porous space
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2022 ◽  
Vol 92 (1) ◽  
pp. 155
Author(s):  
О.А. Алексеева ◽  
А.А. Набережнов

This contribution is devoted to discussion of questions related to the influence of a possible contribution from a bulk material on the lineshape of elastic peaks observed in diffraction experiments at neutron and / or X-ray radiation scattering on nanoporous matrices containing substances embedded into their porous space (channels). The proposed algorithm permits to estimate the input of massive component into diffraction peaks using the analysis of the experimentally observed distortions of the lineshape of the Bragg peaks. This preliminary analysis greatly simplifies the profile analysis of nanocomposite diffraction patterns, especially for molecular sieves based on powders of SBA-15, MCM-41, MCM-48, etc. types.


2021 ◽  
Author(s):  
Małgorzata Uliasz

A workover fluid is a type of special liquids used at the end of borehole drilling, i.e. during well operation or during reconstruction works. Such works, carried out at various stages of borehole operation, are aimed at maintaining or increasing the production of a specific well and at maintaining its proper technical condition. They may be carried out only after injecting the workover fluid into the borehole, which should generate counterpressure on the reservoir, preventing the inflow of reservoir media into the borehole, and should enable the maintaining of the hydraulic conductivity of the reservoir rock. To ensure that the basic requirements are satisfied by the workover fluid injected into the borehole, its physical and chemical properties must correspond to the geological and reservoir conditions of the specified level of reservoir rocks. Due to this, the composition of the workover fluid should be determined based on the reservoir pressure gradient, mineralogical composition of reservoir rocks and of their binder, as well as the chemical composition of reservoir waters. These are the basic criteria for selection of the composition and evaluation of the quality of the workover fluid, which enable control of the physicochemical processes occurring within the borehole zone, such as clogging of the porous space of rocks, hydration of clay minerals, capillary effects and changes in the surface tension at the interface, as well as the interaction of fluid with reservoir waters. Limitation of the intensity of occurrence of such processes, which affect the degree of damage to the permeability of the reservoir rocks in horizons featuring normal or reduced reservoir pressure, largely depends on the type of workover fluid used, i.e. brine without a solid phase and brine containing a solid phase or a liquid with density below 1.0 kg/dm3. The composition and technological properties of the workover fluid, properly selected to the specific geological and reservoir conditions, allow one to maintain the productivity of the well to a degree that does not require application of additional treatment, such as acid-treatment, fracturing and reperforations. The aim of the monograph is to show the role of a workover fluid in the conducted reconstruction treatments, as well as the importance of its technological properties in limiting damage to the permeability of reservoir rocks within the borehole zone. The presented issues comprise: • causes and threats to the deterioration of reservoir rock permeability resulting from the application of an improperly selected workover fluid; • tasks of the workover fluid and methods to improve its technological properties in terms of protecting the hydraulic conductivity of reservoir rocks; • types of workover fluids developed, the methodology for determination and assessment of their technological properties, as well as usability under reservoir conditions. The monograph also includes a short description of other special liquids used in the preparation of a well for exploitation. These are: washing and cleaning liquids, packer fluids and those used for perforation, as well as buffers for rope operations and pipe cleaning prior to packer fluid injection. The presented issue is a synthesis of a wide range of research and development works carried out at the INiG - PIB. It has been prepared based on the obtained results of laboratory tests carried out for geological and reservoir conditions existing in the productive horizons of the Carpathian Foredeep, as well as of the Carpathians and the Polish Lowlands. Keywords: borehole reconstruction, geological and reservoir conditions, workover fluid tasks, workover fluid properties, chemicals, blockers, permeability


Heat Transfer ◽  
2021 ◽  
Author(s):  
Mani Ramanuja ◽  
Gunduboina G. Krishna ◽  
Vatkuru Nagaradhika ◽  
Sreedharamalle Sreenadh ◽  
Satyaranjan Mishra

2021 ◽  
Vol 82 (3) ◽  
pp. 28-30
Author(s):  
Tsveta Stanimirova ◽  
Georgi Kirov

The existence of a specific gallery type of zeolite framework is confirmed. It has been found that similar to HEU-type, STI-type framework can be represented as a layered structure in which two impermeable to water molecules and exchange cations aluminum-silicate layers, separated by diortho-groups, confined gallery-type of porous free space, which is available for extra-framework components migration in all directions in the plane of the interlayer.


2021 ◽  
Vol 26 (3) ◽  
pp. 317-326
Author(s):  
Maria Papadomanolaki

This article reflects on telematic soundwalking by initially considering the network as it is experienced in response to the COVID-19 pandemic. It uses learnings and writings about our networked lives (during COVID) to generate a framework in order to understand the artist’s pre-pandemic work; more specifically, in the context of a series of telematic soundwalking performances titled A Certain Geography, of which two case studies are presented here. The network is analysed through a diverse and cross-disciplinary selection of ideas and writings on networked cultures, experimental radio, listening, philosophy, anthropology and urban design. This cluster of diverse theoretical notions become important for the creation of a type of networked listening where the authorship of I often collapses into a polyphonic intimacy of voices and soundings affected by all that is taking place in between, including the distortions created by the materiality of technologies, the different layers of ecologies at stake, the words and voices of those who sound and listen remotely and site-specifically. It proposes an incomplete reception loop where the aspiration of walking on a planned trajectory is constantly contested and destabilised. The network becomes a porous space where the I constantly morphs into a convivial-collective action.


2021 ◽  
Vol 13 (21) ◽  
pp. 11780
Author(s):  
Martina Záleská ◽  
Milena Pavlíková ◽  
Martin Vyšvařil ◽  
Zbyšek Pavlík

The subject matter of the work presented here is the development and evaluation of novel lightweight mortars that meet the functional and technical criteria imposed on repair mortars. In a broad experimental campaign, lime, natural hydraulic lime, and lime–cement mortars were designed and tested. Lightweight aggregate, expanded perlite, granules from expanded glass and zeolite were used as full replacements for quartz sand. The hardened mortars were tested at the ages of 28 days and 90 days. The conducted tests and analyses were focused on the assessment of structural, mechanical, hygric and thermal parameters. The salt crystallization resistance and effect of salt presence on the hygroscopicity of the investigated mortars were also investigated. The use of lightweight aggregates in the composition of mortars resulted in their high porosity, low density, satisfactory mechanical parameters, improved water vapor transmission capability and water absorption. The mortars with expanded perlite and glass granulate were ranked among thermal insulation mortars of classes T1 and T2, respectively. The use of lightweight aggregates enabled the development of mortars with great durability in terms of salt action, which was almost independent of binder type. The ability to accommodate water vapor was increased by the effect, i.e., the use of lightweight aggregates and the presence of salt in mortars increased porous space. Taking into account the compatibility, functional, and technical criteria, lime- and natural hydraulic lime-based lightweight mortarswere classified as repair mortars, providing improved thermal performance. The lime–cement lightweight plasters can be recommended only for repair of building structures where cement and lime–cement materials were original applied.


Author(s):  
Ali Raza ◽  
Kamel Al-Khaled ◽  
MI Khan ◽  
Saadia Farid ◽  
Sami U Khan ◽  
...  

This analysis deals with the mixed free convection flow of nanofluid in the presence of porous space. Human blood is supposed to be a base fluid for which the heat transfer characteristics are performed by using the single- and multi-wall carbon nanotubes. The leading equations of the problem are obtained in dimensionless form by following the appropriate non-dimensional variables. The semi-analytical solution for the temperature and velocity field, the famous Atangana–Baleanu time-fractional derivative and Laplace transform techniques are utilized. The effects of different parameters are studied with interesting physical explanations. The summarized results show that the temperature and velocity profile decreases by varying the value of the fractional parameter. An increasing change in velocity is observed for the Grashof number. Moreover, the solution simulated via fractional model for velocity and temperature profile is more consistent and scalable for any value of the fractional parameter.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6814
Author(s):  
Xingxun Li ◽  
Cunning Wang ◽  
Qingping Li ◽  
Qi Fan ◽  
Guangjin Chen ◽  
...  

Natural gas hydrates are widely considered one of the most promising green resources with large reserves. Most natural gas hydrates exist in deep-sea porous sediments. In order to achieve highly efficient exploration of natural gas hydrates, a fundamental understanding of hydrate growth becomes highly significant. Most hydrate film growth studies have been carried out on the surface of fluid droplets in in an open space, but some experimental visual works have been performed in a confined porous space. In this work, the growth behavior of methane hydrate film on pore interior surfaces was directly visualized and studied by using a transparent high-pressure glass microfluidic chip with a porous structure. The lateral growth kinetics of methane hydrate film was directly measured on the glass pore interior surface. The dimensionless parameter (−∆G/(RT)) presented by the Gibbs free energy change was used for the expression of driving force to explain the dependence of methane hydrate film growth kinetics and morphology on the driving force in confined pores. The thickening growth phenomenon of the methane hydrate film in micropores was also visualized. The results confirm that the film thickening growth process is mainly determined by water molecule diffusion in the methane hydrate film in glass-confined pores. The findings obtained in this work could help to develop a solid understanding on the formation and growth mechanisms of methane hydrate film in a confined porous space.


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