Self-regulating Regime Research Articles

Toward ultraclean correlated metal CaVO3

We report the synthesis and electronic properties of the correlated metal CaVO3, grown by hybrid molecular beam epitaxy. Films were grown on (100) LaAlO3 substrates at a temperature of 900 °C by supplying a flux of elemental Ca through a thermal effusion cell and metalorganic precursor, vanadium oxitriisopropoxide, as a source of vanadium. The presence of a self-regulated growth regime was revealed by the appearance of a specific surface reconstruction detected by reflection high-energy electron diffraction. Films grown within the growth window were characterized by atomically flat surfaces. X-ray reciprocal space maps revealed that the films were coherently strained to the substrate and inherited its twinned microstructure. Despite the presence of twin walls, CaVO3 thin films, grown within the stoichiometric growth window, revealed very low electrical resistivities at low temperatures, with residual resistivity ratios exceeding 90, while films grown at either Ca- or V-excess show deteriorated transport properties, attributed to the presence of extrinsic defects arising from the non-stoichiometry present in these films.

Self-regulating plasma-assisted growth of epitaxial BaBiO3 thin-film on SrTiO3-buffered Si(001) substrate

The BaBiO3 perovskite oxide is an interesting material system because of its superconductivity when p-doped and the predicted topological insulating nature when n-doped. Single crystalline BaBiO3 films are grown by molecular beam epitaxy with high quality utilizing the adsorption-controlled regime, where volatile Bi is supplied in excess in the presence of oxygen radicals. BaBiO3 films are integrated on Si(001) substrates through growth on a SrTiO3(001) buffer layer. Despite the 11.77% lattice mismatch, by systematically varying growth parameters, such as plasma conditions, substrate temperature, and metallic fluxes, a growth window for the BaBiO3 is well-established. Within the optimum growth window, films are stoichiometric and of high crystalline quality based on the different physical characterization techniques. The development of robust layers is facilitated by accessing the self-regulating regime, where only the stoichiometric quantity of Bi sticks during the epitaxy.

The The lost canon. Social theory and social regulation from overturning to mirroring

Facing the hitches of the neoliberal global turn, which first emerged with the 2008 financial crisis, social theory doesn’t appear able to provide an overall critical interpretation of the current regulation pattern and to imagine a different institutional regime, addressing the problems on the ground. This is an unprecedented situation. As we contend, social theory has always glimpsed well in advance the social system crises, assessing at the same time an alternative paradigm, thanks to a sort of canone inverso played against the coeval institutional regime: when a horizontal form of social regulation prevails in a given period, sociology adopts a knowledge paradigm based on the primacy of the vertical social dimensions. And vice-versa. This attitude transcends any conceptual content and mainly concerns the “form” of the theoretical building. In general, social theory opposed both the self-regulating market regime of the nineteenth century, and the following state-centered regime of the twentieth century. Sociology has found its raison d’être in this kind of critical monitoring towards social regulation. What happens today is that the dialectic between social theory and social regulation appears jammed. Evoking the case of the generative social action approach, the article shows that, contrary to the past intellectual seasons, the form of social theory “mirrors” the form of social regulation, instead of overturning it.

Rewriting the human genome, rewriting human rights law? Human rights, human dignity, and human germline modification in the CRISPR era.

In most legal orders, human germline modification is either prohibited or severely restricted. A recurring thought in these legal frameworks is that heritable genome editing would result in practices that are at odds with principles of human rights, such as dignity, justice, and equality. However, now that CRISPR is bringing heritable genome editing within human reach, the question has risen as to whether these human rights bans still make sense. The call is growing louder to lift the ban on heritable genome editing for therapeutic purposes as soon as the technology is safe for introduction in the clinic. This article critically examines these recent proposals from a human rights perspective. First, it examines the question as to how realistic the proposed distinction between the therapeutic and the nontherapeutic uses of human germline modification is in the CRISPR era. Second, it argues that these proposals rely on a one-dimensional understanding of the meaning of human rights for this issue. Finally, it suggests that this one-dimensional understanding paves the way for a regime of self-regulation by the scientific community that leaves little room for public debate on the question as to whether or how human germline modification fits in the long-term aspirations of society.

Power Schedule Optimization of the PIK Reactor to Accelerate Power Buildup During Startup

The possibility of accelerating power buildup in the PIK reactor during startup by optimizing the power schedule is investigated. The analysis concerns the neutronic aspects and takes into account xenon processes, fuel burnup, and limits on reactivity excess and reactor power. A numerical method based on the principle of optimality with reactor power as a control is used to solve the problem. It is shown for one of the power start-up phases of the PIK reactor that optimization of the power schedule makes it possible to accelerate the passage of the phase by 1/4 as compared with a four-step power schedule. The possibility of optimal passage of a portion of the phase in the self-regulation regime of the reactor is considered. It is established that this regime is unstable for the actual power range in practice.

Laser-induced breakdown spectroscopy of aluminum plasma in the absence and presence of magnetic field.

The effect of magnetic field on laser-induced breakdown spectroscopy of aluminum (Al) plasma has been investigated. Al targets were exposed to Nd:YAG laser pulses at different irradiances ranging from 1 GWcm-2 to 2.7 GWcm-2, under argon (Ar) and neon (Ne) environments at various pressures ranging from 5torr to 760torr and at different time delays from 0.42μs to 9.58μs. All spectroscopy measurements were performed in the absence and presence of transverse magnetic field of strength 0.9 tesla. When laser irradiance is increased by keeping the pressure (10torr) and time delay constant (1.25 μs), both excitation temperature (Te) and number density (ne) increase up to certain values. The same trend is observed for Te and ne when the ambient gas pressure of Ar and Ne is increased by keeping the irradiance (1.7 GWcm-2) and time delay constant. At higher irradiances and pressures, saturation is observed, which is attributed to the self-regulating regime of plasma. In the case of time delay, both electron temperature and number density decay exponentially, which is according to the adiabatic expansion model. It is revealed that emission intensity and electron temperature are higher in the presence of magnetic field as compared to the field-free case, which is attributed to magnetic confinement, as well as the joule heating effect. Plasma plume confinement is confirmed by analytical evaluation factor β. β is an analytical factor that is the ratio of plasma pressure to magnetic pressure, i.e., β=Plasma pressureMagnetic pressure. It confirms the validity of magnetic field confinement if β is less than 1. As the evaluated values of β are less than 1 for all cases, they confirm the validity of magnetic confinement.

Surface morphology correlated with sputtering yield measurements of laser-ablated iron

AbstractIron (Fe) targets are exposed to 100 pulses of Nd: YAG laser (532 nm, 6 ns, 10 Hz) at various fluences ranging from 4.8 to 38.5 J/cm2. In order to explore the effect of background environment, targets have been exposed under vacuum as well as under five different pressures ranging from 5 to 100 Torr of various background gases like Ar, Ne, O2, and air. The sputtering yield measurements and surface modifications of laser-ablated Fe are explored by quartz crystal microbalance (QCM) and scanning electron microscopy (SEM) analysis, respectively. QCM measurements reveal that the sputtering yield of Fe is strongly affected by laser fluence, pressure and nature of gas. By increasing laser fluence, the sputtering yield initially increases due to enhanced energy deposition and then saturates due to self-regulating regime. However, with increasing pressures of background gases, the sputtering yield of Fe initially increases and then decreases. Owing to thermal conductivity, ionization potential, and mass of background gas, the sputtering yield of Fe varies in accordance with the sequence vacuum >Ar>Ne>O2> air. The SEM analysis reveals the formation of several features like laser-induced periodic surface structures, cones, cavities, channels, multiple ablative craters, and dot-like structures. The difference in the periodicity, size, and shape of features is explained on the basis of confinement and shielding effects of plasma and various energy deposition mechanisms. The surface profilometry analysis reveals that the crater depth increases with increasing the laser fluence in inert environments, while in case of reactive environments, it tends to decrease initially and afterwards it increases. X-ray diffraction and energy-dispersive X-ray analyses confirm the oxide formation in case of Fe treatment in O2 and air; however, no additional phases are observed for Fe irradiation under inert environments.

The role of spatial confinement for improvement of laser-induced Mg plasma parameters and growth of surface features

The role of spatial confinement for improvement of laser-induced Mg plasma parameters and growth of surface features is investigated by introducing a metallic blocker. Nd: YAG laser at various fluences ranging from 7 to 28 J cm−2 was employed as an irradiation source. All measurements were performed in the presence of Ar under different pressures. Confinement effects offered by metallic blocker are investigated by placing the blocker at different distances of 6, 8 and 10 mm from the target surface. It is revealed from laser-induced breakdown spectroscopy analysis that both plasma parameters, i.e., excitation temperature and electron number density initially increase with increasing laser fluence due to enhancement in energy deposition. With further increase in laser fluence, a decreasing trend followed by saturation is observed which is attributable to shielding effect and self-regulating regime. It is also observed that spatial confinement offered by metallic blocker is responsible for the significant enhancement of both electron temperature and electron number density of Mg plasma. This is true for all laser fluences and pressures of Ar. Maximum values of electron temperature and electron number density without blocker are 8335 K and 2.4 × 1016 cm−3, respectively, whereas these values are enhanced to 12,200 K and 4 × 1016 cm−3 in the presence of the blocker. The physical mechanisms responsible for the enhancement of Mg plasma parameters are plasma compression, confinement and pronounced collisional excitations due to reflection of shock waves. Scanning electron microscope analysis was performed to explore the surface morphology of laser-ablated Mg. It reveals the formation of cones, cavities and ripples. These features become more distinct and well defined in the presence of the blocker due to plasma confinement. The optimum combination of blocker distance, fluence and Ar pressure can identify the suitable conditions for defining the role of plasma parameters for surface structuring.

IBR-2M Reactor Power Feedback Parameters Evaluation Using Square Reactivity Oscillations

The parameters of a mathematical model of power feedback are evaluated on the basis of an analysis of transient power processes arising in the IBR-2M reactor as a result of intentional square oscillations of the reactivity during operation in a self-regulation regime. The power feedback is described by three linear difference equations and represented in the form of three aperiodic elements connected in parallel. Two components play the role of negative and one component positive feedback. The total feedback is negative, i.e., it has a stabilizing effect on the operation of the reactor. The slowest negative component of power feedback is probably due to axial swelling of the fuel as it heats up. Since the power feedback parameters change in the course of operation, their periodically repeated evaluations are one way of securing the operational safety and reliability of the reactor.

Laser Induced Surface Morphology of Molybdenum Correlated with Breakdown Spectroscopy

Surface modifications of laser irradiated molybdenum have been correlated with plasma parameters. Nd:YAG laser (1064 nm, 10 ns) was employed at various laser irradiances ranging from 6 to 50 GW/cm2 under argon environment. The ablation efficiency has been investigated by measuring the crater depth using surface profilometry analysis. Scanning electron microscope (SEM) analysis reveals the formation of coarse grains along with cracked boundaries, cavities and cones at the central ablated areas. Whereas, uplifted re-solidified material, cavities, ridges, droplets and cones were observed at boundary regions. Laser Induced Breakdown Spectroscopy (LIBS) analysis has been performed to evaluate electron temperature and number density of molybdenum plasma. Electron temperature and electron density varies from 6670 to 9305 K and 0.62 × 1018 to 0.72 × 1018 cm−3 respectively. Both the parameters showed similar trend in variation with laser irradiance i.e. an initial increase from 13 to 19 GW/cm2 followed by a decrease from 19 to 25 GW/cm2 and then a saturation from 25 to 50 GW/cm2. The initial increasing trend is attributed to the enhanced excited vapor content of the ablated material, confinement effects of the surrounding argon and absorption of laser energy into the molybdenum vapor plasma during the trailing part of laser pulse leading to ignition of laser supported combustion (LSW) waves. The decreasing trend is attributed to the shielding effect and saturation is explainable on the basis of the formation of a self-regulating regime. Surface modifications of laser irradiated molybdenum were correlated with the plasma parameters.

Spectroscopic and morphological studies of laser ablated silver

The spectroscopic and morphological studies of silver has been investigated after irradiation of Nd:YAG laser by employing Laser Induced Breakdown Spectroscopy (LIBS) and Scanning Electron Microscope (SEM) analyses. Silver targets were exposed to various laser fluences ranging from 5.2Jcm−2 to 41.7Jcm−2 under ambient environment of argon at a pressure of 100Torr. LIBS analysis revealed that when the laser fluence was increased from 5.2Jcm−2 to 10.4Jcm−2, an increasing trend for both electron temperature and electron number density of plasma was observed due to enhanced energy deposition. Afterwards, with increasing fluence from 10.4Jcm−2 to 15.6Jcm−2, a decreasing trend was achieved which was attributed to the shielding effect. With further increase in fluence from 15.6Jcm−2 to a maximum value of 41.7Jcm−2, a saturation region was achieved and insignificant changes in both plasma parameters were observed. This saturation is explainable on the basis of the formation of a self-regulating regime. SEM analysis revealed the formation of flakes and ridges on the surface of silver at the lowest fluence of 5.2Jcm−2. For increased fluences ranging from 10.4Jcm−2 to 41.7Jcm−2, distinct and unorganized melted channels were the dominant features. However, at a maximum fluence of 41.7Jcm−2, micro and nano crystallites of lamellar (tabular) shape were also formed. At peripheral ablated areas, flakes, cavities, cones and craters with multiple ablated layers were formed. The modifications in surface morphology of laser-ablated silver have been correlated with plasma parameters.

Plant resource availability and harvesting pressure in Khardung La, Ladakh

Khardung La area (Ladakh, India) happens to be a hot spot for medicinal plant collection by locals and traditional healers but there is hardly any published information on the diversity and abundance of plants from this area. Such an information is a pre-requisite for conservation planning and future reference. We conducted detailed field surveys in and around Khardung La region to know the medicinal plant diversity and current levels of extraction by the local people and herbal healers. Information on vegetation parameters were collected across various habitats (land forms). Group discussions, informal meetings and questionnaire surveys were conducted with the plant collectors to assess the status of collection. Community structure of plants was assessed using standard vegetation sampling method. The study reveals that the area harbors more than 40 medicinal plants species and receives a large number of plant collectors each year. Collection is done mainly for personal use. However, commercial extraction was also evident. The collection method used by locals was destructive which might cause loss of diversity. Fifteen species had very low frequency due to their habitat specificity while 8 of them had very rare occurrence. Indicator Species Analysis (ISA) resulted in 4 communities in different habitats. Current methods and levels of harvesting pressure on various species around this area suggests that many species would soon become extremely rare. Hence, there is a need to generate awareness among the local stakeholders and encourage them to come up with sustainable harvesting practices and self-regulated collection regime so that commercial extraction is minimized.

Financial data breaches in the U.S. retail economy: Restoring confidence in information technology security standards

Managing effective security of personal customer data located in computer networks has become a strategic business and public policy issue for the U.S. retail sector. The article discusses the global credit card payment industry self-regulation regime established by the Payment Card Industry Security Standards Council (“Council”) to combat cybercrime, comparing and evaluating the Council's existing standards regime to the theory and practices found in the industry self-regulation literature. A review of national cybercrime trends in both the volume and financial impacts (“losses”) of electronic financial record breaches on the U.S. retail sector is presented. After identifying the primary areas of retail electronic records breach vulnerability, an improved industry standards framework is developed that proposes to enhance security and minimize data privacy compromises through the adoption of recommended pure industry self-regulation (improved “security standard”) and market force mechanisms (mandatory “cyber liability insurance coverage”). The article concludes with a discussion of the implementation of the proposed industry self-regulation and market force framework; its current limitations; and what technology advancements may bring in the future to provide more effective security and protection for consumers' personal data and financial transactions.

The impact of angular momentum on black hole accretion rates in simulations of galaxy formation

Feedback from energy liberated by gas accretion onto black holes (BHs) is an attractive mechanism to explain the exponential cut-off at the massive end of the galaxy stellar mass function (SMF). Semi-analytic models of galaxy formation in which this form of feedback is assumed to suppress cooling in haloes where the gas cooling time is large compared to the dynamical time do indeed achieve a good match to the observed SMF. Furthermore, hydrodynamic simulations of individual halos in which gas is assumed to accrete onto the central BH at the Bondi rate have shown that a self-regulating regime is established in which the BH grows just enough to liberate an amount of energy comparable to the thermal energy of the halo. However, this process is efficient at suppressing the growth not only of massive galaxies but also of galaxies like the Milky Way, leading to disagreement with the observed SMF. The Bondi accretion rate, however, is inappropriate when the accreting material has angular momentum. We present an improved accretion model that takes into account the circularisation and subsequent viscous transport of infalling material and include it as a "subgrid" model in hydrodynamic simulations of the evolution of halos with a wide range of masses. The resulting accretion rates are generally low in low mass ($\lsim 10^{11.5} \msun$) halos, but show outbursts of Eddington-limited accretion during galaxy mergers. During outbursts these objects strongly resemble quasars. In higher mass haloes, gas accretion occurs continuously, typically at $~10$ % of the Eddington rate, which is conducive to the formation of radio jets. The resulting dependence of the accretion behaviour on halo mass induces a break in the relation between galaxy stellar mass and halo mass in these simulations that matches observations.

Self-regulated propagation of intense infrared pulses in elongated soft-x-ray plasma amplifiers

Increasing the electron density of collisionally pumped plasma-based soft-x-ray lasers offers promising opportunities to deliver ultrashort pulses. However, strong nonlinear effects, such as overionization-induced refraction and self-focusing, hinder the propagation of the laser beam and thus the generation of elongated volume of lasing ions to be pumped. Using a particle-in-cell code and a ray-tracing model we demonstrate that optically preformed waveguides allow for addressing those issues through a self-regulation regime between self-focusing and overionization processes. As a result, guiding intense pulses over several millimeters leads to the implementation of saturated plasma amplifiers.

Morphological and spectroscopic characterization of laser-ablated tungsten at various laser irradiances

The variation in surface morphology and plasma parameters of laser irradiated tungsten has been investigated as a function of irradiance. For this purpose, Nd:YAG laser (1064 nm, 10 ns, 10 Hz) is employed. Tungsten targets were exposed to various laser irradiances ranging from 6 to 50 GW/cm2 under ambient environment of argon at a pressure of 20 Torr. Scanning electron microscope analysis has been performed to analyze the surface modification of irradiated tungsten. It revealed the formation of micro- and nanoscale surface structures. In central ablated area, distinct grains and crack formation are observed, whereas peripheral ablated areas are dominated by cones and pinhole formation. It was observed that at irradiances exceeding a value of 13 GW/cm2, the morphological trend of the observed structures has been changed from erosion to melting and re-deposition dominant phase. Ablation efficiency as a function of laser irradiance has also been investigated by measuring the crater depth using surface profilometry analysis. It is found to be maximum at an irradiance of 13 GW/cm2 and decreases at high laser irradiances. In order to correlate the accumulated effects of plasma parameters with the surface modification, laser-induced breakdown spectroscopy analysis has been performed. The electron temperature and number density of tungsten plasma have been evaluated at various laser irradiances. Initially with the increase of the laser irradiance up to 13 GW/cm2, an increasing trend is observed for both plasma parameters due to enhanced energy deposition. Afterward, a decreasing trend is achieved which is attributed to the shielding effect. With further increase in irradiance, a saturation stage comes and insignificant changes are observed in plasma parameters. This saturation is explainable on the basis of the formation of a self-regulating regime near the target surface. Surface modifications of laser irradiated tungsten have been correlated with plasma parameters.

Misaligned accretion on to supermassive black hole binaries

We present the results of high-resolution numerical simulations of gas clouds falling onto binary supermassive black holes to form circumbinary accretion discs, with both prograde and retrograde cloud orbits. We explore a range of clouds masses and cooling rates. We find that for low mass discs that cool fast enough to fragment, prograde discs are significantly shorter-lived than similar discs orbiting retrograde with respect to the binary. For fragmenting discs of all masses, we also find that prograde discs fragment across a narrower radial region. If the cooling is slow enough that the disc enters a self-regulating gravitoturbulent regime, we find that alignment between the disc and binary planes occurs on a timescale primarily dictated by the disc thickness. We estimate realistic cooling times for such discs, and find that in the majority of cases we expect fragmentation to occur. The longer lifetime of low-mass fragmenting retrograde discs allows them to drive significant binary evolution, and may provide a mechanism for solving the 'last parsec problem'.

Effect of laser irradiance on the surface morphology and laser induced plasma parameters of zinc

AbstractThe effect of laser-irradiance on the surface morphology and laser induced breakdown spectroscopy of zinc has been investigated by employing Nd:YAG laser (wavelength λ = 1064 nm, pulse duration t ~ 10 ns, and repetition rate = 10 Hz) under ambient environment of argon at a pressure of 20 Torr. For this purpose, zinc targets were exposed to various laser irradiances ranging from 13 GW/cm2 to 100 GW/cm2. Scanning electron microscope analysis has been performed to analyze the surface modification of irradiated zinc targets. Scanning electron microscope analysis revealed the formation of various kinds of structures such as ripples, cones, cavities, and wave like ridges at the center and peripheral regions of ablated zinc. In the central ablated region with increasing laser irradiance, the growth of distinct and well defined ripples is observed. Further increase in irradiance makes the appearance of these ripples diffusive and narrow. In order to correlate the plasma parameters with the surface modification, laser induced breakdown spectroscopy analysis has also been performed. The electron temperature and number density of zinc plasma have been evaluated at various laser irradiances. For both plasma parameters, an increasing trend up to a certain value of laser irradiance is observed which is due to enhanced energy deposition. Afterword a decreasing trend is achieved which is attributed to the shielding effect. With further increase in irradiance a saturation stage comes and almost no change in plasma parameters is observed. This saturation is explainable on the basis of the formation of a self-regulating regime near the target surface. A strong correlation between surface modification and plasma parameters is established.

Gamblers, Loan Sharks & Third-Party Funders -- Draft Chapter 5 from Ethics in International Arbitration

International arbitration is proving to be an irresistible allure for third-party funders. International arbitration cases are particularly attractive because of the prevalence of high-value claims, the speed of proceedings, the potential for reduced evidentiary costs and streamlined procedures, the ability to control variables such as expertise of the decisionmaker, the potential for legal arbitrage to avoid national restrictions on such funding, and the highly enforceable nature of arbitral awards. As a result, third-party funding seems to be a permanent fixture in international arbitration. Their increasing presence, however, raises a host of complex legal and ethical questions that can affect all various actors, most notably counsel and arbitrators, as well as the larger framework of the international arbitral regime. Notwithstanding their potential impact, the very definition of third-party funders and the mechanics of how they operate remains largely unknown. Adding to this uncertainty, third-party funders in international arbitration are uniquely untethered from any formal or national professional regulation or national mandatory laws. Meanwhile, ambiguities about counsel ethics in international arbitration and funder participation in arbitrator selection raise peculiar dilemmas that have few ready answers. Debate has begun, but to date, careful analysis of and specific proposals in response to these complex issues has been lacking. This book chapter provides one of the first sources to undertake sustained analysis of the the peculiar quandaries raised by the presence of third-party funding in international arbitration and suggest concrete solutions. As a chapter in a forthcoming book ETHICS IN INTERNATIONAL ARBITRATION (Oxford University Press, 2014), it examines how issues relating to third-party funders should be integrated into a larger regime of self-regulation of professional conduct in international arbitral proceedings.

Delayed star formation in high-redshift stream-fed galaxies

Abstract We propose that star formation (SF) is delayed relative to the inflow rate in rapidly accreting galaxies at very high redshift (z > 2) because of the energy conveyed by the accreting gas. Accreting gas streams provide fuel for SF, but they stir the disc and increase turbulence above the usual levels compatible with gravitational instability, reducing the SF efficiency in the available gas. After the specific inflow rate has sufficiently decreased – typically at z < 3 – galaxies settle in a self-regulated regime with efficient SF. An analytic model shows that this interaction between infalling gas and young galaxies can significantly delay SF and maintain high gas fractions (>40 per cent) down to z ≈ 2, in contrast to other galaxy formation models. Idealized hydrodynamic simulations of infalling gas streams on to primordial galaxies confirm the efficient energetic coupling at z > 2 and suggest that this effect is largely under-resolved in existing cosmological simulations.