Surface Modification of Fe3O4 as Magnetic Adsorbents for Recovery of Precious Metals

Magnetic nanoparticles such as magnetite have been studied intensively for their unique properties that are susceptible to a magnetic field, ready to coat with silica and able to modify with a variety of functional groups. The magnetite-silica core-shell system offers flexibility for extensive modification. The magnetic core is also important in the separation by the use of a magnetic field. The shell, meanwhile, is needed for protection of the magnetic core and further modification. Functional groups at the surface shell are critical in the reaction with target precious metal ions during application. In this contribution, we will have a comprehensive look at the preparation, characterization, and use of the magnetite core-shell modified with functional groups as a magnetic adsorbent. After adsorption, the materials together with the ions can be recovered by the use of magnet before further separation and purification

Silver Nanoparticle Incorporated Titanium Oxide for Bacterial Inactivation and Dye Degradation

This chapter deals with preparation and characterization of silver nanoparticles incorporated in titania or TiO2-AgNP in short and its performance study as a visible light responsive photocatalyst for bacterial inactivation and dye degradation. The preparation of TiO2-AgNP performed by several methods including sol-gel, impregnation, precipitation, and photocatalytic deposition is described. Characterizations by XRD, XPS, FTIR, DRUV, and SEM/TEM machines to confirm the formation of the metallic silver nanoparticle, as well as the shape and size, and to follow the interaction between Ag atoms and other atoms in the crystal lattice of TiO2, are presented. Further, the antibacterial performance and dye degradation activity of TiO2-AgNP, both under UV and visible light, are described

Agricultural event detection from the satellite image zonal statistics

Satellite images have become an important tool for event detection and monitoring. The key advantage for the satellite based monitoring is their ability to cover large areas frequently which in turn makes them very cost-efficient solution for monitoring geographically large areas. Due to advances in the satellite technology and the image processing techniques, satellites are capable of providing high resolution data within real-time from the Earth’s surface. In this thesis we provide a brief introduction to the satellite based remote sensing and how these methods can be used to model different agricultural events. We inspect theoretical satellite signal responses to a common agricultural events and try to detect these patterns from our own dataset. We develop a method to process satellite images into signals and apply preprocessing methods to increase signal to noise ratio. We then train a gradient boosting classifier to the smoothened signals and process the individual predictions so that we can detect the start and end times for various agricultural events from the agricultural parcels

Validation of Analytical Method Determination of Sodium Dodecyl Benzene Sulfonate (DBS) in Catfish (Clarias batrachus L.) by Spectrophotometric Using Methylene Blue

A spectrophotometric method for analysis of DBS anionic surfactant in Clarias batracus has been validated. The method of analysis was divided into two phases. Extraction with solid-liquid extraction using Soxhlet and analysis of DBS. The extraction was performed using solvent of n-hexane and methanol for 9 and 6 hours, respectively. The analysis was performed using Spectrophotometer UV-Vis based on the complex formation of DBS-methylene blue (DBS-MB). This methods is applied to the determination of DBS in local catfish after DBS exposure and that of obtained in markets. The results showed that the parameters of validation methods have high acceptability as linierity (R2 = 0.99), limit of detection (LOD) and limit of quantification (LOQ ) (2.93 mg/g and 9.75 mg/g), sensitivity (ε = 2.44 x 105 L mol-1 cm-1), precision (RSD = 0.14-1.38%) and accuracy (% recovery in a range 82-110 %). The results of analysis of DBS in catfish with 2.5; 5; 10; 15 mg/L of DBS concentration exposure are 0.87; 1.67; 8.50 and 18.10 mg/kg, respectively and catfish from markets in a range 8.5-61 mg/kg. The result showed that the method of analysis of DBS anionic surfactant using MB could be applied for catfish samples. Keywords: Validation methode, extraction, catfish, Clarias batrachus, dodecyl benzene sulfonate, methylene blue

Risk factors for neonatal hypoxic ischemic encephalopathy in Helsinki University Hospital

Syntymäasfyksia on tila, jossa sikiö tai syntyvä lapsi kärsii hypoksemian lisäksi hiilidioksidiretentiosta ja asidoosista. Se voi johtaa aivotoiminnan häiriöön eli hypoksis-iskeemiseen enkefalopatiaan (HIE), jonka hoitona käytetään vastasyntyneen ruumiinlämmön alentamista 33 asteeseen kolmen päivän ajaksi. Vaikea-asteisessa HIE:ssa mortaliteetti on korkea, ja henkiin jääville lapsille kehittyy usein pysyviä neurologisia vammoja. Asfyksialle altistavia äidin sairauksia sekä raskauden ja synnytyksen aikaisia riskitekijöitä tunnetaan monia, ja toisaalta suuri osa asfyksiatilanteista tulee yllättäen eikä ole ennakoitavissa. Tämän tutkimuksen tavoitteena oli kartoittaa erityisesti ammattilaisten toiminnalla vältettävissä olevia riskitekijöitä, jotka ovat johtaneet keskivaikeaan ja vaikeaan vastasyntyneen HIE:aan ja vaatineet viilennyshoitoa. Tutkimus toteutettiin retrospektiivisenä tapaus-verrokkitutkimuksena vuosina 2013 – 2017 Helsingin yliopistollisen sairaalan synnytyssairaaloissa synnyttäneille äideille. Jokaista 88:aa viilennyshoidettua vastasyntynyttä kohden valittiin samaa sukupuolta oleva, samassa sairaalassa ja samalla menetelmällä seuraavaksi syntynyt lapsi. Tiedot äitien terveydentilasta, raskaudesta ja synnytyksestä kerättiin sairaalan potilastietojärjestelmästä. Riskitekijöiden assosiaatiota HIE:n kehittymiseen arvioitiin logistisella regressioanalyysillä. Kaikista kirjallisuuden perusteella valituista todennäköisistä riskitekijöistä monimuuttuja-analyysiin valikoitiin muuttujat, joiden OR yksimuuttuja-analyysissä oli tilastollisesti merkitsevä. Synnytyksen käynnistäminen (aOR 3.08), äidin tupakointi (aOR 1.45) ja obstetriset hätätilanteet (aOR 3.51), osoittautuivat HIE:n itsenäisiksi riskitekijöiksi. Tutkimusryhmän käynnistetyissä synnytyksissä oli enemmän alatiesynnytyksiä kontrolliryhmään verrattuna (p=0.03). Tutkimustulosten perusteella päivystyskeisarileikkausta tulisi harkita aiempaa herkemmin käynnistettyihin synnytyksiin liittyvissä komplikaatioepäilyissä. Jatkossa tutkimuksia kannattanee suunnata erityisesti sikiön hyvinvoinnin seurannassa käytettävien menetelmien kehittämiseen

Donor funds and economic dependence: an investigation of community-driven development in the Eastern Cape, Chris Hani District Municipality

This research focused mainly on the progress of non-governmental organisations (NGOs) and community-driven development projects (CDDs) in assisting the Chris Hani District Municipality (CHDM) community. The research identified the main types of CDDs that are found in the CHDM as agricultural, caregivers, manufacturing, tourism, performing arts, and education services. Thirty-eight NGOs participated in this project with two participants representing each NGO. These NGOs were looked at from a thematic perspective. Three main themes emerged, namely; a) the quality of life in CHDM or specifically in the areas of operation of the NGOs, b) operations of the NGOs where the name and main objectives CDDs were identified, and c) challenges, funding and impact of the CDDs. This research set out to ask the following questions: What is the nature and origin of projects operational in Chris Hani District? What is the impact and sustainability of donor-aided projects on CDD in the Chris Hani District? Can NGO projects be sustained without donor aid? Are there any alternative forms of funding apart from donor funds? To answer these questions, a number of qualitative methods and techniques were used to collect and analyse data. These included focus group discussions with project beneficiaries, observations of projects, activities and individual project participants, and key informant interviews with different categories of respondents depending on their roles and level of involvement in the implementation of projects as well as their experience in the implementation of donor-aided programmes. These discussions were guided by different interview schedules with respective respondents. Random and snowball sampling methods were used to choose the respondents as well as groups that participated in the study. The research also focused on assessing the survivability of donor-aided NGO projects if the donor funds were discontinued for any reason. It sought to determine the continuity and feasibility of developmental projects and their impact on the socio- economic welfare of the rural poor in the Chris Hani District without donations. This research found evidence indicating that, by and large, NGOs in the Chris Hani District play a crucial role in CDD. Be that as it may, this research established that on average, 98 per cent of NGOs had been economically and socially affected by the donor-funded projects. It was established that, on average, the donor dependency ratio was 74 per cent. It was also seen that most donor-funded projects could only survive for 12 days if the funding was withdrawn. However, this hypothetical withdrawal of funds does not cause much concern because of the security found in the funding types of the NGOs in the Chris Hani District. In practical terms, these community-driven projects are likely to continue for decades ceteris paribus

Saccharin Extraction and Analysis of Drug and Food Samples by Derivative Ultraviolet (UV) Spectrophotometry

Saccharin extraction and analysis of drug and food samples was investegated by spectrophotometry ultraviolet (uv) derivative method were studied. The saccharin extraction was carried out using solvent of ethanol/chloroform (2:8 v/v). The limit of detection (LOD) and limit of quantification (LOQ) of the proposed method were 0.50 ppm and 1.82 ppm for the second order and 0.47 ppm and 1.58 ppm for the fourth, while for the zero order were 2,75 ppm and 8,55 ppm. The calibration curve was linear in the concentration range from 20-100 ppm (R2= 0.996 for the second order and R2=0.997 for the fourth). The percent recovery of saccharin was in the range 95.20-104.40% for the second order and 97.20-102.40% for the fourth. The range of saccharin concentration (w/w) in drugs, candies and toothpaste for the fourth derivative were 1.39±0.02 mg/kg until 7.15±0.05 mg/kg, 0.21±0.01 mg/kg until 2.09±0.01 mg/kg, and 0.15±0.03 mg/kg until 0.63±0.04 mg/kg, respectively

Pengaruh Rasio Molar Zn/Al terhadap Sifat Pertukaran Anion [Fe(CN)6]4– pada Hidrotalsit Zn-Al-NO3 dan Zn-Al-Cl

Pengaruh rasio mol kation hidrotalsit Zn/Al dan jenis anion dan sifat penukaran ion telah dipelajari. Hidrotalsit Zn-Al-NO3 dan Zn-Al-Cl disintesis dengan variasi mol Zn/Al dan diikuti dengan penukaran ion yang berada di dalam ruang antarlapis hidrotalsit dengan ion heksasianoferat(II). Hidrotalsit hasil sintesis dikarakterisasi dengan XRD, FTIR dan AAS. Hasil penelitian menunjukkan bahwa anion nitrat dan klorida di dalam ruang antarlapis hidrotalsit Zn-Al-NO3 dan Zn-Al-Cl dapat digantikan dengan heksasianoferat(II). Kapasitas penukaran anion nitrat dalam hidrotalsit Zn-Al-NO3 oleh heksasianoferat(II) untuk rasio molar Zn/Al 2,3, dan 4 masing-masing sebesar 289,35 meq; 233,48 meq dan 137.511 meq/100 g. Sementara kapasitas penukaran anion klorida dalam hidrotalsit Zn-Al-Cl oleh heksasianoferat(II) dengan rasio molar Zn/Al 2,3, dan 4 masing-masing sebesar 205,55 meq; 189,08 meq dan 118,17 meq/100 g. XRD mampu membuktikan penukaran anion nitrat dan klorida di dalam hidrotalsit Zn-Al-NO3 dan Zn-Al-Cl oleh heksasianoferat(II)

IMMOBILIZATION OF Saccharomycess cereviceae BIOMASS ON CHITOSAN AND ITS APPLICATION AS AN ADSORBENT FOR Pb(II) ION

Abstract: An application of Saccharomycess cereviceae biomass immobilized on chitosan (SC-Chi adsorbent) for Pb(II) ion removal was demonstrated. Adsorption experiment was conducted at various mass ratio of Saccharomycess cereviceae biomass to chitosan, contact time, pH of solution and concentration of cation. Total Pb(II) metal ion adsorbed was calculated from the difference of the amount of metal ion before and after adsorption which was measured by AAS. The results showed that optimum condition for adsorption of Pb(II) ion by the SC-Chi was achieved using mass ratio of Saccharomycess cereviceae to chitosan of 50% (w/w), pH solution of 7, contact time of 60 min and concentration of 25 mgL-1. The hydroxyl (-OH) and amino (-NH2) functional groups are believed to be responsible for the adsorption of Pb(II) ion by the adsorbent

Un caso paradigmático : la rehabilitación de las calles d'en Robador y Sant Ramon del barrio del Raval de Barcelona. El oscuro antecedente de la Isla Negra

Rodolfo Rufián Roto és l'heterònim d'un antropòleg i investigador de la Universitat de Barcelona, Miquel Fernández Gonzále