scholarly journals Enhancement of Solvent Resistance of Polyimide Electrospun Mat via the UV-Assisted Electrospinning and Photosensitive Varnish

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2055 ◽  
Author(s):  
Lin Qi ◽  
Chen-Yu Guo ◽  
Meng-Ge Huang Fu ◽  
Yan Zhang ◽  
Lu-meng Yin ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Uv Irradiation ◽  
Starting Material ◽  
Current Work ◽  
Mercury Lamp ◽  
Solvent Resistance ◽  
One Step ◽  
The One

A new methodology for enhancing the solvent resistance of electrospun polyimide (PI) ultrafine fibrous mat (UFM) was investigated in the current work. For this purpose, a negative intrinsically photosensitive polyimide (PSPI) resin was prepared by the one-step high- temperature polycondensation procedure from 3,3’,4,4’-benzophenonetetracarboxylic dianhydride (BTDA) and α,α-bis(4-amino-3,5-dimethylphenyl)phenylmethane (PTMDA). The PI varnish, by dissolving the derived PI (BTDA-PTMDA) resin in N,N-dimethylacetamide (DMAc) at a solid of 20 wt %, was used as the starting material for the standard electrospinning (ES) and ultraviolet-assisted ES (UVAES) fabrications, respectively. The 365 nm wavelength of the high-pressure mercury lamp ultraviolet (UV) irradiation induced the photocrosslinking reaction in the PSPI mat. Solubility tests indicated that the PI UFM fabricated by standard ES procedure showed poor DMAc resistance, while the one by UVAES (PI-UV) exhibited excellent resistance to DMAc.

One-step electrocatalytic synthesis of ammonia and acetone from nitrogen and isopropanol in an ionic liquid

2021 ◽  
Author(s):  
Qikun Zhang ◽  
Ya'nan Zhao ◽  
Liping Yu ◽  
Xiaoyang Zhang ◽  
Yiling Bei ◽  
...  
Keyword(s):  
High Pressure ◽  
Ionic Liquid ◽  
High Temperature ◽  
Synthesis Method ◽  
Environmentally Friendly ◽  
Ambient Conditions ◽  
One Step ◽  
The One

Electrocatalysis is an environmentally friendly synthesis method that overcomes thermodynamic limitations and enables some reactions usually requiring high temperature and high pressure to be realized under ambient conditions. The one-step...

Effect of Small, Acid-Soluble Proteins on Spore Resistance and Germination under a Combination of Pressure and Heat Treatment

2007 ◽  
Vol 70 (9) ◽  
pp. 2168-2171
Author(s):  
JONG-KYUNG LEE ◽  
SARA MOVAHEDI ◽  
STEPHEN E. HARDING ◽  
BERNARD M. MACKEY ◽  
WILLIAM M. WAITES
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
High Temperature ◽  
Spore Germination ◽  
Soluble Proteins ◽  
Wild Type ◽  
Spore Resistance ◽  
Pressure Resistance ◽  
The One

To find the range of pressure required for effective high-pressure inactivation of bacterial spores and to investigate the role of α/β-type small, acid-soluble proteins (SASP) in spores under pressure treatment, mild heat was combined with pressure (room temperature to 65°C and 100 to 500 MPa) and applied to wild-type and SASP-α−/β− Bacillus subtilis spores. On the one hand, more than 4 log units of wild-type spores were reduced after pressurization at 100 to 500 MPa and 65°C. On the other hand, the number of surviving mutant spores decreased by 2 log units at 100 MPa and by more than 5 log units at 500 MPa. At 500 MPa and 65°C, both wild-type and mutant spore survivor counts were reduced by 5 log units. Interestingly, pressures of 100, 200, and 300 MPa at 65°C inactivated wild-type SASP-α+/β+ spores more than mutant SASP-α−/β− spores, and this was attributed to less pressure-induced germination in SASP-α−/β− spores than in wild-type SASP-α+/β+ spores. However, there was no difference in the pressure resistance between SASP-α+/β+ and SASP-α−/β− spores at 100 MPa and ambient temperature (approximately 22°C) for 30 min. A combination of high pressure and high temperature is very effective for inducing spore germination, and then inactivation of the germinated spore occurs because of the heat treatment. This study showed that α/β-type SASP play a role in spore inactivation by increasing spore germination under 100 to 300 MPa at high temperature.

A sintering burden blending model based on one-step optimization method and high-temperature characteristics of iron ore

2019 ◽  
Vol 116 (2) ◽  
pp. 211
Author(s):  
Shengli Wu ◽  
Xiaobo Zhai ◽  
Tiankai Song
Keyword(s):  
High Temperature ◽  
Iron Ore ◽  
Intelligent System ◽  
Quantitative Relationship ◽  
High Strength ◽  
Optimization Method ◽  
Temperature Characteristics ◽  
Positive Effects ◽  
One Step ◽  
The One

A sintering burden blending model is an intelligent system used to obtain the optimal blending proportions of burdens with minimal sintering burden cost. In this study, micro-sintering and sinter pot tests were first carried out to clarify the quantitative relationship between the shatter index (SI) of the sinter and high-temperature characteristics (HTCs) of the ore blends. The result shows that the lowest assimilation temperature (LAT) plays a dual role in SI, whereas the index of liquid phase fluidity (ILF) and compressive strength of the bonding phase (CSB) have positive effects on SI. The effect of the ILF is the largest. Based on the one-step optimization method, suitable ranges of room-temperature characteristics (RTCs) of ore blends, obtained relationship between sinter strength and HTCs of ore blends, sintering theory, and bisection and simplex algorithms, the proposed sintering burden blending model is established. The validation for the model shows that it is effective at utilizing iron ore resources, maintaining high strength of the sinter, while reducing burden costs.

Synthesis of Casein Related Peptides and Phosphopeptides. XIV. Solid Phase Synthesis of Glu-Ser(P)-Leu Through the Use of Protected Boc-Ser(PO3R2)-OH Derivatives

1991 ◽  
Vol 44 (6) ◽  
pp. 771 ◽  
Author(s):  
JW Perich ◽  
RM Valerio ◽  
PF Alewood ◽  
RB Johns
Keyword(s):  
High Pressure ◽  
Peptide Synthesis ◽  
Solid Phase ◽  
Phenyl Group ◽  
High Yield ◽  
Palladium Acetate ◽  
Phase Method ◽  
Phenyl Phosphate ◽  
One Step ◽  
The One

A solid phase method is described for the synthesis of O- phosphoseryl-containing peptides by the use of polystyrene resin (Merrifield) as the peptide support and protected Boc-Ser(PO3R2)-OH derivatives for the incorporation of the phosphorylated seryl residue. The viability of this solid phase approach was demonstrated by the synthesis of HBr.H-Glu-Ser (PO3Et2)-Leu-OH in high yield by the use of Bo -Ser(PO3Et2)-OH in peptide synthesis and subsequent use of HBr/CF3CO2H for cleavage of the Ser(PO3Et2)-containing tripeptide from the resin support. Similarly, the dipeptide, CF3CO2H.H-Ser(P)- Leu -OH, was prepared in high yield by using Boc -Ser(PO3But2)-OH in peptide synthesis followed by the one-step deprotection of the Ser(PO3But2)- dipeptide resin by treatment with HBr/CF3CO2H (90 min). Alternatively, the O-phosphoseryl tripeptide , CF3CO2H.H-Glu-Ser(P)- Leu -OH was prepared by using either Ppoc -Ser(PO3Bzl2)-OH or Boc-Ser(PO3Ph2)-OH in peptide synthesis. The one-step deprotection of the Ser(PO3Bzl2)-containing tripeptide and cleavage of the peptide from the resin support was effected by high-pressure hydrogenolysis (palladium acetate). In the case of phenyl phosphate protection, the Ser(PO3Ph2)-containing peptide was cleaved from the resin support by high-pressure hydrogenolysis (palladium acetate) followed by cleavage of the phenyl phosphate groups by platinum-mediated hydrogenolysis (1.0 equiv. PtO2/phenyl group) in 50% CF3CO2H/AcOH.

Gradation Process by Imbibition in WC-Co for Mining Tools Application

2009 ◽  
Vol 83-86 ◽  
pp. 810-817
Author(s):  
Elodie Lefort-Sorlier ◽  
Christophe Colin ◽  
Alfazazi Dourfaye
Keyword(s):  
Grain Size ◽  
High Pressure ◽  
High Temperature ◽  
Thermal Processing ◽  
Temperature Step ◽  
High Pressure High Temperature ◽  
One Step ◽  
Shock Resistance ◽  
Composition Gradients ◽  
Mining Tools

Continuous composition gradients of several millimetres were generated in commercial WC-Co cutters to improve their shock resistance. This important gradation was obtained in one-step by using the imbibition process. The effects of this thermal processing were analysed in terms of microhardness, cobalt concentration and WC grain size. A gradient of a 300 HV amplitude is measured in the 8 mm-height sample treated by the imbibition process in association with a boron-rich coating. This gradient was preserved after the HPHT (high pressure – high temperature) step used for the diamond table deposition on the WC-Co cutter. To our knowledge, such gradients have never before been reported and should certainly increase cutter service life.

Ultraviolet irradiation combined with manganese ore catalyzed ozonation of 4-chlorophenol in aqueous solution

2010 ◽  
Vol 10 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Jie Fu ◽  
Guo Chen ◽  
Ying Yang ◽  
Zhi-Ming Zhang ◽  
Qing-Fu Zeng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
High Pressure ◽  
Uv Irradiation ◽  
Catalytic Effect ◽  
Ph Value ◽  
Manganese Ore ◽  
Mercury Lamp ◽  
Acid Condition ◽  
Important Species ◽  
Uv Lamp

We have investigated ultraviolet (UV) irradiation combined with manganese ore (MO) catalyzed ozonation of 4-cholorophenol (4-CP) in aqueous solution. The preliminary results showed UV irradiation and MO had a strong synergetic catalytic effect on ozonation. We also studied the effect of UV lamp power, MO dosage, O3 dosage, initial 4-CP concentration, pH value and temperature. The results showed that high pressure mercury lamp (HPML) was more favorable for the degradation of 4-CP than low pressure mercury lamp (LPML). The optimal MO and O3 dosages were 2 g/L and 2 g/h respectively. When the 4-CP concentration was over 15 mg/L, the decrease of degradation efficiency accelerated. The acid condition was favorable for the degradation of 4-CP by UV/MO/O3. The reaction temperature could not be over 50°C. Through the mechanism discussion, we found that Mn2 +  was the most important species to catalyze the ozonation. In addition, UV irradiation could also accelerate the degradation by promoting the production of ∙OH.

Using hydrogen peroxide to mediate through a one-step hydrothermal method for the fast and green synthesis of N-CDs

RSC Advances ◽  
2015 ◽  
Vol 5 (116) ◽  
pp. 95744-95749 ◽  
Author(s):  
Jiangling He ◽  
Bingfu Lei ◽  
Haoran Zhang ◽  
Mingtao Zheng ◽  
Hanwu Dong ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
High Pressure ◽  
High Temperature ◽  
Green Synthesis ◽  
Hydrothermal Method ◽  
Formation Mechanism ◽  
Formation Process ◽  
Top Down ◽  
Bottom Up ◽  
One Step

The strategy for the formation mechanism of N-CDs under high temperature and high pressure can be summarized as consisting of two parts including top-down and bottom-up. It can serve as an efficient way to express the detailed formation process of N-CDs.

High Temperature Mechanical Properties of Ti(C,N)-Co-Mo2C Cermets

2009 ◽  
Vol 423 ◽  
pp. 83-88 ◽  
Author(s):  
Angela Gallardo-López ◽  
A. Morales-Rodríguez ◽  
Arturo Domínguez-Rodríguez ◽  
J.M. Córdoba ◽  
M.A. Avilés ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Inert Atmosphere ◽  
Plastic Behavior ◽  
Compression Tests ◽  
Creep Tests ◽  
Temperature Oxidation ◽  
High Temperature Mechanical Properties ◽  
One Step ◽  
The One

The creep behavior of a TiCxN1-x-Co-Mo2C cermet has been investigated at temperatures between 1100-1200°C in an inert atmosphere to assess the one step mechanically induced self-sustaining reaction synthesis and pressureless sintering process, and the influence of the Mo2C additive in the high temperature mechanical properties of this cermet. The samples deform plastically at the chosen temperatures, and values of the stress exponent (n=1.70.6) and activation energy (Q= 4.30.5 eV) have been estimated from uniaxial compression tests. No significant grain growth has been detected after deformation. The reproducibility of the creep tests compared to other compositions indicates that the Mo2C addition contributes to increase notably the resistance to high temperature oxidation of the samples, so that the plastic behavior is not affected by oxidation when deformation experiments are performed in an inert atmosphere.

scholarly journals Transketolase catalysed upgrading of l-arabinose: the one-step stereoselective synthesis of l-gluco-heptulose

2016 ◽  
Vol 18 (10) ◽  
pp. 3158-3165 ◽  
Author(s):  
Fabiana Subrizi ◽  
Max Cárdenas-Fernández ◽  
Gary J. Lye ◽  
John M. Ward ◽  
Paul A. Dalby ◽  
...  
Keyword(s):  
Stereoselective Synthesis ◽  
Starting Material ◽  
E Coli ◽  
One Step ◽  
Scalable Synthesis ◽  
The One

Biocatalytic conversions using E. coli transketolase variants have been developed for the efficient, scalable synthesis of l-gluco-heptulose from the sustainable starting material l-arabinose.

scholarly journals Synthesis and high-pressure studies of strontium diazenide by synchrotron X-ray diffraction and DFT calculations

RSC Advances ◽  
2020 ◽  
Vol 10 (44) ◽  
pp. 26308-26312
Author(s):  
Yue Li ◽  
Huanpeng Bu ◽  
Qinglin Wang ◽  
Jiani Lin ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Dft Calculations ◽  
Starting Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Conditions ◽  
High Pressure Studies

In this work, strontium diazenide (SrN2) was synthesized using strontium azide as a starting material in a Walker-type module under high-pressure and high-temperature conditions.

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