Optimum dose of Chaetoceros for controlling methanogenesis to improve power production of microbial fuel cell

The marine algae Chaetoceros contains hexadecatrienoic acid, which suppresses methanogen development and improves the coulombic efficiency (CE) of microbial fuel cell (MFC). To inhibit the methanogens, optimum concentration of marine algae should be added to the anaerobic sludge to enhance the performance of microbial fuel cell. A varying concentration of Chaetoceros ranging from 1 to 20 mg/mL was carried out for pretreatment of anaerobic mix-consortium to suppress methanogens. MFC inoculated with pretreated anaerobic sludge with 10 mg/mL Chaetoceros showed a maximum power density of 21.62 W/m3 and a maximum CE of 37.25%, which was considerably higher than the treatment with other concentrations. At 10 mg/mL concentration, Tafel analysis of anode in MFC showed a higher exchange current density of 66.35 mA/m2 and a lower charge transfer resistance of 0.97 Ω.m2, revealing higher bio-electrochemical activity. The performance of MFC improved when the concentration of Chaetoceros was increased up to 10 mg/mL, but then began to decline as the concentration increased further. Thus, the optimum dose of Chaetoceros to be added in the mix-anaerobic consortiumto optimize the power performance of MFC is determined, which can be carried out in scaled-up MFCs.

Synthesis, Characterization and Photoelectric Properties of Fe2O3 Incorporated TiO2 Photocatalyst Nanocomposites

In the present work we report the sol-gel synthesis of pure TiO2 and (TiO2)1−x(Fe2O3)x nanocomposites with different Fe2O3 contents (x = 0, 0.1, 0.5, and 1.0 for pure TiO2, Fe2O3 incorporated 0.1, 0.5, and pure Fe2O3 which are denoted as PT, 0.1F, 0.5F, and PF, respectively). The structural, morphological, optical, and surface texture of the prepared nanocomposites were characterized using various techniques. The structural studies confirm the strong influence of Fe2O3 contents on the crystallite sizes and dislocation values. The size of the crystallites was increased by the increase in Fe2O3 contents. The bandgap values elucidated from DRS analysis were decreased from 3.15 eV to 1.91 eV with increasing Fe2O3 contents. The N2-Physorption analysis has confirmed the mesoporous nature of the samples with a comparable specific surface area of 35 m2/g. The photoelectrochemical measurements (CV, CA and EIS) were performed to assess the photoelectric properties of the prepared materials. It was found that the PT samples have the highest catalytic activity and photocurrent response compared to other composites. The reduction in current density was as follows: 2.8, 1.65, 1.5 and 0.9 mA/cm2, while the photocurrent response was ca. 800, 450, 45, 35 µA/cm2 for PT, 0.1F, 0.5F and PF samples, respectively. The EIS results showed that the (TiO2)1−x(Fe2O3)x nanocomposites exhibit lower charge transfer resistance than pure titania and hematite samples.

Studies on the deposition of copper in lithium-ion batteries during the deep discharge process

End-of-life lithium-ion batteries represent an important secondary raw material source for nickel, cobalt, manganese and lithium compounds in order to obtain starting materials for the production of new cathode material. Each process step in recycling must be performed in such a way contamination products on the cathode material are avoided or reduced. This paper is dedicated to the first step of each recycling process, the deep discharge of lithium-ion batteries, as a prerequisite for the safe opening and disassembling. If pouch cells with different states of charge are connected in series and deep-discharged together, copper deposition occurs preferably in the cell with the lower charge capacity. The current forced through the cell with a low charge capacity leads, after lithium depletion in the anode and the collapse of the solid-electrolyte-interphase (SEI) to a polarity reversal in which the copper collector of the anode is dissolved and copper is deposited on the cathode surface. Based on measurements of the temperature, voltage drop and copper concentration in the electrolyte at the cell with the originally lower charge capacity, the point of dissolution and incipient deposition of copper could be identified and a model of the processes during deep discharge could be developed.

Numerical Analysis of SnO2/Zn2SnO4/n-CdS/p-CdTe Solar Cell Using the SCAPS-1D Simulation Software

This research includes the use of CdTe in the design of a solar cell. The SCAPS-1D computer program was used to simulate thin cell capacity of CdTe/CdS by numerical analysis with the addition of a buffer layer (Zn2SnO4) to enhance cell efficiency. The thickness of the window layer (n-CdS) was reduced to 25nm with the inclusion of an insulating layer of 50 nm thickness to prevent leakage towards the forward bias with respect to the lower charge carriers. As for the absorber layer thickness (p-CdTe), it varied between 0.5µm and 6µm. The preferable thickness in the absorbent layer was 1.5µm. Different operating temperatures (298K-388K) were used, while the highest conversion efficiency (η=18.43%) was obtained with the rest of the solar cell parameters (Voc=0.967 V, Jsc= 26.66 mA/cm2, FF=71.40%).

PQQ-Aza-Crown Ether Complexes as Biomimetics for Lanthanide and Calcium Dependent Alcohol Dehydrogenases

<div>Understanding the role of metal ions in biology can lead to the development of new catalysts for</div><div>several industrially important transformations. Lanthanides are the most recent group of metal ions</div><div>that have been shown to be important in biology i.e. - in quinone-dependent methanol</div><div>dehydrogenases (MDH). Here we evaluate a pyrroloquinoline quinone and 1-aza-15-crown-5 based</div><div>ligand platform as scaffold for Ca2+ , Ba2+ , La3+ and Lu3+ biomimetics of MDH and we evaluate the</div><div>importance of ligand design, charge, size, counterions and base for the alcohol oxidation reaction</div><div>using NMR spectroscopy. In addition, we report a new straightforward synthetic route (3 steps</div><div>instead of 11 and 33% instead of 0.6% yield) for biomimetic ligands based on PQQ. We show that</div><div>when studying biomimetics for MDH, larger metal ions and those with lower charge in this case</div><div>promote the dehydrogenation reaction more effectively and that this is likely an effect of the ligand</div><div>design which must be considered when studying biomimetics. To gain more information on the</div><div>structures and impact of counterions of the complexes, we performed collision induced dissociation</div><div>(CID) experiments and observe that the nitrates are more tightly bound than the triflates. To resolve</div><div>the structure of the complexes in the gas phase we combined DFT-calculations and ion mobility</div><div>measurements (IMS). Furthermore, we characterized the obtained complexes and reaction mixtures</div><div>using Electron Paramagnetic Resonance (EPR) spectroscopy and show the emergence of a quinone-</div><div>based radical during the reaction with substrate and base.</div>

PQQ-Aza-Crown Ether Complexes as Biomimetics for Lanthanide and Calcium Dependent Alcohol Dehydrogenases

<div>Understanding the role of metal ions in biology can lead to the development of new catalysts for</div><div>several industrially important transformations. Lanthanides are the most recent group of metal ions</div><div>that have been shown to be important in biology i.e. - in quinone-dependent methanol</div><div>dehydrogenases (MDH). Here we evaluate a pyrroloquinoline quinone and 1-aza-15-crown-5 based</div><div>ligand platform as scaffold for Ca2+ , Ba2+ , La3+ and Lu3+ biomimetics of MDH and we evaluate the</div><div>importance of ligand design, charge, size, counterions and base for the alcohol oxidation reaction</div><div>using NMR spectroscopy. In addition, we report a new straightforward synthetic route (3 steps</div><div>instead of 11 and 33% instead of 0.6% yield) for biomimetic ligands based on PQQ. We show that</div><div>when studying biomimetics for MDH, larger metal ions and those with lower charge in this case</div><div>promote the dehydrogenation reaction more effectively and that this is likely an effect of the ligand</div><div>design which must be considered when studying biomimetics. To gain more information on the</div><div>structures and impact of counterions of the complexes, we performed collision induced dissociation</div><div>(CID) experiments and observe that the nitrates are more tightly bound than the triflates. To resolve</div><div>the structure of the complexes in the gas phase we combined DFT-calculations and ion mobility</div><div>measurements (IMS). Furthermore, we characterized the obtained complexes and reaction mixtures</div><div>using Electron Paramagnetic Resonance (EPR) spectroscopy and show the emergence of a quinone-</div><div>based radical during the reaction with substrate and base.</div>

Surface-Induced Dissociation of Anionic vs Cationic Native-like Protein Complexes

<p>Characterizing protein-protein interactions, stoichiometries, and subunit connectivity is key to understanding how subunits assemble in biologically relevant multi-subunit protein complexes. Native mass spectrometry (nMS) has emerged as a powerful tool to study protein complexes due to its low sample requirements and tolerance for heterogeneity. For such nMS studies, positive mode ionization is routinely used and charge reduction, through the addition of solution additives, is often used, as the resulting lower charge states are often more compact and considered more native like. When studied with surface-induced dissociation, charge reduced complexes often give increased structural information over their “normal-charged” counter parts. A disadvantage of charge-reduction is that increased adduction, and hence peak broadening, is often observed when charge-reducing solution additives are present. Recent studies have shown that protein complexes ionized using negative mode generally form in lower charge states relative to positive mode. Here we demonstrate that the lower charged protein complex anions, activated by SID in an ultrahigh mass range Orbitrap mass spectrometer, fragment in a manner consistent with their solved structure, hence providing substructural information. Negative mode ionization in ammonium acetate offers the advantage of charge reduction without the peak broadening associated with solution phase charge reduction additives and provides direct structural information, when coupled with SID. </p>

Surface-Induced Dissociation of Anionic vs Cationic Native-like Protein Complexes

<p>Characterizing protein-protein interactions, stoichiometries, and subunit connectivity is key to understanding how subunits assemble in biologically relevant multi-subunit protein complexes. Native mass spectrometry (nMS) has emerged as a powerful tool to study protein complexes due to its low sample requirements and tolerance for heterogeneity. For such nMS studies, positive mode ionization is routinely used and charge reduction, through the addition of solution additives, is often used, as the resulting lower charge states are often more compact and considered more native like. When studied with surface-induced dissociation, charge reduced complexes often give increased structural information over their “normal-charged” counter parts. A disadvantage of charge-reduction is that increased adduction, and hence peak broadening, is often observed when charge-reducing solution additives are present. Recent studies have shown that protein complexes ionized using negative mode generally form in lower charge states relative to positive mode. Here we demonstrate that the lower charged protein complex anions, activated by SID in an ultrahigh mass range Orbitrap mass spectrometer, fragment in a manner consistent with their solved structure, hence providing substructural information. Negative mode ionization in ammonium acetate offers the advantage of charge reduction without the peak broadening associated with solution phase charge reduction additives and provides direct structural information, when coupled with SID. </p>

Surface-Induced Dissociation of Anionic vs Cationic Native-like Protein Complexes

<p>Characterizing protein-protein interactions, stoichiometries, and subunit connectivity is key to understanding how subunits assemble in biologically relevant multi-subunit protein complexes. Native mass spectrometry (nMS) has emerged as a powerful tool to study protein complexes due to its low sample requirements and tolerance for heterogeneity. For such nMS studies, positive mode ionization is routinely used and charge reduction, through the addition of solution additives, is often used, as the resulting lower charge states are often more compact and considered more native like. When studied with surface-induced dissociation, charge reduced complexes often give increased structural information over their “normal-charged” counter parts. A disadvantage of charge-reduction is that increased adduction, and hence peak broadening, is often observed when charge-reducing solution additives are present. Recent studies have shown that protein complexes ionized using negative mode generally form in lower charge states relative to positive mode. Here we demonstrate that the lower charged protein complex anions, activated by SID in an ultrahigh mass range Orbitrap mass spectrometer, fragment in a manner consistent with their solved structure, hence providing substructural information. Negative mode ionization in ammonium acetate offers the advantage of charge reduction without the peak broadening associated with solution phase charge reduction additives and provides direct structural information, when coupled with SID. </p>