Relevant bibliographies by topics / Settling agent

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Settling agent'

Author: Grafiati
Published: 4 June 2021
Last updated: 8 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Settling agent.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Settling agent"

1

Li, Zi Cheng, Ai Ju Zhang, Zhong Qiu Li, and Hui Qiang Xiang. "Synthesis of Compound Foaming Agent of Lightweight Foamed Concrete." Advanced Materials Research 785-786 (September 2013): 163–66. http://dx.doi.org/10.4028/www.scientific.net/amr.785-786.163.

Full text
Abstract:
The foaming agent used in lightweight gypsum-based foam concrete was discussed. The effect of the single-doped foaming agent, codoped foaming agent and ternary foaming agent on the settling height, bleeding volume and defoaming time of fresh foam were investigated. The results show that ternary foaming agent has potential synergistic effects for reducing settling height and bleeding volume and retarding defoaming time of fresh foam. While applying this new compound foaming agent to the manufacture of the lightweight foam concrete blocks, samples with better-performance were obtained.
APA, Harvard, Vancouver, ISO, and other styles
2

Thanikachalam, J., P. Nagaraj, and G. S. Hikku. "Effect of graphene as anti-settling agent for magnetorheological fluid." Journal of Achievements of Materials and Manufacturing Engineering 77, no. 2 (2016): 49–56. http://dx.doi.org/10.5604/17348412.1230097.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Chai, Xiaofeng, Jian Liu, Yao Yu, Jianxiang Xi, and Changyin Sun. "Practical Fixed-Time Event-Triggered Time-Varying Formation Tracking Control for Disturbed Multi-Agent Systems with Continuous Communication Free." Unmanned Systems 09, no. 01 (2020): 23–34. http://dx.doi.org/10.1142/s2301385021500035.

Full text
Abstract:
In this paper, we study the practical fixed-time event-triggered time-varying formation tracking problem of leader-follower multi-agent systems with multi-dimensional dynamics. Fixed-time event-triggered control schemes with continuous communication and intermittent communication are developed, respectively. Continuous communication and measurement are avoided, and computation cost is reduced greatly in the latter scheme. And the settling time is to be specified regardless of initial states of agents. Meanwhile, tracking errors are adjustable as desired with expected settling time. It is demonstrated that time-varying formation tracking can be achieved under the two proposed control schemes and Zeno behavior can be excluded. Finally, numerical examples are provided to illustrate the effectiveness of the proposed control strategies.
APA, Harvard, Vancouver, ISO, and other styles
4

Kirjanova, Ala, Mindaugas Rimeika, Jes Vollertsen, and Asbjørn Haaning Nielsen. "Retainment of the antimicrobial agent triclosan in a septic tank." Water Science and Technology 70, no. 4 (2014): 586–92. http://dx.doi.org/10.2166/wst.2014.271.

Full text
Abstract:
Laboratory experiments were conducted to investigate the fate of the antimicrobial agent triclosan (TCS) in a conventional septic tank. The main mechanism of TCS removal from wastewater was identified to be rapid TCS sorption to suspended particles followed by settling of these particles to the bottom of the septic tank. Sorption to particles was completed within minutes while the settling took several days. Therefore, in a septic tank the removal of TCS from wastewater is mainly determined by the removal of suspended particles by sedimentation. Over 5 days of hydraulic residence time the initial dissolved TCS concentration of 100 μg L−1 was reduced by 87 ± 8%. During the first 24 hours, 66–86% of all removed TCS was retained, whereas during the remainder of the experiment a slight but steady decrease in TCS concentration was observed. This was most likely caused by TCS diffusion and its subsequent sorption onto the septic sludge.
APA, Harvard, Vancouver, ISO, and other styles
5

Schuck, Peter H. "The Role of Judges in Settling Complex Cases: The Agent Orange Example." University of Chicago Law Review 53, no. 2 (1986): 337. http://dx.doi.org/10.2307/1599643.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Naiguo, Wang, Nie Wen, Cheng Weimin, Liu Yanghao, Zhu Liang, and Zhang Lei. "Experiment and Research of Chemical De-dusting Agent with Spraying Dust-settling." Procedia Engineering 84 (2014): 764–69. http://dx.doi.org/10.1016/j.proeng.2014.10.494.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Shi, Shao Fei, Lan Zheng, Yu Qi Wang, et al. "Preparation and Application Study on the Coalmine Wastewater Flocculant - PAM/OMMT." Advanced Materials Research 581-582 (October 2012): 223–27. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.223.

Full text
Abstract:
The modified polyacrylamide/organic montmorillonite (PAM/OMMT) flocculant was prepared by in-situ intercalation polymerization with acrylamide monomer and OMMT under CO2 inert atmosphere. The OMMT was synthesized with MMT and cetyl trimethyl ammonium bromide (CTAB) as intercalation agent by cationic exchange reaction. This flocculant was used to deal with coalmine wastewater. The effects of the flocculant dose on turbidity removal rate and settling time, the influent of pH value, temperature on turbidity removal rate and the comparison with PAM was studied. Experimental results show that PAM/OMMT is a kind of high efficient compound flocculating agent, the formation of hydrophobic micro in polymer surface area has strong adsorption ability and dispersing capability. Then MMT increased the quality of flocculant body so that flocculating settling time is shorter. Its turbidity removal rate can be as high as 95.5%. Compared with PAM, PAM/OMMT presents many advantages with higher turbidity removal rate, higher settling velocity, lower relatively sludge water content and lower sensitivity of temperature and pH in wastewater treatment process. Flocculant dosage in 10 to 20 mg/L is the optimal flocculation condition. Sludge water content treated by PAM/OMMT (63.4%) is relatively lower than PAM (80.2%).
APA, Harvard, Vancouver, ISO, and other styles
8

Yin, Yanhui, Fuyong Wang, Zhongxin Liu, and Zengqiang Chen. "Finite/fixed-time consensus of nonlinear multi-agent systems against actuator faults and disturbances." Transactions of the Institute of Measurement and Control 42, no. 16 (2020): 3254–66. http://dx.doi.org/10.1177/0142331220949354.

Full text
Abstract:
This paper is concerned with the consensus tracking problem in nonlinear multi-agent systems against external disturbances and multiple actuator faults. The nonlinear dynamics are unknown and the leader’s input is unavailable to any follower. By using finite-time Lyapunov stability theory, a distributed discontinuous protocol is developed. On this basis, a fixed-time control protocol is further designed to obtain a settling time regardless of initial conditions. In addition, the practical finite-time consensus and practical fixed-time consensus are investigated by the adaptive technique, under which the bounds of the faults can be estimated online adaptively. The innovation of this work lies in the fact that the finite/fixed-time consensus problem is solved when multiple faults and mismatched nonlinearity are simultaneously considered. The relationship between the settling time and design parameters is well established. Finally, some numerical simulations are given to verify the effectiveness of the theoretical results.
APA, Harvard, Vancouver, ISO, and other styles
9

Ray, Martin. "Conrad, Wells, and "The Secret Agent": Paying Old Debts and Settling Old Scores." Modern Language Review 81, no. 3 (1986): 560. http://dx.doi.org/10.2307/3729180.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Wu, Zhong Yuan, Liang Hu, and Jia Xi Chen. "Surface Hydrophobic Modification of T-ZnOw with Silane Coupling Agent." Advanced Materials Research 634-638 (January 2013): 3048–51. http://dx.doi.org/10.4028/www.scientific.net/amr.634-638.3048.

Full text
Abstract:
Surface hydrophobic modification of T-ZnOw was experimented with silane coupling agent KH-570(gamma-(methylpropyl acyloxy)trimethoxysilane). It was shown by FT-IR that the whiskers was modified by silane coupling agents molecular compounded with the Zn-OH of whiskers. The effect of grafted modification with KH570 on hydrophobicity of T-ZnOw was characterized with dispersion stability test in an organic solvent and measuring the contact angle between the whiskers on distilled water. The results showed that surface treatment of T-ZnOw with KH570 improves hydrophobicity of whiskers simultaneously, and the modified whiskers have much slower settling rates than the pristine whiskers in the liquid paraffin. The contact angle between the modified whiskers with distilled water is 137.75 degrees, which is a significant increase.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Settling agent"

1

Avella, Vasquez Ana Catalina. "Substances polymériques extracellulaires dans les procédés de traitement des eaux usées." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL029N/document.

Full text
Abstract:
L’objectif de ce travail est d’une part (i) étudier le comportement de la biomasse notamment la production d’EPS en présence des composés pharmaceutiques (un agent anticancéreux et cinq antibiotiques); et d’autre part, (ii) étudier les EPS dans le contexte de décantation des boues en présence d’agents fongiques et en situations réelles dans des stations d’épuration. L’étude en présence de l’agent anticancéreux a été réalisée dans des bioréacteurs à membranes. La présence de l’agent anticancéreux a induit l’augmentation de la production d’EPS agissant comme un mécanisme de protection microbienne qui était à l’origine du colmatage des membranes. L’effet de cinq antibiotiques a été évalué en réacteur batch. La famille des macrolides a montré un effet plus important sur l’activité microbienne avec une augmentation significative de la production d’EPS associée à un mécanisme de protection. La décantation des boues en présence des cultures fongiques a été conduite en réacteur pilote. Une amélioration spectaculaire de la décantation a été liée à une meilleure cohésion au sein des flocs imputable en grand partie à l’augmentation de la production d’EPS. Enfin, le diagnostic du procédé de traitement des eaux a été établi sur trois stations d’épuration des papeteries grâce à une double approche d’une part l’analyse physico-chimique des boues et d’autre part, l’exploitation statistique d’analyse en composantes principales (ACP) des paramètres technologiques enregistrées dans chaque station. Nous avons tenté d’exprimer sous forme de régressions linéaires ou polynomiales de deuxième degré, la décantation en fonction d’une quantité réduite des paramètres mesurés<br>The objective of this work is firstly, i) to study the microbial behaviour of the biomass especially the production of the EPS in the presence of pharmaceutical compounds (an anticancer product and five antibiotics); and secondly, ii) to study EPS in the context of the sludge settling in wastewater treatment plants. The study in the presence of the anticancer product was done in membrane bioreactors. The presence of the anticancer product provoked the production of the EPS as the protection mechanism which is at the origin of the membrane fouling.The effect of five antibiotics was evaluated in batch reactors. The family of macrolides showed the most important effect on the microbial activity with a significant increase of the EPS production which was associated with a protection mechanism.Sludge settling in the presence of fungi was carried out in a pilot reactor. The spectacularly improvement of the sludge settleability was related with a better cohesion inside of the flocs attributed to an increase of the EPS production.Finally, the diagnosis of different wastewater treatment processes was established in three paper mill wastewater treatment plants thanks to the double approach used here, the physico-chemical analysis of the sludge and the statistical analysis by principal components analysis of the different parameters recorded in each plant. We tried to describe the parameter related to the settling behaviour by linear or polynomial regressions of second degree in function of a reduced number of the measured parameters
APA, Harvard, Vancouver, ISO, and other styles
2

Oslizlo, Petr. "Strategické řízení likvidace podniku." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2009. http://www.nusl.cz/ntk/nusl-222047.

Full text
Abstract:
Disrespect of economic laws and their relations or the violation of any law standards concerning company’s activities can result in its shutting down and following cessation. The cessation of the company is preceded by its dissolution with or without liquidation provided that its property is passed to a legal successor in title. The term liquidation refers to the settlement of debts and property of the dissolved subject. This diploma thesis is particularly focused on individual stages of liquidating process of business organizations and their relation on legal standards.
APA, Harvard, Vancouver, ISO, and other styles
3

Chen, Wen-Hsuan, and 陳文萱. "A Dynamic Study for the Settling of Heavy Metal Chelating Agent Preparation Conditions in the Flying Ash Stabilization." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/47589473950726398862.

Full text
Abstract:
碩士<br>國立高雄第一科技大學<br>環境與安全衛生工程研究所<br>99<br>MSWI is the most popular MSW treatment currently in Taiwan. After incineration, it will generate flying ash which substances dioxins and heavy metals. The treatment process of flying ash could be solidification, stabilization and recycling such like water washing, acid extraction, melting, etc. At present, the most common process for MSWI flying ash is the stabilization process which uses the chemical chelating agent, cement, and water. This study focused on the simulated experiments and dynamic models for the settling of heavy metal chelating agent and water during the stabilization of flying ash. The settling will stick the mixer of stabilization mixing and the pipeline for transportation, extend the processing time, and reduce the productivity. Therefore, the purpose of the experiments is to figure out the best process which least generates the settling. By controlling the mixing time, settling time, mixing speed, and other parameters, the experiments run to observe the amount of generated settling with water of different hardness levels. The results showed that, under the conditions of mixing speed of 30 rpm with mixing time of 20 minutes, and mixing speed of 50 rpm with mixing time of 30 minutes, the resulting settling is low when the settling time is less than 30 minutes. After analysis, it’s found that the settling generation rate mainly depends on the level of water hardness. The other parameters have less effect on the settling generation rate. As a result, a dynamic mode is applied to analyze the relation between the settling generation rate and the level of water hardness. From the results, the correlation is the highest with the equation obtained from power methods. Finally, it’s proposed to be the formula of the settling generation rate for the settling which is generated by heavy metal chelating agent and water during the stabilization of flying ash. Keywords: fly ash, heavy metal chelator, settling, dynamic
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Settling agent"

1

Mele, Alfred R. Living Without Agent Causation. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780190659974.003.0011.

Full text
Abstract:
This chapter explores a question about agent causation: If we were to learn that agent causation is impossible, what effect might that have on some philosophers’ reasoning about event-causal libertarianism? It is argued that, with agent causation off the table, event-causal libertarianism’s appeal would grow stronger for some philosophers. The stage for this argument is set partly by means of a review of issues about luck, control, and settling that surround some arguments subjected to critical scrutiny earlier in the book: namely, the same-control argument, the more-control argument, and Derk Pereboom’s disappearing agent argument. Special attention is paid to direct control. Two different accounts of direct control are offered.
APA, Harvard, Vancouver, ISO, and other styles
2

Mele, Alfred R. Complete Control and Disappearing Agents. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780190659974.003.0008.

Full text
Abstract:
This chapter rebuts Derk Pereboom’s disappearing agent argument against event-causal libertarianism and explores a notion of complete control over whether one will decide to A. Support is offered for the view that agents with no agent-causal powers can decide freely and be morally responsible for decisions they made. Settling whether a particular decision will occur is a key notion in Pereboom’s disappearing agent argument. Various interpretations of the notion are considered, and the argument is found to be unpersuasive on all of these interpretations. The bearing of agent causation on settling, luck, and control is discussed, and differences between deciding and overt actions are examined.
APA, Harvard, Vancouver, ISO, and other styles
3

Tazzara, Corey. Insecurity and Opportunity in the Middle Sea. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198791584.003.0003.

Full text
Abstract:
Chapter 2 argues that endemic insecurity in the Mediterranean and the instability of religious boundaries conditioned the expansion of Livorno. The process of settling merchants in Livorno raised issues of contract enforcement comparable to that of commerce itself. Medici legislation did not offer sufficient protections against expulsions of settlers and expropriations of property. Regime agents worked tirelessly to provide adequate assurances that Livorno’s privileges would be enforced. These negotiations channeled the city’s growth in unexpected directions. Rather than provide Tuscan merchants with a means of breaking directly into distant markets, Livorno came to serve foreign merchants as a center of deposit and transit for goods traversing the shores of the Mediterranean.
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Settling agent"

1

Gooch, Jan W. "Anti-Settling Agent." In Encyclopedic Dictionary of Polymers. Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_718.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Pham, Duy Hoang, Subhasis Thakur, and Guido Governatori. "Settling on the Group’s Goals: An n-Person Argumentation Game Approach." In Intelligent Agents and Multi-Agent Systems. Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-89674-6_37.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Abbas, Ghulam, Sonny Irawan, Muhammad Khan Memon, Shuaib Ahmed Kalwar, and Sandeep Kumar. "Hydroxypropylmethylcellulose as a Free Water and Settling Control Agent in Oil Well Cement Slurry." In ICIPEG 2014. Springer Singapore, 2015. http://dx.doi.org/10.1007/978-981-287-368-2_11.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

"Anti-settling agent." In Encyclopedic Dictionary of Polymers. Springer New York, 2006. http://dx.doi.org/10.1007/978-0-387-30160-0_707.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Mitchell, Neil J. "Agreement." In Why Delegate? Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780190904197.003.0004.

Full text
Abstract:
Principals delegate in order to resolve disagreements. We would be unwilling to invest energy in any sort of enterprise or activity, without a method to resolve the disputes that may arise. We grant someone the authority to interpret rules. Whether disciplining players in the NFL, deciding which country will host the soccer World Cup or settling disputes between governments in the World Trade Organization, principals turn to a dispute-resolving agent to sort it out. This chapter discusses the use of delegation to solve disagreements. Some scholars depart from principal-agent theory to use the term trustee to describe the autonomy in this type of delegation relationship, but this is an unnecessary departure. The key to controlling this agent lies in the initial selection process.
APA, Harvard, Vancouver, ISO, and other styles
6

Davis, Ellen F. "Settling the Land a Second Time—Ezra–Nehemiah." In Opening Israel's Scriptures. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780190260545.003.0042.

Full text
Abstract:
IN SOME WAYS, Ezra–Nehemiah is a companion piece to Esther, another story of Jews living as vassals of the Persian Empire, although it has none of the patent absurdity of Esther. Nehemiah’s story, like Esther’s, starts in a Persian court, but most of the composite story takes place in Jerusalem. Cyrus “the Great,” the first ruler from the Achaemenid dynasty, in the first year after his conquest of the Neo-Babylonian Empire in 539 BCE issued a decree that allowed Jews to rebuild the temple (Ezra 1:1–4). The decree marked a policy of granting provinces a greater measure of local and regional control in exchange for cooperation with imperial economic and political goals. The book covers a period that exceeds the life of the two individuals for whom Ezra–Nehemiah is named. Four or five Persian kings are mentioned—Cyrus, Darius, Ahasuerus/Xerxes, Artaxerxes I, and maybe Artaxerxes II (Ezra 4:5–7; 6:14)—whose reigns span more than a century (c. 538–400 BCE). The book makes no consistent attempt to specify the chronology. The so-called Nehemiah memoir is considered by some the oldest and most accurately historical part of the book, recording the experience of a highly placed imperial agent. It suggests that some twenty years into the reign of Artaxerxes I (445 BCE), Jerusalem was still largely in ruins (Neh 2:3), even if the temple had been reconstructed two or three generations earlier (c. 515 BCE) at the urging of the prophet Haggai....
APA, Harvard, Vancouver, ISO, and other styles
7

Whiteman, C. David. "Aerial Spraying." In Mountain Meteorology. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780195132717.003.0023.

Full text
Abstract:
Aircraft are used in a number of resource management operations, including fire suppression, seeding and fertilizing operations, and the application of pesticides to agricultural, forest, and rangelands. The objectives of any aerial application are to apply the material, either liquid or solid, to the target area safely, efficaciously, and economically and to avoid drift, that is, off-target displacement of the agents. Barry (1993) is a general reference for aerial spraying of forests. Picot and Kristmanson (1997) provide an overview of all aspects of this topic. Bache and Johnstone (1993) give a detailed description of spray meteorology. The emphasis in this chapter is on the role of meteorology in the aerial application of liquid pest control agents to manage plant, fungal, and animal pests in mountainous forested areas. The effectiveness of a spray operation depends on the timing of the operation relative to phenological conditions, the characteristics of the forest canopy or rangeland being targeted, the spray formulation, pilot skills and attitude, the aircraft type and spray equipment used, and weather conditions. Pest control agents are regulated by federal, state, and local agencies. Restrictions on the use of agents are specified on the product label and may include weather conditions. Drift reduces the efficacy of a spray operation and can have unintended and undesirable impacts on nontarget species, residences, and public areas near the target area. Although there is a driftable component in every spray operation, the drift potential is generally greater for liquids than for solids because the size of liquid droplets becomes smaller after release into the atmosphere, depending on the volatility of the substance itself, the aircraft and spray equipment used, and the meteorological conditions at the time of spraying. The smaller the droplets, the greater the potential for drift. Weather conditions have a significant impact on drift because wind speed and direction, temperature, humidity, and atmospheric stability affect the transport, diffusion, evaporation, settling, and deposition of both solid particles and liquid droplets. The collection of meteorological data and the use of professional weather forecasts are thus an integral part of a spraying operation.
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Settling agent"

1

Ganguli, K. K. "Biopolymers as Free Water and Settling Control Agent." In SPE Production Operations Symposium. Society of Petroleum Engineers, 1993. http://dx.doi.org/10.2118/25437-ms.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Zhao, Yu, Zhisheng Duan, and Guanrong Chen. "Finite-time consensus tracking for multi-agent systems with settling time estimation." In 2014 33rd Chinese Control Conference (CCC). IEEE, 2014. http://dx.doi.org/10.1109/chicc.2014.6896787.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Jianhong, Han, Liu Pai, Xu Haisheng, and Guo Ting. "The Experiment Research for Purification of Cerium Dioxide by Ammonia Water for Settling Agent from Rock Crystal Waste." In 2012 International Conference on Computer Distributed Control and Intelligent Environmental Monitoring (CDCIEM). IEEE, 2012. http://dx.doi.org/10.1109/cdciem.2012.179.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Gutierrez, Gustavo, Juan Catan˜o, and Oscar Perales-Perez. "Development of a Magnetocaloric Pump Using a Mn-Zn Ferrite Ferrofluid." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13784.

Full text
Abstract:
Magnetic fluids or ferrofluids are colloidal dispersions of magnetic nanoparticles in a liquid carrier. These nanoparticles have a specific size range in order to remain suspended in the liquid, about 3 to 15 nm. In this range Brownian motion (thermal molecular motion in the liquid) keeps the particles from settling out. Because magnetic particles tend to aggregate, and aggregates sediment faster than single particles, the particles are coated with a stabilizing dispersing agent. The surfactant must be matched to the carrier type and must overcome the attractive Van der Waals and magnetic forces between the particles to prevent agglomeration even when a strong magnetic field is applied to the ferrofluid. A device that can pump a fluid with no moving mechanical parts represents a very encouraging alternative since such device would be practically maintenance free. A magnetocaloric pump achieves this purpose by providing a pressure gradient to a ferrofluid placed inside a magnetic field while experiencing a temperature change. If the temperature change is produced by extracting heat out of an element that needs refrigeration, coupling this heat via a heat pipe with the magnetocaloric pump will result in a completely passive cooling system. For applications near ambient temperature the ferrofluid must have specific characteristics such as low Curie temperature, high pyromagnetic coefficient, high thermal conductivity and low viscosity. This work presents the detailed description of the synthesis of ferrofluids composed of Mn-Zn ferrite nanoparticles and the characterization of its magnetic and thermal properties. Different composition of Mn-Zn ferrites nanoparticles were produce and evaluated. This ferrite ferrofluid was compared with commercially available magnetite ferrofluid in a magnetocaloric pump prototype. Results of saturation magnetization, pyromagnetic coefficient, Curie temperature, particle size, viscosity and pressure increment inside the magnetocaloric pump are presented.
APA, Harvard, Vancouver, ISO, and other styles
5

Chang, Frank F., Paul D. Berger, and Christie H. Lee. "In-Situ Formation of Proppant and Highly Permeable Blocks for Hydraulic Fracturing." In SPE Hydraulic Fracturing Technology Conference. SPE, 2015. http://dx.doi.org/10.2118/spe-173328-ms.

Full text
Abstract:
Abstract Proppants are used to keep hydraulic fractures open, allowing for reservoir fluids to flow back after external pressure is withdrawn. Proppants are carried by the hydraulic fracturing fluid containing multiple components such as polymers, breakers, or friction reducing agent. These proppant systems have certain disadvantages such as formation and fracture permeability damage due to the viscous gel residue, risk of early screen-out and reduced effective propped area due to proppant excessive leakoff or settling, and abrasion to the pumping equipment and tubular. Acid fracturing is another fracturing technique. It is used in carbonate reservoirs, in which the acid etches the fracture faces to create conductive path. The drawbacks of acid fracturing include short acid etch length due to rapid acid-carbonate rock reaction rate and corrosion to the tubular. The oil and gas industry has been relying on these hydraulic fracturing techniques to proliferate production from low permeability reservoirs, and has made significantly advancement in tools and chemicals used in the fracturing processes. However, the maximized production and recovery is still unattainable due to the reasons mentioned above. This paper discusses a novel chemical compositions and process to overcome the challenges encountered by the current fracturing techniques. The goal is to convert injected fracturing fluid into a highly permeable proppant pack in-situ. Since the fracturing fluid itself forms the proppant, it can penetrate the entire fracture length, height, and complex network, maximizing the effective fracture area and stimulated reservoir volume. The rendered particle size can be significantly larger than conventional proppants without the concern of screen-out. The in-situ formed proppants have strength sufficient to resist fracture closure stress. In addition, no polymer is required to suspend the proppant; therefore no gel residue will be left to damage fracture conductivity. Though it is in its preliminary development stage, interesting and encouraging test results have been obtained. Formulations, photos, and mechanical properties of in-situ generated proppants will be presented in this paper.
APA, Harvard, Vancouver, ISO, and other styles
6

Nunez, Alvaro Javier, Ernest Sayapov, Ahmed Benchekor, et al. "Post Frac Cleanout and Plug Milling Optimization Strategy. Successful Implementation in Extremely Depleted Wells in the Sultanate of Oman." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206147-ms.

Full text
Abstract:
Abstract Post frac cleanout and milling operations are considered some of the most critical activities that leverage on the operational benefits of coiled tubing. Therefore, they deserve the highest focus on continuous improvement and planning since the associated efficiency gains are often immediately quantifiable. This paper will focus on the improvement and optimization of post frac cleanout and milling strategies in extremely depleted wells in the Sultanate Of Oman. The gains from such optimization helped improve wells delivery and overall performances. Plug and perf methodology is still the preferred placement method of hydraulic fractures. One of the main challenges in depleted wells is the need for cleanout and plug milling after each stage to avoid risk of CT becoming stuck either differentially due to depletion or mechanically with plug cuttings in case circulation is lost. For years the frac and mill concept was adopted to complete those wells, resulting in frequent delays to frac operations and huge cost impact to the overall project. An efficiency improvement plan was agreed upon to address this particular challenge. A step-by-step strategy improvement plan was developed via in-depth analysis of frac initiation and reservoir characteristics in order to combine together multiple stages of post-frac cleanout and milling activities. This was done through unique software simulations and fluid selection criteria to achieve the lowest possible bottom hole pressure to minimize the losses in addition to the highest possible lifting velocity and best carrying medium conditions. Moreover, the utilization of engineered fluid solutions with foaming agent and foam generator have demonstrated significant added value through enhancement of carrying fluid properties while achieving the lowest possible settling velocity, which in turn lead to the highest possible velocity factor. After completing the agreed optimization plan, a post frac cleanout with 6-plug milling was performed in a single combined stage instead of multiple individual stages. This improvement reduced the overall frac operation for 6 stages from nearly 30-35 days to 19-20 days. Understanding the field and reservoir pressures in addition to fluid selection for both post frac cleanout and milling operation is crucial to successful implementation of this methodology. This achievement was delivered through a collaboration between many different business units from design to execution and it will help Petroleum Development Oman PDO on the future planning of hydraulic fracturing activity. The completion of the entire wells (well delivery) was achieved in a significantly shorter period of time compared to previous wells; this is reflected on actual cost reduction of more than 20% of total cost/AFE.
APA, Harvard, Vancouver, ISO, and other styles
7

Hrma, Pavel, and Jesse Alton. "Dissolution and Growth of Spinel Crystals in a High-Level Waste Glass." In ASME 2001 8th International Conference on Radioactive Waste Management and Environmental Remediation. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/icem2001-1323.

Full text
Abstract:
Abstract A large fraction of HLW glass readily precipitates spinel. The presence of solid particles, including spinel crystals, is undesirable in a high-level waste (HLW) glass melter because the settling of solids can disrupt melter operation and shorten melter lifetime. Spinel formation in the melter can be reduced by lowering waste loading. When formulating HLW glass to maximize waste loading (thus minimizing the cost), the settling of insolubles must be considered. The rate of nucleation, growth, and dissolution of spinel crystals in a molten HLW glass was measured as a function of temperature and the presence of nucleation agents, such as noble metals. The mass transfer coefficient was calculated using the Hixson-Crowell model and expressed as an Arrhenius function of temperature that was identical for both crystal growth and crystal dissolution. The Stokes law for hindered settling and the Hixson-Crowell equation for crystal growth and dissolution were chosen as a convenient representation of spinel behavior for mathematical models of HLW glass melters. Levich’s analysis of the dissolution or growth of falling particles was used to estimate the effective diffusion coefficient (D) and the concentration-boundary-layer thickness (δ) around growing and dissolving crystals. The estimated values were in reasonable agreement with the measured concentration profile of Fe at a dissolving spinel crystal at 1200°C, determined with energy dispersive spectroscopy. The D value is comparable to that obtained by Borom and Pask for a sodium disilicate-magnetite couple. The calculated δ value agreed with the concentration distribution of Fe around falling crystals of spinel as imaged by optical microscopy. This methodology, in conjunction with mathematical modeling, provides a basis for developing optimized technology and glass formulation for HLW vitrification.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Settling agent' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography