Rural Domestic Water System Peak Flows and Design Innovations, Optimal Water Planning Series

Planning engineers commonly use generous factors of safety for peak flow estimates in urban water supply systems both as a hedge against unforeseen growth and because economies of scale result in relatively low user costs even with such reserve capacity. Transplanting of such design criteria into the rural setting, however, simply does not work. The low density portions of rural domestic systems require very realistic design criteria or the construction costs become infeasible for the small number of customers involved. Peak instantaneous flow rates in a Utah rural system were measured continuously during two summers on three dead-end lines serving various numbers of customers. The second summer included measurement of flows to customers whose maximum flow rate was limited by a simple orifice placed in each meter. Conclusions which emerged from this study included: 1) Actual peak demands were lower than those required for design purposes by some state regulatory agencies, but higher than the Farmers Home Administration minimum standard. 2) Where extremely small mains are required by the economics of low density situations, or where unforeseen growth is overtaxing system capacity, peak demands can be cut significantly by simple, flow restricting devices at each meter without decreasing the quality of water service to the customer. 3) Field measurements of head loss through 10 year old plastic pipe indicated a Hazen Williams friction factor average of 133

Experimental study on dynamic pipe fracture in consideration of hydropower plant model

AbstractIn the case of sudden valve closure, water hammer creates the most powerful pressure and damage to pipeline systems. The best way to protect the pipeline system is to eliminate water hammer. The main reasons for water hammer occurrence are valve closure, high initial velocity, and static pressure. However, it is difficult to eliminate water hammer. Water hammer tends to occur when the valve is being closed. In this study, the pipe fracture caused by static water pressure, gradually increasing pressure, and suddenly increasing pressure were compared experimentally in a breaking PVC test pipe. The quasi-static zone, the dynamic zone, and the transition zone are defined through the results of those experiments, with consideration of the fracture patterns of test pipes and impulses. The maximum pressure results were used to design the pipeline even though it is in the dynamic zone

Rational design of DNA sequence-specific zinc fingers

AbstractWe developed a rational scheme for designing DNA binding proteins. The scheme was applied for a zinc finger protein and the designed sequences were experimentally characterized with high DNA sequence specificity. Starting with the backbone of a known finger structure, we initially calculated amino acid sequences compatible with the expected structure and the secondary structures of the designed fingers were then experimentally confirmed. The DNA-binding function was added to the designed finger by reconsidering a section of the amino acid sequence and computationally selecting amino acids to have the lowest protein–DNA interaction energy for the target DNA sequences. Among the designed proteins, one had a gap between the lowest and second lowest protein–DNA interaction energies that was sufficient to give DNA sequence-specificity

Chronic high fat feeding restricts islet mRNA translation initiation independently of ER stress via DNA damage and p53 activation

Under conditions of high fat diet (HFD) consumption, glucose dyshomeostasis develops when β-cells are unable to adapt to peripheral insulin demands. Few studies have interrogated the molecular mechanisms of β-cell dysfunction at the level of mRNA translation under such conditions. We sought to address this issue through polyribosome profile analysis of islets from mice fed 16-weeks of 42% HFD. HFD-islet analysis revealed clear trends toward global reductions in mRNA translation with a significant reduction in the polyribosome/monoribosome ratio for Pdx1 mRNA. Transcriptional and translational analyses revealed endoplasmic reticulum stress was not the etiology of our findings. HFD-islets demonstrated evidence of oxidative stress and DNA damage, as well as activation of p53. Experiments in MIN-6 β-cells revealed that treatment with doxorubicin to directly induce DNA damage mimicked our observed effects in islets. Islets from animals treated with pioglitazone concurrently with HFD demonstrated a reversal of effects observed from HFD alone. Finally, HFD-islets demonstrated reduced expression of multiple ribosome biogenesis genes and the key translation initiation factor eIF4E. We propose a heretofore unappreciated effect of chronic HFD on β-cells, wherein continued DNA damage owing to persistent oxidative stress results in p53 activation and a resultant inhibition of mRNA translation

Spatiotemporal Control of Ice Crystallization in Supercooled Water via an Ultrashort Laser Impulse

Takahashi H., Kono T., Sawada K., et al. Spatiotemporal Control of Ice Crystallization in Supercooled Water via an Ultrashort Laser Impulse. Journal of Physical Chemistry Letters, 14(19), 4394-4402, 18 May 2023: © 2023 American Chemical Society. DOI: 10.1021/acs.jpclett.3c00414.Focused irradiation with ultrashort laser pulses realized the fine spatiotemporal control of ice crystallization in supercooled water. An effective multiphoton excitation at the laser focus generated shockwaves and bubbles, which acted as an impulse for inducing ice crystal nucleation. The impulse that was localized close to the laser focus and accompanied by a small temperature elevation allowed the precise position control of ice crystallization and its observation with spatiotemporal resolution of micrometers and microseconds using a microscope. To verify the versatility of this laser method, we also applied it using various aqueous systems (e.g., plant extracts). The systematic study of crystallization probability revealed that laser-induced cavitation bubbles play a crucial role in inducing ice crystal nucleation. This method can be used as a tool for studying ice crystallization dynamics in various natural and biological phenomena