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The study investigates the soundness of a popular uncoupled design strategy for diffuser-augmented wind turbines (DAWTs), namely the use of an annular wing to enclose an existing open-rotor. To this aim, the paper presents a numerical analysis of the NREL-Phase-VI rotor enclosed into a shroud whose cross-section consists of the Selig-S1223 airfoil. Particular attention is devoted to the analysis of the blade pressure fields, velocity triangles, blade forces, tip-vortex and wake development. The data show that the duct induces a gain in the rotor inlet axial velocity and, therefore, in the local flow-angle. Consequently, the blade forces, the extracted work, and the risk of flow separation considerably rise. Thanks to the simultaneous increase in the ingested mass flow rate and extracted work, the DAWT experiences a higher power coefficient (C_{P,exit}) which, however, would be further improved if a coupled design-procedure was used. Indeed, in the present case, the maximum C_{P,exit} is obtained for the wind-speed value corresponding to the duct optimal flow behaviour. However, in this condition, the rotor operates at off-design with an extensive flow-separation on the blade suction-side. Finally, while the inefficiencies magnitude is specific of the analysed case, the conceptual relevance of the achievements remains valid in general.

A comparative study has been done on three coatings obtained on steel surface using pure Zn, two Zn-Al alloy baths. The coatings obtained using both Zn alloy baths are thinner than the same obtained using pure zinc bath as Al reacts with steel and forms very thin layer of Fe2Al5 phase which hinders iron-zinc reaction. Coating obtained using pure zinc bath predominantly consists of eta (~ 100 wt.% Zn) and zeta (FeZn13) phases in combination with less extent of delta (FeZn10) and gamma (Fe3Zn10) phases, whereas coatings obtained using Zn-Al alloy baths exhibit zinc-rich phase covered by aluminum rich phase with Al2O3 at the top. Al-rich phase content is higher for Zn-20 wt.% Al alloy coating. The coatings obtained on steel surfaces using both the Zn alloy baths show better ductility compared to pure zinc bath. This can be attributed to the presence of brittle Zn-Fe alloy phase in the coating obtained using pure zinc bath. The coatings obtained using both the Zn alloy baths were found to have a greater passivation characteristics compared to the coating obtained using pure zinc bath without compromising sacrificial characteristic of the coating. Electrochemical and salt spray tests results showed 3 and 6 times improved corrosion resistance properties of Zn-5 wt.% Al and Zn-20 wt.% Al alloy coatings than the pure zinc coating.

Diffuser-augmented wind turbines are known for the potential improvement in power extraction in comparison with open wind turbines. Despite the large number of research works dealing with this subject and unlike the open rotor case, an optimum ducted rotor model is still missing. Since the Joukowsky (free-vortex) optimum rotor exhibits the best power coefficient in the open configuration, this paper presents a newly developed ring-vortex free-wake approach for the performance evaluation of an optimum Joukowsky rotor enclosed in a duct of general shape. The method, which is extensively verified, relies on the exact solution of the steady, incompressible, inviscid and axisymmetric flow, and it naturally takes into account the wake divergence and rotation. The procedure is used to obtain, for the first time, the maximum-power-coefficient/tip-speed-ratio characteristic curve for a diffuser augmented wind turbine. The proposed ducted rotor beats the Betz limit by 14.5% when the power coefficient is referred to the device frontal (exit) area. Additionally, the device experiences a slower decrease in performance with the reduction of the tip-speed ratio, thus extending the design range of ducted rotors in comparison with the open ones. Finally, taking into account the mutual influence of the disk and duct, a new rotor design strategy, capable to evaluate the optimum distribution of the chord and pitch-angle along the blade span, is also proposed. A complete design exercise is carried out and the rotor geometry is obtained for three different values of the nominal tip speed ratio. The paper also proves that a two-dimensional design procedure, which strongly couples the duct and the rotor induced flow, is mandatory to properly evaluate the optimum rotor geometry.

Direct numerical simulations of a turbulent spiral Poiseuille flow (SPF) in a narrow-gap geometry at low Taylor number have been performed to analyse the reverse transition dynamics. The presently investigated SPF results from a Taylor–Couette arrangement with a rotating inner cylinder and a stationary outer one, subject to a time-constant axial pressure gradient. Keeping fixed the Taylor number and reducing the axial Reynolds number, several flow regimes have been obtained until a complete laminarization occurred. In agreement with previous experimental evidence, it has been found that the laminar state is achieved at a Reynolds number significantly smaller than the corresponding non-rotating value. Moreover, the route to turbulence suppression has been shown to differ in the two cases, as confirmed by the increased Reynolds number friction coefficient envelope. The differences occurring in the reverse transition process between SPF and plain Poiseuille flow are attributed to a modification of the isotropy of the Reynolds stress tensor, caused by an alteration of the velocity pressure-strain redistribution mechanisms.

The present article describes the hot-dip coating of a novel Al-Si-Mg-Cu alloy on steel, coating characterization and corrosion property evaluation. Coating morphology and composition were analyzed using SEM, EDS and XRD. The elemental depth profiling of the coating was investigated through GDOES sputtering. The cross-section characterization revealed that the coating consists of two layers: soft thick Al-Si-Mg-Cu alloy layer on the top and hard very thin Al-Fe-Si intermetallic layer underneath i.e. at the steel substrate-coating interface. Further analysis through EDS and XRD of Al-Fe-Si intermetallic layer confirms the presence of Al8Fe2Si phase. The outer Al-Si-Mg-Cu alloy layer is mostly composed of primary α-Al phase along with segregated Si, Mg2Si and θ-Al2Cu phases. The corrosion performances of the coating through potentiodynamic polarization showed superior sacrificial properties compared to aluminized steels reported in literature. Salt spray test (SST) revealed the coating can withstand >2000 h salts spray life without red rust formation. Corrosion rate (mpy) of the coating was found to be seven times lower than galvanized (GI) coating with similar sacrificial property in aggressive chloride environment.

The LHC is expected to reach luminosities up to 3000 fb − 1 and the innermost layer of the ATLAS upgrade plans to cope with higher occupancy and to decrease the pixel size. 3D silicon (3D-Si) sensors are a good candidate for the innermost layer of the ATLAS pixel upgrade since they exhibit good performance under high fluences and the new designs will have smaller pixel size to fulfill the electronics specifications. Detectors located at large η angles, far from the interaction point, will receive the particles almost perpendicularly to the column. In order to have a more precise detection at those positions, thinner 3D detectors are proposed. The thickness of the active wafer can be reduced according to the requirement of the experiments. The first production of these detectors was done on 150 μ m p-type Silicon On Insulator (SOI) wafer with a p-type backside implant and the electrical characteristics and charge collection measurements are reported in this paper.

This paper provides an overview of 3D detectors fabrication technology developed in the clean room of the Microelectronics Institute of Barcelona (IMB-CNM). Emphasis is put on manufacturability, especially on stress and bow issues. Some of the technological solutions proposed at IMB-CNM to improve manufacturability are presented. Results and solutions from other research institutes are also mentioned. Analogy with through-silicon-via technology is drawn. This article aims at giving hints of the technology improvements implemented to upgrade from a R&D process to a mature technology., This work has been financed by the Spanish Ministry of Science and Innovation (MICIN) through the Particle Physics National Program (RTI2018-094906-B-C22 and FPA2017-85155-C4-2-R) and by the European Union’s Horizon 2020 Research and Innovation funding program, under Grant Agreement No. 654168 (AIDA-2020). All the manufacturing were performed at the IMB-CNM clean room facilities, member of the Spanish ICTS Network MICRONANOFABS partially supported by MICIN and FEDER funds.

It was attempted to produce galvannealed dual-phase (DP) steel through a commercial continuous galvanizing line (CGL). The main challenge was to form the DP microstructure even with the slow cooling rate after annealing in the CGL. A two-pronged approach was adopted for this, viz. design of the steel chemistry with calculations and optimization of the CGL parameters with simulation using Gleeble-3800 thermomechanical simulator. The steel thus produced in CGL revealed ferrite and 18 ± 2% martensite microstructure, with tensile strength exceeding 600 MPa and 24% total elongation along with good formability. Weldability study using resistance spot welding indicated the possibility of achieving sound joint with a 4-kA width in weld time–current lobe despite the high carbon equivalence.

Galvanization (GI) and galvannealing (GA) of high strength (HS) steel surface is very prone to develop uncoated spots in coating. Sometimes, GA coating may lead to inferior mechanical performance than GI coating as different brittle (Zn-Fe) intermetallic phases are formed in the coating. In this study an innovative prior Ni plating followed by hot dip galvanization and galvannealing process was thought of to obtain good quality of alloy coating. Adherence of molten zinc on the surface of high strength steel sheet improved significantly by prior Ni coating. SEM-EDS and XRD techniques were used for depth analysis of all coatings. The presence of pure zinc phase was confirmed almost entire depth of the coating when GI coating was formed on HS steel substrate without any prior metallic coating whereas the presence of alloy phase was confirmed up to some depth of the coating when GI coating was obtained on HS steel surface with prior Ni coating. The GA coatings with prior Ni plating primarily compose of the desirable Ni5.225Zn41.8 phase. Interdiffusion of Zn and Fe is controlled by Ni layer to get desirable alloy coating. The GI coatings with prior Ni plating layer provides better resistance against chloride attack and GA coating ensured significance improvement in performance than GI coating. The best GA coating was formed on the steel substrate with prior Ni coating by electrodeposition process. This GA coating showed 3–4 times improvement in performance against aggressive chloride attack, lowest powdering and excellent phosphatability with respect to the GA coating on the steel substrate without any prior Ni plating.

The paper presents a theoretical analysis of three advanced gas turbine recuperative-cycles, that is, the intercooled, the reheat and the intercooled and reheat cycles. The internal irreversibilities, which characterise the compression and expansion processes, are taken into account through the polytropic efficiencies of the compressors and turbines. As customary in simplified analytical approaches, the study is carried out for an uncooled closed-circuit gas turbine without pressure losses in the heat exchangers and using a calorically perfect gas as working fluid. Although the accurate performance prediction of a real-gas turbine is prevented by these simplifying assumptions, this analysis provides a fast and simple approach which can be used to theoretically explain the main features of the three advanced cycles and to compare them highlighting pros and contra. The effect of the heat recuperation is investigated comparing the thermal efficiency of a given cycle type with those of two reference cycles, namely, the non-recuperative version of the analysed cycle and the simple cycle. As a result, the ranges of the intermediate pressure ratios returning a benefit in the thermal efficiency in comparison with the two reference cycles have been obtained for the first time. Finally, for the sole intercooled and reheat recuperative-cycle, a novel analytical expression for the intermediate pressure ratios yielding the maximum thermal efficiency is also given.

Due to the large expected instantaneous luminosity, the future HL-LHC upgrade sets strong requirements on the radiation hardness of the CMS detector Inner Tracker. Sensors based on 3D pixel technology, with its superior radiation tolerance, comply with these extreme conditions. A full study and characterization of pixelated 3D sensors fabricated by FBK is presented here. The sensors were bump-bonded to RD53A readout chips and measured at several CERN SPS test beams. Results on charge collection and efficiency, for both non-irradiated and irradiated up to 1016 neq/cm2 samples, are presented. Two main studies are described: in the first the behaviour of the sensor is qualified as a function of irradiation, while kept under identical conditions; in the second the response is measured under typical operating conditions.

A silicon 3D detector with a single cell of 50 × 50 μ m2 was produced and evaluated for timing applications. The measurements of time resolution were performed for 90Sr electrons with dedicated electronics used also for determining time resolution of Low Gain Avalanche Detectors (LGADs). The measurements were compared to those with LGADs and also simulations. The studies showed that the dominant contribution to the timing resolution comes from the time walk originating from different induced current shapes for hits over the cell area. This contribution decreases with higher bias voltages, lower temperatures and smaller cell sizes. It is around 30 ps for a 3D detector of 50 × 50 μ m2 cell at 150 V and − 20 °C, which is comparable to the time walk due to Landau fluctuations in LGADs. It even improves for inclined tracks and larger pads composed of multiple cells. A good agreement between measurements and simulations was obtained, thus validating the simulation results.

The ATLAS experiment at the LHC will replace its current inner tracker system for the HL-LHC era. 3D silicon pixel sensors are being considered as radiation-hard candidates for the innermost layers of the new fully silicon-based tracking detector. 3D sensors with a small pixel size of $\mathrm{50 \times 50~\mu m^{2}}$ and $\mathrm{25 \times 100~\mu m^{2}}$ compatible with the first prototype ASIC for the HL-LHC, the RD53A chip, have been studied in beam tests after uniform irradiation to $\mathrm{5 \times 10^{15}~n_{eq}/cm^{2}}$. An operation voltage of only 50 V is needed to achieve a 97% hit efficiency after this fluence.

Phosphate conversion coatings on the rebar surfaces with oxide scale (OS) and without oxide scale (WOS) have been tried with or without addition of n-silica particles as an additive to check the effect of n-silica on phosphating behaviour of rebar. All the phosphate coatings were characterised using SEM–EDS, XRD, Tafel, EIS, salt spray and pull out test. Hopeite was identified as major zinc phosphate phase in the coating which was obtained on the OS steel surface, whereas hopeite along with spencerite compounds were identified as major zinc phosphate compounds present in the coating which was obtained on the WOS steel surface. Thicker phosphate coatings were obtained when WOS and OS rebars were treated in n-silica-added and n-silica-free phosphating solution, respectively, and vice versa. Nano-silica acts as a catalyst in the formation of more dense and compact phosphate coating on the surface of WOS rebar, whereas nano-silica acts as a poison for phosphating reaction on the surface of OS rebar. Smoother ...

The constantly increasing global demand of zinc metal along with the decreasing zinc ore reserves has led to an upward trend of zinc production from secondary sources. Galvanizing industry generates byproducts and wastes containing zinc in the form of intermetallic compounds or oxides (zinc dust). One such byproduct, waste pickling liquor (WPL) is generated in galvanizing industry during the pickling of defective galvanized material. WPL contains Zn and Fe in ionic form and is discarded after neutralization. In the present work, chemical precipitation method is used to recover zinc from WPL; with an objective to retain maximum possible iron within the WPL solution. The effect of precipitating agent concentration, number of reactions steps, temperature and stirring speed were considered to determine process parameters for maximum zinc recovery. The iron rich WPL solution with negligible quantities of zinc is a valuable ingredient for production of red oxide pigment. Thereby, two products are obtained by adopting this technique: (i) Zinc rich precipitates and (ii) iron rich pickling liquor. X-ray diffraction (XRD) analysis of precipitates (heated at elevated temperature), shows that zinc oxide and zinc ferrite phases were formed from the zinc rich precipitates.

Ahmed M.A.I., Temerak S.A.H., Abdel-Galil F.A.-K., Manna S.H.M. (2016): Susceptibility of field and laboratory strains of Cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) to spinosad pesticide under laboratory conditions. Plant Protect. Sci., 52: 128–133. The susceptibility of field and laboratory strains against all instars larvae of S. littoralis to spinosad pesticide after a 24- and 48-h exposure and under laboratory conditions was investigated. As a result against 1 st instar larvae, the LC 50 values after 24 h were 12 and 0.275 µg/ml for laboratory and field strain, respectively. In addition, the resistance ratio (RR) of 1 st instar was 43.64-fold. In this interim, the 48 h LC 50 values were 8.7 and 0.18 µg/ml for laboratory and field strain, respectively and the RR was 48.33-fold, which revealed the field strain was more susceptible to spinosad than the laboratory strain. Distinctly similar trend was shown for later instar larvae stages. For instance, in 6 th instar

The ATLAS experiment at the Large Hadron Collider (LHC) will replace its inner tracker system to cope with the extreme particle fluence expected after the High Luminosity upgrade of the accelerator (HL-LHC). The 3D silicon sensor technology has been selected as baseline to instrument the innermost layer of the pixel detector in the future ATLAS Inner Tracker (ITk). A new generation of 3D pixel sensors with thin active substrates and small pixel cells of ( 50 × 50 ) μ m2 and ( 25 × 100 ) μ m2 produced at CNM in Spain, have been interconnected to the RD53A chip, the first prototype of ASIC for the HL-LHC. Performance of these new 3D RD53A modules have been studied before and after uniform proton irradiation up to 1 × 1016 n eq /cm2, i.e. a particle fluence close to the one expected for the innermost layer of ITk. The first results of the power dissipation and hit efficiency for uniformly irradiated 3D RD53A devices will be presented. These revealed a superior radiation hardness of these novel pixel sensors.

Highly irradiated silicon sensors are currently being investigated within the scenario of the most powerful particle accelerator proposed for the post-LHC era, i.e the Future Circular Collider (FCC), for which radiation tolerance up to a level of 8 × 1017 n e q /cm 2 is required. In this paper, 3D strip and pad detectors irradiated with neutrons up to a fluence of 3 × 1017 n e q /cm 2 (1 MeV neutron equivalent) are characterised for the first time: the charge collection measurements with Transient Current Technique (TCT) are carried out at several voltages and the results are reported.

Stereoselective catalysis is described that proceeds with catalyst control but without the need to synthesize preformed chiral catalysts or ligands. Iron-based catalysts were discovered to effect the stereoselective polymerization of lactides starting from a single achiral precursor and the proper choice of an achiral silanol additive. Spectroscopic analysis of the polymer revealed that the stereoselectivity originates from an enantiomorphic site rather than a chain end stereocontrol mechanism. Iron intermediates that are stereogenic at iron are proposed to form in situ as a result of desymmetrization that occurs from a change in the metal coordination number. The proposed mechanism is supported by a combination of spectroscopic measurements, model complexes, kinetic measurements, and DFT calculations.

A study of 3D pixel sensors of cell size 50 {\mu}m x 50 {\mu}m fabricated at IMB-CNM using double-sided n-on-p 3D technology is presented. Sensors were bump-bonded to the ROC4SENS readout chip. For the first time in such a small-pitch hybrid assembly, the sensor response to ionizing radiation in a test beam of 5.6 GeV electrons was studied. Results for non-irradiated sensors are presented, including efficiency, charge sharing, signal-to-noise, and resolution for different incidence angles., Comment: 20 pages, 19 figures

A new generation of 3D silicon pixel detectors with a small pixel size of 50 \(\times \) 50 and 25 \(\times \) 100 \(\upmu \)m\(^{2}\) is being developed for the HL-LHC tracker upgrades. The radiation hardness of such detectors was studied in beam tests after irradiation to HL-LHC fluences up to \(1.4\times 10^{16}\) n\(_{\mathrm {eq}}\)/cm\(^2\). At this fluence, an operation voltage of only 100 V is needed to achieve 97% hit efficiency, with a power dissipation of 13 mW/cm\(^2\) at \(-25\,^{\circ }\)C, considerably lower than for previous 3D sensor generations and planar sensors.

This paper completes the work presented in the companion paper [Bontempo et al., Appl. Ocean Res., 58 (2016) 322–330] by presenting the investigation of the flow around a propeller ducted with a so-called accelerating duct. To this aim, both the axial momentum theory and a nonlinear actuator disk method are used. The straightforward application of the first approach reveals that if the duct and rotor thrusts are concordant, then a beneficial effect on the propulsive efficiency can be readily obtained by enclosing a propeller in an accelerating duct. When the more advanced nonliner actuator disk method is applied to verify the outcomes of the axial momentum theory additional information on the performance of the device are obtained. Moreover, the nonlinear actuator disk method is also employed to investigate, through experimental design techniques, the effect of the key geometrical parameters of the duct onto the efficiency and robustness of this kind of propulsive system. In particular, it has been found that a propulsive efficiency gain can be achieved through a duct thickness, camber and chord increase, and through an incidence decrease.

An iron bis(alkoxide) complex containing a bis(amidinato)-N-heterocyclic carbene ancillary ligand has been synthesized and utilized for the polymerization of (rac)-lactide. This complex was an excellent precatalyst for the controlled polymerization of (rac)-lactide leading to polymer with a number average molecular weight that is approximately four times larger than the analogous bis(imino)pyridine iron complexes while maintaining a similar reaction rate. The unusually high molecular weight observed in these reactions was explained by a fraction of the added complex being the active catalyst for lactide polymerization due to slow initiation versus propagation rates. Mechanistic investigations corroborated this hypothesis revealing an induction period that can be shortened by increasing the concentration of the lactide. This feature of the catalyst system led to a situation where larger observed rate constants were measured as the amount of lactide relative to iron was increased. At the very high lactide to complex ratio of 5000:1 (0.02 mol% catalyst loading), the bis(amidinato)-N-heterocyclic carbene iron bis (alkoxide) complex produced very high molecular weight polymer (Mn > 350 kg/mol, PDI = 1.2) within 8 h (85% conversion). Kinetic studies revealed that the bis(amidinato)-N-heterocyclic carbene iron complex is approximately seven times more active than the corresponding bis(amino)pyridine iron complex. 2014 Elsevier Ltd. All rights reserved.

Hot-dip coating of steel sheets by a novel Al–Mg–Mn alloy, characterization and corrosion property evaluation of the coatings have been described in this article. Morphology and composition of coatings were investigated using SEM and EDS. GDOES sputtering was used for elemental depth profiling of the coating. Microstructural characterization has revealed that the coating consists of broadly two layers; soft Al–Mg–Mn alloy layer on the top and finger-like hard Fe–Al intermetallic layer underneath i.e. towards the steel substrate. The phase analysis carried out using XRD confirms that Fe–Al intermetallic layer consists of two intermetallic layers: outer thin FeAl 3 with Mn-rich layer and inner tongue-like thick Fe 2 Al 5 layer. The growth of the intermetallic layers was found to be governed by volume diffusion, which followed a parabolic rate law. Potentiodynamic polarization measurements in 3.5 wt.% NaCl solution show that the coating exhibits superior sacrificial properties compared to other aluminized steels which can be attributed to the presence of magnesium in the coating. Corrosion resistance of the coating was found to be six times better than that of galvanized (GI) coating with comparable sacrificial property.

In India, approximately 15–20% of Run of Mine (ROM) from any iron ore deposit is reported to slime dam as a byproduct of the iron ore beneficiation process. The proportion of iron ore slime to ROM will increase in the future, with a higher proportion of lean-grade ores in ROM. Furthermore, tonnages of iron ore slime will increase with increasing demand of iron concentrate. Presently, this slime is stored in a dam in the absence of beneficiation technology. A beneficiation flowsheet was developed at Tata Steel based on detailed beneficiation studies in the laboratory and bench scale. This process, on commercialization, will produce a concentrate of 2.2% alumina with 40–45% yield from slime of 7–9% alumina. The Fe content in the reject will be less than 40%, thus adhering to the regulatory norm. In this paper, results of bench-scale studies are discussed along with required characterization findings of feed and products. On commercialization, this process would provide solution to an urgent environmental co...

Galvanization of a dual phase (DP) steel surface is a challenging subject as occurrence of uncoated spots is a very common attribute in coating. In this study, a novel approach was applied where a thin layer of Cu or Cu–Sn (flash coating) was deposited on the DP steel surface before galvanization to resolve this chronic zinc coatability problem. These thin layers on the steel surface were deposited by displacement processes and both flash coated layers had good surface coverage and excellent adherence to the steel surface. Both flash coated as well as without flash coated steel sheets were annealed and subsequently dipped in molten zinc. It is evident from visual appearance that the galvanized coating obtained on the DP steel surface without any flash coating consists of uncoated spots whereas the galvanized (GI) coatings obtained on the DP steel surfaces with prior flash coatings were compact and free from any defects. Galvannealing operation was done for half the number of the total galvanized samples to obtain galvannealed (GA) coating. SEM-EDS and XRD analysis reveal that galvanized iron (GI) coating for the steel without any flash coating consists of almost pure zinc throughout the depth of the coating. However, GI coatings for the steels with both flash coatings consist of alloy phases up to a certain depth of the coating near steel interface. The GA coatings with both flash coatings mainly consist of the desirable δ phase. Both flash coatings promote controlled Fe–Zn reaction. Tafel, salt spray and open circuit potential measurement tests confirmed that performance of GI coatings against chloride attack was improved for both flash coated steels and GA coating has better resistance capability than GI coating.

Galvannealed steel sheets (GA) have become the mainstream steel sheet for automobile applications because of their superior corrosion resistance, paintability, and weldability. To impart specific properties, different coatings on GA steel sheet were reported to improve properties further. In this context, we have developed an electroplating process (flash coating) for bright and adherent Fe-Zn alloy coating on GA steel sheet to enhance performances such as weldability, frictional behavior, phosphatability, and defect coverage. A comparative study with bare GA steel sheet was carried out for better elastration. The electroplating time was reduced below 10 s for practical applicability in an industrial coating line by modulating the bath composition. Electroplating was performed at current density of 200-500 A/m2 which yielded with higher cathode current efficiency of 85-95%. The performance results show that Fe-10 wt.% Zn-coated GA steel sheet (coating time 7 s) has better spot weldability, lower dynamic coefficient of friction (0.06-0.07 in lubrication), and better corrosion resistance compared to bare GA steel sheet. Uniform phosphate coating with globular crystal size of 2-5 µm was obtained on Fe-Zn flash-coated GA steel sheet. Hopeite was the main phosphate compound (77.9 wt.%) identified along with spencerite (13.6 wt.%) and phosphophyllite (8.5 wt.%).

Ecosystem nutrient cycling is often complex because nutrient dynamics within and between systems are mediated by the interaction of biological and geochemical conditions operating at different temporal and spatial scales. Vegetated patches in semiarid and wetland landscapes have been shown to exemplify some of these patterns and processes. We investigated biological and geochemical factors suggested to contribute to phosphorus (P) movement and availability along a forest-marsh gradient in an Everglades tree island. Our study illustrated processes that are consistent with the chemohydrodynamic nutrient (CHNT) hypothesis and the trigger-transfer, pulse-reserve (TTPR) model developed for semiarid systems. Comparison with the TTRP model was constructive as it elaborated several significant patterns and processes of the tree island ecosystem including: (1) concentration of the limiting resource (P) in the source patch [High Head which constitutes the reserve] compared with the resource-poor landscape, (2) soil zone calcite precipitation requiring strong seasonality for evapotranspiration to promote conditions for secondary soil development and calcium phosphate reprecipitation, (3) rewetting of previously dry soils by early wet season precipitation events, and (4) antecedent conditions of the source patch including landscape position that modulated the effect of the precipitation trigger. Thus, our study showed how water availability drives soil water P dynamics and potentially stability of mineral soil P in this tree island ecosystem. In landscapes with extensive water management, these processes can be asynchronous with the seasonality of hydrologic dynamics, tipping the balance between a sink and source of a limiting nutrient.

High-resolution continuum source atomic absorption spectroscopy (HR-CS AAS) is a valuable analytical technique for metal quantification because of its high sensitivity and selectivity for metal atoms as well as its improved background correction mode. However, the quantification of metals in biological materials, e.g. cell lysates, is still challenging because of matrix effects and other experimental complications. A method to quantify the titanium content of tumor cells exposed to titanium-based drugs was developed using HR-CS AAS. This method allows the quantification of titanium in cell suspensions in the low µg L

We herein report the preparation of several mononuclear-metaphosphate complexes using simple techniques and mild conditions with yields ranging from 56% to 78%. Treatment of cyclo-tetrametaphosphate ([TBA]4[P4O12]·5H2O, TBA = tetra-n-butylammonium) with various metal sources including (CH3CN)3Mo(CO)3, (CH3CN)2Mo(CO)2(η(3)-C3H5)Cl, MoO2Cl2(OSMe2)2, and VOF3, leads to the clean and rapid formation of [TBA]4[(P4O12)Mo(CO)3]·2H2O, [TBA]3[(P4O12)Mo(CO)2(η(3)-C3H5)], [TBA]3[(P4O12)MoO2Cl] and [TBA]3[(P4O12)VOF2]·Et2O salts in isolated yields of 69, 56, 68, and 56% respectively. NMR spectroscopy, NMR simulations and single crystal X-ray studies reveal that the [P4O12](4-) anion behaves as a tridentate ligand wherein one of the metaphosphate groups is not directly bound to the metal. cyclo-Trimetaphosphate-metal complexes were prepared using a similar procedure i.e., treatment of [PPN]3[P3O9]·H2O (PPN = bis(triphenylphosphine)iminium) with the metal sources (CH3CN)2Mo(CO)2(η(3)-C3H5)Cl, MoO2Cl2(OSMe2)2, MoOCl3, VOF3, WOCl4, and WO2Cl2(CH3CN)2 to produce the corresponding salts, [PPN]2[(P3O9)Mo(CO)2(η(3)-C3H5)], [PPN]2[(P3O9)MoO2Cl], [PPN]2[(P3O9)MoOCl2], [PPN]2[(P3O9)VOF2]·2CH2Cl2, and [PPN]2[(P3O9)WO2Cl] in isolated yields of 78, 56, 75, 59, and 77% respectively. NMR spectroscopy, NMR simulations and single-crystal X-ray studies indicate that the trianionic ligand [P3O9](3-) in these complexes also has κ(3) connectivity.

Productivity for the hydrogenation of CO2 to formic acid was increased with the addition of catalytic amounts of KHCO3 and other common inorganic salts. Mechanistic experiments revealed that the reaction likely proceeds via the formation of a metal–carbonate species. The effect was general for many noble-metal catalysts and for one of the most efficient non-noble-metal hydrogenation catalysts.

Tube galvanizing is a very old and important process industrially. One of the significant process steps in tube galvanizing is the use of flux materials on cleaned tubes for temporary protection before dipping into the liquid zinc bath. However, the fluxing operation is somewhat hazardous and also causes zinc loss by dross and ash generation. An attempt has been made here for the first time to replace fluxing operation by applying a thin metal flash coating on clean tubes prior to galvanizing. The galvanized tubes are then characterized by SEM and EDS to find out the coating thickness and evolved phases. The galvanized tubes are subjected to corrosion tests and coating adhesion tests. The results are very encouraging confirming the presence of desired phases along with excellent corrosion resistance of these tubes.