Speciation of heavy metals and their distribution in surface sediments of the northwestern part of the ROPME Sea Area

Aim: To analyze samples of marine sediment at 24 stations for heavy metals as per sequential Community Bureau of Reference protocol in order to obtain metal distribution pattern in Kuwait offshore.Methodology: In the present study, a centrifugal particle-size analyzer was used for measuring sediment grain size. The Community Bureau of Reference scheme was deployed for the sequential extraction of heavy metal speciation, and the fractionation was determined by Inductively Coupled Plasma-Mass Spectrometry. Results: Grain-size analysis showed that the study area contained 71.8% silt, 22.6% sand and 5.56% clay at most locations. The average abundance of total concentration of heavy metals was found in the following order: lead< cobalt< copper< zinc< chromium< nickel. The mobility order of exchangeable fraction of heavy metals decreased in the order lead> nickel> zinc> cobalt> copper; in the reducible fraction: lead> copper> zinc> cobalt> nickel; in the oxidizable fraction: lead> chromium> copper> nickel> cobalt> zinc and in the residual fraction:cobalt> chromium> nickel> zinc> copper>lead, respectively. Interpretation: The outcome of the present study cannot establish the actual form of species of a given metal in the sediment; though, it appears to be useful in categorizing the metals within several prevailing geochemical fractions.

Clinical Observations on Wheat-grain Size Cone Moxibustion plus Acupuncture for Mild to Moderate Carpal Tunnel Syndrome / 上海针灸杂志

Objective To investigate the effect of wheat-grain size cone moxibustion plus acupuncture on related high-frequency ultrasonographic indicators before and after its treatment of mild to moderate carpal tunnel syndrome and explore its mechanism of action. Method Sixty patients were randomized to an acupuncture group (20 cases) and a wheat-grain size cone moxibustion groups (40 cases). The acupuncture group received acupuncture at affected-side points Daling (PC7), Hegu (LI4), Neiguan (PC6) and Shousanli (LI10). The wheat-grain size cone moxibustion group received wheat-grain size cone moxibustion on point Daling and acupuncture at the other points. Treatment was given once every other day for a total of 10 times. The thickness of the transverse carpal ligament, the cross-sectional area of the median nerve at the level of the pisiform bone and the flattening ratio at the level of the hamate hook were measured by high frequency ultrasonography before and after treatment. The clinical therapeutic effect was evaluated using the SSS score. Result After treatment, the SSS score decreased in both groups compared with before (P<0.05) and was lower in the wheat-grain size cone moxibustion group than in the acupuncture group (P<0.05). The cure and marked efficacy rate was 71.1％ in the wheat-grain size cone moxibustion groupwhich was higher than 42.1％ in the acupuncture group (P<0.05). There were no statistically significant pre-/post-treatment differences in the thickness of the transverse carpal ligament and the flattening ratio at the level of the hamate hook in the two groups (P>0.05). After treatment, the cross-sectional area of the median nerve at the level of the pisiform bone decreased in both groups compared with before (P<0.05) and was smaller in the wheat-grain size cone moxibustion group than in the acupuncture group (P<0.05). Conclusion Wheat-grain size cone moxibustion plus acupuncture can markedly improve the clinical symptoms of carpal tunnel syndrome. Its mechanism of action is related to reducing the cross-sectional area and edema of the median nerve.

Transport of Pseudomonas aeruginosa via column study trough aquifer at RBF study site, Lubuk Buntar, Kedah, Malaysia 124-130

@#Aims: This study is focused to explore Pseudomonas aeruginosastrain mass transport andassessment of the water quality.Methodology and results:Pseudomonas aeruginosahave been detected in the real location at the RBF study areabyusing molecular method. The bacterium strain was cultivated in the river water sample and column study was performed using soil aquifer collected from the RBF study site.Conclusions, significance and impact of the study:The column experiments show the removal of the bacteria was achieved almost 99%. Concentration of cultured bacteria was detected in range 0.26 g/Lto 0.33 g/Land reduced after flow through the soilpassage in range 0 to 0.148 g/L. This study also examines the water qualities that affected during the transport such as turbidity and color. The range of turbidity for initial concentration for both influents was 84-96 NTU was reduced to range 2.88-49.29 NTU. Meanwhile for color, the initial concentration was 51-58 PtCo was reduced to range 1-18 PtCo

Efeitos do tamanho da partícula e da concentração de sedimentos suspensos sobre a turbidez / Effect of particle size and suspended sediment concentration on turbidity

RESUMO Neste estudo foram avaliados os efeitos do tamanho da partícula e de variações da concentração de sedimentos suspensos (CSS) sobre as leituras de turbidez de três sensores óptico-nefelométricos, com iguais características ópticas e geométricas, utilizando amostras de sedimentos suspensos coletadas na seção fluviométrica da bacia do Turcato (19,5 km²), localizada na Região Sul do Brasil. O material coletado passou por processos de peneiramento e pipetagem para fracionamento nas granulometrias areia e silte. Para cada diâmetro foram separadas frações com diferentes concentrações de sedimentos, variando entre 0,01 e 5,00 g.L-1. Os resultados demonstram grande influência da CSS e do tamanho da partícula sobre a turbidez. Para qualquer situação, o aumento da turbidez é inverso ao tamanho da partícula e diretamente relacionado ao aumento da CSS. As variações da turbidez, expressas em função da CSS (sensibilidade do sensor), são maiores para menores diâmetros, atingindo valores quase constantes para partículas de areia. As leituras de turbidez dos três sensores não apresentaram diferença significativa no nível de 5% pelo teste de Mann-Whitney rank sum . Para uma mesma CSS, a leitura de turbidez pode ser diferente, conforme a classe granulométrica analisada. A turbidez registrada pelo sensor para a classe silte equivale a uma turbidez observada para uma CSS dez vezes menor para a classe das areias.

ABSTRACT This study evaluates the effects of particle size and variations of CSS on turbidity readings of three optical-nephelometric sensors using sediment samples collected in the field. Samples were collected in fluviometric station at Turcato basin (19.5 km²), located in the South region of Brazil. The collected material underwent screening and pipetting processes for fractionation in sand and silt grain size. For each diameter were separated fractions with different sediment concentration ranging between 0.01 and 5.00 g.L-1. The results demonstrate great influence of CSS and particle size on turbidity readings. The increase in turbidity is opposite to particle size and directly related to CSS. Variations in turbidity, expressed in CSS function (sensor sensitivity), are higher for smaller diameters, reaching almost constant values for sand particles. Turbidity readings of the three sensors showed no significant difference in the level of 5% by the Mann-Whitney rank sum test. For a given CSS, the turbidity reading may be different, depending on the granulometric class analyzed. Turbidity recorded by the sensor to the silt-class is equivalent to a sensor response observed for a CSS ten times lower for the sand class.

Evaluation of translucency of monolithic zirconia and framework zirconia materials

PURPOSE: The opacity of zirconia is an esthetic disadvantage that hinders achieving natural and shade-matched restorations. The aim of this study was to evaluate the translucency of non-colored and colored framework zirconia and monolithic zirconia. MATERIALS AND METHODS: The three groups tested were: non-colored framework zirconia, colored framework zirconia with the A3 shade according to Vita Classic Scale, and monolithic zirconia (n=5). The specimens were fabricated in the dimensions of 15×12×0.5 mm. A spectrophotometer was used to measure the contrast ratio, which is indicative of translucency. Three measurements were made to obtain the contrast ratios of the materials over a white background (L*w) and a black background (L*b). The data were analyzed using the one-way analysis of variance and Tukey HSD tests. One specimen from each group was chosen for scanning electron microscope analysis. The determined areas of the SEM images were divided by the number of grains in order to calculate the mean grain size. RESULTS: Statistically significant differences were observed among all groups (P<.05). Non-colored zirconia had the highest translucency with a contrast ratio of 0.75, while monolithic zirconia had the lowest translucency with a contrast ratio of 0.8. The mean grain sizes of the non-colored, colored, and monolithic zirconia were 233, 256, and 361 nm, respectively. CONCLUSION: The translucency of the zirconia was affected by the coloring procedure and the grain size. Although monolithic zirconia may not be the best esthetic material for the anterior region, it may serve as an alternative in the posterior region for the bilayered zirconia restorations.

Effects of the sintering conditions of dental zirconia ceramics on the grain size and translucency

PURPOSE: This study aimed to identify the effects of the sintering conditions of dental zirconia on the grain size and translucency. MATERIALS AND METHODS: Ten specimens of each of two commercial brands of zirconia (Lava and KaVo) were made and sintered under five different conditions. Microwave sintering (MS) and conventional sintering (CS) methods were used to fabricate zirconia specimens. The dwelling time was 20 minutes for MS and 20 minutes, 2, 10, and 40 hours for CS. The density and the grain size of the sintered zirconia blocks were measured. Total transmission measurements were taken using a spectrophotometer. Two-way analysis of variance model was used for the analysis and performed at a type-one error rate of 0.05. RESULTS: There was no significant difference in density between brands and sintering conditions. The mean grain size increased according to sintering conditions as follows: MS-20 min, CS-20 min, CS-2 hr, CS-10 hr, and CS-40 hr for both brands. The mean grain size ranged from 347-1,512 nm for Lava and 373-1,481 nm for KaVo. The mean light transmittance values of Lava and KaVo were 28.39-34.48% and 28.09-30.50%, respectively. CONCLUSION: Different sintering conditions resulted in differences in grain size and light transmittance. To obtain more translucent dental zirconia restorations, shorter sintering times should be considered.

Comparative Analysis for Estimating Hydraulic Conductivity Values to Improve the Estimation of Groundwater Recharge in Yaoundé-Cameroon.

Climate change will deeply affect the precipitation and evapotranspiration around the world. The sustainability of groundwater resources is crucial for regional and local communities, which is intimately tied to the changing recharge rate. To accurately assess the recharge rate, different methods were used to estimate hydraulic conductivity of an unconfined aquifer in this study. Particle size method with four empirical formulae, together with in-situ aquifer tests and the inverse modelling techniques were integrated to evaluate their potential for the determination of hydraulic conductivity of unconsolidated aquifer materials in order to improve groundwater recharge estimation. Results showed a wide disparity between the granulometric estimates of the hydraulic conductivity and the in-situ and modelling techniques. Slug test values range from 5.13 x 10-6 m/s to 4.96 x 10-5 m/s whereas the infiltration test (Porchet method) results vary from 1.91 x 10-7 m/s to 1.16 x 10-6 m/s. The simulated hydraulic conductivity values range from 2.54 x 10-7 m/s to 6.36 x 10-7 m/s, with a decreasing trend in the northeast-southwest (NE-SW) direction. The infiltration method appeared to be better than the granulometric one in the estimation of the vertical hydraulic conductivity within the unsaturated zone of porous formations. This study also pointed out that within an anisotropic formation, the hydraulic conductivity ratio (Kv/Kh) should not always be taken as equal to 10. Specific tests should be implemented to access this value in a given aquifer.The inverse modelling results showed the net recharge values varying from 68.5 mm/yr to 180 mm/yr. The modelling technique appears to be consistent with the in-situ estimates. Therefore, the application of groundwater modelling tool in this study has shown excellent promise for characterizing the spatial distribution of hydraulic conductivity and net recharge values within the targeted aquifer system.

Understanding the Response Characteristics of X-ray Verification Film / 대한방사선종양학회지

PURPOSE: This study is intended to understand the sensitometric charac teristics and the emulsion properties of the commercially available CEA TVS film in comparison with the Kodak X-Omat V film. MATERIAL AND METHODS: For this purpose, we have formulated an analytic expression of the characteristic curves for x-ray film exposed to mixed radiation of electrons, photons, and visible light. This mathematical expression was developed based on reaction-rate and target-hit theories. Unlike previous expressions, it relates optical density to emulsion properties such as grain size and silver bromide content. We have also developed a quantity which characterizes the film response to visible light relative to that to photons and electrons. This quantity could be expressed as a function of grain area. Thus, we have developed mathematical expressions and quantities with which the emulsion properties of the films can be revealed based on the sensitometric characteristics. Demonstrating the use of this analytical study, we exposed CEA and Kodak verification films to the mixed radiation of electrons, photons, and visible light, and interpreted the experimental results accordingly. RESULTS: We have demonstrated that: (1) the saturation density increases as the silver bromide content increases, (2) the time required to reach the threshold dose (to which the film begins to respond) when films are exposed to visible light decreases as the grain size increases, and (3) the CEA film contains more silver bromide, whereas the Kodak film contains larger grains. These findings were supported by the data provided by the manufacturers afterward. CONCLUSION: This study presented an analytical and experimental basis for understanding the response of X-ray film with respect to the emulsion properties.