1,720,982 research outputs found
HEAVY METAL ANALYSIS Ni, Cr AND Zn ON SEDIMENT OF MAMUJU DISTRICT USING INDUCTIVELY COUPLED PLASMA OPTICAL EMISSION SPECTROSCOPY (ICP-OES)
Full text linkThis study discusses the heavy metals of Ni and Zn in aquatic sediments of Mamuju Regency using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Sediment samples were taken at four different locations, namely Rimuku River Estuary, Manakara Beach Pier, Muara River Estuary and Mamuju River estuary. The results obtained for Ni metals ranged from 0.0005 - 0.0019 mg / L and Zn metals ranged from 0.0041 - 0.0066 mg / L and still below the threshold of metal quality standards in the sediment or can be said not polluted
HEAVY METAL ANALYSIS CO AND V ON SEDIMENT DISTRICT OF MAMUJU DISTRICT USING INDUCTIVELY COUPLED PLASMA OPTICAL EMISSION SPECTROSCOPY (ICP-OES)
Full text linkThis research concerning heavy metal analysis of Co and V on Mamuju Regency water sediments using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Sediment sampling was conducted on four stations, namely the mouth of the Mamuju river, the mouth of the river Karema, the mouth of the river Rimuku, and front of Manakarra beach platform. The results showed that Co metes ranged from 0.167-0.208 mg/L while for metal V ranged from 0.649-0.944 mg/L. Of the three metals in the analysis are still below the threshold of metal quality standards in sediments or can be said not polluted
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Sintesis Nanopartikel Fe Menggunakan Bioreduktor Ekstrak Fitoplankton Spirulina platensis
Full text linkThis study aims to synthesize Fe nanoparticles by bioreduction using the phytoplankton extract of S. platensis that acts as a reducing agent. Synthesis process is done by adding extracts of S. platensis to a solution of 1 mM FeCl3. The formed nanoparticles characterized by UV-Vis spectrophotometer, Fourier Transform Infra Red Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Disperse X-Ray Spectroscopy (EDX/EDS), X-Ray Diffraction (XRD) and X-Ray Flourosence (XRF). The results showed that the solution of Fe3+ ions can be reduced by phytoplankton extract of S. platensis Fe nanoparticles formed. The average size of the particles based on the Debye-Scherrer equation was 68.10 nm. While the morphology of Fe nanoparticles was spherical shape
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
DETERMINATION OF AGE OF CORAL REEFS ON PANIKIANG ISLAND, BARRU DISTRICT, SPERMONDE ISLANDS THROUGH MEASUREMENT ACTIVITY 14C USING LSC (LIQUID SCINTILLATION COUNTING) METHOD
Full text linkDetermination Of Age Of Coral Reefs On Panikiang Island, Barru District, Spermonde Islands Through Measurement Activity 14C Using LSC (Liquid Scintillation Counting) Method. This research was using a sample of coral reefs taken from the Panikiang Island, Barru, Spermonde Islands. This research has been carried out by using sample preparation with physic and chemical. Sample preparation was done physically and chemically. Chemical preparation was carried out by using a mixture of NaOH with 30% H2O2 followed by a mixture of HClO4 with 30% H2O2, and finally with HCl solution to produce a clean sample with a weight reduction of 7.94%. Absorption of CO2 through reaction with HCl 10% and NH4OH as Carbosorb .produced K2CO3. The total carbon in the sample solution is 0.2496 gram sobtained through titration method. Radiocarbon dating method based on the measurement of the specific activity of the samples obtained from the results of counts LSC (Liquid Scintilation Counter) Hidex 300 SL.The specific activity of coral sample is 14.68 ± 4.04 DPM/gC. Age of coral sample which were calculated from the specific activity were 342.04 ± 37.66 years
UTILIZATION OF METHYLAMINE COMPOUND AS CO2 ABSORBENTS FOR
Full text linkUtilization of methylamine as CO2 absorbent to measure carbon-14 activity of coral sample has been done. The objective of this research is to Determine the age of Coral Sample through Activity Measurements of carbon-14 with LSC (Liquid Scintillation Counting) method. Sample were taken from Langkai Island which is far from human activities. Sample preparation includes physical and chemical leaching to produce a clean white sample. Carbon in the sample was released as CO2 by reaction with HCl 10 % and than absorbed by methylamine yield carbamate compound. Absorbed carbon in 1 mL absorber was 0,044 g from the results of weight reduction before and after absorption. The specific activity of the coral sample was 14.56 DPM/g C. Age of the coral sample based on the specific activity was 408.48 ± 43.69 years
ELECTRODEPOSITION OF Cu ON THE SURFACE OF SILICA FREE RICE HUSK ACTIVATED CARBON WITH ULTRASONIC IRRADIATION
No full textElectrodeposition of Cu on the surface of silica free rice husk activated carbon with ultrasonic irradiation aimed to increase the value of specific capacitance was carried out. Silica free rice husk activated carbon was synthesized using H3PO4 activator and extraction of silica using KOH. The surface area of rice husk carbon was obtained before and after the extraction of silica and after activation were 57.2833 m2/g, 180.5378 m2/g and 184.6074 m2/g, respectively. XRF analysis showed that Cu depositioned on the surface of silica free rice husk activated carbon and based of CV measurements showed that electrodeposition of Cu with ultrasonic irradiation can increased the value of specific capacitance. Specific capacitance of silica free rice husk activated carbon before and after electrodeposition of Cu with ultrasonic irradiation were 657.75 nF/g and 721.08 nF/g, respectively
- …
