bluuebunny/crossref_metadata_2025 huggingface dataset:
Electric-Flash Welded Pipe
Authors: Kiefner J. F. , Clark E.B.
Published: May 2022

Electric-flash welded line pipe was made between 1930 and 1969 by only one company, A.O. Smith Corporation. A.O. Smith Corporation first produced line pipe in 1927. Their earliest pipe was made in 30-foot lengths from plates cold-formed into tubes with a longitudinal seam made from the outside by means of a shielded metal-arc process. By 1930, they were making flash-welded pipe at their Milwaukee facility in sizes ranging from 8 to 26 inches. Reference 5-1 indicates they were using “stronger“ steels (not specified), making longer lengths (30 to 40 feet compared to 18 to 20 foot lengths of butt-welded and lap-welded pipe), and forming seams by a “new” welding process. Plates were pickled (descaled in an acid bath), sized, formed, welded. The pipes were then cleaned, cold-expanded, end-finished, and tested.
Spiral-Weld Line Pipe
Authors: Kiefner J. F. , Clark E.B.
Published: May 2022

The available literature suggests that spiral-weld pipe was first produced in the U.S. in 1888 using a hammer lap-welding process.(7-1, 7-2) The production speed of such pipe was said to be 1 foot per minute and diameters from 4 to 30 inches were produced. Strips of steel or iron skelp were helically wound, overlapped and heated at the edges and hammer-welded. A sketch of this original spiral welder is shown in Figure 7-1.
Introduction
Authors: Kiefner J. F. , Clark E.B.
Published: May 2022

The American Petroleum Institute has published and updated specifications for the manufacturing of line pipe since 1928. The first such specification, API Standard No. 5-L, First Edition, was issued in January, 1928. The First Edition was a “pocket-sized” (4 × 7 inches) 38 page document. The most recent edition: API Specification 5L, Forty-First Edition, is dated April 1, 1995. It is an 8½- by 11-inch book of 119 pages. Along the ~ay the document has undergone many changes but the essential purpose has remained the same, namely, “to provide standards for pipe suitable for use in conveying, gas, water, and oil in both the oil and natural gas industries”. The elements of pipe manufacturing addressed by the standard have remained essentially the same, namely, processes of manufacturing, material properties, dimensional requirements, workmanship, inspection, testing, threading and couplings, and marking and documentation. Nevertheless, if one were to compare the First Edition to the Forty-First Edition, one would notice significant modifications mostly in response to both increasing emphasis on product quality and improvements in manufacturing technology. Summaries of the requirements of each API 5L edition are listed in Table 9-1, and summaries for API 5LX editions are listed in Table 9-2. Listings of which manufacturers held 5L and 5LX licenses and when they held them are presented in Tables 9-3, 9-4, and 9-5. The contents of the various editions are described below.
An iterative method to evaluate one-dimensional pulsed nonlinear elastic wavefields and mixing of elastic waves in solids
Authors: Selvam Sundaraelangovan , Volker Arno , van Neer Paul , de Jong Nico , Verweij Martin D.
Published: May 2022

Over the last 15 years, literature on nondestructive testing has shown that the generation of higher harmonics and nonlinear mixing of waves could be used to obtain the nonlinearity parameters of an elastic medium and thereby gather information about its state, e.g., aging and fatigue. To design ultrasound measurement setups based on these phenomena, efficient numerical modeling tools are needed. In this paper, the iterative nonlinear contrast source method for numerical modeling of nonlinear acoustic waves is extended to the one-dimensional elastic case. In particular, nonlinear mixing of two collinear bulk waves (one compressional, one shear) in a homogeneous, isotropic medium is considered, taking into account its third-order elastic constants (A,  B,  and  C). The obtained results for nonlinear propagation are in good agreement with a benchmark solution based on the modified Burgers equation. The results for the resonant waves that are caused by the one-way and two-way mixing of primary waves are in quantitative agreement with the results in the literature [Chen, Tang, Zhao, Jacobs, and Qu, J. Acoust. Soc. Am. 136(5), 2389–2404 (2014)]. The contrast source approach allows the identification of the propagating and evanescent components of the scattered wavefield in the wavenumber-frequency domain, which provides physical insight into the mixing process and explains the propagation direction of the resonant wave.
Current dichotomous metrics obscure trends in severe and extreme child growth failure
Authors: Fitzgerald Ryan , Manguerra Helena , Arndt Michael B. , Gardner William M. , Chang Ya-Yin , Zigler Bethany , Taylor Heather Jean , Bienhoff Kelly , Smith David L. , Murray Christopher J. L. , Hay Simon I. , Reiner Robert C. , Kassebaum Nicholas J.
Published: May 2022

Historically, the prevalence of child growth failure (CGF) has been tracked dichotomously as the proportion of children more than 2 SDs below the median of the World Health Organization growth standards. However, this conventional “thresholding” approach fails to recognize child growth as a spectrum and obscures trends in populations with the highest rates of CGF. Our analysis presents the first ever estimates of entire distributions of HAZ, WHZ, and WAZ for each of 204 countries and territories from 1990 to 2020 for children less than 5 years old by age group and sex. This approach reflects the continuous nature of CGF, allows us to more comprehensively assess shrinking or widening disparities over time, and reveals otherwise hidden trends that disproportionately affect the most vulnerable populations.
Planar 2D wireframe DNA origami
Authors: Wang Xiao , Li Shanshan , Jun Hyungmin , John Torsten , Zhang Kaiming , Fowler Hannah , Doye Jonathan P.K. , Chiu Wah , Bathe Mark
Published: May 2022

Two-dimensional (2D) DNA origami is widely used for applications ranging from excitonics to single-molecule biophysics. Conventional, single-layer 2D DNA origami exhibits flexibility and curvature in solution; however, that may limit its suitability as a 2D structural template. In contrast, 2D wireframe DNA origami rendered with six-helix bundle edges offers local control over duplex orientations with enhanced in-plane rigidity. Here, we investigate the 3D structure of these assemblies using cryo–electron microscopy (cryo-EM). 3D reconstructions reveal a high degree of planarity and homogeneity in solution for polygonal objects with and without internal mesh, enabling 10-Å resolution for a triangle. Coarse-grained simulations were in agreement with cryo-EM data, offering molecular structural insight into this class of 2D DNA origami. Our results suggest that these assemblies may be valuable for 2D material applications and geometries that require high structural fidelity together with local control over duplex orientations, rather than parallel duplex assembly.
Puffing ultrathin oxides with nonlayered structures
Authors: Liu Kaisi , Jin Hongrun , Huang Liwei , Luo Yongxin , Zhu Zehao , Dai Simin , Zhuang Xinyan , Wang Zidong , Huang Liang , Zhou Jun
Published: May 2022

Two-dimensional (2D) oxides have unique electrical, optical, magnetic, and catalytic properties, which are promising for a wide range of applications in different fields. However, it is difficult to fabricate most oxides as 2D materials unless they have a layered structure. Here, we present a facile strategy for the synthesis of ultrathin oxide nanosheets using a self-formed sacrificial template of carbon layers by taking advantage of the Maillard reaction and violent redox reaction between glucose and ammonium nitrate. To date, 36 large-area ultrathin oxides (with thickness ranging from ~1.5 to ~4 nm) have been fabricated using this method, including rare-earth oxides, transition metal oxides, III-main group oxides, II-main group oxides, complex perovskite oxides, and high-entropy oxides. In particular, the as-obtained perovskite oxides exhibit great electrocatalytic activity for oxygen evolution reaction in an alkaline solution. This facile, universal, and scalable strategy provides opportunities to study the properties and applications of atomically thin oxide nanomaterials.
An observational approach to mudstone sequence stratigraphy: The Monterey Formation of California
Authors: Schwalbach Jon R. , Bohacs Kevin M.
Published: May 2022

Sequence stratigraphy has proven to be an invaluable tool for the analysis of coarse-clastic depositional systems and the integration of observations across scales from reflection seismic to scanning electron microscope. Applications to mudstone-dominated depositional sequences have been more limited, despite the fact that mudstones make up more than 60% of the global sedimentary volume and generally provide the most complete record of sedimentation in a basin.

During the late 1970s and through the 1980s, Bob Garrison and his students at the University of California–Santa Cruz conducted numerous studies that revealed the basic sedimentary and stratigraphic framework of the Monterey Formation in California, advancing our understanding of the sedimentary processes at work in these deep-margin basins. We expanded on that framework using direct observations from outcrops and cores that have been integrated with other subsurface data, as well as a wide variety of information derived from paleontologic, chronostratigraphic, geochemical, and compositional analyses to illustrate a sequence-stratigraphic approach to interpreting fine-grained rocks and their associated depositional systems in these settings. These were some of the earliest investigations of mudstone sequence stratigraphy focused on slope and basinal environments.

In this study, observations from outcrops in the Pismo Basin, California, provided the basis for developing a detailed sequence-stratigraphic framework for the Monterey Formation, expanding on the broad-scale characterization of Garrison and his colleagues. These outcrops represent deposition during different phases of basin evolution and in different borderland-type basin settings (slope and basin depocenters). Comparison of coeval strata from different depositional settings and locations documented variation at both the sequence and parasequence scale. Variation of parasequence character, in particular, provided a valuable tool for enhanced understanding of deposition and diagenesis in these margin basins. Extrapolation to the subsurface using gamma-ray logs greatly enhanced basinwide application compared to limited, partial-stratigraphic-section outcrops, and it facilitated the lateral characterization of mudstone depositional sequences. These elements served as the building blocks for improved models of deposition in margin-basin settings.
Optimal signal amplification in globally coupled bistable oscillators: The role of weight between positive and negative couplings
Authors: Kang Xiuxiu , Xu Huimei , Jiang Yingchen , Liang Xiaoming , Zhang Xiyun
Published: May 2022

Recently, it was revealed that uniformly positive and negative couplings perform complementary roles in the signal amplification of coupled bistable oscillators. However, the coupling weights between oscillators are usually nonuniform due to adaptivity in many nonlinear systems. For this reason, we introduce a weight ratio of positive and negative couplings and investigate how it affects the response of globally coupled bistable oscillators to a subthreshold signal. We show that the weight ratio can significantly optimize the system response to the subthreshold signal compared to the case of uniform couplings. Finally, we propose a reduced model and compare its analytical approximations with the numerical results.
ISRT rumor spreading model with different influence mechanisms in social networks
Authors: Wang Hongmei , Qiu Liqing , Sun Chengai
Published: May 2022

Rumor, as an important form of information dissemination, has always been a research hotspot in the field of complex networks. How to better understand the rules of rumor propagation and establish a practical dissemination model is a significant challenge. To further study the state transfer in information transmission, this paper established the Ignorant-Spreader-Stifler-Transition (ISRT) model, introduced different influence mechanisms and calculate the influence rate accurately by function. Specifically, (1) Based on SIR model, this paper introduces the transition state, considering that transition may awaken spontaneously to spread rumors due to individual cognition. In this paper, the ratio of the current communicator and the degree of doubt of the transition are introduced into the spontaneous arousal function. (2) This paper redefines the propagation probability function and the forgetting probability function, and introduces the time function to describe the rate from the propagator to the restorer. (3) Due to the presence of highly emotional leader propagators in the network who would awaken the immune to spread rumors again, the model added a link from the recovering person to the infected person. Finally, the nonpropagation equilibrium point [Formula: see text] and propagation equilibrium point [Formula: see text] are obtained by establishing the mean field equation. The experimental results show that different influencing mechanisms can more accurately locate the stage change of rumor transmission, which provides theoretical support for more effective control of information transmission.
INTERNATIONAL TECHNOLOGY TRANSFER, ENVIRONMENTAL POLLUTION AND DOMESTIC WELFARE
Authors: CHANG RAY-YUN , KUO PING-SING , LIN YAN-SHU , HU JIN-LI
Published: May 2022

Licensing of foreign green technologies is not free to the home country, hence causing tradeoffs in the domestic welfare. This paper constructs a two-stage game model to explore the impact of international green technology licensing on the environment and social welfare. Results show that the total amount of pollution under licensing may be larger than that under no licensing whereas the social welfare under licensing may be smaller than that under no licensing. This implies that foreign technology transfer may not be socially preferred and harmful to the domestic environment. In addition, trade liberalization may help reduce the environmental harm when the import tariff is moderate.
FOREIGN INVESTMENT AND PRODUCTIVITY OF LOCAL CHINESE FIRMS
Authors: YUE WEN , ZHAO JINGYAN
Published: May 2022

In this paper, we examine how foreign investment affects the productivity of local Chinese firms based on data from Chinese manufacturing firms. A series of robustness tests reveal that foreign investment significantly improves the productivity of local Chinese firms. Further analysis shows the varying impacts of foreign investment on the productivity of different types of local firms and indicates significant heterogeneity. We decompose the aggregate productivity growth into components, including the effects of technology progress, resource reallocation, firm entry and firm exit. Results show that foreign investment mainly promotes aggregate productivity growth by improving the resource allocation effect and technology progress effect.
Doodles and commutator identities
Authors: Bartholomew Andrew , Fenn Roger , Kamada Naoko , Kamada Seiichi
Published: May 2022

A doodle is a collection of immersed circles without triple intersections in the 2-sphere. It was shown by the second author and Tayler that doodles induce commutator identities (identities amongst commutators) in a free group. In this paper, we observe this idea more closely by concentrating on doodles with proper noose systems and elementary commutator identities. In particular, we show that there is a bijection between cobordism classes of colored doodles and weak equivalence classes of elementary commutator identities.
Remembering Patrick Dehornoy
Authors: Sossinsky A.
Published: May 2022

This is the story of my relationship with Patrick Dehornoy and his family, which began in 1996 and ended when Patrick passed away.
Behind maths: Federating research(ers)
Authors: Bellingeri Paolo
Published: May 2022

Patrick Dehornoy’s mathematical legacy is impressive and it has been celebrated in other papers of this volume. However, I think that there is another important aspect of Patrick’s work that should be stressed, which is his involvement in scientific and managerial leadership in Mathematics. This text wants therefore to be a very personal memory of Patrick Dehornoy and of the impact that he had on my perspective on the relevance and importance of commitments to our community.
Garside groups and geometry: Some thoughts for Patrick Dehornoy
Authors: Wiest Bert
Published: May 2022

This paper in memory of Patrick Dehornoy (1952–2019) is an invitation to Garside theory for mainstream geometric group theorists interested in mapping class groups, curve complexes, and the geometry of Artin–Tits groups.
EVALUATION OF ENERGY CONSUMPTION, CUTTING FORCE, SURFACE ROUGHNESS AND VIBRATION IN MACHINING TOOLOX 44 STEEL USING TAGUCHI-BASED GRAY RELATIONAL ANALYSIS
Authors: ÖZLÜ BARIŞ
Published: May 2022

This paper presents the Toolox 44 steel’s experimental and statistical machinability optimizations conducted for achieving minimum output parameters (energy consumption ([Formula: see text]), cutting force ([Formula: see text]), surface roughness ([Formula: see text]), and vibration (Vib)). Turning experiments have been performed under dry machining conditions on a CNC lathe at different cutting parameters according to the Taguchi L27 orthogonal array. Taguchi-based gray relational analysis (GRA) has also been used to optimize output parameters simultaneously. Moreover, analysis of variance (ANOVA) has been applied to determine the effects of cutting parameters on output parameters. As a result, the lowest Ec was measured 0.06 kW at the 1.5 mm depth of cut, 220 m/min cutting speed and 0.4 mm/rev feed rate. At 0.5 mm depth of cut, 220 m/min cutting speed and 0.1 mm/rev feed rate, the lowest [Formula: see text], [Formula: see text] and Vib are measured at 132.28 N, 0.69 [Formula: see text]m and 2.25 m/s2, respectively. According to GRA, the best machining combination in terms of energy consumption ([Formula: see text]), cutting force ([Formula: see text]), surface roughness ([Formula: see text]), and vibration (Vib) was A1B3C1, and the percentage of improvement in the gray relational degree has been calculated to be 25.25%. Validation test results showed that the optimization of cutting parameters was successful in the machining process of Toolox 44 steel according to the multiple output parameter values.
EFFECT OF MECHANICAL AND TRIBOLOGICAL PROPERTIES OF DIAMOND FILMS ON VARIOUS SUBSTRATES
Authors: HU JIBO , JIAN XIAOGANG
Published: May 2022

Geological drilling required high-performance diamond drill bits. In this paper, diamond films were deposited on different drill bit substrates based on the MPCVD equipment. The properties of diamond films were analyzed by scanning electron microscopy (SEM), Raman spectra, X-ray diffraction (XRD) and tribological tests. The results showed that surface morphology of the four different substrates was good and the grain size was uniform. The diamond drill bit substrates include polycrystalline diamond compact (PDC), cemented carbide (WC–Co), impregnated diamond (IPD) and diamond thick-film welded (DT) sheets. The coefficients of friction of the deposited protective films are 0.15, 0.25, 0.23 and 0.29, respectively. What is more, the wear rates of protective films are [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text][Formula: see text]mm3/N[Formula: see text]m, respectively. Addition of diamond films could effectively reduce the friction coefficient on the surface and improve the service life of drill bit.
Dynamics of stochastic nonlocal reaction–diffusion equations driven by multiplicative noise
Authors: Xu Jiaohui , Caraballo Tomás
Published: May 2022

This paper deals with fractional stochastic nonlocal partial differential equations driven by multiplicative noise. We first prove the existence and uniqueness of solution to this kind of equations with white noise by applying the Galerkin method. Then, the existence and uniqueness of tempered pullback random attractor for the equation are ensured in an appropriate Hilbert space. When the fractional nonlocal partial differential equations are driven by colored noise, which indeed are approximations of the previous ones, we show the convergence of solutions of Wong–Zakai approximations and the upper semicontinuity of random attractors of the approximate random system as [Formula: see text].
On Surrogate Duality and Competition between Entropy and Potential Energy in the Finite Element Model of Elastic Contact Mechanics
Authors: Xuan Zhaocheng , Zhang Lixia
Published: May 2022

The competition between entropy and energy that usually occurs in thermodynamics — an increase in one usually leads to a decrease in the other — was also shown to hold in static–elastic contact mechanics in our previous work on solving contact problems with an iterative algorithm. In this paper, we first present a theoretical analysis of the surrogate duality of the optimization model of contact problems, propose several propositions characterizing the surrogate duality, and identify the condition under which the fractional objective function of the surrogate dual problem is quasi concave. Second, we further clarify the correspondence between the concepts of statistical physics and the finite element model of contact problems so that the concepts of statistical physics can be more cleanly used to solve contact problems. Third, we provide examples to calculate the contact force with an improved iterative algorithm based on the quasi concavity that more clearly verifies the competition between entropy and potential energy, and the competition shows strong negentropy behavior: potential energy increases while entropy decreases throughout the iterative process.
Damping Perturbation Based Time Integration Asymptotic Method for Structural Dynamics
Authors: Lázaro Mario
Published: May 2022

In this paper a novel time integration numerical method based on artificial perturbation of damping is proposed. Viscous dissipative terms in the structural dynamics equations of motion are perturbed by an artificial parameter. The subsequent asymptotic expansion of the transient response results in an infinite series which can be summed, leading to a well-defined new step-by-step explicit iterative scheme. Precise integration algorithms are designed for the construction of the main matrices. Conditions for convergence and numerical properties, i.e., stability and accuracy are also studied in detail. The proposed approach is validated with a numerical example, showing high accuracy with respect to other existing methods in literature.
The nonlinear vibration and dispersive wave systems with cross-kink and solitary wave solutions
Authors: Li Ruijuan , Manafian Jalil , Lafta Holya A. , Kareem Hawraa A. , Uktamov Khusniddin Fakhriddinovich , Abotaleb Mostafa
Published: May 2022

This paper investigates the cross-kink and solitary wave solutions to the nonlinear vibration and dispersive wave systems. The solutions include periodic, cross-kink and solitary wave solutions. The bilinear form is considered in terms of Hirota derivatives. Accordingly, we utilize the Cole–Hopf algorithm to get the exact solutions of the [Formula: see text]-dimensional modified dispersive water-wave system. The analytical treatment of cross-kink, solitary wave solutions is studied and plotted in three forms of two, density and three-D plots. A nonlinear vibration system will be investigated. Employing appropriate mathematical assumptions, the novel kinds of the cross-kink and solitary wave solutions are derived and constructed in view of the combination of kink, periodic and soliton for cross-kink and also a combination of two kinks in terms of exponential functions for solitary of the governing equation. To achieve this, the illustrative example of the [Formula: see text]-D modified dispersive water-wave system is furnished to exhibit the feasibility and reliability of the procedure utilized in this research. The trajectory solutions of the traveling waves are presented explicitly and graphically. The effect of the free parameters on the behavior of designed figures of a few obtained solutions for two nonlinear rational exact cases was also considered. By comparing the suggested technique with the other existing schemes, the results present that the execution of this technique is concise, simple and straightforward.
High-quality BaTiO3 epitaxial growth on GaAs (001) substrate by novel SrTiO3/Ti2.5O3 buffer layers
Authors: Zhou Yunxia , Liu Xingpeng , Zhu Jun
Published: May 2022

Perovskite ferroelectric BaTiO3 material showed promising application in the photovoltaic field due to its positive polarization enhanced open voltage with ferroelectric modulation. Achieving perfect interfaces between the multi-layers based on BTO film was still unresolved. Therefore, we developed the bottom buffer layers SrTiO3/Ti[Formula: see text]O3 films deposited on GaAs for reducing the lattice mismatch between the epitaxial oxide (BTO) GaAs via PLD system. The out-of-plane epitaxial relationship of this heterostructure was [110]BaTiO3//[110]SrTiO3//[010]Ti[Formula: see text]O3//[001]GaAs and the in-plane epitaxial relationship was determined to be [110]BaTiO3//[110]SrTiO3//[100]Ti[Formula: see text]O3//[110]GaAs from RHEED and XRD results. In addition, we found that the inter-diffusions of Ga and As atoms from GaAs substrate to oxides films were prevented greatly by the SrTiO3/Ti[Formula: see text]O3 passivation layer. Using the Gibbs free energies of formations equations, we explained that the Ga atoms couldn’t diffuse through Ti-oxides at Ti[Formula: see text]O3/GaAs interface. Our work provided an effective measurement to develop the BTO application in the photovoltaic field.
Synthesis of star-like BiVO4 photocatalysts by organic-aqueous hetero-phase reaction: Interaction between bismuth and amino group of oleylamine
Authors: Hangai Taisei , Uchiyama Namiki , Hasegawa Takuya , Asakura Yusuke , Yin Shu
Published: May 2022

The bismuth vanadate (BiVO4) photocatalyst was successfully synthesized by an organic-aqueous hetero-phase reaction method using organic additives (oleic acid, oleyl alcohol, and oleylamine) to investigate the reaction mechanism. The BiVO4 with a star-like morphology could be synthesized with oleylamine. Bismuth precursors formed by the interaction between bismuth and the amino group of oleylamine were nano-sized complex particles with amorphous phase, finally resulted in the formation of star-like morphology. Moreover, BiVO4 synthesized with oleylamine showed excellent photocatalytic activity on degradation of rhodamine B.
Dynamics of an eco-epidemiological model with nonmonotonic functional response of susceptible predator on prey species
Authors: Mandal Md. Reduanur , Hossain Sajjad , Sarwardi Sahabuddin
Published: May 2022

In this study, a predator–prey population model has been described with disease in the predator species. This is a three-dimensional study comprising of a prey and a predator taken in two different groups such as susceptible and infected predator species. Dynamical behavior of the spread of the disease having the potential to become epidemic has been discussed. Parametric conditions are determined for the control of disease outbreak. Some basic properties like boundedness, persistence of the system have been ensured. Minimal conditions are framed, in such way that the disease can be naturally controlled. Different qualitative behavior like stability, bifurcation and numerical simulations has been performed. Substantial numerical simulations have been carried out in order to validate the obtained theoretical results.
Efficient Bang-Bang Model Predictive Control for Quadcopters
Authors: Westenberger Jelle , De Wagter Christophe , de Croon Guido C. H. E.
Published: May 2022

Time-optimal model predictive control is important for achieving fast racing drones but is computationally intensive and thereby rarely used onboard small quadcopters with limited computational resources. In this work, we simplify the optimal control problem (OCP) of the position loop for several maneuvers by exploiting the fact that the solution resembles a so-called ‘bang-bang’ in the critical direction, where only the switching time needs to be found. The noncritical direction uses a ‘minimum effort’ approach. The control parameters are obtained through bisection search schemes on an analytical path prediction model. The approach is compared with a classical PID controller and theoretical time-optimal trajectories in simulations. We explain the effects of the OCP simplifications and introduce a method of mitigating one of these effects. Finally, we have implemented the ‘bang-bang’ controller as a model predictive controller (MPC) onboard a Parrot Bebop and performed indoor flights to compare the controller’s performance to a PID controller. We show that the light novel controller outperforms the PID controller in waypoint-to-waypoint flight while requiring only minimal knowledge of the quadcopter’s dynamics.
Heterogeneity, Household Co-Production, and Risks of Water Services — Water Demand of Private Households with Multiple Water Sources
Authors: Zozmann Heinrich , Klassert Christian , Klauer Bernd , Gawel Erik
Published: May 2022

Private households around the world use and combine multiple water sources, including diverse forms of market services and self-supply. The reasons for this have so far not been explained in a coherent framework, nor have the implications for water management and policy been sufficiently analyzed. Here, we examine how heterogeneity of water services, household co-production, and risks of provision influence household demand patterns. We apply an economic household production model that incorporates two water quality levels for different household activities to exemplary situations. We derive a number of explanations why households use and combine water services that expand the current state of research. Relevant findings include: (i) The diverse characteristics of available water services result in different time requirements for water procurement and varying degrees of suitability for household activities. (ii) Differences in the value placed on time can induce households to demand heterogeneous water services because these enable them to find a balance between using time and money to access water. (iii) Certain water services may be demanded because they function as insurance against both uncertain and unreliable supply. Our insights are relevant for water policy, in particular for developing and managing demand-responsive systems, and for the implementation and monitoring of normative goals for access to water.
DATA-DRIVEN UNDERSTANDING OF AI-BASED TRAFFIC SIGNAL CONTROL AND ITS IMPLICATIONS ON LOW-CARBON URBAN TRANSPORT SYSTEMS
Authors: HUNG BENSON K. H.
Published: May 2022

Emission by vehicles is one of the main sources causing the exceedance of the Air Pollution Index at roadside. Therefore, reducing emissions from vehicles in busy corridors has been a priority of the Government in improving roadside air quality. The existing pedestrian lights, which follow a predetermined signal timing for road crossings, are typical static traffic lights. The pushbutton has been added to improve the pedestrian crossing efficiency by rendering the green phase to the pedestrian as soon as possible. However, the current detection devices are not capable of streamlining the traffic flows and prioritizing pedestrians on the curb according to the actual needs. With the use of artificial intelligence (AI) techniques such as deep learning, this project can analyze the traffic conditions of a designated area, including the length of traffic queues and the number of pedestrians waiting at a crossroad. Our system can then manage traffic lights to facilitate efficient traffic flow between vehicles and pedestrians. In addition, the IoT technologies enable the system to collect traffic information for big data analysis and facilitate efficient traffic management. In the implementation stage of the project, a local field study of a crossroad with a school, bus stops, and shopping malls in the vicinity was conducted and relevant data for further analysis was collected. The results showed that the system could help to shorten traffic queues and pedestrian waiting time at the crossroad. The goals are to examine strategies in traffic signal control based on AI to reduce carbon footprint. The deliverables will assess how urban transport systems can reduce carbon emissions and adapt to climate change with a focus on traffic signal rationalization. It provides guidance, policy recommendations, and outlines research and information needs.
IMPDB: Indian Medicinal Phytochemical Database Curated for Drug Designing
Authors: Sinha S. , Hazarika A. , Johari S. , Neog B. , Rajkhowa S. , Biswas A.
Published: May 2022

Background: A paradigm shift towards a multifaceted natural product drug discovery approach has been observed globally. Today, many modern drugs have originated from ethnopharmacology and traditional medicine. The traditionally used medicinal plants are a rich source of biologically active phytochemicals. A paradigm shift has been observed in pharmaceutical industries towards the use of those phytochemicals for the development of drugs over synthetic compounds for minimization of side effects. Methodology: The data have been generated from the printed “Database on Medicinal Plants Used in Ayurveda” published by the Central Council for Research in Ayurvedic Sciences, Government of India. The curation of the phytochemicals and calculation of their physicochemical and drug-like properties has been done using Discovery Studio v 4.5, and the database IMPDB is designed by adhering to the principles of database design and developed using PHP as front-end and MySQL as back-end. The data in IMPDB were analyzed further and comparative analysis of physicochemical properties of IMPDB phytochemicals with other small molecule databases, followed by druggability and novelty analysis of phytochemicals of the database were conducted with wQED score and molecular fingerprinting methods. In addition to that, ADMET properties of IMPDB phytochemical were compared with FDA-approved drugs. Results: Druggability analysis of IMPDB phytochemical shows a substantial number of them are druggable. An extensive review of the existing database was conducted and the quality of data of existing databases was matched with IMPDB data, and IMPDB data was found at par with the standard databases in the same domain, in certain parameters the quality of data of IMPDB was found better. In addition to that, novelty analysis of IMPDB data in comparison to 2068 FDA-approved drugs reveals that 99.96–99.99% of the phytochemical of IMPDB is novel and to some extent better in terms of ADMET properties. The database is available from https://impdb.org.in/ . Conclusion: IMPDB can be a useful database for the drug development industry and a need for the future pharmaceutical industry.
The Link Between Good Governance, Economic Development and Renewable Energy Investment: Evidence from Upper Middle-Income Countries
Authors: Akhtaruzzaman Muhammad
Published: May 2022

Renewable energy (RE) can play a vital role in ensuring a sustainable energy platform for the future, and in addressing climate change. Investment in RE in the upper middle-income countries (UMICs), which are a major contributor to global carbon dioxide (CO[Formula: see text] emissions, can be an important recovery strategy for mitigating climate change damage. Existing literature suggests that governance (also referred to as ‘institutional quality’) is an important determinant of renewable energy investment (RE investment). Yet, governance conditions in UMICs have remained almost unchanged in the recent past, despite the substantive increases in income levels and investment in the RE sector. This paper outlines an investigation into the role of governance in RE investment in UMICs and considers whether the influence of governance on RE investment depends on a country’s income level. This analysis used pooled ordinary least squares (OLS), panel-corrected standard errors and panel-fixed effects models to evaluate data from 35 UMICs, from 1996 to 2017. The results suggest that good governance raises RE investment in UMICs. In particular, the control of corruption, government effectiveness, regulatory quality and rule of law are statistically significant aspects of good governance that boost RE investment. However, this effect is conditional on the level of economic development (income level) of a country. The marginal effect of governance on RE investment is larger in lower income countries and vice versa. Among the controls, trade openness in UMICs is predicted to have an adverse impact on RE investment.
Unusual sauropod slipping tracks preserved on a biostabilized tidal flat from the Lower Cretaceous of northern Patagonia, Argentina
Authors: Heredia Arturo M. , Pazos Pablo J. , Fernández Diana E.
Published: May 2022

Several elongated and other crescent-shaped impressions interpreted as dinosaur tracks and preserved on Lower Cretaceous tidal flat deposits from the Agrio Formation (northern Patagonia, Argentina) are studied in detail. These tracks were documented on a palaeosurface showing palaeotopographic differences over a short distance, related to the lateral migration of a tidal channel. A genetic order between biostabilization and bioturbation of the palaeosurface is recognized. Ripples generated within the channel during the flood tide were first biostabilized; there, horseshoe crab trace fossils were produced. Then, the area bearing the tracks studied here was subaerially exposed, with the biostabilized substrate generating a slippery surface. Scanning electron microscope analysis of the rims indicates that the microbial mat was disturbed by the trampling. Finally, microbial mats recovered, and some tracks preserved wrinkle marks inside the tracks. Taking into account the substrate properties and track features analysed (morphology, size, depth and orientation), it is concluded that the tracks were produced by dinosaurs, probably small sauropods, trampling on a slippery surface and moving parallel to the channel margin. This study is an unusual case of slipping tetrapod tracks preserved on a biostabilized tidal flat developed in a mixed carbonate–siliciclastic environment.
Methods included
Authors: Crusoe Michael R. , Abeln Sanne , Iosup Alexandru , Amstutz Peter , Chilton John , Tijanić Nebojša , Ménager Hervé , Soiland-Reyes Stian , Gavrilović Bogdan , Goble Carole , Community The CWL
Published: May 2022

Standardizing computational reuse and portability with the Common Workflow Language.
HotFuzz: Discovering Temporal and Spatial Denial-of-Service Vulnerabilities Through Guided Micro-Fuzzing
Authors: Blair William , Mambretti Andrea , Arshad Sajjad , Weissbacher Michael , Robertson William , Kirda Engin , Egele Manuel
Published: May 2022

Fuzz testing repeatedly assails software with random inputs in order to trigger unexpected program behaviors, such as crashes or timeouts, and has historically revealed serious security vulnerabilities. In this article, we present HotFuzz, a framework for automatically discovering Algorithmic Complexity (AC) time and space vulnerabilities in Java libraries. HotFuzz uses micro-fuzzing, a genetic algorithm that evolves arbitrary Java objects in order to trigger the worst-case performance for a method under test. We define Small Recursive Instantiation (SRI) as a technique to derive seed inputs represented as Java objects to micro-fuzzing. After micro-fuzzing, HotFuzz synthesizes test cases that triggered AC vulnerabilities into Java programs and monitors their execution in order to reproduce vulnerabilities outside the fuzzing framework. HotFuzz outputs those programs that exhibit high resource utilization as witnesses for AC vulnerabilities in a Java library. We evaluate HotFuzz over the Java Runtime Environment (JRE), the 100 most popular Java libraries on Maven, and challenges contained in the DARPA Space and Time Analysis for Cybersecurity (STAC) program. We evaluate SRI’s effectiveness by comparing the performance of micro-fuzzing with SRI, measured by the number of AC vulnerabilities detected, to simply using empty values as seed inputs. In this evaluation, we verified known AC vulnerabilities, discovered previously unknown AC vulnerabilities that we responsibly reported to vendors, and received confirmation from both IBM and Oracle. Our results demonstrate that micro-fuzzing finds AC vulnerabilities in real-world software, and that micro-fuzzing with SRI-derived seed inputs outperforms using empty values in both the temporal and spatial domains.
Breaking Cellular IoT with Forged Data-plane Signaling: Attacks and Countermeasure
Authors: Tan Zhaowei , Ding Boyan , Zhao Jinghao , Guo Yunqi , Lu Songwu
Published: May 2022

We devise new attacks exploiting the unprotected data-plane signaling in cellular IoT networks (a.k.a. both NB-IoT and Cat-M). We show that, despite the deployed security mechanisms on both control-plane signaling and data-plane packet forwarding, novel data-plane signaling attacks are still feasible. The attacker can forge both uplink and downlink data-plane signaling messages that pass the current security checks used by the receiver. With the capability of forging messages, the attacker can launch attacks that exhibit a variety of attack forms beyond simplistic packet-blasting, denial-of-service (DoS) threats, including location privacy breach, packet delivery loop, prolonged data delivery, throughput limiting, radio resource draining, connection reset, and multicast disabling. Our testbed evaluation and operational network validation have confirmed the attack viability. To combat the threat, we further propose a new defense solution within the 3GPP C-IoT standard framework. It leverages the synchronized timer clock information to protect the data-plane signaling messages with low overhead.
(Digital Presentation) Finite Element Modeling of Thermoelectric Effects in Phase Change Memory Cells
Authors: Kashem Md Tashfiq Bin , Scoggin Jake , Silva Helena , Gokirmak Ali
Published: May 2022

We model the current density in a semiconductor based on the drift-diffusion transport of the charge carriers to accurately determine the thermoelectric effects in the bulk material (Thomson effect) and material junctions (Peltier effect). We utilize the model to perform 2-D finite element simulations of mushroom phase change memory cell with a critical dimension of 20 nm using temperature and electric field dependent material parameters and analyze the contributions of symmetric Joule heating and asymmetric thermoelectric heats during reset and set operations. We investigate the effect of altering the direction of current flow by changing the connection point between the cell and the access device and observe that, corresponding change in thermoelectric effects cause significant difference in operation dynamics, temperature distribution profiles, amorphous volume, energy requirement and resistance contrast between reset and set states.
(Digital Presentation) Effect of N2-Anneal Temperature on Silicon Nitride Film: (II) Fine Structures of ESR Spectrum and FTIR
Authors: Miyagawa Hayato , Kamigaki Yoshiaki , Kurita Hisatsugu , Nakamura Masataka
Published: May 2022

We performed fine analyses on ESR spectra of silicon nitride (SiN) films grown on a Si (0 0 1) substrate via low-pressure chemical vapor deposition and N2-annealed at temperatures ranging from 700°C to 1150°C. We observed two types of temperature dependency for the number of Si dangling bonds (DBs): in one case, a maximum occurred at 900°C, and in the other case, the number of DBs increased with increasing temperature over 1000°C. The former type of DBs was associated with defects of the Pb0 center at the topmost substrate, (three silicon back-bonds present), and the M signal (generated by Si suboxide with one or two oxygen back-bonds). The latter DB group was attributed to the E' center in the natural oxide layer at the interface between the grown SiN layer and the substrate and the K center in the SiN film. Charge breakdown (Qbd) of the MOS capacitor is strongly related to both DB groups and may have started at the defect associated with the Si suboxide state.
(Invited) Nanoscale Wetting and Its Connection with Macroscopic Young's Equation
Authors: Yamaguchi Yasutaka , Kusudo Hiroki , Bistafa Carlos , Surblys Donatas , Omori Takeshi , Kikugawa Gota
Published: May 2022

Wetting behavior of liquids plays a key role in the wet cleaning process of semiconductor fabrication, and quantitative evaluation of the solid-fluid interfacial tensions using molecular dynamics (MD) simulation is needed for the understanding, control, and design of the process. In this report, we summarize the basic features of the interfacial tensions from a microscopic viewpoint, and we show two basic approaches – called the mechanical and thermodynamic routes – to calculate solid-fluid interfacial tensions by MD simulations, which enable the microscopic understanding of Young’s equation at the nanoscale as the basis of wetting physics. In the mechanical route, the local stress anisotropy appearing around the interfaces is related to the interfacial tensions through original Bakker’s equation and its extended versions developed by the present authors. On the other hand, in the thermodynamic route, the solid-related interfacial tensions are extracted as the free energy difference from a reference system.
Hydrophobic Films Surface Preparation And Its Impact On Wet Cleaning
Authors: Mercadier Thomas , Garnier Philippe , Loup Virginie , Tiron Raluca , Martinez Eugenie
Published: May 2022

The cleaning of hydrophobic films is a key challenge for yield. Such films are prone to drying marks formation during aqueous cleaning steps. In the present work, we study how surface preparation can break non-polar bonds, resulting in a hydrophilic surface. Several treatments (ultraviolet, Standard Clean 1 and ozonated water) and materials (amorphous carbon, silicon carbon nitride) have been studied. A specific work on Silicon carbon nitride surface modification with ozonated water has been initiated with X-ray photoelectron spectroscopy. We have evaluated the interest that such step has prior to aqueous wafer cleaning and the possible consequences on electrical properties and surface energy. Further investigations will be required to evaluate the impact and interest of such a step on microelectronic process integration.
Understanding of Etching Mechanism of Si3N4 Film in H3PO4 Solution For The Fabrication of 3D NAND Devices
Authors: Park Taegun , Son Changjin , Kim Taehyeon , Lim Sangwoo
Published: May 2022

The etching mechanism of the Si3N4 in H3PO4 solution is proposed. The effect of H3PO4 concentrations on Si3N4 etching rate is investigated. The Si3N4 etching rate is not simply proportional to H3PO4. Both H3PO4 and H2O participate in the Si3N4 etching reaction and play their roles. First, H2PO4
- which is a weak nucleophile generated from H3PO4 replaces -NH2 on the Si3N4 surface with -H2PO4 by an SN1-like reaction. Next, N-Si which is backbone of Si3N4 network is substituted by H2O with Si-OH by an SN2-like reaction. From the Si3N4 etching mechanism and kinetic studies, it is concluded that the Si3N4 etching rate is proportional to product of concentration of H2O and H3PO4. These results suggest that consumption of H3PO4 can be reduced by using a lower concentration of H3PO4 between two H3PO4 concentrations that can produce a similar Si3N4 etching rates.