Pulse Ratio Research Articles

The effect of cold plasma pretreatment on drying efficiency of beetroot by intermittent microwave-hot air (IMHA) hybrid dryer method: Assessing drying kinetic, physical properties, and microstructure of the product

This study examined the effects of cold plasma (CP) pretreatment with durations of 1, 3, and 5 minutes on drying kinetics, microstructure, and physical properties, including shrinkage, rehydration ratio (RR), and bulk density of beetroot dried samples using intermittent microwave-hot air (IMHA) drying at 40 °C and pulse ratios (PR) of 1 and 2. While increasing PR decreased drying rate (DR) and effective moisture diffusivity (Deff), increasing microwave power from 180 to 600 W increased both, reducing drying time and specific energy consumption (SEC). Extended CP-pretreatment doubled DR, 66% increased Deff, and 24% reduced SEC. Both increasing CP-pretreatment time and microwave power had similar effects on shrinkage, RR, and bulk density, but CP-pretreatment was more prominent; reducing shrinkage by 18%, bulk density by 23%, and increasing RR by approximately 36% in 5-minutes. X-ray imaging showed that 600 W of microwave power increased porosity by 87%, while 5-minute CP-pretreatment increased it by 27%. As the optimum condition, CP-pretreatment for 5 minutes, continuous microwave application, and 600 W of MW power produced the best kinetics and physical properties. Overall, the results demonstrated that the appropriate CP-pretreatment duration could produce high-quality dried samples.

HCN channel-dependent presynaptic potentiation at LA-BA synapses is required for fear memory formation

Previously, we demonstrated that auditory fear conditioning produces presynaptic potentiation at lateral to basal amygdala (LA-BA) synapses, which occludes high-frequency stimulation (HFS)-induced ex-vivo LTP. We also found that the HFS-induced ex-vivo LTP requires presynaptic hyperpolarization-activated cyclic nucleotide-gated (HCN) channel activity. In this study, we investigated whether HCN channels are necessary for auditory fear conditioning in vivo. Our results show that ZD7288, an HCN channel blocker, reduced synaptic transmission and decreased the paired pulse ratio (PPR) only in slices from rats that underwent auditory fear conditioning, but not from naïve rats. This indicates that fear conditioning involves HCN channel-dependent presynaptic potentiation at LA-BA synapses. Importantly, injecting ZD7288 into the basal amygdala (BA) before auditory fear conditioning significantly impaired long-term fear memory formation. Since HCN channel activity is necessary for LTP at LA-BA synapses but not at cortico-BA, cortico-LA, or thalamo-LA synapses, HCN channel-dependent presynaptic potentiation at LA-BA synapses appears to be crucial for auditory fear conditioning.

Nutritional Composition of Developed Bars and Their Impact on Work Performance of Adolescent Swimmers’ Girls

With the growing interest in sports nutrition and its impact on athletic performance, understanding the specific needs of adolescent athletes, particularly females, is crucial for optimizing their training and performance outcomes. The three variants of the Protein-rich bar (PB1, PB2, PB3) with the CB were developed by using different ingredients. The research employs a mixed-methods approach, combining nutritional analysis of developed bars with performance assessments among adolescent swimmers’ girls. Firstly, organoleptic evaluation (9-point hedonic scale) was performed on the variants of Protein-rich bar with the CB. Then nutritional analysis involves proximate (moisture, ash, protein, crude fat, crude fiber, CHO), mineral (calcium, iron), as well as antioxidant analysis (DPPH, TPC, vitamin C) assessed on selected variants of Protein-rich bar with the CB. Pre- and post-intervention were done on two groups for 3 months and performance assessments included anthropometric measurement, sit and reach test, hand grip strength test, Nelson hand reaction time test, and Tuttle pulse ratio test. Preliminary findings suggested that the developed bars (PB1) provide a more balanced nutritional profile than the CB. Moisture 10.2±0.66%, ash 3.7±0.27%, protein 22.3±0.74 g, crude fat 13.1±0.41 g, crude fiber 11.5±0.02 g, CHO 39.4±0.19 g, iron 4.4±0.15 mg, calcium 82.4±0.21 mg, DPPH 47.6±0.31%, TPC 53.1±0.11 mg GAE, and vitamin C 11.2±0.19 mg in 100 g respectively in PB1 and significantly difference at (p<0.05). Additionally, the consumption of PB1 bar appears to positively impact higher work performance among adolescent swimmers girls. Overall, this study contributes to the growing body of research on sports nutrition tailored to adolescent athletes, particularly focusing on the nutritional needs of swimmers girls.

Threshold of stochastic self-focusing from the Poisson property of extreme-event statistics.

Statistics of self-focusing induced by a stochastic laser driver is shown to converge, in the large-sample-size limit, to a generalized Poisson distribution whose mean is given by the exponent of the respective extreme-value statistics. For a given ratio of the laser peak power to the self-focusing threshold Pcr, the mean number of self-focusing counts in a large sample of laser pulses is shown to depend on the number of pulses in the sample, N, and the signal-to-noise ratio of laser pulses, a. We derive a closed-form solution for the threshold of stochastic self-focusing, which, unlike its deterministic counterpart, Pcr, is a function of the sample size N and the signal-to-noise ratio a. The parameter Na = exp (a2/2) is shown to set a borderline between the deterministic and stochastic regimes of self-focusing. When the number of laser pulses in a sample becomes comparable to Na, self-focusing can no longer be viewed as deterministic even for high signal-to-noise laser beams.

Synaptic and membrane properties of cholinergic interneurons in the striatum of aristaless-related homeobox gene mutant mice.

A whole-cell patch-clamp study was carried out to investigate membrane and synaptic properties of cholinergic interneurons in the striatum of aristaless-related homeobox gene (ARX) mutant mice. Brain slices were prepared from mice knocked in two types of ARX, P355L (PL) and 333ins (GCG)7 (GCG). The input resistance of cholinergic interneurons in PL or GCG mice was significantly smaller than that in wild type (WT), whereas resting membrane potential, threshold of action potentials, spontaneous firing rate, sag ratio or afterhyperpolarization of the mutant mice were not significantly different from those of WT mice. In GCG mice, NMDA/AMPA ratio of excitatory postsynaptic currents (EPSCs) evoked in cholinergic interneurons was significantly smaller than that in WT and PL mice, whereas the ratio between PL and WT mice was not significantly different. Although inhibitory effects induced by dopamine D2-like receptor activation on the inhibitory postsynaptic currents (IPSCs) were not significantly different between WT and PL or GCG mice, increase in the paired pulse ratio of IPSCs by dopamine D2-like receptor activation was abolished in PL and GCG mice. The present results have found abnormalities of neuronal activities as well as its modulation in the basal ganglia in ARX mutant mice, clarifying basic mechanisms underlying related disorders.

Computational study of pulse current and thermal stress on thermoelectric cooler

The thermal performance of a Peltier thermoelectric cooler (TEC) can be enhanced by multi-staging, modifying the geometry of the thermoelement, and using new material with improved thermoelectric properties. This study utilizes COMSOL multiphysics to simulate thermomechanical analyses of various geometries of thermoelectric coolers under pulse current conditions. This investigation explores the influence of pulse current parameters, such as pulse width, pulse ratio, and hot-side convective heat transfer coefficient, on a thermoelectric cooler with different leg geometries. Additionally, the impact of the TEC cold-side temperature, hot-side temperature, and thermal stress on both sides is discussed. The results indicate that TEC leg shapes, such as pin and trapezoid, exhibit the minimum cold-side temperature. Increasing the pulse ratio leads to a decrease in the cold-side temperature and an increase in the hot-side temperature. A notable improvement in the cold-side temperature is also observed with higher pulse ratios, with the pin geometry achieving a minimum cold-side temperature of 276 K. Furthermore, the cooling load affects the temperature on both sides of the TEC. These findings provide valuable insights for optimizing thermoelectric coolers for electronic cooling applications using pulse current methods.

Evaluating perioperative stresses in children by noninvasive modalities using salivary cortisol and autonomic reactivity.

Salivary cortisol (SalC) and low to high pulse ratio (LHR) were used for evaluating perioperative stresses in children. Children aged 6months-16years having elective general (thoracic/abdominal) or minor (open/minimally invasive: MI) procedures underwent pulse monitoring during AM (08:00-12:00) and PM (17:00-21:00) saliva collections from the day before surgery (S-1) to 3days after surgery (S + 3). SalC/LHR were correlated with age, sex, caregiver attendance, operative time, and surgical site/approach using mixed model analysis and face/numeric pain rating scales (FRS/NRS). Mean ages (years): minor-open (n = 31) 4.7 ± 2.0, thoracic-open (n = 2) 8.7 ± 4.9, thoracic-MI (n = 6) 9.6 ± 6.1, abdominal-open (n = 14) 4.3 ± 4.1, and abdominal-MI (n = 32) 8.0 ± 5.0. Postoperative SalC increased rapidly and decreased to preoperative levels by S + 3 (p < 0.001). LHR increased slightly without decreasing (p = 0.038). SalC correlated positively with operative time (p = 0.036) and open surgery (p = 0.0057), and negatively with age (p < 0.0001) and caregiver attendance (p < 0.001). SalC correlated positively with FRS (n = 51) at S + 2(PM) (p = 0.023), S + 3(AM) (p < 0.001), S + 3(PM) (p = 0.012) and NRS (n = 34) at S + 1(AM) (p = 0.031), S + 3(AM) (p < 0.044). LHR positively correlated with age (p = 0.0072), female sex (p = 0.0047), and caregiver attendance (p = 0.0026). Postoperative SalC after robotic-assisted MI was significantly lower than after open surgery at S + 2(AM) (p = 0.020). SalC correlated with pain. Caregiver attendance effectively alleviated stress.

High signal-to-noise ratio harmonic mode-locking Mamyshev oscillator at 1550 nm

Harmonic mode-locking is the effective method to improve ultrafast pulse repetition rate for the current research. However, this way of increasing the repetition rate based on pulse splitting has inherent instability characteristics, manifested as low signal-to-noise ratio and loss of mode-locking. In this paper, Mamyshev regenerative oscillation mode-locking technique is used to effectively improve the signal-to-noise ratio of pulses by compressing the nonlinear chirp in the cavity under the condition of near-zero dispersion. In the experiment, we successfully achieved a harmonic mode-locked pulse of up to 16 orders, corresponding to a repetition rate of 78.56 MHz, and the signal-to-noise ratio of the highest harmonic order reached 70 dB. Our research not only solves the inherent defect of low repetition rate of Mamyshev oscillator, but also effectively improves the signal-to-noise ratio of harmonic mode-locked pulse. This mode-locked structure based on Mamyshev oscillator provides reference and operability for improving the stability of ultrafast fiber lasers.

3D fractal model with experimental analysis for assessing surface topography in EDM

This work presents a novel three-dimensional fractal model designed specifically for morphological analysis of specimens made by the EDM. Within the 3D fractal framework, an algorithm is developed to estimate fractal parameters such as fractal dimension and periodic length. AISI 316 stainless steel, dielectric media, electrode materials, and powder variations were used in experimental trials to validate the 3D fractal model. Fixed pulse time ratios were used to control the EDM process. The specimen having the lowest fractal dimension, the shortest periodic length, the least amount of surface roughness, and the least amount of ten-point height was discovered to be the one machined using kerosene oil dielectric, brass electrode, graphite powder, and 1.0 pulse ratio time. On the other hand, the specimen machined using copper electrode, graphite powder, transformer oil dielectric, and 1.5 pulse ratio time produced the largest periodic length, maximum surface roughness, fractal dimension, and ten-point height. The developed 3D fractal model evaluates the EDM process well and provides insightful information on how to improve surface properties.

Analysis, design, and reliability evaluation of a modified multi‐port quasi‐resonant converter with high gain

AbstractHigh‐gain converters play a vital role in all industrial applications such as automobiles, motor drives, renewable energy systems, and railway transportation sectors. The conventional converters have low gain owing to high‐voltage stress on active MOSFET, diode and low efficiency related with high operating pulse ratio. To overcome the limitations associated with the conventional converters, this study proposes a non‐isolated configuration of multiport quasi‐resonant converter (MP‐QRC) with high gain. The proposed MP‐QRC has the merits of high‐voltage gain, reduced number of components, minimum conduction losses, realization of soft switching in the devices and improved reliability. Moreover, the proposed converter is scalable and can serve as a good candidate in microgrid environment where the integration of more than one input is essential. In this paper, first a comprehensive analysis of various operation modes and design constraints are presented. Further, the study is supported with a reliability evaluation of proposed converter based on component failure. Also, the futuristic behaviour of MP‐QRC under continuous conduction mode as a function of operational and environmental variables is investigated to ascertain the reliability. The steady‐state operation of the converter is demonstrated for off‐board electric vehilce (EV) charging using MATLAB/SIMULINK and experiments performed on a 300‐W test rig.

Surface burn prevention based on the probability control of pulses with ignition delay in WEDM

This study aims to address surface burn and increased probability of wire breakage under high-energy cutting conditions in wire electrical discharge machining (WEDM). Firstly, the causes of surface burns are investigated, revealing that the deterioration of cooling, debris removal, and deionization status in the machining gap are the dominating factors. Maintaining a certain ratio of pulse to ignition delay is essential for proper discharge machining. Secondly, a servo control strategy based on the pulse probability of ignition delay is proposed. When the target probability is preset to 25%, the machining stability is significantly improved, preventing surface burns and decreasing the probability of wire breakage. With this servo control, the maximum average machining current free of surface burn is raised from 6 to 8 A. As a result, the max cutting speed is improved by 24%, and the tensile strength of the wire electrode is enhanced by 23.5%. In addition, the machined surface area increases by 22% when the diameter wear of the wire electrode reaches 0.01 mm. The new servo control has been demonstrated to be effective in facilitating machining efficiency and extending wire electrode durability in WEDM.

Ultrasound-assisted extraction of shikimic acid and determination of total phenolic compounds in water hyacinth: Grey-based Taguchi optimization

Shikimic acid (SA) is a precursor for formulating the antiviral drug oseltamivir phosphate (Tamiflu®). Ultrasound-assisted extraction was employed to extract shikimic acid using water as a solvent and to determine total phenolic compounds (TPC) from water hyacinth. Grey-based Taguchi optimization was used to optimize the yield of shikimic acid and TPC by varying four distinct parameters. The best results for the yield of SA, i.e., 3.3 % (20 min time, 20 mL water volume, 60 % amplitude, and 40 % pulse ratio) and 3.2 % (30 min time, 20 mL solvent volume, 40 % amplitude, and 40 % pulse ratio) were observed using single and multi-response optimization, respectively for the stem. The best results for TPC, i.e., 12.24 mg GAE/ g biomass (20 min time, 40 mL solvent volume, 40 % amplitude, and 30 % pulse ratio) and 10.53 mg GAE/ g biomass (20 min time, 20 mL solvent volume, 50 % amplitude, 40 % pulse ratio) were obtained using single and multi-response optimization, respectively for leaves. The extraction was also performed for a whole plant (without segregation), and 1.66 % yield of SA (20 min time, 20 mL solvent volume, 50 % amplitude, 40 % pulse ratio) and TPC value of 8.84 mg GAE/ g biomass (40 min time, 30 mL solvent volume, 40 % amplitude, 40 % pulse ratio) were obtained.

STUDY OF SCINTILLATION RESPONSE OF NEUTRONS AND GAMMA QUANTA BY THE METHOD OF REMOVING SUPERPOSED PULSE

The presented research work is devoted to the problems of studying the digital method for analyzing neutron and gamma ray pulses by eliminating superimposed responses. This method consists of scintillation detectors, photomultiplier tubes, an analog-to-digital converter and an appropriate algorithm. The method was used to analyze the loading of neutron channels in liquid and crystalline scintillation detectors, the ratio of the number of neutrons in the response with a change in the distance of the gamma-ray source, as well as the ratio of neutron and gamma ray pulses for various scintillator loads. Liquid and crystal scintillators were used as analytical instruments.

Optimal dose of vigorous physical activity on cardiorespiratory and perceptual response for sedentary youths using internal load monitoring.

Vigorous physical activity (VPA) has been demonstrated to enhance cardiorespiratory fitness (CRF) in sedentary college students more effectively than other PA. However, differences in training volume may affect this outcome. This study examines the physiological, psychological, and internal training load (ITL) characteristics of VPA with varying volumes in a single session. Thirty sedentary college students were divided into three groups: high-intensity interval training (HIIT), sprint interval training (SIT), and threshold training (THR). PA process was monitored. The study measured various cardiorespiratory parameters, including heart rate (HR), respiratory waveform and amplitude, respiratory rate (RR), tidal volume (TV), minute ventilation volume (VE), fractional concentration of oxygen in end-tidal gas (O2%), fractional concentration of end-tidal carbon dioxide (CO2%), global oxygen consumption (VO2), carbon dioxide discharge (VCO2), and the amount of carbon dioxide in the air. The following physiological indicators were measured: carbon dioxide discharge (VCO2), Oxygen pulse (OP), and respiratory exchange ratio (RER). Additionally, subjective perception indicators were recorded, including the feeling scale (FS), rating of perceived exertion (RPE), and dual-mode model (DMM). The session-RPE (s-RPE) and Edward's TRIMP were used to measure ITL. There were no significant differences in HR across the three conditions. THR had the highest level of TV (p = 0.043), but RR was significantly lower than that of HIIT and SIT (p < 0.01). HIIT had the highest levels of VO2, VCO2, O2%, and OP (p < 0.05). RPE was higher in HIIT and SIT compared to THR (p < 0.01), but the difference in FS was not significant. The DMM time-domain trajectories were similar in HIIT and THR. The correlation between exercise intensity, RPE, and FS was highest in THR group (r = 0.453, r = -0.58, r = -0.885). ITL did not show a significant difference between three conditions, but TRIMP and s-RPE readings were opposite in magnitude. This study proposes that using an appropriate amount of THR to foster interest and adaptive strength during the PA habit establishment period, incorporating HIIT to enhance exercise efficiency during the adaptation period, and implementing SIT to reduce the monotony may effectively enhance the cardiorespiratory fitness of sedentary college students and establish PA habit.

Full-frequency Domain Characteristic-based Multi-constraint Decoupling Controller in Drive Motors with Low Pulse Ratios

Full-frequency Domain Characteristic-based Multi-constraint Decoupling Controller in Drive Motors with Low Pulse Ratios

Structural, chemical and technofunctional properties pectin modification by green and novel intermediate frequency ultrasound procedure

The impact of intermediate frequency ultrasound (IFUS, 582, 864 and 1144 kHz), mode of operation (continue and pulsed) and ascorbic acid (Aa) addition on the structural, chemical and technofunctional properties of commercial citrus high methoxyl-grade pectin (HMP) was investigated. The chemical dosimetry of IFUS, monitored by the triiodide formation rate (I3−), demonstrated that the pulsed ratio (1900 ms on/100 ms off) at the three frequencies was similar to that of continue mode but IFUS1144 kHz produced more acoustic streaming demonstrated by the height liquid measured using image analysis. In presence of Aa, HMP presented higher fragmentation than in its absence. IFUS did not give rise any changes in the main functional groups of the HMP. In general, a reduction in molecular weight was observed, being the presence of Aa the most influencing factor. Regarding monosaccharides, IFUS modified the structure of homogalacturonan and rhamnogalacturonan-I and increased of GalA contents of the HMP in presence of Aa at the above three frequencies. A reducing of the consistency index (k) and increasing of the flow index (n) of HMP were showed by IFUS frequency and Aa addition. The emulsifying activity and stability index were increased for HMP treated by IFUS in continue mode at all frequencies and in presence of Aa. The results presented in this research shown the effectiveness of IFUS as tool to modify pectin into different structures with different functionalities.

Photonic generation and transmission for an X-band dual-chirp waveform with frequency multiplication and power-fading compensation.

The generation of an X-band dual-chirp waveform, which is capable of pulse compression, plays an important role in radar, electric warfare, and satellite communication systems. With the development of applications such as multi-static radar, transmission over long distances has attracted considerable attention. In this paper, a photonic system for X-band dual-chirp waveform generation and transmission based on frequency multiplication and power-fading compensation is put forward and experimentally carried out. Based on a compact dual-parallel Mach-Zehnder modulator (DPMZM), the dual-chirp waveforms of 8.6-9.6GHz and 9.6-10.6GHz are generated by an RF carrier of 4.8GHz and transmitted through a 40km single-mode fiber (SMF) spool. The dispersion-induced power fading of the chirp waveform is compensated for by about 13dB. The full width at half maximum (FWHM) and the peak-to-sidelobe ratio (PSR) of the compressed pulses are 1ns and 11.5dB, respectively. Moreover, the compensation of power fading in the entire X-band is verified to demonstrate the applicability of our system. By flexibly adjusting the bias voltage of the built-in phase shifter, the system can be applied in more scenarios.

Female TgF344‐AD hippocampal plasticity after estrogen deprivation

AbstractBackgroundAlzheimer’s Disease (AD) is the seventh leading cause of death worldwide, disproportionately affecting women, with two‐thirds of individuals with AD being female. A decrease in circulating ovarian estrogen during menopause is believed to be a contributing factor to this discrepancy in disease prevalence. AD pathology is known to impact synaptic transmission in the hippocampus, resulting in memory deficits, a hallmark symptom of AD. This study investigates the effect of estrogen deprivation in the dentate gyrus (DG) and CA1 region, areas affected early on in the disease and crucial for memory. As the disease progresses, deficits are seen in the dentate gyrus prior to CA1 region supporting the anatomical spread of the pathology.MethodSynaptic signaling was assessed in DG and CA1 hippocampal subregions of 9 month old TgF344‐AD female rats who underwent long‐term (from ages 3 to 9 months) ovarian hormone deprivation. Extracellular dendritic field potential recordings were conducted in the DG by stimulating the medial perforant path onto dentate granule cells, and in the CA1 region by stimulating Schaffer collateral axons. Input/output relationship, paired pulse ratio, and long term potentiation were assessed, analyzed, and statistically compared between TgF344‐AD rats and non‐transgenic hormone deprived littermates.ResultIt was found that AD females were able to maintain synaptic transmission as there were no significant differences found in the input/output relationship, paired pulse ratio, or long term potentiation between AD animals and their controls.ConclusionThese results show that at this early stage in the disease, ovarian estrogen deprivation does not accelerate synaptic impairment. These results also suggest the possibility that a compensatory mechanism exists at these synapses to maintain function.

Optimization of the pulsed vacuum drying process of green walnut husk through temperature adaptive regulation.

This study aimed to optimize the temperature adaptive conditions of pulsed vacuum drying (PVD) for green walnut husk (GWH) to tackle the issues of severe environmental pollution and limited utilization of GWH. The results of the single-factor experiment revealed that the optimal drying temperature for PVD of GWH was 65°C, with a pulsed ratio of 9min: 3min. The drying time decreased from 10.87 to 6.32h with increasing drying temperature and from 8.83 to 6.23kW·h/kg with increasing pulsed ratio. Energy consumption also decreased with shorter drying time and shorter vacuum time. Under this optimal variable temperature drying condition, GWH exhibited the highest total active substance content, with respective values of 9.43mg/g for total triterpenes, 35.68mg/g for flavonoids, 9.51mg/g for polyphenols, and 9.55mg/g for quinones. The experimental drying data of GWH were best fitted by a logarithmic model, with R2 values ranging from 0.9927 to 0.9943. Furthermore, the observed microstructure of GWH corresponded to the variations in total active substance content. This study provided valuable theoretical guidance for addressing environmental pollution associated with GWH and facilitating the industrialization and refinement of GWH drying processes. PRACTICAL APPLICATION: There is a growing interest in harnessing the potential value of agricultural waste to transform low-cost raw materials into high-value products while mitigating environmental pollution. In this study, for the first time, the effects of variable temperature pulsed vacuum drying on the content of active substances, drying time, and energy consumption of green walnut husk (GWH) were investigated. The findings serve as a theoretical foundation for addressing environmental pollution issues associated with GWH and enabling the industrialization and precision drying of GWH.

PSII-20 Virtual Fencing of Rangeland Cows During Late Lactation and Following Weaning

Abstract Virtual fencing is a promising alternative to contain livestock dispersal without using physical barriers. This technology uses smart-wearable collars that deliver predictable warning tones to animals when they approach virtual boundaries paired with mild electric pulses. Virtual fencing allows for dynamic management of livestock grazing, based on site-specific variations in the quality and quantity of forages. However, several factors can affect the efficacy of virtual fencing, including the length of prior experience with virtual fencing, climatic conditions, forage availability inside and outside virtual fencing paddocks and collar configuration schedules. Lactation requirements and social interactions between collared cows and uncollared calves can also influence the efficacy of the technology. Virtual fencing trials were conducted at the New Mexico State University’s Chihuahuan Desert Rangeland Research Center from August 27 to December 21 of 2022 to evaluate the efficacy of virtual fencing to manage rangeland cows during late lactation and following weaning. Twenty-six Brangus cows previously trained to use NoFence C2 collars (NoFence, Batnfjordsøra, Norway), were monitored for 30 days during late lactation and 28 days after weaning. Collared cows and uncollared calf pairs were allocated to four virtual fence pastures in late lactation and after weaning, with pasture duration (4.2 ± 0.6 d), size (72 ± 19 ha) and perimeter (4,523 ± 352 m) varying according to forage availability and access to fresh drinking water. Audio cues, electric pulses and ratio of electric pulses to audio cues before and after weaning were compared by ANOVA in a Completely Randomized Design replicated across pre-weaning and post-weaning pastures (n = 8). The average number of electric pulses per cow was greater (P &amp;lt; 0.0004) for pre-weaning (3.7 ± 0.2) than for post-weaning post-weaning (1.6 ± 0.3) pastures. The number of audio warnings per cow was also greater (P &amp;lt; 0.0001) for pre-weaning (52 ± 3.3) than post-weaning (34 ± 3.3) pastures. Conversely, cows had decreased (P &amp;lt; 0.0001) ratios of electric pulses relative to audio tones on post-weaning (4.8 ± 0.5%) than pre-weaning (7.0 ± 0.8%) pastures. These results suggest that cows responded better to virtual fencing after weaning, likely because weaned cows were no longer affected by social interactions with uncollared calves. Furthermore, cows after weaning apparently relied on warning tones and fewer electric pulses to interact safely with virtual fences. However, it is important to note that sources of variation not accounted for or controlled by the present experimental design may have also affected the recorded interactions with virtual fences in the present study.