Tin-free catalysts for the production of aliphatic thermoplastic polyurethanes

2014 ◽  
Vol 16 (9) ◽  
pp. 4401-4407 ◽  
Author(s):  
Yves Schellekens ◽  
Bert Van Trimpont ◽  
Pieter-Jan Goelen ◽  
Koen Binnemans ◽  
Mario Smet ◽  
...  
Keyword(s):  
Iron Compounds ◽  
Thermoplastic Polyurethanes ◽  
Highly Active ◽  
Solventless Reaction

Iron compounds, such as FeCl3, are highly active and temperature resistant catalysts for the solventless reaction of polyols with aliphatic diisocyanates to form thermoplastic polyurethanes.

scholarly journals The Evolution Pathway from Iron Compounds to Fe1(II)-N4 Sites Through Gas-Phase Iron During Pyrolysis

2019 ◽  
Author(s):  
Jingkun Li ◽  
Li Jiao ◽  
Evan Wegener ◽  
Lynne K. LaRochelle Richard ◽  
Ershuai Liu ◽  
...  
Keyword(s):  
Gas Phase ◽  
Active Sites ◽  
Active Catalyst ◽  
Reduction Reaction ◽  
Physical Contact ◽  
Single Atom ◽  
Iron Compounds ◽  
X Ray ◽  
Highly Active ◽  
X Ray Absorption

<div> <div> <div> <p>Pyrolysis is indispensable for synthesizing highly active Fe-N-C catalysts for the oxygen reduction reaction (ORR) in acid, but how Fe, N, and C precursors transform to ORR-active sites during pyrolysis remains unclear. This knowledge gap ob- scures the connections between the input precursors and output products, clouding the pathway toward Fe-N-C catalyst improve- ment. Herein, we unravel the evolution pathway of precursors to ORR-active catalyst comprised exclusively of single atom Fe1(II)- N4 sites via in-temperature X-ray absorption spectroscopy. The Fe precursor transforms to Fe oxides below 300 °C, and then to tetrahedral Fe1(II)-O4 via a crystal-to-melt-like transformation below 600 °C. The Fe1(II)-O4 releases a single Fe atom that flows into the N-doped carbon defect forming Fe1(II)-N4 above 600 °C. This vapor phase single Fe atom transport mechanism is verified by synthesizing Fe1(II)-N4 sites via “non-contact pyrolysis” wherein the Fe precursor is not in physical contact with the N and C precursors during pyrolysis. </p> </div> </div> </div>

scholarly journals The Evolution Pathway from Iron Compounds to Fe1(II)-N4 Sites Through Gas-Phase Iron During Pyrolysis

2019 ◽  
Author(s):  
Jingkun Li ◽  
Li Jiao ◽  
Evan Wegener ◽  
Lynne K. LaRochelle Richard ◽  
Ershuai Liu ◽  
...  
Keyword(s):  
Gas Phase ◽  
Active Sites ◽  
Active Catalyst ◽  
Reduction Reaction ◽  
Physical Contact ◽  
Single Atom ◽  
Iron Compounds ◽  
X Ray ◽  
Highly Active ◽  
X Ray Absorption

<div> <div> <div> <p>Pyrolysis is indispensable for synthesizing highly active Fe-N-C catalysts for the oxygen reduction reaction (ORR) in acid, but how Fe, N, and C precursors transform to ORR-active sites during pyrolysis remains unclear. This knowledge gap ob- scures the connections between the input precursors and output products, clouding the pathway toward Fe-N-C catalyst improve- ment. Herein, we unravel the evolution pathway of precursors to ORR-active catalyst comprised exclusively of single atom Fe1(II)- N4 sites via in-temperature X-ray absorption spectroscopy. The Fe precursor transforms to Fe oxides below 300 °C, and then to tetrahedral Fe1(II)-O4 via a crystal-to-melt-like transformation below 600 °C. The Fe1(II)-O4 releases a single Fe atom that flows into the N-doped carbon defect forming Fe1(II)-N4 above 600 °C. This vapor phase single Fe atom transport mechanism is verified by synthesizing Fe1(II)-N4 sites via “non-contact pyrolysis” wherein the Fe precursor is not in physical contact with the N and C precursors during pyrolysis. </p> </div> </div> </div>

ELNES of Iron Compounds

1990 ◽  
Vol 48 (2) ◽  
pp. 28-29
Author(s):  
Hiroki Kurata ◽  
Kazuhiro Nagai ◽  
Seiji Isoda ◽  
Takashi Kobayashi
Keyword(s):  
Energy Loss ◽  
Metal Ions ◽  
Energy Resolution ◽  
Transition Metal Oxides ◽  
Local Symmetry ◽  
Iron Compounds ◽  
Fine Structures ◽  
Electron Energy Loss ◽  
Fe Ions ◽  
Electron Energy Loss Spectra

Electron energy loss spectra of transition metal oxides, which show various fine structures in inner shell edges, have been extensively studied. These structures and their positions are related to the oxidation state of metal ions. In this sence an influence of anions coordinated with the metal ions is very interesting. In the present work, we have investigated the energy loss near-edge structures (ELNES) of some iron compounds, i.e. oxides, chlorides, fluorides and potassium cyanides. In these compounds, Fe ions (Fe2+ or Fe3+) are octahedrally surrounded by six ligand anions and this means that the local symmetry around each iron is almost isotropic.EELS spectra were obtained using a JEM-2000FX with a Gatan Model-666 PEELS. The energy resolution was about leV which was mainly due to the energy spread of LaB6 -filament. The threshole energies of each edges were measured using a voltage scan module which was calibrated by setting the Ni L3 peak in NiO to an energy value of 853 eV.

Effect of pomegranate fruit supplementation on performance and various markers in athletes and active subjects: a systematic review

2019 ◽  
pp. 1-15
Author(s):  
Alicja Urbaniak ◽  
Anna Skarpańska-Stejnborn
Keyword(s):  
Vessel Diameter ◽  
Whole Body ◽  
Double Blind Study ◽  
Double Blind ◽  
Physically Active ◽  
Highly Active ◽  
Body Strength ◽  
Rate Of Increase ◽  
Study Designs ◽  
Pomegranate Fruit

Abstract. The aim of the study was to review recent findings on the use of POM supplements in athletes of various disciplines and physically active participants. Eleven articles published between 2010 and 2018 were included, where the total number of investigated subjects was 176. Male participants constituted the majority of the group (n = 155), as compared to females (n = 21). 45% of research described was conducted on athletes, whereas the remaining studies were based on highly active participants. Randomised, crossover, double-blind study designs constituted the majority of the experimental designs used. POM supplementation varied in terms of form (pills/juice), dosage (50 ml–500 ml) and time of intervention (7 days–2 months) between studies. Among the reviewed articles, POM supplementation had an effect on the improvement of the following: whole body strength; feeling of vitality; acute and delayed muscle fatigue and soreness; increase in vessel diameter; blood flow and serum level of TAC; reduction in the rate of increase for HR, SBP, CK and LDH; support in the recovery of post-training CK, LDH, CRP and ASAT to their baseline levels; reduction of MMP2, MMP9, hsCRP and MDA; and increased activity of antioxidant enzymes (glutathione peroxidase and superoxide dismutase). In the majority of reviewed articles POM supplementation had a positive effect on a variety of parameters studied and the authors recommended it as a supplement for athletes and physically active bodies.

ANTI-OVULATORY ACTIVITY OF STEROIDS ADMINISTERED BY GAVAGE IN THE ADULT OESTRUS RABBIT

1963 ◽  
Vol 42 (2_Suppl) ◽  
pp. S17-S30
Author(s):  
Fred A. Kind ◽  
Ralph I. Dorfman
Keyword(s):  
Dose Response ◽  
Active Compound ◽  
Subcutaneous Injection ◽  
Response Curve ◽  
Parent Compound ◽  
Dose Response Curve ◽  
Relative Potency ◽  
Reference Standard ◽  
Highly Active ◽  
Dose Levels

ABSTRACT Thirty-seven steroids have been studied as orally effective inhibitors of ovulation in the mated oestrus rabbit. Norethisterone served as the reference standard and a dose response curve was established between the 0.31 and 1.25 mg dose levels. Nine highly active anti-ovulatory compounds are described listed in a decreasing order of potency with norethisterone having the arbitrary value of one: 6-chloro-Δ6-dehydro-17α-acetoxyprogesterone (35), 6α-methyl-Δ1-dehydro-17α-acetoxyprogesterone (≥ 10), 6-fluoro-Δ6-dehydro-17α-acetoxyprogesterone(9), 6-methyl-Δ6-dehydro-17α-acetoxyprogesterone (5), Δ6-dehydro-17α-acetoxyprogesterone (≥ 3), 6α-methyl-17α-acetoxyprogesterone (2.6), 6-chloro-Δ1,6-bisdehydro-17α-acetoxyprogesterone (≥ 2), 2-hydroxymethyl-17α-methyl-17β-hydroxyandrostan-3-one (≥ 2), and 6α-fluoro-16α-methyl-17α-acetoxyprogesterone (≥ 1.25). The anti-ovulatory activity of a compound was not related necessarily to the progestational activity of a compound nor to the anti-gonadotrophic activity as measured in parabiotic rats. 6-Chloro-Δ60dehydro-17-acetoxyprogesterone was as effective by gavage as previously shown by subcutaneous injection. 2-Hydroxymethyl-17α-methyl-17β-hydroxyandrostan-3-one was at least 2.5 times more active by gavage than by injection. While 17α-acetoxyprogesterone was a very weak anti-ovulatory steroid, modifications of the structure by addition of methyl or halogen at the 6α position with or without unsaturation greatly increased the activity. 6-Chloro-Δ6-dehydro-27α-acetoxyprogesterone was the most active compound in this series showing a relative potency of 3500 times that of the parent compound 17α-acetoxyprogesterone.

ISOLEMENT ET QUELQUES CARACTERISTIQUES D'UNE GONADOTROPHINE URINAIRE DE MÉNOPAUSE HOMOGÈNE A L'ELECTROPHORÈSE

1960 ◽  
Vol XXXV (II) ◽  
pp. 225-234 ◽  
Author(s):  
R. Bourrillon ◽  
R. Got ◽  
R. Marcy
Keyword(s):  
Sialic Acid ◽  
Histological Study ◽  
Active Material ◽  
Biologically Active ◽  
New Method ◽  
Female Rats ◽  
Mouse Uterus ◽  
Highly Active ◽  
Zone Electrophoresis ◽  
Human Menopausal Gonadotrophin

ABSTRACT A new method for preparation of Human Menopausal Gonadotrophin involves successively alcoholic precipitation, kaolin adsorption and chromatography on ion exchangers. A highly active material is obtained which corresponds to 1 mg per litre of urine and has an activity of 1 mouse uterus unit at a dose of 0.003 mg. This gonadotrophin possesses both follicle stimulating and luteinizing activities in hypophysectomized female rats, by histological study. It contains 13 % hexose, 10% hexosamine and 8.5 % sialic acid. A further purification, by zone electrophoresis on starch, gives a final product, biologically active at 0.001 mg, which behaves as an homogenous substance in free electrophoresis with mobility −4.76 × 10−5 at pH 8.6.

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