Velocity Monitoring Research Articles

The Fractal Dimension, Structure Characteristics, and Damage Effects of Multi-Scale Cracks on Sandstone Under Triaxial Compression

To study the influence of the spatial distribution and structure of multi-scale cracks on the mechanical behavior of rocks, triaxial compression tests and cyclic triaxial complete loading and unloading tests were conducted on sandstone, with real-time wave velocity monitoring and CT scan testing. The quantitative classification criteria for multi-scale cracks on sandstone were established, and the constraint effect of confining pressure was analyzed. The crack with a length less than 0.1 mm is considered a small-scale crack, 0.1–1 mm is a medium-scale crack, and larger than 1 mm is a large-scale crack. As the confining pressure increases, the spatial fractal dimension of large-scale cracks decreases, while that of medium-scale cracks increases, and that of small-scale cracks remains stable. The respective nonlinear models of the aspect ratio were established with the length and density of multi-scale cracks. The results indicate significant differences in the effects of cracks of different scales on rock damage. The distribution density of medium-scale cracks in the failed specimen is higher, which is the main reason to produce damage. The small-scale cracks mainly originate from relatively uniform initial cracks in rocks, mainly distributed in medium-density and low-density areas. The results of this research provide important insights into how to quantitatively evaluate the damage of rocks.

Development of an Image-Based Borehole Flowmeter for Real-Time Monitoring of Groundwater Flow Velocity and Direction in Landslide Boreholes

Development of an Image-Based Borehole Flowmeter for Real-Time Monitoring of Groundwater Flow Velocity and Direction in Landslide Boreholes

The Impact of Observing Cadence and Undetected Companions on the Accuracy of Planet Mass Measurements from Radial Velocity Monitoring

We conduct experiments on both real and synthetic radial velocity (RV) data to quantify the impact that observing cadence, the number of RV observations, and undetected companions all have on the accuracy of small planet mass measurements. We run resampling experiments on four systems with small transiting planets and substantial public data from the High Resolution Echelle Spectrometer in order to explore how degrading observing cadence and the number of RVs affects the planets’ mass measurement relative to a baseline value. From these experiments, we recommend that observers obtain 2–3 RVs per orbit of the innermost planet and acquire at minimum 40 RVs. Following these guidelines, we then conduct simulations using synthetic RVs to explore the impact of undetected companions and untreated red noise on the masses of planets with known orbits. While undetected companions generally do not bias the masses of known planets, in some cases, when coupled with an inadequate observing baseline, they can cause the mass of an inner transiting planet to be systematically overestimated on average.

Seepage monitoring at variable spatial positions under natural convection with active heating

Monitoring seepage by temperature tracer method has been widely used, where the vertical flow has been proven to be an indispensable factor. However, current research still lacks adequate consideration of it, especially for the natural convection caused by active heating. In this paper, theoretical derivation and experiments are both conducted, a two-dimensional dimensionless temperature rise–seepage velocity formula considering the natural convection is derived. Meanwhile, through the experiment system and a multi-temperature measuring sheets device, heating and temperature measurement experiments are carried out under calm water and various flow velocities ranging from 10−6 cm s−1 to 10−3 cm s−1. By comparing the temperature–time curves of different positions at different heating times in calm water, the mechanism of natural convection caused by active heating is researched. Based on this, several temperature measuring sheets are chosen, the formulas of different positions are obtained by fitting, relative influence to temperature rise–flow velocity patterns of different positions are studied. This study is of great significance for further understanding the temperature-velocity relationship, and for the design of heating-temperature measuring device used in seepage velocity monitoring with active heating.

Proximity to active volcanoes enhances glacier velocity

Volcanic heating is predicted by theory to affect the velocity of nearby glaciers. However, conclusive studies on a large scale are lacking. Here, we conduct a global comparison of the velocities of glaciers near active volcanoes (i.e. within 5 km) and those located elsewhere ( > 5 km from an active volcano). Our findings show that, when considered over an annual scale (e.g. 2017-2018) and controlling for other factors, glaciers near volcanoes flow 46% faster than those located elsewhere (based on median values). This finding strongly suggests that volcanic heating impacts glacier velocity at a global scale, and supports the idea that glacier velocity monitoring could be a valuable indirect tool to help volcano monitoring and eruption prediction, particularly where volcanic heating (and therefore subglacial melt) intensifies months or years prior to eruptions.

S-process nucleosynthesis in chemically peculiar binaries

Context. Around half of the heavy elements in the Universe are formed through the slow neutron capture (s-) process, which takes place in thermally pulsing asymptotic giant branch (AGB) stars with masses of 1 − 6 M⊙. The nucleosynthetic imprint of the s-process can be studied by observing the material on the surface of binary barium (Ba), carbon (C), CH, and carbon-enhanced metal-poor (CEMP) stars. Aims. We study the s-process by observing the luminous components of binary systems polluted by a previous AGB companion. Our radial velocity (RV) monitoring program establishes an ongoing collection of binary stars exhibiting enrichment in s-process material for the study of elemental abundances, the production of s-process material, and binary mass transfer. Methods. From high-resolution optical spectra, we measured RVs for 350 stars and derived stellar parameters for approximately 150 stars using ATHOS. For a subsample of 24 chemically interesting stars, we refined our atmospheric parameters using ionization and excitation balance with the Xiru program. We used the MOOG code to compute one-dimensional local thermodynamic equilibrium (1D-LTE) abundances of carbon, magnesium, s-process elements (Sr, Y, Zr, Mo, Ba, La, Ce, Nd, Pb), and Eu to investigate neutron capture events and stellar chemical composition. We estimated dynamical stellar masses via orbital optimization using Markov chain Monte Carlo techniques in the ELC program, and we compared our results with low-mass AGB models in the FUll-Network Repository of Updated Isotopic Tables & Yields (FRUITY) database. Results. In our abundance subsample, we find enhancements in s-process material in spectroscopic binaries, a signature of AGB mass transfer. We add the element Mo to the abundance patterns, and for 12 stars we add Pb detections or upper limits, as these are not known in the literature. Computed abundances are in general agreement with the literature. Comparing our abundances to dilution-modified FRUITY yields, we find correlations in s-process enrichment and AGB mass, which are supported by dynamical modeling from RVs. Conclusions. From our high-resolution observations, we expand heavy element abundance patterns and highlight binarity in our chemically interesting systems. We find trends in s-process element enhancement from AGB stars, and agreement between theoretical and dynamically modeled masses. We investigate evolutionary stages for a small subset of our stars.

Orthostatic intolerance with tachycardia (postural tachycardia syndrome) and without (hypocapnic cerebral hypoperfusion) represent a spectrum of the same disorder.

Spectrum of chronic orthostatic intolerance without orthostatic hypotension includes postural tachycardia syndrome (POTS), with orthostatic tachycardia and hypocapnic cerebral hypoperfusion (HYCH), without orthostatic tachycardia. This study compared autonomic, cerebrovascular, and neuropathic features of POTS and HYCH. This retrospective study evaluated patients with orthostatic intolerance referred for autonomic testing. Analyzed data included surveys (Survey of Autonomic Symptoms, Compass-31, Neuropathy Total Symptom Score-6, Central Sensitization Inventory) and autonomic tests (Valsalva maneuver, deep breathing, sudomotor and tilt tests), cerebrovascular (cerebral blood flow velocity (CBFv) monitoring in the middle cerebral artery), respiratory (capnography), neuropathic (skin biopsies for assessment of small fiber neuropathy) and invasive cardiopulmonary exercise testing (iCPET). A total of 127 HYCH, 125 POTS, and 42 healthy controls were analyzed. Compared HYCH to POTS patients, there was no difference in the duration of symptoms, the prevalence of younger women, comorbidities, sensory and autonomic complaints, central sensitization syndrome, supine/standing norepinephrine levels, inflammatory markers and medical therapy except for gastrointestinal medication. Autonomic testing showed widespread but similar abnormalities in POTS and HYCH that included: reduced orthostatic CBFv and end-tidal CO2, preload failure (assessed in 16/19 POTS/HYCH), mild autonomic failure, and frequent small fiber neuropathy. HYCH and POTS are syndromes of orthostatic intolerance with cerebral hypoperfusion associated with reduced orthostatic cerebral blood flow, hypocapnia, mild autonomic failure and small fiber neuropathy of a similar degree and distribution; except for tachycardia in POTS. Similarities in peripheral domain abnormalities that affect heart rate suggest that orthostatic tachycardia in POTS is driven by the central nervous system overcompensation of orthostatic challenge. These findings provide additional evidence that HYCH and POTS represent a spectrum of the same disorder. Reduced orthostatic cerebral blood flow is a key unifying feature of HYCH and POTS.

Desing of an observer with real time monitoring speed and load torque for submersible induction motors

Relevance. When operating submersible equipment for oil production in aggressive environments and transferring wells to the cyclic operation mode, a decrease in the service life of the submersible installation for oil production is observed. In the first case, this is due to the formation of salt deposits and clogging of the working parts of the electric pump with mechanical impurities. In the second case – an increase in the number of starts of the submersible electric motor. To solve the existing problems, it is possible to implement closed control systems for submersible electric motors based on state variable observers, which determines the relevance of the study. Aim. To develop an observer with operational monitoring of the angular velocity of the rotor and the moment of resistance on the shaft of a submersible asynchronous motor at inconsistency of the initial conditions in various operating modes and its testing using modeling tools. Methods. The observer is built on the basis of known engine models in a fixed coordinate system α, β, the theory of IIR-filters to obtain a forecast of estimates of the angular velocity of the rotor and the torque on the shaft and their correction in real time. Results. The authors have proposed the original structure of an observer with operational monitoring of the angular velocity of the rotor and the moment of resistance on the shaft of a submersible asynchronous motor. Conclusions. The paper demonstrates the observer performance with inconsistency of initial conditions and electric motor model data in various operating modes. In all modes, stable estimates of the speed and torque of resistance on the electric motor shaft are obtained. At the same time, the error in estimating the angular velocity under the condition of changing the load on the shaft and starting in the loaded state is no more than 1.2%, which is acceptable in submersible electric motor control systems. It is revealed that the developed observer, under the condition of changing the active resistance of the stator and rotor in the ranges from –25 to +25% of the nominal value, obtains estimates of the angular velocity with an integral error of no more than 5%, except for starting the motor with a decrease in the active resistance of the rotor by 25% of the nominal value –5.53%, which is acceptable in engineering practice.

Rationale and Design for the BLOCK-SAH Study (Pterygopalatine Fossa Block as an Opioid-Sparing Treatment for Acute Headache in Aneurysmal Subarachnoid Hemorrhage): A Phase II, Multicenter, Randomized, Double-Blinded, Placebo-Controlled Clinical Trial with a Sequential Parallel Comparison Design.

Acute post-subarachnoid hemorrhage (SAH) headaches are common and severe. Management strategies for post-SAH headaches are limited, with heavy reliance on opioids, and pain control is overall poor. Pterygopalatine fossa (PPF) nerve blocks have shown promising results in treatment of acute headache, including our preliminary and published experience with PPF-blocks for refractory post-SAH headache during hospitalization. The BLOCK-SAH trial was designed to assess the efficacy and safety of bilateral PPF-blocks in awake patients with severe headaches from aneurysmal SAH who require opioids for pain control and are able to verbalize pain scores. BLOCK-SAH is a phase II, multicenter, randomized, double-blinded, placebo-controlled clinical trial using the sequential parallel comparison design (SPCD), followed by an open-label phase. Across 12 sites in the United States, 195 eligible study participants will be randomized into three groups to receive bilateral active or placebo PPF-injections for 2 consecutive days with periprocedural monitoring of intracranial arterial mean flow velocities with transcranial Doppler, according to SPCD (group 1: active block followed by placebo; group 2: placebo followed by active block; group 3: placebo followed by placebo). PPF-injections will be delivered under ultrasound guidance and will comprise 5-mL injectates of 20mg of ropivacaine plus 4mg of dexamethasone (active PPF-block) or saline solution (placebo PPF-injection). The trial has a primary efficacy end point (oral morphine equivalent/day use within 24h after each PPF-injection), a primary safety end point (incidence of radiographic vasospasm at 48h from first PPF-injection), and a primary tolerability end point (rate of acceptance of second PPF-injection following the first PPF-injection). BLOCK-SAH will inform the design of a phase III trial to establish the efficacy of PPF-block, accounting for different headache phenotypes.

The Influence of Silica Fly Ash and Wood Bottom Ash on Cement Hydration and Durability of Concrete.

This research addresses a notable gap in understanding the synergistic effects of high carbon wood bottom ash (BA) and silica fly ash (FA) on cement hydration and concrete durability by using them as a supplementary material to reduce the amount of cement in concrete and CO2 emissions during cement production. This study analyses the synergistic effect of FA and BA on cement hydration through X-ray diffraction (XRD), thermal analysis (TG, DTG), scanning electron microscopy (SEM), density, ultrasonic pulse velocity (UPV), compressive strength, and temperature monitoring tests. In addition, it evaluates concrete properties, including compressive strength, UPV, density, water absorption kinetics, porosity parameters, predicted resistance to freezing and thawing cycles, and results of freeze-thawing resistance. The concrete raw materials were supplemented with varying percentages of BA and FA, replacing both cement and fine aggregate at levels of 0%, 2.5%, 5%, 10% and 15%. The results indicate that a 15% substitution of BA and FA delays cement hydration by approximately 5 h and results in only a 6% reduction in compressive strength, with the hardened cement paste showing a strength similar to a 15% replacement with FA. Concrete mixtures with 2.5% BA and 2.5% FA maintained the same maximum hydration temperature and duration as the reference mix. Furthermore, the combined use of both ashes provided adequate resistance to freeze-thaw cycles, with only a 4.7% reduction in compressive strength after 150 cycles. Other properties, such as density, UPV and water absorption, exhibited minimal changes with partial cement replacement by both ashes. This study highlights the potential benefits of using BA and FA together, offering a sustainable alternative that maintains concrete performance while using waste materials.

Research on high-precision encoder based on optical-magnetic combination structure to measure absolute angle

As a kind of sensor for real-time feedback and dynamic monitoring of angular velocity and angular displacement of the system, the common photoelectric encoder is widely used in many fields such as new energy electric vehicles, servo closed-loop control systems, industrial control, security monitoring. In order to improve the resolution and accuracy, a kind of optical and magnetic combined encoder which combines photoelectricity and multi-pole magnetoelectricity is designed in this paper, where the light-blocking disk of photoelectric sensor is designed according to the pseudo-random sequence, and the photoelectric coding is used to determine the magnetic interval of multi-pole. The absolute angle is calculated according to the number of multiple circles plus the angle of single circle. The experimental results at different temperatures (−40 °C∼100 °C) show that the accuracy of the proposed combined encoder can reach ±0.08°, which is improved by 0.37° compared with that of the single-pole encoder. Finally, the combined encoder was applied to the pan-tilt-zoom (PTZ) camera of a video surveillance enterprise, and the experiment showed that its repeated positioning accuracy reached ±0.02°, which is greatly improved compared with single-pole encoder.

Structural Health Monitoring of a High-Rise Building Using Ambient Noise Recordings and a Regional Earthquake Record

Abstract Resonance frequency and seismic-wave velocity monitoring are both important for structural health monitoring (SHM). However, the limited number of vibration sensors or seismometers in most buildings necessitates the study of the sensitivity of monitoring indicators to ensure effective monitoring while reducing data acquisition costs and processing time. This study compares the changes in resonance frequency and seismic-wave velocity under ambient noise and a regional seismic event. Resonance frequency is calculated by power spectral density, whereas seismic-wave velocity is estimated using impulse response function and moving-window cross-spectrum methods. The results indicate that relative resonance frequency changes are more suitable for overall SHM due to its higher sensitivity and lower instrument requirements. Moreover, the time–frequency analysis method provides higher resolution results in resonance frequency during seismic events, a precision that seismic velocity methods cannot achieve.

Monitoring tides, currents, and waves along coastal habitats using the Mini Buoy

AbstractIntertidal habitats are shaped by the actions of tides and waves which are difficult to monitor in shallow water. To address this challenge, the “Mini Buoy” and associated open‐source App were recently developed for the low‐cost and long‐term monitoring of tidal inundation and current velocities simultaneously. The Mini Buoy is a bottom‐mounted float that measures tilt to infer near‐bed hydrodynamics. Here, we present significant updates to the Mini Buoy and App. Two new Mini Buoy designs were calibrated: the “Pendant” that requires minimal assembly for deployment, and the “B4+” that can also measure wave orbital velocity. Comparisons against industry‐standard water‐level and velocity sensors deployed in the field showed that each new design was effective at detecting tidal inundation (overall accuracy of 86–97%) and current velocities (R2 = 0.73–0.91; accuracies of ± 0.14–0.22 m s−1; detection limits between 0.02 and 0.8 m s−1). The B4+ could reasonably measure wave orbital velocities (R2 = 0.56; accuracies of ± 0.18 m s−1; detection limits between 0.02 and 0.8 m s−1). Reducing the sampling rate to prolong survey durations did not markedly reduce the precision of velocity measurements, except in the original Mini Buoy design (uncertainty increased by ± 2.11 m s−1 from 1 to 10 s sampling). The updated App enhances user experience, accepts data from any Mini Buoy design, is suitable for generic use across any tidal setting, and presents multiple options to understand and contrast local hydrodynamic regimes. Improvements to the Mini Buoy designs and App offer greater opportunities in monitoring hydrodynamics for purposes including ecosystem restoration and flood risk management.

Novel method for in-situ drift velocity measurement in large volume TPCs: the Geometry Reference Chamber of the NA61/SHINE experiment at CERN

This paper presents a novel method for low maintenance, low ambiguity in-situ drift velocity monitoring in large volume Time Projection Chambers (TPCs). The method was developed and deployed for the 40 m3 TPC tracker system of the NA61/SHINE experiment at CERN, which has a one meter of drift length. The method relies on a low-cost multi-wire proportional chamber placed next to the TPC to be monitored, downstream with respect to the particle flux. Reconstructed tracks in the TPC are matched to hits in the monitoring chamber, called the Geometry Reference Chamber (GRC). Relative differences in positions of hits in the GRC are used to estimate the drift velocity, removing the need for an accurate alignment of the TPC to the GRC. An important design requirement on the GRC was minimal added complexity to the existing system, in particular, compatibility with Front-End Electronics cards already used to read out the TPCs. Moreover, the GRC system was designed to operate both in large and small particle fluxes. The system is capable of monitoring the evolution of the drift velocity inside the TPC down to a one permil precision, with a few minutes of data collection.

Glacial lakes control ice flow: new insights from satellite SAR PO-SBAS observations in Duiya Glacier, southern Tibetan Plateau

ABSTRACT This study investigates the effects of glacial lakes on the flow velocities of Duiya Glacier, southern Tibetan Plateau, by employing satellite Synthetic Aperture Radar (SAR) Pixel-Offset-Tracking Small-Baseline-Subset (PO-SBAS) technology. Duiya Glacier, which terminates in a lake, exhibits approximately 10 m/yr higher horizontal speed and a higher melting rate with a vertical Non-Surface-Parallel-Flow (nSPF) velocity of – 7 m/yr than those of its land-terminating counterpart – West Duosangpu Glacier. Notably, Duiya Glacier experiences significant seasonal velocity fluctuations with accelerated flow between May and October. By integrating glacier geometry, changes in glacier boundaries and the extent of proglacial lakes, the distribution of supraglacial lakes, and climatic variables, we reveal that proglacial and supraglacial lakes play a crucial role in increasing the flow velocities of Duiya Glacier. Duiya Glacier flows faster because of increased subglacial water pressure resulting from water influx from these lakes. This phenomenon becomes conspicuously evident during May – October, when increased meltwater due to increased temperatures and precipitation further elevates the subglacial water pressure. Our method highlights the potential for understanding the impact of glacial lakes on glacier movements at a large scale, leveraging the capabilities of satellite SAR PO-SBAS technology for continuous, wide-scale, high temporal resolution, and 3D velocity monitoring.

Disproving the High-eccentricity Planet HD 220773b

HD 220773 has been announced to host a giant planet in an eccentric orbit. Global Architecture of Planetary Systems collaboration followed this target up with the HARPS-N spectrograph at Telescopio Nazionale Galileo, in order to search for additional small planets in the system. This radial velocity monitoring produced approximately 130 HARPS-N data points, leading to the refutation of the announced planet.

TOI-2374 b and TOI-3071 b: two metal-rich sub-Saturns well within the Neptunian desert

ABSTRACT We report the discovery of two transiting planets detected by the Transiting Exoplanet Survey Satellite (TESS), TOI-2374 b and TOI-3071 b, orbiting a K5V and an F8V star, respectively, with periods of 4.31 and 1.27 d, respectively. We confirm and characterize these two planets with a variety of ground-based and follow-up observations, including photometry, precise radial velocity monitoring and high-resolution imaging. The planetary and orbital parameters were derived from a joint analysis of the radial velocities and photometric data. We found that the two planets have masses of (57 ± 4) M⊕ or (0.18 ± 0.01) MJ, and (68 ± 4) M⊕ or (0.21 ± 0.01) MJ, respectively, and they have radii of (6.8 ± 0.3) R⊕ or (0.61 ± 0.03) RJ and (7.2 ± 0.5) R⊕ or (0.64 ± 0.05) RJ, respectively. These parameters correspond to sub-Saturns within the Neptunian desert, both planets being hot and highly irradiated, with Teq ≈ 745 K and Teq ≈ 1812 K, respectively, assuming a Bond albedo of 0.5. TOI-3071 b has the hottest equilibrium temperature of all known planets with masses between 10 and 300 M⊕ and radii less than 1.5 RJ. By applying gas giant evolution models we found that both planets, especially TOI-3071 b, are very metal-rich. This challenges standard formation models which generally predict lower heavy-element masses for planets with similar characteristics. We studied the evolution of the planets’ atmospheres under photoevaporation and concluded that both are stable against evaporation due to their large masses and likely high metallicities in their gaseous envelopes.

Quantifying lumbar mobility using a single tri-axial accelerometer

BackgroundLumbar mobility is regarded as important for assessing and managing low back pain (LBP). Inertial Measurement Units (IMUs) are currently the most feasible technology for quantifying lumbar mobility in clinical and research settings. However, their gyroscopes are susceptible to drift errors, limiting their use for long-term remote monitoring. Research questionCan a single tri-axial accelerometer provide an accurate and feasible alternative to a multi-sensor IMU for quantifying lumbar flexion mobility and velocity? MethodsIn this cross-sectional study, 18 healthy adults performed nine repetitions of full spinal flexion movements. Lumbar flexion mobility and velocity were quantified using a multi-sensor IMU and just the tri-axial accelerometer within the IMU. Correlations between the two methods were assessed for each percentile of the lumbar flexion movement cycle, and differences in measurements were modelled using a Generalised Additive Model (GAM). ResultsVery high correlations (r > 0.90) in flexion angles and velocities were found between the two methods for most of the movement cycle. However, the accelerometer overestimated lumbar flexion angle at the start (-4.7° [95 % CI -7.6° to -1.8°]) and end (-4.8° [95 % CI -7.7° to -1.9°]) of movement cycles, but underestimated angles (maximal difference of 4.3° [95 % CI 1.4° to 7.2°]) between 7 % and 92 % of the movement cycle. For flexion velocity, the accelerometer underestimated at the start (16.6°/s [95%CI 16.0 to 17.2°/s]) and overestimated (-12.3°/s [95%CI -12.9 to -11.7°/s]) at the end of the movement, compared to the IMU. SignificanceDespite the observed differences, the study suggests that a single tri-axial accelerometer could be a feasible tool for continuous remote monitoring of lumbar mobility and velocity. This finding has potential implications for the management of LBP, enabling more accessible and cost-effective monitoring of lumbar mobility in both clinical and research settings.

Land-Use–Land Cover Changes in the Urban River’s Buffer Zone and Variability of Discharge, Water, and Sediment Quality—A Case of Urban Catchment of the Ngerengere River in Tanzania

The physical integrity of the Ngerengere River and its three tributaries drains within Morogoro Municipality were evaluated by assessing the variations in land-use–land cover (LULC) in the river’s buffer zone, the discharge, and the contamination of river water and sediment from nutrients and heavy metals. Integrated geospatial techniques were used to classify the LULC in the river’s buffer zone. In contrast, the velocity area method and monitoring data from the Wami-Ruvu Basin were used for the discharge measurements. Furthermore, atomic absorption spectrophotometry was used during the laboratory analysis to determine the level of nutrients and heavy metals in the water and river sediment across the 13 sampling locations. The LULC assessment in the river’s buffer during the sampling year of 2023 showed that bare land and built-up areas dominate the river’s buffer, with a coverage of 28% and 38% of the area distribution. The higher discharge across the sampling stations was in the upstream reaches at 3.73 m3/s and 2.36 m3/s at the confluences. The highest concentrations of heavy metals in the water for the dry and wet seasons were 0.09 ± 0.01, 0.25 ± 0.01, 0.03 ± 0.02, 0.73 ± 0.04, 4.07 ± 0.08, and 3.07 ± 0.04 mg/L, respectively, for Pb, Cr, Cd, Cu, Zn, and Ni. The order of magnitude of the heavy metal concentration in the sediments was Zn > Ni > Cr > Cu > Cd > Pb, while the highest NO2−, NO3−, NH3, and PO43− in the water and sediment were 2.05 ± 0.01, 0.394 ± 0.527 0.66 ± 0.05, and 0.63 ± 0.01 mg/L, and 2.64 ± 0.03, 0.63 ± 0.01, 2.36 ± 0.01, and 48.16 ± 0.01 mg/kg, respectively, across all sampling seasons. This study highlights the significant impact of urbanization on river integrity, revealing elevated levels of heavy metal contamination in both water and sediment, the variability of discharge, and alterations in the LULC in the rivers’ buffer. This study recommends the continuous monitoring of the river water quality and quantity of the urban rivers, and the overall land-use plans for conserving river ecosystems.

Optimizing exercise prescription during breast cancer rehabilitation in women: Analysis of the load-velocity relationship in the box squat exercise.

The aims of this study were to assess (i) the load-velocity relationship during the box squat exercise in women survivors of breast cancer, (ii) which velocity variable (mean velocity [MV], mean propulsive velocity [MPV], or peak velocity [PV]) shows stronger relationship with the relative load (%1RM), and (iii) which regression model (linear [LA] or polynomic [PA]) provides a greater fit for predicting the velocities associated with each %1RM. Nineteen women survivors of breast cancer (age: 53.2±6.9years, weight: 70.9±13.1kg, and height: 163.5±7.4cm) completed an incremental load test up to one-repetition maximum in the box squat exercise. The MV, MPV, and the PV were measured during the concentric phase of each repetition with a linear velocity transducer. These measurements were analyzed by regression models using LA and PA. Strong correlations of MV with %1RM (R2=0.903/0.904; the standard error of the estimate (SEE)=0.05m.s-1 by LA/PA) and MPV (R2=0.900; SEE=0.06m.s-1 by LA and PA) were observed. In contrast, PV showed a weaker association with %1RM (R2=0.704; SEE=0.15m.s-1 by LA and PA). The MV and MPV of 1RM was 0.22±0.04m·s-1, whereas the PV at 1RM was 0.63±0.18m.s-1. These findings suggest that the use of MV to prescribe relative loads during resistance training, as well as LA and PA regression models, accurately predicted velocities for each %1RM. Assessing and prescribing resistance exercises during breast cancer rehabilitation can be facilitated through the monitoring of movement velocity.