scholarly journals Single Step 2-Port Device De-Embedding Algorithm for Fixture-DUT-Fixture Network Assembly

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1275
Author(s):  
Simone Scafati ◽  
Enza Pellegrino ◽  
Francesco de Paulis ◽  
Carlo Olivieri ◽  
James Drewniak ◽  
...  
Keyword(s):  
Standard Technique ◽  
Single Step ◽  
Scattering Parameters ◽  
Linear Set ◽  
S Parameter ◽  
Parameter Conversion ◽  
Before And After ◽  
One Step ◽  
Typical Measurement

The de-embedding of measurement fixtures is relevant for an accurate experimental characterization of radio frequency and digital electronic devices. The standard technique consists in removing the effects of the measurement fixtures by the calculation of the transfer scattering parameters (T-parameters) from the available measured (or simulated) global scattering parameters (S-parameters). The standard de-embedding is achieved by a multiple steps process, involving the S-to-T and subsequent T-to-S parameter conversion. In a typical measurement setup, two fixtures are usually placed before and after the device under test (DUT) allowing the connection of the device to the calibrated vector network analyzer coaxial ports. An alternative method is proposed in this paper: it is based on the newly developed multi-network cascading algorithm. The matrices involved in the fixture-DUT-fixture cascading gives rise to a non-linear set of equations that is in one step analytically solved in closed form, obtaining a unique solution. The method is shown to be effective and at least as accurate as the standard multi-step de-embedding one.

scholarly journals Fabrication and Characterization of Cu2ZnSnSe4 Thin-Film Solar Cells using a Single-Stage Co-Evaporation Method: Effects of Film Growth Temperatures on Device Performances

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1316 ◽  
Author(s):  
Muhammad Rehan ◽  
Hyeonmin Jeon ◽  
Yunae Cho ◽  
Ara Cho ◽  
Kihwan Kim ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Film Growth ◽  
Critical Factor ◽  
Single Step ◽  
High Quality ◽  
Evaporation Method ◽  
Earth Abundant ◽  
Method Effects ◽  
One Step

Kesterite-structured Cu2ZnSnSe4 (CZTSe) is considered as one of the Earth-abundant and non-toxic photovoltaic materials. CZTSe films have been prepared using a single-step co-evaporation method at a relatively low temperature (i.e., below 500 °C). Due to the volatile nature of tin-selenide, the control over substrate temperature (i.e., growth temperature) is very important in terms of the deposition of high-quality CZTSe films. In this regard, the effects of growth temperatures on the CZTSe film morphology were investigated. The suitable temperature range to deposit CZTSe films with Cu-poor and Zn-rich compositions was 380–480 °C. As the temperature increased, the surface roughness of the CZTSe film decreased, which could improve p/n junction properties and associated device performances. Particularly, according to capacitance-voltage (C-V) and derived-level capacitance profiling (DLCP) measurements, the density of interfacial defects of CZTSe film grown at 480 °C showed the lowest value, of the order of ~3 × 1015 cm−3. Regardless of applied growth temperatures, the formation of a MoSe2 layer was rarely observed, since the growth temperature was not high enough to have a reaction between Mo back contact layers and CZTSe absorber layers. As a result, the photovoltaic (PV) device with CZTSe film grown at 480 °C yielded the best power conversion efficiency of 6.47%. It is evident that the control over film growth temperature is a critical factor for obtaining high-quality CZTSe film prepared by one-step process.

scholarly journals Characterization of PSII–LHCII supercomplexes isolated from pea thylakoid membrane by one-step treatment with α- and β-dodecyl- d -maltoside

2012 ◽  
Vol 367 (1608) ◽  
pp. 3389-3399 ◽  
Author(s):  
Simone Barera ◽  
Cristina Pagliano ◽  
Tillmann Pape ◽  
Guido Saracco ◽  
James Barber
Keyword(s):  
Thylakoid Membrane ◽  
Alkyl Chain ◽  
Single Step ◽  
Head Group ◽  
Structural Studies ◽  
Jan Anderson ◽  
One Step ◽  
Optimized Conditions ◽  
Keith Boardman

It was the work of Jan Anderson, together with Keith Boardman, that showed it was possible to physically separate photosystem I (PSI) from photosystem II (PSII), and it was Jan Anderson who realized the importance of this work in terms of the fluid-mosaic model as applied to the thylakoid membrane. Since then, there has been a steady progress in the development of biochemical procedures to isolate PSII and PSI both for physical and structural studies. Dodecylmaltoside (DM) has emerged as an effective mild detergent for this purpose. DM is a glucoside-based surfactant with a bulky hydrophilic head group composed of two sugar rings and a non-charged alkyl glycoside chain. Two isomers of this molecule exist, differing only in the configuration of the alkyl chain around the anomeric centre of the carbohydrate head group, axial in α-DM and equatorial in β-DM. We have compared the use of α-DM and β-DM for the isolation of supramolecular complexes of PSII by a single-step solubilization of stacked thylakoid membranes isolated from peas. As a result, we have optimized conditions to obtain homogeneous preparations of the C 2 S 2 M 2 and C 2 S 2 supercomplexes following the nomenclature of Dekker & Boekema (2005 Biochim. Biophys. Acta 1706 , 12–39). These PSII–LHCII supercomplexes were subjected to biochemical and structural analyses.

An Electron Microscope Study of Interdiffusion and Compound Formation in Ta-Au Thin Films

1973 ◽  
Vol 31 ◽  
pp. 32-33 ◽  
Author(s):  
T. C. Tisone ◽  
S. Lau
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Thermally Grown Oxide ◽  
Ion Milling ◽  
Compound Formation ◽  
Technology Application ◽  
Transmission Electron ◽  
Before And After ◽  
Au Thin Films

In a study of the properties of a Ta-Au metallization system for thin film technology application, the interdiffusion between Ta(bcc)-Au, βTa-Au and Ta2M-Au films was studied. Considered here is a discussion of the use of the transmission electron microscope(TEM) in the identification of phases formed and characterization of the film microstructures before and after annealing.The films were deposited by sputtering onto silicon wafers with 5000 Å of thermally grown oxide. The film thicknesses were 2000 Å of Ta and 2000 Å of Au. Samples for TEM observation were prepared by ultrasonically cutting 3mm disks from the wafers. The disks were first chemically etched from the silicon side using a HNO3 :HF(19:5) solution followed by ion milling to perforation of the Au side.

Synthesis of Polycycles and Oxacycles by Tandem Metathesis of endo–norbornene Derivatives

Synthesis ◽  
2021 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Sunil Pulletikurti ◽  
Ambareen Fatma ◽  
gopal dhangar ◽  
gonna somu Naidu
Keyword(s):  
Natural Products ◽  
Metal Complex ◽  
Carbonyl Group ◽  
Single Step ◽  
Time Dependent ◽  
Computational Studies ◽  
Nmr Studies ◽  
Tricyclic Compounds ◽  
One Step ◽  
Norbornene Derivatives

Here, we have demonstrated that the presence of a carbonyl group at C7 position is preventing the olefin metathesis of endo-norbornene derivatives due to the complexation of the metal alkylidene. Time-dependent NMR studies showed the presence of new proton signals in the metal alkylidene region, which indicate the formation of metal complex with the carbonyl group of the substrate. These observations were further proved by ESI-MS analysis. Whereas, computational studies provided that the catalyst was interacting with the C7 carbonyl group and aligned perpendicular to that of norbornene olefin. Later, these endo-keto norbornene derivatives were reduced to hydroxyl derivatives diastereoselectively. Ring-rearrangement metathesis (RRM) of these hydroxyl derivatives, produced the [6/5/6], and [5/6/5] carbo-tricyclic cores of the natural products in one step. Whereas the RRM of O-allyl derivatives, delivered the oxa-tricyclic compounds in a single step with excellent yields.

A p-Type PbS Quantum Dot Ink with Improved Stability for Solution Processable Optoelectronics

2021 ◽  
Author(s):  
Fiaz Ahmed ◽  
John Hardin Dunlap ◽  
Perry J. Pellechia ◽  
Andrew Greytak
Keyword(s):  
Quantum Dot ◽  
Ligand Exchange ◽  
Chemical Characterization ◽  
Single Step ◽  
Improved Stability ◽  
Solution Processable ◽  
P Type ◽  
Pbs Quantum Dot

A highly stable p-type PbS-QDs ink is prepared using a single-step biphasic ligand exchange route, overcoming instability encountered in previous reports. Chemical characterization of the ink reveals 3-mercaptopriopionic acid (MPA)...

scholarly journals Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1757
Author(s):  
Yesica Vicente-Martínez ◽  
Manuel Caravaca ◽  
Antonio Soto-Meca ◽  
Miguel Ángel Martín-Pereira ◽  
María del Carmen García-Onsurbe
Keyword(s):  
Magnetic Nanoparticles ◽  
Nitrate Content ◽  
Adsorption Efficiency ◽  
Experimental Conditions ◽  
Dependent Behavior ◽  
Before And After ◽  
Naoh Solution ◽  
High Concentrations ◽  
Interference Studies

This paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe3O4@AgNPs) were synthesized and used as an adsorbent of nitrates. Experimental conditions, including the pH, adsorbent and adsorbate dose, temperature and contact time, were analyzed to obtain the highest adsorption efficiency for different concentration of nitrates in water. A maximum removal efficiency of 100% was reached for 2, 5, 10 and 50 mg/L of nitrate at pH = 5, room temperature, and 50, 100, 250 and 500 µL of Fe3O4@AgNPs, respectively. The characterization of the adsorbent, before and after adsorption, was performed by energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. Nitrates can be desorbed, and the adsorbent can be reused using 500 µL of NaOH solution 0.01 M, remaining unchanged for the first three cycles, and exhibiting 90% adsorption efficiency after three regenerations. A deep study on equilibrium isotherms reveals a pH-dependent behavior, characterized by Langmuir and Freundlich models at pH = 5 and pH = 1, respectively. Thermodynamic studies were consistent with physicochemical adsorption for all experiments but showed a change from endothermic to exothermic behavior as the temperature increases. Interference studies of other ions commonly present in water were carried out, enabling this procedure as very selective for nitrate ions. In addition, the method was applied to real samples of seawater, showing its ability to eliminate the total nitrate content in eutrophized waters.

scholarly journals Synthesis and Polymerization Kinetics of Rigid Tricyanate Ester

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1686
Author(s):  
Andrey Galukhin ◽  
Roman Nosov ◽  
Ilya Nikolaev ◽  
Elena Melnikova ◽  
Daut Islamov ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Single Step ◽  
Polymerization Kinetics ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Diffusion Controlled ◽  
Polymerization Product ◽  
The One ◽  
Kinetics Of

A new rigid tricyanate ester consisting of seven conjugated aromatic units is synthesized, and its structure is confirmed by X-ray analysis. This ester undergoes thermally stimulated polymerization in a liquid state. Conventional and temperature-modulated differential scanning calorimetry techniques are employed to study the polymerization kinetics. A transition of polymerization from a kinetic- to a diffusion-controlled regime is detected. Kinetic analysis is performed by combining isoconversional and model-based computations. It demonstrates that polymerization in the kinetically controlled regime of the present monomer can be described as a quasi-single-step, auto-catalytic, process. The diffusion contribution is parameterized by the Fournier model. Kinetic analysis is complemented by characterization of thermal properties of the corresponding polymerization product by means of thermogravimetric and thermomechanical analyses. Overall, the obtained experimental results are consistent with our hypothesis about the relation between the rigidity and functionality of the cyanate ester monomer, on the one hand, and its reactivity and glass transition temperature of the corresponding polymer, on the other hand.

scholarly journals Exploiting the Amazing Diversity of Natural Source-Derived Polysaccharides: Modern Procedures of Isolation, Engineering, and Optimization of Antiviral Activities

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 136
Author(s):  
Bimalendu Ray ◽  
Martin Schütz ◽  
Shuvam Mukherjee ◽  
Subrata Jana ◽  
Sayani Ray ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Antiviral Drug ◽  
Natural Source ◽  
Target Interaction ◽  
Charge Densities ◽  
Linkage Pattern ◽  
Naturally Occurring ◽  
Antiviral Activities ◽  
One Step

Naturally occurring polysaccharide sulfates are highly diverse, owning variations in the backbone structure, linkage pattern and stereochemistry, branching diversity, sulfate content and positions of sulfate group(s). These structural characteristics bring about diverse sulfated polymers with dissimilar negative charge densities and structure–activity relationships. Herein, we start with a short discussion of techniques needed for extraction, purification, chemical sulfation, and structural characterization of polysaccharides. Processes of isolation and sulfation of plant-derived polysaccharides are challenging and usually involve two steps. In this context, we describe an integrated extraction-sulfation procedure that produces polysaccharide sulfates from natural products in one step, thereby generating additional pharmacological activities. Finally, we provide examples of the spectrum of natural source-derived polysaccharides possessing specific features of bioactivity, in particular focusing on current aspects of antiviral drug development and drug–target interaction. Thus, the review presents a detailed view on chemically engineered polysaccharides, especially sulfated derivatives, and underlines their promising biomedical perspectives.

A Single Step Synthesis By Mechanical Alloying and Characterization of Nanostructured Fe2B of High Magnetic Moment

2021 ◽  
Author(s):  
Telem Şimşek ◽  
Barış Avar ◽  
Tuncay Şimşek ◽  
Buğra Yıldız ◽  
Arun K. Chattopadhyay ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Magnetic Moment ◽  
Single Step ◽  
High Magnetic Moment
Sign in / Sign up

Export Citation Format

Share Document