nils-herrmann/clean_scirepeval huggingface dataset:
The Weld Life Prediction of Frame’s Damper Seat Based on Notch Stress Model

In order to analyze welded fatigue life of welded frame’s accessories correctly, this paper adopts fictitious notch method of 1mm radius and establishes a notch stress model for an A1A-A1A-type locomotive bogie’s primary vertical damper seat. Through FEM analysis, stress state at local weld toe and weld root for damper seat can be obtained. According to stress range, the danger points of welds can be confirmed. The full vehicle multi-body dynamic model is established for simulation analysis, for the sake of acquiring load-time history of vertical damper seat under track irregularity, which considering nonlinear damping speed character of vertical damper. Based on StressLife_Analysis module of nCode DesignLife, welded accumulative damage and life cycles under different stress parameters and fatigue class curves are calculated. Meanwhile, the corresponding nominal stress model is established to carry out analysis comparison. The result shows that in the same case, accumulative damage value calculated by a notch stress method is lower, life cycles is higher, and the normal stress method generally is partial to be conservative.

Field of study: Engineering
METHODS OF SYNTHESIS OF [1,2,4]TRIAZOLO[1,5- а ]PYRIDINES

В микрообзоре обобщены данные по новым методам синтеза [1,2,4]триазоло[1,5-а]пиридинов, опубликованные начиная с 2002 г. Методы классифицированы по типам используемых реагентов.

Field of study: Chemistry
Formation of a Novel Diaqua Disodium Tetrakis(1-methyluracilato)palladium Complex with a Unique Supramolecular Channel Structure

A novel [Na2Pd(1-MeU−)4(H2O)2]n (1) columnar complex is prepared from the reaction of an aqueous solution containing Na2PdCl4 with four equivalent amount of 1-methyluracil (1-MeUH) in the presence of Na2CO3. X-ray structure of 1 reveals that the complex forms an infinite supramolecular channel structure in the crystal.

Field of study: Chemistry
Transport phenomena in the compound: LiFe1/2Mn1/2VO4

The LiFe 1/2 Mn 1/2 VO 4 was prepared by a standard solid-state reaction route. X-ray diffraction (XRD) study confirms the formation of the material under reported conditions and it reveals an orthorhombic unit cell structure with lattice parameter: a  = 3.7111 A, b  = 15.6568 A, c  = 16.3478 A. Complex impedance analysis of the sample indicates: (i) bulk contribution to electrical properties up to 125 °C, (ii) grain boundary effects for all T  ≥ 130 °C, (iii) negative temperature coefficient of resistance (NTCR) effect and (iv) evidence of temperature dependent electrical relaxation phenomena in the material. D.c. conductivity ( σ dc ) shows typical Arrhenius behavior when observed as a function of temperature. The activation energy values were estimated to be ~ 0.53 eV (25–175 °C) and ~ 0.73 eV (175–475 °C) from temperature variation of d.c. conductivity. Modulus analysis has been carried out to understand the mechanism of electrical transport process and this indicates non-Debye type conductivity relaxation in the material.

Field of study: Materials science
Martensitic fcc-to-hcp transformations in solid xenon under pressure: a first-principles study.

First-principles calculations reveal that the fcc-to-hcp pressure-induced transformation in solid xenon proceeds through two mechanisms between 5 and 70 GPa. The dynamics of the phase transition involves a sluggish stacking-disorder growth at lower pressures (path I) that changes to a path involving an orthorhombic distortion at higher pressures (path II). The switchover is governed by a delicate interplay of energetics (enthalpy of the system for the structural stability) and kinetics (energy barrier for the transition). The two types of martensitic transformations involved in this pressure-induced structural transformation are a twinned martensitic transition at lower pressures and a slipped martensitic transition at higher pressures.

Field of study: Physics
Onset of aridity and dune-building in central Australia: sedimentological and magnetostratigraphic evidence from Lake Amadeus

Sediments from Lake Amadeus, a groundwater discharge playa in central Australia, comprise a surface playa sequence (the Winmatti Beds), varying between 0.6 and 3 m in thickness, overlying a long sequence of fairly uniform fluvial-lacustrine clays (the Uluru Clay). The latter extends down to at least 15 m (the maximum depth cored during this study), and possibly down to 65 m below the present playa surface. In the cores studied the Brunhes-Matuyama boundary (0.73 Ma) was identifiable in all the upper sediments, typically at a depth of between 1 and 2 m, but below this there are two plausible chronological interpretations of the palaeomagnetic data. Deposition rates are very low, typically no more than 1.5 cm/ka in the Uluru Clay Beds, and down to 0.2 cm/ka in the Winmatti Beds. These rates suggest that the fluvial-lacustrine phase lasted for at least 5 Ma. The boundary between the Uluru Clay and the Winmatti Beds bears a close correspondence to the boundary between the Blanchetown Clay (a lacustrine sequence) and the Tyrrell Beds (a playa sequence) in palaeo-lake Bungunnia, in what is now the Murray Basin in southeastern Australia. However the transition occurs at about 0.9 Ma (or possibly 1.6 Ma) at Lake Amadeus, whereas it has been dated palaeomagnetically at less than 0.73 Ma (probably 0.5 Ma) in Lake Bungunnia. Records from other locations in southeastern Australia likewise support a major change from wetter to drier conditions at, or shortly after, the Matuyama-Brunhes polarity transition. Thus the current evidence from Lake Amadeus indicates that in central Australia the onset of aeolian and saline gypseous deposits, characteristic of arid-zone facies, may have pre-dated the corresponding change in the southeastern part of the continent by about 0.4 Ma, or possibly by about 1.1 Ma. In common with most playas in central Australia, Lake Amadeus is surrounded by a ring of gypseous dunes derived from material deflated from the surface of the playa. Magnetostratigraphic evidence from Auger Island, in the middle of Lake Amadeus, suggests that the oldest gypseous dune formation on the island must have pre-dated the start of the Jaramillo subchron at 0.98 Ma (or possibly the start of the Brunhes epoch, 0.73 Ma), thus making these the oldest dated dunes in Australia. The age of the Auger Island dunes is probably characteristic of other gypseous dunes around the margins of playas in central Australia.

Field of study: Environmental science, Geography
Teaching Values with Stories and Tales in the Preschool Period

The preschool period is a time when children develop their character and they gain skills they can use throughout their life. During this period, national, religious and moral sentiments of children are shaped and they internalize the values they learn. It is not possible for preschoolers to learn values cognitively through reading, writing, and listening. The introduction of affective and pscyho-motor dimensions requires conscious efforts of role models. The most important materials used for teaching values during the preschool period are stories and tales. We believe that this theoretical study examining how stories and tales can be used as a material to teach children values will be helpful for teachers involved in preschool education, families, program development experts and the relevant departments of the ministry.  Preschool Education, Story, Tale, Value Education

Field of study: Education
Large Diameter Femoral Heads Impose Significant Alterations on the Strains Developed on Femoral Component and Bone: A Finite Element Analysis

Total Hip Arthroplasty aims at fully recreating a functional hip joint. Over the past years modular implant systems have become common practice and are widely used, due to the surgical options they provide. In addition Big Femoral Heads have also been implemented in the process, providing more flexibility for the surgeon. The current study aims at investigating the effects that femoral heads of bigger diameter may impose on the mechanical behavior of the bone-implant assembly. Using data acquired by Computed Tomographies and a Coordinate Measurement Machine, a cadaveric femur and a Profemur-E modular stem were fully digitized, leading to a three dimensional finite element model in ANSYS Workbench. Strains and stresses were then calculated, focusing on areas of clinical interest, based on Gruen zones: the calcar and the corresponding below the greater trochanter area in the proximal femur, the stem tip region and a profile line along linea aspera. The performed finite elements analysis revealed that the use of large diameter heads produces significant changes in strain development within the bone volume, especially in the lateral side. The application of Frost’s law in bone remodeling, validated the hypothesis that for all diameters normal bone growth occurs. However, in the calcar area lower strain values were recorded, when comparing with the reference model featuring a 28mm femoral head. Along line aspera and for the stem tip area, higher values were recorded. Finally, stresses calculated on the modular neck revealed increased values, but without reaching the yield strength of the titanium alloy used.

Field of study: Medicine
The norms and singular numbers of polynomials of the classical Volterra operator in L2(0,1)

The spectral problem (sI − φ(V )∗φ(V ))f = 0 for an arbitrary complex polynomial φ of the classical Volterra operator V in L2(0, 1) is considered. An equivalent boundary value problem for a differential equation of order 2n, n = deg(φ), is constructed. In the case φ(z) = 1 + az the singular numbers are explicitly described in terms of roots of a transcendental equation, their localization and asymptotic behavior is investigated, and an explicit formula for the ‖I + aV ‖2 is given. For all a 6= 0 this norm turns out to be greater than 1.

Field of study: Mathematics
Modulation of NMDA receptor by huperzine A in rat cerebral cortex.

To investigate the effects of huperzine A (Hup A) on NMDA receptors in rat cerebral cortex.



1) The effect of hup A on NMDA-induced current was studied in acutely dissociated rat hippocampal pyramidal neurons using whole-cell recording. 2) The effect of Hup A on NMDA receptor binding was assessed using [3H] dizocilpine (Diz) binding assay in synaptic membrane preparation of rat cerebral cortex.



1) Hup A reversibly inhibited NMDA-induced current in a concentration-dependent manner with IC50 of 45.4 mumol.L-1. 2) Hup A inhibited the specific binding of [3H]MK-801 to extensively washed synaptic membrane of rat cerebral cortex in a concentration-dependent manner with IC50 of 0.5 (0.1-1.9) mumol.L-1 (n = 4). 3) L-Glutamate 10 mumol.L-1 markedly increased [3H] MK-801 binding. In the presence of L-glutamate, Hup A 0.001-0.1 mumol.L-1 caused a further increase of the binding, whereas Hup A 1-300 mumol.L-1 inhibited the binding in a concentration-dependent manner with IC50 of 12.3 (5.8-26.3) mumol.L-1 (n = 5).



Hup A acted as an antagonist of NMDA receptor in cerebral cortex in addition to its inhibitory effect on acetylcholinesterase.

Field of study: Biology, Chemistry, Medicine
Further Validation of the Vengeance Scale

Further validation of the Vengeance Scale was explored. Scores on the scale were significantly and positively correlated with measures of hypermasculinity and inversely correlated with personal values of kindness and self-control for 25 men; however, college women's scores did not correlate significantly with either kindness or self-control. Further research is needed to assess whether the scale is valid for men as well as women.

Field of study: Psychology
Security Analysis of a Multi-factor Authenticated Key Exchange Protocol

This paper shows several security weaknesses of a Multi-Factor Authenticated Key Exchange (MK-AKE) protocol, proposed by Pointcheval and Zimmer at ACNS'08. The Pointcheval-Zimmer scheme was designed to combine three authentication factors in one system, including a password, a secure token (that stores a private key) and biometrics. In a formal model, Pointcheval and Zimmer formally proved that an attacker had to break all three factors to win. However, the formal model only considers the threat that an attacker may impersonate the client; it however does not discuss what will happen if the attacker impersonates the server. We fill the gap by analyzing the case of the server impersonation, which is a realistic threat in practice. We assume that an attacker has already compromised the password, and we then present two further attacks: in the first attack, an attacker is able to steal a fresh biometric sample from the victim without being noticed; in the second attack, he can discover the victim's private key based on the Chinese Remainder theorem. Both attacks have been experimentally verified. In summary, an attacker actually only needs to compromise a single password factor in order to break the entire system. We also discuss the deficiencies in the Pointcheval-Zimmer formal model and countermeasures to our attacks.

Field of study: Computer science, Mathematics
Status Quo, Technical Difficulties and Development Tendency of Helicopter Live-line Maintenance

This article briefly reviews the beginning and development progress of helicopter live-line maintenance in the world,introduces the relevant research and test,the classification of its technologies and their respective features and discusses the key points which should be resolved in practice.The operational model of business is also introduced.At the end,the cost and advantages of it is analyzed compared with the conventional maintenance method.

Field of study: Engineering, Physics
Privacy and Reader-first Authentication in Vaudenay's RFID Model with Temporary State Disclosure

Privacy and mutual authentication under corruption with temporary state disclosure are two significant requirements for real-life applications of RFID schemes. No RFID scheme is known so far to meet these two requirements. In this paper we propose two practical RFID schemes that fill this gap. The first one achieves destructive privacy, while the second one narrow destructive privacy, in Vaudenay’s model with temporary state disclosure. Both of them provide mutual (reader-first) authentication. In order to achieve these privacy levels we use Physically Unclonable Functions (PUFs) to assure that the internal secret of the tag remains hidden against an adversary with invasive capabilities. Our first RFID scheme cannot be desynchronized for more than one step, while the second one avoids the use of random generators on tags. Detailed security and privacy proofs are provided.

Field of study: Computer science, Mathematics
Biochemical and pharmacological neutralization of Indian saw-scaled viper snake venom by Canthium parviflorum extracts

Canthium parviflorum, a traditional plant used for the treatment of snake bites, was explored for its ability to neutralize saw-scaled viper venom effects. Anti-venom potential of the plant against the venom was evaluated by in vitro and in vivo methods. Ethyl acetate and methanol root extracts inhibited 5 ́-nucleotidase, phospholipase A2, phosphodiesterase, hyaluronidase, phosphomonoesterase and methanol extract inhibited protease enzyme activities with varying IC50 values. The methanol extract was found to be very effective in neutralizing the pharmacological effect induced by venoms such as procoagulant and fibrinogenolytic activities. Furthermore, direct and indirect hemolytic activities induced by the venom were significantly neutralized by the methanol extract. C. parviflorum methanol extract effectively neutralized lethal toxicity and hemorrhage induced by the venomin mice and chick embryo models. The effective dose of venom lethal toxicity in chick embryo model was 1.276 mg for 2LD50 of the venom. Edema induced by venom was significantly neutralized by the methanol extract and it was also found to be neutralizing myotoxicity in mice model which was evident by a decline in serum creatine kinase and lactate dehydrogenase enzyme activities. Therefore, C. parviflorum possesses potent anti-venom activities which could potentially be used against envenomation of saw-scaled viper.

Field of study: Biology, Chemistry, Physics
An integrated assessment of the global virtual water trade network of energy

The global trade of energy allows for the distribution of the world’s collective energy resources and, therefore, an increase in energy access. However, this network of trade also generates a network of virtually traded resources that have been used to produce energy commodities. An integrated database of energy trade water footprints is necessary to capture interrelated energy and water concerns of a globalized economy,and is also motivated by current climate and population trends. Here, we quantify and present the virtual water embedded in energy trade across the globe from 2012 to 2018, building on previous water footprinting and energy virtual water trade studies to create an integrated database. We use data from the United Nations Comtrade database and combine several literature estimates of water consumption of energy commodities to generate the global virtual water trade network. Results include a comprehensive database of virtual water trade for energy at the country level, greatly expanding the literature availability on virtual water trade. The total volume of virtual water trade increased 35% from 157 km3 in 2012 to 211 km3 in 2018. The global trade of oil and fuelwood are consistent drivers of virtual water trade over time, whereas coal, hydrocarbons, and charcoal collectively contribute less than 4% of total virtual water trade between 2012 and 2018. Electricity, despite a less dense trade network constrained by infrastructure, contributes notably to virtual water trade, driven largely by water use for hydroelectricity. This study develops an integrated assessment of previous virtual water studies to estimate global virtual water trade of energy, creating a platform for future global studies.

Field of study: Environmental science
Conceptual design of a magnetic bottle for positron containment

Magnetic confinement of positrons has been achieved in small scales, and the key to achieve better confinement is the design of compact and cost-efficient high field superconducting magnets. The paper describes a general algorithm to optimize a magnet design to match a pre-specified magnetic field profile needed to achieve confinement. The numerical model is used to calculate magnetic field, forces, and inductance for the superconducting magnetic bottle (magnetic mirror) based on simple solenoidal configurations. The model incorporates magnet stability and quench constraints in order to arrive at a feasible optimum design. A preliminary design for an experimental facility is presented.

Field of study: Physics
Characterization method of IGBT comprehensive health index based on online status data

IGBT has multiple degradation mechanisms. The existing methods using a single characterization parameter cannot characterize the comprehensive health status of the device, but multiple characterization parameters cannot quantify and intuitively reflect the comprehensive health level. Therefore, this paper proposes a characterization method of IGBT comprehensive health index (CHI) based on online status data of aging life experiment. Different parameters contain different degradation information. By extracting and fusing effective information and eliminating overlapping and invalid information from multiple parameters, the obtained CHI is used to characterize the health level. The main steps are as follows: (1) Determining the sensitive degradation parameters; (2) Using the physical model method for feature selection; (3) Using the data-driven method for feature extraction; (4) Performing feature fusion and obtaining the CHI. The online state data of the IGBT aging life experiment provided by NASA were used to verify the algorithm, and the results proved that the method of feature extraction and fusion can more accurately characterize the comprehensive health status of the device. Based on this work, it is proved that extracting and fusing effective information from features is a valuable technique.

Field of study: Engineering
Iron Compounds in Lake Sediments

Dried surface sediment from various Canadian lakes was characterized by X-ray diffraction and Mossbauer spectroscopy. At most two quadrupole doublets were found at room temperature, one ferrous, the other largely ferric. Their intensity ratio is related to the crystallinity of the sediments. It is also correlated with oxygen content, and inversely correlated with ferrous iron content of the overlying water. The major iron phase in the sediments is X-ray amorphous ferric hydroxide. Chlorite is the major ferrous mineral.

Field of study: Environmental science
Influenza H1N1 surveillance and analysis of genetic characteristics of predominant strains in Quanzhou during 2009

To investigate the influenza H1N1 virus surveillance of 2009 in Quanzhou,and analyze the HA and NA gene of influenza H1N1 virus, explore its genetic variation and molecular characteristics.  During the influenza H1N1 virus surveillance in Quanzhou,specimens of throat swabs from the patients with influenza were collected, and detected by real-time RT-PCR. Viruses were isolated with MDCK cells and identified with serological test. Two influenza virus isolates were extracted, and their HA and NA genes were amplified by RT-PCR. The purified PCR products were sequenced. The data obtained were analyzed with the software DNAMAN.  Of 1020, influenza H1N1 virus RNA was detected in 200 specimens, seasonal influenza virus RNA was detected in 70 specimens. A total of 29 influenza A H1N1 virus strains were isolated. The nucleotide homology in the HA gene was highly homologous with that of pandemic influenza virus in North America. The amino acids sequences deduced from the nucleotide sequences in HA region of the isolated strain had 22 variations compared with A/Brisbane/59/2007 vaccine strain recommend by WHO,the characteristics of α2,6 sialic acid receptor binding remained. The analysis of amino acids sequences of NA indicated that this virus possessed Oseltamivir sensitivity.  The causative influenza H1N1 strains in Quanzhou is highly homologous with that of pandemic influenza in North America, and it is antigenically and genetically different from the vaccine strain. 
 
 
H1N1 influenza virus;  Real-time RT-PCR;  Sequence analysis

Field of study: Biology