Extensive Load Research Articles

Design of photovoltaic and battery energy storage systems through load demand characterization: A case study in Thailand

The integration of photovoltaic (PV) system at behind the meter has gained popularity due to the growing trend toward environmentally friendly energy solutions. Coupling PV systems with battery energy storage systems (BESS) addresses the uncertainties of PV energy production while enhancing energy management. Load characteristics have influence on PV and BESS design both in technical and economic aspects. This paper presents a comprehensive analysis of load demand characterization methodologies tailored for the design of PV and BESS. The fundamental load properties such as daily maximum power, minimum power, and load energy, categorizing loads based on their daily and annual variation degrees are investigated. The techno-economic performance of PV-only and PV+BESS systems is analyzed, focusing on metrics such as excess energy, peak limiting performance, and economic feasibility using the levelized cost of energy (LCOE). The findings of this study reveal three distinct load characteristics based on daily variation: moderate (50–70 %), moderate to high (70–80 %), and high (80–90 %). Load profiles with moderate variation (50–70 %) demonstrate economic feasibility when sized with a PV-only system matching maximum power demand. With BESS prices reduced to less than 140 USD/kWh, these loads could also integrate a 1C-BESS sized at half capacity under the same control strategy, resulting in lower excess energy and LCOE. Conversely, loads with higher variation (>70 %) and lower self-consumption rates (<70 %) face fewer viable options for both PV-only and PV+BESS configurations, especially if BESS costs remain high. These loads require custom-designed solutions and more extensive load analysis. Through analysis, this study establishes the relationship between load characteristics and system design suitability for the loads studied. The findings underscore the importance of incorporating load demand characterization techniques in the design systems, highlighting the need for tailored approaches based on specific load characteristics and economic viability.

Large-scale data processing platform for laser absorption tomography

Abstract Laser absorption tomography (LAT) has been widely employed to capture two/three-dimensional reactive flow-field parameters with a penetrating spatiotemporal resolution. In industrial environments, LAT is generally implemented by measuring multiple, e.g. 30 to more than 100, wavelength modulated laser transmissions at high imaging rates, e.g. tens to thousands of frames per second (fps). A short-period LAT experiment can generate extensive load of data, which require massive computational source and time for data post-processing. In this work, a large-scale data processing platform is designed for industrial LAT. The platform significantly speeds up LAT signal processing by introducing a parallel computing architecture. By identifying the discrepancy between the measured and theoretical spectra, the new platform enables indexing of the laser-beam measurements that are disturbed by harsh-environment noise. Such a scheme facilitates effective removal of noise-distorted beams, which can lead to artefacts in the reconstructed images. The designed platform is validated by a lab-based LAT experiment, which is implemented by processing the laser transmissions of a 32-beam LAT sensor working at 250 fps. To process a 60-second LAT experimental dataset, the parallelism enabled by the platform saves computational time by 40.12% compared to the traditional single-thread approach. The error-detection scheme enables the successful accurate identification of noise-distorted measurements, i.e. 0.59% of overall laser-beam measurements that fall out of the physical model.

Managing lower extremity loading in distance running by altering sagittal plane trunk leaning

BackgroundTrunk lean angle is an underrepresented biomechanical variable for modulating and redistributing lower extremity joint loading and potentially reducing the risk of running-related overuse injuries. The purpose of this study was to systematically alter the trunk lean angle in distance running using an auditory real-time feedback approach and to derive dose–response relationships between sagittal plane trunk lean angle and lower extremity (cumulative) joint loading to guide overuse load management in clinical practice. MethodsThirty recreational runners (15 males and 15 females) ran at a constant speed of 2.5 m/s at 5 systematically varied trunk lean conditions on a force-instrumented treadmill while kinematic and kinetic data were captured. ResultsA change in trunk lean angle from –2° (extension) to 28° (flexion) resulted in a systematic increase in stance phase angular impulse, cumulative impulse, and peak moment at the hip joint in the sagittal and transversal plane. In contrast, a systematic decrease in these parameters at the knee joint in the sagittal plane and the hip joint in the frontal plane was found (p < 0.001). Linear fitting revealed that with every degree of anterior trunk leaning, the cumulative hip joint extension loading increases by 3.26 Nm·s/kg/1000 m, while simultaneously decreasing knee joint extension loading by 1.08 Nm·s/kg/1000 m. ConclusionTrunk leaning can reduce knee joint loading and hip joint abduction loading, at the cost of hip joint loading in the sagittal and transversal planes during distance running. Modulating lower extremity joint loading by altering trunk lean angle is an effective strategy to redistribute joint load between/within the knee and hip joints. When implementing anterior trunk leaning in clinical practice, the increased demands on the hip musculature, dynamic stability, and the potential trade-off with running economy should be considered.

Increased copy-number variant load of associated risk genes in sporadic cases of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is an age-related neurodegenerative disease characterized by selective loss of motor neurons in the brainstem and spinal cord. Several genetic factors have been associated to ALS, ranging from causal genes and potential risk factors to disease modifiers. The search for pathogenic variants in these genes has mostly focused on single nucleotide variants (SNVs) while relatively understudied and not fully elucidated is the contribution of structural variants, such as copy number variations (CNVs). Here, we applied an exon-centric aCGH method to investigate, in sporadic ALS patients, the load of CNVs in 131 genes previously associated to ALS. Our approach revealed that CNV load, defined as the total number of CNVs or their size, was significantly higher in ALS cases than controls. About 87% of patients harbored multiple CNVs in ALS-related genes, and 75% structural variants compromised genes directly implicated in ALS pathogenesis (C9orf72, CHCHD10, EPHA4, FUS, HNRNPA1, KIF5A, NEK1, OPTN, PFN1, SOD1, TARDBP, TBK1, UBQLN2, UNC13A, VAPB, VCP). CNV load was also associated to higher onset age and disease progression rate. Although the contribution of individual CNVs in ALS is still unknown, their extensive load in disease-related genes may have relevant implications for the diagnostic, prognostic and therapeutical management of this devastating disorder.

Ex vivo evaluation of the soft tissue components of the equine stifle using 3 Tesla magnetic resonance imaging under flexion, extension, and loading.

High-field MRI of the equine stifle provides high-resolution information about soft tissues that is useful in the diagnosis of stifle lameness. The aim of this prospective anatomic study was to describe the appearance, position, size, and shape of the equine femorotibial ligaments, meniscal ligaments, and menisci using 3 Tesla MRI under extended, extended-loaded, and flexed conditions. Additionally, histologic examination of the collateral and cruciate ligaments (CLs) of a single stifle was performed to compare with MRI images. In extension, mild variations in MRI signal intensity were apparent in the CLs, and the cranial had two distinct longitudinal regions indicating two ligament bundles. Flexion had minor effects on CL signal intensity and altered the tibial angles of attachment. Histology indicated that both CLs were comprised of two fiber bundles. The collateral ligaments were the same low-signal intensity. The medial collateral ligament had a smaller cross-sectional area than the lateral, and flexion increased the length of the medial collateral ligament and the cross-sectional area of the lateral. Low loads in extension did not affect the MRI appearance of stifle soft tissues. Flexion of the stifle impacted cruciate ligament insertion angles and the size and shape of collateral ligaments. This study provides support for the use of MRI to understand the anatomy and function of stifle ligaments.

Parametric study on the flexural behavior of steel fiber reinforced concrete beams utilizing nonlinear finite element analysis

Reinforced concrete beams undergo significant internal forces and deformations under extensive loading and have flexural or shear failure based on the reinforcement detailing and geometric properties. The addition of steel fibers increases the deformation and load carrying capacities that leads to ductile behavior. The main contribution of fibers is the improvement of the composite tensile capacity, which results in improved flexural and shear responses. This study numerically investigates the effect of fiber properties on the flexural behavior of steel fiber reinforced concrete (SFRC) beams for both compression and tension failure. First, three specimens from prior experimental studies are modeled using the nonlinear finite element program ABAQUS and the analytical results are verified by comparison with the test results. Contrary to prior nonlinear models, the developed model accurately predicts the damage pattern, descending portion of the load-displacement relationship, and ultimate displacement, which lead to a reliable estimation of energy dissipation capacity and ductility. A comprehensive parametric study is then conducted to examine the effect of tension reinforcement ratio, fiber volume fraction, and fiber aspect ratio on the flexural behavior of both reinforced concrete and SFRC beams. The influence of these key parameters is investigated by comparing the peak load, displacement ductility, peak stiffness, service stiffness, energy dissipation capacity, and damage pattern for both reinforced concrete and SFRC beams. The analytical results indicate that the addition of steel fibers up to 2.0 % leads to a slight increase in the load carrying capacity, while the displacement ductility and energy dissipation capacity are significantly improved. Furthermore, the utilization of 1.0 % steel fibers is observed to be sufficient to modify the failure mode of over reinforced concrete beams from brittle compression failure to tension failure.

Transverse patella fracture fixation: A cadaveric biomechanical comparison of cannulated screws and anterior tension band versus low-profile, multiplanar mesh plating

IntroductionMultiplanar mesh plating of patella fractures has become more popular in recent years. It was the goal of this study to compare the biomechanical stability of cannulated screw with anterior tension band to multiplanar mesh plating for fixation of transverse patella fractures in cadaver specimens. Materials and MethodsEight matched pairs of fresh frozen cadaveric knees were obtained and soft tissues dissected leaving the extensor mechanism, joint capsule, and retinaculum intact. Transverse fractures were created at the mid-portion of the patella. For each pair, one specimen was repaired using cannulated screws with anterior tension band, and the second was repaired using multiplanar mesh plating. Each specimen underwent cyclic extension loading with loads increasing by 1.1 kg after every 50 cycles. Interfragmentary displacement was measured at the end of each interval at both 5° and 45° of knee flexion angle, with fixation failure defined by >2 mm displacement. ResultsThe specimens fixed with multiplanar mesh plating survived more cycles and higher loads than the specimens fixed with cannulated screws with anterior tension band (p = 0.011 comparing survival plots). After 150 cycles of extension loading, 3 of 8 of the specimens fixed with screws/tension band had failed, whereas none of the mesh plated specimens had failed. After 400 cycles, 7 of 8 of the screws/tension band had failed, whereas half of the mesh plated specimens had failed. ConclusionsWhile a more technically challenging and expensive technique, mesh plating for patella fractures appears to offer greater durability than traditional cannulated screw with tension banding.

The Usefulness of Deep Tendon Reflexes in the Diagnosis of Lumbar Spine Diseases: A Narrative Review.

The deep tendon reflex (DTR) is a more objective indicator than sensory and muscle assessments for lumbar spine disorders. Further, unlike sensory and muscle assessments that require patient cooperation, the DTR can be assessed even in patients with impaired consciousness or cognition. Therefore, DTR assessment with a hammer is an essential neurological test for lumbar spinal diseases. However, despite the usefulness of DTR assessment, few reports have described the significance of increased, diminished, or absent deep lower extremity reflexes in lumbar spine diseases. This review outlines the history of DTR of the lower limbs and describes the techniques, evaluation, and interpretation of DTR for the diagnosis of lumbar spine diseases. The patellar tendon reflex (PTR) was the first parameter of lower extremity DTR identified to have clinical usefulness, followed by the Achilles tendon reflex (ATR), pathological reflexes (Babinski reflex), and reflex enhancement (Jendrassik maneuver). They have now become an integral part of clinical examination. To determine whether an increase or decrease in DTR is pathological, it is necessary to determine left-right differences, differences between the upper and lower extremities, and the overall balance of the limb. There are several critical limitations and pitfalls in interpreting DTRs for lumbar spine diseases. Attention should be paid to examiner and patient factors that make the DTR assessment less objective. When there is a discrepancy between clinical and imaging findings and the level of the lumbosacral nerve root disorder is difficult to diagnose, the presence of a lumbosacral transitional vertebra, nerve root malformation, or furcal nerve should be considered. In addition, assessing the DTR after the gait loading test and standing extension loading test, which induce lumbosacral neuropathy, will help provide a rationale for the diagnosis.

Design and fabrication of bioinspired pattern driven magnetic actuators

Additive manufacturing (AM) has drawn significant attention in the fabrication of soft actuators due to its unique capability of printing geometrically complex parts. This research presents the design and development of an AM process for bioinspired, deformable, and magnetic stimuli-responsive actuator arms. The actuator arms were fabricated via the material extrusion-based AM process with magnetic particle-polymer composite filaments. Inspired by the rhombus cellular structure found in nature, different design parameters, such as the line width of the interior rhombus sides, and 3D printing parameters were studied and optimized to fabricate actuator arms that exhibit enhanced flexibility while being magnetically actuated. The trigger distance and deformation experiments revealed that the width of the rhomboids’ sides played a critical role in magnetic and bending properties. It was found that the sample with a line width of 550 µm and printing layer thickness of 0.05 mm had the maximum deflection with a measured bending angle of 34 degrees. The magnetic property measurement exhibited that the sample with a line width of 550 µm showed the maximum magnetic flux density of 3.2 mT. The trigger distance results also supported this result. A maximum trigger distance of 8.25 mm was measured for the arm with a line width of 550 µm. Additionally, tensile tests showed that the sample exhibited a 17.7 MPa tensile strength, 1.8 GPa elastic modulus, and 1.3% elongation. Based on these results, we successfully fabricated a 3D printed magnetic gripper with two rhombus cellular structured arms which showed grasping and extensive load lifting capability (up to ∼140 times its weight).

Undrained shear strength of soils with fine fraction content derived from compression and extension loading triaxial tests

In the stability analysis of dams or deep excavations a calculation scheme of soil response is assumed that considers the rotation of main stresses. In the case of tailings dams constructed of granular material with fine fraction content (FC &lt;0.075 mm), an additional factor is to be considered i.e. liquefaction phenomenon. Soil response to undrained shearing in compression loading (increase of vertical stress) and extension loading (increase of horizontal stress) differs significantly, giving various strength values. The paper presents the results of triaxial tests carried out on soils with fine fraction content. The tests were performed under compression loading and extension loading conditions. The test results’analysis was performed, considering grain size impact and main stresses application method at the shearing stage.

Range of motion after 1, 2, and 3 level cervical disc arthroplasty

BackgroundMotion of a solid body involves translation and rotation. Few investigations examine the isolated translational and rotational components associated with disc arthroplasty devices. This study investigates single- and multi-level cervical disc arthroplasty with respect to index and adjacent level range of motion. The investigators hypothesized that single- and multilevel cervical disc replacement will lead to comparable or improved motion at implanted and adjacent levels. MethodsSeven human cervical spines from C2 to C7 were subjected to displacement-controlled loading in flexion, extension, and lateral bending under intact, 1-Level (C5–C6), 2-Level (C5–C6, C6–C7) and 3-Level (C5–C6, C6–C7, C4–C5) conditions. 3D motions sensors were mounted at C4, C5, and C6. Motion data for translations and rotations at each level for each surgical condition and loading mode were compared to intact conditions. Results1-Level: The index surgery resulted in statistically increased translations in extension and lateral bending at all levels with statistically increased translation observed in flexion in the superior and inferior levels. In rotation, the index surgeries decreased rotation under flexion, with remaining levels not statistically different to intact conditions. 2-LevelA device placed inferiorly resulted in statistically increased translations at all levels in extension with statistically increased translations superior and inferior to the index level in flexion. Lateral bending resulted in increased nonsignificant translations. Rotations were elevated or comparable to the intact level for all loading. 3-LevelTranslations were statistically increased for all levels in all loading modes while rotations were elevated or were comparable to the intact level for all loading modes and levels. ConclusionsMicromotion sensors permitted monitoring and recording of small magnitude angulations and translations using a loading mechanism that did not over constrain cervical segmental motion. Multilevel cervical disc arthroplasty yielded comparable or increased overall motion at the index and adjacent levels compared to intact conditions.

Statistical Analysis and Health Risk Assessment: Vegetables Irrigated with Wastewater in Kirri Shamozai, Pakistan.

One of the primary environmental routes through which humans are exposed to metals and may be exposed to health risks is the food chain's contamination with heavy metals. The study observed the risks posed by contaminants in vegetables produced in soil that received wastewater irrigation, as well as their origins and the human health impacts. Eight harmful metals (Cu, Fe, Zn, Mn, Pb, Cd, Ni, and Cr) were tested for concentration levels in water, soil, and vegetable samples using analytical techniques and an atomic absorption spectrophotometer. The present study investigated the potential health implications associated with the consumption of vegetables irrigated using wastewater containing heavy metals. The results indicated a notable accumulation of heavy metals in plant and soil samples obtained from Kirri Shamozai, Pakistan. In comparison to vegetables cultivated in soil irrigated with fresh water, the concentration levels of heavy metals in vegetables grown on soil irrigated with untreated wastewater were considerably higher at (P ≤ 0.001) and above the World Health Organization (WHO) recommended limits. The results showed that heavy metals had significantly accumulated in the soil and had permeated into the crops. Heavy metal concentrations in vegetables cultivated on land irrigated with wastewater were more significant than those grown on land irrigated with freshwater. They exceeded US EPA and World Health Organization (WHO) limits. PCA results for Pb, Cu, and Cr are the main issues impacting water quality and health hazards. The PCA results show that the soil has an extensive loading of heavy metals Cd, Ni, and Mn.

Intradiscal cement leakage (ICL) increases the stress on adjacent vertebrae after kyphoplasty for osteoporotic vertebra compression fracture (OVCF): a finite-element study

This study aimed to explore the biomechanical effects on adjacent vertebra of thoracolumbar Osteoporotic Vertebra Compression Fracture (OVCF) after Percutaneous Kyphoplasty (PKP) with intraoperative intradiscal cement leakage (ICL) by applying a Finite-Element Analysis. We collected pre- and post-operative computer tomography (CT) images of a 71-year-old female patient with single T12 OVCF, who underwent an intraoperative cement leakage into the T12–L1 disc. Three-dimensional finite element models of thoracolumbar spine (T10–L2) were built with the support of Materialise Interactive Medical Image Control System (MIMICS) and ABAQUS software. The stress on adjacent vertebrae and endplates under the uniform compressive pressure (0.3 MPa) and during different loading moments were analyzed. The three-dimensional finite element models reveal an asymmetrical distribution of von Mises stresses on the adjacent endplate unaffected by the surgical intervention. The maximum von Mises stress on adjacent vertebral bodies increased during different loading conditions, especially for lateral bending and rotation loading conditions, whereas the maximum von Mises stress on distal non-treated vertebrae decreased on anteflexion and backward extension loading conditions. Post-operative adjacent vertebra compression fractures after PKP with intraoperative intradiscal cement leakage (ICL) may be closely related to the biomechanical changes of adjacent vertebrae of thoracolumbar OVCF, and it may increase the risk of postoperative fracture.

Posterior intra-articular fixation stabilizes both primary and secondary sacroiliac joints: a cadaveric study and comparison to lateral trans-articular fixation literature

BackgroundPosterior and lateral techniques have been described as approaches to sacroiliac joint arthrodesis. The purpose of this study was to compare the stabilizing effects of a novel posterior stabilization implant and technique to a previously published lateral approach in a cadaveric multidirectional bending model. We hypothesized that both approaches would have an equivalent stabilizing effect in flexion–extension and that the posterior approach would exhibit better performance in lateral bending and axial rotation. We further hypothesized that unilateral and bilateral posterior fixation would stabilize both the primary and secondary joints.MethodsRanges of motion (RoMs) of six cadaveric sacroiliac joints were evaluated by an optical tracking system, in a multidirectional flexibility pure moment model, between ± 7.5 N-m applied moment in flexion–extension, lateral bending, and axial rotation under intact, unilateral fixation, and bilateral fixation conditions.ResultsIntact RoMs were equivalent between both samples. For the posterior intra-articular technique, unilateral fixation reduced the RoMs of both primary and secondary joints in all loading planes (flexion–extension RoM by 45%, lateral bending RoM by 47%, and axial RoM by 33%), and bilateral fixation maintained this stabilizing effect in both joints (flexion–extension at 48%, lateral bending at 53%, and axial rotation at 42%). For the lateral trans-articular technique, only bilateral fixation reduced mean RoM of both primary and secondary sacroiliac joints, and only under flexion–extension loads (60%).ConclusionDuring flexion–extension, the posterior approach is equivalent to the lateral approach, while producing superior stabilization during lateral bend and axial rotation.

Fixation-induced surgical segment’s high stiffness and the damage of posterior structures together trigger a higher risk of adjacent segment disease in patients with lumbar interbody fusion operations

BackgroundAdjacent segment disease (ASD) is a commonly reported complication after lumbar interbody fusion (LIF); changes in the mechanical environment play an essential role in the generation of ASD. Traditionally, fixation-induced high stiffness in the surgical segment was the main reason for ASD. However, with more attention paid to the biomechanical significance of posterior bony and soft structures, surgeons hypothesize that this factor may also play an important role in ASD.MethodsOblique and posterior LIF operations have been simulated in this study. The stand-alone OLIF and OLIF fixed by bilateral pedicle screw (BPS) system have been simulated. The spinal process (the attachment point of cranial ligamentum complex) was excised in the PLIF model; the BPS system has also been used in the PLIF model. Stress values related to ASD have been computed under physiological body positions, including flexion, extension, bending, and axial rotations.ResultsCompared to the stand-alone OLIF model, the OLIF model with BPS fixation suffers higher stress values under extension body position. However, there are no apparent differences under other loading conditions. Moreover, significant increases in stress values can be recorded in flexion and extension loading conditions in the PLIF model with posterior structures damage.ConclusionsFixation-induced surgical segment’s high stiffness and the damage of posterior soft tissues together trigger a higher risk of ASD in patients with LIF operations. Optimizing BPS fixation methods and pedicle screw designs and reducing the range of posterior structures excision may be an effective method to reduce the risk of ASD.

Preserved blood-brain barrier and neurovascular coupling in female 5xFAD model of Alzheimer's disease.

Dysfunction of the cerebral vasculature is considered one of the key components of Alzheimer's disease (AD), but the mechanisms affecting individual brain vessels are poorly understood. Here, using in vivo two-photon microscopy in superficial cortical layers and ex vivo imaging across brain regions, we characterized blood-brain barrier (BBB) function and neurovascular coupling (NVC) at the level of individual brain vessels in adult female 5xFAD mice, an aggressive amyloid-β (Aβ) model of AD. We report a lack of abnormal increase in adsorptive-mediated transcytosis of albumin and preserved paracellular barrier for fibrinogen and small molecules despite an extensive load of Aβ. Likewise, the NVC responses to somatosensory stimulation were preserved at all regulatory segments of the microvasculature: penetrating arterioles, precapillary sphincters, and capillaries. Lastly, the Aβ plaques did not affect the density of capillary pericytes. Our findings provide direct evidence of preserved microvascular function in the 5xFAD mice and highlight the critical dependence of the experimental outcomes on the choice of preclinical models of AD. We propose that the presence of parenchymal Aβ does not warrant BBB and NVC dysfunction and that the generalized view that microvascular impairment is inherent to Aβ aggregation may need to be revised.

Strengthening of a Damaged Concrete Structure - Case Study of an Eleven Stories Building in Dar es Salaam

Concrete structures may become obsolete and be unfit for use to the extent that they need special attendance of repair or strengthening so as to revive them. The weakness in the buildings may be caused by natural disasters like earthquake, floods, changes of use of the buildings in which higher loads more than the design loads, e.g. vertical extension loads, are applied. When the structures are defective they need to be strengthened in order to restore their original structural integrity. Sometimes, the defect or deterioration needs to be scientifically analysed first in order to know the root cause of the problem and apply the right corrective measures. A case study on an eleven stories damaged building in is presented, starting with an investigation on causes of sudden crushing of one column and a strengthening method which embraced a number of techniques such as Land Surveying and non-destructive tests in assessing the building structural integrity. The crushed column and other columns is the ground floor were all strengthened using jacketing method and provision of additional columns at the crushed column. Keywords: Columns, crushing, non-destructive tests, concrete quality, deflection, plumb, jacketing, strengthening

Effect of Stress Ratio on Fatigue Crack Propagation Behavior of Single Crystal Superalloy

In order to study the impact of different stress ratio on the fatigue crack growth behavior of DD6 single crystal superalloy, the fatigue crack growth rate test of different stress ratio (R = 0.05, 0.2, 0.5, 0.6) at 530 °C was conducted, the influence of stress ratio on crack growth rate was studied, and the growth of crack extension rate was corrected by normalization method. The results show that the section includes the fatigue fracture section perpendicular to the load and an angle to the load. The flat section is the main section representing the crack extension. The oblique section is formed with the change of the crack extension load state, and its occurrence is related to the dispersion of (da/dN)−Δk data, reflecting the uniqueness of single crystal. The Paris formula better characterized the crack expansion behavior of DD6 alloy, and the stress is more sensitive than the crack growth rate in the early stable growth phase. Crack growth rate normalized characterization equation constructed under different stress ratios are predicted to be within the 1.3-fold dispersion band.

Control rod driven long-term load-follow operation in small modular reactor

The need for extensive load following with Small Modular Reactor (SMR) is increasing as its potential coupling with intermittent renewable energy sources increases. SMR is generally considered suitable for load following, though, its load maneuvering capability depends on the system design features and reactor control algorithm. In this study, it is shown that a control rod driving algorithm based on the core outlet temperature of a typical IPWR type of SMR, SMART100 facilitates the extensive load following operations (IAEA, 2018, Song et al., 2010, Lee et al., 2012). Addition of control parameter such as Axial Offset (AO) and Boron concentration change into the control algorithm makes a reactor control possible when the AO is close to the limit or control rod position is close to Power Dependent Insertion Limit(PDIL). Simulations for various scenarios were performed to verify the above algorithm Short-term simulations less than 2 days and Long-term simulations longer than 7 days were performed. For each simulation, random demand or scheduled demand considering demand changes incurred by renewable energy was used. In all simulations, it is confirmed that the reactor facilitates control rod driven load-following operation within the operation limit. Further, it is shown that more efficient load-following operation is achieved by additional adjustment of control band of outlet temperature.

Surviving Racism and Sexism in Academia: Sharing Experiences, Insights, and Perspectives

Surviving Racism and Sexism in Academia: Sharing Experiences, Insights, and Perspectives