Pemisahan Cu2+ Dan Cd2+ Menggunakan Silika-kitosan Sebagai Fasa Padat

Ion Cu2+ dan Cd2+ dapat dipisahkan dengan menggunakan metode ekstraksi fasa padat (EFP). Pada penelitian ini digunakan silika-kitosan sebagai fasa padat dan EDTA sebagai eluen. Proses EFP ion Cu2+ dan Cd2+ menggunakan sistem kromatografi kolom. Faktor yang mempengaruhi ekstraksi ion Cu2+ dan Cd2+ adalah pH, konsentrasi eluen, serta panjang kolom. Pengaruh pH eluen yang dipelajari adalah 6 hingga 10 menggunakan buffer fosfat 0,1 M. Konsentrasi eluen yang dipelajari untuk pemisahan ion Cu2+ dan Cd2+ sebesar 0,01 M; 0,05 M; dan 0,1 M. Panjang kolom yang dipelajari adalah 0,3 cm dan 0,6 cm. Hasil dari penelitian ini menunjukkan bahwa kondisi optimum pemisahan ion Cu2+ dan Cd2+ terjadi pada pH 7 dan panjang kolom 0,6 cm. Elusi dilakukan secara bergradien dengan 3,5mL EDTA 0,05 M dan 3,5mL EDTA 0,2 M. Recovery (%recovery) pemisahan ion Cu2+ dan Cd2+ secara berturut-turut sebesar 96,13% dan 83,24%

Seasonal Variability of Light Absorption Coefficient of Surface Water

Absorption coefficient measurement can be used in estimating water quality, optical characteristic of water column, and marine bio-optical models. The purposes of this research were to determine values and variability of sea surface absorption coefficient in the northeastern Gulf of Mexico (NEGOM) based on various seasons. The data were collected in spring, summer, and fall seasons in 1999-2000 with AC-9 instrument. The spatial distribution of absorption coefficient showed that relatively high values were generally found along the run off Missisippi, Mobile, Chochawati, Escambia, Apalachicola, and Suwannee rivers, as well as Tampa Bay. Meanwhile, relatively low values were found in offshore region. This pattern followed the distribution pattern of chlorophyll and CDOM. Based on the local region comparison of spectral average value of absorption coefficient, we found a significant difference (α = 95%) among regions with the highest value in the run off of the Mississippi and Mobile rivers, and the lowest value in the offshore region. Comparison of spectral average value of absorption coefficient among seasons at the three primary wavelengths (blue=440 nm, green=510 nm, and red=676 nm) also showed a significant difference (α = 95%) with the highest value during the summer 1999 (Su-99) and the lowest value during the spring of 2000 (Sp-00). Absorption coefficient values were influenced by oceanographic factors that varied in every season such as wind, surface currents, upwelling, the location and speed of the Loop Current, and the river discharge of fresh water into the NEGOM

Design of Reactor for The Production of Zinc Oxide (ZnO) Nanoparticles Using The Direct Precipitation Method

This study aims to design a continuous stirred tank reactor (CSTR) type reactor used in the production of zinc oxide (ZnO) nanoparticles. Mass balance calculations were carried out in this study as a benchmark to find out whether the reactor was working properly by knowing the flow of incoming raw materials and the products produced by the reactor. Furthermore, the design of the reactor and the design of the stirrer used in the reactor is calculated manually using Microsoft Excel. Based on the calculation results of the reactor design, the reactor volume is 8224.359 liters, with a vessel diameter of 73.298 in, a cylinder height of 166.090 in and a cylinder thickness of 73.444 in. The top cover of the reactor measures 12.387 inches with a thickness of 0.072 inches while the bottom cover measures 21.185 inches with a thickness of 0.083 inches. So that the overall height of the reactor is 37.552 in. The reactor is equipped with 1 stirrer with an impeller diameter of 36.722 in, impeller height from the bottom of the tank is 24.433 in, impeller width is 7.344 in and impeller length is 9.180 in. Turbulent stirring flow conditions with a standard motor power for the stirrer is 6.849 HP. It is hoped that this design will serve as a reference for building more economical, more efficient and highly demanding reactors

Spectral of Remote Sensing Reflectance of Surface Waters

Spectral measurements of remote sensing reflectance (Rrs) of surface waters in the northeastern Gulf of Mexico were conducted in various seasons in 1999-2000 using Fieldspec Analytical Spectral Devices (ASD) Spectroradiometer. Filtering process was performed on the data to eliminate invalid data. In general, in coastal waters particularly near rivers mouth (water type-2) the Rrs spectrals were relatively low at blue, maximum at green, and decreased to a minimum value at the red wavelength. In offshore waters (type-1), the general pattern of Rrs spectrals were maximum at the blue wavelength and then continued to decline at the green wavelength until the minimum value at the red wavelength except during summer where Rrs spectrals in most offshore area having the maximum value at the green wavelength due to the phytoplankton bloom as a result of freshwater intrusion from the Mississippi river. In general, the patterns and values of Rrs ​​were significantly different among seasons and locations. Results showed that Rrs values ​​at the blue wavelength (λ=400 nm) were generally higher in the spring than in other seasons ranging of 0.007-0.018 sr-1 in offshore waters and 0.004-0.015 sr-1 in coastal waters. During spring, Rrs values at the green ​​wavelength (λ=500 nm) were also higher than in other seasons ​​ranging of 0.005-0.013 sr-1 found in coastal waters. However, during summer in coastal waters, the maximum values of Rrs spectrals were found in different green wavelength on different locations showed the differences in the type and composition of phytoplankton, organic materials, and suspension matters at those locations

Hemosuccus Pancreaticus in the Era of Capsule Endoscopy and Double Balloon Enteroscopy Complicated by Multifocal Mycobacterium chelonae/abscessus Infection

Hemosuccus pancreaticus is a rare etiology of obscure gastrointestinal bleeding characterized by bleeding into the pancreatic duct. The diagnosis may be delayed for months to years, due to the episodic nature of bleeding and failure to consider the diagnosis. Patients often undergo multiple endoscopies and radiologic evaluations prior to diagnosis. Incidental gastrointestinal findings may lead to unnecessary endoscopic and surgical interventions. This report describes a patient with hemosuccus pancreaticus diagnosed in the era of video capsule endoscopy and double balloon enteroscopy, whose management was complicated by multifocal Mycobacteria chelonae/abscessus infection

Correlated long-range mixed-harmonic fluctuations measured in pp, p+Pb and low-multiplicity Pb+Pb collisions with the ATLAS detector

For abstract see published article

Measurements of the charge asymmetry in top-quark pair production in the dilepton final state at s √ =8 TeV with the ATLAS detector

Measurements of the top-antitop quark pair production charge asymmetry in the dilepton channel, characterized by two high-pT leptons (electrons or muons), are presented using data corresponding to an integrated luminosity of 20.3  fb−1 from pp collisions at a center-of-mass energy s√=8  TeV collected with the ATLAS detector at the Large Hadron Collider at CERN. Inclusive and differential measurements as a function of the invariant mass, transverse momentum, and longitudinal boost of the tt¯ system are performed both in the full phase space and in a fiducial phase space closely matching the detector acceptance. Two observables are studied: AℓℓC based on the selected leptons and Att¯C based on the reconstructed tt¯ final state. The inclusive asymmetries are measured in the full phase space to be AℓℓC=0.008±0.006 and Att¯C=0.021±0.016, which are in agreement with the Standard Model predictions of AℓℓC=0.0064±0.0003 and Att¯C=0.0111±0.0004

Performance of top-quark and W -boson tagging with ATLAS in Run 2 of the LHC

The performance of identification algorithms (“taggers”) for hadronically decaying top quarks and W bosons in pp collisions at √s=13 TeV recorded by the ATLAS experiment at the Large Hadron Collider is presented. A set of techniques based on jet shape observables are studied to determine a set of optimal cut-based taggers for use in physics analyses. The studies are extended to assess the utility of combinations of substructure observables as a multivariate tagger using boosted decision trees or deep neural networks in comparison with taggers based on two-variable combinations. In addition, for highly boosted top-quark tagging, a deep neural network based on jet constituent inputs as well as a re-optimisation of the shower deconstruction technique is presented. The performance of these taggers is studied in data collected during 2015 and 2016 corresponding to 36.1 fb −1 for the tt ¯ and γ+jet and 36.7 fb −1 −1 for the dijet event topologies

In situ calibration of large-radius jet energy and mass in 13 TeV proton–proton collisions with the ATLAS detector

The response of the ATLAS detector to largeradius jets is measured in situ using 36.2 fb−1 of √s = 13 TeV proton–proton collisions provided by the LHC and recorded by the ATLAS experiment during 2015 and 2016. The jet energy scale is measured in events where the jet recoils against a reference object, which can be either a calibrated photon, a reconstructed Z boson, or a system of well-measured small-radius jets. The jet energy resolution and a calibration of forward jets are derived using dijet balance measurements. The jet mass response is measured with two methods: using mass peaks formed by W bosons and top quarks with large transverse momenta and by comparing the jet mass measured using the energy deposited in the calorimeter with that using the momenta of charged-particle tracks. The transversemomentum and mass responses in simulations are found to be about 2–3% higher than in data. This difference is adjusted for with a correction factor. The results of the different methods are combined to yield a calibration over a large range of transverse momenta (pT). The precision of the relative jet energy scale is 1–2% for 200 GeV < pT < 2 TeV, while that of the mass scale is 2–10%. The ratio of the energy resolutions in data and simulation is measured to a precision of 10–15% over the same pT range