scholarly journals Effect of Different CO2 Treatments on the Metal Leaching in Steel Slag Binders

2021 ◽  
Vol 9 ◽  
Author(s):  
Yaojun Liu ◽  
Jingrui Fang ◽  
Songhui Liu ◽  
Xiaopeng An ◽  
Yanwen Kang ◽  
...  
Keyword(s):  
Steel Slag ◽  
High Volume ◽  
Accelerated Carbonation ◽  
Silicate Structure ◽  
The Matrix ◽  
Curing Methods ◽  
Chemical States ◽  
Eaf Slag ◽  
Carbonation Curing

Carbonation is an effective method to promote the quality of the steel slag binder. In this article, two carbonation approaches, namely hot-stage carbonation and accelerated carbonation, were employed to leach the metals, and the influence mechanism on the metal sequential leachability of the binders composed of 80 wt% of EAF slag incorporating 20 wt% of Portland cement (PC) was revealed. The carbonate products, microstructures, and chemical states were investigated, and the results indicated that chromium, vanadium, and titanium gradually transformed into inactive phases after two carbonation approaches, while zinc appeared the opposite trend. The sequential leachability of chromium declined with the increase of the carbonation efficiency, in which the exchangeable chromium decreased from 1.99 mg/kg in the A2A binder to below the detection limit in the A2C binder and C2C binder. Hot-stage carbonation treatment facilitated particle agglomeration, minerals remodeling, and calcite formation. The carbonation curing of the steel slag paste resulted in the formation of amorphous CaCO3, calcite crystalline and Si-bearing hydrates that covered the pores of the matrix, and silicate structure with a higher disorder. The hot-stage carbonation and accelerated carbonation curing methods were adopted to jointly prevent the leaching of harmful metals and facilitate promising high-volume steel slag-based binders with structural densification and CO2 storage.

The Properties of Steel Slag Bricks Prepared by both Alkali Activation and Accelerated Carbonation

2012 ◽  
Vol 509 ◽  
pp. 113-118 ◽  
Author(s):  
Wen Sheng Zhang ◽  
Di Shi ◽  
Zhong Jun Shao ◽  
Jia Yuan Ye ◽  
Yuan Wang
Keyword(s):  
Compressive Strength ◽  
Dominant Role ◽  
Steel Slag ◽  
Alkali Activation ◽  
Accelerated Carbonation ◽  
Mineral Compositions ◽  
Physical And Chemical ◽  
Carbonation Curing

The physical and chemical evolutions, including strength, porosity, chemical and mineral compositions, of properties of steel slag bricks prepared by both alkali activation and accelerated carbonation were investigated. The results show that alkali activation provides the initial properties, while accelerated carbonation plays a dominant role in such final performances as strength, porosity, chemical and mineral compositions of steel slag bricks. The steel slag bricks with a compressive strength of 33.8MPa, carbonation degree of 8.92% and porosity of 23.25% were successfully prepared after accelerated carbonation curing (T=50°C, RH=60%, P=0.25MPa, ρCO2=80% by volume) for 120min.

Effect of mechanical restraint on the rate of corrosion in concrete

1998 ◽  
Vol 25 (1) ◽  
pp. 81-86 ◽  
Author(s):  
N Hearn ◽  
J Aiello
Keyword(s):  
Mix Design ◽  
Concrete Repair ◽  
Accelerated Corrosion ◽  
One Dimensional ◽  
Mechanical Restraint ◽  
Corrosion Rates ◽  
Accelerated Corrosion Tests ◽  
The Matrix ◽  
The Relationship

Experimental work on prismatic concrete specimens was conducted to determine the relationship between mechanical restraint and the rate of corrosion. The current together with the changes in strain of the confining frame were monitored during the accelerated corrosion tests. The effect of mix design and cracking on the corrosion rates was also investigated. The results show that one-dimensional mechanical restraint retards the corrosion process, as indicated by the reduction in the steel loss. Improved quality of the matrix, with and without cracking, reduces the rate of steel loss. In the inferior quality concrete, the effect of cracking on the corrosion rate is minimal.Key words: corrosion, concrete, repair.

scholarly journals Resilience to maintain quality of intrapartum care in war torn Yemen: a retrospective pre-post study evaluating effects of changing birth volumes in a congested frontline hospital

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Josephine Obel ◽  
Antonio Isidro Carrion Martin ◽  
Abdul Wasay Mullahzada ◽  
Ronald Kremer ◽  
Nanna Maaløe
Keyword(s):  
Quality Of Care ◽  
Birth Outcomes ◽  
Birth Outcome ◽  
High Volume ◽  
Maternal Health Service ◽  
Service Access ◽  
Intrapartum Care ◽  
Health Service Access ◽  
Low Volume

Abstract Background Fragile and conflict-affected states contribute with more than 60% of the global burden of maternal mortality. There is an alarming need for research exploring maternal health service access and quality and adaptive responses during armed conflict. Taiz Houbane Maternal and Child Health Hospital in Yemen was established during the war as such adaptive response. However, as number of births vastly exceeded the facility’s pre-dimensioned capacity, a policy was implemented to restrict admissions. We here assess the restriction’s effects on the quality of intrapartum care and birth outcomes. Methods A retrospective before and after study was conducted of all women giving birth in a high-volume month pre-restriction (August 2017; n = 1034) and a low-volume month post-restriction (November 2017; n = 436). Birth outcomes were assessed for all births (mode of birth, stillbirths, intra-facility neonatal deaths, and Apgar score < 7). Quality of intrapartum care was assessed by a criterion-based audit of all caesarean sections (n = 108 and n = 82) and of 250 randomly selected vaginal births in each month. Results Background characteristics of women were comparable between the months. Rates of labour inductions and caesarean sections increased significantly in the low-volume month (14% vs. 22% (relative risk (RR) 0.62, 95% confidence interval (CI) 0.45-0.87) and 11% vs. 19% (RR 0.55, 95% CI 0.42-0.71)). No other care or birth outcome indicators were significantly different. Structural and human resources remained constant throughout, despite differences in patient volume. Conclusions Assumptions regarding quality of care in periods of high demand may be misguiding - resilience to maintain quality of care was strong. We recommend health actors to closely monitor changes in quality of care when implementing resource changes; to enable safe care during birth for as many women as possible.

scholarly journals Face Grinding Surface Quality of High Volume Fraction SiCp/Al Composite Materials

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Xu Zhao ◽  
Yadong Gong ◽  
Guiqiang Liang ◽  
Ming Cai ◽  
Bing Han
Keyword(s):  
Friction Coefficient ◽  
Surface Morphology ◽  
Surface Quality ◽  
Volume Fraction ◽  
High Volume ◽  
Spindle Speed ◽  
High Volume Fraction ◽  
Machining Parameters ◽  
Al Composite

AbstractThe existing research on SiCp/Al composite machining mainly focuses on the machining parameters or surface morphology. However, the surface quality of SiCp/Al composites with a high volume fraction has not been extensively studied. In this study, 32 SiCp/Al specimens with a high volume fraction were prepared and their machining parameters measured. The surface quality of the specimens was then tested and the effect of the grinding parameters on the surface quality was analyzed. The grinding quality of the composite specimens was comprehensively analyzed taking the grinding force, friction coefficient, and roughness parameters as the evaluation standards. The best grinding parameters were obtained by analyzing the surface morphology. The results show that, a higher spindle speed should be chosen to obtain a better surface quality. The final surface quality is related to the friction coefficient, surface roughness, and fragmentation degree as well as the quantity and distribution of the defects. Lower feeding amount, lower grinding depth and appropriately higher spindle speed should be chosen to obtain better surface quality. Lower feeding amount, higher grinding depth and spindle speed should be chosen to balance grind efficiently and surface quality. This study proposes a systematic evaluation method, which can be used to guide the machining of SiCp/Al composites with a high volume fraction.

Strength Development and Products Evolution of β-C2S and γ-C3S Induced by Accelerated Carbonation Curing

2020 ◽  
Vol 35 (6) ◽  
pp. 1053-1060
Author(s):  
Yanfeng Fang ◽  
Zhichao Liu ◽  
Qinghe Wang ◽  
Yuzhuo Zhang ◽  
Miao Zhang ◽  
...  
Keyword(s):  
Strength Development ◽  
Accelerated Carbonation ◽  
Carbonation Curing

scholarly journals The emergence of coercive federal Australian labour law, 1901–2020

2021 ◽  
pp. 002218562110039
Author(s):  
Eugene Schofield-Georgeson
Keyword(s):  
Industrial Relations ◽  
High Volume ◽  
Union Power ◽  
Labour Law ◽  
Industrial Environment ◽  
The Past ◽  
Low Levels ◽  
Labour Legislation ◽  
Employment Legislation

Over the past two decades, industrial relations scholarship has observed a trend towards an increasingly punitive industrial environment along with the ‘re-regulation’ of labour law. Absent from much of this literature, however, has been an empirical and historical measurement or comparison of the scale and quality of this systemic change. By surveying coercive and penal federal industrial legislation over the period 1901–2020, this study shows empirically that over the last 40 years, there has been a steep increase in the amount of coercive federal labour legislation in Australia. It further measures and compares the volume of coercive labour legislation enacted specifically against ‘labour’ and ‘capital’ or both throughout the same period (1901–2020). Analysis reveals a correlation between a high volume of coercive labour legislation with low levels of trade union power and organisation. Argued here is that coercive labour legislation has been crucial to transitioning from a liberal conciliation and arbitration model of Australian industrial relations towards a neoliberal framework of employment legislation. In the former, regulation was more collective, informal and egalitarian (embodied by the sociological concept of ‘associative democracy’). Under a neoliberal framework, regulation is now more individualised, technical, punitive and rarely enforced, resulting in less equal material outcomes.

scholarly journals Microencapsulation of Flaxseed Oil—State of Art

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 295
Author(s):  
Asma Yakdhane ◽  
Sabrine Labidi ◽  
Donia Chaabane ◽  
Anita Tolnay ◽  
Arijit Nath ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Gum Arabic ◽  
Tween 80 ◽  
Flaxseed Oil ◽  
Review Article ◽  
Wall Material ◽  
Physico Chemical ◽  
Comprehensive Information ◽  
The Matrix

Microencapsulation is a well-known technology for the lipid delivery system. It prevents the oxidation of fatty acids and maintains the quality of lipid after extraction from oil seed and processing. In flaxseed oil, the amount of ω-3 and ω-6 polyunsaturated fatty acids are 39.90–60.42% and 12.25–17.44%, respectively. A comprehensive review article on the microencapsulation of flaxseed oil has not been published yet. Realizing the great advantages of flaxseed oil, information about different technologies related to the microencapsulation of flaxseed oil and their characteristics are discussed in a comprehensive way, in this review article. To prepare the microcapsule of flaxseed oil, an emulsion of oil-water is performed along with a wall material (matrix), followed by drying with a spray-dryer or freeze-dryer. Different matrices, such as plant and animal-based proteins, maltodextrin, gum Arabic, and modified starch are used for the encapsulation of flaxseed oil. In some cases, emulsifiers, such as Tween 80 and soya lecithin are used to prepare flaxseed oil microcapsules. Physico-chemical and bio-chemical characteristics of flaxseed oil microcapsules depend on process parameters, ratio of oil and matrix, and characteristics of the matrix. As an example, the size of the microcapsule, prepared with spray-drying and freeze-drying ranges between 10–400 and 20–5000 μm, respectively. It may be considered that the comprehensive information on the encapsulation of flaxseed oil will boost the development of functional foods and biopharmaceuticals.

STRATEGI PENGEMBANGAN BISNIS BADAN USAHA MILIK PETANI (BUMP) PT PADI ENERGI PROKLAMASI DI KABUPATEN KARAWANG, JAWA BARAT

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Doni Sahat Tua Manalu
Keyword(s):  
Environmental Conditions ◽  
Central Area ◽  
Rice Production ◽  
Quality Of Services ◽  
Qualitative And Quantitative ◽  
The Matrix ◽  
Swot Matrix ◽  
Weighted Score ◽  
Quantitative Descriptive

Currently some areas of Indonesia are being developed Badan Usaha Milik Petani (BUMP) as a form of institutional agribusiness, especially in the central area of rice production. Karawang regency is one of the regions in Indonesia who have great potential in rice production. BUMP PT Padi Energi Proklamasi is one that stands in the Karawang regency, West Java. This research aims to identify environmental external factors into opportunities and threats as well as the company's internal environmental factors that the company's strengths and weaknesses, formulate alternative strategies that the company can run according to environmental conditions and analyze the company's strategic priorities that can be run by enterprises in accordance with the company's environmental conditions. Data analysis was carried out qualitative and quantitative descriptive with EFE matrix-IFE, IE Matrix, SWOT matrix and QSPM. EFE matrix evaluation results in a score of 3.148 indicates that the BUMP PT Padi Energi Proklamasi respond both opportunities and threats that exist in the industry well. Based on the matrix IFE total weighted score is 3.684. The results obtained from processing QSPM priority strategies that can be run by BUMP PT Padi Energi Proklamasi is improving the quality of services to members through the existing facilities and infrastructure as well as government policies and others who support the business with the highest value that is equal to TAS 7.147. Keywords : Strategy, Institutional Agribusiness, BUMP PT Padi Energi Proklamasi

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