characterization in the Town of Sossego – Paraiba State
Authors: Pereira I.D.S. , Lisboa V.N.F. , Silva I.A. , Figueirêdo J.M.R. , Neves G.A. , Menezes R.R.
Published: June 2015

Bentonite exhibt a range of industrial applications moving millions of dollars on the market per year. Among several applications if highlights it is use for petroleum drilling fluids. Thus, this work aims to characterize physical, mineralogical and technologically, the bentonitics clays of Sossego County, Paraíba, Brazil. Mineralogical characterization of clays was done through the following techniques: particle size analysis by laser diffraction, thermogravimetric and differential thermal analysis, chemical analysis and x-ray diffraction. The clays were turned in by treatment with sodium in Na2CO3 and then determined whether the apparent viscosity, plastic and volume of filtrate of clay-water dispersions. The results showed that the samples are of polycationic, showing levels of MgO, CaO and K2O, similar to those from Boa Vista County, Paraíba, Brazil, and consist of clay mineral kaolinite, quartz and esmec. The clays showed rheological properties that indicate potential for use in drilling fluids.
Effect of Solvothermal Treatment on Physical Properties of Nickel and Aluminum Based Oxide Powders Synthesized by Coprecipitation
Authors: Cordeiro Guilherme Luis , Yoshito Walter Kenji , Ussui Valter , de Lima Nelson Batista , Lazar Dolores Ribeiro Ricci
Published: June 2015

Improvements of the catalytic efficiency of nickel–aluminum oxides in reforming reactions for hydrogen production have been achieved by the development of synthesis processes that provide powders with high surface area. The reduction of the crystallization temperature is one of the procedures in this direction. In this work, the effect of solvothermal treatment on coprecipitated gels with 15 wt% nickel content in alumina matrix was evaluated. Powders were obtained by coprecipitation with and without treatment of gels under n-butanol vapor pressure at 150oC. Products were characterized by TG/DTA, X-ray diffraction, specific surface area measurements, scanning electron microscopy and laser beam scattering for granulometric distribution determination. The results showed that calcined powders have high specific surface area (ranging from 170 to 260 m2.g-1) and are composed by gamma alumina and nickel aluminate phases. Aging treatment did not promote hydroxides decomposition under solvothermal conditions, indicating the need of calcination step.
Influence of Power and Synthesis Time in the Formation of Mullite Obtained by Microwave Heating
Authors: de Lima Santana Lisiane Navarro , Gomes Josileido , da Silva Valmir José , Gonçalves Wherllyson Patrício , de Lucena Lira Hélio , de Araújo Neves Gelmires , Menezes Romualdo Rodrigues
Published: June 2015

Front of the large number of applications of the mullite mineral, many researchers seek to synthesize it from the mixture of Al2O3and SiO2powders, or from aluminossilicates, such as smectite. The synthesis of mullite from clays via rapid heating by microwaves emerges as an alternative process. This process accelerates the kinetics of nucleation and the development of mullite phase. Thus, the aim of this work is to study the effect of power and timeon synthesis of mullite from clay, via rapid heating in microwave. The synthesis times were 15 and 20 minutes, with powers of 1.26 and 1.44kW. The obtained powderswere characterized by X-ray diffraction and scanning electron microscopy. The best results were obtained with a power of 1.44kW for 20 minutes.
A Practical Tablet-Based Hearing Aid Configuration as An Exemplar Project for Students of Instrumentation
Authors: Simeoni Ricardo
Published: June 2015

This paper presents the configuration and digital signal processing details of a tablet-based hearing aid transmitting wirelessly to standard earphones, whereby the tablet performs full sound processing rather than solely providing a means of setting adjustment by streaming to conventional digital hearing aids. The presented device confirms the recognized advantages of this tablet-based approach (e.g., in relation to cost, frequency domain processing, amplification range, versatility of functionality, component battery rechargeability), and flags the future wider-spread availability of such hearing solutions within mainstream healthcare. The use of a relatively high sampling frequency was found to be beneficial for device performance, while the use of optional off-the-shelf add-on components (e.g., data acquisition device, high fidelity microphone, compact wireless transmitter/ receiver, wired headphones) are also discussed in relation to performance optimization. The easy-to-follow configuration utilized is well suited to student learning/research instrumentation projects within the health and biomedical sciences. In this latter regard, the presented device was pedagogically integrated into a flipped classroom approach for the teaching of bioinstrumentation within an Allied Health Sciences School, with the subsequent establishment of positive student engagement outcomes.
Bacteremia due to anaerobic bacteria: epidemiology in a northern Bari Hospital, Italy
Authors: Distasi Maria Antonietta , Rizzi Donatella , Sciannandrone Nicola , Caldarone Mirella , Gioscia Simonetta , Leonetti Annamaria , Del Gaudio Tito
Published: June 2015

Background. Anaerobic bacteria are part of the commensal bacterial flora of skin and mucosae. Iatrogenic and pathological conditions altering this commensal relationship cause life-threatening diseases.
Materials and Methods. We analysed the blood cultures sent to the microbiology of our hospital between 2008 and the first quarter of 2013 to measure the frequency of bacteraemia caused by anaerobia. We examined 3138 vials of blood cultures for anaerobia, inoculated following in-house standard procedures. The colonies grown in absence of air were subjected to biochemical analysis. The MICs of metronidazole for 23 of the 26 organisms was tested.
Results. Twelve bacteria of the Bacteroides genus were identified, 9 Propionibacterium acnes, 1 Peptosctreptococcus micros, 1 Lactobacillus acidophilus, 1 Clostridium perfringens, 1 Prevotella oralis, 1 Eubacterium lentum.
Conclusions. The analysis of the results suggests that the incidence of cultures positive to anaerobia was constant across the years. We note that advanced age, altered mucocutaneous tropism, alterations to the oral and intestinal bacterial flora intensify the risk of anaerobial pathogenicity. The analysis of the metronidazole-determined MIC suggests that the intestinal anaerobic flora responds well to therapy and prophylaxis with Metronidazole, while the anaerobic bacteria residing on skin and other mucosae are resistant. It is however hard to determine the clinical impact of anaerobic bacteremiae and their effect on the outcome of the patient, due to the scarcity of available clinical data.
Evaluation of LIAISON® C. difficile glutamate dehydrogenase and LIAISON® C. difficile toxin A and B in Copan FecalSwabTM samples in a three-step algorithm for the diagnosis of Clostridium difficile infection
Authors: Oggioni Massimo , Bielli Alessandra , Nava Alice , Campisi Daniela Adele Pia
Published: June 2015

The presumptive laboratory diagnosis of Clostridium difficile infection is achieved by the means of the detection of a common antigen (glutamate dehydrogenase, GDH) in stool, then confirming the positives either by the detection of toxins A and B or by a molecular test for the detection of pathogenicity locus, encoding for the two toxins and for the binary toxin. A fully automated chemiluminescence system for the GDH antigen (LIAISON® C. difficile GDH) and for the detection of toxins A and B (LIAISON® C. difficile Toxin A and B) (DiaSorin, Gerenzano, Italy) allows for the performance of these tests on large numbers of samples in a short time, ensuring the traceability of the data.
Student perspectives on the value of rural electives
Authors: Couper Ian
Published: June 2015

Background: Medical students in the Faculty of Health Sciences at the University of the Witwatersrand (Wits) in Johannesburg have the opportunity to do electives at the end of the first and third years of a four-year graduate-entry medical programme. Upon their return they are required to write a short portfolio report. Over the period 2005 to 2011, 402 students chose to do rural electives.Aim and setting: To understand the value of rural electives from the perspective of medical students in the Faculty of Health Sciences at Wits, as derived from their assessment reports.Methods: A review was conducted of 402 elective reports. Common themes were identified through repeated reading of the reports, and then content analysis was undertaken using these themes.Results: Major themes identified were the reasons for choosing a rural facility for the elective, including going to a home community; benefits of the elective, especially in terms of clinical skills and personal growth; relationship issues; the multiple roles of the rural doctor, who is often a role model working in difficult conditions; and the challenges of rural electives.Conclusion: The electives were overwhelmingly positive and affirming experiences for students, who developed clinical skills and also learnt about both themselves and their chosen career.
Comparison of the South African Spondaic and CID W-1 wordlists for measuring speech recognition threshold
Authors: Hanekom Tanya , Soer Maggi , Pottas Lidia
Published: June 2015

Background: The home language of most audiologists in South Africa is either English or Afrikaans, whereas most South Africans speak an African language as their home language. The use of an English wordlist, the South African Spondaic (SAS) wordlist, which is familiar to the English Second Language (ESL) population, was developed by the author for testing the speech recognition threshold (SRT) of ESL speakers. Objectives: The aim of this study was to compare the pure-tone average (PTA)/SRT correlation results of ESL participants when using the SAS wordlist (list A) and the CID W-1 spondaic wordlist (list B – less familiar; list C – more familiar CID W-1 words). Method: A mixed-group correlational, quantitative design was adopted. PTA and SRT measurements were compared for lists A, B and C for 101 (197 ears) ESL participants with normal hearing or a minimal hearing loss (<26 dBHL; mean age 33.3). Results: The Pearson correlation analysis revealed a strong PTA/SRT correlation when using list A (right 0.65; left 0.58) and list C (right 0.63; left 0.56). The use of list B revealed weak correlations (right 0.30; left 0.32). Paired sample t-tests indicated a statistically significantly stronger PTA/SRT correlation when list A was used, rather than list B or list C, at a 95% level of confidence. Conclusions: The use of the SAS wordlist yielded a stronger PTA/SRT correlation than the use of the CID W-1 wordlist, when performing SRT testing on South African ESL speakers with normal hearing, or minimal hearing loss (<26 dBHL).
Toxicoepidemiology of acute poisoning cases in a secondary care hospital in rural South India
Authors: Indu TH , Raja D , Ponnusankar S
Published: June 2015

Objective:

To ascertain the trend of poisoning cases admitted to the Government District Headquarters Hospital, a secondary care center in Udhagamandalam, Nilgiris District, Tamil Nadu, India, over a five-year period.

Materials and Methods:

The number of cases that presented to the hospital annually (incidence, mortality, and case fatality rates), socio-demographic pattern, and the nature of the poison were noted.

Results:

A total of 1860 poisoning cases (80 deaths) were reported during the period from October 2008 to September 2013. The incidence of poisoning was found to increase every year. The average incidence was 1.60 per 1000 population, while the average case fatality rate and mortality rates were 40.51 and 0.07, respectively. A total of 1148 (62%) were males. The majority of cases were seen in the 21-30 age group (41.24%). The poisonings were largely deliberate self-harm (n = 1,755; 94.35%), followed by accidental (n = 85; 4.57%). Agrochemicals were the main choice of poisoning agents and among these, organophosphates were the major cause.

Conclusion:

The data generated can help policy makers take decisions on the sale and availability of pesticides in this region.
Allergic Rhinitis
Authors: Sinha B , Vibha  , Singla R , Chowdhury R
Published: June 2015

Background and Objectives:

Allergic Rhinitis is rather erroneously viewed as a trivial disease. It is important in that it can significantly affect quality of life. There is paucity of community based prevalence studies on the disease in India. This study was planned to assess the prevalence of allergic rhinitis in adults, the proportion of asthmatics among them, risk factors associated and treatment seeking behaviour among the patients.

Materials and Methods:

A community based cross sectional study was conducted in Mehrauli, South Delhi among 1200 adults, aged 30 years and over selected by systematic random sampling from two randomly selected wards. A pre-tested questionnaire was used to collect information regarding symptoms, risk factors and treatment seeking behaviour. Allergic Rhinitis was diagnosed as per ARIA guidelines. Spirometry was done to diagnose asthma among them. Multivariate logistic regression analysis was done to find the association of risk factors with disease.

Results:

The prevalence of Allergic Rhinitis was found to be 11% (132 subjects) and 33.3% (44 patients) among them also had asthma. Overcrowding (aOR = 6.4), absence of cross-ventilation (aOR = 2.5), occupational exposure to dust/ smoke (aOR = 2.1), tobacco smoking (aOR = 2.1), family history of allergic diseases (aOR = 2.7) and clinical allergy (aOR = 10.2) were found to be independent risk factors associated with Rhinitis. More patients of Rhinitis with asthma (75%) took treatment, relative to those without asthma (40%) who, mostly relied on home remedies (42%) or, did not seek any treatment (18%) (P = 0.031).

Interpretations and Conclusion:

The burden of Allergic Rhinitis is high with a considerable overlap with asthma. These allergic diseases and emphasize the importance of early and regular treatment.
A successful twin pregnancy in a patient with HbE-β-thalassemia in western India
Authors: Merchant R , Italia K , Ahmed J , Ghosh K , Colah RB
Published: June 2015

Improvements in medical facilities have helped a large number of clinically severe hemoglobin E (HbE)-β-thalassemia patients reach adulthood. Consequently, there is a new challenge, that of managing women with HbE-β-thalassemia during pregnancy. In particular, they have a high risk of abortion, preterm delivery, intrauterine growth restriction, and thromboembolism. A 27-year-old HbE-β-thalassemia patient on regular transfusion, who was splenectomized and heptatitis C (HCV)-positive, conceived for the first time without any infertility treatment. However, there was incomplete abortion with heavy bleeding at 3 months of gestation, which required bilateral uterine artery angiography. The angiogram showed the left uterine artery to be moderately hypertrophied. This was embolized with 300-500 micron polyvinyl alcohol (PVA) to stop the bleeding. Soon after, she conceived again with a twin pregnancy, and at 33.3 weeks of gestation, there was a normal delivery of twin girls without any postpartum hemorrhage or perineal tear. Both babies were given prematurity care. The mother and children were both normal up till the last follow-up 18 months after delivery, and both the girls are HbE heterozygous. Thorough monitoring of endocrine functions along with proper management of transfusions and iron overload can help in reducing the complications related to pregnancy in these patients.
Archwise distraction appliance: A novel approach for developing facial and dental esthetics in cleft lip and palate patients
Authors: Erverdi Nejat
Published: June 2015

Cleft lip and palate (CLP) is defined as a congenital deformity caused by failed fusion of medial and lateral palatine processes during 4-12thweeks of embryogenesis, resulting in an open communication between oral and nasal cavities. In CLP patients, maxillary hypoplasia, velopharyngeal insufficiency, and alveolar clefts are the major issues that have to be taken care of after labiopalatal reconstruction. Rather than several consecutive operations, such as bone-grafting and orthognathic surgery, alveolar distraction can be a better treatment option in many cases. Archwise Distraction Appliance (AWDA) is a rigid, tooth-borne, custom-made appliance that is developed to control the distraction vector with double archwire system. Our experiences show that the AWDA is a successful appliance in cases of distraction osteogenesis. Moreover, alveolar distraction has significant advantages over conventional treatment modalities for CLP patients.
Correlation of upper lip morphology to smile: A photographic study
Authors: Agrawal Neha , Sable R. B.
Published: June 2015

Aims and Objective

The purpose of this study was to examine different components of a smile in subjects with class I occlusion and to formulate a comprehensive photographic analysis of a smile. This study was designed to find a correlation between upper lip elevation and retraction with upper lip morphology during smiling among male and female groups.

Materials and Methods

Lateral cephalogram and standardized frontal photographs were taken at rest and smiling.

Results

A significant sexual dimorphism was apparent in several of the parameters studied. Middle portion of lower border of upper lip (MUL’-MUL) rose significantly higher by 0.91 mm in the male group than in the female group, during smiling (P = 0.003). Decrease in vermillion display (VE-VE’) was significantly higher in the male group than the in female group by 0.668 mm (P = 0.021).

Conclusion

This comprehensive study of lip mobility, when applied to a larger population can enable us to further evaluate the correlation between lip morphology and mobility.
Comparison of rate of maxillary canine movement with or without modified corticotomy facilitated orthodontic treatment: A prospective clinical trial
Authors: Suryavanshi Harshal N. , Das Vaishali R. , Deshmukh Aashish , Rai Raj , Vora Mena
Published: June 2015

Background and Objectives

The average orthodontic treatment time for extraction therapy is 31 months. One of the main disadvantages of orthodontic treatment is time. Alveolar corticotomies have been used in conjunction with orthodontics to reduce the treatment time by increasing the rate of tooth movement. Concerns about the possible risks of corticotomy procedure have led to the modification of this technique. Germeç et al. reported a case treated by their modified corticotomy technique and noted reduced treatment time without any adverse effects on the periodontium and the vitality of teeth with their new conservative corticotomy technique. This study was undertaken to clinically evaluate the efficacy of the aforesaid technique.

Materials and Methods

A split-mouth study design was carried out to compare the rate of maxillary canine movement with and without modified corticotomy facilitated orthodontic treatment in 10 patients requiring maxillary first premolar extractions. The modified corticotomy procedure was performed on the maxillary arch unilaterally. The upper arch was immediately activated bilaterally after surgical procedure using equal orthodontic forces for retraction of the maxillary canines. The amount of tooth movement was recorded at an interval of every month till the completion of canine retraction. The rate of canine movement on experimental and control site was compared. The patients were followed for 6 months to check the occurrence of undesired effects such as root resorption, periodontal damage and loss of vitality of teeth on the experimental side.

Results

Higher mean velocity was observed in canines with modified corticotomy facilitated retraction compared to conventionally retracted canines; with the difference in mean velocity between the two groups was found to be clinically significant as well as statistically significant (P < 0.001).

Interpretation and Conclusion

The results suggested that modified corticotomy technique serves as an effective and safe way to accelerate orthodontic tooth movement, without adversely affecting the periodontium, root resorption, and the vitality of the teeth, as concluded by clinical and radiographic examination.
Towards a long-term dataset of ELBARA-II measurements assisting SMOS level-3 land product and algorithm validation at the Valencia Anchor Station
Authors: Fernandez Moran R. , Wigneron J. P. , Lopez-Baeza E. , Miernecki M. , Salgado-Hernanz P. , Coll M.A. , Kerr Y. H. , Schwank M.
Published: June 2015

La misión de SMOS (Soil Moisture and Ocean Salinity) se lanzó el 2 de Noviembre de 2009 con el objetivo de proporcionar datos de humedad del suelo y salinidad del mar. La principal actividad de la conocida como Valencia Anchor Station (VAS) es asistir en la validación a largo plazo de productos de suelo de SMOS. El presente estudio se centra en una validación de datos de nivel 3 de SMOS en la VAS con medidas in situ tomadas en el periodo 2010-2012. El radiómetro Elbara-II está situado dentro de los confines de la VAS, observando un campo de viñedos que se considera representativo de una gran proporción de un área de 50×50 km, suficiente para cubrir un footprint de SMOS. Las temperaturas de brillo (TB) adquiridas por ELBARA-II se compararon con las observadas por SMOS en las mismas fechas y horas. También se utilizó la inversión del modelo L-MEB con el fin de obtener humedades de suelo (SM) que, posteriormente, se compararon con datos de nivel 3 de SMOS. Se ha encontrado una buena correlación entre ambas series de TB, con mejoras año tras año, achacable fundamentalmente a la disminución de precipitaciones en el periodo objeto de estudio y a la mitigación de las interferencias por radiofrecuencia en banda L. La mayor homogeneidad del footprint del radiómetro ELBARA-II frente al de SMOS explica la mayor variabilidad de sus TB. Los periodos de precipitación más intensa (primavera y otoño) también son de mayor SM, lo que corrobora la consistencia de los resultados de SM simulados a través de las observaciones del radiómetro. Sin embargo, se debe resaltar una subestimación por parte de SMOS de los valores de SM respecto a los obtenidos por ELBARA-II, presumiblemente debido a la influencia que la pequeña fracción de suelo no destinado al cultivo de la vid tiene sobre SMOS. Las estimaciones por parte de SMOS en órbita descendente (6 p.m.) resultaron de mayor calidad (mayor correlación y menores RMSE y bias) que en órbita ascendente (6 a.m., momento de mayor humedad de suelo).
Detección de cambios en los usos de suelo a partir de clasificaciones no supervisadas para la actualización del SIOSE. Implementación en el territorio gallego
Authors: Vila García D. , Gil Docampo M. L. , Iniesto Alba M. J.
Published: June 2015

Uno de los elementos básicos a la hora de diseñar políticas de análisis, gestión y planificación del territorio es una buena cartografía de usos de suelo. Para este cometido, se dispone del Corine Land Cover (CLC) a nivel europeo y del SIOSE (Sistema de Información sobre Ocupación del Suelo de España) a nivel nacional. Los procesos de actualización de esta cartografía suelen ser costosos, y es aquí donde las técnicas de observación remota de la Tierra pueden servir de gran ayuda. En este trabajo se pretende obtener, mediante un análisis multitemporal entre las imágenes Spot 5 de los años 2009 y 2011, un método de detección de cambios efectivo en un terreno tan heterogéneo a nivel de coberturas como el gallego. Para conseguir la identificación de las zonas donde se ha producido modificación de los usos de suelo se generan nuevos canales que recogen diferencias (radiométricas y estructurales) entre las imágenes Spot de ambos años, y luego se realizan sobre ellos varias clasificaciones para obtener una capa de cambios. La capa de cambios obtenida identifica las zonas en donde ha habido variación y, complementada con imágenes PNOA (Plan Nacional de Ortofotografía Aérea), constituye una información fiable útil para realizar una fotointerpretación dirigida en la actualización del proyecto SIOSE, reduciendo así los tiempos de ejecución y manteniendo la calidad de la base de datos final.