Symmetrized Photoinitiated Electron Flow within the [Myoglobin:Cytochrome b5] Complex on Singlet and Triplet Time Scales: Energetics vs Dynamics
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bio-inspired↗
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Loss of virulence in NAD(P)H cytochrome b5 oxidoreductase deficient Leishmania major
Highlights: • Linoleate is an absolute requirement for Leishmania promastigote survival. • Linoleate deficient Leishmania shows avirulence. • Parasite derived linoleate inactivates NF-κB signaling pathway. • Leishmanial linoleate inhibits both COX-2 and TNF-α expression in macrophage. • Supplementing external linoleate reverts most of the observed phenotypes. Leishmania promastigotes have the ability to synthesize essential polyunsaturated fatty acids de novo and can grow in lipid free media. Recently, we have shown that NAD(P)H cytochrome b5 oxidoreductase (Ncb5or) enzyme in Leishmania acts as the redox partner for Δ12 fatty acid desaturase, which catalyses the conversion of oleate to linoleate. So far, the exact role of Leishmania derived linoleate synthesis is still incomplete in the literature. The viability assay by flow cytometry as well as microscopic studies suggests that linoleate is an absolute requirement for Leishmania promastigote survival in delipidated media. Western blot analysis suggested that infection with log phase linoleate deficient mutant (KO) results in increased level of NF-κBp65, IκB and IKKβ phosphorylation in RAW264.7 cells. Similarly, the log phase KO infected RAW264.7 cells show dramatic increment of COX-2 expression and TNF-α secretion, compared to control or Ncb5or complement (CM) cell lines. The activation of inflammatory signaling pathways by KO mutant is significantly reduced when the RAW264.7 cells are pre-treated with BSA bound linoleate. Together, these findings confirmed that the leishmanial linoleate inhibits both COX-2 and TNF-α expression in macrophage via the inactivation of NF-κB signaling pathway. The stationary phase of KO promastigotes shows avirulence after infection in macrophages as well as inoculation into BALB/c mice; whereas CM cell lines show virulence. Collectively, these data provide strong evidence that de novo linoleate synthesis in Leishmania is an essential for parasite survival at extracellular promastigote stage as well as intracellular amastigote stage.
60 APPLIED LIFE SCIENCES↗
Cytochrome b5 diversity in green lineages preceded the evolution of syringyl lignin biosynthesis
Abstract Lignin production marked a milestone in vascular plant evolution, and the emergence of syringyl (S) lignin is lineage specific. S-lignin biosynthesis in angiosperms, mediated by ferulate 5-hydroxylase (F5H, CYP84A1), has been considered a recent evolutionary event. F5H uniquely requires the cytochrome b5 protein CB5D as an obligatory redox partner for catalysis. However, it remains unclear how CB5D functionality originated and whether it coevolved with F5H. We reveal here the ancient evolution of CB5D-type function supporting F5H-catalyzed S-lignin biosynthesis. CB5D emerged in charophyte algae, the closest relatives of land plants, and is conserved and proliferated in embryophytes, especially in angiosperms, suggesting functional diversification of the CB5 family before terrestrialization. A sequence motif containing acidic amino residues in Helix 5 of the CB5 heme-binding domain contributes to the retention of CB5D function in land plants but not in algae. Notably, CB5s in the S-lignin–producing lycophyte Selaginella lack these residues, resulting in no CB5D-type function. An independently evolved S-lignin biosynthetic F5H (CYP788A1) in Selaginella relies on NADPH-dependent cytochrome P450 reductase as sole redox partner, distinct from angiosperms. These results suggest that angiosperm F5Hs coopted the ancient CB5D, forming a modern cytochrome P450 monooxygenase system for aromatic ring meta-hydroxylation, enabling the reemergence of S-lignin biosynthesis in angiosperms.
59 BASIC BIOLOGICAL SCIENCES↗
Materials Data on B5(H2N)2 by Materials Project
BN2(BH)4 is Cubic alpha N2-derived structured and crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of eight 13730-91-1 molecules and thirty-two boranediylradical molecules.
36 MATERIALS SCIENCE↗
Faster Interprotein Electron Transfer in a [Myoglobin, b5] Complex with a Redesigned Interface
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bio-inspired↗
Dynamic Interaction Between Membrane-Bound Full-Length Cytochrome P450 and Cytochrome b 5 Observed by Solid-State NMR Spectroscopy
Microsomal monoxygenase enzymes of the cytochrome-P450 family are found in all biological kingdoms, and play a central role in the breakdown of metabolic as well as xenobiotic, toxic and 70% of the drugs in clinical use. Full-length cytochrome-b5 has been shown to be important for the catalytic activity of cytochrome-P450. Despite the significance in understanding the interactions between these two membrane-associated proteins, only limited high-resolution structural information on the full-length cytochrome-P450 and the cytochromes-b5-P450 complex is available. Here, we report a structural study on a functional ,72-kDa cytochromes-b5-P450 complex embedded in magnetically-aligned bicelles without having to freeze the sample. Functional and solid-state NMR (Nuclear Magnetic Resonance) data reveal interactions between the proteins in fluid lamellar phase bilayers. In addition, our data infer that the backbone structure and geometry of the transmembrane domain of cytochrome-b5 is not significantly altered due to its interaction with cytochrome-P450, whereas the mobility of cytochrome-b5 is considerably reduced.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Characterization of deep level defects and thermally stimulated depolarization phenomena in La-doped TlInS{sub 2} layered semiconductor
Lanthanum-doped high quality TlInS{sub 2} (TlInS{sub 2}:La) ferroelectric-semiconductor was characterized by photo-induced current transient spectroscopy (PICTS). Different impurity centers are resolved and identified. Analyses of the experimental data were performed in order to determine the characteristic parameters of the extrinsic and intrinsic defects. The energies and capturing cross section of deep traps were obtained by using the heating rate method. The observed changes in the Thermally Stimulated Depolarization Currents (TSDC) near the phase transition points in TlInS{sub 2}:La ferroelectric-semiconductor are interpreted as a result of self-polarization of the crystal due to the internal electric field caused by charged defects. The TSDC spectra show the depolarization peaks, which are attributed to defects of dipolar origin. These peaks provide important information on the defect structure and localized energy states in TlInS{sub 2}:La. Thermal treatments of TlInS{sub 2}:La under an external electric field, which was applied at different temperatures, allowed us to identify a peak in TSDC which was originated from La-dopant. It was established that deep energy level trap BTE43, which are active at low temperature (T ≤ 156 K) and have activation energy 0.29 eV and the capture cross section 2.2 × 10{sup −14} cm{sup 2}, corresponds to the La dopant. According to the PICTS results, the deep level trap center B5 is activated in the temperature region of incommensurate (IC) phases of TlInS{sub 2}:La, having the giant static dielectric constant due to the structural disorders. From the PICTS simulation results for B5, native deep level trap having an activation energy of 0.3 eV and the capture cross section of 1.8 × 10{sup −16} cm{sup 2} were established. A substantial amount of residual space charges is trapped by the deep level localized energy states of B5 in IC-phase. While the external electric field is applied, permanent dipoles, which are originated from the charged B5 deep level defects, are aligned in the direction of the applied electric field and the equilibrium polarization can be reached in a relatively short time. When the polarization field is maintained, while cooling the temperature of sample to a sufficiently low degrees, the relaxation times of the aligned dipoles drastically increases. Practically, frozen internal electric field or electrets states remain inside the TlInS{sub 2}:La when the applied bias field is switched off. The influence of deep level defects on TSDC spectra of TlInS{sub 2}:La has been revealed for the first time.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
Base-pair opening dynamics of the microRNA precursor pri-miR156a affect temperature-responsive flowering in Arabidopsis
Internal and environmental cues, including ambient temperature changes, regulate the timing of flowering in plants. Arabidopsis miR156 represses flowering and plays an important role in the regulation of temperature-responsive flowering. However, the molecular basis of miR156 processing at lower temperatures remains largely unknown. Here, we performed nuclear magnetic resonance studies to investigate the base-pair opening dynamics of model RNAs at 16 °C and investigated the in vivo effects of the mutant RNAs on temperature-responsive flowering. The A9C and A10CG mutations in the B5 bulge of the lower stem of pri-miR156a stabilized the C15∙G98 and U16∙A97 base-pairs at the cleavage site of pri-miR156a at 16 °C. Consistent with this, production of mature miR156 was severely affected in plants overexpressing the A9C and A10CG constructs and these plants exhibited almost no delay in flowering at 16 °C. The A10G and A9AC mutations did not strongly affect C15∙G98 and U16∙A97 base-pairs at 16 °C, and plants overexpressing A10G and A9AC mutants of miR156 produced more mature miR156 than plants overexpressing the A9C and A10CG mutants and showed a strong delay in flowering at 16 °C. Interestingly, the A9AC mutation had distinct effects on the opening dynamics of the C15∙G98 and U16∙A97 base-pairs between 16 °C and 23 °C, and plants expressing the A9AC mutant miR156 showed only a moderate delay in flowering at 16 °C. Based on these results, we propose that fine-tuning of the base-pair stability at the cleavage site is essential for efficient processing of pri-miR156a at a low temperature and for reduced flowering sensitivity to ambient temperature changes. - Highlights: • A mutation in pri-miR156a B5 affected base-pairing stability at the cleavage site. • Mutations in the B5 bulge increased base-pair stabilities and decreased miR156. • The A9AC mutation affected opening dynamics between 16 and 23 °C. • Cleavage site base-pair stabilities reflected miR156 levels and flowering time.
60 APPLIED LIFE SCIENCES↗
B2, B7 or B10: Which palm-based blend mandate wise to be chosen in Malaysia?
The diminishing fossil energy resources, coupled with heightened interest in the abatement of greenhouse gas emissions and concerns about energy security have motivated Malaysia to produce palm-based biodiesel and it has been started to be exported since 2006. In line with this issue, the government in Malaysia launched the palm-based biodiesel blending mandate of five percent (B5) in the federal administration of Putrajaya on 1{sup st} June 2011. This was then followed by four states: Malacca on July 11, Negeri Sembilan on August 1, Kuala Lumpur on September 1 and Selangor on October 1 of the same year but it is yet to be implemented nationwide. However what is the wise blend mandate to be chosen? Thus, this paper seeks to examine the possible impact of various blend mandates implementation (B2, B7 and B10) on the palm oil industry market variables (stock and price) since the main aim of biodiesel industry in Malaysia is to reduce domestic palm oil stock to below one million tones and provide a floor price to support Crude Palm Oil (CPO) prices at RM2,000 per tonne. A structural econometric model consisting of nine structural equations and three identities was proposed in this study. The model has been estimated by two stage least squares (2SLS) method using annual data for the period 1976-2013. The study indicates that counterfactual simulation of a decrease from B5 to B2 predicts a decrease (11.2 per cent) in CPO domestic consumption for biodiesel usage, 731.02 per cent reduction in CPO stock and an increase of 27.41 percent in domestic price of CPO. However the increase in the blend mandate from B5 to B7 and B10 suggest that domestic consumption of CPO for biodiesel purpose increase 7.40 and 18.55 percent respectively. The interesting findings in this study suggest that no matter whether Malaysian government increase or decrease the blend mandate the increase in the price of CPO are the same with an increase of is 27.41 percent. Hence, this study suggests that the lower blend mandate is the most favourable on.+-e compared to increasing it in this short period due to high production cost of CPO prices. However, future study on economic feasibility of palm-based biodiesel has to be conducted to support this study.
29 ENERGY PLANNING, POLICY, AND ECONOMY↗
Materials Data on B10Pb4O21 by Materials Project
(B5(PbO5)2)4O2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional and consists of two water molecules and one B5(PbO5)2 framework. In the B5(PbO5)2 framework, there are five inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.35–1.39 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.35–1.38 Å. In the third B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There is two shorter (1.47 Å) and two longer (1.49 Å) B–O bond length. In the fourth B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.51 Å. In the fifth B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.46–1.54 Å. There are two inequivalent Pb3+ sites. In the first Pb3+ site, Pb3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Pb–O bond distances ranging from 2.37–2.99 Å. In the second Pb3+ site, Pb3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Pb–O bond distances ranging from 2.33–2.93 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two B3+ and two Pb3+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two B3+ and one Pb3+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two B3+ and one Pb3+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two B3+ and two Pb3+ atoms. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two B3+ and one Pb3+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Pb3+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two B3+ and one Pb3+ atom. In the eighth O2- site, O2- is bonded in a bent 120 degrees geometry to two B3+ and two Pb3+ atoms. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to two B3+ and one Pb3+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two B3+ and one Pb3+ atom.
36 MATERIALS SCIENCE↗
Biocatalytic system for comparatively assessing the functional association of monolignol cytochrome P450 monooxygenases with their redox partners
Lignin is a complex heterogenous polymer derived from oxidative radical polymerization of three monolignols, i.e., p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. These lignin monomeric precursors structurally differ in their methoxy groups of the benzene rings. In phenylpropanoid-monolignol biosynthetic pathway, the endoplasmic reticulum (ER)-resident cytochrome P450 monooxygenases, cinnamate 4-hydroxylase, coumaroyl ester 3´-hydroxylase and ferulate 5-hydroxylase, establish the key structural characteristics of monolignols. The catalysis of cytochrome P450 monooxygenase requires reducing power, which is supplied by the ER electron transfer chains, composed of cytochrome P450 oxidoreductase (CPR), cytochrome b5 reductase (CBR) and/or cytochrome b5 protein (CB5), from cofactor NADPH or NADH. While NADPH-dependent CPR serves as the typical electron donor for most P450 enzymes, in some cases, the CBR-CB5 or CPR-CB5 electron transfer system also transfers electrons to the terminal P450 enzymes. There are tremendous studies focusing on the discovery and characterization of cytochrome P450 monooxygenases. However, very limited attention has been paid to the versatility and the roles of electron transfer components in the P450 catalytic system. Due to the membrane-residence property of both P450 enzymes and electron transfer components, it is challenging to establish an effective experimental system to evaluate the functional association of P450s with their redox partners. This chapter describes a yeast cell biocatalytic system and the related experimental procedures for comparatively assessing the functional relationship of monolignol biosynthetic P450 enzymes and different redox partners in their catalysis.
59 BASIC BIOLOGICAL SCIENCES↗
Multi-scale boron penetration toward stabilizing nickel-rich cathode
Nickel-rich layered oxides LiNi x Co y Mn 1-x-y O 2 (x≥0.8) have been recognized as the preferred cathode materials to develop lithium-ion batteries with high energy density (>300Wh kg -1 ). However, the poor cycling stability and rate capability stemming from intergranular cracks and sluggish kinetics hinder their commercialization. To address such issues, a multi-scale boron penetration strategy is designed and applied on the polycrystalline LiNi 0.83 Co 0.11 Mn 0.06 O 2 particles that are pre-treated with pore construction. The lithium-ion conductive lithium borate in grain gaps functions as the grain binder that can bear the strain/stress from anisotropic contraction/expansion, and provides more pathways for lithium-ion diffusion. As a result, the intergranular cracks are ameliorated and the lithium-ion diffusion kinetics is improved. Moreover, the coating layer separates the sensitive cathode surface and electrolyte, helping to suppress the parasitic reactions and related gas evolution. In addition, the enhanced structural stability is acquired by strong B-O bonds with trace boron doping. As a result, the boron-modified sample with an optimized boron content of 0.5% (B5-NCM) exhibits a higher initial discharge capacity of 205.5mAh g -1 at 0.1C (1C=200mA g -1 ) and improved capacity retention of 81.7% after 100 cycles at 1C. Furthermore, the rate performance is distinctly enhanced by high lithium-ion conductive LBO (175.6mAh g -1 for B5-NCM and 154.6mAh g -1 for B0-NCM at 5C).
25 ENERGY STORAGE↗
New molecular components of high and low affinity iron import systems in Drosophila
The high abundance and molecular versatility of iron have led to its universal presence in biological systems, yet its absorption is exceptionally challenging. Animals and yeasts use divalent metal transporters to import iron, but yeasts also employ the multicopper oxidase Fet3p for high-affinity iron uptake when iron-starved. Using long-term iron depletion in Drosophila, we identified four components involved in iron absorption: Multicopper oxidase-4 (Mco4), a Fet3p ortholog, is essential for surviving iron starvation, whereas the cytochrome b561 enzymes Fire (Ferric Iron Reductase) and Fire-like, as well as cytochrome b5 protein Firewood, are required for iron absorption under normal conditions. This study reports the presence of a high-affinity iron uptake system in an animal, a cytochrome b5 electron donor for ferric iron reduction, and intestinal ferric reductases, and provides a valuable resource for further exploration of genes involved in iron homeostasis, transport, and absorption.
Iron↗
Effect of first and second generation biodiesel blends on engine performance and emission
The biodiesel is a potential source of alternative fuel which can be used at different proportions with diesel fuel. This study experimentally investigated the effect of blend percentage on diesel engine performance and emission using first generation (soybean) and second generation (waste cooking) biodiesel. The characterization of the biodiesel was done according to ASTM and EN standards and compared with ultralow sulfur diesel (ULSD) fuel. A multi-cylinder test bed engine coupled with electromagnetic dynamometer and 5 gas analyzer were used for engine performance and emission test. The investigation was made using B5, B10 and B15 blends for both biodiesels. The study found that brake power (BP) and brake torque (BT) slightly decreases and brake specific fuel consumption (BSFC) slightly increases with an increase in biodiesel blends ratio. Besides, a significant reduction in exhaust emissions (except NO{sub x} emission) was found for both biodiesels compared to ULSD. Soybean biodiesel showed better engine performance and emissions reduction compared with waste cooking biodiesel. However, NO{sub x} emission for B5 waste cooking biodiesel was lower than soybean biodiesel.
09 BIOMASS FUELS↗
Pyrethroid Activity-Based Probes for Profiling Cytochrome P450 Activities Associated with Insecticide Interactions
Pyrethroid insecticides are used to control a diverse spectrum of diseases spread by arthropods. We have developed a suite of pyrethroid mimetic activity based probes (PyABPs) to selectively label and identify P450s associated with pyrethroid metabolism. The probes were screened against pyrethroid metabolizing and non-metabolizing mosquito P450s, as well as rodent microsomes to measure labeling specificity, plus CPR and b5 knockout mouse livers to validate P450 activation and establish the role for b5 in probe activation. Using a deltamethrin mimetic PyABP we were able to profile active enzymes in rat liver microsomes and identify pyrethroid metabolizing enzymes in the target tissue. The most reactive enzyme was a P450, CYP2C11, which is known to metabolize deltamethrin. Furthermore, several other pyrethroid metabolizers were identified (CYPs 2C6, 3A4, 2C13 and 2D1) along with related detoxification enzymes, notably UDP-g’s 2B1 - 5, suggesting a network of associated pyrethroid metabolizing enzymes, or ‘pyrethrome’. Considering the central role that P450s play in metabolizing insecticides, we anticipate that PyABPs will aid the identification and profiling of P450s associated with insecticide pharmacology in a wide range of species, improving understanding of P450-insecticide interactions and aiding the development of new tools for disease control.
drug metabolism↗
Materials Data on CoB10H23C13 by Materials Project
CoB3C11H13B5(CH4)2(BH)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of eight boranediylradical molecules, four B5(CH4)2 clusters, and four CoB3C11H13 clusters. In each B5(CH4)2 cluster, there are five inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a bent 120 degrees geometry to one C4- and one H+0.91+ atom. The B–C bond length is 1.73 Å. The B–H bond length is 1.20 Å. In the second B3+ site, B3+ is bonded in a bent 120 degrees geometry to one C4- and one H+0.91+ atom. The B–C bond length is 1.73 Å. The B–H bond length is 1.19 Å. In the third B3+ site, B3+ is bonded in a bent 120 degrees geometry to one C4- and one H+0.91+ atom. The B–C bond length is 1.71 Å. The B–H bond length is 1.19 Å. In the fourth B3+ site, B3+ is bonded in a bent 120 degrees geometry to one C4- and one H+0.91+ atom. The B–C bond length is 1.69 Å. The B–H bond length is 1.20 Å. In the fifth B3+ site, B3+ is bonded in a bent 120 degrees geometry to one C4- and one H+0.91+ atom. The B–C bond length is 1.68 Å. The B–H bond length is 1.20 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded in a 6-coordinate geometry to five B3+ and one C4- atom. The C–C bond length is 1.52 Å. In the second C4- site, C4- is bonded in a trigonal non-coplanar geometry to one C4- and three H+0.91+ atoms. All C–H bond lengths are 1.10 Å. There are eight inequivalent H+0.91+ sites. In the first H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the second H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the third H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one B3+ atom. In the fourth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one B3+ atom. In the fifth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one B3+ atom. In the sixth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the seventh H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one B3+ atom. In the eighth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one B3+ atom. In each CoB3C11H13 cluster, Co1+ is bonded in a 6-coordinate geometry to six C4- atoms. There are a spread of Co–C bond distances ranging from 2.06–2.19 Å. There are three inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a bent 120 degrees geometry to one C4- and one H+0.91+ atom. The B–C bond length is 1.55 Å. The B–H bond length is 1.20 Å. In the second B3+ site, B3+ is bonded in a bent 120 degrees geometry to one C4- and one H+0.91+ atom. The B–C bond length is 1.55 Å. The B–H bond length is 1.20 Å. In the third B3+ site, B3+ is bonded in a water-like geometry to one C4- and one H+0.91+ atom. The B–C bond length is 1.76 Å. The B–H bond length is 1.20 Å. There are eleven inequivalent C4- sites. In the first C4- site, C4- is bonded in a 5-coordinate geometry to one Co1+, three B3+, and one C4- atom. The C–C bond length is 1.51 Å. In the second C4- site, C4- is bonded in a trigonal non-coplanar geometry to one C4- and three H+0.91+ atoms. All C–H bond lengths are 1.10 Å. In the third C4- site, C4- is bonded in a 4-coordinate geometry to one Co1+ and three C4- atoms. There are a spread of C–C bond distances ranging from 1.42–1.45 Å. In the fourth C4- site, C4- is bonded in a distorted single-bond geometry to one Co1+, one C4-, and one H+0.91+ atom. The C–H bond length is 1.09 Å. In the fifth C4- site, C4- is bonded in a distorted single-bond geometry to one Co1+ and one H+0.91+ atom. The C–H bond length is 1.09 Å. In the sixth C4- site, C4- is bonded in a distorted single-bond geometry to one Co1+, one C4-, and one H+0.91+ atom. The C–C bond length is 1.44 Å. The C–H bond length is 1.09 Å. In the seventh C4- site, C4- is bonded in a 4-coordinate geometry to one Co1+ and three C4- atoms. The C–C bond length is 1.42 Å. In the eighth C4- site, C4- is bonded in a distorted single-bond geometry to two C4- and one H+0.91+ atom. The C–C bond length is 1.38 Å. The C–H bond length is 1.09 Å. In the ninth C4- site, C4- is bonded in a distorted trigonal planar geometry to two C4- and one H+0.91+ atom. The C–C bond length is 1.43 Å. The C–H bond length is 1.09 Å. In the tenth C4- site, C4- is bonded in a distorted single-bond geometry to two C4- and one H+0.91+ atom. The C–C bond length is 1.38 Å. The C–H bond length is 1.09 Å. In the eleventh C4- site, C4- is bonded in a distorted trigonal planar geometry to two C4- and one H+0.91+ atom. The C–H bond length is 1.09 Å. There are thirteen inequivalent H+0.91+ sites. In the first H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one B3+ atom. In the second H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one B3+ atom. In the third H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one B3+ atom. In the fourth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the fifth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the sixth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the seventh H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the eighth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the ninth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the tenth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the eleventh H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the twelfth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom. In the thirteenth H+0.91+ site, H+0.91+ is bonded in a single-bond geometry to one C4- atom.
36 MATERIALS SCIENCE↗
Scaling solid resuspension and sorption for the small column ion exchange processing tank
The Small Column Ion Exchange (SCIX) process is being developed to remove cesium, strontium, and actinides from Savannah River Site (SRS) Liquid Waste using an existing 1.3 million gallon waste tank (i.e., Tank 41H) to house the process. Savannah River National Laboratory (SRNL) is conducting pilot-scale mixing tests to determine the pump requirements for suspending and resuspending Monosodium Titanate (MST), Crystalline Silicotitanate (CST), and simulated sludge. In addition, SRNL will also be conducting pilot-scale tests to determine the mixing requirements for the strontium and actinide sorption. As part of this task, the results from the pilot-scale tests must be scaled up to a full-scale waste tank. This document describes the scaling approach. The pilot-scale tank is a 1/10.85 linear scale model of Tank 41H. The tank diameter, tank liquid level, pump nozzle diameter, pump elevation, and cooling coil diameter are all 1/10.85 of their dimensions in Tank 41H. The pump locations correspond to the proposed locations in Tank 41H by the SCIX Program (Risers B5 and B2 for two pump configurations and Risers B5, B3, and B1 for three pump configurations). MST additions are through Riser E1, the proposed MST addition riser in Tank 41H. To determine the approach to scaling the results from the pilot-scale tank to Tank 41H, the authors took the following approach. They reviewed the technical literature for methods to scale mixing with jets and suspension of solid particles with jets, and the technical literature on mass transfer from a liquid to a solid particle to develop approaches to scaling the test data. SRNL assembled a team of internal experts to review the scaling approach and to identify alternative approaches that should be considered.
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Investigating suspension of mst slurries in a pilot-scale waste tank
The Small Column Ion Exchange (SCIX) process is being developed to remove cesium, strontium, and actinides from Savannah River Site (SRS) Liquid Waste using an existing waste tank (i.e., Tank 41H) to house the process. Savannah River National Laboratory (SRNL) is conducting pilot-scale mixing tests to determine the pump requirements for suspending monosodium titanate (MST), crystalline silicotitanate (CST), and simulated sludge. The purpose of this pilot scale testing is for the pumps to suspend the MST particles so that MST can be removed from the tank. The pilot-scale tank is a 1/10.85 linear scaled model of Tank 41H. The tank diameter, tank liquid level, pump nozzle diameter, pump elevation, and cooling coil diameter are all 1/10.85 of their dimensions in Tank 41H. The pump locations correspond to the proposed locations in Tank 41H by the SCIX program (Risers B5 and B2 for two pump configurations and Risers B5, B3, and B1 for three pump configurations).
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗