Cr Chloride Research Articles

Title: Investigation of Kinetically Favorable Chromium Speciation Distribution for Iron Chromium Redox Flow Batteries

Chromium is a promising active material for redox flow battery (RFB) electrolytes due to its low cost and reduction potential very near the negative limit of the electrochemical window of water. However, many challenges exist with the performance of the Cr3+/2+, most notably sluggish electron-transfer kinetics and parasitic hydrogen evolution during the charge cycle. This presentation will focus on our recent efforts to overcome these challenges by understanding the interplay between electrolyte composition, speciation, and electron-transfer kinetics for the aqueous Cr3+/2+ redox couple.Among the earliest published work on flow batteries was a program based at NASA introducing the iron chromium redox flow battery (ICRFB) [1,2]. These studies were valuable in demonstrating both the promise and the complications of chromium for flow battery electrolytes. The NASA team went to great lengths to enhance chromium redox kinetics and suppress the hydrogen evolution via extensive modification of the carbon negative electrode with Au, Pb, and Bi additives. The present study is based on a key observation from this early work that the electron-transfer rates for Cr-chloride complexes depend strongly on the inner-sphere coordination environment, and specifically the number of chloride ions directly bound to the Cr center.Extensive prior studies from the inorganic coordination chemistry literature further demonstrate that Cr(III) chloride complexes undergo slow equilibration in aqueous solutions to form distributions of four species where the coordination environment around the metal center can be described generally as [CrClx(H2O)6-x](3-x)+ with 0 < x < 3 [3,4]. Each of these species yields a distinct optical absorption signature, enabling quantification of the composition with UV-VIS spectroscopy. Our overarching hypothesis, based on the early NASA work, was that increased chloride coordination (i.e., higher values of x in CrClx(H2O)6-x) would yield enhanced electron-transfer kinetics by reducing inner-sphere reorganization barriers associated with aquo ligands, or by enhancing catalytic mechanisms mediated by chloride surface adsorbates. Thus, we measured optical absorbance and electrochemical reversibility for Cr(III) chloride solutions with HCl, NaCl, and LiCl supporting electrolytes over a range of total chloride concentration from 0.1 to ~10 mol/L.Representative results are summarized in Figure 1 for 0.1 M CrCl3 in aqueous LiCl. Notably, at Au electrodes the reversibility of the Cr3+/2+ redox feature increases dramatically as chloride concentration increases above 5 mol/L (Figure 1a). This shift in reversibility is broadly correlated with UV-VIS results (Figure 1b) demonstrating that the primary Cr(III) species present initially remains the predominant species in the aqueous environment for high concentrations of chloride over time, but the predominant species shifts significantly at lower concentrations of LiCl. Ongoing work, which will be discussed in this presentation, is focused on full quantification of the relationship between speciation and electron-transfer kinetics as well as performance properties for ICRFBs with a range of supporting electrolyte concentrations. We anticipate that understanding the most kinetically favorable speciation distribution will allow us to develop improved electrolytes for functional ICRFBs.

Effect of KCl on high‐temperature corrosion of low‐alloyed steel under low oxygen partial pressure

AbstractLow oxygen environments in biomass gasification and the presence of chlorine in feedstocks can influence the corrosion rate of steel by affecting the formation of protective oxide scales. The effect of KCl on the high‐temperature corrosion of low‐alloyed steel (13CrMo4‐5) under low oxygen partial pressure is investigated by KCl salt spray (0.1 mg·cm−2) and exposure to 3 vol% H2 + 30 vol% H2O + Ar (balance) at 500°C for up to 168 h. Specimens without KCl salt are exposed for reference. Specimens are characterized after exposure by mass change, SEM/EDS, and XRD. KCl‐deposited specimens exhibit about 30% lower mass gain after exposure compared to non‐sprayed specimens. Their scale shows a porous innermost layer and a denser layer on top. No Fe or Cr chlorides are identified. The specimens without salt exhibit a similar two‐layered scale, with a porous inner Fe‐Cr oxide, followed by a denser and thicker Fe‐oxide above. KCl could potentially protect the surface from further degradation by physically covering the specimen, altering the scale morphology, and forming a less permeable barrier, hindering the transport of species through the scale.

Effect of chlorides and sulfates on the corrosion of SS347 and GH3539 in molten solar salt

Adding an appropriate amount of chloride or sulfate salts to molten nitrates is an effective way to improve the thermal stability temperature and energy density of solar salts. However, the corrosivity of the mixed solar salts is enhanced significantly. In this paper, the effect of chlorides and sulfates on the corrosion of SS347 and GH3539 in molten solar salt is investigated. The high oxygen pressure and basic environment in molten nitrates causes the formation of an external Fe oxides layer and inner FeCr2O4 layer for SS347. Unlike SS347, the corroded GH3539 presents an exclusive film of NiO and many core-shell structured nodules with Ni as core and NiO as shell, followed by a region of internal oxidation involving Ni, W and Cr. The additives chlorides produce an oxidation-chlorination environment, causing spallation of oxide scale from SS347, but without significant effect on GH3539 due to lower thermodynamic stabilities of Ni and W chlorides than Fe and Cr chlorides. The addition of sulfates to solar salt also harms the adhesion of the scale on SS347 to a certain extent. While the additives sulfides accelerate the corrosion of GH3539, forming a thick porous NiO layer and a serious internal sulfidation zone.

Synthesis and Characterization of Pyridine Acetohydrazide Derivative for Antimicrobial Cotton Fabric

An increase in textile resistance to antimicrobial agents has posed a pressing need for the development of new antimicrobials. Therefore, the antimicrobial characteristics of thiophene and pyridine acetohydrazide derivatives have been developed as novel textile-modified complexes exhibiting antibacterial agents. Synthesis and characterization of pyridyl-thienyl acetohydrazide derivative (AHZ) using NMR (13C and 1H) and FTIR. Modification of cotton fabric (CF) with acetohydrazide (AHZ) and metal chlorides of divalent Cr, Mn, Co, Ni, Cu, and Zn and trivalent Fe, and Cr. SEM-EDX and Fourier-transform infrared were utilized to characterize cellulose-based cotton fabric (CF) attached to AHZ and their metal (M) complexes. Antimicrobial activity was examined against two types of bacteria, namely S. aureus and E. coli, and two types of fungi, namely C. albicans and A. flavus. All modified samples exhibited higher efficiency towards bacterial strains than fungal strains. In addition, cellulose modified with Ni (II) confers the most antibacterial protection efficiency.

Bone and Soft Tissue Reaction to Co(II)/Cr(III) Ions Stimulation in a Murine Calvaria Model: A Pioneering in vivo Study.

Metal ions released during wear and corrosion of the artificial knee/hip joints are considered to contribute to aseptic implant failure. However, there are few convincing in vivo studies that demonstrate the effects of metal ions on bone and soft tissue. This study examined the in vivo effects of Co(II)/Cr(III) ions on mouse calvaria and the supra-calvaria soft tissue in an original mouse model. With the implantation of a helmet-like structure, we set up a subcutaneous cavity on the calvaria in which Co(II) Chloride or Cr(III) Chloride solutions were administered respectively. A layer of interface membrane formed on the calvaria along with the implantation of the helmet. The administered Cr(III) ions accumulated in the interface membranes while Co(II) disseminated into the circulation. Accumulated Cr(III) and related products induced local massive macrophage infiltration and skewed the bone metabolic balance. At last, we revealed that lymphocyte aggregates, which are the pathologic hallmark of human periprosthetic tissue, could be caused by either Co(II) or Cr(III) stimulation. These in vivo results may shed light on the effects and pathogenic mechanism of the Co(II)/Cr(III) ions released from the joint prosthesis. STATEMENT OF SIGNIFICANCE: Macrophage infiltration and lymphocyte aggregates are hallmarks of human joint periprosthetic tissue. We chronically administered Co(II)/Cr(III) ions on mouse calvaria and reproduced these two histopathologic hallmarks on mouse tissue based on an implanted helmet-like structure. Our results reveal that Cr(III) ions are locally accumulated and are effective in inducing macrophage infiltration and they can be phagocytosed and stored. However, the lymphocytes aggregates could be induced by both Co(II), Cr(III) and other unspecific inflammatory stimuli.

New dimeric complexes with semicarbazone mannich-based ligand; formation, structural investigation and biological activity

The formation of a new semicarbazone Schiff-base ligand (E)-2-(2-(phenyl(2-phenylhydrazinyl)- methyl)cyclohexylidene)hydrazine-1-carboxamide (HL) and its complexes are reported. The new ligand was prepared from the condensation of the Mannich-base 2-(phenyl(2-phenylhydrazinyl)methyl)cyclohexan-1-one (M) with the semicarbazide. A series of metal complexes were prepared by the reaction of the ligand with the metal chlorides of Cr(III), Mn(II), Co(II), Ni(II), Cu(II)), Zn(II) and Cd(II). The structure of the ligand and its complexes were elucidated through analytical and spectroscopic techniques. The analyses indicated the ligand behaves as a monobasic tridentate species and the isolation of dimeric complexes with the general formula; [Cr(L)(Cl)2(H2O)]2, [M(L)Cl]2 (where M= Mn(II), Co(II), Ni(II), Cu(II)), Zn(II) and Cd(II)). These studies revealed a distorted octahedral geometry for Cr(III), a distorted square planar for Cu(II) and a tetrahedral arrangement for Mn(II), Co(II), Ni(II), Zn(II) and Cd(II). The biological activity of the prepared compounds against Escherichia coli, Pseudomonas auroginosa, Staphylococcus aureus and Bacillus subtilis compared with Cefotaxime (as a standard antibiotic) was also explored. Some of the examined compounds indicated a similar antibacterial activity to Cefotaxime. Furthermore, antifungal activity against Candida albicans and Rhizopus sporium was investigated, which showed that the ligand and its complexes exhibited good antifungal activity. Keywords: Schiff-base ligand; Structural characterization; Dimeric semicarbazone complexes; Biological activity.

The Co-catalyst Effects of Mn(II), Zn(II), and Cr(III) Chlorides on Acidic Ionic Liquid Catalyzed Synthesis of Value-added Products from Cellulose in Aqueous Ethanol

Background: Catalytic depolymerization and processing of cellulose can be used to produce value-added renewable feedstock chemicals. Objective: This study aimed to develop an acidic ionic liquid-metal ion chloride catalyst system-based single-reactor method for processing cellulose into value-added products. Methods: The effect of metal chlorides as co-catalysts on 1-(1-propylsulfonic)-3-methylimidazolium chloride acidic ionic liquid catalyzed degradation of cellulose in 40% (v/v) aq. ethanol was studied by measuring levulinic acid, ethyl levulinate, and 5-hydroxymethylfurfural yields. Results: In experiments with Mn(II) and Zn(II) chloride co-catalysts at 160 and 170°C for 12 h, the initial yields of ethyl levulinate and 5-hydroxymethylfurfural improved from ~ 7% to ~ 12-15% due to co-catalytic effects. The highest enhancements in ethyl levulinate yields were observed with CrCl3, where the yield increased from 6 to 27% with the addition of a 10 mol% co-catalyst. Conclusion: All three transition metal chlorides studied caused improvements in yields of secondary products, ethyl levulinate and 5-hydroxymethylfurfural, in acidic ionic liquid catalyzed degradation of cellulose in aqueous ethanol. The most significant enhancements in ethyl levulinate yields were observed with CrCl3 as a co-catalyst.

Lignin-based activated carbon-supported metal oxide catalysts in lactic acid production from glucose

In this study, heterogeneous biomass-based activated carbon-supported metal oxide catalysts were prepared and tested for lactic acid production from glucose in aqueous solution. Activated carbons were produced from hydrolysis lignin by chemical (ZnCl2) or steam activation and modified with a nitric acid treatment and Sn, Al, and Cr chlorides to obtain carbon-based metal oxide catalysts. The modification of the carbon support by nitric acid treatment together with Sn and Al oxides led to an increase in lactic acid yield. The highest lactic acid yield (42 %) was obtained after 20 min at 180 °C with the Sn/Al (5/2.5 wt.%) catalyst on steam-activated carbon treated by nitric acid. Reusability of the catalyst was also studied with the conclusion that the deposition of carbonaceous byproducts and leaching of Al oxides led to a decrease in catalyst selectivity to lactic acid.

Effects of chromium supplementation on inflammatory biomarkers: A systematic review and dose-response meta-analysis of randomized controlled trials

IntroductionAccumulating evidence suggests that chromium (Cr) supplementation may prevent inflammation, however, the results have been inconsistent. To derive a more precise estimation of the efficacy of Cr supplementation on inflammatory mediators such as tumor necrosis factor‐alpha (TNF‐α), high-sensitivity C‐reactive protein (hs-CRP), and interleukin‐6 (IL‐6), this systematic review and meta-analysis was performed. MethodsAn advanced search of PubMed and Scopus was conducted from inception to 14 April 2020 to find randomized controlled trials that assessed the effect of Cr supplementation on inflammation among the adult population. ResultsThe search resulted in identifying 10 articles which met the inclusion criteria for the systematic review. Our results indicated that Cr supplementation significantly decreased serum levels of hs-CRP (weighted mean differences (WMD): -0.95 mg/l; 95 % CI, -1.54 to -0.36, P = 0.002). Greater effects on hs-CRP were detected in trials using Cr picolinate and Cr chloride, dosage <300 μg with duration ≤12 weeks. Also, 12 weeks supplementation with Cr dinicocysteinate led to a significant reduction in the level of TNF-α but Cr picolinate did not show significant changes in serum levels of TNF-α. Moreover, both Cr picolinate and Cr dinicocysteinate had no significant differences in the level of serum IL-6 and IL-8. Although, a significant non-linear association was found between serum hs-CRP changes and study duration (Pnon-linearity = 0.03), we did not find any significant association between serum hs-CRP changes and dosage (Pnon-linearity = 0.86) with Cr picolinate supplementation. ConclusionSupplementation with Cr picolinate and Cr chloride at dose <300 μg for ≤12 weeks could significantly decrease serum hs-CRP levels.

Trinuclear Schiff Base Complexes Containing P-Phenylene Diamine, 2, 3-Pentanedione and 3-Aminocoumarin Ligand: Synthesis, Characterization, DNA Cleavage and Antimicrobial Activity

Trinuclear Schiff base complexes were synthesized by using p-phenylene diamine, 2,3-pentanedione and 3-aminocoumarin and Cu (II), Ni (II), Mn (II), Zn(II) and Cr(III) chloride salts. The category of compound was [M3LCl6]. All trinuclear compounds were analyzed by C, H&amp;N analysis and spectral studies. Mechanism of thermal analysis of trinuclear Schiff base metal complexes was studied. The electrophoresis data confirmed that Schiff base compounds cleaved DNA with Hydrogen peroxide. Additionally, the antibacterial action was tested by disc diffusion method. The efficiency of compounds was assessed against selected microbes. The result of minimum inhibitory concentration confirmed that trinuclear Schiff base metal compounds have got more efficiency.

Corrosion behavior of a precipitation hardened Ni–Cr–Co–Mo alloy under partial slagging coal gasification conditions

Abstract A mechanistic exposure experiment was performed on the commercially available precipitation hardened VDM® alloy C–263 (Nicrofer® 5120 CoTi) Ni-Cr-Co-Mo alloy samples (21 wt.-% Cr, 21 wt.-% Co, 6.1 wt.-% Mo, 2.4 wt.-% Ti, 0.7 wt.-% Fe, 0.6 wt.-% Al, 0.6 wt.-% Mn, 0.4 wt.-% Si, 0.2 wt.-% Cu, 0.08 wt.-% C and bal. Ni) at coal gasification pilot plant facilities affiliated with the Institute for Advanced Engineering in Yongin, South Korea. Thermodynamic Ellingham–Pourbaix stability diagrams were constructed to provide insight into the mechanism of the observed corrosion behavior prevailing in the piping materials between the particulate removal unit and water scrubber of the coal gasification pilot plant. The thermodynamic inference on the corrosion mechanism was supplemented with the morphological, compositional and microstructural analyses of the exposed samples using scanning electron microscopy and energy-dispersive X-ray spectroscopy analyses performed on the external and cross–sectional surfaces of the recovered corrosion test samples to comprehensively examine the corrosion scale. Corrosion products with conspicuous spallation were observed after 139 h exposure to the corrosive environment (60 vol.-% CO, 28.4 vol.-%H2, 2.5 vol.-% CO2, 0.8 vol.-% CH4, 600 ppm H2S, and 110 ppm carbonyl sulfide under 2.005 MPa and 170 °C). Scanning electron microscopy and energy-dispersive X-ray spectroscopy positively identified formation of rather extensively peeled–off oxides as corrosion scales on the post–exposure alloy samples, which were attributed to the combined effects of evaporation of hydrated Fe, Al, and Cr chlorides and their subsequent transformation into thin (spalled) oxides. This article contains technical contents on the effects of Cr, Mo, Fe, and Al on the observed corrosion behavior which supplement and cast engineering insight into the previously published MP 2-2018 article on corrosion behavior of Ni-Cr-Mo-Fe alloy in a similar environment.

Chromium-Catalyzed Cross-Couplings and Related Reactions

Transition-metal-catalyzed cross-couplings have been recognized as a powerful tool for sustainable syntheses. Despite the fact that remarkable progress was achieved by palladium and nickel catalysis, the high price and toxicity still remained a drawback. Recently, naturally more abundant and less toxic low-valent chromium salts, such as Cr(II) and Cr(III) chlorides, displayed notable unique catalytic reactivity. Thus, recent progress in the field of chromium-catalyzed cross-couplings and related reactions are highlighted in the present short review until December­ 2018.1 Introduction and Early Chromium-Mediated Reactions2 Chromium-Catalyzed Cross-Couplings and Related Reactions3 Conclusion

Dietary supplementation of organic or inorganic chromium modulates the immune responses of broilers vaccinated with Avian Influenza virus vaccine

Dietary supplementation with the organic chromium (Cr) has been shown to positively affect the immune function of poultry. However, to our knowledge, no experiment has been done to directly compare the impacts of Cr chloride and chromium picolinate (CrPic) on the immune responses of broilers vaccinated with Avian Influenza (AI) virus vaccine. Therefore, the present experiment was conducted to investigate the effects of supplemental Cr sources (Cr chloride and CrPic) and levels on the growth performance and immune responses of broilers vaccinated with AI virus vaccine so as to provide an effective nutritional strategy for improving immune function of broilers. A total of 432 1-day (d)-old male broiler chicks were used in a 1 plus 2×4 design. Chickens were given either a diet without Cr supplementation (control) or diets supplemented with 0.4, 0.8, 1.6, or 3.2 mg Cr/kg as either Cr chloride or CrPic for 42 d. Compared to the control, dietary Cr supplementation had no effect (P>0.05) on average daily gain, average daily feed intake and gain : feed of broilers during the starter and grower phases, but increased (P<0.05) the relative weights of bursa of fabricius on d 21 and thymus, spleen, or bursa of fabricius on d 42, serum antibody titers against AI virus on d 21, 28, 35 and 42, blood T-lymphocyte transformation rate on d 28 and 42, blood T-lymphocyte percentage on d 42, and serum interleukin-2 contents on d 28. Broilers fed the diets supplemented with the inorganic Cr chloride had higher (P<0.05) weights of thymus, spleen and bursa of fabricius than those fed the diets supplemented with the CrPic on d 42. In addition, broilers fed the diets supplemented with the CrPic had higher (P<0.05) antibody titers against AI virus than those fed the diets supplemented with the inorganic Cr chloride on d 21 and 35. These results indicate that dietary Cr supplementation improved immune responses of broilers vaccinated with AI virus, and the inorganic Cr chloride was more effective than the CrPic in increasing the relative weights of lymphoid organs, however, the CrPic was more effective than the inorganic Cr chloride in enhancing the serum antibody titer against AI virus.

Effects of alloying elements on the corrosion behavior of Ni-based alloys in molten NaCl-KCl-MgCl2 salt at different temperatures

The effects of alloying elements on corrosion of Ni-based alloys in NaCl-KCl-MgCl2 under Ar in the temperature range of 600∼800 °C were investigated by immersion test, SEM/EDS, EPMA and XRD techniques. A thermodynamic potential-pO2− diagram for Cr, Ni at 700 °C was constructed. The alloy corrosion is attributed to the dissolution of Cr to form Cr chlorides into salt. The elements Cr, Mo and W can affect the alloy corrosion. The corrosion is accelerated and the intergranular corrosion becomes more pronounced with temperature. Furthermore, the effects of the alloying elements on corrosion have a strong temperature dependence. The related mechanisms are discussed.

Effect of Azide and Chloride Binding to Diamino-bis(phenolate) Chromium Complexes on CO2/Cyclohexene Oxide Copolymerization

The affinity for nucleophile (azide, N3–, and chloride, Cl–) binding significantly influences the catalytic activity of chromium complexes for the copolymerization of cyclohexene oxide (CHO) and CO2. The binding of N3– and Cl– to two amino-bis(phenolate) Cr(III) chloride complexes [L1Cr(μ-Cl)]2 (1) and [L2CrCl(THF)] (2·THF), where L1 = methoxyethylamino-N,N-bis(2-methylene-4,6-di-tert-butylphenolate) and L2 = dimethylaminoethylamino-N,N-bis(2-methylene-4,6-di-tert-butylphenolate), were studied by both matrix assisted laser desorption/ionization time-of-flight and electrospray ionization mass spectrometry (MALDI-TOF-MS and ESI-MS, respectively). Upon reaction with [PPN][N3] ([PPN] = bis(triphenylphosphine)iminium), 1 exhibited greater ability to form six-coordinate bis-azide ions [L1Cr(N3)2]− and produced fewer five-coordinate species detected by MS than 2·THF. This corresponded to 2·THF having a significantly faster rate of polymerization with anionic nucleophile cocatalysts than 1. In the presence of 1 e...

Unusual Crack Formation on an Autoclave during Thermal Cracking Experiments on Anthropogenic Resources

Abstract Thermal cracking experiments were performed on anthropogenic resources (post consumer plastics with PVC impurities) in an autoclave under N2 atmosphere and at 500 °C. After about 48 h, a crack near the flange resulted in pressure loss. Deposits of FeCl2 · 2H2O, NiCl2 · 2H2O and Ni2O2OH could be evidenced on the cracks using XRF and XRD. In the crack itself, mainly Cr2O3 could be found at the crack initiation site, while chlorides of Fe, Cr, and Ni could be observed at the tip of the crack using EDS. Metallographic examinations using V2A and Beraha etchants revealed that the crack propagated transgranularly. The basic structure exhibits not only dendritic segregations (cast structure) but also segregation bands (deformed microstructure). In addition to that, Ti(C,N) precipitations could be found. TiN (yellow) mainly occurred in the core, while TiC (white) was primarily found at the edge of the sample.

PCDD/F-isomers signature - Effect of metal chlorides and oxides

A recent paper presented the results from de novo tests, involving 11 distinct catalytic systems (oxides and chlorides of Cd, Cr, Cu, Ni, and Zn, as well as a blank sample). Their PCDD and PCDF formation activity was shown. This paper further assesses their isomer signature, with special emphasis on those congeners associated with chlorophenol precursor routes, and on 2,3,7,8- and 1,9-substituted congeners. Each metal catalyst generates a significantly different signature, also affected by the presence or absence of oxygen in the reaction atmosphere. Oxide and chloride catalysts supply distinctive signatures, suggesting singly weighted pathways. Quite a large number of data was handled, so that throughout this analysis special attention was given to testing and developing an appropriate methodology, allowing appropriate correlation analysis and statistical data treatment. The large tables resulting relate to the 11 catalytic systems, studied at 3 levels of oxygen concentration, with 94 PCDD/F-congeners considered individually. They constitute an extensive reference data bank for confronting novel experimental data with this vast data set.

Corrosion Behavior and Mechanism of Fe-14Cr-Mn Alloy in Molten Eutectic NaCl-MgCl 2 at Different Temperatures

Operating temperature waves around the melting temperature of molten eutectic NaCl-MgCl2 which is thermal storage media at medium-high temperature. But the corrosion behavior of the molten salt on metal at different temperatures is not clear. In the present paper, the corrosion behavior and mechanism of the molten salt on Fe-14Cr-Mn alloy were studied by an immersion salt corrosion method at 718, 768 and 818 K. Results show that corrosion rate increases lightly with the increase of corrosion temperature. Corrosion kinetics characteristics obey the linear law (slope k≈−4.806×10−4). At the early stage of corrosion, there are lots of vacuoles, while a large number of pit holes are formed after corroding for 80 h. Corrosion products are mainly Fe, Fe-Cr and MgO. Corrosion mechanism is as follows: absorbed oxygen on molten salt surface and oxygen atom that is introduced in the form of moisture-absorbed MgCl2 are as depolarizing agents. Chlorides of Cr and Mn are got when oxide of Cr and Mn react with Cl−. The chlorides of Cr and Mn with water, e.g. CrCl3·6(H2O) and MnCl2·n(H2O) that have low melting point would escape from corrosion system. In addition, there is a salt crust that is composed of MgCl2·(H2O)6, NaCl and MgO on molten salt upper surface, while NaCl coexists with NaMgCl3 inside mixture salt.

Structural, DFT and biological studies on Cr(III) complexes of semi and thiosemicarbazide ligands derived from diketo hydrazide

Three ligands have been prepared by addition ethanolic suspension of 2-hydrazino-2-oxo-N-phenyl-acetamide to phenyl isocyanate (H2PAPS), phenyl isothiocyanate (H2PAPT) and benzoyl isothiocyanate (H2PABT). The Cr(III) chloride complexes were prepared and characterized by conventional techniques. The data confirmed that the complexes have the following formulaes, [Cr(H2PAPS)Cl3], [Cr(HPAPT)Cl2(H2O)2] and [Cr(HPABT)Cl2(H2O)]. The IR spectra of complexes shows that H2PAPS behaves as neutral tridentate via both CO of hydrazide moiety and CN(azomethine) due to enolization of CO isocyanate without deprotonation. H2PAPT suggests the coordination as mononegative bidentate via both CO of hydrazide moiety in keto and deprotonated enolic oxygen atoms. H2PABT act as mononegative tridentate via carbonyl oxygen (CO)3, the deprotonated enolic oxygen atom (CO)1 and NH1 groups. The experimental IR data of ligands are compared with those obtained theoretically from DFT calculations. Also, the bond lengths, bond angles, HOMO, LUMO and dipole moments have been calculated. The calculated HOMO-LUMO energy gap reveals that charge transfer occurs within the ligand molecules. The calculated values of binding energies indicates the higher stability of metal complexes than of ligands. Also, the kinetic and thermodynamic parameters for the different thermal degradation steps of the complexes were determined by Coats-Redfern and Horowitz-Metzger methods.

Effects of Supplemental Chromium Source and Concentration on Growth Performance, Carcass Traits, and Meat Quality of Broilers Under Heat Stress Conditions.

The objective of this study was to investigate the effects of dietary supplemental chromium (Cr) on growth performance, carcass traits, and meat quality of broilers reared under heat stress. A total of 252 1-d-old Cobb 500 commercial female broilers were randomly allotted by body weight (BW) to one of six replicate cages (six broilers per cage) for each of seven treatments in a completely randomized design involving a 2×3 factorial arrangement of treatments with three Cr sources (Cr propionate, CrPro; Cr picolinate, CrPic; Cr chloride, CrCl3) and two concentrations of added Cr (0.4, or 2.0 mg of Cr/kg) plus a Cr-unsupplemented control group. Feed and distilled-deionized water were available ad libitum for an experimental phase of 42days. For induction of heat stress, the house temperature was set at 33±2°C from 15 to 42days of age. Results showed that birds supplemented with Cr, regardless of Cr source, had increased ADG (P=0.032) than controls. Birds fed 2.0mg Cr/kg diet had greater ADG (P=0.005) than birds fed 0.4mg Cr/kg diet. Compared to controls, birds fed with Cr had greater dressing percentage (P=0.021). Percentage of abdominal fat decreased (P=0.013), whereas, breast intramuscular fat (IMF) remained unaffected (P=0.147) in Cr supplemented vs control broilers. Broilers supplemented Cr had decreased b* values of meat color (P=0.042) in breast muscle. B*values were also lesser (P=0.049) in birds fed CrPro than birds supplemented with CrCl3 or CrPic. Regardless of Cr source, the percentage of cooking loss was decreased (P=0.025) with Cr supplementation in breast muscle when compared to controls. Results from this study indicate that Cr supplementation, independent of its source, could promote growth and improve carcass traits and meat quality of broilers under heat stress conditions. Chromium propionate seems to have greater beneficial effects on meat color in comparison with CrPic and CrCl3.