Tunneling Escape Research Articles

Evaluating Tunnel Users’ Literacy on Expressway Tunnel Fire Safety: Questionnaire Analysis and Policy Decisions

The number of tunnel fire accidents has increased with the scale of expressway tunnel construction and traffic flow. Due to the severity of tunnel fires, improving tunnel fire safety and reducing fire accident hazards has become a societal concern. It is essential to explore and evaluate tunnel fire safety literacy among the population. In this study, an online and on-site questionnaire survey was conducted in Hunan Province, China. A total of 1990 questionnaires were collected, of which 1573 were valid. Overall statistical analysis, descriptive statistics, and correlation analysis were performed on valid questionnaires. The results show that the overall level score rate of awareness of drivers and passengers regarding tunnel fire safety was only 0.43. In total, 58.42% of people were unaware of the pedestrian cross passages in expressway tunnels, and 68.40% were unable to recognize them. Similarly, 46.47% of people were unable to recognize evacuation signs in expressway tunnels. In addition, 39.29% of people chose the wrong evacuation behavior. The percentage of people who were aware of the correct usage of firefighting facilities in expressway tunnels was below 50.00%. Correlation analysis results show that tunnel users’ demographic characteristics significantly affected their cognition of expressway tunnel escape methods. This study shows that tunnel users’ emergency escape knowledge regarding tunnels is relatively low. Corresponding countermeasures were proposed to guide policy decisions for enhancing tunnel fire safety.

Preserving Holocaust history: Geophysical investigations at the Ponary (Paneriai) extermination site

Holocaust mass grave sites in eastern Europe can be difficult to investigate due to a paucity of historical documentation relating to the events and because the use of traditional invasive archaeology methods raises concerns around the disturbance of the remains of Jewish people. When combined with other lines of evidence, including historic photos and eyewitness testimony, noninvasive geophysical methods help to effectively identify and demarcate buried features at Holocaust sites, limiting unnecessary excavations. Between 1941 and 1944, as many as 100,000 people were murdered at the Ponary (Paneriai) extermination site in Lithuania, but many critical details of the site layout during this period are still to be resolved, including the location of some of the mass graves and confirmation of an escape tunnel that was used by slave laborers to escape captivity and certain death at the site. At Ponary, a combination of electrical resistivity tomography (ERT) profiling, limited ground-penetrating radar data, and bare-earth elevation data (from a light and distance ranging data set) was used to confirm the location of a large unmarked mass grave with a diameter of approximately 25 m and depth of approximately 4 m. Additional ERT profiling at a second location imaged the entrance to an escape tunnel previously uncovered by an archaeological excavation in 2004, and it detected an approximately 5 m section of the continuation of the tunnel, approximately 33 m away from the tunnel entrance. The geophysical results are supported by evidence from limited archaeological excavations, historical photographs, eyewitness descriptions of the site layout, and testimonies from the few survivors who managed to escape Ponary.

Nie do przebycia? O granicach i ich przekraczaniu w powieści "Tunel" Magdaleny Parys

This article is an analysis of Tunel (The Tunnel), the novel by Magdalena Parys, a Polish author living in Germany. The action of the book focuses on the fictional construction of an escape tunnel built under the border wall between the western and eastern part of Berlin in the early 1980s. This, somehow, predestines Parys’s work to be read in the context of transgression, and crossing limitations. Starting with the writer’s non-literary inspirations, the article shows the multiplicity of literal and metaphorical meanings of the term “border” and examines how the motif functions in the presented world.

Sociability, but not spatial memory, is correlated with regional brain volume variation in the striped mouse Rhabdomys spp.

Local environmental conditions associated with different geographic areas may elicit variations in behavioural responses in animals, leading to concomitant differences in functional brain region volumes. We investigated the behavioural correlates of hippocampus and amygdala volumes in three sister taxa of the murid rodent genus Rhabdomys, occurring in different environments. We used a Barnes maze to test spatial memory, dyadic encounters to test social behaviour, and histological brain sections to calculate hippocampus and amygdala volumes. Arid-occurring R. pumilio made fewer errors and had shorter latencies in locating the escape tunnel compared to moist grassland-occurring R. d. dilectus and R. d. chakae in two probe trials, 48 and 96 h after the last learning trial. R. pumilio was more amicable than the R. dilectus subspecies in intra-specific dyadic encounters. R. pumilio had larger hippocampus and amygdala volumes than the other species. Smaller amygdala volumes were correlated with longer latencies in females for probe trial 1, but males showed similar latencies regardless of taxon. Higher amicability scores were correlated with larger amygdala volumes in all taxa. Higher amicability scores were correlated with larger hippocampus volumes in R. pumilio and R. d. chakae but smaller hippocampus volumes in R. d. dilectus. Correlative relationships between spatial memory and amygdala volume appeared 48 h, but not 96 h, after the last learning trial. Local environmental conditions may influence spatial navigation, but social correlates drive regional brain size within cryptic striped mouse taxa.

Primary Support Design for Sequentially Excavated Tunnel Junctions in Strain-Softening Hoek–Brown Rock Mass

Modern highway and railway tunnel projects include cross passages at regular intervals along the main tunnel length as escape routes. Such areas have complex geometry and incorporate three-dimensional stress redistributions in the tunnel support system and the rock mass. The sequential procedure of excavation and primary support installation of a tunnel junction area can be approximated only with complex three-dimensional numerical simulations. This study presents a practical methodology for the estimation of the displacements and loads induced to the main tunnel lining, after the construction of the escape tunnel. The methodology is based on the evaluation of three-dimensional numerical simulations results. All simulations incorporate sequential excavation and support cycles in confinement depended strain-softening Hoek–Brown rock mass. The results indicate that the area of the main tunnel lining in proximity to the crown of the escape tunnel is severely unloaded and tensile axial forces are possible to appear, while the main tunnel lining in proximity to the side walls of the escape tunnel is compressively overloaded. Finally, suitable support measures are proposed.

C-Space tunnel discovery for puzzle path planning

Rigid body disentanglement puzzles are challenging for both humans and motion planning algorithms because their solutions involve tricky twisting and sliding moves that correspond to navigating through narrow tunnels in the puzzle's configuration space (C-space). We propose a tunnel-discovery and planning strategy for solving these puzzles. First, we locate important features on the pieces using geometric heuristics and machine learning, and then match pairs of these features to discover collision free states in the puzzle's C-space that lie within the narrow tunnels. Second, we propose a Rapidly-exploring Dense Tree (RDT) motion planner variant that builds tunnel escape roadmaps and then connects these roadmaps into a solution path connecting start and goal states. We evaluate our approach on a variety of challenging disentanglement puzzles and provide extensive baseline comparisons with other motion planning techniques.

Scallywag bunkers: geophysical investigations of WW2 Auxiliary Unit Operational Bases (OBs) in the UK

ABSTRACT In 1940, with the fall of France imminent, Britain prepared secret ‘Auxiliary Units’ tasked with guerrilla activities [Scallywagging] in the invading army’s rear. Patrols of four to eight highly skilled men used below-ground Operational Bases (OBs) in remote locations to avoid detection. No official records are released, but OBs were ‘Mark I’, enlarged deer setts, smuggler caves, etc., and Mark II, prefabricated designs by the Royal Engineers. This paper details three sites in Suffolk: one unknown Mark I was destroyed, a Mark II was partially intact and a Mark II was fully intact, all in secluded woods. Geophysical surveys found metal detectors optimal for location, with mid-frequency GPR/ERT optimal for characterisation. Archaeological finds included home-made braziers, 1940 kerosene heater stove, metal pans, ventilation systems and escape tunnels. This study shows OBs varied in construction and condition, with surveys detecting and characterising them, bringing WWII British ‘invasion’ history into the wider scientific community and public domain.

‘For you, the war is over? Not a chance!’ Captivity and escape at Cultybraggan prisoner of war camp, Comrie, Perthshire

ABSTRACT A project to investigate stories of escape attempts at the Second World War Prisoner of War camp at Cultybraggan in Perthshire undertook geophysical survey and excavation to try to locate escape tunnels. While the limited fieldwork did not locate any traces of the tunnels themselves, the work provided insights into the psychology and practice of escape attempts amongst the German PoWs.

Effect of spin–orbit coupling on tunnelling escape of Bose–Einstein condensate

We theoretically investigate quantum tunnelling escape of a spin–orbit (SO)-coupled Bose–Einstein condensate (BEC) from a trapping well. The condensate is initially prepared in a quasi-one-dimensional harmonic trap. Depending on the system parameters, the ground state can fall in different phases—single minimum, separated or stripe. Then, suddenly the trapping well is opened at one side. The subsequent dynamics of the condensate is studied by solving nonlinear Schrödinger equations. We found that the diverse phases will greatly change the tunneling escape behavior of SO-coupled BECs. In the single minimum and separated phases, the condensate escapes the trapping well continuously, while in the stripe phase it escapes the well as an array of pulses. We also found that SO coupling has a suppressing effect on the tunnelling escape of atoms. Especially, for BECs without inter-atom interaction, the tunnelling escape can be almost completely eliminated when the system is tuned near the transition point between the single minimum and stripe phases. Our work thus suggests that SO coupling may be a useful tool to control the tunnelling dynamics of BECs, and potentially be applied in the realization of atom lasers and matter wave switches.

Discovery of an Escape Tunnel in Sobibor

Discovery of an Escape Tunnel in Sobibor

Challenges and innovative solutions at the new construction of the Bözberg Tunnel

AbstractIn order to further increase the transfer of transalpine traffic through Switzerland from road to rail, the Gotthard axis is to be improved to a 4 m corridor. For this purpose altogether 270 km of railway line between Basel and the Italian border is to be improved to a corner height of 4 m by 2020. The largest individual structure is the new Bözberg Tunnel in the canton Aargau. Various options were investigated for the preliminary design. The best variant turned out to be the new construction of a two‐track tunnel parallel to the existing tunnel. The existing two‐track Bözberg Tunnel, which is not suitable for upgrading to the 4 m standard, will be used as a service and escape tunnel. Various emergency exits lead through five cross passages from the new to the old tunnel. The short construction time of five years until opening on the one hand, and the challenging geology in the Faltenjura with swelling rock mass on the other pose great problems for client, designers, and the contractor. This article reports on these challenges and describes how they have also led to innovative solutions.

Evolution and Genetics of Precocious Burrowing Behavior in Peromyscus Mice

A central challenge in biology is to understand how innate behaviors evolve between closely related species. One way to elucidate how differences arise is to compare the development of behavior in species with distinct adult traits [1]. Here, we report that Peromyscus polionotus is strikingly precocious with regard to burrowing behavior, but not other behaviors, compared to its sister species P.maniculatus. In P.polionotus, burrows were excavated as early as 17days of age, whereas P.maniculatus did not build burrows until 10days later. Moreover, the well-known differences in burrow architecture between adults of these species-P.polionotus adults excavate long burrows with an escape tunnel, whereas P.maniculatus dig short, single-tunnel burrows [2-4]-were intact in juvenile burrowers. To test whether this juvenile behavior is influenced by early-life environment, we reciprocally cross-fostered pups of both species. Fostering did not alter the characteristic burrowing behavior of either species, suggesting that these differences are genetic. In backcross hybrids, we show that precocious burrowing and adult tunnel length are genetically correlated and that a P.polionotus allele linked to tunnel length variation in adults is also associated with precocious onset of burrowing in juveniles, suggesting that the same genetic region-either a single gene with pleiotropic effects or linked genes-influences distinct aspects of the same behavior at these two life stages. These results raise the possibility that genetic variants affect behavioral drive (i.e., motivation) to burrow and thereby affect both the developmental timing and adult expression of burrowing behavior.

Effect of temperature and ridge-width on the lasing characteristics of InAs/InP quantum-dash lasers: A thermal analysis view

We investigate the thermal characteristics of multi-stack chirped barrier thickness InAs/InGaAlAs/InP quantum-dash-in-a-well lasers of different ridge widths 2, 3, 4 and 15µm. The effect of varying this geometrical parameter on the extracted thermal resistance and characteristic temperature, and their stability with temperature are examined. The results show an inverse relation of ridge-width with junction temperature with 2µm device exhibiting the largest junction temperature buildup owing to an associated high thermal resistance of ∼45°C/W. Under the light of this thermal analysis, lasing behavior of different ridge-width quantum-dash (Qdash) lasers with injection currents and operating temperatures, is investigated. Thermionic carrier escape and phonon-assisted tunneling are found to be the dominant carrier transport mechanisms resulting in wide thermal spread of carriers across the available transition states of the chirped active region. An emission coverage of ∼75nm and 3dB bandwidth of ∼55nm is exhibited by the 2µm device, thus possibly exploiting the inhomogeneous optical transitions to the fullest. Furthermore, successful external modulation of a single Qdash Fabry-Perot laser mode via injection locking is demonstrated with eye diagrams at bit rates of 2–12Gbit/s incorporating various modulation schemes. These devices are being considered as potential light sources for future high-speed wavelength-division multiplexed optical communication systems.

Inhibition of p75 neurotrophin receptor does not rescue cognitive impairment in adulthood after isoflurane exposure in neonatal mice

BackgroundIsoflurane is widely used for anaesthesia in humans. Isoflurane exposure of rodents prior to post-natal day 7 (PND7) leads to widespread neurodegeneration in laboratory animals. Previous data from our laboratory suggest an attenuation of apoptosis with the p75 neurotrophin receptor (p75NTR) inhibitor TAT-Pep5. We hypothesized that isoflurane toxicity leads to behavioural and cognitive abnormalities and can be rescued with pre-anaesthesia administration of TAT-Pep5. MethodsNeonatal mouse pups were pretreated with either TAT-Pep5 (25 μl, 10 μM i.p.) or a scrambled control peptide (TAT-ctrl; 25 μl, 10 μM i.p.) prior to isoflurane exposure (1.4%; 4 h) or control (n = 15–26/group). Three to 5 months after exposure, behavioural testing and endpoint assays [brain volume (stereology) and immunoblotting] were performed. ResultsNo significant difference was observed in open field, T-maze, balance beam or wire-hanging testing. The Barnes maze revealed a significant effect of isoflurane (P = 0.019) in errors to find the escape tunnel during the day 5 probe trial, a finding indicative of impaired short-term spatial memory. No difference was found for brain volumes or protein expression. TAT-Pep5 treatment did not reverse the effects of isoflurane on neurocognitive behaviour. ConclusionA single isoflurane exposure to early post-natal mice caused a hippocampal-dependent memory deficit that was not prevented by pre-administration of TAT-Pep5, although TAT-Pep5, an inhibitor of p75NTR, has been shown to reduce isoflurane-induced apoptosis. These findings suggest that neuronal apoptosis is not requisite for the development of cognitive deficits in the adults attendant with neonatal anaesthetic exposure.

The shell effect on the room temperature photoluminescence from ZnO/MgO core/shell nanowires: exciton–phonon coupling and strain

The room temperature photoluminescence from ZnO/MgO core/shell nanowires (NWs) grown by a simple two-step vapor transport method was studied for various MgO shell widths (w). Two distinct effects induced by the MgO shell were clearly identified. The first one, related to the ZnO/MgO interface formation, is evidenced by strong enhancements of the zero-phonon and first phonon replica of the excitonic emission, which are accompanied by a total suppression of its second phonon replica. This effect can be explained by the reduction of the band bending within the ZnO NW core that follows the removal of atmospheric adsorbates and associated surface traps during the MgO growth process on one hand, and a reduced exciton–phonon coupling as a result of the mechanical stabilization of the outermost ZnO NW monolayers by the MgO shell on the other hand. The second effect is the gradual increase of the excitonic emission and decrease in the defect related emission by up to two and one orders of magnitude, respectively, when w is increased in the ∼3–17 nm range. Uniaxial strain build-up within the ZnO NW core with increasing w, as detected by x-ray diffraction measurements, and photocarrier tunneling escape from the ZnO core through the MgO shell enabled by defect-states are proposed as possible mechanisms involved in this effect. These findings are expected to be of key significance for the efficient design and fabrication of ZnO/MgO NW heterostructures and devices.

Dynamics of First and Second Switches in Bi$_{2}$ Sr$_{2}$CaCu $_{2}$O$_{8+\delta }$ Intrinsic Josephson Junction Stacks Measured by Specifically Designed Electronics

We measure switching probability distributions for the first and the second switches of stacks of Bi 2 Sr 2 CaCu 2 O 8+δ intrinsic Josephson junctions. To measure switching probability distributions, we design a current source and introduced a microcontroller. The resolution and accuracy are sufficient for measuring switching probability distributions of intrinsic Josephson junctions. For the first switch, crossover temperatures between thermally activated escape and macroscopic quantum tunneling are in the range between 0.8 and 2.2 K. The crossover temperatures of the second switch are approximately 8.0 and 6.8 K for the samples with critical densities of 1.0 and 2.0 kA/cm 2 , respectively. We analyze critical current density dependence of the crossover temperature of the second switch. The crossover temperature decreases with increasing critical current density. This anticorrelation can be explained neither by the single-junction model nor by the heating effect. The anticorrelation is a peculiar phenomenon observed in the second switch. We consider that the anticorrelation is attributed to the capacitive coupling. The strength of the capacitive coupling is weaker in IJJs with higher critical current density because the charge screening length is shorter due to increase of carrier density.

Numerical analysis of surface subsidence in asymmetric parallel highway tunnels

Tunnelling related hazards are very common in the Himalayan terrain and a number of such instances have been reported. Several twin tunnels are being planned for transportation purposes which will require good understanding for prediction of tunnel deformation and surface settlement during the engineering life of the structure. The deformational behaviour, design of sequential excavation and support of any jointed rock mass are challenging during underground construction. We have raised several commonly assumed issues while performing stability analysis of underground opening at shallow depth. For this purpose, Kainchi-mod Nerchowck twin tunnels (Himachal Pradesh, India) are taken for in-depth analysis of the stability of two asymmetric tunnels to address the influence of topography, twin tunnel dimension and geometry. The host rock encountered during excavation is composed mainly of moderately to highly jointed grey sandstone, maroon sandstone and siltstones. In contrast to equidimensional tunnels where the maximum subsidence is observed vertically above the centreline of the tunnel, the result from the present study shows shifting of the maximum subsidence away from the tunnel centreline. The maximum subsidence of 0.99 mm is observed at 4.54 m left to the escape tunnel centreline whereas the maximum subsidence of 3.14 mm is observed at 8.89 m right to the main tunnel centreline. This shifting clearly indicates the influence of undulating topography and in-equidimensional noncircular tunnel.

Open-Circuit Voltage in AlGaAs Solar Cells With Embedded GaNAs Quantum Wells of Varying Confinement Depth

We investigate the photovoltaic properties of AlGaAs solar cells with embedded GaNAs quantum wells (QWs) with N concentrations in the range of 0–3.1%, for which the QW confinement energy can be tuned by adjusting the N concentration. We systematically study the dependence of open-circuit voltage $V_{{{\rm OC}}}$ in relation to the lowest band-to-band transition energy. In samples with low N concentrations (shallow QW confinement), $V_{{\rm{OC}}}$ degrades and is limited by the lowest transition energy in the solar cell, i.e., the QW transition. With increasing N concentration, N > 0.5% (deep QW confinement), $V_{{\rm{OC}}}$ does not degrade further and is no longer limited by the QW transition energy. The highest N sample exhibits a remarkably small offset between the lowest transition energy and the achieved $V_{{\rm{OC}}}$ of 0.23 V, which is beyond the detailed balance limit of standard solar cells. $V_{{\rm{OC}}}$ dependence is explained by analyzing the current–voltage (I–V) characteristics under different illumination conditions, from which information about the balance of escape and recombination rates of carriers from the QWs is extracted. In the deeply confined QWs, tunneling and thermal carrier escape is completely suppressed, allowing the recovery of $V_{{{\rm OC}}}$ .

Multi-disciplinary investigations at PoW Camp 198, Bridgend, S. Wales: site of a mass escape in March 1945

The largest escape of German Prisoner of War (PoW) in WW2 was in March 1945 from Camp 198, situated in Bridgend, South Wales, UK. Since camp closure the site has become derelict, and has not been scientifically investigated. This paper reports on the search to locate the PoW escape tunnel that was dug from Hut 9. This hut remains in remarkable condition, with numerous PoW graffiti still present. Also preserved is a prisoner-constructed false wall in a shower room behind which excavated material was hidden, though the tunnel entrance itself has been concreted over. Near-surface geophysics and ground-based LiDAR were used to locate the tunnel. Mid-frequency GPR surveys were judged optimal, with magnetometry least useful due to the above-ground metal objects. Archaeological excavations discovered the intact tunnel and bed-board shoring. With Allied PoW escape camp attempts well documented, this investigation provides valuable insight into German escape efforts.

Take the long way home: Behaviour of a neotropical frog, Allobates femoralis, in a detour task

Detour behaviour, an individual's ability to reach its goal by taking an indirect route, has been used to test spatial cognitive abilities across a variety of taxa. Although many amphibians show a strong homing ability, there is currently little evidence of amphibian spatial cognitive flexibility. We tested whether a territorial frog, Allobates femoralis, can flexibly adjust its homing path when faced with an obstacle. We displaced male frogs from their calling sites into the centre of circular arenas and recorded their escape routes. In the first experiment we provided an arena with equally high walls. In the second experiment we doubled the height of the homeward facing wall. Finally, we provided a tube as a shortcut through the high wall. In the equal-height arena, most frogs chose to escape via the quadrant facing their former calling site. However, when challenged with different heights, nearly all frogs chose the low wall, directing their movements away from the calling site. In the “escape tunnel” experiment most frogs still chose the low wall. Our results show that displaced A. femoralis males can flexibly adjust their homing path and avoid (presumably energetically costly) obstacles, providing experimental evidence of spatial cognitive flexibility in an amphibian.