bluuebunny/crossref_metadata_2025 huggingface dataset:
Directional growth effect on magneto-mechanical properties of Fe81Al19 alloy
Authors: Chang H. W. , Jen S. U. , Liao Y. H. , Wong Y. J. , Chiu C. H. , Chang W. C.
Published: February 2023

Directional growth effect on magneto-mechanical properties of Fe81Al19 alloy is studied. The ideal model of heat flux for directional solidification (DS) technique is proposed, and the tuned A/L (the ratio of cross-sectional area and length for the ingot) and ΔT (temperature difference) are adopted to increase heat flux (q). The experimental result shows that the increase of q effectively promotes the degree of (011)[100] Goss texture and therefore helps to form an oriented stripe domain structure. Large λ100 of 93.8 ppm attained for this optimized Fe81Al19 alloy prepared by DS method is very close to that of the Fe81Al19 single crystal (95.0 ppm). For the optimized DS prepared Fe81Al19 alloy, high magnetostriction sensitivity (dλ/dH) of 0.45 ppm/Oe leads to huge ΔEs/E0 of ∼10% and attractive ΔE/E0 of 8.2% at small H = 0.25 kOe. The above remarkable magneto-mechanical properties, low cost of Fe81Al19, and simple process of DS favor for applications. This work proposes an ideal model to emphasize the importance of heat flux in DS, and experimentally attains the remarkable magneto-mechanical properties for Fe81Al19 alloy prepared by DS.
Magnetic stability of low corrective force PM in series hybrid magnet memory machine under inverter open-circuit fault
Authors: Zhao Xifang , Lin Heyun , Liu Wei , Zeng Xianxian
Published: February 2023

Variable flux memory machine (VFMM) can dynamically adjust its air-gap magnetic field by changing the magnetization states of the employed low corrective force (LCF) permanent magnets (PMs). Due to the demagnetization risk of LCF PMs under armature current, it is necessary to analyze their magnetic stability in various operation states. The magnetic stability of LCF PMs in series hybrid magnet VFMM (SHM-VFMM) under inverter open-circuit (IOC) fault is studied in this article. Firstly, the topology of the investigated SHM-VFMM is introduced, and the field-circuit coupled model of the machine under IOC fault is established. Then, the magnetic stabilities of LCF PMs during the normal and fault operations are analyzed and compared by using the finite element method. The effects of LCF PM demagnetization and fault current on torque are also studied. Afterward, the influence mechanism of the fault armature magnetomotive force (MMF) on LCF PM demagnetization is revealed by using the synthetic MMF graphic method. Finally, the main factor affecting the LCF PM demagnetization under IOC fault is highlighted and an effective method for recovering the magnetic stability of LCF PM is proposed.
Fabrication and soft magnetic properties of FeSiB based flakes with insulating surface layer suitable for high frequency power applications
Authors: Das Rajasree , Ye Liang , Lal Sumit Sukhbasi , Baghbaderani Hasan Ahmadian , Sai Ranajit , Hayes Michael , Morris Michael A. , McCloskey Paul
Published: February 2023

FeSiB based soft magnetic flakes (SMFs; ϕ: 63-106 µm, t: 2-5 µm) coated with optimally thick (∼10 nm) SiO2 were fabricated as the potential magnetic material for pressed cores suitable for use in power inductors operating beyond 10 MHz. Such thin SMFs were produced by mechanical ball milling of commercially available thick (∼27 µm) ribbons followed by an optimized sol-gel coating in presence of a silane coupling agent. Milling helped to reduce ribbon thickness below the skin depth to minimize eddy current loss at high frequencies. The effect of milling (medium, duration, rotation speed, and ball-to-powder ratio) and coating conditions on the soft magnetic properties of the SMFs were investigated. An optimally tiny fraction of the milled flakes was allowed to become nanocrystalline, which augments saturation flux density (BS) and permeability (µ) without incurring additional losses. The results from X-Ray photoelectron spectroscopy and magnetization measurement confirm that a stress-releasing post-annealing process reduced coercivity from ∼62 Oe to ∼6 Oe and enhanced the magnetic saturation moment from 126 emu/g to 142 emu/g without affecting the thin yet robust insulating SiO2 layer.
Ferrimagnetic-ferromagnetic phase transition in Au-doped Mn4N epitaxial films confirmed by x-ray magnetic circular dichroism
Authors: Horiuchi Takumi , Komori Taro , Yasuda Tomohiro , Hirose Taku , Toko Kaoru , Amemiya Kenta , Suemasu Takashi
Published: February 2023

The antiperovskite ferrimagnet Mn4N has perpendicular magnetic anisotropy and small spontaneous magnetization, both of which are favorable properties for current induced domain wall motion. Previously we have investigated the magnetic structure of 3d-element-doped Mn4N thin films and demonstrated ultrafast domain wall velocities reaching 3000 m s−1 in the vicinity of the magnetic compensation composition of Ni-doped Mn4N at the current density of j = 1.2 × 1012 A m−2 at room temperature (RT). In this study, we investigate the effect of Au doping on the magnetic structure of Mn4N films, and present a composition ratio-dependent sign reversal of the anomalous Hall effect at RT. X-ray magnetic circular dichroism measurement revealed that the magnetic moment of the face-centered Mn atoms of Mn4−xAuxN reversed between x = 0.1 and 0.2, and became parallel to that of the corner-site Mn atoms for x = 0.2 and 0.3. This result suggests that the ferrimagnetic-ferromagnetic phase transition occurred in Au-doped Mn4N epitaxial films as in the In-doped Mn4N epitaxial films.
A model order reduction of hysteretic eddy-current fields in electric machines using Cauer ladder network method
Authors: Tobita M. , Matsuo T.
Published: February 2023

This study aims to establish a hysteretic model order reduction method for electric machines using the Cauer ladder network (CLN) method. The first inductor of the CLN represents the hysteresis effect, which is computed using the scalar play model identified from the static I–ϕ (current–magnetic flux) loops. An iron-core inductor was analyzed, and pulse-width modulation (PWM) voltage input was applied to the coil. The proposed method yielded results that agreed with the transient finite element (FE) analysis and effectively reduced the computation time.
Temperature dependent intrinsic Gilbert damping in magnetostrictive FeCoSiB thin film
Authors: Hu Wenbin , Zhang Lei , Jin Lichuan , Bai Feiming
Published: February 2023

A low Gilbert damping factor is crucial for emerging magneto-acoustic devices. In current work, angle-dependent and temperature-dependent Gilbert damping of magnetostrictive FeCoSiB thin films have been investigated using electron spin resonance (ESR) and vector network analyzer ferromagnetic resonance (VNA-FMR) techniques, respectively. A very low Gilbert damping factor ∼0.0038 was measured with in-plane magnetic fields at room temperature. Temperature-dependent VNA-FMR results between 10 K and 300 K exhibit a conductivity-like damping feature, which can be attributed to the spin-orbital coupling dominantly controlled by the intraband scattering. Our results clearly indicate that highly magnetostrictive or piezomagnetic film does not necessarily have a high intrinsic damping factor.
Analysis and design of constant current and constant voltage outputs of integrated coil wireless EV charging system
Authors: Chen Long , Wu Fei , Ben Tong , Zhang Chunwei
Published: February 2023

To simplify the circuit design and control complexity, a wireless charging system with a switchable hybrid topology based on an integrated coil structure is proposed in this paper. Constant current (CC) and constant voltage (CV) outputs under zero phase angle (ZPA) conditions can be achieved at a fixed frequency by simply throwing the compensation element at the receiver. Firstly, the system is modeled using mutual coupling theory, and the parameter configuration conditions for implementing CC or CV outputs under ZPA conditions are analyzed. Then, according to the obtained parameter configuration conditions, the parameters of the switchable hybrid topology are designed. Finally, an experimental prototype with 72 V charging voltage and 4 A charging current is implemented to validate the proposal. The experimental results agree well with the theoretical analysis.
The effects of Cu substitution on magnetocaloric effects of the HoCo1−xCuxSi (0 ≤ x ≤ 0.4) phases
Authors: Liu Botao , Zeng Guoqing , Chen Jiamin , Cui Weibin
Published: February 2023

By hetero-structural alloying ferromagnetic (FM) TiNiSi-type orthorhombic HoCoSi with antiferromagnetic (AFM) Ni2In-type hexagonal HoCuSi, the magnetic and structural evolutions have been observed in HoCo1−xCuxSi (0 ≤ x ≤ 0.4) alloys. The magnetic property is changed from ferromagnetic for x ≤ 0.3 to antiferromagnetic for x = 0.4 in HoCo1−xCuxSi system. With the field change Δμ0H = 5 T, the maximum magnetic entropy changes (−ΔSMmax) are 10.1 J kg−1 K−1, 8.6 J kg−1 K−1, 7.6 J kg−1 K−1, 10.0 J kg−1 K−1 and 13.6 J kg−1 K−1 in HoCo1−xCuxSi (x = 0, 0.1, 0.2, 0.3 and 0.4) alloys, respectively. With the enhancement of substitution amount, the −ΔSMmax is decreased for x ≤ 0.2, which is caused by magnetic moment dilution effects. But the −ΔSMmax is increased for 0.3 ≤ x ≤ 0.4, which is caused by the field-induced metamagnetic transition at the critical component.
Effect of film thickness on the electrical transport in Co2FeAl0.5Si0.5 thin films
Authors: Longchar Lanuakum A. , Rahaman Mainur , Hazra Binoy Krishna , Raja M. Manivel , Rawat R. , Kaul S. N. , Srinath S.
Published: February 2023

The effect of film thickness on the structural- and electrical-properties is investigated in Co2FeAl0.5Si0.5 (CFAS) thin films of thickness, t, in the range 12–75 nm. These films are grown by ultrahigh vacuum dc magnetron sputtering on Si(100) substrates with SiO2 buffer layer (300 nm), at the substrate temperature of 500 ◦C. The GIXRD patterns reveal that B2 structural order decreases with increasing t. The film with t = 75 nm has sizable A2 disorder. Irrespective of t, ρ(T, H = 0) goes through a minimum at Tmin. An elaborate quantitative analysis of the ρ(T, H = 0) data, taken over the temperature range 5 K to 300 K, demonstrates that the electron-diffuson (e–d) and weak localization (WL) effects (responsible for the negative temperature coefficient of resistivity (TCR) for T < Tmin) compete with the electron-magnon (e–m) and electron–phonon (e–p) scattering (positive TCR) contributions to produce a minimum at Tmin. Residual resistivity, ρ5K, and the e–d, wl, e–m and e–p scattering contributions to ρ(T, H = 0), ρe–d, ρwl, ρe–m and ρe–p, all go through a minimum at t = 50 nm. Regardless of t, the thermal renormalization of the spin-wave stiffness makes a significant contribution to ρe–m.
A method to distinguish local demagnetization and short-circuit faults of six-phase interior permanent-magnet machine based on voltage in synchronous frame
Authors: Yuan Zihang , Wang Minghao , Bai Jingang , Liu Wei , Zheng Ping
Published: February 2023

Short-circuit fault and local demagnetization faults are two common fault types of permanent-magnet machines, aiming to improve the reliability of multi-phase PM machines in safety-critical applications, a method to distinguish these two kinds of faults in six-phase interior PM machines is proposed. The voltage characteristics in synchronous frame of local demagnetization fault and short-circuit fault are investigated, and the influences of load current and internal power factor angle on the voltage harmonic characteristics are analyzed. To solve the problem of the interaction between the extracted harmonic amplitudes in integer and non-integer orders, the average and variance of the harmonic coefficients of the voltages in synchronous frame are utilized to distinguish two types of faults. Through comparing the fault indices under different load conditions of the six-phase interior PM machine, the distinguishing ability of the method is validated.
High wave vector non-reciprocal spin wave beams
Authors: Temdie L. , Castel V. , Dubs C. , Pradhan G. , Solano J. , Majjad H. , Bernard R. , Henry Y. , Bailleul M. , Vlaminck V.
Published: February 2023

We report unidirectional transmission of micron-wide spin waves beams in a 55 nm thin YIG. We downscaled a chiral coupling technique implementing Ni80Fe20 nanowires arrays with different widths and lattice spacing to study the non-reciprocal transmission of exchange spin waves down to λ ≈ 80 nm. A full spin wave spectroscopy analysis of these high wavevector coupled-modes shows some difficulties to characterize their propagation properties, due to both the non-monotonous field dependence of the coupling efficiency, and also the inhomogeneous stray field from the nanowires.
Plasmonic near field transducer of nanocomposite with distributed feedback
Authors: Du Tianxiang , Laughlin David E. , Bain James A. , Zhang Wenyi , Zhu Jian-Gang (Jimmy)
Published: February 2023

In this paper, we present a novel near field transducer (NFT) design concept for heat assisted recording. In this design, metal bars separated by thin dielectric are used to form a resonance plasmonic grating with distributed feedback (DFB). The motivation for such structure design is the use of dielectric separation for enhancing the material stability at elevated temperature so that best materials can be used without compromising much needed plasmonic properties. COMSOL Multiphysics software is used to simulate the plasmonic excitation and propagate to provide a detailed performance analysis on novel NFT with a nanocomposite structure to create distributed optical feedback (DFB) for maintaining the plasmonic resonance. The NFT is composed of an array of Au rectangular gratings separated by a constant gap, with each grating component embedded in the dielectric medium. It is shown that the grating based NFT could have the same NFT efficiency compared with a solid piece of Au NFT of the same geometric dimensions.
Introduction of VN underlayer and caplayer for preparation of Mn4N(001) single-crystal thin film with perpendicular magnetic anisotropy
Authors: Imamura Kosuke , Ohtake Mitsuru , Isogami Shinji , Futamoto Masaaki , Kawai Tetsuroh , Kirino Fumiyoshi , Inaba Nobuyuki
Published: February 2023

A Mn4N thin film is prepared on MgO(001) single-crystal substrate by introducing VN underlayer and caplayer which are respectively expected to inhibit the oxidation from substrate and surface. The thin film is prepared by ultra-high vacuum radio-frequency magnetron sputtering. The growth, the structure, and the magnetic properties are investigated. A fully epitaxial VN/Mn4N/VN film with sharp interfaces is formed on the substrate. The Mn4N film has low out-of-plane and in-plane orientation dispersions of about 1° and high N site order degree of 0.88. The lattice of Mn4N film is slightly deformed along the perpendicular direction (c/a = 0.9872) possibly due to accommodation of the lattice mismatch at Mn4N/VN interfaces. The film shows a low saturation magnetization of 85 kA/m (85 emu/cm3) and a strong perpendicular magnetic anisotropy. The present study has shown that introduction of VN underlayer and caplayer is useful for preparation of well-defined Mn4N thin films with perpendicular magnetic anisotropy.
Size-dependent magnetic properties of Mn-Co-NiO based heterostructured nanoparticles
Authors: Ishrak Farhan , Mayanovic Robert A. , Benamara Mourad
Published: February 2023

In this work, we investigate the synthesis, along with the structural and magnetic properties, of novel Mn-Co-NiO-based heterostructured nanocrystals (HNCs). The objective is to develop novel, well-structurally ordered inverted antiferromagnetic (AFM) NiO–ferrimagnetic (FiM) spinel phase overgrowth HNCs. Inverted HNCs are particularly promising for magnetic device applications because their magnetic properties are more easily controlled by having well-ordered AFM cores, which can result in magnetic structures having large coercivities, tunable blocking temperatures, and other enhanced magnetic effects. The synthesis of the HNCs is accomplished using a two-step process: In the first step, NiO nanoparticles are synthesized using a thermal decomposition method. Subsequently, Mn-Co overgrowth phases are grown on the NiO nanoparticles via hydrothermal nanophase epitaxy, using a fixed pH level (∼5.3) of the aqueous medium. This pH level was selected based on previous work in our laboratory showing that NiO/Mn3O4 HNCs of constant size have optimal coercivity and exchange bias when synthesized at a pH of 5.0. The crystalline structure and gross morphology of the Mn-Co-NiO-based HNCs have been analyzed using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques, respectively. Analysis using these techniques shows that the HNCs are composed of a NiO core and a CoMn2O4 overgrowth phase. Rietveld refinement of XRD data shows that the NiO core has the rocksalt (Fm3̄m) cubic crystal structure and the CoMn2O4 overgrowth has the spinel (I41/amd) crystal structure. Moreover, an increased relative amount of the CoMn2O4 overgrowth phase is deposited with decreasing NiO core particle size during the synthesis of the HNCs. The results from PPMS magnetization and high-resolution transmission electron microscopy (HRTEM) characterization of the Mn-Co-NiO-based HNCs are discussed herein.
Study of the anisotropic Sm2Fe17N3 powders with high performance
Authors: Liang Dong , Yang Wenyun , Wang Xinan , Xu Qing , Han Jingzhi , Liu Shunquan , Wang Changsheng , Du Honglin , Zhu Xiaoyu , Yuan Tao , Luo Zhaochu , Yang Jinbo
Published: February 2023

The strip casting technique was first used in this work to prepare the Sm2Fe17 parent alloys. Next, the Sm2Fe17N3 powders were synthesized using a gas–solid reaction of Sm2Fe17 powders with N2. Then, the anisotropic Sm2Fe17N3 powders with high performance were prepared by a surfactant-assisted grinding method in gasoline solvent. It was found that the coercivity (iHc) of ground powders increases with decreasing the average particle size (Dm), while the saturation magnetization (Ms) decreases. The maximum value of iHc of 17.5 kOe was obtained at the Dm = 1.3 µm. The ground powders with Dm of 3.1 µm show a remanence ratio (Mr/Ms) over 95% and a maximum energy product [(BH)max] of 35 MGOe. The Sm2Fe17N3 powder exhibited a very high iHc of 36.1 kOe at 10 K. Above 300 K, Sm2Fe17N3 powders mixed with epoxy resin showed a low remanence temperature coefficient of α(RT-100°C) = −0.077% °C−1.
The challenge to reduce crude protein contents of wheat-based broiler diets
Authors: Selle Peter H. , Macelline Shemil P. , Chrystal Peter V. , Liu Sonia Yun
Published: February 2023

The challenge to reduce crude protein (CP) contents of wheat-based broiler diets is both justified and formidable because the performance of broiler chickens offered reduced-CP, wheat-based diets is usually compromised. Moreover, broiler chickens offered wheat-based diets do not accommodate CP reductions as well as do those offered maize-based diets; this appears to stem from the higher protein concentrations and more rapid starch digestion rates of wheat. The higher protein concentrations of wheat than maize result in elevated inclusion levels of non-bound (synthetic, crystalline) amino acids (NBAA). This may be an impediment, because non-bound and protein-bound amino acids are not bioequivalent and intestinal uptakes of NBAA are more rapid than their protein-bound counterparts. This leads to post-enteral amino acid imbalances and the deamination of surplus amino acids, which generates ammonia (NH3). Because NH3 is inherently detrimental, it must be detoxified and eliminated as uric acid, which attracts metabolic costs. Moreover, inadequate NH3 detoxification may seriously compromise broiler growth performance. Also, consideration is given to some intrinsic wheat factors, including soluble non-starch polysaccharides, amylase–trypsin inhibitors and gluten, that may hold relevance. Several strategies are proposed that may enhance the performance of birds offered reduced-CP, wheat-based diets, including capping dietary starch:protein ratios, blending wheat with sorghum, whole-grain feeding in association with phytase, dietary inclusions of L-carnitine and the use of protected or slow-release amino acids. In future research, it should prove instructive to compare different wheats with a wide range of protein contents that, importantly, have been fully characterised for relevant parameters, to ascertain the most appropriate properties. The successful development and adoption of reduced-CP, wheat-based diets would be an enormous advantage for the Australian chicken-meat industry as it would diminish the huge dependence on imported, expensive soybean meal.
Improved soil fertility, plant nutrition and grain yield of soybean and millet following maize intercropped with forage grasses and crotalaria in the Brazilian savanna
Authors: Brito Lucélia de Cássia Rodrigues de , Souza Henrique Antunes de , Araújo Neto Raimundo Bezerra de , Azevedo Diógenes Manoel Pedroza de , Sagrilo Edvaldo , Vogado Renato Falconeres , Carvalho Suzane Pereira , Ferreira Ane Caroline de Melo , Cavigelli Michel André
Published: February 2023

Context Intercropping maize with tropical forages is known to provide multiple benefits for the agricultural sustainability in the Brazilian savanna. Despite that, more studies are needed to define strategies to improve soil quality and increase crop yield of subsequent crops. Aims This study aimed to evaluate the impacts of cultivating maize in monoculture or in double- and triple-intercropping with brachiaria and crotalaria on the chemical and microbiological attributes of soil, nutritional status of soybean, and the productivity of soybean and millet in succession in the cerrado of eastern Maranhão. Methods The intercropping systems implemented in 2017 were as follows: maize (Zea mays) + Urochloa ruzizienses (brachiaria); maize + Crotalaria juncea (crotalaria); maize + brachiaria + crotalaria; and monoculture maize as a control. In 2018 and 2019, soybean and millet were cultivated on the same plots. Key results The triple-intercropping promoted immediate improvement in the biological and chemical attributes of the soil, especially when compared with monoculture maize. Intercropping maize with brachiaria, with or without crotalaria, increased soybean productivity by 21% and millet by 44% in the subsequent year, compared with monoculture maize system. Intercropping maize with brachiaria, with or without crotalaria, increased the leaf concentrations of nitrogen, potassium, magnesium, and sulfur of the subsequent soybean crop, suggesting improved nutrient cycling with intercropped forages. Conclusions Intercropping maize + forage, especially brachiaria, can be recommended for crop rotation and succession systems in the Brazilian savanna. Implications These results quantified the benefits of crop rotation following intercropping with maize and forage, which can be an alternative for farmers in the Brazilian savanna.
Equine
Authors: Lewis Niamh , Canesin Heloisa , Choi Young Ho , Foss Rob , Felix Matheus , Rader Kindra , Hinrichs Katrin
Published: February 2023

Context Information on factors associated with developmental competence of equine in vitro-produced (IVP) blastocysts is lacking. Aims To determine the relationships of stage, grade, day of development, and specific morphological parameters of equine IVP blastocysts, to pregnancy and foaling rates. Methods Photomicrographs of 316 IVP embryos with known pregnancy outcomes were scrutinised individually by four observers. Inter-observer variation was assessed, and pregnancy outcome evaluated in relation to day of blastocyst development and assigned grade and stage. Individual component analysis was performed to determine the association of specific morphological parameters with foaling rate. Key results Overall pregnancy rate was 76.9% and foaling rate was 56.3%. The day of embryo development did not affect pregnancy rate but significantly affected foaling rate. Embryo stage did not affect foaling rate. Embryo grade affected foaling rate only for Day-9 embryos. Some morphological features in the bovine grading system did not predict outcome in equine IVP embryos. Significant individual parameters differed between Stage 5 and Stage 6 equine blastocysts. Conclusions Day of blastocyst development is the major factor related to foaling rate for equine IVP embryos. Notably, there was no effect of embryo stage on foaling rate and no evidence that prolonging culture until embryos advance in stage increases foaling rate. The standard bovine grading system is not directly applicable to equine IVP embryos; equine-specific staging and grading systems are proposed. Implications This information will allow laboratories to identify embryos with the highest developmental competence. Use of the proposed systems will increase consistency in embryo assessment among laboratories.
“You know she didn’t have no country”
Authors: Kontovas Nicholas
Published: February 2023

This study focuses on switches into and out of African American English among contestants of the television series RuPaul’s Drag Race. FollowingBarrett (1995), I note that Black contestants who are comfortable in White Middle-Class American English tend to use it as their primary dialect, switching to AAE in order to develop rapport. I suggest that non-Black performers switch into AAE either in order to mitigate the effects of comments which might otherwise be interpreted as rude, or to reinforce strength in moments of emotional self-disclosure, and that this is possibly reflective of an interpretation on the part of the speaker that forwardness and strength constitute a normal element – ‘sass’ – of Black women’s speech. Finally, I explore the possible social impact of this phenomenon from the perspective of two common themes in the popular discourse on race: one centered on cultural appropriation, the other on the perception of Black Women’s Language.
Negotiating normativities of gender, sexuality and the family in gay parents’ small stories
Authors: Mackenzie Jai
Published: February 2023

This article considers how two gay male parents negotiate normative discourses of gender, sexuality and the family in an interview context. Employing a three-level framework for exploring narratives-in-interaction, the micro-linguistic analysis identifies and unravels two gay parents’ multiple layers of self- and other- positioning through their telling of ‘small stories’. The findings support insights from existing sociological and psychological research to some degree, showing how these parents’ liminal situation amidst multiple and intersecting normative discourses can lead to conflict as they work to position themselves as partners, parents, and gay men. However, the analysis also reveals new insights about the specific and nuanced forms such conflict can take, depending on individuals’ circumstances and experiences. The findings suggest that everyday encounters are important sites for the (re)constitution of such normative discourses, and that the small stories parents tell about these encounters can be important resources for making sense of their lives in relation to broader social norms and structures.
The dynamics of bilingualism in language shift ecologies
Authors: Grenoble Lenore A , Osipov Boris
Published: February 2023

A large percentage of the world’s languages – anywhere from 50 to 90% – are currently spoken in what we call shift ecologies, situations of unstable bi- or multilingualism where speakers, and in particular younger speakers, do not use their ancestral language but rather speak the majority language. The present paper addresses several interrelated questions with regard to the linguistic effects of bilingualism in such shift ecologies. These language ecologies are dynamic: language choices and preferences change, as do speakers’ proficiency levels. One result is multiple kinds of variation in these endangered language communities. Understanding change and shift requires a methodology for establishing a baseline; descriptive grammars rarely provide information about usage and multilingual language practices. An additional confounder is a range of linguistic variation:regional(dialectal);generational(language-internal change without contact or shift);contact-based(contact with or without shift); andproficiency-based(variation which develops as a result of differing levels of input and usage). Widespread, ongoing language shift today provides opportunities to examine the linguistic changes exhibited by shifting speakers, that is, to zero in on language change and loss in process, rather than as an end product.
Metalinguistic discourse and dialect performance
Authors: Guerra Kathleen S.
Published: February 2023

This investigation examines how dialect identity and linguistic ideologies are negotiated and performed throughdar+gerund, a northern Andean Spanish construction used to express an attenuated request or favor. Specifically, positive, neutral, and negative sentiments expressed through metalinguistic commentary are analyzed from a corpus of 450 tweets collected on Twitter between 2008- May 2019. This analysis shows how a higher degree of emotional intensity in negative sentiments signals linguistic and cultural discrimination towards this Kichwa-contact induced construction. On the other end, positive sentiments celebrate and defend this feature as an intrinsic part of the Andean Ecuadorian dialect and identity. This negotiation of the linguistic and cultural significance ofdar+gerund serves to destabilize dominant negative perceptions and renegotiate the meaning of this NAS feature.
Effect of welding speed on microstructural and mechanical properties of EB Ti-15V-3Al-3Cr-3Sn welds
Authors: Krishna K. Vamsi , Talari M. K. , Bandi Bharath , Rowthu Sriharitha , Khan M. I. , Mastanaiah P. , Kishore Babu N.
Published: February 2023

In the current study, the influence of welding speed (500, 700 and 800 mm/min) and post-weld heat treatment (PWHT) on microstructure and mechanical properties of electron beam welded Ti-15V-3Al-3Cr-3Sn was systematically studied. The welds at 800 mm/min welding speed showed higher ultimate tensile strength (UTS) (751 MPa), and hardness (245 HV) compared to welds prepared with 500 mm/min welding speed (UTS 670 MPa; hardness 235 HV). The higher strength at 800 mm/min welding can be attributed to the lower columnar width of β grains and the formation of equiaxed grains at the weld root and centre. A significant increase in UTS and hardness values was observed in samples subjected to the post-weld heat treatment (PWHT) for all the weld speeds.
Microstructure and enhanced mechanical performances of dissimilar Mg alloys fabricated by pulse current-assisted friction stir welding (PCaFSW)
Authors: Wang Ziqian , Liu Yongyong , Yuan Tao , Wang Lei , Chen Shujun , Gao Qiang
Published: February 2023

The dissimilar AZ31B/AZ61 Mg alloy joints were fabricated by pulse current-assisted friction stir welding (PCaFSW). The maximum tensile strength and elongation were 314.28 MPa and 13.66%, respectively. A micro interlocking structure was formed and the grain refinement effect was enhanced by the PCaFSW process, which was improved relative to that in the conventional FSW. The enhanced strength and plasticity with increasing pulse current were attributable to the grain refinement, weakening of texture strength, formation of nano-scale precipitates and increase of short dislocation lines. The fracture mode was transformed from a brittle fracture mode to a combined fracture mode of brittle and ductile fractures.
Heritage politics in the case of Black Lives Matter in Bolzano-Bozen, Italy
Authors: Budabin Alexandra Cosima
Published: February 2023

This contribution looks at the Black Lives Matter (BLM) protests that took place in Bolzano-Bozen, the capital of the autonomous province of South Tyrol (Italy). As part of the BLM protests, an iconic statue of Italian cultural heritage was doused with red paint, transmitting a message with local, national, and international resonance. The case demonstrates how the USA BLM diffusion in Europe interacted with the ongoing statue wars to not only advance national level dialogues around racist legacies related to imperialism and colonialism but also specific local grievances. I marshal the concept of ‘ideological vandalism’ to argue that red paint attacks on public monuments can link transnational messages around racism and colonialism with local and national debates particularly regarding participation in heritage politics. This case underscores how claims can arise when national and international sociopolitical debates connected to colonialism and imperialism activate and surface additional local grievances around participation.
Imaginary-Time Quantum Relaxation Critical Dynamics with Semi-Ordered Initial States
Authors: Li Zhi-Xuan , Yin Shuai , Shu Yu-Rong
Published: February 2023

We explore the imaginary-time relaxation dynamics near quantum critical points with semi-ordered initial states. Different from the case with homogeneous ordered initial states, in which the order parameter M decays homogeneously as M ∝ τ
−β/νz
, here M depends on the location x, showing rich scaling behaviors. Similar to the classical relaxation dynamics with an initial domain wall in model A, which describes the purely dissipative dynamics, here as the imaginary time evolves, the domain wall expands into an interfacial region with growing size. In the interfacial region, the local order parameter decays as M ∝ τ
−β/νz
, with β
1 being an additional dynamic critical exponent. Far away from the interfacial region the local order parameter decays as M ∝ τ
−β/νz
in the short-time stage, then crosses over to the scaling behavior of M ∝ τ
−β/νz
when the location x is absorbed in the interfacial region. A full scaling form characterizing these scaling properties is developed. The quantum Ising model in both one and two dimensions are taken as examples to verify the scaling theory. In addition, we find that for the quantum Ising model the scaling function is an analytical function and β
1 is not an independent exponent.
Electronic structure characteristics of two-dimensional ferroelectric heterostructures α-In2Se3/ZnSe
Authors: ZhuoLiang Yu , Tao Jiayou , Lin Lang , Xiaoxiang Sun , Zhijun Zou , Fen Li , Yu-Qing Zhao , Biao Liu , Chang Li , Gaohua Liao
Published: February 2023

At present, chips urgently need breakthrough development in the power consumption and integration. The chip integrates billions or even tens of billions of electronic components, such as field effect transistor, diode and so on. Therefore, the research and development of new low-power electronic components with smaller size is an effective method to reduce chip power consumption and improve chip integration. In this paper, the ferroelectric field effect transistor (Fe-FET) based on two-dimensional heterostructures α-In2Se3/ZnSe is proposed. Based on the first principle, the program will analyze the stability and band structure of α-In2Se3/ZnSe under different stacking modes. In the heterojunction, the microphysical mechanism of ferroelectric polarization affecting the electronic structure is revealed from the aspects of charge transfer at the interface and the asymmetric surfaces with different work function. Combined with the non-equilibrium Green’s function transport theory, the transport properties of Fe-FET based on their α-In2Se3/ZnSe will be studied. The application will provide sufficient theoretical support for research and development of the device based on α-In2Se3/ZnSe structure.
Interaction of two Rydberg atoms in the vicinity of an optical nanofibre
Authors: Stourm E , Lepers M , Robert J , Nic Chormaic S , Mølmer K , Brion E
Published: February 2023

We consider two rubidium atoms, prepared in the same S or P Rydberg states, near an optical nanofibre, and we determine their van der Waals interaction potential as a function of their separation along the nanofibre axis, their distance to the nanofibre axis, and their relative azimuthal angle. We compare results obtained through direct diagonalisation of the Hamiltonian (including quadrupolar interaction terms) with second-order perturbation calculations, and we identify which couplings mainly contribute to the potential in the presence of the nanofibre and in free-space. We relate the appearance of new allowed couplings to the broken rotation symmetry around the interatomic axis due to the presence of the fibre. These couplings induce novel features and cause a reshaping of the interaction anisotropy and formation of an interaction potential well for P states near the nanofibre. Our work constitutes an important step in the assessment of Rydberg atom-nanofibre quantum interfaces and devices.
Energy transport and optimal design of noisy Platonic quantum networks
Authors: Javaherian C , Ferrie C
Published: February 2023

Optimal energy transport is one of the primary goals for designing efficient quantum networks. In this work, the maximum energy transport is investigated for three-dimensional quantum networks with Platonic geometries affected by dephasing and dissipative Markovian noise. The network and the environmental characteristics corresponding the optimal design are obtained and investigated for five Platonic networks with 4, 6, 8, 12, and 20 number of sites that one of the sites is connected to a sink site through a Markovian dissipative process. Such optimal designs could have various applications like switching and multiplexing in quantum circuits.
Driving skyrmions with low threshold current density in Pt/CoFeB thin film
Authors: Ojha Brindaban , Mallick Sougata , Panigrahy Sujit , Sharma Minaxi , Thiaville André , Rohart Stanislas , Bedanta Subhankar
Published: February 2023

Magnetic skyrmions are topologically stable spin swirling particle like entities which are appealing for next generation spintronic devices. The expected low critical current density for the motion of skyrmions makes them potential candidates for future energy efficient electronic devices. Several heavy metal/ferromagnetic (HM/FM) systems have been explored in the past decade to achieve faster skyrmion velocity at low current densities. In this context, we have studied Pt/CoFeB/MgO heterostructures in which skyrmions have been stabilized at room temperature (RT). It has been observed that the shape of the skyrmions are perturbed even by the small stray field arising from low moment magnetic tips while performing the magnetic force microscopy (MFM), indicating presence of low pinning landscape in the samples. This hypothesis is indeed confirmed by the low threshold current density to drive the skyrmions in our sample, at velocities of few ∼10 m s−1.
Gauged quintessence
Authors: Kaneta Kunio , Lee Hye-Sung , Lee Jiheon , Yi Jaeok
Published: February 2023

Despite its dominance in the present universe's energy budget, dark energy is the least
understood component in the universe. Although there is a popular model for the dynamical dark
energy, the quintessence scalar, the investigation is limited because of its highly elusive
character. We present a model where the quintessence is gauged by an Abelian gauge symmetry. The
quintessence is promoted to be a complex scalar whose real part is the dark energy field while the
imaginary part is the longitudinal component of a new gauge boson. It brings interesting
characters to dark energy physics. We study the general features of the model, including how the
quintessence behavior is affected and how the solicited dark energy properties constrain its gauge
interaction. We also note that while the uncoupled quintessence models are suffered greatly from
the Hubble tension, it can be alleviated if the quintessence is under the gauge symmetry.
Blue (0.44 µm) and red (1.7 µm) diode laser activated bleaching—dental shade changes determination
Authors: Dostálová T , Kratochvíl J , Jelínková H , Nocar A , Vavříčková L
Published: February 2023

Tooth whitening or bleaching is one of the most common dental procedures that optimize the white color of the teeth and minimize the simultaneous damage to the tooth structure. Light can speed up the whitening process with halogen lamps, light-emitting diodes, plasma arc lamps, and lasers. Our results show that combinations of a teeth whitening agent with laser light irradiation with a 0.44 µm blue laser diode or a 1.7 µm near-IR laser diode accelerate the whitening process not only during tooth irradiation but also within two weeks after the procedure.
Analysis of high frequency Alfvén eigenmodes observed in ASDEX Upgrade plasmas in the presence of RF-accelerated NBI ions
Authors: Ochoukov R. , Sipilä S. , Bilato R. , Bobkov V. , Dreval M. , Weiland M. , Dendy R. , Faugel H. , Johnson T. , Kappatou A. , Kazakov Y. , McClements K.G. , Moseev D. , Salewski M. , Schneider P. , Team ASDEX Upgrade , MST1 Team EUROfusion
Published: February 2023

High frequency Alfvén eigenmodes in the ion cyclotron frequency range are actively researched on the ASDEX Upgrade tokamak (AUG). The general properties of this particular mode type are: (a) the mode is beam-driven and, if excited, can persist for the entire duration of the beam-on time window; (b) the mode is sub-cyclotron with the frequency ω ∼0.5ω
ci, where ωci corresponds to the on-axis cyclotron frequency of the beam ions; (c) the mode propagates in the counter-current/counter-injection direction; and (d) the field-aligned (∼toroidal) mode number is large: |n
//| ∼50. It has been observed on AUG that radio frequency- (RF)-acceleration of beam-injected ions at the 3rd cyclotron harmonic significantly expands the number of excited modes. In this work we demonstrate how this observation is consistent with the global Alfvén eigenmode (GAE) behavior. The RF-driven fast ion population is modeled using a combination of an orbit-following Monte Carlo code (ASCOT-RFOF) and an electro-magnetic wave code (TORIC). The application of this code combination is a first to model beam-ion RF-acceleration at the 3rd cyclotron harmonic. The RF-accelerated fast ion distributions are then used to analytically calculate anisotropy-driven mode growth rates. We see that the region of positive (unstable) growth rates is expanded by RF-accelerated fast ions in both the frequency and the mode number directions for the GAEs, consistent with the measurements. Although the compressional Alfvén eigenmode growth rates are also positive for our particular fast ion distributions, the growth rate values are ∼3 orders of magnitude lower. The plasma conditions on AUG are more destabilizing to the GAEs. Overall, our results are consistent with the observation of similar modes on other conventional tokamaks, namely JT-60U and DIII-D.
Using Artificial Intelligence and Machine Learning Model for Prediction of Uniaxial Compressive Strength of GGBS Concrete
Authors: Shanmukh Bandaru Sri Sai , Sasirekha Bandaru Sri Veera Bhadra , Sampath Varikuti Raja Sai
Published: February 2023

Ground Granulated Blast-furnace Slag (GGBS) concrete is sustainable and also proven to show enhanced properties such as reduced heat of hydration, refinement of pore structure and increased resistance to corrosion and chemical attacks when compared with Ordinary Portland Cement concrete. Uniaxial compressive strength (UCS) and enhanced properties of the GGBS concrete are dependent on the proportions of GGBS and other elements in the mix. It is essential to accurately predict the UCS of the blended mix. Developments in computer hardware and the easy availability of research data made artificial intelligence and machine learning (AI & ML) prediction techniques feasible. In this study AI & ML techniques namely, linear regression, lasso regression and ridge regression are used to predict the UCS of GGBS concrete. Algorithms are trained using data collected from various standard publications. All data points are cleaned and then normalized with standard scalar function to avoid biased predictions. Root Mean Squared Error, Mean Squared Error, Mean Absolute Error and Coefficient of Determination for all three techniques are found to be almost identical. The above-mentioned AI & ML models have high prediction accuracy. Hence, based on the results AI & ML algorithms specified above can be reliably used in the above-mentioned GGBS concrete.
Thermal Analysis of Reinforced Beam-Column Joint
Authors: Agnihotri Utkarsh , Mishra Vinayak , Singh R. P.
Published: February 2023

In concrete structures, temperature changes can cause strains of the same order of magnitude as live and dead loads in some circumstances. When thermal expansion or contraction is controlled, thermal stresses are induced. This report discusses the performance of reinforced joints under thermal loading conditions. Here we analysed the variance in stress and deflection when the temperature increases. The joints are modelled in ETABS and imported into ANSYS for further thermal analysis. The aim is to evaluate the RC beam-column joints at high temperatures in transient response. The results discuss how RC joints respond to temperature variations. The deformations with temperature variation are examined at high-temperature conditions.
The Implications of Sustainable Fine Aggregate on Self-Compacting Concrete: A Review
Authors: Waliitagi Asha , Rathanasalam Vijaya Sarathy , Bramendra Kishore H R , chithambaram S.Jeeva
Published: February 2023

Concrete that is self-compacting or self-consolidating is referred to as SCC with unique properties such as flowability, self-consolidation, and workability and it can be placed in any type of Reinforced cement concrete (RCC) work where reinforcements are congested and not able to do compaction. In this fast-moving modern era, the role of SCC is unavoidable. It is an advanced method of concreting and sustainable materials that can be utilized as an alternative to river sand or crushed stone sand which includes waste foundry sand, steel slag, stainless steel slag, and iron slag, among others. These materials are the product of industries and create dumping problems in the environment. These materials have a similar composition to fine aggregate there for can be replaced by some percentage with fine aggregate. To bring an alternative to existing river sand and to prevent sand mining In this novel paper detailed investigation has been made to review different sustainable material as fine aggregate and a critical review is done about the SCC features (fresh and hardened) produced using waste foundry sand, steel slag, stainless steel slag and iron slag respectively. In addition, mechanical properties along with microstructure studies of different sustainable fine aggregates are discussed. The optimum substitution rate for sustainable fine aggregate and its benefits are studied. All the alternative fine aggregate has made a significant impact on fresh and hardened properties. Due to their unique performance, various fine aggregates notably waste foundry sand, steel slag, stainless steel slag and iron slag can be employed in making SCC.
Effect of Base Isolation under Different Soil Conditions
Authors: Rajput Gautam , mishra Vinayak , Singh R. P.
Published: February 2023

Severe seismic activity is a cause of grave concern for all kinds of structures. In order to safeguard buildings from earthquakes we use novel techniques based on performance-based seismic design. The base isolation method is one such technique utilized to reduce the effect of large-scale vibration produced during a seismic vibration. In this paper, we analyze two models: the first G+6 building and the second G+18 building using Lead Rubber Bearing (LRB). The analysis is done using ETABS software and here we use the non-linear time history method. Using the soil intrinsic effects like flexibility and stiffness, this research considers variation in displacement, drift, and repositioning of the soil in accordance with IS code 1893:2016. A greater spectral displacement was detected in medium soil in a fixed base structure. The time period for Lead Rubber Bearing building is greater than the conventional building. Base shear is minimized in (LRB) Lead rubber bearings as compared to a conventional building.