Miracle-dz/UniFAR-FTUs huggingface dataset:
Design of Virtual Inertia Controller for DC Microgrid Using Zero Placement Technique

Abstract With DC microgrids becoming popular, the concept of virtual inertia control (VIC) is gaining attention to minimize the DC bus voltage fluctuations caused by intermittent sources and loads. VIC scheme controls the power electronic converter (PEC) to achieve a smooth voltage profile. However, the intrinsic output impedance of the converter acts as an output disturbance and distorts the inertial response. An additional feed-forward controller has been used in previous works to mitigate this. However, the design proposed in this paper eliminates the additional controller while achieving a smooth voltage profile. This paper proposes a zero placement technique-based design of virtual inertia controller for a DC microgrid. Small-signal models for the system with the proposed controller designed using zero placement were developed to analyze the stability and the effect of parameter variation for optimal performance. Next, the application of the proposed design methodology is extended to a system employing two battery energy storage system units for analyzing parallel operation. Finally, the effectiveness of the controller designed using the zero placement technique was verified under different loading conditions through MATLAB/Simulink simulations and experiments carried out on the developed laboratory prototype.
Mitigating Range Ambiguity Method Based on DDMA for SAR Systems

Range ambiguity can lead to deterioration of imagery quality for space-borne synthetic aperture radar (SAR). To solve this problem, we propose a mitigating range ambiguity method based on Doppler division multiple access (DDMA) in this paper. With the orthogonality of the DDMA waveform, transmit channels are separated at the receiver. Afterwards, a pre-processed operation for definition domains of different transmit channels is put forward to transform all definition domains into the same one. Thereafter, by multiplying measured data in a transmit channel by the complex conjugation of those in the other channel, a coupling phase term between the ambiguous range and the Doppler can be generated. So, utilizing the coupling phase, the echoes of different ambiguous regions can be distinguished in the slow-time domain, and they are extracted by designing time domain passband filters. Moreover, the images of different extracted ambiguous regions can be reconstructed to compose the whole unambiguous image. Finally, simulation results exhibit the effectiveness of the proposed method.
Dust dynamics and evolution in H II regions - II. Effects of dynamical coupling between dust and gas

In this paper, we extend the study initiated in PaperI by modelling grain ensemble evolution in a dynamical model of an expanding HII region and checking the effects of momentum transfer from dust to gas. The radiation pressure on the dust, the dust drift, and the lug on the gas by the dust are all important process that should be considered simultaneously to describe the dynamics of HII regions. With accounting for the momentum transfer from the dust to the gas, the expansion time of the HII region is notably reduced (for our model of RCW120, the time to reach the observed radius of the HII region is reduced by a factor of 1.5). Under the common approximation of frozen dust, where there is no relative drift between the dust and gas, the radiation pressure from the ionizing star drives the formation of the very deep gas cavity near the star. Such a cavity is much less pronounced when the dust drift is taken into account. The dust drift leads to the two-peak morphology of the dust density distribution and significantly reduces the dust-to-gas ratio in the ionized region (by a factor of 2 to 10). The dust-to-gas ratio is larger for higher temperatures of the ionizing star since the dust grains have a larger electric charge and are more strongly coupled to the gas.
Occurrence of Listeria spp. in Soft Cheese and Ice Cream: Effect of Probiotic Bifidobacterium spp. on Survival of Listeria monocytogenes in Soft Cheese

Listeria monocytogenes is one of the most important emerging foodborne pathogens. The objectives of this work were to investigate the incidence of Listeria spp. and L. monocytogenes in soft cheese and ice cream in Assiut city, Egypt, and to examine the effect of some probiotic Bifidobacterium spp. (Bifidobacterium breve, Bifidobacterium animalis, or a mixture of the two) on the viability of L. monocytogenes in soft cheese. The existence of Listeria spp. and L. monocytogenes was examined in 30 samples of soft cheese and 30 samples of ice cream. Bacteriological analyses and molecular identification (using 16S rRNA gene and hlyA gene for Listeria spp. and L. monocytogenes, respectively) were performed on those samples. Additionally, Bifidobacterium spp. were incorporated in the making of soft cheese to study their inhibitory impacts on L. monocytogenes. Out of 60 samples of soft cheese and ice cream, 25 samples showed Listeria spp. , while L. monocytogenes was found in only 2 soft cheese samples. Approximately 37% of soft cheese samples (11 out of 30) had Listeria spp. with about 18.0% (2 out of 11) exhibiting L. monocytogenes. In ice cream samples, Listeria spp. was presented by 47% (14 out of 30), while L. monocytogenes was not exhibited. Moreover, the addition of B. animalis to soft cheese in a concentration of 5% or combined with B. breve with a concentration of 2.5% for each resulted in decreasing L. monocytogenes efficiently during the ripening of soft cheese for 28 d. Listeria spp. is widely found in milk products. Probiotic bacteria, such as Bifidobacterium spp. , can be utilized as a natural antimicrobial to preserve food and dairy products.
Robust Point Matching for Non-Rigid Shapes: A Relaxation Labeling Based Approach

Abstract : Shape matching, or image registration, which is often formulated as a point matching problem, is frequently encountered in image analysis, computer vision, and pattern recognition. Although the problem of registering rigid shapes was widely studied, non-rigid shape matching has recently received more and more attention. For non-rigid shapes, most neighboring points cannot move independently under deformation due to physical constraints. Therefore, though the absolute distance between two points may change significantly, the neighborhood of a point is well preserved in general. Based on this observation, we formulate point matching as a graph matching problem. Each point is a node in the graph, and two nodes are connected by an edge if their Euclidean distance is less than a threshold. The optimal match between two graphs is the one that maximizes the number of matched edges. The shape context distance is used to initialize the graph matching, and relaxation labeling (after enforcing one-to-one matching) is used to refine the matching results. Non-rigid deformation is overcome by bringing one shape closer to the other in each iteration using deformation parameters estimated from the current point correspondence. Experiments on real and synthesized data demonstrate the effectiveness of our approach: it outperforms shape context and TPS-RPM algorithms under non-rigid deformation and noise on a public data set.
Critical currents and vortex-unbinding transitions in quench-condensed ultrathin films of bismuth and tin

We have investigated the I-V characteristics of strongly disordered ultrathin films of Bi and Sn produced by quench condensation. Our results show that both these systems can be visualized as strongly disordered arrays ofJosephson junctions. The experimentally observed I-V characteristics of these films are hysteretic when the injected current is ramped from zero to critical current and back. These are remarkably similar to the hysteretic I-V of an underdamped single junction. We show by computer simulations that hysteresis can persist in a very strongly disordered array. It is also possible to estimate the individual junction parameters (R, C, and I c ) from the experimental I-V of the film using this model. The films studied are in a regime where the Josephson-coupling energy is larger than the charging energy. We find that a simple relation I c (t)=I c (0)[1-(T/T c ) 4 ] describes the temperature dependence of the critical current quite accurately for films with sheet resistance ∼500 Ω or lower. We also find evidence of a vortex-unbinding transition in the I-V taken at temperatures slightly below the mean-field T c .
On a new measure of dependence and its applications

Abstract A new measure of dependence called pseudo-covariance and related to covariance is proposed. It can be applied in problems when the classic covariance fails. We show that it can be used as a measure of dependence of uncorrelated random variables and in characterizations of continuous distributions (here power distribution on (0, 1) and exponential distribution).
Collapse of the critical state in superconducting niobium

Giant abrupt changes in the magnetic-flux distribution in niobium foils were studied by using magneto-optical visualization, thermal, and magnetic measurements. Uniform flux jumps and sometimes almost total catastrophic collapse of the critical state are reported. Results are discussed in terms of thermomagnetic instability mechanism with different development scenarios.
Flux rope proxies during 2013 detected by the Solar Dynamics Observatory

Context. The relationship between ﬂux ropes and coronal mass ejections (CMEs) is of great importance for understanding the CME initiation, but we do not know how many ﬂux ropes in the atmosphere can be detected. Aims. We aim to determine the number of ﬂux rope proxies and understand the distribution of the proxies over the visible solar disk. Methods. By employing the observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory, we counted the number of the ﬂux rope proxies from 2013 January to 2013 December. Results. We detected 1354 (3.7 every day) rope proxies during this period and classiﬁed them into three types according to their temperature properties and particular (sigmoid) structures. The ﬁrst type is that the rope proxies are detected in both lower and higher temperature lines. The second is that the rope proxies can only be detected in higher temperature lines, and the third is that the proxies display sigmoid structures in extreme ultraviolet channels. Six hundred and ﬁfty-eight proxies of the 1354 that belong to the ﬁrst type are tracked by active or eruptive material of ﬁlaments or prominences. Four hundred and eighty-seven proxies appear to be rising from the lower atmosphere or brightening in the corona, and belong to the second type. The remaining 209 display sigmoid structures, and they are attributed to the third type. We detected 497 rope proxies, which is 37% of the total, in the northern hemisphere. Conclusions. Our ﬁndings imply a signiﬁcantly asymmetric distribution of the rope proxies over the visible solar disk.
Mineral matter hydropyrolysis of Tarfaya oil shale and influence of sedimentation edge

In hydrotreating the reactivity of the mineral matter of the oil shale from the five layers of the Tarfaya deposit and the M layer of the Timahdit deposit, both located in Morocco, is different. This reactivity is a function of the climates of the geological eras: Z0 (Tertiary era: cold climate), Z1 (Maestrichtian: hot climate), Z2 (Senonian: cold climate), Z3 (Turonian: warm climate) and Z4 (Cenomanian: warm climate). This explains why the Z3 and Z4 layers are the most reactive, also due to the location of the low peak temperatures as established by derivative thermogravimetry (DTG) for these two layers. There was also a disproportion between the DTG peak area values and the reactivity of the mineral material. The composition of dolomite CaMg(CO 3 ) 2 in the Z1 layer is responsible for the low reactivity observed for this layer.
Effect of Agricultural Social Services on Green Production of Natural Rubber: Evidence from Hainan, China

It is vital to concentrate on conserving the ecological environment and promoting production efficiency in the process of planting natural rubber. Agricultural social services (ASSs) play an essential role in helping rubber farmers to achieve green production. Based on the survey data of 552 natural rubber farmers in Hainan Province, this study builds an index system regarding socialized services for rubber production from three factors: technology extension services, financial insurance services, and market information services. This research uses the slack-based measure (SBM) model and the Tobit model to analyze the green production efficiency (GPE) and the influences of rubber production socialized services on the rubber growers’ green production efficiency. Our results revealed that (1) the average green productivity of rubber planting in Hainan is approximately 0.41, which means that there is ample space for improvement; (2) ASSs have a significant positive effect on increasing the green rubber production efficiency; and (3) among ASSs, the technical extension service has the most significant effect on improving the green production efficiency of the growers. To further raise GPE of natural rubber, the socialized service system can be strengthened in terms of technology, capital, and information. ASSs have noticeable potential in improving the efficiency of rubber green production while ensuring economic, social, and ecological sustainability.
Associations between Deformation of the Thoracolumbar Fascia and Activation of the Erector Spinae and Multifidus Muscle in Patients with Acute Low Back Pain and Healthy Controls: A Matched Pair Case-Control Study

Background: The thoracolumbar fascia (TLF) is thought to play a role in the development of LBP, but it is not yet clear which factor of TLF changes is a cause and which is an effect. Therefore, some studies used the cross-correlation function (CCR) to reveal time-dependent relationships between biomechanical and neuromotor factors. Methods: Ten patients with acute low back pain (aLBP) were matched to healthy controls. Simultaneous recording of surface electromyography (sEMG) of the erector spinae and multifidus muscle (ESM) and dynamic ultrasound (US) images of TLF deformation were performed during trunk extension. CCR functions and Granger causality (GC) were used to describe the relationship between the two measures. Results: CCR time lags were significant higher in the aLBP group (p = 0.04). GC showed a direct effect of TLF deformation on ESM activation only in the aLBP group (p < 0.03). Conclusions: The results suggest that in aLBP, ESM activity is significantly affected by TLF, whereas this relationship is completely random in healthy subjects studied with CCR and GC comparisons of dynamic US imaging and sEMG data signals. Fascia-related disturbances in neuromotor control, particularly due to altered muscle spindle functions, are suspected as a possible mechanism behind this.
Effect of Bovine Colostrum Dietary Supplementation on Rabbit Meat Quality

Bovine colostrum (BC) is rich in nutrients, antimicrobial, and antioxidant factors; for these reasons, it has been used as supplement in animal nutrition. However, its possible effects on meat quality have not been studied yet. Thirty-nine New Zealand White rabbits (n = 13/group) were assigned to three groups and fed until slaughter with a commercial standard diet, control group (C), and C supplemented with 2.5% and 5% (w/w) of BC (BC-2.5 and BC-5 groups, respectively). After slaughtering, the effect of dietary supplementation on microbiological and chemical characteristics of the rabbit loins was evaluated at 48 h postmortem (D0) and after 3 (D3) and 8 (D8) days of refrigerated storage. Results showed no difference in the microbiological parameters. In the supplemented groups, TBARS and TVBN values were lower and higher than in the C group, respectively (p < 0.01), and their fatty-acid profile was increased in SFA and decreased in MUFA (p < 0.05). In conclusion, research must continue to examine in depth the possible effects of BC byproduct reuse in animal nutrition on meat quality (e.g., antioxidant power, and physical and sensory characteristics).
Quantum simulators by design: Many-body physics in reconfigurable arrays of tunnel-coupled traps

We present a novel platform for the bottom-up construction of itinerant many-body systems: ultracold atoms transferred from a Bose-Einstein condensate into freely configurable arrays of micro-lens generated focused-beam dipole traps. This complements traditional optical lattices and gives a new quality to the field of two-dimensional quantum simulators. The ultimate control of topology, well depth, atom number, and interaction strength is matched by sufficient tunneling. We characterize the required light fields, derive the Bose-Hubbard parameters for several alkali species, investigate the loading procedures and heating mechanisms. To demonstrate the potential of this approach, we analyze coupled annular Josephson contacts exhibiting many-body resonances.
Atomically thin semiconductors as nonlinear mirrors

We show that a transition metal dichalcogenide monolayer with a radiatively broadened exciton resonance would exhibit perfect extinction of a transmitted field. This result holds for s- or p-polarized weak resonant light fields at any incidence angle, due to the conservation of in-plane momentum of excitons and photons in a flat defect-free two dimensional crystal. In contrast to extinction experiments with single quantum emitters, exciton-exciton interactions lead to an enhancement of reflection with increasing power for incident fields that are blue detuned with respect to the exciton resonance. We show that the interactions limit the maximum reflection that can be achieved by depleting the incoming coherent state into an outgoing two-mode squeezed state.
Calcium and Boron Fertilization Improves Soybean Photosynthetic Efficiency and Grain Yield

Foliar fertilization with calcium (Ca) and boron (B) at flowering can promote flower retention and pod fixation, thereby increasing the number of pods per plant and, in turn, crop productivity. The objective of this work was to investigate the effects of Ca + B fertilization during flowering on the nutritional, metabolic and yield performance of soybean (Glycine max L.) The treatments consisted of the presence and the absence of Ca + B fertilization in two growing seasons. Crop nutritional status, gas exchange parameters, photosynthetic enzyme activity (Rubisco), total soluble sugar content, total leaf protein concentration, agronomic parameters, and grain yield were evaluated. Foliar Ca + B fertilization increased water use efficiency and carboxylation efficiency, and the improvement in photosynthesis led to higher leaf sugar and protein concentrations. The improvement in metabolic activity promoted a greater number of pods and grains plant−1, culminating in higher yields. These results indicate that foliar fertilization with Ca + B can efficiently improve carbon metabolism, resulting in better yields in soybean.
The Analysis of the Power Law Feature in Complex Networks

Consensus about the universality of the power law feature in complex networks is experiencing widespread challenges. In this paper, we propose a generic theoretical framework in order to examine the power law property. First, we study a class of birth-and-death networks that are more common than BA networks in the real world, and then we calculate their degree distributions; the results show that the tails of their degree distributions exhibit a distinct power law feature. Second, we suggest that in the real world two important factors—network size and node disappearance probability—will affect the analysis of power law characteristics in observation networks. Finally, we suggest that an effective way of detecting the power law property is to observe the asymptotic (limiting) behavior of the degree distribution within its effective intervals.
BEARING CAPACITY OF T BEAM UNDER DIFFERENT PRESTRESS LEVELS: FULL-SCALE EXPERIMENT AND FEM ANALYSIS

Insufficient prestress will cause cracks in the T beam, which will influence its stiffness and bearing capacity. This paper is devoted to studying the influence of prestress levels on the bearing capacity of T beam, and then judging its working state. A full-scale model experiment is carried out on the 13 meters prestressed concrete T beam. At the same time, a nonlinear finite element model is established and verified. The experimental results show the numerical simulation results are in good agreement with the experimental results. Finally, the finite element model is used to make a simulation of the bearing capacity of T beams under different prestress levels. The mathematical relationship between prestress levels and bearing capacity is obtained based on the results of the finite element model. The relationships between the mid-span deflection and load of the experimental beam are basically the same under different prestress levels, both including three stages: elastic stage, crack development stage and failure stage. With the increase of the prestress levels, the stiffness of the experimental beam before cracking is improved significantly.
A Micron-Range Displacement Sensor Based on Thermo-Optically Tuned Whispering Gallery Modes in a Microcapillary Resonator

A novel micron-range displacement sensor based on a whispering-gallery mode (WGM) microcapillary resonator filled with a nematic liquid crystal (LC) and a magnetic nanoparticle- coated fiber half-taper is proposed and experimentally demonstrated. In the proposed device, the tip of a fiber half-taper coated with a thin layer of magnetic nanoparticles (MNPs) moves inside the LC-filled microcapillary resonator along its axis. The input end of the fiber half-taper is connected to a pump laser source and due to the thermo-optic effect within the MNPs, the fiber tip acts as point heat source increasing the temperature of the LC material in its vicinity. An increase in the LC temperature leads to a decrease in its effective refractive index, which in turn causes spectral shift of the WGM resonances monitored in the transmission spectrum of the coupling fiber. The spectral shift of the WGMs is proportional to the displacement of the MNP-coated tip with respect to the microcapillary’s light coupling point. The sensor’s operation is simulated considering heat transfer in the microcapillary filled with a LC material having a negative thermo-optic coefficient. The simulations are in a good agreement with the WGMs spectral shift observed experimentally. A sensitivity to displacement of 15.44 pm/µm and a response time of 260 ms were demonstrated for the proposed sensor. The device also shows good reversibility and repeatability of response. The proposed micro-displacement sensor has potential applications in micro-manufacturing, precision measurement and medical instruments.