transport capacity
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2022 ◽  
Vol 354 ◽  
pp. 00024
Author(s):  
Daniel Cosmin Vitan ◽  
Daniel Ion Matei ◽  
Ionela Cristina Lăpăduș (Măceșaru) ◽  
Ionela (Dăjic) Grecea

The paper deals with the subject of rehabilitation and mechanical modernization of the extraction plant within the mining operation of the salt mine from Slanic Prahova region. The extraction plant serves the 23 August mine shaft of the Unirea mine, and also this mine has been converted into a tourist mine. The rehabilitation of the extraction installation consists in the change of the cutting wheels from the extraction tower due to excessive degradation, requiring the redesign under strict conditions, and also the rehabilitation and extension of the saline water extraction system from the tourist mine. The modernization of the extraction plant consists in the change of the DC hoist engine with an asynchronous engine of the same energy power and research on the possibilities of increasing the cable transport capacity with technical changes made to the extraction tower, mine shaft and the sump. Modernization and rehabilitation carried out on the extraction installation at the Slanic Prahova salt mine, will provide a safety in operation and efficiency to using the necessary electricity for hoist engine operations.


Author(s):  
Victor-Marian Cocris ◽  
Mihaela Amoraritei

The present work is focused on ship resistance performances assessment for a given capacity containership. Starting from the main dimensions of a parent ship, other ten hull forms have been generated using DELFTship free program. For each case, the hydrodynamic ship resistance has been calculated using an inhouse code. The objective was to modified some geometrical parameters to obtain shapes of the hull that would provide the least resistance at the required transport capacity. The results obtained will be used in a future analysis related to the impact of hull forms improvements and ship resistance reduction on the propulsive performance and CO2 emissions per transport work.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2065
Author(s):  
Maria C. Lucana ◽  
Yolanda Arruga ◽  
Emilia Petrachi ◽  
Albert Roig ◽  
Roberta Lucchi ◽  
...  

Peptides show high promise in the targeting and intracellular delivery of next-generation bio- and nano-therapeutics. However, the proteolytic susceptibility of peptides is one of the major limitations of their activity in biological environments. Numerous strategies have been devised to chemically enhance the resistance of peptides to proteolysis, ranging from N- and C-termini protection to cyclization, and including backbone modification, incorporation of amino acids with non-canonical side chains and conjugation. Since conjugation of nanocarriers or other cargoes to peptides for targeting and cell penetration may already provide some degree of shielding, the question arises about the relevance of using protease-resistant sequences for these applications. Aiming to answer this question, here we provide a critical review on protease-resistant targeting peptides and cell-penetrating peptides (CPPs). Two main approaches have been used on these classes of peptides: enantio/retro-enantio isomerization and cyclization. On one hand, enantio/retro-enantio isomerization has been shown to provide a clear enhancement in peptide efficiency with respect to parent L-amino acid peptides, especially when applied to peptides for drug delivery to the brain. On the other hand, cyclization also clearly increases peptide transport capacity, although contribution from enhanced protease resistance or affinity is often not dissected. Overall, we conclude that although conjugation often offers some degree of protection to proteolysis in targeting peptides and CPPs, modification of peptide sequences to further enhance protease resistance can greatly increase homing and transport efficiency.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sebastian A. Tamayo Rojas ◽  
Virginia Schadeweg ◽  
Ferdinand Kirchner ◽  
Eckhard Boles ◽  
Mislav Oreb

AbstractAs abundant carbohydrates in renewable feedstocks, such as pectin-rich and lignocellulosic hydrolysates, the pentoses arabinose and xylose are regarded as important substrates for production of biofuels and chemicals by engineered microbial hosts. Their efficient transport across the cellular membrane is a prerequisite for economically viable fermentation processes. Thus, there is a need for transporter variants exhibiting a high transport rate of pentoses, especially in the presence of glucose, another major constituent of biomass-based feedstocks. Here, we describe a variant of the galactose permease Gal2 from Saccharomyces cerevisiae (Gal2N376Y/M435I), which is fully insensitive to competitive inhibition by glucose, but, at the same time, exhibits an improved transport capacity for xylose compared to the wildtype protein. Due to this unique property, it significantly reduces the fermentation time of a diploid industrial yeast strain engineered for efficient xylose consumption in mixed glucose/xylose media. When the N376Y/M435I mutations are introduced into a Gal2 variant resistant to glucose-induced degradation, the time necessary for the complete consumption of xylose is reduced by approximately 40%. Moreover, Gal2N376Y/M435I confers improved growth of engineered yeast on arabinose. Therefore, it is a valuable addition to the toolbox necessary for valorization of complex carbohydrate mixtures.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260086
Author(s):  
Xin Ran ◽  
Xiao Wang ◽  
Xiaokuan Gao ◽  
Haiyong Liang ◽  
Bingxiang Liu ◽  
...  

Objective The purpose of this study was to explore the adaptive mechanism underlying the photosynthetic characteristics and the ion absorption and distribution of white willow (Salix alba L.) in a salt stress environment in cutting seedlings. The results lay a foundation for further understanding the distribution of sodium chloride and its effect on the photosynthetic system. Method A salt stress environment was simulated in a hydroponics system with different NaCl concentrations in one-year-old Salix alba L.branches as the test materials. Their growth, ion absorption, transport and distribution in the roots and leaves, and the changes in the photosynthetic fluorescence parameters were studied after 20 days under hydroponics. Results The results show that The germination and elongation of roots are promoted in the presence of 171mM NaCl, but root growth is comprehensively inhibited under increasing salt stress. Under salt stress, Na+ accumulates significantly in the roots and leaves, and the Na+ content and the Na+/K+ and Na+/Ca2+ root ratios are significantly greater than those in the leaves. When the NaCl concentration is ≤ 342mM, Salix alba can maintain relatively stable K+ and Ca2+ contents in its leaves by improving the selective absorption and accumulation of K+ and Ca2+ and adjusting the transport capacity of mineral ions to aboveground parts, while K+ and Ca2+ levels are clearly decreased under high salt stress. With increasing salt concentrations, the net photosynthetic rate (Pn), transpiration rate (E) and stomatal conductance (gs) of leaves decrease gradually overall, and the intercellular CO2 concentration (Ci) first decreases and then increases. When the NaCl concentration is < 342mM, the decrease in leaf Pn is primarily restricted by the stomata. When the NaCl concentration is > 342mM, the decrease in the Pn is largely inhibited by non-stomatal factors. Due to the salt stress environment, the OJIP curve (Rapid chlorophyll fluorescence) of Salix alba turns into an OKJIP curve. When the NaCl concentration is > 171mM, the fluorescence values of points I and P decrease significantly, which is accompanied by a clear inflection point (K). The quantum yield and energy distribution ratio of the PSⅡ reaction center change significantly (φPo, Ψo and φEo show an overall downward trend while φDo is promoted). The performance index and driving force (PIABS, PICSm and DFCSm) decrease significantly when the NaCl concentration is > 171mM, indicating that salt stress causes a partial inactivation of the PSII reaction center, and the functions of the donor side and the recipient side are damaged. Conclusion The above results indicate that Salix alba can respond to salt stress by intercepting Na+ in the roots, improving the selective absorption of K+ and Ca2+ and the transport capacity to the above ground parts of the plant, and increasing φDo, thus shows an ability to self-regulate and adapt.


2021 ◽  
Author(s):  
Robert J Hawley ◽  
Kathryn Russell ◽  
Kristine Taniguchi-Quan

Abstract Stream channel erosion, enlargement, and habitat degradation are ubiquitous in urban watersheds with conventional stormwater management. Hydrologic-based restoration aims to discharge a more natural flow regime via stormwater management interventions. Whether such interventions facilitate geomorphic recovery depends, in part, on the degree to which they restrict discharges that would otherwise contribute to channel erosion. Erosion potential (E), the ratio of post-developed to predeveloped sediment transport capacity, provides a simplified, mechanistic framework to quantify the relative influence of stormwater interventions on the geomorphic effectiveness of the flow regime. This paper compiles ca. five years of data following stormwater-based interventions in three distinct settings in the United States and Australia to demonstrate how the E framework can be used to elucidate the role of hydrologic restoration interventions in helping to facilitate trajectories of geomorphic recovery (or lack thereof). In a previously developed watershed with unstable streams, substantial reductions in E coincided with a trajectory of geomorphic recovery, whereas our case study that did not reduce E between the study periods exhibited continued instability. Furthermore, a greenfield study site that used the E framework to optimize their SCMs to match the sediment transport capacity of the predeveloped regime (E = 1) was able to maintain a recovery trajectory in a legacy-impacted setting that is otherwise highly susceptible to hydromodification. Although available space and funding will limit the ability to fully reduce E in previously developed watersheds, these case studies underscore the mechanistic value of using stormwater controls to maximize reductions in E if geomorphic stability is a goal of stormwater interventions. Streambed material size and channel evolution stage also likely affect the level of E reduction necessary to promote geomorphic recovery, with coarser-grained and/or over-widened streams potentially needing less reduction than finer-grained and/or more entrenched channels.


Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3054
Author(s):  
Linh Nguyen Van ◽  
Xuan-Hien Le ◽  
Giang V. Nguyen ◽  
Minho Yeon ◽  
Sungho Jung ◽  
...  

Estimation of sediment transport capacity (STC) plays a crucial role in simulating soil erosion using any physics-based models. In this research, we aim to investigate the pros and cons of six popular STC methods (namely, Shear velocity, Kilinc-Richardson (KR), Effective stream power, Slope and unit discharge, Englund-Hansen (EH), and Unit stream power) for soil erosion/deposition simulation at watershed scales. An in-depth analysis was performed using the selected STC methods integrated into the Grid Surface Subsurface Hydrologic Analysis model for investigating the changes in morphology at spatial-temporal scales at the Cheoncheon watershed, South Korea, over three storm events. Conclusions were drawn as follows. (1) Due to the ability of the KR and EH methods to include an additional parameter (i.e., erodibility coefficient), they outperformed others by producing more accurate simulation results of sediment concentration predictions. The KR method also proved to be superior to the EH method when it showed a more suitable for sediment concentration simulations with a wide range of sediment size and forcing magnitude. (2) We further selected 2 STC methods among the 6 methods to deeply explore the spatial distribution of erosion/deposition. The overall results were more agreeable. For instance, the phenomenon of erosion mainly occurred upstream of watersheds with steep slopes and unbalanced initial sediment concentrations, whereas deposition typically appeared at locations with flat terrain (or along the mainstream). The EH method demonstrated the influence of topography (e.g., gradient slope) on accretionary erosion/deposition results more significantly than the KR method. The obtained results contribute a new understanding of rainfall-sediment-runoff processes and provide fundamental plans for soil conservation in watersheds.


2021 ◽  
Author(s):  
Guoxiang Zhao ◽  
Yuedong Yao ◽  
Caspar Daniel Adenutsi ◽  
Lian Wang ◽  
Fengrui Sun

Abstract Shale oil is an unconventional petroleum resource which has high total organic carbon (TOC) content and abundant nanopores. The transport behavior of oil through organic rich shales cannot be described by the classical Darcy law due to its complex pore structure and the complicated distribution of organic matter, which results in nanoconfined effects. In this work, on the basis of the boundary slip phenomenon and the fractal scaling theory, a model for oil transport in shale matrix is established considering nanoconfined effects and adsorbed organic matter. The results show that it is necessary to make correction of viscosity and the boundary slip length in order to accurately describe the flow behavior of oil in shale matrix with mixed wettability nanopores. Long chain molecules are more sensitive to nanoconfined effects, especially when adsorbed organic matter is considered. Also, the oil transport capacity in organic shale matrix is greatly enhanced compared to the classical no-slip permeability model. Meanwhile is the oil transport capacity is significantly reduced in inorganic shale matrix. This work shows that the identification of higher TOC region and considering the nanoconfined effects are necessary from the concept of oil transport in shale matrix.


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