Local Shock Research Articles

Fluorinated graphene nanoparticles with 1–3 nm electrically active graphene quantum dots

A new approach to creating a new and locally nanostructured graphene-based material is reported. We studied the electric and structural properties of partially fluorinated graphene (FG) films obtained from an FG-suspension and nanostructured by high-energy Xe ions. Local shock heating in ion tracks is suggested to be the main force driving the changes. It was found that ion irradiation leads to the formation of locally thermally expanded FG and its cracking into nanoparticles with small (∼1.5–3 nm) graphene quantum dots (GQD), embedded in them. The bandgap of GQD was estimated as 1 -1.5 eV. A further developed approach was applied to correct the functional properties of printed FG-based crossbar memristors. Dielectric FG films with small quantum dots may offer prospects in graphene-based electronics due to their stability and promising properties.

Preferred orientation distribution of shock-induced planar microstructures in quartz and feldspar.

Shocked quartz and feldspar grains commonly exhibit planar microstructures, such as planar fractures, planar deformation features, and possibly microtwins, which are considered to have formed by shock metamorphism. Their orientation and frequency are typically reported to be randomly distributed across a sample. The goal of this study is to investigate whether such microstructures are completely random within a given sample, or whether their orientation might also retain information on the direction of the local shock wave propagation. For this work, we selected samples of shatter cones, which were cut normal to the striated surface and the striation direction, from three impact structures (Keurusselkä, Finland, and Charlevoix and Manicouagan, Canada). These samples show different stages of pre‐impact tectonic deformation. Additionally, we investigated several shocked granite samples, selected at different depths along the drill core recovered during the joint IODP‐ICDP Chicxulub Expedition 364 (Mexico). In this case, thin sections were cut along two orthogonal directions, one parallel and one normal to the drill core axis. All the results refer to optical microscopy and universal‐stage analyses performed on petrographic thin sections. Our results show that such shock‐related microstructures do have a preferred orientation, but also that relating their orientation with the possible shock wave propagation is quite challenging and potentially impossible. This is largely due to the lack of dedicated experiments to provide a key to interpret the observed preferred orientation and to the lack of information on postimpact orientation modifications, especially in the case of the drill core samples.

Flooded through the Back Door: The Role of Bank Capital in Local Shock Spillovers

This paper demonstrates that low bank capital carries a negative externality because it amplifies local shock spillovers. We exploit a natural disaster that is transmitted to firms in non-disaster areas via their banks. Firms connected to a strongly disaster-exposed bank with lowest-quartile capitalization significantly reduce their total borrowing by 6.6% and tangible assets by 6.9% compared to similar firms connected to a well-capitalized bank. These findings translate to negative regional effects on GDP and unemployment. Additionally, following a disaster event, banks reduce their exposure to currently unaffected but generally disaster-prone areas.

Outcomes of the treatment of trigger digits by extracorporal shock wave therapy (ESWT).

Currently, extracorporal shock wave therapy (ESWT) has been widely used in tendinopathies, including trigger fingers. The objective of this study was evaluation of effectiveness of ESWT for trigger digits in a short and mid-term follow-up. Thirty-two patients, 28 women and 4 men, in a mean age of 60 years, with a total of 50 affected digits underwent local extracorporal shock wave treatment. Each patient received 3 applications in a weekly interval. Results were assessed at 1 week and 3 months follow-up, using numeric rank scale for pain and Froimson scale for clinical severity. One-week post-treatment, pain and triggering ceased completely or reduced significantly in 30 patients (94%). At 3 month follow-up, in 30 patients (94%) the symptoms resolved completely and they were considered recovered. Two patients (6%) failed to improve and in these cases the treatment was considered ineffective. ESWT is an effective therapy for trigger digits in II° i III° severity grade and may be an alternative for other, noninvasive measures such as physiotherapy or steroid injection.

Effects of Quintessence Dark Energy on the Action Growth and Butterfly Velocity

In this work we are about to investigate the effects of quintessence dark energy on evolution of the computational complexity relating to the AdS/CFT correspondence. We use “complexity=action” conjecture for a charged AdS black hole surrounded by the dark energy at the quintessence regime. Then we try to find some conditions on the quintessence parameters where the Lloyd bound is satisfied in presence of affects of the quintessence dark energy on the complexity growth at the late time approximations. We compare late time approximation of the action growth by perturbed geometry in small limits of shift function. Actually we investigate the evµolution of complexity when thermofield double state on the boundaries is perturbed by local operator corresponding to a shock wave geometry as holographically. Furthermore we seek spread of local shock wave on the black hole horizon in presence of the quintessence dark energy.

The Propagation of Local Credit Shocks: Evidence from Hurricane Katrina

A local credit shock, induced by hurricane Katrina, propagated through banks’ internal networks to produce real and credit markets’ effects in distant regions. Driven by abnormal mortgage and housing demand in Katrina-hit areas, financially constrained multi-market banks reallocated resources towards the damaged areas leading to a credit tightening in the undamaged local markets. Depending on their housing supply elasticity, local housing markets in the undamaged regions responded to this credit disruption with a mix of housing prices and housing supply declines. These spillovers depended on undamaged markets’ financial linkages to disaster areas. In the undamaged regions, community banks, being local and unexposed to disaster areas, partially insulated their markets from these spillovers.

Facile synthesis of hollow mesoporous nickel sulfide nanoparticles for highly efficient combinatorial photothermal-chemotherapy of cancer.

Traditional techniques for the synthesis of nickel sulfide (NiS) nanoparticles (NPs) always present drawbacks of morphological irregularity, non-porous structure and poor long-term stability, which are extremely unfavorable for establishing effective therapeutic agents. Here, a category of hollow mesoporous NiS (hm-NiS) NPs with uniform spherical structure and good aqueous dispersity were innovatively developed based on a modified solvothermal reaction technique. Upon the successful synthesis of hm-NiS NPs, dopamine was seeded and in situ polymerized into polydopamine (PDA) on the NP surface, followed by functionalization with thiol-polyethylene glycol (SH-PEG) and encapsulation of the chemotherapeutic drug, doxorubicin (DOX), to form hm-NiS@PDA/PEG/DOX (NiPPD) NPs. The resultant NiPPD NPs exhibited a decent photothermal response and stability, attributed to the optical absorption of the hm-NiS nanocore and PDA layer in the near-infrared (NIR) region. Furthermore, stimulus-responsive drug release was achieved under both acidic pH conditions and NIR laser irradiation, owing to the protonation of -NH2 groups in the DOX molecules and local thermal shock, respectively. Lastly, a strong combinatorial photothermal-chemotherapeutic effect was demonstrated for tumor suppression with minimal systemic toxicity in vivo. Collectively, this state-of-the-art paradigm may provide useful insights to deepen the application of hm-NiS NPs for disease management and precision medicine.

Losing in a Boom: Long-term Consequences of a Local Economic Shock for Female Labour Market Outcomes

This paper examines the long-term labour market consequences of a positive economic shock, the first discovery of oil and gas in Norway. Existing studies focus on the short-term and men, while less is known about women and the persistence of such shocks. Oil discovery increased male earnings (by 7%), while female earnings declined (by 10%). These shifts persist for two decades. Labour force participation and occupational change account for the earnings divergence. Within married couples, wives’ earnings declined, but household earnings increased. However, women’s income loss in oil regions is transitory: younger cohorts catch up to women in non-oil regions.

Spillovers and Redistribution through Intra-Firm Networks: The Product Replacement Channel

We study how regional shocks spill over across US local markets through intra-firm market networks and explore how such spillovers reshape household welfare across regions. We identify spillovers by linking data on barcode-region-level prices and quantities with producer-level information and by exploiting variation in firms' exposure to sudden differential drops in local house prices. We find that a firm's local sales decrease in response to a direct negative local demand shock and do so more strongly to indirect negative demand shocks originating in its other markets. The intra-firm cross-market spillover effects occur because (i) firms replace higher-value products---higher sales per product, unit price, and organic sales share---with lower-value products in response to negative demand shocks, and (ii) such product replacements are synchronized across markets within each firm. Counterfactual analysis using multiregion model with endogenous quality adjustment shows that our channel generates a novel and economically sizable regional redistribution effect during the Great Recession.

Physical mechanisms analysis of ultrasonic high amplitude cleaning

The article discusses physical factors that have the greatest impact on the high-amplitude ultrasonic cleaning process course. It has been revealed that an increase in oscillations amplitude a piston ultrasonic transducer over 10 … 12 μm leads to qualitatively new effects formation, which make it possible to expand ultrasonic cleaning technological capabilities. Usually, dynamic effects organization during ultrasonic cleaning is associated with cavitation bubbles action capable collapsing with local shock waves formation, pressure of which reaches 1000 atmospheres, narrow cumulative liquid streams directed toward the solid surface, and new fragmentation bubbles-germ. In high-amplitude regimes, various scale hydrodynamic flows play a decisive role for cavitation effects distribution functions formation in working capacity and for occurrence in it of spatial self-organization certain manifestations. Different-scale acoustic flows effect influence on ultrasonic treatment zone erosion activity has been analyzed. Studies have revealed technological zones presence specific for this type of treatment. Ultrasonic cleaning features with direct collapsing cavitation bubbles use are given in the articles. Possibility for expanding active cavitation erosion zone with high-amplitude ultrasonic cleaning is considered. Research conducting allowed to create effective specific technologies and several technological devices, as well as introduce them at leading industrial enterprises.

THE EXPORT DETERMINANT OF SOCIO-ECONOMIC RESILIENCE IN FOREIGN ECONOMIC ACTIVITY

An undoubted advantage of the diversified economies is their less sensitivity to dynamics fluctuations of local sectors and shock destructions. A downturn in one industry can be compensated by growth in another. Formed in Soviet times significant industrial potential of Ukraine was not possible to implement only in the national economy. A significant part of Ukrainian manufacturing and extractive industries products was consumed by foreign consumers. Formed absolute and relative advantage in international trade ensured the enrichment of a limited set of stakeholders and have become the drivers of system economic crisis and the loss of Ukraine's ability to adsorb (to leap back) shock disturbance. The results of the analysis indicate the negative impact of resources specificity on the Ukraine's ability to ensure sustainable development. Proved the validity of conclusions about the negative effects of high exports concentration (low commodity diversification) on the economy's response from shock disturbances.

Redchyts Evaluation of aerodynamic and thermal loads on the HYPERLOOP capsule fuselage in a partly evacuated tube

Aerodynamics occupies an important place in the design of high-speed ground transportation systems. When a vehicle is moving at a speed above 500 km/h under atmospheric pressure, the main energy is spent to overcome the aerodynamic drag. Creating a rarefied atmosphere inside a sealed pipe in order to significantly reduce energy loss is one of the key ideas of the HYPERLOOP project [1].The paper assesses the aerodynamic and thermal loads on the HYPERLOOP capsule fuselage in a partly evacuated tube based on the numerical solution of the Navier-Stokes equations of compressible flow closed by a differential turbulence model [2-4]. Numerical modeling was carried out with the help of the computational fluid dynamics software developed by the scientific researchers of the Institute of Transport Systems and Technologies of the National Academy of Sciences of Ukraine [5].It was shown that even under conditions of low air pressure in a partly evacuated tube the high-speed movement of the HYPERLOOP capsule will be accompanied by the formation of local supersonic zones, shock waves and non-stationary vortex systems. The structure of the flow essentially depends on geometry of the streamlined capsule and the speed of its movement.It was found that the flow structure and the values of aerodynamic dimensionless coefficients weakly depend on the pressure in the partly evacuated tube. Thus, the aerodynamic forces acting on the HYPERLOOP capsule at the same speeds are almost directly proportional to the pressure value in the tube.A certain problem in the design of the HYPERLOOP type high-speed vehicles will be the aerodynamic heating of the capsule fuselage. When the capsule moves at transonic speed the temperature of the outer surface of the capsule will be 60÷900 C. This heat load can have a negative impact on the performance of onboard power supply and control systems, as well as on the ensuring of the passengers’ comfort on the way.

Employment Hysteresis from the Great Recession

This paper uses US local areas as a laboratory to test for long-term impacts of the Great Recession. In administrative longitudinal data, I estimate that exposure to a 1 percentage point larger 2007–9 local unemployment shock reduced 2015 working-age employment rates by over 0.3 percentage points. Rescaled, this long-term recession impact accounts for over half of the 2007–15 US age-adjusted employment decline. Impacts were larger among older and lower-earning individuals and typically involved a layoff but are present even in a mass-layoffs sample. Disability insurance and out-migration yielded little income replacement. These findings reveal that the Great Recession imposed employment and income losses even after unemployment rates signaled recovery.

Blast responses of pultruded GFRP fluted-core sandwich panels: Testing and analyzing

Abstract Pultruded glass fiber reinforced polymer (GFRP) fluted-core sandwich panel is easily made and may be a lightweight construction for protective structures. Blast resistance of the GFRP fluted-core sandwich panels are investigated by explosion testing. In current research, when the scaled distance is larger than 1.494 m/kg1/3, the panel exhibits excellent anti-blast ability without any damage. Decreasing the scaled distance to 1.357 m/kg1/3, fluted-core shear damage is observed. Decreasing the scaled distance to 1.186 m/kg1/3, fluted-core shear damage and dense longitudinal cracks at front face are observed. Longitudinal cracks are caused by the anisotropy of the pultruded GFRP panels and the local shock wave impact on the mono-cell panels of the front face. Damage degree is investigated quantitively through static three-point bending experiments. Equivalent static load method is developed to predict the damage mode and decide the permitted blast wave the panel can sustain. To improve the anti-blast ability of the pultruded GFRP fluted-core sandwich panel, the core density and the transverse strength of the GFRP should be strengthened.

Identifying fragility for the stock market: Perspective from the portfolio overlaps network

In a financial system, the interconnectedness among entities from investing in common assets (portfolio overlaps) is considered an important channel for the propagation of systemic risk because this interconnectedness can facilitate the contagion of fire sales and lead to widespread sales as well as spiral devaluation of assets. This mechanism also applies to the stock market. Particularly, it is responsible for the presence of fragility, which is defined as the potential global instability of stock prices when confronted by a local negative shock. Thus, we propose to quantitatively explore the temporal pattern of the topological features of the portfolio overlaps network (PON) to identify fragility, with the aim of either capturing a precursor for imminent market crashes or confirming further downward falls during market turmoil. Here, PON is the projected monopartite network used to characterise the mutual overlaps between funds pairs, which is induced from the bipartite network of stocks-funds ownerships. Further, we adopt a solid statistical procedure to construct the validated PON by filtering out mildly risky connections that are not statistically robust. Based on an empirical investigation of the Chinese stock market from 2005 to 2018 that witnessed collective unquenchable price slumps, we found that the topology of the validated PON can indeed provide some sensible indicators for identifying market fragility. The results suggest that (i) the average closeness centrality and the critical value of effective infection rate could serve as leading indicators of impending market turmoil, and (ii) the simple degree-based measure for nodes and relative frequency measures for links are actual synchronous indicators that could also explain the source of fragility.

The Impact of a Local Human Capital Shock: Evidence from the World War II GI Bill

As a result of the GI Bill, returning World War II veterans were generally highly educated, but their locations following the war were uneven across cities in the US. Exploiting the spatial variation in the returning veterans driven by the network of veterans, I study the long run consequences of an increase in the local human capital. After the war, the shock produced a large and uneven increase in local skills. Furthermore, this shock had persistent effects on the local human capital during 1940–2010, and it greatly increased the local skill premium because of directed technical change after 1970.

Heat shock response in noise-induced hearing loss: effects of alanyl-glutamine dipeptide supplementation on heat shock proteins status

IntroductionThe 72kDa heat shock protein, HSP72, located intracellularly provides cochlear cytoprotective and anti-inflammatory roles in the inner ear during stressful noise challenges. The expression of intracellular HSP72 (iHSP72) can be potentiated by alanyl-glutamine dipeptide supplementation. Conversely, these proteins act as pro-inflammatory signals in the extracellular milieu (eHSP72). ObjectiveWe explore whether noise-induced hearing loss promotes both intracellular and extracellular HSP72 heat shock response alterations, and if alanyl-glutamine dipeptide supplementation could modify heat shock response and prevent hearing loss. MethodsFemale 90 day-old Wistar rats (n=32) were randomly divided into four groups: control, noise-induced hearing loss, treated with alanyl-glutamine dipeptide and noise-induced hearing loss plus alanyl-glutamine dipeptide. Auditory brainstem responses were evaluated before noise exposure (124dB SPL for 2h) and 14days after. Cochlea, nuclear cochlear complex and plasma samples were collected for the measurement of intracellular HSP72 and extracellular HSP72 by a high-sensitivity ELISA kit. ResultsWe found an increase in both iHSP72 and eHSP72 levels in the noise-induced hearing loss group, which was alleviated by alanyl-glutamine dipeptide treatment. Furthermore, H-index of HSP72 (plasma/cochlea eHSP72/iHSP72 ratio) was increased in the noise-induced hearing loss group, but prevented by alanyl-glutamine dipeptide treatment, although alanyl-glutamine dipeptide had no effect on auditory threshold. ConclusionsOur data indicates that cochlear damage induced by noise exposure is accompanied by local and systemic heat shock response markers. Also, alanyl-glutamine reduced stress markers even though it had no effect on noise-induced hearing loss. Finally, plasma levels of 72kDa heat shock proteins can be used as a biomarker of auditory stress after noise exposure.

Mechanics of the influx phase in the jet regurgitant mode of a powered resonance tube

Time-resolved visualisation of shock wave motion within a powered resonant tube (PRT) is presented for the regurgitant mode of operation. Shock position and velocity are measured as functions of both time and space from ultra-high-speed schlieren visualisations. The shock wave velocity is seen to vary across the resonator length for both the incident and reflected waves. Three mechanisms are explored as explanations for the variation in velocity: change in local fluid velocity, variation in shock strength and variations in local temperature. For the incident wave, local fluid velocity and shock strength are extracted from the data and both are demonstrated to contribute to the observed variation, with a non-trivial remainder likely explained by variation in temperature.

First Observations of Irregular Surface of Interplanetary Shocks at Ion Scales by Cluster

Abstract We present the first observational evidence of the irregular surface of interplanetary (IP) shocks by using multispacecraft observations of the Cluster mission. In total we discuss observations of four IP shocks that exhibit moderate Alfvénic Mach numbers (M A ≤ 6.5). Three of them are high-β shocks with upstream β = 2.2–3.7. During the times when these shocks were observed, the Cluster spacecraft formed constellations with inter-spacecraft separations ranging from less than one upstream ion inertial length (d i ) up to 100 d i . Expressed in kilometers, the distances ranged between 38 km and ∼104 km. We show that magnetic field profiles and the local shock normals of observed shocks are very similar when the spacecraft are of the order of one d i apart, but are strikingly different when the distances increase to 10 or more d i . We interpret these differences to be due to the irregular surface of IP shocks and discuss possible causes for such irregularity. We strengthen our interpretation by comparing observed shock profiles with profiles of simulated shocks. The latter had similar characteristics (M A, θ BN , upstream ion β) as observed shocks and the profiles were obtained at separations across the simulation domain equivalent to the Cluster inter-spacecraft distances.

Proton Acceleration in Colliding Stellar Wind Binaries

Abstract The interaction between the strong winds in stellar colliding-wind binary (CWB) systems produces two shock fronts, delimiting the wind-collision region (WCR). There, particles are expected to be accelerated mainly via diffusive shock acceleration. We investigate the injection and acceleration of protons in typical CWB systems by means of Monte Carlo simulations, with both a test-particle approach and a nonlinear method modeling a shock locally modified by the backreaction of the accelerated protons. We use magnetohydrodynamic simulations to determine the background plasma in the WCR and its vicinity. This allows us to consider particle acceleration at both shocks, on either side of the WCR, with a realistic large-scale magnetic field. We highlight the possible effects of particle acceleration on the local shock profiles at the WCR. We include the effect of magnetic field amplification, due to resonant-streaming instability, and compare results without and with the backreaction of the accelerated protons. In the latter case, we find a lower flux of the nonthermal proton population and a considerable magnetic field amplification. This would significantly increase the synchrotron losses of relativistic electrons accelerated in CWB systems, lowering the maximal energy they can reach and strongly reducing the inverse Compton fluxes. As a result, γ-rays from CWBs would be predominantly due to the decay of neutral pions produced in nucleon–nucleon collisions. This might provide a way to explain why, in the vast majority of cases, CWB systems have not been identified as γ-ray sources, although they emit synchrotron radiation.