Влияние маневрирования движителя колесной лесной машины на ее проходимость в сложных геотехнических условиях

Unraveling the dependency on multiple passes in laser-induced graphene electrodes for supercapacitor and H2O2 sensing

<meta name=citation_journal_title content=Biological Engineering Transactions><meta name=citation_publisher content=American Society of Agricultural and Biological Engineers><meta name=citation_author content=K. Liu><meta name=citation_author content=P. Ayers><meta name=citation_author content=H. Howard><meta name=citation_author content=A. Anderson><meta name=citation_author content=J. Kane><meta name=citation_title content=Multi-Pass Rutting Study for Turning Wheeled and Tracked Vehicles><meta name=citation_publication_date content=2011><meta name=citation_volume content=54><meta name=citation_issue content=1><meta name=citation_firstpage content=5><meta name=citation_lastpage content=12><meta name=citation_doi content=10.13031/2013.36247><meta name=citation_journal_abbrev content=Biol. Eng. Trans.><meta name=citation_abstract_html_url content=http://elibrary.asabe.org/abstract.asp?aid=36247&t=1&redir=&redirType=><meta name=citation_fulltext_html_url content=https://elibrary.asabe.org/azdez.asp?JID=3&AID=36247&CID=t2011&v=54&i=1&T=1><meta name=citation_pdf_url content=http://elibrary.asabe.org/azdez.asp?JID=3&AID=36247&t=2&v=57&i=6&CID=t2014&downPDF=Y><meta name=citation_issn content=2330-0337><meta name=citation_issn content=2162-643X><meta name=citation_language content=English><meta name=citation_keywords content=Multi-pass; Rut; Tracked and wheeled vehicles; Turning><meta name=citation_reference content=citation_title=Multi-Pass Rutting Study for Turning Wheeled and Tracked Vehicles; citation_author=K. Liu;citation_author=P. Ayers;citation_author=H. Howard;citation_author=A. Anderson;citation_author=J. Kane;citation_journal_title=Biological Engineering Transactions;citation_volume=54;citation_issue=1;citation_firstpage=5;citation_lastpage=12;citation_issn=2330-0337;citation_issn=2162-643X;ciation_doi=10.13031/2013.36247;citation_publication_date=2011;> In this article, the effects of multiple vehicle passes and turning maneuvers by wheeled and tracked vehicles on rutting are discussed. Field tests were conducted at Fort Riley in August 2008 using an M1A1 combat tank, an armored personnel carrier (APC), a heavy expanded mobility tactical truck (HEMTT), and a high-mobility multi-purpose wheeled vehicle (HMMWV). These vehicles were operated in spiral patterns to evaluate the effect of different turning radii. Along each spiral in the same rut, each vehicle was driven up to eight passes. A vehicle tracking system (VTS) mounted on each vehicle utilized a Global Positioning System (GPS) to determine the vehicle dynamics (velocity and turning radius). As expected, compared to a single pass, results show that soil deformation and compaction increased with the increase in the number of passes. Multiple passes and turning maneuvers by vehicles resulted in rut depth increases in the range of 65% to 548%. The results of this study also confirmed that the multi-pass coefficient (a = 2) is appropriate to predict multi-pass rut depth for turning vehicles in loose soils.

<h3>Introduction/purpose</h3> Endovascular mechanical thrombectomy is the most effective treatment for patients presenting with acute large vessel occlusion. However, recanalization is sometimes not achieved even after multiple passes of the thrombectomy device. Repeated attempts at clot retrieval come at a cost of increased procedure time and risk of complications. Clear criteria for when to halt attempting recanalization do not currently exist. We address this question by estimating the probability of recanalization after each pass and compare this with the decreased outcomes associated with multiple passes. <h3>Materials and methods</h3> We studied a retrospective group of patients treated with mechanical thrombectomy for large vessel occlusion at a single center from 2012–2017. For each patient, the TICI reperfusion score after each pass (including aspiration, stentriever, or wire manipulation) was estimated by reviewing the angiography and associated procedure report. Adequate reperfusion was defined as TICI 2b/3. Demographics were obtained from the electronic medical record and included age, gender, vascular risk factors, presenting NIHSS and mRS, procedure time, discharge mRS, and periprocedural complications. Statistics were computed using the open source, R statistics platform. <h3>Results</h3> Reperfusion with TICI 2b/3 was achieved in 146 of 198 patients (74%) after on average 1.8 thrombectomy passes (median 1, IQR 1–3). Most patients underwent stentriever thrombectomy or some combination of aspiration and stentriever. The probability of achieving TICI 2b/3 peaked on the third pass. Although many patients achieved TICI 2b/3 after three or more passes, the probability of achieving TICI 2b/3 decreased precipitously after the third pass. No patients achieved TICI 2b or 3 on the fifth or sixth pass. Patients were sub-stratified by number of passes (1–3 or &gt;3). The group with greater than 3 passes was less likely to achieve TICI 2b or 3 (7/18 (39%) compared with 139/172 (82%), p=0.003) and less likely to achieve good functional outcome, mRS 0–2 (3/18 (17%) compared with 78/164 (48%), p=0.01). The number of passes was weakly correlated with the procedure duration (R² 0.4). <h3>Conclusion</h3> With modern aspiration catheters and stentrievers, target reperfusion is usually achieved within 3 passes. Patients who require greater than 3 passes are less likely to achieve TICI 2b/3 reperfusion and more likely to have poor outcomes. Because the probability of recanalization markedly decreases after 3 passes, and is lost after 5 passes, the diminishing benefit of repeated recanalization attempts must be weighed against the additive risks. <h3>Disclosures</h3> <b>S. Raymond:</b> None. <b>M. Koch:</b> None. <b>J. Rabinov:</b> None. <b>T. Leslie-Mazwi:</b> None. <b>C. Stapleton:</b> None. <b>A. Patel:</b> 2; C; Medtronic, Penumbra.

The article analyzes the floristic composition, ecological groups in relation to soil moisture and substrate, and life forms in the phytocenoses of avalanche paths in Central Altai. It was found that the species composition of the plant communities of the avalanche paths of Central Altai differs significantly. The floristic similarity of the communities, estimated by the index of biotal dispersion (IBD), is weak in all parts of avalanche paths and reaches the highest value (14.2 %) for undisturbed forest communities (Z), and the lowest (9.3%) – in sites X, the central parts of avalanche paths. Data on the higher biodiversity of the central parts of avalanche paths (X) compared to the surrounding forest communities have been confirmed. It was found that family Gentianaceae and genus Gentiana indicate the central parts of avalanche paths, where avalanches occur most frequently. Shrub species of genera Salix and Betula and Lonicera altaica are characteristic of the avalanche path vegetation, have a high abundance, indicate frequent avalanching and can be indicators of avalanche ecotopes. At the same time, species of genus Betula (B. humilis, B. rotundifolia) and Lonicera altaica have high projective cover at level of the B track, while Salix glauca has high projective cover at level of the C track. Using the EcoScaleWin program, geobotanical descriptions on the ecological scales of D.N. Tsyganov were processed to assess the ecological conditions of ecotopes in avalanche paths of Central Altai. In turn, we used the obtained values of ecological scales to identify the dependencies between factors and their influence on the ecotopes using the principal component analysis (PCA). According to the analysis, in the central areas in avalanche paths located on the northwestern slopes, vegetation is influenced to a greater extent by 4 factors: high soil moisture, their nitrogen richness, salt richness, and lower soil acidity. However, in sites X (the central trough) there are more ecotopes, the soils of which are rich in nitrogen and salts, in sites Y (intermediate sections) soil moisture plays an important role. Ecotopes with high shading are typical for forest communities (sites Z). The sites of the avalanche paths studied are located in the forest belt, which is emphasized by the predominance of mesophytes and a high percentage of short-rhizome and long-rhizome herbs in the avalanche paths of Central Altai. Besides, in the central areas of the paths in avalanching sites, there is a high proportion of plants living on waterlogged soils, including cold and moist soils (hygrophytes, hygropsychrophytes, mesohygrophytes, psychrophytes, and mesopsychrophytes), i.e. these ecological groups are indicators of avalanche paths and point out frequent avalanches. On the eastern and southeastern (less often northwestern but then on rocky substrates) slopes in sites X and Y, species of dry and rocky habitats appear in the avalanche paths – xerophytes and petrophytes, many of which are tap-rooted herbs. In the spectrum of life forms of the avalanche paths of Central Altai, in addition to the predominant short-rhizome, long-rhizome and tap-rooted herbs, there is a large proportion of shrubs and brush-rooted herbs in the central parts, indicating frequent avalanches. In open areas, shrubs are abundant in herbaceous-shrubby communities, they are dominant and edificators. In general, short-rhizome, tap-rooted, and brush-rooted herbs (as well as brush-rooted tuber-forming and bulbous), which dominate in shrub-herbaceous cenoses of the avalanche paths, are confined to habitats with poor soil aeration in the X and Y sites; in forest communities (site Z), long-rhizome and loose-bush (also creeping herbs) are characteristic of sufficiently moist and loose soils.

The ability of an invasive plant to occupy new areas is often attributed to both morphological and physiological plasticities that allow them to remain viable over a wide range of environmental conditions. Studies addressing the ecological requirements of Microstegium vimineum often consider soil moisture or soil moisture along with other factors as important explanatory components for the establishment and persistence of this invasive monocot. However, controlled studies specifically targeting water relations in M. vimineum are needed. Therefore, the purpose of this study was to determine how different water availabilities influence the growth and physiological performance of M. vimineum. This study utilized experimental microcosms to achieve different water availabilities including low soil moisture (<15% water), moderate soil moisture (ca. 20–30%), and flooded conditions. While both flooded and low soil moisture resulted in diminished growth, M. vimineum still survived under these conditions. Physiological processes including C4 metabolism, minimum stress under low water conditions, and the ability to increase tissue rigidity may confer some advantages to M. vimineum during periods of limiting water conditions. Similarly, the proportionally low root biomass, shallow root structure, and its ability to maintain stable water relations during flooding and/or soil waterlogging may facilitate M. vimineum’s ability to invade mesic habitats. It is likely, therefore, that the capacity to tolerate both low soil moistures and flooded conditions has enhanced the ability of M. vimineum to populate disturbed systems in central North Carolina.

We assessed how reprocessed and damaged drill bits perform relative-to-new drill bits in terms of drilling force required, heat generated at near and far cortices, and number of usable passes. Nine pairs of nonosteoporotic human cadaveric femora were tested using 3 types of 3.2-mm drill bits (new, reprocessed, and damaged) in 3 investigations (force, temperature, and multiple usable passes). Operating room conditions were simulated. Force and temperature data were collected for each type. The multiple pass investigation measured only force. New and reprocessed drill bits performed similarly regarding force required and heat generated; both outperformed damaged bits. New and reprocessed bits had a similar number of usable passes in ideal conditions. Damaged bits required nearly 2.6 times as much force to maintain drilling rate. Reprocessed drill bits seem to be a viable alternative to new drill bits for fracture treatment surgery in terms of force required, heat generated, and number of usable passes. Drill bits that are damaged intraoperatively should be replaced. In ideal conditions, new and reprocessed drill bits can be used for multiple consecutive cases. Reprocessed drill bits may be as effective as new drill bits, representing potential cost savings for institutions. Both types can be considered for reuse.

Membrane distillation (MD) is an interesting process for desalination; however high thermal energy consumption remains one of the main obstacles in its widespread adoption. The current study presents multipass hollow fiber membrane modules to improve thermal efficiency of MD process. Fundamentally three module designs are considered: conventional one shell and one tube (fiber) pass (A), 1 shell and multiple tube passes (B/C) and equal but multiple shell and tube passes (D). The performance of the proposed designs is analyzed as a function of length of each pass, number of passes and operating conditions by using Aspen Plus simulator. The results demonstrate that the traditional design A yields the highest flux — up to 92 % higher than the multipass design D. On the other hand, the multipass design D is the most energy efficiency and shows up to 35 % less thermal energy consumption than the conventional single pass design of the same length. Single shell and multiple tube pass designs (B/C) show higher flux than D; however, their specific thermal energy consumption remains the highest among all the designs investigated. The pressure drop in multipass modules was marginally (1.5 %) higher than the conventional single pass modules.

Main factors regulating microbial inactivation by high-pressure homogenization: Operating parameters and scale of operation

Hydrodynamic cavitation results in flow restriction in a flow system causing rapid pressure fluctuations and significant fluid forces. These can be harnessed to mediate microbial cell damage. Hydrodynamic cavitation was studied for the partial disruption of E. coli and selective release of specific proteins relative to the total soluble protein. The effects of the cavitation number, the number of passes, and the specific growth rate of E. coli on the release of periplasmic and cytoplasmic proteins were studied. At the optimum cavitation number of 0.17 for this experimental configuration, 48% of the total soluble protein, 88% of acid phosphatase, and 67% of beta-galactosidase were released by hydrodynamic cavitation in comparison with the maximum release attained using multiple passes through the French Press. The higher release of the acid phosphatase over the total soluble protein suggested preferred release of periplasmic compounds. This was supported by SDS-PAGE analysis. The absence of micronization of cell material resulting in the potential for ease of solid-liquid separation downstream of the cell disruption operation was confirmed by TEM microscopy. E. coli cells cultivated at a higher specific growth rate (0.36 h(-1)) were more easily disrupted than slower grown cells (0.11 h(-1)). The specific activity of the enzyme of interest released by hydrodynamic cavitation, defined as the units of enzyme in solution per milligram of total soluble protein, was greater than that obtained on release by the French Press, high-pressure homogenization, osmotic shock, and EDTA treatment. The selectivity offered indicates the potential of enzyme release by hydrodynamic cavitation to ease the purification in the subsequent downstream processing.

BackgroundHigher expanded Treatment In Cerebral Ischemia (eTICI) reperfusion scores after endovascular treatment (EVT) are associated with better outcomes. However, the influence of the number of passes on this association is...

Laser bending has emerged as an efficient technique for bending sheet metals without the need for mechanical force or hard tooling. This study investigates the bending angle and residual stress in ST12 steel sheets under direct CO2 laser irradiation. Finite element simulations, experimental investigations, and statistical analysis were employed to systematically examine the influence of laser power (1600–2400 W), scanning speed (65–93 mm/s), and the number of passes (1–5) on the bending process. Seventy-five numerical simulations and a subset of 15 experiments – selected via the Central Composite Design (CCD) method – were conducted to optimize process parameters and validate the simulation model. ANOVA identified the number of passes as the most significant factor; additionally, higher scanning speeds reduced both the bending angle and residual stress, whereas increased laser power had the opposite effect. Notably, higher compressive residual stresses, resulting primarily from multiple passes, help mitigate the spring-back effect, thereby enhancing the final form accuracy of the bent sheet. Simulation outcomes, validated with a maximum error of 6.48%, were used to determine the optimal conditions (2400 W, 65 mm/s, and five passes) for achieving the desired bending performance. Overall, this research advances our understanding of laser bending phenomena and provides practical guidelines for optimizing sheet metal forming processes.

Tracked vehicle impacts to vegetation structure and soil erodibility

Climate change and soil wetness limitations for agriculture: Spatial risk assessment framework with application to Scotland

Soil moisture field has an obvious influence on the stability of reservoir bank slope. Thus, effective, real-time, reliable, and high precision monitoring methods are imperative. However, the existing soil moisture monitoring methods have more or less deficiencies. In this paper, a novel soil moisture monitoring and estimation method based on an ultra-weak fiber Bragg grating (UWFBG) array is proposed which is suitable for large-scale in-situ monitoring. A soil moisture monitoring device is designed and fabricated. This monitoring device consists of several monitoring units, and each monitoring unit consists of a soil container, protector and two UWFBG. Laboratory calibration tests were conducted to establish a relationship between wavelength change and soil moisture content. The test results show that the monitoring accuracy of the device is related to the quality of the loaded dry soil. When the mass of dry soil is 100 g, the monitoring accuracy of soil moisture content is 1.68 % (mass ratio).

External ventricular drain (EVD) placement is a frequently performed neurosurgical procedure. Inaccuracies in drain positioning and the need for multiple passes using the classic freehand insertion technique is well reported in the literature, especially in the traumatic brain injury (TBI) population. The purpose of this study was to evaluate if electromagnetic neuronavigation guidance for EVD insertion improves placement accuracy and minimizes the number of passes in severe TBI patients. Navigation was applied prospectively for all new severe TBI patients who required ventricular catheter placement over a period of 1 year, and compared with a retrospective cohort of severe TBI patients who had EVD inserted freehand in the preceding year. The placement accuracy was evaluated using the Kakarla grading system; the number of passes was also compared. Fifty-four cases were recruited: 35 (64.8%) had their EVD placed using the freehand technique and 19 (35.2%) using navigation guidance. In the navigation group, the placement accuracy was: 94.7% (18/19) grade 1, 5.3% (1/19) grade 2, and none at grade 3. In comparison, freehand placement was associated with misplacement (grades 2 and 3) in 42.9% of the cases (p value=0.009). The number of passes was significantly lower in the navigation group (mean of 1.16±0.38), compared with the freehand group (mean of 1.63±0.88) (p value=0.018). Using the navigation to guide EVD placement was associated with a significantly better accuracy and a lower number of passes in severe TBI patients.