Digital asthenopia: blue-blocking lenses and + 0,40D additional power in the near zone, for eye strain, accommodation and convergence functions / Astenopia digital: avaliação de lentes com filtro de luz azul e poder adicional de +0,40D na zona de perto, para fadiga visual e nas funções de convergência e acomodação

ABSTRACT Purpose Evaluate blue-violet light filter and additional power of +0.40 D in the near zone ophthalmic lenses, on convergence, accommodative functions, and symptoms of digital asthenopia (DA). Methods Randomized study in cross-over design conducted on 49 volunteers (age, 29 ± 5.5 years; male: female, 18:31). Each subject wore test (+0.40 D in the near zone) and control lenses (regular single vision) for 4 weeks in randomized order. Both lenses had a selective blue-violet light filter. A baseline measurement was taken with the subjects' current updated glasses. Accommodation amplitude (AA) and near point of convergence (NPC) were measured binocularly with the RAF ruler. DA was evaluated by a questionnaire. Results No significant difference (p=.52) was found for AA comparing baseline (11.50±1.88 D), test (11.61± 1.62 D), and control SV lenses (11.88±1.50 D). No significant difference was found for NPC (p=.94), between baseline (6.50 ± 2.89cm), test (6.71± 3.49) and control SV lenses (6.82± 3.50 cm). No significant difference was found comparing test and control SV lenses in symptoms of DA (p=0.20). Conclusions The +0.40 D lenses have no negative impact on convergence or loss of accommodation power. The +0.40 D and control SV lenses had a similar impact on attenuating symptoms of DA.

RESUMO Objetivo Avaliar os efeitos do uso de lentes oftálmicas com filtro seletivo de luz azul-violeta, sem e com poder adicional de + 0,4D na zona de perto nas funções de acomodação e convergência e para sintomas de astenopia digital (AD). Métodos Ensaio clínico controlado, randomizado e mascarado, com 49 voluntários (idade, 29 ± 5,5 anos; masculino: feminino, 18: 31). Cada participante usou lentes de teste (+0,40 D na zona de perto) e controle (visão simples), por 4 semanas de forma randomizada. Ambas as lentes tinham filtro seletivo de luz azul-violeta. A medição inicial (baseline) foi feita com os óculos atualizados de cada participante. A amplitude de acomodação (AA) e o ponto de convergência próximo (PPC) foram medidos binocularmente com a régua RAF. A AD foi avaliada por um questionário. Resultados Não houve diferença estatisticamente significante (p=0,52) para as medidas de AA comparando as lentes baseline (11,50±1,88 D), teste (11,61±1,62 D) e controle VS (11,88±1,50 D). Nenhuma diferença significativa foi encontrada para a medida do PPC (p=0,94), entre as lentes baseline (6,50 ± 2,89cm), teste (6,71±3,49) e controle VS (6,82±3,50 cm). Nenhuma diferença significativa foi encontrada comparando lentes teste de VS e controle nos sintomas de AD (p=0,20). Conclusões As lentes com +0,40 D não têm impacto negativo na convergência ou na perda de acomodação. As lentes +0,40 D e controle VS, tiveram impacto semelhante na redução dos sintomas de AD.

Research of Disposable Respiratory Filter to the Measurement of Impulse Oscillometery / 中国医疗器械杂志

OBJECTIVE@#To study the influence of disposable respiratory filter on the results of impulse oscillometery.@*METHODS@#90 healthy subjects were randomly selected and impulse oscillometery results were taken repeatedly through disposable respiratory filter and control device. All results were statistically analyzed.@*RESULTS@#When using the disposable respiratory filter, respiratory impedance (Zrs) and resistance at all frequency (R5Hz-R35Hz) were significantly increased compared with the control device (P<0.01). The two measurements had a significant linear correlation (P<0.01) and a regression equation was established. The disposable respiratory filter did not exist in statistic difference to response frequency (Fres) and the elastic resistance (X5Hz-X15Hz) at all frequency(P>0.05).@*CONCLUSIONS@#The disposable respiratory filter can be used when testing pulmonary compliance, chest wall disease and obstruction outside the airway in impulse oscillometery system to avoid infection and ensure quality.

Evaluación de la remoción de arsénico en agua superficial utilizando filtros domiciliarios / Evaluation of the arsenic removal in superficial waters using home filters

RESUMEN El objetivo del estudio fue evaluar filtros domiciliarios para remover arsénico presente en agua proveniente del río Sama. El sistema estuvo compuesto de un filtro tradicional de arena y un filtro con el material adsorbente de hierro cerovalente estabilizado en quitosano. La evaluación del sistema fue por un período de 12 semanas en 18 puntos de uso; las primeras ocho semanas se determinó la concentración de arsénico del agua filtrada empleando tiras reactivas, y las cuatro últimas fueron a través de espectrometría de absorción atómica (EAA-FIAS). Durante las primeras ocho semanas se redujo la concentración de arsénico en el rango de 0,005 y 0,025 mg/L, y durante las cuatro últimas en el rango de 0,001 y 0,052 mg/L, a partir de una concentración promedio de 0,51 mg/L. Se demostró que el sistema de filtración es eficiente para remover arsénico a condiciones naturales.

ABSTRACT The objective of the study was to evaluate home filters to remove arsenic present in waters coming from the Sama river. The system consisted of a traditional sand filter and a filter with the adsorbent zerovalent iron material stabilized in quitosan. The evaluation of the system lasted for a period of 12 weeks in 18 points of usage; the first eight weeks the arsenic concentration of the filtered water was determined using reactive strips, and the last four assessment was made through atomic absorption spectrometry (AAS). During the first eight weeks the arsenic concentration was reduced in a range of 0.005 and 0.025 mg/L, and during the last four weeks in the range of 0.001 and 0.052 mg/L, from an average concentration of 0.51 mg/L. This research showed that the filtration system is efficient to remove arsenic to natural conditions

Performance of a biotrickling filter employing Thiobacillus thioparus immobilized on polyurethane foam for hydrogen sulfide removal

The removal of hydrogen sulfide [H[2]S] from contaminated airstream was studied in a biotrickling filter [BTF] packed with open-pore polyurethane foam as a carrier of Thiobacillus thioparus [DSMZ5368] with counter current gas/liquid flows. The effect of operating parameters on BTF performance was studied. Experiments were performed at different Empty Bed Residence Times [EBRT] from 9 to 45 seconds, and different initial H[2]S concentration from 25 to 85 ppm. The results showed reasonable performance of the BTF, in H[2]S removal from the synthetic gas stream. However, the performance was somewhat lower than other studies in BTF in which either Thiobacillus thioparus with other packings or polyurethane foam with other microbial cultures were used. The effect of liquid recirculation rate [LRR] in the range of 175-525 ml/min [0.46-1.34 m/h] on BTF performance was also studied. Results showed that increasing LRR from 175 to 350 mL/min resulted in significant enhancement of H2S removal efficiency, but further increase in LRR up to 525 mL/min had an insignificant effect. H[2]S elimination at different heights of the bed was studied and it was found that decrease in EBRT results in more homogeneous removal of the pollutant in BTF. Determination of microbial species in the BTF after 100 days performance showed that during BTF operation the only H[2]S degrading specie was Thiobacillus thioparus

Prevalence of toxoplasmosis, HIV, syphilis and rubella in a population of puerperal women using Whatman 903® filter paper

OBJECTIVES: to determine the seroprevalence rate of toxoplasmosis, HIV, syphilis and rubella in a population of puerperal women. METHODS: a prospective, cross-sectional study was performed from February 2007 to April 2008 at Hospital Geral, Universidade de Caxias do Sul in a population of 1,510 puerperal women. Women that gave birth to live born or stillborn infants were included in the study; maternal and perinatal variables were analyzed. Descriptive statistics and Pearson's chi-square with occasional Fisher's correction were used for comparisons. Alpha was set in 5 percent. RESULTS: a total of 148 cases of congenital infection (9.8 percent) were identified: 66 cases of syphilis (4.4 percent), 40 cases of HIV (2.7 percent), 27 cases of toxoplasmosis (1.8 percent) and 15 cases of rubella (1.0 percent). In ten cases there was co-infection (four cases of HIV and syphilis, two cases of HIV and rubella, one case of HIV and toxoplasmosis, two cases of rubella and syphilis, and one case of toxoplasmosis and rubella). In a comparison between puerperal women with and without infection there was no statistical significance in relation to incidence of abortions, small for gestational age, prematurity, live births and stillbirths, and prenatal care. Need of neonatal intensive care unit (NICU), maternal schooling, maternal age higher than 35 years and drug use (alcohol, cocaine and crack) had statistical significance. CONCLUSION: the prevalence rate of infections was 9.8 percent. Need of NICU, maternal schooling lower than eight years, maternal age higher than 35 years and drug use were significantly associated with occurrence of congenital infection.

Evaluation of HA negatively charged membranes in the recovery of human adenoviruses and hepatitis A virus in different water matrices

Human adenoviruses (HAdV) and hepatitis A virus (HAV) are shed in the faeces and consequently may be present in environmental waters, resulting in an increase in pathogen concentration that can affect water quality and human health. The aim of this study was to evaluate an adsorption-elution method which utilizes negatively charged membrane HA to determine the efficient recovery of HAdV and HAV from different water matrices and to combine this procedure with a qualitative molecular method (nested RT-PCR and nested PCR). The best efficiency recovery was achieved in distilled water and treated wastewater effluent (100 percent) for both viruses and in recreational lagoon water for HAV (100 percent). The efficiency recovery was 10 percent for HAdV and HAV in seawater and 10 percent for HAdV in lagoon water. The viral detection limit by nested PCR for HAV in water samples ranged between 20-0.2 FFU/mL and 250 and 25 TCID50/mL for HAdV. In conclusion, these results suggest that the HA negatively charged membranes vary their efficiency for recovery of viral concentration depending upon the types of both enteric viruses and water matrices.

Extraction of high-quality host DNA from feces and regurgitated seeds: a useful tool for vertebrate ecological studies

DNA extraction methods for genotyping non-invasive samples have led to great advances in molecular research for ecological studies, and have been particularly useful for analyzing threatened species. However, scarce amounts of fragmented DNA and the presence of Taq polymerase inhibitors in non-invasive samples are potential problems for subsequent PCR amplifications. In this study we describe a novel technique for extracting DNA from alimentary tract cells found on external surfaces of feces and regurgitated seeds. The presence of contaminants and inhibitors is minimized and samples are preserved intact for use in other ecological research (e.g. trophic studies). The amplification efficiency and purity of the extracted DNA from feces were significantly higher than in commonly used extraction procedures. Moreover, DNA of two bird species was identified from seeds expelled by regurgitation. Therefore, this method may be suitable for future ecological studies of birds, and other vertebrate groups.

Avaliação da captura de fragmentos por meio da filtração intra-aórtica em pacientes submetidos à troca valvar aórtica / Particulate emboli capture by an intra-aortic filter device during aortic valve replacement

OBJETIVO: O objetivo deste estudo foi avaliar a atividade embólica de pacientes portadores de estenose aórtica calcificada submetidos a troca valvar aórtica por meio da filtração intra-aórtica com dispositivo EMBOL-X® System (Edwards Lifesciences Inc., Mountain View, CA, USA). MÉTODOS: De janeiro de 2007 a julho de 2007, foi utilizado o filtro intra-aórtico EMBOL-X após o despinçamento aórtico em 13 portadores de estenose aórtica calcificada submetidos a troca valvar aórtica consecutivamente. A média de idade dos pacientes foi 63,7 anos (34-79) e 61,5% eram do sexo feminino. A média do tempo de CEC foi 60,2±7,5 (45-72) minutos e a média do tempo despinçamento aórtico foi 50±7,5 (35-63) minutos. Após a retirada dos filtros, eles foram fixados em formalina, analisados macroscopicamente e quantificados os fragmentos capturados. Foi realizado exame histológico do material capturado. RESULTADOS Não foi observado nenhum caso de complicação neurológica. Nenhum paciente apresentou insuficiência renal pós-operatória. Não houve óbitos hospitalares. Partículas embólicas foram encontradas em cinco (38,5%) dos filtros. Das partículas embólicas capturadas, em dois (40%) filtros havia fibrina, dois (40%) apresentavam tecido conjuntivo, um (20%) continha hemácias e em um não foi possível determinar a natureza. CONCLUSÃO: O dispositivo EMBOL-X® System foi efetivo na captação de fragmentos intra-aórticos na substituição da valva aórtica em pacientes com estenose aórtica calcificada.

OBJECTIVE: This study aims to analyze the embolic activity in patients with calcified aortic stenosis who underwent aortic valve replacement using intra-aortic filtration with an EMBOL-X® System device (Edwards Lifesciences Inc., Mountain View, CA, USA). METHODS: From January 2007 to July 2007, 13 consecutive patients with calcified aortic stenosis, who underwent isolated aortic valve replacement using intra-aortic filtration by an EMBOL-X® System for 5 minutes after aortic clamp release, were evaluated. Mean patient age was 63.7 years (range 34 to 79 years) and 61.5% were female. The mean bypass time was 60.2 ± 7.5 minutes (range 45 to 72 minutes) and the mean cross-clamp time was 50 ± 7.5 minutes (range 35 to 63 minutes). Following removal, each filter was fixed in formalin and analyzed macroscopically with the captured fragments being counted. Histological examinations of the captured material were performed. RESULTS: There were no strokes or gross neurological events. There were no cases of postoperative renal failure. No deaths were reported during hospitalization. Particulate emboli were found in five (38.5%) of the filters. On histological analysis of the particulate emboli captured, two (40%) contained fibrin, two (40%) presented conjunctive tissue, one (20%) contained red blood cells and in one it was not possible to determine the nature of the particulates captured. CONCLUSION: The EMBOL-X® System device was effective in particulate emboli capture in aortic valve replacement surgery of patients with calcified aortic stenosis.

intelligent neural network model for evaluating performance of immobilized cell biofilter treating hydrogen sulphide vapors

Biofiltration has shown to be a promising technique for handling malodours arising from process industries. The present investigation pertains to the removal of hydrogen sulphide in a lab scale biofilter packed with biomedia, encapsulated by sodium alginate and poly vinyl alcohol. The experimental data obtained under both steady state and shock loaded conditions were modelled using the basic principles of artificial neural networks. Artificial neural networks are powerful data driven modelling tools which has the potential to approximate and interpret complex input/ output relationships based on the given sets of data matrix. A predictive computerised approach has been proposed to predict the performance parameters namely, removal efficiency and elimination capacity using inlet concentration, loading rate, flow rate and pressure drop as the input parameters to the artificial neural network model. Earlier, experiments from continuous operation in the biofilter showed removal efficiencies from 50 to 100% at inlet loading rates varying up to 13 g H2S/m[3]h. The internal network parameter of the artificial neural network model during simulation was selected using the 2[k] factorial design and the best network topology for the model was thus estimated. The results showed that a multilayer network [4-4-2] with a back propagation algorithm was able to predict biotilter performance effectively with R[2] values of 0.9157 and 0.9965 for removal efficiency and elimination capacity in the test data. The proposed artificial neural network model for biofilter operation could be used as a potential alternative for knowledge based models through proper training and testing of the state variables

Improvement of gas exchange measurements in ergospirometry with the use of optimal filters for O2 and CO2 transducers

O aperfeiçoamento da acurácia em dedições de trocas gasosas respiração-a-respiração em seres humanos requer um método adequado de compensação da estreita banda de passagem dos transdutores de gás utilizados. Apesar de um projeto de filtros ótimos para estes transdutores requerer técnicas como filtragem de Wiener ou aproximações recursivas por mínimos quadrados, estas técnicas ainda não têm sido aplicadas em trnsdutores para ergoespirometria. Neste trabalho é proposto um método para projetos de filtros digitais para tais transdutores com aplicação em ergoespirometria. Os filtros obtidos foram aplicados em sinais adquiridos com transdutores de dióxido de carbono, transdutores de oxigênio eletroquímicos e um transdutor de oxigênio paramagnético. Duas técnicas foram avaliadas com sucesso: um algoritmo adaptativo NLMS modificado e um filtro FFT-Wiener modificado. Os filtros ótimos foram projetados utilizando o critério de mínimo erro quadrático médio. A densidade espectral de potência média dos sinais de concentrações de oxigênio e dióxido de carbono foi considerada no cálculo dos filtros ótimos. O desempenho dos filtros foi avaliado com um mecanismo simulador de respiração com as trocas gasosas controladas. As medidas de trocas gasosas obtidas com e sem os filtros ótimos foram comparadas com os valores preditos pelo simulador. Os resultados mostraram que os filtros ótimos podem reduzir em até 8 vezes a subestimação média nas medições das trocas gasosas. A tendência de aumento do erro de medição com o aumento da freqüência respiratória também foi reduzida em até 65 por cento.

Accuracy of filter paper method for measuring glycated hemoglobin.

BACKGROUND AND OBJECTIVES: Glycated hemoglobin (HbA1c) provides an accurate and reliable method to assess the glycemic control in patients with Diabetes. Its measurement is limited by the inconvenience of sample collection that requires venipuncture, sample handling and storage factors. The aim of this study was to assess the feasibility of using a dried capillary blood spot on a filter paper to estimate HbA1c, to check its stability at room temperature and to compare these values with the venous sample HbA1c by Turbidimetric Inhibition Immunoassay (TINA, Tina-quant HbA1c II). METHODS: Venous blood samples of seventy eight patients with Type 1 or type 2 diabetes, were collected in EDTA containing vacutainers. Stability of HbA1c was studied in capillary blood samples blotted on to Whatman number 1 filter paper and stored at room temperature, for the first 20 patients enrolled in the study. After establishing the stability over a ten day period, HbA1c values obtained on the capillary blood spots were compared with those obtained from the venous blood samples of the remaining 58 patients. RESULTS: Glycated hemoglobin is found to be stable in dried capillary blood spots on filter paper till the 10th day, stored at room temperature. It however, shows an inherent variability of +/- 15%, which falls within the permissible variability (18%) of the quality control material. Seventy nine percent of the capillary HbA1c values were found to fall within this range. With linear regression, we derived the relationship between filter paper and venous HbA1c values. The regression equation was as follows: Cap.HbA1c = 0.95 (Ven.HbA1c) + 1.4. The filter paper results were highly correlated with the venous sample values (r = 0.889, p < 0.01). CONCLUSION: Measurement of glycated hemoglobin in dried blood spots on filter paper gives reliable and reproducible results. In our study, the mean capillary sample HbA1c value was 12% higher compared to the venous sample HbA1c values. Therefore a higher normal range may have to be used for interpreting the dried blood spot capillary blood HbA1c values.

Influence of blue light spectrum filter on short-wavelength and standard automated perimetries / Influência de filtro para o espectro azul da luz na perimetria computadorizada branco-branco e azul-amarelo

PURPOSE: To evaluate the influence of a blue light spectrum filter (BLSF), similar in light spectrum transmittance to the intraocular lens Acrysof NaturalTM, on standard automated perimetry (SAP) and short-wavelength automated perimetry (SWAP). METHODS: Twenty young individuals (<30 y.o.), without any systemic or ocular alterations (twenty eyes) underwent a random sequence of four Humphrey visual field tests: standard automated perimetry (SAP) and short-wavelength automated perimetry (SWAP) with and without a blue light spectrum filter. All patients had intraocular pressure lower than 21 mmHg, normal fundus biomicroscopy, and no crystalline lens opacity. Foveal threshold (FT), mean deviation (MD), and pattern standard deviation (PSD) indexes obtained from the visual field tests and the difference caused by eccentricity in short-wavelength automated perimetry examinations were analyzed using paired t test. Interindividual variability (standard deviation) was calculated using Pitman's test for correlated samples. RESULTS: Statistically significant reductions in the mean deviation (p<0.001) and in the foveal threshold (p<0.001) measured by short-wavelength automated perimetry with the use of the blue light spectrum filter in comparison to short-wavelength automated perimetry without the use of the blue light spectrum filter were observed, but not in standard automated perimetry exams. No other parameters showed statistically significant differences in the short-wavelength automated perimetry and standard automated perimetry tests. Interindividual standard deviation of the test points in the short-wavelength automated perimetry exams increased with eccentricity both with and without the use of the blue light spectrum filter, as sensitivity for inferior and superior hemifields (inferior hemifield minus superior hemifield), but no statistically significant difference in the variability when comparing the use or not of the blue light spectrum filter was noted. When comparing...

OBJETIVO: Avaliar a influência de um filtro para o espectro azul da luz, semelhante à lente intra-ocular Acrysof Natural®, nos exames de perimetria automatizada padrão (branco-no-branco) e de comprimento de onda curto (azul-no-amarelo). MÉTODOS: Vinte pacientes jovens sem alterações oculares (20 olhos) realizaram seqüência de 4 exames de campo visual: perimetria automatizada padrão e azul-no-amarelo com e sem o filtro para o espectro azul da luz. Os índices de limiar foveal (FT), desvio médio (MD) e desvio-padrão (PSD) obtidos em todos os exames e a diferença causada pela excentricidade nos exames de perimetria automatizada azul-no-amarelo foram analisados. Variabilidade interindivíduos (desvio-padrão dos pontos testados) foi calculada. RESULTADOS: Observou-se redução estatisticamente significante no desvio médio (p<0.001) e no limiar foveal (p<0.001) medidos pela perimetria automatizada azul-no-amarelo com o uso do filtro para o espectro azul da luz comparado quando realizado sem o filtro. Nenhum outro índice avaliado apresentou diferença estatisticamente significante nos exames de perimetria automatizada padrão ou azul-no-amarelo. Foi notado aumento da variabilidade interindivíduos com a excentricidade nos exames de perimetria automatizada azul-no-amarelo com e sem o uso do filtro para o espectro azul da luz, assim como a diferença de sensibilidade entre os hemisférios inferior e superior (hemisfério inferior menos superior), mas não houve diferença estatisticamente significante quando comparados os exames com e sem o uso do filtro. Quando foram comparados os 4 pontos mais inferiores e os 4 pontos mais superiores, a diferença inferior-superior aumentou com e sem o uso do filtro para o espectro azul da luz. CONCLUSÃO: Observou-se redução estatisticamente significante no desvio médio e limiar foveal nos exames de perimetria automatizada azul-no-amarelo com o uso do filtro para o espectro azul da luz, mas não nos exames de perimetria automatizada padrão.

Degradation of microcystins by adsorbed bacteria on a granular active carbon (GAC) filter during the water treatment process.

The degradation of microcystin by adsorbed bacteria on GAC (granular active carbon) filter from a water treatment facility was investigated. Dominant bacteria isolated from GAC were indigenous microorganisms, Psuedomonas sp. and Flavobacterium sp. The direct exposure of dominant GAC bacteria to microcystins resulted in a significant reduction of microcystin levels in both shaking and static conditions (t-test; p < 0.01). In bacteria-treatments, the half-life of microcystin was 2.6-3.5 days in both conditions. Based on this result, approximately 9-10 days would be estimated for 90% or up to 18-21 days of 99% of toxin to be degraded. This biological degradation by the GAC bacteria in combination with existing purification systems has potential to increase the efficiency of water purification.

Laboratory efficacy of metabolites of Lagenidium giganteum (Couch) on Anopheles stephensi (Liston) after filterations by Column Chromatography.

This study was conducted in laboratory to evaluate the efficacy of filtered extracellular metabolites of Lagenidium giganteum against all the four instars of An. stephensi larvae. Fungal colonies have been cultured in PYG broth and after 15 days of culturing the fungus, metabolites have been filtered twice by whatman filter paper. These metabolites were again filtered by column chromatography and by rang syringe filters. Filtered metabolites were then used against all instars of An. stephensi larvae. The bioassays were conducted at five significantly different concentrations (1.68, 1.99, 2.17, 2.30, 2.40 ppm). The results suggest significant mortality on first three instar larvae and very low on fourth instar larvae.

Comparison of Glass Particle Contamination according to Method of Ampule Cutting and Needle Aspiration / 간호학회지

PURPOSE: Glass particle contamination of the contents of single-dose glass ampules can occur upon opening. Different aspiration techniques, different sizes of needles, different sizes of ampules, and different cutting methods were studied to determine if they had any effect on glass particle contamination. METHOD: Different aspiration techniques(with filter, without filter), different sizes of needles(18G, 25G), different sizes of ampules(2ml, 20ml), and different cutting methods(with cotton, without cotton) were evaluated. METHOD: Twenty ampules were randomly assigned in each group. Three slides containing glass particles for each ampule were made and counted under a microscope by 3 study blind persons. RESULT: The number of glass particle contamination is much less when using a filter rather than without a filter. The number of glass particle contamination is much less when using a 25G needle rather than on 18G needle. The number of glass particle contamination is much less when using 2ml ampules rather than 20ml ampules. The number of glass particle contamination is much less when using cotton rather than without cotton. CONCLUSION: It was shown that using a filter, a small size needle, smaller sized ampules and using cotton when cutting the ampule will decrease the risk of parenteral injection of glass particles.

Environmentally safe design of tailing dams for the management of iron ore tailings in Indian context.

The need for the disposal of iron ore tailings in an enviornmentally firiendly manner is of great concern. This paper investigates the soil engineering properties for the construction of iron ore tailing dam, its foundation, construction materials and design data used for the construction analysis of the tailing dam. Geophysical investigations were carried out to establish the bedrock below the spillway. A computer programme taking into account the Swedish Slip Circle Method of analysis was used in the stability analysis of dam. It also focuses on the charactierstics of the tailings reponsible for the determination of optimum size of tailing pond for the containment of the tailings. The studies on the settling characteristics of tailings indicate much less area in comparison to the area provided in the existing tailing ponds in India. In the proposed scheme, it is suggested to provide an additional unit of sedimentation tank before the disposal of tailings to the tailing pond.

Investigation of the performance of non-conventional pressure filter system in potable water treatment.

The biflow pressure filter system installed at a residential campus was investigated for its performance under different operating conditions. The investigation was carried out to evaluate raw water quality, chemical dosing systems, filter media and overall filtration performance. Treatability studies were carried out to decide optimum doses of chemicals sused in potable water treatment system. It was found that the biflow pressure system could not deliver filtrate of desired quality and therefore its use in potable water treatment may cause ill effects in human-beings.

Use of PercuSurge in primary angioplasty.

Thrombus load and its subsequent distal embolization causing slow flow makes primary angioplasty a challenging task. Although data is scanty, these complications may be potentially mitigated by use of distal protection devices. We report 6 cases of PercuSurge distal protection device-assisted primary angioplasty. All lesions were stented with patients achieving brisk TIMI 3 flow; none of the patients had in-hospital major adverse cardiac events. The strategy of PercuSurge Guardwire-assisted primary angioplasty seems encouraging in improving successful outcome in this subset of patients.

Effects of aluminum-copper alloy filtration on photon spectra, air kerma rate and image contrast

Este estudo avaliou a redução da taxa de kerma no ar, o espectro de energia dos raios X e alterações na qualidade da imagem radiográfica. Comparações com várias espessuras do filtro de liga de alumínio-cobre em três diferentes porcentagens foram feitas com o filtro de alumínio. Os experimentos foram feitos utilizando-se um aparelho de raios X odontológico convencional, obtendo radiografias com auxílio de um fantoma de segmento de mandíbula e de uma escala de densidade confeccionada com alumínio laminado. Dependendo da espessura da filtração da liga de alumínio-cobre, o feixe de raios X pôde ser endurecido em relação ao filtro de alumínio. O uso do filtro de liga de alumínio-cobre resultou em 8,40% a 47,33% de redução da taxa média de kerma no ar e indicou contraste da imagem radiográfica sem alteração, quando comparado com a filtração de alumínio, mostrando que os filtros de liga de alumínio-cobre tornam-se alternativas aceitáveis em relação aos filtros de alumínio.