scholarly journals Molecular Imprinting for High-Added Value Metals: An Overview of Recent Environmental Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
George Z. Kyzas ◽  
Dimitrios N. Bikiaris
Keyword(s):  
Molecular Imprinting ◽  
Low Cost ◽  
Precious Metals ◽  
Added Value ◽  
Biological Macromolecules ◽  
Environmental Application ◽  
Molecular Imprinted Polymers ◽  
Guest Molecules ◽  
Small Organic Molecules ◽  
Gold Silver

One of the most hot topics of recent research is the reuse of some compounds existing as pollutants in environment. These compounds (molecules, ions, complexes, etc.) are of high-added value and it will be ideal to selectively bind them with any environmental application and reuse them in their initial or modified form. The latter can be achieved using molecular imprinting. In the present review article, an overview of the recent attempts for the selective binding of some precious metals (i.e., gold, silver, and platinum) of high-added value is done using molecular imprinted polymers (MIPs) as materials. The simplicity of their use, their relatively low cost, and the broad range of possible guest molecules (small organic molecules, ions, metals, and also biological macromolecules) have since led to the important development of molecular imprinting.

Graphene Modified Molecular Imprinting Electrochemical Sensor for Determining the Content of Dopamine

2019 ◽  
Vol 15 (6) ◽  
pp. 628-634
Author(s):  
Rong Liu ◽  
Jie Li ◽  
Tongsheng Zhong ◽  
Liping Long
Keyword(s):  
Electrochemical Sensor ◽  
Molecular Imprinting ◽  
Neurological Disorders ◽  
Room Temperature ◽  
Low Cost ◽  
Differential Pulse ◽  
Current Response ◽  
Specific Selectivity ◽  
Pulse Voltammetry

Background: The unnatural levels of dopamine (DA) result in serious neurological disorders such as Parkinson’s disease. Electrochemical methods which have the obvious advantages of simple operation and low-cost instrumentation were widely used for determination of DA. In order to improve the measurement performance of the electrochemical sensor, molecular imprinting technique and graphene have always been employed to increase the selectivity and sensitivity. Methods: An electrochemical sensor which has specific selectivity to (DA) was proposed based on the combination of a molecular imprinting polymer (MIP) with a graphene (GR) modified gold electrode. The performance and effect of MIP film were investigated by differential pulse voltammetry (DPV) and cyclic voltammetry (CV) in the solution of 5.0 ×10-3 mol/L K3[Fe(CN)6] and K4[Fe(CN)6] with 0.2 mol/L KCl at room temperature. Results: This fabricated sensor has well repeatability and stability, and was used to determine the dopamine of urine. Under the optimized experiment conditions, the current response of the imprinted sensor was linear to the concentration of dopamine in the range of 1.0×10-7 ~ 1.0×10-5 mol/L, the linear equation was I (µA) = 7.9824+2.7210lgc (mol/L) with the detection limit of 3.3×10-8 mol/L. Conclusion: In this work, a highly efficient sensor for determination of DA was prepared with good sensitivity by GR and great selectivity of high special recognization ability by molecular imprinting membrane. This proposed sensor was used to determine the dopamine in human urine successfully.

scholarly journals Towards Iron-Titanium Oxide Nanostructures from Ecuadorian Black Mineral Sands

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 122
Author(s):  
Karina J. Lagos ◽  
Bojan A. Marinkovic ◽  
Alexis Debut ◽  
Karla Vizuete ◽  
Víctor H. Guerrero ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Titanium Oxide ◽  
Low Cost ◽  
Mineral Resources ◽  
Added Value ◽  
Secondary Phases ◽  
Hydrothermal Route ◽  
Oxide Nanostructures ◽  
Transmission Electron ◽  
Pre Treatment

Ecuadorian black mineral sands were used as starting material for the production of iron-titanium oxide nanostructures. For this purpose, two types of mineral processing were carried out, one incorporating a pre-treatment before conducting an alkaline hydrothermal synthesis (NaOH 10 M at 180 °C for 72 h), and the other prescinding this first step. Nanosheet-assembled flowers and nanoparticle agglomerates were obtained from the procedure including the pre-treatment. Conversely, nanobelts and plate-like particles were prepared by the single hydrothermal route. The nanoscale features of the product morphologies were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The ilmenite and hematite molar fractions, within the ilmenite-hematite solid solution, in the as-synthetized samples were estimated by Brown’s approach using the computed values of unit-cell volumes from Le Bail adjustments of X-ray powder diffraction (XRPD) patterns. The resulting materials were mainly composed of Fe-rich ilmenite-hematite solid solutions (hematite molar contents ≥0.6). Secondary phases, which possibly belong to lepidocrocite-like or corrugated titanate structures, were also identified. The current study demonstrated the feasibility of employing Ecuadorian mineral resources as low-cost precursors to synthesize high-added-value nanostructures with promising applications in several fields.

scholarly journals Gold, Silver, and Electrum Electroless Plating on Additively Manufactured Laser Powder-Bed Fusion AlSi10Mg Parts: A Review

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 422
Author(s):  
Dana Ashkenazi ◽  
Alexandra Inberg ◽  
Yosi Shacham-Diamand ◽  
Adin Stern
Keyword(s):  
Additive Manufacturing ◽  
Low Cost ◽  
Ion Beam ◽  
Surface Finishing ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Finishing Process ◽  
Gold Silver ◽  
3D Printed

Additive manufacturing (AM) revolutionary technologies open new opportunities and challenges. They allow low-cost manufacturing of parts with complex geometries and short time-to-market of products that can be exclusively customized. Additive manufactured parts often need post-printing surface modification. This study aims to review novel environmental-friendly surface finishing process of 3D-printed AlSi10Mg parts by electroless deposition of gold, silver, and gold–silver alloy (e.g., electrum) and to propose a full process methodology suitable for effective metallization. This deposition technique is simple and low cost method, allowing the metallization of both conductive and insulating materials. The AlSi10Mg parts were produced by the additive manufacturing laser powder bed fusion (AM-LPBF) process. Gold, silver, and their alloys were chosen as coatings due to their esthetic appearance, good corrosion resistance, and excellent electrical and thermal conductivity. The metals were deposited on 3D-printed disk-shaped specimens at 80 and 90 °C using a dedicated surface activation method where special functionalization of the printed AlSi10Mg was performed to assure a uniform catalytic surface yielding a good adhesion of the deposited metal to the substrate. Various methods were used to examine the coating quality, including light microscopy, optical profilometry, XRD, X-ray fluorescence, SEM–energy-dispersive spectroscopy (EDS), focused ion beam (FIB)-SEM, and XPS analyses. The results indicate that the developed coatings yield satisfactory quality, and the suggested surface finishing process can be used for many AM products and applications.

scholarly journals Seasonal Influence on the Performance of Low-Cost NO2 Sensor Calibrations

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7919
Author(s):  
Sjoerd van Ratingen ◽  
Jan Vonk ◽  
Christa Blokhuis ◽  
Joost Wesseling ◽  
Erik Tielemans ◽  
...  
Keyword(s):  
Low Cost ◽  
Added Value ◽  
Sensor Data ◽  
Sensor Technology ◽  
Monitoring Networks ◽  
Technical Problems ◽  
Eu Directive ◽  
Short Period ◽  
No2 Sensor ◽  
One Year

Low-cost sensor technology has been available for several years and has the potential to complement official monitoring networks. The current generation of nitrogen dioxide (NO2) sensors suffers from various technical problems. This study explores the added value of calibration models based on (multiple) linear regression including cross terms on the performance of an electrochemical NO2 sensor, the B43F manufactured by Alphasense. Sensor data were collected in duplicate at four reference sites in the Netherlands over a period of one year. It is shown that a calibration, using O3 and temperature in addition to a reference NO2 measurement, improves the prediction in terms of R2 from less than 0.5 to 0.69–0.84. The uncertainty of the calibrated sensors meets the Data Quality Objective for indicative methods specified by the EU directive in some cases and it was verified that the sensor signal itself remains an important predictor in the multilinear regressions. In practice, these sensors are likely to be calibrated over a period (much) shorter than one year. This study shows the dependence of the quality of the calibrated signal on the choice of these short (monthly) calibration and validation periods. This information will be valuable for determining short-period calibration strategies.

scholarly journals Iranian Steel Industry: Domination of Dispersed Direct Reduction Plants in an Inefficient Value Chain and a Droughty Environment

2021 ◽  
Author(s):  
Sepehr Ghazinoory ◽  
Mehdi Fatemi ◽  
Abolfazl Adab
Keyword(s):  
Value Chain ◽  
Steel Industry ◽  
Material Flow ◽  
Steel Ingot ◽  
Direct Reduction ◽  
Low Cost ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Added Value ◽  
Easy Access

Abstract Iran has a great advantage in the development of the steel industry due to its access to mineral resources and energy, extensive consumer market, and low-cost labor. In this article, the Iranian steel value chain in 2014-2016 is studied using the value chain analysis and material flow analysis. Accordingly, based on the statistics related to the input and output of each echelon in the chain, the material flow is analyzed throughout the value chain. Then the total added value from the chain, the share of different stages, and the various costs in each echelon are calculated. According to the research findings, weakness in the development of transportation infrastructure and poor geographical distribution of value chain units has led to the deviation of production from nominal capacity and frequent imports/exports throughout the chain. On the other hand, the upstream industries have a permanent advantage that deeply roots in easy access to the minerals and lower costs in transportation and energy. Finally, the pricing of intermediate products based on the ratio of steel ingot prices is criticized, while wage conversion and commodity purification contracts are proposed as possible solutions for the reduction of overhead costs.

MIP-Based Impedimetric Sensors

2013 ◽  
Vol 543 ◽  
pp. 499-502 ◽  
Author(s):  
Florence Lagarde
Keyword(s):  
Molecular Imprinting ◽  
Molecular Imprinted Polymers ◽  
Imprinted Polymers ◽  
Molecular Imprinting Technique ◽  
Recognition Elements ◽  
Target Molecules

Molecular imprinting technique allows the preparation of tailor-made materials with high recognition faculty towards target molecules. Molecular imprinted polymers (MIPs) are more robust, easier to manipulate and cheaper than biological receptors, constituting very attractive alternatives to biomolecules as recognition elements in the elaboration of biosensors. In this paper, the principles and advantages of MIP-based impedimetric sensors are described and some examples of application in the biological or environmental fields are given.

Strategic Value Framing for Brownfield Redevelopment

2021 ◽  
Author(s):  
Norsyuhada Ab Razak ◽  
Normawani Kerya ◽  
May Sari Hendrawati ◽  
Syarah Syazana Nordin ◽  
Noor Shakila Abd Rahman ◽  
...  
Keyword(s):  
Low Cost ◽  
Development Stage ◽  
Design Concept ◽  
Recovery Factor ◽  
Added Value ◽  
Facility Design ◽  
Brownfield Redevelopment ◽  
Full Field ◽  
Strategic Value ◽  
Value Framing

Abstract Objectives/Scope Field A is a brownfield that has been produced for 52 years under natural depletion via a total of 207 strings. The field comprises 7000 ft of reservoir section, multiple fault blocks and over 200 separate reservoir units has been produced to date. Despite the long period of production, the field recovery factor (RF) to date is only 29%. To improve the RF, a strategic assest value framing exercise was carried out to identify the additional subsurface opportunities i.e. infill well drilling, secondary recovery, late field life appraisal in underdeveloped fault blocks as well as adopting standardized low well concepts and the design one build many facility design concept to reduce cost and accelerate development. The main purpose of the exercise was to capture the overall opportunities for the field, outline the roadmap and phase out the project with suitable wells and facilities design to bring down the cost for project commerciality. Methods, Procedures, Process The integrated workflow of the exercise involved subsurface, drilling, facilities, operations and economist and took a total of 3 months to complete. The process started off with a RF benchmarking exercise utilizing a newly developed inhouse RF benchmarking tool to compare the current attained vs the attainable RF(EUR) and identify incremental reserves. The number of new wells required to develop the incremental reserves was estimated by analyzing EUR per well trends over time. This analysis indicated that on a campaign basis the current realistic average EUR per well is in the order of 0.7-1.0 MMstb per well. The preliminary well placements are guided by bubble maps of all reservoirs, in a top to bottom & block by block approach, to identify underdeveloped areas and combining these areas into stacks of reservoirs that can be combined and developed with simpler wells from existing or future facilities. The drilling team has designed a few simple trajectories to penetrate shallower to deeper reservoirs and proposed the drilling center within a radius of 2 km from the targets. This approach differs from the object-based approach where individual high EUR targets are chased with more complex wells drilled from a specific location during a platform campaign. Result, Observations, Conclusions Potential additional reserves and 6 new projects have been identified which would result in a field recovery factor increase of 11%, of which 2 projects are being accelerated to realize early first oil. Timelines for all the projects have been mapped out with the aim of completing all within the next 10 years. A dedicated project management team has been formed to support the project from the initial stage. Detail Full Field Review study will be conducted to mature all the opportunities up to development stage. The listed projects will follow the low cost well guideline established in the framing as well as fast track facility design concept. Novel/added value The strategic value framing exercise is a systematic approach that provide a total picture of the future opportunities to optimize field production/EUR and maximize commercial value of brownfield redevelopment.

scholarly journals Tracking Cobalt, REE and Gold from a Porphyry-Type Deposit by LA-ICP-MS: A Geological Approach towards Metal-Selective Mining in Tailings

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 109 ◽  
Author(s):  
Germán Velásquez ◽  
Daniel Carrizo ◽  
Stefano Salvi ◽  
Iván Vela ◽  
Marcial Pablo ◽  
...  
Keyword(s):  
High Resolution ◽  
Porphyry Copper ◽  
Precious Metals ◽  
Copper Deposit ◽  
Mineral Deposit ◽  
Critical Metals ◽  
Mining Operations ◽  
Gold Silver ◽  
Selective Mining ◽  
Mineral Characterization

High-resolution mineral characterization performed on mine material from a giant porphyry copper deposit shows that critical and precious metals, such as cobalt, lanthanum, gold, silver, and tellurium, are concentrated in pyrite in the form of visible micro-inclusions, invisible mineral nano-inclusions, and trace metals in the mineral lattice. Visible and invisible inclusions consist of Ag-Au-Te sulfosalt and monazite-(La) particles. Trace metal concentrations grade up to 24,000 g/t for cobalt, up to 4000 g/t for lanthanum, and up to 4 g/t for gold. Pyrite, considered a waste material, is removed from the valuable copper ore material and sent to the tailings. Thus, tailings with high contents of pyrite can represent a prime target to explore for critical metals in the porphyry copper mining operations, transforming it into a new source of supply for critical metals. We propose that high-resolution mineral characterization is the key to evolve from a quasi-single-metal (copper) operation to a multi-metals business by developing metal-selective mining. To address this challenge, we coined the Metal-Zone concept to identify zones enriched in a specific metal within a mineral deposit, instead of zones enriched in an ore mineral.

scholarly journals Molecularly Imprinted Polymer Based Sensors for Medical Applications

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1279 ◽  
Author(s):  
Yeşeren Saylan ◽  
Semra Akgönüllü ◽  
Handan Yavuz ◽  
Serhat Ünal ◽  
Adil Denizli
Keyword(s):  
Surface Modification ◽  
Homeland Security ◽  
Molecular Imprinting ◽  
Molecularly Imprinted Polymer ◽  
Structural Changes ◽  
Low Cost ◽  
Dimensional Structure ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Physical And Chemical

Sensors have been extensively used owing to multiple advantages, including exceptional sensing performance, user-friendly operation, fast response, high sensitivity and specificity, portability, and real-time analysis. In recent years, efforts in sensor realm have expanded promptly, and it has already presented a broad range of applications in the fields of medical, pharmaceutical and environmental applications, food safety, and homeland security. In particular, molecularly imprinted polymer based sensors have created a fascinating horizon for surface modification techniques by forming specific recognition cavities for template molecules in the polymeric matrix. This method ensures a broad range of versatility to imprint a variety of biomolecules with different size, three dimensional structure, physical and chemical features. In contrast to complex and time-consuming laboratory surface modification methods, molecular imprinting offers a rapid, sensitive, inexpensive, easy-to-use, and highly selective approaches for sensing, and especially for the applications of diagnosis, screening, and theranostics. Due to its physical and chemical robustness, high stability, low-cost, and reusability features, molecularly imprinted polymer based sensors have become very attractive modalities for such applications with a sensitivity of minute structural changes in the structure of biomolecules. This review aims at discussing the principle of molecular imprinting method, the integration of molecularly imprinted polymers with sensing tools, the recent advances and strategies in molecular imprinting methodologies, their applications in medical, and future outlook on this concept.

Analyzing precious metals returns using a Kalman smoother approach

2019 ◽  
Vol 36 (1) ◽  
pp. 89-111
Author(s):  
Marco Erling
Keyword(s):  
Consumer Price Index ◽  
Precious Metals ◽  
External Factors ◽  
Specific Factor ◽  
Content Type ◽  
Kalman Smoother ◽  
Integration Test ◽  
Gold Silver ◽  
Time Dependencies ◽  
Similarities And Differences

Purpose This paper aims to analyze the sensitivity of different external factors to the returns of the precious metals of gold, silver, platinum and palladium. The goal is to find similarities and differences between the dependencies of every factor to each metal in a time-varying framework. Design/methodology/approach A brief co-integration test for the precious metals is conducted followed by a Kalman smoother approach to study the different sensitivities to the price changes of precious metals. A dynamic time warping (DTW) approach finally compares sensitivities for pairs of precious metals to a specific factor. Findings Results point to strong time-dependencies of the sensitivities, such as a declining relationship of gold to equity volatility. Consistent strong relationships are rare and can be identified for the consumer price index and the dollar. the DTW approach finds higher similarities between platinum and palladium compared to other pairs. Practical implications The similarities and differences of the precious metals can be used by investors and risk managers in portfolio construction processes and risk analyses. Originality/value The focus of the research is put on a broader context of precious metals with different external factors instead of focusing on a single factor, enabling a comparison of differences and similarities of the sensitivities. The analysis via a Kalman Rauch–Tung–Striebel smoother together with a DTW approach has not been conducted before in this way and is able to characterize the dependencies by a single number.

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