230 research outputs found
El concepto de propiedad: una evaluaciĂłn crĂtica de las consideraciones extrasistemáticas carnapianas
En Meaning and Necesszty, Carnap pre(ende aclarar a travĂ©s de consideraciones extrasistemátĂcas quĂ© entiende por tĂ©rminos tales como 'propiedad', 'concepto' y 'entidad'. Pone mucho cuidado en explicar el carácter que tienen las consideraciones extrasistemáticas Destaca que deben ser tomadas como una clarificaciĂłn terminolĂłgica informal, y que no constituyen en absoluto un intento de soluciĂłn al problema de los universales. Asimismo, advierte que si bien no son necesarias desde un punto de vista teĂłrico son provechosas en la práctica, porque proporcionan sugestiones Ăştiles o asociaciones plásticas convenientes que pueden hacer más fácil el aprendizaje del uso de estas expresiones
Optimization of Coagulation-floculation of Water from the Djoué River at the Drinking Water Treatment Station in Brazzaville
The present work proposes to study the clarification of raw water by the elimination of organic (OM), mineral and colored matter thanks to the process of coagulation-flocculation by aluminum sulfate. We were first interested in a first part in the study of the process applied to the drinking water treatment plant. In a second part, we carried out this same process at the laboratory level by jar-test. A comparison of turbidity reduction by aluminum sulfate coagulation was estimated. For all samples, a sharp drop in turbidity was observed in the first three beakers for doses ranging from 0.06 to 0.08 g/L of aluminum sulfate. These doses were adopted in the study of the effect of pH set at 7. The resulting turbidity after 30 minutes of settling varies between (reduction of 25 to 81 %) depending on the dose and the sample. Very good elimination is observed with a dose of aluminum sulfate equal to 0.08 g/L (reduction in the order of 67.31 to 81.06 %). At this optimum dose, it can be considered that all the surface charges have been neutralized
Evaluation of primary stability of innovated orthodontic miniscrew system (STS): an ex-vivo study
Background: Stability is determined as one of the requirements in use of Temporary Anchorage Devices (TAD) in
orthodontics. Miniscrew has been a widely used Bone Anchor. Compared with mini-implant that necessitates osseointegration;
mechanical retention is a determining factor for primary stability of miniscrew. Studies investigated
various ways to increase primary stability. The aim of this study is to introduce a new configuration of miniscrew
system which is believed to obtain more primary stability.
Material and Methods: Freshly ovine mandibles were cut in blocks. Twenty-seven miniscrews (diameter 1.6 Ă— 8
mm; G2, Dual Top Anchor System, Jeil Medical, Seoul, Korea) were inserted in the blocks and divided in 2 experimental
groups: single miniscrew and the innovated design “Seifi Twin Screw (STS)”. Primary stability was
evaluated by Periotest “M”® device.
Results: Independent t-test showed a significant difference between 2 experimental groups in periotest evaluation
(p< 0.05). STS demonstrated higher primary stability due to its mechanical configuration and design.
Conclusions: The STS provides higher primary stability and was found to be effective in increased success rate of
miniscrew systems from the standpoint of primary stability
Laser Surgery of Soft Tissue in Orthodontics: Review of the Clinical Trials
Introduction: Â Recently, a wide variety of procedures have been done by laser application in Orthodontics. Apart from the mentioned range of various treatments, laser has become a tool for many soft tissue surgeries as an alternative to conventional scalpel-based technique during orthodontic treatments in the management of soft tissue. Due to scarce information in the latter subject, this study was designed in order to include clinical trials that included soft tissue ablation by laser in orthodontics.Methods:Â Literature was searched based on PubMed and Google Scholar databases in 5 years (2010-2015) with English Language restriction and clinical trial design. Studies that performed soft tissue application of laser during orthodontic treatment were extracted by the authors.Results: Only eight studies met the inclusion criteria. No significant difference were found between laser ablation and conventional scalpel technique in the matter of treatment outcome. However, few issues remained to clarify the differences in the mentioned procedures.Conclusion: Laser performance can be recommended in case of preceding less bleeding and discomfort during surgical procedure. There are still quandaries among clinical application of scalpel-based surgery in aesthetic region with bracket-bonded teeth.Precaution and knowledge regarding the characteristics of laser beam such as wavelength, frequency, power and timing is extremely needed
Lobpreis des Königs der Götter. Zwei sumerische (Kult)lieder an Enlil
Das Thema der Promotionsarbeit ist die philologische und inhaltliche Erschließung zweier sumerischer literarischer Kompositionen. Sie gehören zu einer sehr verbreiteten und langlebigen Gattung der keilschriftlichen Literatur, die unter dem sumerischen terminus technicus balag (= "Klagelied") bekannt ist. Die sogenannten "Klagelieder" beschreiben mittels eindrucksvoller Metaphern die verheerenden Konsequenzen des Gotteszornes. Sie wurden länger als zwei Jahrtausende (von der altbabylonischen - 1. Hälfte des 2. Jahrtausends v. Chr. - bis in die parthische Zeit - 1. Hälfte des 1. Jahrtausends n. Chr.) während des Gottesdienstes im Tempel und im Rahmen diverser Rituale vom sogenannten "Klagesänger" rezitiert und stellen eine der wichtigsten Quellen für die Untersuchung der altorientalischen Religion dar
Heavy metals in soil on spoil heap of an abandoned lead ore treatment plant, SE Congo-Brazzaville
Total concentrations of 4 heavy metals (Pb, Zn, Cu, and Mn), non-metal As and three reference elements (Ti, Fe and Al) of a soil profile on spoil heap were examined. 54 soil samples were collected in the soil profile at different depths: 15 to 45, 45 to 75, 75 to 105, 105 to 135 and 135 to 150 cm. The first 15 cm of top layer contained an accumulation of ores and was not sampled. Lead, zinc, copper, manganese and arsenic levels in the soil profile decreased from 11800 to 2000, 2400 to 1200, 270 to 90, 6700 to 750 and 1300 to 600 mg/kg, respectively. The levels of these trace elements were higher than the permissible limit level in soil according to European norms. The concentration levels of heavy metals and arsenic in the soil profile are listed in the following order: Pb > Mn > Zn > As > Cu. High positive correlations were observed between As, Cu, Zn and Al, Fe, Mn, Ti. Among the heavy metals, lead was not significantly correlated with Al, Fe and Ti. Evaluation of enrichment factor, geo-accumulation index and pollution load index values from the measured concentrations of heavy metals and continental crust values shows a very high contamination of the soil profile by the heavy metals studied and arsenic.Key words: Heavy metals, spoil heap, contamination, enrichment factor, geo-accumulation index, pollution load index
Evaluation hydro-chimique des eaux souterraines en milieu urbain au Sud-Ouest de Brazzaville, Congo
La qualité physico-chimique des eaux souterraines au sud-ouest de Brazzaville a été évaluée pour l’usage eau de boisson. Les eaux de 27 puits et 1 source ont été prélevées entre mars et avril 2007 (saison des pluies) puis analysées. 16 paramètres ont été déterminés dans les échantillons d’eau: pH, conductivité électrique (C.E), solides totaux dissous (TDS), Ca2+, Mg2+, K+, Cl-, SO4 2-, NO3 -, THt (dureté totale), TAC (titre alcalimétrique complet), fluorure (F -), ortho phosphate (PO4 3-), fer total (Fetot), manganèse total (Mntot), chrome (Cr(VI)). L’application des méthodes exploratoires multivariées (analyse factorielle et classification ascendante hiérarchique) a permis, respectivement : (i) d’identifier les paramètres les plus pertinents qui décrivent la qualité de ces eaux souterraines ; (ii) de montrer leur variabilité spatiale; (iii) de réduire le nombre de points de prélèvements d’eaux (puits et source) en groupes homogènes dans le cadre d’une étude possible du suivi temporel et spatiale de la qualité de ces eaux souterraines. Le pH variait entre 3,85 et 6,08, ce qui montre un caractère acide. 28,57% des eaux analysées avaient une conductivité électrique comprise entre 300 μS/cm et 431μS/cm. Les autres soit 71,43%, faiblement minéralisées avaient une conductivité inférieure à 300 μS/cm. Une corrélation significative a été observée entre la conductivité électrique (C.E) et d’autres paramètres (TDS, Ca2+, Cl-, SO4 2-, PO4 3-, Cr(VI), Mntot) exceptés Mg2+ et K+. Lesconcentrations en ions majeurs (Ca2+, Mg2+, K+, Cl-, SO4 2-) étaient toutes inférieures à la valeur guide O.M.S respective. Ces eaux sont douces et d’une faible alcalinité essentiellement due aux ions bicarbonates (HCO3 -). Le paramètre le plus déclassant pour l’usage eau de boisson a été le chrome VI pour lequel 78,57% des points d’eaux analysées (y compris la source) avaient une teneur supérieure à 0,05 mg/L.Mots-clés : Eaux souterraines, chrome VI, analyses exploratoires multivariées, Brazzaville Congo
Post Disaster Virtual Revival: 3D CG Manual Reconstruction of a World Heritage Site in Danger
Evaluation of knowledge of vitamin D aspects among pharmacy and engineering students in University of Sharjah, United Arab Emirates
Background: Vitamin D plays a major role in health. Several health disorders have been associated with its deficiency. The objectives of this study were to evaluate the knowledge of and attitude towards vitamin D of pharmacy and engineering students in the University of Sharjah, United Arab Emirates.Methods: A descriptive cross-sectional study was conducted during February-April, 2018. A 30 questions survey in English was designed, pre-validated and distributed to 250 students. The questionnaire was designed to evaluate and compare student’s knowledge and awareness of vitamin D.Results: 213 participants completed the survey producing a response rate of 85.2%. The majority of students were Arabs, females and of age ranging 21-23 years. Almost all pharmacy students were familiar with many aspects of vitamin D. Unlike engineering (66; 66.6%), most (113; 99.1%) pharmacy students know the meaning of osteoporosis. Knowledge of pharmacy students on vitamin D was generally better than that of engineering students particularly with questions on technical parameters of vitamin D levels and dosage. Students who took vitamin D test were advised by a physician. Most of the students from both colleges have a positive attitude to receive information on vitamin D through brochures, lectures/seminars and workshops.Conclusions: Awareness of non-health sciences and to some extent of pharmacy students seems to be inadequate and efforts are needed to increase awareness of the public in general of the importance of vitamin to health status
Prospection Hydrogéologique et Géophysique du Système Aquifère du Plateau de Mbé, District de Ngabé, Congo
La prospection hydrogéologique et géophysique entreprise sur les sites des villages d’Imvouba et d’Ingah dans le plateau de Mbé a permis de déterminer la qualité des eaux souterraines et de surface ainsi que les niveaux aquifères favorables à l’implantation des forages productifs. La prospection géophysique utilisant les méthodes des résistivités électriques avec le dispositif Schlumberger est menée dans le but de déterminer les emplacements favorables à l’implantation des forages positifs avec des débits d’exploitation importants pour un approvisionnement en eau potable des populations. Cette prospection géophysique a révélé que la foration devrait se faire à des profondeurs prévisionnelles de 200 à 250 m voir plus afin d’atteindre les débits prévus par le projet. La prospection hydrogéologique des eaux souterraines et de surface a montré la dominance du faciès chimique bicarbonaté et calcique et que la bonne qualité physico-chimique des eaux de la région est remise en cause par la présence de certains éléments comme le fer total, le manganèse, les phosphates et l’aluminium à des teneurs élevées dépassant parfois les concentrations maximales admissibles pour l’eau de boisson (OMS, 2017). Les formations géologiques présentes dans le plateau de Mbé renferment un système aquifère multicouche bien alimentés par l’infiltration directe des eaux de pluie (1600 à 2500 mm/an).
The hydrogeological and geophysical prospection carried out on the sites of the Imvouba and Ingah villages in theMbé plateau has made it possible to determine the quality of the groundwater and surface water as well as the aquifer levels, which is favorable to the implantation of the productive boreholes. Geophysical prospecting, based on electrical resistivity methods using the Schlumberger device, was conducted in order to determine the favorable locations for the implantation of positive boreholes with high exploitation rates for a drinking water supply of the populations. This geophysical survey revealed that the drilling should be done at predicted depths of 200 to 250 m or more in order to reach the projected flows of the project. Hydrogeological prospecting of groundwater and surface water has shown the dominance of the bicarbonated and calcic chemical facies. The good physicochemical quality of the waters of the region shows the presence of some elements such as total iron, manganese, phosphates and aluminum at high levels which sometimes exceeds the maximum permissible concentrations for drinking water (WHO, 2017). The geological formations present in the Mbé plateau contain a multilayer aquifer system well fed by the direct infiltration of rainwater (1600 to 2500 mm / year)
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