bluuebunny/crossref_metadata_2025 huggingface dataset:
Verbal reaction times based on tracking lip movement
Authors: Liu Qiang , Holbrook Bryan B. , Kawamoto Alan H. , Krause Peter A.
Published: March 2022

Valid and reliable measurements of response latency are crucial in testing empirical predictions across fields of
psychology. In research utilizing verbal responses, acoustic latency is the typical measure of response latency, but its validity
has been questioned. We describe a simple and affordable alternative – articulatory latency based on tracking lip position. Using
this method, we measured the acoustic and articulatory latencies of syllables beginning with various simple and complex onsets and
ending with “uh” using the speeded naming task, where participants were instructed to have their mouths either closed or open
before articulating. The initial oral configuration, place of articulation, and voicing all had significant effects on this
measure of articulatory latency across segments, factors that researchers must consider in designing experiments and selecting
stimuli.
Word order effect in collocation processing
Authors: Vilkaitė-Lozdienė Laura , Conklin Kathy
Published: March 2022

Collocations are words associated because of their frequent co-occurrence, which makes them predictable and leads to facilitated processing. While there have been suggestions that collocations are stored as unanalysed chunks, other researchers disagree. One of the arguments against holistic storage is the fact that collocations are not fixed phrases, for example, their word order can vary. To explore whether reversed collocations retain the processing advantage that they have in their canonical form, we conducted two primed lexical decision experiments: Experiment 1 in English, and Experiment 2 in Lithuanian, an understudied language. We presented both forward and backward collocations and compared them to matched control phrases. We also explored which collocational measure (phrasal frequency, MI,t-score, or ΔP) worked as the best predictor of processing speed. We found a clear priming effect for both languages when collocations were presented in their forward form, which is in line with previous research. There was no priming for the backward condition in English, but a priming effect for it in Lithuanian, where the reversed word order is acceptable albeit marked. These results are not easily explained by holistic storage. As far as collocational measures are concerned, they all seem to perform reasonably well, with none of them being clearly better than the others.
Processing lexicality in healthy aging and Alzheimer’s disease
Authors: Azevedo Nancy , Atchley Ruth Ann , Vasavan Nair N. P. , Kehayia Eva
Published: March 2022

To explore how processing lexicality may change with aging and in the presence of Alzheimer’s disease (AD), we
conducted two experiments investigating lexicality judgements using an on-line behavioural psycholinguistic methodology and
electrophysiological/event-related potential (ERP) methods; oddball lexical decision tasks. Results from these lexical decision
tasks showed that while those with AD show similar rates of accuracy for their lexical decision as compared older adults (OA),
they are particularly slowed when making judgements for pseudowords. Our results from the ERP tasks also showed that the two
groups behaved differently with regard to elicitation of the P3 ERP response, which indicates differences in how these two groups
form lexical categories. The pattern of ERP responses suggests that older adults are sensitive to the orthography/phonology of the
stimuli during the course of lexical processing as compared to participants with AD who show less sensitivity to
orthographic/phonological cues. Additionally, the ERP P3 amplitude results suggest further linguistically related differences
between healthy older adults and those with AD, and highlight the importance and usefulness of combining behavioural
psycholinguistic and ERP methodologies.
A case for velarization of Spanish word-internal coda stops as hypercorrection
Authors: Bongiovanni Silvina
Published: March 2022

In many dialects of Spanish, a word such asaceptar/aseptáɾ/ ‘to accept’ may be variably produced as [asektáɾ]. Previous research has shown that velarization patterns are the result of speakers’ sensitivity to phonotactic distributions (Brown 2006;Bongiovanni 2022). This study examines a different result of pattern generalization: hypercorrection. The production of bilabial word-internal coda stops was analyzed in a corpus of sociolinguistic interviews from Mérida, Venezuela. Variation between retained, deleted and velarized variants ([aseptáɾ], [asetáɾ] and [asektáɾ]) is constrained primarily by age and education. While velarization was the preferred variant among older speakers regardless of their educational attainment status, for the younger cohort it was speakers in the lower educational attainment group who favored it. These linguistic patterns reflect known societal changes regarding access to education in Venezuela (and therefore, contact with the standard variety) and show that under the pressure of a prescriptive rule, speakers default to a non-normative generalized pattern.
Philanthropy, Local Employment, and Environmental Audits at Ngala Private Game Reserve, South Africa
Authors: Spenceley Anna
Published: March 2022

Ngala Private Game Reserve is a safari lodge owned by the World Wide Fund for Nature – South Africa (WWF-SA) within the Kempiana Contractual National Park in South Africa. andBeyond has a 20-year lease to operate a safari lodge and tented camp, and traverse the reserve. The lodge generates benefits for local people through employment and by channelling donations through the Africa Foundation into community health, education and small business development initiatives. The lodge monitors its environmental impacts through bi-annual audits that are submitted to the Department of Environmental Affairs.

Information

Snyman, S. and Spenceley, A. (2019) Private Sector Tourism in Conservation Areas in Africa, CABI

© CAB International 2022
Creating Community Conservation Areas and Sustainable Livelihood Options at Nkwichi Lodge, Lake Malawi, Mozambique
Authors: Spenceley Anna
Published: March 2022

Nkwichi is a 14-bed lodge located on the shores of Lake Malawi. The lodge has collaborated with 16 communities to establish the 120,000 hectare Manda Wilderness Community Conservation Area of Mozambique. The lodge supports 40 permanent local employees, and represents the only formal employment available in the area. Nkwichi has facilitated a halt to hunting in the reserve, sustainable agriculture initiatives and the application of solar power for electricity.

Information

Snyman, S. and Spenceley, A. (2019) Private Sector Tourism in Conservation Areas in Africa, CABI

© CAB International 2022
The quadrupole moment of compact binaries to the fourth post-Newtonian order: II. Dimensional regularization and renormalization
Authors: Larrouturou François , Blanchet Luc , Henry Quentin , Faye Guillaume
Published: March 2022

The regularization and renormalization of the radiative mass-type quadrupole moment of inspiralling compact binaries (without spins) is investigated at the fourth post-Newtonian (4PN) approximation of general relativity. As clear from the conservative 4PN equations of motion, a dimensional regularization has to be implemented in order to properly treat the non-linear interactions experienced by gravitational waves during their propagation towards future null infinity. By implementing such procedure, we show that the poles coming from the source moment (computed in a companion paper) are exactly cancelled in the radiative moment, as expected for a physical quantity. We thus define and obtain a ‘renormalized’ source quadrupole, three-dimensional by nature, which is an important step towards the computation of the gravitational-wave flux with 4PN accuracy. Furthermore, we explicitly prove the equivalence between the dimensional regularization and the previously used Hadamard partie finie scheme up to the 3PN order.
On regularization via frame decompositions with applications in tomography
Authors: Hubmer Simon , Ramlau Ronny , Weissinger Lukas
Published: March 2022

In this paper, we consider linear ill-posed problems in Hilbert spaces and their regularization via frame decompositions, which are generalizations of the singular-value decomposition. In particular, we prove convergence for a general class of continuous regularization methods and derive convergence rates under both a priori and a posteriori parameter choice rules. Furthermore, we apply our derived results to a standard tomography problem based on the Radon transform.
Qualitative effect of internal resonance on the dynamics of two-dimensional resonator
Authors: Arora Nishta , Naik Akshay K
Published: March 2022

Nonlinear modal interactions and associated internal resonance phenomena have recently been used to demonstrate improved oscillator performance and enhanced sensing capabilities. Here, we show tunable modal interaction in a molybdenum disulfide (MoS2) resonator. We achieve the tunability of coupling between these initially uncoupled modes by using electrostatic gate voltages. This tunable coupling enables us to make the modes commensurate and observe energy exchange between the modes. We attribute the strong energy exchange between the vibrational modes to 1:2 internal resonance. This interaction strongly impacts the dynamics of the modal response of such resonators. We observe peak splitting, a signature of energy exchange between the modes even when the modal response is in the linear regime. We model our device to explain the observed effect of excitation, detuning of modal frequencies, and intermodal coupling strength on the resonator dynamics. MoS2 resonators explored in this work are ideal for understanding the rich dynamics offered through the intermodal coupling.
Valley degree of freedom in two-dimensional van der Waals materials
Authors: Soni Ashish , Pal Suman Kalyan
Published: March 2022

Layered materials can possess valleys that are indistinguishable from one another except for their momentum. These valleys are individually addressable in momentum space at the K and K′ points in the first Brillouin zone. Such valley addressability opens up the possibility of utilizing the momentum states of quasi-particles as a completely new paradigm in both quantum and classical information processing. This review focuses on the physics behind valley polarization and discusses carriers of valley degree of freedom (VDF) in layered materials. We then provide a detailed survey of simple spectroscopic techniques commonly utilized to identify and manipulate valley polarization in van der Waals layered materials. Finally, we conclude with recent developments in the manipulation of VDF for device applications and associated challenges.
Signatures of superconducting triplet pairing in Ni–Ga-bilayer junctions
Authors: Costa Andreas , Sutula Madison , Lauter Valeria , Song Jia , Fabian Jaroslav , Moodera Jagadeesh S
Published: March 2022

Ni–Ga bilayers are a versatile platform for exploring the competition between strongly antagonistic ferromagnetic and superconducting phases. We characterize the impact of this competition on the transport properties of highly-ballistic Al/Al2O3(/EuS)/Ni–Ga tunnel junctions from both experimental and theoretical points of view. While the conductance spectra of junctions comprising Ni (3 nm)–Ga (60 nm) bilayers can be well understood within the framework of earlier results, which associate the emerging main conductance maxima with the junction films’ superconducting gaps, thinner Ni (1.6 nm)–Ga (30 nm) bilayers entail completely different physics, and give rise to novel large-bias (when compared to the superconducting gap of the thin Al film as a reference) conductance-peak subseries that we term conductance shoulders. These conductance shoulders might attract considerable attention also in similar magnetic superconducting bilayer junctions, as we predict them to offer an experimentally well-accessible transport signature of superconducting triplet pairings that are induced around the interface of the Ni–Ga bilayer. We further substantiate this claim performing complementary polarized neutron reflectometry measurements on the bilayers, from which we deduce (1) a nonuniform magnetization structure in Ga in a several nanometer-thick area around the Ni–Ga boundary and can simultaneously (2) satisfactorily fit the obtained data only considering the paramagnetic Meissner response scenario. While the latter provides independent experimental evidence of induced triplet superconductivity inside the Ni–Ga bilayer, the former might serve as the first experimental hint of its potential microscopic physical origin. Finally, we introduce a simple phenomenological toy model to confirm also from the theoretical standpoint that superconducting triplet pairings around the Ni–Ga interface can indeed lead to the experimentally observed conductance shoulders, which convinces that our claims are robust and physically justified. Arranging our work in a broader context, we expect that Ni–Ga-bilayer junctions could have a strong potential for future superconducting-spintronics applications whenever an efficient engineering of triplet-pairing superconductivity is required.
Double stochastic energetic resonance of underdamped two-scale bistable system
Authors: Mao Jiangen , Lin Min , Huang Yongmei , Hu Xiaofeng
Published: March 2022

Multistable structures have abundant nonlinear characteristics, a multi-level system with large-scale and small-scale bistable structures is constructed, and its dynamic characteristic is discussed. Based on the complete Langevin equation with an inertial term and a variable damping term, the relationship between the Kramers escape rate and the damping coefficient is deduced and the approximate analytical expression of the output response in the underdamped state is established. From the view of the energy, the mechanism of double resonance and resonance effect enhancement induced by damping is further revealed with the energy dissipation caused by damping as the core. The physical quantity work is introduced to measure the strength of the resonance effect. The results of theoretical analysis and numerical simulation indicate that as the damping coefficient decreases into the underdamping or even the weak damping scope, the double stochastic resonance phenomenon induced by noise still exists. The strongest resonance effect can be obtained with the optimal damping value.
Structural, electrical and optical properties investigation of nano-sized Sb0.1(SnO2)0.9
Authors: Mohamed Sara A , Ahmed Mahrous R , Ali H M , Abdel Hakeem A M
Published: March 2022

Solid state reaction method was used to prepare Sbx(SnO2)1−x (x = 0 and 0.1) with sintering temperatures, 600 °C and 800 °C. The crystallographic properties of undoped and doped SnO2 materials results showed the tetragonal rutile structure of SnO2. The crystallinity was clear and increased with increasing the heat treatment. For the most diffraction peaks the microstrain is negative because do ˂ ds indicating the generation of residual compressive stress in the surface. Rietveld refinement proved that a good fitting parameters Rp, Rwp, and χ
2 makes the derived samples to be in a high quality, especially Sb0.1(SnO2)0.9 sample. Scanning Electron Microscopy (SEM) indicated that a spherical shape of SnO2 with nanoparticles but plates and nanorods shaped of SnO2 were detected for Sb0.1(SnO2)0.9 compound that was sintered at 800 °C. SnO2 has grain size 67 nm and 86 nm at sintering temperatures 600 °C and 800 °C respectively, but after adding Sb the grain size decreases to be ≈44 nm at the same sintering temperatures. The electrical resistivity, ρ, of Sb0.1(SnO2)0.9 behaved as semiconductor-like. The magnetoresistance, MR, results showed that ρ(0.6 tesla) < ρ(0 tesla) at Tsint = 600 °C where ρ (0.6 tesla) > ρ (0 tesla) at Tsint = 800 °C because the crystallinity increased with increasing of the sintering temperatures. The results of seebeck showed that charge carriers are n-tape at Tsint = 600 °C and p-type at Tsint = 800 °C. The optical energy band, E

g
of Sb0.1(SnO2)0.9 which were 2.49 eV and 3.21 eV at Tsint = 600 °C and 800 °C respectively and the high values of the transmittance make this compound is candidate to work as window layer in solar cell applications. The results of susceptibility denotes that the Sb0.1(SnO2)0.9 compound is a paramagnetic material.
Herschel Investigation of Cores and Filamentary Structures in the Perseus Molecular Cloud
Authors: Zhang Chang , Zhang Guo-Yin , Li Jin-Zeng , Li Xue-Mei
Published: March 2022

Cores and filamentary structures are the prime birthplaces of stars, and play key roles in the process of star formation. Latest advances in the methods of multi-scale source and filament extraction, and in making high-resolution column density map from Herschel multi-wavelength observations enable us to detect the filamentary network structures in highly complex molecular cloud environments. The statistics for physical parameters shows that core mass strongly correlates with core dust temperature, and M/L strongly correlates with M/T, which is in line with the prediction of the blackbody radiation, and can be used to trace evolutionary sequence from unbound starless cores to robust prestellar cores. Crest column densities of the filamentary structures are clearly related with mass per unit length (M
line), but are uncorrelated by three orders ranging from ∼1020 to ∼1022 cm−2 with widths. Full width at half maximum has a median value of 0.15 pc, which is consistent with the 0.1 pc typical inner width of the filamentary structures reported by previous research. We find 70% of robust prestellar cores (135/199) embedded in supercritical filaments with M
line > 16 M
⊙ pc−1, which implies that the gravitationally bound cores come from fragmentation of supercritical filaments. On the basis of observational evidence that the probability distribution function with power-law distribution in the Perseus south is flatter than in the north, the number of young stellar objects in the south is significantly less than that in the north, and dust temperature is different. We infer that the south region is more gravitationally bound than the north region.
New Energy and UHVDC Power Absorption Capacity Analysis Method Based on Refined Operation Simulation Technology
Authors: Hu Gebiao , Hong Shaoyun , Yang Weikang , Shu Zhan , Wang Jie
Published: March 2022

In order to comprehensively consider a variety of complex factors such as new energy integration, maximum and minimum load, network security constraints, and analyse the new energy absorption capacity of the power grid before and after the UHVDC power access in the province, and study the steady-state power absorption capacity of UHVDC, this paper deeply studies refined time series operation simulation model, designs constraints before and after the UHVDC power access, and establishes a new energy and UHVDC power absorption capacity analysis method based on refined operation simulation technology, and applies this method to analyse the power grid of the province before and after the UHVDC power is put into operation. This method provides technical support for demonstrating power supply and power grid planning schemes.
Characteristic analysis of compressed air energy storage system based on intermediate cooling
Authors: Sun Huan , Xu Haorong , Teng Xinbo , Liu Xinghua , Zhu Junda
Published: March 2022

With the shortage of traditional fossil energy and the aggravation of global warming, the demand for transformation from traditional fossil energy to renewable energy becomes more and more urgent. Compressed air energy storage technology is a guaranteed technology to overcome the time limit of renewable energy and achieve sustainable, efficient and large-scale application of renewable resources. In order to solve the traditional compressed air energy storage technology energy output variety is single, there is low grade energy waste defects. This paper presents a compressed air energy storage system based on intermediate cooling. Through the intercooler, the system adjusts the inlet temperature of the expander, improves the output cooling quality, and realizes the coupling operation of refrigeration and energy storage. This paper establishes a thermodynamic model of the system, analyzes the effects of ambient air temperature and inlet temperature of expander on system performance, and compares the energy efficiency ratio of the system with that of compressed air refrigeration system. The simulation results show that the system can adjust the inlet temperature of expander to increase the net power consumption and achieve high quality cooling output.
Abnormal Detection Model of Energy Consumption Data in Beneficiation and Metallurgy Enterprises based on Transfer Learning
Authors: Yu Zhuchao , Chu Gaixia , Zhang Yuanzheng , Zhou Siyuan , He Shaowei , Li Jing
Published: March 2022

The energy consumption data of beneficiation and metallurgy enterprises has the characteristics of multi-dimensional and timing. An energy consumption data anomaly detection model based on transfer learning is proposed to help enterprises monitor the abnormal energy use. The combination of transfer learning and DTW algorithm is used to eliminate the adverse impact of timing on the model, and the ensemble learning is used to realize data detection. Finally, an efficient and accurate energy consumption data anomaly detection model is formed. The detection accuracy of the model is 91.6%, which can effectively meet the requirements of enterprise energy management.
Unravelling the effects of ibuprofen-acetaminophen infused copper-bioglass towards the creation of root canal sealant
Authors: S Chitra , Chandran Riju , R Ramya , D Durgalakshmi , S Balakumar
Published: March 2022

Impact towards the tuneable characteristics of bioactive glasses (BAGs) has been explored; as there is no root canal sealant till date with ideal characteristics competent enough to manoeuvre the perplexing root canal architecture. Combeite, calcite and traces of cuprorivaite crystalline phases were validated for material formation, in which Cu 2P (XPS) peak authenticating the presence of copper in bioglass network (Cu-BAG). Spherical and platelet-like morphologies were observed and the grain size of Cu-BAG (∼100 nm) was lesser as compared to BAG (∼1 µm). These particle distributions impacted the porosity, and dominant non-bridging oxygens in Cu-BAG influences ionic dissolution, which subsequently enhanced the mineralization. These bioactive materials were loaded with acetaminophen and ibuprofen, corresponding organic moieties was confirmed through Fourier transform infra-red. These drugs loaded bioactive materials exhibited tremendous anti-inflammatory and anti-microbial behaviour with better sealing ability. Drug loaded bioglass paste filled in biomechanically prepared root canal was estimated for sealing potential, mineralization, micro leakage, and fracture resistance properties. Hydroxyl apatite growth was noted on the sealants, flower like protuberance confirmed the sealing potential of the prepared material. Bioglass exhibited promising characteristics required in a root canal sealant. This investigation is a step further towards tailoring the properties of bioactive materials as promising candidates in root canal obturation and thereof.
Fisheries yields and species declines in coral reefs
Authors: McClanahan T R
Published: March 2022

Negative trade-offs between food production and biodiversity and the positive functional diversity–productivity relationships are potentially conflicting paradigms that are frequently evoked in conservation and sustainability science and management. While the complementary niches of species could potentially increase fisheries yields, stark food-diversity trade-offs have been proposed for wild-caught fisheries. Nevertheless, this first evaluation of stock biomass, yields, and species relationships in 115 coral reef locations in the Western Indian Ocean found that management for multispecies-maximum sustained yield (MMSY) will increase both food production and numbers of species relative to open access fisheries. A precipitous loss of >50% of species did not occur until >70% of the fishable and target biomasses was depleted. At MMSY, 6%–15% of total predicted number of fish species were lost indicating a need for other conservation mechanisms. These patterns occurred because the best-fit to the yield-numbers of species relationship was either a saturation or convex parabolic relationship. Fishing at MMSY in coral reefs should provide considerable diversity required to support many ecosystem services. Low biomass and overfishing were common and around 80% of studied locations were losing ∼2.0–2.5 tons km−2yr−1and 15%–40% of their species relative to MMSY.
Random access test as an identifier of nonclassicality*
Authors: Heinosaari Teiko , Leppäjärvi Leevi
Published: March 2022

Random access codes (RACs) are an intriguing class of communication tasks that reveal an operational and quantitative difference between classical and quantum information processing. We formulate a natural generalization of RACs and call them random access tests (RATs), defined for any finite collection of measurements in an arbitrary finite dimensional general probabilistic theory. These tests can be used to examine collective properties of collections of measurements. We show that the violation of a classical bound in a RAT is a signature of either measurement incompatibility or super information storability. The polygon theories are exhaustively analysed and a critical difference between even and odd polygon theories is revealed.
Tempered fractionally integrated process with stable noise as a transient anomalous diffusion model
Authors: Sabzikar Farzad , Kabala Jinu , Burnecki Krzysztof
Published: March 2022

We present here the autoregressive tempered fractionally integrated moving average (ARTFIMA) process obtained by taking the tempered fractional difference operator of the non-Gaussian stable noise. The tempering parameter makes the ARTFIMA process stationary for a wider range of the memory parameter values than for the classical autoregressive fractionally integrated moving average, and leads to semi-long range dependence and transient anomalous behavior. We investigate ARTFIMA dependence structure with stable noise and construct Whittle estimators. We also introduce the stable Yaglom noise as a continuous version of the ARTFIMA model with stable noise. Finally, we illustrate the usefulness of the ARTFIMA process on a trajectory from the Golding and Cox experiment.
Study on economic operating mode for combined desulfurization system of circulating fluidized bed unit
Authors: Yang Rufei , Zhang Hongfu , Gao Mingming
Published: March 2022

With the stricter emission regulation taking effect, most of circulating fluidized bed (CFB) power generation units operates with conventional desulfurization in CFB furnace and flue gas desulfurization (FGD) technology to meet the requirements of ultralow SO2 emission. Therefore, it is urgent to analyse operating cost of the combined desulfurization system and explore the low-cost operating mode for CFB units. In this paper, the operating cost model of combined desulfurization system was established, in which the influence of desulfurization in furnace on thermal efficiency of the CFB boiler was considered. Then, the operating cost of combined desulfurization system under different load conditions for a 300MW subcritical CFB unit was analysed, combined with measured data. The operating cost optimization result shows that, under different loads, when Ca/S is in the range of 0.4 to 0.5, the operating cost of combined desulfurization system reaches the minimum. In addition, as the unit load increases, the higher proportion of SO2 removal in FGD is required to achieve low-cost operating mode for CFB units.
Parameter optimization and field test of nano variable-viscosity slick water fracturing in Changqing shale reservoir
Authors: Liu Hanbin , Bai Hao , Lv Baoqiang , Li Chengzheng , Liu Jin , Huang Guopeng , Yao Erdong , Zhou Fujian
Published: March 2022

After the development of the directional and horizontal wells of Chang 7 shale reservoir in Ordos Basin, the formation pressure decreases rapidly and the production decreases naturally. There is an urgent need for fracturing fluid with oil displacement and enhancing oil recovery (EOR) function, and the on-site fracturing process parameters are optimized. Through laboratory experimental research, nano variable-viscosity slick water has the advantages of high drag reduction, strong sand-carrying, and imbibition oil displacement capacity, which significantly improves the deficiency of sand-carrying and oil displacement performance of conventional slick water. At the same time, the numerical simulation shows that when the injection displacement is 18 m3/min, the cluster spacing is 5 m, the number of perforation clusters is 7 and the sand addition intensity is 3 t/m, the fracturing reconstruction volume can be maximized, which is the optimal parameter for fracturing construction of Chang 7 reservoir. Combined with nano variable-viscosity slick water and optimal construction parameters, field fracturing tests were carried out in 13 wells, including 9 directional wells and 4 horizontal wells; The average daily oil production of horizontal wells is 17.77 t, the cumulative oil production is 377.33 t, and the production is increased by 10∼15 times. It is a new and effective method for the development of Changqing shale reservoir to combine the nano variable-viscosity slick water system of strong oil displacement and sand-carrying capacity with high displacement construction technology.
Study on Influence of temperature on cementing in deep shale oil and gas exploitation
Authors: Zhang Xiaoyu , Yang Hanzhi , Bi Zhenhui
Published: March 2022

In this paper, the mechanical model of sheath has been established according to the engineering practice and analysed in two aspects: temperature acts alone and temperature and pressure act together. The results demonstrate that it is unnecessary to worry the negative influence of individual temperature action. Temperature can cause many adverse characteristics temperature on cementing: thermal stress and material properties. The coefficient ∃ coming from the effective conduction of heat, prove the adverse condition of temperature on cement ring in terms of stress, and its size is positively correlated with temperature difference. Mechanical properties usually will be changed at high tempature, it can be measured by the later experiments, which can discuss the role of temperature is further.
An experimental investigation on the influence of temporary plugging fibers and particles on the fracture conductivity
Authors: Luo Yao , Han Shaobo , Kong Hui , Wang Rong , Dong Enjia , Cai Zhuolin , Zhou Fujian
Published: March 2022

After temporary plugging and fracturing, some of the difficult-to-degrade temporary plugging agents (fibers and particles) in the fractures will affect the conductivity and ultimately affect the rate of oil production. However, the influence law and mechanism of the fibers and particles on the fracture conductivity are still unclear. In order to solve this problem, based on the FCS-842 fracture conductivity test system, the influence law and mechanism of fibers and particles on the fracture conductivity were investigated. The experimental results show that the larger particles support the fracture wall when particles are contained, resulting in higher conductivity. Further studies have found that high fibers content will lead to a significant decrease in the fracture conductivity under low closure pressure. However, high particles content means high fracture conductivity. The placement position of fibers and particles also affects the fracture conductivity. When the pressure is 10 MPa, the conductivity is maximum when the fibers and particles are placed at the fracture opening. Then, when the pressure increases, the conductivity drops sharply by about 88%. When the closure pressure is ≥ 20 MPa, the conductivity is the highest when the fibers and particles are placed at the fracture tip, followed by the middle of the fracture and the smallest at the fracture opening. After analysis, at the fracture opening, the high flow velocity forms a fiber “Barrier” in the fracture, which makes the conductivity decrease rapidly. In the middle of the fracture, the “Dot-net” structure composed of fibers and particles makes the fracture conductivity decrease, but the decrease amplitude and speed are small. At the fracture tip, the lower flow rate makes the fibers and particles form “Clusters”, and the large flow channel between the clusters makes the fracture conductivity higher than the former two. When the fibers and particles are evenly laid, the fibers are easy to form clusters with the particles to block the flow channel, reducing the fracture conductivity.
Experimental study on settlement law of multi-particle compound temporary plugging material in rough fracture
Authors: Lv Bei , Lang Hao , Luo Yao , Zhang Wei , Shi Peize , Wang Bo , Kong Hui , Hu Xiaodong
Published: March 2022

To study the migration and settlement law of temporary plugging particle in fractures, a set of fracture visualization device with controllable pumping rate was built. Based on the experimental device, the influence of the parameters such as pumping rate, particle size combination and adding sequence on the sedimentation and accumulation of temporary plugging particle was studied respectively. The experimental results show that the amount of particle deposition in the fracture is the largest when the pumping rate is 0.04 m3⋅min-1; Under different particle size combinations, 3 mm particles settle earlier than 1 mm particles and the volume of the accumulation is proportional to the proportion of 3 mm particles. The effect of the sequence of addition on the morphology of the particle accumulation is mainly reflected in the layering of the accumulation. When the 3 mm particles are added first and then the 1 mm particles are added, the accumulation volume is larger and the particles settle more. In summary, when a combination of 0.04 m3⋅min-1 rate and 3 mm: 1 mm=4:2 particle size is selected, and 3 mm is added first, and then 1 mm particles are added, the temporary plugging particle has a larger volume of sedimentation in the fracture.
Investigation on the influence mechanism of wall-fluid interaction on flow around nanoscale circular cylinder
Authors: Yao Shuting , Pan Yu , Wang Jiansheng , Liu Xueling
Published: March 2022

The influence of atomic interaction strength between solid wall and fluid on the flow around a nanoscale circular cylinder was numerically probed with the molecular dynamics method. The results show that when the flow velocity is 2.2 and Reynolds number is 23, vortices are periodically formed behind the circular cylinder at the nanoscale, and go through the development and shedding. With the weakening of wall-fluid interaction between cylinder surface and fluid atoms, the vortex shedding period decreases, the Strouhal number increases, the weak wall-fluid interaction is beneficial for increasing vortex shedding frequency. It reveals that the length of time-averaged vortex behind the nanoscale cylinder decreases slightly with the decrease of wall-fluid interaction. Furthermore, the fluid density and velocity are symmetrically distributed along the central axis of nanoscale cylinder. As the wall-fluid interaction decreases, the binding force of cylinder surface to the fluid atoms decreases, which results in the decrease of the minimum value of fluid density in the upper right and lower right regions near the cylinder. And, the argon fluid is more prone to occur velocity slip on the cylinder surface, the corresponding velocity near the cylinder surface increases significantly.
Fracturing scheme design for unconventional reservoirs based on geology-engineering integration method
Authors: Su Hang , Zhou Fujian , Zheng Ao , Dong Rencheng , He Bencheng , Wang Fei , Liu Hongtao , Li Junjian
Published: March 2022

Horizontal drilling and hydraulic fracturing can effectively increase the contact area between fractures and reservoir, which are important method to realize the economic and efficient development of unconventional reservoirs. In the traditional fracturing scheme design, “sweet spots” guide the fracturing construction. However, due to lack of the interaction process of using engineering data to validate and correct the original data until the final convergence with reality, it cannot be dynamically optimized and matched in time. To overcome above shortcomings, this paper proposes a new network fracturing scheme design workflow based on the integrated geological-engineering integration (GEI) method. The tight carbonate reservoir X layer of oil field A in the Middle East is set as a case. A comprehensive sweet spot evaluation method is established using the partial correlation coefficient analysis method, considering the physical properties and fracturing performance of reservoir. The comprehensive sweet spot model is calibrated and optimized using experimental data, stimulation parameters, well tests, and production data. Based on the comprehensive sweet spot model, the quadrant chart is plotted and varied single well fracturing scheme designs are implemented for different quadrant areas. The numerical simulation results show that it can improve the development efficiency of unconventional reservoirs.
Study of the possibility of using biomass coniferous in the production of composite materials
Authors: Krivorotova A I , Usoltsev O A
Published: March 2022

Processing of softwood biomass is a promising direction in the production of wood composite materials. Pre-treatment of waste debarking allows you to create chipboards with high thermal insulation and strength properties.
Processing red mud as a factor of removing the risk of environmental disasters: RUSAL experience
Authors: Litovchenko V I , Shumakova N A
Published: March 2022

The paper considers the current problem of waste management of aluminum production in the Krasnoyarsk Territory. The negative consequences of the existence of sludge collectors of aluminum production for the natural environment and the population of the region are shown. The analysis of the consequences of environmental disasters, such as cancer in the population, chemical pollution of groundwater and surface water caused by leakage of hazardous substances, is presented. The experience of RUSAL, as well as international experience in the field of waste processing is presented.
Concentration dependences of the structural, magnetic and kinetic properties of manganese chalcogenides doped with tellurium
Authors: Romanova O B , Sitnikov M N , Loginov Yu Yu , Hichem Abdelbaki
Published: March 2022

The effect of anionic substitution on the structural, magnetic, and kinetic properties of chalcogenides of the MnSe1-XTeX system in the temperature range of 77-400K in magnetic fields up to 12 kOe was studied. With an increase in the substitution concentration, changes in the structural and magnetic characteristics, which correlate with changes in the electronic structure, were found. The type and mobility of the main current carriers were determined from the Hall effect measurements.
Applications of group theory in crystallography
Authors: Senashov V I
Published: March 2022

Group theory is a powerful tool for studying symmetric physical systems. Such systems include, in particular, molecules and crystals with symmetry. Group theory serves to explain the most important characteristics of atomic spectra. Group theory is also applied to the problems of atomic and nuclear physics. This paper gives examples of the use of the apparatus of group theory in research on crystallography, quantum mechanics, elementary particle physics. In particular, in these studies matrix groups and representations of unitary groups are actively used. For such groups we give an overview of the results on their recognition by the spectrum (by the orders of the elements of the group). This direction has been intensively developed in recent years both in our country and abroad. Recognition of finite simple non-Abelian groups by spectrum has been studied for last thirty years in Yekaterinburg at the Institute of Mathematics and Mechanics of the Ural Division of the Russian Academy of Sciences, in Chelyabinsk Federal University and in the Novosibirsk Institute of Mathematics of Siberian Division of the Russian Academy of Sciences. Some simple non-Abelian groups are not recognizable by their spectra. We have proposed an approach for recognizing groups by the bottom layer. The bottom layer of a group is the set of its elements of prime orders. A group is called recognizable by the bottom layer under additional conditions if it is uniquely restored by the bottom layer under these conditions. The paper considers some examples of simple non-Abelian finite groups that are not recognizable by spectra. For these examples, simultaneous recognition by spectrum and by the bottom layer is proved.
An intelligent voice recognition system based on fuzzy logic and the bag-of-words technique
Authors: Stefanenko O S , Lipinskiy L V , Polyakova A S , Khudonogova J A , Semenkin E S
Published: March 2022

This paper describes a method for recognizing voice command based on a fuzzy logic system capable of perceiving fuzzy commands, i.e. commands containing fuzzy terms, for example, ‘close’, ‘closer’, ‘close to’, ‘closer than’, ‘further’ and ‘very far’. The developed approach has the ability to be trained for a specific user. The developed fuzzy logic system is used to recognize linguistically inaccurate commands in order to increase the expressiveness of the language for control of a moving robot.
Multiprocessing implementation for MCNP using Python
Authors: Arif Sazali Muhammad , Syahir Sarkawi Muhammad , Syazwani Mohd Ali Nur
Published: March 2022

Monte Carlo N-Particle (MCNP) is a widely-used code in nuclear engineering, but it needs high computation times due to the tracking of every single particle and interaction event. This causes shielding optimization using trial-and-error to take long times to complete. It can be solved by using multiprocessing, but this requires the MCNP source code which can be difficult to obtain. Therefore, this paper aims to suggest a solution on how Python can be used to run multiple instances of the code in shielding optimization. Two hardware setups were tested: one with a dual-core CPU, and one with a six-core CPU. Each of them would run several repeated simulations with and without multiprocessing enabled. Comparisons were made between each case of the same setup to observe the improvements in completion time. A tutorial of the Python algorithm is also provided in the methodology.
Evaluation of scattering effects for radiation shielding or filter materials by using Monte Carlo simulation
Authors: Miza Osman Nur , Mohamad Tajudin Suffian , Hanim Aminordin Sabri Adila , Faddilah Mohd Noor Arif , Zahri Abdul Aziz Mohd
Published: March 2022

Most radiology departments utilize ordinary concrete and lead for radiation shielding as the primary radiation can be reduced through photon absorption. There are many studies done focusing on the transmitted photons that penetrate the shielding materials for radiation shielding. However, the scattering from the shielding materials would be ignored. When high-energy photons impinge on thick shields, most of the incident energy is absorbed in the shielding materials, but some of it can also be deflected sideways or in a backward direction. This is important as the backscatter radiation can contribute to unnecessary additional radiation dose to healthcare workers. Hence, this study evaluates several shielding materials namely aluminium, iron, copper, lead, ordinary concrete, and heavy concrete particularly for its attenuated and scattered photons for radiation shielding. The shielding materials were evaluated using the Monte Carlo simulation, specifically PHITS code. In the simulation, all shielding materials were modelled as a fixed 30 x 30 cm rectangular shape with a fixed thickness of 10 cm. Mono-energy and pencil beam photon energies ranging from 100 keV until 1 MeV were directed to the shielding materials. As a result, at 100 keV, lead shielding showed the least amount of transmitted dose compared to other shielding materials. However, lead shielding also showed the highest reflected dose at the same incident photon energy. As copper showed the least amount of reflected dose at this incident energy, hence applying a thin layer of this material to lead shielding can tolerate the compromise between low transmitted dose and high reflected dose. Therefore, this can improve the radiation shielding at various irradiation facilities. In conclusion, the reflected dose for all materials studied will increase or higher when the incident photon energy increase, except for lead as well as for low-Z element materials rather than high-Z element materials.
Superconducting properties of (Bi,Pb)2Sr2Ca2Cu3Ox (BSCCO-2223) superconductor ceramics prepared by conventional solid-state reaction and co-precipitation methods
Authors: Mohiju Zaahidah ‘Atiqah , Mujaini Madihah , Hamid Nasri A.
Published: March 2022

The (Bi,Pb)2Sr2Ca2Cu3Ox (BSCCO-2223) samples were prepared by conventional solid-state reaction and co-precipitation methods. The crystal size, cell parameter, and crystal structure were identified from X-ray diffraction (XRD). The peaks drawn by co-precipitation have higher intensities and the width of peaks were narrower compared to the sample prepared by solid-state method. Slight difference in the value of lattice parameters between the samples were also noticeable. Concentration of defects increased the distortion of crystal lattice that cause the changes in these parameters. The electrical properties of the superconductors were investigated by using cryogenic four-point probe and AC susceptibility. The sample prepared by co-precipitation method was able to reach higher critical temperature, TC at 106 K compared to the other sample, TC at 97 K. Meanwhile Scanning Electron Microscope (SEM) micrographs for solid-state method sample showed more random grain alignment and porous structures. The microstructures and grain growth results of Bi-2223 were reflected to the heat and temperature applied during sintering process. In short, the research work reveals that co-precipitation method produces better quality of high temperature superconductor compared with solid-state method due to higher homogeneity resulted by chemical reactions.
Polyethylene composite with boron and tungsten additives for mixed radiation shielding
Authors: Arif Sazali Muhammad , Khair Alang Md Rashid Nahrul , Hamzah Khaidzir , Mohamad Idris Faridah , Syahir Sarkawi Muhammad , Syazwani Mohd Ali Nur
Published: March 2022

Mixed neutron and gamma radiations are common in many nuclear applications. Several materials can be combined to obtain a composite material that is better for mixed radiation than the individual component materials. The aim of this paper is to investigate the shielding effectiveness of a polyethylene (PE)-based composite with boron and tungsten additives. Several compositions are tested to shield against a 252Cf fission neutron source using an attenuation experiment. The composite is also manufactured using the melt-mixing method of component raw materials. Comparisons are made between the different compositions and the experimental results. Results suggest that the PE composite with 16%wt boron and 16%wt tungsten show the best mixed radiation attenuation as compared to pure PE, PE composite with 25%wt boron, and PE composite with 25%wt tungsten.