bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantifying the dynamics of migration after Hurricane Maria in Puerto Rico
Authors: Acosta Rolando J. , Kishore Nishant , Irizarry Rafael A. , Buckee Caroline O.
Published: December 2020

Significance

Understanding the population composition and distribution of a region affected by a major natural disaster is vital for the allocation of resources to communities in need and critical to inform mortality estimates. Currently, the US Census Bureau is the only institution that publishes reliable population estimates for the United States and its territories. Since these are published once per year, it is impossible to use census-based population estimates to assess short-term postdisaster out-of-jurisdiction migration and within-jurisdiction migration. The utilization of social media traces, coupled with mobile phone data, could provide live estimates of postdisaster population changes in disaster-affected areas.
Negation and mood in epistemic contexts
Authors: Gielau Elizabeth
Published: December 2020

This squib examines mood contrasts in Spanish and
(Modern) Greek. It is argued that the dual interpretation of
negation, first analyzed in Horn’s (1989) seminal work, can provide new insights for
mood contrasts in negated epistemic contexts. I show that
metalinguistic (narrow-scope) negation of Spanish
creo ‘I believe’ and Greek
pistévo ‘I believe’ entails an intentional,
rather than intensional, pragmatic function: the speaker wishes to
reserve truth-value judgment, resulting in an unevaluated
propositional complement. In intentional contexts, the subjunctive
is exhibited in Spanish, and the indicative in Greek. I suggest that
the subjunctive is exhibited in Spanish because unevaluated
propositions fail to update the context, in keeping with Farkas (2003). Conversely,
the indicative surfaces in Greek because unevaluated propositions
are not non-veridical, aligning with Giannakidou (1997, 1998, 1999, 2006,
2009, 2013). I then
extend the investigation to emotive predicates, another context of
mood variation, providing more evidence that metalinguistic negation
marks unassertive propositional complements.
The complicated timeline of Spanish
Authors: O’Neill Sarah , Shea Christine
Published: December 2020

Sound change is a dynamic process that shapes the
phonology and lexicon of a language across a language’s history. The
existence of loanwords and cultismos
(learned forms) complicate this process. Not
all words are equally subjected to sound change. In Spanish,
cultismos and loanwords often exhibit
characteristics that differ from derived words
(words that underwent regular phonological sound changes in
Spanish). In either instance, the resulting word differs from other
items in the Spanish lexicon. We discuss the significance of
loanwords and cultismos for the Spanish lexicon. We
suggest that although they result in less regularity across the
lexicon, there are also consistent patterns that arise. Through
these ‘regular irregularities,’ speakers may build associations
between lexical forms and possibly access them to facilitate lexical
activation.
Spanish impersonal se in control infinitivals
and the ungrammaticality of se se sequences
Authors: MacDonald Jonathan E. , Vázquez-Lozares Almike
Published: December 2020

In this paper, we offer an analysis of impersonal
se (Impse) constructions in control
infinitivals. We claim that se itself spells out
the valued version of the [uD] feature that Holmberg (2010) and Roberts (2010) propose is a property of T
in consistent null subject languages. As a corollary, we link
Impse constructions to the consistent null subject
status of a language (in the spirit of Belletti, 1982). Moreover, we claim that in
Impse constructions there is a projected null
external argument (pro
se) interpreted as non-referential because of the valued
version of Holmberg’s [uD] feature in T that se
spells out. We also argue that ungrammatical sequences of
Impse and other se result from the
featural deficiency of pro
se; specifically, it lacks a specification for
number.
System-Level Factors Shaping the Implementation of “Hub and Spoke” Systems to Expand MOUD in Rural Areas
Authors: Snell-Rood Claire , Willging Cathleen , Showalter David , Peters Hannah , Pollini Robin A.
Published: December 2020

Background

Hub and spoke systems (HSS) are increasingly promoted as a systems-level intervention to expand access to medication for opioid use disorders (MOUD), particularly in rural areas with limited treatment options. The HSS model consists of sub-systems in which “hubs” deliver specialized expertise to a regional network of office-based opioid treatment (OBOT) providers in “spokes,” who together create a continuum of acute and chronic care. Yet, little is known about system-level factors (e.g., system structure, financing) that influence HSS implementation and sustainability in rural areas.

Methods

For this case study, we conducted semi-structured interviews with substance use disorder treatment providers ( N = 26) and system-level stakeholders ( N = 16) in five rural HSS sub-systems throughout one state. We undertook iterative textual analysis of interview transcripts, identifying and coding themes related to key implementation constructs associated with the Exploration, Preparation, Implementation and Sustainability (EPIS) framework.

Results

California policy-makers adopted HSS to expand rural access to opioid treatment programs (OTPs, i.e., providers of methadone and other medications for opioid use disorder). However, stakeholders questioned the model's fit for rural regions featuring few established OTPs that could function as hubs and critiqued its treatment-focused approach, felt to sideline harm reduction service providers. Contracts to serve rural regions were awarded entirely to for-profit methadone providers, contributing to stigma and distrust among many buprenorphine providers whose organizations were later recruited as spokes. While hubs offered financial resources enabling some spokes to expand MOUD, the needs of spokes varied considerably. Relationships between hubs and spokes to facilitate the care continuum under HSS were restricted by limited behavioral health resources and the large distances characterizing rural California.

Conclusions

This case study reveals how rural contextual factors such as geography and behavioral healthcare resource availability can dramatically influence differential HSS implementation.
Whose Opinion Matters about Medications for Opioid use Disorder? A Cross-Sectional Survey of Social Norms among Court Staff
Authors: Andraka-Christou Barbara , Atkins Danielle N.
Published: December 2020

Background

Criminal problem-solving and dependency courts set treatment standards for opioid use disorder (OUD) but sometimes prohibit or limit utilization of medications for OUD (MOUD). Court staff beliefs about MOUD inform court treatment policies. Court staff MOUD policies may also be influenced by social norms, meaning perceptions of opinions of other individuals/entities about MOUD, including opinions of fellow staff in their court, staff in other courts, the state supreme court, other state agencies, the National Association of Drug Court Professionals (NADCP), federal agencies, and local peer support groups. To date no study has examined social norms among court staff with respect to MOUD.

Methods

We distributed an online cross-sectional survey in 2019 to all criminal problem-solving and dependency court staff in Florida. Respondents were asked to identify the extent to which they cared about different entities’/individuals’ opinions about MOUD and the extent to which they perceived each of those entities/individuals as encouraging MOUD. We hypothesized that court role and court type would be associated with responses. We used descriptive statistics, logistic regressions, and difference of proportions tests to analyze data.

Results

20% of the population ( n = 119) completed the survey. Respondents cared most about the opinions of external treatment providers with whom they collaborate, fellow staff in their court, and the NADCP regarding MOUD. Fewer than half felt that any of these entities/individuals encourage methadone or oral buprenorphine. Additionally, fewer than 11% of respondents felt that local twelve-step peer support groups encourage the use of any form of MOUD.

Conclusions

MOUD education should target all members of court teams, including collaborating treatment providers. Since court staff care relatively little about the MOUD opinions of staff in other courts, changes in opinions in one court may not affect changes in opinions in a neighboring court. The NADCP should more explicitly state its support for MOUD, and specifically oral buprenorphine and methadone treatment.
Reflection‐impulsivity in athletes: A cross‐sectional and longitudinal investigation
Authors: Vaughan Robert S. , Hagyard Jack D. , Edwards Elizabeth J. , Jackson Robin C.
Published: December 2020

Reflection‐impulsivity is a dimension of cognitive or decision‐making style. We conducted two quasi‐experimental studies to examine reflection‐impulsivity in athletes using an information sampling task. In Study 1 (n = 108; Mage = 22.7 ± SDage = 1.42; 50% female), we used a cross‐sectional design to compare performance across athletic expertise (super‐elite, elite, amateur, novice or non‐athlete) and sport type (external‐paced or self‐paced). In Study 2 (Time 1 n = 106; Mage = 21.32 ± SDage = 5.77; 53% female and Time 2 n = 64; Mage = 21.19 ± SDage = 5.12; 44% female), we examined changes in reflection‐impulsivity across a 16‐week playing season. Study 1 showed more accurate and more efficient performance as athletic expertise increased. Study 2 revealed better effectiveness and efficiency following sport participation, a 16‐week playing season, most notably in elite‐level performers. No sport‐type differences were noted. Taken together, the studies demonstrate an association between reflection‐impulsivity and athletic expertise, while also providing evidence that competitive sports participation leads to efficient decisions based on reflection, without sacrificing accuracy, which is often a consequence of impulsive decision‐making.
Geometry of AdS-Melvin spacetimes
Authors: Kastor David , Traschen Jennie
Published: December 2020

We study asymptotically AdS generalizations of Melvin spacetimes, describing gravitationally bound tubes of magnetic flux. We find that narrow fluxtubes, carrying strong magnetic fields but little total flux, are approximately unchanged from the Λ = 0 case at scales smaller than the AdS scale. However, fluxtubes with weak fields, which for Λ = 0 can grow arbitrarily large in radius and carry unbounded magnetic flux, are limited in radius by the AdS scale and like the narrow fluxtubes carry only small total flux. As a consequence, there is a maximum magnetic flux

Φ

m
a
x

=
2
π
/

−
Λ

that can be carried by static fluxtubes in AdS. For flux Φtot < Φmax there are two branches of solutions, with one branch always narrower in radius than the other. We compute the ADM mass and tensions for AdS-Melvin fluxtube, finding that the wider radius branch of solutions always has lower mass. In the limit of vanishing flux, this branch reduces to the AdS soliton.
Low-energy electromagnetic processes affecting free-falling test-mass charging for LISA and future space interferometers
Authors: Grimani Catia , Cesarini Andrea , Fabi Michele , Villani Mattia
Published: December 2020

Galactic cosmic rays and solar energetic particles charge gold-platinum, free-falling test masses (TMs) on board interferometers for the detection of gravitational waves in space. The charging process induces spurious forces on the test masses that affect the sensitivity of these instruments mainly below 10−3 Hz. Geant4 and FLUKA Monte Carlo simulations were carried out to study the TM charging process on board the LISA Pathfinder mission that remained into orbit around the Sun–Earth Lagrange point L1 between 2016 and 2017. While a good agreement was observed between simulations and measurements of the TMs net charging, the shot noise associated with charging fluctuations of both positive and negative particles resulted 3–4 times higher that predicted. The origin of this mismatch was attributed to the propagation of electrons and photons only above 100 eV in the simulations. In this paper, low-energy electromagnetic processes to be included in the future Monte Carlo simulations for LISA and LISA-like space interferometers TM charging are considered. It is found that electrons and photons below 100 eV give a contribution to the effective charging comparable to that of the whole sample of particles above this energy. In particular, for incident protons ionization contributes twice with respect to low energy kinetic emission and electron backscattering. The other processes are found to play a negligible role. For heavy nuclei only sputtering must be considered.
Self-dual Einstein spaces and the general heavenly equation. Eigenfunctions as coordinates
Authors: Konopelchenko B G , Schief W K , Szereszewski A
Published: December 2020

Eigenfunctions are shown to constitute privileged coordinates of self-dual Einstein spaces with the underlying governing equation being revealed as the general heavenly equation. The formalism developed here may be used to link algorithmically a variety of known heavenly equations. In particular, the classical connection between Plebański’s first and second heavenly equations is retrieved and interpreted in terms of eigenfunctions. In addition, connections with travelling wave reductions of the recently introduced TED equation which constitutes a 4 + 4-dimensional integrable generalisation of the general heavenly equation are found. These are obtained by means of (partial) Legendre transformations. As a particular application, we prove that a large class of self-dual Einstein spaces governed by a compatible system of dispersionless Hirota equations is genuinely four-dimensional in that the (generic) metrics do not admit any (proper or non-proper) conformal Killing vectors. This generalises the known link between a particular class of self-dual Einstein spaces and the dispersionless Hirota equation encoding three-dimensional Einstein–Weyl geometries.
A double beam Fabry–Perot interferometer for measuring laser wavelength
Authors: Santosa I E
Published: December 2020

A modified Fabry–Perot interferometer has been used for measuring the laser wavelength. Two laser beams are directed to the Fabry–Perot interferometer. The first laser, i.e. a HeNe laser, is used as a reference, and the second laser is the measured laser. A driving mechanism is coupled to the interferometer to move the mirror. During the scanning the resulting fringes are monitored using two light sensors. A fast Fourier transform is used to determine the frequency of the fringe pattern shift of both lasers. The wavelength of the unknown laser is then calculated using the ratio of the frequency of the fringe pattern shift and the known reference laser’s wavelength. The performance of the system has been tested by determining the wavelength of three pointer lasers. The accuracy of this system can reach 3 nm, which is appropriate for undergraduate experiments.
Viscous properties of nickel-containing binary metal melts
Authors: Khusnutdinoff R M , Khairullina R R , Beltyukov A L , Lad’yanov V I , Mokshin A V
Published: December 2020

The paper presents the results of molecular dynamics study of the viscosity of nickel-containing binary metal melts for a wide range of temperatures, including the region of the equilibrium liquid phase and supercooled melt. It is shown that the temperature dependencies of the viscosity of binary metal melts are described by the Kelton’s quasi-universal model. Based on the analysis of the viscosity coefficient of the binary melt composition within the framework of the Rosenfeld’s scale transformations, it has been established that to correctly describe the viscosity of binary/multicomponent metal melts within the framework of entropy models, it is necessary to use a more complex representation of the excess entropy S
ex than in the approximation of pair correlation entropy S
2.
Hydrodynamic effects in the capture of rod-like molecules by a nanopore
Authors: Waszkiewicz Radost , Lisicki Maciej
Published: December 2020

In the approach of biomolecules to a nanopore, it is essential to capture the effects of hydrodynamic anisotropy of the molecules and the near-wall hydrodynamic interactions which hinder their diffusion. We present a detailed theoretical analysis of the behaviour of a rod-like molecule attracted electrostatically by a charged nanopore. We first estimate the time scales corresponding to Brownian and electrostatic translations and reorientation. We find that Brownian motion becomes negligible at distances within the pore capture radius, and numerically determine the trajectories of the nano-rod in this region to explore the effects of anisotropic mobility. This allows us to determine the range of directions from the pore in which hydrodynamic interactions with the boundary shape the approach dynamics and need to be accounted for in detailed modelling.
Sparse representations for fault signatures via hybrid regularization in adaptive undecimated fractional spline wavelet transform domain
Authors: Xiong Qingchun , Zhang Xin , Wang Jiaxu , Liu Zhiwen
Published: December 2020

Recent studies on vibration-based machine diagnostics have highlighted the role played by the wavelet transform (WT). However, common WT-based denoising methods (e.g. wavelet thresholding and non-penalty regularization) are often challenging in attaining accurate sparse representations of fault signatures in practice due to artifacts. In this paper, a method via hybrid regularization in the adaptive undecimated fractional spline WT (AUFrSWT) domain is introduced to achieve the accurate sparse representations of fault signatures from strong noise environments. The method promotes wavelet sparsity by two aspects: wavelet basis design and wavelet coefficient processing. For the former, a new wavelet family, i.e. a fractional spline wavelet, is used, and the AUFrSWT is originally proposed to customize the optimal wavelet basis and meanwhile address the translation-invariant issue. For the latter, the wavelet coefficients are estimated by minimizing a single convex model function with hybrid regularization, where nonconvex arctangent penalty is employed for wavelet sparsity promoting and total variation is used to improve the reconstruction performance of the shrunken coefficients. The method is validated by the analysis of actual bearing and gear vibration data from fault-injection experiments. Analysis and comparison results show great potential for signal sparse representations and machinery fault diagnostics.
Calculation of permanent magnet arrangements for stellarators: a linear least-squares method
Authors: Landreman Matt , Zhu Caoxiang
Published: December 2020

A problem arising in several engineering areas is to design magnets outside a volume that produce a desired magnetic field inside it. One instance of this problem is stellarator design, where it has recently been shown that permanent magnets can provide the required shaping of the magnetic field. Here we demonstrate a robust and efficient algorithm REGCOIL_PM to calculate the spatial distribution of these permanent magnets. The procedure involves a small number of fixed-point iterations, with a linear least-squares problem solved at each step. The method exploits the Biot–Savart Law’s exact linearity in magnetization density and approximate linearity in magnet size, for magnets far from the target region. No constraint is placed on the direction of magnetization, so Halbach solutions are found naturally, and the magnitude of the magnetization can be made uniformly equal to a target value.
Quantitative evaluation of process-induced line-edge roughness in FinFET: Bayesian regression model
Authors: Yu Sangho , Shin Changhwan
Published: December 2020

With the aggressive scaling down of the minimum feature size of advanced metal–oxide–semiconductor devices, it has become imperative to design and fabricate process-variation-immune devices. Technology computer-aided design simulations are typically used to test thousands of devices for process-variation immunity, but the process is computationally expensive. In this work, we propose a novel approach to simulate and predict the current–voltage characteristics of fin field-effect transistor devices with process-induced line-edge roughness (LER), within a few seconds. We exploit the Bayesian linear regression model to estimate the mean and standard deviation of the drain-to-source current (I
DS) for an arbitrary gate voltage (V
GS) and LER profile. We evaluate the prediction accuracy in terms of the mean absolute percentage error (MAPE) and root mean square error (RMSE). The MAPEs for the mean and standard deviation of I
DS are <1% and <20%, respectively, and the corresponding RMSEs are 0.0804 and 0.0263, respectively. Once the I
DS–V
GS distribution is estimated by means of this novel approach, the distributions of other device metrics such as the threshold voltage and off-state leakage current can be estimated.
The transport properties of ultrathin 2H–NbSe2
Authors: Lei L B , Zhang C , Yu A B , Wu Y F , Peng W , Xiao H , Qiao S , Hu T
Published: December 2020

The competing orders arising in a two-dimensional limit are the key to understanding unconventional superconductivity. The monolayer NbSe2 possessing a charge density wave (CDW) and superconducting orders provides a playground to study unconventional superconductivity. Here we fabricate an ultrathin 2H–NbSe2 device based on the mechanical exfoliation method and our electrode transfer technique. Detailed four-lead and two-lead transport measurements are performed in the ultrathin sample. The superconducting transition (
T

c

) at 4.3 K and CDW transition at 70 K are found in the sample, consistent with the literature report for ultrathin 2H–NbSe2. The superconducting gap (Δ) of ultrathin 2H–NbSe2 is estimated by fitting the two-lead transport spectroscopy with the Blonder–Tinkham–Klapwijk (BTK) theory. We found that Δ(
T
) exhibits a BCS-like temperature dependence with Δ

≈

1.1 meV at 0 K and

Δ

/

k
B

T
c

≈

3

. Meanwhile the gap-like features persist in the normal state and become unresolvable with the increasing temperature and magnetic field, suggesting a possible precursor superconductivity similar to the cuprate superconductors. Our results provide a new insight into superconductivity in ultrathin 2H–NbSe2.
Coupled dynamics of polaron and Bose–Einstein condensate in a parabolic potential
Authors: Mardonov Sh N , Sherman E Ya
Published: December 2020

We study various regimes of coherent coupled motion of a polaron and one-dimensional Bose–Einstein condensate in a harmonic potential. By using qualitative analysis, perturbation theory and direct numerical solution of the Gross–Pitaevskii equation, we show that the entire dynamics is strongly nonlinear and critically depends on the sign of the self-interaction in the condensate and the sign of the interaction between the polaron-forming embedded particle and the condensate. Strongly mutually related evolution of the condensate shape, its center of mass position, and polaron coordinate is studied for coupled nonlinear polaron-condensate oscillations and transmission/reflection of the polaron through/by the condensate.
Enhanced thermoelectric properties in two-dimensional monolayer Si2BN by adsorbing halogen atoms*
Authors: Wu Cheng-Wei , Xiang Changqing , Yang Hengyu , Zhou Wu-Xing , Xie Guofeng , Ou Baoli , Wu Dan
Published: December 2020

Using the first principles calculation and Boltzmann transport theory, we study the thermoelectric properties of Si2BN adsorbing halogen atoms (Si2BN-4X, X = F, Cl, Br, and I). The results show that the adsorption of halogen atoms can significantly regulate the energy band structure and lattice thermal conductivity of Si2BN. Among them, Si2BN-4I has the best thermoelectric performance, the figure of merit can reach 0.50 K at 300 K, which is about 16 times greater than that of Si2BN. This is because the adsorption of iodine atoms not only significantly increases the Seebeck coefficient due to band degeneracy, but also rapidly reduces the phonon thermal conductivity by enhancing phonon scattering. Our work proves the application potential of Si2BN-based crystals in the field of thermoelectricity and the effective method for metal crystals to open bandgaps by adsorbing halogens.
Plasmonic properties of graphene on uniaxially anisotropic substrates*
Authors: Wang Shengchuan , You Bin , Zhang Rui , Han Kui , Shen Xiaopeng , Wang Weihua
Published: December 2020

Most of the current graphene plasmonic researches are based on the substrates with isotropic dielectric constant such as silicon. In this work, we investigate optical properties of graphene nanoribbon arrays placed on a uniaxially anisotropic substrate, where the anisotropy provides an additional freedom to tune the behaviors of graphene plasmons, and its effect can be described by a simple effective formula. In practice, the substrates of semi-infinite and finite thickness are discussed by using both the formula and full wave simulations. Particularly, the dielectric constants ε
∥ and ε
⊥ approaching zero are intensively studied, which show different impacts on the transverse magnetic (TM) surface modes. In reality, the hexagonal boron nitride (hBN) can be chosen as the anisotropic substrate, which is also a hyperbolic material in nature.
Quasi-delta negative ions density of Ar/O2 inductively coupled plasma at very low electronegativity
Authors: Zhao Shu-Xia
Published: December 2020

One of the novel phenomena of Ar/O2 inductively coupled plasma, the delta negative ions density profile is discovered by the fluid simulation at very low electronegativity. The anions delta is found to be formed by the collaboration of successive plasma transport phases. The plasma transport itself is affected by the delta, exhibiting many new phenomena. A new type of Helmholtz equation is devised to mathematically explain the delta forming mechanism. For revealing the physics behind, a revised spring oscillator dynamic equation has been constructed according to the Helmholtz equation, in a relevant paper [Zhao S X and Li J Z (2021) Chin. Phys. B
30 055202]. The investigation about the anions delta distribution is a nice prediction of new phenomenon in low temperature electronegative plasmas, waiting for the validation of related experiments.
H-mode scrape-off layer power width in the TCV tokamak
Authors: Maurizio R. , Duval B.P. , Labit B. , Reimerdes H. , Faitsch M. , Komm M. , Sheikh U. , Theiler C. , the TCV team
Published: December 2020

Obtaining acceptable conditions at the divertor targets of a next-step fusion experiment based on the tokamak concept is expected to be particularly challenging because of the small predicted value of the plasma power exhaust channel width. An increased confidence in this prediction is important to forestall any power exhaust issue and in developing corresponding divertor solutions. With the present prediction relying on empirical scaling laws based on data from six tokamaks, this letter tests these scaling laws on an additional device, the TCV tokamak. Estimates of the exhaust channel width, λ

q
, based on Thomson scattering measurements of the electron temperature and density profiles, correlate well with outer target infrared thermography. Reasonable agreement with multi-device scaling laws is found only when including both the power crossing the separatrix and the Greenwald density fraction as regression parameters. TCV’s λ

q
is 2 to 3 times smaller than in spherical tokamaks for the same value of the poloidal field. The inclusion of TCV data in the scaling laws would, therefore, require the retention of an explicit aspect ratio dependence, with consequences for all other dependencies.
New designs of target and cooling scheme for water cooled divertor in DEMO
Authors: Qian X.Y. , Peng X.B. , Song Y.T. , Mao X. , Liu P. , Song W. , Huang J.J. , Lu P. , Wang L. , Meng L.Y.
Published: December 2020

Developing a robust and reliable divertor with an adequate heat removal capability is one of the most crucial issues for the realization of DEMO. Although lots of designs and technologies have been accumulated for the water cooled divertor and a full tungsten water cooled divertor for ITER has been successfully developed, there is still a gap to catch up the requirements of DEMO mainly because of the neutron irradiation. For the purpose of putting forward a feasible proposal of the divertor for DEMO concept in a short to medium term, new designs for the target and cooling circuit have been explored in this article. According to the distribution characteristics of heat load and neutron irradiation damage on the divertor and the unique properties of materials, CuCrZr and RAFM are chosen as the heat sink material for the plasma facing unit (PFU) at strike zone and other zone respectively, which is named ‘dual PFUs’. A single coolant circuit is applied to both PFUs and a new design ideology of the cooling scheme has been developed. To assess the performance of the designs, corresponding thermal and structural response for the PFUs and thermal-hydraulics analysis for the cooling circuit had been performed. The property of CuCrZr in neutron irradiation environment is the main limitation for the performance of the target. And the new design for cooling circuit can effectively reduce the pressure drop without any negative impact on the divertor by rationally allocating the coolant through outer vertical target to inner vertical target and dome.
Project Coolbit: can your watch predict heat stress and thermal comfort sensation?
Authors: Nazarian Negin , Liu Sijie , Kohler Manon , Lee Jason K W , Miller Clayton , Chow Winston T L , Alhadad Sharifah Badriyah , Martilli Alberto , Quintana Matias , Sunden Lindsey , Norford Leslie K
Published: December 2020

Global climate is changing as a result of anthropogenic warming, leading to higher daily excursions of temperature in cities. Such elevated temperatures have great implications on human thermal comfort and heat stress, which should be closely monitored. Current methods for heat exposure assessments (surveys, microclimate measurements, and laboratory experiments), however, present several limitations: measurements are scattered in time and space and data gathered on outdoor thermal stress and comfort often does not include physiological and behavioral parameters. To address these shortcomings, Project Coolbit aims to introduce a human-centric approach to thermal comfort assessments. In this study, we propose and evaluate the use of wrist-mounted wearable devices to monitor environmental and physiological responses that span a wide range of spatial and temporal distributions. We introduce an integrated wearable weather station that records (a) microclimate parameters (such as air temperature and humidity), (b) physiological parameters (heart rate, skin temperature and humidity), and (c) subjective feedback. The feasibility of this methodology to assess thermal comfort and heat stress is then evaluated using two sets of experiments: controlled-environment physiological data collection, and outdoor environmental data collection. We find that using the data obtained through the wrist-mounted wearables, core temperature can be predicted non-invasively with 95 percent of target attainment within ±0.27 °C. Additionally, a direct connection between the air temperature at the wrist (T

a,w
) and the perceived activity level (PAV) of individuals was drawn. We observe that with increased T

a,w
, the desire for physical activity is significantly reduced, reaching ‘Transition only’ PAV level at 36 °C. These assessments reveal that the wearable methodology provides a comprehensive and accurate representation of human heat exposure, which can be extended in real-time to cover a large spatial distribution in a given city and quantify the impact of heat exposure on human life.
The refill gap: clean cooking fuel adoption in rural India
Authors: Cabiyo Bodie , Ray Isha , Levine David I
Published: December 2020

From 2016 to 2019, the Indian Pradhan Mantri Ujjwala Yojana (PMUY) distributed over 80 million liquefied petroleum gas (LPG) stoves, making it the largest clean cooking program ever. Yet, evidence shows widespread continued use of the traditional chulha, negating the potential health benefits of LPG. Here we use semi-structured interviews with female and male adults to understand the drivers of LPG usage in Mulbagal, Karnataka, the site of a proto-PMUY program. We find that respondents perceive the main value of LPG to be saving time, rather than better health. We also find that norms of low female power in the household, in addition to costs, delay saving for and ordering LPG cylinder refills. Namely, female cooks controlled neither the money nor the mobile phone required to order a timely refill. These factors together contribute to the ‘refill gap’: the period of non-use between refilling cylinders, which may range from days to even months. Our work reveals how gender norms can amplify affordability challenges in low-income households.
Scattering data and bound states of a squeezed double-layer structure
Authors: Zolotaryuk Alexander V , Zolotaryuk Yaroslav
Published: December 2020

A heterostructure composed of two parallel homogeneous layers is studied in the limit as their widths l
1 and l
2, and the distance between them r shrinks to zero simultaneously. The problem is investigated in one dimension and the squeezing potential in the Schrödinger equation is given by the strengths V
1 and V
2 depending on the layer thickness. A whole class of functions V
1(l
1) and V
2(l
2) is specified by certain limit characteristics as l
1 and l
2 tend to zero. The squeezing limit of the scattering data a(k) and b(k) derived for the finite system is shown to exist only if some conditions on the system parameters V

j
, l

j
, j = 1, 2, and r take place. These conditions appear as a result of an appropriate cancellation of divergences. Two ways of this cancellation are carried out and the corresponding two resonance sets in the system parameter space are derived. On one of these sets, the existence of non-trivial bound states is proven in the squeezing limit, including the particular example of the squeezed potential in the form of the derivative of Dirac’s delta function, contrary to the widespread opinion on the non-existence of bound states in δ′-like systems. The scenario how a single bound state survives in the squeezed system from a finite number of bound states in the finite system is described in detail.
Characteristics and petroleum geological significance of high-quality source rock in Gufeng Member of Middle Permian Maokou Formation in northern Sichuan Basin, China
Authors: Fu X D , Chen Y N , Wang X F , Lv X J , Li W Z , Yao Q Y
Published: December 2020

Based on the comprehensive analysis of drilling and outcrop profile data, the stratigraphic boundary between Middle Permian and Upper Permian in northern Sichuan Basin is redefined systematically. It is confirmed that the source rock of carbonaceous and siliceous mudstone is widely developed in the Gufeng Member of Middle Permian Maokou Formation in the northern part of the basin, and its thickness is mainly between 5-40 m. The source rock in the Gufeng Member has large variation scope of TOC, mainly in the range of 0.5%-30%, and the average value of most profiles more than 2.0%. It is a set of high-quality source rock as a whole. Its major organic matter is type II. At present, its thermal maturity changes greatly, and it is in the mature-over mature stage. The deep-water sedimentary environment, strong reduction conditions and high paleo-productivity jointly controlled the development and distribution of high-quality source rock in the Gufeng Member under the background of extensional structure at the end of the Middle Permian. High-quality source rock in the Gufeng Member is of great significance to the exploration of marine conventional natural gas and shale gas in northern Sichuan Basin.
A GIS-based grid model for spatial data management and preliminary applications for assessing deep oil-gas resources
Authors: Li Na , Zheng Yangcheng , Ma Hongyan , Shi Shuyong , Wang Yunpeng
Published: December 2020

With the development and maturity of mid-shallow reservoirs, deep reservoirs have become the main exploration targets recently. Deep oil-gas exploration and evaluation are facing great challenges of multi-source data utilization. The aim of the exploration is to verify the resources, location and scale of deep oil and gas, which could be well managed and calculated by the means of Geographic Information System (GIS). In this paper, a grid management and calculation method of deep oil and gas resources is proposed based on ArcGIS 10.5 software, which was preliminarily applied to evaluate the deep oil and gas resources in Tarim Basin. The hydrocarbon generation intensity is calculated and analyzed according to distinct source rocks, spatial patterns, and temporal sequence. The results show that the hydrocarbon generation intensity in the Lower Cambrian strata of Tarim Basin is considerable in total and concentrated in spatial distribution. The total hydrocarbon generation intensity in argillaceous source rocks is higher than that in carbonate source rocks. Among the four types of hydrocarbons including oil, light oil, gas and methane, the generation intensity of the oil is the highest.
Characteristics of Paleogene source kitchen and its control on hydrocarbon accumulation in Qikou Sag, Bohai Bay Basin
Authors: Li Yongxin , Bian Congsheng , Li Qiufen , Liu Haitao
Published: December 2020

Source kitchen is an important factor to control the distribution of oil and gas. In this paper, the characteristics of Paleogene source kitchen of Qikou Sag in Bohai Bay Basin and its relationship with hydrocarbon accumulation were analyzed using data from structure, geochemistry and thermal history. The results show that Qikou sag was a large continental fault–depression basin with long-term continuous subsidence, and multiple lacustrine source rocks were developed with the 1st and 3rd section in the Shahejie Formation of the Paleogene (hereafter referred to as Es1 and Es3, respectively) as the main source rocks. The tectonic evolution of Qikou sag was controlled by basement subsidence and fault growth that leaded to the formation of multiple depressions in local subsidence centers. As a result, multiple source kitchens were developed in Es1 and Es3 with different oil and gas characteristics. Oil and gas fields were mainly distributed in the uplifts and slopes around the source kitchen which showed that source kitchen acted as an important factor in the process of oil and gas accumulation.
The role of volcanic ash in the formation of organic-rich source rock and its source identification
Authors: Liu Jiayi , Liu Quanyou , Meng Qingqiang , Zhu Dongya , Li Peng
Published: December 2020

Volcanic ash promotes the formation of organic-rich source rocks by increasing the productivity of sedimentary basins and the formation of conducive preservation environment. In terms of productivity, volcanic ash provides Fe, Mn, Zn and other trace metal elements to sedimentary basins, and promotes the prosperity of water organisms and the improvement of primary productivity. The thickness of volcanic ash deposition is proportional to the concentration of nutrients released. Generally, the thickness of volcanic ash deposits around the crater is much thicker than far away, and more like to obtain the high concentration of nutrients, and make it easier to bloom. In terms of preservation environment, by increasing the salinity of sedimentary basins and participating in the biological sulfate reduction reaction (BSR), volcanic ash promote the formation of a reducing environment conducive to the preservation of organic matter. In addition, in order to deepen the research on the relationship between volcanic ash and the distribution of high-quality source rocks, this article discusses the sources and identification methods of volcanic ash, and proposes that lithium, as an effective geological tracer may have the ability to identify volcanic ash sources.
Hydrocarbon generation from confined pyrolysis of Xujiahe Formation coal in the northwest Sichuan Basin, China
Authors: Liu Min , Wang Huaichang , Li Yan , Zhao Weibo , Guo Huijuan , Zhang Hui , Wang Yunpeng
Published: December 2020

The northwest depression of Sichuan Basin is an important gas-producing region. Previous studies have shown that large amount of gas was discovered in the Xujiahe Formaion. Several sets of source rocks from different formations including Xu1, Xu3 and Xu5 sections in Xujiahe Formation contribute to the gas resources. To investigate the gas generation potential of coal measure source rocks of Xujiahe Formation widely distributed in the Sichuan Basin. A coal sample from Xujiahe Formation was used in confined gold tube pyrolysis experiment and the activation energy and frequency factor of the coal sample were obtained. Based on the kinetic parameters of hydrocarbon generation, collected stratigraphic data, the burial, thermal and gas generation history of two wells in the northwest depression of Sichuan Basin were simulated by using Petromod I. Results showed that the activation energy of the coal sample was distributed in the range of 45-67 kcal/mol (main activation energy peak was58 kcal/mol) and the frequency factor was 4.7×1011s−1. For the two investigated wells, the gas generation started at 169-184 Ma, terminated at about 65 Ma. The well CHQ173 closer to the northwest depression entered the threshold of hydrocarbon generation earlier, was of deeper maximum buried depth and higher maximum thermal maturity and greater gas yield. The amount of expelled gas resulted from the uplift was small in this region. If combined with the tectonic evolution and sealing conditions of the study area, the gas generation history of Xujiahe formation would be of great significance for the exploration of natural gas in this area.
Hydrocarbon occurrence characteristics and charging differences in Chengbei Fault Zone based on fluid inclusions
Authors: Hong Zhang , Xianzheng Zhao , Jufeng Wang , Changyi Zhao , Xiugang Pu , Haitao Liu , Xiaowei Dong , Xiongying Dong , Fengcheng Wu
Published: December 2020

Hydrocarbon accumulates in multiple layers of the high, middle and low parts of Chengbei fault zone, in vicinity of Qikou Sag and Qinan Subsag, which represents a breakthrough for large-scale hydrocarbon exploration in recent years. Based on the size, abundance, and attitute of hydrocarbon inclusions, as well as their microscopic polarization and fluorescence characteristics, the hydrocarbon occurrence and the charging difference in the high, middle and low faulted terraces were analyzed systematically in this paper. There are two types of occurrence in the intergranular pores and fractures in the reservoirs, namely, the medium to light oil that shows green fluorescent light, and the solid bitumen charged with a certain amount of hydrocarbon that does not show any fluorescent light. This indicates that the zone has experienced at least two stages of hydrocarbon migration and accumulation, and that diversified forms of hydrocarbon exist in the reservoirs of the zone. The characteristics of hydrocarbon inclusions show that two stages of inclusions were found in the tectonic positions of different faulted terrace. The first-stage inclusions were developed in the early secondary enlargement of quartz grains, with a low degree of development abundance; while the second-stage inclusions were developed after the secondary enlargement of quartz grains, with a high degree of development abundance. The second-stage hydrocarbon inclusions of the reservoir samples obtained at tectonic positions of the high, middle and low fault terrace represent the main filling stage of the present-day reservoirs. Their fluorescence characteristics demonstrate the oil charging difference, which is the maturity of the hydrocarbon decreases as the terraces lift up along the slope. Identifying the hydrocarbon occurrence and charging differences from the perspective of inclusions is conducive to recognizing the regularity of hydrocarbon charging and migration and the distribution patterns in fault terrace zones, and lay the foundation for hydrocarbon exploration of slopes in the future.
Investigation of the smelting reduction mechanism and of iron extraction from high-iron red mud
Authors: Wang Kun , Liu Yan , Zhang Ting-an , Li Xiao-fei , Chen Xin
Published: December 2020

High-iron red mud presents a problem due to its alkalinity which leads to significant risks to the environment. In order to realize the harmless and large-scale utilization of high-iron red mud, the smelting reduction experiments were carried out to investigate the reaction mechanism for extraction iron from high-iron red mud. FactSage 6.4 software was used to conduct thermodynamic analysis of the carbon thermal reduction system. The results showed that the direct reduction with carbon involved a process of Fe2O3 → Fe3O4 → FeO → Fe, in which the theoretical required molar ratio of C/O (oxygen in Fe2O3) was 1:1. The maximum degree of iron extraction was 92.8% with anthracite as reductant and 88.8% without anthracite smelting at 1500 °C for 30 min in a graphite crucible. XRD was conducted to analyze the mineral phase of the samples and slags. The results showed that the minerals contained in high-iron red mud were hematite, quartz, rutile, and sodium aluminosilicate hydrate. The blank sample was consisted of hematite, nepheline quartz, and the reduced slag without quenching consisted of perovskite and gehlenite, indicating that the reaction processes occurred from sodium aluminosilicate hydrate to nepheline and then occurred from nepheline to gehlenite in slagging process. The overall smelting reduction process was described as three mass transfer steps and three chemical reaction steps. These results provide useful information for large-scale and harmless utilization of high-iron red mud.
Experimental and mechanism research on carbothermal reduction of spodumene ore via vacuum
Authors: Lyu Fei , Du Hao , Shi Lei , Tian Yuan , Zhang Xiao-Pan , Qu Tao , Yang Bin , Dai Yong-Nian
Published: December 2020

Considering the low resource utilisation rate and high environmental pollution afflicting the current technology for extracting Li from spodumene ore, this report proposes a clean process for the vacuum carbothermal reduction of spodumene ores for Li extraction, ferrosilicon alloy preparation, and alumina recovery. Thermodynamic analysis indicated that vacuum conditions can significantly promote the carbothermic reduction of spodumene ores and that the initial reaction temperature can be reduced by 480 K when an environmental pressure of 20 Pa is applied. According to the experimental results, two important factors in the above procedure are the reduction temperature and reduction time. When the reduction temperature was 1648 K and the reduction time 3 h, the reduction rate of Li in the spodumene ore exceeded 90%. Furthermore, the ferrosilicon alloy and alumina slag could be effectively separated from the reduction residue. The thermodynamic equilibrium simulation of the reduction process was combined with the experimental results to assess the vacuum carbothermal reduction mechanism of spodumene ores. Compared with the existing Li extraction approach, this method has the advantages of a straightforward process flow, almost zero waste water/waste residue production, environmental compatibility, and increased resource exploitation. Based on the above, this work provides new insights for advancing the conventional technology used for Li extraction from spodumene ores.