First Field Application of In-Situ Gelled HCl-Formic Acid System

Author(s):  
Hisham A. Nasr-El-Din ◽  
Saad M. Al-Driweesh ◽  
Leopoldo Sierra ◽  
Mary van Domelen ◽  
Thomas Welton
2002 ◽  
Author(s):  
H.A. Nasr-El-Din ◽  
S. Al-Mutairi ◽  
B. Al-Malki ◽  
S. Metcalf ◽  
W. Walters

BioResources ◽  
2018 ◽  
Vol 13 (2) ◽  
Author(s):  
Rongge Zou ◽  
Yunfeng Zhao ◽  
Yunpu Wang ◽  
Dengle Duan ◽  
Liangliang Fan ◽  
...  

2016 ◽  
Vol 20 (3) ◽  
pp. 985-991
Author(s):  
Zhi Liu ◽  
Yuqin Wan ◽  
Hao Dou ◽  
Ji-Huan He

Salt-acid system has been proved to be of high efficiency for silk fibroin dissolution. Using salt-acid system to dissolve silk, native silk fibrils can be preserved in the regenerated solution. Increasing experiments indicate that acquirement of silk fibrils in solution is strongly associated with the degumming process. In this study, the effect of sodium carbonate degumming concentration on solution properties based on lithium bromide-formic acid dissolution system was systematically investigated. Results showed that the morphology transformation of silk fibroin in solution from nanospheres to nanofibrils is determined by sodium carbonate concentration during the degumming process. Solutions containing different silk fibroin structure exhibited different rheological behaviors and different electrospinnability, leading to different electrospun nanofibre properties. The results have guiding significance for preparation and application of silk fibroin solutions.


2021 ◽  
Vol 11 (23) ◽  
pp. 11286
Author(s):  
Marina Paula Secco ◽  
Débora Thaís Mesavilla ◽  
Márcio Felipe Floss ◽  
Nilo Cesar Consoli ◽  
Tiago Miranda ◽  
...  

The increasingly strong search for alternative materials to Portland cement has resulted in the development of alkali-activated cements (AAC) that are very effective at using industrial by-products as raw materials, which also contributes to the volume reduction in landfilled waste. Several studies targeting the development of AAC—based on wastes containing silicon and calcium—for chemical stabilization of soils have demonstrated their excellent performance in terms of durability and mechanical performance. However, most of these studies are confined to a laboratory characterization, ignoring the influence and viability of the in situ construction process and, also important, of the in situ curing conditions. The present work investigated the field application of an AAC based on carbide lime and glass wastes to stabilize fine sand acting as a superficial foundation. The assessment was supported on the unconfined compressive strength (UCS) and initial shear modulus (G0) of the developed material, and the field results were compared with those prepared in the laboratory, up to 120 days curing. In situ tests were also developed on the field layers (with diameters of 450 and 900 mm and thickness of 300 mm) after different curing times. To establish a reference, the mentioned precursors were either activated with a sodium hydroxide solution or hydrated with water (given the reactivity of the lime). The results showed that the AAC-based mixtures developed greater strength and stiffness at a faster rate than the water-based mixtures. Specimens cured under controlled laboratory conditions showed better results than the samples collected in the field. The inclusion of the stabilized layers clearly increased the load-bearing capacity of the natural soil, while the different diameters produced different failure mechanisms, similar to those found in Portland cement stabilization.


2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Haocai Huang ◽  
Liang Huang ◽  
Wei Ye ◽  
Shijun Wu ◽  
Canjun Yang ◽  
...  

Isobaric gas-tight hydrothermal samplers, with the ability to maintain pressure, can be used to keep in situ chemical and biological sample properties stable. The preloading pressure of the precharged gas is a major concern for isobaric gas-tight hydrothermal samplers, especially when the samplers are used at different sampling depths, where the in situ pressures and ambient temperatures vary greatly. The most commonly adopted solution is to set the preloading pressure for gas-tight samplers as 10% of the hydrostatic pressure at the sampling depth, which might emphasize too much on pressure retention; thereby, the sample volume may be unnecessarily reduced. The pressure transition of the precharged gas was analyzed theoretically and modeled at each sampling stage of the entire field application process. Additionally, theoretical models were built to represent the pressure and volume of hydrothermal fluid samples as a function of the preloading pressure of the precharged gas. Further, laboratory simulation and examination approaches were also adopted and compared, in order to obtain the volume change of the sample and accumulator chambers. By using theoretical models and the volume change of the two chambers, the optimized preloading pressure for the precharged gas was obtained. Under the optimized preloading pressure, the in situ pressure of the fluid samples could be maintained, and their volume was maximized. The optimized preloading pressure obtained in this study should also be applicable to other isobaric gas-tight hydrothermal samplers, by adopting a similar approach to pressure maintenance.


2019 ◽  
Vol 1 (2-2) ◽  
Author(s):  
Mohd Jumain Jalil ◽  
Intan Suhada Azmi ◽  
Arif Aminuddin Ahmad Zulkifli ◽  
Mohamad Helmi Mohd Asbi

The epoxidized vegetables oils can be used a raw material for a broad range of products, from pharmaceutical and plastics to paint and adhesives. Epoxidation of oleic acid was carried out by using hydrogen peroxide as an oxygen donor and formic acid as an oxygen carrier in the presence of sulphuric acid act as catalyst. The crude oleic acid contained 75% oleic acid, 12.2% linoleic acid, 6.5% palmitic acid and 7.5% stearic acid, and had an iodine value of 98.99 g/100 g. The epoxidation of oleic acid with almost complete conversion of unsaturated carbon and negligible oxirane cleavage can be obtained by the in situ techniques. An analytical approach for the prediction of the partition coefficient for formic acid between oleic acid and water, dependent on temperature and composition, has been proposed.


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