Even Electric Trains Use Coal: Fixed and Relative Costs, Hidden Factors and Income Inequality in HSR Projects with Reference to Vietnam’s North–South Express Railway

High-Speed Rail is often advertised as a sustainable alternative to air travel, and accordingly numerous initiatives for the construction of new HSR infrastructure are currently being pursued across Southeast Asia and the globe. However, beneath promises of “zero-emissions travel” frequently lie numerous hidden factors—how much steel is needed to build the railway? What energy sources are being used to generate the electricity which drives the train? Moreover, how many passengers are required for the train to be efficient relative to other forms of transport? This paper seeks to examine these questions to uncover what “hidden factors” may be present in HSR, using Vietnam’s proposed North–South Express Railway (NSER) as an example. This study calculates the CO2 emissions likely to be produced by the NSER from the construction steel and the power consumed in operation using publicly available data on the technical standards of the railway and existing data on emissions per energy source, combining this data with market size analyses of the central provinces of the proposed line based on official population and income statistics across a range of scenarios to estimate what level of ridership will be required to outperform an equivalent-length air journey. The research finds that under current projections, the HSR may emit more CO2 per end-to-end journey than a plane, that even in per-capita terms the emissions may be worse depending on the seat fill rate, and that the market size of Vietnam’s central provinces will present significant challenges in ensuring that the railway is efficient enough to outperform the plane in ridership terms. This demonstrates both the outstanding impacts of coal and other fossil fuel use in the energy mix and the potential link between environmental performance and regional inequality which constitute the hidden costs in HSR projects, and the exacerbated risks to the environment posed by inequality.

Determination of Length of Individual Pellets and Pellets’ Lengths Distribution

A form and dimensions of fuel particles influence the intensity of their burning and approaches to the mathematic description of the process. Known methods do not allow correctly measuring all pellets’ lengths and describing pellets’ lengths distribution. The purpose of the study is to substantiate method for determining the individual pellet length and to specify statistical characteristics of pellets’ lengths distribution. The purpose was achieved by applying the proposed method of indirect determination of the length of each pellet by weighing it, followed by calculation of the equivalent length and modal cluster analysis of the distribution of pellets by length, based on the probability density distribution. The most noteworthy results are that the experimental calculation of the equivalent length gives results that coincide with direct measurements for pellets of the correct shape, but in contrast to direct measurements can also be used to determine the equivalent lengths of irregularly shaped pellets and their fragments. Clustering allowed grouping pellets around objectively existing local maxima in the probability density distribution, which can be identified at intervals of pellet lengths not exceeding 2 mm. The importance of the obtained results is that the indirect method of determining the length of pellets allows replacing the measurement of pellet lengths by their weighing, which eliminates subjective factors when measuring the length of irregularly shaped pellets and their fragments. Clustering characterised the granulometric composition of pellets with histograms of probability, mass fraction, and average length by clusters. Upon using proposed approaches, granulometric composition of industrially produced pellets was specified and increased probabilities were noted for 8 mm pellets in clusters of smaller lengths, compared to 6 mm pellets; while straw pellets are characterised by a higher probability in clusters with shorter lengths compared to wood pellets

A Knowledge Graph Based Approach to Social Science Surveys

Recent success of knowledge graphs has spurred interest in applying knowledge graphs in open science, such as on intelligent survey systems for scientists. However, efforts to understand the quality of candidate survey questions provided by these methods have been limited. Indeed, existing methods do not consider the type of on-the-fly content planning that is possible for face-to-face surveys and hence do not guarantee that selection of subsequent questions is based on response to previous questions in a survey. To address this limitation, we propose a dynamic and informative solution for an intelligent survey system that is based on knowledge graphs. To illustrate our proposal, we look into social science surveys, focusing on ordering the questions of a questionnaire component by their level of acceptance, along with conditional triggers that further customise participants’ experience. Our main findings are: (i) evaluation of the proposed approach shows that the dynamic component can be beneficial in terms of lowering the number of questions asked per variable, thus allowing more informative data to be collected in a survey of equivalent length; and (ii) a primary advantage of the proposed approach is that it enables grouping of participants according to their responses, so that participants are not only served appropriate follow-up questions, but their responses to these questions may be analysed in the context of some initial categorisation. We believe that the proposed approach can easily be applied to other social science surveys based on grouping definitions in their contexts. The knowledge-graph-based intelligent survey approach proposed in our work allows online questionnaires to approach face-to-face interaction in their level of informativity and responsiveness, as well as duplicating certain advantages of interview-based data collection.

Interaction of ground and surface water in Khabarovsk water node area

This research presents the results of long-term monitoring of groundwater levels within the Khabarovsk water node in the Amur and Tunguska interfluve on the area of the Middle Amur artesian basin in the aquifer of Pliocene-Lower Quaternary alluvial deposits. Observations have been carried out on 9 groups of wells of external monitoring and 5 groups of wells of internal monitoring at the Tunguska reservoir, with a depth of 3 observation wells in the group from 15 to 50 m. The interaction parameters of groundwater and the Pemzenskaya channel have been specified for the period from 2012 to 2020. When the channel causes groundwater afflux during the flood, the average value of the equivalent length parameter ∆L is 40 m for the upper level of the aquifer, 87 m – for the middle level, and it is 605 m for the lower level. Vertical water exchange in the productive strata in the shore zone of the channel is characterized by the values of the overflow coefficient of 0.136 days-1 between the upper and middle observation levels and 0.0116 days-1 between the middle and lower levels.

Post-operative pain after laparoscopic right hemicolectomy for Crohn’s disease: a case control study

Aim: Surgery for Crohn’s disease (CD) is characterized by an enhanced inflammatory response. While inflammation can induce hyperalgesia, post-operative pain following surgery for CD has not been characterized. This retrospective study compared a consecutive series of patients undergoing laparoscopic right hemicolectomy for CD and neoplasia performed by a single surgeon. Method: Elective resections performed between Jan-2016 and Aug-2017 managed in an enhanced recovery pathway were eligible for inclusion. Patients were excluded if open surgery was performed, an ileostomy was fashioned, no patient-controlled analgesia (PCA) was used or data were incomplete. Results : 38 cases were included, 20 for neoplasia and 18 for ileocolonic CD. There was no difference in patient gender (P=0.520). CD patients were younger (39.8±2.8 Vs 77.2±2.1 years, P<0.001) but had an equivalent length of resection (312.9±43.5 Vs 283.3±71.7 mm, P=0.915). CD patients had higher pain scores on post-operative day 1 (6.8±0.8 Vs 2.6±1.0, P<0.001), day 2 (5.0±0.5 Vs 1.6±0.9, P<0.001) and day 3 (4.1±0.6 Vs 1.3±0.7, P=0.008). CD patients used their PCA for longer (85.7±16.3 Vs 47.7±4.2 hours, P=0.017) and used a greater total amount of morphine (148.6±33.8 Vs 37.0±7.8 mg, P<0.001). Post-operative CRP was higher in patients with CD on day 1 (P=0.011), day 2 (P=0.001), day 3 (P=0.001) and day 4 (P=0.007), but no leak or intra-abdominal abscess occurred in either group. Results: 38 cases were included, 20 for neoplasia and 18 for ileocolonic CD. There was no difference in patient gender (P=0.520). CD patients were younger (39.8±2.8 Vs 77.2±2.1 years, P<0.001) but had an equivalent length of resection (312.9±43.5 Vs 283.3±71.7 mm, P=0.915). CD patients had higher pain scores on post-operative day 1 (6.8±0.8 Vs 2.6±1.0, P<0.001), day 2 (5.0±0.5 Vs 1.6±0.9, P<0.001) and day 3 (4.1±0.6 Vs 1.3±0.7, P=0.008). CD patients used their PCA for longer (85.7±16.3 Vs 47.7±4.2 hours, P=0.017) and used a greater total amount of morphine (148.6±33.8 Vs 37.0±7.8 mg, P<0.001). Post-operative CRP was higher in patients with CD on day 1 (P=0.011), day 2 (P=0.001), day 3 (P=0.001) and day 4 (P=0.007), but no leak or intra-abdominal abscess occurred in either group. Conclusions: CD patients experience increased post-operative pain, require more post-operative analgesia and have an enhanced post-operative inflammatory response. Further studies to elucidate the mechanism of this hyperalgesia and strategies to obviate it are required.

Effect of Normalizing Treatment on Mechanical Properties of AISI 441 Stainless Steel Prepared by Investment Casting

In this paper, AISI 441 stainless steel was investigated as a casting steel using the investment casting process (ICP). The microstructure and mechanical properties of the as-cast and normalizing treatment samples were analyzed. The results show that the tensile strength of as-cast AISI 441 prepared by ICP is 458 MPa, and the elongation is 22.7%. Normalizing treatment can improve the mechanical performance of AISI 441 prepared by ICP, but strength and elongation have a slightly decreasing trend with increasing normalizing temperature and time. The suitable normalizing treatment condition is 850 °C for 2 h. It was found that normalizing temperature and time have little effect on grain size and carbonitride. There was an increasing trend in the mean equivalent length (MEL) of the Laves phase as normalizing temperature and time increases. The effect of normalizing treatment on strength increase was mainly related to the change of the Laves phase size.

Scour monitoring of a bridge pier through eigenfrequencies analysis

This paper presents an innovative method for scour monitoring, based on the analysis of the dynamic response of a bridge pier embedded in the riverbed. Apart from the mechanical and physical characteristics of the pier itself, soil-structure interaction (SSI) has an impact on the dynamical behaviour of the system. This is particularly the case for eigenfrequencies of the pier which decrease when the free length increases. In this paper, analytical developments are carried out for an Euler–Bernoulli beam, modelling the pier which is embedded in the soil with Winkler springs for SSI. By using Hamilton’s principle and endowing the specific boundary conditions, the system frequencies are assessed by looking for roots of the characteristic equation of the system. These eigenfrequencies are then compared with those of an equivalent cantilevered beam, which can be expressed analytically. Moreover, experiments are carried out to validate the concept of equivalent length as a parameter of the inverse problem, linking the dynamic behaviour of the system and the embedded length.

Contacting Stability of Sliding Electrical Contacts

It is stated that the operation of the sliding contact unit is accompanied by vibrations of the brushes that occur as a result of internal and external mechanical influences. The resulting violations of the sliding contact (SC) and the instability of contacting lead to a deterioration in the quality of current transmission, increased sparking, accelerated wear of the SC. The article is devoted to the derivation and verification of universal formulas for calculating the relative instability factor (RIF) of the SC. Derived formulas allow calculating the RIF of any SC compounds. Mathematical expressions are obtained to determine the distributions of instability in the tangential and axial directions of the transition layer of the SC. An experimental stand for studying the instability of various SC compounds at idle and in the rated load mode is described. The contacting cycle, which establishes a correspondence between the instantaneous value of the length of the measuring platform and the movement of the collector is described. Expressions for determining the equivalent length of the measuring area for different cases of placing the measuring brush relative to the zone of the main sliding contact are derived. These formulas allow us to find the RIF of various SC regions on experimental data based.