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Classical Biodynamics and Biomechanics
Published in Thomas M. Nordlund, Peter M. Hoffmann, Quantitative Understanding of Biosystems, 2019
Thomas M. Nordlund, Peter M. Hoffmann
Sedimentation, the drift of particles through a liquid under the influence of gravitational or centrifugal forces, is governed by the sedimentation coefficient s=mnetb≅mnet6πηR, where mnet is typically m/4 for globular proteins. Also, s∝m1−pη, where p is the scaling coefficient. Values are p = 1/3 for a solid and 1/2 for a freely jointed chain.
The emergence of nanoporous materials in lung cancer therapy
Published in Science and Technology of Advanced Materials, 2022
Deepika Radhakrishnan, Shan Mohanan, Goeun Choi, Jin-Ho Choy, Steffi Tiburcius, Hoang Trung Trinh, Shankar Bolan, Nikki Verrills, Pradeep Tanwar, Ajay Karakoti, Ajayan Vinu
In a typical study of pH-responsive gateways, Huang and co-workers have explored the dissolution mechanism of ZnO quantum dots in acidic pH. Mesoporous carbon nanoparticles (MC) were loaded with rhodamine 6 G (Rh6G) through electrostatic interactions and conjugated with ZnO via amide linkage (Figure 10A) [325]. The MCN were synthesised using the modified Stӧber method and exhibited a specific surface area of 1575 m2/g with an approximate pore size of 2.2 nm. After the amide functionalization, the specific surface area was reduced to 881 m2/g. The Rh6G interacts with the aromatic domains of the MCN through π–π interactions, making a strong bond with MC at a neutral pH. Zinc oxide quantum dots dissolved in the acidic media (pH 5.5), resulting in the release of the drugs into the tumour environment. A 65% toxicity was observed at a dose of 0.066 ng/cell with little toxicity of naïve ZnO-gated MC in A549 cells. The total sedimentation coefficient of these particles and the corresponding toxicity in in vivo system need to be analysed for further validation.
Experience in Decontamination of Naval Reactor Plants
Published in Nuclear Technology, 2020
B. A. Gusev, I. S. Orlenkov, L. N. Moskvin, N. G. Sandler, A. A. Efimov, А. M. Aleshin, V. V. Krivobokov, V. N. Vavilkin
The standard IEFs effectively remove the ionic and colloidal forms of ACPs, but they have low efficiency in removing the solid-phase impurities even under the steady-state operating conditions of NRPs (Ref. 9). The efficiency of cleanup filters depends on the duration of impurity residence in the coolant. The experiments have proved that the sedimentation coefficient decreases by several times under cooldown conditions when compared to nominal operation conditions. The influence of particle size is also important as larger particles are more effectively removed from the coolant. Previously it has been found23 that there is a dependence on the rate of particle removal from the coolant on pH, whose value is defined by the ammonia concentration at a given water chemistry (Fig. 1).
Long-term regional nutrient contributions and in-lake water quality trends for Lake Okeechobee
Published in Lake and Reservoir Management, 2020
Sayena Faridmarandi, Yogesh P. Khare, Ghinwa Melodie Naja
TP net sedimentation coefficient decreased during the POR and we project that the lake sediments would become a permanent source of P in WY2035. We are already observing a negative net TP sedimentation rate during hurricane years, indicating that the lake sediments were a net source of TP during these years. This is not unique to Lake Okeechobee. Belmont et al. (2009) showed that the sediments in Lake Istokpoga and the upper chain of lakes that drain into Lake Okeechobee were approximately 50 to 62% saturated with TP. The same authors (Belmont et al. 2009) also showed that Lake Istokpoga and the upper chain of lakes would become sources of TP in 7 to 25 yr under 0 to 25% inflow TP loading reductions. This additional internal TP source from the sediments will delay Lake Okeechobee restoration efforts by 12–31 yr from the point when inflow TP concentration reaches 0.04 mg/L (Reddy et al. 2011). Blasland Bouck and Lee Inc. (BBL; 2003), conducted a Lake Okeechobee sediment management feasibility study that screened and evaluated 36 sediment management options, including chemical treatment and dredging. With a cost of $3 billion and a 15 yr time frame for completion, dredging was deemed not effective, as this technology will not remove the upper flocculant layer of the sediments that will continue to release TP in the water column. Chemical treatment using alum was estimated at $493 million, would take 3 yr to complete, and would need to be repeated every 15 yr. Unless a proven cost-effective technology is developed to tackle the legacy P problem in the lake sediments (Reddy et al. 2011), a prioritization of state resources is required while focusing on the Lake Okeechobee watershed.