Laboratory Experimental Study on Influencing Factors of Drainage Pipe Crystallization in Highway Tunnel in Karst Area

The crystalline blockage of tunnel drainage pipes in a karst area seriously affects the normal operation of drainage system and buries hidden dangers for the normal operation of the tunnel. In order to obtain the influencing factors and laws of tunnel drainage pipe crystallization in a karst area, based on the field investigation of crystallization pipe plugging, the effects of groundwater velocity, drainage pipe diameter, drainage pipe material, and structure on the crystallization law of tunnel drainage pipe in karst area are studied by indoor model test. The results show that: (1) With the increase of drainage pipe diameter (20–32 mm), the crystallinity of drainage pipes first increases and then decreases. (2) With the increase of water velocity in the drainage pipe (22.0–63.5 cm·s−1), the crystallinity of the drainage pipes gradually decreases from 1.20 g to 0.70 g. (3) The crystallinity of existing material drainage pipe is: M3 (poly tetra fluoroethylene) > M2 (pentatricopeptide repeats) > M4 (high density polyethylene) > M1 (polyvinyl chloride); M8 (polyvinyl chloride + coil magnetic field) is used to change the crystallinity of drain pipe wall material. (4) When the groundwater flow rate is 34.5 cm·s−1, M1 (polyvinyl chloride) and M8 (polyvinyl chloride + coil magnetic field) can be selected for the tunnel drainage pipe. The research on the influencing factors of tunnel drainage pipe crystallization plugging fills a gap in the research of tunnel drainage pipe crystallization plugging. The research results can provide a basis for the prevention and treatment technology of tunnel drainage pipe crystallization plugging.

SP10.2.1 Use of a cost-efficient Colonoscopy simulation model to improve endoscopy skills

Aims The use of endoscopic simulators as a learning aid in surgical training has been well established, particularly in those with less experience. In the challenging time of COVID-19, when endoscopic procedures are at a minimum, this can become more valuable. However, their utility for training is countered by the high cost of equipment. We demonstrate a cost-efficient alternative to traditional endoscopy simultators, which can be easily made in any centre. Methods A polypectomy simulator model was created using a drain-pipe and surgical gloves. Junior doctors were timed in their ability to remove the 3 polyps from within the simulator. The exercise was repeated over 6 sessions over the course of 3 weeks. Means were compared using ANOVA. Results There was a mean relative reduction of 75% in overall time taken to complete the task (p < 0.0001). This improvement was seen for both surgical trainees with previous endoscopy experience (p = 0.005) and FY1 novices (p < 0.0001). Conclusions In our group, we have seen improvement in performance across both surgical trainees and novices. In today's era of COVID-19, when direct training opportunities may become more scarce, simple alternatives may become vital in ensuring progression of basic surgical skills such as endoscopy. This cheap polypectomy simulator can be easily re-created across surgical units and can be used as an adjunct to traditional endoscopic training.

Medzikultúrny dialóg v súčasnej slovenskej dráme a divadle

The study deals with the possible inspirations from the external environment being the part of works by Karol Horák which undergo a creative transformation and produce a new aesthetic quality on the level of text, as well as the on the level of new staging forms or genesis of a completely new autochthonic theatre form (authorʼs theatre, postmodern theatre, medial theatre, happenings, performances, site-specific, etc.) There was a continuous pulsation among Slovak national theatre culture, or rather metonymically understood Prešov´s regional student theatre, and American (Living Theatre of J. Becka and J. Malinova, Schumannʼs Bread and Puppet, etc.), Polish (Kantorʼs Cricot 2, Grotowskiʼs Theatre Laboratory, Raczakʼs Theatre of Eighth Day, Mądzikʼs Plastic scene, Słupczynskiʼs Theatre Studio of Těšín, the Theatre Academy of Movement, Cracowian KTO, etc.) and Czech provenance (Theatre Orpheus Prague, Theatre X Brno, Theatre under Drain Pipe Ostrava, Quite Small Theatre Litvinov, Theatre on the Periphery, Prague, Quidam Brno, etc.) They have the form of a rational as well as a spontaneous reaction to the external stimulus which often acquired a form with surprisingly authentic aesthetic value. This value usually represented the latent affinity with the original stimulus and it often created an authentic theatre artefact with respect to the recipient having the peculiar status within the national context (e.g. Džura [1968], Démon [1967], Fragmenty [1974], Živý nábytok [1975], Tip-top biotop [1976], Materstvo [2011], Človek etudový alebo Konšpirácia alebo Od skúšky k predstaveniu [2013] etc.) This was the way how one wing of Slovak theatre tried to balance falling short of the European or world context.

Durability of Road and Bridge Concrete and Spray-Coating Waterproof Material

Different from traditional waterproof methods for road and bridge concrete, the spray-coating waterproof material can effectively prevent rainwater and other corrosive liquids from entering the concrete structure, and it has a few functional advantages such as anti-carbonization, resistance to sulfate attack, and high elongation. Existing studies have discussed the impact of the microstructure of waterproof material on the structure of waterproof coating, the optimization of the mix ratios of waterproof material, and the influencing factors of the waterproof performance of waterproof material, etc., however, few researches have concerned about the mechanical properties of concrete after coated with the spray-coating waterproof material. Therefore, to fill in this research gap, this paper researched the durability of road and bridge concrete and the spray-coating waterproof material. At first, it analyzed the bridge deck water pressure and the internal force of the drain pipe structure under multiple drainage methods, and calculated the water pressure at the gutter inlet, the stress, and the permeability coefficient of the waterproof coating. Then, this paper elaborated on the experimental methods for measuring the durability of the road and bridge before and after coated with the spray-coating waterproof material, and introduced the methods for testing the waterproof material and the concrete. At last, this paper gave the corresponding experimental results, the analysis, and the conclusion.

Complex Weblike Hydrogen Bonding in Large “Drain Pipe” Channels of Wightmanite Revealed by New X-Ray and Spectroscopic Measurements

ABSTRACT The wallpaper-type crystal structure of wightmanite, Mg5(BO3)O(OH)5·1–2H2O, has been reanalyzed in order to better understand the position and bonding of hydrogen atoms. Single-crystal structure refinement yielded the monoclinic I2/m unit cell a = 13.5165(18), b = 3.0981(3), c = 18.170(3)Å, ß = 91.441(6)°, and V = 760.65(17)Å3, Z = 4. Hydrogen atoms of OH groups pointing to the inside of the elliptical channels oriented parallel to [010] are arranged in the form of two overlying, a–c parallel planar pentagons. The two pentagons point in opposite directions. Hydrogen-bond analysis shows that the hydroxyl groups are linked by complex polyfurcated, intra-molecular hydrogen bonds forming a web-like network coating the walls of the channels. The longest distance between hydrogens (7.226 Å) is observed in the pentagonal planes of the channel. The anisotropically refined oxygen atoms of the zeolitic water show their strongest vibration parallel to the b axis and in the direction of the largest diameter of the elliptical channel and similarly form a complex inter-molecular hydrogen-bond system to the hydroxyl groups coating the channel walls. This complex bonding is expressed in the Raman spectrum by a broad band between 3100 and 3300 cm–1 that is assigned to the OH / H2O stretching mode and one strong band at 3661 cm–1 attributable to an OH-stretching mode. Infrared spectra also show a pronounced broad band between 3200 and 3700 cm–1 attributed to H2O and OH-stretching modes. The weak bands around 1600 cm–1 observed in the Raman and IR spectra are probably due to relatively weakly bound water in the channels.

Methane Oxidation Biosystem In Landfill Fugitive Emissions Using Conventional Cover Soil And Compost As Alternative Substrate – A Field Study

Landfill is an important anthropogenic source of greenhouse gases (GHG). Aiming at methane mitigation through the use of a cover layer in the form of fugitive emissions, this study investigated the methane passive bioxidation in a Brazilian landfill in biofilters under two conditions: control column (packing material using a 60 cm landfill cover soil with ≅0.8% organic matter) and enriched column (packing material using 45 cm landfill cover soil and 15 cm mixture of cover soil plus compost with ≅6% organic matter). The biogas was collected from a vertical drain pipe of a four-year-old cell and injected into the base of the columns with a high inlet loading (1000 g CH4 .m - ².d - ¹ at standard temperature and pressure conditions) in the upward flow mode. Ten campaigns were carried out for six months in order to determine the efficiency of the methane oxidation in each column. Parameters related to the biogas oxidation were also determined, such as soil temperature and moisture content and nutrients content in both filter beds. The oxidation global efficiencies were higher in the enriched column throughout all campaigns, with »71 and »95% for the control and enriched columns, respectively. Our study demonstrated that the use of substrates with high organic matter content and low cost (such as the compost) in landfill cover layers might present high efficacy in the reduction of methane fugitive emissions. Landfill is an important anthropogenic source of greenhouse gases (GHG). Aiming at methane mitigation through the use of a cover layer in the form of fugitive emissions, this study investigated the methane passive bio-oxidation in a Brazilian landfill in biofilters under two conditions: control column (packing material using only landfill cover soil with ≅0.8% organic matter) and enriched column (packing material using 45 cm landfill cover soil and 15 cm mixture of cover soil plus compost with ≅6% organic matter). Biogas was collected from a vertical drain pipe of a four-year-old cell and injected into the base of the columns with a high inlet loading (1000 gCH4.m-².d-¹) in upward flow mode. Ten campaigns were carried out for six months in order to determine the efficiency of the methane oxidation in each column. Soil temperature, moisture and nutrients content in both filter beds were also determined. The oxidation global efficiencies were higher in the enriched column throughout all campaigns, with »71 and »95% for the control and enriched columns, respectively, demonstrating that this technology can be applied even in landfills where there is no energy recovery from biogas (as in most landfills in developing countries). Our study demonstrated that the use of substrates with high organic matter content and low cost in landfill cover layers might present high efficacy in the reduction of methane fugitive emissions. Even operating in field-scale conditions, the results of this study were comparable to those obtained with biofilters on lab-scale (under controlled operational conditions).

536 Use of A Cost-Efficient Colonoscopy Simulation Model to Improve Endoscopy Skills During the COVID Pandemic

Introduction The use of endoscopic simulators as a learning aid in surgical training has been well established. This has been emphasised during the challenging times of COVID-19. However, their utility for training is countered by the high cost of the equipment, with the most basic simulators costing upwards of £50,000. Method A simple polypectomy simulator model was created using a drain-pipe and surgical gloves. n = 9 junior doctors were timed in their ability to remove the 3 polyps from the simulator. The exercise was repeated over 6 sessions over the course of 3 weeks. Means were compared using ANOVA. Results There was a mean relative reduction of 75% in overall time taken to complete the task(p < 0.0001). This improvement was seen for both surgical trainees(p = 0.005) and FY1 novices(p < 0.0001) and junior doctors reported feeling more confident with basic Colonoscopic skills. Conclusions We have demonstrated an improvement in performance times across both surgical trainees and novices. In today’s era of COVID-19, when direct training opportunities may become more scarce, simple alternatives may become vital in ensuring progression of basic surgical skills such as endoscopy. This cheap polypectomy simulator can be easily re-created across surgical units and can be used as an adjunct to traditional endoscopic training

Evaluating the Efficiency of Crushed Gravel Filters around Field Drains

Engineers have employed various ways to protect drain openings from the entry of sediment with varying degrees of success. This study aims to compare and evaluate the hydraulic performance and efficiency of using natural graded gravel filter and crushed gravel filter in drainage systems. An aquifer tank (sand tank) 70 cm long, 50 cm wide and 80 cm high, a perforated drain pipe of 50 mm diameter was used in the laboratory work. The laboratory study was performed with two types of soil: loam and loamy sand. These two soils were used with the two types of gravel filters after taking the particle size distribution test for the two soils. For each case, the inflow was applied to the model from the soil surface (to represent irrigation condition) and from the sides of the tank (to represent sub –surface flow condition and effluence of the groundwater). Each case involved ten runs; for each run, discharge, total head loss, and amount of sediment were recorded. It was found that crushed gravel filter would work similarly to natural graded gravel filter after a certain time from the beginning of runs. It was also found that the discharge and sediment when using crushed gravel filter were close to or equal to that with natural graded gravel filter. The hydraulic conductivity and the exit gradient values were calculated in this research. It was found that their values were so different between the two types of filters, but at the end of the laboratory work, the hydraulic conductivity would be approximately the same. The exit gradient of crushed gravel filter was lower than that of natural graded gravel filter due to the large pores between the filter particles. Finally, the results showed that, it is possible to use crushed gravel filter material in drainage systems, which is less costly and easier to place than natural graded gravel filter.

Evaluation of Parallel Pipe Subsurface Drainage System in a Waterlogged Paddy Field

Inadequate natural drainage facilities and flat lands causes, some of the Cauvery river basin command are suffering waterlogging and alkalinity problems during the canal water supply and period of excess rainfall. Subsurface drainage system is the method to lower the depth to groundwater level below the root zone and creates a favorable environment for crop growth. A study aimed to evaluate the performance of the parallel pipe subsurface system installed in farmers’ field at Sembari village, Lalgudi Taluk, Trichy District, Tamil Nadu in a waterlogged paddy field from October 2020 to February 2021. The field experiment was conducted with the combination of three lateral drain spacing (7.5, 10.0 and 12.5 m) and two drain depths (60 and 80 cm). 63 mm PVC perforated pipes wrapped with coir envelope were laid as lateral drains at a grade 0.3%. Inspection chambers connected with collector drains laid at a grade of 0.6% were used to measure the drain water discharge, observation wells installed midway between lateral pipes drains were used for measuring the depth to groundwater level. Hydraulic properties of soil, depth to water level, discharge collected in drain pipe were used as evaluation parameters. This study revealed that soil hydraulic conductivity had been increased to 30%, pH, EC and ESP has been reduced to 12, 54 and 20%, respectively. The system has performed well to alleviate the waterlogged condition in 7.5 m lateral drain spacing and 80 cm drain depth treatment by observing the higher rate of decrease in depth to water of 0.3 to 0.4 m and a drainage coefficient of 0.069 to 0.29 cm/day.