bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on properties of porous SiO2/GO modified polyurethane coatings loaded with corrosion inhibitor
Authors: Yan Ran , Xue Bing , Wang Can , Zhang Huayuan , Yue Yongyong , Luo Jing
Published: February 2022

Polyurethane (PU) coating can provide physical barrier for metal surface, but the penetration of corrosive ions will affect the long-term corrosion resistance of the coating. In order to improve the corrosion resistance of the coating, it is necessary to modify the coating to reduce the internal defects of the coating and improve the corrosion resistance of the coating. Using mesoporous silica (SiO2) as the carrier to support the corrosion inhibitor 2- mercaptobenzimidazole (MBI), and using the silane coupling agent GPTS as the bridging agent to compound with graphene oxide (GO) to prepare f-GO-MBI @SiO2 composite nano-materials, f-GO-MBI @SiO2 composite nano-materials are added to the polyurethane varnish in different proportions, and the f-GO-MBI @SiO2 modified PU coating is obtained on the surface of carbon steel by spraying method to improve the carbon corrosion resistance of steel substrate. The composition and loading conditions of drug-loaded composite nanomaterials were characterized by fourier infrared spectroscopy (FTIR) and laser particle size analyzer; electrochemical impedance spectroscopy (EIS) and neutral salt spray test were used to study the properties of different coatings corrosion resistance. The results shows that the addition of f-GO-MBI @SiO2 composite nano-materials significantly improves the corrosion resistance of the coating, the low addition amount will reduce the anti-corrosion effect, and the addition of too high can easily lead to agglomeration of composite nano-materials and produce paint film defects. When the addition amount of f-GO-MBI @SiO2 is 5 wt%, the low-frequency impedance of the coating is two orders of magnitude higher than that of the pure polyurethane coating, the corrosion spread width at the neutral salt spray scratches is reduced to 1.5 mm, and the coating has the best corrosion resistance.
Study on the Time-dependent Rheological Properties of AlSi4Mg2 Alloy
Authors: Ju Liping , Guan Yanlong , Luo Hongchao
Published: February 2022

The time-dependent behaviour of AlSi4Mg2 alloy has been investigated with the ICF model. It shows that the apparent viscosity increases with decreasing the shearing time and increasing the resting time, especially at the initial stage. The above variations depend on its microstructure affected by solid volume fraction and shear rate, respectively. It is found that the agglomerating time is about 100 times as long as the deagglomerating time, which agrees with the experiment data.
Battery State Estimation based on Dual Extended Kalman Filtering with Fixed Step
Authors: Zang Weihong , Wang Facheng , Li Zhonghua , Zhou Wei
Published: February 2022

With the rapid popularization of new energy vehicles, users pursue reliable mileage as well as stable and efficient power battery charging and discharging performance, which puts forward higher requirements for on-board battery management system (BMS). Realizing online update of battery model parameters and accurate estimation of charged state has also become one of the key technical problems in the field of new energy vehicles at present. In this paper, based on the second-order resistor-capacitor (RC) equivalent circuit model, multiple parameters in the voltage relaxation stage were obtained through the curve relationship between open circuit voltage and state of charge, and the fast time-varying parameters were converted into parameters of different step sizes. An estimation model of state of charge based on fixed step Kalman Filtering algorithm was built by Simulink to realize online estimation of battery parameters and state of charge estimation. In this paper, a kind of ternary lithium battery was selected to establish data sets and test, which verified good robustness and high accuracy of the model.
Levitt’s CO breath test in the differential diagnosis of chronic isolated hyperbilirubinemia
Authors: Kang Ling-Ling , Liu Ze-Lin , Han Quan-Sheng , Chen Yuan-Wu , Liu Ling-Wen , Xie Xian-Hui , Luo Jun-Feng , Ji Yong-Qiang , Zhu Guo-Liang , Ma Yong-Jian , Ji Kun-Mei , Zhang Hou-De
Published: February 2022

A key component of the differential diagnosis of isolated hyperbilirubinemia (HB) is distinguishing between hemolytic and non-hemolytic types. Routine hemolysis screening markers have unsatisfactory sensitivity and specificity. Erythrocyte (RBC) lifespan shortening, the gold standard marker of hemolysis, is seldomly measured due to the cumbersome and protracted nature of standard methods. A new Levitt’s CO breath test method may enable simple, rapid RBC lifespan measurement. In this pilot prospective diagnostic study, Levitt’s CO breath test was evaluated to discriminate hemolytic from non-hemolytic HB in adults. One hundred and thirty eligible non-smoking adult patients who were aged 18 or older, referred for chronic (>6 months) isolated HB or had a known diagnosis of isolated HB of a rare cause, were recruited, including 77 with non-hemolytic HB and 53 with hemolytic HB. ROC curve analysis was applied to determine the optimal cutoff for discriminating between hemolytic and non-hemolytic HB, and the performance was calculated. Results showed that the mean RBC lifespan in non-hemolytic HB (93 ± 26 d) was reduced (p = 0.001 vs. normal reference value of 126 d), but longer than that in hemolytic HB (36 ± 17 d; p = 0.001). RBC lifespans did not differ significantly between 26 patients with simple hemolytic HB (32 ± 14 d) and 27 patients with a Gilbert syndrome comorbidity (40 ± 18 d). ROC curve analysis revealed an optimal lifespan cutoff for discriminating between hemolytic and non-hemolytic HB of 60 d (AUC = 0.982), with a diagnostic accuracy of 95.4%, 94.3% sensitivity and 96.1% specificity respectively. These results indicate that Levitt’s CO breath test seems to be very sensitive and specific for detecting hemolysis in adult patients with chronic isolated HB, and could enable simple, rapid, and reliable differential diagnosis of isolated HB. A large-scale validation study of the method is warranted.
Utilization of Shoot Multiplication Medium for In-Vitro Conservation of Vanda tricolor
Authors: Rineksane I A , Alifianindya N D , Samidjo G S
Published: February 2022

Vanda tricolor is an orchid endemic to Mount Merapi in Yogyakarta Indonesia, whose existence is threatened due to the eruption and exploitation of its original habitat. This orchid conservation effort can be done through in vitro culture. Multiplication is one of the in vitro culture techniques used for propagation of the Vanda tricolor orchid by growing explants on various types of multiplication medium. This study aims to determine the effect of medium types on the multiplication of Vanda tricolor orchids. The method used in this research is a laboratory research method prepared with a completely randomized design, with the treatment of the growth medium consisting of 5 types, namely New Dogashima Medium, Murashige and Skoog, Vacint and Went, leaf fertilizer and liquid organic fertilizer medium. All mediums were supplemented with 150 ml / l coconut water, 150 g / l banana extract, and 0.2 g / l activated charcoal. Each treatment was repeated 3 times, each replication consisted of 3 samples. The results showed that liquid organic fertilizer medium is the best medium for multiplication of Vanda tricolor orchids as indicated by the addition of the shoots.
The Yield of M7 Mentik Wangi Rice Irradiated With Several Doses of Gamma Rays Under Drought Stress
Authors: Puspitasari H M , Kurniasih B , Indradewa D
Published: February 2022

The possible risk of yield losses due to drought stress could threaten rice production and national food security. One way to deal with drought limitations is by developing drought- tolerant varieties using gamma-ray irradiation. This research aimed to get the optimal dose of gamma-ray radiation to create an M7 generation of Mentik Wangi variety that is drought tolerant. Field experiments were conducted from December 2020 to March 2021 at the Screen House of the Faculty of Agriculture, Universitas Sebelas Maret, Surakarta, the Laboratory of Soil Physics, and the Laboratory of Plant Production Management, Faculty of Agriculture, Universitas Gadjah Mada. This study has carried out using a Randomized Complete Block Design with two factors. The first factor is gamma-ray irradiation dose (0gy. 100gy, 200gy, 300gy), and the second factor is drought stress treatment (without drought stress and drought stress in the flowering stage) with three replications. The results showed no interaction between gamma-ray irradiation dose and drought stress on all observed variables except plant dry matter. Drought stress in the flowering stage increased the percentage of unfilled grain, reducing the harvest index and grain weight significantly by 40.9%. Gamma-ray irradiation in a range of 100 to 300 gy did not affect panicle numbers and length, also the percentage of unfilled grain, but reduced the number of grains per panicle, thereby reducing the harvest index and grain weight 45.0% compared to those without irradiation.
Application of Intermittent Irrigation to Improve Growth and Yield of Various Rice Varieties (Oryza sativa L.)
Authors: Isnawan B H , Hidayat T , Ansori A S
Published: February 2022

Intermittent irrigation can save water use in rice cultivation, which is essential, especially during the dry season. This study aims to improve the physiology of the growth and yield of rice in various varieties by applying intermittent irrigation. The research was conducted from February to June 2019 in the experimental field of the Faculty of Agriculture, Universitas Muhammadiyah Yogyakarta. The research used a factorial experimental method 3 x 4 strip plots arranged in a Completely Randomized Block Design with three replications. The factor I rice varieties consist ofCempo Merah, Inpari23,Sintanur,andInpari42. Factor II is the irrigation system consisting of continuous flooding, ten days of inundation, five days of drying, seven days of inundation, and three days of drying. There is an interaction between types of irrigation and rice varieties on the number of tillers. In Ten-day watering five-day drying,SintanurandInpari42 variety produce more tillers thanInpari23. On Seven days watering five-day drying, theInpari42 variety produces more tillers thanInpari23. There are the differences in the responses of various rice varieties to the Specific Leaf Weight and yield. Specific Leaf Weight riceCempo Merahvarieties are higher than,Inpari23,SintanurandInpari42. Rice yield ofInpari42 variety is higher thanCempo Merah, Inpari23, andSintanurvarieties. Roots with watering seven days watering, three days of drying is longer than Ten-day watering five-day drying. Roots with watering Ten-day watering five-day drying is longer than conventional.
The Effect of Antiviral Ribavirin, Explant Size, Varieties on Growth and Development in Potato Meristematic
Authors: Karjadi A K , Karjadi  , Gunaeni N
Published: February 2022

Potato (Solanum tuberosum L) is included in the genus Solanaceae, which were propagated by vegetative through tubers. Viral systemic disease is an important seed-borne disease, with tissue culture technique combined with explant size, added antiviral Ribavirin, could be used for eliminated diseases in growth and development. The aim of this study was to determine the effect of antiviral Ribavirin concentrations, explant size and varieties on growth and development of meristematic. The treatment was concentration antiviral Ribavirin (0, 15, 20 mg/l), in MS media, explants size (meristems, shoot tips), varieties (Granola, Medians, Atlantic). The research was conducted from March to September 2019 in the IVEGRI tissue culture laboratory. The results were concluded as follow 1). the percentage of explant shoot tip contamination were higher than the meristem. 2) the average number of shoots, nodes and roots per plantlet from the treatment of varieties, explant size and the added of antiviral Ribavirin has an effect, where the average number of shoot tips were higher than the meristem. 3) The percentage of plantlets abnormal up to 12 WAP was 20 to 50%. 4) The results of the serology DAS ELISA test for both varieties, the added of antiviral Ribavirin and explant meristem has been decreased the number of PLRV infected.
Land Suitability Re-evaluation for Fruit Crops in the Post-Eruption Merapi 2010
Authors: Aini L N , Isnawan B H , Hanudin E
Published: February 2022

The Mt. Merapi eruption in 2010 devastated the economic and ecological conditions in the affected areas. However, the volcanic material from the eruption has a positive impact on land rejuvenation, due to the addition of weatherable minerals which are rich in nutrients for plants. This study aims to re-evaluate the land suitability of the areas affected by the 2010 Merapi eruption for fruit crops. The research was conducted at 7 areas (Kaliadem, Kinahrejo, Jambu, Petung, Ngepringan, Pager Jurang, and Gadingan) based on the volcanic material distribution map. The selected commodities and will be developed are based on the existence of fruits that grew in this area before the eruption, namely jackfruit, avocado, banana, and arabica coffee. The results of this study indicate that land that has been affected by the Merapi eruption is classified as unsuitable for the proposed commodity with the main limiting factor being low nutrient and water retention, in addition to the upper slope area there are additional slope limiting factors. However, this area still has the opportunity to be developed because it is rich in "weatherable minerals" which can be a source of nutrients for plants. Amendment materials that can increase nutrient and water retention and accelerate the release of nutrients from rocks need to be provided, such as compost rich in organic acids.
Extending the Shelf Life of Curly Red Chili (Capsicum annuum) Using KMnO4
Authors: Widyastuti T , Gahayu R
Published: February 2022

Curly Red Chili have a shelf life of only a few days. In order to be more durable, post-harvest handling is needed to extend the shelf life of the fruit, among others, by reducing the ethylene content. There are several ways to reduce the ethylene content; one can use potassium permanganate (KMnO4), which works as an ethylene absorber. The purpose of this study was to determine the appropriate concentration of KMnO4to extend the shelf life of Curly Red Chili. The research was conducted at the Post-Harvest Laboratory, Faculty of Agriculture, Universitas Muhammadiayah Yogyakarta. The research was arranged in Completely Randomized Design (CRD) with a single factor. Treatment including four concentrations, that is: KMnO40%, KMnO40.05%, KMnO40.10%, KMnO40.15%. Each treatment was repeated three times, each replicating three samples. The data were analyzed using variance analysis at the 5% level and mean separations with Duncan's Multiple Range Test at the 5% level. The results showed that KMnO4has a positive effect of extending the shelf life of Curly Red Chili, where the KMnO4concentration of 0.10% is the best. At this concentration, the shelf life of Curly Red Chili can be extended up to 21 days.
Diversity of Natural Enemies in Corn - Soybean Intercropping with Different Plant Compositions
Authors: Lisdayanti H , Nurkomar I
Published: February 2022

Intercropping is one of the polyculture crop cultivation techniques. Polyculture cropping system can increase the diversity of insects. This research aims to determine the effect of different plant composition of soybean and corn on the diversity and abundance of natural enemies. This research was carried out using a single factor experimental method arranged in a single plot field design. The treatment tested was the plant composition of soybean and corn which consisted of 4 compositions setting as treatment i.e., 2:1, 3:1. 4:1 and 5:1. In addition, monoculture soybeans and monoculture corn were also planted for comparison. Observation and sampling of natural enemies were carried out using insect sweeping net, yellow pan trap, and pitfall trap. Samplings were done 7 times when the plant at 2, 3, 4, 6, 8, 10, and 12 weeks old. The results showed that the plant composition of soybean and corn affected the number of species and abundance of insect natural enemies. Nonmetric multidimensional scale analysis shows that there are less differences in the composition of insect natural enemies between different plant compositions.
Stress–strain behavior of rock mass around the roadway with roof support of rock fall-hazardous zones by the phenolic resin fill
Authors: Seryakov VM , Krasnovsky AA
Published: February 2022

The authors discuss roadway heading and support in unstable rock mass. The stress–strain analysis is performed for rocks and mine support system when voids generated by rock falls in roof and sidewalls of a roadway are filled with phenolic resin. The change in the stresses when the zone of rock fall-hazardous zone in the roadway roof grows in height is shown.
Impact of conditions of coal supply to hard-to-reach northern areas on its useful properties
Authors: Fedorov VI , Gavrilov VL , Khokholov YuA
Published: February 2022

Hard-to-reach northern areas of Russia are supplied with coal via complex and extended delivery chains. Long-term storage and large haulage distances between the coal production sites and the heat power generation points result in degradation of useful properties of coal and its high quantitative losses. The authors discuss the causes of change in the fuel quality as it travels from production faces to boiler-houses, as the consequences of lower quality fuel burning. The current approaches to alteration of coal properties are reviewed. The influence of oxidation and cryogenic effects is analyzed. Assuming the delivery chains as the integrated systems in blocks and their performance evaluation by the final result allows disengaging new reserves in quality management. An element of the refreshed quality management can be technological and managerial procedures in open pit coal mining and in pre-treatment of coal before shipment.
Improvement of air distribution in DTH air hammer
Authors: Alekseev SE , Kubanychbek B , Chernienkov EM
Published: February 2022

Advancement trends in DTH air hammer engineering are described, and the modern design requirements are presented. The schematic of DTH air hammer to comply with the current standards is given. Reliability of the machine with three-stage hammering unit is discussed. The process of bottomhole cleaning in this DTH air hammer operation is described. The capacities of an elastic valve arrangement at the largest stage of the hammering unit are determined. The theoretical and full-scale test data of the proposed DTH air hammer design are presented.
Polyethylene pipe socket welding technology in mining
Authors: Ammosova OA
Published: February 2022

The proposed technology of polyethylene pipe socket welding can be used in construction of polyethylene piping systems in the mining industry. Based on numerical simulation of thermal process, the effect of low temperatures on the temperature field dynamics in socket weld joint is investigated. The need of preheating and usage of thermal insulation at the cooling stage during welding at low temperatures for the thermal process to develop according to the patterns of welding at acceptable temperatures is shown. A procedure is given for determining the size of a heat-insulating chamber for cooling a welded socket joint at low temperatures from the condition of ensuring the cooling rate characteristic of welding at permissible temperatures.
Experimental studies of pneumatic impact device with a reduced specific consumption air
Authors: Tambovtsev PN
Published: February 2022

The article presents the results of experimental studies of a pneumatic impact device the air distribution system of which has two controlled chambers of compressed air and four valves. The peculiarity of the pneumatic impact device is its efficient operating cycle with a reduced specific consumption of compressed air. The operating cycle of a laboratory prototype was investigated and its main operating parameters were determined: the frequency and energy of impacts, the compressed air consumption. The experimental specific consumption of compressed air is established, a comparative analysis of the results of experiments with the results of numerical simulation is carried out.
Means of providing temperature regimes for extended transport tunnels of the Baikal-Amur Railway in the cold period of the year
Authors: Kiyanitsa LA , Lugin IV , Krasyuk AM
Published: February 2022

The paper presents the results of studying the distribution of air temperature along the length of an extended railway tunnel depending on various configurations and locations of tunnel heating and ventilation units. It is shown that the most rational way is the uniform arrangement of heating and ventilation units along the length of the tunnel combined with the installation of air-thermal curtains. This allows ensuring a positive air temperature in all sections along the length of the tunnel.
Mathematical modeling of air distribution dynamics due to piston effect of trains in long railway tunnels
Authors: Lugin IV
Published: February 2022

The stationary and nonstationary problems on air flow under piston effect of trains in long railway tunnels are solved using the methods of computational aerodynamics. The comparison of the results reveals erroneous calculation of air exchange in case of the stationary problem formulation. The validity of calculating tunnel ventilation by integration of the static air distribution network models and the quasi-dynamic models of piston effect is justified.
On the question of using natural zeolites to increase the environmental safety of mining regions
Authors: Razmakhnin KK
Published: February 2022

The possibility of using natural zeolites in technologies for protecting the components of the natural environment during the operation of mining enterprises has been investigated. The issues of complex processing of zeolite-containing rocks have been studied. The most effective technologies for enrichment of zeolites, modification and activation of their properties, as well as purification from enclosing impurities have been determined and substantiated. The main parameters of the application of the proposed technologies for enrichment of zeolite-containing rocks have been established. The results of experimental studies of the processing of natural zeolite rocks using various enrichment methods are presented. The main directions of the use of natural zeolites in order to ensure the comprehensive environmental safety of mining enterprises have been determined.
Change in the elastic and rheological properties of structurally heterogeneous geomaterials under multiple weak impacts
Authors: Kosykh VP
Published: February 2022

The paper discusses the lab-scale studies of the effect exerted by multiple weak impacts on creep in a sample of an equivalent geomaterial additionally subjected to static compression. It is found that under weak impacts for a long time, the creep strain rate first grows and then lowers down to a stationary value. Weak impacts initiate P-waves in the sample. The P-wave velocity increases non-monotonously with growing number of impacts. The change in the elastic and rheological properties of the material is connected with the change in its internal structure under the influence of external loading.
Enhancement of a silicon waveguide single photon source by temporal multiplexing
Authors: Adcock Jeremy C , Bacco Davide , Ding Yunhong
Published: February 2022

Efficient generation of single photons is one of the key challenges of building photonic quantum technology, such as quantum computers and long-distance quantum networks. Photon source multiplexing—where successful pair generation is heralded by the detection of one of the photons, and its partner is routed to a single mode output—has long been known to offer a concrete solution, with output probability tending toward unity as loss is reduced. Here, we present a temporally multiplexed integrated single photon source based on a silicon waveguide and a low-loss fibre switch and loop architecture, which achieves enhancement of the single photon output probability of 4.5 ± 0.5, while retaining g
(2)(0) = 0.01.
Broadband absorbing mono, blended and hybrid nanofluids for direct absorption solar collector: a comprehensive review
Authors: Sreekumar Sreehari , Shah Nihilkumar , Mondol Jayanta Deb , Hewitt Neil , Chakrabarti Supriya
Published: February 2022

The evolution of nanofluids over the years has opened new research opportunities in the field of renewable energy. Research on the optical properties of nanofluids for application in direct absorption solar collectors (DASCs) is progressing at a burgeoning speed. In a DASC system, nanofluid with high optical absorptivity can convert the incident solar energy into the thermal energy of the fluid. The dispersed nanoparticles in the fluid act in the process through the phenomenon of absorption and scattering. Studies conducted on the optical property characterization of monocomponent nanofluids have become saturated. Moreover, the photothermal efficiency (PTE) of the nanofluid can be enhanced by using multicomponent nanofluids. Nanofluids prepared using varying materials, shapes and sizes of nanoparticles can tune the absorption spectra of the bulk fluid to improve the PTE. A hybrid nanocomposite can similarly enhance the absorptivity due to the synergy of materials present in the nanocomposite particle. In this review, a comprehensive survey on the synthesis and optical characterization of different monocomponent, blended and hybrid nanocomposite nanofluids has been performed.
A methodology for formulating dynamical equations in analytical mechanics based on the principle of energy conservation
Authors: Zhou Yinqiu , Wang Xiuming
Published: February 2022

In this work, a methodology is proposed for formulating general dynamical equations in mechanics under the umbrella of the principle of energy conservation. It is shown that Lagrange’s equation, Hamilton’s canonical equations, and Hamilton-Jacobi’s equation are all formulated based on the principle of energy conservation with a simple energy conservation equation, i.e., the rate of kinetic and potential energy with time is equal to the rate of work with time done by external forces; while D’Alembert’s principle is a special case of the law of the conservation of energy, with either the virtual displacements (‘frozen’ time) or the virtual displacement (‘frozen’ generalized coordinates). It is argued that all of the formulations for characterizing the dynamical behaviors of a system can be derived from the principle of energy conservation, and the principle of energy conservation is an underlying guide for constructing mechanics in a broad sense. The proposed methodology provides an efficient way to tackle the dynamical problems in general mechanics, including dissipation continuum systems, especially for those with multi-physical field interactions and couplings. It is pointed out that, on the contrary to the classical analytical mechanics, especially to existing Hamiltonian mechanics, the physics essences of Hamilton’s variational principle, Lagrange’s equation, and the Newtonian second law of motion, including their derivatives such as momentum and angular momentum conservations, are the consequences of the law of conservation of energy. In addition, our proposed methodology is easier to understand with clear physical meanings and can be used for explaining the existing mechanical principles or theorems. Finally, as an application example, the methodology is applied in fluid mechanics to derive Cauchy’s first law of motion.
Ferroelectric memory based on two-dimensional materials for neuromorphic computing
Authors: Chen Li , Pam Mei Er , Li Sifan , Ang Kah-Wee
Published: February 2022

Ferroelectric memory devices with fast-switching speed and ultra-low power consumption have been recognized as promising building blocks for brain-like neuromorphic computing. In particular, ferroelectric memories based on 2D materials are attracting increasing research interest in recent years due to their unique properties that are unattainable in conventional materials. Specifically, the atomically thin 2D materials with tunable electronic properties coupled with the high compatibility with existing complementary metal-oxide-semiconductor technology manifests their potential for extending state-of-the-art ferroelectric memory technology into atomic-thin scale. Besides, the discovery of 2D materials with ferroelectricity shows the potential to realize functional devices with novel structures. This review will highlight the recent progress in ferroelectric memory devices based on 2D materials for neuromorphic computing. The merits of such devices and the range of 2D ferroelectrics being explored to date are reviewed and discussed, which include two- and three-terminal ferroelectric synaptic devices based on 2D materials platform. Finally, current developments and remaining challenges in achieving high-performance 2D ferroelectric synapses are discussed.
A finite element elasticity complex in three dimensions
Authors: Chen Long , Huang Xuehai
Published: February 2022

A finite element elasticity complex on tetrahedral meshes and the corresponding commutative diagram are devised. The

H
1

H^1

conforming finite element is the finite element developed by Neilan for the velocity field in a discrete Stokes complex. The symmetric div-conforming finite element is the Hu-Zhang element for stress tensors. The construction of an

H
(
inc
)

H(\operatorname {inc})

-conforming finite element of minimum polynomial degree

6
6

for symmetric tensors is the focus of this paper. Our construction appears to be the first

H
(
inc
)

H(\operatorname {inc})

-conforming finite elements on tetrahedral meshes without further splitting. The key tools of the construction are the decomposition of polynomial tensor spaces and the characterization of the trace of the

inc
\operatorname {inc}

operator. The polynomial elasticity complex and Koszul elasticity complex are created to derive the decomposition. The trace of the

inc
\operatorname {inc}

operator is induced from a Green’s identity. Trace complexes and bubble complexes are also derived to facilitate the construction. Two-dimensional smooth finite element Hessian complex and

div
⁡
div

\operatorname {div}\operatorname {div}

complex are constructed.
Spun normal surfaces in 3-manifolds III: Boundary slopes
Authors: Kang E. , Rubinstein J.
Published: February 2022

Spun normal surfaces are a useful way of representing proper essential surfaces, using ideal triangulations for 3-manifolds with tori and Klein bottle boundaries. In this paper, we consider spinning essential surfaces in an irreducibleP2P^2-irreducible, anannular, atoroidal 3-manifold with tori and Klein bottle boundary components. We can assume that such a 3-manifold is equipped with an ideal 1-efficient triangulation. In particular, we prove that for a given choice of a set of boundary slopes for a proper essential surface, there is a set of essential vertex solutions for the projective solution space at these boundary slopes, answering a question of Dunfield and Garoufalidis [Trans. Amer. Math. Soc. 364 (2012), pp. 6109–6137], so long as the slopes are not of a fiber of a bundle structure.
Hyperbolic knots given by positive braids with at least two full twists
Authors: de Paiva Thiago
Published: February 2022

We give some conditions on positive braids with at least two full twists that ensure their closure is a hyperbolic knot, with applications to the geometric classification of T-links, arising from dynamics, and twisted torus knots.
A vanishing theorem for the Mathai-Zhang index
Authors: Zhang Xin
Published: February 2022

We establish a vanishing theorem for spin manifolds admitting proper cocompact Lie group actions. To be more precise, when the connected component of the identity element in the action group is non-unimodular, we prove that the Mathai-Zhang index [Adv. Math. 225 (2010), pp. 1224–1247] vanishes.
Diffraction by a Dirichlet right angle on a discrete planar lattice
Authors: Shanin A. , Korolkov A.
Published: February 2022

A problem of scattering by a Dirichlet right angle on a discrete square lattice is studied. The waves are governed by a discrete Helmholtz equation. The solution is looked for in the form of the Sommerfeld integral. The Sommerfeld transformant of the field is built as an algebraic function. The paper is a continuation of the work by A. V. Shanin and A. I. Korolkov, Sommerfeld-type integrals for discrete diffraction problems, Wave Motion 97 (2020).
On a version of the slicing problem for the surface area of convex bodies
Authors: Brazitikos Silouanos , Liakopoulos Dimitris-Marios
Published: February 2022

We study the slicing inequality for the surface area instead of volume. This is the question whether there exists a constant

α
n

\alpha _n

depending (or not) on the dimension

n
n

so that
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper S left-parenthesis upper K right-parenthesis less-than-or-slanted-equals alpha Subscript n Baseline StartAbsoluteValue upper K EndAbsoluteValue Superscript StartFraction 1 Over n EndFraction Baseline max Underscript xi element-of upper S Superscript n minus 1 Baseline Endscripts upper S left-parenthesis upper K intersection xi Superscript up-tack Baseline right-parenthesis comma">

S
(
K
)
⩽

α
n

|

K

|

1
n

max

ξ
∈

S

n
−
1

S
(
K
∩

ξ

⊥

)
,

\begin{equation*} S(K)\leqslant \alpha _n|K|^{\frac {1}{n}}\max _{\xi \in S^{n-1}}S(K\cap \xi ^{\perp }), \end{equation*}

where

S
S

denotes surface area and

|

⋅

|

|\cdot |

denotes volume. For any fixed dimension we provide a negative answer to this question, as well as to a weaker version in which sections are replaced by projections onto hyperplanes. We also study the same problem for sections and projections of lower dimension and for all the quermassintegrals of a convex body. Starting from these questions, we also introduce a number of natural parameters relating volume and surface area, and provide optimal upper and lower bounds for them. Finally, we show that, in contrast to the previous negative results, a variant of the problem which arises naturally from the surface area version of the equivalence of the isomorphic Busemann–Petty problem with the slicing problem has an affirmative answer.
Temporal Associations Between Daytime Napping and Nocturnal Sleep: An Exploration of Random Slopes
Authors: Mead Michael P , Huynh Phat , Le Trung Q , Irish Leah A
Published: February 2022

Background

Restricting daytime naps is a common sleep hygiene recommendation to improve nocturnal sleep, but research on whether napping is related to sleep is mixed. The current literature is limited in that day level, bidirectional associations have not been tested in college students, and existing studies have not sufficiently examined the role of individual differences in these daily associations.

Purpose

The current study addressed these limitations by assessing the temporal associations between self-reported daytime nap duration and objectively assessed nocturnal sleep, and whether these associations were moderated by chronotype or nap frequency, in college students.

Methods

Participants (N = 384) self-reported nap duration and wore an actiwatch to measure nocturnal sleep for 14 consecutive days and nights. Mixed linear models were used to test the daily associations between daytime nap duration and total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), and wake after sleep onset (WASO). In addition, random slope modeling was used to test whether these associations significantly varied between participants.

Results

Longer nap duration was significantly associated with greater WASO, lower SE, and longer SOL. Shorter TST, shorter WASO, and greater SE were related to longer next-day nap duration.

Conclusions

There were several significant associations between daytime napping and nocturnal sleep, and nap frequency significantly moderated the association between TST and next-day nap duration. Future research should test daily and contextual moderators of daytime napping and nocturnal sleep, which could refine sleep hygiene efforts by identifying individuals for whom recommendations would be most helpful.
North American Documentary Poetry and Poetics
Authors: Ehlers Sarah , Herd Niki
Published: February 2022

The terms documentary poetry and documentary poetics have been used to describe a diverse range of poetic projects that either make use of historical materials or narrate historical events. In the Anglophone context, the documentary poetry tradition emerged in the late 1920s and coalesced in the 1930s in conjunction with advancements in documentary film and the heightened cultural relevance of documentary photography. The term documentary was first used in an arts context by the Scottish filmmaker John Grierson in his 1926 review of Robert Flaherty’s Moana, and Grierson’s subsequent theorizations of documentary filmmaking depended on ideas about poetry and the poetic. While, as several critics have pointed out, documentary poetry constitutes a long tradition that goes as far back as the poems of Lucretius, Ovid, and Virgil, documentary poetry is largely a 20th-century construction, one that has shifted in relation to major technological changes that transformed the landscape of poetic composition and circulation, ongoing debates over the status of the poetic lyric, and developing ideas about the relationship of poetry writing to capitalist crisis and left political activism. The long-standing critical concern with defining documentary poetry and poetics indexes changing

ideas about the relationship between poetry and other historical and political registers. Such critical concerns, however, have often treated documentary poems as if they lack generic distinction or unique formal qualities outside of the incorporation of historical documents or materials. Across the 20th and 21st centuries, documentary poets have innovated in specific modes (e.g., as Jill Magi points out using Bill Nichols’s film theory, the expository, observational, interactive, and reflexive) and forms (especially the paratactical, collage, curatorial, and restricted). Engaging with the terrains of labor precarity, ecological collapse, and widening racial inequities and violence, such forms work in tandem with socially engaged content to address historical and political realities. In the contemporary moment, major contributions to documentary poetic traditions have been from Black, Indigenous, and people of color (BIPOC) writers who innovate with documentary practices and forms to imagine new spheres of social engagement and world-building in lieu of a singular focus on institutional critique. Contemporary poets addressing the exigencies of the 21st century have also emphasized the long-standing relationship between documentary poetry and social engagement, pointing to social activism and radical pedagogy as defining features of documentary poetry and poetics.
Nuns’ Writing in Colonial Mexico
Authors: Kirk Stephanie
Published: February 2022

During the colonial period in Mexico, convents and their inhabitants played a central role in society. Nuns, who lived in permanent enclosure behind convent walls, were living emblems of New World orthodoxy and of the success of the Spanish evangelization project. Subject to a repressive gender ideology and the misogyny of the Church, nuns’ lives were carefully monitored and contained. While becoming a nun represented a valid and often attractive choice for the Spanish and criolla women who were permitted to profess as nuns in convent, the Church authorities went to great lengths to ensure they followed strictly circumscribed rules regarding their daily lives and spiritual trajectories. Nuns, however, succeeded in finding a variety of ways to exercise agency and demonstrate their individuality including the writing of different types of texts. Sor Juana Inés de la Cruz (1648–1695), was both a nun and the most influential writer of her age. While the depth of her erudition and the breadth of her literary skill set her apart from other nuns, she nonetheless shared their devotion to God and their experience of convent life in colonial Mexico. While most other nuns did not always possess such great literary skills, their works stand as documents that detail women’s spirituality and the affective response this engendered in them, as well as providing evidence of their daily lives. Their writings allow us a glimpse into their worlds, in which they express their great devotion and love of God but also detail the challenges they encounter as “brides of Christ” subject to male control. The most significant genre of convent writing is the spiritual autobiography or vida. Nuns could only embark on the drafting of these texts at the instigation of and under the supervision of the male confessor. These men would reorganize and rescript them to ensure they conformed to male-defined norms of spiritual exemplarity for women. However, women’s own words show how, even while they understood the power dynamics of this relationship, they drew on rhetorical and discursive strategies to communicate their subjectivity. Nuns also wrote a variety of different texts including letters, poetry, and theater (mostly, but not exclusively, of a religious nature).
History and Culture of the Bulgarian Book
Authors: Zagorov Vasil
Published: February 2022

The concept of Bulgarian book (Balgarska Kniga) is inclusive of manuscripts and printed and digital books written and reproduced in Old Bulgarian, Middle Bulgarian, and Modern Bulgarian in the period from the 9th to the 21st centuries. Along with language, due to a number of historical circumstances related to political, cultural, and economic factors, categories of Bulgarian books also comprise literary products created in foreign languages by Bulgarians with a clear Bulgarian national consciousness. Because of the long period of existence of the Bulgarian state (681–2021) and its two periods of political dependence—the Byzantine rule (1018–1185) and the Ottoman rule (1396–1878)—historical boundaries regarding the creation, distribution, and influence of the Bulgarian book far exceed the political borders of the modern Bulgarian state. The cultural influence of the Bulgarian manuscript book can be attributed to Bulgarian rulers and high clergy who were the first to successfully apply, develop, and disseminate Glagolitic and Cyrillic written systems, thus helping to build an independent Slavic Christian culture in the Balkans and Eastern Europe. This influence accounts for the Bulgarian book’s wide distribution as early as the Middle Ages and explains its 21st-century presence in a number of foreign libraries and museums. As a material object and a cultural phenomenon, the Bulgarian book can be studied in five main periods: the manuscript book (9th–19th century); the printed book in the period of the Ottoman Empire (1508–1878); the printed book in the period from the Liberation of Bulgaria to the imposition of the socialist centralized planned model of book publishing (1878–1948); the printed book during the socialist period (1944–1989); and the book in the postsocialist period (1989–2021).
Human Rights and Activism in Theater and Performance Studies
Authors: Son Elizabeth W.
Published: February 2022

A robust body of theater and performance studies scholarship examines the interplay between human rights, activism, and performance. These works tend to focus on gross human rights violations and highlight the interplay between political action and artistic works in grappling with histories of violence such as crimes against humanity. The studies range from investigations of the protests against the “disappearance” of dissidents during the “Dirty War” in Argentina, the performative dimensions of the South African Truth Commission, water rights of Ghanaians, and communal courts trying crimes of genocide in Rwanda, to artistic works addressing Japanese military sexual slavery, among others. Central to these discussions are questions around the politics of space, embodiment, the performativity of violence and identity, the politics of memory, and the ethics of research.
Leader–Member Exchange: A Commentary on Long-Term Staying Power and Future Research Directions
Authors: Scandura Terri A. , Gower Kim
Published: February 2022

In 1975, the phrase “vertical dyad linkage” (VDL) was introduced to begin examining the quality of the roles between the leaders and direct reports, and it was soon discovered that the linkages ranged between high quality and low quality. That linkage progressed into “leader–member exchange” (LMX) in 1982. In essence, research reached a point where it found a continuum of the quality of the relationship between the two members. High-quality relationships put the employees into the leader’s “ingroup,” while low-quality relationships left employees on the outside looking in. It followed that those in the ingroup would have some say in the decision-making, would have easier access to the leader, and would garner more respect and “liking.”

Researchers have used the LMX-7 to examine how the quality of superior/subordinate relationships affects individual, interpersonal, and organization factors like job satisfaction, communication motives, and organizational identification (as did the original LMX scale). Although the LMX-7 remains one of the most prominent psychometric measures of LMX, researchers still debate whether the construct should be considered unidimensional or multidimensional.

While the intricacies of LMX-7 versus LMX have been argued, and with teams becoming more of an organizational resource, team–member exchange (TMX) was found to be a supported extension of LMX. While at this point TMX is lacking in the volume and pace of research, due to the difficulties of measurement among a group of people who might have a variety of leaders during the process, the existing research has produced some results that are extremely relevant, now and in the future. Examples of what has been found when the team exchange relationship is high include reduced stress, increased psychological empowerment, increased creativity, increased team performance, increased individual performance, increased organizational citizenship behaviors, increased organizational commitment, and increased job satisfaction, just to name a few.

In sum, the investigation into LMX provides a history of the field of LMX and its many iterations and the role it plays in leadership studies. This research includes LMX antecedents, consequences, moderators, mediators, and outcomes, as any field in which over 4,500 papers have been published needs an effective way to highlight the progress and pathways.