Comparative analysis of the effect of Ca and Mg-Al modification on the composite inclusions in S50C Die steel

2021 ◽  
Vol 118 (5) ◽  
pp. 512
Author(s):  
Chen-wei Cao ◽  
Gao-feng Wang ◽  
Jie Li ◽  
Qian-ren Tian ◽  
Qiang-bin Zhu ◽  
...  
Keyword(s):  
Solid Phase ◽  
Equilibrium Shape ◽  
Die Steel ◽  
Al Content ◽  
Treatment Processes ◽  
Nucleation Sites ◽  
Effect Difference ◽  
Kinetic Calculations ◽  
And Control ◽  
Mg Content

At present, the effective ways to improve the cleanliness of S50C die steel are Ca or Mg-Al treatment processes. In order to explore the effect difference of two kinds of modification process of S50C killed steel, evaluate the industrial application prospect of the two processes, and clarify the modification mechanism. In this paper, the advantages of Mg-Al modification are demonstrated from the aspects of theoretical basis and actual sample modification effect. The thermodynamics and kinetics of inclusion precipitation, composition, morphology, and distribution are analyzed. The results show that: the precipitation temperature of MnS in S50C die steel is 1686 K, the corresponding solid-phase rate is 0.98. In Mg-Al modification, when the Al content is 332 ppm, the Mg content should be controlled below 14.1 ppm. When the Al content is higher than 0.02%, the Ca content should be controlled below 28.7 ppm. Kinetic calculations show that the equilibrium shape size of MnS is in the range of 0.3‑1.4 µm. Both modifications increase the nucleation rate of inclusions and control the shape and size of inclusions by pre-precipitation. Ca treatment is preventing the formation of large inclusions by forming calcium aluminate. Mg can provide more uniform nucleation sites and form smaller inclusions.

scholarly journals Fate of selected pharmaceuticals and personal care products after secondary wastewater treatment processes in Taiwan

2010 ◽  
Vol 62 (10) ◽  
pp. 2450-2458 ◽  
Author(s):  
Angela Yu-Chen Lin ◽  
Cheng-Fan Lin ◽  
Yu-Ting Tsai ◽  
Hank Hui-Hsiang Lin ◽  
Jie Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
High Performance ◽  
Wastewater Treatment Plants ◽  
Solid Phase ◽  
Personal Care Products ◽  
Personal Care ◽  
Matrix Interference ◽  
Treatment Processes ◽  
Liquid Chromatography Tandem Mass ◽  
Removal Efficiencies

Pharmaceuticals and personal care products (PPCPs) constitute a class of chemicals of emerging concern due to the potential risks they pose to organisms and the environment, even at low concentrations (ng/L). Recent studies have found that PPCPs are not efficiently removed in secondary wastewater treatment plants (WWTPs). This study has: (1) simultaneously investigated the occurrence of sixty-one PPCPs using solid phase extraction and high-performance liquid chromatography-tandem mass spectrometry, (2) evaluated removal efficiencies of target PPCPs in six WWTPs that discharge effluents into major Taiwanese rivers, and lastly (3) examined matrix interference during analysis of target PPCPs in water samples. The twenty target PPCPs were chosen for their high detection frequencies, high influent concentrations, and stability during wastewater treatment processes. Caffeine and acetaminophen were detected at the highest concentrations (as high as 24,467 and 33,400 ng/L) and were effectively removed (both >96%); other PPCPs were detected in the high ng/L range but were not effectively removed. Matrix interference (by ion suppression or enhancement) during the analysis resulted in underestimation of the removal efficiencies of erythromycin-H2O, cefazolin, clarithromycin, ibuprofen, diclofenac, clofibric acid and gemfibrozil.

Biosolids odor reduction by solids inventory management in the secondary activated sludge treatment system

2009 ◽  
Vol 59 (2) ◽  
pp. 241-247 ◽  
Author(s):  
K. Sekyiamah ◽  
H. Kim
Keyword(s):  
Activated Sludge ◽  
Inventory Management ◽  
Process Parameters ◽  
Treatment Plant ◽  
Treatment System ◽  
Sludge Treatment ◽  
System A ◽  
Treatment Processes ◽  
Dominant Process ◽  
And Control

A wastewater treatment plant consists of unit processes designed to achieve specific waste reduction goals. Offensive odors associated with these treatment processes are a constant source of public complaints. The purpose of this study was to statistically determine the process parameters that influence the formation of volatile sulfur compounds (VSCs) in the secondary treatment system. A statistical model was developed to relate the process parameters to the formation of VSCs in this system. The model established that F/M ratio, sludge blanket depth and SSV60 were the dominant process parameters that influenced the formation of VSCs in the secondary sedimentation basin. This model provides a useful tool for plant engineers to predict and control the VSC formation in a secondary activated sludge treatment system.

scholarly journals Thermodynamic assessment of (semi-)volatile hydrophobic organic chemicals in WWTP sludge – combining solid phase microextraction with non-target GC/MS

2018 ◽  
Vol 20 (12) ◽  
pp. 1728-1735 ◽  
Author(s):  
Karina Knudsmark Sjøholm ◽  
Matias Flyckt-Nielsen ◽  
Thomas D. Bucheli ◽  
Philipp Mayer
Keyword(s):  
Solid Phase Microextraction ◽  
Thermodynamic Assessment ◽  
Chemical Potential ◽  
Solid Phase ◽  
Exposure Level ◽  
Organic Chemicals ◽  
Hydrophobic Organic Chemicals ◽  
Digested Sludge ◽  
Treatment Processes ◽  
Effective Reduction

Equilibrium HS-SPME non-target GC/MS assessment of chemical potential of (semi-)volatile HOCs across treatment processes revealed increase from inlet to digested sludge, and effective reduction of the exposure level by co-composting.

scholarly journals Solidification and superlubricity with molecular alkane films

2019 ◽  
Vol 116 (51) ◽  
pp. 25418-25423 ◽  
Author(s):  
Alexander M. Smith ◽  
James E. Hallett ◽  
Susan Perkin
Keyword(s):  
Solid Phase ◽  
Molecular Layer ◽  
Friction Coefficients ◽  
Model Studies ◽  
Surface Alignment ◽  
Hydrocarbon Films ◽  
Nanoscale Films ◽  
Alkane Films ◽  
And Control ◽  
Single Molecular Layer

Hydrocarbon films confined between smooth mica surfaces have long provided an experimental playground for model studies of structure and dynamics of confined liquids. However, fundamental questions regarding the phase behavior and shear properties in this simple system remain unsolved. With ultrasensitive resolution in film thickness and shear stress, and control over the crystallographic alignment of the confining surfaces, we here investigate the shear forces transmitted across nanoscale films of dodecane down to a single molecular layer. We resolve the conditions under which liquid–solid phase transitions occur and explain friction coefficients spanning several orders of magnitude. We find that commensurate surface alignment and presence of water at the interfaces each lead to moderate or high friction, whereas friction coefficients down toμ≈0.001are observed for a single molecular layer of dodecane trapped between crystallographically misaligned dry surfaces. This ultralow friction is attributed to sliding at the incommensurate interface between one of the mica surfaces and the laterally ordered solid molecular film, reconciling previous interpretations.

scholarly journals Increased Aluminum Content in Certain Brain Structures is Correlated with Higher Silicon Concentration in Alcoholic Use Disorder

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1721 ◽  
Author(s):  
Cezary Grochowski ◽  
Eliza Blicharska ◽  
Jacek Bogucki ◽  
Jędrzej Proch ◽  
Aleksandra Mierzwińska ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Brain Structures ◽  
Brain Regions ◽  
Protective Role ◽  
Emission Spectrometry ◽  
Inductively Coupled ◽  
Al Content ◽  
And Control ◽  
The Brain

Introduction: Alcohol overuse may be related to increased aluminum (Al) exposure, the brain accumulation of which contributes to dementia. However, some reports indicate that silicon (Si) may have a protective role over Al-induced toxicity. Still, no study has ever explored the brain content of Al and Si in alcoholic use disorder (AUD). Materials and methods: To fill this gap, the present study employed inductively coupled plasma optical emission spectrometry to investigate levels of Al and Si in 10 brain regions and in the liver of AUD patients (n = 31) and control (n = 32) post-mortem. Results: Al content was detected only in AUD patients at mean ± SD total brain content of 1.59 ± 1.19 mg/kg, with the highest levels in the thalamus (4.05 ± 12.7 mg/kg, FTH), inferior longitudinal fasciculus (3.48 ± 9.67 mg/kg, ILF), insula (2.41 ± 4.10 mg/kg) and superior longitudinal fasciculus (1.08 ± 2.30 mg/kg). Si content displayed no difference between AUD and control, except for FTH. Positive inter-region correlations between the content of both elements were identified in the cingulate cortex, hippocampus, and ILF. Conclusions: The findings of this study suggest that AUD patients may potentially be prone to Al-induced neurodegeneration in their brain—although this hypothesis requires further exploration.

Microstructure Characteristic of AZ31/7005 Joints by GTAW with Filler Wire of Mg-Al Alloy

2014 ◽  
Vol 1004-1005 ◽  
pp. 168-171
Author(s):  
Hong Yan Du ◽  
Yaj Jang Li ◽  
Juan Wang
Keyword(s):  
Solid Solution ◽  
Intermetallic Compounds ◽  
Fusion Zone ◽  
Weld Zone ◽  
Dissimilar Materials ◽  
Eutectic Structure ◽  
Al Alloy ◽  
Test Results ◽  
Al Content ◽  
Mg Content

Mg/Al dissimilar materials were welded successfully by GTAW with SAlMg-1 and SAlMg-2 welding wire of Mg-Al system. The nice weld shape and free defects of joints are obtained. The test results indicated that continuous lamellar intermetallic compounds is not found The structure of Mg side in the fusion zone is composed of α-Mg solid solution+ β-Al12Mg17eutectic structure and precipitates β-A112lMg17on the grain boundary. The structure in the weld zone is mainly α-Mg solid solution + β-A112lMg17solid solutions. Mg and Al content are stable in the fusion zone of Mg side. However, in the weld zone of Mg side the Mg content is decreased gradually, and the Al content is increased that reaches a stable level in the weld zone of Al side. As a result, when Mg content in the wire can hold a proper level, the intermetallic compounds will be controlled effectively, and the performance of AZ31/7005 welding joint can be improved.

Study on Determination Method of the Volatile Organic Compounds Emissions from Particleboards for Indoor Finishing

2011 ◽  
Vol 250-253 ◽  
pp. 935-938 ◽  
Author(s):  
Shi Jing Sun ◽  
Jun Shen ◽  
Zhong Yuan Zhao
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Solid Phase ◽  
Practical Method ◽  
Simple Operation ◽  
Good Shape ◽  
Volatile Organic ◽  
Static Head ◽  
And Control ◽  
Larix Gmelini

In order to comprehensive understand and control volatile organic compounds (VOCs) release from particleboards, this paper takes Larix gmelini particleboard as example and analyzes VOCs by three different methods. First of all, VOCs of Larix gmelini particles were detected by the static head space solid-phase micro-extraction (HS-SPME) technique. Secondly Larix gmelini particleboards were analyzed using the method of adsorbed by activated carbon, desorpted with methylene dichloride and measured by GC/MS. Finally, Tenax-T Thermal desorption -GC/MS was used to qualitative VOCs emissions. The best method for determination VOCs from particleboards was found. SPME is a simple operation method with short time. But the pretreatment of sample was troublesome and it is not easily measured for lower concentration particleboards. Active carbon absorption method is not suitable for quantitative because of much error in extraction. It is suitable for qualitative analysis. Tenax-T is a simple operation way with short analysis time and good shape of chromatographic. It is a convenient and practical method. Further study of VOCs emission of panels can be supported by this method.

scholarly journals Effect of Model Sorptive Phases on Phenanthrene Biodegradation: Molecular Analysis of Enrichments and Isolates Suggests Selection Based on Bioavailability

2000 ◽  
Vol 66 (7) ◽  
pp. 2703-2710 ◽  
Author(s):  
M. Friedrich ◽  
R. J. Grosser ◽  
E. A. Kern ◽  
W. P. Inskeep ◽  
D. M. Ward
Keyword(s):  
Natural Organic Matter ◽  
Contaminated Soils ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Solid Phase ◽  
Cation Exchange Resin ◽  
16S Rrna Sequence ◽  
Enrichment Cultures ◽  
Gradient Gel Electrophoresis ◽  
Weak Cation Exchange ◽  
And Control

ABSTRACT Reduced bioavailability of nonpolar contaminants due to sorption to natural organic matter is an important factor controlling biodegradation of pollutants in the environment. We established enrichment cultures in which solid organic phases were used to reduce phenanthrene bioavailability to different degrees (R. J. Grosser, M. Friedrich, D. M. Ward, and W. P. Inskeep, Appl. Environ. Microbiol. 66:2695–2702, 2000). Bacteria enriched and isolated from contaminated soils under these conditions were analyzed by denaturing gradient gel electrophoresis (DGGE) and sequencing of PCR-amplified 16S ribosomal DNA segments. Compared to DGGE patterns obtained with enrichment cultures containing sand or no sorptive solid phase, different DGGE patterns were obtained with enrichment cultures containing phenanthrene sorbed to beads of Amberlite IRC-50 (AMB), a weak cation-exchange resin, and especially Biobead SM7 (SM7), a polyacrylic resin that sorbed phenanthrene more strongly. SM7 enrichments selected for mycobacterial phenanthrene mineralizers, whereas AMB enrichments selected for a Burkholderia sp. that degrades phenanthrene. Identical mycobacterial andBurkholderia 16S rRNA sequence segments were found in SM7 and AMB enrichment cultures inoculated with contaminated soil from two geographically distant sites. Other closely relatedBurkholderia sp. populations, some of which utilized phenanthrene, were detected in sand and control enrichment cultures. Our results are consistent with the hypothesis that different phenanthrene-utilizing bacteria inhabiting the same soils may be adapted to different phenanthrene bioavailabilities.

Polycrystalline Si Films Fabricated by Low Temperature Selective Nucleation and Solid Phase Epitaxy Process

1997 ◽  
Vol 485 ◽  
Author(s):  
Claudine M. Chen ◽  
Harry A. Atwater
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Crystal Growth ◽  
Incubation Time ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Grain Sizes ◽  
Random Nucleation ◽  
Nucleation Sites ◽  
Si Films

AbstractWith a selective nucleation and solid phase epitaxy (SNSPE) process, grain sizes of 10 μm have been achieved to date at 620°C in 100 nrm thick silicon films on amorphous SiO2, with potential for greater grain sizes. Selective nucleation occurs via a thin film reaction between a patterned array of 20 rnm thick indium islands which act as heterogeneous nucleation sites on the amorphous silicon starting material. Crystal growth proceeds by lateral solid phase epitaxy from the nucleation sites, during the incubation time for random nucleation. The largest achievable grain size by SNSPE is thus approximately the product of the incubation time and the solid phase epitaxy rate. Electronic dopants, such as B, P, and Al, are found to enhance the solid phase epitaxy rate and affect the nucleation rate.

Sign in / Sign up

Export Citation Format

Share Document