Machines and technology for the manufacture of textile yarns fully drawn in a one-stage process

1994 ◽  
Vol 25 (4) ◽  
pp. 239-242
Keyword(s):  
One Stage ◽  
Stage Process

scholarly journals Effect of Corrosive Media on the Chemical and Mechanical Resistance of IPS e.max® CAD Based Li2Si2O5 Glass-Ceramics

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 365
Author(s):  
Anna Švančárková ◽  
Dagmar Galusková ◽  
Aleksandra Ewa Nowicka ◽  
Helena Pálková ◽  
Dušan Galusek
Keyword(s):  
Wear Resistance ◽  
Acetic Acid ◽  
Prolonged Exposure ◽  
Glass Ceramics ◽  
Mechanical Resistance ◽  
Two Stage ◽  
Lithium Metasilicate ◽  
Dynamic Conditions ◽  
One Stage ◽  
Stage Process

The influence of 4% acetic acid (pH~2.4) and an alkaline solution of NaOH (pH~10) on the corrosion resistance and micromechanical properties of disilicate crystals containing glass-ceramics (LS2-GC’s) is studied. Partially crystallized lithium metasilicate crystal containing glass-ceramics (LS-GC’s) are annealed to fully LS2-GC’s using a one stage and a two-stage heating to induce nucleation. Materials with various chemical and wear resistance are prepared. The content of the crystalline phase in the material annealed in the two-stage process A is 60.0% and increases to 72.2% for the material heated in the one-stage process B. The main elements leached in the acidic medium are lithium and phosphorus, while lithium, silicon, and phosphorus leached into the alkaline environment. Material B exhibits better chemical resistance to the corrosive influence of 4% acetic acid under quasi-dynamic conditions. In the alkaline corrosion medium, silicon is leached from material A faster compared to the material B. After prolonged exposure to acidic or basic environments, both materials show evidence of surface structural changes. A decrease of the sliding wear resistance is observed after corrosion in the acidic environment under dynamic conditions. In both materials, the wear rate increases after corrosion.

Modelling thermophilic cheese whey bioremediation in a one-stage process

2007 ◽  
Vol 35 (3) ◽  
pp. 281-288 ◽  
Author(s):  
M.R. Kosseva ◽  
A. Fatmawati ◽  
M. Palatova ◽  
C.A. Kent
Keyword(s):  
Cheese Whey ◽  
One Stage ◽  
Stage Process

scholarly journals Comparison of the Properties of Activated Carbons Produced in One-Stage and Two-Stage Processes

2018 ◽  
Vol 4 (3) ◽  
pp. 41 ◽  
Author(s):  
Davide Bergna ◽  
Toni Varila ◽  
Henrik Romar ◽  
Ulla Lassi
Keyword(s):  
Carbon Content ◽  
Activated Carbons ◽  
Total Carbon ◽  
Activation Process ◽  
Two Stage ◽  
One Stage ◽  
Surface Areas ◽  
Significant Difference ◽  
Stage Process ◽  
The One

Activated carbons (ACs) can be produced from biomass in a thermal process either in a direct carbonization-activation process or by first carbonizing the biomass and later activating the bio-chars into activated carbons. The properties of the ACs are dependent on the type of process used for production. In this study, the properties of activated carbons produced in one-stage and two-stage processes are considered. Activated carbons were produced by physical activation of two types of starting materials: bio chars produced from spruce and birch chips in a commercial carbonization plant and from the corresponding raw chips. The activated carbons produced were characterized regarding specific surfaces, pore volumes, and pore size distributions. The un-activated bio chars had varying surface areas, 190 and 140 m2 g−1 for birch and spruce, respectively, and pore volumes of 0.092 and 0.067 cm3 g−1, respectively. On the other hand, 530–617 and 647–679 m2 g−1 for activated bio chars from birch and spruce, respectively, and pore volumes 0.366–0.509 and 0.545–0.555 cm3 g−1, respectively, were obtained. According to the results obtained, two slightly different types of activated carbons are produced depending on whether a one-stage or a two-stage carbonization and activation process is used. The ACs produced in the one-stage process had higher specific surface areas (SSA), according to the BET-model (Brunauer–Emmett–Teller), compared to the ones produced in a two-stage process (761–940 m2 g−1 vs. 540–650 m2 g−1, respectively). In addition, total pore volumes were higher in ACs from the one-stage process, but development of micro-pores was greater compared to those of the two-stage process. This indicates that the process can have an influence on the ACs’ porosity. There was no significant difference in total carbon content in general between the one-stage and two-stage processes for spruce and birch samples, but some differences were seen between the starting materials. Especially in the one-stage procedure with 2 and 4 h steam activation, there was nearly a 10% difference in carbon content between the spruce and birch samples.

scholarly journals Comparison of the Properties of Activated Carbons Produced in a One-stage And a Two-Stage Process

2018 ◽  
Author(s):  
Davide Bergna ◽  
Toni Varila ◽  
Henrik Romar ◽  
Ulla Lassi
Keyword(s):  
Activated Carbons ◽  
Total Carbon ◽  
Physical Activation ◽  
Activation Process ◽  
Two Stage ◽  
Total Carbon Content ◽  
One Stage ◽  
Pore Size Distributions ◽  
Significant Difference ◽  
Stage Process

Activated carbons (ACs) can be produced from biomass in a thermal process either in a direct carbonization-activation process or first by carbonizing the biomass and later on activating the biochars into activated carbons. The properties of the ACs are dependent on the type of process used for production. In this study, the properties of activated carbons produced in a one-stage and a two-stage process are considered. Activated carbons were produced by physical activation of two types of starting materials, biochars produced from spruce and birch chips in a commercial carbonization plant and from the corresponding raw chips. The activated carbons produced were characterized regarding specific surfaces, pore volumes and pore size distributions. The unactivated biochars had some degree of surface area and some porosity. According to the results obtained, two slightly different types of activated carbons are produced depending if a one-stage or a two-stage carbonization and activation process is used. The ACs produced in the one-stage process had higher specific surface areas compared to the ones produced in a two-stage process. In addition, total pore volumes were higher in one-stage process but development of micropores is greater compared to two-stage process. There was no significant difference in total carbon content between one-stage and two-stage process.

scholarly journals Activated carbons from golden shower upon different chemical activation methods: Synthesis and characterizations

2017 ◽  
Vol 36 (1-2) ◽  
pp. 95-113 ◽  
Author(s):  
Hai Nguyen Tran ◽  
Huan-Ping Chao ◽  
Sheng-Jie You
Keyword(s):  
Thermal Stability ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Two Stage ◽  
One Stage ◽  
Crystal Properties ◽  
Boehm Titration ◽  
Stage Process ◽  
The One ◽  
Subsequent Chemical

Activated carbons (ACs) were synthesized from golden shower (GS) through chemical activation. Two synthesis processes were used: one-stage and two-stage processes. In the one-stage process, GS that was impregnated with K2CO3 was directly pyrolyzed (GSAC), and the two-stage process consisted of (1) pyrolytic or hydrolytic carbonization to produce biochar or hydrochar and (2) subsequent chemical activation was defined as GSBAC and GSHAC, respectively. The activated carbon’s characteristics—thermal stability and textural, physicochemical, structural, and crystal properties—were thoroughly investigated. Results demonstrated that the characteristics of activated carbons strongly depend on the method used for their synthesis. The Brunauer–Emmett–Teller surface area followed the order GSAC (1413 m2/g) > GSHAC (1238 m2/g) > GSBAC (812 m2/g). The existence of acidic groups was determined through Fourier transform infrared spectroscopy and Boehm titration. The excellent adsorptive capacities of the activated carbons were confirmed from the iodine number (1568–2695 mg/g) and methylene number (143–233 mg/g).

A comparison between thin film solar cells made from co-evaporated CuIn1-xGaxSe2using a one-stage process versus a three-stage process

2014 ◽  
Vol 23 (4) ◽  
pp. 470-478 ◽  
Author(s):  
Pedro M.P. Salomé ◽  
Viktor Fjällström ◽  
Piotr Szaniawski ◽  
Joaquim P. Leitão ◽  
Adam Hultqvist ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Thin Film Solar Cells ◽  
One Stage ◽  
Stage Process

Ethylene from Methane by a One-Stage Process: Product Distribution along a Tubular Reactor

1994 ◽  
Vol 33 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Marian Taniewski ◽  
Alfred Lachowicz ◽  
Rita Lachowicz ◽  
Dymitr Czechowicz ◽  
Krzysztof Skutil
Keyword(s):  
Tubular Reactor ◽  
Product Distribution ◽  
One Stage ◽  
Stage Process ◽  
Process Product
Sign in / Sign up

Export Citation Format

Share Document